WORLD BANK GROUP INFORMAL ENVIRONMENTAL SUSTAINABILITY

SEMINAR SERIES

WORKSHOP ON

WHAT IS SUSTAINABILITY IN SANITATION? October 15, 1997

Chair: Kirsten Hommann

Abby Rockefeller The ReSource Institute

Laura Orlando The ReSource Institute

Gary Gardner Worldwatch Institute

Robert Goodland The World Bank

Steve Latham University of Maryland

Dianne Hughes The World Bank

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WHAT IS SUSTAINABILITY IN SANITATION? October 15, 1997

Contents

Civilization and Sludge: Notes on the History of the Management ofHuman Excreta

The Sewage Scam: Should Sludge Fertilize Your Vegetables?

Recycling Organic Waste: From Urban Pollutant to Farm Resource

What is Environmental Sustainability in Sanitation?

Managing Human Waste in Indonesia's Flooded Urban Areas (The On-site Option)

The Humane Handbook

Compost Toilets Reconsidered

Abby Rockefeller

Laura Orlando

Gary Gardner

Robert Goodland Abby Rockefeller

Dianne Hughes

Joseph C. Jenkins

Carol Steinfeld

AUTHORS

Abby Rockefeller is President of the Cliws Multrum Company, which she founded in 1973. It promotes public and regulatory acceptance of the concept of source separation and on-site stabilization of human excreta. The goal is to recycle to agriculture the nutrient value intrinsic to these materials. Rockefeller is also founder and President of the ReSource Institute for Low Entropy Systems.

:Laura Orlando is the Executive Director of the ReSource Institute for Low Entropy Systems. She has a degree in civil engineering from the University of Michigan. For the past ten years Orlando has been developing ecological waste management programs and systems in LDCs.

Gary Gardner is a Research Associate at the Worldwatch Institute, where he writes on agriculture and waters issues. Since joining the Institute in 1994, he has written chapters in State of the World and contributed to Vital Signs and World Watch magazine. He also wrote Worldwatch Paper 131, Shrinking Fields: Cropland Loss in a World of Eight Billion, released in July. Gardner was previously a project manager at the Soviet Non­proliferation Project, a research and training program run by the Monterey Institute of International Studies in California. While there, he authored Nuclear Nonproliferation: A Primer. Mr. Gardner spent two years helping Peruvian women's groups develop urban small livestock projects. He holds master's degrees in Politics from Brandeis University, and in Public Administration from the Monterey Institute of International Studies. He received his bachelor's degree from Santa Clara University.

Robert Goodland is a tropical ecologist working in the World Bank for 20 years on environmental aspects of development projects in developing countries, on which he has published more than 20 books. He was President of the International Association of Impact Assessment (IAIA) and chair of the Ecological Society of America (Metropolitan).

Civilization and Sludge: Notes on the History of the Management of Human Excreta

by ~bby A. Rockefell~r Founder and President of the ReSource Institute for Low Entropy Systems, Boston, Massachusetts

Disposal of human excreta and industrial wastes by means of the water-carriage system of sewerage has been the preferred method of management of these wastes for more than a century in all industrialized nations ofthe world. The pollution of water bodies caused by this practice led to treaunent of the centrally collected sewage. Treatment of sewage Jed, in tum, to the production of sludge. Sludge consists not only of human excreta and industrial wastes, but of a myriad of nonpoint somce wastes as well. Although sewage sludge was officially treated as a hazardous material by the environmentaJ protection agencies of the sewered nations of the world, these same agencies nonetheless allowed it to be disposed of by dumping into the ocean and major inland bodies ofwater, by land filling, and by incineration. EnvironmentaJ damage to ocean ecosystems, air, and groundwaters caused by these practices aroused opposition from environmentaJ groups. Between the late 1970s and early 1990s, a policy shift by the environ­mental protection agencies changed the classification of sludge from hazardous material to fertilizer, and, through banning ocean dumping and curtailing land filling and incineration, mandated, instead, land application of sewage sludge. The hazards associated with the decision to dispose of sludge by puning it on the land is now the subject of increasing controversy among policymakers, scientists, and citizens' groups. Ms. Rockefeller can be reached at I 04 Irving Street, Cambridge, h1A 02138.

People have been "civilized" --have been settled as opposed to nomadic or hunting-and-gathering-for a mere ten thousand years. And most of us Homo sapiens sapiens remained "uncivilized," in this narrowly meant sense of living without the advantages or constraints of a settled abode, for probably at least the flrst half of that ten thousand year period.

Before people became "citizens" living in "cities," these smartest alecks of the animal world deposited their excreta-their urine and feces-on the ground, here and there, widely dispersed, in the manner of all other land creatures. Of course, some groups, such as the cats, bury their feces and urine in shallow holes. But the effect of surface deposit or shallow burial is the same: ready access by the decomposer creatures in the soil to the nutrients and stored energy in the excreta; ready cycling through life of the elements necessary to it, attended by an incremental enrichment and diversification of the fonns of life.

This meant keeping the nutrients characteristic of excreta in the cycle of soil-to-bacteria-to-plants-to-aJ.limals-W::SoiL. The soil and its communities of life long ago grabbed hold, so to speak, of this major source of nutrients. Keeping these nutrients--especially the major, or "macro," ones such as nitrogen and phosphorus-locked up in the cycles of the land, besides making the land-based life cycles nutrient-rich, kept them out of the waters of the Earth. The lakes, rivers, streams, ponds, oceans, and aquifers were conse-

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quently relatively nutrient-poor-what we call "pure." Aquatic life forms evolved in precise relation to such pure waters, so that the characteristic of macro-nutrient scarcity has become, gradually but absolutely, crucial to the health of the species and the ecosystems of the aquatic environment.

When we speak of "healthy" eco-systems, we mean stable ecosystems: that is, both tending toward diversity and not subject to cataclysmic drops in diversity. Such conditions, also called balanced, create relationships-ever more intricate relationships-that increasingly locate the inorganic elements necessary to life in cycles that make those inorganic elements increasingly available to life. The more extensive these relationships, the more consis­tently available the nutrient-elements will be to the life forms within those relationships. Expanding diversity of life forms is, relatively speaking, a low entropy enterprise. The more diverse the forms of life, the more matter and energy are kept available for use, or "work," and the less they are lost to use or work through either irretrievable dissipation or unresolvable mixing.

So, when we talk of"pure" water, we do not mean pure in the chemical sense. We mean, rather, a dynamic balance between the non-living macro-nutrient­scarce matter and the Jiving organisms in water; a balance whereby the relationships of life forms to one another, perhaps developed over the course· of a couple of billions of years, are, though always changing, never­theless (excepting cataclysmic events), always stable, expanding in diversity, and healthy.

It is not that life will disappear in waters suddenly enriched by an infusion of macro-nutrients. (Nitrogen and phosphorus, both called macro-nutrients because most plants need large quantities in order to grow, are also sometimes called "limiting factors" since, when they are scarce, the growth of plants­such as algae-not accustomed to nutrient-poor waters, is limited.) But the effect of sudden infusions of any of the macro-nutrients will be to reduce the diversity of life in any body of pure water. We call waters polluted that look like pea soup-so full are they with living algae-because we understand that even a very great abundance of a single form of life in, say, a lake doesn't mean that all's well with the life system in the waters of that lake.

And, indeed, all is not well-much is, in fact, dreadfully wrong-with most of the waters on Earth. What happened to make this so? In brief, there was a sudden infusion (sudden compared to the slow pace of evolution) of nutrients into the Earth's waters-in the form of water-borne human excreta. What follows touches on of how water came to be used to transport human excreta, how bodies of water came to be used as the recipient dumps for the water-borne excreta, and what environmental effects have been associated with the chain of behavioral and technological developments resulting from these practices.

Much of the history of human behavior is before our eyes in living societies today, the history of our excretory practices not excepted. It is likely that all

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practices ever associated with the disposition o( excreta continue in some societies still. The patterns of settled community behavior early split into two courses: one that unambiguously assumed there to be in human excreta a fertilizer value to agriculture, and one that did not regard it as having such a value or that was at least ambivalent about its value.

It was, to be sure, agriculture that "caused" civilization: in its simplest and in its most elaborate forms, civilization altogether depends on agriculture. This dependence, however, has not inspired all agricultural societies. with reverence for the economy of the cycles on which agriculture is dependent. Especially uneven has been awareness of the economy of giving back to the soil in the fonn cif excreta what has been taken out in the form of food. The cultures that did consistently employ their own manure in agriculture were primarily Asian. Much has been written about the longevity of these civili­zations and the significance of the persistent use of human manure to that longevity (King 1927).

Those settled cultures that do not-and did not--connect human manure with sustainable agricultural productivity followed, and still follow, a fairly stand­ard pattern of "development" of their "sanitation" habits. Urinating and defecating on the ground's surface in the manner of pre-civilized days, but in the immediate vicinity of their dwellings, is the first phase. This soon becomes unviable-that is, too unpleasant-due to the increasing density of the settlers, which leads to the creation of the community pit. When privacy of excretory functions comes to be deemed important, then comes the pit privy, the privacy structure on top of the hole in the ground.

This "outhouse," on account of the smell, is placed at a distance from the dwelling. The odor caused by concentrating excreta in one spot in the manner of the pit latrine-an olfactory offense that causes many to choose the bushes-is legendary for its unpleasantness. But stink aside, and contrary to what some people think, the pit latrine-with or without the privacy struc­ture-is not, and never was, environmentally viable. The pit toilet causes two related troubles-waste and pollution: waste through loss of the unretrieved nutrients in the excreta and polluti.Pn of the ground waters by those same wasted nutrients. The pit privy is not, from an environmental point of view, anywhere near as damaging as the flush toilet, but the kind of damage it caused-and still causes-is of a piece wiili the kind caused by the string of technologies, flush toilet included, that evolved in response to the pit privy's inadequacies.

European societies were for centuries ambivalent in their attitude toward their own excreta. Was it a fertilizer source for agriculture or a nuisance to be "got rid of'? Before the advent of piped-in water, human excreta was deposited in cesspools (lined pits with some drainage of liquids) or vault privies (tight tanks from which there is no drainage) in the backyards of European towns. The "night soil"-human manure collected at night-was removed by

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"scavengers" and either taken to farms or dumped into streams and rivers or in "dumps" on the land. In Europe, there was, in other words, no consistent perception of the agricultural value of these materials: not as in Asian cultures, where the husbanding of human excreta was (until very recently) unexceptional and routinized. Five hundred years before Christ, Rome already had in place a system both for bringing in pure water through its famous aqueducts and for the removal via sewers of fouled water that included water-borne excreta from public toilets and from water closets in the homes of the rich (Pliny the Elder 1991; Mumford I96I). But until the middle of the 19th century, most of Europe prohibited the use of sewers for the disposal ·of human excreta. Sewers consisting of open gutters or sometimes covered trenches in the center or sides of streets had long been in use in European cities, but only for the drainage of rain run-off and for city fiJth. However, householding transgres­sors used the sewers to dump their kitchen slop water, and-to save on the cost of paying scavengers-the contents of chamber pots and overflowing cesspools. And when going all the way to the farm was an inconvenience or an extra expense for professional cesspool scavengers, they too took surrep­titious advantage of the sewers to dump the product of their nightly labors. The putrefying matter in these stagnant ditches moved along only when it rained enough (hence the name "stonn" sewers), and digging them out with shovels was the job of the "sewennen" (Reid 1991 ).

The "water closet" (so-called to distinguish it from the "earth-closet," an early species of compost toilet much favored by 19th century environmen­talists) afforded the enonnous convenience of simultaneously putting the toilet in the house while getting the excreta out of the house. The so-named "flush" toilet had been known to the privileged at the height of the Roman era and since the 18th century in northern parts of Europe. But this pivotal technology, symbol of civilization still, came to widespread use only after piped-in water had been made available to the major cities in Europe and the United States. The first waterworks in the United States was installed in Philadelphia in 1802. By 1860 there were I36 systems in the U.S., and by 1880 the number was up to 598 (Tarr and Dupuy 1988). The convenience of a constant water supply stimulated the adoption of residential water fix­tures-baths and kitchen sinks as well as flush toilets-dramatically increas­ing the per capita use of water on average from three to five gallons per person per day to 30 and even 100 gallons per person per day.

Of course, once water was in great quantities piped into homes, it had to be piped out again, and the first "logical" place to pipe it, including the flush water from water closets, was backyard cesspools. These cesspools, which hitherto had received the contents of chamber pots-urine and feces­only, now regularly overflowed with fecally polluted water, and a new level of horrendous odors and the spread of water-borne diseases was the imme­diate result.

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Thus the system of cesspools and vault privies, which had been to some extent effective in avoiding pollution of waterways through their periodic cleanout by scavengers and the at least partial returning of human manure to fanns, was overwhelmed by the pressure created by the new availability of running water. The next "natural" step in the solve-one-problem-at-a-time approach was to connect the cesspools to the sewers, thereby moving the sewage from overflowing cesspools into the open sewers of city streets. The result: epidemics of cholera. In 1832 20,000 people died of cholera in Paris alone (Reid I 99 I). Wherever and whenever this combination of piped-in water, flush toilets, and open sewers has appeared in the world, epidemics of cholera have followed.

By the middle of the 19th century, the diseases spawned by the convenience of running water and the flush toilet gave rise to a demand for the construction of sewers that would carry the sewage not only out of and away from the home, but away from the city as well. This demand entailed the evolution of the ditch-type storm sewer into the closed-pipe water-carriage system of sewerage. The wastewater itself was in this system the medium of transpor­tation, so a large and regular supply of water was a built-in requirement to keep the wastes moving in the pipes (Tarr and Dupuy 1988). (Today, efforts to conserve water by promoting the use of low-flush toilets-1.6 gallons vs. five to seven gallons-have led to plugging up of sewers engineered for a minimum hydraulic flow offive gallons per flush. To deal with this problem, owners of these "water-conserving" toilets have been Instructed to flush two or three times per use.)

The water-carriage system of sewerage introduced a new set of problems and, about these problems, a new set of debates among sanitary engineers in Europe and the United States. The engineers were divided again between those who believed in the value of human excreta to agriculture and those who did not. The believers argued in favor of "sewage fanning," the practice of irrigating neighboring farms with municipal sewage. The second group, arguing that "running water purifies itself' {the more current slogan among sanitary engineers: "the solution to. pollution is dilution"), argued for piping sewage into lakes, rivers, and oceans. In the United States, the engineers who argued for direct disposal into water had, by the tum of the 19th century, won this debate. By 1909, untold miles of rivers had been turned functionally into open sewers, and 25,000 miles of sewer pipes had been laid to take the sewage to those rivers (Tarr and Dupuy 1988).

In the cities with water-carriage sewers, cholera epidemics abated. However, in cities downstream from those dumping raw sewage into the river, death rates from typhoid soared. This led to the next debate: whether to treat the sewage before dumping it into the recipient bodies of water or whether to filter the drinking water downstream. Health authorities argued that sewage should be treated before disposal into any bodies of water, but the sanitary engineers preferred filtration by the next town down the river. The engineers

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prevailed, and indeed, in those cities with filtered water, deaths from typhoid then dropped dramatically (Tarr and Dupuy I 988).

The practice of "purifying" water polluted with sewage from upstream in order to make drinking water safe downstream, rather than treating sewage where it is produced, persisted until the middle of the 20th century. By then, the rate of industrial development had been enonnous, and every industry wanted cheap disposal of its wastes. And since the public was paying, this was cheap as could be. Industries' demand for more sewering to serve their own disposal needs stimulated the industrialized nations of the world to allocate vast sums of money for massive sewer construction programs.

To the nutrient burden on recipient waters from human excrement, then, was added a new and ever increasing flow of industrial waste, much of it toxic. Wherever on the globe there were sewers, the recipient rivers, lakes, and streams were discovered to have become unacceptably filthy, and in response came pressure to treat the sewage before it entered those waters. And so began the "treatment" phase of the get-rid-of-it approach to dealing with wastewa­ter now consisting of human excrement mingled with all industrial wastes transported.by water. ·

The first step in the effort to clean up the sewage before sending the effluent into the river is tenned "primary treatment." From the point of view of improving water quality, it is a crude method, consisting of little more than settling and screening the sewage to remove the largest and most aesthetically offensive objects: all nutrients and chemicals not tied up in dead cats and intact feces remain in the water.

The next stage, called "secondary treatment," includes some biological stabilization through forced aeration of the sewage, and chemical flocculation and precipitation of some of the phosphates deriving from laundry detergents. But in spite of the great energy and financial cost of this fonn of treatment, the effluent reaching the recipient bodies of water continues to be rich in nitrates and phosphates. (These nutrients, as noted above, are called limiting factors. When they are present in water, they cause an explosive growth of algae, which in tum causes lakes to die of eutrophication as the decaying algae robs the water of its oxygen.) Industrial pollutants, such as toxic chemicals and heavy metals, are not addressed by this level of treatment.

So engineering ingenuity developed another, yet more complex, yet more energy intensive and expensive form called "tertiary" or "advanced waste­water treatment." Because of its enonnous cost it has been difficult to get American taxpayers to fund this level to any great extent. But even where funded, treatment remains incomplete: some nitrates, some heavy metals, and many toxic chemicals continue to evade tertiary treatment and remain in the water.

Central collection and treatment of sewage cannot be said to have succeeded in solving the underlying problem of water pollution caused by using water

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to transport wastes. The problem is deeper and systemic. The trouble with the treannent approach to managing the pollution caused by water carriage of excreta and the by-products of industry lies only partly in the inadequacy of even the most advanced processes. Though the trouble may seem to have been ameliorated because this bay or that river is less polluted than it was without wastewater treannent, the pollutants that were in the water have simply been reorganized and concentrated in a new form: sludge.

Sludge is the dewatered, sticky black ''cake ''consisting of every waste material capable of being sent down the drains of homes and industries and into the sewers, and which the treatment process is able to get back out again.

Sludge is the dewatered, sticky black "cake" consisting of every waste material capable of being sent down the drains of homes and industries and into the sewers, and which the treatment process is able to get back out again. If sewage can be said perfectly to exemplify a high entropy process of matter lost through irretrievable dissipation, sludge is the quintessential example of disparate matter lost to use through unresolvable homogenization.

In the United States Federal Register (Volume 55, Number 218, November 9, 1990), the United States Environmental Protection Agency (EPA) says of sludge:

The chemical composition and biological constituents of the sludge depend upon the composition of the wastewater entering the treatment facilities and the subsequent treatment processes. Typically, these constituents may include volatiles, organic solids, nutrients, disease­causing pathogenic organisms (e.g., bacteria, viruses, etc.), heavy metals and inorganic ions, and toxic organic chemicals from industrial wastes, household chemicals, and pesticides.

This short list of what sludge "may include" is shorthand for the enormous list of constituents that can actually be present in it. For instance, of the I 00,000 or so organic and inorganic chemicals produced and used in indus­trialized nations, a huge number will end up in the sewers. One thousand new ones are produced every year and are added to the cocktail of synthetic substances affecting life processes. Those pollutants that are put in the sewers-and that are removed from the wastewater by the treatment proc­ess-will end up in the sludge. There are the heavy metals which, though they are micro-nutrients crucially needed in tiny amounts for growth of life, are toxic to life when they cross the threshold firmly established in the cells of life. There are organochlorines estrogen mimicars, the best known of which are DDT, chlordane, alpha-hexachlorocyclohexane, 2,4,0, PCBs, and dioxin. There are halogenated aliphatic (chain) hydrocarbons, aromatic (ring) hydrocarbons, chloro- and nitro-aromatic hydrocarbons, phthalates, halogen-

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ated ethers, and phenols. There is radioactive matter from hospitals. All of these are destructive of life processes (Reutergardh 1996).

Attitudes toward sludge-this heterogeneous product of wastewater treat­ment processes-and toward its disposition have a convoluted history of their own. Clearly, sludge contains constituents that are-hazardous to life. If we persist in producing sludge, something must be done with it. What to do with it is the subject of intense present debate. To understand this debate. one must know something of the interplay among the following forces: the environ­mental movement that began in the early 1970s; the organic food movement that began decades earlier; the traditional sanitary engineering/regulatory posture; and the exigencies of the prevailing economic/industrial arrange­ment. The character of the debate taking place in the United States is illustrative of the way thes.e forces interact regarding the technical and management patterns in all the sewered, and about-to-be-sewered, parts of the world. To begin, it may be clarifying to focus this history on the question of why decentralized solutions to water pollution were not developed and promoted · over sewering, since, environmental considerations aside for the moment, they would have saved taxpayers immense amounts of money. The answer is in part the engineering/regulatory bias in favor of top-down, centrally controlled solutions. Health authorities are traditionally skeptical of the people's ability to manage problems themselves. The regulatory and sanitary engineering community (very much one body, in general) also feels that troubles are safer in its hands. Moreover, it is the case that there has been a widespread conviction on the part of environmental groups that treatment at the "end of the pipe" is the surest way of cleaning up polluted water. The environmental movement in the United States played a large part in creating the pressure that resulted in the Clean Water Act of 1977. This Act was effectively a sewering act. Enormous sums of money were allocated exclu­sively for the laying of sewer pipes and the construction of treatment plants. The Clean Water Act has funded virtually no on-site, site specific, decentral­ized systems--either for remediation or for new construction.

But the greatest force behind the drive to sewer has been the interests of industry: first, because public sewers are the cheapest place for industries to put their wastes, and second, because it is the enormously expensive system of central collection that generates the highest profits for engineering and construction firms. For example, 80% of the total cost of sewering and treatment is in the laying of nipes, and engineering and construction firms get a flat 20% of the total project cost. Fixing the 5-10% of septic systems that are failing (i.e., polluting or overflowing) would never generate the profits associated with sewering 100% ofthese communities' central collec­tion and treatment works.

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This powerful coincidence of seemingly disparate interests-regulatory, environmental, and industrial-overwhelmed any popular opposition to the tax burden required to fund this massive public project, which in cost is second only to that of the U.S. highway construction program. When envi­ronmentalists are for it, and the governments are for it, corporate interests can just lay low, fm:who.butaphilistine would object to tax increases for so good a cause? Thus, town after town, each, as noted above, with typically 5-l 0% of on-site wastewater systems (mostly old cesspools and "modem" .septic tank/leach fields) deemed to be failing, has been herded down the sewer path, and so has come to have I 00% of its sewage centrally collected and treated. Since it is treatment of sewage that creates sludge-and. since the more extensive the treatment, the more and worse the sludge will be-the issue of how to dispose of it became for municipalities a major and growing problem.

What was being done with it? In some places sludge was dumped in "sanitary" landfills, where it caused serious groundwater pollution. In other places it was incinerated, causing serious air pollution. And, remarkable as it may seem (given the stated objective of removing poliutants from the water), during the first phase of the sewage treatment era, cities built on ocean shores saw fit to dump the sludge into the ocean-that is, back into the water. As early as 1924, New York City, whose new treatment plant was a striking case in point, began dumping its sludge 12 miles outside New York Harbor. ·Sixty years later, the U.S. EPA determined that the coastal waters had been unacceptably damaged and ordered that the sludge be barged farther out-to a site I 06 miles offshore. Although this strategy seems to suggest a failure of imagination, it remained an acceptable solution in the eyes of the federal authorities until the 1980s, when hypodermic needles and other medical debris from hospitals started washing up on the beaches. (These needles actually came from "solid waste," or trash, which was also routinely dumped into the ocean.) Though barren moonscape on the ocean floor created by the unwonted concentrations of heavy metals and other toxins present in the sludge had been of little concern to the public (who couldn't see it and for the most part didn't know about it);othe AIDS epidemic and its attendant focus on hypodermic needles caused a public and media commotion suffic~ent to cause Congress to ban ocean dumping altogether in 1988.

It seemed that the old debate had reappeared, only this time about sludge: is it a nuisance--<Jr worse, a hazard--that must be "disposed of"; or is it, like the old "night soil, "a valuable fertilizer?

This was a triumph for many environmental groups who had fought ocean dumping because of its toxic effects on marine ecosystems. But the ban on

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ocean dumping only moved the sludge problem to other grounds: what to do with it now? And, although not a conflict known to many-not even to many environmentalists-there was a disagreement within and between the groups in the environmental movement over what should be done with the sludge. It seemed that the old debate had reappeared, only this time about sludge: is it a nuisance--or worse, a hazard-that must be "disposed of'; or is it, like the old "night soil," a valuable fertilizer? Some of the major environmental organizations-including the Environ­mental Defense Fund (EDF) and the National Resources Defense Council (NRDC)-struck a deal with the EPA, which agreed to shut down ocean dumping if they would join in promoting land application as the longaterm solution to the disposition of sludge. Both EDF and NRDC were among the signers of the "consent decree," the legal document mandating land appli­cation in place of ocean dumping. To many in these organizations, this must have seemed a very good arrangement: in one fell swoop it ended a poisonous process (ocean dumping) and, it seemed, began a very good one. Wasn't this a promise to "recycle"? Wasn't it "sewage farming" at last?

The organic farming and natural food movement, developed as a response to the post-World War II period when agriculture was turning to chemical fertilizers and synthetic pesticides. By the 1970s the movement had attracted a diverse, passionate, and international following. Organic gardeners and fanners were "environmentalists" before the emergence of the more encom­passing environmental movement in the 1970s. Fundamental to the organic movement's philosophy is the belief that human health depends on food grown on healthy soil-soil alive with humus, the partly decomposed residue of organic matter. Feeding the soil-rather than feeding the plants "intrave­nously" with soluble synthetic chemical fertilizers, as is the practice in agribusiness-is, according to this view, the way to support the health of the soil. And humus is the "food" for soil. Hence, compost, the managed creation of humus, is the essential ingredient of the organic method. Crucial to this orientation, also, has been the belief that, since all life is related, the pesti­cides, herbicides, and fungicides routinely employed in chemical agribusi­ness will damage human health at least as much as they will damage the smal1er and rapidly multiplying creatures they were designed to destroy. It is logical to expect that using sludge in agriculture would be abhorrent to the organic movement.

The organic food and agriculture movement gained in strength in spite of the silent but monumental opposing interests of the agro-industry, whose eco­nomic health has depended on the petrochemical-based fertilizers and, given vertical integration of the chemical and agricultural industries, on pesticides of every sort. The organic food and agriculture movement also gained strength in spite of the ruling view of the EPA, which to a large extent is composed of engineers who have little respect for ideas associated with anything "organic." Indeed, the U.S. Department of Agriculture and the EPA

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regarded the practice of com posting, the organic fanners means of achieving healthy soil, as being unscientific-until, that is, the late 1980s when, soon after signing the consent decree stopping ocean dumping of sludge, "land application" of sewage sludge came into its own.

In 1992, the ocean dumping ban went into effect, and then, with the full fanfare and pomp of a-fonnidable public relations campaign, ·sewage sludge was rechristened "beneficial biosolids." Thus the EPA's classification of sludge as a hazardous material was evaporated and then reconstituted with the trappings of the recently despised word "compost": sludge would be composted; the.word "compost" would achieve official dignity. And envi­ronmental groups such as EDF and NRDC blessed this conversion.

At the same time, industry and the big environmental organizations were forging a new kind of relationship. These groups believed they could modify the behavior of industry for the sake of the environment by sitting at the same table in a spirit of negotiation. Industry on its part began to fund these organizations. EDF and NRDC both received funding from the waste han­dling industries, and subsequently were notably silent when questions were raised about the toxic constituents of sludge and the likely dangers of its application to the land. And within the organic movement, Compost Science, a spinoff ofRodale 's very popular Organic Gardening & Farming magazine, became the prime publicist ofland application of sludge, not only through its articles, but also through its copious advertisements for sludge hauling and sludge spreading equipment.

This sanction by the most respectable environmental organizations was key to getting public and regulatory acceptance for what would be, for the waste industry the most profitable sludge disposal method among all the altema­tive·s. Land filling is expensive for them because of tipping fees. Incineration is expensive because of unabated environmental opposition. Land applica­tion, on the other hand, is profitable. Municipalities pay waste haulers to take the sludge away and then dump it-for free (hence no tipping fees)--on farms. But beyond free dumping, through high-powered public relations expropriation of the words "natural" and "organic" and "compost," this same sludge, neatly pelletized and bagged, could be sold retail to gardeners. And, as long as there were environmentalists who condoned it, gardeners would buy it.

For every municipality with a sewer system and some kind of sewage treatment, the growing mounds of sludge are becoming an increasingly serious problem. This problem gives them a compelling interest to support land application:- every town and city needs a way-a cheap way, if possi­ble-to dispose of this sludge. The public, already burdened by taxes first for sewering and then for treatment of sewage, will not easily take on the further cost of the treatment of sludge. Land application isn't treannent: it's "bene­ficial reuse" that costs taxpayers nothing. Waste haulers began offering

Volume 39, No.6 109

sludge as a "free fertilizer" to the fanners along with free spreading of lime, a bonus of thousands of dollars to small and middle sized fanns in those pans of the country with acid soils in need of liming. This offer has made advocates of many of those fanners.

The claim that "biosolids" are beneficial is based on the presence in sewage sludge of nutrients deriving from human excreta. But the benefit of this content compared to the dangers of the toxic matter in it is a key point in the debate about the land application of sludge. It is the view of this writer that the menace of toxic and otherwise non-life-compatible substances that can be found in sludge so greatly outweigh the potential nutrient benefit as to make that potential benefit an irrelevance. Let me now present the reasoning on which my position is based.

Nitrogen is the main nutrient promoted to farmers as the ufree fertilizer" in sludge. The land application wing of EPA (primarily the wastewater division) claims that the total nitrogen fertilizer requirement of agriculture can be met by using sewage sludge. However, most of the nitrogen in excreta derives from the urine, and the forms of nitrogen in urine are highly soluble and, one~ mixed with water, are not easily removed from it. Therefore, sewage treat­ment processes allow most of the nitrogen to remain in the wastewater. transferring correspondingly little to the sludge. Since the concentrations of nitrogen are so relatively low, and the concentrations of heavy metals (e.g., lead, cadmium, zinc, copper, mercury, chromium, and arsenic) are. relative to ambient levels in soils, so high, it follows that massive quantities of sludge must be spread on fannland to attain the levels of nitrogen needed to act as fertilizer. This means heavy metals will accumulate in the soil. Or they will move. Where? Into bacteria, into plants, into the chain of life.

The offers of free lime, besides serving as an inducement to farmers to accept sludge on their land, serves another purpose. The regulations governing land application of sludge require the maintenance of a: pH above 6.5 in soils on which sludge is spread. This 6.5 pH is needed to bind up the heavy metals­precisely to prevent them from moving--either up, causing "bio-accumula­tion" in life chains, or down, causing pollution of groundwater. There is an active debate between soil scientists and advocates ofland application about this effort to "bind up" the heavy metals. This debate has two questions: whether or not liming works on all the metals from a strictly chemical point of view, and whether or not it matters if it works, since the monitoring and enforcement of pH levels on farms is a vinual impossibility.

There are many problems surrounded by intense controversy over the issue of land application of sludge. Its noxious odor is the first to be complained of, if the least threatening to life. Disease-from viability and regrowth of human pathogens in raw sludge, and other diseases caused by the sludge composting processes-is of major concern to many. But, serious as these concerns are, serious as is the danger of heavy metals' toxicity due to land

1 I 0 II, December 1996

Feature Articles

application, sludge has another yet more threatening characteristic. Far more dangerous to all life is the fact that combinations of some chemicals can cause levels of life process disruptions many times in excess of the effects of any chemical alone. For example, recent research has demonstrated dramatic increases in the estrogenic effects of common pesticides when they act in combination.· Whereas the endocrine disrupting effect is 1: I in the case of the doubling of one single compound, where two or more are combined, their destructive effects are not just doubled but, rather, multiplied and magnified to the order of 600 or even I ,600 times. Sludge provides perfectly the conditions for combinations of thousands of chemicals to cause a cataclysmic devastation of life (Colborn et al. 1993; Arnold et al. 1996).

What is to be done with sludge, then? This question has two parts. The first is immediate: is there a safe way to deal with the sludge that the world is now producing? The second is a policy question: should we continue to commit resources to a sewering-and-treatment-of-sewage system which creates so · unresolvable a problem as is embodied in sludge?

In answer to the immediate question, the sludge that is still being produced by existing treatment plants should be treated as the hazardous waste that it is. It should either be isolated in secure storage, as is nuclear waste, or it should be processed by means of emerging technologies such as gasification which, through high-heat oxidation, avoids the creation of dioxin in the stack gases and reduces the sludge to a mineral ash. Both strategies make possible the minimizing of the contact of sludge with life, rather than the maximizing of it as is currently the case with land-application.

The answer to the second part-the policy part-is prevention. Prevention rather than inevitably futile attempts at "cure" is the form any positive change must take. Prevention in this case means not creating in the first place. Communities that are not already sewered should practice sewer avoidance. Sewering is the most expensive technology. It degrades the environment more than protects it, and it unceasingly produces sludge in overwhelming quantities. Communities need to take the political initiative to insist that substandard or failing on-site systems (e.g., pit latrines, cesspools, septic tank/leach fields) must be remediated by on-site technologies that solve, instead of merely moving the problem. Many options now exist for on-site remediation of failing or polluting septic systems. There are waterless com­posting toilets, greywater purification-by-use systems and reed beds, and other water-based biological systems for cleaning organically polluted waste­water from some industrial processes. The key to preventing the trouble caused by this homogenizedmess of mixed matter is separation at the source.

Conclusion No society in the world today deals well with human excreta. At all levels of technical sophistication, damage is done to water, soil, and human health­whether by the pit latrine, the flush toilet, the septic tank/leach field, or, most

Volume 39, No.6 Ill

insidiously and destructively, by the central sewage collection and treatment plant, which creates an unpredictably toxic, and therefore unrecyclable, sludge. The only principle by which we can simultaneously protect the :soil, the water, and human health is through technologies and management sys­tems that systematically segregate human "wastes" and recycle them to agriculture, from which, for the past I 0,000 years, they have come.

The sheer number of dangers associated with treating sludge as if it were a fortilizer is so great, so various, and so serious that it would be the lifo work of thousands of profossionals to divide up and respond to the categories of problems that will arise from this practice.

The sheer number of dangers associated with treating sludge as if it were a fertilizer is so great, so various, and so serious that it would be the life work of thousands of professionals to divide up and respond to the categories of problems that will arise from this practice. The real significance of the names and numbers, of the "anecdotes" about human illness, about cows and horses dying after eating hay grown on sludge, lies in the unknowability of it all: what goes down the drains is unpredictable; what goes into the sewer-from hour to hour, from week to week, from month to month-is unpredictable; what is extracted from the wastewater can neither be predicted nor monitored to an extent even remotely adequate. And no system of regulations can be either designed or enforced in such a way as to protect life chains from the potential of devastation by the constituents of sludge.

Collecting our "wastes" in sewage, then "treating" them so as to disentangle them again, then distributing the residue, the sludge, on agricultural land, can be made to look like "recycling," for some of the sludge did come from food growth and food use processes. But much of it did not come from such processes, and when those materials, foreign to the cycles of life, are insinu­ated into these cycles through the food chain, the consequences for life can be terrible. Because we cannot find a certain way either to keep all the toxics out of the sludge or to get all the toxics out of the sludge, we must say, I think, that the consequences of dumping sludge on agricultural land will be terrible.

To entertain the view that the benefits of application of sewage sludge to agriculture will outweigh the harm is either sentimental evasion or short­sighted greed. Uncertainty because of unpredictability is the unavoidable character of sewage sludge. And when uncertainty risks damage to all life of the order that industrial society's toxic chemicals certainly involve, gambling on the dangerous route is absurd. •

112 II, December 1996

Feature Articles

References

Arnold, Steven F., Diane M. Klotz, Bridgette M. Collins, Peter M. Venier, Louis J. Guiiiotte, Jr., and John A. McLachlan. 1996. "Synergistic Activation of Estrogen Receptor with Combinations of Environmental Chemicals." Science. June 7. 272: 1489-1492.

Colborn, Theo, FrederickS. vom Saal, and Ana M. Soto. 1993. "Develop­mental Effects of Endocrine-Disrupting Chemicals in Wildlife and Humans." Environmental Health Perspectives. October. (101)5:378-384.

King, F. H. I 927. Farmers of Forty Centuries. London: Jonathan Cape. (Reprinted in 1972 by Ron dale Press, Emaus, P A).

Mumford, Lewis. 1961. The City in History. New York: Harcourt, Brace & World, Inc. 214-217.

Pliny the Elder. 1991. Natural History. London: Penguin Books, Ltd.

Reid, Donald. 1991. Paris Sewers and Sewermen. Cambridge: Harvard University Press. 161.

Reutergardh, Lars. 1996. "An Overview on Organic Contaminants, Focus­ing on Monitoring of a few Chlorinated Organic Pollutants, Through Emission Studies." Resources, Conservation and Recycling. 16:361-382.

Tarr, Joel A. and Gabriel Dupuy, eds. 1988. Technology and the Rise of the Networked City in Europe and America. Philadelphia: Temple University Press.

For more information contact:

CURRENT WORLD LEADERS

INTERNATIONAL ACADEMY AT SANTA BARBARA 800 Garden Street, Suite D Santa Barbara, CA 93101 U.S.A.

The Quic.:kest Way to Rc!'earch Government Lcadas Volume 39, No.6 I J3

THE SEWAGE ratepayers. These publicly owned treatment works also collect the private in­dustrial waste from com-

SCAM mercial enterprises and factories. In 1992 alone, local governments spent $20 billion on sanitary sewers and sewage treat-

SHOULD SLUDGE FERTILIZE YOUR VEGETABLES?

ment facilities. That same year, corporations collect­ing and disposing of the byproducts from these fa­cilities earned $352 million. Since 1970, it has cost U.S. taxpayers over $100 billion

Humpty Dumpty sat on a wall. Humpty Dumpty had a

grc:at fall. All the king's horses and all the king's men

couldn't put Humpo/ together again.

The king promised Humpty Dumpty that with all his

horses and all his men they'd pick him up again. But

Humpty learned the truth. Broken, he waited and waited,

never to find himself together again.

And so it goes with sludge. Since the early 1990s, the

U.S. Environmental Protection Agency (EPA) has been

working with the waste management industry and mu­

nicipalities to establish sewage sludge, the semi-solid waste

byproduct from municipal sewage treatment plants, as a

safe fertilizer for application on land. But a growing num­

ber of your neighbors, farmers and environmentalists are

crying foul. They say sludge is roxie and must sray out oflife

c~cles and rhus off the soil. They say the stakes are too high

to wait and see if the EPA can pick up the pieces when its

sludge policy comes crashing down and leaves in its wake a

health and ecological disaster.

/v\unicipal sewage treatment plants collect the domestic waste of over 75% of the U.S. population, at a cost of over S 15 billion per year to local

:34 dollars and sense

Lauro Orlando is a

member of the Dollars

and Sense Collective

and Executive Director

of the ReSource Institute

for Low Entropy Systems.

BY LAURA ORLANDO

to upgrade wastewater treatment plants and extend the coverage of public treat­ment facilities to more households and industries.

Sewers and sewage treatment plants are big business. They are expensive to build and to maintain. No one wants to add to the price tag the landfilling of sludge, because it is the American taxpayer that will have to pay the piper. So call it a fertilizer and spread it on land. It's che cheapest option and, at first glance, the most environmentally benign and media savvy solution to an enormous problem.

For the EPA, the trouble with sludge is twofold. First, the near doubling of sewers - and therefore doubling of sludge- as a resulr of the 1972 Clean Water Act. Second, the 1988 Congressional ban on ocean dumping. Munici­palities have enormous quantities of this material and the EPA is in charge of regulating where it can go. For the rest of us, the trouble with sludge starts with the flushing of industrial ranks and ends with an unpredictable potpourri of chemicals, nutrients, bacteria, fungi and heavy metals.

Treatment plants have various degrees of sophistica­tion, though most in this country have the capacity for what is called secondary treatment. Sewers bring to the treatment plants whatever domestic, industrial, and com­mercial sources pour, flush or dump into their drains. A combination ofbiological and mechanical processes render the wastewater "clean," that is, it satisfies federal pollution regulations. What can be extracted from the wastewater is either hauled away in trucks to landfills or is found in the sludge. There is no magic here. What goes in has to come out. The better the treatment process is for the water the worse the quality of the sludge.

The federalToxics Release Inventory (TRI) attempts to

keep track of toxins in the United States. The Washington D.C.-based Environmental Working Group, in irs report "Dishonorable Discharge: Toxic Pollution of America's

/ .,.

Waters," usedTRI data to estimate that 1.5 billion pounds of toxic chemicals were transferred to public treatment facilities between 1990 and 1994. 450 million pounds ended up in water bodies from the discharged "treated" wastewater. The rest - over one billion pounds of chemicals- are in the sludge, were broken down, or evapo­rated into the air. TheEnvironmentalWorking Group notes that their numbers are "drastically underestimated."

Eastman Kodak, Monsanto, Dupont, liT, Procter and Gamble, Sun Chemical, Ciba-Geigy, Upjohn Co, James River Paper Co., 3M, the garage down the street, your neighbor's paint shop, your toilet and millions of other industries and households are connected to the network of sewers that cover this nation.

The Resource Conservation and Recovery Act, which sets the regulations on hazardous wastes, excludes do­mestic sewage. If you dump your hazardous waste into rhe nearest river, you are breaking the law. If you dump ir in the sewer, you may be doing nothing illegal. The EPA does not include so-called "transfers" of toxic chemicals to sewer systems as an official "release" of a roxie chemical into the environment. The Clean Water Act does call for some industries to voluntarily pretreat their waste- but looking at the Toxic Release Inventory numbers, it doesn't look like anyone is paying much at­tention ro what is going down rhe drain.

Sellin'g rhe idea of sludge as a "safe fertilizer" starred in earnest after rhe 1988 ban on dumping sewage sludge inro rhe ocean. The first order of business was a name change: sludge had ro go, so the Water Environment Federation ('X'EF), an industry-sponsored organization formerly known as the Federation of Sewage Works Asso­ctanons, went into action.

In 1991, the Name Change Task Force ofWEF settled on "biosolids," defined as the nutrient-rich organic byproduct of the nation's wastewater treat­ment process. Change the name and you redraw the battle lines. It's nor about sludge disposal anymore, it's about "organic" fertilizers, "biosolids recycling" and "composting." Consumers, gardeners, and farmers are confused, and rightly so.

The Water Environment Federation, whose member­

ship is almost entirely drawn from chose who have a stake in the sludge production business - treatment plant managers and operators, state and federal employees, waste management corporations, engineering firms, con­struction companies, and equipment manufacturers and suppliers - became the chief non-governmental spokes­man for "biosolids." It wrapped itself in the language of environmentalism and locked arms with the EPA.

WEF received a $300,000 grant from EPA to "educate the public" about the "beneficial use of sludge." Dr. Alan Rubin, who served as the chief of the EPA's sludge man­agement branch, was loaned to WEF in 1994. The EPA continued to pay half his salary while he became the nation's leading cheerleader for "biosolids." WEF hired Powell Tare, a powerful Washington-based public relations and lobby firm, to draw up the strategic and communi­cations plan to push public acceptance of "biosolids." This 44-page document laid the groundwork for an all­out assaulr on those who question the safety of using ~sludge as a fertilizer.

Publications on "biosolids recycling" were churned out at an impressive speed. The level of confidence in biosolids from these publications- pur our by waste management companies like Wheelabraror Water Technologies, state environmental protection agencies and industry­sponsored nonprofits- is impressive. They do nor flinch when they say that "the amounts of metals from biosolids application are usually no larger that those that exist naturally in soil. In fact, many of these trace metals are beneficial or essential nutrients for people. These metals are common ingredients in vitamin tablets and enriched breads and cereals" (from a Wheelabraror brochure tided "What New England Should Know About Biosolids Re­cycling and Land Application").

ILLUSTRATION BY MAURICIO ALBERTO CORDERO May/June 1997 35

Aft.e:r the name change and marketing behind it were put into place, the next step in the sludge shenanigans was regulatory revision. The use or disposal of sewage sludge is regul:ated by the Code of Federal Regulations, Tide 40, Part 503 (colloquially called "503s"). In 1992 those regu­lations were revised, relaxing the standards in each risk

TISSUE AND BLOOD

SAMPLES FROM

category. A 1989 letter from the commissioner of New York's Department ofEnvironmental Protec­tion, Harvey Schultz, to

THE DEAD COWS William Reilly, the head

POINTED TO SEVERE of the EPA, is an example of the kind of pressure the

LIVER DAMAGE. EPA was under to change

its standards. Schultz said that "the City ofNew York found that compliance with the pollutant standards (503s) will be difficult, if not impos­sibl,~ to achieve for 80% of the city's sludge."

The 1992 revisions of the 503s reflected the commissioner's concerns. Acceptable cumulative load lim­its (accumulated amounts) increased for every heavy metal regulated by the 503s: lead rose from 110 to 265 pounds per acre, zinc jumped from 150 to 2,469 pounds per acre, arsenic levels were raised threefold, and chromium bal­looned from 467 to 2,645 pounds per acre.

'With these and similar changes in the 503s, "beneficial use" (the industry euphemism for disposing of sludge on farm land) became the mantra of municipalities and in­dustry. Cities already had been spreading sludge on land or selling it as "organic" fertilizer to gardeners and fertilizer manufacturers. Now they had a new badge to flash, one that boosted their profile and further legitimized their actions.

The 503s regulate 10 heavy metals, pathogen (disease causing organisms) levels, reporting, record keeping, ap­plication and management. Dioxins and most of the 700 to 1,000 new chemicals added annually to the 60,000 chemicals currently used by U.S. industry are not regu­lated. The rules are "self-implementing," meaning the government conduces no oversight, and any testing is done by the sludge producers themselves.

A recent publication from Cornell University's exten­sion service recommends that farmers "limit the total cu­mulative load of metals in soil to no more. than 1 I 10 the cumulative loading limits set under federal 503 regula­tions." Why? Because some heavy metals ingested by aquatic organisms, wildlife and humans can cause physi­ological mayhem: troubles like kidney disease, hyperten­sion, liver damage, neural damage, structural change in ri:ssues, and reproductive problems. On average, the 503 re:gulations for cumulative loading of heavy metals are eight

36 dollars and sense

times higher than those set in Denmark, Canada, the Euro­pean Economic Community, France and the Netherlands.

Why the discrepancy? Europe uses "non-degradation standards" aimed at preserving farmland free from con­tamination for future generations. The EPA uses "risk as­sessments," which seem to have floating benchmarks, a high tolerance for risk, and no consideration for the syner­gistic effect of the chemicals in municipal sewage sludge. (Combined, some chemicals are much more dangerous than they are as individual substances).

A panel convened by former EPA administrator Will­iam Reilly warned in 1992 that research at EPA was "un­even and haphazard." David Lewis, a microbiologist at the EPA, wrote about the agency's science "gridlock" in a 1996 article in Nature, and used sludge as an example. He said political pressure and court-imposed deadlines prevailed when the agency finalized its sludge rules in 1992. The regu­lations relied, in part, on experiments Lewis and others label as "sludge magic" with little relevance to the real world.

The composition of sludge changes as often as materials are flushed into the system. On any given day, according to

Cornell University and the American Sociecy of Civil En­gineers, Polychlorinated Biphenyls (PCBs); chlorinated pesticides such as DDT, aldrin, and 2,4,-D; heavy metals from wood preservatives, pesticides, metal plating, and batteries; bacteria; viruses; fungi; chlorinated compounds; flame retardants (asbestos); petroleum products; indus­trial solvents; nitrogen; phosphorous; potassium; and di­oxin can be found in sewage sludge. These substances can be highly disruptive to life, resulting in reproductive problems, disease and death. Bur as with many pervasive reproductive toxins, carcinogens and persistent toxic metals in the envi­ronment, there is no smoking gun to identifY the culprit.

A national grassroots effort, spearheaded by the New York-based National Sludge Alliance, to stop the land ap­plication of sludge has grown out of several horror stories from people around the country. In Rutland, Vermont, 24 months after spreading sludge on his 99 acre farm, dairy­man Robert Ruane's cows started getting arthritis and milk production dropped from 18,000 pounds per year to

14,000 pounds per year. Over a rwo year period, 66 cows died. "They cold me how much money it was going to save me on fertilizer," Ruane said. The municipality furnished him with rwo tractors, a manure spreader and a set of transport harrows. Tissue and blood samples from the dead cows pointed to severe liver damage. Bur EPA labels

all such evidence circumstantial. Milk-producing cows drink up to 25 gallons of water

per day. Most grazing animals also ingest soil together with their food. Any metals in the water or soil would be picked

up by the liver. Since the liver's main function is to filter toxins, it makes sense that Ruane's dairy cows acted like canaries in a coal mine. A 1992 Farm journal article calls sludge a potential "land bomb." Several farm and food orga­nizations, including the American Frozen Food Institute and the Northeast Organic Farmers Association, are calling for a halt to the practice of applying sludge to farmland.

Darrell Turner, Washington State Farm Bureau Presi­dent and university researcher, asks "Can you trust the analysis that you get when they are desperate to get rid of the stuff at the least possible cost?" If a farmer wants to test the sludge before it is spread, he or she can expect to pay $250 per sample for PCBs and heavy metals and $2,000 for a dioxin test. Once it is spread, all liability transfers co the land owner.

Municipalities transfer millions of dollars to sludge haulers like Wheelabrator, BFI and Merco Joint Ventures. It's big business run by corporations who are no strangers to bullying. When Hugh Kaufman - a champion of en­vironmental justice and an engineer in the EPA's Hazardous Waste Division- called the transfer of sludge from New York City to the Texas town of Sierra Blanca an "illegal haul and dump operation masquerading as an en­vironmentally beneficial project" on Michael Moore's "TV Nation," he was sued for libel by Merco, the sludge hauler in charge of the op­eration. Kaufman and his four co-defendants, including TriStar Television, lost the first round in court but are appealing the verdict. Kaufman and TriStar were ordered ro pay .\1erco $500,000 and $4.5 million respec­tively in punitive damages. Kaufman argues that this was a slapsuit aimed at silencing him and ochers like him. According to Kaufman, no proof was offered by Merco that the infor-mation presented on the television program was false. Michael Moore said it was about "shutting up the people of Sierra Blanca" and their call to end the sludge dumping.

If sludge is not spread on land or sold as fertilizer under brand names like Milorganite, Nu-Earrh, Nirrohumus and Baystate Organic, what should be done with it? The first step is to limit its production. Take industry off the public sewer systems and do nor sewer additional commu­nities. Safe, culturally acceptable and economical alterna­tives to conventional sewers exist. Use them. The Clean \'Vater Act mandates billions of dollars for sewering. In­stead. use this money ro refine alternative technologies, and implement them on a large scale. Such alrernatives

include waterless and low-flush com posting toilets paired with greywater recycling systems, biogas digesters and duster systems fed to constructed wetlands. Many indus­tries treat their own effiuents and safely recycle waste, sav­ing money and preventing environmental degradation. Encourage more behavior like this.

The second step is to safely contain the sliLldge that is being produced. Advanced technologies, such as gasifi­cation, an incineration process that does not produce dioxin, should be explored.

