Desalination 324 (2013) 72–78

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Desalination

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A case for an ecological-economic research program for desalination☆

Brent M. Haddad ⁎Department of Environmental Studies, University of California, Santa Cruz, 95064, USA

H I G H L I G H T S

• Places desalination in the context of research on sustainable water supply.• Discusses the potential role of the field of ecological economics in evaluating desalination projects.• Identifies research questions emerging from debates in California over proposed desalination facilities.• Research questions range from system governance to social and environmental impacts of desalination.

☆ This paper emerges from the California PropositionGuide State and Local Desalination Planning, agreement #at http://ciwr.ucsc.edu. The author gratefully acknowleearlier drafts from Heidi Luckenbach and Robert Rauche⁎ Center for Integrated Water Research, University o

Tel.: +1 831 331 0654; fax: +1 831 459 4015, +1E-mail address: bhaddad@ucsc.edu.

0011-9164/$ – see front matter © 2013 Elsevier B.V. Allhttp://dx.doi.org/10.1016/j.desal.2013.06.003

a b s t r a c t

a r t i c l e i n f o

Article history:Received 30 July 2012Received in revised form 31 May 2013Accepted 3 June 2013Available online 28 June 2013

Keywords:DesalinationCaliforniaEcological economicsImpactsResearch agenda

As desalination capacity expands in the United States and elsewhere, it raises questions about environmentaland societal impacts. Research in the field of ecological economics could provide insights that help regionsand the public evaluate whether to pursue and approve desalination proposals, and how to configurethem. This paper explores the possible role of ecological economics in addressing many of these questions.Using California as a focal point, this paper identifies issues that are emerging as the number of desalinationproposals increases and installed capacity grows. It then identifies existing literature; and frames the re-search needs. Research needs include improving desalination's ability to operate using intermittent, renew-able power sources; understanding societal economic impacts including desalination's impact on marginallyemployed people; ecological impacts of desalination from a variety of perspectives, and (in the case of oceandesalination) governance of near-shore environmental impacts. Desalination research already spans multipledisciplines.

© 2013 Elsevier B.V. All rights reserved.

1. Introduction: desalination and sustainability

The reliability of desalination technology, and the water world'sfamiliarity with it, continue to grow [1–3]. Thermal desalination hasdecades of proven use from small to large scale. Membrane technolo-gy has become the standard in North America and many other loca-tions (e.g., Australia, Europe), and is in regular use in both large-and small-scale facilities. Additional technological breakthroughs insuch areas as low-pressure membranes are expected as the publicand private sectors continue to invest in research. Membrane andsupporting pre-treatment technologies are already mature enoughthat desalination has taken its place as an accepted water-supplytechnology. In North America, it is providing a supplemental supplyto areas that already have some surface and groundwater. Similar tourban water reuse, it is distinguishable from surface waters in that

50 project: Developing a Tool to4600004121, results availabledges insightful comments onr, and anonymous reviewers.f California, Santa Cruz, USA.831 459 4482.

rights reserved.

it is non-cyclical and therefore has a reliability value when combinedwith surface supplies.

While cities like Los Angeles and Phoenix expanded rapidly inprecipitation-short regions in the 20th century, in the 21st century,they do not have another Colorado River available. Nearly all readilyavailable surface water has been claimed for urban, agricultural, envi-ronmental, or other uses. Brackish groundwater and ocean water areexceptions and could be tapped for supplemental water supply. Desa-lination therefore becomes part of a much larger set of questions ofsocial organization, governance of technology and environmental im-pacts, and regional control of water resources.

Another motivation for desalination is that the advanced watertreatment technologies that remove salt also remove other contami-nants. Water that passes through desalination treatment steps willhave its nitrates, synthetic chemicals, and other contaminates largelyremoved. It will have a higher quality than many existing surfacewater supplies. Water agencies facing tighter water quality standardsmay utilize desalination treatment technologies to improve waterquality and meet water quality standards even when the sourcewater is not considered saline.

