Publications

This publication, Water Quality in Agriculture: Risks and Risk Mitigation, emphasizes technical solutions and good agricultural practices, including risk mitigation measures suitable for the contexts of differently resourced institutions working in rural as well as urban and peri-urban settings in low- and middle-income countries. With a focus on sustainability of the overall land use system, the guidelines also cover possible downstream impacts of farm-level decisions. As each country has a range of site-specific conditions related to climate, soil and water quality, crop type and variety, as well as management options, subnational adjustments to the presented guidelines are recommended.; Water Quality in Agriculture: Risks and Risk Mitigation, is intended for use by national and subnational governmental authorities, farm and project managers, extension officers, consultants and engineers to evaluate water quality data, and identify potential problems and solutions related to water quality. The presented guidelines will also be of value to the scientific research community and university students.

Soil aquifer treatment (SAT) is an emerging, nature-based, economically viable wastewater treatment solution. Currently, most SAT experiments are done at the laboratory scale, which cannot generate the same conditions as natural field sites and limits the understanding of treatment efficiency. The current study carried out in situ SAT experiments in the Musi River basin in India, where wastewater irrigation is a common practice. SAT efficiency was determined using an integrated approach, including electrical resistivity tomography (ERT) surveys, soil investigations (grain size, permeability, and moisture measurements), and biochemical characterization of raw and SAT treated wastewater. The ERT scans of SAT column show lower order electrical resistivity 10-30 O-m with enhanced chargeability gt;5–6 mV/V attributed to the vadose zone, characterized by clay-rich soil and sandy soil up to 5–6 m depth. The increase in sand percentage (gt;70%) below 140–160 cm depth corroborates with the high moisture content (23.5%). The vadose zone permeability (K) 1.58 m/day and discharge (Q) 38.19 m3/day is used to determine the pollutants reduction efficiency of SAT column. Hydrogeological and biogeochemical observations reveal that the improved dissolved oxygen from lt;1.0 to 5–6 mg/L in the vadose zone catalyzes the oxidation of organic matter resulting in the reduction of BOD and COD up to 92% and 97%, respectively, and denitrification reducing NO3-- (0.55 kg/day). In addition, the precipitation and adsorption by kaolinite clay prompted the reduction of PO42- (0.26 kg/day). Furthermore, the oxic-vadose zone could not support the growth of coliforms and faecal coliforms, and the reduction observed was up to 99.99% in the SAT production well. Overall, the results indicated a positive outcome with SAT efficiency and framed the SAT sitting criteria for different geological environments.

Processing biomass from different waste streams into marketable products such as organic fertilizer and bio-energy is increasingly realized through public-private partnerships (PPPs). In developing countries, the private sector can be expected to contribute technical skills, organizational capabilities and marketing expertise, and leverage capital inflow. In contrast, the public sector will provide the regulatory framework and help its enforcement, plan public investment, involve and educate stakeholders, and ensure waste supply. This report reviews case studies that implemented PPPs in resource recovery and reuse (RRR) from waste streams with a particular focus on Asia and Africa, including those PPPs facilitated by the authors. Critical factors behind the success and failure of these cases are analyzed. The review indicates three key barriers to success: (i) waste-related bottlenecks, (ii) limited awareness about RRR products and their market(ing), and (iii) lack of proper institutional frameworks. Common shortfalls concern failure to meet commitments related to the quality and quantity of waste, missing understanding of the reuse market, etc. The report points out mitigation measures addressing possible challenges around appropriate technologies, finance and revenue streams, legal issues, as well as social and environmental concerns. It is required to establish close monitoring, appropriate procurement mechanisms and due diligence during the project preparation and pre-bid. If possible, such a PPP project should consider risk and commercial viability assessment as well as financial strategy planning (scaling). Successful involvement of the private sector in the RRR market is critical to close the resource loop and safeguard human and environmental health, which is the overarching objective of sustainable waste management.

Currently, in Sri Lanka, strategies to address FW prevention and reduction are being considered by different state and non-state stakeholders. However, in the current scenario, solutions for FW are mostly addressing (bio-)waste management. Quantifying FW is of paramount importance in understanding the magnitude and socio-economic as well as environmental impacts of the problem. A good understanding of the availability and quality of FW data is a prerequisite for tracking progress on reduction targets, analyzing environmental impacts, and exploring mitigation strategies for FLW (Xue et al., 2019). FW quantification aims at creating a robust evidence base for developing strategies, action plans, and policies towards FW prevention, reduction, and management as well as guide prioritization of actions, evaluation of solutions, and monitoring progress (CEC, 2019).