The regulators that sec the levels of contamination in our environment do not differentiate between risk, which

is an event with a known probability, and true uncertainty. Environmental contaminants in municipal sludge pose true uncertainty about the dangers they impart on human and ecological healrh. No public relations spin, earnest proclamations, regulations, recycling claims or good in­tenrions can change char. •

Resources: Toxic Sludge Is Good For You: Lies, Damn Lies And the Public Relations Industry, John Stauber and Sheldon Rampcon, Common Courage Press, 1996, hrrp:/ /www.envitolink.org/is­sues/sludge/sludge.hrml; Rachel's Environment & Heahh Weekly, hnp:/ /www.moniror.ner/rachel/; "Civilization and Sludge: Nares on the Management of Human Excreta," Abby A. Rockefeller, Current World Leaders, Volume 39, No. 6, December 1996; The National Sludge Alliance, P.O. Box 130, Copake, New York 12345, (518) 329-2120.

May/June 1997 37

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Recyc~g OrganiC Waste:. From Urban Pollutant to Fann Resource

Gary Gardner

Recycling Organic Waste: From Urban Pollutant

to Farm Resource

GARY GARDNER

Jane A. Peterson, Editor

WORLDWATCH PAPER 135 August 1997

/

TBE WORLDWATCB INSilTVTE is an independent, nonprofit enVi­ronmental research organization in Washington, DC. Its mission is to fos­ter a sustainable society tn which human needs are met in ways that do not threaten the health of the natural enVironment or future generations. To this end, the Institute conducts interdisdplinary research on emerging global issues, the results of which are published and disseminated to ded­sionmakers and the media.

FINANCIAL SUPPORT for the Institute is proVided by the Nathan Cummings Foundation, the Geraldine R. Dodge Foundation, The Ford Foundation. the Foundation for Ecology and Development, The William and Flora Hewlett Foundation, W. Alton jones Foundation, john D. and Catherine T. MacArthur Foundation, Charles Stewart Mott Foundation, The Curtis and Edith Munson Foundation, The Pew Charitable Trusts, Rasmussen Foundation, Rockefeller Brothers Fund, Rockefeller Financial Services, Summit Foundation, Turner Foundation, U.N. Population Fund, Wallace Global Fund, Weeden Foundation, and the Winslow Foundation.

TBE WORLDWATCB PAPERS proVide in-depth, quantitative and qual­itative analysis of the major issues affecting prospects for a sustainable soci­ety. The Papers are written by members of the Worldwatch Institute research staff and reViewed by experts in the field. Published in five lan­guages, they have been used as condse and authoritative references by gov­ernments, nongovernmental organizations, and educational institutions worldwide. For a partial list of available Papers, see back pages.

REPRINT AND COPYRIGHT INFORMATION for one-time academic use of this material is available by contacting Customer SerVice, Copyright Clearance Center, at (508) 750-8400 (phone), or (508) 750-4744 (fax), or writing to CCC, 222 Rosewood Drive, Danvers, MA 01923. Nonacademic users should call the Worldwatch Institute's Communication Department at (202) 452-1992, x517, or fax a request to (202) 296-7365.

<!:1 Worldwatch Institute, 1997 Library of Congress Catalog Number 97-061125

ISBN 1-878071-37-8

Printed on 100-percent non-chlorine bleached, partially recycled paper.

Table of Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

The Cost of Breaking the Loop . . . . . . . . . . . . . . . . . . . . . 9

Organic Material Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Composting Urban Wastes ........................ 23

The Potential and Peril of Human Waste . . . . . . . . . . . . . . 30

Sustainability and Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Returning to Our Organic Roots . . . . . . . . . . . . . . . . . . . . 45

Notes ......................................... 51

Tables and Figures

Table 1: Share of Nutrients from Domestic Grain Consumed Domestically by Humans and Animals . . . . . . . . . . . . . . . . 17

Table 2: Share of Nutrients from Domestic Grain That Is Exported: Seven Largest Grain Exporters . . . . . . . . . . . . . . . . . . . . . . 1 9

Table 3: Net Flows of Nutrients in 15 Foods, by Region, Mid·1980s . . ~0

Table 4: Effidency of Fertilizer Use on Grainland: United States, China. and World • . . . • . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 5: Composted Share of Organic Wastes, Selected OECD Countries . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . 25

Table 6: Nutrients in Organic Munidpal Solid Waste (paper excluded) as a Share of Fertilizer Use, Selected OECD Countries. . . . . . . . 27

Table 7: Nutrients in Human Waste as a Share of Nutrients in Fertilizer Applied, Selected Countries . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 8: Concentration of Livestock Production in the United States . . -!3

Figure 1: Natural and Human Sources of Nitrogen Fixing • . . . . . . . . 11

The views expressed are those of the author and do not necessarily represent those of the Worldwatch Institute; of its directors, officers, or staff; or of its funding organizations.

ACKNOWLEDGMENTS: I would like to thank Sidonie Chiapetta, Laurie Drinkwater, Robert Goodland, josefina Mena Abraham, Laura Orlando, Mark Ritchie, David Wedin, Ray Weil, and my colleagues Lester Brown, Chris Flavin, Jennifer Mitchell, and Molly O'Meara for their helpful comments on an early draft of this paper. Worldwatch interns Yasmin Daikh and Giovanna Dore provided thorough research assistance. Jane Peterson, our editor, and Jim Perry, Denise Byers Thomma, and Mary Caron of our communication staff were instru­mental in sharpening the paper's message. Liz Doherty was quick and accurate in the production process, in spite of a tight schedule. And Sally Bolger provided unfailing good humor and unwavering moral support. To aU, a heartfelt thank you.

I am grateful to the Wallace Genetic Foundation for its generous finan­cial support of this project.

GARY GARDNER is a Research Associate at the Worldwatch Institute, where he writes on agriculture and water issues. Since joining the Institute in 1994, he has written chapters in State of the World and con­tributed to Vital Signs and World Watch magazine. He also wrote Worldwatch Paper 131, Shrinking FieldS: Cropland Loss in a World of Eight Billion, released in July 1996.

Mr. Gardner was previously a project manager at the Soviet Non­proliferation Project, a research and training program run by the Monterey Institute of International Studies in California. While there, he authored Nuclear Nonproliferation: A Primer. Mr. Gardner spent two years helping Peruvian women's groups develop urban small livestock projects. He holds master's degrees in Politics from Brandeis University, and in Public Administration from the Monterey Institute of International Studies. He received his bachelor's degree from Santa Clara University.

5

Introduction

I n 1876, a German chemist studying the agricultural his­tory of North Africa became increasingly troubled over the fate of that region and its implications for his day. In

the first century AD, North Africa's fertile fields were sup­plying two thirds of the grain consumed in Rome. But the nutrients and organic matter in that food were not returned to the farms where they originated; instead, they were flushed into the Mediterranean. By the middle of the third century, the one-way flow of nutrients out of North Africa's grainland soils, along with declining levels of organic mat­ter, had contributed to the region's tumble into environ­mental and economic decline. 1

The chemist, justus von Liebig, worried that Europe's rapidly expanding cities also depended too heavily on one­way nutrient flows, with consequences that would eventu­ally undermine both urban and agricultural areas. To solve the problem, he invented chemical fertilizer, essentially a mixture of condensed and easily transportable nutrients that made it possible to escape dependence on recycling organic matter. The new fertilizer revived the fertility of nutrient-depleted farmland. And because a ton of this plant food could pack as many nutrients as dozens of tons of organic matter, it could be shipped cheaply over great dis­tances. Cities could now expand, and food could be import­ed from great distances, without concern for returning urban garbage and sewage to farmlands. Thus, garbage and sewage became waste products to be discarded, rather than soil builders to be reused.

Today, nearly 3 billion of us-half of the human fami-

/

6 RECYCLING ORGANIC WASTE

ly-live in dties, more dependent than ever on long, one­way flows of nutrients and organic matter. But reliance on linear flows instead of the traditional organic "loop" comes at a price that is paid at both ends. To start with, many regions of the globe are now overfertilized, a trend with con­sequences well beyond the farm. Drinking water in several European countries is contaminated with fertilizer runoff. Species diversity is reduced in some land-based ecosystems by excess applications of nitrogen. The quality of organic matter declines, and plant diseases become more prevalent, in soils dependent on manufactured fertilizer. And aquatic life in rivers, lakes, and bays suffocates as blooms of algae fatten on nitrogen and phosphorus that have leached and eroded from these soils. In short, a host of new problems arise once the circular flow of nutrients (essential for plant growth) and organic matter (essential for soil health) is dis­rupted and made into a linear flow. z

At the disposal end of the linear flow, meanwhile, nat­ural sources of nutrients and organic matter in urban garbage and human excreta are increasingly difficult to eliminate safely. Landfills for solid waste are not only near capacity in many countries, they are leaking toxic chemicals into groundwater and methane into the atmosphere. Discarded garbage piles high on street comers in many developing countries, spawning rats and disease. And human waste is either dumped indiscriminately or mixed with industrial chemicals in urban sewers, which makes safe disposal much more difficult. In any case, sewage systems are expensive and water intensive-flush toilets account for 20-40 percent of residential water use in sewered cities of developed countries-making them an inaccessible luxury for the growing number of cash-strapped and water-short cities in the developing world. 3

Returning nutrients in organic matter to farm soils--­" closing the organic loop" -would help alleviate all of these problems. Urban wastes such as food scraps, paper, and yard clippings can be composted and applied to soils, thereby improving soil structure, supplying nutrients, and suppress-

INTRODUCTION 7

ing disease. Indeed, nutrients in the garbage and yard wastes of states belonging to the Organisation for Economic Co­operation and Development (OECD) equal some 7 percent of the nutrients in fertilizer applied in those countries, and the level is much higher in many developing countries. In addition, nutrients in discarded human waste in OECD countries equal another 8 percent of applied fertilizer. While urban organic wastes will not displace fertilizer entirely, they can help reduce excessive fertilizer use (and the pollution this causes) as they build healthier soils.4

Recycling organic matter would also ease the pressure on costly waste disposal facilities. Organic matter accounts for. a third of inflows to landfills in industrialized countries, and as much as two thirds in developing countries, and is largely to blame for the acidic leaching and methane problems that these facilities generate. Meanwhile, opting for a "dry" system of human waste management­through the use of composting toilets, for example-would free up clean water

Closing the organic loop would help alleviate many urban problems.

for more vital uses, and avoid costly infrastructure construc­tion as well. 5

Before extensive reuse of organic material can take place, however, certain changes in agricultural production and trade practices must occur. As organic flows extend across oceans, and as agricultural production becomes more specialized and intensified, nutrients inevitably accumulate in some areas. Centralized livestock facilities, for example, like the giant poultry- and hog-raising operations in the United States, buy feed from far away, and then have trou­ble disposing of all the manure they produce. Manure is one nutrient source that has commonly been recycled, for live­stock and crops located on the same farm easily fed each other. But as livestock operations increase in size and become separated from agriculture, more and more of this resource is viewed as waste material. 6

8 RECYCLING ORGANIC WASTE

Such regression is alsO evident in some developing countries that mimic the nutrient management practices of industrialized nations. China, for example, used organic sources for more than 98 percent of the fertilizer applied to soils in 1949; today, because of rising labor costs, the share is less than 38 percent. On the other hand, some industrial­ized regions are paying greater attention to reuse of organic matter as the problems created by linear flows of nutrients mount. In the U.S., 23 states now restrict the inflow of grass clippings to landfills; this material is composted or re-used as mulch. And well over a third of U.S. and European sewage sludge is now applied to land, though often with only min­imal precautions for safe reuse/

Continued progress in recycling organic material requires that it be viewed as a natural resource, not as waste matter. Such a shift in perspective will require education on many levels. Policymakers and citizens will need to learn to manage organic matter in ways that facilitate its reuse. Processors of organic matter, such as compost makers, will need to tailor their products to the diverse needs of different soils and crops. And farmers will need to understand how organic matter works in soils, and how they can avoid overuse of chemical fertilizers. Once this educational process is complete, other steps will follow naturally. Communities will close dumping sites to organic materials as people adopt environmentally supportive disposal technologies and man­agement practices-such as gar~age and sanitation systems that segregate organic matter from harmful chemicals and non-organic wastes. Together, these steps will promote cir­culation of more organic matter.

Recycling organic wastes and returning them to pro­ductive soils would be a large step toward sustainability for the world's cities and national economies. But the current trend in most of the world-toward greater dependence on extended, one-way nutrient flows facilitated by heavy fertil­izer use-promises increased ecosystem disruption, greater waste disposal problems, and eventually a negative effect on food production itself. As policymakers grapple with the

THE COST OF BREAKING THE LOOP 9

multiple problems of today's burgeoning cities, they would do well to ponder the multiple advantages that emerge from the wise reuse of organic matter. By retapping this important natural resource, decisionmakers can ease the urban burden on several fronts.

The Cost of Breaking the Loop

"{ A ]hen the natural circular flow of organic material is bro­V V ken, two challenges immediately arise: the flow must

be fed at one end, and emptied at the other. What once occurred automatically in a cycling system, where feed and waste chased each other perpetually, now requires conscious intervention at either end. The inflow challenge is typically met with a steady stream of manufactured fertilizer, while disposal is handled in several ways, depending on the mate­rial's final form: sewage, garbage, or manure. These endpoint manipulations make linear flows possible. But they also cre­ate new problems. Today, the price for breaking organic loops is a diverse set of problems, from pollution and poor soli health caused by excessive dependence on fertilizer, to diffi­culty disposing of nutrient-laden wastes cleanly.

At the front end of the organic pipeline is a set of prob­lems created largely by the overuse of fertilizer, the pipeline's "pump." When it was invented, fertilizer was viewed as a godsend: by separating the major nutrients from their host environments-nitrogen from the air, and phosphorus and potassium from rocks and minerals-scientists developed a potent and portable resource that eliminated the need to recycle bulky organic matter. Fertilizer also increased crop yields, and in combination with cheap transportation it allowed the development of large cities, which could grow without concern for returning organic wastes to the ever­more-distant fields on which they depended for food. Unforeseen, however, was the growing human and environ­mental toll that would result from excessive dependence on

10 . RECYCLING ORGANIC WASTE

chemical fertilizer, a toll now felt even at the global level. Fertilizer production has spurred a sharp increase in the

global rate of nitrogen fixation-the process that converts nitrogen to a form usable by many living organisms. Nitrogen is now fixed at more than twice the natural, pre­industrial rate, which essentially means a boost in fertility over most of the planet. (See Figure 1.) This surge is caused by a variety of human activities, chief among them being fertilizer production, which has grown more than ninefold since 1950. Because half of the manufactured fertilizer used in human history has been applied only since 1982, the greatest surge in nitrogen (and phosphorus and potassium) levels is quite recent, and its full effects are yet to be under­stood. a

Many of the consequences of the planet's overfertiliza­tion are more pernicious than might be expected. The pres­ence of fixed nitrogen at greater than natural levels, for example, has been shown to reduce plant diversity in prairie ecosystems at an alarming pace. In a recent 12-year study, scientists applied nitrogen to 162 test plots of Minnesota grasslands at varying rates. The nitrogen spurred the growth of plants that were best able to take it up-but at the expense of plants that were less well adapted. Indeed, species diversity declined by more than 50 percent. This loss of diversity is consistent with the experience of parts of northern Europe, where high levels of nitrogen deposition have converted species-rich heathlands to species-poor grasslands. 9

The loss of species diversity, lamentable in itself, also made the ecosystem "leakier," and therefore more polluting. Because the invasive species were less able to store nitrogen than the native grasses they replaced, nitrogen leaching-an important source of water pollution-increased over the study period as the ecosystem became biologically impover­ished. The Minnesota study is another contribution to the growing body of research documenting the harmful impact of excessive levels of nitrogen, once considered a relatively benign nutrient. 10

THE COST OF BREAKING THE LOOP 11

FIGURE 1

Natural and Human Sources of Nitrogen Fixing

300 Million Tons of Nitrogen Fixed per Year

Fossil-Fuel Burning "' Q)

~ Leguminous Crops ;:, 0

V)

c: 200 0

E FERTILIZER :E PRODUCTION

Nutrient leaching can be especially high on a farm (a cropped ecosystem with little species diversity), particularly when manufactured fertili1er is used. A recently completed 15-year study by the Rodale Institute compared nitrogen budgets in three farming systems: one using manufactured fertilizer, one using manure, and the third using leguminous crops as nitrogen sources. The conventional fields leached 270 kilos of nitrogen per hectare, compared with 180 kilos on the manure-fed land, and only 110 kilos on the legume­cropped fields. Moreover, the conventional fields received relatively heavy inputs of nitrogen (a common occurrence on today's conventional farms), much more than was taken up by crops. This combination of high inputs and high leak­age-akin to opening a faucet full-force into a sieve-meant that the conventional fields lost nitrogen in large quantities.

12 RECYCLING ORGANIC WASTE

Indeed, after 15 years, soil nitrogen in the conventional fields had decreased by 11 percent, while the manure-fed fields gained nitrogen (which the soils stored for future use by crops), and ttie legume-fed soils kept it roughly in bal­ance. The study demonstrates the "leakiness" of conven­tionally fertilized soils, and the much greater capacity of organic nitrogen amendments to increase or maintain soil fertility. 11

Nutrient leakage like that documented in the Rodale experiment contributes heaVily to water pollution. In an aquatic equivalent of the Minnesota grasslands species loss­es, eroded or leached phosphorus and nitrogen promote overgrowth of algae in rivers, lakes, and bays at the expense of other species, including various fish. In fact, leached and eroded nutrients help make agriculture the largest diffuse source of water pollution in the United States.· So extensive is the agricultural pollution of the Mississippi River-the main drainage conduit for the U.S. Com Belt-that a "dead zone" the size of New Jersey forms each summer in the Gulf of Mexico, the river's terminus. Rich in fertilizer nutrients that feed algae, the once productive area now has far fewer fish and shrimp, which cannot compete with the decom­posing algae for oxygen. The phenomenon is repeated on a smaller scale around the world in countless rivers and lakes that receive agricultural pollutants.12

Pollution caused by overuse of nitrogen and phospho­rus is also harmful to human health. Nitrates in drinking water can be converted to potential carcinogens when digested by humans, and can cause brain damage or even death in infants by affecting the oxygen-carrying capacity of the blood. The OECD lists nitrate pollution as one of the most serious water quality problems in Europe and North America. Indeed, every member state of the European Union has areas that regularly exceed maximum allowable levels of nitrates in drinking water. The problem is expected to worsen in developing countries whose fertilizer use is accelerating, such as India and Brazil.13

All of these front-end problems could be ameliorated

-!'

' " < THE COST OF BREAKING THE LOOP 13

to some degree if more organic wastes were recycled. Organic wastes typically contain the major nutrients sup­plied by fertilizer-nitrogen, phosphorus, and potassium­as well as a series of trace nutrients. And unlike fertilizer, these wastes contain organic material, which builds soil structure and creates a hospitable environment for plant roots that nurtures crop growth. At the national level, recy­cled organic material could supplant only a portion of total fertilizer use, because too little organic matter exists close enough to farms to provide all the nutrients needed by high­yielding varieties. But in combination with more efficient fertilizer use, organic recycling to cropland can reduce a major source of water pollution and ecosystem degradation in countries that use fertilizer heavily. 14

In some regions, however, a shortage rather than a sur­plus of nutrients plagues agricultural soils. Poor farmers in many African countries, unable to afford enough fertilizer, essentially mine their soils, with more nutrients leaving for cities or other countries than are returned in fertilizer or organic matter. In the worst cases, nutrients leave agricultur­al soils three to four times faster than they are replaced. In Sub-Saharan Africa overall, fertilizer usage is so low that it replaces only 28 percent of the nitrogen, 36 percent of the phosphate, and 15 percent of the potash absorbed by crops. Given this clearly unsustainable situation, the region would benefit from greater cycling of organic material from cities to farming areas.· Systematic use of what is now considered waste material could help to keep fertilizer use on these farms from reaching the excessive levels found in many industrial countries. 15

At the back end of the organic pipeline is a different series of problems, most of which are related to waste dis­posal. Landfills in many industrialized countries, for exam­ple, are closing at a record clip. In the United States, the 8,000 landfills in operation in 1988 had dwindled to 3,091 by 1996, as many sites were unable to comply with federal environmental regulations, and as others simply filled up. While total capacity has actually. increased in this decade

-·

14 RECYCLING ORGANIC WASTE

(because landfills are now bigger) some areas are feeling a waste capadty squeeze. For example, New York City's Fresh Kills dump-the dty's last remaining landfill, and the largest in the world, covering 1,200 hectares-is set to close in 2001. City offidals are drawing up plans to export their garbage, some 13,000 tons per day, to other states. Other dis­posal options such as indneration and ocean dumping are expensive or environmentally problematic, or are banned outright.16

Organic material forms the bulk of the growing moun­tains of munidpal waste: 36 percent of the waste flow in OECD member states is food or garden wastes. In develop­ing countries, organic matter typically accounts for more than half, and often more than two thirds, of the total waste stream. Besides taking up space, rotting organic material pol­lutes land, water, and air by leaching acids and emitting methane, a greenhouse gas assodated with climate change. New York's Fresh Kills dump emits more than 5 tons of methane and millions of gallons of acidic liquids each day; sanitation officials estimate that methane will continue to leak from the facility for 30 years after it is closed. 17

The environmental costs and space needs of organic waste have raised offidal interest in reducing the tidal wave of trash into landfills. Several U.S. states have ordered inflows to dumps cut in half by the year 2000. In the U.K., authorities are working to reach a 25 percent recycling level for household refuse by the same year. And packed landfills in the Tokyo area have led the city to ponder a garbage col­lection fee to discourage waste generation. Composting organic matter, on the other hand, would free up space and reduce the pollution hazards created by decaying organic material. Indeed, the state of California sees composting as the natural solution to burgeoning dumps. But the chal­lenge is great: the state will have to compost some 70 per­cent of urban organic wastes by the end of the decade to meet its waste reduction goals, a hefty boost from the cur­rent rate of 40 percent (which already represents an enor­mous increase from recycling levels of a decade ago). 18

' ! THE COST OF BREAKING THE LOOP 15

Human excrement is another resource-turned-waste product whose disposal is increasingly difficult as urban­rural organic loops are broken. For millennia, many cultures returned human waste to soils, and a few still do today. But increasingly the material is sewered, a disposal option that typically leads directly to landfills, indnerators, or oceans, dumping areas that are limited today or are easily polluted. The human toll from improper disposal (and from an unclean water supply, often a related problem) is intolerably high: some 2 million children die each year and billions of people become sick because of inadequate water and sanita­tion facilities. Yet the logical and tradi­tional alternative-the recycling of sewage to farmland-is often unsafe because of the toxic industrial wastes that are mixed into many sewage flows. 19

Disposing of waste by sewer is also water intensive and expensive. But sew­ers remain the disposal option of choice, despite growing water scarcity in more and more regions. The United Nations' Comprehensive Freshwater Assessment,

Organic material forms the bulk of the growing mountains of municipal waste.

released in Aprill997, notes that a third of the world's pop­ulation lives in countries with moderate to high water stress; that share could reach two thirds by 2025. As levels of stress increase, the water needs of fanners, businesses, and house­holds are unlikely to be met fully. Using dry methods of human waste disposal, such as composting toilets, would save a meaningful share of domestic water. These alternative sanitation technologies would also ease the strain on city budgets, since on-site systems cost only a fraction as much as sewer infrastructure. And local containment of human waste would increase the prospects for returning nutrients and organic matter to farm soils, not to mention the bene­fits for the health of the rivers and bays that formerly received them. zo

That organic recycling could have so many diverse

16 RECYCLING ORGANIC WASTE

benefits is not surprising; the problems cited here were cre­ated by the move away from a circular economy in the first place. Therein lies the good news: just as straight-line organ­ic flows have produced multiple problems, the return to greater cycling of organic material promises a wide range of benefits. The challenge is to send the organic portion of eco­nomic activity back to its source, as was done in earlier times.

Organic Material Flows

I f the flow of nutrients from farm soils were mapped, the picture would resemble a tree, with a major trunk line

branching out to smaller flows as nutrients travel farther from the farm. The nitrogen, phosphorus, and potassium in Iowa soils, for example, might be taken up by com, which after harvest becomes food or feed. Each of these products, in turn, branches out to one or more waste flows-sewage, garbage, or manure. These nutrient-laden wastes then make their way to thousands of landfills, incinerators, rivers. or bays, which may be hundreds or even thousands of kilome­ters from the original soils.As nutrient flows multiply and extend, the potential for returning nutrients to productive soils diminishes.

This general picture, however, varies by country. Rural economies have. relatively simple and short nutrient flows­com may be consumed only locally and only as food, for example-so returning nutrients to farm soils is relatively uncomplicated, though often unpracticed. Industrialized and urbanized economies face greater challenges in recy­cling, because their nutrient paths are long and multi­pronged. Like a tree whose shape mirrors its root structure, nutrient flows tend to reflect the complexity of the underly­ing economy.

Crop nutrients are analogous to vitamins for humans. They assist the fundamental process of photosynthesis-the

' ~

r -·- ~--

• ORGANIC MATERIAL FLOWS 17

plant's use of light energy to transform carbon dioxide and water into organic compounds that give the plant its ener­gy. Nutrients are found naturally in soils, but nitrogen, phosphorus, and potassium-the nutrients needed in major quantities for healthy plant growth-can also be added. This is done by applying organic matter and minerals, or by spreading manufactured fertilizer, the customary practice in conventional farming. Manufactured fertilizer is essentially a collection of nutrients drawn from natural sources and processed for use on plants. Nitrogen, for example, is taken from the atmosphere and "fixed" (converted to a form that plants can use) through an energy-intensive process. Phosphorus and potassium are mined, then processed into a form that is effective for use with crops.21

In addition to leaving soils through harvested crops, nutrients also erode away with wind and water, or leach down to an aquifer or out to a river or lake, or volatilize in a process akin to evaporation, changing to a gaseous form. Most of this paper focuses on nutrients that leave through harvested crops. But some of the efforts to return crop nutri­ents to farm soils-through composting of food wastes, for example-have the added advantage of reducing erosion and leaching as well.

Accounting for all nutrient flows of all crops in all

TABLE 1

Share of Nutrients from Domestic Grain Consumed Domestically by Humans and Animals

Region (poorest to wealthiest}

Africa Asia Latin America European Union North America

Share of Nutrients from Grainland Consumed

Domestically by Humans

83 80 A9 28 22

Source: See endnote 23.

Share of Nutrients from Grainland Consumed

Domestically by Animals

15 16 39 Al AS

18 RECYCLING ORGANIC WASTE

countries would be exceedingly complex. But if one focuses on grain in selected countries and regions, the essential fea­tures of nutrient movements become clearer. Grain provides more than half of the calories ingested directly by most humans, and data on grain use and trade is reliable, making grain a revealing and manageable proxy for nutrient flows in general.zz

In most countries, grain nutrients flow predominantly from farms to the nation's own people, rather than to ani­mals, industry, or other countries. In developing countries, for example, more than three quarters of the grain produced is consumed domestically as food. (See Table 1.) And this share rises in less complex economies. Sub-Saharan African nations, for example, use 97 percent of the grain they grow for food. (By contrast, direct human consumption of grain in the United States accounts for only 28 percent of the total grain flows, the smallest of all U.S. grain nutrient trails.) These poorest nations produce virtually no exportable sur­plus, and their animals are largely pasture- rather than grain­fed, leaving nearly all of the grain harvest for domestic human consumption. This simple, rural-to-urban flow of nutrients would require an equally simple return flow to close the nutrient loop. Indeed, in most developing coun­tries the recycling challenge is to return human and munic­ipal wastes from cities to agricultural lands, a task made more difficult by the widespread absence of sanitation systems. 23

With greater prosperity, people tend to eat more meat, and nutrient flows become more complex as grain is diverted to animal consumption. Impoverished Sub-Saharan Africa, for example, feeds only 2 percent of its grain to ani­mals, but in the United States, 41 percent of grain nutrients go to animal consumption. (See Table 1.) Indeed, more U.S. grain nutrients are fed to animals than are consumed by Americans, by people in other countries, or by industry. Thus, in wealthy nations, nutrient recycling involves not only human and industrial wastes, but large volumes of ani­mal wastes as well. 24

Finally, some countries export a considerable share of

l

' ·"­

l ! I

ORGANIC MATERIAL FLOWS

TABLE 2

Share of Nutrients from Domestic Grain That Is Exported: Seven largest Grain Exporters

Country

Australia Argentina Canada France United States Thailand Vietnam

Share of Nutrients Leaving Grainland for Other Countries

67 46 45 44 37 31 12

Source: See endnote 26.

19

their nutrient outflow, which complicates recyclir.g possibil­ities still further. These are countries with large productive capacity relative to domestic demand, and their ranks include both wealthy and developing nations. Among the world's top seven grain exporters, which includes nations as diverse as Canada and Vietnam, exports of grain nutrients range from 12 percent to 66 percent of domestic production. Unlike flows to the domestic populace and to animals, ex­ported nutrients are largely unrecoverable by the exporting nation, although reuse in the redpient country is possible.25

In all, 10 percent of the world's grain nutrients flow across borders in grain; the figure would be somewhat high­er if the grain content of exported meat were included in the analysis. (See Table 2.) As economies become increasingly integrated, and if import dependence grows, the volume of crop nutrients crossing national borders will rise. For net food exporters, the nutrient defidt is covered by using fer­tilizer. But even net food importers-who are accumulating nutrients from natural sources-often resort to heavier than necessary fertilizer use because they do not recycle organic wastes, or because getting organics back to farms is too expensive or difficult.26

20 RECYCLING ORGANIC WASTE

TABLE 3

Net Flows of Nutrleats Ia 15 Foods, •r Regioa, Mld·l980s

Region·

Net Nutrient Importers

Africa Europe Asia Former Soviet Union

Net Nutrient Exporters

North & Central America South America Oceanic

Source: See endnote 27.

Magnitude of Net Flows (kilotons of nutrients)

Net Inflows

533 2,809 1,034

981

Net Outflows

3,387 1,566

225

Research from the mid-1980s that focused on a larger set of commodities gives an idea of the net regional flows of nutrients. Tracking nutrients in 15 sets of foods, including grains, researcher G.W. Cooke found a large net shift out of the Americas and Oceania and toward the rest of the world: Africa, Europe, Asia, and the former Soviet Union. (See Table 3.) Perhaps more remarkable was the relative imbalance (inflows compared to outflows) for each region. The small­est relative imbalance was found in Asia, which nevertheless imported four times as many nutrients in food as it export­ed. North and Central America, by contrast, exported 76 tons of nutrients for every one it imported. Cooke's data demonstrate that nutrients in food flow across regions in highly skewed quantities. 27

A heavy flow of nutrients in food into a nation does not mean that its farm soils are well supplied, however. Africa is a case in point. The continent takes in six times more nutrients in food than it sends out, but the soils of many African farms are steadily losing nutrients, thus exac­erbating their need for imported fertilizer. Nutrients in food

ORGANIC MATERIAL FLOWS 21

imports (like nutrients in domestic supplies of food) do not make their way to farm soils, but wind up instead in land­fills or at the bottom of rivers or bays. Thus, even net nutri­ent importers tum to fertilizer to replenish their soils, or-as in many African countries-watch soil fertility slowly decline.za

The use of manufactured fertilizer is the standard way to raise soil fertility in much of the world, and it is what allows large imbalances in food nutrient flows to be ignored. But fertilizer is often applied more liberally than necessary for plant growth (Sub-Saharan Africa is a notable exception), usually to ensure that crops are not underfed. Indeed, in the United States between 1991 and 1995, close to 56 percent more fertilizer was applied to grainland soils than left those soils in crops. (See Table 4.) In China, overapplication appears to be even higher, with nearly three quarters of the fertilizer applied unaccounted for in harvested grain. Although some of the excess is building up in farmland in the short run, a large share is leached or eroded away, and is responsible for the water pollution and ecosystem degrada­tion associated with heavy fertilizer use.29

Overuse of manufactured fertilizer could be reduced and soil quality raised if nutrient outflows were reused on farmland. The "waste" flows from food, feed, or exports are all potentially drcular. Food becomes human excreta or garbage, which can be returned as sewage or composted food wastes. Feed becomes animal waste, which is applied to soils as solids, as liquid slurry, or as compost. Exported food and feed can follow similar paths once they reach their des­tination country. And these reused nutrients can be aug­mented using other wastes that did not originate on the farm, such as leaves and grass clippings. As it is now, how­ever, most of these branch paths are only partially looped back toward agricultural soils, if the loop is established at all.

The most widely recycled nutrients from crops are those in animal manure. For millennia, manure from cattle, pigs, poultry, sheep, and other farm animals has served both as a convenient and plentiful source of nutrients for plants,

22 RECYCLING ORGANIC WASTE

and as a tool for improving soil structure. Manure is still widely recycled to agricultural soils close to where it was produced. But in some countries, environmentally safe recy­cling is a growing challenge. As livestock operations become more centralized, manure is measured in hundreds of tons or thousands of cubic meters, and farmlands near these operations are challenged to absorb all of the waste that is produced.JO

Recycling of human waste varies widely by region. Many Asian nations have long re-incorporated human wastes into farm soils, but the practice is on the decline. On the other hand, recycling of sludge and wastewater is on the rise in many sewered countries. The United States and Europe recycle a quarter to a third of the sludge they produce. While increasingly common, application of sludge to agricultural land is also controversial; sewage typically includes industrial as well as household wastes, and often contains heavy metals, toxic organic matter, and pathogens that are dangerous to human or environmental health. Thus the growth in recycling of human wastes is not alwavs a positive trend. Jt

In many countries, municipal solid waste is a read!l\· available but largely untapped source of nutrients and organ­ic matter that could enrich soils. Organic material accounts for more than a third of urban wastes in industrialized coun­tries and well over half in many developing countries. Only a small portion of this material is returned to soils: OECD member states composted just over one tenth of their organ­ic wastes in the early 1990s. In developing countries, the potential for recycling is also largely unrealized.32

Greater reuse of organic matter on farms will not elim­inate the need for outside sources of nutrients. Extensive nutrient losses are inevitable. The share of nitrogen in manure or sewage that is returned to the atmosphere through volatilization, for· example, can be large-even as much as SO percent (although these losses can be minimized through careful management of wastes). In addition, the high-yielding crop varieties in use today require more fertil-

COMPOSTING URBAN WASTES

TABLE 4

Efficiency of Fertilizer Use on Grainland: United States, China, and Worlcl

United States China World

Share of applied fertilizer in harvested grain 64 27 53

Share not taken up by grain (calculated) 36 73 47

Source: See endnote 29.

23

izer than native varieties did. Still, reuse of organic matter can reduce the need for manufactured fertilizer while build­ing soil fertility and health. In the process it can also help solve a surprisingly wide array of problems, from leaching and erosion to waste disposal.33

Composting Urban Wastes

The world's cities generate tons of natural wealth daily in the organic garbage-food scraps, yard trimmings, and

paper wastes-that every household and many businesses and institutions throw away. This garbage is rich in organic matter-an essential ingredient for healthy soils-and it contains a modest supply of plant nutrients. Instead of exploiting this resource, however, most cities are intent on burying or burning it, or dumping it into rivers, lakes, or the sea. But as the benefits of reusing such material become evi­dent, more cities are reclaiming it. To do so, they are turning to an ancient practice-composting-as a natural way to prepare the "waste" for reuse.

All organic materials contain both organic matter and nutrients. But working raw organic materials directly into the soil is not always the best way to exploit its organic mat­ter and release its nutrients. Nutrients in materials that

24 RECYCLING ORGANIC WASTE

decompose slowly, for example, are "locked up" and unavailable for plant use. And in some soils, decaying organ­ic matter can tie up soil nitrogen that would otherwise fuel plant growth. Fortunately, organic material can be convert­ed-through composting-to a stabilized product that builds soils and releases nutrients in a steady and environ­mentally healthy way. Composting is a several-month-long process in which bacteria, worms, and other organisms feast on piles of carbon-rich matter and digest it, leaving behind humus, a rich, stable medium in which roots thrive. Worked into farm soils, humus builds soil structure and provides a productive environment for plants and essential soil organ­isms.

The ingredients for compost can come from a variety of sources. Food scraps, yard trimmings, paper, and sewage are all compostable, but most of this material is currently dis­carded. Food scraps and yard trimmings alone account for more than a third of the municipal waste flow in industrial­ized countries and well over half in many developing coun­tries, which can afford fewer throwaway items. (Low-income countries have relatively small waste flows, but a large share of these flows is organic waste.) Yet, like OECD member states, most countries return only a small portion of this material to soils. (See Table 5.)3

• ·

If paper is included in the analysis, the compostable share of municipal solid waste jumps to more than 50 per­cent in industrial countries. Paper is best recycled into paper, not compost, but under certain conditions it is appropriate for composting. Where organic material is deficient in car­bon, for example, paper can be added to raise its level. And when the market for recycled paper is saturated, composting paper can help to maintain the value of recycled paper. Had surplus paper been composted in 1996, when recycling cen­ters were inundated, it would have stabilized paper prices and eased pressure on landfills and incinerators-in addi­tion to returning organic matter and nutrients to farm soils.35

Beyond its contribution to waste reduction, the long-

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COWPOSTING URBAN WASTES

TABLES

Composted Share of Organic Wastes, Selected OECD Countries ·

Country

Portugal Spain Denmark France Netherlands United States Sweden Austria Luxembourg Belgium Finland Norway Canada Hungary Poland

AVERAGE

Composted Share of Organic Wastes (percent I

39 25 23 19 15 13 10 10 6 5 5 4 3 2 2

11

Source: See endnote 34.

25

run value of compost lies in its capacity to build soils. Because it is riddled with pores, the humus in compost shel­ters nutrients and provides extensive surface area to which nutrients can bond; indeed, humus traps three to five times more nutrients, water, and air than other soil matter does. These characteristics also help retain nutrients that could otherwise be leached or eroded away. Thus, adding organic matter to soils further reduces the need for additional nutri­ent applications. 36

Another important contribution of compost-suppres­sion of plant diseases-has only recently been extensively documented. Since the 1970s, field tests have shown that compost limits the spread of root rot as effectively as many ·fungicides. Indeed, horticulturalists have found that com­post in potting mixes makes fungiddal drenches largely

...

26 RECYCLING ORGANIC WASTE

unnecessary. Harry Hoitinck, a plant pathologist at Ohio State University and a pioneer in disease suppression research, asserts that compost use by nurseries in Ohio has eliminated the use of methyl bromide-a potent fungicide highly poisonous to humans, and an ozone-depleting sub­stance whose use is soon to be banned. Because chemical alternatives to methyl bromide are less effective or are also unsafe, the disease-suppression capacity of compost is wel­come news. Scientists are now learning to augment this capacity by inoculating compost with beneficial organisms. 37

Compared to its advantages for soil building, water retention, and disease suppression, the nutrient contribu­tion of composted urban organic material is modest, but significant nonetheless. Nutrients in municipal solid waste (not including paper) in OECD countries amounted to an average 7 percent of their commercial fertilizer use in the early 1990s. (See Table 6.) Because fertilizer is commonly overapplied, however, the potential contribution of urban nutrients is actually larger than the 7 percent figure indi­cates. If fertilizer use in OECD countries were reduced by a third-less than the rate of nutrient overapplication in many industrialized countries-nutrients in solid waste would amount to 12 percent of nutrients applied as fertiliz­er. This level of nutrients (which does not yet include those available from human waste) begins to offer potential for cutting the pollution of water caused by fertilizer overuse. 38

How much reduction in fertilizer use is allowed by incorporation of compost depends~on the makeup of the compost, the amount applied, soil and climate conditions, and the crops being cultivated. Compost can reduce fertiliz­er use because of its own nutrient contributions, but also because of its capacity to reduce leaching, which allows a greater share of applied fertilizer to be used by plants. On the other hand, the fact that compost releases its nutrient supply very gradually (unlike fertilizer, whose nutrients are immediately available to plants), only allows the full nutri­ent contribution of compost to be realized over time, after soils have been built. Still, compost use has already led to

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. COMPOSTING URBAN WASTES

TABLE 6

Nutrients in Organic Municipal Solid Waste (paper ezcludecl) as a Share of Fertilizer Use, Selected OECD Countries Country

Mexico Turkey Japan Netherlands

Nutrients in Organic MSW as Share of Commercial NPK Use

17 15 14 12

Belgium-luxembourg 11 Italy 9 Portugal 9 Switzerland 9 Au5tralia 8 Spain 7 Au5tria 6 Canada 6 Sweden 6 Finland 5 Greece 5 United States 5 Norway .4 Denmark 3 France 3

AVERAGE 8

Source: See endnote 38.

27

reductions in fertilizer applications in some areas. According to a World Bank report, for example, farmers in India who use a commercial compost called Celrich cut chemical fertil­izer consumption by some 25 percent. 39

·

Finally, composting is accessible to people who are poor. Because it is a decentralized and natural source of wealth-every household produces composting ingredi­ents-it can promote better nutrition among the urban poor who cultivate their own food. An estimated 200 million city dwellers worldwide now practice urban agriculture, supply­ing part of the food needs of some 800 million people. In

28 RECYCLING ORGANIC WASTE

Kampala, Uganda, for example, 35 percent of households produce their own food. And in Accra, Ghana, urban resi­dents supply the city with 90 percent of the vegetables con­sumed there. For the urban poor, compost is a virtually free fertilizer and soil builder, whose production requires little space, virtually no equipment, and a modest amount of labor. Such a valuable and affordable resource, available without reliance on outside suppliers, can make a large eco­nomic and nutritional difference to people living on the economic margins. 40

For all its wonders, compost presents some important managerial challenges. Composts vary from place to place;­and even from batch to batch-because the combination of inputs can vary so widely. Yard clippings are more available in summer than in winter, for example, and their nutrient make-up changes with the seasons. Paper availability may depend on the ups and downs of the economy. The good news is that this complexity allows composts to be tailored to the particular soils and crops they will serve. But it also requires that compost makers know their customers and respond to their diverse needs, and that users understand how the product works in soils. Creating the right compost for a particular use and employing it optimally will require more research and outreach than is typically available today."

As the many advantages of composting become appar­ent, its practice is taking off. In the United States, compost­ing facilities multiplied more than fourfold between 1989 and 1996, from some 700 to more than 3,200. Many cities and counties now make organic matter available to the pub­lic for use as mulch, or as the feedstock for compost making. In San jose, California, a recently completed three-year pilot program to promote the use of compost led to a 54 percent increase in its production by local processors, and demand for the product was brisk. 42

Compost is increasingly recognized as good business. Evidence of this is the experience of Community Recycling of Southern California, which saw gold in the spoiled fruits and vegetables of area supermarkets. The company mixes

·-.· COWPOSTING URBAN WASTES 29

the produce with yard wastes from the area to generate 125,000 tons of compost per year-the maximum allowed under its permit. Today, the two largest supermarket chains in southern California, representing more than half of the grocery outlets in the region, have their organic wastes com­posted by this firm. ~3

Community Recycling is not the only beneficiary of its organic recycling program. The compost is spread over some 12,000 hectares of farmland, whose soils enjoy the multiple benefits of higher levels of organic matter. Farmers profit directly too: the company calculates that nutrients in one ton of its compost would cost $58 if pur­chased as fertilizer. But the company sells its compost for $10 per ton.~4

Composting also has economic benefits for institutions that generate organic waste. Some schools, prisons, hospitals, arid other food-serving estab­lishments save money by having food

Compost is a virtually free fertilizer and soil builder.

scraps composted instead of hauled away for disposal. Middlebury College in Vermont, for example, reports annu­al savings of some $25,000 by sending food residuals to a compost facility rather than to a waste disposal operation. The New York State Department of Corrections has saved more than $1 million by composting food scraps at 31 sites around the state. The key is for composters-whether indi­vidual farmers or large, centralized operations-to charge less to accept the organic material than a landfill or other disposal destination would. The generator of the waste saves on disposal costs, and the composter receives revenue to haul away material that will be transformed into a profitable product. The "win-win" possibilities of composting are indeed extensive. ~s

Such mutual advantages, however, are not automatic or guaranteed. The Indian government, for example, has tried several times in recent decades to promote composting of municipal wastes, but the schemes have largely failed, for various reasons. Inputs to the composting process were not

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30 RECYCLING ORGANIC WASTE

well monitored, and inclusion of non-organic material low­ered the quality of the resulting compost. Poor equipment maintenance led to breakdowns and inconsistent produc­tion. City governments were seldom committed to the fed­eral government's vision of widespread composting. And subsidies on fertilizer made compost economically uncom­petitive. While the potential benefits of composting are manifold, the Indian experience demonstrates that effort is required to avoid a number of potential pitfalls. 46

It is ironic that composting, so lately embraced in many economies, is one of the oldest forms of recycling known to humankind. As societies become reacquainted with this practice, its value as a natural solution to problems from overflowing landfills to anemic soils will become apparent. Then, with the proper institutional and economic incentives, composting could become as commonplace as the recycling of cans, newspapers, or paper is today.

The Potential and Peril a( Human Waste

M ost of the world's cultivated food passes through human beings, so it is no surprise that human waste is

a trove of nutrients and organic matter. Harvesting this material for agriculture is a natural way to close an impor­tant organic loop; indeed, Chirrese farming thrived on recy­cled excreta for thousands of years. But as more cities process these wastes using technologies designed to dispose of them, rather than reuse them, safe recycling of human waste becomes much more difficult. Safe reuse is best ensured by shifting away from disposal technologies-such as conventional treatment plants, or sewers that mix indus­trial and domestic waste-and toward technologies engi­neered to produce a clean fertilizer. For countries not yet committed to expensive disposal systems, this shift can occur more quickly than for those that are. Until such a shift takes place, the reuse of human excreta can be safely prac-

THE POTENTIAL AND PERIL OF HUMAN WASTE 31

ticed only by observing the strictest standards. 47

Most excreta is not reused, although reuse-often . unsafely practiced-is growing. In developing countries, where 72 percent of the population has access to adequate sanitation, sewers, septic systems, and pit latrines are the dominant disposal systems. Sewers and septic tanks pre­dominate in Latin America and the Middle East, while Mricans and Asians rely at least as heavily on pit latrines. Most sewers flow to the nearest river, bay, or ocean; only 10 percent of this sewage receives treatment. Where pit latrines are used, waste material typically remains buried. Except for parts of Asia, which has a long history of excreta reuse, and some arid regions, where sewage water (often untreated) is

, commonly used for irrigation, human waste is widely regarded as unwanted debris. 48

Industrial countries have long had the same perspec­tive, but this is changing. Many now encourage reuse of

· sewage sludge on farmland, and the practice is growing. European countries applied roughly one third of their sewage to. agricultural land in the early 1990s, while the United States applied 28 percent. The growing interest in reuse may reflect dwindling options for cheap disposal. rather than a strong interest in building farm soils. Traditional dumping sites-landfills, incinerators. and oceans-are less available, more costly to use, or legally off. limits today, while farmland is often an inexpensive alterna­tive disposal site. But just as sewers and treatment facilities are not designed for recycling, farmland is not suited to absorb the chemicals and heavy metals often contained in the sewage stream. '9

If human wastes are made safe for use on farmland, however, their reuse can help. reduce applications of chemi­cal fertilizer. In many developing countries, the nutrient content of human waste is equal to a substantial share of the nutrients applied from fertilizer, even after losses of nitrogen to volatilization are taken into account. (See Table 7.) For OECD countries, nutrients in human waste that is not already spread on land equal roughly 8 percent of the nutri-

32 RECYCLING ORGANIC WASTE

ents applied as fertilizer. As with munidpal organic waste, thp figure understates the potential contribution of nutri­ents in human waste. If fertilizer use in OECD countries were reduced by a third, nutrients in human waste would amount to 12 percent of nutrients applied as fertilizer . .so

Recycling human waste, however, will require different technologies, or different ways of using existing ones. Modem methods for disposing of human ·waste are not designed for reusing it. Sewers, for example, commonly serve residences and industry together, a practice that often con­taminates organic matter with heavy metals or toxic chemi­cals. Conventional treatment plants are designed to remove nutrients (and other matter) from wastewater, which lowers the enrichment level of effluent used for irrigation. Moreover, conventional treatment methods (with the ex­ception of disinfection, which is rarely practiced in develop­ing countries) reduce pathogens by too little for safe reuse in agriculture. Thus, many of todats disposal technologies are not suited to produce fertilizing products. 51

Where sewers and treatment plants have been turned to waste reuse, there have been mixed results, at best. Even in countries considered successful with reuse-Israel, for example, which diverts treated wastewater to irrigation­caution is warranted. The country began large-scale reuse of sewage effluent in 1972, and today recycles 65 percent of its wastewater to crops. No excessive rates of illness have been linked to its use. Nevertheless, cadmium levels have been shown to increase by 5 to 10 percent annually in Israeli effluent-fed soils, and heavy metals were found to have accumulated in an aquifer below land that was irrigated with effluent for 30 years. If industrial wastes were not dumped in sewers, the country could more safely apply sewage effluent to crops. Better yet, if human wastes were managed using dry (non-sewered) methods such as com­posting toilets, the water currently used to carry sewage would be available to agriculture as clean water.52

Where sewers are little more than feeder lines to irriga­tion canals, and where the sewage they carry is untreated,

t.jo: . '~_-:_. THE POTENTIAL AND PERIL OF HUMAN WASTE -.=.:' "-:'!'~-·

TABLE 7

N•trleats Ia Humaa Waste as a Share of Nutrients Ia Fertilizer Applied, Selected Countries

Country

Kenya Tunisia Indonesia Zimbabwe Colombia Mexico South Africa Egypt India

Nutrients in Human Waste as a Share of Nutrients in Fertilizer Applied

(percent)

136 52 49 38 31 31 29 28 26

Note: assumes loss af 50% of nitrogen content to volatilization. Sourre: See endnote 50.

risks to human health are much greater. Raw sewage used to irrigate vegetables and salad crops is blamed for the spread of worm-related diseases in Berlin in 1949, typhoid fever in Santiago in the early 1980s, and cholera in jerusalem in 1970 and in western South America in 1991. Even so, the risky use of wastewater continues in many developing coun­tries. In the Mexican state of Hidalgo, wastewater from Mexico City is used in the world's largest wastewater irriga­tion scheme, covering some 80,000 hectares. The effluent, which is 55-80 percent raw sewage (the balance is storm water), is barred from use on some salad crops, but other foods, including com, wheat, beans, and some vegetables, are irrigated with sewage water. 53

In contrast to wastewater reuse, application of sludge to farmland carries a different set of risks, especially where industrial wastes or household chemicals are part of the sewage flow. Researchers from Cornell University and the American Society of Civil Engineers have found more than 60,000 toxic substances and chemical compounds in U.S. sewage sludge, and report that 700-1,000 new substances are

34 RECYCLING ORGANIC WASTE

developed every year, some of which also enter the sewage stream. These substances include PCBs, pesticides, dioxins, heavy metals, asbestos, petroleum products, and industrial solvents, many of which are linked to ailments ranging from cancer to reproductive abnormalities. They are also a threat to soils: once introduced to cropland, for example, heavy metals persist for decades (as in the case of cadmium) or even centuries (as in the case of lead). Because little control is exercised over what enters sewers, the contents of a given load of sewage sludge can be highly unpredictable and potentially dangerous to people and soils. 54

Although industrialized nations maintain standards for sludge reuse, these may be lax. Such standards in the United States are the least stringent of any in the industrialized world, with allowable levels of heavy metals an average eight times higher than in Canada and most of Europe. Indeed, Cornell University researchers have recommended that U.S. farmers apply sludge at no more than one tenth the levels permitted by the U.S. Environmental Protection Agency. Moreover, testing in the United States is required infrequently-as seldom as once a year for the smallest applied amounts-even though the contents of sludge can vary greatly from load to load. 55

Clearly, reliance on mixed-waste sewers and treatment plants, the "modem" way to process human waste, does not guarantee output that is safe for use in agriculture. Other technologies, most of which are simpler and cheaper than sewers and treatment plants, may offer greater possibilities for recycling wastes. Indeed, opportunities exist for develop­ing countries to "leapfrog" past industrial nations by adopt­ing cutting-edge technologies that are affordable and envi­ronmentally sound, and that help to close the organic loop by safely returning human wastes to agriculture.