Desalination's growth in installed capacity and new-project pro-posals is generating new questions that move beyond its current

73B.M. Haddad / Desalination 324 (2013) 72–78

range of research disciplines. Current disciplines interested in desali-nation performance and impacts include biological and earth sciences,civil and environmental engineering, and economics. As the use of de-salination grows, new questions are emerging. These questions call forinterdisciplinary perspectives covering ecological and social impacts.These are consistent with perspectives and research tools found inthe field of ecological economics. Ecological economics is a field of re-search that investigates economic performance and societal impactsunder natural resource constraints. While resource constraints arecommonly applied in economic optimization problems, ecologicaleconomics assumes that resources not directly involved in productionare also constraining and that polluting byproducts of production canalso generate constraints [water-related examples include 4–6].Ecological economics studies common-property and “tragedy of thecommons” questions, both of which arise when dealing with theocean as a water source and effluent depository. Lant describes howecological economics extends the concept of “capital” to include natu-ral and human capital in ways that help us capture what is gained andlost when society pursues new water infrastructure projects [7].Methods from the disciplines of economics, natural sciences, publicpolicy, and sociology are often utilized in ecological economics re-search (Table 1).

Connections between desalination and ecological economics arepresented here and the case made for extending current researchprograms to include these perspectives and tools. The researchareas of environmental impacts, energy choice, societal impacts, eco-system health, and project size are all considered. Examples focus onCalifornia where research on the costs and benefits of desalinationwas undertaken (footnote 1). Conclusions address the scale of re-search questions and who should be involved in answering them.

2. Desalination: from a local to a national perspective

When coastal desalination plants have been proposed in California,unexpectedly strong public questioning has arisen [8,9]. A Santa Cruznewspaper editorial calls for more thorough investigations of energyuse and climate change, total cost to ratepayers, marine impacts, prod-uct water safety, and public decision-making processes [10]. In Carls-bad and Marin, opponents raised legal challenges to environmentalimpact reports (EIRs). Sometimes the opposition has taken unusualforms, such as anti-desal songs, poems, and sit-ins at meetings.

Regardless of the method of delivery, a theme emerges in the pub-lic challenges—that desalination should be understood in its broadestcontext of societal/ecological relations. Skeptics are asking: What isdesalination's role in an ecologically and socially sustainablefuture? Questions of interest to skeptics are partially answered inan EIR, but other issues remain.

The role of individual water agencies in the sustainability agendais still being defined. In the public's mind, the already-broad questionof sustainability is framed well beyond the purview of any wateragency. It includes questions such as whether we are already living

Table 1Research fields and methods contributing to ecological economics.

Natural and physical sciencesThermodynamics, ecology

EconomicsGame theory, cost analysis

Public policyCase study analysis of public decision-making

SociologyCase studies, surveys

Integrative/Multi-disciplinaryOptimization and other quantitative models of social and market behaviorsubject to ecological/thermodynamic constraintsCost analysis that integrates non-market value of ecological systemsMulticriteria analysis

too far beyond our environmental means, how we address not justwater but energy, air quality, species preservation, other culturalpreservation, and how one balances social justice, economic develop-ment, and sustainable living. While certainly playing a role in theselarger questions, water agencies are not an ideal location to focusthese discussions since their legal purview, expertise, and resourcesare more narrowly drawn.

One might choose to downplay or postpone desalination/sustainability questions by arguing that desalination is now or willsoon be just one of numerous existing water treatment technologies.As membrane technologies improve in performance and efficiency,desalination will lose its leading-edge reputation and will be moreeasily integrated into existing water systems.

But improvements already made in membrane performance andother technical, financial, and managerial advances qualify desalina-tion for the larger conversation now demanded of it. Broad debatesin intellectual and popular circles continue today on groundwatermanagement, dam/reservoir management, water reclamation andreuse, water transfers, water conservation, and other acceptedwater supply methods. The expansion of interest in desalination is arecognition of the technical achievements that have made it a real op-tion for water planners. While this article focuses on research needsrelated to desalination, a decision to invest in the technology shouldbe made in light of other potential water supplies, water conserva-tion, and the no-project option. Each of these has its own set of ques-tions and required analyses to get a complete picture of the water-supply choices facing a region.

