Low-cost wastewater treatment technlogies for agricultural use

Study of the applicability of low-cost wastewater treatment effluents for the urban agricultural plots of Bhubaneswar city, Odisha (India)

MSc. Thesis by Eva Estevan Rodriguez February 2014

Water Resources Management group Sub-department of Environmental Technology

Low-cost wastewater treatment technlogies for agricultural use

Study of the applicability of low-cost wastewater treatment effluents for the urban agricultural plots of Bhubaneswar cty, Odisha (India)

Master thesis Water Resources Management submitted in partial fulfillment of the degree of Master of Science in International Land and Water Management at Wageningen University, the Netherlands

Eva Estevan Rodriguez

February 2014

Supervisor(s): Ing. Harm Boesveld Dr.ir. Katarzyna Kujawa-Roeleveld Water Resources Management group Sub-department of Environmental Technology Wageningen University Wageningen University The Netherlands The Netherlands www.iwe.wur.nl/uk www.ete.wur.nl

Acknowledgements

This Master thesis was carried out at the Water Resource Management group in a close collaboration with the Sub- Department of Environmental technology. I wish to express my sincere gratitude to my supervisors Kasia and Harm for making this collaboration possible and their entirely kindness, professionalism and willingness to support me during all the thesis process. I would like to thank also my family, my life-long friends and my new friends for encouraging me during my last few months of this exciting and difficult academic (life) adventure. Thanks to all of you this experience was possible, nicer and totally unforgettable.

Table of content

GLOSSARY OF TERMS ...... 1 EXECUTIVE SUMMARY ...... 3 1. INTRODUCTION ...... 5 1.1 PROBLEM ANALYSIS ...... 6 1.2 RESEARCH DESCRIPTION ...... 7 1.2.1 Objective and questions ...... 7 1.2.2 Research phases ...... 7 1.2.3 Research methodology ...... 8 2. BACKGROUND RESEARCH ...... 10 2.1DESCRIPTION OF THE AREA ...... 10 2.1.1 Location and demography ...... 10 2.1.2 Climate and rainfall...... 11 2.1.3 Hydrography and topography ...... 11 2.1.4 Study of the water context ...... 13 Water resources ...... 13 Water scarcity ...... 13 Water regulations ...... 14 Water and wastewater management ...... 15 Agriculture and irrigation ...... 18 2.2 THE SCENARIO: WARD NUMBER 3 ...... 20 2.2.1 Location ...... 20 2.2.2 Settlement description ...... 20 2.2.3. Energy utilities ...... 22 2.2.4 Land availability ...... 22 2.2.5 Agricultural characteristics ...... 22 2.2.6 Irrigation water resource ...... 23 2.3 STAKEHOLDERS ANALYSIS ...... 24 3. GUIDELINES AND STANDARDS OF WASTEWATER QUALITY FOR AGRICULTURAL PURPOSES ...... 28 3.1 INDIAN REGULATION FOR IRRIGATION WATER QUALITY ...... 28

i Low-cost wastewater treatment technologies for agricultural use 3.2 INTERNATIONAL GUIDELINES REVIEW FOR HEALTH PROTECTION WHEN WASTEWATER IS REUSED FOR IRRIGATION ...... 28 3.3 EFFLUENT QUALITY STANDARDS AND MANAGEMENT RECOMMENDATIONS 30 4. LIST OF WASTEWATER TREATMENT SYSTEMS ...... 31 4.1REVIEW OF WASTEWATER TREATMENT SYSTEMS ...... 31 4.2TECHNOLOGIES FACT SHEETS ...... 34 4.2.1 Coarse screens (Bar racks) ...... 35 4.2.2 Sand traps (grit chamber) ...... 36 4.2.3 Grease traps ...... 37 4.2.4 Septic tanks ...... 38 4.2.5 Imhoff tank ...... 38 4.2.6 Baffled reactor (anaerobic baffled reactor, ABR) ...... 39 4.2.7 Anaerobic Filter ...... 41 4.2.8 Green filters ...... 42 4.2.9 Soil biotechnology (SBT) or Constructed soil biofilter (CSB) or Constructed soil filter (CSF) ...... 43 4.2.10 Anaerobic Stabilization ponds ...... 44 4.2.11 Facultative ponds ...... 45 4.2.12 Aerobic stabilization ponds (Maturation ponds/Oxidation pond) ...... 46 4.2.13 Constructed wetlands. Free flow(surface) ...... 47 4.2.14 Horizontal subsurface flow constructed wetlands (HSF) ...... 48 4.2.15 Vertical flow constructed wetlands (VF) ...... 49 4.2.16 Slow Sand Filter (SSF) ...... 50 5. ANALYSIS OF THE RESULTS ...... 51 5.1 SELECTION OF PRINCIPLES, CRITERIA AND INDICATORS ...... 51 5.1.1 Principles ...... 51 5.1.2 Criteria ...... 51 5.1.3 Indicators ...... 52 Nutrient (N, P) content ...... 52 Salinity reduction ...... 52 Total Suspended Solids (TSS) reduction ...... 53 Biochemical Oxygen Demand (BOD) ...... 53

ii Low-cost wastewater treatment technologies for agricultural use Heavy metals ...... 53 Pathogen removal ...... 54 Size ...... 54 Centralized or decentralized systems...... 55 Design and construction cost...... 55 Simplicity of O & M...... 55 Energy requirements ...... 55 Robustness ...... 56 Environmental nuisances ...... 56 5.2 MULTI CRITERIA ANALYSIS ...... 57 5.2.1 Criteria weighting ...... 57 5.2.2 Indicators rating technique ...... 58 5.2.3 Scoring matrix ...... 61 6. DISCUSION ...... 65 7. CONCLUSION ...... 69 7.1 RECOMMENDATIONS ...... 70 REFERENCES ...... 71 Personal communication(4th March, 2013) ...... 82 ANNEX 1 ...... 83 Institutions and Organizations: Online sources ...... 83 Initiatives & Projects ...... 84 ANNEX 2. Results ...... 85 Relative salinity tolerance of crops ...... 85 Domestic wastewater constituents ...... 86 Review of International guidelines of waste quality for irrigation ...... 87 FAO Guidelines of waste quality for irrigation ...... 89 Wastewater treatment technology cost comparison ...... 92 Water uses classification for the Indian Central Pollution Control Board ...... 93 Wastewater treated quality parameters for crop production ...... 97 ANNEX 3. Maps of Bhubaneswar Ward n°3...... 98

iii Low-cost wastewater treatment technologies for agricultural use GLOSSARY OF TERMS

Centralized water management: Consist of conventional or alternative wastewater collection systems (sewers), centralized treatment plants, and disposal/reuse of the treated effluent, usually far from the point of origin (Tchobanoglous, 1996).

City: It refers to a big community (>2000 inh.).

Constructed wetland systems: Constructed wetlands are natural systems that imitate natural depuration processes that take place in to rivers or lakes. The difference to the lagooning systems is that aquatic vegetation is planted, taking in an important role in the treatment performance.

Decentralized water management: Decentralized wastewater management (DWM) may be defined as the collection, treatment, disposal and reuse of wastewater from individual homes, clusters of homes, isolated communities, industries, or institutional facilities, as well as from portions of existing communities at or near the point of waste generation (Tchobanoglous, 1996).

Domestic wastewater: The domestic effluents consist of black water (excreta, urine and associated sludge) and grey water (kitchen and bathroom wastewater) (Raschid-Sally and Jayakody, 2008). In this research it is also considered effluent from commercial establishments and institutions, including hospitals (Van der hoek, 2004).

Household: It refers to a private house, building or plot occupied by a family or a group of families (WSP, 2008).

Industrial wastewater: It is the wastewater generated by industrial processes and its characteristics vary depending on the type of industry.

Lagooning systems (Stabilization ponds): Different terms are being used to name this kind of process, stabilisation ponds, facultative ponds, anaerobic ponds or maturation ponds. All these technologies are anthropogenic systems that imitate natural depuration processes that take place in to rivers or lakes. The natural self depuration would consist of physical process of sedimentation and flotation, chemical process of neutralization and oxidation and biological process of microbiological degradation. Therefore, this chain of ponds completes a very efficient treatment that complies, primary, secondary and tertiary treatment, however, pre- treatment technologies are required at the beginning of the chain.

Neighbourhood: It refers to an area that comprise cluster of houses or buildings, around 10 to 200 households (WSP, 2008).

Pucca housing: Pucca housing (or pukka) refers to dwellings that are designed to be solid and permanent. The term is applied to housing in South Asia built of substantial material such as stone, brick, cement, concrete, or timber (Qadeer, 2006).

Settlement: It refers to an area with 200 to 1000 households. Inside a town or a city it could be defined as a district or ward. These parts of the cities have often their own administrative division area (WSP, 2008). 1 Low-cost wastewater treatment technologies for agricultural use Soil based systems: Land application compiles various techniques that use soil as a filter. The soil is the media where all the physical, chemical and biological processes take place. Therefore it can perform as a primary and secondary treatment device. The organic matter is decayed by soil bacteria in oxygen and anoxic processes.

Storm wastewater: Water from rainfall is not clean. It is affected by atmospheric pollution and by sweeping along the street contaminants. The most common type of sewage system for this type of water is the unitary, where water from urban runoff is mixed with domestic and industrial effluents.

Total coliform: It is a measure to analyse the presence of pathogens in wastewater. Part of coliform bacteria is naturally present in the intestines of mammals. The concentration of coliform bacteria constitutes an indicative of faeces contamination. Total coliform is referred both to faecal coliform and enteric coliform.

Urban wastewater: It is a combination of domestic wastewater, industrial wastewater and the urban runoff and storm water (CENTA, 2007a).

Wastewater treatment technology: Wastewater treatment technology is defined as a group of physical, chemical and biological processes, in order to treat wastewater by reducing or removing its pollutants load.

2 Low-cost wastewater treatment technologies for agricultural use EXECUTIVE SUMMARY

Urban farmers in India have few options to irrigate their crops. When precipitation is not enough, tap water is too valuable therefore it is not a possible and affordable alternative. Wastewater becomes the most logical input. In fact, wastewater is a potential input for agriculture and can help to increase yields (Yadav, et al 2002). This research is part of REOPTIMA project, Reuse options for marginal quality water in urban and peri-urban agriculture and allied services in the ambit of WHO guidelines (New Indigo, 2011). This is an initiative for the Development and Integration of Indian and European Research. The aim of REOPTIMA is to create an expertise network on the development of integrated wastewater management systems, and develop a roadmap for research on urban wastewater reuse in Indian cities (New Indigo, 2011). The design of the present study comprises a study of the scenario area, the city of Bhubaneswar.

Bhubaneswar is the overpopulated capital city of Odisha State in India. Its fast uncontrolled growing pace make the urban planning unachievable, therefore the urban infrastructures remain under dimensioned and the wastewater treatment capacity far behind the real necessities. Water bodies suffer high loads of pollution. Although agriculture is a marginal sector inside the city, it is still located in located in the bank of the city rivers. Urban farmers have few options to irrigate their crops.

The high content of macronutrients as nitrogen and phosphorous and organic matter in wastewater are beneficial and profitable for the agricultural production. However, other found compounds in wastewater can create a health risk for farmers and consumers. Therefore in order to use the municipal wastewater in agricultural plots, the treatment of not only pathogens but also other pollutants (toxic compounds, heavy metals, etc) is necessary.

The goal of wastewater treatment plants is the improvement of water quality from an environmental point of view, not for use in agriculture. The discharge of the effluent in the existing water bodies or water drains is the main practice. Therefore, the wastewater treatments use to focus in the reduction of the load of pollutants with the primary treatments (to remove suspended solids by physical processes) and secondary treatments (to remove colloidal and organic and inorganic constituents by biological processes). The removal of pathogens by tertiary treatment is mainly applied in the case of direct reuse of the effluent, for instance irrigation.

Furthermore, conventional technological treatments require high energy, chemical inputs, skilled labour; infrastructure and maintenance works to work properly and therefore their sustainability depends on economic aspects. Even in industrialized countries not all small settlements can afford operating costs of modern wastewater treatment plants (Hophmayer- Tokich, 2006). These preconditions make it difficult if possible to sustain high technological wastewater treatment plants in developing countries. Therefore, high technical methods would not be always the most suitable option in a long term perspective.

Consequently, urban farmers have to deal with a polluted source of water because the treatment solution is not affordable for them.

3 Low-cost wastewater treatment technologies for agricultural use The present study aims to devise a integrate approach to look for a technological feasible solution for urban farmers of Bhubaneswar city. An in-depth study of the scenario area was developed in order to integrate in the technologies assessment, the physical, social and economical criteria of the local context. The research design involves also a description of the low-cost wastewater treatment technologies. Following, there is selection of possible low cost technologies for agricultural purposes for the studied case. The selection was made by a scoring multi criteria evaluation process (MCA). In order to develop the MCA were defined various principles, criterion and indicators that cover the aforementioned crucial aspects for this research; (1) compliance with health protection (for consumers and farmers), (2) compliance with crop production and (3) sustainable solutions for local context. Regarding to each principle, the criteria were established to choose the technology. The criteria are further divided into indicators that are characteristics of the technology and were used to assess the adequacy of the technology. These indicators were related not only with the technical characteristics but also with other local socioeconomic factors that might affect the success of the implementation. Finally a technological solution is recommended for the urban agricultural plots of Bhubaneswar.

4 Low-cost wastewater treatment technologies for agricultural use 1. INTRODUCTION

There is a trend of people migrating from the countryside to the cities creating new huge metropolitan areas. The spatial reorganization of people to urban areas has also concentrated food demands in cities (Jimenez et al, 2008, p 229). At the same time, the settlement of people in the cities involves a rapid change of land use. As a consequence, the urban planning becomes chaotic and the traditional rural agricultural plots suddenly coexist with high density population settlements. Urban and peri-urban agricultural activities increasingly gain an important role in the urban economy (reviewed by Jimenez et al, 2008, p 228), and become essential to avoid problems of food security.

Water is an essential natural resource and is used in many human activities. Plants require water and nutrients to grow, but in arid and semiarid areas water is a scarce resource. Where rainfall is insufficient, irrigation is a necessary practice that ensures the production for the farmers. However, the availability of fresh water for urban agricultural plots is decreased by competing with an increasing domestic and industrial demand (Jimenez et al, 2008, p 199). Driven by the new urban activities, the amount of wastewater is growing. Therefore, less fresh water is available and reclaimed water is sometimes the only source available for the agricultural plots located close to the city. Reclaimed water is widely used as a low-cost alternative to conventional irrigation water (Scott et al 2004, p 1) because is a reliable source of water supply.

Water closes a triangle of inter-dependences, in this report referred to as “Water-City- Agriculture” (Figure 1).

CITY URBAN AGRICULTURE

Figure 1: Triangle of interdependence Water-City-Agriculture (self-designed)

The reuse of wastewater for agriculture is not a new practice. For centuries, urban wastewater has been used as an input for agricultural plots, and today there are many examples of such practices all over the world. For instance there are cases of direct use of untreated wastewater in Dakar (Senegal) and Ghana (Scott et al, 2004), or treated wastewater from the cities as the

5 Low-cost wastewater treatment technologies for agricultural use

case of El Mezquital in Mexico, were 250000 ha which are irrigated with wastewater from Mexico City (Lazarova, et al 2005, p 345). In fact, wastewater is used extensively (20 million ha.) and 10% of population worldwide consumes wastewater irrigated foods (Reoptima workshop, 2012). This use brings both advantages and disadvantages to the farmers, as well as to the consumers. For instance, the high nutrient concentration of the wastewater maximizes yields; therefore, the possibility of irrigation with reclaimed water ensures the incomes of households of urban farmers (Carr et al, 2004). On the contrary, wastewater not only contains large quantities of nitrogen and phosphate, but in many cases also heavy metals, pharmaceutical residues or other micro pollutants, viruses, bacteria, protozoa and helminths. Adverse effects of surplus nutrients, toxic compounds and pathogens on the quality of the crop are possible. Furthermore, beside the effects on the crops, a direct use of dirty and smelly wastewater is not a pleasant work for the farmers. The use implies also high risk of waste waterborne diseases like hook worm infection or intestinal nematode infection (Ensink et al 2005). Moreover, from the consumer’s perspective, the consequences of the consumption of food with remains of toxic compounds or pathogens on human health can be fatal (WHO, 2006). Therefore, in order to use the municipal wastewater in agricultural plots, the treatment of reclaimed wastewater has to assess all these factors.

1.1 PROBLEM ANALYSIS

In developed countries, the possible negative effects of wastewater reuse on human health and environment have been overcome or minimised by implementation appropriate wastewater treatment technologies that maximize water quality standards for safe discharge. For example, municipal parks in the city of Madrid (Spain) are irrigated with reclaim water. To minimize the health risk of citizens is treated with ultraviolet devices. Such highly technological wastewater treatment is not what it is found in developing countries, where there is no access to advanced treatment or even basic treatment. In many cases it results in the use of untreated wastewater. Therefore, despite the possible negative effects on human health, with the high risk of disease infection for the farmers (as hookworm, ascaris, Diarrhoeal disease, giarda intestinalis infection), and food contamination (e.g. cholera, typhoid, ascaris infection) (Carr et al, 2004), farmers are faced with polluted water as the only available input.

The use of treated and untreated wastewater in urban and peri-urban agriculture is a quite common practice in India. Unfortunately, remains of toxic compounds and infectious substances in wastewater irrigated food are common as well. However, the use of reclaimed water for irrigation is not regulated by the Indian legislation, (New Indigo, 2011). Therefore, wastewater management protocols and techniques should be developed based on sound scientific knowledge to support farmers (New Indigo, 2011).

On the contrary, many organizations and institutions worldwide (WHO, FAO, etc.) have developed guidelines that maximize the protection of human health and environment, so as not to waste this important resource. They also propose some wastewater treatments in order to achieve this. Nonetheless there is a need to identify wastewater treatment technologies that not only reduce the health risks of wastewater use (Reoptima workshop, 2012) but also keep the wastewater properties improve the growth of crops. The reason behind that is that urban agricultural sector maintains and increases the socioeconomic and environmental

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qualities of the cities (Van der Hoek, et al. 2002). This is not only a question of health security but also food security.

1.2 RESEARCH DESCRIPTION

1.2.1 Objective and questions

The objective of this research is the identification of the most appropriate low cost technological solutions for improving the wastewater quality, in order to irrigate urban agricultural plots of the city of Bhubaneswar.

My main research question is what could be the most appropriate technological solutions to upgrade wastewater in order to minimize the health risks and maximize crop benefits, in the city of Bhubaneswar, Odisha (India).

1. Which are the criteria that will define the multi criteria analysis for the selection of the solution?

2. Which factors would influence the performance or implementation of the wastewater technology?

3. What are the required characteristics of reclaimed water that result beneficial and profitable for agriculture?

4. Which are the current low cost wastewater treatments methods that are able to supply water with beneficial characteristics for agriculture?

5. To what extent can low cost wastewater treatment reduce the health risk of consuming reclaimed water irrigated crops?

6. What are the most suitable low cost wastewater treatment methods to minimize the health risks for farmers?

1.2.2 Research phases

The research project is divided in the following stages:

Baseline analysis

The first phase of my research comprises a concise analysis of the area, regarding to the geophysical characteristics, sociological aspects and water specific aspects (water resources, water treatment, water infrastructure, water management, drinking water, types of wastewater, etc.).

The objective of this first phase is to gather deep knowledge of the area, in order to make a baseline that will be used to develop the further stages of my research.

Also during this phase, the definition of the specific quarter of the city is chosen.

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Guidelines and standards of wastewater quality for agricultural purposes

The second part of this study is related to water quality standards, in terms of health and agricultural purposes. During this phase the international guidelines for the reuse of wastewater for agricultural purposes is studied. Also standards for the quality of water effluent are analysed. A description of information on agricultural water standards from different institutions is presented.

Inventory and categorization of low cost wastewater treatment technologies

The third part of this research consists of a list of technologies. First of all a general overview of the conventional wastewater treatment processes is given. After the review of technologies, the criteria indicators are described base on the agricultural reuse. A review of the existing examples of low cost wastewater treatment plants in India and other countries is carried out, followed by a selection of the technologies based on the criteria and indicators. A detailed characterisation of each selected technology is then presented.

Multi criteria analysis

Finally, after the definition of the technologies the elaboration of multi criteria analysis is achieved. Once the criteria indicators are defined and described for each selected technology, the next step is to assess and put a value to each criteria indicator. The multi criteria model will be chosen and adapted to the purpose of the research.

Selection

The selection of the most feasible technology for urban agriculture in Bhubaneswar will be based on the results of the multi criteria analysis.

1.2.3 Research methodology

In order to address the research objective the methodology consists of:

Literature study.

The literature review studies relevant background information on quality standards for use wastewater in agriculture, as well as the current wastewater treatment technologies in application within the context of India and Bhubaneswar.

In order to gather as much information as possible, the collection of the data is done by different sources:

-Documents: scientific books, journal articles, publications and expert reports, documents and summaries.

- Official websites: State, regional and local institutions related to agriculture, environment, water and administrative subjects, and research organizations and NGOs.

-REOPTIMA project: The thesis research topic is related to REOPTIMA project; reuse options for marginal quality water in urban and peri-urban agriculture and allied services in the gambit

8 Low-cost wastewater treatment technologies for agricultural use

of WHO guidelines. The aim of REOPTIMA is to create an expertise network (Indian and European researchers) and to develop a roadmap for research on urban wastewater reuse in Indian cities (New Indigo, 2011). Information available from meetings, workshops, conferences between the different counterparts of this project is consulted and used.

The literature study is specifically developed to find answers to the first four sub questions, and also is used to back up the definition of the 5th and 6th sub questions.

Interviews.

The study area characteristic´s is defined with the assistance of the scientists from the Directorate of Water Management. The local characteristics of the area related to: Geo- hydrology, Agriculture, Rainfall, Climate and Topography are studied, therefore semi- structured interviews were held to provide additional information on water quality and the management context.

Although the aim of the REOPTIMA project is the wastewater management of the city, due to the size of the area, it is essential to optimize the study, to reduce the unit of analysis to a specific representative part of the city. The contacts and questionnaires are constructed as to yield information about the city, and therefore are useful to answer the fifth research sub question.

All the obtained data are triangulated in order to guarantee the transparency and reliability of the information.

Multi criteria analysis.

The background information of Bhubaneswar ward will be reviewed. Based on the data collected from the literature review, from the interviews and the assumptions of the missing data, the assessment of the local situation will be developed. On the other side, criteria indicators will be valued with a range of figures. The value of each indicator will change depending of the local context. The total values of the indicators will be added to obtain a final assessment of the criteria. The technology will be scored with the sum of the values of the criteria indicators.

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2. BACKGROUND RESEARCH

2.1DESCRIPTION OF THE AREA

2.1.1 Location and demography

Bhubaneswar is located in the district of Khordha of Odisha state (see Figure 2). It is the capital city and the largest city of the state. By the Census of India 2011, Odisha had a population of almost 42 million inhabitants in 2011. It is located in the eastern coastal area of India. It is among the poorest and least developed states in the country (India today, 2008; Prakash et.al. 2011) and one of the least urbanized states with 14.97% of urban population (Sethy et al, 2007).

Figure 2: Location map of Odisha, Khordha district and Bhubaneswar in India. (Self design base on: Antur, Wikipedia, 2013. Available at: http://en.wikipedia.org/wiki/File:OrissaKhordha.png)

The metropolitan area of Bhubaneswar is merged with the nearby city of Cuttack. These two cities conglomerate to a total population of 1.2 million people. The rapid growth of population, driven by rural migration from the southern states, has resulted in a proliferation of slum settlements. In 2001, Bhubaneswar had a total of 190 urban slums having 38142 households spreading over 300 acres of land (Sethy, 2007), but nowadays according to Bhubaneswar Municipal Corporation (BMC, 2013) there are already 377 slums settlements (see Figure 3).