One simple-and ancient-alternative to sewage treat­ment plants is waste stabilization ponds, a series of holding areas in which sewage is retained for 10 days to a few weeks. Bacteria and algae work to convert the effluent to a stable form as it passes from pond to pond. Stabilization ponds

THE POTENTIAL AND PERIL OF HUMAN WASTE

require more land than conventional treatment plants, but they are much cheaper, simpler to build and maintain, and, best of all from a recycling perspective, more effective at pro­ducing safe irrigation water. A conventional treatment plant can reduce the number of fecal coliforms in a milliliter of water from 100 million to 1 million, a 99 percent reduc­tion-but not enough for use on crops. For unrestricted irri­gation use, the World Health Organization recommends a fecal coliform level a thousand times lower-no greater than 1,000 per milliliter-and waste stabilization ponds can achieve this. 56

One variant of the waste stabiliza-tion pond is a wetland modified to process wastes, the showcase example being the one in Calcutta. For more than half a century, s~wage has been channeled to a wetland east of the city, where multiple ponds are used not only to process waste, but also to raise fish and provide nutrient-rich irrigation water for farmers. The system works by mimicking the interconnectedness of a natural ecosystem. Nutrients in the waste feed fish, plants, and organisms in the ponds. The fish, in turn, greatly reduce or eliminate algal blooms, mak­ing the final wastewater product more

Opportunities exist for developing countries to "leapfrog" past industrial nations by adopting cutting-edge technologies.

useful· for agriculture. Water hyacinth cultivated at the ponds' edges further purifies the water and protects the banks from erosion. And the hyacinth is either harvested for animal feed or composted. These multiple benefits, com­bined with a cost less than a quarter that of a conventional sewage treatment plant, have made the area a valuable municipal resource. 57

A constructed micro-version of the Calcutta wetlands system could provide waste-processing capacity for some industries, thereby preventing their wastes from entering the sewer system. Complete with plants, microorganisms,

36 RECYCLING ORGANIC WAST

and even fish, these facilities consist of a series of pools and constructed wetlands, often built in a garden-like setting, which progressively treat industrial wastes. One U.S. firm has found a robust market for these fadlities, with 20 pro­jects built or under construction since 1992 at businesses and institutions as diverse as the M&M/Mars Company in Brazil and Oberlin College in Ohio. 58

For all their advantages, these natural filtering systems are land intensive. Stabilization ponds are estimated to require 30 hectares for every 100,000 people served. And Calcutta's wetlands system required 3,200. hectares to process roughly a third of the city's wastewater in 1991. The industry-level facilities also require an extensive area, which may prove prohibitive in crowded cities. Where land is tight, other choices are available, some of which can avoid the expense of sewage infrastructure. 59

One of the more promising options for processing sewage safely is a series of simple technologies developed and patented in Mexico and known collectively by their Spanish acronym, SIRDO. SIRDO systems build on the "dou­ble-vault" waste treatment concept developed in Vietnam, under which one chamber collects current deposits of waste while the other is closed for several months as previously deposited material composts. Solar heating and bacteria transform wastes and other carbon matter into a safe and odorless "biofertilizer" that is sold to nearby farms. ao

SIRDO technology is ..applied in diverse ways. Some designs are "dry," requiring no water-and no sewage infra­structure-for their operation. Dry units are self-contained structures that are detached from a house and serve one or two families. They compost household organic matter together With human waste, thereby easing pressure on landfills and sewage treatment plants. "Wet" SIRDO units are neighborhood-level mini-plants that biologically process the wastes of up to 1,000 people, operating in conjunction With existing flush toilets and local sewer lines. Even these "wet" systems are water savers, because they separate grey­water from solids and percolate it through a bed of sand and

THE POTENTIAL AND PERIL OF HUMAN WASTE 37

gravel until it is purified enough to reuse on gardens, or to irrigate non-food crops. These systems are simple enough to maintain and operate that they do not require constant oversight by an engineer. A trained lay person can handle day-to-day operations, with occasional assistance from a SIRDO specialist. Several of the wet units in Mexico City are maintained by the gardeners of the condominium complex­es in which the units are located."

SIRDO's advantages extend beyond fertilizer produc­tion and water savings. As an effective sanitation technolo­gy, SIRDO improves the level of public health by reducing illnesses caused by pathogen-tainted water supplies. In the warm climates where SIRDOs are currently used, the unit's solar-heated waste chambers generate higher temperatures, over longer periods, than are needed to ensure that pathogens are killed. In the town of Tres Marias, Mexico, introduction of SIRDO technology and a new potable water system are credited with cutting the rate of gastrointestinal illness from 25 cases per person in 1986 to less than one case per person in 1990. Since contaminated water is a ma1or cause of sickness and death among children in developmg countries, the technology's success in sterilizing wastes 1s a welcome advance. 62

Moreover, the SIRDO systems are affordable, and they even generate modest flows of revenue. A cost-benefit analy­sis undertaken by the Nati_p.Jlal Wildlife Federation (NVVF) found that all five SIRDO models studied-three wet and two dry-offered net financial gains under Mexican market conditions for water, labor, and bio-fertilizer. The simplest dry design, for example, costs $307 for set-up and $20 per year for maintenance-a total of $607 over 15 years-but earns the owner $2,088 in fertilizer revenues in the same period. The net income for user families is modest-on the order of $30-60 dollars per year-but nonetheless meaning­ful for people living on the economic margin. 63

Significantly, the NWF analysis was limited to private costs and benefits. It did not consider the technolog1s social benefits, which include the reduced need for sewage treat-

38 RECYCLING ORGANIC WASTE

ment, boosted levels of public health, and improved soil structure and fertility on farms that use the bio-fertilizer. SIRDO's multiple advantages to users and society have spurred its adoption in Guatemala, Chile, and nine states in Mexico.64

Another non-sewer approach to waste processing dou­bles as a source of energy. Since the 1970s, China has installed more than 5 million anaerobic digesters-large chambers, sitting mostly underground, that break down a rural family's organic waste, including manure, human exc­reta, and crop residues, producing gas in the process. Toilets and pigsties drain directly into the digester, which yields enough biogas to meet 60 percent of a family's energy needs, mostly for cooking and for fueling gas lamps. The unit also produces an odorless dark slurry, used primarily for fertiliz­er, but also viable as feed for livestock or fish. The digesters are inexpensive-$80 covers the cost of materials and the help of a technician in construction. 65

In cities that are already sewered, and whose popula­tions are accustomed to flush toilets, separation of human and industrial wastes will be more challenging, and may need to be viewed as a medium- to long-term goal. Nevertheless, current technologies suggest several possible approaches. Dry composting toilets, for example, can be installed in the bathrooms of many suburban homes. They look like standard flush models-without the water tank­and can hold up to several years' worth of excreta. They require some maintenance, including occasional additions of carbon material, such as sawdust or leaves, and periodic inspection of the equipment and the compost itself. Service contracts, however, can minimize the burden on homeown­ers. Other non-sewer technologies include micro-flush toi­lets, which use as little as one pint of water per flush, and vacuum-powered toilets similar to those in aircraft lavato­ries. All of these systems create a fertilizing product that can be applied to home gardens or, where economically feasible, collected and sold to farmers. And because the excreta is seg­regated from the flow of detergents, cleaning products, sol-

THE POTENTIAL AND PUlL OF HUMAN WASTE 39

vents, and other chemicals used in many households, the coinposted material is clean. The systems are not cheap, however, ranging in price from $1,000 to $6,000 per unit.66

Large buildings, such as multi-story apartment com­plexes, would be served with different technologies. (Composting toilets usually require that the holding cham­ber be located directly below the toilet, which makes their use in multi-story buildings impractical.) Constructed wet­lands are one possibility for buildings that have plenty of land. A more viable option is the use of biogas digesters, sim­ilar in concept to those used by some Chinese peasants, but built on a larger scale. Located in the building's basement, the digester would collect wastes from standard low-flush toilets and produce two products: methane, which could provide part of the building's power, and uncontami­nated sludge, which could be collected and applied to farmland. Digesters offer a glimpse of the multiple benefits possi­ble from full exploitation of human "waste."•7

The nutrients in human waste con-

The nutrients inhuman waste consti-tute a vast, untapped agricultural resource.

stitute a vast, untapped agricultural resource. Getting them safely back to farmland would help to build soils and reduce the need for additional nutrients from fertilizer. But separat­ing human excreta from ingustrial wastes-the prerequisite for safe recycling-will require imagination and commit­ment. Ironically, unsewered cities may be in the best posi­tion to capitalize on new technologies for excreta manage­ment, technologies designed to produce an uncontaminated fertilizer product.

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Sustainability and Scale

Fertilizer and cheap transportation were the original scis­sors that snipped open organic loops, thereby unleashing

the pollution and waste problems described earlier. Today, the globalization and ·concentration of agriculture com­pound these problems by stretching and fattening nutrient flows. The surge in agricultural trade, for example, redistrib­utes nutrients unevenly around the world, driving some regions to a heavier-than-necessary dependence on fertilizer, and leaving others with unhealthy nutrient surpluses. And concentration of production can swell nutrient streams until nutrient accumulations become unmanageable. The emerging lesson is that scale matters, and that too large a scale can lead to distortion and mishandling of nutrient flows. Even the scale of recycling operations can determine whether cities are successful in actually closing nutrient loops. Prospects for restoring circularity to organic flows may depend on limiting the scale of agricultural operations and some recycling operations so as to shorten and unplug today's linear movements.

The globalization of food flows may be the sleeper agri­cultural story of recent decades. The last 40 years are widely heralded for their unprecedented growth in output, but agri­cultural trade-and the displacement of soil nutrients that trade entails-grew even faster than production. World grain output, for example, doubled between 1960 and 1995, but grain exports tripled during the same period. Indeed, growth in agricultural trade has outpaced production con­sistently since 1960, except for a short period in the mid-1980s. Today, more dinner plates are filled with food of dis­tant origin, and more nutrients cross national borders, than ever before.68

The uneven redistribution of food nutrients resulting from increased international trade generates net losses in some areas, and net gains in others. Several countries in northern Europe, for example, suffer from excessive accu-

SUSTAINABILITY AND SCALE 41

mulations of nutrients, many of which are imported across oceans. An extensive European livestock industry purchases feed from as far away as Brazil, Thailand, and the United States. But the industry has outgrown the capacity of nearby lands to absorb its wastes, so manure has steadily accumu­lated. Indeed, early this decade, the Netherlands could boast the world's largest "manure mountain"-some 40 million tons' worth.69

These accumulations, coupled with heavy fertilizer use, are responsible for serious pollution problems in the Netherlands. Nitrate levels in the country's groundwater were more than double the recommended maximum level in the early 1990s. So saturated was the country in nitrogen and phosphorus at mid-decade that farmers could have met their crops' nutrient requirements from manure alone­without a single application of nitrogen or phosphorus fer­tilizer-and still ended up with a nutrient surplus in their soils. The mismatch between the scale of activity-heavy flows of nutrients from three continents that converge on a single small region-and the environment's limited capacity to absorb the output of that activity demonstrates the rele­vance of scale. The inflow of nutrients to the region was so large that they could not be recycled there, nor could they be returned to their original soils.70

Taiwan finds itself with similar problems, after building a substantial, but import-dependent, hog-raising industry. The country buys more than 90 percent of its corn feed from farmers in the midwestern United States, an ocean and half a continent away. But the oversized hog-raising industry produces more manure than the country can handle, result­ing in extensive pollution, as in the Netherlands. Indeed, officials in Taiwan estimate that two thirds of Taiwan's water pollution is the result of manure discharges from hog farms. As a result, the government has been struggling since 1991 to reduce the number of hogs by one third. 71

Lengthened nutrient supply lines are also found with­in countries. This is especially clear in the United States, where feed is shipped ever greater distances as cattle-, hog-,

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42 RECYCLING ORGANIC WASTE

and chicken-raising facilities move away from feed produc­tion regions. Cattle feedlots, for example, were once located in the Com Belt states that supplied them with feed, but they began to move hundreds of kilometers west to the Great Plains in the 1950s and 1960s. More recently, hog pro­duction has shifted hundreds of kilometers east, from the Midwest to Virginia and North and South Carolina. The sup­ply line connecting feed and livestock, which once extend­ed a few hundred meters from field to barnyard on a single farm, has now been stretched across state lines, essentially precluding the return of nutrients to feedcrop fields.72

The separation of livestock from crops is linked to another issue of scale, the size of agricultural operations. Large operations realize economies of scale that allow them to absorb the transportation costs resulting from long-dis­tance food and feed shipments. Not surprisingly, then, the shift of livestock production away from feed-producing regions in the United States was accompanied by an increas­ing concentration of operations. (See Table 8.Y3

As livestock operations have centralized, however, so has manure, creating a waste disposal dilemma where farm­ers once saw only a resource. Indeed, facilities with tens of thousands of animals measure their waste production in hundreds of tons of manure or thousands of _cubic meters of slurry. The slurry lagoon on one mega-farm in Missouri, for example, covers 2.8 hectares, is 5 meters deep, and holds more than 87,000 cubic meters of effluent. Such large accu­mulations of waste cause serious environmental damage: the U.S. Environmental Protection Agency reports that effluent from centralized livestock fadlities accounts for more than a quarter of the water pollution caused by agriculture in the United States. In North Carolina alone, over half a dozen major lagoon spills were reported in 1995, including one involving some 95,000 cubic meters of lagoon effluent/•

The buildup of nutrients from large animal-raising facilities has been documented in several states. In Delaware, for example, farmers were applying 72 percent more nitrogen and phosphorus than their crops needed in

St15TAINABILITY AND SCALE

TABLE B

Concentration of livestock Production in the United States Livestock Degree of Concentration

43

Beef More than a third of marketed cattle come from just 70 of the nation's 45,000 feedlots. The number of feedlots in the top beef-producing states has fallen by 75 percent over the past two decades. The largest facilities are found in Kansas, Nebraska, and Texas.

Poultry 97 percent of U.S. sales are now controlled by operations that each produce more than 100,000 broilers per year.

Pork U.S. hog and pig inventory has climbed some 18 percent in the past decade, while the number of operations has decreased by 72 percent. In North and South Carolina and Virginia, where the industry is increasingly located, nearly 80 percent of hogs come from facilities with 5,000 or more head. In traditional hog-raising states, only 6 per­cent of hogs come from facilities of this size.

Dairy The number of dairies has fallen from 250,000 o decode ego to 150,000 today, end overage herd size has increased by more then 50 percent.

Source: See endnote 73.

the early 1990s, thanks in large part to heavy use of manure from the state's extensive pj>ultry-producing operations. Without enough cropland to absorb the mountains of manure generated each year, the material is applied wherev­er possible, at a rate of overapplication that averages some 50 kilos per hectare. The manure generated by poultry could meet well over half of the state's crop nutrient needs if it could be easily and economically distributed, but large, cen­tralized operations make this difficult. 75

The case of burgeoning livestock facilities demonstrates that operations can be too large relative to the absorptive capacity of the surrounding environment. In other cases, operations are too large relative to a region's base of tech-

44 RECYCLING ORGANIC WASTE

nology or skilled labor. In many developing countries, for . example, com posting munidpal solid waste is more likely to occur-and recycling is more likely to be realized-if it is pursued in a decentralized way. Centralized fadlities often require expensive imported machinery, which eliminates jobs and requires technical skills that may not be available. Neighborhood-level composting, by contrast, requires less capital investment, creates more jobs, and can use simple methods that rely on nature to do the composting work/6

Consider the history of composting in India. Despite a commitment by national governments as early as 1944 to increase composting and recycling in major Indian cities, most initiatives have been spectacular failures. Projects were designed to handle large quantities of organic material­between 150 and 300 tons per day-and were supplied with imported machinery for large-scale processing. But the machinery was poorly maintained and workers were inade­quately trained. Moreover, the garbage fed into it contained large amounts of non-organic material-70 percent of the compost ingredients in Calcutta, for example-which dam­aged machinery. These problems raised operational costs. and with little effort to market the final product, cities soon found themselves operating financial sinkholes. 77

Small-scale, low-tech composting efforts in other developing countries offer an encouraging contrast to the Indian experience. The city of Coimbra, Brazil, for example, wanted to reduce inflow to its dump, which was leaching contaminants into a stream used for irrigation and as a water supply for animals. Using local materials and local labor, the city built a simple facility that could process 15 tons of waste per day. Twelve handcarts and three animal carts collect refuse daily from the city's 7,000 residents. The organic material is then manually sorted and composted naturally in various piles at different stages of maturation. The center produces more than 12 tons of compost per month from waste that would previously have been buried. More important, the labor-intensive composting process provides work for eight people-five of whom had lived and

RETURNING TO OUR ORGANIC ROOTS 45

worked as scavengers at the landfill.78

A still more decentralized process is used in Cairo by the Zabbaleen, a group of poor Coptic Christians who sur­vive by collecting garbage from wealthy neighborhoods and using it as feed for pigs, which are raised in enclosed court­yards throughout the city. The Zabbaleen deliver the manure and other organics to a local composting facility. Because the manure is already partially decomposed, com­posting time is greatly reduced, to a week or two. The result­ing compost is coveted by farmers within a 100-150-kilome­ter radius of Cairo, who pay for its delivery. The product is not perfect-it often has high levels of lead and zinc-but an effort to have households separate their organic garbage from other wastes before it is collected could largely elimi­nate this problem/9

The question of scale is often treated solely as an eco­nomic issue. From this limited perspective, bigger is better, because economies of scale typically make large operations more competitive than small ones. But equally relevant are "ecologies of scale," under which larger operations may be more environmentally damaging because they reduce the possibilities for successful recycling. These ecologies of scale provide a more complete picture of the costs and benefits of large, centralized operations.

Returning to Our Orgcmic Roots

As the drawbacks of today's linear organic flows become evident, interest in recycling organic material is grow­

ing. But a return to time-honored recycling practices is not simple in an increasingly urbanized and industrialized world. Many economies are deeply invested in linear flows of organic matter, and will require time to reestablish organ­ic loops. They will also have to wrestle with fundamental issues of sustainability, including the maximum sizes of viable cities and agricultural operations, and the maximum

...

I I I I

46 RECYCLING ORGANIC WAST£

extent to which food should be traded and food raising should be concentrated. But commitment to a series of prin­ciples of organic matter management is a good first step; from these principles, specific policies can emerge to close the loop.

The baseline precept for organic matter management is this: in a fully sustainable world, all organic flows must cycle. By this principle, any instance of organic dumping-whether of garbage sent to a landfill or incinerator, sewage flowing to a .. bay, or manure overapplied to farmland-represents unac­ceptable waste of a natural resource. just as policymakers and citizens would not tolerate the wanton burning, dump­ing, or burial of natural resources, neither would they allow organic matter to be casually discarded if they saw its true value. Appreciation of the contribution of organic matter to sustainable urban living will require a diverse set of policies affecting the individuals, municipalities, and industries that produce organic waste and the farmers that use it.

As a starting point, organic material can be turned away from traditional disposal sites using taxes or legal restrictions. The U.K., for example, has instituted a landfill tax designed to discourage landfill use, while several U.S. states have mandated cuts in organic inflows to landfills, or bans on particular kinds of organic matter, such as grass clip­pings. The U.S. has also banned ocean dumping of sewage, and Europe is set to do so as well. Each of these diverse poli­cies closes another door on organic dumping.80

Outlawing dumping, however, is only half the battle. Viable recycling options are necessary to ensure that mater­ial is actually reused. Such options are best governed by two more principles, first, that organic wastes should be segregated from other wastes. It is generally simpler and cheaper to pre­vent contamination of organic material than to try to clean up dirty material. Segregation of wastes from the beginning is the best way to do this. Once this precept is accepted, a third principle can expedite the search for viable recycling options: those who generate waste must recycle it, or pay for its recycling. This variation of the "polluter pays" principle

•.. . .

... '*r... > •. RETURNING TO OUil ORGANIC ROOTS 47

applies to individuals, businesses, and institutions alike, and spurs each to find the most efficient way to reuse material, and possibly to reduce its flow. City government can still play a large role in helping citizens and businesses to recy­cle, howeveL

Armed with these precepts, the search for viable recy­cling options can proceed on different levels. Municipal educational programs, for example, can equip residents to take responsibility for their food and garden wastes. Sonoma County in California has reduced landfill inflows through a citizen training program for composting, and participants have cut their landfilled wastes by an average of 18 percent. Best of all, this and similar programs are cost effective: they spend $12 for every ton of waste divened, which amounts to less than 40 percent of what a landfill would charge to take the material. 81

Where capital investments by individuals or institu­tions are required, an education program describing the potential financial gains could help to grease the wheels. Most institutions that generate large amounts of food wastes, such as hospitals, schools, or prisons, have likely given little thought to composting. Yet the experiences of Middlebury College and the New York State Department of Corrections cited earlier demonstrate that composting can make finan­cial as well as environmental sense. Getting the word out could help jumpstart recycling by such institutions.

For human wastes, moving toward viable recycling technologies may be a long-term process, especially where cities are committed to disposal technologies. Again, educa­tion is the first step. Cities and citizens will have to deter­mine whether their current system is capable of producing a clean fertilizing product. If not, exploration of alternative systems designed for recycling is warranted, along with plans for adoption of an appropriate technology. In devel­oping countries-many of which need to invest in construc­tion or maintenance of sanitation systems anyway-such a reassessment of sanitation represents an opportunity to leapfrog over the costly problems encountered by industrial

48 RECYCLING ORGANIC WASTE

countries with their "modem" systems. Funding limitations are dted as the chief obstacle to construction of sanitation infrastructure in low-income countries. Yet a system of com­posting toilets-an option that most dties do not consider­costs less than one seventh that of sewage systems. In any case, weaning a city of its sewers is not a quixotic notion. The entire province of Tanum in Sweden is converting to composting toilets, and is already enjoying the environ­mental benefits of the shift: nitrogen and phosphorus pol­lution has been reduced by 90-95 percent compared to the levels experienced when the region was sewered. 82

Converting organic wastes to a useful product, howev­er, does not ensure that organic matter will be recycled; farmers have to want to use it. One reason farmers are slow to choose organic materials over fertilizer is that they are uneasy about it. Synthetic fertilizer comes in specific formu­lations, with the amount of N, P, and K marked on the pack­age label. But compost, sludge, and manure are often highly variable products made from equally variable inputs. Farmers may be unsure of how much to apply and at what rate nutrients will become available to plants. Indeed, mar­kets for organic matter will not mature until farmers can be confident about the product they are buying, and until sup­pliers can respond to the diverse needs of different soils and different crops.

This level of sophistication will require greater research into the nature and properties of organic matter, especially compost, and how these function in different soils and cli­mates, and with different crops. But research in organic agri­culture receives little official support. An innovative inves­tigative project by the California-based Organic Farming Research Foundation determined in 1997 that just 34 of the 30,000 research projects-one tenth of one percent-funded by the United States Department of Agriculture between 1991 and 1996 focused on organic agriculture. Moreover, no provision was made for dissemination to farmers of the results of these few projects. Such institutional indifference will need to be reversed if organic recycling is to make the

IETVINING TO OUI ORGANIC lOOTS 49

maximum possible contribution to agriculture.13

Even if organic dumping were proscribed and farmers were eager to apply organic matter, sustainable organic flows · would not necessarily be achieved. Nutrients might still accumulate in one area and be unnecessarily depleted in another. Here, a fourth principle emerges: budgets for nutri­ents should be established to keep nutrient flows in rough bal­ance. Nutrient budgets are most meaningful at the farm level, and can be as useful to farmers as they are helpful to the environment. A simple tool known as the Nutrient Management Yardstick has been developed by the Center for Agriculture and the Environment in the Netherlands to track farm-level nutrient flows. The tool is a workbook that helps farmers to keep track of all nutrients brought onto the farm-whether in fertilizer, feed, manure, or other materi­als-and all nutrients that leave the farm in crops, livestock products, or other materials. Dutch farmers using the yard­stick have registered reductions in nutrient surpluses in each of its six years of use, and its adoption is likely to be wide­spread as farmers develop mandated nutrient management plans starting in 1998. Dissemination of this simple tool through agricultural extension programs could be an inex­pensive way to get a handle on nutrient flows at the source."

Because nutrient flows are measurable, agricultural operations can be held accountable for safely maintaining nutrient balances. Indeed, any operation likely to have large on-site nutrient imbalances-like the massive nutrient inflows common to centralized livestock facilities-should have a plan for disposing of nutrient surpluses in a way that is enVironmentally healthy. Until a facility, for example, can demonstrate that nearby landowners are willing to receive its excess manure, and that the manure will be applied at rates that can be safely absorbed by those soils, the facility should not be allowed to expand.

Farmer understanding of nutrient dynamics is neces­sary to fulfill the fifth principle of organic cycling: chemical fertilizer should supplement inflows of organic matter, and levels of application should not exceed the crop's capacity to assimilate

50 RICYCUNG OIGANIC WASTE

it. Farmers are well aware of the nutrient content of the fer. tWzer they apply, but may be less knowledgeable about nutrients in other inputs to their soils, such as aop residues or manure. Those who look to fertilizer for their crop's nutri­ent needs sometimes apply manure simply to get rid of it, without accounting for the additional nUtrients that the material adds to the soil. The resulting nutrient overload leads to pollution of nearby water. But education can pre­vent much of this overapplication. The U.S. state of Maryland, for example, initiated a nutrient management program in 1989 to help farmers monitor and control flows of nutrients on their farms. In just seven years, the program has enrolled well over half of the state's cultivated crop­lands, and nutrient overapplications on them have been reduced. In 1996, program consultants recommended an average reduction of 15 pounds of nitrogen per acre.a.s

Once they internalize these principles, citizens .and palicymakers essentially achieve a major shift jn thinking and in world view. Organic matter is no longer seen as dis­posable garbage, but as a soil-building natural resource. And nutrients are no longer viewed as wholly benign, to be scat­tered wantonly throughout the environment, but are under­stood to serve economies and ecosystems best when kept in balance. Such reacceptance of the ancient appreciation ot organic material will be a large step in the direction of build­ing sustainable dties and farms.

. f f. ,, i

·i ;

...

NOTES 51

Notes 1. Grain to Rome from "History of North Africa," Encyclopedia Britannica, vol. 13 (maaopaed.ia), 1976; environmental decline from Herbert Girardet, "Cities and the Biosphere," paper presented to the UNDP-Marmaris Roundtable, Cities for People in a Globalizing World. 19-Zl April1996.

z. Drinking water from Organisation for Economic Co-operation and Development (0ECD}, "Towards Sustainable Agricultural Production: Cleaner Technologies" (Paris, 1994); species diversity from David Wedin and David Tilman, "Influence of Nitrogen Loading and Species Composition on the Carbon Balance of Grasslands," Science, 6 December 1996: quality of organic matter from Harry A.J. Hoitink. et al., "Making Compost to Suppress Plant Disease," Biocycle, April 1997; Gulf of Mexico from jonathan Tolman, "Poisonous Runoff from Farm Subsidies," Wall Street Journal, 8 September 1995.

3. Flush toilets from Peter Gleick, "Basic Water Requirements for Human Activities: Meeting Basic Needs," Water International, june 1996.

4. Share of nutrients in municipal waste is a Worldwatch calculation based on data from OECD, OECD Environmental Data: Compendium 1995 (Paris: 1995), on U.S. waste data from Environmental Protection Agency (EPA) "Characterization of Municipal Solid Waste in the United States: 1995 Update," Executive Summary (Washington, DC: March 1996), on nutrient value of municipal waste from Xin-Tao He, Terry J. Logan, and Samuel]. Traina, "Physical and Chemical Characteristics of Selected U.S. Municipal Solid Waste Composts." Journal of Environmental Quality, May-June 1995, and on fertilizer use from Food and Agricultural Organization (FAOl, FAO web site http://www.fao.org. Countries selected were those for which com­plete data was available. Share of nutrients in human waste does not include the 33 percent of sludge produced in OECD countries that is already applied to land. Share is a Worldwatch calculation based on nutri­ent value of human waste from E. Witter and J.M. Lopez-Real, "The Potential of Sewage Sludge and Composting in a Nitrogen Recycling Strategy for Agriculture." Biological Agriculture and Horticulture, 5, 1987; pop­ulation from U.S. Agency for international Development (USAIDl and U.S. Department of Commerce, World Population Profile 1996, and on fertilizer use from FAO, op.cit. this note.

5. OECD. op. cit. note 4. Share is an average of member states' reporting rates for the early 1990s. If paper is included in the organic total, the organ­ic share rises to nearly two thirds. Composting toilets from Robert Goodland and Abby Rockefeller. "What Is Environmental Sustainability in Sanitation?" UNEP-IETC Newsletter. Summer 1996.

6. Teresa Glover, "Livestock Manure: Foe or Fertilizer?" Agricultural Outlook, June 1996.

i :'

52 RECYCLING ORGANIC WASTE

7. China from A.E. Johnston, "The Effident Use of Plant Nutrients in Agriculture," (Paris: International Fertilizer Industry AsSOCiation, 1995); 23 states from Nora Goldstein, "The State of Garbage in America," Biocycle, April 1997; United States from National Research Council, Use of Reclaimed Water and Sludge in Food Crop Production (Washington, DC: National Academy Press, 1996); Europe from Peter Matthews, ed., A Global Atlas of Wastewater Sludge and Biosolids Use and Disposal (London: International Assoctation on Water Quality, 1996) and Peter Matthews, Director of Innovation, Anglian Water, Cambridgeshire, U.K .• letter to author, 24 June 1997.

8. Nitrogen fixation from Peter M. Vitousek et al., "Human Alteration of the Global Nitrogen Cycle: Causes and Consequences," Ecological Issues, February 1997; fossil-fuel burning and cultivation of nitrogen-fixing crops are the other human sources of nitrogen fixation~ Still other human aetivi· ties-the burning of forests, wood fuel, and grasslands; draining of wet· lands; and clearing of land for crops-release trapped nitrogen that was already fixed. Figure 1 from Vitousek et al., op. dt. this note, and Ann P. Kinzig and Robert H. Socolow, "Human Impacts on the Nitrogen Cycle," Physics Today, November 1994. Fertilizer application from Lester R. Brown, "Fertilizer Use Rising Again," Vital Signs 1997: The Environmental Trends That Are Slulping Our Future (New York: W. W. Norton and Company, 1997).

9. Wedin and Tilman, op. dt. note. 2; northern Europe from Vitousek, op. dt. note 8, and C. Mlot, "Tallying Nitrogen's Increasing Impact," Science News, 15 February 1997.

10. Wedin and Tilman, op. dt. note 2.

11. L. Drinkwater, P. Wagoner, M. Sarrantino, and S. E. Peters, "Net prima­ry productivity, nitrogen balance and carbon sequestration in organic and conventional maiZe/soybean cropping systems," submitted for publication to Ecological Applications, and Laurie Drinkwater, Rodale Institute Research Center, Kutztown, PA, letter to autho_r, 12 june 1997. Like the convention­ally fertilized field, the manure-fed fields received more nitrogen than was taken up by crops. But unlike the conventional field, which had a high rate of leaching, the manure-fed land was effeCtive at storing nitrogen for later use by crops.

12. Tolman, op. dt. note 2.

13. OECD, op. cit. note 2; India and Brazil from "Comprehensive Assessment of the Freshwater Resources of the World," report to the United Nations, UN Commission on Sustainable Development web site <http://www.un.org/dpcsd/dsd/freshwat.htm>, viewed 14 March 1997.

14. Content of organic matter from Nyle C. Brady and Ray R. Well, The Nature and Properties of Soils, 11th edition (Upper Saddle River, NJ: Prentice Hall, 1996).

,_-of:

..

NOTE.S 53

15. African fertilizer use from Amitava Roy, "Nutrient Inputs as Critical Variables in the Long-Term Projections for Sustainable Global Food Security," unpublished paper (Muscle Shoals. AL: International Fertilizer Development Center, undated).

16. Landfill closures from Goldstein. op. cit. note 7; capacity increase from Council on Environmental Quality, Environmental Quality (Washington, DC: U.S. Government Printing Office, 1997); Fresh Kills from Vivian S. Toy, "Bids for Exporting Trash Are Lower than Expected," New York Times, 3 March 1997; Institute for Local Self-Reliance. Beyond 25 Percent: Materials Recovery Comes of Age (Washington, DC, 1989).

17. OECD, op. cit. note 4. Share is an average of member states' reporting rates for the early 1990s. Including paper in the organic total boosts the organic share to nearly two thirds; leaching and methane from EPA, "Yard Waste Composting," Environmental Fact Sheet, (Washington, DC: Office of Solid Waste, January 1991); Fresh Kills from Nancy Redder, "New Yorkers Near World's Largest Landfill Say City Dumps on Them," Washington Post, 7 August 1996.

18. Robert Steuteville, "The State of Garbage in Ametica," Biocycle, April 1996; Alastair Guild, "Britain's landfill tax raises stakes for compost mak­ers," Financial Times, 10 October 1996; "Tokyo Examines Fees for Collection of Garbage from Households by 1999," International Environmental Reporter, 5 February 1997; Paul Relis and Howard Levenson, "Using Urban Organics in Agriculture," Biocycle, April 1997.

19. John Briscoe and Mike Gam, "Financing Agenda 21: Freshwater," paper prepared for the United Nations Commission on Sustainable Development (Washington, DC: World Bank, february 1994).

20. Water stress from "Comprehensive Assessment," op. cit. note 13; flush toilets from Gleick, op. cit. note 3; cost from Briscoe and Gam, op. cit. note 19.

21. "Photosynthesis" in Encyclopedia Britannica, vol. 14 (macropedia), 1976.

22. Share of calories from Tim Dyson, Population and Food: Global Trends and Future Prospects (London: Routledge, 1996).

23 •. U.S. Department of Agriculture (USDA), Production, Supply, and Distribution (PS&D), electronic database, Washington, DC, updated October 1996; Table 1 based on data in USDA. op. cit. this note.

24. USDA, op. cit. note 23.

25. USDA, op. cit. note 23.

26. Ten percent calculated from data in USDA, op. cit. note 23; Table 2

54 RECYCLING ORGANIC WASTE

based on data in USDA, op. cit. note 23.

27. G.W. Cooke, "The Intercontinental Transfer of Plant Nutrients,'' in Nutrient Balances and the Need for Potassium, Proceedings of the 13th International Potash Institute Congress, August 1986. Reims. France (Basel. Switzerland: International Potash Institute, 1986); Table 3, op. cit. this note.

28. African flows from Cooke, op. cit. note 27; Roy, op. cit. note 15.

29. Overapplication based on data in USDA, op. cit. note 23; Table 4 based on data in USDA, op. cit. note 23.

30. Recycling rate of manure from Council for Agricultural Science and Technology (CASTI Integrated Animal Waste Management, Task Force Report No. 128 (Ames, lA, November 1996).

31. Asia from Johnston, op. cit. note 7; United States from National Research Council, op. cit. note 7; Europe from Matthews, ed., op. cit. note 7, and Matthews, op. cit. note 7.

32. Organic share is an average of member states' reporting rates for the early 1990s, and is calculated from data in OECD, op. cit. note 4; including paper in the organic total boosts the organic share to nearly two thirds. Developing countries from Centre de Cooperation Suisse pour Ia Technologie et le Management (SKATI, Valorisation des dechets organiques dans les quartiers populaires des villes africaines (St. Gallen, Switzerland, 1996); 11 percent is an average of member states' reporting rates for the early 1990s, and is based on data in OECD. op. cit. note 4.

33. Volatilization from Witter and Lopez-Real, op. cit. note 4; high-yielding varieties from Balu L. Bumb and Carlos A. Baanante, "The Role of Fertilizer in Sustaining Food Security and Protecting the Environment to 2020." Food, Agriculture, and the Environment Discussion Paper 17 (Washington, DC: International Food Policy Research Institute, September 1996).

34. Organic share is an average of member states' reporting rates for the early 1990s, and is calculated from data in OECD, op. cit. note 4; including paper in the organic total boosts the organic share to nearly two thirds; developing countries from Valorisation, op. cit. note 32; 11 percent is an average of member states' reporting rates tor the early 1990s, and is based on data in OECD, op. cit. note 4; Table 5 calculated from data in OECD, op. cit. note 4.

35. Paper data from OECD, op. cit. note 4.

36. Brady and Wei!, op. cit. note 14.

37. H.A.J. Hoitink, A.G. Stone, and D.Y. Han, "Suppression of Plant Diseases by Composts," accepted for publication in HortScience, 1997;

I I I

l

NOTES 55

replacement of methyl bromide from William Quarles and Joel Grossman, "Alternatives to Methyl Bromide in Nurseries-Disease Suppressive Media," IPM Practitioner, August 1995.

38. For calculation of share of nutrients in municipal waste, see note 4. Estimate of nutrient overapplication based on Dale Lueck, "Policies to Reduce Nitrate Pollution in the European Community and Possible Effects on Uvestock Production." Economic Research Service (Washington, DC: USDA. September 1993), which reports nitrogen overapplication in Europe to be 57 percent greater than crop needs; on U.S. grain data from USDA, op. cit. note 23. and fertilizer application rates from Economic Research Service, "Agricultural Resources," February 1993, which are used to calculate a fer­tilizer overapplicaton rate in the U.S. of 36 percent; Table 6 is Worldwatch calculation based on data from OECD, EPA, and FAO, op. cit. note. 4. Countries selected were those for which complete data was available.

39. Slow release from Brady and Weil, op. cit. note 14; India from Panneer Selvam, "A Review of Indian Experiences in Composting of Municipal Solid Wastes and a Case Study on Private Sector Participation," paper presented to the Conference on Recycling Waste for Agriculture: The Rural-Urban Connection, held at the World Bank, Washington, DC, 23-24 September 1996.

40. Toni Nelson, "Closing the Nutrient Loop," World Watch, November/ December 1996.

41. Integrated Waste Management Board, "Agriculture in Partnership with San Jose," Final Report. (Sacramento, CA: Integrated Waste Management Board, April 1997); need for customizing from Francis R. Gouin, "Compost Use in the Horticultural Industries," Green industry Composting, undated.

42. Composting facilities from Goldstein, op. cit. note 7; San Jose from Integrated Waste Management Board, "Agriculture in Partnership with San jose," Final Report (Sacramento, CA, Aprill997).

43. Dave Baldwin, Community Recycling and Resource Recovery, Inc., Lamont, CA, conversation with author, 21 February 1997.

44. Value of compost from Community Recycling and Resource Recovery, Inc., "Community Recycling Compost Typical Analysis," factsheet (Lamont, CA, undated).

45. "Institutions Save by Composting Food Residuals," Biocycle, january 1997.

46. Selvam, op. cit. note 39.

4 7. China from Alice B. Outwater, Reuse of Sludge and Minor Wastewater Residuals (Boca Raton, FL: Lewis Publishers, 1994). While sludge is already

...

56 RECYCLING ORGANIC WASTE

recycled with few problems in many countries. the risk lies in the lack of control over materials that enter sewers. This lack of control means that any batch of sludge could contain materials that are harmful to human or enVi­ronmental health. Laura Orlando, Resource Institute for Low-Entropy Systems, Boston. MA, conversation with author, 18 June 1997.

48. Regional distinctions from World Resources Institute (WRI), World Resources 1996-97 (New York: Oxford University Press. 1996); 10 percent from Witter and Lopez-Real. op. cit. note 4; arid regions from Carl R. Bartone. "International Perspective on Water Resources Management and Wastewater Reuse-Appropriate Technologies," Water Science Technology, 23, 1991.

49. Official encouragement from Peter Matthews. ed., op. cit. note 7; reuse rates: United States from National Research Council, op. cit. note 7; Europe from Matthews, ed., op. cit. note 7, and Matthews, op. cit. note 7; dump­ing sites from National Research Council, op. cit. note 7. Ocean dumping. once a common method of sewage disposal for some coastal cities, was out­lawed in the United States in 1992, and will be illegal in Europe after 1998. See Cecil Lue-Hing, Peter Matthews, juraj Namer. Nagaharu Okuno. and Ludovico Spinosa, "Sludge Management in Highly Urbanized Areas," in Matthews, ed., op. cit. note 7.

50. Assumes that 33 percent of sludge produced in OECD countries is already land applied. For calculation of share of nutrients in human waste, see note 4. For an explanation of the estimate of nutrient overapplication. see note 38; Table 7 is Worldwatch calculation based on data as follows: fer­tilizer use from fAO. op. cit. note 4; nutrient value of human waste from Witter and Lopez-Real. op. cit. note 4; population from USAID and U.S. Department of Commerce, op. cit. note 4.

51. Bartone, op. cit. note 48.

52. Israeli reuse from Sandra Postel, ~"Dividing the Waters: Food Security, Ecosystem Health, and the New Politics of Scarcity," Worldwatch Paper 132 (Washington, DC: Worldwatch Institute, September 1996); heavy metal lev­els from Yoram Avnimelech. "Irrigation With Sewage Effluents: The Israeli Experience," Environmental Science and Technology, 27, no. 7, 1993.

53. Outbreaks from Hillel I. Shuval. "Wastewater Irrigation in Developing Countries: Health Effects and Technical Solutions," Summary of World Bank Technical Paper Number 51 (Washington. DC: World Bank. 1990); Mexico from Duncan Mara and Sandy Caimcross, Guidelines for the Safe Use of Wastewater and Excreta in Agriculture and Aquaculture (Geneva: World Health Organization. 1989).

54. Substances from Laura Orlando, "The Sewage Scam: Should Sludge Fertilize Your Vegetables?" Dollars and Sense, May/June 1997; persistence of metals in soils from "Land Application of Sewage Sludge," excerpt from

r NOTES 57

~· t •cornell Recommends," In press, August 1996. 0:

55. Standards from Orlando, op. cit. note 54; testing from Mark Lang, Carolyn E. Jenkins, and W. Dale Albert, "USA: Northeastern States," in Peter Matthews, ed., op. cit. note 7.

56. Ponds from Bartone, op. cit. note 48; pathogen kill from D.O. Mara, G.P. Alabaster, H.W. Pearson, and S.W. Mills, "Waste Stabilization Ponds: A Design Manual for Eastern Africa" (Leeds, U.K.: Lagoon Technology International, 1992). Other sources list the rate of pathogen kill in conven­tional plants as only 90-95 percent. See Shuvai, op. cit. note 53.

57. Peter Edwards. Reuse of Human Wastes in Aquaculture, Water and Sanitation Report No.2, UNDP-World Bank Water and Sanitation Program, 1992. Multiple uses from Dhrubajyoti Ghosh, "Wastewater-Fed Aquaculture in the Wetlands of Calcutta-an Overview," in P. Edwards and R.S. V. Pullin, Wastewater-Fed AqUDculture, Proceedings of the International Seminar on Wastewater Reclamation and Reuse for Aquaculture, Calcutta, India, 6-9 December 1988.

58. Living Technologies, "What Is a Living Machine?" (factsheet) (Burlington, VT, 1997).

59. Pond area from Shuval, op. cit. note 53; Calcutta from Carl R. Bartone. op cit. note 48.

60. SIRDO's tull name is Sistema Integral de Reciclamiento de Desechos Organicos. or Integral System for Recycling Organic Waste.

61. Grupo de Tecnologia Altemativa (GTAJ. "The SIRDO from Mexico. 1979-1992" (Mexico City: Grupo de Tecnologia Altemativa. undated); ]osefina Mena Abraham, Grupo de Tecnologia Altemativa, Mexico City. e­mail to author, 16 June 1997, and Sidonie Chiapetta. National Wildlife Federation (NWF), e-mail to author, 18 June 1997.

62. Sidonie Chiapetta, NWF. conversation with author. 17 June 1997; Tres Marias from josefina Mena Abraham, Grupo de Tecnologia Alternativa. Mexico City, letter to author, 20 February 1996.

63. Sidonie Chiapetta, "Costs and Benefits of SIRDO Technology," infor­mation sheet, (Washington, DC: NWF. September 1996). The NWF analysis works out to S33 per household per year (assuming 7-8 persons per house­hold). The GTA estimates net household revenues of $30-60 per year, Abraham, op. cit. note 61.

64. Chiapetta, op. cit. note 63.

65. J. Paul Henderson, "Anaerobic Digestion in Rural China," Biocycle, January 1997.

•

-·

58 RECYCLING ORGANIC WASTE

66. Carol Steinfeld, "Compost Toilets Reconsidered," Biocycle, March 1997.

67. Orlando, op. cit. note 47.

68. Grain output and exports from USDA, op. cit. note 23; trade and pro­duction from FAO, "Characteristics of Agricultural Trade," in World Food Summit, Technical Background Documents 12-15, Volume 3 (Rome, 1996).

69. Angela Paxton: "The Food Miles Report: The Dangers of Long-Distance Food Transport" (London: SAFE Alliance, September 1994).

70. Nitrate levels from Dale J. Leuck. "PoliCies to Reduce Nitrate Pollution in the European Community and Possible Effects on Livestock Production." Economic Research Service (Washington, DC: USDA. September 1993).

71. Com from USDA, op. cit. note 23; Taiwan pollution from USDA. "U.S. Grain Producers Have Big Steak in Taiwan's Market," Grain: World Markets and Trade, June 1997.

72. Glover, op. cit. note 6.

73. Table 8 based on Glover, op. cit. note 6.

74. Missouri farm from Mark Schultz. Land Stewardship Project, Minneapolis, MN, discussion with author, March, 1997; pollution from Glover, op. cit. note 6.

75. Brady and Wei!, op. cit. note 14.

76. SKAT. op. ctt. note 32.

77. Selvam, op. cit. note 39.

78. E.I. Stentiford, J.T. Pereira Neto, and D.O. Mara, Low cost composting, Research Monograph No. 4 (Leeds, U.K.: Dept. of Civil Engineering, University of Leeds, 1996).

79. lnge Lardinois and Arnold van de Klundert, "Recycling Urban Organics in Asia and Africa," Biocycle, june 1994.

80. Steuteville, op. Cit. note 18; Guild, op. cit. note 18.

81. Cut in flows from Paul Vossen and Ellen Rilla, "Trained Home Composters Reduce Solid Waste by 18%," California Agriculture, September­October 1996; costs from Ellen Rilla, "CE Offices Facilitate Community Com posting Efforts," California Agriculture, September-October 1996.

82. Funding limitations and composting toilets from Peter H. Gleick, ed., Water in Crisis: A Guide to the World:S Fresh Water Resources <New York:

NOTES 59

Oxford University Press, 1993). Note that a much higher cost differentiai-28 times-is given in Briscoe and Gam, op. cit. note 14; Sweden from Goodland and Rockefeller, op. dt. note 5.

83. Bob Scrowcroft. Organic Farming Research Foundation, Santa Cruz, CA, conversation With author. 25 June 1997.

84. Emily Green and Jim Kleinschmidt, "Nutrient Management Yardsticks" information sheet (Minneapolis. MN: Institute for Agriculture and Trade Policy, 1996).

85. Cooperative Extension Service, "Maryland Nutrient Management Program Annual Report. 1996" (College Park. MD: Maryland Department of Agriculture. 1996).

WORLDWATCH PAPER 135

Recycling Organic Waste: From Urban Pollutant

to Farm Resource Metal, paper, and plastic are commonly recycled, but most of the world continues to throw away an abundant, reusable resource: organic matter. Today, we normally send organic garbage and sewage to landfills and incinerators, or dump them into rivers, bays, and oceans. And manure is increasingly dumped or overapplied to farmland because of large, centralized livestock production.

These disposal methods clog landfills, pollute air and drinking water. and encourage cities to invest in costly, water-intensive sewage infra­structure. They also promote excessive depen­dence on manufactured fertilizer, which cre­ates its own problems, from ecosystem disrup­tion to disease-prone soils.

Recycling organic matter from cities to farms would help solve many of these problems. Urban organic garbage and yard waste can be composted and used on farms. Human waste­if separated from industrial waste-can be processed into a clean, fertilizing product. And the production of manure can be man­aged to avoid dumping or overapplication.

Recycling will require that organic material be viewed as a resource, rather than a waste prod­uct. We need policies to educate municipal authorities and citizens about the value of recycling organic waste and the steps to achieve it. Initiatives to assist farmers in man­aging the quantities of nutrients and organic matter that are applied to their land can reduce pollution and rebuild soil. Once implemented, recycling of organic matter will make cities more sustainable, and save them money.

IJORLDWATCH N S TIT UTE

1776 Massachusetts Ave., NW • Washington, DC 20036-1904

.... ~-. ~-

·~· -- ,. ~'-

·. ~O;ll~~ ·:~l.::-vt;;::.; , ..•• ,,._ - _,_ ....-·.

I. Th U • abili ·•: - · ·'"';·· : man plant), land acquisition for I'CSCI'VOirs, and

~- of:· · 05~ . . . ?" ...... •"r•'"' d: imrolunwy resc:alement of people to make room ,, ,.,.~ •• · .;:;:.o. • ;.,. .. for dlesc: I'CSCI'VOirs . .About 10-20% of the ovaaii

For the reasons ~udined below, the present COlt is in the treatment processes. Energy costs

app~ ~- the disposal of human_ wasres • a;n- for both pumping and aatment arc enormous.

a2l collc:c:tion and _aatment of sewage • is unsus- ... House-to-sewer connections, trunlt lines. and

tainable •.. Nevertheless, the f~ to .cwer tbc: c:olJc:c:mrs lc:ading to peri-urban sewage aaanent

globe seems II) be growing. For dlc. sake of CDYi- ·· Eacilities arc increasingly expensive for affiuc:nt

ronme~cll 'IJSWI12bility, we: must stop mixing. Orpnization for Economic Cooperation toe

hWIWl ca:ma with drinking w.ater, then collccr- Dcvdopment (OECD) cities. Initial construc-ing and further wo_rscni~g this mixture with

industri•Ll and non-point source wastes, then

"crating" the minurc. then polluting waa:r, air,

or soil by cfforu to dispose of the poisonous

sludge acarcd by the treatment pi'OI:CSS. Such

practices may have _appcaJed affordable dcadc:s

tion costs alone for ICWI:ring in OECD cities arc

about $50,000 per household. This docs not

include organization and management or

hoolcups from sewer mains to each house:. Even

if the cost is half that in Less Dc¥1:lopc:d Country

(LDC) cities, it is dearly prohibitive for poor ago. Now population densities, urbanization, nations. and ~ivc pollution of nearly all w.ater bodies ,.. _ . . . . _._ ••. __ _ show the unsustainability of the system. . , _

0 .• f =-~"-~l!:,>:~~...:oil!daV~-,,' ~

~- r.:' -1. Drinking:;_ ·; •':"• . .:.. ~ '~ . -.~., This pap::r calls for a fundamcnw rethinking of r- · - ......