Careful scrutiny of desalination is also due to its high initial capitalcosts. Like many new infrastructure projects, capital costs represent asubstantial regional financial commitment [3]. Once the investmenthas been made, due to the vastness of its source of supply (the oceanor often large, unexploited brackish groundwater basins), desalinationhas immense potential to supplement, augment, and substitute forexisting source water. An existing facility is relatively easy to scaleup if expansion was anticipated during the initial design stage. Re-gions that adopt desalination are making more than a few-decadescommitment; they are making a “foreseeable future” commitment,or what von Medeazza describes as desalination “lock-in” [11].

3. Sustainability is already integrated into water curriculumand certification

Sustainability is a common theme in water research and analysis.AWWA's 2009 Sustainability Ad Hoc Committee produced a mile-stone report orienting the Association to the theme of Sustainability,defined as a long-term commitment to “economic growth, environ-mental protection, and social development” [12]. AWWA researchoften focuses on actions that fall within the control of water agencies.It proposed the development of a “G” (for Green) Standard similar toexisting standards for O&M Security and Source Water Protection.

Similarly, the ASCE Summit on the Future of Civil Engineering 2025,published in 2007, anticipates broad discussions of future infrastructureplanning in which engineers will play a central role. The 2008 CivilEngineering Body of Knowledge for the 21st Century, which provides guid-ance to engineering schools and accrediting bodies, includes social sci-ences, humanities, natural sciences, and more broadly “sustainability”as essential elements of undergraduate and pre-certification civil-engineering training [13,14]. At the individual researcher level, manygroups constitute awater agency's “community” and all have an interestin how water is managed, priced, and used [15]. “Community sustain-ability,” which focuses on the role the community plays in influencingagency policy and direction, is seen as complementary to a utility'sfinancial sufficiency.

This paper offers an ecological-economic perspective on the evolv-ing research agenda desalination, including how this agenda links toexisting research on desalination.

74 B.M. Haddad / Desalination 324 (2013) 72–78

4. Desalination research today

The national agenda for desalination research has been guided by anumber of documents. One is the 2001 NWRI/USBR “Desalination Re-search and Development Workshop Report” [16]. Soon after came theSandia/Bureauof ReclamationDesalination andWater Purification Tech-nology Roadmap, published in 2003 by the National Academies Press,and a review the following year affirming the main research proposalsNational Academies' Water Science and Technology Board [17]. Theroadmap focused on improving technologies used to purify impairedwaters, including cost reduction, efficiency improvements, and contam-inant removal improvements. The roadmap identified membrane tech-nology as the leading approach but endorsed research on thermaltechnologies and what it called “evolutionary and revolutionary” tech-nologies (p. 61). By 2003, the federal government had spent more than$1.4 billion on desalination research [17]. These reports informed the re-search program proposed in the 2008 national review of desalinationcalledDesalination: A National Perspective [18]. This report divided its re-search recommendations into efforts to reduce environmental impactsof desalination and efforts to reduce its cost. It also included a recom-mendation to study how to link desalination to renewable energysources.

Another detailed guide to desalination and water purification re-search emerged in 2008/09 entitled “Implementation of the NationalDesalination and Water Purification Technology Roadmap.” This re-port was a joint product of Sandia National Laboratories, the WaterResearch Foundation, and the WateReuse Foundation. In addition toits technological focus, the roadmap included a section proposing re-search on institutional issues ranging from finished water cost to en-ergy use, marketing, regulations, water rights, customer outreach,and communications.

In California, Proposition 50, a voter-approved initiative, funded re-search on desalination in the mid-2000s, including the social-scienceresearch on costs and benefits of desalination that informs this paper(available at http://ciwr.ucsc.edu/desalplanning/index.html). Wateragencies are studying the use, impacts, and integration of desalinationin their own systems. Private sector firms are working to improve alltechnical aspects of desalination, including improving membrane char-acteristics and reducing power needs. University researchers are inves-tigating engineering performance of desalination. Research is publishedin a variety of venues, including municipal utility reports required bylaw, professional and academic journals such asDesalination, private re-search institute white papers, publications of industry-sponsored re-search groups such as the WateReuse Research Foundation, web sites,and conference proceedings.

More broadly, desalination research remains a global endeavor asscientists from the Middle East and Asia regularly contribute to lead-ing peer-reviewed journals.

