CONSTRUCTED WETLANDS FOR WASTEWATER REUSE AND ECOSYSTEM REHABILITATION OF THE IRAQI MARSHLANDS - The case of the small city of Al- Chibayish in Thi-Qar Province, Iraq

Master’s Thesis

2010

Author

Ali T. Hassan

Supervisor

Jean O. Lacoursière Associate Professor

Degree Project (15 Credits) - in Applied Environmental Science Programme

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Key Words: Marshlands; Constructed wetlands; Water scarcity; Wastewater reuse; Agriculture; Sustainable development

Titel/Title: CONSTRUCTED WETLANDS FOR WASTEWATER REUSE AND ECOSYSTEM REHABILITATION OF THE IRAQI MARSHLANDS - The case of the small city of Al-Chibayish in Thi-Qar Province, Iraq

Språk/Language Engelska/English

Examinator/Examiner Stefan Weisner, Ph.D. Professor i biologi med inriktning miljövetenskap/Professor of Biology with specialism in Environmental Science Högskolan i Halmstad/Halmstad University

Författare, program/Author, programme Ali T. Hassan

Höst 2009, Magisterprogram i tillämpad miljövetenskap (60 hp) Fall 2009, Master in Applied Environmental Science (60 ECTS)

Handledare/Supervisor Jean O. Lacoursière, Ph.D.

Docent i vattenvård / Associate-Professor in Sustainable Water Management Högskolan Kristianstad/Kristianstad University

Högskolan i Halmstad Halmstad University

Sektionen för ekonomi och teknik School of Business and Engineering

SE-301 18 HALMSTAD SE-301 18 HALMSTAD

SWEDEN

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Dedicated to my

birthplace: the city of An Nasiriyah

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ABSTRACT

The risk of the Iraq’s marshlands disappearing is still high unless serious measures are adopted. Sewage discharge and irrigation-water pressure, compounded by the effects of climate changes and the extent of the planned dam construction in upstream countries, make this event more likely. Most of the marshlands’ inhabitants (Marsh Arabs) are suffering from lack of access to safe, clean water and lack of sanitation and are reluctant to look for better places to live and work. Constructed wetlands are among the best alternatives to solve their problems. The application of constructed wetlands to meet more stringent standards for wastewater reuse in agriculture contributes to mitigating the wastewater impact and irrigation pressure on the marshland ecosystem. It is here proposed that a 3.6 ha free-surface flow wetland could manage the more stringent standard for reuse (15 mg/l) for BOD5 and TSS. A monitoring programme should nevertheless be associated with this kind of project to minimize health risks that may arise as a result of implementation. Despite the absence of studies that deal with wastewater reuse in irrigation projects at the national level (in Iraq), similar studies worldwide provide evidence of reuse possibilities. Furthermore, a performance requirements framework for wastewater reuse in irrigation projects such as the one suggested by Biswas, draws an approach to meet sustainable development indicators and would likely contribute to support and encourage the Marsh Arabs to settle back in their own areas.

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ACKNOWLEDGMENTS

I heartily thank my supervisor Dr. Jean O. Lacoursière from Kristianstad University. He has always been an inspiration and guided me through this project despite his busy schedule. I am really grateful to Professor Stefan Weisner, Director of the Applied Environmental Science Programme of Halmstad University, for his kind advices and support during my studies. Special thanks go to Mr. Raji Naima, Engineer and Manager of the Department of the Environment in Thi-Qar province, for answering letters and providing information. My appreciation also goes to Mr. Akeel Najeem, Engineer and Manager of the Department of the Environment in An Najaf Province for the provision of raw sewage data from the An Najaf sewage treatment plant. Last but not least, my thanks extend to all my friends and colleagues too numerous to list here. You know who you are and I hold each of you in great esteem in my heart.

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ABBREVIATIONS AND SYMBOLS

As Wetland surface area, m2 or ha BOD5 5-day Biochemical oxygen demand, mg/l C* Background pollutant concentration, mg/l Ci Influent pollutant concentration, mg/l Ce Effluent pollutant concentration, mg/l COD Chemical oxygen demand, mg/l CWs Constructed wetlands DALYs Disability-Adjusted Life Years ET Evapotranspiration FAO Food Agriculture Organization FC Fecal coliforms, log/ 100 ml FW Free surface flow constructed wetland ha Hectare HLR Hydraulic loading rate, cm/d or m/d HRT Hydraulic retention (detention) time, day (d) k First order areal rate constant, m/yr l/d Litre per day n Voids or porosity; expressed in fraction NO3 Nitrate, mg/l (P.E) p.e Population (or person) equivalent pppp per person per year Q Discharge or inflow through wetland, m3 SSF Subsurface flow constructed wetland STP Sewage treatment plant TN Total nitrogen, mg/l TP Total Phosphorus, mg/l TSS Total suspended solids, mg/l UNEP United Nations Environmental Programme USEPA U.S. Environmental Protection Agency WHO World Health Organization y Water depth in wetland, m

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TABLE OF CONTENTS Abstract

Acknowledgments Abbreviations and Symbols List of Tables List of Figures and Boxes

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1. INTRODUCTION 1.1 The Iraqi Marshlands Ecosystem

1.1.1 Changing Environmental Significance 1.1.2 The Socioeconomic Realities

1.2 Can Wastewater for Agriculture help the Marshlands and its people?

1.2.1 A Water Stress Iraq 1.2.2 Wastewater is a Valuable Resource 1.2.3 Wastewater Reuse and Public Health Risks 1.2.4 Example of Guidelines for Wastewater Reuse 1.2.5 The Importance of Public Participation

1.3 Wastewater Reuse and Sustainable Development 1.4 The United Nation Environment Programme Involvement in

the Marshlands Rehabilitation 1.4.1 Treating Wastewater with Constructed Wetlands 1.4.2 A Pilot project that Failed to Fully Work 1.4.3 Optimizing Sewage Treatment by Constructed

Wetlands 1.5 Objectives of the Study 1.6 Research Questions

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2. METHODS 2.1 Dimensioning a Constructed Wetlands by the Kadlec and

Knight Method 2.2 Framework for Wastewater Reuse

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3. RESULTS 3.1 Expected Efficiency for BOD5 and TSS Removals 3.2 Possibilities and Constraints of the Proposed Constructed

Wetlands in Achieving Water Reuse 3.3 An Investigation on Sustainability Indicators

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4. DISCUSSION 4.1 Revival of the Environmental Values 4.2 Towards for Sustainable Development

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5. CONCLUSIONS 23

References 24

Appendix 1 26

Appendix 2- Calculation 30

Appendix 3 34

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LIST OF TABLES

Table 1 Increases in crop yield production from wastewater reuse in irrigation projects

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Table 2 Example of different kinds of hazards associated with wastewater use in agriculture in developing countries

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Table 3 Iraqi Effluent standard for discharge to watercourse and the more stringent standard for wastewater reuse in agriculture

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Table 4 Different levels of tools for public participation in the decision process to reuse wastewater

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Table 5 Socio-economic and environmental sustainability matrices 08 Table 6 Expected performance of indicators for sustainable development in

correlation with possibilities and constraints of the proposed constructed wetlands in achieving water reuse

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Table 1-A1 DALY losses, disease risks, disease/infection ratios and tolerable infection risks for rotavirus, Campylobacter and Cryptospridium

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Table 2-A1 WHO microbiological guidelines for wastewater use in agriculture 28 Table 3-A1 Pathogen reductions achievable by selected – protection measures 29 Table 1-A2 Historical data of raw wastewater of An Najaf (STP) for ca. 19 months

over 2006 and 2007 31

Table 2-A2 Typical constructed wetland influents in combination with septic tank system

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Table 3-A2 Summary of Area calculation 32 Table 4-A2 Summary of calculation of effluent concentration and removal

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LIST OF FIGURES AND BOXES

Fig. 1 Map of southern Iraq including the former extension of the Mesopotamian marshlands and the current remaining of permanent marshes

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Fig. 1-A3 Geographical distribution of mean annual evapotranspiration, ET (mm), in the study area

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Box 2 Framework for the analysis of wastewater irrigation projects 13 Box 3 Summary of wetland calculation 15 Box 1-A1 Disability-Adjusted Life Years 26

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1. INTRODUCTION 1.1 The Iraq Marshlands Ecosystem 1.1.1 Changing Environmental Significance

The Iraq’s marshlands consist of three adjacent areas of roughly 20,000 km2; the Central Marsh, Hammar Marsh and Huwaizeh Marsh, the latter extending to the Iran-Iraq border (Fig. 1). They were until not so long ago the largest natural ecosystems in the Middle East, located at the confluence of the Euphrates and Tigris Rivers. These vast areas were famous for their biodiversity and cultural richness. They were the permanent habitats for millions of birds and flyway for billions that migrated between Siberia and Africa (UNEP, 2001). Sixty-six bird species may be near extinction, while other populations have seriously declined. The marshlands were also used as nursery grounds for shrimp and fish (UNEP, 2001). Naturally, the marshlands served as a filter for wastes and other pollutants from the Tigris and the Euphrates Rivers. During the former political era (the Saddam regime), the marshlands have been extensively damaged in large parts between 1975 and 2003 following an intensive engineering programme to drain them (Fig. 1). In 2001, the United Nations Environmental Programme (UNEP) warned the international community when it reviled satellite pictures showing that 90% of the marshlands had been lost. In the post-conflict period (after 2003), UNEP immediately implemented an environmental initiative in Iraq. This project ran from 2004 to 2009 to secure and sustain the environmental management of the Iraqi marshlands (UNEP, 2010).