Figure 3: Rising trend of slums in the city from 1994- 2008. Department of Urban Poverty Alleviation. Bhubaneswar. (Source: Bhubaneswar Municipal Corporation website, 2013)

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2.1.2 Climate and rainfall

Bhubaneswar is situated in a humid area and the climate is tropic template. The Indian Meteorological Department defines the climate by four different periods: winter (cold) season (January and February); pre-monsoon (summer)season (March, April and May); summer monsoon season (June, July, August and September) and Post-monsoon season (October, November and December). Precipitation is concentrated during monsoon period from 15th June to the end of September (Government of Odisha, 2010). The overage annual rainfall is 1451.2mm. The temperature oscillates between the 15 o C in the winter months of January, and maximum of almost 38 o C in the summer months of May (see Figure 4). There is a low moderate risk of drought, and by contrary is highly vulnerable to Tropical Cyclones that form during the monsoon season (Attri, et al, 2012).

Figure 4: Monthly mean maximum & minimum temperature (o C) and total rainfall based upon 1952-2000 period (49 years data). Station name: Bhubaneswar (A) (Source: self design adapted from IMD, 2012)

2.1.3 Hydrography and topography

Bhubaneswar is located in the coastal zone of the region, in the Mahanadi river delta. In the near city of Cuttack Mahanadi River, third largest river of the Indian Peninsula (India WRIS, 2011), is divided in different branches before its mouth in Bengali Coast (see Figure 5: Map of Khordha district, River and Drainage. Odisha, India. (Source: The District. Portal of Khordha, 2013)Figure 5).

Kuakhai River originates as a branch of Mahanadi and enters Bhubaneswar from the north and it streams form the eastern boundary of the city. Likewise, at the south of the city Kuakhai river is divided in two, originating the Daya River. Daya defines the south boundary of the city. Therefore Bhubaneswar is bounded by Mahanadi River in the north, Kuakhai River in the east and by Daya River in the south (see Figure 5).

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Figure 5: Map of Khordha district, River and Drainage. Odisha, India. (Source: The District. Portal of Khordha, 2013)

The topography has been shaped by erosion of the laterite plateau over the one Bhubaneswar lies on. So the city is rather hilly, with continuous raises and falls. However there is a clear slope towards the eastern city parts from the upper western areas (CCIP, 2006). Therefore the river Kuakhai on the east and the river Daya in the south define also the natural drainage channels of the city the water runoff is split up in these two watersheds (Mishra, 2004).

Inside the city it is important to mention the Gangua Nallah stream. It flows from Gadakhan village crossing the city towards south parallel to Daya River until they joint near Kanti village. Despite Gangua Nallah is a natural canal form as rainwater drain, nowadays it has become the main conveyor of city wastewater. This is due to at least 10 drains that run from west to east of the city discharge their flows into Gangua Nallah stream (Van Beusekom, 2012; Kumar Sabat, 2012). Chilika lake is located some kilometres at the south of the city (see Figure 5). This water body is fed by different streams but the Daya River is one of the main tributaries. Therefore the water quality and its environmental condition are totally influenced by the Bhubaneswar wastewater discharges.

Figure 6: Location of water streams in Bhubaneswar, Odisha, India. (Source: Van Beusekom, 2012)

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2.1.4 Study of the water context

Water resources

India is a large country with a geographical area of almost 3.3 million Km3. Its great size also implies differences in rainfall, reaching over 11000mm at north east Meghalaya state, and only 100mm in western Rajasthan (Gulati et al, 2005). Nevertheless, not only exist areas drought prone, but also there are areas under flood damage risk (CWC, 2010). Furthermore, there is an uneven distribution of water not only in space but also in time. The main water resource of the country results from the natural runoff that drains into the rivers (Gulati et al, 2005). It is estimated of 1122 billion m3 usable water, surface water of 690 billion m3 and groundwater 432.94 billion m3 per year (CWC, 2010).

Water scarcity

Water scarcity can broadly be understood as the lack of access to adequate quantities of water for human and environmental uses (White, 2012) Therefore the concept of water scarcity could be approached from two different perspectives: Socio-economical and physical.

(1) Socio-economical scarcity could be understood as a result of growing population and competing demands for water (Metha, 2007). The high pressure demands force to allocate water among several stakeholders. Is predicted that the world population will increase within the next fifty years, by 40-50% (WWC, 2012) and these figures are even more accentuated in India. The growing population and its concentration in particular areas, stems a raise of water needs. Furthermore, socioeconomic development and the increase of life standards trigger a higher consumption of water in urban areas, and these activities compete with agriculture whose yields, in addition, have also to guarantee food security. As it is indicated in Table 1 a steady increase of water demand is predicted in the next few years. While agriculture will increase from 16% (Standing Sub-Committee for assessment of availability and requirement of water, MOWR) up to 55% (National Commission on Integrated Water Resources Development ,NCIWRD) until 2050, the foreseen increment of all the other types of uses is very much higher as for example drinking water that will increase from 82% (MOWR) up to 164% (NCIWRD).

Table 1: Project water demand in India (by different uses) (Source: CWC, 2010, table 71)

3 Water Demand in Km ( or Billion Cubic Meter) Standing Sub-Committee of National Commission on Integrated Water SECTOR availability and requirement of Resources Development . (NCIWRD) water. (MOWR) 2010 2025 2050 2010 2025 2050 low High Low High Low High Irrigation 688 910 1072 543 557 561 611 628 807 Drinking 56 73 102 42 43 55 62 90 111 Water Industry 12 23 63 37 37 67 67 81 81 Energy 5 15 130 18 19 31 33 63 70 Other 52 72 80 54 54 70 70 111 111 TOTAL 813 1093 1447 694 710 784 843 973 1180

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Source: Basin Planning Directorate, CWC, XI Plan Document. Report of the Standing Sub-Committee on "Assessment of Availability & requirement of Water for Diverse uses-2000" (2) The term physical scarcity refers to a volumetric lack of water. Droughts or pollution are factors that can trigger this problem and the consequences of the scarcity could be even more severe if all of them overlap at the same period of time. However, droughts are natural climatic phenomena produced by a shortage of rainfall during a long period of time. These droughts have been a regular feature of India’s geo-physical profile since time immemorial. In some parts of India, droughts occur almost every year (Jairath, et al. 2008, p.158). The south- west monsoon (June – September) is a periodic phenomenon that produces the 73% of total annual precipitation, therefore when monsoon fails, drought is originated (CMP, 2012). Indian Government consider drought as a management issue, therefore they develop Crisis Management Plans, Drought Prone Areas Programme (DPAP) where it is considered drought management (CMP, 2012). Pollution is another factor that determines the reduction of the physical water availability and therefore generates a rise of scarcity. Industrial activities and urban development generates pollutants that reduce quality of water bodies, and therefore diminish the directly usable quantity (Brands, et al 1997, p21). The pollution is cause by the discharge of untreated or partly treated domestic (and industrial) wastewater from the fast growing urban centres. In India, it is estimated that only 25-30% of the urban wastewater flow receives some form of treatment (CUPS /70/2009-10) (New Indigo, 2011). In Bhubaneswar, despite that there is a low risk of drought water scarcity could be triggered by the high pressure over water resources. Although it is a humid region, the rainfall concentrates only during the monsoon period. Bhubaneswar is located in an overpopulated river delta area. During winter and summer season, there is an overexploiting of groundwater in the area (Mishra, 2004), but also surface water bodies are threatened by huge loads of pollutants released by upstream discharges. In case of scarcity, Odisha State Water Policy fulfil with the National regulation. Water allocation priorities, are defined as following: Drinking water and domestic use (human and animal consumption), Ecology, Irrigation, agriculture and other related activities including fisheries, Hydro power, Industries including Agro Industries and finally Navigation and other uses such as tourism (HLTC, 2007).

Water regulations

Bhubaneswar is regulated by Odisha´s policies (based on the Indian state regulation). The national water policy developed by the government of India in 1988, was modified in 2002, and recently change in 2012. It is a general regulation that is applied to all the states of the country. Based on this, each state develops its own regulation. Odisha State created its own State Water Policy in 1994 and the last adaptation was in 2007 (HLTC, 2007). With the new National water policy, the main water management issues in the country and related to Odisha are covered, it is worthy to mention the section 3.5 of State Water Policy, where it is aim strengthened of water use infrastructure in north eastern regions. The policy is oriented to prevent the pollution rather than invest in cleaning or remediation, as is shown in the section 8.5 of State Water Policy, sources of water and water bodies should not be allowed to get polluted. It is much related to the aim of this research, the section 11.7 of State Water Policy subsidies and incentives should be implemented to encourage recovery of industrial pollutants and recycling / reuse, which are otherwise capital intensive. Therefore the regulation shows the national government willingness to address the target of wastewater reuse. However, no

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specific measures have been done so far. In fact, the regulation for water or wastewater is the same and mainly related to environmental pollution (EBTC, 2011). The Central Pollution Control Board (CPCB) is the institution in charge of controlling pollution in water bodies and reports it to the Ministry of Environment and Forests (MoEF). In general, regarding to the water bodies pollution, there are some environmental regulations (i.e. Act 1974) that forbid the discharge of an effluent if it has not accomplished quality the standards required (CSE, 2011). CPCB control the performance of the wastewater treatment plants, but despite that, there is no regulation that supervises the on-site treatment systems (EBTC, 2011).

Water and wastewater management

Indian water resources allocation is done at state level. In case of Bhubaneswar, it is done by the Department of Water Resources of Odisha Government. This institution controls water allocation among different users; Department of Agriculture, Urban water supply, etc.

The management of wastewater in Indian cities is done by local authority bodies that try to face the uncontrolled increasing waste generation with a very short budget (CPCB, 2013). In Bhubaneswar, the local sewage system and the wastewater treatment is built by the public Odisha water supply and sewage board (OWSSB), from Odisha State. Once the infrastructure is implemented, the Odisha Public Health Engineering Organization (OPHEO) is in charge of the operation and maintenance. Drinking water supply to most parts of the City is also maintained by the State, OPHEO. However the local authority, Bhubaneswar Municipal Corporation (BMC), is providing water supply to certain fringe areas of the city mostly at the outskirts through well production.

Sewage infrastructure

In Indian cities, the municipal sewer system does not cover the most part of the urban areas. Furthermore, the infrastructure is unsuitable, deficient and in poor condition, aggravates the problem. As a consequence, a large proportion of the domestic wastewater is either discharge directly in natural drains or in some cases is directed to decentralized treatment systems. In fact, it is estimated that about 29% of the India’s population uses septic tanks (USAID, 2010; CSE, 2011). However, it should be stressed what has already been indicated by Water Aid India (2005). In order to achieve the Millennium Development Goals (MDG), great investments in sewerage and waste disposal infrastructure are needed in India. Furthermore, in case the MDG would be accomplished, they also remarked on that slums population and the rural poor people would be out of these measures. Therefore, Indian urban areas are complex frame to work on. It is not only a question of implementing infrastructure but also dealing with the inequalities of the poorest citizens settle in slums.

As a capital city of the state, Bhubaneswar has a high density population that implies a production of huge volumes of wastewater. By the CSE (2011), the total sewage generated is around 141 to 194 million Litres per day (see Figure 7 ). The existing infrastructure covers the 35% of all the districts of the city (Anon, 2011). But the households that are not cover by the sewage system have their onsite facilities, septic tanks or soak pits (Mallick, 2012, Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013). The problem is that untreated effluent from the septic tanks in the individual premises, overloaded due to lack

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of any maintenance, is discharged into the natural drains, Kuakhai and Daya watersheds. (Mishra, P, 2004). On the other hand, the uncontrolled and massive spread of the population in the city of Bhubaneswar (see Figure 3) leads to unplanned slums settlements which makes it rather difficult to set up the basic urban infrastructures in the new areas. The sewage infrastructures that exist in these parts of the city consist on natural earthen drains for rainfall that are used as a sewage system (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013). Most of the drains are earthen basin. Only three of them have concrete construction of walls. There are not gates or weirs in most of the major canals. Consequently, the discharge of domestic wastewater is done into the natural drains. There are not separated canals for rainfall and wastewater and, even so, it is not possible to separate domestic and industrial effluents, hence rainfall runoff, domestic wastewater and industrial wastewater end up in the natural drains. Urban farmers use these canals for watering their crops. (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013).

Wastewater treatment

The existing centralized wastewater treatment plants are not able to keep pace of the growing cities. That explains that in India only the 30% of municipal wastewater is treated (CPCB, 2013). On the other hand, according to Centre Pollution Control Board (2013), the reason behind the improper performance of WWTP is predominately due to lack of operation and maintenance. Therefore, although big centralized wastewater systems were constructed in India during the last few decades, their sustainability has being questioned (Kumar, 2012). Low cost for onsite treatment seems to be an option to treat the huge volumes just at the point of generation (Kumar, 2012). In the city of Bhubaneswar, there is not only a lack of sewage infrastructure but also under dimensioned centralized treatment plants. For Bhubaneswar city there are two wastewater treatment sites (Reoptima workshop, 2012). The wastewater treatment plant located in the close city of Cuttack has a capacity of 33000 m3/day and consists of two pairs of stabilisation ponds (anaerobic + facultative). The other site is located in Bhubaneswar for the hospital wastewater treatment and has a capacity of 70 m3/ day. There are also various septic tanks in the city but not in very good conditions as it is explained by Mishra, 2004. Water- Excreta Survey 2005-06 (CSE, 2013) forecasted that it will be required an increase of 16% the treatment capacity of the city (see figure 3.2.1). However, these figures are below the present needs. Cuttack´s Plant could treat urban wastewater of an equivalent population of about 120000 people. City of Bhubaneswar is divided into 30 wards, under the Bhubaneswar Municipal Corporation control, and there are also 204 more villages along the rural periphery (Mishra, 2004) and the closer city of Cuttack. Only the two cities gather a population of about 1.2 million people. In order to treat the wastewater generated in these settlements a treatment plant with 10 times higher capacity would be necessary, compared to the one located in Cuttack (Reoptima workshop, 2012). Nonetheless, the main wastewater treatment plant of the city is under dimensioned and does not work properly. As it was pointed out by Nitya Jacob, director of CSE’s water programme (CSE, 2012) the sewage is discharged into drains that flow through oxidation ponds or aeration lagoons, these do not function, but merely act as flow-through systems. Despite that Stabilisation Pond it is perceived as a low-cost wastewater treatment option, the fact that the efficiency of the plant should be checked, make wonder if it is the best solution for the city.

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Figure 7: Bhubaneswar wastewater portrait. (Source: Centre for Science and Environment, 2013. Available at: http://www.cseindia.org/content/excreta-matters-0)

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Agriculture and irrigation

India is the second most populated country of the world after China, with more than 1.2 billion inhabitants in 2011(World Bank, 2013). Although it represents the 18% of world population, in India only the 2.3% of geographical area is used for agriculture (Icar, 2011). The economic importance of agriculture in India (in terms of gross domestic product) is declining in the last few decades. In 2008-09 reached 15.7% from about 30% in 1990-91 (NAAS, 2009) and nowadays it is just the 8% Gross Domestic Product (Icar, 2011). During the last two decades agriculture has been replaced by other sectors as industry and services (Icar, 2011).The most common agricultural production in India consists of small landholdings managed by small farmers (Icar, 2011). The types of crops and varieties depend on the region of India. The food grain is an important production, highlighting rice, wheat and pulse, also sugarcane, cotton, jute and mesta. (Agricultural census, 2012). Nevertheless, the production of fruits and vegetables is the most noticeable, where India pose the second ranking in the world. It is important to mention okra and pea production, but also fruits as mango, banana or papaya (Department of Agriculture and Cooperation, 2013).

According to CWC, (2010, data of 2007-2008) in India there are in total 62.3 million hectare of irrigated agriculture. The type of irrigation varies; there are 16.5 million hectares by canal irrigation, 2.0 million hectare irrigate by tanks, 37.8 million hectare by wells and 6.0 million hectare by others means. In urban irrigated agriculture the reuse of reclaimed water is common. Although there is a lack of realistic wastewater irrigation data in India (Kumar, 2012), the use of wastewater is reported in many cities, as for example: indirect use of wastewater for 40500 ha. in the city of Hyderabad (Kumar, 2012; Buechler, et al. 2002) or 14576 ha. in the city of Vadodara ( Kumar, 2012; Bhamoriya, V., 2002.).

Although agriculture provides employment, both direct and indirect, to about 64% of the total workforce of the Odisha region (Government of Odisha, 2011), in the city of Bhubaneswar the agriculture is a minor activity, less than 5% of the workforce. Most of the people are employed in the service sector (Van Beusekom, 2012). Urban agriculture production is mainly to sell in local markets, but also for self-consumption. The activity of the farmers is individual, but they have some kind of collaboration. There is a water users association to use the pumped water and they also decide the percentage of crops at community level land (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013). According to the Agriculture census (2012) in Bhubaneswar Municipality there are 2186 agriculture holdings that cover an area of 1289 hectares. The 93% of the holdings are plots smaller than 2 hectares and the 60% below 0.5 hectare. There is no agricultural plot in the city bigger than 5 hectares (see Figure 8). However, the number of hectares for agriculture plots is diminishing due to the change of land use. The farmers sell their plots that are converted to urban land (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013). Majority of urban agriculture remains located on the banks of the Daya and Kuakhai rivers.

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Figure 8: Estimated area by size classes and land use. (Self design based on data available in Agricultural census, 2005-06. State)

There are not official data of wastewater irrigated plots in the city. However, this was studied by Van Beusekom (2012) using satellite images from the dry season. The results of his study revealed that 50 hectares in the city were identified as potential wastewater irrigated areas. Nevertheless the irrigation is necessary only during few months. The irrigation period is from November until May. Inside the city wastewater is a constant flow and very accessible stream. The irrigation technique used is surface, furrow and flood (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013). The Unit – V, Bhubaneswar Dean Orissa University of Agriculture and Technology (OUAT) is the department responsible of Bhubaneswar urban agriculture. The types of agricultural crops that are grown the most in the urban agricultural plots of Bhubaneswar city are Rice (in June), vegetables (e.g. tomato, cucumber, amaranth, spinach, okra, sugarcane, snap melon,etc) and ornamental plants (flower production) (from November until April) (Dr. S. K. Rautaray and Dr. S. Raychaudhuri , personal communication, 4th March, 2013). One of the objectives of the Annual plan Odisha 2012 (Government of Odisha, 2012, chap 6, p2) is the introduction of large scale vegetable cultivation in peri-urban areas and encouraging off season vegetable cultivation thereby increasing the income of the farmers.

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2.2 THE SCENARIO: WARD NUMBER 3

2.2.1 Location

The ward number 3 of the city has being chosen as a representative quarter for this study (see Figure 9). The selection was based on the research developed by Van Beusekom in 2012, where this area was identified as a possible location of wastewater irrigation. Furthermore, this ward is crossed by Gangua Nallah stream that was defined in the Chapter 2.2.3 as the main drainage canal of the city, therefore an easy source of irrigation water for the farmers. In addition the ward boundary is defined by the Kuakhai River on the East. The irrigation scheme result very logical; use upstream Gangua Nallah Canal as irrigation water source and Kuakhai River as down slope natural drainage. Furthermore, according to the Comprehensive Development Plan for Bhubaneswar in 2030, the existing agricultural land use covers large part of the ward (see Figure 10.).

Figure 9: Bhubaneswar Municipal Corporation Wards Map. (Source: BMC, 2013, accessed on July 11, 2013)

2.2.2 Settlement description

Ward number 3 is formed by the localities of Chakeisihani, Sameigadia, Kalaraput, Mancheswar, Bhotapada and PHED colony. It is located in the eastern part of the city in a relatively low density area (2262 inh. /km2) comparing the rest of the city (average 4800 inh. /km2). The ward measures 5.05 km2 and has a population of 11421 inhabitants (CCIP, 2006). The reason behind this low density is the presence of agricultural plots and also the fact that a large part of the ward is occupied by the Kuakhai River and it is a flood prone plain (see Figure 10.). In the ward number 3, there are two large residential areas formed by residential plots and independent houses, Chakeisihani (southwest) and Satya Vihar (south). The majority of

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the households in Bhubaneswar are formed by nuclear families (non joint families) and most of them low raise housing and the 70% in Pucca houses (IITK, 2008). The Chakeisiani slum settlement is located on the south west border. Some other settlements are located out of the ward, such as VSS Nagar (close to drain 2 an 3) and Garakana Slum (close to drain 4). One of the largest industrial areas of the city, Mancheswar, is located in the ward number 6 close to ward number 3, and there is no separation of industrial and domestic effluents in the sewage system. Drinking water supply facilities do not cover all the extension of the ward; in the entire city only the 34% of households have their own tap. There are public water stand post for supply water and also ground water is been extracting by wells. The phreatic level of ground water is 18-24 m. b. g. l. as an average in the city (IITK, 2008).

Figure 10: Existing land use in ward nº3, Bhubaneswar, Odisha.( (Source: Self-designed adapted from IITK, 2008).

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2.2.3. Energy utilities

The power supply of Bhubaneswar city is done by three different power grids so the city is split in three electrical areas (BCDD-I, BCDD-II and BED). The Central Electricity Supply Utility (CESU) it is the private company in charge of power distribution. The network power´s infrastructure is old and inefficient. Furthermore there are problems of power theft by illegal connections, sporadic power outages and low voltage supply especially on the periphery of the city. According to IITK (2008), in 2008 there was no electricity substation (11KV) in Sribantapur. Sribantapur is the zone of the city where Ward number 3 is located. Power supply is deficient and it is predicted and steady increasing of the electricity demand in all the districts of the city (IITK, 2008).

2.2.4 Land availability

There is a mixture of different land uses in ward number 3. They are reported in the Figure 10. However, the ownership is well defined. Mainly, the private land covers the greatest part of the ward. Government land only occupies a few areas (see Figure 14, Annex 3). The existence of available municipality land for the purpose of implementation of a wastewater treatment plant is difficult to forecast. Basing on current land use, land ownership and the Bhubaneswar development plan Vision 2030 (IIKT, 2008) it is assumed that there is a high probability of this availability.

2.2.5 Agricultural characteristics

The agricultural specifications of the ward number 3 are the following.

Soil characteristics: Due to the proximity to the river, the ground in the ward is mainly alluvial, and the soil condition is hard (CCIP, 2006; IITK, 2008). By definition, an alluvial soil located in a flood plain of a river, is a soil with high fertility and low drainage capacity. The proximity to the river makes the phreatic layer rather shallow in these areas (Carías et al, 2004). Beside the general characteristic of alluvial soils, the local specifications of the soil located at the banks of Kuakhai River were not found by literature review.

Crop typology: The specific crop production of Bhubaneswar city was not found by literature research. According to the data obtained by the interviews (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013) and the citation of different papers (IIKT, 2008; EMP, 2003, CCIP, 2006), vegetables and paddy will be most likely crops cultivated in ward number 3. Rainfall is not enough to irrigate the crops from November to May. The irrigation season match exactly with vegetables growing period. I will assume then that tomato, cucumber, amaranth, spinach, okra, sugarcane, snap melon and flower ornamental will be irrigated with wastewater. All possible crops cultivated in the area are moderate sensible to salinity according to FAO (see Table 13, Annex 2). Regarding to type of crop consumption, in case of vegetables like cucumber, tomato, okra or spinach, they might be eaten raw (Pescod, 1992).

The exact number and size of agricultural plots are unknown. Under the data from agricultural census (2012) it is assumed that there are small plots about 0.5 to 1 ha.

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Water users are not formally associated in the area however they collaborate within each other in case of well water extraction or crop selection (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013).

2.2.6 Irrigation water resource

The slope of the ground drains naturally towards the East. Although South Easter railway and the Daya West Channel form a physical division, the existing crossings under both infrastructures allow the drainage from the west uplands to the eastern lowlands (CCIP, 2006). Gangua Nallah Canal crosses the ward from north to south. Four out of the 10 major drains of the city (nº 1, nº. 2, nº. 3 and nº. 4) confluence with Gangua Nallah Canal before or inside the ward, and conveys the upstream urban wastewater to it (TCGI, 2006). Although the minor rivers of the area dry during some months of the year, the wastewater origin of the effluents make the Gangua Nallah canal and its drains, a perennial water source. It is essential to remark that Daya West Channel is an irrigation canal that defines the west border of the ward and the agricultural plots are located far from it. I assumed that the use of this water would involve the construction of a canal infrastructure, so this option would not be contemplated in this study.