1 These complications were helpfully identified by a reviewer.

5. Supplementing Current Research withEcological-Economic Perspectives

When considering costs and benefits of one's water supply optionscalculations need to be accurate, though not necessarily exact. If risksare involved, the Precautionary Principle allows one to make choiceseven if the numbers aren't exact. Some costs are quickly estimated,especially those that are initially monetized, including equipment/capital, land purchase, consulting costs. Other costs, including envi-ronmental, human-health risk, and fire protection risks, are less easilyidentified. Yet they contribute to a thorough cost–benefit analysis andare therefore necessary to estimate.

Attempting to calculate and assign the full cost of desalination raisesnew issues while avoiding others associated with existing surface- andground-water supplies. New issues include estimating and assigningthe cost of new, supplemental infrastructure, or, for international

facilities, identifying and accounting for construction or operatingsubsidies.1

In terms of avoiding some complex aspects of cost analysis, desa-lination does not have the long history of cumulative impacts ofexisting water systems. “Ecosystem services” describes a category ofbenefits provided by in situ environmental services and processes. Ex-amples range from the flood-attenuating potential of intact forests tothe water filtration benefits provided by wetlands. Intact river sys-tems provide habitat for fish with commercial value, such as salmon.In California, the collapse and near-extinction of salmon populationsis an example of a long-term cost of fresh-water supply. The impactshave emerged over several decades, are cumulative, and are difficultto apportion to beneficiaries of the complex system. A compoundingcomplexity is that harms to complex natural systems could have mul-tiple causes. In the case of salmon decline, water supply infrastructureis one contributing factor among many. Others include overfishing,interbreeding wild with farmed salmon, hydropower demands,flood control, and any regional impacts that alter aspects of riversvital to salmon survival. Determining who gets the bill, how muchthey should be charged, and for what verges on the impossible.

Similar costs associated with historical water infrastructure andpractices include groundwater and surface water degradation, in-creased flood risk, loss of species abundance, introduction of non-native damaging species, and loss of scenic and recreational uses ofwater supply. As a new water supply, desalinated water does not bearthese historical costs of infrastructure and transmission of water.

With desalination, additional research could bring us closer to anestimation of its true cost. Although exceptions exist internationally(e.g., Riyadh, Saudi Arabia), desalination is likely to remain a regionalwater technology, consumed near its point of production. This couldsimplify an accounting of costs and benefits and create an opportuni-ty to design cost allocation systems that assign accurate water costs towater users.

5.1. Environmental impact costs

Datasets exist that help us understand ocean impacts of desalina-tion. One example is the City of Long Beach library of research presenta-tions on their desalination pilot plant (http://ciwr.ucsc.edu/document_links/long_beach_library_annotations.pdf). Society is unsettled as tothe extent of new impacts it will tolerate to coastal systems. There isgrowing awareness of global damage to oceans and ocean fisheries,and of our dependence on oceans. As desalination impact studies im-prove, they need to be integrated into largermodels of ocean processes.From these models will come policy agendas for ocean recovery.

Numerous articles describe potential impacts of desalination facil-ities (e.g., [19,20]) and estimate the cost of desalinating both brackishand ocean water (see review in [21]). Recent studies, including theRegional Seawater Desalination Project in Santa Cruz, have generatedextensive data on impacts of ocean intakes and outfalls on sea life andocean processes.

One important finding of this research is that direct ocean impactsof desalination are comparatively small. Coastal Power Plants, pollut-ed coastal runoff in streams, the historic dewatering and delinking ofcoastal wetlands, estuaries, and near-shore zones, and direct impactsof over-fishing all result in more substantial ocean impacts comparedto coastal desalination.

Yet oceans are still in decline and the coastal desalination process, bywithdrawing coastal waters and returning higher-salt-concentratedwaters, could impact regional ocean health. One is faced with trade-offs: which of the other, larger adverse impacts on oceans can be con-sciously curtailed so that desalination can substitute for it/themwithoutcausingmore ocean harm? The no-net-impact scenario for desalination

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follows the logic of “in exchange for less of this other ocean-impactingactivity, we will allow increased impacts from desalination.” One is pri-oritizing ocean uses and implementing policies that carry out the rank-ing. This research agenda takes one well beyond the purview of wateragencies to the realm of coordinated ocean policy involving state andfederal legislative and regulatory bodies and the myriad public and pri-vate parties engaged in ocean policy.