Fig. 1 Map of southern Iraq including the former extension of the Mesopotamian marshlands and the current remainder of permanent marshes (Modified from source: UNEP, 2001)

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Release of water to the marshlands started in 2003. So far, nearly 40 percent of its area has been re-flooded. Different parts of the marshlands’ ecosystem showed various level of recovery, reflecting the local severity of the former heavy destruction policy. Marsh water was suspected to be heavily contaminated due to a long period of desiccation, with salt intrusion, pesticides accumulation and sewage discharged from the upstream cities. Securing Marsh water quality is now identified as an urgent priority, to protect human health and conserve marsh ecosystems. However, with the actual trend to build dams on the Tigris and Euphrates Rivers by the neighbouring upstream countries, the marshlands are expected to disappear again unless the Iraqi authorities adopt a successful management policy to ensure water flow to the marshes and protect it from upstream wastewater discharges. 1.1.2 The Socio-Economic Realities Indigenous people, often called, Marsh Arabs, have been settled in this region for a long time; images of their reed houses are found on 5000 year old Sumerian clay tablets. Nowadays, they are living as small, disarranged and random communities (villages) and are suffering from lack of sanitation and access to safe drinking water. Public water supply is limited and the quality of supply networks is poor. People have small outdoor toilets. Treatment of household wastewater does not exist or is limited to collection in adjacent ponds. Where they do exist, septic tanks are simplistic or poorly built. They are often made of reed stems, only retaining larger suspended solids without much treatment capacity. Water from washing and other needs (i.e., grey-water) is gathered and thrown on yards outside the houses and let to percolate into the soil. The inhabitant’s livelihood of this region depended on fisheries, livestock and on dairy and agricultural production (rice production). This is particularly true for those living on the edge of the marshlands. Because of discrimination and intentionally disregarding their needs during the last decades, the Marsh Arabs are now thinking to move away and look for alternative lands and alternative job opportunities. Lack of sanitation and other sustainable services do not appear as a problem before the marshland drainage. There was plenty of water then to dilute incoming sewage (solution by dilution) and the healthy marshland ecosystem was providing self-cleaning capacity. Furthermore, these people had no intention to leave the region in which their ancestors had lived. The assessments report of 2003-2004 indicated that 85,000-100,000 Marsh Arabs resided within or near the remaining marshlands, that 100,000 to 200,000 were internally displaced and that about 100, 000 migrated to nearby Iran (UN Water, 2009). In this context, the rehabilitation of the environment for both marshlands and the Marsh Arabs turn out to be essential to avoid more degradation of water under these present water scarcity conditions. It is a rational solution to think about wastewaters treatment and to reuse it as a resource for agriculture. The wastewater generated from households in this region can reduce the pressure on freshwater resources (the marshlands) and downstream pollution from the discharged waste. The added benefit is the recycle nutrients for agricultural purposes.

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1.2 Can Wastewater for Agriculture help the Marshlands and its People? 1.2.1 A Water Stress Iraq Iraqi waters face serious challenges in availability and in quality. By 2025, the combination of intensive dam construction in upstream countries, forecasted climate change impacts, the pervasive unsustainable wastewater treatment and a lack of a strategy for reuse, could lead Iraq to be classified as a water-stressed country. Water resources planners are always looking for additional sources to meet freshwater demand when the sources are limited in their regions. Wastewater reuse may become a suitable alternative to substitute water shortage in agricultural purposes for a scenario of using large quantities of treated wastewater in irrigation. The way was staged already in 1958 when the United Nations Economic and Social Council provided an approach to sustain this concept through the following statement: ‘’no higher quality water, unless there is a surplus of it, should be used for a purpose that can tolerate a lower grade’’ (in Hespanhol, 2007). With a further reduction in water availability expected with climate changes, the search for appropriate technologies and alternative sources to solve this problem has become a pressing issue, especially when global trends in population growth acceleration and rapid economic development will most likely lead to acceleration in freshwater withdrawals (UN Water, 2009). In Arab region particularly, (Iraq is a part of this region) there is now calls for an improvement in municipal waters treatment to create an affordable supply to mitigate the high dependence on uncertain trans-boundary rivers flow (the Euphrates and Tigris). The total consumption of water in the Arab region is distributed among three different sectors: agricultural, industrial and domestic. Water use for agricultural purpose is 88 %, 7% for domestic and 5% for industrial sector (Mohamed F., 2004). These mentioned values exhibit an important role of improvement to wastewater collection and treatment to meet water shortages which are expected to be more complicated in the coming decades. 1.2.2 Wastewater as a Valuable Resource The huge burden on scarce fresh water resources calls for the incorporation of the reuse of treated wastewater in water conservation and demand management strategies. Reuse planning is distributed among several applications such as irrigation in agriculture, reuse in aquaculture, groundwater recharge and industrial recycling or reuse. In this context, reuse application in irrigation can reduce the cost in wastewater treatment technologies and fertilizer applications. For instance, nutrients removal (such as N and P), which has high costs in wastewater treatment, is not always necessary when the treated water is reused in agriculture or aquaculture. In contrast, reuse of treated wastewater for agricultural purposes has benefits for crops through the recycling of nitrogen and other nutrients. A study was done by the World Bank which estimated that farmers can save about $130/ha/year in fertilizer costs through using treated municipal effluents (Mohamed F., 2004).

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Studies in several countries have further shown that crop yields can be increased if wastewater irrigation is properly provided. For example, field experiments in India recorded an increase in crop yields using wastewater-reuse in comparison with freshwater (Table 1). Table 1 Increases in crop yield productiona from wastewater reuse in irrigation projects in Nagpur, India.

Irrigation water Wheat 8 yrb

Moong Beans 5 yrb

Rice 7 yrb

Potato 4 yrb

Cotton 3 yrb

Raw wastewater 3.34 0.90 2.97 23.11 2.56

Settled wastewater 3.45 0.87 2.94 20.78 2.30

Stabilization pond effluent 3.45 0.76 2.98 22.31 2.41

Freshwater+NPK fertilizers 2.70 0.72 2.03 17.16 1.70 Source: Shende, 1985 cited in Hespanhol, 2007 a

yield in ton /ha annually

b years of harvest used to calculate average

1.2.3 Wastewater Reuse and Public Health Risks Public health is the most critical issue in reuse application. Policy-makers are always facing the trade-off between public health protection and the ethical questions of whether to prevent the use of wastewater by farmers as the limited source of water that is available for them (Drechsel et al., 2010). According to this position, WHO supported the policy-makers in developing countries by establishing guidelines for microbiological standards where wastewater reuse is permitted (Drechsel et al., 2010). As wastewater reuse in irrigation reduces the pressure on the conventional freshwater resource, there are possibilities and constraints which should be considered. In contrast with benefits that have apparently been gained, there are serious risks. In this respect, the most affected groups are the farm workers due to the duration and intensity of direct contact with wastewater and contaminated soil (Drechsel et al., 2010). Recent epidemiological studies that surveyed groups of rice farmers in Vietnam using wastewater gave evidence of increased diarrhoea and skin irritations and infections (Drechsel et al., 2010). The financial gains from agricultural production using these wastewater utilities can lead farmers having to pay for medication to treat themselves. This situation enhances the need for farmers to be educated about the risks that can arise when using wastewater for irrigation. On the other hand, consumption of irrigated production also set up an exposure route to health risks. Several studies demonstrated higher Ascaris infections in both adults and children consuming uncooked vegetables irrigated with wastewater. Several records for diarrhoeal outbreaks have been associated with the consumption of vegetables irrigated with wastewater (WHO, 2006). Different kinds of hazards facing developing countries presenting as challenges that come from wastewater-irrigated agriculture are shown in Table 2.

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Table 2 Example of different kinds of hazards associated with wastewater use in agriculture in developing countries

Hazard

Exposure route

Relative

importance Excreta-related pathogens Bacteria (for example E. Coli, Vibrio cholerae, Salmonella spp, Shiggella spp.) Helminths (parasitic worms)

Soil- transmitted (Ascaris, hookworms, Taenia spp)

Schistosoma ssp. Protozoa (Glardia intentinalis, Cryptosporidium, Entamoeba ssp.) Viruses (for example hepatitis A virus, heptatitis E virus, adenovirus, rotavirus, norovirus) Skin irritants and infections Vector-borne pathogens (Filaria spp., Japanese encephalitis virus, Plasmodium spp.) Chemicals Heavy metals (for example arsenic, cadmium, lead, mercury) Halogenated hydrocarbons (dioxins, furans, PCBs)

Pesticides (aldrin, DDT)

Contact; Consumption Contact; Consumption Contact Contact; Consumption Contact; Consumption Contact Vector-contact Consumption Consumption; Contact Consumption

Low-high

Low-high

Nil-high Low-medium

Low-high

Medium-high

Nil-medium

Generally low

Low

low

Source: Modified from WHO, 2006

Not all hazards lead to diseases and end up causing illness. At the same time, the disease burdens vary from area to area based on the local status of sanitation and hygiene, in addition to the level of wastewater treatment before reuse in irrigation projects. The disease burden is measured in disability-adjusted life years (DALYs)1 The WHO estimates that diarrhoea alone causes nearly 3 per cent of all deaths and 3.9 per cent of DALYs worldwide (Drechsel et al, 2010). However, the remaining question here is how much of the disease burden is relevant to wastewater-irrigated food production (Drechsel et al, 2010). The large number of confounding factors makes any specific attribution to wastewater is difficult; one way to address that challenge is achieved through microbiological risk assessment, taking into consideration the location and exposure route (Drechsel et al.,2010). _____________________ 1 For more events see Box 1 in Appendix 1.