Gangua Nallah effluent quality

The water quality of the Gangua Nallah is clearly determinated by the drains discharges. Gangua Nallah enters into the ward already containing the Patia Nallahs (Drain number 1) effluents. One third of the ward would be irrigated with this water. After around 2 km, Sainik school Nallah (Drain number 2) and OAP Area Nallah (Drain number 3) together confluence to Gangua Nallah. Only at the end of the ward, close to the industrial area of Mancheswar, the Vanivihar Nallah (Drain number 4) outflow into the canal. The quality of the canal and its principal drains has been monitored. The flowing Table 2 shows the wastewater quality of theses drains.

Table 2: Wastewater quality and quantity of Drains number 1, 2, 3, 4 and Gangua Canal of Bhubaneswar city. (Source: Self-design based on data from EMP, 2003).

- Sample PH SS(mg/l) TDS BOD(mg/l) COD(mg/l) Cl NO3(mg/l) Total Average Drainage point (mg/l) (mg/l) Fe(mg/l) discharge Area (ML/D) Km2

A 7.6 100 200 60 120 34 - - 17 16.93 B 5.9 160 200 24 52 28 1.55 1.44 C 7.4 120 180 100 130 36 - - 3.55 3.31 D 7.4 140 490 20 180 699 0.0592 0.319 E 8.3 19 - 3 8.6 - 0.370 2.4

Average 2001 A. Drain nº 1; B. Drain nº 2; C. Drain nº 4; D Gangua Canal at Mancheswar Industrial area; E. Gangua canal

The samples of the drains were taken few km upstream before the confluence with Gangua Canal. The drain number1 was sampled at Chandraeskapur. The drain number 2 was sampled at Mancheswar, and drain number 4 at Acharya Vilhar settlement. The quality of Gangua Canal has been monitored at the confluence with the Mancheswar industrial area, therefore with the impact of the industrial effluent (See Figure 11).

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Figure 11: Location of water quality sample points of drains number I, II, IV and Gangua Nallah (Source: Self- design adapted from EMP, 2003)

The exact wastewater quality of Gangua Nallah across the ward number 3 was not found by literature review. The assumption of the quality has been done basing on the data of the samples (see Table 3) and the location (see Figure 11). Due to the cultivated land is located from the medium to the north part of the ward, the drain number IV will not be considered to deduce irrigation water quality. In the Environmental Bhubaneswar Plan (2003) was reported that the BOD levels of Gangua Nallah are directly linked with the domestic human waste, and diminish by sedimentation with the long distance transportation. The COD are related to industrial pollution. The total coliform and faecal coliform were really high in all the sample points around 16000 MPN/100ml. Therefore the assumed wastewater quality of Gangua Nallah is shown in the following table.

Table 3: Assumed water quality of Gangua Canal in the north part of the Ward number 3, Bhubaneswar city. (Source: Self-design).

PH SS (mg/l) TDS (mg/l) BOD(mg/l) COD(mg/l) Cl-(mg/l) FAECAL Coliform (MPN/100ml) 5.9-7.6 100-160 200 24-60 52-120 28-34 16000 Gangua Canal has a weak concentration of pollutants according to the classification of FAO (Pescod, 1992) (See Table 16 Annex2).

2.3 STAKEHOLDERS ANALYSIS

The aim of this stakeholder analysis is to identify who are involved and what interest they have in the results of this research. With this analysis a general view of stakeholders will be shown. The following table summarize the stakeholder considered in this analysis.

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Table 4: Stakeholder register (Source: Self design)

NAME POSITION ROLE Bhubaneswar Directorate Of Ministry of Agriculture. Water management Water Management (BDWM) Indian Council of Agricultural technologies for sustainable Research (ICAR) agricultural production.

Odisha Public Health Government of Odisha. Housing and Provides plans and executes Engineering Organization urban development (H & UD) projects related to urban (OPHEO) department. water supply and sewerage systems Odisha Water Supply And Is in charge of the operation Sewage Board (OWSSB) and maintenance of the urban water supply and sewerage infrastructure

Bhubaneswar Municipal Municipality Provides basic amenities to its Corporation (BMC) inhabitants Engineering Department of BMC Creates & Maintain Civil Infrastructures Health and Sanitation Department of Health control and food BMC security Regional Centre Of Odisha NGO, located in Water management for Development Cooperation. Bhubaneswar. domestic use Informal water User - Wastewater users Association (WUA) Local Urban Farmers - Wastewater users Residents - Products consumers

BHUBANESWAR DIRECTORATE OF WATER MANAGEMENT (BDWM). This organization depends on ICAR. The Institute aims to develop improved water management technologies for sustainable agricultural production and disseminate it amongst researchers, government functionaries, NGOs and farmers. It is also one of the main partners of REOPTIMA project (see ANNEX, initiatives & projects), that is linked to this research.

ODISHA PUBLIC HEALTH ENGINEERING ORGANIZATION (OPHEO) and ODISHA WATER SUPPLY AND SEWAGE BOARD (OWSSB). Under the administrative control of Housing and Urban Development (H & UD) Department of the Government of Odisha, these organisations provide the city with the infrastructure and services for water supply and sewage collection and treatment.

BHUBANESWAR MUNICIPAL CORPORATION (BMC). The aims and objectives of the Bhubaneswar Municipal Corporation is to provide basic amenities to its inhabitants like health and sanitation, maintenance of roads and drains, education, improvement of slum dweller, relief at the time of natural calamities etc.

o Engineering department of Bhubaneswar Municipal Corporation, which objectives are to create and maintain civil infrastructures of B.M.C area such as drains and culverts?

o Health and Sanitation department of Bhubaneswar Municipal Corporation. This department is the one that will be interested in health control and food

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security. Among other activities, this department develops campaigns for food hygienic and also for epidemic prevention and control of the mosquito antifilaria.

REGIONAL CENTRE OF DEVELOPMENT COOPERATION. This is a NGO located in Bhubaneswar, whose mission is “to play a facilitative role in the struggle for rights of the poor and marginalised over resources, opportunities, institutions and processes”. This organization is trying to facilitate the access of clean water and address problems of water contamination. It provides consultancy services and support to campaigns of water safety measures, and also works on the lack of mechanisms for operation and maintenance of water facilities.

JAPAN INTERNATIONAL COOPERATION AGENCY (JICA): It is an active agency in the area, that have funded different projects in Bhubaneswar and Cuttack related to sewage and drainage canals.

WATER USER ASSOCIATIONS (WUA). Although it is not clear the type of agreements and negotiation between farmers, the existence of an informal farmer association, make the involvement of the water user in the selection and implementation process of the technology, an essential issue. The safe and beneficial use of the effluent will be assured by farmer’s commitment with the correct performance of the system. They would get motivate to participate if they see the reason behind (Singhirunnusorn, 2009). However, poor urban farmers are probably not the higher social status, the literacy of farmers might not take it as granted and might be also considered the possible illegality of the settlement. These factors complicate their participation in the selection and implementation of the technology.

LOCAL URBAN FARMERS. Users of the wastewater canals. They are the main stakeholders of this research. They have to confront the dilemma of using or not wastewater for irrigation. Most of the times this is the only way to assure their livelihood.

RESIDENTS OF BHUBANESWAR. The citizens of Bhubaneswar have to deal with their own excreta flowing open pit in the drains or overflowing from the septic tanks. The use of these water streams as flood irrigation also implies a problem of odours. The onsite treatment might suppose for them an improvement of life conditions. However, the implementation of wastewater infrastructures sometimes implies the construction of noisy, smelly and mosquito’s reservoirs facilities. Therefore, technology can also cause many nuisances for the local dwellers.

FOOD CONSUMERS. Their interest might be high. Contaminated food implies a direct risk for their health.

The Directorate of Water Management of Bhubaneswar is a research institute related to the Ministry of Agriculture. Although it belongs to the ICAR (Indian Council of Agricultural Research), it is possible to develop some kind of collaboration with the Sewage Board (Dr. S. K. Rautaray and Dr. S. Raychaudhuri, personal communication, 4th March, 2013) in order use reclaimed water for agriculture. There is awareness from the policy makers of the importance of a good water management. In fact, there are many different initiatives within the State of Odisha and also form Bhubaneswar municipality (see initiatives & projects, ANNEX):

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In order to develop a better water and wastewater management. The annual plan 2012-13 of Odisha government (Government of Odisha, 2012) considers: the implementation of Integrated Watershed Development Programme (IWDP), Drought, Prone Area Program (DPAP), Watershed development programme under Special and Plan for KBK districts and Integrated Watershed Management Programme (IWMP).

There are many initiatives related to the sewage and sanitation of the city.

- For example the workshop on “Bhubaneswar’s Water and Sewage problems” organized by the Centre for Science and Environment celebrated 14th June 2012.

- Also the Japan International Co-operation Agency (JICA) developed a project of sewage Infrastructure for the city of Bhubaneswar. The project is related to dive a new sewerage system in six districts of the city. Although was planned to be already implemented in 2011, it is not developed yet.

Regarding specifically to sanitation in slums, there are different projects:

- Odisha Water Supply And Sewerage Board (OWSSB) is working in the comprehensive sewerage project (CSP), but the project is very behind the schedule, meanwhile, the department of Housing And Urban Development wants to create community toilets in slums and areas not covered by CSP using integrated up-flow filter technology.

- Also public toilets in Bhubaneswar and Cuttack slums, has been funded by Bill and Melinda Gates Foundation.

- The Samman project is another initiative to improve the sanitation in the slums of Bhubaneswar and Cuttack cities. It is developed by a partnership of diverse group of organizations and government entities united to tackle the sanitation and hygiene crisis in India's urban slums.

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3. GUIDELINES AND STANDARDS OF WASTEWATER QUALITY FOR AGRICULTURAL PURPOSES

3.1 INDIAN REGULATION FOR IRRIGATION WATER QUALITY

The use of wastewater for irrigation is not specifically regulated by the Indian legislation. However Indian Government has indirectly addressed this issue in several occasions by the Ministry of Environment and Forests (MoEF). The pollution is regulated and controlled by the Central Pollution Control Board (CPCB) of India. This board supports the MoEF with technical advice to promote the environmental protection (Act 1974). They provided minimal national standards to control pollutants discharges. The first approach to irrigation water standards was mentioning in the Act, 1974. For preventing and controlling water pollution was set up some water quality parameters according to different water uses or classes; “designated best use” (DBU). The appropriate water quality for irrigation use was identified as use E; pH between 6.0 to 8.5, Electrical Conductivity at 25°C micro mhos/cm Max.2250, Sodium absorption Ratio Max. 26, Boron Max. 2mg/l (see Table 20, Annex2). These criteria were only used as water quality classification, as an assessment tool for Indian water bodies, in order to develop an Indian Water Uses Map (CPCB, 2013b. pg 8). In 1999 was constituted a Committee by the National River Conservation directorate. They not only recommended some standards for treated wastewater discharge in water bodies. In this case it was considered the possible use of land irrigation. For crops not eaten raw the recommended standards were: BOD <100 mg/L, TSS <200mg/L and Fecal Coliform 1000-10000 MPN/100 ml. Although other recommendation even more restricted were given during the last few years (i.e. Ministry of Urban Development and Poverty, Committee 2004), all of them were related to the outfall into water bodies (CPCB, 2008). Therefore, these parameters will be taken into account as a reference in this research. However an analysis of the international standards will be done in the following section in order to have more complete guidelines.

3.2 INTERNATIONAL GUIDELINES REVIEW FOR HEALTH PROTECTION WHEN WASTEWATER IS REUSED FOR IRRIGATION

There are guidelines from World Health Organization (WHO), United States Environmental Protection (USEPA), California Department of Public Health (CDPH), Food and Agriculture Organization (FAO), etc. A review of the most influencing guidelines used worldwide for wastewater use in agriculture, has been made (see Table 15. Annex 2). All the guidelines or regulations take, as a starting point, the classification of the wastewater in terms of type use of the wastewater. In the Table 15, Annex 2, are only shown and reviewed the types of crops that could be found in the ward number 3 of Bhubaneswar. Although the infectious agent’s concentration is considered in all guidelines, WHO (1989) recommend also some general measures of health protection as for example; crop selection or restriction, different wastewater application, human exposure control and wastewater treatment. However, the WHO (1989) only consider E. Coli as a sign for significant human health treat, and as it was indicated by Adhya, T.K. (Reoptima workshop, 2012) no other viruses and pathogens are analysed. Scott (2004) remarked that in a situation of lack of infrastructure for treatment, the achievement of WHO (1989), turns out completely unaffordable, and therefore the guidelines

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turn into targets rather than norms to practise. Furthermore, the California water recycling criteria entailed high technological treatments to achieve the water quality that is stipulated. It makes that these standards become rather complicate to apply for low budget situation, as in developing countries (Scott, et al 2004). On the other hand, physical and chemical parameters are contemplated only for American and FAO regulations. Indeed, FAO guidelines are unique. Not only are the health issues considered in these guidelines but also the importance of wastewater quality for agricultural targets. They also proposed a table with the trace element of toxic compounds that could contaminate the crop (see Table 16 and

Table 17, Annex2). The existing regulations or guidelines in many developed countries are based on California guidelines or even WHO ,that are less restrictive, as is the case of some countries of Mediterranean Europe (Lazarova et al, 2005, p73). But actually, the regulation for the use of reclaimed water in agriculture varies among countries and even within regions of the same country. Water quality restriction is set up depending on many different aspects: crop choice, irrigation technique, wastewater treatment availability, economic input or health protection (Lazarova et al, 2005, p.73). But the fact remains that, for the urban agriculture of developing countries, the WHO guidelines (1989) result very strict (Lazarova et al, 2005, p.75) and in many cases difficult to apply. The trade of agricultural products across boundaries makes this issue an international concern (Carr, et al 2004.p 42). Have been done an effort by the international agencies in order to develop effective guidelines for health and environment protection. Hence, in 2006, due to the need to develop more flexible approach so adjust the best to local circumstances, WHO, UNEP, and FAO issued the new guidelines basing on the Australian National Guidelines for Water Recycling. This approach combines treatment and post-treatment barriers compared to the old approach that relied solely on the treatment plant as the only reliable control measures (Ardakanian et al., 2012). Consequently, the guidelines and the parameters considered, have not only to deal with health protection but also with the agricultural profit the two aspects that were pointed out in the objective of this research. WHO 2006 suggests a very complete guideline including both issues. According to Ardakanian (2012), these guidelines approach the local socioeconomic conditions in an adaptive way. In order to make the approach more specific, they not only assess the hazards but also include diseases risk management. Primarily, they focus on the health risk derived of using the wastewater. It is suggested to analyse the possible microbial risk of using the wastewater for agriculture. This is developed by a Qualitative Microbial Risk Analysis (QMRA), were the tolerable maximum load of disease is calculated in order to know the tolerable risk of infection. To optimize the risk analysis the Monte Carlo simulation tool is used. Base on that it is deduced the requirements of pathogens reducing. The risk study has a multiple approach, considering not only treatment and post treatment measures, but also measures adopted with no treated effluent. Once it is defined the required pathogen reduction, health protection proposed measures will be related to; (1) wastewater treatment, (2) safe irrigation measures and the possibility of restrict or even change the type of crop, (3) product manipulation post harvesting and (4) in-kitchen product preparation (see

Table 18, Annex2).The framework proposed is quite complete and adapted to the local conditions. However, the health risk assessment it is base on the measure of very specific pathogens; rotavirus, Campylobacter and Cryptosporidium. The lack of information makes the guideline not applicable for the scenario analysis.

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3.3 EFFLUENT QUALITY STANDARDS AND MANAGEMENT RECOMMENDATIONS

Therefore, based on the recommended standards from Indian MoEF (see chapter 3.1), the proposed guidelines by FAO and WHO in 1989 and USEPA in 1992 ( see Table 15, Annex 2) and the recommendation for reducing health risk from WHO, World Bank and FAO 2006 (see

Table 18, Annex2) the following Table 5 was developed.

Table 5: Water Quality reference value according to different uses in agriculture (Source: self design base on Lazarova et al, 2005, WHO 2006b, World Bank, 2010)

PHYSICAL & CHEMICAL PARAMETERS To preserve irrigation properties Recommendation (1,3) Moderate restriction Maximum (5) of use (1) 1 Ecw (dS/m)- < 0.7 0.7 - 3.0 2.25 TDS (mg/l) < 450 450 - 2000 - Sodium. Surface irrigation (SAR) < 3 3 - 9 - Sodium. Sprinkler irrigation (me/I) < 3 > 3 - BOD(mg/l) <10 - <100 mg/L TSS (mg/l) <30- - <200mg/L Chloride (Cl) Surface irrigation < 4 4 - 10 - (me/I) Chloride (Cl) Sprinkler < 3 > 3 - irrigation(m3/l) Boron (B) (mg/l) < 0.7 0.7 - 3.0 - 3 Nitrogen (NO3-N) (mg/l) < 5 5 - 30 - Bicarbonate (HCO3) (me/I) < 1.5 1.5 - 8.5 - pH 6.5-8 > 8.5 BIOLOGICAL PARAMETERS To avoid health problems Recommendation (1,2) Maximum (5) Intestinal nematodes Crops type A <1 Intestinal nematodes (nº eggs/L)- - Intestinal nematodes Crops type B <1 Intestinal nematodes (nº eggs/L)- - Faecal coliform Crops type A <1000 Faecal coliform (nº/100mL) 10000MPN/100mL Faecal coliform Crops type B No standard recommended for Faecal coliform 10000MPN/100mL (nº/100mL) RECOMENDED MEASURES Post treatment-health protection control measures recommendation (4) Furrow irrigation Crop density and yield may be reduced. Low-cost drip irrigation 2-log unit reduction for low – growing crops, and 4-log unit reduction for high- growing crops. Reduction of splashing Framers trained to reduce splashing when watering cans used (splashing ads contaminated soil particles on to crop surfaces which can be minimized) Pathogen die off Die-off between last irrigation and harvest (value depends on climate, crop type, etc.) Overnight storage in baskets Selling produce after overnight storage in baskets. Produce separation prior to sale Rinsing salad crops, vegetables and fruits with clean water, running tap water or removing outer leaves. Produce disinfection Washing salad crops, vegetables and fruit with appropriate disinfectant solution and rinsing with clean water. Produce peeling Fruits, root crops. Produce coking Option depends on local diet and preference for cooked food. A: Irrigation of crops likely to be eaten uncooked, sport fields, public parks. B: Irrigation of cereal crops, industrial crops, fodder crops, pasture, and trees. 1. FAO 1989 guidelines; 2.WHO 1989 guidelines; 3.USEPA 1992 guidelines, 4.WHO 2006 guidelines (Note. The recommendations are done depending on the health risk assessment); 5.Indian Ministry of Environment and Forestry recommendations.

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4. LIST OF WASTEWATER TREATMENT SYSTEMS

4.1REVIEW OF WASTEWATER TREATMENT SYSTEMS

Generally, the treatment of wastewater is described as a multistage system. The more stages are made, the more level of treatment is done, according to the different substances that are removed or separate from the water bulk. The most complex system template for wastewater treatment would comprise four stages; pre-treatment, primary treatment, secondary treatment and tertiary treatment. Each stage could be done by various processes and technologies. A review of the different processes involve in wastewater treatment is done in the Table 6. Following there is a brief analysis of the treatment stages.

(1) During pre-treatment or preliminary treatment, big solids are removed and grits and oil loads are reduced. Preliminary processes prevent problems of equipment clogging or erosion. Therefore this stage supports and optimizes the subsequent treatment stages.

(2) The primary treatment involves physical and chemical operations, like flocculation coagulation or sedimentation. These processes are induced in order to remove solid particles not easy to settle. This stage removes up to 25-50% of BOD, 70% of suspended solids (SS) and 65% of grease (Armenante, 1999).

(3) The secondary stage consists of processes that remove biologically the organic matter. Afterwards use to be done sedimentation of suspended solids. Therefore, the secondary treatment aims to remove the 90% of the organic matter dissolved and the 80% of the suspended solids by biological processes (Armenante, 1999).

(4) The tertiary treatment is applied to produce an effluent with very low level of organic matter and suspend solids. This stage is an additional treatment that guarantees quite acceptable quality of effluent. Beside organic matter also toxic compounds, pathogens and odours are removed. Indeed these processes are the one recommended for a safety reuse of the effluents (in terms of health protection).

The kind of treatment will depend on the characteristics of wastewater. Wastewater is generated by human activities. These activities determine the quantity and the quality of produced wastewater. Urban wastewater comprises domestic wastewater, industrial wastewater and urban runoff. Domestic wastewater would consist of black (toilet) and grey water (kitchen and bathroom). Therefore they would contain organic matter, fats, salts, tens active compounds, nutrients, solids, pathogens, etc. However industrial wastewater composition is not possible to standardize and it varies depending on the industry type. Likewise, urban runoff characteristics could differ according to the surface pollution. In an urban area it could contains different solids, sediments, oils and heavy metals deriving from roads (CENTA, 2007a). The wastewater collection system and the possible separation of industrial and domestic effluents, by separate sewage system, is a factor to consider. Besides the quality, wastewater volume is also an essential factor that influences the selection and design of the technology. In small and medium size settlements, wastewater generation is not that constant the fluctuations of quantity ensue more extreme. As a consequence, wastewater quality is related with the quantity. In small settlements, wastewater volumes are smaller and therefore the water pollutants are less diluted.

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On the other hand, when it is designed a wastewater treatment system, there is a choice between centralized, semi-centralized and decentralized systems.

The definitions of centralized and decentralized water treatment are often blurry. Depending on the specific situation (presence and /or cost effectiveness of a sewage system, topography, population density, etc.), both offer advantages and disadvantages. Centralized systems are characterized by collective wastewater treatment so they treat wastewater of medium to large scale communities (Tchobanoglous, 1996). They have upscale sewage systems to conduct wastewater in to a central site of treatment. The collection sometimes involves conduction over large distances therefore high investments in infrastructure. However centralized systems are used worldwide in many cities. The fact that they are able to cover higher population demands makes them a good alternative to access high tech for a relatively low cost per inhabitant. Furthermore the monitoring and control of larger amount of wastewater is simplified in a single point of discharge (Crites, et al 1998). As an example, for big settlements, centralized systems would use mechanical systems like activated sludge, oxidizing beds, membrane technology or lagooning (Seto, 2005). By the contrary, decentralized systems are aimed for individual or low scale communities; households, neighbourhoods or spread settlements. Therefore they do not have connection to a centralized sewage system. They consist of alternative wastewater collection systems (i.e. septic tanks) and the disposal (reuse) of the treated effluent is close to the point of origin. As an example, for small or spread settlements would be used soil based systems or package plants (Seto, 2005). These decentralized systems can use high technology but more often they use simple natural technologies that require relatively low energy or even no energy (CSE, 2013b). Yet, it should be mention that there are many situations in between. Small settlements, or even dispersed households could be interconnected forming what is called semi-centralized treatment sites. Tuning the attention on the decentralized systems, mention should be made of the spreading use in India. The suitability of these systems for Indian urban contexts was mentioned by Kumar (Reoptima workshop, 2012), and the Centre for Science and Environment reports various examples of successful implementation in cities like for example at Kachpura slum near Mehtab Bagh in the city of Agra. (CSE, 2013b). Decentralized onsite systems are closely related to sanitation treatments. Onsite treatment (at the point of generation) allows also the separation of wastewater streams of various origins and therefore a better control of wastewater quality inlets. Moreover, it has been proved that the treatment of black and grey water separately reduces the energy, materials and emissions cost of the treatment process (Balkema, et al. 2002)

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Table 6: Summary of processes of wastewater treatment (Source: self-design base on World Bank, 2013; Armenante, 1999; CENTA 2007a, Card, 2005)

PROCESSES DEVICES PRE-TREATMENT or PRELIMINARY Removal of coarse easy separable solids, fat –grease- oil separation and equalization of flow Removal of coarse Grit removal Screens: Coarse screening (Bar racks), Medium screening (Inclined solids rotary screens, drum rotary screens, rotary disk screens), fine screening (drum rotary screens, rotary disk screens, centrifugal screens, micro strainer. Grinders: Vertical screens, semicircular cutting disks, cutting blades, conical shaped screen grid. Grit chambers (sand trap): Sedimentation tank (horizontal, aerated, or vortex) Fat/grease/oil Separation of free oil by gravity or flotation Grease trap (Sedimentation tank). Air flotation devices (diffusers, separation blowers) Separation of emulsified oil De-emulsifying agents addition Equalization of flow rate and pollutant concentration Tank (reservoir) PRIMARY TREATMENT Physical-chemical operations to remove organic and inorganic solids and separation solids from solid-liquid suspension Sedimentation of solids Clarifiers (Sedimentation tank): magnetite, vortex separators. Thickeners (Sedimentation tank) Filtration of solids Mechanical straining Sedimentation on filter SECONDARY TREATMENT Biological process to remove dissolved organic matter and separation of suspended solids Aerobic Activated sludge treatment (several chambers) Reactor tank. Air diffusers (Oxygen blowers). Sludge pumps. process Sequence batch reactors (one chamber) Trickling filtration/ biofilter/ biological filter Septic tank for fermentation or raw water tank. (rotating) / oxidation beds/ filter beds Bioreactor containment, Filter for biofilm. Air diffusers (Oxygen (carbonized coal is called oxidation bed) blowers). Sludge pumps. Percolation ponds. Treated water tank.