A similar question is whether the use of desalination can introducechanges to coastal water management that will improve the health ofthe ocean more than the desalination process impacts it. This oppor-tunity has arisen in Santa Cruz as federal regulators attempt to restorethe endangered tidewater goby (Eucyclogobius newberryi) and salm-on (Oncorhynchus spp.) on streams from which the City of SantaCruz draws water supply. Supplementing the city's water supplywith desalinated water would reduce city withdrawals from thestreams. The relatively minor ocean impacts of desalination occurringat the intake and outfall infrastructure is seen as a net-positivetrade-off.

5.2. Energy choice

There is growing awareness in the public of the adverse impactsand risks associated with fossil-fuel-based energy systems. The pri-mary adverse impact is climate change. A system in which no green-house gas-producing energy source is used leaves no doubt that it isresponding to the challenge of climate change.

Major risks include interruption of fossil fuel supplies or grid fail-ures that lead to power shortages. Grid failure in the U.S. Northeast in2003 resulted in boil orders for four million customers in the Detroitregion, and other cities and regions experienced sewage spills intowaterways when sewage pumps lost electrical power. A reverseosmosis water system is even more dependent upon electricalpower than the Detroit system since (1) the saline source water al-most always originates at a lower elevation (either underground orin the ocean) than where it will be treated and used, and (2) energyis needed to pump the source water through membranes and pre-treatment. So systems relying on saline source waters can be highlydependent on a reliable electrical system.

Energy is an essential input to desalination. Hanafi provides energytransfer equations for wind-powered desalination [22]. The theoreticalminimum energy requirement for reverse-osmosis desalination is0.706 kWh/m3 water produced, but in practice, electrical requirementsrange in the 3–4 kWh/m3 and as high as 9 kWh/m3 [23; similar rangein 24], lowering to 2–2.3 kWh/m3 if energy recovery devices are used[20]. Brackish desalination energy demand has been estimated at 2–3kWh/m3 [1].

Kerri et. al. provide a comprehensive method for determininggreenhouse gas generation from water facilities in the Sacramento re-gion [25]. Their study extends beyond the gates of the water facility toinclude chemical production and transportation, and staff transporta-tion. This kind of approach can be carried out for proposed andexisting desalination facilities. Desalination technology readily re-veals an important connection between energy and water. The energyinput to water treatment is easily measured, and energy require-ments for introducing desalinated water into existing systems canalso be determined.

In terms of operations, historically, California water agencies haveutilized grid-provided power (in some cases generated from theirown hydropower plants), with gas-fueled generators as back-up.Energy sustainability can be folded into this approach through a com-bination of:

- minimizing energy consumption through investment in energy-efficient pumps and other equipment;

- purchasing renewable energy credits that offset the greenhousegas loading of the electricity consumed by the facility; and

- investing in greenhouse gas-reducing projects, from new renew-able energy projects to carbon storage projects.

Another approach is possible, but requires further research and test-ing. It is to operate one's desalination facility using exclusively off-gridrenewable power. Eltawil et al. [26] provide an overview of cost andtechnology options for combined desalination-renewable energy sys-tems. Systems powered by renewable energy sources are generallymore expensive than systems powered by fossil fuels [21]. Ma and Luprovide a review of wind-powered systems, including twelve systemsin use around theworld [27]. Only one of these, a small facility, is locat-ed in the US, on the Island of Oahu. Miranda and Infield report on asmall-scale no-battery wind-powered reverse osmosis experiment[28]. Typically the performance of desalination technologies, especiallymembrane systems, is optimized based on an assumption of steady, re-liable electricity input. Wind power and solar power both are intermit-tent, although solar ismore predictable. Today's large-scale desalinationsystems are not designed for intermittent power. Among the many po-tential problems with intermittent power are themore rapid deteriora-tion of membranes, interruption of back flushing and other cleaningcycles, and interruption of application of UV processes. Continuouswater monitoring can also be interrupted. All of these problems can re-sult in unreliable water quality, earlier replacement of parts, and in-creased costs. Wind power intermittency and the coupling of windturbines to desalination systems are two leading challenges for techno-logical research [27]. In terms of coupling, not all wind-generatedpower needs to be converted to electricity. Some can be used asmechanical power to drive pistons that pressurize water vessels, orfriction-induced thermal desalination can be pursued, with bothapproaches bypassing the relatively inefficient wind-to-electricityconversion.