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The revised WHO guidelines for safe wastewater use (published in 2006) are established to ensure the ability to use wastewater safely in irrigation crops, including even those that can be eaten uncooked, with minimal risk to health. The responsible local authorities can therefore choose to adopt or adapt these guidelines, as recommendations of good national practice, in order to minimize health risk caused by pathogens resulting from wastewater reuse. The WHO guidelines are based on the more stringent DALY loss (10-6) per person per year (pppy) which means that a city of million people suffers the loss of 1 DALY per year (see appendix 1; Box 1 and Table 1). This value might not be appropriate as a first step for areas which are currently engaged in extensive use of untreated wastewater for irrigation (Ismail et al., 2008). 1.2.4 Examples of Guidelines for Wastewater Reuse The World Health Organization (WHO) and the Food and Agricultural Organization (FAO) approved a group of regional guidelines for treated wastewater in order to be reused. WHO’s recently revised guidelines (2006) for a stringent wastewater reuse standard for agricultural purposes identifies three categories for wastewater reuse based on the group of people likely to be exposed and the degree to which health protection measures are required:

Category A: protection required for consumers, agricultural workers and public. This category includes crops likely to be eaten uncooked, spray- irrigated fruits, sport fields, public parks. Category B: protection required for agricultural workers only because there would be no microbiological health risks associated with the consumption of the crops because the crops in this category are not eaten raw or processed before they reach the consumer. Category C: The crops are the same in category B, but no exposure of workers and public occurs (see Appendix 1; Table 2).

Table 3 shows the Iraqi standard for effluent discharged to watercourses in comparison to the more stringent standard for reuse in some of the neighbouring countries (Kuwait, Saudi Arabia and Oman) adopted from WHO guidelines (2006). So far, there is no specific standard for reuse in Iraq (WHO, 2006). Table 3 Iraqi Effluent standard for discharge to watercourses and the stringent standard for wastewater reuse in agriculture (WHO, 2006)

Parameter, mg/l Iraqi standard More stringent reuse standard

BOD5 40 15A- 20B

TSS 60 15A- 20B COD 100 90 FCs - ≤ 1000a

A- means Category A limits; 2 samples/month; irrigation should stop two weeks before fruit picked up, and no fruit should be picked off the ground. B- means Category B limits; 1 sample/month a- This is during the irrigation period. A more stringent guideline (≤ 200 FCs per 100 ml) is appropriate for public come in direct contact (such as; public lawns).

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1.2.5 The Importance of Public Participation Not only environmental impacts and health risks should be taken into consideration when using wastewater for irrigating crops. Culture and ethnic values play a vital role in the acceptance process of wastewater-irrigated agricultures. Efforts should be made to ensure public acceptance of wastewater reuse in agriculture. Crook et al. (1992) suggested an aspect for public participation in the decision process to reuse wastewater. Application of this aspect includes different purposes with different levels of tools to achieve them (Table 4). Table 4 Different levels of tools for public participation in the decision process to reuse wastewater

Purpose Tools Education and information Newspapers articles, radio and TV programmes,

speeches and presentations, field trips, exhibits, information depositories, school programmes, films, brochures and newsletters, reports, letters, conferences

Review and reaction Briefings, public meetings, public hearings, surveys and questionnaires, question and answer columns, advertised ‘’hotlines’’ for telephone inquiries

Interaction dialogue Workshops, special task forces, interviews, advisory boards, informal contacts, study group discussions, seminars

Crook et al., 1992 cited in Hespanhol, 2007

1.3 Wastewater Reuse and Sustainable Development Through a more efficient use of agricultural water linked to wastewater reuse, more sustainable water management and more progress towards sustainable development can be achieved. The broad concept of sustainable development was concluded from the Brundtland report (1987) which stated: ‘’ we must ensure development meets the needs of the present without compromising the ability of future generations to meet their needs’’ (in Joseph H., 2009). A group of authors connected to the Global Development and Environment Institute at Tufts University (2001) discussed several perspectives; three aspects were recognized regarding sustainable development. These three aspects were later defined as dimensions (targets) of sustainable development (Joseph H., 2009):

1. The environmental dimension concerns the maintenance of stable resources and the avoidance of overexploitation of non-renewable resource systems. Maintenance of biodiversity, atmospheric stability and ecosystems are included.

2. The social dimension concerns fairness in distribution and opportunity among all people to gain an adequate provision of such as health and education.

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3. The economic dimension concerns the ability to produce goods and services on a continuing basis to avoid extreme sectorial imbalances that damage agricultural and/or industrial production.

The problem of safe water access is predicted to become even worse in developing countries, where more than 80% of water is used in agriculture, particularly for crop irrigation. Competition for water from other sectors, such as industry and energy, is increasing. Domestic use is also expected to increase by more than 70%, with the greatest increase being forecasted in nations which are described as developing (Joseph H., 2009). By 2025, industrial water consumption in developing countries is expected to be higher than in industrialized nations (Joseph H., 2009). In Iraq, where competition for water among different sectors of water consumption is certainly high, a combination of environmental degradation factors (compounded by climate change impact and upstream discharged pollution) and an increased agricultural water demand is putting further pressure on an already compromised marshlands’ ecosystem. The socio-economic reality of the Marsh Arabs can become even more complicated and uncertain, forcing them to leave this region in search of a better life. Table 5 shows an example of a sustainability matrices using reclaimed wastewater for agriculture purposes (Virginia Region projects, South Australia as paradigm); which is developed according to the farmer’s perception and field observations. These matrices represent the three dimensions of sustainable development, where economic profits and social benefits can be achieved in related to environment. Table 5 Socio-economic and environmental sustainability matrix for Virginia region projects (Ganesh B. and Jennifer Mc., 2007)

Economic sustainability Social sustainability Environmental sustainability Production volumes Purchase of off-farm fertilizers Market value of land Markets for produce

The social capital Farming income Job opportunities Community cohesion

Groundwater recharge Freshwater environment (Marshland ecosystem) Soil quality Health concerns

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1.4 The United Nations Environmental Programme Involvement in the Marshlands Rehabilitation To revive the Iraqi marshlands and enhance their sustainable development, UNEP introduces constructed wetlands as the best option for the marshlands’ sanitation problem in view of their low cost operation and maintenance. 1.4.1 Treating Wastewater with Constructed Wetlands In mimicking the natural marshlands (Mesopotamia)’s functions, UNEP’s initiative proposed free surface flow constructed wetlands (FWs) to treat small cities’ domestic wastewater; hence contributing to a reduction in pollutant burdens on the marshland ecosystem. The first full-scale system of 5 hectares was to be set in the Thi-Qar province to serve the city of Al-Chibayish (ca. 4000-5000 P.E). It was however decided to test the approach in a smaller pilot project. 1.4.2 A Pilot Project That Failed to Fully Work

UNEP therefore built, in the same region, a 540 m2 subsurface (SSF) wetland planted with native species of reeds (Phragmites australis or similar) designed to serve 170 residents. The objective of this pilot study was to generate relevant data and experience for the wider implementation within the marshlands and beyond. Operational in December 2007, the project unfortunately failed to mimic the expected wetland functions and deliver suitable wastewater treatment. It was later assessed that the failure of the pilot project was rooted in the lack of experience of the local people involved in its construction (lack of supervision to adhere to the design) and implementation (operation and maintenance). This lead to the refusal of the city administration to take-over the project upon its completion. 1.4.3 Optimizing Sewage Treatment by Constructed Wetlands A treatment system often consists of centralized septic tanks or sedimentation tanks and a free surface flow wetland receiving the effluents. The size of the septic tanks depends on the number of households that are connected to them. This pre-treated wastewater is then conveyed to the constructed wetland through a pipe networks to reduce pollutant-loading before it reaches the distribution box. Septic tanks A septic tank system is a partial treatment (as anaerobic biological treatment) for wastewaters. Further treatment is required for the effluents. Therefore, it is common to combine the septic tank with percolating filters, or reed beds in small communities’ wastewater management (decentralized wastewater management). The septic tank does not require power to operate, and can achieve 40-50% and 80% of BOD5 and TSS removal respectively (Gray, 1999). The septic tank’s operations include the setting of solids, flotation of grease, the anaerobic degradation of organic matter and storage of sludge; the latter should be removed every 3-5 years (Warren and Hammer, 1993).