Soil based filter technology/ terrestrial system Land filter: Land application. Leach field. Soak pit( soak away) Soil biotechnology (SBT)/ (trickling filtration Green filter: trees or crops. using soil as a filter) Aerobic reactors (rotating biological Tank. Rotating disks contactors) Ponds/Lagoons/ stabilization ponds /oxidation Earthen basin or tank. Measurement devices. Sampling systems. ponds or lagoons Pumps Constructed wetlands Earthen basin or tank. Phytoremediators (reed beds, ...) Anaerobic Anaerobic digesters (reactors) that produce Tanks. (Imhoff tank. Anaerobic baffled reactor (ABR). Anaerobic process septic treatment/Anaerobic activated sludge clarigester. Anaerobic expanded-bed reactor. Anaerobic filter. Biological OM of consumption Biological process/.Up flow anaerobic sludge blanket Anaerobic fluidized bed. Anaerobic MBRs. Continuous stirred-tank digestion (UASB)/ Expanded granular sludge reactor (CSTR). Anaerobic migrating blanket reactor. Batch system bed digestion (EGSB). anaerobic digester. Internal circulation reactor (IC). One-stage anaerobic digester. Plug-flow anaerobic digester) Pumps Anaerobic lagoons or ponds/ stabilization Earthen basin. Measurement devices. Sampling systems. Pumps ponds Secondary sedimentation Sedimentation tank (clarifier) Drum rotary screen. Centrifugal screen TERTIARY TREATMENT (Polishing) Remove toxic or recalcitrant organic pollutants (halogenated, not easy biodegradable, Phosphorus, Nitrogen...) and disinfection Filtration or Adsorption. Odour removal Sand tank. Activated carbon tank. Lagooning: Earthen basin or tank. Membrane filtration Nutrient removal (N and P). De-nitrification tanks (anoxic tanks) with mixers Disinfection. Pathogen removal. Chorine addition. Ozone addition. U.V. lamp. Lagooning.

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4.2TECHNOLOGIES FACT SHEETS

Base on the criteria indicators, the following list of technologies are preselected due to the simplicity of the devices, easy to operate, low or non energy requirements and already tested locally.

(1) Pre-treatment devices could be very simple in terms of operation and maintenance works, can be operated without energy supply and cleaned manually (e.g. some screens, grease traps or grits traps). However, in some occasions to remove emulsified oil or fat droplets are required air blowers or de-emulsifying chemical agents that complicate the operation and increase the maintenance costs. In order to remove solids, fine screens have not being considered because the small light hole could be easily clogged. This complicates the O&M works in terms of cleaning and reparations. The screening systems that require energy to work as rotary screen or centrifugal are also rejected. Grinders are not considered because it is a mechanical device for removing coarse solids and can be substituted by a manual device like bar racks.

(2) Selection of primary treatment devices. As far as agriculture concern, during coagulation/flocculation phase, some phosphates could be removed by precipitation during the addition of the coagulants. This phosphate removal is not that positive for a possible agricultural reuse.

(3) Selection of secondary treatment devices. Activated sludge is the most common biological process use worldwide (CENTA, 2007a). However a constant supply of energy is required for the use of blowers or diffusers to produce the oxygen that microorganisms need or pumps that transfer sludge back to the biological reactor. In order to reduce the energy requirements, other biological treatments, as lagooning or constructed wetlands are taken into consideration. The oxygen in that cases are is supply by plant roots. (4) Selection of tertiary treatment devices. Polishing processes produce very acceptable effluent characteristics that in case of reuse of effluent turn out decisive. Mechanical devices as UV lamps or chemical agents as ozone are not considered. Facultative or maturation lagooning and sand filters seem to be the most economically feasible process.

To summarize, the selection of the technologies was made upon the recommendations proposed by Sasse (1998) to define low maintenance wastewater treatment devices for developing countries. Therefore, despite the proven efficiency in other socio-economical context, all processes that depend on; chemical additions (coagulation), aeration (flocculation), recirculation (activated sludge processes), membrane (desalination) and therefore; skilled labour, constant energy and chemical supply and expensive materials were not included in the list. In the scenario, ward number 3, wastewater source is a sewage drain. Therefore, it is considered as a semi-centralized situation. For this case study, it would not be possible to use onsite sanitation systems as treatment option; like pit systems, or urine storage tank (for more information consult Tilley, 2008). However, due to the existence of septic tanks in the city (IITK, 2008), as part to the urban sewage facilities, they have been included in the technology selection. Besides that, all the technologies selected are known locally or have been already implemented in India.

The fact sheets attempt to synthesize and examine the information compiled from several authors. In the content there is a brief description of the device and working principle besides the outline of the characteristics, advantages and limitations.

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4.2.1 Coarse screens (Bar racks)

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): No retention time. The wastewater passes through the bars without stopping. Although the removal performance improves at low velocities, that also produce solid settlement. To avoid this problem the design of the system should allow a velocity through the bars < 0.3 m/s. Dimensions: Bar dimensions: width: 5 to 15mm. length: 25 to 37.5 mm. Bars clear opening is 15- 50mm. Construction. Bar tracks are installed in wastewater canal. Therefore, in order to drive the flow through the screen, a canal should be part of the system. Canal with rectangular profile shape is the most This device retains coarse materials of large size (6 to 150mm). It common. Materials: Steel, stainless steel consists of a series of parallel bars (straight or curved) that form a O & M REQUIREMENTS screen. They are placed vertical to the water flow at an angle of 25o o Operation. to 50 . In some cases is an essential device in order to protect Simple operation. Wastewater can flow by gravity in to the canal and throw the screen. pumps, valves and pipes in subsequent treatment stages. Maintenance. PRELIMINARY TREATMENT The maintenance consists of cleaning of the bars and also removal of sediments from the bottom Input Domestic wastewater/ Urban wastewater of the canal. This should be done periodically (even daily) and maximizing during rain periods. Household/Neighbourhood/City Mechanical cleaning devices are used for large systems however they require power supply and Effluent BOD reduction 0% periodical greasing. Spare parts (bars or screens) are easy to find at local markets. TSS reduction 0% CONSIDERATIONS Pathogen reduction 0% Advantages. TN reduction 0% Low capital cost investment. TP reduction 0% Good efficiency for coarse solids reduction. Limitations. (Source. CENTA, 2007b;www.aboutcivil.org) It is a preliminary unit that does not reduce pollutants and pathogens loads, only removes large particles. The cleaning task results unpleasant for the operators. A disposal for removed solids is required.

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4.2.2 Sand traps (grit chamber)

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): 45 to 90 seconds. Dimensions: Rectangular or square tank, with trapezoidal or parabolic profile. Wastewater flows horizontally throw the chamber at 0.3 m/s. Spillways are required to prevent problems of overloads. In small treatment plants sand is removed by hand, so the canal should have accumulation capacity of 4 -5 days. Construction. It is a very simple system to build and O&M, that allows solid removals with high rates of performance Materials. Simple tank construction of concrete, brick or plastic. Prefabricated tanks are available but might increase the cost. Although parabolic shape is most suitable, it is difficult The sand trap also called grit chamber consists of a static to build. Therefore trapezoidal section is the most used. sedimentation tank. This device aims to remove small particles O & M REQUIREMENTS bigger than 0.2mm, in order to protect pumps, canals or pipes Operation. Simple operation. Wastewater flows horizontally by gravity in to the tank and from deposit of sediments and erosion. Sand, gravel, mineral not extra energy supply is required. particles, and organic materials not easy broke down (seeds, Maintenance. The maintenance is easy and does not need qualified personal. Consist of eggs, bones, grains) are removed. In many occasions grease and cleaning by removal of sediments from the bottom of the tank. There is no need of spare sand traps are combined at the same device (see figure of grease trap). In some cases is an essential device to avoid parts and other equipment replacements. problems of clogging in the subsequent treatment stages. CONSIDERATIONS PRELIMINARY TREATMENT Advantages. Input Domestic wastewater/ Urban wastewater Low capital cost investment. Household/Neighbourhood/City Good efficiency for solids reduction. Effluent BOD reduction COD≤20% Remove eggs Practically the total of the large inorganic particles are removed. Prevent TSS reduction ≤20% blockages and erosion of irrigation systems. Pathogen reduction 0% Limitations. TN reduction ≤10% Effluent properties do not change from the input. It is a preliminary unit that does not TP reduction ≤10% reduce pollutants and pathogens loads, only removes large particles.

(Source. CENTA, 2007b, Morel et al, 2006)

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4.2.3 Grease traps

TECHNICAL DESIGN Design criteria. The design should follow two criteria: - Proper HRT. Wastewater has to stay in the tank enough time to cool down. Thus, in cooler wastewater fat droplets emulsify easier. - Minimum turbulence: This is necessary in order to avoid the flush of grease and grits in to the next device. Hydraulic retention time (HRT): Minimum 15 to 30 min. Dimensions. Enough depth is required to difference the two layers of substances. I.e. for individual households the common dimensions are: length 1.3 – width 2.0, minimum The grease trap consists of a static sedimentation tank. The volume 200-300l. device aims to remove floating fat droplets. Once wastewater Construction. Materials. Simple tank construction of concrete, brick or plastic. enters into the tank, substances with lower density than water remain floating at the surface. The rest of the fluid flows away by Prefabricated tanks are available but might increase the cost. the bottom of the device. The tank could be also used to remove O & M REQUIREMENTS grits by sedimentation. In some cases is a basic or essential device Operation. in order to avoid problems in further treatment stages. Manual device. The management is easy and does not need qualified personal. PRELIMINARY TREATMENT Wastewater can flow by gravity in to the tank and not extra energy supply is required. Input Domestic wastewater/ Urban wastewater Maintenance. Household/Neighbourhood/City Manual cleaning. The oil and the scum should be removed periodically. The fat is scooped Effluent BOD reduction COD≤20%? by hand. Minimum a monthly revision is required. No need of spare parts and other TSS reduction ≤20% equipment replacements. Pathogen reduction 0% CONSIDERATIONS Advantages. The oil and grease removal could reach 70%. TN reduction ≤10% Limitations. Requires frequent maintenance. TP reduction ≤10% Not covered (sealed) tanks could produce odours.

(Source. CENTA, 2007b; Morel et al, 2006) The cleaning task results unpleasant for the operators

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4.2.4 Septic tanks

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): The size should let hydraulic load retention of at least one day. There is a potential risk of dangerous gases release; therefore tanks should be designed with vent holes. Dimensions: The dimension design of the tank depend on many factors like temperature, wastewater quantity, wastewater quality and frequency of desludging. Considering these entire factor, the volume of the tank will be calculate for the maximum sludge storage capacity and scum accumulation. The first chamber use to be bigger than the second, 50 to 65%. Tank height around 2.5 m and length should be twice width. I.e. Normal size of septic tank is calculated for around 250 – 300 l /inhab. Construction. The construction is not simple and requires experience labour. Materials: The tank could be made of different materials, concrete, plastic, PVC or fibreglass. There are buried systems therefore the construction requires excavations. These earthworks could raise the costs. The construction could be on site, but there are also prefabricate It is a sedimentation tank use for primary treatment. It is an underground systems that are transport to the specific location. Spare parts are required but there are easy to find in local market. system that received the WW by gravity. It is used to remove TSS by O & M REQUIREMENTS sedimentation. The solids sink and accumulate at the bottom of the tank Operation. Manual device. The management is easy and does not need qualified personal. Wastewater can flow by mineralizing by anaerobic reactions. The tank is divided in to row chambers gravity in to the tank and not extra energy supply is required. No electrical consumption. The system has to be desluged (usually 2-3). At the first chamber, the particles of highest density settle out at periodically. This requires a truck with a pumping device. the bottom forming the sludge. The less dense particles (oil and fat) remain Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the tank is working correctly. floating at the surface forming a scum layer. Clarified water pass to the other The system has to be clean and desluged regularly. The floating solids, oil and the scum should be removed periodically. chamber by a hole located under the water level. The same process occurs at In case of WW contains non biodegradable items (napkins, tampons) cleaning operations are more often required. the second chamber. The reason behind this is processed in at least 2 chambers, Desludging requires a truck with a pumping device. A manual desludging is not recommended because the hazardous is because bubbles produced by anaerobic digestion disturb the sedimentation pathogen content of the sludge. Sludge formed in the chambers suffers anaerobic decay process, mineralizing and of small particles. The second chamber contains less sludge, fewer burbles are reducing it volume. Sludge accumulation rate is 70 to 100 litres per year. Due to this, tanks can keep the sludge for long produced and it allows sedimentation of lighter particles. term. Desludge frequency varies from 2 to 5 years. Overloading of tanks is the most common result of mismanagement. PRIMARY TREATMENT CONSIDERATIONS Input Domestic wastewater Advantages. Small size. Compact systems and underground, small land areas are required. Household The removal of SS is variable with a max of 60%, let good performance of agricultural devices. Effluent BOD reduction COD 30%-50% The effluent contains high amount of nitrogen therefore it is completely available for the crops. TSS reduction 40-60% No flies or odorous problems if the tank is well sealed and maintenance. Pathogen reduction 0% Long term device services than with well maintenance could last many decades. TN reduction Low Limitations The infrastructure for transport the effluent is required as well as enough space to vacuum truck operation. TP reduction 20-30% (sedimentation) Regarding to the health aspects, pathogens contents of the effluent is very high. Source. Tilley, et al, 2008;CENTA 2007b, Morel, et al. 2006) In colder climate the treatment efficiency is reduced. The sludge generated is odorous. Risk of ground water pollution by percolation if not constructed properly. Not suitable if phreatic surface is shallow (<4m) or in areas with flood tendency. Low robustness. No adaptation to load fluctuations. The system is designed for certain volume of WW. If there is a sudden change of this volume (from rainfall or increase of WW) the device will overload and the process fails. Despite the good quality of sludge that can be used as fertilizer, it has high pathogens content therefore the sludge should be treated, appropriately disposed or managed. 4.2.5 Imhoff tank

38 Low-cost wastewater treatment technologies for agricultural use

TECHNICAL DESIGN Design criteria There is a potential risk of dangerous gases release, therefore tanks should be designed with vent holes. Hydraulic retention time (HRT): Sedimentation zone are sized for hydraulic loads of 1 to 4 hours. For digestion zone 0.3m3 / inhab., for 6 months of sludge retention. Dimensions: Although there are circular tanks, the most common shape is rectangular. Tank height use to be around 2.5 m and the length 3 to 5 time’s width. Construction. The construction is more complicated than a standard septic tank and requires experience labour. Materials: The tank could be made of different materials, concrete, plastic, PVC or fibreglass. There are buried systems therefore the construction requires excavations. The construction could be on site, but there are also prefabricate systems that are transport to the specific location. O & M REQUIREMENTS Operation. Manual device the management is easy and does not need qualified personal. Wastewater can flow by gravity in to the tank and not extra energy supply is required. No electrical consumption. The Imhoff tank is a variation of septic tank. The Imhoff tanks Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the tank is working consist on a unique deposit divided in two parts. Process correctly. The system has to be clean and desluged regularly. The floating solids, oil and the scum should be characteristics of this device are similar to septic tank. removed, or brake it to allow gas releases. Sometimes solids have to be pushed to the sludge accumulation area Sedimentation is developed at the upper part meanwhile through the slot. This could be done manually with a simple hand tools like a squeegee. Sludge settle at the bottom anaerobic digestion of sludge is produced at the bottom part. of the chambers suffers anaerobic decay process, mineralizing and reducing it volume. However, comparing to a Tank´s zones design aims burbles do not enter into septic tank, the desludging is easier and more accessible. Imhoff tanks have a pipe with a valve to drain the sludge. sedimentation area. Likewise the fluid part of the liquor, barely The removal is more frequently made. The normal sludge storage capacity is 3 to 12 month comparing to 2-5 years get in contact with the sludge. Generally these systems are in a normal septic tank. used to treat domestic wastewater; black and grey wastewater CONSIDERATIONS for small buildings or houses. Advantages. The specific baffle walls designed on this tank remains the effluent separated from the sludge. PRIMARY TREATMENT Therefore the outflow effluent is odourless and fresher than the one from a septic tank. Input Domestic wastewater Packed systems of small size and underground, do not large land required Household/Neighbourhood Applicable for decentralized systems. Effluent BOD reduction 15-35% Low cost, works by hydraulic gradient, no need of energy supply TSS reduction 40-65% Limitations. The cleaning task results unpleasant for the operators. Pathogen reduction 0% Risk of ground water pollution by percolation. TN reduction Low Low robustness. No adaptation to load fluctuations. The system is designed for certain volume of WW. If there is a sudden change of this volume (from rainfall or increase of WW) the device will overload and the process fails. TP reduction 20-30% (sedimentation) Despite the good quality of sludge that can be used as fertilizer, it has high pathogens content therefore the sludge (Source. CENTA, 2007b; Morel et al, 2006, Crock et al, WUTAP, 2007) should be treated, appropriately disposed or managed.

4.2.6 Baffled reactor (anaerobic baffled reactor, ABR)

39 Low-cost wastewater treatment technologies for agricultural use

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): Sedimentation zone are sized for hydraulic loads from few hours up to 48 to 72 hours. Dimensions: There are systems designed for capacities from 2 to 200 m3 / day wastewater inflow. There is a potential risk of dangerous gases release, therefore tanks should be designed with vent holes. Construction. The design and construction is not simple and requires experience labour. Materials: The tank could be made of different materials, concrete, plastic, PVC or fibreglass. There are buried systems therefore the construction requires excavations. The construction could be on site with available local materials. O & M REQUIREMENTS Operation. Manual device. The management is easy and does not need qualified personal. Wastewater can flow by gravity in to the system and not extra energy supply is required. No electrical consumption. Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the tank is working

Baffled reactor is an improved variation of septic tank. Instead of one correctly. The system has to be clean and desluged regularly. The floating solids, oil and the scum should be single chamber device it consists of a sequence of 2 or 3 chambers. removed periodically. In case of WW contains non biodegradable items (napkins, tampons) cleaning operations are Wastewater is force to pass by each baffled chamber up flowing, so more often required. Desludging requires a truck with a pumping device. A manual desludging is not recommended that wastewater keep contacting sludge layer every time it moves to because the hazardous pathogen content of the sludge. Sludge formed in the chambers suffers anaerobic decay the other chamber. This extra contact provides additional digestion process, mineralizing and reducing it volume. Desludge frequency varies every 2 to 3 years. Overloading of tanks is of organic matter. Generally these systems are used to treat the most common result of mismanagement. domestic wastewater; black and grey wastewater for small buildings CONSIDERATIONS or group of houses. WW should have controlled characteristics due Advantages Small size. They are really compact systems and underground, small land areas are required. to some chemicals like caustic soda, pesticides, paints, etc can No flies or odorous problems if the tank is well sealed and maintenance. damage the tank. Long term device service than with well maintenance could last many decades. PRIMARY TREATMENT Applicable for decentralized systems. Low cost, works by hydraulic gradient, no need of energy supply Input Domestic wastewater Limitations. The infrastructure for transport the effluent is required as well as enough space to vacuum truck Household/Neighbourhood operation. In colder climate the treatment efficiency is reduced. Effluent BOD reduction 80-90% Risk of ground water pollution by percolation. Not suitable if phreatic surface is shallow (<4m) or in areas with flood TSS reduction 50-90% tendency. Pathogen reduction 0% It requires a relatively constant flow of wastewater. TN reduction 0% Regarding to the health aspects, pathogens contents in effluent is very high. TP reduction 0% Low robustness for volume fluctuations. The system is designed for certain volume of WW. If there is a sudden change of (Source. Tilley et al, 2008; Morel et al, 2006) this volume (from rainfall or increase of WW) the device will overload and the process fails. Despite the good quality of sludge that can be used as fertilizer, it has high pathogens content therefore the sludge should be treated, appropriately disposed or managed.

40 Low-cost wastewater treatment technologies for agricultural use

4.2.7 Anaerobic Filter

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): retention times from 0.5 to 1.5 days. Dimensions: There is a potential risk of dangerous gases release therefore tanks should be designed with vent holes. Construction. The design and construction is not simple and requires experience labour. Materials: The biofilter can be made by gravel, rocks, cinder or plastic material, depending on the local availability. The size of the filter elements varies from 12 to 55mm diameter, and is disposed in different layers. The tank could be made of different materials, concrete, plastic, PVC or fibreglass. It is often a buried system (not always) therefore the construction requires excavations. The construction can be on site with available local materials. O & M REQUIREMENTS Operation. The operation is simple, not skilled labour is needed to operate the system. Wastewater can flow by gravity in to the pit and not extra energy supply is required. No electrical consumption Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the device is working correctly. When the layer of microorganisms becomes too thick the filter can clog, therefore, cleaning is needed. The cleaning consists of backwashing or removing biomass materials and refilling again. The floating solids, oil and the scum should be removed periodically. In case of WW contains non biodegradable items (napkins, tampons) cleaning operations are more often required. Desludging requires a truck with a pumping device. A manual desludging is not recommended because the Consist of one sedimentation chamber (similar to a septic tank) hazardous pathogen content of the sludge. Sludge formed in the chambers suffers anaerobic decay process, mineralizing and follow by several filtration chambers (normally from 1 to 3). The reducing it volume. Tanks can keep the sludge for long term. Desludge frequency varies from 2 to 5 years. Overloading of filter materials allow higher contact area for the bacteria with the tanks is the most common result of mismanagement. wastewater promoting physical, chemical and biological processes CONSIDERATIONS to break down the organic matter. Therefore the biofilter increase Advantages Small size. They are really compact systems and underground, small land areas are required. the surface area for biological processes comparing with a normal Adaptable to fluctuations of load. No flies or odorous problems if the tank is well sealed and maintenance. septic tank or baffled reactor. Around 90 to 300 m2 per 1m3 of Long term device service than with well maintenance could last many decades. reactor. In order to guarantee a correct performance, water level The effluent contains high amount of nitrogen therefore it is completely available for the crops. might cover the filter. Applicable for decentralized systems. Low cost, works by hydraulic gradient, no need of energy supply PRIMARY AND SECONDAY TREATMENT Limitations. The cleaning task results unpleasant for the operators. Input Domestic wastewater It requires a relatively constant flow of wastewater. Household/ Neighbourhood Requires inflows with low load of TSS. Not suitable for wastewater with high load of suspended solids. Effluent BOD reduction 50-90% Long start up period: from 6 to 9 months. TSS reduction 50-90% Risk of ground water pollution by percolation. Not suitable if phreatic surface is shallow (<4m) or in areas with flood tendency. Pathogen reduction Low Low robustness for volume fluctuations. The system is designed for certain volume of WW. If there is a sudden change of this volume (from rainfall or increase of WW) the device will overload and the process fails. TN reduction 15% Moderate robustness for organic load fluctuation. TP reduction Low In order to avoid problems of clogging in the filter, pre treatment processes might be done. (Source. Tilley et al, 2008; Morel et al, 2006) Despite the good quality of sludge that can be used as fertilizer, it has high pathogens content therefore the sludge should be treated, appropriately disposed or managed.