' 2. Cooltlng -~-· 10 : _. . ,_ the human waste problem if t~c world is to ,. _____ _;.,;.;.;..__;;;..__.;_ __ .;...;.:~_;,; n:YCr$C ic• decline from the currcn t unsustainable

sanicacion practic:cs to approaches which would ~ '-. ,.., --- -

~ .3. a.thing : ... :

:- ·-4. Sanitation ·

. '··-- 1.-.. ...... . ~ .. _ ..

promote 'cnvironmencal sustainahiliry. _0

_, . ,~, , t: .,.otal _ _. · .. _.- - - ~ . f

. "'"'· . ::-"-" · ,, ~ · !' · Figure 1: ·· Recommend;d Minimum .. · ~- ~r RequirBrtlflnts for ·Residsrrtilll Use ··

• -·-'· tfrom Gleick. 1996) ·" '.: .. · '· • ... ·~·- '"

In ccnmJ eollccion ~d trca~~; ~f ~c. Figure. I dt~ -~~ .flush toilca usc 40% of the

80-90% of the · tocal ~ts go ~o ~~rcation total rcsidcnciaJ demand for _municipal waa:r •... If ..

(e.g., Jayi~g ~{pi~ waa:r iS'somctim~ con~ . ~sroppc:d ~-:_~-C:,~n h~ ex-· . . . ... '-~· _ ..... ~ ...... ..."~;"'~~ -- - ... - ...

. vcyc:d s~veral hundred k.ilometcrs from water crc:ca, n:savoirs could be half as large and there-supply to users and from thcic to a scw:igc treat~·;.; .,.f~rc much kss ~y. When cities were fewer .

• ..,&-•·· ........ ;.;. :'1...:-~ - ~~ ::... '- .• . . . --

--------------- .•. ·-.. -:--;·-- ------ ..

::;~· i ;.~::_.:~.... -·---~ \:.; . ..t.'t»5W ~-£::-. -i~J;..V~:.:..;;1-

and smaller and population densities lower, the"··

cost of collcccing and storing water for such pur­

poses seemed, in financial terms, affordable.

That era has long gone. Soaring costs of peri·

urban land for sewage aatmcDt and rescnoin;

and the cosa of imroluncary rcsmlcment make this approach less affordable. -~ :'lll:et: . .;:Atu• .,., :.- .,. ·

If the recommended minimum 'Water use.for

.LOC cities of appr. 36 lia:rlpenon as ~ggcstcd

in Figure 1 is ciisaggrcgatcd iru:o its four main

components, it is evident that flushing toiletS is ..

the Jargcst single caccgoty of domaric.warcr usc

and the only one with significant-room ·for·­

tcduaion. (The average OECD sanitation usc is •

40 1/day and all other uses. except drinking. arc:·:

comparably greater.) There is ao TOOm for con-­

scrntion of drink.ing water; vinually none in

cooking; some in the barhing .c:aqory throUgh.·

for example, waa:r-conscrving showa and faucet

fixtures. Sanication using flush toileu has,.by

contraSt, substantial scope for water conserva­

tion; and sustainability demands that it be strin­

gently rccluccd, preferably to zero., Thal waa:r

-~ for flushing toilets can be reduced to zero has .

. been demonstrated suc:ccssfully by the usc of

composting toilets at public facilities and rcsi•

dena:s in the U.S., Sweden, and South Korea (to

name a few countries where this technology has

been seriously applied), where a household of

~saves 40,000 gal.sJyar and·'a.pubiic'&dlity

serving 70,000 people saves -350,000 gals.lycar:;

....

Sweden's entire provinc:c ofTaiaum is convening · ·

to ~mpcsting wilcu in ordcno reduce pollu: · ··

UNEP·IETC Newsletter, Summer 1996'

~- .: ..

have enough fresh water to justify continuing

with central collection sewage systems.

T ransporration of wasta by water requires huge

amounts of water just to 1ceep the wasta moving

in the pipes. This has been demonstrated in a

number of U.S. cities where many sewer lines

plugged up after water conserv.ation programmes

inaoduc:cd the use of 1.6 p1s. toilets instead of

me usual 3-5 gals. flush. People with such low­

water toilets miut now flush twice or thrice.

The situation in. many areas is ..a sewere that

some countries have to seek alternative sowa:s of

water. In Hong Kong. Ka-water is now used for

a paralld sanitation system. But. since building a

par.allc:l system of distribution for sea water

would be roo expensive for most older cities,

brine may be pumped into existing frahwarer

systems. However, a likely danger of such a

choice would be contamination of fresh pound­

water supplies by ezfilrr.ation from leaking ·

sewage. This would further degrade ground­

water • the world's primary source of available

freshwater. Further, current infrastructure for

effort to extract clean water from sewage is a

wasted cost, since this vast expenditure of public

funds has nor • and cannot • provide environ­

mencally sustainable sanitation. Thar · is, it can­

not solve the multiple problems caused by this

form of water poUution. As a system, it cannot

-dean the water we have chosen to poUure with­

our inaoducing·more complex and cnvironmen­

caUy unsustainable dfa:rs. The reason lies in the

.. flawed concept of the separation technology

itself. it is a virtual impossibility to dean water

that has been used to transport human wastes.

The incvicable products of this system :arc first

more or less dc:gradc:d water, and second more or

less roxie sludge. The more advanced the acar­

mc:nr of the sewage (i.e., the more sua:cssful the

separation of the pollutants &om the water), the

more sludge will be produc:cd and the worse - the­

more unpn:diccablc and dangaous - this sludge will be.

The problems associacrd with cc:na:al collcaion

and rrcarmcnr of ~pipe l:ayiDg. leabgc and

loa of water from sewas, the com and the &i.l­

ure of ever more elaborate forms of ucarmcnr:

·and finally, the creation of sludge - thac :arc. aU

endemic to central collection and treatment. --· -. . - ~- -··- ---~ --- --· ,___

Each stage only leads in its aun to more unsolv-

transporting fresh groundwater to people for

drinking. coolcing. and washing would be ren·

derc:d unusable. Freshwater would then have to

be supplied by truck or containers, vr piped from

even greater distances -· clearly an expensive

proposition.

able problems as the primary p~ is mcrcly

· - moved from one place to another. and from one

r.: •-•. form to another. The result of this attempt to

Both landfilling and incineration were employed

for a number of years until environmental objec­

tions intensified. -To fill the: vacuum caused br

this opposition. the US Environmental Protec·

tion Agency (EPA) adopted the id~ ~£-disposing of the sludge by spreading it ~ aS a "fcrrilizc:r" •

on agricultural land. Sludge's four inain ate:· .,

goria of poUucants - nutrients, Jladiogais. mJclc ,.

organics and heavy mccals- 6chi"ve'differcndy '

and cannot be managed by a single ·lcind of Ui:at­

mcnt. Land application was implc:menr~d i~ ~ Sweden in the early 1980s with diSaSUoU:S. r;wts,­

which to date the US EPA seems to be ignoring.

Such a praaice must lead to accumulation in Jiv.

ing tissues of heavy mcrals and Persistent organic

chemicals: fim they accumulate: in the soil. then

in decomposer microbes and soil-conditioning

inYCrtebratc:s. Other life forms :arc ~ as

thousands of non-biocompatible substances

mOYC up the food chain. The toxi~ effc:ct ·~~

crops. as wc:U as on the: c:Onsuiners of ~ch Crops,

is buying risks for the future. _.J..J:,. -~._ .•

Despite creating such risks, gove~~~nts and

environmental protection ~gen~i~i rhc:-~orld

over :arc forcc:fully promoting land applu;~ion of

sludge· because ir'_is ... the.cheaPc:st fo~ of d~- .,.

posal. It is misguided of regulators to try to per­

suade the: world that sludge, though undispos- -

able, is rc:cydable • suicable for "beneficial reuse'

,, :-r.·"'" ·~-, .>::o manage human and industrial Wa.te itrcams ·is - · - as the phr;uc;·-~ow goes. In a sustainable world,

.:cdtat the end produer, Slu~ t;' so. iq»l~ ,;nth-:. ~orbing can be "disposed of," but ~'does not

;,..;;.!! ~·- ;., ~"""' pathoP, orpruc iUid inoig:uiic'i~ii~:and ~ ·~can tha:i~i~g now in iuun~.~~can be

._ ~: ~

•

r ...

Maintenance of water supply and sewage collcc- virrually unknowable range of Ch~iah: that it,... ~ed. ~~'~or be~ is ;o,'s~tain-.-=)

is'dassific:d as a bazardow ~teriafnqui~ing ~le and ~~~i:i n~;·t,;produccd. Sludge-1s one •• 'f micr rcgubtion for rranspo~~on and disposal. · ·. . ·~ ma~: '-""~ · - '. -

tion infrasauaurc, even in afilucnt OECD cities,

encails an increasingly onerous .cost.' since <many.·.

.'