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Constructed wetlands Constructed wetlands use same processes that occur in natural wetlands (when they are designed properly). The components of the wetland system; vegetation, selected substrate, water column, and communities of microorganisms that developed naturally, all contribute to control treatment mechanisms into the wetland. Wetlands’ processes are influenced by the change in environmental conditions; whether these conditions are of diurnal changes, including variation in temperature and dissolved oxygen content, or seasonal changes including variation in daylight hours from season to season and temperature. Vegetation growth, chemical reactions, microbiological activities increase during warmer seasons (Malcolm B. et al., 1997). Wetlands provide a diversity of micro-environmental species which play an important role in pollutant removal processes. Various processes occur within plants strands, the water column and on the substrates. The wetland substrates typically contain a high proportion of organic matter, coming as a result of annual vegetation production, whereas sediment and litter that accumulate in the wetlands provide an ideal condition for chemical and microbial processes. Wetlands performance Typically, removal efficiency is based on the inflow-outflow comparisons of the pollutant concentration (i.e., % reduction) or the assessment of the pollutant mass being removed by unit of wetland surface and time (i.e. kg/m2/yr). In evaluation of performance process, it is important to select criteria that accurately reflect the actual performance of the wetland in relation with understanding of the wetland objectives established (Kadlec and Knight, 1996). In this context, the characteristics of wastewater that are most treated in constructed wetlands depend on pre-treatment processes. They play a role in the alleviation of wastewater concentration loading (see Appendix 2; Table 2). In a similar manner, DeBusk et al. (2001) reported that hydraulic retention within the wetland treatment system (HRT) affects the pathogen removal efficiency. Studies with different wetland configurations have shown 1-2 log in viral and bacterial reduction. A study recently done on constructed wetland by Redder et al. (2010) reported that infections with the protozoan parasites (Cryptospridium and Giardia ssp.) are mostly occurring with crops irrigated by treated wastewater and they caused diarrhoea. In this study, Redder et al. (2010) concluded that constructed wetlands can easily achieve a reduction to a rate of ≈ 2 log for the protozoan pathogens. Redder et al. (2010) also confirmed that, although natural wastewater treatment systems (constructed wetlands) are more effective in protozoan parasites reduction than conventional treatment (mechanical), but no correlation between protozoan parasites reduction and other organisms reduction. On the other hand, combination of minimal wastewater treatment system (constructed wetlands in this case) with drip irrigation and washing vegetables, after harvesting, can easily achieve a 6 log unit of pathogen reduction (Drechsel P. et al.,2010; see also Appendix 1 Table 3).

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1.5 Objectives of the Study The constructed wetland proposed by UNEP could have in part satisfied the mentioned socio-economic needs of the Marsh Arabs and reduce the marshlands’ ecosystem degradation. It however did not consider the continuously increasing demand for water for agricultural use in an already quite limited safe water access. Furthermore, this water demand is also competing with the environmental needs for maintaining the marshlands. Accordingly, one must now consider both the need for proper sanitation, the need to reduce the burden of agricultural demand for water on the Iraqi Marshes. As the UNEP full-scale constructed wetland has yet to be implemented, this thesis aims at drawing attention on what should be included in that initiative to further address the problem of increasing water scarcity in this area of Iraq. It more specifically explore the use of a constructed wetland specifically dimensioned to achieve outflow quality suitable for wastewater reuse, hence reducing the impact of sewage outflow and water abstraction on the Marshlands. 1.6 Research Questions Would the constructed wetland built on the available land be sufficient to: 1) ensure that the actual Iraqi effluent standards are rarely exceeded;

2) meet the more stringent standards of water reuse for agriculture, namely those for watering of vegetables and fruits to be eaten uncooked, to reduce the irrigation pressure on the marshes;

3) introduce further improvement for the quality of wastewater effluents to return water to the marshes and prevent deterioration of its ecosystem; and

4) establish an approach for sustainable development through partial meeting of the socioeconomic needs of Marsh Arabs (the dwellers) and the revival of environmental values of the marshland ecosystem.

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2. METHODS 2.1 Dimensioning a Constructed Wetlands by the Kadlec and Knight Method Several methods1 are used for sizing constructed wetlands for wastewater treatment: the Kadlec and Knight method (1996) is one of them. Kadlec and Knight consider wetlands as attached growth biological reactors. Therefore, they use a first order plug flow kinetic model as the basis for their performance equations. First order kinetic means that the rate of removal of a particular pollutant is directly proportional to the remaining concentration at any point within wetland cells. Kadlec and Knight’s equations assume an areal basis which makes the rate constant related only to the surface area of wetlands. The changes in temperatures are considered significant only for nitrogen removal. They arranged the areal model as follows:

As= 0.0365Q/k ln (Ci – C*)/ (Ce- C*) [ 1 ] Where: As = Surface area of the wetland in hectare (ha) Ce = effluent concentration (mg/l) Ci = influent concentration (mg/l)

C* = background pollutant concentration (mg/l); it is equal to (3.5+0.053Ci) for BOD and (5.1+0.16Ci) for TSS

k = first order areal rate constant (m/yr); it is equal to 34 for BOD and 1000 for TSS; and Q = average flow rate through the wetland (m3/day). This above equation might be written in another shape to calculate (Ce) depending on known values of (Ci, C*, k and A).

Ce= C*+(Ci- C*)exp(-kA/(0.0365×Q) [ 2 ]

2.2 Framework for Wastewater Reuse The strategy of wastewater reuse programmes and projects, especially in the arid and semi-arid regions (the Middle Eastern countries as an example), needs to adopt a systematic approach to sustain overall water resources policy and planning (Hespanhol, 2007). Hespanhol (2007) reported that Biswas (1988) introduced guidelines for wastewater reuse to support and identify the possibilities and constraints in the irrigation projects. Biswas (1988) suggested a framework for the analysis of wastewater irrigation projects in the planning phase. This framework includes six tools expressed in questions that should be examined (Box. 1). __________________________________ 1 Rule of thumb approaches which are famous in the UK’s wetlands application, Reed et al. (1995) method and Kadlec and Knight (1996)

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Box 1 Framework for the analysis of wastewater irrigation projects Nature of the problem

How much wastewater will be produced and what will be the seasonal distribution?

At what places will wastewater be produced?

What will be the characteristics of wastewater that be produced?

What are feasible alternative disposal possibilities? Legal feasibility

What uses of wastewater are possible under national and/or state regulation if they exit?

If no regulation exit, what uses seem feasible under WHO and FAO guidelines or Irrigation?

What are the prevailing water rights and how will these be affected by wastewater use? Technical feasibility

Is the quality of treated wastewater produced acceptable for restricted or unrestricted irrigation?

How much land is available or required for wastewater irrigation?

What are the soil characteristics of land to be irrigated?

What are the present land use practices? Can these be changed?

What types of crops can be grown?

How do crops-water requirements match with seasonal availability of wastewater? What types of irrigation techniques can be used?

If groundwater recharge is a consideration, are the hydrogeological characteristics of the study are suitable?

What will be the impact of such recharge on groundwater quality?

Are there additional health and environmental hazards that should be considered? Political and social feasibility

What have been the political reactions to past health and environmental hazards which may have been associated with wastewater reuse?

What is the public perception of wastewater reuse?

What are the attitudes of influential people in areas where wastewater will be reused?

What are the potential benefits of reuse to the community?

What are the potential risks? Economic feasibility

What are the capital costs?

What are operation and maintenance costs?

What is the economic rate of return?

What are the costs of development of effluent-irrigated agriculture, e.g. cost of conveyance of wastewater to the irrigation site, and-levelling, installation or irrigation system, agricultural inputs, etc.?

What are the benefits from the effluent-irrigated agricultural system?

What is the benefit-cost ratio for the irrigation project? Personal feasibility

Is adequate local labour and expertise available for adequate operation and maintenance of: wastewater treatment, irrigation and groundwater recharge works, agricultural facilities, and health and environmental control aspects?

If not, what types of training programmes should be instituted? Source: Biswas, 1988 cited in Hespanhol, 2007

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3. RESULTS

3.1 Expected Efficiency for BOD5 and TSS Removals1 Wetland area estimation, (As)2 Based on the Kadlec and Knight method (see section 2.1) and, according to the design requirements of constructed wetland (Appendix 2); using the influent pollutant concentrations for BOD5 and TSS from the raw wastewater (mentioned in Table 1 in Appendix 2); to estimate the wetland area (As) is based the inflow discharge in the wetland system ( 820 m3/day). The estimated required area is about 3.6 ha. Effluent loading and removal efficiency, (Ce) & (eff.) Relying on this estimated area and according to the material and equations mentioned in the appendix 2, the efficiency removals (eff.%), effluent concentration (Ce) and effluent loading for BOD5 and TSS parameters are calculated. Box 2 shows the effluent loading for BOD5 and TSS removal expressed in mg/l. The efficiency removals are slightly higher than assumed (see also Appendix 2). Hydraulic retention time and hydraulic loading rate, (HRT) & (HLR) Referring to the equations mentioned in Appendix 2, the hydraulic retention time (HRT) is estimated to be ca. 9.5 days with assumed average depth of water in the wetland equal to 0.35 m. The hydraulic loading rate is therefore ca. 2.3 cm/d. Consequently, the effluent concentrations for BOD5 (13.08 mg/l) meets the requirement of the stringent standard (15 mg/l), while the effluent concentration for TSS (15.18 mg/l) is not significantly higher than the stringent standard (15 mg/l, refer to Table 3). With these influent pollutant concentrations (140 mg/l for BOD5 and 63 mg/l for TSS), the CW effluent will therefore rarely exceed the Iraqi standard for BOD5 and TSS (refer to Table 3). The efficiency removals are slightly higher than initially assumed (90% and 70% for BOD5 and TSS respectively, see Appendix 2). ______________________________________ 1

Kadlec and Knight (1996) have stated equations for other parameter removals; TN, TP,

NO3, NH4 and pathogens. These parameters are not included in the calculation. Wetland functions basically contribute to reducing their influent concentration through different processes; flocculation and sedimentation, nitrification and denitrification, decomposition process, in addition to predation, sunlight killing and natural die-off for pathogens.