41 Low-cost wastewater treatment technologies for agricultural use

4.2.8 Green filters

TECHNICAL DESIGN Design criteria Hydraulic load depend on soil permeability and nitrogen concentration. Therefore infiltration capacity of the soil and the vegetal species will define the dimensions of the plantation. Dimensions: The quantity of wastewater to treat depends on the dimension of the plant. But these systems are design to treat the wastewater of small communities, with hydraulic loads ‹ 0.02-0.05m3/m2.d Construction. Vegetation. Species with; high capacity of nutrient and water absorption, low sensibility of wastewater micro compounds, minimum management requirements is used. I.e. grass (Lolium s.p.; Gram s.p) or forest trees (Populus sp., Eucaliphtus sp.) are commonly used. Mechanical devices. The wastewater is applied by gravity over the land Therefore no pumping system is required. The construction expenses as very low in terms of capital cost. Construction costs consist of Green filter is a land application or soil based system implementation of the plantation. where wastewater is applied superficially on the land. The O & M REQUIREMENTS media is formed by the ecosystem soil-plants-water. Operation The operation is simple, not skilled labour is needed to operate the plant. The operation might assure irrigation Wastewater irrigates the land that is cover with in turns in order to let the soil dry. Wastewater irrigate by gravity (furrow or flood) therefore not extra energy supply is vegetation. The irrigation technique is flood or furrow. required. Other irrigation techniques would require pumping and electrical consumption. Once wastewater is treated is not re usable, because the Maintenance. Maintenance costs are very low. Mechanical devices like valves and irrigation gates require grease. filtrated effluents end up in the ground water bodies. Tillage of land could be recommended to break the possible formed crust. Eventually biological state of trees should be Lysimeters are used to control effluent quality at different analysed in order to prevent pest and diseases. Non sludge removal is need. depths. Wastewater is treated preliminary to remove CONSIDERATIONS coarse solids Advantages. SECONDAY AND TERTIARY TREATMENT The operation in very simple reduced of the pre-treatment phase and the irrigation control scheme. Input Domestic wastewater/ Urban wastewater From the agricultural aspects, wastewater keeps all the properties. Phosphorus and Nitrogen is available. However, it also Household/Neighbourhood/City contains many other micro pollutants than could result toxic for the plants. Effluent BOD reduction high Limitations TSS reduction high Large land surfaces. Therefore, the main capital cost of the system is the cost of the land that in urban areas could be high. Appropriate soil permeability. Very permeate soil will percolate the wastewater releasing the effluent without enough Pathogen reduction 99% total coliform treatment. Non permeable soils will produce water collapse of the system. Possible problems of ground water pollution. TN reduction high Pre-treatment and primary stages do not achieve the minimum health protection requirements. Health aspects acceptance TP reduction high is not reached. (Source. Bustamante, 1990, Tilley, et al, 2008, Shankar, Not suitable for high rainfall areas because only low volumes of wastewater can be treated. unknown date, Crites, et al. 2000; CENTA, 2007b; CPCB, Aim for urban settlements of very small or very small volumes of wastewater size. 2008)

42 Low-cost wastewater treatment technologies for agricultural use

4.2.9 Soil biotechnology (SBT) or Constructed soil biofilter (CSB) or Constructed soil filter (CSF)

TECHNICAL DESIGN Design criteria Hydraulic retention time: 0.6 to 2 hours. Dimensions: The quantity of wastewater to treat depends on the dimension of the plant. But these systems are design to treat the wastewater of small communities with hydraulic loads ‹ 0.4- 0.6 m3/m2. Construction. Material soil and additives as a filter media, vegetation, 2 tanks. Mechanical devices. Pipes and pumps. The construction expenses might be high because it requires civil engineer construction of tanks, bioreactors and pump site. O & M REQUIREMENTS Soil biotechnology is a land application or soil based system Operation The operation is simple but some knowledge is needed to operate the plant. Training is required. The operation is where wastewater is applied superficially on the land to be related to the pumping equipment and vegetation control (pruning and maintaining). In some occasions, is needed a treated. The filter media is formed by the ecosystem soil- recirculation of the effluent to increase the retention time of the effluent. This operation requires the use of pumps. plants-water that includes soil macro and micro organisms, However no oxygen devices are required because the soil is the natural supplier for the system. Therefore, relatively low geophagus worms, soil minerals and plants as bioindicators. electrical consumption for wastewater comparing to conventional systems. Wastewater irrigates the land that is cover with vegetation. Maintenance. Maintenance costs are very low. Mechanical devices like valves and pumps require grease. The difference between other land application systems is Although non sludge removal is needed, a crust of solids is formed over the soil surface. This might be frequently manually that once wastewater is treated the effluent is collected in a scraped (daily or weekly). Periodical cleaning of tanks is also required. tank and effluent can be reused afterwards. The system is CONSIDERATIONS made up of 2tanks (raw and treated effluent), the bioreactor (soil media + plants) and the pumping system. Advantages. Systems with pleasant appearance that create nice landscape. No odour problems. SECONDAY AND TERTIARY TREATMENT No pre-treatment is required. Input Domestic wastewater/ Urban wastewater No mosquito reservoir. Household/Neighbourhood/City No sludge production. Effluent BOD reduction 85-90% High reduction of turbidity, <5NTU. TSS reduction 85-95%l Pathogen removal capacity increase with the time of operation, are maturing systems. Pathogen reduction 99% total coliforms Limitations. (<103 CFU/100 mL.) In colder climate the treatment efficiency is reduced, in that case a greenhouse is built over the system. TN reduction High Large land surfaces are required. TP reduction High Energy consumption, around 40 to 50 Kwh per 1000m3 treated. (Source. Bustamante, 1990; Tilley, et al, 2008, Shankar, High electrical conductivity produce a reduction of the performance of the system, maximum admissible salinity <2500 unknown date; Kadam, et al. 2008a; Kadam, et al. 2008b; mg/L. Crites, et al. 2000; CENTA, 2007b; CPCB, 2008)

43 Low-cost wastewater treatment technologies for agricultural use

4.2.10 Anaerobic Stabilization ponds

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): 1 to 7 days. Dimensions: 2-5m depth. In order reduce the oxygen exchange layer from the surface; the ponds are designed deeper than wider. Relation length - width: 2/1 or 4/1. Square shape is the most usual. Sloping banks (horizontal vertical) 2:1. Anaerobic pond is a lagooning system. In case it is part of a series of Construction The construction requires earthworks and ground compaction processes. Experience labour pond would be located at the beginning of the treatment chain. Aside during construction phase is required. Materials: Concrete (small) or earthen basin (large). In case of the shallow surface layer of water, anoxic conditions are in the rest of earthen basin, the terrain might be impermeable otherwise compacted clay layer or plastic sheet the pond. The reason behind this is that they receive high O.M loads (geotextile) are required. Specifications Flow meter is required to control the inflow, and also an outlet (›100gBOD/m3·d), so the dissolved oxygen that supplies wastewater is control for outflow regulation. To prevent scum coveys to the subsequence process and outflow baffle fast consumed. Sulphates are reduced to sulphur compounds that are might be designed. For large ponds several inlets and outlets will be available. dark (not suitable for photosynthesis) and toxic to micro algae. O & M REQUIREMENTS Sedimentation is done at the bottom of the pond. Biogas is produced Operation The operation is simple but some knowledge is needed to operate the plant. Two different and methane and carbon dioxide burbles are release. Sedimentation of phases, acidogenesis and methanogenesis, should be done in a balance way to avoid problems of surface the solids and stabilization of sludge is the aim of this performance. microalgae growing. Wastewater can flow by gravity in to the basin and not extra energy supply is PRIMARY TREATMENT required. No electrical consumption. Input Urban wastewater Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the pond is Neighbourhood/City working correctly. The system has to be clean and desluged regularly. The floating solids, oil and the scum should be removed periodically. This could be scooped by hand. The sludge that is accumulated at the Effluent BOD reduction 50-80% bottom at the same time is broken down and mineralized reducing the volume. Therefore desludge is TSS reduction 60-80%% required every 5-10 years. The correct isolation of the impermeable layer should be regularly checked to Pathogen reduction 100 % total coliform (Tc ≤2- 3 log.) avoid leakages. The removal of the growing vegetation on the pond banks might be done periodically to 80-100% Helminths eggs prevent mosquito reservoirs. TN reduction 5-10 %( N is break down in to Ammonium CONSIDERATIONS Compounds) Advantages Low capital cost in construction and O&M. TP reduction 0-5 % Easy sludge management. Sludge does not need any treatment before disposal. (Source. Tilley, et al, 2008; Shilton, 2005 , WUTAP, 2007; CPCB, 2008) Beside lagooning, anaerobic ponds can be used as a primary treatment for other treatment technologies to facilitate and simplify sludge management. Limitations Odour problems (biogas realising) In colder climate the treatment efficiency is reduced. Large land surfaces requirement. Risk of ground water pollution by percolation. Possible mosquito (vector disease) reservoir. Proper maintenance works minimizes the risk.

44 Low-cost wastewater treatment technologies for agricultural use

4.2.11 Facultative ponds

TECHNICAL DESIGN Design criteria Hydraulic retention time (HRT): Between 5 to 120 days (30 days required for pathogen removal).Dimensions: 1-2 m depth. Relation length - width: 2/1 or 4/1. Rectangular, curve or kidney shape. Sloping banks (horizontal vertical) 3:1. Construction The construction requires earthworks and ground compaction processes. Experience Facultative pond is a lagooning system. In case it is part of a series of pond, labour during construction phase is required. Materials: Earthen basin. The terrain might be would be located after the anaerobic ponds as a second stage of the treatment impermeable otherwise compacted clay layer or plastic sheet (geotextile) is required. Specifications: chain. They combine aerobic conditions (at the surface) and anaerobic Flow meter is required to control the inflow, and also an outlet control for outflow regulation. To condition (at the bottom). Three different layers are formed in theses ponds. prevent scum coveys to the subsequence process and outflow baffle might be designed. For large (1) At the surface, they develop aerobic conditions by the oxygen produce by ponds several inlets and outlets will be available. microalgae and air movement. During the night, photosynthesis activity O & M REQUIREMENTS decrease therefore the thickness of this layer is reduced. During spring and Operation The operation is simple but some knowledge is needed to operate the plant. High rate of summer season these layers increase. (2) At the bottom they have anaerobic suspended solids could be an operation problem due to the high microalgae growing. Wastewater can condition due to the mineralization of the sediment. If the pond received and flow by gravity in to the basin and not extra energy supply is required. No electrical consumption. overload of organic matter, this layer could extend over all pond volume. Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the pond is (3)An intermediate zone is formed with variable conditions and facultative working correctly. The system has to be clean and desluged regularly. The floating solids, oil and the bacteria. Aerobic, anaerobic and facultative microorganisms are found in these scum should be removed periodically. This could be scooped by hand. The sludge that is accumulated ponds. Protozoa, purple sulphur bacteria and microalgae develop at the bottom at the same time is broken down and mineralized reducing the volume. Therefore photosynthetic processes. desludge is required every 12-24 years. The correct isolation of the impermeable layer should be

regularly checked to avoid leakages. The removal of the growing vegetation on the pond banks might SECONDAY TREATMENT be done periodically to prevent mosquito reservoirs. Input Urban wastewater CONSIDERATIONS Neighbourhood/City Advantages Effluent BOD reduction 60-90% Low capital cost in construction and O&M. TSS reduction 0-70% High microalgae concentration that is a value input for agriculture.(as fertilizers, humus soil and Pathogen reduction 100 % total coliform (Tc ≤2- 3 log.) increasing soil hydraulic retention) 100% Helminths eggs Limitations TN reduction 30-60 Odour problems. TP reduction 0-30% Large land surfaces requirement.

(Source. Tilley, et al, 2008; Shilton, 2005; CPCB, 2008) In colder climate the treatment efficiency is reduced. Risk of ground water pollution by percolation. High microalgae concentration is a risk of clogging for drip and sprinkler irrigation. Possible mosquito (vector disease) reservoir. Proper maintenance works minimizes the risk.

45 Low-cost wastewater treatment technologies for agricultural use

4.2.12 Aerobic stabilization ponds (Maturation ponds/Oxidation pond)

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): 21 to 30 days. Dimensions: 1-2 m depth. Relation length - width: 2/1 or 4/1. Rectangular, curve or kidney shape. Sloping banks (horizontal vertical) 3:1. Maturation pond is a lagooning system. In case it is part of Construction. The construction requires earthworks and ground compaction processes. Experience labour a series of ponds would be located at the end of the during construction phase is required. Materials: Earthen basin. The terrain might be impermeable treatment chain. The maturation pond is shallow to allow otherwise compacted clay layer or plastic sheet (geotextile) is required. light entry and ensure photosynthesis reactions. Aerobic Specifications: Flow meter is required to control the inflow, and also an outlet control for outflow microorganisms are found in these ponds. Therefore it regulation. To prevent scum coveys to the subsequence process and outflow baffle might be designed. For keeps aerobic conditions The inflow is a low organic load large ponds several inlets and outlets will be available. influent. And the treatment removes suspended solids, O & M REQUIREMENTS organic matter, nutrients and pathogens. It is a final Operation. The operation is simple but some knowledge is needed to operate the plant. Wastewater can polishing treatment. flow by gravity in to the tank and not extra energy supply is required. No electrical consumption. TERCIARY TREATMENT Maintenance. Maintenance costs are very low. Periodic monitoring is needed to check if the pond is Input Urban wastewater working correctly. The system has to be clean and desluged regularly. The floating solids, oil and the scum Neighbourhood/City should be removed periodically. This could be scooped by hand. The sludge that is accumulated at the Effluent BOD reduction 75-85% bottom at the same time is broken down and mineralized reducing the volume. Therefore desludge is TSS reduction 40-80% required every 10-20 years. The correct isolation of the impermeable layer should be regularly checked to Pathogen 100 % total coliform (Tc ≤2- 3 log.) avoid leakages. The removal of the growing vegetation on the pond banks might be done periodically to reduction 100% helminths eggs. prevent mosquito reservoirs. TN reduction 35-80% CONSIDERATIONS TP reduction 1-60% Advantages. (Source. Tilley, et al, 2008; Shilton, 2005, Card, 2005; CPCB, 2008, Low odour problems. Von Sperling et al 2005) Low capital cost in construction and O&M. Total pathogen removal. Disinfection system due to the long retention times. Limitations. In colder climate the treatment efficiency is reduced. Large land surfaces requirement. Risk of ground water pollution by percolation. Possible mosquito (vector disease) reservoir. Proper maintenance works minimizes the risk.

46 Low-cost wastewater treatment technologies for agricultural use

4.2.13 Constructed wetlands. Free flow(surface)

TECHNICAL DESIGN Design criteria. An important design part is the wastewater inlet because a correct distribution of the wastewater will assure the performance of the system. Construction: The construction is complicated and might be expensive depending of the materials availability and the size. Experience labour during construction phase is required. Materials: Local materials. Earthen basin. The basin is compound of several layers with different material’s permeability like rocks, gravel and clay. Vegetation. Native plants species are required (reeds, rushes…). Specifications: Flow meter is required to control the inflow, water level and also an outlet control for outflow regulation. O & M REQUIREMENTS The free flow constructed wetland is the wetland treatment system most Operation. The operation is simple, not skilled labour is needed to operate the plant. similar to the processes that occur in a natural water body. The bottom of the Wastewater can flow by gravity in to the basin and not extra energy supply is required. No basin is cover with gravel, rocks and the roots of plants forming the ground of electrical consumption. Vegetation might be prune and cut regularly. the wetland. The ground has mainly anaerobic conditions although some Maintenance: Maintenance costs are very low. Periodic technical monitoring is needed to check oxygen is realised from the roots of the plants. A shallow (10-50cm) layer of if the wetland is working correctly and prevent blockages or short-circuits. In case of clogging, wastewater flow free over the ground. The slowly flow of wastewater throw the basin allow efficient treatment of the inflow, with physical, chemical and the wetland might be drained out. biological processes (filtration, precipitation, nitrification, predation, etc.). CONSIDERATIONS Therefore toxic compounds, suspended solids, nutrients, organic load and Advantages. Low capital cost in construction and O&M. pathogens are reduced by process of decantation and by the action of Adaptable technology for flow fluctuations. microorganisms and plants. Sub products: grown vegetation could be reuse as biomass of for feeding animals. Systems with pleasant appearance that create nice landscape. PRIMARY & SECONDAY TREATMENT & TERCIARY No odour problems with proper maintenance works Input Domestic wastewater/ Urban wastewater No energy consumption. Household/Neighbourhood/District Easier to operate than subsurface systems. Effluent BOD reduction 80%-90% Limitations. TSS reduction 30-45% Large land surfaces requirement. Pathogen reduction 100 % total coliform Possible mosquito (vector disease) reservoir. (Tc ≤2- 3 log.) Limited to low polluted wastewater. TN reduction 15-40% In colder climate the treatment efficiency is reduced (low biological activity). TP reduction 30-45% In order to avoid problems of clogging in the filter, pre treatment processes might be done.

(Source. Tilley, et al, 2008; Tanaka, et al. 2011, WUTAP, 2007; CPCB, 2008; Palm2010 EPA 2004)

47 Low-cost wastewater treatment technologies for agricultural use

4.2.14 Horizontal subsurface flow constructed wetlands (HSF)

TECHNICAL DESIGN Design criteria. Hydraulic retention time (HRT): from 3 to 7 days. Dimensions: Porous media depth around 70cm. The reason behind this is to avoid anoxic conditions, assuring a water level of 60 cm and maintaining a top layer of 5 to 15 cm of media without water. However, to assure the oxygen transfer wastewater inflow might be small and the wetland surface large. Construction. The construction is complicated and might be expensive depending of the materials availability and the size. The basin is compound of several layers with different permeability. Experience labour during construction phase is required. Materials: Earthen basin, gravel, clay. Pipes. Plants (reed bed like Phragmites sp.). Specifications: Flow meter is required to control the inflow, water level and also an outlet control for outflow regulation. O & M REQUIREMENTS The constructed wetland with horizontal subsurface flow (HSF) is a Operation. The operation is simple, not skilled labour is needed to operate the plant. Anaerobic conditions wetland system where wastewater flow horizontally throw a porous should be avoided by reducing load or resting the system. Aerobic conditions are easy to detect by odour. If media. The basin is filled up with the porous material, gravel or sand (3 the slope of the basin is correctly design (and possible by topography conditions), wastewater can flow by to 30 mm diameter). These materials allow higher contact area with the gravity in to the basin and not extra energy supply is required. No electrical consumption. Vegetation might wastewater flow, therefore an efficient treatment with physical, be pruned and cut regularly. chemical and biological processes (filtration, precipitation, nitrification, Maintenance: Maintenance costs are very low. Periodic technical monitoring is needed to check if the predation, etc.) is done. In order to guarantee the horizontal subsurface wetland is working correctly and prevent blockages or short-circuits. In case of clogging, the wetland might flow, water level might be kept around 5 to 15cm below the surface of be drained out. the porous media. The effluent treated is drained to an outlet pie CONSIDERATIONS located at the bottom of the basin. Advantages. PRIMARY & SECONDAY TREATMENT & TERCIARY Systems with pleasant appearance that create nice landscape. Input Domestic wastewater/ Urban wastewater No odour problem (subsurface system). Household/Neighbourhood/District No health risk because of mosquito reservoir if the maintenance is correct. Effluent BOD reduction 80-90% Land requirements are lower than for free surface wetlands (for the same wastewater volumes). TSS reduction 80-95% No sludge production. Pathogen reduction 100 % total coliform Limitations. (Tc ≤2- 3 log.) More complicate to operate than a free flow wetland system. TN reduction 15-40% Large land surfaces requirement. TP reduction 30-45% Grease clogging could be a problem. In order to avoid problems of clogging, pre treatment processes is required. (Source. Tilley, et al, 2008; Tanaka, et al. 2011; CPCB, 2008, Hoffmann, 2011)

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4.2.15 Vertical flow constructed wetlands (VF)

TECHNICAL DESIGN Design criteria Hydraulic retention time (HRT): The applications are made intermittently from 4 to 12 times per day. Dimensions: 1 to 4m2 per population equivalent. Construction: The construction is complicated and might be expensive depending of the materials availability and the size. Experience labour during construction phase is required. The basin is compound of several layers with different permeability. The wastewater distribution system should be designed. Materials: Earthen basin, gravel, clay. Pipes. Plants (reed bed like Phragmites sp.). Specifications: Flow meter is required to control the inflow, water level and also an outlet control for outflow regulation. O & M REQUIREMENTS The constructed wetland with vertical flow (VF) it is a wetland system Operation. The operation is simple, not skilled labour is needed to operate the plant. In order to where wastewater flow vertically throw a porous media. The basin is apply the inflow vertically, a pump or siphon is required. The application is intermittent to assure filled up with the porous material, gravel or sand. These materials oxygen transfer. Wastewater can flow by gravity in to the basin and not extra energy supply is allow higher contact area with the wastewater flow, therefore an required. No electrical consumption. Vegetation might be pruned and cut regularly. efficient treatment with physical, chemical and biological processes (filtration, precipitation, nitrification, predation, etc.) is done. The Maintenance: Maintenance costs are very low. Periodic technical monitoring is needed to check if pre-treated wastewater is spread over the filter media flowing the wetland is working correctly and prevent blockages or short-circuits. In case of clogging, the vertically through it. The effluent treated is drained to an outlet pie wetland might be drained out. The emptying process might be done with proper health risks located at the bottom of the basin. prevention measures. PRIMARY & SECONDAY TREATMENT & TERCIARY CONSIDERATIONS Input Domestic wastewater Advantages. Systems with pleasant appearance that create nice landscape. Household/Neighbourhood No odour problem (subsurface system). Effluent BOD reduction 75-90% No health risk because of mosquito reservoir. TSS reduction 65-85% Land requirements are lower than for free surface wetlands (for the same wastewater volumes). Pathogen reduction 100 % total coliform No sludge production. (Tc ≤2- 3 log.) Limitations. Energy is required to pump the inflow. TN reduction <60% More complicate to operate than a free flow wetland system. TP reduction <35% Large land surfaces requirement. (Source. Tilley, et al, 2008; Tanaka, et al. 20;,CPCB,2008, Grease clogging could be a problem. Hoffmann, 2011) In order to avoid problems of clogging, pre treatment processes might be done.

49 Low-cost wastewater treatment technologies for agricultural use

4.2.16 Slow Sand Filter (SSF)

TECHNICAL DESIGN Design criteria Hydraulic retention time (HRT): Hydraulic loads ≤ 0.1-0.05m3/h.m2. Dimensions: no specific dimensions. For gravity filters, certain high is required. Construction: The construction is very simple. Not experience labour during construction phase is required. Materials: Simple tank construction of concrete, brick or plastic. Sand filter is made by sand of different size and gravel, locating the coarses at the bottom and the finest sand at the upper layers. Gravity provides enough pressure to make water cross the filter (Pumps can also be used). O & M REQUIREMENTS Operation. The operation is simple, not skilled labour is needed to operate the device. Wastewater flow by gravity through the tank and not extra energy supply is required. No electrical consumption. Maintenance: Maintenance costs are very low during all working life of the device. When the layer of microorganisms becomes too thick the filter can clog, therefore, periodic cleaning is needed every few week or months. The cleaning consists of draining the tank and scrapping the surface layer of

Slow sand filtration is a typical wastewater purification system use for sand. Backwashing is also possible but requires energy supply. drinking water purposes. Consist of a vessel, chamber, tank or reservoir CONSIDERATIONS filled up with sand. Therefore the system is based on using the sand as Advantages a filter. The sand increase the contact surface with the effluent, Aim for medium size settlements or district level. promoting physical and chemical processes, moreover the biological Low capital cost in construction and O&M. process is done by the microbiota settle on the upper layers of the Robust system relatively adaptable to effluent fluctuations. sand. . It is quiet effective to reduce turbidity and pathogenic Limitations compounds. No odour removal. TERTIARY. High turbidity of inflow effluent (>30NTU) limits the use because the high risk of clogging. Input Treated effluent. Neighbourhood/Settlements/District Hence, it is a system use for the treat of fresh water, the use for wastewater as a polishing Effluent BOD reduction Low treatment, requires a relatively good quality of effluent. In order to avoid problems of clogging, pre TSS reduction 80% treatment processes might be done. Pathogen reduction 90-99% pathogens and heavy metals Slow filter, water moves 100 to 300 litres per hour. TN reduction Low In colder climate the treatment efficiency is reduced. Large land surfaces requirement. TP reduction Low

(Source: Tilley, et al, 2008 LDWQ, 2013; Brikke et al, 2003, EWB, 2010;Huisman et al,1974)

50 Low-cost wastewater treatment technologies for agricultural use

5. ANALYSIS OF THE RESULTS

5.1 SELECTION OF PRINCIPLES, CRITERIA AND INDICATORS

5.1.1 Principles

In the previous chapter a general review of wastewater treatment processes has been done. But not all the described processes are suitable to be used by local farmers, assuring health protection and crop production with minimum cost. The concept and the scope of the selection might cover technical, socioeconomically, agricultural and health aspects. Therefore are defined the following principles. Principle 1. Compliance with crop production. The treated effluent might represent an input to enhance agricultural productivity without threaten the future production or damaging soil conditions. Principle 2. Compliance with health protection. Ensure the achievement and maintenance of a minimum level of health protection for farmers and for consumers. Depending on the type of crop, the irrigation techniques, the consumption of the crop (raw or cooked), the effluent quality requirements for the farmers are different. Hence treatment technology has to achieve certain effluent qualities (previously mentioned, see Table 5). Principle 3. Integration of the technology in the local context. The technology has to be adapted to the socio economical context. There are some parameters of local conditions or availability of resources that assure the sustainability of the technique in terms of robustness, energy dependency, operation and maintenance requirements.