Food waste (FW) is a key challenge on the sustainable development agenda of countries worldwide. The lack of FW data and insights from its analysis about quantities, causes, and characteristics is a significant obstacle in implementing adequate reduction and prevention interventions for different sectors. The primary purpose of the case studies was to review FW prevention, reduction, and management initiatives. Lessons and best practices that enable and facilitate solutions were identified. Nine case studies were conducted targeting five sectors: food services (one restaurant and one hotel), wholesale markets (one fruits and vegetables wholesale market), retailers (one retail market, one retail shop, and one supermarket), caterers (one hospital), and households (five middle- and five high-income households). The case studies consisted of a FW audit that measured the amounts generated from various processes and identified drivers/causes and current best practices. Quantification involved physical separation, weighing, and categorizing the different food components. The separation classified quantities into edible and inedible portions. The study also focused on assessing the environmental and socio impacts, based on assessed and categorized FW quantities. FW is a complex phenomenon where the amount, causes and consequences are contextually different. It is not easy to compare and contrast country-level data and the individual actors in the same country. Therefore, the case study approach has been used in many FW-related studies. Multiple case studies can be expensive and time-consuming to implement. Under this study, we analyzed nine case studies targeting five sectors: food services (four restaurants, a dessert shop and one hotel), wholesale markets (one fruit and vegetable market ), retail markets (one supermarket, one fruit and vegetable retailer, one Dedicated Economic Center), caterers/institutional canteens (one hospital) and households (five middle-income households and five low-income households). Entities were selected based on willingness to participate and an actual FW reduction need.

This report explores and analyses the governance framework (i.e. policies, laws, and regulations) relevant to urban food waste (FW) prevention and reduction in the wholesale, retail, hospitality (restaurants, hotels), food services (schools, hospitals), and households in Sri Lanka. The project quot;Innovative approaches to reduce, recycle and reuse food waste in urban Sri Lankaquot; was implemented from June 2019 to August 2021 under the oversight of the Ministry of Urban Development and Housing and in collaboration with the Food and Agriculture Organization of the United Nations (FAO) and the International Water Management Institute (IWMI).

The management of domestic wastewater and rainwater is a major concern for the population of Yopougon. The study presents the causes of wastewater discharge from dysfunctional sewers and their health impacts on the population. It also highlights the environmental and health risk associated with poor solid and liquid waste management. This was based on literature search, semi-participatory workshop, physicochemical and bacteriological characterization of wastewater and finally through a household survey. The field survey was conducted on 245 household heads obtained using the Canadian statistical guidelines. The results obtained indicated that all main pollution indicators were; total nitrogen (TN, 525 0.02 to 3077 0.3 mg/l), nitrates (NO3, 146 0.01 to 1347 0.12 mg/l), biochemical oxygen demand (BOD, 278 195.16 to 645 391.74 mg/l), chemical oxygen demand (COD, 940 650.54 to 4050.5 71.42 mg/l) and total dissolved solids (TDS, 151 9.9 to 766 237.59 mg/l) which were above the values recommended by the World Health Organization (WHO) and Cote dapos;Ivoire national policy guidelines standards for the discharge of effluents into the environment. The analysis of the bacterial flora of the effluents revealed that the concentrations of Total Coliforms and fecal streptococci exceeded the values recommended by the WHO and national policy guidelines standards. This means that the populations of this area are prone to infectious diseases. Diseases such as malaria (84.53%), respiratory infections (61%), diarrhea (48.66%), intestinal diseases (44.5%), and typhoid fever (28.84%) were prevalent in the surveyed households.

In Cote d’Ivoire, the failure of urban sewage systems is a crucial problem for the drainage of wastewater and rainwater. This failure is due to many factors and therefore, calls for diagnostic studies. The present study aimed at analyzing these networks in order to identify the dierent factors that contribute to the operational and structural degradation in selected sewerage and drainage networks in Abidjan, Cote d’Ivoire. The method used in the study involved semi-structured interviews, video camera inspection and socio-environmental field surveys (geographical survey and household survey), followed by descriptive statistics. The results revealed that many structural, environmental and behavioral practice contribute to the progressive degradation of urban sewage systems. These factors are essentially those that prevent the normal flow of wastewater in the pipes such as the illegal dumping of solid waste, the unauthorized connection of wastewater networks, unsustainable urban agricultural practices, as well as the high concentration of vegetation on both sides of the network and the dilapidated infrastructure of the wastewater and rainwater networks. It was found that these factors are at the origin of the clogging and degradation of the sewers since 85% of the residents used these sewers as a dumping ground for solid waste.