2 The area available is 5 ha. The area required is 3.6 ha. The remaining area will be specified

for the remaining treatment system components (septic tanks, distribution boxes, inlets and outlets structures of the constructed wetland, in addition to other facilities. The area (3.6 ha) can also be configured in a three-cell wetland (1.2 ha each).

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Box 2 Summary of Calculation*

Q= 820 m3/d; and As= 3.6 ha

Details BOD5 TSS

Influent pollutant concentration at wetland inlet, Ci mg/l 140 63 Effluent pollutant concentration at wetland outlet, Ce mg/l 13.08 15.18 Removal efficiency, eff.% 91 76

HRT= 9.5 days HLR= 2.3 cm/d * See the calculation in Appendix 2

3.2 Possibilities and Constraints of the Proposed Constructed Wetlands in Achieving Water Reuse WHO (2006) revised guidelines for the use wastewater in agriculture and aquaculture for health protection of the groups at risk from exposure and recommended the microbiological water quality standard for wastewater reuse (refer to Appendix 1.3). These guidelines have always yielded to basic criteria for public health protection and the preservation of the environment. According to these basic criteria, using tools included in Biwas’s framework (1988) is possible to emphasize the possibilities and constraints of using reclaimed wastewater in irrigation projects. Six tools expressed in questions are identified in this framework. They should be handled to reflect a clear image about the legality and feasibility of these matrices (Box 2). Nature of the problem The produced wastewater (820 m3/d) is an additional water resource in this water-scarce region. It could be also used in irrigation for the pilot project to enhance the feasibility of wastewater reuse in irrigation projects. On other hand, the Iraqi farmer still depends on the traditional methods in irrigation so far. However, they should look for another alternative of irrigation techniques.

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However, this new water resource can be significantly reduced by evapo-transpiration as it is high in this region (ET= 3050 mm annually)1. Even so, this lost, even during the summer months, would however not cause a zero outflow from the constructed wetland outflow. It could nevertheless cause a loss of one quarter of the produced volume. This reduction does not reduce the valuable benefits of the daily and locally produced water which can support farmers in meeting the water demand. However, an increase in soil salinization can occur with this high evapo-transpiration, and it makes the effluent highly salty and unsuitable for irrigation purposes (Rousseau et al., 2008). According to this anticipated condition, the soil’s physical characteristics must be closely monitored to avoid long-term detrimental effects on soil characteristics. A suitable dilution ratio with freshwater (marshlands water), associated with an evaluation process of soil characteristics, introduces a solution to this potential problem (Zupanc V., and Justin M.Z., 2010). Legal feasibility As mentioned earlier, there is still no specific Iraqi standard for reuse (WHO, 2006), while the trend of wastewater reuse worldwide becomes well-known. This trend should make the Iraqi policy-makers seriously think about reuse feasibility. The wastewater reuse concerning crops irrigation is associated with two main types of legal issues; establishment of legislation of wastewater’s reuse, and securing tenure of users (Hespanhol, 2007). Responsibility arrangements between different ministries and other governmental agencies minimize the administrative conflicts. According to this, the national level arrangement (by the Iraqi authorities) should base targets upon environmental protection, land tenure, and rural development. In Iraq, where most land tenure concerns the private farmers, the participation in decision making process of the farmers should be supported by non-governmental organization in cooperation with all the authorities to secure the legal reuse. Technical feasibility With application of more stringent standards for reuse on the wetland design requirements, the quality of treated wastewater will be more connected to the Category A (refer to section 1.2.4). With this category, the effluent can be used to irrigate produce, likely to be eaten uncooked, such as spray-irrigated fruits as well as to sport field and public parks without precaution requirement for consumers, agricultural workers and public. A monitoring programme should be established to ensure that the effluent always meets the category A demands (more stringent standard) or the effluent should be applied for the next category (Category B); where the protection for the workers is required and the consumption of crops is restricted to crops not to be eaten raw or processed before they reach the consumer (see also Appendix 1; Table 2). _________________________________ 1 Evapotranspiration (ET) in the marshlands region is 3050 mm annually (See appendix 3).

The daily ET is equivalent to 8.35 mm/d. According to the wetland surface area and daily ET; the total ET losses are nearly 200 m3/d for a two-cell wetland supposed in operation during the high evapotranspiration period (equivalent to ~ 25% of the effluent flow of 820 m3/d).

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In addition, there are often potential risks from wastewater reuse which can be associated with those anticipated benefits. Some of the potential negative impact can be associated with groundwater contamination. This problem becomes evident when the groundwater is used as a resource of water supply. There is a little possibility of nitrate (NO3) contamination; the uptake of nitrogen by crops reduces this possibility (Hespanhol, 2007). A build up of chemical contaminants in the soil is another potentially negative impact, building up organic and inorganic toxic compounds (Hespanhol, 2007). Political and social feasibility In contrast with the anticipated positive policy-makers’ reaction to wastewater reuse, it is expected that the public perception may move in the opposite direction. Cultural and ethnic factors play a role in the acceptance process. Several measures should be adopted and followed to make public perception follow the right track without any rejection. The use of reclaimed wastewater in agriculture is always influenced by socio-cultural and religious aspects. In most parts of the world, there is no cultural objection to the use of wastewater, particularly after treatment. In several Islamic countries, where the impurities are removed from wastewater, the economic needs are dominant rather than cultural aspects. Self-purification, addition of pure water in sufficient quantity to dilute impurities, or the removal of the impurities by time or by physical effects, transforms the water into pure water. In other words, religious beliefs should be considered as an important step in the preliminary planning for a wastewater reuse project. In making the public perception more realistic, the public should be involved from the planning phase to the final implementation process (refer to Table 4). This early contact between potential users and authorities ensures a continuous exchange of information and enables the adoption of a successful water reuse programme. Besides that, the direct potential risk concerning public health should be seriously considered. Ministries of health and the environment are responsible for managing wastewater reuse guidelines to protect farm-workers, consumers and even nearby dwellers who could be exposed to the risk of transmission of diseases (see appendix 1; Table 2). Vector-borne diseases can spread through the extension of water reuse irrigation. In this case, vector control techniques should be associated with extended irrigation to avoid the transmission of vector-diseases. Thus, when focusing on reclaimed water for irrigation, it is important to raise public awareness to eliminate risk. Training and adequate information for the potential user (group of exposure), for proper handling, should be included in project planning stage. Public health protection The WHO guidelines for wastewater reuse, based on a health-based target as a new approach, expressed in DALY loss pppy, and concerning three index pathogens, were selected1. For helminth eggs, this approach can not be used (Ismail et al., 2008) and the guidelines suggest that wastewater should contain ≤ 1 human intestinal nematode egg per year. (see Appendix 1; Table 2). _______________________________ 1 Three ‘‘index’’ pathogens are selected in estimating the disease burden and disease and

infection risks: rotavirus (the most common viral cause of diarrheal disease worldwide), Campylobacter (the most common bacterial cause of diarrheal disease worldwide) and Cryptosporidium (one of the three most common protozoan causes of diarrheal disease

worldwide, the other two being Giardia and Entameoeba). Source: Ismail et al., 2008

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The chosen value for DALYs does not exceed 10-6, and this value seems more stringent in countries that commonly use untreated wastewater in irrigation. The decision to apply this guideline at a national level may not be appropriate unless relying on DALY loss less than 10-6. Some countries apply less stringent DALY loss pppy is 10-4 rather than 10-5. It is suitable to use this less stringent requirement as the first step to adapt with this stringent requirement (Ismail et al., 2008). In fact, this stringent value for DALY loss pppy was made previously by WHO (2004) in drinking water quality standards, when the consumption of wastewater-irrigated food should be safe as well as fully treated drinking water (Ismail et al., 2008). This trend led to increase costs of wastewater treatment to meet that requirement (10-6 DALY loss pppy). Countries with a high diarrheal disease incidence, including developing countries, may decide that the level of health protection of less than 10-6 DALY loss pppy is sufficient with this local incidence of diarrhoeal disease (Ismail et al., 2008). The policy-maker’s decision at the national level is called to choose whether they choose the 10-6 DALY loss pppy as more stringent standard or adopt the higher value, 10-5 DALY loss pppy as initial baseline in short to medium term. Economic feasibility To assess the economic incomes of wastewater reuse in irrigation project according to this trend, the benefits and cost should be adjusted carefully in order to make the benefit/cost ratio greater than 11. Regarding benefits, nutrient inputs through wastewater reuse can reduce the need for some commercial fertilizers. In addition, organic matter can act as a soil conditioner by increasing the capacity of soil to store water (Hespanhol, 2007). Most of these direct benefits can be easily observed (increase in yield production and fertilizer application reduction). However, it is a different with indirect benefits. Policy makers and specialists should be able to foresee several indirect benefits, such as an increase in job and settlement opportunities, development of new recreation areas (educational and truism benefits), reduction in damage to the urban environment (increase in buffer zone areas/ reduction in desertification), in addition to reflection on the freshwater source (the marshes) from further pollution (i.e eutrophication); that can lead to increase drinking water treatment costs in water supply plants of downstream areas. _______________________ 1 ‘‘Benefit-cost ratio is the total benefits divided by total costs. The higher the ratio, the greater the benefits relative to the costs. Projects with a benefit-cost ratio greater than 1, have greater benefits than costs’’. Source: UN Water 2009