Yet another source of power is energy recovery during the RO pro-cess. Water pressure can be recaptured through pressure exchangers,reducing the overall energy utilized by an RO facility. The private sec-tor is developing and refining pressure exchange systems.

The journal Solar Energy has maintained a regular stream of articleson desalination, focused primarily on solar thermal technologies.García-Rodríquez also reviews RO-connected renewable systems, identi-fying combinations of wind and solar as most promising, as well as ef-forts to adapt pre-treatment methods to solar inputs [29]. Rybar et al.describe an experimental wind-energy with grid back-up desalinationsystem for vegetable irrigation on Gran Canaria [30]. Eltawil et al.present comparative cost data on numerous projects. While individual-project energy costs are readily measured, project-to-project energycomparisons are nearly impossible due to the idiosyncrasies of each pro-ject, including source water quality, throughput, system design, andother factors [26].

If one begins with an assumption of intermittent power, the optimi-zation challenge (costminimization; reliablewater supply) changes. Anobvious but high-capital-cost early adaptation is the addition of batteryor fuel cell storage of power for use when renewable power isn't avail-able. Increased storage capacity along the treatment train and for fin-ished water is another adaptation that would allow water treatmentprocesses to be intermittent without impacting supply. Another alter-native is to provide back-up grid power to smooth the valleys inrenewable-resource power production.

The more profound adjustments involve the evolution of thetreatment technologies themselves so they can successfully operateunder intermittent power conditions. One example would be abackflushing system that consults energy storage levels before auto-matic activation. If insufficient power is available, the procedure isdelayed. At the end of a delay period, operators are notified that analternative power source is needed to carry out the procedure.Membranes that operate efficiently under intermittent power areanother important research area in merging renewable power withdesalination technology.

76 B.M. Haddad / Desalination 324 (2013) 72–78

5.3. What desalination enables

von Medeazza points out that even if one maximizes the energy ef-ficiency of a process such as desalination, if it is used for frivolous or un-necessary purposes, it should be seen as wasteful [11]. This puts a focuson the intended uses of desalinated water once generated, connectingthe technical analysis of desalination with social analysis and socialvalues. The argument that expanding water supply changes other as-pects of a region's economy, population, building patterns, energy con-sumption, traffic congestion, or other urban systems is a staple ofpopular discussion in California. Multiple water planning requirementshave created awealth of information that can be applied to the questionof what desalination could provide a region that utilizes it. The 1995urban water planning requirements and more recent legislation (SB610 and SB 221 rules, now found in Sections 10610–10656 of the Cali-fornia Water Code, and called the California UrbanWater ManagementPlanning Act) require extensive water planning and analysis by wateragencies. Similarly, the Water Conservation Act of 2009 calls uponurban water agencies to generate plans for cutting water consumptionover the next decade. Finally, individual project EIRs are a source ofdata and analysis on the interaction between water supply and eco-nomic growth. EIRs serve a political as well as a planning purpose sothe choices of datasets, analytical methods and results of projectionsfound in EIRs should be considered in that light.

These laws as a whole have placed large data-gathering and anal-ysis burdens onmunicipal and privately owned water agencies. Thou-sands of reports are being generated throughout the state describingsupply and demand for urban water in California. These reports couldhelp as a starting point for ecological-economic research related todesalination.

Some infrastructure investments may seem expensive but willprovide benefits to vulnerable segments of society. Other invest-ments, although lower in overall cost, may provide minimal benefits.We can't fully evaluate the value of a supplemental non-cyclicalwater supply such as desalination until we have a better understand-ing of its value to all parts of society. In urban areas augmented watersupply may provide the amenity of lush irrigated landscapes, foun-tains and other water features, more reliable drought resistance, ex-panded fire protection, and the ability to expand economically intohigh-water-demanding businesses. It may also provide a basis forbuilding more homes and businesses of all kinds. If desalination isused for drought protection, it may protect water-demanding urbanlandscape during a drought while also maintaining water supply toat-risk businesses, maintaining the employment of workers withfew employment alternatives. These potential impacts are poorly un-derstood and their documentation where desalination exists wouldbe of great value. Ecological economics has the capacity to undertakethis research.