The failure of sewage and drainage systems in SubSaharan African cities is frequent and can be considered as a critical issue, both from an environmental standpoint and in terms of associated maintenance costs. This study analyzes the state of the sanitation systems, the elements behind the failures, the environmental concepts used to classify the problems, and the tools and methodological alternatives for ranking the various management solutions. This research illustrates the causes that contribute to the dysfunctions in the sewage systems of Abidjan as a typical example of sewerage systems management challenges in SubSaharan Africa’s large cities. Poor solid waste and wastewater management practices by residents, e.g., illegal dumping of solid waste into the sewers, unauthorized and defective connections to the network, structural dysfunctions related to the age of the network (cracked, denuded, or broken), urban agriculture in the vicinity of the channels, natural phenomena such as erosion, landslides in the undeveloped parts, and the high concentration of vegetation in the network, wholly contribute to the degradation of the network. A variety of decision support systems for the management of the assets of the urban sewage network were presented. The instruments have been categorized based on their capacity and functionality. The operating concept of each of these tools has been outlined, as well as their respective data needs. In addition, the study analyzes challenges related to the usage of existing decision support systems and provides an outlook on future research requirements in this area. This study offers a detailed analysis of the issues of sanitation management and could serve as a reference for other emerging nations in SubSaharan Africa.

The Middle East and North Africa (MENA) region is suffering from severe water scarcity. Decision-makers in MENA are tackling this challenge by tapping the potential of reusing treated wastewater in agriculture so that large volumes of freshwater sources can be released for priority domestic needs. This aligns with the global efforts to make wastewater reuse mainstream in developing countries by overcoming the technological, infrastructural, health, and socio-cultural barriers that are limiting the expansion of wastewater reuse in agriculture. In this regard, this paper analyses the management modalities of wastewater reuse practices in agriculture in MENA by studying two case studies from Egypt and Jordan. The result of this analysis is a proposed decision-tree tool to help decision-makers in making optimal wastewater reuse decisions based on contextual factors including agricultural field demands, location, freshwater resources, sanitation coverage, and infrastructure, as well as regulations, policies, and restrictions for wastewater reuse. The decision-tree framework was operationalized and validated using the two case studies. The decision tree proved to be an effective framework in assisting decision-makers in making the optimum choice for wastewater reuse in agriculture. It aided the decision maker in evaluating potential reuse options and selecting between several courses of action.

Jordan’s water scarcity prompted a national plan whereby treated wastewater is utilized to amend agricultural irrigation water so as to reallocate freshwater to urban/domestic uses. The policy, however, has engendered farmers’ resistance in the Northern Jordan Valley (NJV), causing a stalemate in putting new infrastructure into operation. This research investigated the socio-economic causes of farmer resistance and contestation, and examined the government’s institutional approach to overcome the challenges. We found that the perceived risks of wastewater reuse such as salinization and restrictions from international markets figure prominently in the farmers resistance. As yet, farmers have managed to avoid the shift to treated wastewater use by using the political agency of elite farmers who control the Water Users Associations. These same farmers have adopted informal water access practices to overcome freshwater shortages. At the same time, small producers who don’t have possibilities to access extra water and with less political clout seem more willing to irrigate with treated wastewater. We conclude that understanding the heterogeneous context in which the envisioned wastewater users operate is key to predicting and solving conflicts that arise in treated wastewater reuse projects.

This study developed the SEWAGE-TRACK model for disaggregating lumped national wastewater generation estimates using population datasets and quantifying rural and urban wastewater generation and fate. The model allocates wastewater into riparian, coastal, and inland components and summarizes the fate of wastewater into productive (direct and indirect reuse) and unproductive components for 19 countries in the Middle East and North Africa (MENA) region. As per the national estimates, 18.4 km3 of municipal wastewater generated in 2015, was disaggregated over the MENA region. Results from this study revealed urban and rural areas to contribute to 79 % and 21 % of municipal wastewater generation respectively. Within the rural context, inland areas generated 61 % of the total wastewater. The riparian and coastal regions produced 27 % and 12 %, respectively. Within the urban settings, riparian areas produced 48 %, while inland and coastal regions generated 34 % and 18 % of the total wastewater, respectively. Results indicate that 46 % of the wastewater is productively used (direct reuse and indirect use), while 54 % is lost unproductively. Of the total wastewater generated, the most direct use was observed in the coastal areas (7 %), the most indirect reuse in the riparian regions (31 %), and the most unproductive losses in inland areas (27 %). The potential of unproductive wastewater as a non-conventional freshwater source was also analyzed. Our results indicate that wastewater is an excellent alternative water source and has high potential to reduce pressure on non-renewable sources for some countries in the MENA region. The motivation of this study is to disaggregate wastewater generation and track wastewater fate using a simple but robust approach that is portable, scalable and repeatable. Similar analysis can be done for other regions to produce information on disaggregated wastewater and its fate. Such information is highly critical for efficient wastewater resource management.