5.1.2 Criteria

The criteria outline the overarching aim of each principle, driving the attention to the local characteristics of the scenario. Therefore the technological criteria are the following:

Crop production efficiency: The first criterion is related the effluent quality. Water is an input for agricultural production. Wastewater has compounds that can whether enhance or harm the crop production. The different wastewater components and their properties could influence in the performance of the yield. Therefore the parameters commonly analysed to check the performance of the wastewater technologies will be use as indicators for crop production.

Health protection efficiency: The second criterion is not only related to the effluent quality but also with the irrigation techniques, product management and local climate conditions. In compliance with health protection principle, the efficiency of the technology in terms of effluent quality is pointed out (see Table 20, Annex2). The reduction of pathogens is usually achieved by the wastewater treatment to some extent. The less pathogen the less risk for farmers and consumers. Moreover, there is a risk of creation a reservoir for vectors of waterborne disease; this is related to the geographical location. It will be also assessed the irrigation technique. For instance, drip irrigation might reduce drastically the water contact with the product and farmers however it will required higher effluent quality in order to avoid clog up the drips.

51 Low-cost wastewater treatment technologies for agricultural use

The third principle involves many different aspects. Aside technological characteristics for agricultural or health compliance there are some other socio-economic, political, environmental and institutional factors necessary to analyse. They could represent key issues for success of the implementation of certain technologies. Some features make the technology easy to integrate in the local practices. Therefore, regarding to the integration capacity of the technology to the local context, the affordability, and sustainability and environmentally friendly characteristics will be considered.

5.1.3 Indicators

To assess the criteria are defined the indicators. The indicators are characteristic of the technology. In the Figure 12 are represented the technology criteria. The indicators are characteristics of the technology that will be used to assess its adequacy. They were deduced driving the attention to the local context (See Figure13).

Nutrient (N, P) content

Nitrogen in wastewater is found in organic (mainly proteins) and inorganic compounds (Ammonium Ion) dissolved or forming solid particles. In anaerobic treatment processes organic nitrogen is transformed into inorganic compound by the action of bacteria and proteolytic microorganisms. Therefore sometimes after the treatment the effluent has higher concentration of Ammonium compounds. During the aerobic process ammonium compounds are transformed in nitrate by microorganism. Both nitrates and ammonium ions are compounds easy to assimilate by plants. Phosphates are either found dissolved in wastewater or forming solid particles. Solid phosphates use to settle in the sediments and be reduced by microorganisms to orthophosphates forms that are easy to decay. Therefore, orthophosphates remain in the sludge giving to this product an added value for agricultural input (CENTA, 2007b). Irrigation with untreated wastewater will produce a long term increase of the amount of carbon and macronutrients in the soil (Yadav, et al 2002). Nutrients (N and P) are required by the crops therefore a high nutrient content of effluent is a quality objective. They are normally removed from the bulk, but in that case the water would loss the added value for the crops. However, certain limits have to be considered, because too high concentration of Nutrients might cause negative effects on the crops, such as delaying fruit formation in fruit trees or developing weak stems in grain crops. The tolerance rate is up to the sensibility of the crop, for example, high sensible with 5 mg N/l, to high tolerant 30mgN/l. Furthermore, might also cause illness to animals that feed with excess N fodder (Palm, 2010).

Salinity reduction

Not all the crops are tolerant to high load of salinity (see Table 13, Annex 2). Furthermore, high salinity in the irrigation water will produce long term effects on soil hydraulic conductivity and reduce the C available for the plants (Setiaa, et al 2013). It could become a great hazard for the future of the land regarding to the soil properties deterioration. However, as was argued by Patterson (2000), aside industrial pollution, domestic wastewater is the most common origin of chemical compounds in the sewage. Inorganic salts are added to the wastewater by the use of soaps, detergents, rests of food, paper and feces. Patterson (2000) valued as an average of 63m/L (equivalent of 158kg/ML of sodium chlorine) the increase of sodium compounds in

52 Low-cost wastewater treatment technologies for agricultural use

wastewater due to domestic contamination. Sodium salts are very soluble and the conventional wastewater treatment plants are not able to remove them (Harussia, et al 2001). The only way to remove them is with a desalination process for instance by reverse osmosis process (Patterson, 2000). Therefore, soil salinity is a big hazard of reclaimed water use. Unfortunately, the high energy and equipment cost of these treatments will leave this problem uncover with the proposed techniques (no economical feasibility). Therefore as far as salinity reduction concerns, the irrigation management is crucial. Martinez (1999) proposed a guideline to manage saline water in a sustainable way for the agriculture. Good agricultural practices and measures like leaching would reduce the harm effects of high salinity irrigation water (WHO, 2006a).

Total Suspended Solids (TSS) reduction

Wastewater only contains 0.07 % of solids. They are dissolved or suspended in the water bulk that forms the 99.93% rest. The solids are organic and inorganic particles (in half to half proportions). The importance of removing them is because many pollutants are in solid state, as for example nutrients or heavy metals. Treatment technologies aim to make solids settle and remove them by the sludge (Ellis, 2005). TSS is a normal parameter use to assess the efficiency of the treatment therefore it is easy to measure. Furthermore, total suspended solids may cause clogs in irrigation facilities, overall for drip and sprinkler irrigation. For instance, according to Capra (2007) for drippers is not possible to use wastewater with TSS >50mg/l without compromising the performance of the system. With surface irrigation techniques (furrow or flood) the high TSS will affect to the soil saturated hydraulic conductivity. This was checked out by a lab experiment carried by Viavini (2004), where the infiltration capacity was reduced and the formation of a scaled layer over the surface. This effect was increased noticeable in clay type soils.

Biochemical Oxygen Demand (BOD)

Biochemical oxygen demand (BOD) is a normal parameter use to assess the efficiency of the treatment therefore it is easy to measure. BOD represents the oxygen need by bacteria to break down the organic compounds of the water. Around 10% of the organic compounds are toxic pollutants like pesticides, phenols, phthalates, polynuclear aromatic hydrocarbons (PAHs). They can be removed by secondary treatment technologies (Petrasek, et al 1983). However, irrigation with high oxygen demand water (high load of organic compounds) could affect soil properties, causing problems of soil tilth and decreasing infiltration capacity (Oster, 1994). Furthermore, if waters with high oxygen demand are used for irrigation, they will cause changes in soil pH, EC, NO3 and NH4, modifying the nitrification and other aerobic process that normally take place in the soil (Nashikkar , 1993).

Heavy metals

If toxic compounds like heavy metals (Ni, Mn, Cu, Pb, Zn, Fe or Cd,) are present in the irrigation effluent in high loads might be absorbed by the crops and become a hazard to consumer’s health (see Table 16, Annex 2). The accumulation of heavy metals differs between crops. For instance, in a research developed by Singh (2010), in crops irrigated with reclaimed water, the higher levels of heavy metals were found in vegetables, since cereals and milk had less

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concentration. However the potential risk is higher with dietary food like rice because of the higher consumption. On the other hand, heavy metals could have phytotoxicity effects on the crops (Fuentes, 2004; Ernst, 1996). Depending on crop sensibility, certain concentrations could produce crop reductions. The level of crop damage is closely related to uptake availability (FAO, 1985). Therefore heavy metals might represent also a hazard for the agricultural land because of their long term accumulation (ICON, 2001). It is worthy to mention that, heavy metals are, at certain concentration, also toxic for microorganisms in charge of biological treatment. Domestic wastewater usually has low loads of heavy metals (Omu, 2009; ICON, 2001). Heavy metals usually end up in sewage streams as a consequence of industrial wastewater discharges or because of the runoff from oils road´s pollutants. Depending on the precipitation rate, heavy metals are partly accumulated in the sediments (majority) and partly remain in the liquid phase of the effluent (around 20%) (ICON, 2001). Wastewater treatment technologies aim to remove heavy metals by sedimentation and filtration. The settlement is triggered with chemical and physical processes and with microbiological process (Kulbat, 2003).The variation of pH is a factor that influence in the precipitation of the sediments. Anaerobic processes have high heavy metals removals rates due to reactions produce by hydrogen sulphide compounds that makes them precipitate and settle (CENTA, 2007b). In order to know the removal efficiency of heavy metals the sludge load is normally analysed. However, in the absence of this data, as the polluting load is transferred by sedimentation, the efficiency of suspended solids removal could be used to measure it (ICON, 2001).

Pathogen removal

Pathogens microorganisms are regularly found in urban wastewater. Water quality has to ensure health protection for consumers and workers. Therefore, it will differ from the farmer (as hookworm, ascaris, Diarrhoeal disease, giarda intestinalis infection) and for the consumers of the products (e.g. cholera, typhoid ascaris infection) (Carr et al, 2004). In case of helminths eggs or protozoa cysts, they stay latent and they can survive for a long period outside the host. They become a high risk for consumers and farmers (World Bank, 2010, pg 33). However, they settle easily, therefore sedimentation or filtration are the most basic processes to remove them (CENTA, 2007b).The removal of virus or bacteria in the wastewater treatment plants depend on two factors, the time that stay in the process and the time requires to kill them (Curtis, 2003). Viruses are unable to multiply outside their host, but they can survive in the wastewater for a short while. Bacteria are able to multiply out of the host, and persist in the wastewater for a medium-long term. Both involve high risk for consumers (World Bank, 2010, pg 33). Pathogen removal is a common parameter measured and reduced in the treatment plants in order to prevent the transmission of wastewater borne diseases.

Size

It is evident that in urban environment land may be expensive. To reduce capital costs, small and compact systems could seem the most appropriate technology for urban sites, where there is no room available and the price of the land is high. However, CENTA (2007a) stated that energy requirements are inversely proportionate to the size of the plant. Therefore small plants could spend 5-6 times more energy than the big ones. Furthermore, wastewater systems that occupies large surfaces as wetlands and pond could result cheaper in terms of

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operational and maintenance. The dimension of the system and it relatio to the cost will be assessed.

Centralized or decentralized systems

Centralized treatment plants require the transport of wastewater over larger distances. Therefore it involves high investments in infrastructure for wastewater transport from wastewater production to the site-of treatment. Furthermore in rural areas a longer length of the infrastructure is required to connect dispersed households. According to Seto (2005), the collection system implies the 70% of the cost per capita meanwhile 30% is the cost of the treatment. Therefore, also due to the fact that they cannot benefit of from the economy of scale, the inhabitants from small villages might pay 2 or 3 times as much as a resident of a big city (Hophmayer-Tokich, 2006). Decentralization involves local/onsite treatments that reduce the investment costs for implementation and maintenance of large sewage infrastructure. These onsite treatments let a better control of wastewater type and even with possibility of separation different effluents (black water, grey water, urban water, etc). However, the particular case of ward number 3 allows considering the infrastructure as granted. Gangua Nallah can be considered a large sewage canal. No separation of sewage is possible in this case.

Design and construction cost.

A proper design could simplify the performance of the system so this phase results essential. In many occasions has being confused simplicity of maintenance and working with simplicity of treatment plant design and implementation. Enough attention has to be paid in design and implementation phases (CENTA, 2007a). Local technologies that has being already proved and successfully implemented in the area, would assure the long term life of the project. Acknowledge and availability of the construction material or spare parts is required for the sustainable performance of the technology (Hellströma, 2000). In case of underground systems and earth basin designs, especially in rugged terrains, earth works can be rather extensive. Therefore the topography might be also a factor to consider.

Simplicity of O & M.

While the design and construction of the treatment last few months, operation and maintenance (O&M) remains during useful life of the Plant. At the local context, the O&M of the treatment plant would be done by a public institution, private or in case of agriculture reuse by water user association. Depending on that, the possibility of skilled labour employment varies. Looking at the technology, simplicity and minimized costs will guarantee the correct performance. In other terms, low levels of sophistication and high robustness and trustfulness are aimed. Complicated systems require the hire of skilled labour, the use of chemical additives, expensive and fragile devices (membranes, pumps or filters) and availability of spare parts therefore are more costly.

Energy requirements

The requirement of energy supply is an important criteria indicator. Energy supply is expensive so energy consumption should be minimized or non existing. Furthermore it may also be kept

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in mind the importance of energy supply reliability. Electricity is not always fully ensured in many cities. Bhubaneswar suffers of continuous electrical power failures (see chapter 2.3.3). Therefore, with random power breakdowns, plant operation should not depend on energy. One third of the O&M costs are related to the energy requirements. Electromechanical devices could result very expensive, as an example aeration devices consume up to 75% of the total energetic cost (CENTA, 2007a). Manual devices that do not depend on external energy supply to work may reduce this cost.

Robustness

Bhubaneswar is steady growing and developing. The high developing rate of the city makes difficult to set figures of wastewater generated from a specific area. Furthermore, there is a time discrepancy among the actions and plans than local authorities develop and the city growing requirements. At the end result barely impossible to keep the pace of the city. Therefore the most appropriate solution for the farmers, perhaps also change accordingly (Balkema, et al, 2002). An important indicator is the robustness of the technology in terms of adaptability of load and flow fluctuations. The quality and quantity of the stream that flow through the drains will change over the time in an unpredictable way and the capacity to adapt is essential.

Environmental nuisances

The implementation of the technology is associated to additional outcomes that might impact the local environment of users or workers. Therefore concepts like odour, landscape, mosquitoes or noise are by-products to contemplate. There is also necessary to keep in mind the possibility of overflowing of devices and tanks that could cause a threat for groundwater bodies pollution. The interrelation between local parameters, principle, criteria and indicators is shown in the following Figure 12).

Figure 12: Principles and criteria for the selection of wastewater treatment technology and the related indicator (Self-design).

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5.2 MULTI CRITERIA ANALYSIS

The Multi Criteria Analysis (MCA) is a methodology widely used to support the decision making processes. The tool allows clearing up complicated dilemma with multi-faceted characteristics. This is made by assessing the different elements of the problem and afterwards classifying them according to their relevance. Therefore, the MCA provides to the decision makers a comparison and evaluation of the elements of the processes. MCA are not only able to compare quantitative and qualitative aspect but also to compensating possible conflicts of contradictory criteria (Singhirunnusorn, 2009). There are plenty of different MCA methodologies based on complex mathematical models. For this study it will be used the Scoring Rating model. This model was chosen because of its simplicity. The analysis is based on a scoring comparison. In the Scoring Rating model, the criteria of the different solutions are assessed with a score. The criteria are previously weighted by the level of importance. Therefore the result of the model is a matrix with the scored criteria of the different solutions, the weight of the criteria and the final score of the different options. The model allows using a large amount of criteria in a simple and flexible way. However, as was argued by Singhirunnusorn (2009), the pitfall of this model is that the inter connection of the criteria is barely achieved.

5.2.1 Criteria weighting

Commonly, during the technology selection process, the criteria weight is backed up with expert’s surveys or stakeholder´s interviews. In the absence of this information I based the weighting highlighting the importance of the 2 first principles of the study, “wastewater treatment to assure the health protection and crop production”. The reason behind that is that the aim of this research is to find out a useful technology for the local farmers. The usefulness of the technology is only achieved by the 2 first principles. The third principle, “Contextualise”, would lose its value whether the other two were not accomplished.

Base on the indications reported by Fischer (2008), the weight among each criterion was calculated as following. First of all, the criteria were compared two by two according to the level of importance (see Table 7).

Table 7: Scale level of importance of criteria for technology selection

Level of Importance No preference 1 Slight preference 2 Some preference 3 Significant preference 4 Very strong preference 5

For instance, to emphasize health protection over environmental friendly characteristics, health protection was assessed with a very strong preference, value 5. (See Table 8, cell; first column, fifth row). However health protection and crop production were equally considered. Assessed with 1 means that there is no preference over the other. (See Table 8, cell; first column, second row). The total importance of each criterion is calculated by the sum of the

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each comparison. Once the total importance of each criterion is obtained, the weight (relative values) is calculated. The relative values were calculated dividing the individual rating criteria between the total importance of each criterion. (see table 8).

Table 8: Rating criteria (Self-desinged base on Fischer, 2008)

RATING CRITERIA Health Crop Environmental TOTAL Affordability Sustainability protection production Friendly Importance Health protection 1,000 1,000 0,250 0,250 0,200 2,700 Crop production 1,000 1,000 0,250 0,250 0,200 2,700 Affordability 4,000 4,000 1,000 1,000 0,333 10,333 Sustainability 4,000 4,000 1,000 1,000 0,333 10,333 Environmental 5,000 5,000 3,000 3,000 1,000 17,000 Friendly RELATIVE VALUES Health protection 0,370 0,370 0,093 0,093 0,074 1,000 Crop production 0,370 0,370 0,093 0,093 0,074 1,000 Affordability 0,387 0,387 0,097 0,097 0,032 1,000 Sustainability 0,387 0,387 0,097 0,097 0,032 1,000 Environmental 0,294 0,294 0,176 0,176 0,059 1,000 Friendly RANKING OF IMPORTANCE 0,362 0,362 0,111 0,111 0,054 1,000 WEIGHT

5.2.2 Indicators rating technique

The different indicators were assessed by a rating technique. The sum of the scores of all the indicators for each criterion might be 100, therefore the weight between indicators is considered. The total criterion score (X) will obtained by summing the points of the indicators (W), therefore: 0 ≤ wji ≤ 100

X= Σwji = 100

Where W: indicator score and X: criterion score (Singhirunnusorn, 2009).

Each indicator was analysed previously in the chapter 5.1. However, the importance varies depending on the local context. For instance, a technology that could be a possible mosquito reservoir, is an important factor to consider in regions where exists the risk of vector born diseases (i.e. Malaria). Based on that, a score has been assigned. The indicator´s maximum score assigned base on Bhubaneswar conditions is explained in Table 9. A more detailed explanation in explained in Table10.

In this context, the following should be pointed out:

-Salinity reduction will not be addressed by the technologies selected.

-Heavy metals removal is assessed by the TSS reduction.

-There is no need of sewage implementation, Gangua Canal is already built. It is considered a constant flow of urban sewage as the water inflow. 58 Low-cost wastewater treatment technologies for agricultural use

-Due to the variable characteristics of the crops cultivated in the area, the importance of the indicators related to effluent efficiency, has been assessed base on the most sensible, risky and least adapted crop. i.e. Pathogen removals has been consider high important due to possible cultivation of vegetables to eat raw.

- All the technologies selected are known and has been implemented in India urban context. Therefore the construction methods ability has been assessed by; (1) The need of skilled labour for the design and the implementation of the device, and (2) the complexity of the civil works that involves the construction of the technology. The reason behind is that this would rise the financial requirements of the technology.

-Ground water threat and odour problems are two indicators that can easily be produced normally or as a consequence of mismanagement of the system. The mismanagement risk is considered in the assessment.

Table 9: Ranting of different indicators based on the local conditions (Source: self-design)

Milestones of Ward Number 3 Related Indicators/criteria SCORE RANGE PRINCIPLE1: AGRICULTURE Crop production efficiency Total 100 Crop characteristics Nutrients 40 Crop sensibility Crops are moderate sensitive to salinity concentration. Salinity* 0 Nutrient crop requirements. BOD 20 Soil characteristics The soil composition is alluvial with low filtration capacity. TSS 20 Heavy Metals 20 PRINCIPLE 2: HEALTH Health protection efficiency Total 100

Crops type A by WHO 1989 (see table 3.2a, Annex2) The Heavy Metals 20 Crop consumption wastewater is applied by furrow irrigation. Bhubaneswar is located in a tropic template area, very humid with high risk Pathogens removal 40 Irrigation techniques of mosquito vector diseases as malaria. Vector-borne diseases Mosquito reservoir 40 PRINCIPLE 3: CONTEXTUALITY Affordability Total 100 Land availability Size 60 There are not financial resources available. Gangua Nallah Financial resources considered as a sewage facility. There is not municipal land property in the ward (although it is contemplated to make a Centralized or decentralized** 0 Sewage infrastructure green belt area for the vision 2030 plan). As a capital city, Local material and construction material and construction ability is not a problem. Correct design and construction 40 methods knowledge PRINCIPLE 3: CONTEXTUALITY Sustainability TOTAL 100 WUA The skill labour availability is assured; however financial 10 Institutional initiatives resources to pay them are not clear. Odisha annual plan, as 15 Skill labour availability well as Bhubaneswar Municipal planning consider urban Simple O&M 5 Spare parts availability and peri-urban activities as part of their plans. There is an 5 informal water user association (WUA). 5 Financial resources 10 Energy supply in the city is not covering all the areas and Energy supply infrastructure Energy requirements 10 suffer of cut offs frequently. Energy reliability 15 Fluctuation of volume of High risk of wastewater fluctuation due to, the fat growing 5 wastewater of the city, changing of land use and lack of separated Robustness Fluctuation of load of sewage system. 15 pollutants PRINCIPLE 3: CONTEXTUALITY Environmentally friendly Total 100 Deep phreatic surface (18-24m.b.g.l.). Ground water is Geomorphology Ground water threat 50 commonly used as a drinking water source. Proximity to residential areas Lower population density than the city average. Mixed land Odour problem 25 use although agriculture plot occupy a large compact part Landscape impact of the north of the ward. Pleasant infrastructure 25 (*) Salinity reduction will not be addressed by the technology. (**) There is no need of sewage implementation, Gangua Canal is already built.