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In total cost estimation, additional potential costs are expected through wastewater reuse application. Therefore, the following should be taken into account:

- Training and public health protection programmes

- On-farm cost, including conveyance of treated wastewater and other facilities

- Maintenance and operation costs, and

- Monitoring and testing costs The trade-off between the benefits with these potential cost (e.g, monitoring, education, health protection programme) in comparison with total cost of another alternative is expected to be feasible. Personal feasibility Indeed, the adequate local labour is available. However, training programmes for those locally in charge of the operation and maintenance should be considered with project implementation. The workers and other group of exposure should be involved in health protection programmes to minimize the health risk.

3.3 An Investigation on Sustainability Indicators The feasibility of irrigation projects should be investigated to show whether they meet sustainable development indicators or not. Sustainable development is always expressed in three, inter-connected dimensions: environmental, economic and social. Indicators of sustainable development that are mentioned in table 5 (see section 1.3) are allocated between these three dimensions. The investigation of this assumption comes through an approach to match the possibilities and constraints of the proposed constructed wetlands in achieving wastewater reuse in irrigation projects (Box 1), with sustainable development indicators (Table 5). According to this matching the investigation is expected to show these following results (see also Table 6): Economic sustainability

1) Production volumes: even though the exact production is not available, an

increase in production volumes is expected. Several studies have been carried out worldwide, and have produced evidence of increase in yield.

2) Purchase of off-farm fertilizers: nutrient recycling and reduction in off-farm artificial fertilizers purchase is achieved.

3) Market value of land: farmers are encouraged to exploit their lands which, in turn, contribute to raising their values.

4) Markets for produce: nowadays, due to water scarcity in this region, there is trend to depend on imports from the neighbouring countries, especially concerning vegetables and fruit. With irrigation projects, the national produce will increase to satisfy at least part of the market demand, in addition to providing food for the local region.

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Social sustainability 1) The social capital: better livelihood, more educational opportunities,

enhancement of knowledge and power of society. 2) Farming income: more income, better livelihood 3) Job opportunities: more income, better livelihood 4) Community cohesion: reduction in migration to urban areas.

Environmental sustainability

1) Groundwater recharge: protection to groundwater from depletion. However, the monitoring programme should be established to minimize the health risk (e.g., NO3 contamination).

2) Freshwater environment: conservation of the marshlands’ ecosystem through a reduction in pollutant burden (reduction in nutrient inputs) and a reduction in irrigation pressure.

3) Soil quality: additional benefits to soil characteristics associated with potential risk. Soil salinization is the greatest potential risk in case of high sodium content in irrigation water causing a reduction of permeability which, in turn, obstructs plant growth (Ganesh B. and Jennifer Mc., 2007). Therefore, soil analysis should be done periodically.

4) Health concerns: public health is the crucial issue in wastewater reuse. Therefore, monitoring programmes should be established, education and training and awareness programmes should be carried out to minimize health risks.

Table 6 Expected performance of indicators for sustainable development in correlation with possibilities and constraints of the proposed constructed wetlands in achieving water reuse

Economic sustainability Social sustainability Environmental sustainability Production volumes (+) Purchase of off-farm (+) fertilizers Market value of land (+) Markets for produce (+)

The social capital (+) Farming income (+) Job opportunities (+) Community cohesion (+)

Groundwater recharge (±) Freshwater environment (+) (marshland ecosystem) Soil quality (±) Health concerns (±)

+ more sustainable (benefits towards for sustainable development) ± less sustainable (potential risk associated with benefits)

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4. DISCUSSION

4.1 Revival of the Environmental Values

The marshlands are sources of food (fisheries), artificial rice fields, biodiversity and other natural resources for people, animals and plants. The marshland also supports the natural environment through additional wastewater purification, waste detoxification and mitigation of climate change impacts (buffer zones for storms and dust). In addition, they offer significant cultural benefits, such as aesthetic, educational and spiritual benefits, and can control waves of flooding by storage water or recharge groundwater. The marshlands are resources of freshwater and marsh dwellers, which still have no access for safe water, depend on this natural resource. Therefore, these dwellers will be vulnerable to any degradation of marshlands’ ecosystem. According to the above marshland functions and considerations, a 3.6 ha constructed wetland is selected to meet the more stringent standard for reuse (Table 3). The effluent concentrations for BOD5 (13 mg/l) easily meets for reuse requirement of 15 mg/l. However, the effluent concentration for TSS (15.18 mg/l) is a little bit higher than the stringent standard of 15 mg/l. With these average values of influent pollutant concentrations (140 mg/l for BOD5 and 63 mg/l for TSS), the CW easily meets the Iraqi standard (Table 3). If the influent concentrations is still with the range of these average values of wastewater loading (i.e not extreme high wastewater loading), the Iraqi standard is rarely exceeded. Background pollutant concentration, C* (=15.18 mg/l), within wetland system for TSS does not corresponded with the typical values. The typical one is about 10 mg/l (DeBusk et al., 2001). Therefore, because of high influent of TSS, the C* was high. It is expected to be within the range of typical influent of wetland receiving septic tank discharge (Table 2 in Appendix 2). Also, in order to take flocculation in pollutant concentration into consideration, the based value of TSS influent was chosen according to the heavier raw wastewater concentration of 192± 122 mg/l (Table 1 in Appendix 2). Therefore, even if the wetland land area was to be extended to more than 3.6 ha, this problem of effluent concentration could not be solved by area increase only unless the influent concentration is reduced to correspond with the typical values that can wetland received and achieved. In other words, the reduction in (C*) value is associated with the reduction in effluent concentration.

Effluent concentration and removal efficiency depend on hydraulic retention time (HRT) and hydraulic loading rate (HLR). The longer the water stays in FWS wetland, the longer the contact time with surfaces; high sedimentation rates are due to lower current velocities (Kadlec and Knight, 1996). In this study, the hydraulic retention time (HRT) is approximately 9.5 days. The most effective (HRT) ranges from 4 to 15 days (Metcalf and Eddy Inc, 1991 cited in Shuh-Ren J. et al., 2002). In addition, even a short detention time ranged between 3 to 6 days was effective in bacteria and viruses removal (Gersberg et al., 1989 cited in Shuh-Ren J. et al., 2002). The treatment efficiency of pollutants in CWs is usually improved by a reduction in the hydraulic loading rate. The hydraulic loading rate (HLR), 2.3 cm/d, is in the range of typical (HLRs); between 0.7 and 5.0 cm/d for FWS constructed wetlands (Kadlec

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and Knight, 1996). The wetlands can introduce further improvement for the quality of wastewater effluents to return water to the marshes. They can also achieve their functions when a configuration based on the understanding of the objective of wetland construction is selected1. On the other hand, an island within the constructed wetland is preferable for reflecting some of the biodiversity richness for which the marshes are commonly famous. When the wastewater effluent does not return to the marshes ecosystem and is reused in irrigation instead, the recycling of nutrients can be achieved to increase crops’ yield and save the costs for nutrients removal. In other words, the reuse of treated wastewater contributes partially to solving the marshland destruction problem by mitigating the impact of wastewater disposal on its ecosystem through reusing them for agricultural purposes, preventing a potential eutrophication and reducing irrigation pressure on the marshlands.

4.2 Towards for Sustainable Development The main problem of the Marsh Arabs is the migration to alternative lands and looking for alternative job opportunities. Therefore, the rehabilitation of the Iraq marshlands through constructed wetland, and wastewater reuse in irrigation projects, alleviate the impact of these mentioned problems upon the Marshlands dwellers and on the ecosystem of the marshlands themselves.

With the achievement of sustainable development indicators (Table 6), irrigation projects can respond to the environmental, social and economic dimensions. These are the recycling of resources through handling wastewater as a resource; protecting of natural resource (freshwater marshland conservation), guiding land ethic by considerations of all members of land community (individual and communities), and achievement of profitability. In other words, this irrigation project can move towards for sustainable development target (Brundtland definition) in meeting needs of today’s generation without compromising the ability of tomorrow’s generations to meet their needs, is attained.