Globally, collection of tipping fees is being promoted as a solution to sustain the operation of fecal sludge treatment plants (FSTPs). Currently, there are six large-scale FSTPs in Ghana, of which five were in operation in June 2017. In Kumasi, Sekondi-Takoradi and Tamale, fecal sludge (FS) is co-treated with landfill leachate using waste stabilization ponds (WSPs). In Tema and Accra, FS is treated using WSPs and a mechanical dewatering system coupled with an upflow anaerobic sludge blanket (UASB). The focus of this study is FSTPs and to assess how, and if, the tipping fees set by the municipalities could enable cost recovery to sustain their long-term operation. Using a questionnaire survey to interview plant managers from the public and private sectors, and directors of waste management departments, we found that the overall average operation, maintenance and management (OMamp;M) costs per 1000 m3 of treated waste (FS or FS + leachate) in 2017 were USD89 in Kumasi, USD150 in Tamale, USD179 in Tema, USD244 in Sekondi-Takoradi and USD1,743 in Accra. There were important disparities between FSTPs due to their scale, age, and level of treatment and monitoring. Currently, most FSTPs charge tipping fees that range between USD310 and USD530/1000 m3 of FS, averaging USD421 98/1000 m3 of FS discharged at FSTPs. Our study also showed that the OMamp;M costs of large-scale intensive FSTPs cannot be sustained by relying solely on tipping fees. However, there could be potential to cover the routine expenditures associated with operating smaller FSTPs that relying on WSP technologies.

Urban and peri-urban agriculture (UPA) is widely distributed throughout the Global South. Despite urban population growth and diversifying food habits, UPA delivers an important part of urban food supply, as well as other types of services to cities, such as employment and waste reuse. Nevertheless, the extent and importance of UPA varies between different urban areas, while challenges like limited recognition, land conversion, and water pollution and competition threaten the potential of UPA to contribute to urban resilience. Key investment priorities for research and innovation for overcoming current challenges include incentivized peri-urban zoning, urban allocation of productive lands, and increasing capacities for controlled environment agriculture (CEA). Innovative repositioning of food marketing can help to strengthen supply of healthy food from UPA production, increase decent employment, and turn food markets into nutrition hubs. Priority innovations for contributing to the circular bioeconomy of cities include scaling the safe use of wastewater for irrigation through investments in the adoption of multiple risk-barrier approaches and scaling UPA-based ecosystem services for valorising solid waste and environmental management. Innovations in urban governance are required to support these processes by bringing food systems into urban planning through food mapping and the multisectoral platforms for dialogue and policy formulation across city regions and with vertical levels of government.

Kolkata being a metropolitan city in India has its main municipal solid waste dumpsite situated at Dhapa just adjacent to the East Kolkata Wetlands (Ramsar site). The current prevalent situation at Dhapa is open dumping leading to various contaminations and hazards putting forth the need to look for alternative sites where the landfiilling operation can be shifted to using scientific methods. A user interface (UI)–based analytical hierarchy process (AHP) tool has been developed within the Google Earth Engine (GEE) cloud platform to find out the alternative dumping sites using geospatial layers. AHP function is not available as a native algorithm or developed by any researcher in GEE. The tool has three major functionalities, of which the first one handles the UI elements. The AHP procedure is within another function, and the last function integrates the AHP coefficients to the layers generating the final suitability layer. Users can also upload comparison matrix as GEE asset in the form of CSV file which gets automatically integrated into the AHP to calculate the coefficients and consistency ratio to generate the spatial suitability layers. This approach showcases a generalized AHP function within the GEE environment, which has been done for the first time. The tool is designed in the cloud platform which is dynamic, robust and suitable for use in various AHP-based suitability analysis in environmental monitoring and assessment.