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Table 10: Detailed scoring of indicators (Source: self-design)

INDICATORS CRITERIA Score Range Total score CROP PRODUCTION EFFICIENCY Partial score 100 Nutrients 50-100% Nutrients removal 0 40 25%-50% Nutrients removal 20 Low/No nutrient removal 40 BOD No BOD reduction 0 20 25%-50% BOD reduction 10 50-100% BOD reduction 20 TSS No TSS reduction 0 20 25%-50% TSS reduction 10 50-100% TSS reduction 20 Heavy Metals Low removal of heavy metals 0 20 High removal of heavy metals 20 HEALTH PROTECTION EFFICIENCY Partial score 100 Heavy Metals Low removal of heavy metals 0 20 High removal of heavy metals 20 Pathogens removal No removal 0 40 Partial removal ( of most of pathogens) 20 Total removal of pathogens (helminths, viruses, protozoa and bacteria) 40 Mosquito reservoir No possibility of mosquito reservoir 0 40 Risk of mosquito reservoir if missmanagement 20 Possible mosquito reservoir 40 AFFORDABILITY Partial score 100 Size Large systems 0 60 Small system 60 Correct design and Difficult construction, requires hire skilled labour for the design and implementation 0 30 construction Simple construction, does not require to hire skilled labour for the design and implementation 30 Construction methods No local ability and material for construction. 0 10 knowledge and availability Local ability and material for construction 10 of local materials SUSTAINABILITY Partial score 100 Skilled labour Technology requires skilled labour in order to be managed. No possible management by WUA 0 15 members. No requirement of skilled labour or small training is enough for the correct management of 15 the system. Possible management by WUA members Financial resources or Requires large financial investment or institutional initiatives to be implemented and promote 0 15 initiatives for implementing the project. the project Requires the existence of small budget, loan, charity capital, NGO funds, etc. 15 Spare parts No spare parts availability at local market 0 5 Spare parts availability at local market 5 Energy requirements Requirement of energy supply 0 35 Non requirement of energy supply 35 Robustness No flexible, no adaptable to changes of volume 0 5 Flexible, adaptable to moderate changes of volume 5 No flexible, no adaptable to changes of pollutants load 0 15 Flexible, adaptable to moderate changes of pollutants load 15 ENVIRONMENTALLY FRIENDLY CHARACERISTICS Partial score 100 Ground water threat High risk of pollution 0 50 Some possibility risk of ground water pollution 20

No risk of ground water pollution 50 Odour problem Produce odours 0 25 Some possibility of odour release 10 No odour production 25 Pleasant infrastructure Do not contribute to create a pleasant view for landscape 0 25 Contribute to create a pleasant view for landscape 25

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5.2.3 Scoring matrix

In the Table 11, the scoring matrix is shown. These are the results of the technologies evaluation by the scoring comparison. The evaluation has been carried out analysing each indicator one by one according to the Table 10. It should be mentioned the Direct Use as a non treatment situation. The Direct Use evaluation has been assessed considering the use of untreated wastewater, with all content of nutrients and pollutants. The sustainability, affordability and environmental friendly criteria has been scored base on the "Green filter" technology (further details see Table 11). The final score of the criterion of each technology and the final score of the technologies is shown in the Table 12. The technologies in the Table 12 have been classified by their treatment stage. However, note that this final score cannot be used to compare all the technologies. As it was discussed in the chapter 4.1, the technologies are usually part of treatment processes chain (see Figure 13). They work combined in order to achieve a complete treatment. Multiple combinations of technologies are possible. Therefore, the evaluation result is a reference to compare technologies that develop similar stage of the process.

A sensibility analysis was made in order to verify the uncertainty grade of the results. Giving the maximum score to the health protection and crop production criteria, and making the local context criterion zero, the technology would obtain a 72.4 final score. This means that this method would assume that a very expensive technology, difficult to manage and non environmental friendly will be chosen rather than a technology easy to manage that get an effluent of less quality. Therefore, the scoring comparison is a supporting tool but should not be considered the selection method.

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Table 11: Detailed scoring of technology (Source: self-design).

Soil Free Vertical TOTAL Direct Coarse Sand Grease Septic Imhoff Baffed Anaerobi Anaerobic Facultative Maturation Horizontal INDICATORS biotechnolog flow flow Sand filter SCORE Use screen traps traps tank tank reactor c filter ponds ponds ponds flow CW y CW CW Crop production 100 40 40 40 40 90 100 100 100 60 100 60 60 60 80 80 60 efficiency 1 40 40 40 40 40 40 40 40 40 0 40 20 0 20 20 20 40 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 20 0 0 0 0 10 20 20 20 20 20 20 20 20 20 20 0 4 20 0 0 0 0 20 20 20 20 20 20 10 20 10 20 20 0 5 20 0 0 0 0 20 20 20 20 20 20 10 20 10 20 20 20 Health protection 100 40 40 40 40 40 40 40 40 100 40 50 60 70 80 80 80 efficiency 5 20 0 0 0 0 20 20 20 20 20 20 10 20 10 20 20 20 6 40 0 0 0 0 0 0 0 0 40 20 40 40 40 40 40 40 7 40 40 40 40 40 20 20 20 20 40 0 0 0 20 20 20 20 Affordability 100 100 100 100 100 70 70 70 70 10 10 10 10 10 40 40 100 8 60 60 60 60 60 60 60 60 60 0 0 0 0 0 30 30 60 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 30 30 30 30 30 0 0 0 0 0 0 0 0 0 0 0 30 11 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Sustainability 100 100 100 100 100 75 75 75 75 25 80 65 95 95 90 40 105 12 15 15 15 15 15 15 15 15 15 0 0 0 15 15 15 15 15 13 10 10 10 10 10 5 5 5 5 0 5 5 5 5 0 0 15 14 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16 50 50 50 50 50 50 50 50 50 0 50 50 50 50 50 0 50 5 5 5 5 5 0 0 0 0 5 5 5 5 5 5 5 5 17 15 15 15 15 15 0 0 0 0 15 15 0 15 15 15 15 15 Environmentally 100 35 75 75 75 60 75 75 75 85 75 60 75 85 100 100 60 friendly 18 50 0 50 50 50 25 25 25 25 50 50 50 50 50 50 50 50 19 25 10 25 25 25 10 25 25 25 10 25 10 0 10 25 25 10 20 25 25 0 0 0 25 25 25 25 25 0 0 25 25 25 25 0

TOTAL SCORE 53.05 55.21 55.21 55.21 66.395 70.825 70.825 70.825 66.395 64.72 51.385 59.145 63.305 77.75 72.2 76.675

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Note. Direct use of wastewater has been assessed base on the green filter characteristics in terms of design and O&M. The effluent characteristics were considered as non treated effluent therefore: 0% nutrients removal, BOD reduction, TSS reduction, heavy metals reduction and pathogen reduction. As the technology does not exist the affordability and sustainability score are maximized. 1-Nutrients: (0) 50-100% Nutrients removal. (20) 25%-50% Nutrients removal. (40) Low/No nutrient removal. 2-Salinty: (0) Not considered. 3-BOD reduction: (0) <25% BOD reduction. (10) 25%-50% BOD reduction. (20) 50-100% BOD reduction. 4-TSS reduction: (0) <25%TSS reduction. (10) 25%-50% TSS reduction. (20) 50-100% TSS reduction. 5-Heavy metals reduction: (0) <25%TSS reduction. (10) 25%-50% TSS reduction. (20)50-100% TSS reduction. 6-Pathogens removal: (0) No removal. (20) Partial removal (of most of pathogens). (40) Total removal of pathogens 99% (helminths, viruses, protozoa and bacteria). 7-Mosquito reservoir: (0) Possible mosquito reservoir. (20) Risk of mosquito reservoir if mismanagement. (40) No possibility of mosquito reservoir 8-Size: (0) Large systems. (30) Medium size. (60) Small system. 9- Centralized or decentralized: (0) Not considered. 10-Correct design and construction: (0) Difficult construction, requires hire skilled labour for the design and implementation. (30) Simple construction does not require hiring skilled labour for the design and implementation. 11-Local ability and material for construction: (0) No local ability and material for construction. (10) Local ability and material for construction. 12-Skilled labour: (0) Technology requires skilled labour in order to be managed. No possible management by WUA members. (15) No requirement of skilled labour or small training is enough for the correct management of the system. It is possible to be managed by WUA members. 13-Financial resources or initiatives for implementing the project: (0) Requires large financial investment or institutional initiatives to be implemented and promote the project. (10) Requires the existence of small budget, loan, charity capital, NGO funds, etc. 14-Spare parts and local materials: (0) No spare parts availability at local market. (5) Spare parts availability at local market 15-Construction methods knowledge: (0) Not considered. 16-Energy requirements: (0) Requirement of energy supply. (60) Non requirement of energy supply. 17-Robustness: (0) No flexible, no adaptable to changes of volume. (5) Flexible, adaptable to changes of volume. (0) No flexible, no adapting to changes of pollutants load. (15) Flexible, adaptable to moderate changes of pollutants load. 18-Ground water pollution threat: (0) Buried systems, risk of ground water pollution. (40) No risk of ground water pollution. 19-Odour problem: (0) Produce odours. (10) Some possibility of odour release. (20) No odour production. 20-Pleasant infrastructure: (0) does not contribute to create a pleasant view for landscape. (20) Contribute to create a pleasant view for landscape.

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Figure 13: Classification of the selected technologies according to the treatment stage.

The ranking matrix of the technologies selected with the final scored is the following:

Table 12: Scoring matrix of the different technologies regarding to the five criteria assessed.

Crop production Health protection Environmentally TOTAL TECH. Affordability Sustainability TREATMENT efficiency efficiency friendly SCORE STAGE Max. Score 100 100 100 100 100 100 ALL DIRECT USE 40 0 100 100 35 53.05 Coarse screen 40 40 100 100 75 55.21 PRE-TREAT. Sand traps 40 40 100 100 75 55.21 Grease traps 40 40 100 100 75 55.21

PRIMARY Septic tank 90 40 70 75 60 66.395 TREATMENT Imhoff tank 100 40 70 75 75 70.825 PRIMARY/ Baffled reactor 100 40 70 75 75 70.825 SECONDARY TREATMENT Anaerobic filter 100 40 70 75 75 70.825 Soil ALL 60 100 10 25 85 66.395 biotechnology PRIMARY Anaerobic 100 40 10 80 75 64.72 TREATMENT ponds SECONDARY Facultative 60 50 10 65 60 51.385 ALL TREATMENT ponds TERTIATY Maturation 60 60 10 95 75 59.145 TREATMENT ponds Free flow CW 60 70 10 95 85 63.305 SECONDARY Horizontal flow TREATMENT 80 80 40 90 100 77.75 TERTIATY CW Vertical flow TREATMENT 80 80 40 40 100 72.2 CW TERCIATY Sand filter 60 80 100 105 60 76.675 TREATMENT 64 Low-cost wastewater treatment technologies for agricultural use

6. DISCUSION

Bhubaneswar is an overpopulated city, in which urban infrastructures remain under dimensioned behind the fast growing pace of the city. Gangua canal, a natural topographical drain, has become the main sewage stream of the city due to the lack of any sewage infrastructure in the 70% of the urban area. Located in a tropical climate, the uneven distribution of rain during the year and the increasing demand makes water a scarce resource form a socioeconomic and a physic point of view.

Agriculture is a marginal sector but still located in the urban banks of the eastern and southern rivers. The ward number 3 of Bhubaneswar has a large urban agricultural area, located in the bank of Kuakhai river. Despite the high potential change of land use in to urban plots, the development plans of the city for 2030 consider part of this area as agricultural land. The urban settlement expansion of the city is not considered in this area that remains as a green belt for urban planners. Although there is no irrigation infrastructure, watering is required for vegetables and flower production from November to May. The irrigation is made by flood.

Gangua canal crosses the ward from north to south. There is a continuous flow stream of urban wastewater in Gangua Canal. This is the cheapest and the most affordable source of water for the local farmers.

Quality parameters of wastewater for irrigation

Wastewater use for irrigation is not yet covered by Indian regulation. The situation regarding the availability and quality of water in India, has been reported for years by the Central Pollution Control Board. Although there are no registered data of wastewater irrigation in Indian cities, the use is reported by several authors (Van Beusekom, 2012; Kumar, 2012). These activities are potential health hazards for the dwellers. Some recommendations regarding to water quality parameters for irrigation were given by the National River Conservation Directorate. The Indian government also included in the last water law of 2012, some quotes about incentives of wastewater reuse. However these initiatives are not feasible measures, and represent a timid response to the scope of the problem.

Worldwide there is increasing use of urban wastewater for irrigation. This fact makes this issue to be an international concern. The last international guidelines were proposed in 2006 by FAO, WHO and World Bank. Although the measures suggested are flexible and adaptable to the local context, the calculations are complex and the required water quality data very specific. The lack of data makes these guidelines to be inapplicable in the analysis of Bhubaneswar scenario. Therefore, during this study, in order to have a reference of water quality parameters for irrigation, a summary of the recommended standards was done. Indian MoEF, FAO and WHO in 1989, USEPA 1992 and the reducing health risk recommendation of WHO, World Bank and FAO 2006 were considered.

Water quality of Gangua Canal is not good. Base on the above mentioned guidelines, the direct use of Gangua water for irrigation overcomes the recommended limits regarding to suspended solids, BOD, chloride and faecal coliforms. On the contrary, the water quality parameters revealed a low concentration of pollutants according to the wastewater quality classification of

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Pescod (1992). This could be due to the dilution suffered by the pollutants in the water stream. However it is unknown the period of the year when the data were collected, therefore this assumption is not possible to verify.

Urban wastewater is normally characterized by high loads of organic and inorganic compounds. Some of these compounds are plant´s macronutrients such as Nitrogen or Phosphorous. Nitrogen is highly present in wastewater, however only the inorganic forms (Nitrate and ammonium) can be directly absorbed by plants. During the treatment process, organic N is transformed into inorganic N. Phosphorous is also a valuable macronutrient of wastewater. Solid phosphates either are dissolved or are formed solid particles. Therefore are partially concentrated in the sludge formed during the treatment processes. Sludge spreading is a frequent agricultural practice. Phosphates are decayed by natural, physical and microbiological processes in the soil and assimilated by the crops afterwards. Regarding to macronutrients, a direct use (untreated) of wastewater can produce a long term increase of the amount of carbon and macronutrients in the soil (Yadav, et al 2002). Reliable data of macronutrient content of Gangua Canal were not available.

Wastewater contains also other organic and inorganic compounds that are not beneficial for the crop production. Heavy metals (Ni, Mn, Cu, Cr, Se, Pb, Zn, Fe or Cd) are frequently found in urban wastewater mainly from industrial discharge and road´s runoff. The heavy metal´s concentration in urban wastewater is usually low. Although the use of (untreated) wastewater for irrigation does not have immediate effect on soils, however there are potential long term effects because of the accumulation over the time. High loads of certain compounds are toxic for soil microorganism and crops and can affect to crop yields and human health. Heavy metals are usually removed by precipitation and sedimentation. This is normally enhanced by anaerobic processes. Therefore heavy metals are accumulated in the sludge.

Additionally, urban wastewater is characterized by the high content of salts. Inorganic salts are added to the wastewater by the use of soaps, detergents, rests of food, paper, urine and feces. Sodium compounds in wastewater are very soluble. Crops have different tolerance to salinity and this could be a determining factor of crop production failure. Furthermore, the continued use of high salinity irrigation causes long term effect on soil properties, such as hydraulic conductivity and carbon availability. Despite the great hazard of soil salinization due to the use of reclaimed water, wastewater desalinization requires high energy and costly equipment. Nowadays there is no low cost treatment solution for this problem.

Urban wastewater contains high loads of pathogens. The wastewater borne disease risk due to the use of wastewater is high. The direct use of reclaimed water (not treated) implies health hazard both to the farmer that manage the water and to the consumers that eat the products. However, the extent of risk of disease transmission is variable and related to many external factors; irrigation techniques, crop consumption, local habits, hygienic customs, etc (Ardakanian, 2012). Therefore, the treatment of Ganghua water before use it for irrigation seems to be a logical solution.

Wastewater treatment technology

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Wastewater treatment technologies are designed for environmental purposes. The possible use of the effluent as reclaimed water for irrigation is only consider as a possibility not as a target. Their purpose is environmental water protection with no agricultural consideration. However, for this study the main purpose of the water treatment system is the improvement of the wastewater quality, in order to enable poor urban farmers to benefit from it. In fact, the final quality of the effluent is linked with the treatment process.

While wastewater treatment technologies and drinking water technologies are disciplines clearly defined. Agriculture water treatment is not considered as a discipline only as a marginal potential use of water. However irrigation is not a marginal use and the potential use of reclaimed water for agriculture is exponentially increasing. It results paradoxical that over decades the environmental technologists have been developing treatment methods to treat water in order to make it suitable for human activities such as drinking, industry and environmental protection, but not for agriculture. Although, agriculture is an ancient practise developed by humans in prehistoric era, and irrigation is used for crop production since more that 2000 years. The agricultural sector is the human activity totally ignored by water quality technicians. The biggest wastewater user has been totally sidetracked for the wastewater treatment methods. Crop production has to use technologies designed for environmental measures that bear no relation to the agricultural sector.

The fact is that wastewater technology is aimed to get an effluent quality that ensures compliance with the environmental standards. These standards are completely different to the agricultural ones. The eutrophication risk of water bodies, pushes to reduce the nitrogen and phosphorus concentration of the effluents before discharges them into water bodies. Regarding to the health protection, wastewater treatment technologies only cover health issues when direct reuse of effluent is considered. In that case tertiary treatments are implemented as a complementary treatment stage at the end of the process chain. Therefore these polishing technologies are designed to treat a pre-treated effluent. This means that has already reduced nutrient loads, therefore it is against the crop production if using the current technologies available.

On the other hand, although wastewater´s high tech treatment plants have spread in India over the last few decades, the performance was not as satisfying as initially intended (CPCB, 2013). The low performance of the plants leads to drain effluents with high COD and pathogen´s loads. The reason behind this has been reported by researchers like Sato (2006) and also by local institutions like Sankat Mochan Foundation (1993) and the CPCB (2013). The mismanagement of conventional treatment plants was pointed out as the main reason. The high demand of operating cost, lack of qualified staff and the inability of spare parts replacement are the scope of the problems.

Low cost and water quality are the main targets of any wastewater treatment project. Aside from goals and standards towards water quality, the technology has to be appropriate for the local situation and the social context regarding to land availability, local materials, construction and operation know-how or skill labour availability. On the other hand some studies (Singhirunnusorn, 2009) suggest that low investment and operating costs are of great importance to guarantee the sustainability of the system. Other fingers pointed directly

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towards decentralized solutions (Sasse, 1998) and stakeholder participation (Van Buuren, 2010). However, even in these cases, in many occasions, the implementation of any of the proposed solutions looks far from feasible considering the investment required. In case of the ward number 3, the cost of infrastructure implementation does not constrain the selection of the technology. This is because Ganghua Canal becomes a sewage infrastructure itself.

Technology selection process

All the above mentioned factors and limitations were taken into account when the technologies were analysed. Furthermore, due to the large amount of characteristics (indicators) that could influence the suitability of the technology, a multi criteria analysis tool was used to support the selection process of the technology. The scoring comparison method results a very simple and feasible tool for the process.

The preliminary devices obtained the same score. The aim of these devices is to facilitate the performance of the other technologies. Therefore, the low compliance regarding to health and agronomic properties is not taken into consideration. Any of them would be suitable because of the high affordability and sustainability features. Therefore the selection among them would be done according to the requirements of the following technologies. Although the relation health protection/crop production achieved by soil biotechnology is very acceptable, the final score is not that optimal because of the low sustainability and affordability. This is due to the dependency of energy in order to be operated, the large land requirements and the high capital cost for implementation. The combined typologies of septic tanks (septic tank, Imhoff tank, baffled reactor and anaerobic filter) have a good performance for crop production; however the health risk remains non-covered. Between the different primary and secondary treatment technologies, the combined typologies of septic tanks are higher scored over anaerobic stabilization ponds. Although the score is similar regarding to crop protection and crop production, the septic tank typologies obtained higher punctuation regarding to affordability and sustainability. This difference is due to the size of the system. Urban land is expensive and ponds technologies require larger land. A combination of stabilization ponds would optimize the performance regarding to health protection. However, despite the high rates of sustainability and environmental respect, a combination of three large ponds in an urban area results a solution barely affordable. By contrary, despite the large land required, horizontal constructed wetland has been scored the highest. Comparing with the other constructed wetland technologies, free flow wetland requires larger land and vertical flow implies the use of energy and increase the risk of mosquito reservoir. Horizontal flow constructed wetlands have risk of clogging because of grease, and therefore completing the system with a pre-treatment device of grease/sand trap, will result the most appropriate system for wastewater irrigation in ward number 3 of Bhubaneswar.

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7. CONCLUSION

-Horizontal subsurface constructed wetland is a suitable technology for treating the water of Gangua Canal at the north part of Ward number 3. This technology provides an effluent that keeps at least the 60% of nutrients. The effluent final quality minimizes the risk of pathogen transmission to the farmers and the products. Furthermore, the system is easy to manage and does not create potential vector disease reservoirs because of the subsurface flow of the wastewater. In order to avoid clogging problems, a grease/sand trap might be installed as a pre-treatment device.

-The criteria used for the selection of the technology; health protection efficiency, crop production efficiency, affordability, sustainability and the environmental friendly characteristics provide a very complete and representative analysis.

-The defined indicators; nutrient (N,P) content, salinity reduction, total suspended solid (TSS) reduction, biochemical oxygen demand (BOD), heavy metals, pathogens removal, size, design and construction cost, energy requirements, simplicity of operating and maintenance, robustness and environmental nuisances, are representative for the criteria. Most of them result easy to identify and to analyse because they are parameters commonly used by environmental technicians.

-There are various socio, economical, political and physical factors that influence in the implementation and performance of a wastewater treatment technology for the treatment of urban agricultural wastewater. These are:

- Agricultural characteristics: Irrigation requirements, crop consumption.

-Social context: Existence of water user association, skilled labour availability.

-Political: land availability, institutions initiatives, financial support.

-Physical: energy reliability, sewage infrastructure.

-The high content of macronutrients as Nitrogen and Phosphorous, and organic matter in wastewater are beneficial and profitable for the agricultural production. However, heavy metals and a high content of inorganic salts might be also present in urban wastewater and can be a hazardous for agricultural production.

- Aerobic processes of treatment technologies break down the nitrogen into compounds highly assimilated by plants, like nitrates and ammonium. Therefore this treatment could be used to enhance the assimilation capability of plants. Regarding to phosphorus, during the primary treatments, phosphorus is partially settled down with the solid part forming the sludge. The spread of the sludge over the fields is a common way of phosphorus utilization in agriculture.

- Due to the lack of chemical and energy devices, low cost disinfection is based on the longer retention times of the technologies. The reduction of viruses, that are not able to survive long time without be hosted, is ensured. Bacteria can persist in the wastewater multiplying for a medium-long term period, the correct removal requires therefore longer time of treatment.

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However, the reduction of helminths eggs or protozoa cysts can be achieved in previous stages by simple sedimentation processes.

-There are low cost wastewater treatment technologies that can achieve the polishing treatments with a high rate of reliability. Maturation stabilization ponds, free flow, horizontal and vertical constructed wetlands and sand filters are technologies suitable for a low cost requirement.

7.1 RECOMMENDATIONS

There are several low cost technologies that could be applied successfully to the case study. The missing information triggered high amount of uncertainties and data assumptions during all the study process. These results must be considered as a recommendation and further studies should be done. It is highly recommended to look for reliable data regarding to water quality of Gangua Canal. In case this data are not available or feasible, it is recommended to take samples and analyse them manually.

Further research regarding to wastewater treatment specifically designed for agricultural use are recommended.

Agricultural plots can be considered as a wastewater treatment themselves. Technologies as Soil biotechnology, Land application, Green filters or Constructed Wetlands are in fact cases of wastewater treatment in a soil -plant system. On the other hand, health risk can be minimized by appropriate irrigation and management techniques. Base on the fact that non treatment would be an acceptable option. However, crops and soil can be affected by some wastewater compounds. Further research might be done about to what extent in some occasions the treatment is really required.

High salinity is a common characteristic of urban wastewater. Inorganic salt end up in the sewage from the soap, detergents and food preparation. Desalinization technologies use to be high energy demanding. Irrigation management techniques and tolerant crops selection seem to be the only manner to deal with the use water. Further research about low cost energy technologies should be promoted in order to prevent irreversibly damage to urban agricultural soil.

Although in this study stakeholder’s participation has not been analysis, much research point out participatory approach as key factor for the sustainability of the implementation of technology. In case of agriculture use of reclaimed water, water user association could play an important role. During the review, many literature has been found regarding to participatory approach of stakeholders in sanitation selection processes or participatory processes of water user association in order to implement irrigation systems. Farmers are concerned of health risks because the use of wastewater. However, I barely found articles of farmer’s participatory approach for the selection of wastewater treatment technologies in with agricultural targets.

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Personal communication(4th March, 2013)

Dr. S. K. Rautaray

Directorate of water management. Bhubaneswar Principal Scientist (Agronomy) Email: [email protected]

Dr. S. Raychaudhuri.