that arc: tenviroamentally benign (e.g .• organic

procluas that arc: compatible: with normal mc:ta·

bolic pi'Cl~CCSSCS). Ocher materials that arc: not ·

life-compatible:, especially heavy metals, toxic

chemicals. _and toxic _4)rganic: materials used in

industrial p~--~us~_be retained in dosed-

loops ;and r~~ed ~i~in the: i~~ustri~ from which d~c:y come. Industry must be: held

~~~;le "ior ch~ aPP~P~rc: ~c:nt o{ its oWi.- br?roclu~~--This m~ mdusay must- . ·

not. be. ;:llowed l:o"~bdicate envir~~~ental·

accounabiliry by using sewcn'as a cheap "dump:

It is society in che form of human beings and

their communities who nciw pay the financial

and hc:alth COSts of subsidizing this cheap garbage disposal for industries.

lored to local conditions such as climate and

geology. All arc applicable in most cities, and

implc:meadag im."oiae' of d.~ would pdy . allcriate aiiftac UDS~iable practi.;u. All arc:~le to convc:ncion21 trc:ndS.~This f,aper •..

supu they lie evaluated in.vicw.ofthe un·

suminabiliry of conventional pru:tic.a: · ' c;

The th.rte SC!'cral principles arc: first, institute

a policy or'~ ~~fciana: (i.e., ~y off or get

off sewers). Second, promote·~~~ cost, on­

site resource rccyding technologies, such a.S ·

composdag ~ilcts. that avoid polluting water

and preclude wasdag resourc:es. Third, price -· ·- ., ...

If loW stopped using waster to transport human excreta, reservoirs could be half IJS large an({' ""~ ... -thereforfr much less costly (here an artificial lake in Australia}.

lution becomes solvable instead of merely

aansfcr.able. · - . , .. ).j.t,W ~ :•i.J~ ... tsf~:tC ~m-n_,

Sc:cond, in citi~ -~~ t~ -~~;.a:c already sew·

crcd. implement a baclt-off-th~ prognmme. -~-Ql :

That is, begin the process of mterl%pcing • and

recovering for rccyding • the1'CSOIII'CCS (the con­

stituents of ~lied "wurc") ascdose. to the

~DUtCe as possible. This does not mean dosing

existing central treatment facilities now: ·rather,

it means implementing a policy of mandates to

fund the llllSC of existing technologies that c:an

accomplish scp;uation, rccoveiy, aNI .recycling at

IOW'CC. The aim is gradually to ~ the range

and quanl:liry of random marc:rials · cnrc:ring the

sewage stream, in order gradualll'~ dccrc:asc: the

burden on central treatment £2clli~~d. there:·

by. me volume of ~udge procluccd. •• This back­

off-thc-$CWUS prognmme indudes~e following:

; ' ' . : ..-':' . ' -(-··. . ·- ~·P:;1i\:,r~ "'";.,.., -- -·--a) DO· not extend sewer lines. 1..oCa.l pollution

0 • • • •, -r!" 'l}E ·~ • "•:. ~"J·'" ~ "• • •

of groundW3rc:r is not, ovcra11, more environ· -- . ·~'Uif.':': ... ~· ---··

mcnally· desrruaivc than massive rc:loated

polluti.;n caused by'~~ ~~~ ~utfatls of'"'partially' u~;~ cffi'ue~( ~;rihc:~ d~;p-

• . . - • . ~ ...... ":". ~ _...:;: I' '::.;.':; t. ; _: : -..

ing, burning. or land application of sewage

slUdge. 1~,-~ds- ~;;~~~~"'ro·/ the

cxrc:nsion of sewer li~;;o~uld ''~d for

. implemenation of systematic aoura: rc:duc-

UNEP·IEJC ~ewslener,. Stimmer ..1 996 ·

- -~ · ......... ; . ~-- ... z_-

_indusuial proasses are :av:aibble;·ir is com~,~

puam-ely e:a5'Y m :apply specific SQ.UtCe scp:an·

tion cechniques to industrial \!o':IStCS. It is also

rebtivdy euy for regulatory :agencies to ~on­iror :and control indUStrial disch:arges.

d) BcgiMing :IE the peripherieS of ~red com­

munities whose: cenual m:am;enr &cilirles a.:e

alre:ad}· overloaded. install componiitg equip-

• menr designed m eonviri:' :all' human excm:a

to humus on-sire. This would intercept most

org:anic :and nutrient ·w:ane· m:ateri:als :It

their source, rhus :avoiding 'ihe ·problems

char:acteristiC of all effortS tO remove them

:aherw:ards.

.. -.. ...... On-site Separation and

rure. · The w:ashw:arer is used for irription of

trees, shrubs, and gardens around the dwelling.

in which process it Will'be'dcaDecf·b~i~p;;n :and

then replenish ground w:arer. -In this nutrienr·:­

cycling configur:ation, tod:ay's dam:aging path • ·

acmplified by sc:w:age c:re:ation .. cenual collection

and-tre:atment and .the result:anr production oi

sluclgc - c:an be avoided altogether;" ~ ~b--t~ n:~;~-~~i.·~·W.. 4-~!~-·

Such genuinely sustainable technologies should ....... . .. . . ... , ... -

be systema~cal!y supported ~y educ:ationltrain-

ing p_rogr:aD1m~~·- as ~ell :a~, by development money for mass installation, both for remedi:a-

tion and for new eonsrruaion.

~ ~ Getting the Price of.· (_1-_ ~, j: w~ Right ·· .,-,.: """'-r '- _,~ R ~ . -·

..._. ~ ,L_·---· _Resource ecovery · 'ii· -·~- ~.- - ·...:.·;. .:•·:: ....

~ , Tedmol9gies ~' _. Many technologies exist and have been in use

long enough to be wdl understoOd which repre·

sent ddinire improvements over either .cptic sys­

tems or pit latrines from the point of view of sus-

, "- Clwging the aue value of w:arcr will nea:ss:arily

rend m mala: more IUSC'inable tedmologies more

:attractive to governmenu :and.to industries

which now misuse w:uer simply bccwsc ir is so

cheap. The impon::ancc of such a policy shift is ICif<Yident. · ·· -- ~ - ~ -

i :~~,.;fi~t:~ w-<~ ::~. -~ ~,·= _·' -~-:-.:.: ::·:::-7-~--=::-:.-::.··;..:··:.;··:::;~::;:;:T:"';.:::.;~::::::~~Illl-

VA 22207, L(SA. --.:- ; ~,y_-~ •. 7 .~ ~ ,!l,..- ; Dr.-IWnt G-a-1 i16 ~ ~ rm-mn:fin' 20 JWITI ,;,· ~

IISf«l1 ttf Mw!Dpmm: f"1iet:# in Mw~Dpilft ctnDUries. H~ IMt ;.-lisJ.i ;,;_ th.m 20

'-h~7o~,~-~. _ .. ,.;;.,~,~·-•· ~n~p~ fo:ms. "~"· ir~z 117111 -•. ·"''~ .. ::.: • .,..., .. ,.,

~- H~·;;Pmuu;,,·ttf,;}~ Ast.d.~ ~~~~~~-~~(lAW 117111 tlx ;;,;:-~ ~tk-~ S«inJ ttf~ fM~~:·~----~ ~-~-, .. ·-.

liNE P-I ETC Newslener. Summer 1996

......

-~~.ot.J• ~ci:: .. ,,·::.·.,...-i .~ ... !.i~;~~f j!\.1~t.:i::~rt'V't~ From the poinr of •·iew of en•·ironmental sust;ain·

-.:-.--'4.-.u-. _.:;._; ~ til:J'.t&.."""-i:··~ :·.o ... :,!,.:~ ·:-.-to..--~ . ·:.. .. ,

abi!.~~·,..,a,~~::,n_~si~~~-ira_ti~~.s~-~~~~ is. bcnc:r .. th:an ccnrr:al collc:ction and treatment. This is

···•'\..-L ......... . ... # ,._,,_, •• ·- ·- F .......... ·- -

rrue even of rr:aditional and conventiollal on-sire:

systems such as pit latrines :and septic: s~·stc:ms

which c:an • and do • pollute. But ir is pn:cisel~·

beause they""Ue on-site th:ar their·remedi:ation

:and upgrade through repbcement with' non-pol­

luting. resource-recovery technologies is fe:asible.

And given that such remediation is -techniallr

possible to do now without ~y i~?g ~f the

quality oflife, there is no lcgitim:ate-re:aso~ why

this eou~-sh~d n~r be ~tiall~ p~~;ed . ..:L. - - ~. -~-· . ~

The technologies exist: the political ~ 't~--~ .

_ it happen mun be mobilized.

~ . . ..

~ -.

L

----·- --· ..... -.-, ... ---··-·-~-...,. .. -~.

'·

Managing Human Waste in Indonesia's Flooded Urban Areas (The On-site Option)

Table o'l Contents IN"fRODUCfJON ......................................... o.............. 1

Human Waste Management ··the On-Site Treatment Option ................... :.. 1 Background .......... , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Existing On-Site Systems in Indonesia's .................................... 2 Summary ........ ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

POLLUTANTS IN HUMAN WASTE AND THEIR IMPAcr ON HUMAN HEALTH AND ENVIRONMENT .....•• ~..... . • . • • . • • • • • • • . . • . . • . . • • • • • • • . • . • • • • 9 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Health Impact ... ·. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Environmental Impact .................................................. 13 Sununary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

FUNDAMENTALS OF WASTEWATER TREATMENT ..........•....••.•••• 18 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Physical Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Chemical Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Biological Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 The Processes and Stages in Wastewater Treatment .......................... 25 The Processes and Stages in Composting Systems ........................... 25 Sununary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

SUBSURFACE DISPOSAL OPTION ....•..•.......................•...... 37 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Sub-surface Treatment Mechanisms ....................................... 37 Soil Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Site Criteria and Space Requirements for Subsurface Adsorption . . . . . . . . . . . . . . . . 43 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

PILOT ON-SITE SYSTEl\1 ''CONSTRUCfED WETLANDS" ................. 47 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7 Design ....................... . J. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 50 Construction ........................................................ ~. 57 Findings ............................................................. 64

PILOT ON-SITE SYSTE:\1 "CASCADE CHANNEL" ........................ 65 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Design .............................................................. 66 Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Nlonitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 Findings ............................................................. 74

PILOT ON-SITE SYSTE:\l .. CONSTRUCTED WETLANDS ................... 76 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 TcchnolO!,'Y Options ................................................... 76 Recommendations . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

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INTRODUCTION

Hunran Waste ManagenJent ~~the On-Site Treatnrent Option"

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The World Bank Country Study for Indonesia on Environment and Development states that i) '"about two thirds of the public water supplies are·derived from increasingly polluted surface water'': ii) rivers arc polluted beyond the capacity of existing \Vater treatment plants: and iii) ''the lack of adequate sanitation facilities is a primary cause of fecal contamination of urban water supplies"(World Bank 1994).

~ c,_, I' ,t;.o-~ c:-

Thc Country Study focusf on drinking water cant mation Ua!S covers only a portion of the impact of inadequate sanitation to the environ ent and to human health. From the environmental perspective. the over nutrification surface waters kills life in the rivers. canals. and seas and fuels the gro,,1h of undesir le and sometimes deadly micro-organisms. From the health perspective. children and adultiwash daily in the nvcrs and canals adjacent to their homes: sometimes because there is no o'thcr option and sometimes Just for fun. Poorer communities arc especially affected since they tend to live in the lo\\cr lying Jrcas where the sewage from the town or city concentrates and because the: r;;h most on the water from the rivers and canals for bathing and washing.

The Country Study lists the management of human waste :~s a pnont' :md Cites the need to explore the least cost options for the expansion of sewerage and s.:mnauon scr. 1ccs. including in situ (on-site) and off-site ::1pproaches (World Bank 199-1) Se,,crcd SYStems ~may not be feasible everywhere. For example. sewers require r::-!.:llt\ ch large amounts of water to transport waste: therefore urban slums. ''hich typ,c:-~11: bd: ptpcd water to the homes. arc unable to connect to sewers. The Country Study mcludcs a recommendation lor increasing investments in poverty oriented progr:tms to tmpro,·e on-sttc sanitatiOn in urban slums 1 \Vorld Bank 1994 ). ./ / . v

6 Tt!'c?..-. => 7 ..,/' Ct-.?/ c. .

If on-sttc samtation is to be an option for human wast ~emcnt in I ndoncstan cities. the investments must include dcYcloping a better menu oR . Currently. on-sne treatment systems either discharge directly to surface \\·atcrs. to so aKa\\ a: systems. or at best. to septic t:mks with subsurface disposal. These systems pronde no real reltci" from the negati\·c impacts of human waste m Indonesia ·s flooded and cro\\dcd urban areas.

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Background The islands of Indonesia comprise less than two million square kilometers ofland.

Thirteen ofJndonesia"s 13.000 islands account for 97 percent of the total land mass. Figure 1-8 is an illustration of Indonesia· s main islands. The rest of Indonesia is classified as territorial seas inclusive of 2. 7 million square kilometers of enclosed marine waters, 0.4 million square kilometers of open ocean. and 1.5 million square kilometers of continental shelf waters. The length of coastline is estimated at about 80,800 kilometers. (Socgiarto & Polunin 1982) ·'-~

Figure 1-8: Map oflndoncsia ·s Islands and the two largcsL .;ontincntal <=helves.

Today nearly 200 million Indonesians arc densely packed into only I 000 out of the 13.000 islands. Because of the advantages of water transport. communities arc rooted on river banks and coastal areas. These settlements arc prone to seasonal or constant flooding and water saturated soils caused by a consistently wet climate. In fact the relative humidity oli.en exceeds XO percent 111 most months and monsoons pound the country for se,·cral months per year ( i\lullcr J 01>2 l

The urban population in Indonesia exceeds 55 million and is growing o\·er 5 percent per year. more than twice the o\·crall n:uional population gr0\\1h rate (World Bank KUDP SAR J 995) Though the govcmmcm and donor agencies finance masstvc infrastructure tmprovements to meet population demands. sanitation programs fail to keep up with development. The few sanitation programs that arc initiated promote technologies which cannot work m the crO\\ded and flooded environments m which they arc installed.

Existing On-Site Systems in Indonesia's

Human waste is a common site in rivers and canals in Indonesia ·s urban areas (Figure 1-2)" :\large number of homes m lndonesta arc b.;ilt on stilts abo\·e Hood pl:1ins. rivers. cJnals. lakes. and oceJns. In these homes. human waste discharges directly into the water bclo'' the home. Homes built on land hJ,·e non-functioning humJn \vaste disposal systems. These systems often discharge sewage eftlucm directly from the septic tank into nearby bodies of water.

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Figure 1-2: Rivers arc the community ·s dumping ground. Human feces float by the lower left comer. This is the same river people use for washing, bathing, and even brushing their teeth.

According to the World Bank Country Study, there are four significant problems with septic tanks in Indonesia (World Bank 1994):

I. septic tanks arc often never emptied: 2. septic tank effluents often discharge directly into channels and rivers:

. 3. on-site systcn1s disrcgnrd guidelines specifying \vhich t;;pcs of on-snc systems arc appropri:~tc for local populations densities. water intakes, soil permeability. and depths to the groundwater table: and -+ dcsludgmg services discharge waste directly into rivers and canals. possibly because of the um\iilingncss to pay the fcc for proper disposal.

The above points arc accurate. however. they imply that the solution lies in properly installing and m:untaining septic systems which discharge directly to the subsurface. According to guidelines mentioned in point number .3. subsurface discharge, in gcncr:~l. cannot \\ork tn lndoncsia·s urban environments because typically these flooded and cr~vded environments arc inappropriate for subsurface disposal.

:\!though Jttcmpts were made to identify functioning on-site sanitation systems. to date. none of the s~·stcrns found in Indonesia ·s crowded urban areas could possibly provide any noucc:~ble benctit to human health or the cn\'ironment. Some of the systems found arc shown in Figures 1-3 to 1-R. The structure in Figure 1-3 is simply a hole in the floor disch:~rgmg to the m crs below. The structure pictured in Figure 1-·t known as a \·crucal septic t::mk. is a \·crucal tubular tank with the effluent below the water level. In this system. the m·cr \Yater readily mixes with the sewage inside the tank thus resulting in no clTecttvc treatment. Additionally. sludge removal from the tank is vinually impossible.

... ·.-~- .. _-,;.~~~- ~-

Figure 1-3: Helicopter toilet (as nicknamed by the rndonesians) is th .. made of vertical wood slats. The waste shoots dire. !y dO\m to then the floor.

~cturc on the right ;.hrough a hole in

Fi~u re I -4: ( Le ll) V ertic::~J Septic Tank. Since the effluent is below the water lc\·eJ. there 1s no effective detention time in the t::~nk. Consequently. the water in the tank is the same as the \Yater in the river.

::-Another tank, d~veloped by CARE USA. is designed to discharge directly-to the nearest

drainage canal or waterway (Figure l-5). The system appears to use turbulence and velocio/ to break the waste up into finer particles. Data regarding the effectiveness of this system is' unavailable for this report, but there docs not appear to be any real treatment involved as evident by the short detention time in the tank and lack of sludge build up. The mixing may enhance the aesthetics of the. wastes (i.e. no ~oating feces) but the sewage still discharges into the drainage canals without treatment. CARE is installing these systems in Surabaya, · one of the more populated and flooded Indonesian cities. ,. ·

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1 ASA.IIGf-tl ....

- r·-~';';;;;;:-'1 . : > .. X'-...:,.t ~'.:; ..... , : ·-.... ~ .. _....

Figure 1-5: 1\n example of the CARE hox (!rom a CARE brochure). The box is small and solids reportedly do not accumulate. lt1s doubtful that this ~)Stem provides any real treatmc.:nt.

The present altemntivc to dischargmg sewage directly into a water way is almost always subsurt':lcc discharged into the soli Yin a soakaway or scpuc systems. Soakaway systems arc basically boxes or tanks without bottoms or with drainage holes in the sidewalls. A working septic system has a water tight tank ,\·ith a minimum of a one dny storage volume. The scpllc tank cmucnt discharges into the soil. typically by way of perforated pipes or sccpngc pit. The bottom or the pipe or pit must be at least one meter above the high wmcr lc\·cl (sec chapter 4 ). In Indonesia. septic tanks ollcn do not h:l\·c a one day detention time and ate often located below the water table. \Vhcn the effluent discharges below the water table. 11·atcr enters the tank anci Hushes the waste out before any treatment c:1n occur. S.:ptic tanks ~~r~ also trequcntly installed 11ith the diluent discharging directly to ri1·ers and canais or to seepage p1ts which arc generally 11oodcd.

The public tmlet shown 111 Figures 1-6 and 1-7 is a typical soaka,,·ay box. Tl:c tloor less oox sns d1rectly on top or the sod. In tidally t1oodcd areas. the box tills with water d;1ily as the udc goes m :md out. In seasonally !1oodcd areas the box mny only lill with water during the ra1m· season. Either scenario lacks ciTcctivcncss and poses a danger to public hc:1lth and

the environment Figure l-8 schematic:dly provides nn inside view of the soakaway box. As river or tidal water level rises outside the box, so does the water level on the inside. ·Pollutants easily leach out into the groundwater and surrounding surface waters.

Figure 1-6: (Top Left) The commun:~·· toilet in this picture ....... ...:;::: !h~ ·• ~--..: through 4 in PVC p1pe to a floor less soak away box .. Pollutants seep to the river water in the back ground.

Figure 1-7: (Bottom Left) The boardwalk to the communny toilet provides easy access for sw1mmmg.

~VENT PIPE: 1' DIAMffiR PVC ~ mENDED ABOVE THE ROOF UNt

Ri~~ ~

I I ~:.-

WOODEN BOX: THE SOX HAS ;-- ABOUT tn INCH CEMENT

PLA!lii ON THE OUTSIDE.

Figure 1-8: Cross section of the lloor less box. !Dra\\n bv Gr~g ~loor~ :md Diannd lug.h~s1

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SunJIJ"'ary Water pollution c:1uscd by untrc:Jtcd domestic sewage is a significmu environmental :llld

he:1lth problem in Indonesi:1. Addressing this problem in areas with flooded conditions, in high density areas poses speci:1l challenges. Local sanitation solutions do not work under :lilY of these circwnst:lllces. L:1ck of effective sanitation negatively impacts the health and environment of the community. Poorer communities are especially affected since they tend to live in the lower lying areas where the sewage from the to\m or city concentrates :llld because· they rely on water from the rivers :llld canals· for bathing :llld washing.

Based on the types of wastewater technologies installed in Indonesia. there seems to be a considerable amount of misunderst:lllding as to which types of systems work. Although sanitation may not yet be a priority for the Government oflndoncsia. considerable amounts of money have been expended to purchase numerous types of"low cost" c:vstcms. Most systems arc constructed without any scientific basis and no evidence~ ..•. .- Jbilitv to trc wastewater. The majority. if not all the systems installed, discharge ..!ntrentcd wastcw<ucr dircctiy to the subsurface or receiving water.

If on-site systems arc to be 3 viable option for human waste m:lllagcment. better efforts arc required to develop functioning on-site systems. Towards that goal. greater understanding is needed as to why waste treatment is import:lllt. what the fundament3ls o:· waste treatment entails, how and when to properly design on-site systems which discharge primary effiuent to the soils. :llld how to go about developing potential alternatives to sub­surface discharge systems.

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POLLUTANTS IN HUMAN WASTE AND THEIR IMPACT ON HUMAN HE"LTH AND ENVIRONMENT

Introduction The World Resource Institute estimate that 75 percent of all illnesses and 80 percent

of child mortality cases worldwide are associated with poor sanitation (WRI 1994). Water pollution is cited as the most widespread environmental problem in Asia with domestic sewage as the primary pollutant. especially around large urban areas (Carter & Ramancutty

Figure 2-2: Hand dug shallow well. The small rooms in th!! background arc toilets which discharge Jircctly into the soil.

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1993). Sewage produces noxious odors, accelerates eutrophication, and chokes the water ways of their natural aquatic life by depleting available oxygen. In spite of overwhelming evidence that poor and nonexistent sanitation is an international dilemma with millions of children dying of water born diseases, financing concentrates on tasks such as greenhouse computer projections (Eastbrook 1995).

In Indonesia, like many Asian countries. large quantities of sewage are found in the ground water, drainage canals, and rivers where the people live. Most lower income residences lack the luxury of indoor plumbing relying instead on shallow wells adjacent to the home tor wash water supply. Those who live on the river usc the river water for bathing and washing. Figures 2-1 and 2-2

Figure 2-2: Bathing water from river.

depict typical wash water wells and river water usage. Figure 2-3 shows some visible wastes products found in these waters.

Figure 2-3: Contaminated river water. Feces tloat by on the left.

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Health lnJpacl

OVerview Human waste is a habitat for a wide variety of disease causing pathogens which live on

and bring damage to a host (Brocket al.l994). Pathogens are generally categorized as viruses, bacteria, protozoa, and helminths. For all pathogens, quantity of infection (i.e. the number of pathogenic sp~ies present) is a primary factor in dctennining the seriousness of a

·disease.

Human waste is the principal source of a variety of communicable diseases. They primarily attack those living in impoverished areas with potentially lethal consequences, especially to the young (Feachem et all983). Diarrhea, for example, was listed as the number one cause of death for infants and children between the ages of one and four in Indonesia (Ministry of Health 1991 ). Several epidemiological studies have documented the risks of acute gastroenteritis from bathing in contaminated water. One study showed the risks to be three times greater for children under the age_ of two, who immerse their heads in water. than for adults (NRC 1993). As this section will show, the pathogens in human waste not only cause gastrointestinal diseases but also many respiratory diseases, skin diseases, meningitis, fever, encephalitis, eye infections, polio, and anemia. These diseases are typically not associated with poor sanitation .

VIruses Viruses arc incomplete organisms \Vhich cannot metabolize new ceiKs without the host

cell. Their tiny structure enables them to perform only those functions that cannot be adapted from their hosts. The extracellular fonn of many viruses enables them to replicate themselves in a way that is destructive to the host cell. The result is a viral infection (Brock -1994). In humans. many waterborne viruses infect the intestinal tract and can be passed on in the feces. A single gram ofhuman feces may contain 109 infectious virus panicles, even though the individual has no s~mptoms (Feachem ct al 1983). Virus types and their associated illnesses arc sho\m in Table 2-1.

Table 2-1: Viruses Found in Human Waste Virus Diseases or Svmptoms

Poliovu1ts Poliomyelitis. meningitis, fever

Coxsackie vit1lS A Hei1Jangina, respiratory disease, meningitis, fever

Coxsackie ~·irus B Myocarditis, congenital heart anomalies, meningitis, respiratory disease, pleurodynia, rash, fever

Echovims Meningitis, respiratory disease. rash. diarrhea, fever

New emerovintses Meningitis. encephalitis, respiratory disease, acute hemorrhagic conjunctivitis, fever

Adenov1111S Respiratory disease. eye infections

Reovi111S Found with \'a.rious diseases but the \'irallink is not clearly established.

Rotovi111s Vomiting and diarrhea

Astrovims Unkn0\\11

C alcivims Vomiting and diarrhea

C OI"OilQVl11/S Common cold

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Virus Diseases or Symptoms

Norwalk: agent and Vomiting and diarrhea small round viruses

adapted from Fcachcm ct all983 and Polprascn 1979.

Bacteria Bacteria are complete organisms with all the machinery necessary to metabolize new

cells (i.e. function and reproduce independently}. Bacteria in human feces are typically mutualistic and cohabit well with the hosC On occasion, some bacteria, listed in Table 2-2, may cause disease. Diarrhea is a major symptom of many bacterial intestinal infections. The bacteria may also cause generalized or localized infection, such as typhoid from the Salmonella bacteria (Feachem et al 1983).

Table 2-2· Bacteria Found in Human Waste . Bacteria Diseases or Symptoms

Camp(vobacter

Escherichia coli Diarrhea

Lept.spira Salmonella Typhoid fever, gastroenteritis, septicemia ·

Shigella Bacterial dysentery (Bloody dysentery)

Vibro cholerae Cholera

Tersinio adapted from Fcachcm ct al 1983 and Polprasert 1979.

Protozoa Protozoa are unicellular eukaryotic microorganisms that lack cell walls. Protozoa arc

important predators of other pathogens found in soils and water (Metcalf & Eddy 1991 ). They usually obtain food by ingesting other organisms or organic particles (Brock ct al 1994). Several species of protozoa can infect humans and cause disease. Among them are several species that inhabit the intestinal tract. Only the four species listed in Table 2-3 arc considered to be frequently pathogenic (Feachcm ct al 1983).

Table 2-3: Protozoa Found in Human Waste Protozoa Diseases or Svmptoms

Balamidium coli Dysentery, intestinal ulcers Crypto sporidium Diarrh..:a

Entamoeha h_-.·sto~•·tica Amoebic dysentery, infections of other org:ms Giardia Diarrhea (intestinal parasite)

adapted from Fcachcm ct al !9lD. Polprascn !979. and Metcalf & Eddy 1991.

Helminths Helminths arc parasitic worms. some of which can cause serious illnesses. Table 2--+

lists the pathogenic helminths. Schistosoma haematobium is the only helminth voided in the urine. Helminths do not multiply within the human host as do other parasites. instead eggs arc excreted in the feces. Worm burdens and level of egg output arc not evenly or randomly distnbuted among their human hosts. Within any sex and age group of an infected community there will be a lew people carrying the lions share of the worms while others only carry a Jew (Fcachcm el all 1983).

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Table 2-4· Helminths Found in Hwnan Waste . Helminth Diseases or Symptoms

Ancylostoma, Necator, HooJ..:worm (infection of the small intestine). anaemia. and Ancylostomiasis - --

Ascaris Ascariasis (roundworm) Clonorchis Livert1uke

Diphyllobothrium Broad fish tapeworm- abdominal pain, loss of weight. vomiting -· ---iintei-obius Disturbed sleep, catarrhal mflammatio0: vomiting, nauseii. diarrhea

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- ~ ·- Fasciola 1nfection of the bile ducts, dyspepsia, nausea, vomiting fever,liver enlargement

Fasciolopsis Intestinal obstruction, nausea, diarrhea, fever, abdominal pains Hymenolepis and Tapeworm, abdominal pain, diarrhea, dizziness

Hymenolepis

Paragonimus Chest pains, dyspnea, bronchitis, meningitis Schistosoma Schistosomiasis or bilharziasis

Strongyloides Nematode worm, diarrhea, abdominal discomfort. recurrent respiratory Taenia Beef or Pork tapeworm - cysticercosis causes a severe somatic diseases

of different organ tissues where encystment may occur. Most common in muscles. brain and heart.

Trichuris Whipworm - bloody diarrhea Minor Intestinal Flukes Nausea. diarrhea. fever. abdominal pain

adapted 1rom Fcachcm ct al 1983 and Polprascrt 1979

Environmental Impact

Overview In addition to pathogens, human waste contains environmental contaminants which

cause objectionable odors and fuel the grov.th of microorganisms which arc the primary cause of eutrophication in surface waters. Some microorganisms Though often not thought of as a serious pollutant. when compared to heavy metals or other industrial pollutants, the impact to the environment is generally more devastating, world wide, than any other pollutant. The parameters listed in Table 2-5 fonn the clements and compounds which create objectionable states in the environment.

Table 2-5: Dailv Excreted Elements in Human Waste J minimum grams j

Dry wctg.ht 80.00

organic matter

Nitrogen (N)

Phosphorus as (P p,) Carbon ·c: BOD (Feachcm ct al 1983)

Odors

72.90

9.00

2.15

18.70

25.00

maximum grams 130.00

15.40

17.50

6.74

44.30

30.00

Odors arc the result of the microbial decomposition of the organics and nutrients in raw wastewater. During the decomposition process. compounds of nitrogen. sulphur. and

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organics form and produce distinctively foul odors. Ironically, fresh wastewater, though some what objectionable, is less odoriferous than partially treated wastewater. Septic tanks, for example, produce hydrogen sulfides (rotten egg odor) by reducing sulfate to sulfide under anaerobic conditions. The compounds associated with odors are described in Table 2-6 below.

Figure 2-6: Odor producing compounds in wastewater. Name Compound of Odor

Amincs Nitrogen Fishy Ammonia Diamines Hydrogen Sulfide Mercaptans Mercaptans Organic sulfide Skatole

(Metcalf and Edd~· 1991 ).

Nitrogen Nitrogen Sulphur Sulphur Sulphur Sulphur Organics

Ammonia smell Rotten flesh Rotten eggs Rotten Cabbage (.:.g.. methyl&. ethyl>

Sl"Ullk c.:.g.. t-butly & c:rotyl.:>

Rotten cabbage Feces

Odors arc more a psychological problem than a direct health risk. They can cause poor appetite. nausea, vomiting, and impaired respiration. The impact often extends into economic problems like declining tourism or real estate values. Odors warn against swimming in polluted waters and provide inhabitants with a major incentive to develop a sanitation program. Unfortunately, it is possible to remove or prevent odors without removing the more devastating health and environmental contaminants. Consequently, preventing odors psychologically eliminates a major incentive for developing good sanitation programs. Also, when odors are reduced, there is nothing to prevent children from swimming in contaminated waters.

Figure 2-5: Children s\vimrning in highly polluted waters. The rains m<lkc the water smell better but the pathogens arc still just as dangerous.

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.. . Nutrient ·Enrichment o' Waters Overview

Nutrient enrichment of waters causes massive algal blooms (Smith 1992). Algal blooms have two impacts, i) the over abundance of algae leads to oxygen depletion and ii) some algae are toxic to the environment and can cause fish kills (Day et all989).

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Oxygen Depletion Oxygen levels indicate the health of waters. Healthy waters generally have dissolved

-oxygen levels of at least 5 mg/1 throughout the year. Over nutrification lowers dissolved oxygen levels causing hypoxia (dissolved oxygen levels less than 2 mg/1) and/or anoxia (no dissolved ox-ygen). These conditions need not last long to cause fish kills. It would be like asking a fish to hold its breath until enough oxygen returned to the water. The loss of resources can be staggering.

0~-ygen depletion occurs when the oxygen is consumed faster than it can be formed. Oxygen sources to the aquatic environment have two primary pathways: i) atmospheric diffusion - the transfer of oxygen from the air at the air-water interface (or surface); and ii) photosynthesis - the conversion of carbon dioxide into oxygen by chlorophyll containing organisms such as plants. Conversely, oxygen is depleted due to oxygen demand (particularly by microorganisms), turbidity, and siltation.

Figure 2-6: Human waste contains organics and nutrients which cause algal blooms; As the algae die. aerobic microorganisms consume them and deplete the dissolved o:-.:ygen in the water. Dead algae and microorganisms sink to the bottom thus increasing siltation and preventing light trom reaching aquatic plants. The plants, deprived of light tor photosyntheses. die. As the plants die so do the tish, crustaceans. plankton, and other o:-.:ygen consuming creatures.

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Oxygen demand is the oxyge~n required for the chemical reactions, which are primarily biochemical, to occur in water. Microorganism use oxygen to produce energy and metabolize new cells. These organisms are fueled by dead algae whic!t are fueled by the over

· nutrification of the water. Although algae produces oxygen during photosynthesis, as the algae die, they sink to the bottom and as they sink, oxygen consuming bacteria feed on them. Algal blooms not only cover the surface, thus preventing the transfer of oxygen from the air at the surface, they also block the light to submerged aquatic plants which produce oxygen through photosynthesis .

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Siltation and turbidity also block light and inhibit plant growth. Turbidity is the measurement of light passing through the water. As the dead algae sink, the level of colloidal solids increases and thus turbidity increases. Siltation is the settling of solids, both from the solids in the waste and the additional solids created by the continually fonning and dying algae and microorganisms. Settling material cover submerged plants further blocking light. Turbidity and siltation especially impact the bottom dwelling animals who rely more heavily on the oxygen created by the submerged plants than surface diffusion. Algal blooms and silted canals are quite common in Indonesia. Figure 2-7 shows a typical algal bloom in a drainage canal fueled by the carbon. nitrogen, and ph~sphorus from human waste.

Figure l-7: Algal bloom in a typical drainage canal in Banjarmasin.

Toxic Algal Blooms Various aquatic microorganisms produce chemical toxins which can c:lUse disease to

humans and other aquatic species. The main culprits arc dinoflagellates. diatoms. and cyanobactcna. Dinol1agcllates and diatoms arc species of algae. Cyanobacteria is actually a kind of bacteria though it is commonly knO\m as blue green algae. Aerosols caused by blooms of dinotlagcllatcs can cause throat irritation (Barnes and Mann 199!), Table 2-7 shows some of the toxms produced by some aquatic microorganism.

16

Ta bl 2 7 s e - orne kn od db uce own toxmspr v aquatic m1croorgarusms.

Toxin.--·-~'_:,~'.:;~ -·Description·

Diarrhetic Dinoflagellates(i.e. Dinophysis and Protocentrum) can cause Shellfish symptoms similar to those after eating a spoiled mussel (Barnes and Poison (DSP) Mann 1991). c .....

Sa.xitoxine This new:otoxin is associated with red tides caused by high . ;.·

concentrations of accessory pigments, other than chlorophyll a. caused by large concentrations of diatoms and Dinoflagellates. The ,..'.,..r_

- symptoms of this toxin include numbness _and loss of sensation sometimes paralysis of the diaphragm resulting in respiratory failure -·· .. (Barnes and Mann 1991).

DomoicAcid Diatoms (Nitzschia pun gens) have been found with high levels of this neurotoxin and mussels feeding on this algae are believed to have high enough levels of toxins to cause illness and death to humans consuming contaminated mussels (Barnes and Mann 1991 ).

Brevetoxin Dinoflagellates (Ptychodiscus brevis) is also a red tide organism has been known to causes fish kills (Barnes and Mann 1991).

Neurotoxin Cyanobacteria have been know to produce neurotoxin and animals ingesting the water can become ill and die. (Brock ct al 1994)

Summary

The pollutants found in human waste severely impact the health and environment of the adjacent community as well as communities dO\m stream. The pollutants. grouped as pathogens and nutrients, affect lower income residents most because they tend to live in low lying areas where the pollutants concentrate and because they depend more on the rivers and canals for bathing and washing. Though the health impacts are usually associated w1th common diarrhea or gastrointestinal diseases. human feces carry pathogens which produce a wide variety of symptoms. The impact to the environment include odor production. oxygen depletion, and the production of toxic microorganisms. Managing these pollutants requires a good understanding of the fundamentals ofhuman waste treaunent.

17

--- ..... ·--·

3-.. ..

FUNDAMENTALS OF HUMAN WASTE TRE4TMENT

Introduction

•··

Waste trcauncnt refers to i) the reduction, removal. or recycling of organic and nutrient content: and ii) the removal or inactivation of pathogenic microorganisms and parasites found in human waste as defined in chapter 2. For treauncnt to occur, waste must undergo certain physical, chemical, and biological processes in various stages. The stages of treaunent depend on the type of waste treated. Traditionally, water is added to waste to facilitate off-site transport. This type of waste is referred to as wastewater. Once the waste reaches a wastewater treaunent facility, tremendous energy is expended to remove the waste from the water. On-site systems do not require off-site transport so addir.; water is an option. Dry human waste exists in the simplest form and is often referred to as compost. Since compost contains no additional water from flushing, no energy is required to separate the water from the waste.

Treating wastewater is very different than treating compost though some of the physical. chemical, and biological process arc similar. Wastewater trcauncnt. as previously mentioned. is much more complex. A typic:li wastewater treatment system requires multiple stages (i.e. settling system. filters. mixing tanks. disinfection. and sludge removal). Some natural on-site waste systems may be Jess complex. For example, wetlands arc relatively simple systems which can \\ithstand a wide range of environmental conditions and still function. Water adds tremendous volume to waste and the various physical. chemical and biological processes generate sludge which must also be treated. Composting is much simpler and often involves only one tank or possibly a series of tanks to allo\v one tank to sit while the other is being used. Mechanical aeration and heating devices can increase efficiencies but arc usually optionaL Both systems require at least some maintenance and monitoring of the environments within the system.

Physical Processes Physical processes occur at every stage of treatment in some form. Waste has physical

propenics such a panicle size. weight. and shape. Physical processes take advantage of the vanous physical characteristics of the waste to remove or separate particles in the waste. Many physical processes also facilitate biological and chemical processes by mixing or breaking the \\"aste panicles into sizes that the microorganisms or chemicals can react with.

18

On-site systems use relatively simple physical mechanisms since the cost of complex systems would be too expensive for individual homes or clusters of homes to afford Below are some examples of physical mechanisms.

Table 3-l · Phvsical Mechanisms in Waste Treatment . .

Mechanism Type ofWaste Process

Screening wastewater In wastewater systems, screens or barriers, such as a series of parallel bars or woven meshes, prevent large

- particles from passing but allow wastewater to ·pass.

Grinding wastewater/ Grinders shred coarse solids to a uniform size. This is compost common in wastewater systems. Bulking agents in

composting systems are often shredded to match the size of the particles in the compost.

Mixing wastewater/ Mixing allows chemical, gases, microorganisms, and compost suspended solids to remain in suspension so that they

can react In compost, the compost pile can be mixed to increase the amount of o~'}'gen in the pile and to distribute the mix evenly throughout the tank.

Flocculation wastewater Small suspended particles combine to form larger heavier particles which settle out.

Sedimentation wastewater Tanks provide a quiescent state which allow settleable solids to sink due to gravity.

Filtration wastewater Filters are smaller meshes than screens but perform similar functions. Filters physically stop fine particles

-from passing.

Temperature wastewater/ Temperature control ensures more efficient usc of Control compost microbes and chemicals which react best in certam

temperature ranges. High temperatures (i.e. from boiling) can effectively kill pathogens.

0:\.-ygen wastewater/ Physical addition of o:\.·-ygen (usually via pumping) addition compost ensures more efficient usc of microbes which react best

in high O:\.~·gcn environments.

Chemical Processes

Chemical processes involve the addition of chemicals to waste to enhance treatment. Adding chemicals is less cost effective than physical and biological processes and, as a result. not common in on-site systems. Soils sometimes contain chemicals such as clay or lime which naturally cause chemical processes to occur. In composting systems. ash or other chemicals are added after each usc to enhance the compost process. The three main chemical processes used in treating waste include disinfection, precipitation. and adsorption.

Chemicnl Disinfection selectively destroys harmful pathogens. Chlorine. bromine.

19

iodine, ozone, phenol and phenolic compounds, alcohols, heavy metals and related compounds, dyes, soaps and synthetic detergents, quaternary ammonium compounds,

· ·hydrogen peroxide, and various alkalies and acids have been used as disinfectants. Chlorine and other oxidizing compounds inhibit enzyme activity by altering the chemical arrangement of enzymes and deactivating enzymes. Acidic or alkaline agents alter the colloidal nature of

~. a cells protoplasm and denature proteins. DetergentS-alter the penneability of the cytoplasmic membrane until the cells can r,o longer select which clements pass through their cell wall. Yital ~utrients (i.e. nitrogen and phosphorus) escape. (Metcalf & Eddy, 1991)

-Ch~cals can be dangerous· to handle, difficult to control, and most are highly corrosive. Chlorine, and other oxidizing chemicals, may also mix with organics to fonn dangerous compounds. (Metcalf & Eddy, 1991)

Cbemjca! Precipitation is the use chemicals (i.e. alum, ferric chloride, ferric sulfate, ferrous sulfate, and lime) to fonn floes to settle out the dissolved and suspended solids. The chemicals react with the solids which begin sticking to each other to fonn floes. These floes eventually become heavier than the water and sink. Multivalent metal ions (i.e. calcium, aluminum. and iron) fonn precipitates with soluble phosphates. (Metcalf & Eddy, 1991) Chemical precipitation is not common for on-site systems. Not only do precipitation systems require constant chemical inputs, they also generate large volumes of sludge.

Chemical Adsorption is the attraction of waste elements to a chemical caused by the polarity in their charges. Activated carbon is a common wastewater adsorption process used to remove organics from wastewater. The process occurs in three steps; (i) macro transport (the movement of material through water to the liquid solid interface by advection and diffusion: (ii) micro transport (the diffusion of the organic material to the site) and (iii) sorption (the attachment of the organic material to the activated carbon). Phosphorus is also commonly removed by adsorption processes. (Novotny & Olem, 1995)

Biological Processes

Overview-Biological systems arc designed to create specific environments to !,'!"Ow mtcroorg:umms

and/or higher level species with specific functions. All biological organisms arc conglomerates of mainly carbon (C), hydrogen (H), oxygen (0), and nitrogen (N) Nutrients such as phosphorus. sulphur. sodium. calcium. and iron also play a role in cell metaboltsm Biological organisms derive all their nutrients from the surrounding environment A shonagc of any of these clements would limit their metabolic gro\\'th.

W astcwatcr contains the C. H. 0, N and many of the other nutrients reqwrcd by mtcrobes, plants. and animals. It is the unique combination of the specific organic and nutncnt constituents in wastewater along with oxidation processes that allow b10logical organtsms to grow and. in the process. break do\\n pollutants and mactivate pathogens.

Microbial Metabolism Microbial metabolism is the reduction of carbon in a low entropy cnnronment. This

me::ms in order to reproduce and maintain cell functions. a constant supply of encq;y is rcqutrcd. Energy is produced by oxidation and reduction (redox) reactions which is the

20

transfer of electrons or protons between chemical compounds. Oxidation removes electrons from a substance and reduction accepts electrons. There are three basic types of metabolism; fermentation, aerobic respiration, and anaerobic respiration. All three types of metabolism undergo redox reactions and have an electron donor and an electron acceptor as sho\\n in Table 3-3. Energy capture indicates the metabolic efficiency of a particular process. High energy capture breaks do'Mt waste more efficiently but, because more cells are produced, more sludge is generated.

Table 3-3: The three metabolic processes found in secondary and tertiary treatment of .wastewater

Metabolic Process electron electron acceptor Energy Sludge/ donor (accepts electron) Capture Cell (gives up Production electron)

Aerobic Respiration Waste or 0 2 (BOD Reduction and Most Most (oxygen present) inorganic Nitrification)

substances

Anaerobic Waste or N03 (Denitrification) ' I I

Respiration inorganic 504 (Sulfate Reduction) i i (void of o:.:ygc:n but

substances CO: (Methanogenesis)

~ ~

oxygen compound present)

Fermentation (void of Waste Waste Least Least oxygen & oxygen compounds)

Aerobic respiration is an oxidation process which occurs in the presence of 0:. Anaerobic respiration occurs in the presence ofN03, 504, or CO:. Aerobic respiration yields the highest energy which results in higher cell production (thus more sludge generation) and more complete decomposition of the waste. During respiration, complex carbohydrates in waste arc broken dO\m into a simple sugar such as glucose. Glucose is highly soluble, dissolves easily, and is easily accessible to microorganisms.

Fermentation occurs in the absence of oxygen and favors slow growing microorganisms which means the retention time is long compared to aerobic systems (Metcolf & Eddy 1991 ). Anaerobic digesters, an example of fermentation. usc a consortia of microbes. It takes four groups ofbacteria in a series of transformations to digest the waste (Bitton 1994). Each process is important because they creote the right environment (pH. temperature, and food) for the subsequent bacteria.

Group 1 (Hydrolytic Bacteria)- These bacteria break dO\m complex organic molecules such as proteins. cellulose, lignin. and lipids into soluble amino acids, glucose. fatty acids and glycerol. These molecules arc difficult to digest for most other organisms. Hydrol!tic Bacteria arc able to break them do\m and excrete simpler molecules. Group 2 (Fermentative acidogenic bacteria)- These are essentially acid producing bacteria. They convert sugars, amino acids, and fatty acids produced by the hydrol!1ic bacteria to organic acids. These acid producing bacteria \vork quickly. The acid changes the pH of the mixture to a more acidic state. Group 3 (Acetogenic Bacteria)- Acctogcnics produce acetate. hydrogen, and carbon

21

dioxide by consuming the fatty acids and alcohols produced by acid producers. Group 4 (Methanogens) - Methanogens produce methane from acetate and carbon dioxide. -·

Fermentation, aerobic respiration, and anaerobic respiration processes transform wastewater into carbon dioxide (CO:J, methane (CH4), new cells, and, depending on the level of treaunent, various fonns of nitrogen and phosphorus. During these processes carbon. nitrogen, and phosphorus are removed.

Carbon Removal A sample anaerobic process is as follows:

Complex Carbohydrates----->Simple--->Giucose ->Reaction->C02 + H20 or Wastewater or (COHNs) Sugars Intermediate CH4+H20

An aerobic process might be as follows (Metcalf & Eddy 1991 ): COHNs + 0: +nutrients --bacteria-->CO: + NH3 +new cells +end products

. The .. new cells'' created eventually die and, along with the wastewater, become the CORNs (Carbon, Oxygen, Hydrogen, and Nitrogen) for the next set of reactions. The cannibalisw:: bacteria feed on their dead cousins and consume more O~')'gen and nutrients.

Nitrogen Removal 1. Deaminatjon - The breakdown of amino acids to fonn ammonia (NH3) or ammonium (NH4) This occurs almost instantly after leaving a person and requires no special treaunent facility. (EPA, Nitrogen manual 1993).

2. Nitrification - The oxidation of ammonia to nitrate. The two bacteria involved in nitrification, nitrosomonas and nitrobacter, use inorganic carbon (CO:) as their source of cellular carbon as apposed to the organic carbon in wastewater. The transformation reactions usually proceed rapidly if enough O~')'gen is present. Because the bacteria used to reduce BOD out competes the nitrifying bacteria. BOD levels must be below 30 mg/1 for nitrifying bacteria to survive. The nitrate form of nitrogen is the best form to promote plant growth (EPA, Nitrogen manual 1993).

The process of converting ammonium (NH4 ·) to nitrate (N03 4") is as follo\vs:

(nitrosomonas)

NH4 • + 3/: 0: ---nitrite-fanning bacteria---> NO/" + H:O

( nitrobacter)

NO: J. + \12 0: ---nitrate-forming bacteria---> N03 4"

NH 3- + 2 0: ----------------------------------> N034 •. + H:O

For each mole of ammonia it takes two moles of oxygen to form Nitrate.

3. Denitrification - Microbially mediated process which converts nitrate (used as the electron acceptor) to nitrogen gas. Nitrogen gas is essentially inert and abundant in the atmosphere. Denitrification occurs in the absence of O~')'gen. If O~')·gen is present, the bacteria will prefer oxygen (0:) rather that nitrate (N03) in the oxidation process. Thus. for denitrification to proceed, anoxic (without O~')·gen) conditions must prevail. During the

22

nitrification process organic carbon must not be present, however in the denitrification process, organic carbon is essential (EPA, Nitrogen manual 1993). This often means adding carbon during denitrification processes. Adding carbon later in the treatment process poses special problems because in a single pass or non-recirculating wastewater treatment system, the organic carbon in wastewater is consumed before the nitrification process (carbon dioxide (CO:) becomes the carbon source). Suddenly, organic carbon is required for denitrification to occur but none exists. Since denitrification is at the end of the treatment process, conventional systems recirculate the nitrified waste back to the beginning of the waste stream where an abundant supply of organic carbon exist There are creative ways of

- adding organic carbon to a denitrification process without recirculating. Growing plants, for example, provide a source of organic carbon in the litter. Potentially, organic filters such as composted waste high in organic carbon might also supply a pathogen free anaerobic environment suitable for denitrification.

N03 - + organic carbon --> N02 +organic carbon -> N: (gas) +carbon dioxide and water

Phosphorus Removal Biological phosphorus removal uses phosphorus in alternating anaerobic-aerobic

contacting which results in competitive substrate utilization and the natural selection of phosphorus-storing microorganisms. In other words, by varying the oxic and anoxic conditions, a particular short, plump rod shaped bacteria belonging to the Acinetobacter genus, tends to gorge on phosphorus. The bacteria consumes more than it needs for metabolism. Studies have shown that the anaerobic phase was necessary to produce simple carbohydrates such as ethanol, acetate, and succinate which serves as a carbon sources for these bacteria. (EPA, Phosphorus Removal 1987)

Factors in the Removal Process There arc many factors necessary for treatment to run smoothly. Some of the main

factors include temperature and pH, chemical composition of the waste, and retention time.

Temperature and pH- In general, optimal growth occurs w-ithin a nJJTow range of temperature and pH. The constant wann temperature in the tropics fJ\Ors htg.h gro\\th rates throughout the year. Based on temperature. treatment effictenctes \\ Jllltkcly be greater in Indonesia than in colder climates.

Chemical composition of waste - Often wastewntcr in developing countries ts considered strong or high in carbon than in developed countries, perhaps because of the high c:ll"bohydrnte diets and lower water content. The carbon to nitrogen r::~tio is also extremely important when considering which process is most suitable. If nitrogen is limited. desirable organisms may not sun·ive and other less favorable organisms might take over. An example of less desirable organisms arc sulfide producing bacteria which producers of the rotten egg odor.

Retention time - Retention time is the time allowed for microorganisms to mature and consume \\aste. Microbes might take five days to mature. they would then require an additional amount of time to utilize the nutrients and organics in the waste for thetr metabolic grO\\th. Unless ample time is given. the microbes simply wash out with the \Vater without transfonning the waste. The maturation pcnod can be optimized by providing a site for mature cells to attach (as in a filtration process or by recycling

23

mature cells back into the system). Cells grow very quickly in aerobic processes whereas anaerobic processes are slow. The retention time in an anaerobic digester can be up to 25 days. · · ..

L .··::.~

Microbial treatment can b~ difficult to control because any ch~ge in the above factors can throw the whole system out of balance. An out of balance system might favor problematic bacteria which would interfere with the treatment process.

Plants· and Animals __ _ EcOsystems, have a natural assimilative capacity to treat the pollutants found in human

waste. Plants and animals play an important role in these environments and, depending on the type of ecOsystem, aid in managing human waste by:

1. proyjdini: sites on which microbes mw Plant roots and other plant parts, when submerged in wastewater, provide a site for microbes to attach. These microbes contently wait for organics and nutrients to pass by. Microorganisms exploit the roots of hydroponic systems. ponds with floating plants such as duck-weed and hyacinths, and wetland plants. Microbes also attach to exposed plant parts.in surface flow wetland systems and agricultural systems. Since·microbes grow proliferously, they can very quickly transform waste;

u. actin~ as filter Filtration is a physical proc=~-c;. The filtration capacity of plants effectively reduce waste by filtering larger par:1cles through root systems and stems;

111. encouragjn~ sedimentation The same roots and stems slow the flow creating a quiescent state thus encouraging sedimentation. This is also a physical process;

IV. utilizing organics and nutrients Plants and animals uptake organics and nutrients. Plants require frequent harvesting or the system may reach capacity and begin releasing nutrients to the environment. Animals at all levels, consume plants. thus ensuring the demand for nutrient uptake by the plants. Worms, snails, and other small organisms break down waste and make the organics and nutrients available to plants and microorganism:

v. Up takin~; mctnls. Wetlands and land treatment systems have demonstrated excellent capacity in uptaking metals. Most metals like copper. zinc, and nickel would kill the plant before it becomes a health risk. Cadmium. however, can accumulate in mnny plants with toxic effect to the plant and may represent health risks (Reed et al 199 5 ); and

v1. Consuming pmho~;cns Protozoans and other small organisms arc predators to pathogens.

24

The Processes and Stages in WasteiiVater · Systems

Introduction Treating wastewater involves the removal, or reduction, of various environmental

pollutants and pathogens in ihe wastewater and the treaunent and disposal of the sludge generated. Wastewater systems create a series of environments where various physical,

··chemical, and biological process work to convert the waste into hannless byproducts. The changing environments and long detention times can effectively reduce pathogens. Disinfection chemicals and ultra-violet light can also kill pathogens. Finally, sludge treatment and disposal is complex. For on-site systems, the treatment traditionally requires frequent pumping of sludge out of septic tanks and transportation to an otT-site treatment facility.

WasteJNater Treatment Wastewater treatment occurs at multiple stages. Each stage creates a different

environments where different physical, biologicaL and chemical conditions exist or arc made to exist, as described in the earlier part of this chapter. These conditions allow for such. activities as settling, mixing, and the existence of different consortiums of microorganisms. The stages of treatment are conventionally classified as primary, secondary, and tertiary. Stages of treatment arc sequential (primary comes before secondary) and each stage represents different levels of investment.

Primary treatment removes a large percent of the settleable and floatable solids thus preparing the waste for secondary processes which arc more sensitive to fluctuations in the influent. Primary treatment is considered the first line of defense in wastewater treatment and can reduce suspended solids and BOD loading on do\mstrcarn processes by as much as 50 percent or more (Metcalf & Eddy 1991 ). This initial reduction results in lower o"'--ygen demand dO\\nstrcarn and smaller secondary systems. Scum removal during primary treatment protects downstream processes by preventing the buildup of scum on equipment. Since secondary systems arc typically more expensive. the cost of primary systems ultimately results in a lower overall cost of a treatment facility.

Although primary treatment is high!}· recommended for most treatment facilities. the ''Living System·· pioneered by John Todd of Ocean Arks docs not usc primary treatment.. Instead the waste is blended by fine bubble aeration to keep the solids in suspension and available for biological brcakdo\m by plants and animals. The aquatic system claims five to

40 percent less sludge production (Farrell 1996).

Secondary treatment is directed principally toward the removal of biodegradable organics and suspended solids. Tertiary treatment or ··advanced wastewater treatment" is the reduction of waste beyond secondary standards which rcmo\'cs more organic carbon and nutrients. Physical. chemical. and biological processes arc used in various complimentary ways to accomplish primary. secondary, and tertiary treatment. Table 3-4 describes several treatment processes and the stage of treatment they occur.

25

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991)

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s is

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&

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e, u

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ana

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ith a

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g bi

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, and

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se m

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is

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. A

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ds a

rc

good

prim

ary

treat

men

t bec

ause

they

pre

pare

the

was

te f

or s

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quen

t 'sta

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The

se

pond

s ca

n sm

ell a

nd s

houl

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t be

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clos

e to

res

iden

ts.

' ·,

(Haa

ndel

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ga 1

994)

"

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low

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ical

&

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was

tew

ater

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ers

thl!

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botto

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bia

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me

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logi

cal

up th

roug

h th

e se

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g zo

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The

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dec

reas

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ore

slud

ge s

ettle

s ou

t. B

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s sl

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sl

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s, w

hich

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e sl

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noe

s at

tach

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ise

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nd a

re r

elea

sed

into

the

gas

j : (U

ASB

) ph

ase.

(H

aand

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Lct

tinga

199

4)

Sub-

surf

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y Ph

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treat

s or

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, ino

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in w

aste

\vat

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. ~

abso

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g as

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sur

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on

whi

ch m

any

chem

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and

'

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logr

c :-.1

hrnc

hcnu

caltr

catm

ent p

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sses

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ur.

(EPA

, On-

site

198

0)

--·-

-·

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ltali\

'e s~condary

Ph, $

tc;tl

&

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livc

lago

ons

ha1

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n to

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bic

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r on

botto

m.

., '

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oons

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tt.ll

(Met

calf

& E

ddy

1991

) ···-

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Seco

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Seco

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Seco

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ess

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. B

iolo

gica

l O

xyge

n is

mec

hani

cally

add

ed.

The

re a

re tw

o ty

pes,

one

max

imiz

es a

lgal

gro

\\1h

and

the

othe

r oxy

gen

prod

uctio

n.

A sy

mbi

otic

rela

tions

hip

exis

ts ~etween a

lgae

, bac

teri

a,

\

and

rotif

ers

and

prot

ozoa

ns.

Aer

obic

pon

ds a

rc e

xpen

sive

to o

pera

te s

ince

oxy

gen

mus

t be

pum

ped

into

the

syst

em.

The

y ar

e di

ffic

ult t

o co

ntro

l and

pro

duce

larg

e qu

antit

ies

of

slud

ge.

Aer

obic

sys

tem

s ar

e th

e m

ost e

flic

icnt

sys

tem

s an

d pr

ovid

e so

me

of t

he

quic

kest

trea

tmen

t.

Phys

ical

&

Rin

g or

ova

l sha

ped

chan

nels

equ

ippe

d w

ith m

echa

nica

l aer

atio

n de

~ice

s at

spe

cifi

c B

iolo

gica

l po

ints

in th

e ch

anne

l. T

he w

aste

cir

cula

tes

thro

ugho

ut th

e ch

anne

l and

is e

xpos

ed to

bo

th o

xic

and

anox

ic e

nviro

nmen

ts.

(Met

calf

& E

ddy

1991

)

Phys

ical

&

A b

ed o

f hig

hly

penn

eabl

c m

ediu

m to

whi

ch m

icro

bes

atta

ch.

The

was

tew

ater

, typ

ical

ly

Bio

logi

cal

dist

ribu

ted

by a

rota

ting

am1,

tric

kles

pas

t the

filt

er m

edia

. A

s th

e m

icro

orga

nism

s gr

ow

they

cre

ate

a sl

imy

laye

r on

the

med

ia.

The

slim

e la

yer p

rogr

essi

vely

thic

kens

and

ev

entu

ally

slo

ughs

off

. W

onns

, ins

ect l

arva

e, a

nd s

nails

are

als

o pr

esen

t. (M

etca

lf &

Ed

dy 1

991)

.

Phys

ical

&

Was

tew

ater

is a

pplie

d in

dos

es to

a s

peci

fied

med

ia s

and

or g

rave

l. T

here

are

.two

type

s B

iolo

gica

l of

filte

rs, s

ingl

e pa

ss a

nd r

ecirc

ulat

ing.

T

he w

aste

wat

er p

asse

s th

roug

hout

the

sing

le

pass

filt

er o

nly

once

. In

a re

circ

ulat

ing

syst

ems,

a p

ortio

n o

f the

was

te r

ecirc

ulat

es b

ack

thro

ugh

the

syst

em.

Ven

t tub

es, p

lace

d th

roug

hout

the

syst

em, d

eliv

er o

xyge

n to

the

mic

roor

gani

sm a

ttach

ed to

the

med

ia.

(Was

hing

ton

Stat

e D

epar

tmen

t ofH

eahh

199

2)

Phys

ical

&

Clo

sely

spa

ced

parti

ally

sub

mer

ged

circ

ular

dis

ks r

otat

e sl

owly

thro

ugh

the

was

tew

ater

. B

iolo

gica

l M

icro

orga

nism

atta

ch to

the

disk

s an

d ar

c in

tcm

1itte

ntly

exp

osed

to o

xyge

n. (

Met

calf

&

Eddy

199

1)

;

N

00

Syst

ems

A qu

acul

turc

Con

stru

cted

"c

t lan

ds

--

Sta

ge

Ter

tiary

Ter

tiary

(s

omet

imes

sc

cund

ary)

-

Proc

ess

Bio

logi

cal

(Phy

sica

l w

hen

Oxy

gen

is ad

ded)

~ Phys

ical

(w

etla

nds

act

as a

filte

r) &

bi

olog

ical

Des

crip

tion

Aqu

acul

ture

is th

e gr

owth

of p

lant

s an

d/or

ani

mal

s in

a fa

culta

tive

or a

erob

ic p

ond.

I

Typ

ical

pla

nts

incl

ude

float

ing

hyac

inth

s or

dud

.:wec

d.

Hya

cint

hs h

ave

long

roo

ts w

hich

ca

n ta

ke u

p la

rge

quan

titie

s of

nitr

ogen

and

pho

spho

rus.

D

uck\

\•eed

hav

e sh

orte

r ..O

Ots

1 I

but a

rc m

ore

effi

cien

t in

abso

rbin

g ni

troge

n.

Duc

kwee

d an

d hy

acin

ths

mus

t be

harv

este

d to

be

effe

ctiv

e.

1

A m

inim

um le

vel o

f oxy

gen

is re

quire

d to

gro

w f

ish.

T

here

are

cer

tain

spe

cies

of f

ish

whi

ch c

an w

ithst

and

very

low

dis

solv

ed O

:\:yg

en le

vels

. It

is i

mpo

rtan

tto c

hoos

e '·

mos

quito

larv

ae e

atin

g fis

h to

kee

p m

alar

ia d

own.

T

he f

ish

is ed

ible

but

the

fish

shou

ld

be c

ooke

d th

orou

ghly

. Fi

sh a

lso

prod

uce

a co

nsid

erab

le a

mou

nt o

f was

te b

ut i

fthe

fish'

are

fed

with

onl

y th

e al

gae

or d

uckw

eed

and

the

fish

are

regu

larly

han

•est

ed, t

here

sho

uld

be a

net

con

sum

ptio

n o

f nut

rient

s. (

Ree

d et

al,

1995

) ,

In J

ohn

Tod

d's

livin

g sy

stem

, was

tew

ater

is c

once

ntra

ted

in c

ylin

dric

a' •

anks

~v,1ich

utili

ze a

com

bina

tion

of e

colo

gica

l and

mic

robi

olog

ical

prO

cess

es to

trea

t was

tew

ater

. Sm

all m

outh

bas

s, s

nails

, and

daf

fodi

ls th

rive

in th

ese

syst

ems.

(F

arre

lll9

96)

Con

stru

cted

wet

land

s ar

e im

itatio

n na

tura

l wet

land

s.· W

etla

nd p

lant

s liv

e in

hig

h or

gani

c an

d nu

trien

t ric

h en

viro

nmen

ts.

The

ir ho

llow

ste

ms

brin

g ox

ygen

to th

eir

root

s so

they

ca

n w

ithst

and

the

wet

ana

erob

ic s

oils

. M

icro

bes

live

on th

e ro

ots

and

stem

s.

In s

urfa

ce

flow

wet

land

s, w

ater

flo

ws

free

ly o

n to

p of

the

soil.

T

here

is a

pot

entia

l fo

r odo

rs b

ut

mor

e ox

ygen

is t

rans

ferr

ed to

the

wat

er.

Land

req

uire

men

ts f

or w

etla

nds

is h

igh

and

harv

estin

g is

re• 1

•• i.

" .I

f, ,f

ther

e to

be

a ne

t red

uctio

n. in

nut

rient

s.

Subs

urfa

ce F

low

Wet

land

s-In

sub

surf

ace

flow

wet

land

s, th

e w

ater

flo

ws

thro

ugh

a pe

a gr

avel

sub

stra

te.

Les

s ox

ygen

is tr

ansf

erre

d an

d th

e sy

stem

mus

t be

Jarg

er th

at th

e ·

· su

rfac

e flo

w s

yste

m.

How

ever

, the

re is

less

cha

nce

for o

dors

. T

he la

nd r

equi

rem

ents

are

ev

en h

ighe

r th

an s

urfa

ce fl

ow w

etla

r l •

• nd

harv

estin

g is

als

o re

quire

d. (

Ree

d et

al,

1995

)

---

..,

N

\0

Sys

tem

s

Agr

icul

ture

Peat

Bio

filtc

r

Sta

ge

Ter

tiary

Ter

tiary

L_

__

__

,__

,

Pro

cess

Phys

ical

&

biol

ogic

al

Phys

ical

, bi

olog

ical

, &

Che

mic

al

Des

crip

tion

The~e

are

seve

ral m

etho

ds o

f agr

icul

ture

trea

tmen

t fro

m f

ores

try a

pplic

atio

ns to

cro

ps to

pa

rk a

nd g

olf c

ours

e irr

igat

ion.

'

In o

verla

nd f

low

sys

tem

s w

aste

wat

er c

asca

des

over

a sh

allo

~v s

lope

d re

lativ

ely

i ·

impe

rmea

ble

soil.

Pr

imar

y tre

atm

ent a

nd f

ine

scre

enin

g pr

eCed

es o

verla

nd'O

ow.

Var

ious

gra

sses

are

gro

wn

(i.e.

Bem

mda

gra

sses

, yel

low

fox

tail,

and

Joh

nson

gra

sses

). H

arve

stin

g is

requ

ired.

Peat

fib

er is

use

d as

filt

er.

500

on-s

ite s

yste

m in

Ire

land

hav

e ac

h~ev

e up

to 9

? pl

us

I

perc

ent r

emov

al o

f BO

D a

nd f

ecal

col

iform

bac

teria

. Pe

at a

re p

hysi

cal f

ilter

s,:ha

ve

abso

rptio

n ca

pabi

litie

s, a

re h

ome

to a

ple

thor

a o

f mic

robe

s, a

nd p

ro\'i

de a

nd a

cid

envi

ronm

ent a

ntib

acte

rial e

nviro

nmen

t. (C

anod

y 19

96)

-------

,;

. I

''

.. ,

Pathogen Destruction Pathogens are removed during the various treatment process as a result of detention

time, adsorption; pH, temperature, settling, screening, and predation. Detention allows for the natural die off of many organisms. Many microorganisms can only survive in a small range of pH and temperatures so extremes in these parameters effectively eliminates many pathogens. Pathogens also attach themselves to particles so they ma: · settle or filter out with the particles. Finally, predators in the 'wastewater, like rotifcrs, consume various pathogenic microorganisms. Unfortunately not all organisms are destroyed during treatment so chemical and physical disinfectants are employed at the end of treatment to remove all, or nearly all, pathogens.

Chemical disinfection was discussed earlier in the chapter. Oxidizing compounds such as chlorine alter the chemical arrangement of or deactivate enzymes. pH changes can occur with chemical addition and detergents alter the cells ability to pass elements through their cell wall allowing nutrients to escape. Physical disinfectants include heat and light. Heat coagulate the cells protein which kills the cell. Sunlight is also a disinfectant (in particular ultra-violet light). However: solids. water, and microbes absorb the radiation. If the water has high concentration of solids then light may not reach many of the pathogens.

Pathogens pose potential health risks in aquatic and land treatment svstcms. Contaminated crops and fish can threaten human health. The removal of pathogen in ponds is due to natural die-off, predation, sedimentation, and adsorption. The destruction of bacteria and viruses in multiple-cell ponds is very effective for both aerobic and anaerobic systems. Fecal coliform removal in ponds depends on detention time and temperature. In· wetland systems. pathogens arc destroyed in much the same way as in pond systems except for shorter detention times and greater opportunities for adsorption and filtration. Most infection in land application is from the direct disposal of raw wastewater. Land treatment systems should have good primary and sometimes secondary treatment. Bacteria and virus removal is due to filtration. desiccation. adsorption, radiation, and predation. Finally, the pathogenic content of sludge must be carefully considered if the sludge is to be used in agriculture. Sludge stabilization with earthworms can help reduce pathogens. Drying and composting can reduce pathogens by desiccation. temperature. and a long detention time. (Reed et al 1995)

Sludge Treatment and Disposal Overview

Wastewater treatment processes generate sludge through the seLtling of solids. biological activity, and the addition of chemicals which induce settling. Sludge is essentially the concentration of eveJ!thing foul about wastewater including terribly stinJ...:· substances which. left untreated, become even fouler and stinkier. Sludge is certainly a ,·cry difficult to substance to handle. It is too foul to discharge into water ways. too thick to discharge via soils. difficult to pump because of relatively high solids contcnl. and too liquid to haul away cheaply.

Sludge contains pathogens. solids. grease and fats, protein. nitrogen, phosphorus. sulfer. potash. cellulose. iron. silica. and organic acids (Metcalf & Eddy 1991 ). There arc also trace clements (i.e. hea\'Y metals) in sludge which can be detrimental to plants and animals. These clements do not come from human waste but from industrial and commercial

30

--wastes. It is possible that households might deposit these elements in the waste stre::un:·. - ....

__ _ _ . Countries without wastewater treatment regulation, have little incentive to dispose of sludge properly. Septage from septic tanks are hardly ever pumped. Desludging services discharge their waste directly into rivers and canals rather than pay the fee (World Bank 1993).

Sludge Characteristics · Sludge characteristics and volume vcuy depending on the source of the waste, age of the

- sludge, and treatment process at a particular stage of treatment (i.e. anaerobic verses aerobic process and primary verses secondary treatment). As seen in Table 3-4, aerobic processes produce more sludge than anaerobic processes. Table 3-5 describes the characteristics of different sludges.

T bl 3 5 Sl d T d Ch a e - u1ge .~es an aractensucs.

Sludge Solids lb/ Comments lOOOgal

Primary 0.9-1.4 Primary sludge trom settling ~ is generally slimy and offensive but settling tank easily digested. (Metcalf and Eddy I 991 )

Rock/trickling 0.2-0.2 Relatively inoffensive and easily digested. Worms in filters help keep the filter) sludge ino1Tcnsivc. (Metcalf and Eddy 1991)

Aerobic 0.7-1.0 Brown to dark brown. Inoffensive musty characteristics. High sludge digestion production compared to anaerobic process. Easily dewaters in sludge

drying beds. (Metcalf and Eddy 1991)

Anaerobic Dark brown to black. High methane production. Inoffensive when digestion thoroughly digested. Smells like hot tar, burnt rubber or sealing wa:<.

Gases cause good separation of phases (liquid, solid, and gas). Thefmal sludge is like garden loam. (Metcalf and Eddy 1991)

Activated 0.6-0.8 Brownish. If dark, the sludge may be septic. If light, to little o:-.:ygcn and sludge (waste slow settling. Good conditions produce inoffensive "earthy" odor but the recycling) sludge can rap1dly become septic. Activated sludge d1gests readily when

combined with primary sludge. (Metcalf and [ddv 1991)

Sludge from lime Metal salts cause chem1cal precipitations ti.e. alum or l!mcJ. Sludge chemical addition: production is high. The sludge is usually dark. Lime sludge 1s ~rray1sh precipitation 2.0-11.0 bro\\11 and the presence of iron creates a reddish surface. Chemical

sludge is generally slimy and objectionable. The hydrate of iron or aluminum makeJ it gdatinous. Decomposition is slow (Metcalf and Eddy 1991)

Com posted Composted sludge requires a bulking agent (i.e. wood chips)_ The odor Sludge ofwel!-composted sludge is inoffensive and is much like garden

condi tion~.-rs. (Metcalf and Eddy 1991)

Scptagc Hydrogen sulfide in septic tanks creates a rotten egg odor. The sludge can be dried on porous beds. Digestion prior to drying is recommended because the odors can be quite objectionable while drying unh!ss the septa?c is well digested. cMetcalf and Eddv 1991)

31

Sludge Solids lb/ Comments lOOOgal

Living_ little sludge Living systems are ecologically engineered treatment systems. All have a Systems generated plethora of microorganisms. In addition. one pond or tank might have (series of cells water hyacinths with snails on the plants roots. Another might have fish with relatively and a variety of plants. Because of the multiple layers of species, some of complete which consume sludge (like snails), little to no sludge is generated. ecosystems) Harvesting is required to ensure the demand for pollutants remains high.

Nightsoil (dry The biggest cost in treating sludge is removing water or thickening with systems i.e. polymers. The advantage of compost is that water is never added. Dry composting · systems arc the least expensive and simplest to treat. Gray water will toilets) require some treatment.

Sludge Processing There arc millly methods used to treat sludge. Even though on-site systems arc the main

focus of this paper, sludge processing often involves ofTsite disposal. This cost can be considerable illld all on-site waste waster systems generate sludgq which must be removed illld treated. The main objective to sludge treatment is to concentrate the sludge then stabilize, disinfect, dewater, illld ultimately dispose the sludge. (The information in this section is taken from Metcalf and Eddy 1991 and Bitton 1994)

S/udu concentration or thickeninf increllSes the solids content of sludge by removing liquid. Volume reduction makes it ellSier to digest and dry the waste. It also makes it cheaper to transport the sludge. Three of the most common methods of thickening include: (1) gravity thickening (compaction illld thickening by gravity) is one of the most common methods used to thicken sludge; (2) floatation thickening gasses are added to the mixture, the solids stick to the bubbles, and buoyant forces carry the solids to the top where they arc skimmed-ofT: illld (3) centrifugal thickening is a rotation process which spins the sludge so that centrifugal forces separate higher density solids from the liquids.

Sludge srahili=atron reduces pathogens. eliminates odors, and prevents putrefaction caused by microorganisms. Typical methods of treatment include: (I) lime srahili=ation which raises the pH to 12 or higher thus creating an uninhabitable environment for microbes: l2) heat treatment heats the sludge to a temperature of260 degrees Celsius for about 30 minutes. a condition microbes equally hate: (3) anaerobic and acrohic sludge digestion uses anaerobic bacteria to break dO\m waste and kill pathogens due LO pH and tcmpcr:nurc extremes: and (4) composting biologically degrades sludge to a humus like end product with the help of bacteria. actinomycetes. and fungi. Dewatering is often required prior to sludge stabilization. Composting is a highly recommended method of sludge treatment.

Conditionin'l is similar to thickening in that it decreases the water content in sludge. There arc two types of conditioning, chemical and heat. Both process may also help stabilize the sludge. Chemical conditionmg ~the addition of lime. ferric chloride. alum. or polymers 1

coagulates the solids and releases absorbed water. Heat addition coagulates solids, breaks the sludge down into a gel structure. and reduces the sludge ·s affinity for water.

Disintccnon destroys pathogens. Disinfection can occur :n any time and during any process. Many treaunent mechanisms listed abo\'c I lime addition. heat treatment. composting.

32

digestion) create deadly environments for pathogens. Because the liquid content in the sludge is still relatively high, most methods should occur before drying, though pathogen destruction also occurs during drying. Additional disinfection me~ods include: (1) _ Pasteurization achieved by steam injection or indirect heat exchange (2) other thermal processes such as heat drying, incineration, pyrolysis, or starved air combustion; (3) retention which requires large land areas so that pathogen may die of old age; (4) Chlorine or other chemical addition; and (5) irradiation.

·­~ # .- ••

Dewaterjng is a physical process which decreases the water content as much as _ . economically possible so that sludge can be handled more easily. It is not always necessary. · For example, sludge disposed ofby spray irrigation requires a high water content. Typical

methods of dewatering include: (1) natural evaporation; (2) percolation through a filter by gravity ; (3) vacuum filtration uses a pressure gradient (lower pressure on top and higher pressure below) to suck liquid through a porous media; ( 4) cemr:ifuges separates liquids of different density using centrifugal forces; (5) belt filter press uses conditioned sludge then· gravity or a vacuum to thicken the sludge before applying pressure to squeeze out the liquid between two porous cloth belts; (6)filter presses force water from the sludge under high pressure between plates: (7) sludge drying bed is the simplest method where sludge is simply laid out on a drying bed and the liquid both evaporates and drains by gravity (sometimes it is vacuum assisted); and (8) heat/thermal drying which vaporizes the liquid. Sludge drying is perhaps the most appropriate method of sludge dewatering.

Slud~e disposal is the last step in sludge handling. Final disposal is usually by either landfill disposal or land application. Landfills arc common final resting places for sludges, especially if there arc hazardous materials which can not be applied to land. Landfills arc expensive to operate properly and the addition of sludge leaves less room for other solid wastes. Sludge also can increase the gas production in a landfill. If the sludge is suitable, land application on agricultural land, forests, or wasteland is a better disposal option. Care r:nust be taken since sludges produce odors, attract insects and rodents, and potentially spread pathogens. Sludge runoff into water ways, like wastewater, also spreads environment and health related pollutants. Sludge applied to land requires greater levels of treatment to reduce pathogens and organics. Sludge application can be in a liquid fonn or solid fonn. Liquid sludge application requires less dewatering and is easier to spread. Liquid sludge can be applied by furrow irrigation. sprayed. or injected below the soil surface. Dcwatcrcd sludge application requires fewer trips and is typically cheaper and easier to handle.

The Process and Stages in Cornposting Systems

Introduction Composting toilets arc just beginning to gain acceptance in developed countries largely

due to the problems associated with waterborne systems. It costs nearly $2 billion dollars to repair. replace and expand private and public sewers in Maryland and in Virginia and Maryland. five percent of the septic tanks and drain fields arc failing (Fchr & Pac. Washington Post 05118/97). In the Galvaston Bay area in South Texas, the Harris County Sanitation Office receives 30- 45 complaints per month regarding malfunctioning septic tanks. The office attributes the problem to clay soils. small lot sizes, and heavy amounts of

33

rainfall (Paul Jensen from Espey Huston and Associates). In Massachusetts, conventional systems (i.e. septic tank and drainfield) were considered a threat to public health and composting toilets were recently approved as a safe alternative (Steinfield 1997). In fact, composting toilets are being considered as an .alternative to the ever increasing sewer rates (Steinficld 1997). -· · ·

The technologies so far developed arc mostly for the developed world but there are some groups trying the technology in developing countries .. The composting toilet technology is extremely basic and generally is a one stage process as opposed to the complex multiple stages in·wastewater treatment It makes sense to develop the technology in lesser developed countries. Though the prices appear high for the technology, the pric immediately drops when local manufactures develop the systems.

Processes The composting toilet technology is basically a one stage process which can occur with

or without ox-ygen. The anoxic (void of ox-ygen) process is a fcnnentation process. As table 3-3 indicates, the fcnncntation process is the least efficient of the microbial processes and thus require more time and space to convcn the waste into stable compounds. Non­pourflush pit latrines arc typical examples of fcnnenting composting toilets. Fennentation and anoxic condition arc more likely to produce foul odors caused by hydrogen sulfides. The VIP (Ventilated Improved Pit Latrine) solved the problem of odors by providing a vent pipe which sucks the putrid air of the toilet out and above the building.

In urban areas or areas with flooded conditions, both anaerobic and aerobic compost must be sealed in water tight containers. VIP latrines are not appr~;riate because the liquid from the waste drains to the subsurface which contaminates the surrounding environment. Aerobic processes arc more attractive because they arc not putrid and because aerobic processes _work more efficiently and require less space than anaerobic systems.

The key to efficient aerobic composting is maintaining proper temperature, pH. moisture, and oxygen ranges. Carbon to nitrogen ratios arc also imponant and can impact such parameters as pH. Various physical and even chemical processes can help maintain optimal environmental conditions. Mechanical mixing or ventilation. for example. improves the o~.:ygen availability to the microbes. Heat addition can ensure high temperatures which favor the more efficient thcnnophilic bacteria. Carbon can help n~ .. orb excess moisture (Stcinficld, 1997) and bring the carbon to nitrogen ration to a beLL-.. balance.

Available Technologies Composting technologies work as either continuous or batch systems. In a continuous

system. the waste is added at one end of the tank and slowly moves to the other end while aerobic microorganisms break dO\m the waste. The composition of the waste will vary at any point along the path. Towards the end. the waste should be well treated. In a batch system. as one tank fills up, others sit and compost for a set period or time. There arc several types of aerobic com posting toilets available. Examples of the various technologies available arc sho\m in Figure 3-6 as well as in the attached annex.

34

T bl 3-6 E a e : xam__pJes o fC ompostmg T 'I T hn I 01 et ec 0 OgJeS an dC osts

Product Description Cost

BioLctNon- For cabins and weekend usc. The toilet has two com posting $895 Electric chambers for batch composting. When the first fills. the chamber

slides back and the second chamber is filled. Claims to reduces the volume of waste by 9()0/e. (Jade Mountain Inc.) Since the air is not heated, the total volume ofliquid may not evaporate fully so a leachate system or closed container may be required (BioLct). The . electric models have mixers and heaters (BioLct) .

.. Carousel Leading Norway design and NSF approved. Over 30,000 installed Non-electric Com posting since 1972. Inner container has four revolving chambers for a batch SS67 System process. The system h~ a three year detention time. A separate wlheatcr&fan

container evaporates liquids (available with or without electricity). $2678 Processing units arc available separately allowing user to build their Processing own chamber. Good for 5 persons. (Jade Mountain Inc.). InsPected chamber by Grcenpeace and used in the Pacific Islands where efficiencies $1600 improved dramatically (Jade Mountain Inc.)

Vera Cottager Has interchangeable 5.6 gallon batch composting containers. Rated Non-electric for two full time people. More maintenance required than the S567 Carousel model. (Jade Mountain Inc.) w/fanS6S6

wlheater& fan S700+

Clivus Rated at 4-5 persons continuously. Fully treats both solids and S2500 Multrum 1 liquids. Produces tow types of high quality fertilizer 2-3 gallons of Com poster compost per person per year) and no noticeable odors. Claims to be

virtually fool proof with low maintenance. Cost docs not include toilet. (Jade Mountain Inc.)

Clivus Odorless and cost effective. Reduces biomass by 95o/o. Produces 2- $3000 Multrum 2 3 gallons of compost per person per year. Built in moisture system to Com poster ensure best com posting conditions.

SunMarNon Uses natural convection (4" vent pipe) to circulate air and evaporate $949 Electric the moisture. Rated for 2-3 persons on a full time basis. Fan optional w/fan 5995

to increase capaci(V and evaporation. (Jade Mountain Inc.)

The composting technology has been applied in the Pacific Islands \Vhcrc conditions arc similar to those in Indonesia. The group ''Sustainable Sratcgies" have developed both a composting technology and gray water management system. According to David Del Port, System Designer, the first systems were installed in 1992 and arc working well. The construction costs for the prototype systems was about $1200. David Del Port suggestS that the cost is high because the prototype uses imported materials. The company is looking at using locally available materials to bring the costs do\m. The annex has more infonnation on this application.

Advantages and Disadvantages to the Technology

Composting toilets would be ideal in Indonesia except for one problem, the culture and existing perceptions. Indonesians traditionally usc water for cleansing and they have a particular fondness for flush toilets with water seals. According to John Brisco of the World Bank. previous efforts to install composting toilets have failed. Why they have failed is

35

unclear and why other programs are considered successful is equally unclear. Nevertheless, composting systems should be one of the options presented to the Indonesians and more work-should be done (both socially and technically) to determine if acceptable composting technologies can be developed. -~ · - -

··-·

Intuitively, composting toilets, compared to traditional on-site options, are potentially the least expensive, most technologically effective, and safest method of on-site human waste disposal. The comparison of the composting technology has often been made with other on-site.systems which do work in urban areas such a$ those seen in chapter I. Even the simplest functioning on-site subsurface adsorption system, a septic tank and drainfield, is more expensive than a composting toilet. Composting toilets septic tanks are similar sizes. The cost of a composting toilet iri the United States is roughly $1000 {plus or minus) which includes the commode (see the annex on composting toilets). The cost of a septic tank, alone, in the United States is roughly $1000 plus or minus. Added to the septic tank systems to make a complete sanitation facility arc commodes, plumbing and water connection (or residents must cany water to flush), land, pipe, sludge treatment and disposal. Composting toilets do not discharge any effluent to the environment whereas septic tank and drainfield systems discharge high levels of organics. pathogens. nitrogen. and phosphorus to the environment. Composting toilets have no soil requirements and they can be installed in high ground water regions without impact. Septic tank and drain field systems cannot (see chapter 4).

Su~nrnary

Human waste treatment works when the pathogens and nutrients are effectively reduced, removed, or recycled. This is accomplished through various physical, chemical, and biological processes which occur in stages. Each process, like a puzzle, sequentially readies the waste for the next stage. Adding water to human waste makes for more complicated treatmenf systems. Wastewater treatment requires multiple stages of treatment geared towards removing the pollutants from the water. Wastewater also produces sludge which is difficult to manage. Dry waste can be treated in a single stage in one container with a one to three year retention time. The relative unfamiliarity of the composting toilet technology means that there is still a long way to go.

36

4 SUBSURFACE DISPOSAL

OPTIONS

Introduction

: [.

-~····· . . . . -·

Sub-surface disposal is the direct disposal of primary cffiuent (i.e. the effiuent from a septic tank) to the soils. Sub-surface disposal systems tend to be popular because the effiuent seemingly disappears with little need for maintenance except when the system backs up into the homes signaling the end of its useful life. All soils eventually clog with biological buildup rendering them ineffective to treat waste. Designers often double the land requirements for a subsurface system, especially in less coarse soils. When the system eventually fails, area is available for an additional system. But for a time, if conditions are favorable and the soils are good, sub-surface systems can treat hwnan waste. Unfortunately, this is rarely the case for the flooded urban arc in Indonesia's cities. However, since subsurface disposal is the most popular choice for on-site sanitation systems in these areas, this chapter covers how sub-surface disposal systems work, how to conduct proper soil analysis, and the site criteria and space requirements for two of the most popular subsurface disposal systems.

Sub-surface TreatnJent MechanisiTis

Overview Discharging wastewater via the sub-surface can be a reliable and inexpensive method of

wastewater treatment and disposal. if and ,\·hen the conditions arc favorable. Soil treats organic materials, inorganic substances, and pathogens in wastewater by acting as a filter~ exchanger, adsorber, and a surface on which many chemical and biochemical treatment processes occur.

Filtration - Filtration of wastewater through the soil physica/Zv entraps particulate matter thus removing solids and. since solids contain organic material, filtration also removes a significant amount of organics. However, filtration only works when the soils arc not water saturated and only when the wastewater can drain through the soil. Flooding allows the wastewater to flow through the larger pores to surface waters. If the soils are impermeable. wastewater is forced to flow to the surface. There arc two kinds of impermeable soils: i) impermeable soil types (i.e. silt clay, or solid rock); and ii) soils

37

clogged by thick and slimy biological growth. Clays and silts consists of fme soil particles which fit so tightly together nothing flows past. Loamy and sandy soils have larger grain sizes and subsequently larger void spaces. All soils eventually clog with biological gro,,th when organics and nutrients are applied. (US EPA Onsite Treatment 1981).

Ion Exchan2e (Adsorption - Desorption) - Ion exchange is a chemical process. Most soil panicles nnd orgnnic matter arc negatively charged so, like a magnet, they attract nnd hold positively charged particles such 'as bacteria, viruses, ammonium, nitrogen, and phosphorus. Pathogens eventually die or are eaten by predators such as protozoas and rotifers. · Adsorption of organic particulate occurs mostly with clays. Anunonium ions can be adsorbed onto clay· particles in anaerobic conditions. Although clay adsorbs pollutnnts well, wastewater can not pass through impenneable soils with high clay content, thus treatment is ineffective in clay soils. In flooded conditions, pollutants tend to desorb or unstick from the soil particles nnd flow with the water. (Novotny & Olem ·1994)

Chemical and Biochemical Transformations - Chemical and biochemical transfonnations arc the mineralization or transfonnation of waste components. Chcmic:d decomposition is the natural tendency for chemicals to react when they come in contact \\ith other chemicals under various conditions. For example, solids may dissolve into a liquid or liquids may volatilize into a gas. Microbial orgnnisms arc the most proliferous conveners of pollutants. Bacteria, fungi, nnd protozoa live on soil panicles, nnd as wastewater passes by, the orgnnisms consume the waste and transfonn it into less hannful elements. Aerobic bacteria are the best conveners of waste. Flooded soils arc anaerobic (void of oxygen) and less efficient at transfonning waste. (Novotny & Olem 1994)

Treatment o., Pollutants In Solis Viruses

Vi~ survival in soil depends on the nature of the soil, temperature, pH, moisture. and predation of other soil organisms. Viruses prefer cooler temperatures. They readily adsorb onto soil panicles. however. they arc still infectious and can survive for seven days to as long as six months in soil. Enteric viruses can survive for more than six months in fresh water (Novotny and Olem 1994). Transport and survival is most prominent when the groundwater is shallow. Survival in the groundwater is generally longer than on the surface since the virus is protected from the sun and the temperatures arc generally lower tF each em et al 1983). Because of this. l-'irus sun.·il-·al is pervasil-·e in areas with high ground water or flooding conditions and without adequate waste disposal

Viruses arc so smalL they arc very difficult to monitor and treat. In the environment viruses arc most effectively removed by adsorption on soil particles. The best adsorption of viruses is achieved at pH 7. Adsorption of viruses docs not mean their complete immobilization, since desorption of viruses can occur when pH or other environmental conditions change. In other words, even though viruses stick to soil panicles. they can unstick under favorable conditions. For example. viruses can be dcsorbcd from soil panicles following a heavy rain (Novotny and Olem 1994). Having said this, there arc populations of protozoa which consume free-floating organisms such as viruses. These protozoa arc abundant in wastewater.

Bacteria Pathogen bacteria may survi\·e in soil for a period of from a few hours to several

38

months, depending on the type of organism. type of soil, the moisture capacity of the soil, organic content of the soil, pH, temperature , sunlight, rain, and predation by the soil micro flora. Enteric bacteria persist for two to three months, however, under certain favorable conditions, they may reproduce. Enteric bacteria survive longest in cool moist soils. They move in ·the .soil with the groundwater. Fine soil particles can effectively adsorb bacteria. Soils containing clay remove most microorganisms through adsorption. Sandy soils remove them through filtration (Novotny & Olem 1994).

Protozoa Protozoa form cysts and in that form they are quite protected from the environment Up

to 900 million cysts may be passed in the stools of one person during one day. Unaffected by pH and osmotic pressures, they survive where organisms cannot. Little is known on the transfer and fate of these organisms, but there is a direct correlation between sanitation and infection. Filtration through the soil seems to have no ill-affect . The only known way to kill them is by dr)ing or freezing. Drying is possible in developing countries, though difficult in monsoon climates. Long detention times may be the next best alternative (Novotny and Olem 1994).

Helminths The survival and transport of helminths in the ground vary from type to type. Under

unfavorable conditions in soil (too hot, cold, or dry) hook-worm eggs pose no risk. If they hatch, they only survive for 12 weeks. The micro habitat of the hook-worm larvae in soil is the moisture film surrounding the soil particles. Following rain they move up to the surface. Ascaris eggs will survive for several years in soil. Diphyllobothrium Latum and Clonorchis can be transferred to fish (Feachem et al 1983).

Nitrogen Dissolved nitrogen moves readily v.ith soil moisture and ground water. The dissolved

fractions include nitrates and ammonium ions. Nitrogen immobilization in soils and sediments results from physical-chemical attractions, chemical precipitation. biochemical reactions, and nitrogen uptake by micro-organisms and plants. In environments high in pH and ammonium. ammonia can be lost by volatilization (conversion into a vapor). A high moisture content. moderate application rates. high clay and organic content of the soil. and calcium availability play an important role in ammonia volatilization (Novotny and Olcm 1994). In normal dry environments ammoniwn exists in soil adsorbed on soil particles. Ammonium. when sorbed onto soil particles or sediment. is considered immobile as long as the substrate is immobile. Unfortunately, in flooded em·ironments, soils and sediments dislodge and erode to the receiving waters. Although ammonium can be immobilize, nitrate is always dissolved and mobile. If the nitrates flow through an anaerobic environment high in organics. then a process know as denitrification occurs. Denitrification converts nitrates into nitrogen gas which becomes part of the atmosphere.

Phosphorus The usual forms of phosphorus in domestic wastewater include orthophosphate,

polyphosphatc. p:Tophosphate. and organic phosphate (EPA, On-site). The primary pathway to surface water is direct disposal. In aerobic soils. phosphorus is relatively immobile and phosphate ions do not leach easily, especially in clays Clays. soil particulate, and organic matter hold the phosphorus tightly. Phosphorus will precipitate in combination with calciwn below a pH of 7 which is characteristic of soils with high clay and organic

39

matter content like many areas in Indonesia. When the calcium disappears from soils, phosphorus then reacts with the iron and aluminum ions in the soils (Novomy and Olem 1994). In flooded conditions soils tends to be anaerobic. Under anaerobic or micro aerobic conditions, phosphorus leaches out of the soil. When phosphorus is dramatically mobilized. iron complexes become soluble.

Soil Analysis

Overview On-site systems require individual soil analysis. A soil analysis will identify the soil

texture, soil structure, depth to bedrock or cemented pan, depth to the high water mble, soil permeability or infiltration rate, slope, and porosity. Soil fonns over time. through geological processes. There arc anywhere from one to dozens of layers of soil types at any given site. Each site must be individually tested since adjacent sites can have totally different characteristics. All these conditions will help detennine which kinds of on-site systems (i.e. sub-surfnce disposnl. evnporntion. or surfnce water disposnl) can be built at n given site.

The best way to detennine n soil's charncteristics is to simply dig a hole or pit either by hand or with n backhoe. A soilnuger can also work but it only provides a limited area to view equal to the diameter of the auger. Big holes allow an investigator to really view the soil profile. The hole should be as deep as the deepest treatment depth required for a system. For example, if n twin pit pour flush toilet is on the menu and asswning the pit is about one meter deep, there should be at least one to two meters below the pit for treattnent. Therefore the hole should be at least 2.5 meters deep. A drainfield is laid at a more shallow :. ·. cl and would require only 1.5 meters of depth. Since the point of soil analysis is to deter·. , 1e the soils suitability for trentment, it is pointless to dig below any condition which prectu.le the soil as a treatment option including the water table, bed rock, or cemented layers.

Unsnfc conditions nrc common on construction sites, cspccinlly in developing countries where little training and regulations exists. A deep hole can collapse and potentially kill an investigator. Precnutions should be taken. The hole should not be dug straight down. mstead step the hole dO\m in layers or slope the sides. If this is not poss1ble. then shore the sides of the hole with a sturdy materinl such as wood or steel and do not dig below the water table. water can destabilize the soil.

Sloped Sides Sloped and Stepped Sodes Shored Sides

Figure 4-1: Safe methods of digging deep holes.

40

Soil Texture · Texture is closely related to the soil's most important physical properties including grain

size and distribution. Soil texture is described for soil particles less than two millimeters in diameter. (US EPA Onsite, 1989) There are three factions of soil in that size range; sand, silt and clay .. Sand has. the largest grain sizes and clay particles have the smallest individual grains. Various agencies and organizations categorize soil particle sizes differently. . ·Two methods of assessing soil te.xt..ire include, (i) moist soil field tests and (ii) sieve

analysis. -In the moist soli field tests small palm size soil samples are slightly moistened. -The vanations on the moist soil tests includes: (i) The ball and rub test is done by fanning a ball or lump and simply rubbing it; (ii) The puddle test is done by forming a small ball with the sample and depressing the thumb in the mixture; (iii) The ribbon test is done by squishing the sample between the fore fmger and the thumb to form the longest ribbon possible with that sample; and (iv) The worm test is similar to the ribbon test except it fonns a solid tubular worm. To do the worm test, rub the sample between the ·palms ofmy hands (like making spaghetti noodles out of clay). The table below describes how a particular soil class will behave in the four tests.

T bl l T a c4- cxtura propcrttcs o fM" mcra l S "1 A 01 s sscss cdb F r v ee m an dA .ppcarance

Soil Ball and Rub Test Puddle Test Ribbon and Worm Test

Sand Crumbles when touched. Easy to Does not form a Does not form a ribbon or feel the individual grains of sand. puddle. worm. Also easy to feel the

sand grains.

Sandy The ball must be carefully Forms a puddle Docs not form a ribbon or Loam handled to prevent breaking. Can but docs not stay worm. Can feel the sand

feel sand particles between the together. grains between the smaller smaller particles. particles.

Loam Forms a ball which can easily be Forms a puddle Tends to ribbon but breaks handled. Sand grains arc still felt easily but is a quickly. Docs not form a when rubbed. little rough. worm.

Silt Forms a ball and is easily Forms a puddle Ribbons easily but docs not Loam handled. Rubbing leaves a easily. hold it long. Does not form a

rippled broken pattern. Has a worm. velvety feel.

..

Clay Forms a ball easily and can Forms a puddle Forms a ribbon and a worm Loam withstand rough handling without easily and can breaks but the worm breaks

breaking. The soil feels plastic even hold water. after about 1/4 to Yl inch. \Vith a touch of grit.

Clay Ball can withstand rough Forms a puddle Forms a ribbon and a worm. handling, including throwing it and holds water. Docs not break Elastic and against a hard surface. Silk-y stretches easily. smooth feel when rubbed. Sticky when wet.

41

In the sieve analysis, a pre weighed sample is passes through a series of · sieves or meshes. Each sieve retains a certain size particle and allows smaller

- particles to pass through. The sieves get ·progressively smaller. The retained

. amount of soil between two mesh sizes is weighed and calculated as a percentag..: of the total soil mass. Soil often contains vlrious particle sizes. The US Department of Agriculture developed the textural triangle in Figure 4-2 to correlate

~~~~~~~~~~~~~~-. 111 percentages of the various particle sizes a

Ptn:ellt Sled (by Welgllt)

Figure 4-2: Textural Soil Triangle from the US Department of Agriculture.

with a textural label. Only particles smaller than 2 n1m are used to determine soil texture. If the total percent of gravel and cobbles is more than about IS or 20

percent. then the soil is labeled cobbly. possible results from a sieve analysis.