5.4. Desalination and ecosystems

The research questions above are connected to the issue of humanneed for economic security and the benefits of a reliable water supply.The preservation of regional cultural history as it is found in the existinglandscape is also of interest. Human society remembers its local historyin part through the wild plants and animals found locally. The presenceof these species and their combinations and arrangements on land inand near cities directly connect one to a region's heritage. The preserva-tion of local minimally disturbed ecosystems also provides society witha guide and genetic stock for reestablishing diminished open space, andfor understanding how plants and animals have adapted to the climaticconditions of the region. A resilient, well-adapted ecosystem not domi-nated by recent arrivals is less likely to allow an outbreak of pests thatharm crops, bring disease, or increase the chance of fire.

Many important ecosystems found in open spaces are dependenton their historical water regime, including the presence of standing

or flowing surface water for all or certain parts of the year. The histor-ic flow regime predates the establishment of today's water rights sys-tems. Property rights in water were established over the past coupleof centuries for the purpose of rerouting the historical flow regimesin an orderly way. In California, the resulting system moves millionsof acre-feet of water annually from east to west and north to south.As less and less public open space can be found near cities, its valuehas grown. Ecological science research has clarified the crucial rolewater plays in maintaining the functioning and diversity of these sys-tems [31].

Desalination as a non-cyclical water supply creates an opportunityto increase the ability of open space to play the roles described above.With rare exception (one being the original Yuma Project connectedto the Colorado River system), desalination projects are intended toprovide urban water. The direct ecological impacts of desalinationuse will occur either in cities through its application to plantedareas or through displacing other water in the system—water that ar-rives from or passes into open space. Desalinated water is new waterto a system, entering either from the ocean or from brackish under-ground sources. In California's Monterey County an existing small de-salination plant and a planned larger one will help maintain instreamflows in the nearby Carmel River. Demand for a desalination facilityarose specifically in response to damage caused by unauthorizedwithdrawals from the river for nearby urban use. Also in California,the proposed Santa Cruz regional desalination facility will in part re-store flows to coastal streams to protect endangered fish species al-though the primary purposes will be to enhance drought waterreliability and reduce pressure on overdrafted coastal aquifers.

Desalination also has indirect ecological impacts. The introductionof desalinated water provides additional water for consumption byexisting users and possible new users. Water supply is meant to en-able General Plans that have already been debated and approved.But it is also possible that actual growth can exceed what wasenvisioned if additional investment and population are attracted.Water could enable additional construction, population inflow, andeconomic activity that itself could encroach on remaining or nearbyopen spaces. Additional water supply could also result in urban re-newal, including reclamation of urban brownfields. All of these topicscan be explored through ecological economic lenses that combinetechnological, economic, environmental, and social perspectives.

It is also possible that no indirect ecological impacts will occur thatwouldn't otherwise occur. This would be the case if urban planners, in-vestors, builders, speculators, and regulators see other factors besideswater as crucial to their decision-making. Other factors that outweighwater supply could include development project cost and financing, po-tential markets for products, and cost and availability of labor. If watersupply is a minor factor on the developer's checklist then other factorswill determine the fate of nearby open space, not water availability. Ifdesalinated water is a substitute for cyclical water supply or for watersupply otherwise lost to a region then minimal environmental impactscould result from its introduction.

5.5. Scale and governance of desalination

Individual homes and many ocean vessels have desalination units.Small-scale desalination units range in size from 1 to 10 m3 per day.There can also be extremely large systems, such as Ashkelon, Israel,which produced 300,000 m3 per day on average in 2008. The size ofthe unit or system influences the institutional form of governanceranging from primarily the private sector for small, privately ownedunits to primarily the public sector for large-scale systems.

The choice of governance system is linked to scale and influencesthe level of transparency to the public, incentives for technology inno-vation, types of public oversight, management of energy impacts, andother factors. If desalination were a mature technology, like hydro-power, there would be less need to include the private sector with

Table 2Summary of research questions related to desalination in the field of ecological economics, and the scale of interest.