Directorate of water management. Bhubaneswar Sr. Scientist (Soil Fert./Che./Microbio.) Email: [email protected]

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ANNEX 1

Institutions and Organizations: Online sources

INDIA (State Level) Web site link Ministry of water resources http://wrmin.nic.in/ Water quality assessment authority (WQAA) http://wqaa.gov.in/ Central Water Commission (CWC) http://cwc.gov.in/ Central ground water board (CGWB) http://cgwb.gov.in/ Central water and power (CPRS) http://cwprs.gov.in/ National Water Development Agency (NWDA)* http://nwda.gov.in/ Agri Census Portal/ Agricultural census http://agcensus.nic.in/ Agrimet, Pune www.imdagrimet.org Centre for Science and Environment www.cseindia.org Department of Agriculture &Cooperation. Ministry of Agriculture. www.agricoop.nic.in India Meteorological Department www.imd.gov.in Indian Council for Agricultural Research http://www.icar.org.in Central Pollution Control Board http://cpcb.nic.in/ Indian sanitation portal Indian sanitation portal.org Ministry of Home Affairs www.ndmindia.nic.in (Disaster Management) National Centre for Medium Range Weather Forecasting www.ncmrwf.gov.in State Government’s website http://goidirectory.nic.in/stateut.htm ODISHA (Regional Level) Website link Government of Odisha http://www.odisha.gov.in/portal/default. asp Department of water resources. Government of Odisha http://www.dowrorissa.gov.in/ Directorate of Agriculture & Food Production. Government of http://www.agriorissa.org/Directorate_A Odisha gri/ Directorate of Economics & Statistics, D/o Agriculture & www.agricoop.nic.in/Agristatistics.htm Cooperation Odisha Water Supply And Sewage Board (OWSSB) http://urbanorissa.gov.in/water_supply_ sewerage_board.html Odisha Public Health Engineering Organization (OPHEO) http://urbanorissa.gov.in/OPHEO.html Odisha Platform to discuss infrastructure developments http://www.orissalinks.com/orissagrowt h/ The District. Portal of Khorda, 2013 http://www.ordistricts.nic.in/district_ho me.php?did=kdh The district portal of khordha http://www.ordistricts.nic.in/district_ho me.php?did=kdh Regional centre of development cooperation http://rcdcindia.org/ BHUBANESWAR (City level) Website link Bhubaneswar municipal corporation http://bmc.gov.in/ Bhubaneswar development authority http://bdabbsr.in/ Directorate of water management. Bhubaneswar http://www.dwm.res.in/ (*) Autonomous society

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Initiatives & Projects

Programs, Initiatives and Projects related to wastewater treatment, sewage infrastructure, sanitation and reclaim water use in the city of Bhubaneswar, Odisha (India). Samman project. http://projectsammaan.com/ It is a project to improve the sanitation in the slums of Bhubaneswar and Cuttack cities. It is developed by a partnership of diverse group of organizations and government entities united to tackle the sanitation and hygiene crisis in India's urban slums. Drought Prone Areas Programme (DPAP) http://dolr.nic.in/dolr/dpap.asp Rajiv Awas Yojana (RAY) program Inside Bhubaneswar Municipal Corporation the RAY for the slum dwellers and the urban poor envisages a ‘Slum-free India’ through encouraging States/Union Territories to tackle the problem of slums in a definitive manner. It calls for a multi-pronged approach focusing on: Bringing existing slums within the formal system and enabling them to avail of the same level of basic amenities as the rest of the town. Redressing the failures of the formal system that lie behind the creation of slums; and Tackling the shortages of urban land and housing that keep shelter out of reach of the urban poor and force them to resort to extra-legal solutions in a bid to retain their sources of livelihood and employment. Rajiv Awas Yojana envisages that each State would prepare a State Slum-free Plan of Action (POA). The preparation of legislation for assignment of property rights to slum dwellers would be the first step for State POA. The POA would need to be in two parts; Part-1 regarding the up gradation of existing slums andPart-2 regarding the action to prevent new slums Total Sanitation Campaign (TSC). http://orissa.ngoregistry.com/2011/01/total-sanitation-campaign-tsc-project.html The objective of this project is to bring about an improvement in the general quality of life in the rural areas working on the sanitation coverage Eco cities India http://ecocityindia.org/Ecocity.aspx In the year 2002, as a part of the X Plan activities, the Eco-City Program was initiated by the Central Pollution Control Board with the grants-in-aid from the Ministry of Environment & Forests, Government of India. The program received technical assistance from the German Technical Cooperation (GTZ) under the Indo-German Environment Program on "Advisory Services in Environmental Management" (ASEM). Japanese program http://www.orissalinks.com/orissagrowth/topics/urban-renewal/bhubaneswar/integrated-sewerage The project has been planned to be implemented by 2011, housing and urban development minister KV Singhdeo said that the detailed project report (DPR) of the project was presented to the ministry of urban development, Government of India, Japan Bank for International Cooperation and 12th Finance Commission of Government of India for funding. The new has been planned by diving the city are into six sewerage districts that shall be provided with an independent sewerage network, pumping system, sewage treatment and disposal system. Reoptima Project Reuse options for marginal quality water in urban and peri-urban agriculture and allied services in the ambit of WHO guidelines (New Indigo, 2011). This project is part of an initiative for the Development and Integration of Indian and European Research. The aim of REOPTIMA is to create an expertise network on the development of integrated wastewater management systems, and develop a roadmap for research on urban wastewater reuse in Indian cities (New Indigo, 2011). In this network project are involved several researchers and institutes as: Bhubaneswar Directorate of Water Management (Indian Council of Agricultural Research, India), Irrigation and Water Engineering Department and Sub-department of Environmental Technology ( Wageningen University and Research Centre, The Netherlands), Institute of Soil Science and Land Evaluation (Universitaet Hohenheim, Germany) and Irrigation Department (Centro de Edafologia y Biología Aplicada del Segura, CEBAS-CSIC, Spain). Information available from meetings, workshops, conferences between the different counterparts of this project is consulted and used. Experts meetings. Excreta Matters: Workshop on Bhubaneswar’s Water and Sewage problems.14th June 2012. http://www.cseindia.org/node/4274 Organized by the Centre for Science and Environment in order to discuss on Bhubaneswar’s water and sewage problems

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ANNEX 2. Results

Relative salinity tolerance of crops

Table 13: Relative salt tolerance of herbaceous crop – vegetables and fruit crops (Source; Phocaides, 2008, Maas 1990)

Common name Botanical name Threshold dS/m Slope % per Rating dS/m Artichoke cynara scolymus - - MT* Asparagus asparagus officinalis 4.1 2.0 T Bean phaseolus vulgaris 1.0 19.0 S Bean, mung vigna radiata 1.8 20.7 S Beet, red beta vulgaris 4.0 9.0 MT Broccoli brassica oleracea botrytis 2.8 9.2 MS Brussels sprouts b. oleracea gemmifera - - MS* Cabbage b. oleracea capitata 1.8 9.7 MS Carrot daucus carota 1.0 14.0 S Cauliflower brassica oleraca botrytis - - MS* Celery apium graveolens 1.8 6.2 MS Corn, sweet zea mays 1.7 12.0 MS Cucumber cucumis sativa 2.5 13.0 MS Eggplant solanum melongena esculentum 1.1 6.9 MS Kale brassica oleracea acephala - - MS* Kohlrabi b. oleracea gongylode - - MS* Lettuce lactuca sativa 1.3 13.0 MS Muskmelon cucumis melo - - MS Okra abelmoschus esculentus - - S Onion akkium cepa 1.2 16.0 S Parsnip pastinaca sativa - - S* Pea pisum sativa - - S* Pepper capsicum annuum 1.5 14.0 MS Potato solanum tuberosum 1.7 12.0 MS Pumpkin cucurbita pepo pepo - - MS* Radish raphanus sativus 1.2 13.0 MS Spinach spinacia oleracea 2.0 7.6 MS Squash scallop curcubita melo melopepo 3.2 16.0 MS Squash zucchini curcubita melo melopepo 4.7 9.4 MT Strawberry fragaria sp. 1.0 33.0 S Sweet potato ipomoea batatas 1.5 11.0 MS Tomato lycopersicon lycopersicum 2.5 9.9 MS Tomato cherry l.esculentum var cerasiforme 1.7 9.1 MS Turnip brassica rapa 0.9 9.0 MS Watermelon citrullus lanatus - - MS* *: Ratings are estimates. Notes: − S sensitive, MS moderately sensitive, MT moderately tolerant, T tolerant. The above data serve only as a guideline to relative tolerance among crops. Absolute tolerance varies, depending upon climate, soil conditions, and cultural practices. − In gypsipherus soils, plants will tolerate an ECe about 2 dS/m higher than indicated.

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Domestic wastewater constituents

Table 14: Major constituents of typical domestic wastewater. (Source; Pescod, 1992)

Constituents Concentration (mg/l) Strong Medium Weak Total solids 1200 700 350 Dissolved 850 500 250 solids(TDS) Suspended solids 350 200 100 Nitrogen (as N) 85 40 20 Phosphorus 20 10 6 Chloride(1) 100 50 30 Alkalinity (as 200 100 50 CaCo3) Grease 150 100 50 (2) BOD5 300 200 100

(1) The amounts of TDS and chloride should be increased by the concentrations of these constituents in the carriage water. (2) BOD5 is the biochemical oxygen demand at 20°C over 5 days and is a measure of the biodegradable organic matter in the wastewater.

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Review of International guidelines of waste quality for irrigation

Table 15: Review of guidelines and regulations of water reuse for food crops. (Source: self-design based on Lazarova et al, 2005; WHO, 1989; WHO, 2006b)

Location Review of guidelines or regulations (International Categorization Parameters Group of Treatment Institution or health risk Country) Type of use. Crops and irrigation. Physical & Chemical biological WHO (1989) A: Irrigation of crops likely to be eaten uncooked, - <1 Intestinal nematodes (nº Workers, A series of stabilization ponds sport fields, public parks eggs/L) consumers, designed to achieve the <1000 Faecal coliforms public microbioical quality indicated, or (nº/100mL) equivalent treatment. B: Irrigation of cereal crops, industrial crops, fodder - <1 Intestinal nematodes (nº Workers Retention in stabilization ponds crops, pasture, and trees eggs/L) for 8-10 days or equivalent No standard recommended for helminths and faecal coliform Faecal coliforms (nº/100mL) removal. USEPA (1992) Agricultural reuse-food crops commercially pH 6-9 Reclaimed water should not Setback Secondary processed. ≤30mg/L BOD contain measurable levels of distances Disinfection Surface irrigation of orchards and vineyards ≤30mg/L SS pathogens. 90 m potable (provide treatment reliability) water supply Consult recommended agricultural ≤200 faecal coli/100mL wells (crop) limits for metals. ≥1mg mg/L Cl2 residual 30 m to areas High nutrient levels may adversely accessible to the affect some crops during certain public growth stages. Agricultural reuse-food crops not commercially pH 6-9 Reclaimed water should not Setback Secondary processed. ≤10mg/L BOD contain measurable levels of distances 15 m Filtration Surface or spray irrigation of any food crop, ≤2NTU® pathogens. potable water Disinfection including crops eaten raw Consult recommended agricultural No detectable faecal coli/100mL supply wells (provide treatment reliability) (crop) limits for metals. ≥1mg mg/L Cl2 residual Chemical (coagulant and/or polymer) Higher chlorine residual and/or a addition prior to filtration may be longer contact time may be necessary to meet water quality necessary to assure that viruses recommendations. and parasites are inactivated or High nutrient levels may adversely destroyed. affect some crops during certain growth stages. 87 Low-cost wastewater treatment technologies for agricultural use

Location Review of guidelines or regulations (International Categorization Parameters Group of Treatment Institution or health risk Country) Type of use. Crops and irrigation. Physical & Chemical biological CDPH (2000) Irrigation of pasture for milking animals, landscape - Total coliform limits: Secondary areas, ornamental nursery stock ≤23/100mL (maximum) Disinfection Irrigation of food crops (no contact between - Total coliform limits: Secondary reclaimed water and edible portion of crop). ≤2.2/100mL Disinfection ≤23/100mL in more than one sample in any 30 day period Irrigation of food crops (contact between reclaimed - Total coliform limits: - Secondary water and edible portion of crop: includes edible ≤2.2/100mL root crops) and open access landscape areas (parks, playgrounds, schoolyards, residential landscaping, unrestricted access golf courses, and other uncontrolled access irrigation areas. FAO (1989) WHO* (See table 16 ) WHO* WHO* WHO* WHO, FAO, Unrestricted irrigation: consumption of wastewater Determination of risk and Workers Wastewater treatment and UNEP irrigated salad crop (lettuce and onion as tolerance. Use of “reference” references) pathogens to calculate the (2006) health risk assessment: Viral Restricted irrigation: involuntary ingestion of pathogens ( norovirus), Workers and Wastewater treatment and post wastewater saturated soil. Two scenarios: labour Bacterial pathogen consumers treatment-health protection intense or highly mechanize (Campylobacter), protozoan control measures pathogen (Cryptosporidium) <1 Intestinal nematodes (nº eggs/L)**

®NTU. Nephelometric turbidity units WHO* FAO follow WHO guidelines of 1989. ** According to World Bank (2010) a new estimation of helminths has been proposed similar to the risk simulation for viruses, bacteria and protozoa.

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FAO Guidelines of waste quality for irrigation

Table 16: Guidelines for interpretation of water quality for irrigation (FAO, 1985)

Potential irrigation Degree of restriction on use problem

None Slight to moderate Severe Salinity 1 Ecw (dS/m) < 0.7 0.7 - 3.0 > 3.0 TDS (mg/l) < 450 450 - 2000 > 2000 Infiltration 2 SAR = 0 - 3 and ECw > 0.7 0.7 - 0.2 < 0.2 3 -6 > 1.2 1.2 - 0.3 < 0.3 6-12 > 1.9 1.9 - 0.5 < 0.5 12-20 > 2.9 2.9 - 1.3 < 1.3 20-40 > 5.0 5.0 - 2.9 < 2.9 Specific ion toxicity Sodium (Na) Surface irrigation (SAR) < 3 3 - 9 > 9 Sprinkler irrigation (me/I) < 3 > 3 Chloride (Cl) Surface irrigation (me/I) < 4 4 - 10 > 10 Sprinkler irrigation(m3/l) < 3 > 3 Boron (B) (mg/l) < 0.7 0.7 - 3.0 > 3.0 Trace Elements (see Table 5.2.c) Miscellaneous effects 3 Nitrogen (NO3-N) (mg/l) < 5 5 - 30 > 30 Bicarbonate (HCO3) (me/I) < 1.5 1.5 - 8.5 > 8.5 pH Normal range 6.5-8 1 ECw means electrical conductivity in deci Siemens per metre at 25°C 2 SAR means sodium adsorption ratio 3 NO3-N means nitrate nitrogen reported in terms of elemental nitrogen

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Table 17: Threshold levels of trace elements for crop production (FAO, 1985)

Element Recommended Remarks maximum concentration (mg/l) Al (aluminium) 5.0 Can cause non-productivity in acid soils (pH < 5.5), but more alkaline soils at pH > 7.0 will precipitate the ion and eliminate any toxicity. As (arsenic) 0.10 Toxicity to plants varies widely, ranging from 12 mg/l for Sudan grass to less than 0.05 mg/l for rice. Be (beryllium) 0.10 Toxicity to plants varies widely, ranging from 5 mg/l for kale to 0.5 mg/l for bush beans. Cd (cadmium) 0.01 Toxic to beans, beets and turnips at concentrations as low as 0.1 mg/l in nutrient solutions. Conservative limits recommended due to its potential for accumulation in plants and soils to concentrations that may be harmful to humans. Co (cobalt) 0.05 Toxic to tomato plants at 0.1 mg/l in nutrient solution. Tends to be inactivated by neutral and alkaline soils. Cr (chromium) 0.10 Not generally recognized as an essential growth element. Conservative limits recommended due to lack of knowledge on its toxicity to plants. Cu (copper) 0.20 Toxic to a number of plants at 0.1 to 1.0 mg/l in nutrient solutions. F (fluoride) 1.0 Inactivated by neutral and alkaline soils. Fe (iron) 5.0 Not toxic to plants in aerated soils, but can contribute to soil acidification and loss of availability of essential phosphorus and molybdenum. Overhead sprinkling may result in unsightly deposits on plants, equipment and buildings. Li (lithium) 2.5 Tolerated by most crops up to 5 mg/l; mobile in soil. Toxic to citrus at low concentrations (<0.075 mg/l). Acts similarly to boron. Mn (manganese) 0.20 Toxic to a number of crops at a few-tenths to a few mg/l, but usually only in acid soils. Mo (molybdenum) 0.01 Not toxic to plants at normal concentrations in soil and water. Can be toxic to livestock if forage is grown in soils with high concentrations of available molybdenum. Ni (nickel) 0.20 Toxic to a number of plants at 0.5 mg/l to 1.0 mg/l; reduced toxicity at neutral or alkaline pH. Pd (lead) 5.0 Can inhibit plant cell growth at very high concentrations. Se (selenium) 0.02 Toxic to plants at concentrations as low as 0.025 mg/l and toxic to livestock if forage is grown in soils with relatively high levels of added selenium. As essential element to animals but in very low concentrations. Sn (tin) Ti (titanium) - Effectively excluded by plants; specific tolerance unknown. W (tungsten) C (vanadium) 0.10 Toxic to many plants at relatively low concentrations. Zn (zinc) 2.0 Toxic to many plants at widely varying concentrations; reduced toxicity at pH > 6.0 and in fine textured or organic soils. 1 The maximum concentration is based on a water application rate which is consistent with good irrigation practices (10 000 m3 per hectare per year). If the water application rate greatly exceeds this, the maximum concentrations should be adjusted downward accordingly. No adjustment should be made for application rates less than 10 000 m3 per hectare per year. The values given are for water used on a continuous basis at one site

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Table 18: Health protection control measures and associated pathogen reduction (WHO, 2006b)

Control measure Pathogen Reduction Notes (log units) Wastewater treatment Pathogen reduction depends on type and 1-7 degree of treatment selected. On-farm options Crop restriction (i.e., no food crops eaten Depends on (a) effectiveness of local uncooked) enforcement of crop restriction, and (b) 6-7 comparative profit margin of the alternative crop(s). On-farm treatment: Three-tank system 1-2 Simple sedimentation 0.5-1 Sedimentation for ~18hours Simple filtration 1-3 Value depends on filtration system used Method of wastewater application Furrow irrigation 1-2 Crop density and yield may be reduced Low-cost drip irrigation 2-log unit reduction for low-growing crops, 2-4 and 4-log unit reduction for high-growing crops. Reduction of splashing Farmers trained to reduce splashing when watering cans used (splashing adds 1-2 contaminated soil particles on to crop surfaces which can be minimized) Pathogen die-off Die-off between last irrigation and harvest 0.5-2 per day (value depends on climate, crop type, etc.) Post-harvest options at local markets Overnight storage in baskets Selling produce after overnight storage in baskets (rather than overnight storage in 0.5-1 sacks or selling fresh produce without overnight storage) Produce preparation prior to sale Rinsing salad crops, vegetables and fruit 1-2 with clean water. Washing salad crops, vegetables and fruit 2-3 with running tap water Removing the outer leaves on cabbages, 1-3 lettuces, etc. In-kitchen produce-preparation options Produce disinfection Washing salad crops, vegetables and fruit 2-3 with an appropriate disinfectant solution and rinsing with clean water. Produce peeling 2 Fruits, root crops Produce cooking Option depends on local diet and 5-6 preference for cooked food.

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Wastewater treatment technology cost comparison Table 19: Summary of Wastewater treatment technologies and cost comparison (CSE, 2013b)

Name of the Treatment Treatment Capital cost O&M Cost Reuse of technology Method capacity (RS/KLD) (Rs/KLD/year) treated wastewater Decentralised Sedimentation, 1- 1000 35000- 70000 1000-2000 Horticulture wastewater anaerobic KLD Biogas treatment digestion, generation (DWWT) filtration and phyto- remediation Soil Bio Sedimentation, 5KLD- tens 10,000-15,000 1000-1500 Horticulture technology filtration, of Cooling biochemical MLD systems process Biosanitatizer/ Bio-catalyse- 100mg/KLD Chip cost Rs. 10000 Not available In situ eco chip breaking the excluding civil treatment of toxic. Organinc /construction cost water bodies, contents horticulture Soil scape filter Filtration through 1-250KLD 20000-30000 1800-2000 Horticulture biologically activated medium Ecosanitation Separation of Individual 40000 – 50000 Not available Flushing zero discharge fecal matter and and (excluding the cost Horticulture toilets urine community of toilet Composting level construction)

Nualgi Phycoremediation 1Kg treats Rs. 350 / MLD 9000- In situ technology (use of micro/ upto 10000/MLD treatment of macro algae)- fix M lakes/ CO2, remove L ponds, nutrients and Increase in increase DO in fish yield water

Bioremediation Decomposition of 1 billion 2.25 – 3.0 lakhs/ 2-2.5 In situ organic matter CFU/ml MLD Lakhs/MLD treatment of using Persnickety lakes/ 713 (biological ponds, product ) Green bridge Filtration, 50 – 200 200-500 20-50 In situ technology sedimentation, KLD/ sq treatment if bio-digestion and m water bodies biosorption by microbes and plants

Note: 1. Cost of the technologies for lakes and water bodies remediation have been indicated in per MLD per year. 2. Costs have been estimated on the basis of the year of implementation of listed case studies. The current cost involved may vary

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Water uses classification for the Indian Central Pollution Control Board

Table 20: Water Quality Criteria according to different uses. (Source: CPCB, 2013b)

Designated best use (DBU) Class of Criteria Water Drinking Water Source without conventional A - Total Coliforms Organism MPN/100ml shall treatment but after disinfection be 50 or less - pH between 6.5 and 8.5 - Dissolved Oxygen 6mg/l or more - Biochemical Oxygen Demand 5 days 20°C 2mg/l or less Outdoor bathing (Organised) B - Total Coliforms Organism MPN/100ml shall be 500 or less - pH between 6.5 and 8.5 - Dissolved Oxygen 5mg/l or more - Biochemical Oxygen Demand 5 days 20°C 3mg/l or less Drinking water source after conventional C - Total Coliforms Organism MPN/100ml shall treatment and disinfection be 5000 or less - pH between 6 to 9 - Dissolved Oxygen 4mg/l or more - Biochemical Oxygen Demand 5 days 20°C 3mg/l or less Propagation of Wild life and Fisheries D - pH between 6.5 to 8.5 - Dissolved Oxygen 4mg/l or more - Free Ammonia (as N) 1.2 mg/l or less Irrigation, Industrial Cooling, Controlled Waste E - pH between 6.0 to 8.5 disposal - Electrical Conductivity at 25°C micro mhos/cm Max.2250 - Sodium absorption Ratio Max. 26 - Boron Max. 2mg/l Bellow-E Not Meeting A, B, C, D & E Criteria

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Wastewater treated quality parameters for crop production

Table 21: Effluent quality importance. Information required on effluent supply and quality (Source: Pescod, 1992)

Information Decision on irrigation management Effluent supply The total amount of effluent that would Total area that could be irrigated. be made available during the crop growing season. Effluent available throughout the year. Storage facility during non crop growing period either at the farm or near wastewater treatment plant and possible use for aquaculture. The rate of delivery of effluent either as Area that could be irrigated at any given m3 per day or litres per second. time, layout of fields and facilities and system of irrigation Type of delivery: continuous or Layout of fields and facilities, irrigation intermittent, or on demand. system, and irrigation scheduling. Mode of supply: supply at farm gate or The need to install pumps and pipes to effluent available in a storage reservoir transport effluent and irrigation system to be pumped by the farmer. Effluent quality Total salt concentration and/or electrical Selection of crops, irrigation method, conductivity of the effluent. leaching and other management practices. Concentration of cations, such as Ca++, To assess sodium hazard and undertake Mg++ and Na+. appropriate measures. Concentration of toxic ions, such as To assess toxicities that are likely to be heavy metals, Boron and Cl-. caused by these elements and take appropriate measures. Concentration of trace elements To assess trace toxicities and take (particularly those which are suspected appropriate measures. of being phyto-toxic). Concentration of nutrients, particularly To adjust fertilizer levels, avoid over nitrate-N. fertilization and select crop. Level of suspended sediments. To select appropriate irrigation system and measures to prevent clogging problems. Levels of intestinal nematodes and To select appropriate crops and irrigation faecal coliforms. systems.

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ANNEX 3. Maps of Bhubaneswar Ward n°3

Figure 14: Existing land property in the ward no3, Bhubaneswar, Odisha.(Source: Self-design adapted from IITK, 2008)

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Figure 15: Existing natural sewage drains in the ward number 3, Bhubaneswar, Odisha.(Source: Self-design adapted from IITK, 2008).

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