(USEPA On-Site, 19801 Table 4-2 shows some

a e - : T bl 4 2 E f '1 . xamp1es 0 SOl Sieve ana VSIS. (USEPAO .t 1980) n-sr e.

Soil Oass Tyler Particle sizes . Soil Soil So;i Standard (mm) Sample 1 Sample 2 Sample3 Sieve No. •;. o/o U• ,.,

Cobbles/ -- >2.0 0 20 0 Gravel1

Very Coarse 10-16 mesh 2.0-1.0 2 8 0 Sand

Coarse Sand 16-35 mesh l.0-0.5 9 2 0

Medium Sand 35-50 mesh 0.5-0.25 20 5 ; -

Fine Sand 60-140 mesh 0.25-0.1 7 5 3

Very Fine 140-270 0.1-0.05 32 10 5 Sand mesh -

Silt: -- 0.25- 0.002 20 20 60

Clay: -- <0.002 10 50 30

Soil Classification Sandy Loam Clay1 Silty Clay (From the USDA Textural Triangle) Cobbly Loam

I. Particles greater than 1 mm arc nol considered in the texture but the textural class is modified (becomes classiticd as cobbly) if more than 10% of the total mass of soil is made up of particles greater than 1 mm. the soil is considered cobbly. 1. The Tyler Standard docs not measure particles as small as silt or clay. Soils With line pnrtrclcs should be taken to a soil lab.

42

Sol/ Structure ·,Soil sttucture refers to how soil particles cluster together. Theses clusters are separated

by surfaces of weakness which are often seen as cracks in the soil. The form, particles sizes, and the bonds between the particles detcnnine the soils sttucturc. Soil structure can be platy, blocky, prismatic and granule (See Figure 4-2). Well sttuctured soils have large voids between clusters and, therefore, transmit water quickly. Fine-textured soils have little structure and, as a result, transmit water very slowly. Som clays and sodium rich soils swell when they become wet In such instances, the pore spacing shrinks and slows the movement

· of water. The ideal sttucturc allows the water to percolate evenly at medium pace. If the water moves too quickly, the micro-organisms do not have time to degrade the waste. Too slow and the land area requirements and potential for clogging increases. (USEP A, On-site, 1980)

Prismatic Columnar Blocky Platy Granular

Figure 4-2: Structural Characteristics of Soil

Soil Color and Water Table The color and color pattern in the soil can tell an investigator if the is periodically

saturated with water. Soils that are saturated at various times in the year often are streaked or spotted due to biochemical reactions. These reactions are caused when water, organic matter and bacteria are present. The bacteria feed on the organic material and deplete the oxygen supply. Anaerobic bacteria continue feeding on the organic material using oxidized · iron and manganese for respiration instead of o:-..1·gen. Since the oxidized iron and manganese contribute to the color of the soil so when the bacteria reduce the iron and manganese. the color is taken out and the soil turns to grey. When the soil drains. iron and magncsiwn (reduced manganese) arc carried by the water to the larger soil pores \vherc they are rcoxidizcd in aerobic soils. This process leaves a mottling effect (spotting and streaking) on the soils. (USEPA Onositc, 1980)

Site Criteria and Space Require~r~ents for Subsurface Adsorption

Subsurface absorption systems treat primary effluent such as the effluent from septic tanks. Two of the most common types of soil adsorption systems are seepage pits and trench and bed systems. Trench or bed systems arc shallow systems with perforated pipes which distribute the wastewater evenly throughout the trenches or beds. The pipes are surrounded by !:,'Tavel. To keep soil from penetrating the gravel, a semi penneable layer is placed on top of the gravel. Seepage pits arc deep cylindrical pits \\ith porous sidewalls. The wastewater percolates through the sidewall which arc often made of spaced brick surrounded by gra\'el. Figure 4-4 shows the basic trench and bed system and seepage pit.

43

. --· ' .. _..,._- .~ . ..; ...

Trench· or· Bed System

Seepage Pit

Table 4-3 defines site criteria for seepage pits and trench and bed syster:~s.

Figure 4-4: Cross sections of Trend or Bed System and Seepage Pit.

T J s· c · · ti ab e4- : 1te· ntena or seepage p1ts an d trcnc h db d an c USEPAO svstems ( n-slte. 1981)

Condition Criteria

Site The site should be well drainca. Depressions, iL.;..:s of slopes and conca•. · slci- .. ;; description should be avoided unless suitable surface drainage is provided. The site should and slope have no more than a 25% slope (bed systems should slope no more than 5%).

Distances I 5 - 30 meters to water supply wells, surface waters and springs 3 -6 meters to escarpments, cuts, and building foundations

Soil Texture Sandy or loamy soils work best. Gravel or cobble soils drain too quickly. Silt and - clay soils drain too slowly, tend to clod, or don't drain at all. It is possible to

replace the soil in the trench with another soil but this can become expensive.

Soil Granular, block-y or prismatic work best. Platy soils or unstructured massive soils Structure do not work well.

Soil Color Unitorrn and bright soils work best. Dull. gray or mottled soil indicat~s s~a.sonally high water table.

Soil Layers A variation in soil layers can significantly alter the drainage pattern of the primary ctlluent

Deplh to There should be at least I meter for trench & bed systems of unsaturated soil Water Tahlc below th~ bottom oftn.'Ilch. For secpagc pits. there should be 1.3 mcters tor of

unsatur:u~d soil hdow lh~ bottom of the s~~page pit.-. Again. unsunablc soils l:an be replaced with loamy sand or sandy soils as long as the water table remains below the treaunent bed.

Application S - -lX lpd/m: (Seepage Pits 24--lR lpd/m: 1

Rate

Calculating the space requirements for a seepage pits or trench or bed systems depends on the soils application rate and the basic geometry of the system. The application rate is the rate of flow of primary effluent per unit surface area of soil. This rate Yaries depending on

44

the soil type. For example, coarse sand can absorb more waste more quickly per unit area than clay because come sand has larger grain sizes and thus the particles are more loosely packed. The geometry of the systems have become fairly standard. Trenches arc usually 0;30 to 1.0 meter. wide and up to 30 meters long per pipe section. The space between trenches (sidewall to sidewall) is about 2 meters. Beds require smaller surface areas because ·the pipe sits on a flat plane without sidewalls so less space is required between pipes (typically 1.0 to 2.0 meters). However, because beds do not use sidewalls for absorbing the waste, they are less effective_ than trench systems. Seepage pits are usually about 1.0 meter deep and use the paras sidewall for distributing the wastewater. The diameter and number of pits vary depending on the soil type. Seepage pits require smaller surface areas than trench

-or bed systems, however, they need deep soils with deep water tables. Table 4-4 lists the application rates for various soil textures and the estimated geometries for the various types of systems assuming 1000 lpd of waste flow.

Table 4-4: Application Rates for Various Soil Textures and approximate area requirements. (Based on calculations from data in USEP A On-site 1981) .

Soil Texture Application Surface Area for Area for Area for Seepage Pit Rate Area for Trench Bed Diameter x Depth

( lpdlm:) 1000 lpd System .

System (mxm) of Waste. WxL WxL

(mz) ( mz) (mz) 1 pit 2 pits

Coarse to 48 20 lx20 3x7 2.3x3 l.Sx2.5 medium sand 4xl0 4xS 2.Sx2.6 1.6x2

7x6.7 3x2.3 2xl.6 3.Sx2 2.5xl.S

Fine sand. 33 30 lx30 3xl0 3.5x2.75 1.7x3 loamy sand 4xl5 6x5 4x2.5 2x2.S

7xl0 3xl.7 4xl.3

Sandy loam. 24 40 4x20 3xl3 Mmof 2.3x3 loam 7xl3.3 ·hlO 2 ptts or 2.6.,2.6

6x6.7 a depth ~ ., ~ .l~ . ..l

or"4 + 3.5x2 m..:tcrs 4xl.7

Loam. porous 18 55 4x28 3xl8.3 NA silt loam 7xl8 5xll (The system would be

9xl4 6x9.2 too big)

Silty clay loam, 8 125 17x25 5x25 NA clay loam 6x2l (The system would be

8x!5.6 too big) 9xl3.9 !Oxl2.5

Note: For::! ptt systems. a space ot 3 umcs the d1ametcr ot the largest p1t ts rcqutred. For thc trench system. there should be a 2 meter space between each trench to allow for reserve area when the drainticld clogs (table above uses 2 meters between trenches). It is acceptable. though not recommended. to space the trenches 0.5 meters apart.

45

The calculations for the above table is based on BOD effiuent standards from the home of around 200 mg/1. In Kampung areas without plumbing, water usage is much less and the BOD levels can be significantly higher. A family of 4 in the Kampung in Banjarmasin used only 200 lpd of water. On the other hand, water usages could easily exceed I 000 lpd in some homes. Observations of plumbing systems in homes with water connections showed tremendous wastage such as cons~tly flowing taps or leaking pipes.

' Conclusion

-Based on the requirements for subsurface adsorption systems as described in this

chapter, it would be extremely unlikely to fmd a deep enough water table, suitable soil types. and space enough for these types of systems. There are other sub-surface adsorption systems which require pumping, expensive site modification. or intennittent dosing to raised beds. These types of systems might work technically but would be fmancially limiting.

Perhaps the principles of sub-surface disposal can be used if applied in a more appropriate way. There arc some examples of raised systems for soils with high groundwater tables but the area requirement arc not appropriately calculated. There still must be 1.0 meter of treatable soil to the top of the water table. For a 1.0 meter deep seepage pit, the toilet would need to be 2.0 meters tall. For a bed or trench system. the toilet would need to be at least 1.3 meters tall and using a bed system with'· ;: best soil condition~. a 20m= bed. Clearly, other options need to be explored.

46

Pilot On-site SystenJ ~~constructed Wetlands''

/nlroduc::lion

Overview The task of developing low cost alternatives to subswface adsorption systems in

Indonesia's crowded urban areas is a difficult one. Even more difficult is testing on-site alternatives in lower income Kampung neighborhoods. Kampungs have special problems including: i) residents often have less income to work ,.,;th; ii) lack of piped water; and iii) homes in the more flooded zones are often accessible only by boat or foot path. Sewer systems in these areas arc virtually impossible without piped water connection. Also since the canals and rivers arc the sources for bathing, children are commonly found S\vimming in the highly contaminated waters. Despite these challenges, the first pilot would be located in a Kampung in Banjarmasin (the most flooded of the Indoncsisian cities). The design team consited of two engineers, myself and Ikin Sodikin. Pak Riduan from Bappeda. at the local government level, provided tremendous support and help to ensure we had all the materials and staff needed to do the work.

Site Evaluation Because this was an experiment, the site selection was influenced by a \\illing guinea pig

from the local government staff. Apud Fauziansyah, from the Banjarmasin Department of Public Works. volunteered his home for the pilot. The home is located in a typical Karnpung and. like most homes in these neighborhoods. the home sits atop stilts with ne\lf constant flooding below. Pak Apud, Ibu Fauziah, and their two children Herliani and Heryadi lived in the modest one bedroom with a living area, kitchen, and dining area. The lack of i:lnd above the water table was an obvious obstacle to on-site systems.

The site evaluation was straight forward. The ncar constant flooding indicated that there was no possibility for subsurface adsorption. StilL a soil evaluation form and site map (figures 5- I and 5-2) were completed to provide the basis for design. The soils consisted of a mix of clay. possibly silt. and organic material. Garbage was also found intermixed in the soil. Garbage is commonly used as a fill material in these flooded areas. The soil had no noticeable structure or layers. During the rainy season the soil was constantly flooded and during the dryer season. tides would flood the area daily.

47

...

House

we

Blowup of site

/

Site Location Hot to Scale

House of Pak Aput

WC Pour Flush Toilet I I...._ __

Ffoorfeu ~nan• Trees ..__.Box . ~

,!

Site Map

Trees

....... z.

I~ --. --....... ~, ,...:_.4-..._ ,__.,' ; ,.. I . .....____.-- . ....__,...

House

Scale 1mm = 1 m em

Soil Log 1 ~ ,.. '" --

............ _ . ~ ..

:bepth (em) Texture -· Structure ~- COlor Soil Saturation ... ... I ~ ~

1 Water table is hi'h as 25 Ground Level (30cm ~elow high water level) ..

I .. - • i ~ ". .. ~ ., . - 30 em a&.ove sroand

50 Primarily clay with No noticeable Soil color is dark based on water mark

quite a &it of organic I

brown and organic. from hoate. I structure. .......

75 matter and possibly I ...

some silt. The soil -

.100 holds its form well. i.

I No evidence of sand. I I 125 According to the soil ! I I ! I

ehart, the soil would ; I

150 I be a elay or a silty ' i . .. . .. . ······ -· ... . .. ··- -· .. . ....

j

I

elay. I

175 r

200 I I

Notes: Only one test is needed. Ground conditions are constantly flooded during the wet season and tidally flooded during the dry season. The soils ue flooded and the soil type is a silty clay. Not suitable for subsurface adsorption.

100

80 70 60 50 40 30 20 10 0

SystenJ Selection

There arc so many problems associated \\ith on-site systems including: i) lack of suitablcland; ii) potential high cost for a functioning system; iii) the demand from each individual to purchase an on-site system; iv) ability or desire of each individual to maintain the system; v) pathogen destruction before discharge to the environment; and vi) sludge.or septage removal. The most logical tcthnology choice is the composting toilet technology.

Thc-composting toilet technology met with resistance with the residents. Since the technology does not use a pour flush toilet, the residents were skeptical about odors, pests. cleanliness, health, and cost. Demonstrations and awareness would be useful before attempting to construct composting toilets. Because of the demand for a waterborne system, the residents preferred the constructed wetland technology. The site was large enough for the technology but it is unlikely the technology would fit on individual sites. Never-the-less, the technology could be promising for small community systems and the system should be a useful demonstration tool in showing an entire wastewater treatment process including primary settling, secondary treatment, sludge disposal and pathogen destruction.

Design

The chosen desi!:,'ll uses the tried and tested treatment processes. First, primary settling followed by filter(s) will remove much of the settleable solids. Next, an aerobic process like the reed bed will conswne much of the remaining BOD and, once the BOD levels arc below about 20 mg/1, nitrify some of the ammonia. To convert the nitrified ammonia (nitrates) to nitrogen gas, an anaerobic process must follow. Since soil is not available, a contained pond should provide a facultative environment for tertiary treatment. Plant (if harvested) can also remove some nitrogen and phosphorus. Disinfection can occur by predation, pH extremes, temperature extremes, and long retention times. Figure 5-3 is a schematic of the system and Figure 5-4 shows the design layout.

QFrom house

Septic Tank

Filter Reed Bed

Figure 5-3: Schematic of on-site treatment processes

J;: To Environment

Pond

Pathogen destruction and sludge management in this system arc weak. Unless the homcO\mer can add chemicals at the end point. pathogen destruction may not be sufficient. There may need to be further research on pathogen destruction without chemical addition for example the hydroponic waste management system at Cornell University claims to have virtually pathogen free wastewater at the end of the system ( 1996). Solar may also be another option.

50

-" "" "" . -""- -

"" -

House of Pak Aput . "'"

". -.. ... "" ".

-we - Pour Flush Toilet .. - "

-' - I

•"

- t/J . Roorlm .. __ -· ~Banana Tr~es Box

1...-I ' ... ... - ...

..a& .. -- ~

~1 -- -~ as ..

-~ .. .. - ~ .. tl!

A - .oM -" A ... u -- ct QC j.

t ~ "' ....

I

. House

v ,v:

:00.: ~~~~ ~ ~

~__, c~~ " 1 we \~ +j\~u ~

til \~7 Profile VieVi of Section A-A -

Design Layout Scale 11Hm = 1 m ern

.. ------------. -------Sludge management. is also weak in this system. Septic tanks and ponds generate sludge. The rock filter and reed bed produce biomass in the fonn of plants which must be harvested periodically and the biomass disposed of. A compost bin might be capable of reducing the volume of sludge, however, septage (septic tank sludge) is too liquid to compost The solution might be to build a tank on top of the septic tank and aJiow the septage to drain back into the septic tank and filter the solids out The biomass could co­compost with the sludge from the septic tank. For this to be effective, a privatized Operation and Maintenance program must be developed to ensure the tanks are pumped regularly into the compost tank. Septage pumping trucks can not reach these sites, however since a transportation tank is not required, a port3ble pump could man3ge the task.

Septic Tank ... ----- Septic tanks provide primruy settling, anaerobic digestion. and are logical first steps in

wastewater tre3tment in small are:tS. Normally 3 septic tank has about 3 Cine day retention time, that is, it takes one day for the waste to pass through the tank. Pak Apud's home used about I 00 lpd or 50 liters per c3pit3 per d3y (lpcd). The septic tank is oversized to 3llow for other users to connect if the systems works. The resulting septic tank volume W:tS I 000 liters ( 1 m3

) "ith dimensions of .6m deep x . 7m wide x 2.5m long. Assuming water consumption will likely rise in the future. 3 total of four homes could connect to the t:tnk. The influent concentr3tions were estim3ted based on figures in table 2-5.

BODin = 30000 mg/cap I 50 Vcap = Nitrogen in = 17500 mg/cap I 50 Vcap = Phosphorus in = 6740 mg/c3p /50 Vcap =

60i"i mg/1 263 mg/1 162 mg/1

Septic t:tnks can remove a significant amount of solids and thus reduce the BOD levels. The have a limited ability to treat nitrogen and no real ability to treat phosphorus. Empirical data exists for the low range and high range reduction of wastes (Metcalf and Eddy 1991 ). Table 5-I-shows the design parameters for the influent to the septic tank and anticipated cffiucnt. No phosphorus removal is expected since phosphorus docs not sorb onto particles in anaerobic environments (Novotny & Olem 1995).

Table 5-l: Anlicip:llcd septic t:mk influent and effluent qu:mtitics. Low ran!!c :md hiuh ranee values arc from Metcalf & Eddv 1991

Low Ranf!e Hit!h Range BOD in (mg/1) 210 530

BOD out {mg/1) 140 200 0 1, Remnw·d ·no;. h '?0/.

Nitrogen in (mg/1) 35 80 Nitrogen out (mg/1) 25 60

••-;, Remrwed ;qo;. ;.::;o;.

This Svstem 600 210

t'l.;o;,;-

350 263 ., .;o;,;

•To enhance the removal ot soilds. a septic tank et11ucnt tiller was added to the systems. A tishmg net glued to the el11uent tiller allows long stringy bacteria to grow adding extra liltering and biological removal. This \\Ill likcl~· 1mprove the remo\"al etlieicncv by a lew percent more so the removal cllicicncy has been adjusted from 61" a to 65° o.

52

_.:..._!.

Upllow Filter In the up flow filter, wastewater flows up\\;ard through the column of rock. The bottom

of the filter exists in an anaerobic state and the top is aerobic. If the upflow rock filter becomes too anaerobic, odor could become a problem (Reed ct al 1995). As described in Chapter 3. bacteria do not require long retention times to grow and mature since the mature bacteria live attached to the racks. This up flow filter was designed to allow vines to grow on the rock media (figure 5-5). The roots provide more surface areas for the bacteria to grow on. The plants attach their roots to the rocks and the ,;incs grow on the fences. Some organic and nutrient uptake could occur through the root system. if the homeo\mcr harvests the plants. Since nitrifying bacteria can not out compete BOD reducing bacteria, the main purpose of the Up-flow Filter is to reduce as much of the BOD as possible to allow the nitrifying bacteria to grow.

Upflow filters arc especially good for highly concentrated wastes such as industrial waste with influent COD concentrations between 10,000 to 20,000 mgll. Hydraulic detention time lasts for 10 hours to 50 hours with COD removal rates can be from 50% to 85%. This system docs not have the same high concentration as the industrial systems and the detention time is short, in fact this system is actually more like a subsurface flow wetland. Plant roots live in the rocks and the waste water Figure 5-5: Roots attach to the rocks and the vines passes through a rock substrate which is grow on a nearby fence. This was taken one year largely anaerobic with micro aerobic after construction. environments.

BODRemm•a/ Terms(Reedetall995)

T = Design Temperature, (°C) Kr = Temperature dependent. first order rate constants. (d' 1

)

K=o = Temperature dependent. first order rate constant at 20 oc. (d'1)

A Fraction of BOD not removed as settleable solids ncar the head works of the system. a variable depending on water quality, (decimal)

L = Length of system (parallel to !low path). (m) W = with of system. (m) v A vcrage depth of system. ( m) n Porosity of system (space available for water to t1ow). (decimal) Q Average t1ow in the system. (m3 /d) c. = Effiuent BOD. (mg/1) Co = Influent BOD. (mgt!)

53

Calculations (Reed et al 1995) K:o = 1.104 d"1 (for subsurface flow systems) T = Assuming the lowest temperature is 25 oc L = 3.0m ·· W := 0.4m y = · 0.1 m n. = . 0.38 (assumed for Jaige river rock) Q · = 200 J/day = .2 m3/day • · · A- = 0.52 after primmy treatment (from emplncal data)

Kr = K:o(l.06)<T-:ol Kr = 1.1 04( I. 06)1::s.:ol d"1

Kr = 1.477 d"'

C. = exp(ln A • In Co -[(L>(\V)(KT~ D Q

c. = exp(ln .52+ In 210- [(3 Qm)(O 4m)(J _ _:!_:"_:d·'W' ! m)t~Sij id

c. = 78 mg/1

(Eq. 5-l)

(Eq. 5-2)

Based on the above calculations. the percent removal :·ctcd is about 63%. BOD is still too high to achieve any microbial nitrogen reduction.

Reed Bed Reeds are natural wetland plants which do.well in flooded conditions even though the

soils contain virtually no ox-ygen. Reeds survive by bringing ox-ygen in from the stem to the roots rather than through the soil. The condition in a reed bed is both anaerobic and aerobic or facult~tivc. In facultative conditions, micro-habitats exist simultaneously. For example the root system imports oxygen from the stem and some of the oxygen leaks out mto the soli The micro habitat in that case would be comprised of oxygen consuming microorg:uusms The cJiculations for the uptlow filter is based on a subsurface flow wetlands. The reed bed is a free water system since the waste water flows freely above the substrate mstcJd o(

through a Iiller media. The calculations arc similar to those for the subsurface S\ stem except for the Kr value and the porosity value. Also since the amount of suspended sohd.s rs less. the value for A is greater.

BOD removal Calculations (Reed ct al 1995)

K~o = 0.678 d·' (for surface flow systems. this value is less for surface bceJusc there is less surface area for microbes to grow)

T Assummg .the lowest temperature is 25 oc L = 3.0 m W 1.4m , 0.05 m n 0.75 Q 200 1/day = .2 mJ/day A 0. 7 aflcr basic secondary treatment but the upt1ow filter is some'' here between

primary and secondary. So we usc . 65.

54

Kr = K:zo(l.06)'T·20l Kr = 0.678( 1.06)'25.:01 d·1

Kr = 0.907 d"1

' -

(Eq. 5-3)

c. = cxp(ln A - In Co -[CUCW)CKrlli::lliUD (Eq. 5-2) Q

c. = cxp {In 0.65 +In 78 -' [(3.0m)( 1.4m)(0.907d"1 )(0.05m)(O. 75)/0.2 m3/d]} c. = 25 mgll '

"The percent BOD removal is about 68%. BOD levels arc still too high for much nitrogen removal, although there could be some.

Nitrogen Removal Additional Terms

No = Influent Nitrogen (mgll) N. = Effiucnt Nitrogen (mgll)

Calculations Kr = K:o ( 1. 048)1T-:Ol Kr = 0.2187(1.048)':s.::Old·1

Kr = 0.2765 d"1

No = 263 mg/1

(Eq. 5-4)

N. = cxp (In No - [CUCW)(Krlli.lli!l] (Eq. 5-5)

N. =

N. =

Q exp(ln 263 - [(3.0m)( l.4m)(0.2765d·1 )(0.005m)(O. 75)/0.2 m3/d]} 257 mg/1

Total removal is less than 1%. Effiucnt nitrogen and phosphorus removal will mostly be from plant uptake. For nitrogen removal to be effective. the plants must be harvested.

Pond W astcwatcr stabili7.ation ponds have been used to treat wastewater for thousands of

years (Metcalf and Eddy, 1991 ). This pond is facultative, the upper layer is aerobic and the lower layer anaerobic. Since the BOD levels arc low enough for discharge, the main function of the pond is to remove or reduce the levels of nutrients. The addition of aquaculture. defined as the usc of aquatic plants or animals, enhances the uptake of nutrients. Hyacinths and duckweed arc the primary plants used since they arc found locally. Nitrogen and phosphorus removal is similar to that found in the reed bed. In the southern United states, where hyacinth grov.th is possible, significant reduction of BOD, N, and P have been achieved. For plant uptake to be effective. harvesting is required. Nitrification/ denitrification processes also remove nitrogen from the system. Phosphorus will be taken in with cell gro\\th since phosphorus docs not travel well in soils, a final filtration should help.

BOD remo..-al Additional Terms

k = first order reaction rate constant, ct·• = hydraulic residence time, d

55

D . = dimension less dispersion number kr = 0.15(1.09)(~·=0! d"1

kr- = 0.23 d"1

D = .2 (from the Wehner-Wilhelm equation chart with relationships ofk-t and %BOD remaining)

Calculations t = ~ (Assuming only 'Yz the volume of the pond is used)

Q ··t- ·- · 0 5 (3x3xDm3

0.2 m3/d t = 22.5 d

k"t = 22.5 d X .23 d"1

k"t = 5

a = (1 + 4ktD)05

a = [1 + (4)(5)(.2)1'' 5

a = 2.2

(Eq. 5-6)

(Eq. 5-7)

From the Wehner-Wilhelm equation for facultative ponds representing a mix between ideal plug flow and complete mix.

c. = c. 4 a exp1r.D (Eq. 5-8) [ ( 1 +a):( eil/-=0 )- ( 1-a )~( e·"'20)]

C. = 2.5 m~/1 C4lC2 2lCe1'c:x:1)

[(I +2.2)::( e=-:~c:x.: 1) -(1-2.2):!( c·=-:~c:. ... :J)]

-C. 1 mg!l (Note: even though the pond can reduce the BOD to 1 mg/1, other

carbon sources from birds plants and animals will likely increase the BOD in the pond)

Nitrogen remm·al Additional Terms

k = 0.5 based on rate constants for 269C and a plant density of I 0.230 kg;l1a dry weight

= hydraulic retention time (for nitrogen removal this is only for the top .25 meters of the pond.

Calculations From Eq. 5-6

t = (3m x 3 m x .2"m l .2m3/d

= 11 d N/No exp [-ktJ N. 257 cxp r-.5 X llj

= 1.05 mg/1 (assuming plants arc harvested)

56

(Eq. 5-l 0)

Phosphorus removal . Phosphorus removal will not usually exceed 30-50% of the phosphorus present in typical cffiuents. Plants require phosphorus at a ratio of 6 parts of nitrogen to 1 part of phosphorus. The ma.ximum removal by plant uptake is as follows:

Total Nitrogen uptake Ph~phorus uptake

-Emue~~ Phosphorus

= 256 mg/1 = 256mgll/6 •46mgll = l35mg/l- 46 mg/1 = 89 mg/1

To facilitate more phosphorus removal a final filter peat moss filter will filter out the remaining phosphorus. The filter requires periodic replacement. ·

Construction Now that the concept was developed. the next step was to built the system. We

employed .utisans from the local community were employed to do the construction work. Never before had there been a market for this type of wastewater management system and. consequently, components and materials, taken for Granted in the developed countries, were simply not available. It took several trips to the market to adequately survey the available materials. The system needed to be somewhat flexible and non-permanent since there were several construction issues which we wanted to experiment with.

The first issue was how to stabilize the frame. In chapter 4, the section on digging holes illustrates the need to shore and slope the walls to prevent the sides from collapsing. We decided to stake the site with galum poles (Figures 5-4 and 5-5). The poles provide stability in an unstable soil which is better seen in figure 5-12. We also borrowed a pump to keep the site dewatcred as much as possible. From there it was relatively easy to dig out the nght shapes for the system components.

Second. since the system sits in the ground water, an impermeable !mer \\aS needed Three option were considered. i) buy plastic and glue the pieces together. 11 J make the system out of cement. or iii) try to stabilize the soil with a soil cement. The second opuon \\Ould be too permanent for a prototype so it was eliminated. Soil stabilization m1ght work but more time is needed to test the soil's stabilization ability and the possibility of bnngmg addttional soil and sand might be needed to amend the soil. The only option left was the lmcr. The­liner would be the most expensive but it would be the least permanent and the quickest to build. There were two options for liners. The first was to buy an inexpensive tarp material which comes in large sizes. The second was to buy a more expensive vinyl carpet and glue the carpets together. We chose the vinyl carpet because the life cxpcctanc:· would be much longer than the inexpensive plastic tarp. The cost for the carpet was about 764.000 Rp (or $380). The local government provided a clean room to glue the carpets together. It took long hours and several volunteers to glue the narrow sections together. \Ve were concerned that the liner would leak at the scams so we double glued the scams. Finally the liner was complete.

57

The liner was heavy and cumbersome. Never-the-less. with several workers to help carry and place the liner, we installed the liner and filled the pond. Immediately we noticed some small leaks. Clearly this was not going to work Frustrated and nmning out of time. we purchased the inexpensive tarp material which come in large sizes and installed it over the c:upet. The tarp seemed to hold the water but the life expectancy would only be a few years at most. This was enough to see if the concept would work.

Our first lesson which cost nearly $400. The stabilized soil method would have required up to 20 or (at most) 30 bags of cement at 8000 Rp/bag or 240,000Rp ($120) which is a cheaper-alternative but more research is required. The cement liner would probably be the best option. especially if combined with the stabili7.ation poles to reduce external pressures. The construction workers and artisans, although excellent woodworkers, were comparatively weak in cement work. The mixes were often to wet and the sand dirty. In wastewater systems, the cement work must be water tight which means lean mixes and low water. More training on mixing cement would be required to ensure future systems remain watertight. Figure 5-8 shows the vinyl c:upet draped over the septic tank area to the rock filter. The final construction completely covers the liners to prevent UV degradation.

The third construction issue was how to raise the toilet. We worked backwards to determine the final toilet elevation which would allow a 6% hydraulic grodient in the system. Figure 5-9 shows the artisans a brick and cement pedestal to put the pour flush toilet on. One of the failings of the system was that I did not properly ventilate the effiuent or the toilet believing that the septic tank would vent and the water seal would prevent odors from returning to the home. This turned out to be a costly mistake since the homeO\\ners eventually rejected the system because of occasional odors.

The total cost for the system was about $600. The cost for the c:upet could reduce the cost by nearly half. The system is actu<~lly sized for two families and If the system were accepted and the appropriate materials were made available, the cost would likely go do\m. Figures 5-6 through 5-15 shows the construction process in more detail.

58

Fig

ures

5-6

and

5-7

: Th

e si

te w

as s

take

d us

ing

thin

lat

hs a

nd s

tring

. Th

e so

il on

the

site

was

hig

hly

orga

nic

and

unst

able

due

: to

the

high

\v

ater

tabl

e.

To

stab

ilize

the

soil,

gal

um p

oles

wer

e pu

nche

d in

to th

e gr

ound

. T

hese

che

ap, f

arm

gro

wn,

arid

rea

dily

av.a

ifabl

e po

les ~f

eden

ser

than

wat

er a

nd t

hey

last

25 to

30

year

s. Th

e lo

ps o

f the

pol

es w

ere

plac

ed 3

0 em

abo

ve th

e hi

gh g

roun

dwat

er le

vel.

· '

'

. .~

.I

Figu

re S

-8:

Abo

\'e is

the

basi

c la

yout

of t

he s

yste

m.

The

liner

is m

ade

of a

vin

yl c

arpe

t m

ater

ial.

It to

ok S

C\'e

ral p

eopl

e 3

days

to g

lue

the

liner

toge

ther

. It

is lik

ely

this

line

r will

he

pro

blem

atic

. H

owev

er, t

he s

yste

m is

onl

y at

the

prot

otyp

e st

age.

B

ette

r u .

. t.:

l.tl w

ill b

e re

quire

d fo

r m

ore

pcnm

mcn

t con

stru

ctio

n.

. Fi

gure

S-9

: Th

e ex

isti

ng't

oi~e

J }!a

s too

Jow

to .

· flo

w in

to th

e sy

stem

and

hav

e til

e ef

fluen

t of t

he ..

.. sy

stem

dis

char

ge a

bove

the

high

gro

und'

-iva

ter \

,~ le

vel.

a pl

at.fo

rm o

f bric

k w

as b

uilt

to ra

ise

the

t)

toile

t. ·

' · ·

Fig

ure

5-t 0

: O

n th

e le

ft is

the

cove

red

sept

ic ta

nk w

ith

the

effiu

cnt f

ilter

lead

ing

to th

e up

flow

filt

er.

Whe

n th

e lit

ter

is fin

ishe

d, r

ock

will

be

pile

d on

top

of a

tabl

e of

ga

lum

pol

es.

The

was

te w

ill n

ow u

p th

roug

h th

e ro

ck

and

out t

o th

e re

ed b

ed o

n th

e fa

r rig

ht.

.I

Fig

ure

5-t l

: M

ater

ials

nee

d to

m

ake

the

prot

otyp

e se

ptic

tank

ef

fiuen

t filt

er (

fish

net,

plas

tic

garb

age

can,

saw

, and

glu

e)

·.Fig

ure

5-12

: a fi

nal v

ersi

on o

f ,;

'.the p

roto

tYpe

sep

tic ta

nk' •

; ' •

:• · 'e

fflu

ent f

ilter

: Th

e fis

h ne

t is

cons

tant

ly s

ubm

erge

d in

.~~

i '

sept

ic ta

nk.

LOng

hai

r'iik

e '

··~ '

bact

eria

ire

expe

cted

to g

row

;

and

filte

r out

solid

s ar

id ..

. 4 1 ,;

· ~

·~

~..~

orga

mcs

.

...

I

''·

~ ,,

.,. .··: .

...

: .. ~·¥;:,

~ .; ,, "

y .:

' .

··~:

~!'·

.4

tl ~

,1

J}~''

' ' ~~,,

, ..

·(

Figu

re 5

-13:

Th

e rl!

cd b

ed w

as p

lant

ed w

ith lo

cal

plan

ts f

rom

the

cana

ls.

j

Figu

re S

-14:

Afte

r th

e fir

st d

ay th

e po

nd w

as d

ug,

the

pond

w

alls

col

laps

ed.

It w

as i

mpo

ssib

le to

wor

k in

this

mat

eria

l.

Figu

re 5

-15:

a ra

ft fo

unda

tion

was

con

stru

cted

in b

oth

the

pond

and

the

sept

ic ta

nk n

oor to

preve

nt th

e w

alls

from

· co

llaps

ing.

·

' ·

· '

Figures 5-16 and 5-17: The final system. Hyacinths and other plants float in the pond. Within one night frogs and other animals moved in. A peat filter will be added later. A small garden of trees. flowers and shrubs were planted on the side to prevent children from getting too close.

-·~ ·-~':"'!'-

Findings'· After ~e year, the system was found to be unsustainable. The following table

summarizes the problems \\ith the system. -: -,._, ..

Table 5~2· Cbnstructed Wetlands

Comments •• ----J~' ~ ... ·_ · .. r--

Problem ,. ~-

..

- ..

Odors The homeowner discOnnected the system beca~e of occasional odors and . reconnected to the floorlcss box . .·.

Soil stability The system sank a few crucial em after the first several months of construction. During the monitoring visit, efforts were made to bring in truck loads oflaterite soils, but it was never enough. The idea of filling ;;: the area was fraught with problems since the system was located in the center of a Kampung and laborers had to cany the soil to the site. The cost for soil was high and the feasibility of constructing a land intensive system in this environment seemed hopeless.

Construction The biggest lesson was the construction technique. Building in flooded technique, soils (even during the dry season) was a special challenge. We clearly are materials a not clued in on the best construction techniques and materials. Also, system because of the cry for "low cost" sanitation, we cut comers and used longevity inferior materials. The long term implications are short lived and broken

do\m systems. The trick will be to build "affordable systems·· without sacrificing quality.

Liner _ Lining the system with a vinyl carpet was a bad idea. Though there were no good options. The larger the system, the more difficult it will be to line the system. Also. installing liners in flooded areas is a difficult task.

Size The size of the system is too large for most homes (sec the design layout in fi£,rure 5-4) The system consumes most of the resident· s property.

Raised toilet The residents also disliked the raised toilet. The cost of raising the toilet in a satisfactory manor to the home O\\ner would be almost as costly as the system itself. This is likely to be a problem in most homes.

Dead The residents raised chickens. Over a period of about 6 months, two of chickens in their chickens dro\med in the pound. Although a sanitation system the pond should not contribute to the death of chickens. chicken fatalitY is

apparently high in Banjannasin (sec figure 2-3 ). Short of recommending raising ducks, ponds must be chicken proofed.

Pathogen The b cl of pathogen destruction is unsatisfactory. Shon of adding destruction chemicals. other methods of pathogen distruction arc required.

Sludge We were never able to develop a proper sludge dispos<1l system. The next disposal system should address this issue.

64

-----·.- -··-- . - ~-- ---------~ ------· .---· --------·~ ______ .. _. _ _. ___ ... - .. -- - -

----~·------·--···-·-- .. _. ____ ·-----~---

. ·i~- ;.. .

Pilot On-site SysteiTI ~~cascade Channel''

Introduction The obstacles found in the previous chapter raises the question of whether or not onosite

wastewater management is even possible at an affordable price. The compost tcchnolgy may be the only real option. However, the residents arc still reluctant to give up their pour flush system so we tried one more attempt at waterborne waste management. The second attempt tries to address each of the problems found in the first system. One of the biggest obstacle was the construction technique and materials. In addressing this problem we copied the same technique used in home construction in the flooded areas, we decided to build the system on stilts. No additional soil was required. the foundation was relatively simple, and there was no chance of the system sinking. Table 6-1 addresses the problems found in the first system.

T bl 6 1 P a e - : repose d S I . o utton tot h p bl e ro ems [! d. h c oun m t c onstructc dW I d ct ~m

Problem Comments

Odors The entire :-.-ystem will be ventilated to remo\'c any potential odors.

Construction The system will usc the same construction technique as the homes. they will be technique built on sti Its. The construction technique and material have been tned and tested

in thl! environment and the wood is an e:xtremely hard wood and should last a life time.

Liner The wood lorms a channel or lrame and the lining is a strong mortar cement mixture.

SiZI! The size of the system is long and narrow which should ultimately attach to the c:xisting house structure. The: foot print is relatively small.

Ra1scJ toilet The homeowner has been given a loan of 100,000 Rp to build a new toilet room one meter above the high ):.'found water k:\'el.

65

Problem Comments

Dead There are no ponds in this system. chickens "'-~f.'; ..... ,i~----~~ .• - - -- ·- - -- ··- --- - ·- -- -··

,-~'''~_ .....

Pathogen The level of pathogen destruction is still uncertain. The system will look for destruction possible solutions. By covering with a clear corrugated fiberglass sheet, the

temperature inside the channel may reach high enough levels to kill pathogens. The risk is that the temperatures will not be sufficiently high and instead pathogens might thrive in the moist wann environment If that is the case, modifications should be made (i.e. convert the channel into a hydroponic channel and let the water evapotranspirc through the plants).

Sludge The compost bin has been developed to manage sludge. The same principle as the disposal constructed wetlands was used. The septic tank will be pumped out periodically

and filtered through the tank. The tank will drain the filtered septage back into the septic tank. An access port was provided in the compost bin from the water closet so that the residents can. dispose of their kitchen garden waste in the same bin.

Design

The design included a prefabricated septic tank donated by the Water Department followed by a cascade channel. The cascade channel is the main innovation since it docs not require large land areas and the construction technique mimics the construction technique in the area. The system designed here is only a prototype. The shape is not the most efficient because it was designed fonn monitoring. Figure 6-2 shows the monitoring locations. A more efficient design would cantilever the channels off the existing homes to minimize material costs.

The-channel is mainly a concept with many potential variations. In this system, we arc keeping the system as simple as possible. Like the constructed wetlands system, the cascade channel combines bathing water with the human wastewater. The wastewater flows through the septic tank to a simple channel which is covered with a correlated clear fiberglass top. The enure system is scaled from the outside. The effiuent discharges to a small raised garden which could be used to plant several species of trees and flowers. Edible plants arc not yet recommended. Fi,gurc 6-1 is the basic schematic system schematic. Detailed designs arc sho\m in Figures 6.2 and 6.3.

O Frotn houae '

C:>----1 1-CJ-:IkTo Envlrontnent

Septic Cascade Channel Garden Tank ! !

I l •

--Figure 6-1: Schematic of Cascade Channel

66

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Septic Tank In the interest of time, the septic t:mk was donated by the water department Since the

water department was using fiberglass pipe for water distribution, they had plenty of resin and fiberglass to modif.:.V the water tank below to a two compartment septic tank. The holes in the bottom were scaled and a baffie was installed. The tank should work much like the tank for the constructed wetlands since the size is approximately the same. Therefore the same influent and effiuent concentrations were used (Table 6-1) for the cascade channel.

-T bl 6 1 S . T nk . fl d ffi a e - : epuc a ·m uent an e uent concentrations. Influent Effluent (m£11) (m£11)

BOD 600 210

Nitrogen 350 263

Phosphorus 135 135

Cascade Channel The cascade channel is an attempt to provide some treatment above the water table. The

cascade channel is a plug flow system. Though no real empirical information exists on this types of system, as a basis for sizing, calculations are based on the overland flow system which is probably the closest technolo&'Y to the channel.

BOD Removal New Terms:

L_. = hydraulic loading rate, (mid) q = application rate per unit width of the slope, (m3/m h) W = Width of the slope Q = Waste water flow rate, (m3/d) Z = slope length. (m) P application period (h) F Fraction of BOD remain

Calculations: Calculate the application rate:

q = Q!W W 0.18 m Q 0.2 m3/d q 0.2 m3/d x hi

0.18 m 24h q 0.05 m3/m h

(Eq. 6-1)

Calculate the loading rate (hydraulic loading rates generally range from .02 to .1 mid): Lw = ~ (Eq. 6-2)

Lw 0 05 m3/mh X lG hid 24m

Lw = 0.03 mid

69

From here the BOD faction remain can be obtained from figure 7.7 in Reed et al, 1995.

F = ~ Co

F = .1 Ce = .ICo+Smgll Cc ·= .1(210mgll) +Smg/1 Cc .= (21+5)mgll Ce = 26 mg/1

Nitrogen Removal

_i,_ ~ :...""'

Nitrogen removal is dependent on adequate retention time (low application rate and long slopes) and temperature. Temperature is not a problem in Indonesia. At this time, no calculations arc available for determining nitrification rates in overland flow systems. More testing of this system will be required to test the systems ability to remove nitrogen.

Nitrification only occurs when BOD levels arc below 30 mg/1. The BOD levels are sufficiently reduced to allow for nitrogen removal. Because of the high I;· ~ls of O:\:ygcn. nitrification should proceed well. The available length of channel for nitrogen removal is the remaining length after BOD levels go below 30 mg/1.

Calculations F = ~

Co F 30msfl- 5

210 mg/1 F .12

When F = .12 the slope length (Z) is only about 15 meters.

(Eq. 6-3)

Therefore. there arc 3 meters remaining to nitrify the ammonia in the waste water. The lengths should probably be longer to achieve acceptable nitrification rates. There arc no provision for phosphorus removal in this system.

Garden The garden works much more like an overland flow system than the cascade channel.

Therefore the equations used above will be used for the garden system.

Calculations: Calculate the application rate:

q Q/W (Eq. G-1 l W = 1.5 m (the distribution is from a single pomt but there is 3 meters of land

available (assume 1.5 m for the system width) Q = 0.2 m3/d q 02m1/d x ld

1.5 m 2-fil q = 0.006 m1/m h

70

Calculate the loading rate (hydraulic loading rates generally range from .02 to .1 mid):

~=f ~~

L. .= _ 0 006 ~3/mh X 16 b/d 4m

~ = · 0.004 mid (this is low)

·From here the BOD faction remain can be obtained from figure 7. 7 in Reed et al 1995.

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.1

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.1(26mgll) +5mgll (2.6+5)mgll 7.6mgll

Nitrogen and Phosphorus Removal

(Eq. 6-3) /.

As mentioned above, nitrogen removal is dependent on adequate retention time (low application rate and long slopes) and temperature. Temperature is not a problem in Indonesia. The BOD levels arc low enough to have adequate nitrogen removal. The clay soils and plants should also facilitate good phosphorus removal.

Sludge and Pathogen Manage~nent The compost bin can handle the sludge and organic waste generated from the garden,

kitchen. or even a future hydroponic system. A portable sludge pump would periodically pump the septage from the septic tank though the composting bin. Solids would filter out in the compost bin and the liquid would drain back into the septic tank. More frequent pumping would be required since the portable pump is less powerful than a septage truck and as septage thickens it becomes more difficult to pump.

Only monitoring will determine whether or not the system can manage pathogens. It is possible that the fiberglass top will create a temperature environment which encourages microbial metabolism which is good for BOD and Nitrogen removal but bad for pathogens. The overland flow section is sufficiently impermeable and above the groundwater to encourage more pathogen destruction.

Construction

Construction for the cascade channel was relatively painless. In the inercst of time, a septic tank was donated by the water department. A future system would use the foundation of the new water closet as the frame for a ferro cement septic tank. The fiberglass tank will likely heat up which is not good for the tank. Certainly it will be good for ventilation since hot air will want to rise through the vent pipe. ft will also encourage good air exchange through the cascade channel. Figures 6-4 through 6-9 show the construction process.

71

Figure 6-4: Modified fiberglass water storage tank for usc as a septic tank.

Figure 6-5: Construction of the cascade channel. Two planks sloped at I% and lined with a lean concrete mixture. The turning point is a lined box where the system can be sampled.

72

Figure 6-6: Completed channel (without the cap). The hydraulic gradient has about a 6% slope.

Figure 6-7: Construction of the prototype compost bin. It is foreseeable, if this concept works, that prefabricated systems could be installed easier and cheaper.

Figure 6-8: Completed compost bin. The bm is lined with cement (lean and strong mixture). The box is scaled so no odors can escape except through the vent pipe. The door on the side is for cleaning, a tray or open box can be installed and slid out when the time comes for emptying the compost. The box may need to be bigger iflargc ,·olumes of kitchen or garden waste arc added.

73

~~- _, -:.~~·~~ . .,.:.,._: __

Figure 6-9: The final system.

The final cost for the sytcm was about $150 (including the $50 for the water closet). The cost docs not include the free septic tank. This system is only a prototype and if the system were designed with the a ferro cement tank below the water closet and the channel cantilevered off the house. the entire cost might be as low as $150 to $250.

Monitoring

This system had been set up to monitor. The design in Figure 5-17 shows the location of the monitoring points. Two volunteers from the local government level depanmem of health (Dinas Kcpersihatan), were trained to take samples of the points. The central government level Dinas Kepcrsihatan Lab agreed to measure the samples. Much to the sadness of all, lbu Fauziah died giving binh to her third child shonly after construction was completed. The three children went to live with there grandparents. Though the system was monitored for a shan period, it never had a chance to become balanced.

Findings

Though we were unable to determine the system· s effectiveness. we were able to develop a workable construction technique which has tremendous scope for modification. The compost bin concept is a reasonably good option for managing sludge and even kitchen waste. A management program for a small monthly fcc would ensure the tank was pumped frequently and the compost removed as needed. Ensuring pathogen destruction still requires further research. It can be possible to develop environmental variation in the cascade channel which ultimately would kill most if not all the pathogens .. -\cti\·ated carbon or clay filters at the end point might also improve the pathogen removal.