R-N: can be addressed regionally or nationally;L: can be addressed at the local levelNatural science focus- R-N: What other uses of the coastal ocean have impacts similar to coastal desalination? What are the scale and location of those impacts?- L: What connections between groundwater and surface water would be influenced by groundwater withdrawals or brine deposition of an inland desalination facility?

Economics focus- R-N: What are the costs and benefits of alternative uses of the ocean compared to increased ocean desalination?- R-N: What economic functions are protected and economic expansion made possible by a non-cyclical water supply compared to a drought-impacted water supply?- R-N: What is the relationship between drought and employment? What jobs are more at risk in a drought?

Public policy focus- R-N: How is desalination governed today and how should it be governed in the coming years and decades? Governance includes ownership, management, and permitting.- R-N: How does one institutionally generate a system of trade-offs that potentially decrease the impacts of other marine activities so that desalination can expand without

an overall net increase in ocean impacts?Sociology focus- R-N: How do poor and marginalized segments of society interact with municipal water supply? Are their uses/dependence the same as other segments of society? Is there

greater vulnerability when water supply is cyclical?Integrative- R-N: For regions with existing desalination facilities, did demographics or economic activity change following the launch of production? What changes can be attributed to

the existence of supplemental water?- L/R-N: Which segments of society most/least benefit from introduction of desalination?- L/R-N: Following introduction of desalinated water, what are the regional ecological impacts of water supply?- L:/R-N: Given the beneficial nature of restoring water to natural systems near cities, how are these benefits accounted for in the cost and pricing of water systems that

invest in desalination?- L: What indirect ecological impacts can be attributed to desalination at existing systems?- L: For a region considering desalination, what nearby or co-located areas of ecological significance are threatened by urban expansion? How are the areas currently

protected? What are the threats? What role, if any, does a supplemental non-cyclical water supply play in protection or loss of the areas?

77B.M. Haddad / Desalination 324 (2013) 72–78

its power of innovation and R&D strengths. But desalination researchis still dominated by improving the actual technology so that perfor-mance improves and costs decline. It will be valuable to maintain astrong private-sector presence for several more years. Anotherelement of governance involves how projects are evaluated and ap-proved, including improving the EIR process itself. This crucial ques-tion is linked to project scale, ownership, norms and expectations ofpublic participation, and legal and regulatory precedent, and requiresfurther investigation both within and outside the realm of ecologicaleconomics.

6. Conclusions

Table 2 summarizes research questions raised here that could beaddressed from an ecological economics perspective. They are dividedby core disciplines although each is clearly interdisciplinary in thatknowledge of desalination engineering and environmental science isrequired to address the social/policy/economic issues.

Progress has already been made on every question posed here so itis an issue of building on existing findings. It should not be the soleresponsibility of the water agency to answer these questions. Somequestions are best addressed at the local level; others at the regionalor national level. Water agencies have essential data and analyticalcapacity, but their scope of interest lies with their customers and ser-vice territory. The research agenda described here is broader since ittakes on the question of where and how urban regions will grow,what kind of coastal development should occur, broader ecosystemimpacts, and how to provide support services to desalination, includ-ing electrical power. Research collaborations will be necessary thatcan produce datasets, expertise, and funding spanning water, energy,land use, and social and economic impacts. Such collaborations arecommon to the field of water, though typically not in the constella-tions suggested here.

Foundation-sponsored research with strong peer-review elementscould play an important role in advancing the broader agenda. Re-search foundations are typically multi-regional, retain the appropri-ate “applied” orientation, are expert at collaborative research, andcan insulate themselves from local political interests in some caseseven more than state government. General sponsors of research foun-dations are often water agencies, so research products typically have

an agency perspective. Foundations therefore cannot sponsor all theneeded research since many questions are broader than the interestsof their subscriber base.

This discussion has focused on questions that the field of ecologi-cal economics can play a role in addressing. There are other pressingsocial-science issues, such as comparative research leading to im-provements in the public review process for new facilities. Such re-search falls in the field of public policy. Likewise, research on publiccommunications regarding water typically occurs in the fields of so-cial psychology, marketing, and communications. So while the focushere has been on desalination and ecological economics, a largercase for integration of social sciences into the study of advancedwater treatment technology can also be supported.

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