__________ 1 Three possible configurations for wetland cells used for wastewater treatment: in parallel, in

series, or a combination of the two. Shaping of the wetland by these configuration systems facilitates operation and maintenance by giving wetland systems the redundancy in operation and flexibility by taking cells off-line for maintenance and repair. The proposed wetland area (3.6 ha) is suggested to be configured in cells. The final dimensions of the wetland can be designed with three parallel cells. Each cell has an area of 1.2 ha (50×240 m) the length to width (aspect ratio), and will be 5:1 taking adequate hydraulic gradient into consideration.

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5. CONCLUSIONS The proposed 3.6 ha constructed wetland can achieve the objectives of agriculture through meeting more stringent standards for wastewater reuse. This design also ensures that wetland effluent would not exceed the level required by the present Iraqi standard and can introduce further improvements for the quality of wastewater to return water to the marsh. The application of Biswas’s framework of reclaimed wastewater for irrigation purposes is correlated with indicators of sustainable development for agriculture. It is certain that a monitoring programme should be associated with the reuse application to enhance wastewater quality and minimize the public health risk. Wastewater reuse application can reduce irrigation water pressure on the marshlands ecosystem. Studies have been done in many areas of the world regarding wastewater reuse for agriculture despite the absence of similar studies at a national level (in Iraq), giving evidence on the feasibility of wastewater reuse in irrigation projects. As a consequence of wastewater reuse application for agriculture, Marsh Arabs will settle in their places (marshlands), and gain a better livelihood through an increase in job opportunities. Public awareness should be a target of the policy-makers to enhance their participation, which plays a key role in sustainable development achievement.

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REFERENCES

Andreas R. et al. (2010). Constructed wetlands: Are they Safe in Reducing Protozoan Parasites?. Int. J. Hyg. Environ. Health. 123. 2010 ( 72-77). Elsevier. DeBusk, T. et al., (2001). Wetlands for Water Treatment. In: Applied Wetlands Science and Technology. Ch. 9. Edited by Donald M. Kent. Boca Raton: CRC Press LLC. Drechsel P. et al., eds. (2010). Wastewater Irrigation and Health: Assessing and Mitigating Risk in Low-Income Countries. Chapter 2 and 3. Part 1. Published by International Water Management Institute, IWMI and International Development Research Centre, IDRC. UK & USA. Ganesh B. Keremane and Jennifer Mckay (2007). Successful Wastewater reuse Scheme and Sustainable development: a Case Study in Adelaide. Water and Environment journal 21 (2007) 83-91. Gray N.F (1999). Water Technology: An Introduction for Environmental Scientists and Engineers. Butterworth Heinemann. Hespanhol I. (2007). Wastewater as a Resource. In: Water Pollution Control- A guide to the Use of Water Quality management Principles. Hespanhol I. And Helmer R. Published by Taylor & francis. New York. Iraqi Ministries of Environment, Water Resources and Municipalities and Public Works (2006). New Eden Master Plan. For Integrated Water resources management in the Marshlands Area. Prepared in cooperation with the Italian Ministry and Territory and Free Iraq Foundation. Italy- Iraq. Available at: http://www.newedengroup.org/EXECUTIVE_SUMMARY_%2020060915.pdf Ismail et al., eds (2008). Efficient Management of Wastewater. Ismail et al. Ch. 1 and 2 . Springer. Berlin. Germany. Joseph H. (2007). Sustainable Development at Risk: Ignoring the Past. Published by Manas Salikia for Cambridge University Press. Kadlec, R. H and Knight, R.L (1996). Treatment Wetlands. Lewis-CRC Press. Boca Raton, New York. Mohamed F. Hamoda (2004). Water Strategies and Potential of Water Reuse in the South Mediterranean Countries. Desalination 165(2004) 31-41. Elsevier. Malcolm B. et al. (1997). Chemical, Biological and Physical Processes in Constructed wetlands. In: The Constructed Wetlands Manual. Department of Land and Water Conservation, DLWC. Chapter 3. Vol.2. New South Wales, Australia.

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Merz S.K (2000). Guidelines for Using Free Water Surface Constructed Wetlands to Treat Municipal Sewage. The Queensland Department of Natural Resources, Australia. Rousseau D. et al. (2008). Constructed Wetlands for Water Reclamation. Desalination 218 (2008) 181-189. Elsevier. Shuh- Ren J. et al. (2002). Wetlands and Aquatic Processes. J. Environ.Qual. 31 (2000) 690-692. UNEP, Patrow H. (2001). The Mesopotamia Marshlands: Demise of an Ecosystem. Early Warning and Assessment technical report. UNEP/DEWA/TR.01-3 Rev.1. Division of Early Warning and Assessment. United National Environmental Programme. Nairobi, Kenya. Available at: http://www.grid.unep.ch/activities/sustainable/tigris/mesopotamia.pdf United Nations Environmental Programme, UNEP (2010). Supporting for environmental Management of The Iraqi Marshlands. Available at: http://www.unep.or.jp/ietc/Publications/Water_Sanitation/Support_for_EnvMng_of_IraqiMarshlands_2004-9.pdf UN Water, United Union Water (2009). The United Nations World Water Development. Report 3: Water in A changing World. UNESCO Publishing. U.S. Environmental Protection Agency, EPA (1988). Design manual: Constructed Wetlands and Aquatic Plant systems for municipal wastewater Treatment. EPA/625/1- 88/022.office of Research and Development, Cincinnati, OH. U.S. Environmental Protection Agency, EPA (1999). Design Manual: Constructed Wetlands Treatment of Municipal Wastewaters. EPA/625/R-99/010. Office of Research and Development, Cincinnati, OH. Warren Viessman Jr., and Mark J. Hammer (2005). Water Supply and Pollution Control. Seventh edition. Pearson Prentice Hall. USA. World Health Organization, WHO (2006). A Compendium of Standards for Wastewater Reuse in the Eastern Mediterranean Region. Document WHO-EM/CEH/142/E. Regional Centre for Environmental Health Activities, CEHA. Available at: http://www.emro.who.int/ceha/pdf/Compendium%20wastewater%20standards.pdf World Health Organization, WHO (2006). WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater. Vol. 1 & 2. Zupanc V. And Justin M.Z. (2010). Changes in Soil Characteristics during Wastewater Irrigation of Populus Deltoids. Waste Management Elsevier.

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APPENDIX 1

Box 1-A1 Disability- Adjusted Life Years (DALYs) DALYs are a measure of the health of a population or burden of disease due to a specific disease or risk factor. DALYs attempt to measure the time lost because of disability or death from a disease compared with a long life free of disability in the absence of the disease. DALYs are calculated by adding the years of life lost to premature death (YLL) to the years lived with a disability (YLD). Years of life lost are calculated from age-specific mortality rates and the standard life expectancies of a given population. YLD are calculated from the number of cases multiplied by the average duration of the disease and a severity factor ranging from 1 (death) to 0 (perfect health) based on the disease (e.g. watery diarrhoea has a severity factor from 0.09 to 0.12 depending on the age group) (Murray and Lopez, 1996; Prüss and Havelaar, 2001). DALYs are an important tool for comparing health outcomes because they account for not only acute health effects but also for delayed and chronic effects, including morbidity and mortality (Bartram et al., 2001). Thus, when risk is described in DALYs, different health outcomes (e.g., stomach cancer and giardiasis) can be compared and risk management decisions prioritized. Thus the DALY loss per case of campylobacteriosis in Table 1-A1 includes the appropriate allowance for the occurrence of Guillain-Barré syndrome (which is an inflammatory disorder of the peripheral nerves, which may lead to paralysis, and which occurs in around 1 in 1000 cases of campylobacteriosis). The tolerable additional disease burden of 10-6 DALY loss adopted in the Guidelines means that a city of 1 million people collectively suffers the loss of one DALY per year. The highest DALY loss per case of diarrhoeal disease in Table 1-A1 is 2.6 × 10-2, for rotavirus disease in developing countries. Assuming that the recommendations in the Guidelines are completely followed, this means that the tolerable number of cases of rotavirus disease, caused by the consumption of wastewater-irrigated food, in this city of 1 million people in a developing country is: 1 DALY loss per year ––––––––––––––––––––––––– = 38 cases per year 2.6 x 10-2 DALY loss per case The chance of an individual living in this city becoming ill with rotavirus diarrhoea in any one year is (38 × 10-6 ) – i.e., 3.8 × 10-5 , which is the tolerable rotavirus disease risk per person per year in developing countries, as determined in Table 1-A1. Source: WHO, 2006

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Table 1-A1 DALY losses, disease risks, disease/infection ratios and tolerable infection risks for rotavirus, Campylobacter and Cryptosporidium Pathogen DALY loss per

case of disease*

Tolerable disease risk pppy equivalent to 10-6 DALY loss pppya

Disease/infection ratios

Tolerable infection risk pppyb

Rotavirus: (1)Cc (2) DCc Campylobacter Cryptosporidium

1.4 × 10-2 2.6 × 10-2 4.6 × 10-3 1.5 × 10-3

7.1 × 10-5 3.8 × 10-5 2.2 × 10-4 6.7 × 10-4

0.05d 0.05d 0.7 0.3

1.4 × 10-3 7.7 × 10-4 3.1 × 10-4 2.2 × 10-3

Source: WHO, 2006 a Tolerable disease risk = 10-6 DALY loss per person per year (pppy) ÷ DALY loss per case of disease. b Tolerable infection risk = disease risk ÷ disease/infection ratio. c C, industrialized countries; DC, developing countries. d For developing counties the DALY loss per rotavirus death was reduced by 95 per cent to discount deaths occurring in children under the age of two who are not exposed to

wastewater-irrigated foods. The disease/infection ratio for rotavirus is low as immunity is mostly developed by the age of three.