74

...,

It would be worth C."q'loring other variations of the cascade channel in the future. Separating the wastes with only the human waste entering the septic tank and the bathing water flowing directly to the cascade channel. There are several potential variations for the cascade channel such as converting it into a hydroponic system or a channel with plants. Even further. there could be section of plants. then open to facilitate oxygen transfer, and then more plants. The permutations are endless. One possible permutation is show below in figure 6-10.

j.-final discharge belor1 grade. A• activated earboa filter r~ould likely easure good pathog111 removal.

Narror~er channel r~ith more valuable and more mthetic plants.

The channel length depends on the loading from the homi(s).

All channels are cantilevered from the existing. dructure to save 011 condruction costs.

Rock filter for odor control 111d additional solids removal.

wider channel with plants capable o{ withstanding high BOO and Nutrients levels

ferro-cement Septic tank located under the Kamar Mandy ud integrated into the room's foundation.

Figure 6-1 0: Adaptation of the cascade channel. In this ~}·stem. a rock tilter is added to reduce solids, plants arc added to the channel to improve aesthetics and removal rates, and a final narrow channel is added. An activated carbon tilter could provide good pathogen removal at the end of the ::.j'stem 1f there 1s any liquid remaming. (Pl.ants could evapotranspirc much or the water).

75

•I

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Surn~nary and Rec:o~n~nendations

Introduction

The pollution caused by untreated domestic waste significanUy degrades human health and the environment in Indonesia ·s flooded urban areas. Both the World Resource Institute and the World Bank cite water pollution caused by poor sanitation as one of the biggest environmental problems facing Asia. Human waste produces noxious odors, accelerates eutrophication, chokes waterways, and carries a variety of disease causing microorganisms. Poorer communities are particularly affected since they tend to live in the low lying areas where the sewage from the town or city concentrates and because they use the contaminated river or canal water for bathing and washing. The technologies currently used in Indonc cities arc constructed without any scientific basis for treating waste and therefore provide •~-­real health or environmental benefit. The World Bank Study for Indonesia on Environment and Development recommends increasing investments to improve on-site sanitation m urban slums (World Bank 1994). If on-site is to be an option for managing human waste. then better technology options arc needed.

Technology Options

Overview-Managing human waste requires removing, reducing or re~·cling the org:mic and

nutnent content and removing or inactivating pathogenic microorganisms and parasncs found in human waste. For this to occur, waste must undergo certain physical. chemical, and btological processes in a series of stages. The processes and stages of treatment depend on the type of waste being treated. The simplest form of waste. compost. contams no additional water from Hushing or bathing, can be treated in just one stage, and is rclatJ\·ely stmple to build and operate. Wastewater is a more complex type of waste requiring more stages of treatement.

Cornposting Toilets The composting technology has only recently begun to achieve acceptance in developed

countnes as a result of the problems associated with waterborne systems. Several states m the United States arc experiencing failures with both sewered and on-site septic systems.

76

As a result the composting toilet has been introduced as an alternative.

··The available composting technologies work as either continuous or batch sytems which require only one or two tanks. Various physical and even chemical processes have been added on some technologies to improve efficiencies. The more add ons, the greater the cost. Most technologies in the developed countries cost $600 or greater. The cost seems prohibitive but if the market and supply exist i~ the local area, then the cost will surely go down. , , ·

Compsting toilets are probably the most logical tcchnolgy choice in crowded flooded-._ areas since no wastewater discharges into the environment. Unfortunately, logic does not always prevail in choosing .technology options. The technology is still too new in Indonesia to gain immediate acceptance and the Indonesian's, like many western inhabitants, are tOO entrenched in the flush toilet out of site out of mind technolgoy. · -

Wastewater Treatment Options Subsurface Adsorption

Subsurface adsorption systems, though the most popular technology option in Indonesia, arc consistantly designed improperly. Soils have the capacity to treat wastewater but the conditions must be appropriate. Soil types, water table, and land availability arc just some of the conditions which must be evaluated before determining whether or not subsurface adsorption is an option.

Soak pits and trench bed systems are the simplest subsurface disposal option. Even in the best soils (coarse to medium sand) a 2 pit soak system requires at least 1.5 meters of depth (with and additional 1.3 meters to the high water table) and two 2.5 meter diameter tanks to treat 1000 !pd. Seepage pits would be prohibitively large in non sandy soils. A trench or bed system can be installed in more shallow soils (i.e. 1 meter to the water table below the bottom of pipe) but they require about a 20m: bed area in coarse sand or about a 130m= bed area in silt clay loam or clay loam. The land area and depth to ground water requirements essentially eliminate subsurface adsorption as an opption for on-site wastewater treatment in Indonesia's crowded and llooded urban areas.

Constructed Wetlands A pilot constructed wetland system was built in a Kampung neighborhood in

Banjannasin. The system was a flow through type with a septic tank followed by an upflow filter, reed bed. and pond. The system was extremely land intensive and difficult to build and after just one year. the system failed. The main problems associated with this particUlar system included odors (due to inadequate ventilation). poor soil stability, poor quality construction and materials. poor liner. the system· s large size. and inadequate pathogen and sludge management.

Because land requirements arc high. constructed wetlands arc probably not appropriate in crowded areas. Perhaps as the technology evolves in Indonesia, constucted wetlands could be used for ccnain applications. For example. a constructed wetland system could be used as a small off-site community system. Another option potential usc would be to modify drainage canals to treat the high nutncnt and organic loading rates in the channels from the storm water runnoff

77

Cascade Channel _When the constructed wetland system failed a second pilot was built at the same

site. This system was also a flow through type with a septic tank followed by a cascade channel and garden. The system was non land intensive and easy to build. Most of the concerns with the first system were addressed in the cascade channel. The major breakthrough in this system is the construction technique and the sludge management system. The channel provides a surface for a variety of systems.

Reco~nmendalions

Waste management :. - these flooded and crowded urban areas is a difficult prospect \\ith technology development as only one factor. Developing technology options is not a one time design and construction process but rather an evolutionary process which incorporates the scientific basis for waste management and develops the material and construction techniques. Prototypes tend to be expensive, but as these prototypes arc developed and markets arc created, the price should drop dramatically. Based on what we have learned so far, the recommendations for the future include:

I. Training on subsurface adsorption systems and site investigation techniques and requiring a certification program to ensure that the installer knows how to properly design and install a subsurface adsorption system.

2. Develop maps delineating kno\m areas where subsurface systems should not be installed.

3. A new intensive program to research and develop the composting •t')ilct technology should be immediately instigated. The process of technology development should include high levels of participation with communities and private sector to ensure O\mcrship and increase marketability. If the community participates in the development of the technology, they will better understand the technology and be better able to provide input on what designs they arc willing to accept.

4. Develop a program '"·here the private sector can de\·elop technology opt1ons and ha,·e the options tested and certified if they meet minimum standards. Encourage the designers and builders to meet and discuss ideas.

5. The cascade channel concept is worth developing further. Pathogen destruction should be looked at more closely. If the compost toilet technology works. then the channel concept might provide a good means for gnty water (wash water) treatment.

6. \Vhcther the compost. casc:1dc channel, or other technologies arc found :1cccpt:1blc: a sludge management program should be dc\'elopcd. Since many arc:1s do not have sludge pumping trucks access. a portable pump program like the one mentioned in Chapter .5 and 6 might be a viable option. If the compost toilet system is found to be successful. then a maintenance program should be de\'eloped.

7. Incorporate environmental education (especially the hands on monitoring programs) on the community lc\'el and in the schools to increase awareness.

78

Annex- Co~nposting Toilets

Projects

The C.K. Choi Building at the University of British Columbia

In"Vancouver, British Columbia, a 30,000 ft:.: office complex which houses the Institute · of Asian Research, utilizes composting toilets and urinals for human waste disposal. The aew building is not conncctcd to the city's sewers. A gray water recycling system cleauses ··· :·•' the gray water and recycles the cleansed water for on-site irrigation. (from the city farmer bomcpagc http://www.cityfarmcr.orgfcomptoilet64.html#toilct) .

Project Architects: Matsuzaki Wright Architects Inc. Suite 2410-1 177 W Hastings St. Vancouver. B.C. V6E 2K3 Fa.x: ( 604) r,H5-31 KO

Texis

Future Fertility Transforming Human Waste Into Human Wealth By John Beeby Bounuful Gardens 1800 I Shafer Ranch Road Willits CA 'J5490 - %26 USA _1995 164 pages S I K 40 pIus sh1ppmg

The Humanurc Handbook :\Guide To Compostmg Human ~1anure ( Emphas11:mg \1immum T ..:chnolol,;: :md Yiaxtmurn f-h·g,emc Safety J

bv J C Jcnkms Chclse:1 Green Pubhshmg Co_ Phone llW2l 2<J.:'-Il.300 1994 . IIJ8 pages

.-\-1

.. ~-

Manufacturers Oivis Multrum

Clivis Multrum I 800 425-4887 Cliws Multrum Canada Ltd.

- . PO Box 3212. Winnipeg ManRJC4E7

Com posting Toilets Western J. Rockandel. Tel/Fa.x (604) 533-5207 Langley R. C. Tapp Tel. (604) 926-3748, W. Vancouver

Oivus Multrum Inc. 104 Mr. Auburn St. 5th Floor

Cambndgc MA 02138-5051 USA

(617) 491-0051

Phoenix Composting Toilet Ad\'anced Composung Systems 195 _Meadows Road Whitefish. MT 59937 USA

Sunergv Sv~tems l..td. Box 70. Cremona. Albena. TOM ORO. Canada Phone~Fax (-HJ3) (,37-3973

British Columbia Office Sunergy Systems Ltd. 2945 Halid:1v (resent Nan:11mo. BC V9T 182. Canad:1 Tel: (250) 751-0053 Fa.x: 1250) 751-0063

-crs .. Toilet Composting Toilet Svstcms PO Box I '.J28 \Iewpon. \\'A 99156-1928 L:SA Tel t:\09) _. . .P-3i08 Fa.x: !:'09) _._.7-37.53

A-2

Envirolet Composting Toilet Sancor Industries Ltd. 140-30 Milner Ave. Searborough, Ontario M 1 S 3 R3 Canada

Sun Mar Composting Toilet Sun Mar Corporation 5035 N. Service Road. C-9 Burlington, Ontario L 71 5V2 Canada

Nature-Loo An Australian comp;my spcci<IIising in composung toilet technolO!::'Y

Roto-Loo Environment Equipment 2132 Jarrah Drive Braeside, VIC. 3195 Australia Tel: (03) 587-2447 Fa.x: (03) 587-5622 e-mail: rota.Ioor~:environq.com. au

VERA/Eco-Tech Carousel Manuf<lctured in NoC'\\'<lY and now m Concord M<1ss<1chusetts. For a detailed cat<llog of <1 Wide \"arte~ of Compostmg tOilets and gr~ water systems:

ECOS/Water Conservation Svstems 152 Commonwealth .-he .. Concord. MA 01742 .., Tel: (508) 369-3951 Fax: (508) 369-2484 c-m<lil: watcrcon ciigc.apc.org

.Jade \fountain Jnc. :\Ltn: .:SLc\·c Trov P 0 Box _.f>l G Boulder. CO 80306 L'S.-\ Td: I ~00 442-1972 F01x: 1 .~03) 4_.9-X266 .::-mall• J:ldc-mtna mdracom

AlasC:m Toilet Svstem Attn: Da\'ld Kern

. 3498 St. Albans Road ·Cleveland Heights. Ohio -+-+ 121 Tel: (216) 38204151

. e-mail: Dre\\1d:4,.star2l.com

. Aguatron international -· Rolf Kornemark or S vcnOKristcr Walberg

Bjornasvagen 21 113 47 Stockholm, Sweden Tel: 46-8-790-98 95 Fa.x: 46-8-15 75 04 e-mail: rolf@cinerea.se

Ekosanic Scandinavia Attn: Rickard Forsman Box 620. S-135 26 Tyrcso. Sweden Tel: 46&-7 ~5 OC1 30 Fax: 468-777 45 07 e-mail: m-20071 '4.malibax.swtpnet.se

DOWMUS Composting Toilets Attn: David Campbell P.O. Box323

-·- Cooroy. Queensland. Australia4563 · · ·- Tel: (074) 476 342

Mobil: (018) 711 438 Fax: (074) 425-228 International telephone: 61 74 476 342

·, e-mail: djrcamp@peg.apc.org

Bio-Sun Systems, Inc. RR#2 Box 134A Millerton, P A 16936 USA Tel: 1 800 841-8840 Fax: (717) 537-6200 e-mail: bio-sun@ix.netcom.com

EKOLET Composting Toilets Attn: Matti Ylssjokt Esteue 3. 00430 Helsinki. Finland Tel: 358 40 5464775 Fax: 358 9 5635056

Sun Mar Cornposting Toilets Excerpts Fro,., the Sun-Mar Web Page (http://WININ/}ade,.,ounta/n.oo,.,/co,.,p.ht,.,l)

HoJN Cornposting Toilets Work Workmg like the compost heap m the backyard. but odoricssly and much faster. Sun-Mar tOilets break down human waste and tOilet paper through the natural process of dccompos1t10n. I3ecause most of this waste 1s C\"aporated. only a \"cry hmucd quanuty of fimshcd compost IS produced. J

Oxygen. moisture. heat and organic material arc needed to allow mmutc natural organtsms to trans form the \\ <:~stc to ti::m hzmg sod Oxygen 1s prondcd by drum rotation and by the \·emdauon system \l01sturc IS obtamcd d1rcctly from human waste.

Orgamc matenal tn the tonn of peat moss IS added manually. smce th1s orgamc carbon IS

absorbent. holds u-.;,·gcn. and IS cheap and readd~· a\·a!lablc. Hcatts generated by the compost Itself. Jss1sted b' the hcatmg clement (on clectnc models) \1icrobes arc contamed m nch top soli \\h1ch 1s added to the compost.

The engmeered Jlr t10\\ \\lthm Sun-\lar umts ensures thJt a parual \ acuurn IS mamtamed wtthin the umt at <:~II limes. Because <11r is cominuouslv dra'm mto the tOilet. there IS no back

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--draft. an~ h~nce no smell.

In addition. the twnbling action of the composting drum results in such a moist and beautifully oxygenated compost that an aerobic breakdo\m takes place which is both fast and odorless. Breakdo\\n is odorless because aerobic microbes produce ~·nly carbon dioxide and water vapor. quite unlike the unpleasant anaerobic smell often founc.: ; a septic tank. outhouse. or backyard compost

(~cerpls tronr ·Sun·M•r honrep•ge http://WWW/sun-nr•r.oonr)

The Com posting C~mber

.. ---------• Sun-Mar engineers found that the idea! conditions for fast. odorless composting were best provided in a rotating drum. (we call it the

Bio-drum lM), where the compost c:m be kept completely oxygenated. mixed. moist and warm.

Waste and peat moss enter through a pon in the top of the Bio-drum. The drum handle on the front of the umt is turned penodically to rotate the Bio-drum rhis tumbling :tcuon thoroughly oxvgenates and nuxes

._ ___________ .:very part of the compost. keepmg 11 un1fonnlv mo1st.

·\s the drum rotates. a door closes autom:lllcallv to keep the waste ms1de the orum After tummg, a lock automaucailv rnaantams the U1o-urum m a top dead ~.:enter position readv tu rece1ve new matenal.

To prevent the compost from getting saturated. a screen :u the rear of the drum filters any excess liquid d1rectlv mto the evaporaung cn:J.mber Dy protecting the compost from direct heat. the Sic-drum also keeps the ~.:ompost umrormtv mOISt

Lastlv. the UHl·Urum can hold the necessarv mass of matenal to ret:J.tn the natural heat developed an the core of the compost On some untts. ansulauon on the outside of the drum prevents heat loss ti'om the

_ B1o•drum 1.\'hcn tnc drum t;ets tull. some compost 1s extracted 1nto the rinrshmt; ura"er fh1s IS done ~1moiv h,· puthnc the drum locker. and rotaun~ the drum backwards :\ow. the drum aoor remams open . . md comou:.t ralls Into the :.ccond ch:J.mber - the compost rinisiung dra"cr

\d\·:mtagrs nf \omposttne in a 8io·Drum

Tumbling 1mpiants ox~·e~n throughout th~ compost lor u~e b,· arro01c bact~rt3 • Tumbling ensures that the bulking material is w~ll mixed into 1he compost. - The screen :u the rear ensures the compost does not get salur:ncd and dnve out lhr 1nygen

Tumbling dislrlbules the moisture evrnly throu~J;houl the compost The compos1 is shielded from direct heat and so does nor dry out.

- The mass in the drum enables the compost to hold warmth in the core of the composL-

The Compost Finishin~ Drawer

'

The comoost rinssiunt; ura•.\cr. :i:c sccona sndeoenaent chamber. 1s below rnc comoostmc l!rum Jna 1ust aoove the evaooraum; ..:hamoc~ 1 .. moo:.t ::-s ::-:1s urJ\\Cr 1s totarlv 1suiatea from matenai sn tne Bto-drum. :·, ,urrounaca b\· ar.1ng &Jr. ami is no longer suo1cct w ..:untamsnauon :rom rrcsn waste lt IS

here that the comoostmt; ana sanuauon orocesses are comoicted. and the c:>moost cc::a:;~cs ~ate :o h.1ndlc The pull-out :inssn1m: c~:l\\t:r :s rcmO\ ca ::v n:ma ana the saruuzcd comoost mav be c:;~oucu ',\ ne:~c' c~ :t :s necessar.· to extract

----------------more comoost !rom me urum 1'..1 he auuoiv sate. compost 'houid nat be usc a on c::1blc ·. c:.:ct.loic:,

.\dvanr:u~es of a Separ:ue Compost 1-'inishins; Drawer

• Compostine un be completed in the drawer without contamination by fresh waste. Compost in che drawer is eradually dried ready for removal Finished compost can be simply and safely removed

The £\·apor:Jting ( 'hambcr

The third chamber. the b:1sc or the"toalet. 1s the evapor:1ung surtacc r'i'om where :lnyP-. .. ••111•1111 e:ccess liquids whach c:1nnot be :1bsorbcd by the compost arc cv:1porated or dra1ned. i: · i ;_·~~5, Air is drawn an throuuh mtake holes :1t the base or' the toalct. over the e\'3poraung .. ~~ .. Surface. and up the v~nt stack. On electric models. air is drawn in by a fan. while ·: r·.··'"'~·-··· ,-~ non electric models use natural draft induced by the chimney effect or a 4" vent ' ~~'-~i~ . ~-

~ stack. In both cases a partial vacuum IS maintained which ensures that no odors can ~~=·=~i~~-~~ escape. Evaporation is assisted on electric models by a thermostatically controlled · ··· ·P-''"'"' heating element an a sealed compartment underneath the evaporaung ch:1mber This heater keeps the tloor of the chamber warm

.-\dvanta~es of a Separate F:vaporatine Chamber

The l;trl!C ~urfacc :1rl"a m;uimtze~ rvaporauon. • .\ laree \nlume nf air mo\'l'~ direcrh' o\·er the l'\'aporacine surface to ~peed moisture removal . . \ base hearer din•t•tl\· n arms the t•,·:aporatc for opumum rl."sulls. ( Electrtc unns only!)

MODEL SELECTION

There are two different categories of Sun-Mar systems to choose from. Self Contamed units or Central Composunc r oilet Svstems :\II of our models. some 15 in number. tit into one or other category Within .:Jch catc~orv \\C o1fcr umts tor anv power svstcm. on-gnd. otf-gnd. or no power at all

Findanl! the toilet best suued to vour needs is as easv as selecung the nght c:uccorv and then answenng a few \lmptc questions

/(.·~ ; . ~ 'I ' i l \ --·';

: ""'\"::'!... •. ~'.} -... ~

SELF CO~T .. \I:"F.D I ':"ITS

\re waterle~s. :1nd so rcquarc no plumbing wr \\:Her connection or sewage rhis means mstallauon 1s \ crv qu1ck ana c:1sv \rc more suuco to wmter nocrauon oecJusc 11 :> ,Jlten c:lslcr to kc:ep the

bathroom w:trm \fest tcspcc1ailv cicctw.: umtsl ..:an cvaoor:llc ail h4uHis. ><l approvals arc not normallv rcqu•rcd Are J\ a!lablc m wtli:rcnt capacav umts

CF.:"TR\1. CO\JPOSTI"'(; TOII.FT S\'STF.\IS

·\re •deal tor ~~~1sc \\no want a rcl.!ular loolo.ml! tc'dct m tnc bathroom. tlr

·.\hO \\.101 to _.1nnc:;: mort: th:ln <'rlt.: :odct tl' tnt: C<lmCt)SliOI.! unit .\rc norm:ulv r:accu under <'r nursadc tr:..: h:lthroom l.'mts arc orien up to :J or more :: .:·.,,IV

.·\re ott en una01c to ..:vaoor:llc allllushml! ia.Ju1d t 1Lm\'l l'his excess ,hould rc C>liiCC!CO m dramca to an lOp~ov~cJ tJ.cliuv

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_4i'~7f4' ~ The Sun-Mar Centrex Plus . .

~//.0,, / Follow this link to our ncwcs; produ~:t ian~- m:1de especially for residential /' (' :1nd high ~:ott:1ge 1:3p3~:sty use Titis eJt~:stsng development brings the

• o envtronment:ll and cost advant:lgcs of the composung toile.t into the home.

For over 1~ \"C:lrs Sun-,\lar ~:ott:lsze tmlets h:1ve been the 1dc:1l soluuon lor -·-·· ·--·-[ottaues·. ~abins. ~:amps. ur remo'le work places. Sun-Mar totlet systems are

·c."CCnomsc::ll. qurck to anstall. :1nd casv to use. ~1:1nv models require no water - ·--':'~-supply or plumbing

Sun-Mar Systems (Prices from Jade Mountain)

Excel N.E. (Bowli ,\:£.) S949 Our best seller - needs no water or cicctncity Large 4" vent pipe facilitates atr-tlow and eliminates the need for clcctncity. Handles a family of 4-6 for cottage usc with ample capacity for guests. Eastly scn·es 2-3 people on a continuous basis. The 2 watt. 1:! volt fan option (5 -16) increases capacuy and cvapor<~tion for heavy or rcstdcnual usc. Fan opuon uses 1.4 watts. 571bs 22.5"\V :-..: 29"H :-..: 32"L.

Compact Compo."iting Toilet S/049 Not much larger than a conventional toilet All the same h1gh quahty fc:1turcs of the other Sun-M:1r models m a small pacb;;c Bto­drum tumbles compost for supcnor m1:xtng, :lCf:lUon. and compostmg speed :hrec mdcpcndcm ch:1mbcrs for composung. compost timshmg. and e\ aoorauon :) JSe neater maxtmlzcs c\·:lpor:ltlon \\ hdc m:lmtammg m01st compost. 810-Jrum rc\·crses to -rroo compost Into puU-ouL drJ\\·cr . .3-5 people for \vcck-cnd t~-pc usc. 2 pcopic conunuous 2::.5" W x 3l"H :-..: 32" L. -+5 lbs I 15V he:ltcr :1nd fan a\·er:lgc I 25 \\alts

AC/DC Composting Toilet ACIDC S 1239 I .-1 C vniy Sl U9 Usc when you have AC power. l:!V power. or no power at all . The popular Sun-Mar Bowh Excel now comes mth du:1l ,-em st:1cks and O\·crt1ow drams \\ nen \ ou haYe cxtr:l power for ~-our m\·crter or h:1vc :1 generator on. you c:1n ooer:uc n from .-\. C Jnd mcrc:1sc the capacuy \\ ncn you need to conscn·c power. you c:1n usc It m the non-eicctnc mode or wtth the opuon:ll l::: V fan The perfect ch01ce when you expect occ:lsionJl ~ucsts \ \'orks well bcc:1usc pcopic usually h:l\ c more\ Isuors durmg the summer \\hen Sl)Lar o.:mcis oroducc more po\\~o.'r J.nd ~;;cner:ltors arc more bus\· mth bulidmg pro_1cw; :mJ othcr _lllOS \\'nh power avatlablc. c:1pacay r:ltcd {,Ox people mtcrrnlltcnt usc and -t.r. people commuous. \\'ilh power \ ou can plan ..+.r. people !'or J few days at :1 lime Jnd 2- ~ :)copi.: on ;m ..:•. cr. CJ\ DJSIS Fan uses I -+ \\:lltS. \\ 1th hcJtcr I 25 \\atts.

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. • 'J."

Centre_-c $949- Sl279 Improved low-t1ush ccnual co~postcrs High capacity electric, non-electric. AC/DC models. Uses the same bio-drum and three chambers as the older model Bowli-WCM and adds several impro\'cments. The height lowered from 31" to only 26.5" -more locations workable .. The inlet accc:Ss can come from any direction. The \'Cnt pipe now comes from the from and makes many installatrons easier. All the components including the fan and

.. -removable thermostat now mount on the from for easier access. AC/DC version has dual -. .-vents and opuonal 12V fan. New ··Air Flush"' models for usc \\ithout water. Vent kit

included .

Aqua Iron (I!IID/Dflloa/ C~:~mp~:~sllng Toilet with Water Closet) I!!Xcerpts lrwm Aquatron hDmepage

hllp://WWIN.InfDnu.se/FDretag/AQUATRD:Z.HTM

P:isvcnsl\a :.;ck'

fhe full~· rompostmc tOih.•t ~~'tcm .\!juatron -h!Uil

fhe toilet sv~rcm :\LlUatron 4't.Z00 is based on the .-\uuatron separator '.\hlch sccaratcs ltoUtd and faccals from an ordmarv iow rlushmg \Vater toilet fhc hqu1d 1s dramcd orr ro a ~-trev \\ atcr sewage and Infiltrated •nto thc :..:~c~und r.tccals and paper fall into a composun~ cox - .

In :\ttu.Jtrnn -h.:·Hl thc \\:JStc IS rullv comoostcd and thc ..:nu nrnuucr ;-; canh The bwlog1cal comcosttnl,! ·ncans : ::;t: :::t.: ·., •1umc t'f t:Jrth 1~ <lniv I 1).1 ~ pcrcc:-tt , 11 rh.: , ·r ll!tnal , ·•iurm: ,,, so ltd \\Otstc atldcd \<JU:l!ft•n h.:'.'') tl!lcrs \llnOiC handhnl! r::c mnt:r Clnt:Jtr.C~ ·.•.:ttl ltlUI' ~llffipOSllnl; bO'tt:S IS turned

,;,Jcl-.•.\"t: :.• ,::.lnl!c t•"-: ( ·hJnl!IOI,! t•r'~nxc\ 1" .:nnc ,:~:.1r:l·~:· .. •r '.\llt:n nccdcd .\!ic:r :1 ..:omoietc n~und <1 tr.c u::Jt.:~ _.·r.::ur.cr t.lllllut (>nc vt:;.tr later 1 rnc :~:..:.:ah .:~<.: :::!1\ .:1•mro,tctl anu ~Jn Dt: usctl m tnc ~.JrUt.:n

\dUJli('~ ·.·. I• .:::r-n".\.':.l i">\ :he '..l!lonai 'i·.\t.:UI>:l iL•.::..: :! L'u"tn~ tl\,>\t:~~o.ctl !n '-"•'vt:mDcr !''0 : \lore ·:-~an,. ".-.,tcrn\ IU\t: n..:cn sott1 anu mstarlcd :r. ''"~tc :.:::111\ n,,u~cs. -~nooh ,tnu orlicc cUtidmgs

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·Phoenix Co171posting Toilet . £xcerpts trolrf Phoenix ho~nepage

·· http://www.co~r~postlngtollet.co~r~/schnJitlc.hllrf

Phoenix Comp_osting Toilet Design Features /f/ - I. One or two toilets coMect to the Phoerux with 12 inch diameter pape. The toilets arc molded

from vandal resistant polyethylene and ASS plastac. - 2. Ventilation is provided by an efficient, 4 watt. direct current fan. - 3. The accumulated liquid is rcsprayed on top of

the pale to maintain moisture 4 Continuous air baffles aiong the tank sides provtde acrauon

- S The leakproof joint 1s accomplished w1th a gasket and intertockin2 n:an2e 6 Rolatim~ tines control the downward movement of the matenal m a he compost pile ~ .-\seated path titr vcnulauon arr. and a lan,!e ..:ontact area. mcrc:ase venulauon etticacncv and Jliow 'upplemcnt:~l hcaunL! l! Fimshcc.J ~:ompost rs rr-mo\red e:1sily through the lower access door from the enure oottom of the Phoenax assunng ma.x1mum :~nd unuorm rctenuon umc 9 A permanent medium provrdc:s secondary liquid lrc:ument bene:~th the sioped bottom batllc .-\rr tr:~vcls m.er the enure surr:~ce of the lrqu1d to mcre:~sc evaporauon and aerob1c .:ondruons I 0 Lrqurd rs separated !rom tne solids bv a ~creened baffie rtu.: dram l'onnecuon ~:an he made frnm cuher ssde through an m<.:h and a half :lc:'<rbic ilmc

Selecune a Site. Choosmg a sue tor a Phoemx racaiitv wril have ar.ll'Tlauc erfects on svstem capacity, budding dcsrgn. user accessrbilitv. energy use. mamtenance erfon. and construcuon cost. Thererorc. thougnttilllv consrder the needs or the composung totiet t and mamtcnance personnel) when selecting a me.

,mad deck to the hdlsicic:

Slopet.l rcrram. The Phoerux can be instalTcd on levei ~?round. but takrnl! advantage of sloped terram \\til reaucc the c.xcavauon reau1rcmcnts .ma Jikm ..:asrer ::cccss to the tanics tor maante:J:mcc It rs more converucnt tor mamtcnancc oersons to enter a riavhght basemcr:: :nrouL!il a ·. crtrcai door than to dcscer:u s:arrs mto a ruil basement :\ davlighted basemcr:r CJ:J atso oc smatier. smce large doors tn tror.: ot cacn Phocmx oe:mlt the requtred mamtc:Jar..:c ::rca 10 cx:cnc cutsade the building \\ c rc..:om:ncr:a a ..J.l\'lll.!htcc basement tithe tc:-ratr: s:oces .:.o Jegrecs or more .-\ccess to the rnuct :;:oms ts orovrticd easuv bv extending a

Nutterram rcqusrcs a ti.Jll basement or an elevated building. in a litll husement. an alternating-tread $tlurcase allows compact. convement access to the tank area. Pro\1ding a S-foot f 1.5 metres) area in front

'of the Phoeruxcs. armiciallighting, and retlecti..,·e white walls. tacilitates maintenance. Avoid a flooded basement by buddim; above rnaxsmum high ground water. elevating the building slightly, sloping soil away from the toundauon. :md adhenng to good dr3inage practices.

If htKh ground 11·uter or tmpelletrable roclc precludes excavation. an ele\'tJted butldm,:: is necessary. A staJrwav. or an extended ramp ror universal access. IS required for user access. We have constructed a bench tvpe toilet th:u reduces door height. and a scrpcnnne r:~mp around the building, tor these situations.

Disposal of liquids. Su1tablc conditions must cxsst tor disposing of the liquid end product from the • Phoemx lflocai conditions. such :1s high ground water. preclude a leach field. then provide a holding

tank. a rassed bed evapotranspiration system. or a Phoemx iiqusd evaporauon system. A holding tank · requtres stnct attenuon to prevent overtlows.

Prevrntin2 unauthorized dumpin~ and vandalism. If the Phoensx is located ncar a parking area. the des1gn must prevent the cmptymg ofrccrcauonai vehicle holding tanks mto the tOilet. Locate the building tar enough awav trom the pa.rkmg area tha.t drain hoses cannot rca.ch it. or elevate the building slightly so that the todet IS above a.n R V's holding tank. ProVJde a waste dump nca.r the building that offers a ~onvenu:nt a.ltemauvc. Jnd post Sls,tns advi!11m; users :1gamst dump&nf.! chcm1cai toilets and holding tanks mto the Phoemx

'•mliariv !, •cate tr;t>il ems anc.i ~ll!arcttc c.itsposal ~ontamcrs unmec.iiJ.Ictv nms1dc the budding to reduce m1suse or the Phocmx tt' trasn collection needs to be mm1m1zea. J tra.sh contamer ms1dc the toilet room w1ll mtercept those Intent upon m1suse. whtlc not attra.cung others 10 d1sposc of the1r trash.

Designing the building, :-.I early any building design satisfying the following conditions is compatible with the Phoerux:

The Phoerux must be located directly below the toilet(s).

The tank must rest upon a smooth. level. flat surface.

Converuent access. good lighting :md venulation. and adequate sp:1ce m front oi the Phoerux. must be pro\1ded for mamtenance operauons

.\deauate scace rnr storm~ the bulkinf.! agent a.nd suppiies must be prov1dcd

The Phoentx -l-1nch ( l 0 1 mm 1 DWV venulauon p1pe should be supported bv the butldim:z trarn.mg. and extend above the roof ridge for proper a1r t1ow -

.-\ dram. huldmg tank. ur cvaporauon system for the liqu1d end product must be proV1ded J

Electncav must be avatlable tor the Phoentx s venulation fan. pump( s). and other systems

The ta.nk area must be mamta.med at or above the temperature upon whtch rhc Phoemx s capacav rarm~ 1s based

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Placinrc the tank. The dimensions ofthe Phoenix's components and installation c:learances are shown tn Fibrures I through 6 (to be added soon1. The Phoerux liquid end product's dram connects to predrilled holes in the forward lower comer on either stde of the tank. The drain is supplied with five feet of flexible hose tor connec:ttng to a floor drain or another tank. In either case. the hose should be kept out of the way of mamtenancc activities.

Provtde convenient access to the Phoenix so that the composted end product an be removed easilv from the basement area. It is very converucnt wtth a daylighted basement to locate a 3-foot (I metre 1-wide or larger door directly in front of each Phoerux so that the composted material an be shoveled directly into a wheelbarrow or other container ewe provide a bin). For full basements. a good stairway is essenual. Ladders and wall-mounted runus not onlv are inconvenient. they are dangerous. Lapeyre manufactures; very compact 56-degree

3Jtem3ung tread stair that is quite conventent tor basement access

Placine: the toilets & urinals. One or two toilets can connect to a Phoentx tank. The I 2-inc:h (305mm) diameter toilet chutes can enter the Phoemx tank top anywhere within the dashed lines an Figure S. ;tlthoul!h ccntcnn~_; the chutes as preterable For a two-toalet in~tallation. the toalets must be located back-to-nack a~:aanst 3 common p3nltlon wall Oimcnsaons of the Phoemx tnalets 3nd anstatlauon dear3nces arc shown an the tollowanl! tigurc

.·\ traoless porcelaan or 'it3anless steel unnal can be connected to the Phoemx. wnh conventional 1-112-inch ( 38mma 0\V\" p1pe rhe pape must slope conunuousiv toward the Phoemx. and enter tr.e tank at least b anches 1 151mml awav tram s1dc wails. The OWV oaoe connects to the unnai dram and extends ventc:ally through the floor or horizontally through the wall.

Options for managing the liquid end product. Your selection of a site and building design should accommodate a sensable system for disposing of the liquid end product from the Phoerux. as not all liquid will be evaporated. Three strategies are viable (but some are better than others 1

;.;;~~~;;ii; Ground disposal on-sue. If soil conditions and pen anent em1rorunental consrderauons are tavorable. the simplest strategy as papmg the liquid to a small leach tield If high ground water and/or a thm soli laver as a problem. an eanhen ra1sed bed can be constructed

(~(f.,·uc ciJsno.\ai. r!:c excess ilautd c::n be :ranstcr~c: 1r.to a nolding tank. and subsequenttv diseased of at an approvca snc

E\·aporatwn rm-.we. :\ secondarv evaporauon svstem 1s a \Uble strate~_;y m warm. drv climates L'nder tavorable conamons. the Phoemx s compamon evaporauon svstem can cvaoorate ail of the liquid end product and limned amounts of gravwater In coid. hurrud siti::s. no appreciable evaporauon occurs Please see Appendax .-\. ana/Or contact us. tor stte·specllic mtormauon on cvaoorauon svstems

Th~ nnlilation W~t~m. r::c Phoemx IS Cl!UIDC1C:.i .... :th a ru~L!ed . ..:fficaent. vcnutau~n svstem The tan housmc ;~ounts mrectlv ~ver a

!'recut hole on either s1de or the tank ton. or at anv Pther accessabie lccauon tn :he tJ.::K tot' ihis allows ~!'le tan:,, tH! ·~:cancc cJ.s1iv w11hout rcmo\·mc 11 rr~m tnc nt~u~mc .... -~ :o nc re:::a.:ec e..!S!Iv

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Four-men flc:tlble hose co Meets the tan housmg to 4-inch ( 1 02mm 1 DWV pipe. The hose and pipe are ' -' easily contamcd \VIthin a o-mch ( 15:mml tramed wail. The pipe and hose should slope conunuously

towards the fan housmg so that liquid trom r:un or condensauon will run back to the fan dram. A fairly honzontal run of hose should be supponed so 1t does not sag, as a sagging secuon will fill with liquid and

~· .:::• blockventdation ' '·

The 4-mch ( lO::!mml DWV p1pe should cxu through the roof near the ndge to avoid potenual snow loads and downdr:uis Severai shroud arrangements c:tn conce:ll one or several juxtaposed Phoerux and evaporator vent p1pes as long as the exhaust a1r Cltlts several feet above the roof in an upward direction. It IS unacceptable to enclose any vents m a louvered cupola .

. , ~· .;. 'j -- .j ~. '.

If the Phoe~l~ IS used in subfreezmg 'icmperatures. ;nsulating the extenor vent pipe and the interior secuons passmg through cold areas helps prevent condensation and freezmg. The room in which the Phoemx as located should be proVIded With a 15 -square-inch ( I 50-square-em 1 openmg for ventilation makeup a1r

The electric:ll system. All clectncal dev1ces and acci:ssones supplied with the Phoemx operate on direct current e:othaust fans. pumps. light tixtures. :md the system monitor and controller. Twelve-volt systems are the dct3ult. but 1~--.·oit svstems are avatlable (we mstall both. and can help you determme which is hest tor vour sauauon 1 I r power trom a uulitv's dectnc:1i gnd is not ava1lablc. clcctncal reau1rements can

·be met rrom an mdepcndent ~cncraung system. such as our photovoltalc svstcm We pro"1de an a. c. power suppiy for u~c where I :o or .:-tO-vult a 1: 1s :1vatlablc

l~~~~~~~~~~~~iii Pbocovoltaies. If a photovoltaic system is reqund. provtsions must be made for mounting the photovoltaic array in an unshaded area, routing the array output conductors into the building, and locating the baneries and conuoller in the maintenance area (please see Advanced Composting Systems Photovo/taic System Appllcauon Gu1de) If utility supplied electricity is available, locate an electncal outlet close to the Phoenix for the power supply and controller.

Str:ue~ies for mana~ing the tank temperature. As expiamed above. the Phoemx must be m a warm enVIronment to compost etfecuvely. The composting process Itself generates energy that mcreases the temoer:uure or· the compost pile. but first the compost p1ie must be warm enough for sufficient actiVIty to take place :\s the temperature of the PhoerJ:ot IS mcreased. the

rate of composun~ and heat generauon mcreascs

In a below-ground basement. the predomm:mt mtluencc on the temperature of the tank room IS the temperature of the ground. wh1ch can be much cooler than the outside a1r temperature during the season of usc. !\1oreover. m some climates the outs1de a1r temperature vanes greatlv throughout a 24-hour penod If the amb1ent temperature m the Phoerux room drops below o5 degrees F ( 18C). the tank cools :1nd the rate or" decompOSitiOn declines sharoiv. reducmg capac1tv :\t amb1ent temperatures of 55 ( 13() Jegrecs F .:ma lower. comoosum; slows to a vtrtuai stanasttil

Prevenune a cold t:mk room. !3aslcailv tt:c~e :1re three strategies

:n.\"Uiutwn r::c tir~t )teo I) msulatm(! tne cmtre :ani< room. mciudinu the rloor and foundauon walls to reduce nc:at loss to :ne grouna

Suppt.·mo:111at heat tor the: wnK room wzu or ta!IK. In a wdl msuiated room. a relauveiv modest mput of cnen._.._. results tr. J. Sll!ntricant nse m temoerature \\'e have constructed manv bu1ldin11.s mcorooraun~t an .Jcttv~ soiar ;;t'ticctor 1n tne root framml! I!ot a1r trom tnts cotiector 1s ductea mto th~ tank r~om. o~ to tne Phoen1'\ s ;m tr.lct C unvenuonal clectnc or ~as soace heaters aiso can be u~cd to heat the room

.-\-I I

_- -- -Tanic mocidkarum. In some C:Jrcumstances_.supplemerttarv Insulation wrapped around the tank can be an -- · _c:ffec:trve strategy t(lr reduang the rate of heat loss thr~uyn the tank.

We have mam1 ye:~rs or" expenence 10 designing and installing temperature management systems. and we would be haopy ro help vou analvze -:nur suuauon and 1denur\· the most productive temperature management str:ue~y

~ M~inte~ance requiremen-ts .

. . ~The Pho~mx opera~es much like a ~:~en c~mpost pile. requirin~ adequate food. air, morsture. and heat to support the organisms that transrorm wastes 1nto a stable end produc_f:.. "I:he key rmished material shouJd be removed from the Phoenix at least annually beginning after the first year of use. Approximately 12 trays ofmatenal (90 U.S. gallons. JSO liters, or ·12 cubic feet) shouJd be removed &om beneath the unes. The amount of solid end product which must be removed from the Phoeaix so use is sustainable will be about JO liters (8 gallons) for every 1,000 uses, less if the tank is used at a lower rue or receives mostly urine. If this is too much, some material can be reintroduced at the top of the tank to maJntain the compost level or some loosened material c311 be left in the cle311 out area below the tines.

The tinished end product must be h311dled carefully since 1t can cont3Jn some parasues and pathogens. However. :t also cont3Jns valuable nutnents. Buryrng It near some plar.:_ ... ;; allow tnese nutrients to be reused If it IS pasteurized first. the smail quantity ofPhoemx solid end product c311 be used for revegetation uhc p3steunzer·s heat source C311 be a solar collcc:on

Liquid end product. After tiltenng through the compost pile. the liqurd receiVes secondary treatment in the well-aerated. stable. peat moss medium beneath the bottom baffle. The stabilitv and tremenoco.. .. surface area of peat proVIdes an excellent filtering medium for treaung hquid. · -

The amount ofliqu1d discharged from the Phoenix depends upon the amount of use 1t receives. and the temperature and relauve hum1ditv of the ventilation a1r. Approximately .!0 liters 1 5 gailons ) ofliquid is added to the Phoemx tor everv I 00 uses

I nummg \ enulauon a1r c1rculaun~ above the secondary liqu1d treatment med1um can evaporate some of th1s hqwd The remammg hqu1d drammg trom the tank should be d1rectea to a leachmg rield. holding tank. or a secondar.· evaporator r!le hqu1d end product contams cnns1aeracic bactena and dissolved ,aJts. but cenerailv has a 1nw coliform md1cator concentration ,. :'JO orl!.' J•JO m11. iuw BOD. •-=50m~utre 1 and low rss c· i IJO m~U I ure1 compared to secuc :anK crllucnt. su a snort t10-ti>ou3-rnetreJic;Jcn line 1s J.il that I!> necessary ·

Zero discharge. If the Phocmx as loc:ued m a!) area where ~cro UlscharL!c I\ Jcs1reo or mandatorv, the liqu1d can be stored m a holdmg tank for penodic removal. or 11 can be cilmmateo wuh a secondary evaporauon svstem Either a small evapotr311Splratlon bed or a compact acuve evaporator system can be emploved We can ass1st wuh design of the former and can supply the latter Our hquici evaporation system mcludes J stora~e tank for peak loadmg, and a vent S\'stem ana contrOls to oourruze evaporauon while usm~_; cncn.·y erficJcntiv Please ~_;et m touch wnh us ror ::tid1uon:u mr·orm:mor.

._,

A-12

Nature-Loa ~cerpts from Nature·LDo homepage http://www.ozemail.eom.au/-nal/oo/love.html

The DO-IT-YOURSELF (DIY) 1Yature-Loo

With international freight costs being what they are. ordering an indi1•iduai Nature-Loo from outside Australia probab(v isn't an option. If owner. with the right plans. yo11 can build your own Naturc-l.uu !rt)•/e composting toilet fnr a ltJI less than a ctJmmercial(v manufactund unit.

~o one else can do what we do with a tOilet Believe us. We've checked ~ature-Loo as the most etiicicnt composung totlet on earth.

rhe !'ature-Luo saves orecmus drinkml,! water It stops a tilthv amount of f'IOIIUttOn and It produces heaUUIUi fertthser It doesn't leap tair bulidinL!S. OUt hev. "h:u do vnu \\;tnt trom a 101let'

rhe rcallv \\Ondertul thmL! ~~ th:u u·~ so s1mple. vou can make 11 voursdf You \\On't even need ;1 duld ll> help you read the mstructtons rhc conc1se •ntormauve o4 pag~.: !\ature·l.ou Do-lt· Yourself Plans & I nstrucuon ~ tanual spells evervthmg out. wuh ZJ pages of detailed drawmgs on exactly how to make 1t work w1th a vanetv ofmatenals If you're willing to proVIde the hard work. you can produce a .\lature·Loo everv bit as efficient as the tullv manufactured umt

fhe !\ature·l.<>U DIY Plans,\: lnstrucuon \lanual also mcludes 1dcas on \\hat second hand matenals vou ..::m recvcie to make the tina! cost even cheaper In tact. you couid have a svstem cies1gned for constant use bv 4 to C> people nn a tuli ume bas1s m operation wuhin a ti:w davs tor a t'rJctlon of the cost of a

- commcrc1al unn

\\'c can also sucpi\ :nrormauon :mu drawml!s on what to Jo \\llh vllur t.:rcV'-\atl:r: :~~m vour. laundrv. ~1tchc!1 Jnc.l h:uhroPml Y.•u mtl!nt nnt \"tnt to drmk vr,ur n::l!h\\.1tcr rut \Pur :.:::ruc:1 '·"ii love l!

Massive Price Reduction · Ut.:till( .·a trmn I 'SS 135 to olt/1· I SS5t!J

Best ot .1!! .liunt.: \\lth '-<'llf '..tturc-l.uu Do It Yuursett'P!Jns ,\:. lnstru~uon \Lmu;u · . .,u also ~et ail the ''JCk uo .1nd Jd\t<.:c ::~:tt \<•u rn:l\ nl:ctl !:'. l:mali lf·.ou na\l: .1 •!UC.:Slll'n. ;u,t :1'" 1.\'<.: i-.now more about .. :~lmoo..,ttnL! rc'dcts ~~~!n .l!l'-·'nc '·'·L'\t: t:'-t:r met o~Hnl! t:'.t:n.1htn1.! \.,ursclr"f~\':11 , •. :r·atc:1..:J.n it.:Jd to some ·:astv mt~tJl-..l:s \\'-· 1-.rllm t l· . .:r tnt: H':tr> \\C\l: maoc them all \\.llh t:1c '..nur<.:-1.,'•' DIY P!ans 6.: lnstnJc::;'n \IJnU.ll ·.,·u .:.::1 .:,, 11 .,,,urs<.:t! :,, .1 orm.:n cJ<.:s1.!n Y 'lll!ct ::ti :he !·.:nc:its .•t Jmm.! 1t vourseif

·.\ttn n''r.t: ~'t" tht.! :~.!:"'l"'i~'

i"hc 1:1\<.:,:m.:r.r ::l·~:.:~u :.• ::.:'.l: .1 '..tturc·l .:.: Uo·lt· Y.•ursc:t· P!:!ns ,\:. !;,,tn.;c::.·:: \l.:nuJI J: \Our olacc ~lt:ii(Jl: .~ ..:.~lll'.,lt: l'! ... ,:1..:'1'\.S i' :i:": t ~ ~~ .. ·: . ....:tuUtnl! .!trmatl ~~n\L1L!t.: .~nu hJ~~Ut1!1~

A-13

Ekolei-Co17'1posling Toilet 1/becerpts from Elcolet homepage http://llnal.dystopia.tl/ekolet/yearuse.hlm

The EKOJ.J=:T - Gomposting. Toilet - · - ·· · A toilet tor year-round use

•-,

The £kolet toilet for year-round use composts toilet and food w•sre and biolo~ically deans liquids. It :also allows for the use of a h:1nd showt"r. fhere as suffic!ent r:apacit~· for conunual use by 1-7 people.

The to del is made up of a pedestal in the w :a:shroom ... ~elf plus a rotatine. four-compartment compostine tank beneath the floor. rhe clectracally :assasted air circulation lhroueh the venul:uion pipe keeps the toilet completely odor-free. fhe e:uernal appearance of the toilet is just like that of an ordinary water roilet. ~o additives are needed. and no seweraee pipes or water for flushine.

When one compartment an the compostine tank is full. a thin layer of soil or compost ·~ sprinkled onr the top. and a new compartment ror:ued inro position. Dependine on use. a new compartment is JIUl an place. and the re:ad~·-1o-use compost

removrd. at intervals of abour a year. fhe compost. which can be taken out \'ia a side door. lakes 1he form of a ready-ro-use. nearly odorlt-,, ft-rtilizt-r which can be spread \lr:ueht on1o plants. fhe biologrrallv rle:an~rlllif!UIIi,. can be parJed. alont! '"1h household nash me w:aler. 11110 a \Cpllc lank. and from I here oul rruo n:uure.

!"he t:l,olt•l I\ "mple :and rrliahle 111 rons1rucuon. and can al~o he 11\l'll durrne t•trenllrd power cuts. It conr:uns no monne or re,·olvine parts which could break or ht"cornc hlorkcd and prevcnr u~e nf I he lnrk-1. !"he IOIII.'t seat is 1.':15\" In n•rno\1' fur rlunrne. Bt-rause of the t:kolel' s \ ertacal ronstrucuon. il reqUJrrs unh a 'mall floor are:a .. \n mdica1or lieht show me nhen the waste rompartmenc in use 1s full. is available as an optional extra.

l'ht rornfHl\1111!! toilel IS manufaclurrd of lnnl!-la,llnl! mall'rrais 1h:11 ran Ill' n•c,·cied. :rnd rh:ll "'II rwl 1~1 an\· harmful ~uhsl:lllrl.'~ 111111 lh~ n:Jiur~ .

. -\-1~

.,

Excerpts from laboratory analysis of Ekolct compost

The compost is well broken down. The level of coliform bacteria is very low. i.e. all hazardous cpou:ntially

harmful to health} micro-organisms are killed durin~; the composting process.

Ekolet compost is :an excellent o~anic fertilizer :ts it contains relatively hi~h levels of nicrogen and

phosphorus. which are easily assimilated by plants.

fF ' r . .-9~~. Coliform bacteria

! <l:p~~l lp lS°C

IN 12.6% IK jt.S% I E. coli

! ~11.&-:\ '0.2% ,12 i O.S~o Salmonella ! :"'one

:"j()J."', ,,,7~;. J>h ! o.o~·o l>ry rbalter content iO.O% I - . . .. -·-

I Laboratof')· .\nalysis of Liquids :

I DESCRIPTIO~ /units IEKOLET !wASHING TOILET 1) lwATER2)

I Pll I· 17 5 I· jam>-; - .\TU lmg 02.'1 ~~ 128

)CODer !mg 02.'L ,~2 I· JWhole nuroeen. :-< jmg.d I~ 9 19.5

i Whole phosphorus. I' !mgt I ~~ 2 !0.2~

.\mmomurn nitroeen .. \:II-'·" mg.~ I :: ~ . C:tdmmm. < ·c..1 ;m~l ··o 001

'1errun. lh~ m~,;:l ,·.() ooo: . Fecal coliform h:tcrena. J-l.5°(' unns:ml 1) -

' !l10lm!t<.::ulv trt:.:ltcc.l l!o~utc.l t'r0m .tn Li-.. ... lict c:omoosunu tolit:t m ., t:Jr-r< 'Unc.l usc bv :.lur r..:rsons Jticr St:c.ltmt:ntJ!lon m .1 normJt :.t::JllC t.:m~o; t ':' JJVSI

:\.-15

Providi~g s-usta~~able ~: -· - -

SOlutions-for :the Sanitation - ... -~- . ··~"-···'¥~ .. . . --. . . . : . .