* DALY values from Havelaar and Melse (2003)

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Table 2-A1 WHO microbiological guidelines for wastewater use in agriculturea

Category Reuse conditions Exposed group Intestinal nematodesb (arithmetic mean no of

eggs per litre)

Fecal coliforms

(geometric mean no per

100 mLc) A

Irrigation of crops likely to be eaten uncooked, sport fields, public parksd

Workers, consumers, public

≤ 1 ≤ 1000

B

Irrigation of cereal crops, industrial crops, fodder crops, pasture and treese

workers ≤ 1 No standard recommended

C Localized irrigation of crops in category B if exposure of workers and the public does not occur

none Not applicable Not applicable

Source: WHO, 2006

a- In specific cases, local epidemiological, sociocultural and environmental factors should be taken into account, and the guidelines modified accordingly. b- Ascaris and Trichuris species and hookworms.

c- During the irrigation period.

d- A more stringent guidelines (≤ 200 faecal coliforms per 100 mL) is appropriate for public lawns, such as hotel lawns, with which the public may come into direct contact. e- In the case of fruit trees, irrigation should be cease two weeks before fruit is picked, and no fruit should be picked off the ground. Sprinkler irrigation should not be used.

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Table 3-A1 Pathogen reductions achievable by selected – protection measures Control Measures Reduction

(log units) Comments

Wastewater treatment (primary + secondary) Drip irrigation used for: Low- growing crops High-growing crops Pathogen die-off Produce-washing with water Produce disinfection Produce peeling Produce cooking

1-4 2 4 0.5-2 per day 1 2-3 1-2 6-7

Reduction usually achieved by wastewater treatment depending on the type and functionally of the treatment system. Root crops and crops such as lettuce that grow just above, but partially in contact with the soil. Crops, such as tomatoes, fruit trees, the harvested parts of which are not in contact with soil. Die-off on crop surfaces that between last irrigation and consumption. The log unit reduction achieved depends on climate (temperature, sunlight intensity, and humidity), time, crop type, etc. Washing salad crops, vegetables and fruit with clean water. Washing salad crops, vegetable, and fruit with weak, often chlorine-based disinfectant solution and rinsing with clean water. Fruits, cabbage, root crops Immersion in boiling or close-to boiling water until the food is cooked ensures pathogen destruction.

Source:Modified from WHO, 2006

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APPENDIX 2

CALCULATION

1. Guidelines for Wetland Design a) Detention time Detention time is the period of time that wastewater is retained within the wetland. It is also common to be expressed as hydraulic retention time (HRT).

HRT = nyA/Q [3] Where; HRT= detention or retention time (days) n = void ratio or porosity, typically equal to 0.65 to 0.75 in typical wetland cross section not occupied by vegetation (Kadlec and Knight, 1996). y = average depth of wetland (m) A = wetland surface area (m2) Q = Average flow rate (m3) Or; A= (HRT)×Q/(y×n) [4] b) Hydraulic loading rate A measure of the volumetric application of wastewater in the wetland is termed as hydraulic loading rate. It is often used to indicate the potential overloading by wastewater within wetland system (Merz, 2000). It is calculated by using the following expression:

HLR= 100 Q/A [5] Where; HLR = hydraulic loading rate (cm/d) c) Removal efficiency The actual wetland performance is calculated referring to percent reduction which means the decrease in concentration between wetland inlet and outlet. It is calculated by using the following equation:

Removal efficiency (eff.) % = (1- Ce/Ci) × 100 [6] It might be written in another shape to calculate Ce depending on known values of Ci and removal efficiency to be appeared as follows:

Ce= (Ci – eff.%) × Ci [7]

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2. Raw Wastewater Data To design the whole treatment system (including the constructed wetland); raw wastewaters data for approximately 19 months over 2006 and 2007 (Table 1-A2) will be relied on. These historical data concern the influent discharge in conveying sewer systems to An Najaf’s sewage treatment plant; 1 of 13 larger sewage treatment plant in Iraq (located at approximately 200 km north of Thi-Qar) can be used as influent discharge in the treatment system. The parameters that are set in Iraqi standard for effluent discharge to the water courses; only BOD5, TSS and COD in addition to temperature and pH measurement are investigated. Table 1-A2 Historical data of raw wastewater of An Najaf (STP) for approximately 19 months over 2006 and 2007

Variables 2006 2007

Summer Winter Summer Winter

May – Oct. Nov. – April May – Oct. Nov. - April

BOD mean± S.D, mg/l 65±27 82± 40 84± 51 101± 38 BOD max., mg/l 148 182 314 194 TSS mean± S.D, mg/l 107± 34 177± 112 131± 75 192± 122 TSS max., mg/l 229 768 640 949 COD mean± S.D, mg/l 220±106 317±225 265±175 314±206 COD max., mg/l 625 1252 970 1390

3. Wetland Design a) Water budget According to the design requirements, inflow within wetland should be calculated. People’s equivalent (p.e) for 5000 inhabitants with 1.3 (3% annually) increase rate in population growth for ten years, with 140 litre/day for each (daily water consumption), the total flow enters the wetland after leaving the septic tank systems is: Qin=5000×1.3×140×0.90/1000= 820 m3/d through assuming only 90% of consumption is conveyed to the sewer system as wastewater. b) BOD5 pollutant influent Based on literature review; septic tank can achieve reduction (removal efficiency) in BOD5 concentration to 50 % while the wetland system can achieve the removal efficiency reaching 90% or more. Referring to raw wastewater mentioned in table 1-A2 (historical data from An Najaf STP); average value of BOD5 concentration in worse condition is 101 mg/l plus standard deviation 38 mg/l. Therefore, the estimated BOD5 that is expected to enter the wetland is approximately 70 mg/l after the reduction of 50% due to the removal achievement in the septic tank system. A worse condition occurs when the septic tank fails to achieve any reduction in BOD5 due to the sludge accumulation (absence of sludge removal process).

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To design with reliable value, assume BOD5 influent with concentration equal to 140 mg/l instead of 70 mg/l. In addition, this value also highlights the typical maximum value, mentioned in table 2-A2 (typical influent of wetland receiving from septic tank). Table 2-A2 Typical constructed wetland influents in combination with septic tank system. Modified from USEPA, 1999

Constituents Septic tank effluent BOD5, mg/l 129- 147 TSS, mg/l 44-54 COD, mg/l 310-344 TN, mg/l 41-49 NH3 28-34 TP 12-14 Orthro P 10-12 FC, log/1000 ml 5.4-6.0

c) Target efficiency Literature review indicate that the wetland system can achieve reduction in BOD5 exceeding 90% in optimum conditions. To calculate the expected effluent according to this assumption; based on equation [7] the predicted (Ce) is 14 mg/l. d) Expected area Referring to the equation [1]; using (k) value equal to 34 and C* equal to 10.92 mg/l (coming from 3.5+0.053Ci). The expected total area will be 3.29 ha (see Table 3-A2). e) TSS effluent Referring to table 1-A2; historical data with worse condition show that high value of TSS receiving from sewer system (sewerage network) is 314 mg/l including the standard deviation (192±122), with the assumption that the septic tank can achieve 80% of TSS settling. Further reduction in TSS occurs within the wetland so a reduction of 70% can be safely assumed. Using k=1000 and C* value equal to 15.18 mg/l (coming from 5.1+0.16Ci) the area required is only 0.08 ha (see Table 3-A2).

Table 3-A2 Summary of wetland calculation

Details BOD5 TSS Ci, mg/l 140 63 Target eff., % 90 70 C*, mg/l 10.92 15,18 K, m/yr 34 1000 As, ha 3.29 0,08

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f) HRT & HLR Referring to equation [3]; values of porosity (n) and depth of water within wetland (y) should be estimated to calculate the predicted hydraulic retention time (HRT). Take As=3.3 ha. Assume n=0.65 and y=0.35. So, the HRT will be equal to 9.16 days [equation 3]. Take HRT=9.5 days; and using equation [4] to recalculate the wetland area again (As=3.42 ha). Take the final area approximate to 3.6 ha to calculate the HLR; it will be equal to 2.28 cm/d [equation 5]. 3. Wetland Effluent and Efficiency

Relying on the final area estimation (A=3.6 ha) and, according to the previous equations [6] and [2], calculate the expected efficiency and effluent that discharges to the waterway or serves the agricultural purposes. Table (4-A2) shows the effluent concentration and removal efficiency for BOD5 and TSS.

Table 4-A2 Summary of calculation of effluent concentration and removal efficiency

Details BOD5 TSS With A, ha 3.6 3.6 Q, m3/d 820 820 Ci, mg/l 140 63 Ce, mg/l 13.08 15.18 Eff.,% 91 76

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APPENDIX 3

Fig. 1-A3 Geographical distribution of mean annual evapotranspiration, ET (mm) southern Iraq including the marshes (study area). Source: New Eden Master Plan, 2006