Needs of-~the- Pacific Islands

~-_, :Z.,. i-· .... '·-·~-::

-.*r, .. · .-; •. :~~ •. -

Protection Agenc:y in Pohnpei and in Chuuk States have failed due to

. lack of trained personnel and _fund-ing for maintenance. .::_~""}, -~.,..,

j:"" .. _::_,..

In addition, septic systems used in some rural areas arc said to be of pOQr design and construction, while pour-flush toilets and . latrin~s-which frequently overflow in heavv rains-are more common. Over-the-water latrines are found in many coastal areas as well.

Eutrophication

Water res<ources in the South Pacific, like this waterway in Kosrae, are contami­nated by poorly functioning wastewater treatment systems, jeopardizing both public and environmental health.

In the ~tarshall Islands. signs of eutrophication resulting from sewage disposal are evident next to settlements. particularly urban cen­ters. Acconling to a draft by th~ ~larshall Islands :--:E~lS, "one-gallon blooms occur along the coastline in ~lajuro and Ebeye, and are especial­ly apparent on the lagoon side adja­cent to households lacking toilet facilities.·· Stagnation of lagoon w;lters. rL·ct dt:grad;l!ion and tish '-;iih rl·~ultllll! rrnrn me iow ll'\·els of oxn;en have been \Veil documented over the wJrs .. \dditionally. n:d

tides plal!ue tt11.: lagoon waters adja­cent to \lajuru.

:t!fi~ .. roblem, the:Solution:-. ·.

The Problem in lllSl2. the South P:1c!!k Re~::tonal Erwtr(mmcnt Prol!ramme tSPREPl ,md a LmJ-IIased Pollutants lnnntory stated that "ltjhe disposal ut soltd and liqutJ wastes tparticu­larl\' nt human excrement and household l.!arbJI!C 111 urban areas l. \\"htcil i1an~ lonl! ptal!ued the i':tut>C. emen.;e nu1v a'> pcrhap~ tl1e tmernost regional environmental nrobll'm or the Je~alie. ··

i ltl!tl lt.:'-·ets llt recai coitrurm hacte­na ha\·e llt.:t:n round tn surt'ace and ~·oJstal \'.-aters. T~:c SPREP Land-

Sustainable Straregies

Based Sources of ~Ianoe Pollution InventorY describes the Federated States or \licronesia's sewage pollu­tiOn problems m stnking terms:

The prc\·alence ot water-related dis­~:.~ses .:::;d water qua!i,.n.· n:r:miton:-:1! data indicate that the sewage pollu­tant loadtnli to the environment is ven· higl1 .. \ recent waste qualitY :no111ton nl! studv t as part ot a workshop 1 \vas unable to tlnd a clean. uncontarninated.site 10 the holun:a. l'uhnpet Jrea.

Ct:n trJl \\"J'> rewa ter treatment plants constructed wtth tunds from Lnned State~ Ennronmental

Groundwater Pollution rilCfl' I~ ~il!l11!lGU1t groundwater ;1ollut1un in ttH: \l;usl1;ill Islands as welL Tllt.: \larst1all Island EP.-\ esti­~natc-. that more than :-s percent of the rurai weib tested are contami­nateu \\"ltn kcal colitorm anLI other bactcna. Chul~::ra. typhoid and \·ari­<JUS diJrrneal di'iorders all occur.

Sustatnabie Strategtes is a consortium of archttecturai and ecological engineers. '.Ve cJn oe reacnea at !52 Commomveatth Ave .. Concord. MA USA 01742 ;-'lone-vOICe-mall: 01-508-369-9440 i=ax: 01-508-369-2484 ~-mali: watercont..iU igc.aoc.org Worldwide vVeb oage: YVWW.ecologicat-engmeenng.com

Public health students and staff members at the Fiji School of Medicine, with the help of local residents, helped construct this non-polluting waterless toilet

How Conventional Systems Fail With very little industry present, most of these problems are blamed on domestic sewage, with the great­est contamination problems believed to bt.• from pit latrines. sep­tic tanks and the ~.:omplete lack of sanitation fadliti<:s tor 60 percent of rural lwu~l'lwiJ~ .. ·\~ i~ otten the case. poor Jes1~n and inappropriate plaom1L'nt ot these wstcms are Otten ILk!HiliL'd J\ tht: CJUS\: of COn­

tJmll1atiOI1 protJlcrns. In tact. even tile best ot these W'itt:ms 111 the

most ta\·orable \OJ! conditions

a II ow \ i g n .ti­cant

amounts ot

nutrients and pathogens into the surrounding environment, and the soil characteristics and high · r table typically found on ate: ~-

• .ificantly inhibits treatment. in addition, the lack of proper mainte­nance, due a lack of equipment to pump out septic tanks, is likely to have degraded the performance of these systems even further.

Forty percent of the population in the Republic ot Palau is served by a secondary 'iewagc treatment plant m the state of 1-.:oror. whidl 1s gen­erally thought to pro,·idc adequate treatment. Howe\·er the 1-.:uror State government has recent!\· expressed ~.:oncern o\·er the possible contami­nation of \lalakal Harbor. 1nto which the plant discharges ... \Iso. some low-l,·ing areas ser\'ed by the svstem cxpericm:e periodic ba~.:k­flows of sewage which run into mangron Jrca~. due tu mechanical failures mth pumps and cle~o:mcal power out:1ges. In other low-lying

areas not con~red b~· the sewer , __ __, __ system. septic t:mks and latrines

are used. which also o\·erflow. affecting marine water quality.

In some commun1t1es. ecolog1cal waste­water systems produce fertilizer for plants.

Rural areas primaril\· rely on latrines. causmg lo~.:al­ized marine wntammation

in some areas. Though there hav~ been an increasing number of sep­tic systems installed as part of a rural sanitation program funded by

·- the United States, there is anecdo-tal evidence that they may not be very effective. \!any of the septic tank leach fields may not be of adequate size. In addition, anum­ber of the systems are not used ;;;: all, as some families prefer instead to use latrines since the actUal toi- · lets and enclosures are not provid- .. ed with the septic tanks as part of the program.

Piggery Pollution on Pohnpei Wastewater problems als ult from agriculture. Accord •he EPA, pig waste is conside: .: "1nre o;i<m :f:.:ant .,roblerr: human se·.· lge in many..&"'--··

The Solution Ecological Toilet Demonstration Projects In the South Pacific Since 1992. David Del Porto oi

·Sustainable Strategies has served as a design engineer and consultant to environmental organizations. Greenpeace. the Center tor Clean Development. the Republics ot Palau and Fiji and the Federated States of \fi~.:ronesia on proje~o:ts to demonstrate how composting toi­lets and \\'astewa ter l~ardcns r" can contribute to solving these prob­lems. Both the commercial Carousel toilet and concrete. site-built Soltran II toilets. designed IJ\· Del Porto and Luwell Robinson of Sustainable Strate~ies. ha\·e been successfullY demonstrated on se,·er­al deYeloping island nations oi the Pacific

The success of these projects has shown not onlY that these tech­nologies can work in de\·elopmg island nations nt the Pacitic's cli­mate. but that people readily accept

I • (

them and are willing and able to · ~rtorm the simple routine mainte­

nance \\'hi1ch they require.

Kosrae Sustainable Strategies, through Greenpeace. conducted a workshop in 1992 to install a large-capacity Vera Carousel biological toilet on the island of Kosrac. FS:\-f, at the home of the Chief of Sanitation. It has been used regularly by his fami­ly of five. with occasional visitors, since January 1993.

Yap Also in 1992, a version of the Carousel toilet made in Australia was installled and began operation at the Yap Institute of :--.:atural S<.:icnccs. in Yap .State. FS:\1. It has been used by the Institute's staff of three. as well as by several members or the director's family, who live in an adjactmt house.

Yap and Pohnpei Followmg the success of these demonst1rations, Sustainable Strategies designed a site-built com­posting toilet !Called "Soltran II") made from concrete, hca,·y fishing nets and other locally available rnatcnals. These units were piloted <>!1 tt:c islands of Yap and Pohnpei tluou.:h a proJect begun in 1994. Sub~e'1Ul:ntl\·. the FS\1 n:monal gowrnmcnt has begun to construct up to 40 additional units on !'ohnpci witl1 tunds lett over from a rural ~at11tJtHJ!1 pro.:ram .

. \!'ill dunn~.! tl1l' pro1cct. a \\.a\tL'\\.Jtcr l;Jrt.len 1 ~1 for the treat­ment ot greywatcr m·ash water) trom a wast11n>: machine was lmtJ!il'J at a private home. This ;lcroh!c l'\·apotranspiration garden bed. wh 1cl1 uses a \'ariety of plant \pecies round growing nearby, was reported b\' the owners to be suc­ccsstull\ preHnting any wastewater discharge trom clothes washing. \!ore recently. se\·eral of these gar­Jcm. inte~rated with site-built

composting toilets. have been built to provide zero-discharge treatment for preschool centers in Yap.

Republic ~f Fiji

Toilet Demonstration Project for Public Health Professionals In December-1996, Sustainable Strategit'S-conducted il ~orkshop in Fiji,_ sponsored byrhe South Pacific Commission: in which the two-chambered concrete-and-fish­net Soltran II was constructed.

The workshop was held both in the classrooms of the Fiji School of ~ledicine and in the Vatuvalcwa/Tovata settlement in :--.:asinu. a rural and remote settle­ment of citizens trom Lau. an outer island group of the Republic of Fiji. This settlement has no pub­lic utilities to support electric power, treated water or reticulated sewer-to-treatment plant system. The soil is not suitable for waste­water disposal by soil infiltration !i.~:: .. septic tanks). This settlement typifies rural \'illages on every island in the South and Western Pacific.

Resource management expert bavid Del Porto explains how a water-clean­ing plant can be harvested for animal feed.

The Fiji School of :\ledicinc has a three-year pro!!ram for the educa­tion and trainin~ of -;tudcnts prcpanng tor carl·crs as publi\: health and cn\·ironmcnt inspectors. Following their graduation: they will return to their island states and nations to perform these key roles in their communities. The entire third-year class and other visiting health inspectors participated in the lecture and construction work­shop. In addition. the members of the Vatuyalewa/Tovat<l settlement also participated in all len~ls of the program.

A villager m Pohnpei, FSM, constructed this enclosure around his waterless non-polluting toilet designed by Sustainable Strategies. The toilet can be used by a family of 15.

To be sustainable, resource management solutions should not only be ecological, they should involve local materials and local workers.

Republic of Palau

Establishing Biological Toilet Manufacturing Operations In December, 1996 the Koror State government of the Republic of Palau retained Sustainable Strategies to assist in developing the produc­tion capacity to manufacture the Carousel Toilet Systems on Palau. The first phast! onhe project involves designing and installing seven samtary facilities or comfort stations for use on the world­famous Rock Islands that are most frequented by tourists. Five of the facilities will have a capacity of about 75 to I 00 uses per day and two with 25 co 50 uses per day.

This sustainable development pro,ect will: • Pronde zero-discharge, non-pol­

luting sanitary facilities • Develop the manufacturing

operations for the Carousel com­post systems in Kuror for use m Palau and for export

• Training for new jobs as ecologi­cal technicians in constructing, operating and maintaining these environmentallv appropnate technologit!S

carousel compost toilet systems with 28 private toilet rooms. These facilities will be arranged in a shared-wall modular building or single or double units in scattered locations. The design will be har­monious with the natural beauty of the islands and rich cultural her­itage of Palau.

New Initiatives

Piggery Pollution A Small-Scale Piggel')' Pollution Prevention System Proposal is under development for early 1997.

This ecologicaJly integrated technol-ogy composts the fecal and feed ,.. • , '¥

spill solids and evaporates and tran­spires excess water into the air, avoiding wastewater discharge. Among the plants grown in the Wastewater Garden will be kangkon and water hyacinth to be used for high-protein pig feed. Construction and furniture-grade bamboo will be grown to we up remaining·water and nutrients. It is hoped that the production of feed from waste will create a valuable incentive for use of this technology by off-setting the high cost of commercial pig feed. The system will also be designed to mi.limize transmission of Leptospirosis through pig wastes.

Kankong and water hyacinth !40 percent crude protein when dried) will make good. low-cost pig feed. Commercial feed currently sells on­island for about S0.20-0.2S per pound, and that an average pig is fed five pounds a day. Given this exoense (more than .. <:r pig per: ~Jr), the cost of ~--.lstructing a Wastewater Garden would be returned over a relatively short peri­od of time. as plants grown in the garden replace a substantial amount of commerc1al feed. \Vater hyacinth. in parucular. is known to grow extreme!\· tJst tn nutrient-rich conditions. •

The se\·en tacillties will rcqu1rc 2S

A low-cost zero-dis­charge treatment system for \\·aste­water from small­scale piggeries w1ll be designed and tested in a pilot project on Pohnpei. The system will use Wastewater Garden technology and a modified Soltran II composter to con­vert the nutrient­rich pig waste into \·aluable plants.

A non-oolluting to1let system in Palau's Rock Islands uses locai oiants to treat water used for washing.

\ .. , Fl'eferences

Barnes, RS.K., Mann, K.H., 1991. Fundamentals of Aquatic Ecology. Boston: Blackwell Scientific Publications.

Bitton, G., 1994. Wastewater Mierobiology. New York: Wiley-Liss.

Brock, T.D., 1994. Biology of Microorganisms. Englewood Cliffs, NJ: Prentice Hall.

Canody (to be added)

Carter, B., Ramankutty, R, 1993. Toward an Environmental Strategy for Asia. Washington, D.C.: The World Bank Asia Technical Environment and Natural Resource Division.

. Day (to be added)

EPA (Environmental Protection Agency). 1980. Design Manual: Onsite Wastewater Treatment and Disposal Svstems, EPA #625,1-80-012., Washington, D.C.: EPA, Office ofWater Program Operations.

EPA (Environmental Protection Agency). 1993. Manual: Nitrogen Control. EPA #625/R-93/010, Cincinnati, OH: EPA, Office of Research and Development..

EPA (Environmental Protection Agency). 1987. Manual: Phosphorus Control, EPA# Cincinnati, OH: EPA, Office of Research and Development.

Feachem, R., Coghlan, J., 1983. Sanitation and Disease- Health Aspects ofExcrelta and Wastewater Management. New York: John Wiley & Sons.

Ferrell, M., 1996, Purifying Wastewater in Greenhouses. BioCycle, January 1996, pp 30-33.

Haandel, A.C. van, Lettinga, G., 1994. Anaerobic Sewage Treatment. A Practical Guide for Regions with a Hot Climate. New York: John Wiley & Sons.

Hammond, A.L., editor-in-chief, 1994. World Resources. New York: Oxford University Pr~ss.

Muller, K., 1992. Underwater Indonesia, Lincolnwood, IL: Passport Books.

National Research Council, 1993. Managing Wastewater in Coastal Urban Areas. Washington, D.C.: National Academy Presses.

Novotny, V., Olem, H., 1994. Water Oualitv Prevention. Identification and Management of Diffuse Pollution. New York: Van Nostrand Reinhold.

Polprasert, C., 1989. Organic Waste Recycling, 2nd Ed. New York: John Wiley & Sons.

Reed, S.C., Crites, R.W., Middlebrooks, E. J., 1995. Natural Svstems for Waste Management and Treatment, 2nd Ed. Washington, D.C.: McGraw-Hill, Inc.

\

THE

HUMANURE

HANDBOOK A GUIDE TO COMPOSTING HUMAN MANURE

(Emphasizing Minimum Technology and Maximum Hygienic Safety)

Copyright 1994 by Joseph C. jenkins All Rights Reserved

Third Printing

The author permits the use of substantial excerpts from this book, providing that the use of

such excerpts is not for the purpose of financial profit, and that the source of the informa­tion, including title of this book and the publisher's address, is acknowledged on the copied

information. This license is granted for the purpose of making information on the subject of

com posting humanure available to those people who cannot afford to purchase the entire book.

Correspondences and/or book orders may be addressed to: Jenkins Publishing, PO Box 607, Grove City, PA 16127 USA

ISBN 0-9644258-4-X Library of Congress Catalog Card Number: 95-94239

TEXT PRINTED WITH SOY INK ON 100% RECYCLED PAPER PROCESSED TOTALLY CHLORINE FREE.

TABLE OF CONTENTS

INTRODUCTORY INFORMATION Page?

Chapter 1 CRAP HAPPENS

Page 13 Soiled Water; Waste Reduction-Resource Recovery; Waste vs. Manure; Experience

Helps.

Chapter 2 MICRO HUSBANDRY

Page29 Naturalchemy; Gomer the Pile; The Carbon/Nitrogen Ratio; Misinformation; Have a

Good Blend; Newspaper; Lime.

Chapter 3 DEEP SHIT

Page 51 Waste vs. Manure, Again; The Advances of Science; Holy Sheesh; When the Crap Hit

the Fan.

Chapter 4 A DAY IN THE LIFE OF A TURD

Page 65 Mexican Biological Digester; The Old Fashioned Outhouse; Septic Systems; Sand

Mounds; Ground Water Pollution from Septic Systems; Wastewater Treatment Plants; Chlorine; Alternative Wastewater Treatment Systems; Agricultural Use of Sewage

Sludge; Global Sewers and Pet Turds.

THE HutiANURE HANDBOOK - CONTENTS 3

ChapterS COMPOSTING TOILETS AND SYSTEMS

Page85 The Non-Commercial (Homemade) Mouldering Toilet; Commercial Mouldering (or

Multrum) Toilets; More Commercial Composting Toilets; Asian Composting; Simple, Low-Tech Humanure Composting.

Chapter6 WORMS AND DISEASE

Page 109 The Hunzas; Pathogens; Indicator Pathogens; Persistence of Pathogens on Soil, Crops, Manure and Sludge; Eliminating Pathogens From Humanure; More on

Parasitic Worms; Summary of Conditions Needed to Kill Pathogens; Conclusions.

Chapter7 THE TAO OF COMPOST

Pagel37 Primal Compost; The Evolution of Compost; Thermophilic Microorganisms; Four

Necessities for Good Compost; Doing It; The Sawdust Toilet; Analyses; Low-Impact Composting; Monitoring Compost Temperature; Legalities.

·chapterS THE END IS NEAR

Page 175

APPENDICES

Page 185 1) Sources of compost thermometer!; 2) Metric conversions; 3)

Centigrade/Fahrenheit conversions; 4) Sawdust toilet temperature curve.

4 THE HuMANURE HANDBOOK - CoNTENTS

GLOSSARY

Page 189

INDEX Page 193

TABI.f.S AND FIGURES PAGE INTRODUCI'ORY INFORMATION

FiJgnl A: 1be .._ Dllllinr .... in181:t •••••••••••••••••••••••••••••••••••••••••••••••••••••• : • ••••••••••••••••• 11 FisaN 8: 1be ._ JIUirieDt cycle • bro1u111 •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 12

CILU'TER ONE FisaN 1.1: Gmsuolid w.te .,..,.-lin 1be USA. JIDtillcluding ICWII8C ................................................ IS riJIII'I 1.2: A-m ofbumalllll &YaillbJe wwlllwidc per tqUR~IDilc of

tilllble lad ................................................................................... 16 FiJgni13:Sew811oliudlodumpedin U.S.-wallerl.l9'73-1986 •.•••••••••••••.••••••.•••••••••.••••.••.•••••••••..• 11 F'111D" JA: Awmae ..-!per AJrita Wlller 1IIC in tcledled c:ountries ......... • • • • •••••••••• • ........................... .20 FisaN l.S: Usio offertili2Jer worklwide ainc:e 1950 ................................................................... 19 Fillft 1.6: A-m ofaitroaca Ulld in fertiiizm in 1be USA derived fiom

oqaaic-(1900and1941) ................................................................. 19 FiJanl 1.7: CGmpmitioa of lllll'eCycloddilcudecliiDiid- in tbo

USA, 1~2000 ............................................................................. .23 Fillft 1.1: Perc:elltaF ofworldpiiJIIIWtion witboutadeqaale unilalion .................................................. .21 FisaN 1.9: COIIIpOiilion of Jllllllic:jpld -in USA, 1986 ............................................................. 21 Fipre 1.10: Our me-iDa im]*t on plmet Ellrtb • world popa1llion

puwlb, pmdlll:tioa Ed fuel COiliUIIIPiiotuiac:e 1900 ................................................ .22 CIIAPTER 1WO

Fipre 2.1: Sill:ofbllcteria mlaliw to a Jed blood ceU. a bair, Ed a ~Din of-.1 ...................................................................................... 33

Fipre 2.2: The MariJID toilet. 11S8 • COJICIIha8ea ................................................................... 42 Table 2.1: Compositioa ofbumamue .............................................................................. 39 Tablc 2.2: Cubonlaitroaca ralioa fouome compoaable matcriala ..................................... -.................. 40 Tllble 2.3: NitiOIJCII lou and CJN mtio ............................................................................. 39

CIIAPTER FOUR FisaN 4.1: Biological Digea~er. SoUib ladia ........................................................................ 66 FiJraN 4.2: SpJad of pollution tbm1J8h dry soil by outholdea ........................................................... 66 Fillft 4.3: Pour flush lalrines .................................................................................... 67 Fipn: 4.4: The B01VIP latrine: Bolswua'1 nn1 ventilaled. implo¥al

pit latrinea ................................................................................... 67 Fipre 4.S: Spread of polllllioa from outbousea (pit lmilles) in - soil .................................................. 68 Fipn: 4.6: C10111111:Ction of •IICJIIiC tank .......................................................................... 68 Fi~Juae 4.7: Septic tank sravity diltrilnllion ays1em ................................................................... 69 Fi~JUN 4.8: Sand molllld waste diJiriblllion aylltem ................................................................... 69 Fi~~~n~ 4.9: Solm:es of groomd water conlaminantl in the United Slallcs .................................................. :ro rJ1111'114.10: GmUDd -amtaminanta in the United Staa . .. . . . . . . .. . .. . .. .. . . .. .. .. .. .. .. . . .. . . . . . . . . . . . . . . . . _ .. 71 Fi~~~n~ 4.11: Activated sludse ----=t proc:esa ........................................... _ .. . 12 Fi~JUN4.12: WctlandwaslieWatertlaltmcntsystcm ............................................... _ 76

CIIAPTER FIVE FiiJIIN 5.1: Mouldcring toilet (cutaway aide view) ................................................ . Figure :5.2: Mouldering toilel(cutaway 110111h view) ................................................ . Fi~~~n~ 5.3: Gualemalan IIIOlllderins toilet . . . . . . . . . . . .. . . .. . . . . . . .. .. .. . . . . . . . . .. .. .. .. .. . .. . . . . . . .. Figure 5.4: Multrum IDilct ••••••••••••..••••••••••.•••••••••..••..•.•••••.••.••••••..•••...•.... Figure 5.5: ViciDamcae double vault .............................................................. .

CHAPTER SIX

11'1 90 .91 9\

.99

Table 6.1: Pathogens in urine . . . . . . . . . .. .. .. .. .. .. .. • . . .. . .. .. . . . • .. • • .. .. . • • . . .. .. • .. • • • .. • .. . . . . . . . . . . . . • . . . ..112 Table 6.2: Vinal palhiii!CDS in feces .................................................................. _ ..... _ .I U Tablc6.3: Badt:rial patbo(!caain feces ............................................................................ 114 Table 6.4: Protozoan pathiii!CDS in fec:ea ........................................................................... 114 Table 6.:5: Worm pathogens in feces .............................................................................. II S Table6.6: Survival ofcnterovinucainsoil ......................................................................... 119 Table 6.7: Survival time of someproiDZOII in IOiJ ........................................... , ........................ 119 Table 6.8: Survival time of some bKtaia in soil. .................................................................... 120 Table 6.9: Survival time ofpo1ioviruscs in soil ...................................................................... 120 Table 6.10: Survival time of some pathogenic worms in soil ........................................................... 121 Table 6.11: Pathogen survival by c:ompoatiJ<g or soil application ........................................................ 127 Table6.12: Hookworms ........................................................................................ 129 Table 6.13: Averase density of fecal colifonna exc:med in 24 bolD'S

by vuioua animals ............................................................................. 117 Table 6.14: Paruilic Worm Egg Death .......•..•.•...•...•..•......•..........••...•...•.•.••••.•.....•.......... Ill Fi~~~n~ 6A: Tnmsmisaion of palhiii!CDI tbmlll!h septic tank waalc

THE HUMJINURE HANDBOOK • CONTENTS 5

dilpoalay- .............................................................................. 123 F!pN68:T,.nenri•ejooof ........ liuouah-lioaiiOWIIF

llUIIDcDt pima •.•.••••••••••••••••••.•••••••••.••.•••••••••••••••.•.••••••••••••.••••••••••• 124 fi8me 6C: T..-iuicmof~duough-~poada ••••••••••••••••••••••••••••••••••••••••••••••••• 124 Fipro 6D: T,._jaejoo ofpalbopaaliuouah puaive,low llllllipCIIIllllf;

ICCJIIIIIC*iDg eoilcls lllld 1IICIIIldeliDs tDUe1a •••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 12S FJIIIN 6E: Trammjaejoo of ....... duouPalhenDapbilic

ICCIIIIPI*iDB .,uaD • •. • ......................................................... • .. • • • •••••••••• 126 Figllle 6F: Safety JDDII for~ ........................................................................... 133 Figure 6G: SurviYal times of fecalroliforms in 1011 •••••.•••••••••••.•••••••••••••••••••••••••••••••••••••••••••••••• 118

CIIAPTER SEVEN Figllle 7.1: The Taooftbeuwdaat1Dilet ...•....••.•.•.•.••.•..••...•••...•.•.••.•••..•...•.....••••.••••.••..•••• 1S4 Fi111R17.2: Diagramaof....m..& IDilet •••••••••••••••••••••.•••••.•••••.••••••••••••••••••••••••••••••••••••••••• • 1SS Figare 7.3: Coaalnlclill1a aimplo COIIIJIOIIl bill •.....•.••.••••••...••••.••...•......•.•..••••.•.•••.••••••••.•••••.•• 1S7 Figare 7.4: Two aty1ca of lbnlo-cillulbcnld compoll billa •••••.••••••.••••••••••••.••••••••.••••••••••••••••••••••••••• 159 Figure 7 .S: Analomy of a contiJJ-.CX1111J'C»l bin •...••••••..•••.••••••.•....•••.•.•••.•...•••••..••••••..•••.•.•••• 160 Figare7.6: Tempaa1111e curve offiozml bum1111ure COIIIpOSt pile

aft« llpriDg tbaw ••.••.•••.••..•••••.••••..••...•.•••......•.••••••••..•••..•.•..••••••••••..•• 164 Figare 7.7: Camp C0J11!10S1er •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 168 Figare 7.8: Camp c:omp01111:r011 a baDk ••••..••••.••••••.•••.•...•..••.••••••.••.•••.•••••••..•..•••••.••••••.•••.• 171

SIDEBMS PAGE CILU'TER ONE

FunF-=lli:W-DOtWIIDtDDL .••....•••••••.•••..••••.••..••..••••..•..•••.••.••.•.•••.••••.••••••••••••.•..••• 14 Fun FIK:IB: About wa~~:r ........................................................................................ 18

CILU'TER TWO Fun Facta: CazboalaitroBCD lldio ••.••..•••••••••.•••••••••••...•••••••••••••.•. : • ••.••••••••••.••••••••••••••••.. 41 c-lial Readiug for Insomniacs· pH ............................................................................. 47

CIIAPTER SEVEN c-tial Readiug for l11110111Dillca: Tbermopbilic microorpuisms ....................................................... 143 A Tip from Mr. Turdley: Sawduat •......•..•.•••.......•..•.•..••..•....•......••...•....•••••••.••.•..•..•••.... lSI Another Tip lirom Mr. Tllldley: The aecmto compoating lnlnwnllftl is

to Dcp it c:ove~Qi •••.••..••••••••••••••.•••..•.••••••••.••.•••••••.•••••••••••••••••••••••••.• 1 53 Yet Allolbcr Tip from Mr. Turdlcy: Preaswe trearod lumber abould-

be uaed. forCOIIIIJ\lCting compost bins •.••....•.•.•.••..•.•....••.•.•..•••...•..••.•.•.••....•..••. 156 Do's Uld Dont's of a Tbclmopbilic Toilet Compoating Sys~~m~ .•.•....•.•.....•..•...•.•..•.••.•..•.•.••••..••....•....• 166

PHOIOGMPHS PAGE CHAPTER ONE

Humamm: c:ompoll being wbeclbanowed to a ganlcn ..............................•.•...•..............•.•.......... 17 Humamm: c:ompost ~lied by hand to Barden beds ••..•••••••••••.••••.•••.••.•••..••...••.•••••••.••.•••......•.•.. 24

CHAPTER TWO Humamm: compost being removed from a double duaniJeRd bill ..........•.......................•................... .34 Humamm: c:ompo1t being applied to a rai1led bed in tbe spring ••••...•••..•••...•......••••..••.••.•...•..•••..••••.••• 45 ProbiDg a compost pile with c:ompost tbermome~~:ra .....•.......••.•.••..••.•.........•.............•.....•....•...•. 46

CHAPTER FIVE A Oivus Multnnn toilet at Slippery Rock Univcnity •••.••.•••.•••••.•••••.•••.•..•.••...••...••••••••.•............. 94 The COD1nl8 of a Clivua Multnnn toilet being ClWIIillllld lbnJugb

lbeaQ;CS&door .•.•.•.••••••.••••••••••••.•••.•••.•.•.•••....••••...••.•••••..••.••••••••..•.• 95 A ytlllDI! lady aetting cedar posts for a c:ompoll bin ......•..•...•••..•...•...........•.•.•.........•••........••...•. 97 A sawdusuoilct I 00 A sawdust toiletsbowing removability of oontenta .•...•••.•.•....•••••••..••......•••••••••...••.••••.•••••.••••.•.• 101 A sawdust abed at a sawmill .......•...•••••••••.•.••.....•....•..•••..••.•.•••••..•••••.•.•••••••.•.••••••.•.. ,103

CHAPTER SEVEN Indoor uwduattoilet in new home ...........•............................•........•..•....•...••.•.•••••....•... 152 Sawdnat toilet with rec:esaed peat mosa container .....•.......•.......•...•.......................•.•.•....••..•••.•• I 58 Sawdust toilet in a buc:ment .....................•....••••......•••..•.•••..•••••.••••.•..•••...•...•.•••••..•• .162 Sawdust toilet made of wooden box .......•.....................................•......••.••....•......•....•.... 165 Sawdust toilet in mobile bome .......•.••.•••.......••........•..•••..•.•••..•.••.....••••••••••.•••.•••••.•••..• 167 Outdoor uwdust toilet .........•.....•..•••.......•.....•.....•.•••.•••••.••..••.••..••.••.•.•••••••....•.•••.• 169 Sawdust toilet "outhouse" ...................••••.•....•....•............•••.•.•....•.•....••••.••.....••.•••.•• 170

CHAPTER EIGHT The autbor at tbe end of along day ..•....•......•..•...•....•...•....•.....•........•..•••.....•.....••.••••....• 183

6 THE HUIIANURE HANDBOOK - CONTENTS

On &ire/In Spmt? lnnovGtronr,

MODELS AND METHODS

COMPOST TOILETS RECONSIDERED From sm4'lller self-contt:~.ined units to centraliz1ed systems, composting toilets a1·e finding a market in cottages, off-the­grid homes and public facilities.

Carol Steinfeld

Ernest Schneider bought a compoeting toilet in 198S for the house he waa building eouth of San Francisco, his family waa apprehen•ive. "They had been to campground• and

weren't sure what to expect." he says. Even though there was a septic ayatem on the property, he decided to install a compoating toilet becauae water in hie area ie expensive and occasionally unavailable. He also liked the idea of conserving reeoUl'cee and not cre­ating pollution.

Schne1der says he and his family have been "very aatiefied· with the Carousel aye• tem he purchased. He empties it once every fuur or five yean and BPreade the compoeted "humuaM on his yard. Apart from that, the unit is checked every two weeks for mois­ture, and sawdust or leaves are sometimes added to the c:ompost­ing waste. "It takes some maintenance, but it just makee senBe to me, • he eays.

One could argue that compoeting toi· lets are the oldest toi­let system there is. •Jt'a nature'• way," ~taya David Del Porto, who hu distributed several lines of com· posting toilets since 1978. Hi& company, Ecoa, ie based in Con­cord. Massachusetts. "You can compost in a teacup; 'it's not Tocket science," he notes. "What is science is managing the pTOcees for a minimum of odors, cost, safety and pathogen destruction." To some, compoeting toilets are akin to bringing the outhouBe in· aide. However, unlike outhouses, compost­ing toilets are deaigned to aerobically de­compose human excrement, urine and toilet paper. "The emphasis is on contTOlled pro­ceeeee," Del Porto says. "As long a& the tern· perature, aeration and moisture are con.-

trolJed, the material ahould be composting. Technologies differ and some toileta e1mply allow contents to sit at low tem_perature& and slowly decompose. This is known ae mouldering, and it takes muc:h lonpr.•

Today, commercial1y available compost­ing toileta can be divided into two broad cat· egories: self-contained unite and centralized eyetems, both of whic:h typically use either e batch or continuous processing methodolo­gy. Central compoatena are remotu &om the toilet bowl. usually located in the buement or in ita own enclosure to the aide of the

building. Self-contained units, ae the name suggests, are single unit c:ompoaten wh8!'8· by the toilet eeat and the compost reactor are both part of the same appliance. These can sit in the bathroom, and becau&e they re· quire no plumbing, baeements or crawl spaces to a reactor below are not needed.

In terms of processing, "batch compoat­ini'" as it applies to today'• toilets, ie done in moTe than one compost chamber. These are switched or rotated as they fill up. The ad­vantage, some say, is that older or advanced compoat ie not contaminated and is allowed

MARCH 1997 49

'"'-~--------..---------:.:-'.-~r=-::-.~ .. ~ .. -~:":'--:":'r:: .. :-:.~ .. ~ .. -. ":: .. :":: .. ~ .. ~ .. :-::-;:.-.. -.--.. -.:-_:: -;;;.::-~-""'-~-~-~-~-"!'.-~-~--~~~~.!!!-!!!-~--!!'!-!"!!'_!!!!'_!!!!'_"'!I.#$1!-'IIIMIP.!!'-IIIIAII!t--•

2

to mature without being diarupted by the new nutril!nt. and pathoprq in rruh wut.. In some ayatems. the chambers can be re-

. moved from the toilet to take outtide. ·con· t.inuoua• eompoating, on the other hand, takes plac:e in a aingle chamber in which the freah and older material. arl! commincled. Finished compost is removed from one end or the unit.

These days, systems alao are available with microfluah toiletl- a factor that baa helped to change the public's perception of them for the better. •Many people don't like tha 'black hole' concept," ea)"' Bill Wall, the New England distributor for Clivus Mul­trum, ruferring to what many compost toilet

MIX, TRANSPORT AND MAKE WINDROWS. MAKES CONSISTENT, HOMOGENOUS MIX­REDUCES ODORS AND PROMOTES MAXIMUM BIOLOGICALACTMTY WITHIN WINDROWS, STACKS, VESSELS AND PROCESS SYSTEMS.

SSI self-~lled mixer does it all. ThiS 3-in-1 ~tool mixes, hauls and wiridrows­on-$e-go. Blends sludge, lime, ard waste, industrial .... ~.~ ~.J • IVJ}I~VW~~

mw aemtton agents. t saves tune and labor-mixes in 3 to 6 minutes. Mixer is essential for efficient co~ in ;pw\ stack and in-vessel ~c. i::>ena for literature. "'./ .. -~-

60

llilliii SlUDGE SYSJfMS. •Nil 11ZIIIWir.AW, ~Clift, Wl .. 701 (T11)a31-a,., ....... (T1D)UMall ,_

users see when they lift. the lid of the toilet. "Now you can have a flush toil•t connected to your com poster. It's more traditional. And you don't have to have a straight chute."

Another factor in increaaing public aa:ep· tance is making them eaaier to maintain. Wallaa)"' nearly all ofhia customers now opt for a service contract he offers. Service is available on au annual buis (once per year) for about $200 and on a quarterly buia (four " times per year> for about $600 (prices de­pend on location). It ueually includes check­mg all parts, leveling the compost and re­movinc it if nac••sary. "This makee tha operation and maintenance eaay now, ao it's a viable solution for moru people," he sa)"'.

BIULATIO•I &•D ITA.DAIDI Compoating toilets ueually requir• apac:ial

permits from town and state officials. Some state&, such aa Minnesota, Maine and Waahington, are more amenable to them than others. Elsewhere, a com­poating system is only allowed when it is installed with a convantional ayst•m. Many states allow counties to make their own decisions. Ap­proval typically involves local and regional authorities, but due to lack of knowledge of these systems, officials are often wary of granting permits.

In Massachusetts. composting toilet sys­tems recently were approved in response to increasing evidence that conventional B)"'·

tems are a threat to public health. Many homeowners are unable to install new eep­tic eyetema or continue using their current onee, due to poor eoil drainage (see "Proper­ty Owner• Turn to Leaat-Coet Solutions," April. 1996). Massachusetts' plumbing code now recognizes these toilets as plumbing fix­tures that must be installed by licensed plumbers. Other states are expected to fol­low thia state's lead.

Property owners also are reconsidering compo1ting toilets a• an alternative to pay­ing akyrocketing aewer rates and holding tank pumping costs. In addition, a zero dis­charge ayatem allowa some property owners ' to use more of their land. Bill Wall notes that some customere have opted for com­pelting toilet. to aave trl!ea that would have come down to make way for septic system leaching beda.

About 40 states require composting toilets to be tested and approved by the National Sanitation Foundation (NSF), essl!ntial1y the Underwriters Laboratories of the public health industry. NSF's Standarcl4l ie a per· formance atandard developed in 1982 to teat the operation, maintenance and perfor­mance to include the deatruction of fecal co· liform. It is undergoing its five-year review thi• spring. Companies that otTer some NSF· Jiated models are Clivue Multrum, CTS Compost Toilet Systems. BioLet and Sun-

MAKCIJ1997

.c:z:. ___ .. _

Mar. Vera-EcoTec:h Ca:rousel, the fint syu­tem to be NSF listed, is awaiting renewal. 'nle Phoenix Campoating Toilet haa Canadi­an Standards Association approval, which also is recognized by NSF.

CIIIIIIT CIIITUL JYJTUlMIIU Vault comp1osten like the Clivua Multrum

and the CTS models consist of a large in-

elined bos where mat.eriil ia added to a starter bed of wood c:hips or sawdust. Waste movee down an incline whic:h slows its pas· sage to the· bottom, helping to aerate it.. A baflle at the base of the unit keeps new mat­ter on top. Compoat ia removed through an access hatch at the bottom of the tank. Oc­cuionallev.Jing or the pile with a pitchfork is required. Some users also turn the com­post at that time to prevent densifying. The Clivus Multrum is conatrueted of croealink polyethylene; the CTS ia fiberglaee. Coets range from $3,850 for a reaidentialaize CTS (about 18 daily uaea) to more than $10,000 for an in1titutional unit. A reeidential Clivua for a family of four will coat $S,OOO to $6,000, excluding the toilet stool or a flush toilet (ae is the caee for moat prices given here for the central systems>.

The Phoenix ie a tall, polyethylene three part system. Waste falls to a high area, where rotable tinH act as a mixing device to break it up and aerate it. Next it falla to a grate, then to a collection box. The tine& can h. UHd to hold the newer material while re­moving composted material. Urine drains to an evaporator at the bottom. Three residen· tial modele and three modela for public fa­cilities range in price from $3.600 to $5,500. Clivue Multrum, CTS and Phoenix brands come with fans but no heater.

The Vera-EcoTeth Carousel is a cylindri­cal fibergla•• container consiating of an out­er ca&e and an inner cue which ie divided

Systems are available with microflush toilets -a factor that has helped to change their perception for the better in the public eye.

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Nearly all toilets are available with optional heaters and fans (electrical or solar-powered), if they are not part of the units.

into four nvolvable compollt chamber&. Liq­uid drain• to the bottom of tlw outw case where it evaporates or can be removed for utiliz.ation or dilpoaal. ThiJ eneurea liquid and compoeting salida are separated. When one chamber filla up, the next is rotated into poaition. With typical uee. t.he first chamber would be emptied in two years. It's avail­able in three eisea ranging in price from $2.153 to $3,389. The Vera Toga 2000 ia e.­eentially two remov­able rollaway 60·gallon compost reactora. Extra containen can be purclia..d for more capacity. It costa about $1,100.

Sun-Mar'a new Centrex Plus features a •bio-drum, ·e.g. a rotatable canister divided into two parta. A built in bar improves turn­ing. When t.he primary chamber in the drum ia full. material spills into the secondary chamber. which automatically emptie1 into a fini1hing container. When that ia full, it can be replaced with an empty container. Twin 250-watt heating elemente can be turned off, on or aet at 60 percent. The unit' a capacity ia aix adult. year round, and the priee is $1,649 ($1.899 for the nonelectric model). Sun-Mar'• Centrex, a smaller unit featuring an undivided bio-drum and juat

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Backyard composting programs wiU work -in the cities that offer the Biostack• Composter.

The unique three-tiered design of the Bioatack• makes light of the harden part of the ccmpcsting job -turning the pile. BecauM it makn compoaung t10 euy, the Bionack maurcs a aucceuful munici­pal compo&tlng pro­gram. And it's fabricated of601Jb rec:vc:led polyethylene.

~/tcwJ b, W foJ.lo4Aiifll CIWI and COUJWI fr;lr dwir badr,md c:ompostfnt P'OI'llntS~ AlotMd4Co .• CA. Scm Ma1e0 Co .. CA, Ki~Co .. WA.lm AJ11'!ka. Burllani,

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one collection tray, ia typica1ly only used in cottages. lt rangea in price from $999 for a nonelectric to $1,199. In aU ofthuae models, leachate - urine and other liquid - draina to the bottom, where it i1 evaporated or must be drained for dispoaal or utilization.

Ouuide of North America, other central­ized eystema include the Rota·Loo in Aus­tralia, the Ekolet in Finland and the Aqua· tron in Sweden, all of which are similar to the Vers-EcoTech Carouael. Natura Loo in Australia and the Dowmus in England are round. aingle chamber compoaters.

Wbile large, central compoating toilet·~· tem111allow long-term rtltention (two years or more) and more capacty. theJT large a1r.es­a few are eix to 10 feet high - require &pe· cial installation ccmaiderationa, and many are beet suited to new construction or parks and recreation areaa. The larger single chamber unita also an more auacaptible to compaction of the compoating man.

CUIUIT SILF.CO.TAIRID MODIU Due to their •mall size, these units typi­

cally are used in cottage• and seasonal ' homes with capacity ranges from two to aix adulta, varying with the model. Sun-Mar of­fers four self-contained modela, each featur· ing a revolving canister-like composter mounted horizontally. A hand crank allows users to periodically rotate the drum, mix· ing and urating the material. Urine drains to an evaporating chamber. When the bio· drum is full. about a third of its contenta are removed to a 1iniahing tray beneath it, where a heating element raises the temper· ature and evaporates the liquid.

BioLet's XL feature& a primary chamber where a mixing arm slices through the com· posting waate, aerating it and pushing it

.l'tLucH 199'

through a ll'&:te. Finiehed compoet falle into a removable tray. It feature• a radiant heater in the Door of the unit and a convec· tion heater that circulate• heated air around the co~mpoeter to warm the compoet and evaporatla leachaw.

Vera'• Tog~a aerie• includee ewviBI'Ill eelC­contained model• of various capacitiee, all bued on batc:h compoeting. lneide are two interehangeelble compoating chamber•. (An exception i!l the To11a 2000 deacribed above.) Some extend below the Door to al­low more cap1acity. All come with optional fane and hea·ten. Tlw BioLet NE aleo uti· Hzea thia deaign.

Sancor's E1:1virolet ia much like the Bio· Let, but feat.unt a perf'oreted inner con­tainer that l~olds waete, and a movable srate called a •mulc:herator" that can be manually pullled to break up, mix and aer­ate the material. All of theM eysteme fea· ture ABS or J:IOlyetyrene pleatic outer ceeee, except the fiberglass Sun-Mar models.

Pric:ea ran1r• from about $850 for a Vera Cottager to $1,470 for a BioLet XL. In gen­eral. smaller eyeteme ensure fewer installa· tion difficultiea. However, uaera muat con. stantly remave the finished compost while adding new material. Due to their small size, they ott.!n ere overloaded and proc:eu· iniJ can be inc:ompletfil. Exceee liquid or leachate ia the bane of the ameller onea. Odors can oc:cur due to faulty ventilation eyetema or broken fans.

MICIOPLUII, triUTWIJII UD ICCUSOIIIS Available 1mierofluah toilet& include the

SeaLand, which usee one pint of water fiuehed with 8 foot pedal, and Evac vacuum toilets, such l!lll thoae used on airplanes and trains. The new Vera Wawrless usee the maaa of the waste itaelf plua limple fluidic engineering to move the material while Nepon toilet!• from Japan use foam.

The extra water from these toilets must be treated by evaporation. disposal or uti· hustion. Clivua and EcoTech offer wastewa· ter systems 1~0 treat this liquid. WJ well as the rest of 8 home' a waahwater, or •graywa. ter.u Clivu11 and EcoTech offer graywater ir­rigation systems that treat the water through garden beds. Theae ayatema muat be approved by states on a case by case bs­•ns. Graywat~r irrigation is gaining accep· t'bnce in atetes, such as California and Ari­zona, according to Del Porto.

Nearly all toilet. are available with op­tional heaters and fans (electrical or eolar­powered), if they are not part of the units. Some comp1mie11 aleo offer eolar compo­nents. such as Ecos' Soltran solar assisted composting Elystem.

A system without a fan or heater may tJwing with l!lmbient temperatures, result­ing in leu c1ontrol of the proeeaa. Fane ere recommendE~d. especially if the ventilation pipe ia six inches in diameter ar leas. A fan improves ventilation (reducing the risk of odor} and aeration. Supplementary heat apeeds up :the compoating process, al· t.hou!Jh too much heat can dry out and halt

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~mposting. Ideally, the compo•ting mate­rial should have the con&ietenc:y of a wrung out sponge. Using a moi•t.ure meter or in· stalling a humidistat helps use!'& maintain ideal moisture level• of 50 and 70 percent by weight.

Nearly aU manufacturers sell bulking agents to aerate. add carbon and absorb aome exaa•• moi&ture. Another option Del Porto recommends is uaing stale popped pgpcom or dime-sized wood chipa. •Jt has the ideal shape to r::nate air apaces, nooks and crannies for bacteria to grow and good nutrients that are totally consumed in the compoating process," he aayB. "You want to auate and add carbon, and absorb Borne ex· cess liquid.~ He alao sella an additive mix consisting of perlite, vermiculite, screened dark peat, wetting agents and starting nu· trients. Wall recommend• finely mulched waod. compoeted leaves, planar shavings or gerbil bedding and pine bark mulch. Both discourage using peat moaa alone. •It doesn't really decompose: Wall says.

To manage any leachate from the sys­tem&, Ecoa offers a Wastewater Garden sys­tem, which is enentially a mini-evapotran­spiration bed where plants in a specially chosen medium use up the liquiciin a five­gallon pail.

Finished humua from a compa.t toilet has the consistency of compoat.ed leaves. It may b• pungent but not offenaive if it'1 been properly proces1ed. Typic:aJly, it's 10 to 20 percent of the original volume (unlee• a lot of bulking agent was added). Most atatea re· quire sending the material to a treatment facility or burying it under at leaet 12 inc:h· es of soil but within the root zones of plants that can use the nutrienta. Any leachate emptied from composters muat, by law, be disposed of in a septic tank. removed by a eeptage hauler or remanded to a treatment plant for furth11r treatment.

f'OIITIYI PUTUIII Talk to a group of r::ompoat toilet users.

and you're bound to find someone who has had a bad experience with a r::ompoating toi-

-r- iziCL·. :.:-__ .· __ : ...... '!l. -------·

let- ueually odors or incomplete compost· ing. Some manufacturers claim it's the poor dui8ft of put model1, but most often, they eay. it'1 improper maintenance or inatalla· tion. "Many people overload them, • saya Del Porto. •or they take material out too eoon. Or th~ loae the manual. and pretty aoon

.. they're puttins dirt in th• com poster!· Com­po•tml toilets 10t a bad rap in the paat, he adds, becauae manufacturers failed to in­form the ownen of their extenaive mainte~ nanc:e requirement. for fear this would de­ter people from purchaain1 them. Coneequently, people's expectation• for ease of uae far exceeded the actual day·tc'l· day maintenance. ·

Only time will tell whether public health concems. improved perfomumc:e. flush toi­lets and aervice contracts will usher compollt­ing toileta into maimtream America's bath­rocnna. 'We've got a long way to go, .. warns Sun-Mar'• Wilkinson. "The mainstream still prefers 'out of sight. out of mind."' •

Co.rol Steinfdd is a frnlance writer ba..d in Concord, MA. She ill writi1111 a book on corn· po•ting toildR o.nd groywoter ->'•tem•.

COMPOST TOILET MANUFACTURERS Aquatron lntemational Bjomasvagen 21 ,,3 47 Stockholm, Sweden +46·8-790 96 95

B1oLet 2 Oamonm•ll SQuare Concord. MA 01742 800·524-6538

Clivus Multrum 1 04 Mount Auburn St., 5th Floor Cambridge. MA 02138·5051 508-725-559,

CTS Compostlng Toilet Systems P.O. Box 1928 Newport. WA 99156·1928 509-44 7-3706

Dowmus Composting Toilets P.O. Box 323 Cooroy. Queensland Australia 4563 +074-476 342

El<osan1c Scandinavia Box 620 S·135 26 Tyreso, Sweden •468·745 OS 30

Envirolet Composting Toilet SanCor tndustrles 140·30 Milner Ave. Scarborough. Ontario M,S JRJ Canada

w =

Nature-Leo P.O. Box 1213 Milton 0 4064 Australia +07. 33157-060 1

Phoenix Composting Toilet Advanced Compostlng Systems 195 Meadows Road Whitefish. MT 59937 406-862·3854 phoenlx@eompostingtollet.com

Rota-Loo Environment EQuipment 2/32 Jarrah Drive Braeslde. VIC.3195 Austra11a +03-587·2447

Sun-Mar Corporat1on 5035 N. Service Road. C9·C, 0 8urtingtol"'. Ontario L7L 5V2 Canada 905-332·1314 compostCsun-mar.eom

Vera-EeoTech Carousel Vera-EcoTeel"' 152 Commonwealth Ave., Concord. MA 01742 508-369-395, waterconC1gc.apc.org

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