Water scarcity and pollution are major threats for human development in the Middle East and North Africa (MENA) region, and Lebanon is no exception. Wastewater treatment and reuse in agriculture can contribute to addressing the increasing water crisis in the MENA region. However, what is the actual potential of water reuse as a solution for agriculture in Lebanon? This report addresses this question and provides the most comprehensive assessment of water reuse potential up to now. Using geographic information system (GIS) modelling and the best and most recent data available in the country, the report develops a detailed technical assessment of the quantities of treated water available for safe reuse in irrigation, and identifies the wastewater treatment plants that have the highest potential for that purpose. The report also examines the governance barriers that need to be overcome for the water reuse potential to materialize in practice. These barriers include structural shortcomings in the wastewater sector combined with challenges of governance and the lack of a regulatory framework for reuse management. Once the current economic, financial and political crisis in Lebanon eases, addressing these barriers will be key to achieving more and safer water reuse in the country.

As urbanization increases, meeting the challenges of urban food supply and food security requires coherent and holistic strategies. Attention too often focuses solely on best practices without addressing the required behavior change. This policy brief highlights the importance of minimizing food loss and waste, which accounts for some 30% of current global production, in order to link and achieve SDGs 2, 11 and 12. The strategy comprises four interrelated elements, namely adopting holistic and circular planning perspectives; facilitating urban and peri-urban farming; integrating innovative behavioral interventions; and providing enabling environments. The G20 has the capacity to act rapidly, without the need for major capital investment, thereby also providing leadership to the entire international community.

This study investigated the potential of using locally available municipal solid wastes (MSW) (such as food wastes from restaurants, charcoal dust, coconut husk and shell, and sawdust) as feedstock to produce noncarbonized fuel briquettes. A low-cost briquetting machine sourced from Alfaster Industries in Kenya served to demonstrate the concept. Using decomposed food waste resulted in briquettes with higher bulk density (+4%), greater net calorific value (+18%) and lower burning rate (-24%), compared to the use of regular food waste. There was no significant difference in ash content from the two briquette types. The results also indicate that decomposing food waste and mixing it with tree-based raw materials such as coconut waste, charcoal waste or sawdust improves the quality of briquettes, and enhances the temperatures achieved during combustion. This recycling solution has the potential to serve multiple benefits in MSW management for sustainable cities while reducing rural land degradation and deforestation.

Fish inhabiting freshwater environments are susceptible to the ingestion of microplastics (MPs). Knowledge regarding MPs in freshwater fish in South Africa is very limited. In this study, the uptake of MPs by common carp (Cyprinus carpio) in the Vaal River in South Africa was assessed. MPs were detected in all of the twenty-six fish examined, 682 particles of MPs were recovered from the gastrointestinal tracts of the fish with an average of 26.23 12.57 particles/fish, and an average abundance of 41.18 52.81 particles/kg. The examination of the physical properties of MPs revealed a predominance on fibers (69%), small-sized particles of less than 0.5 mm (48%), as well as prevelance of coloured MPs (94%), mostly green, blue, and black. Using Raman Spectroscopy, the following plastic polymers were identified: high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE). To the best of our knowledge, this study, is the first to report MPs uptake by freshwater biota in the Vaal River using common carp as a target organism. It provided evidence of MP contamination in the Vaal.

The use of polluted water to irrigate is an increasing problem in the developing world. Lebanon is a case in point, with heavily polluted irrigation waters, particularly in the Litani River Basin. This study evaluated the potential health risks of irrigating vegetables (radishes, parsley, onions, and lettuce) using three water sources (groundwater, river water, and treated wastewater) and three irrigation methods (drip, sprinkler, and surface) over two growing seasons in 2019 and 2020. Water, crop, and soil samples were analyzed for physicochemical parameters, pathogens, and metals (Cu, Cd, Ni, Cr, and Zn). In addition, the bioaccumulation factor, estimated dietary intakes, health risk index, and target hazard quotients were calculated to assess the health risk associated with metal contamination. The study showed that, for water with less than 2 log E. coli CFU/100 mL, no pathogens (Escherichia coli, salmonella, parasite eggs) were detected in irrigated vegetables, irrespective of the irrigation method. With over 2 log E. coli CFU/100 mL in the water, 8.33% of the sprinkler-and surface-irrigated vegetables, and 2.78% of the drip-irrigated root crops (radishes and onions), showed some degree of parasitic contamination. E. coli appeared only on root crops when irrigated with water having over 3 log CFU/100 mL. The concentrations of most metals were significantly lower than the safe limits of the FAO/WHO of the Food Standards Programme Codex, except for zinc and chromium. The trends in the bioaccumulation factor and the estimated dietary intakes of metals were in the order of Cu lt; Cd lt; Ni lt; Cr lt; Zn. The target hazard quotient values for all metals were lower than 1.0. Under trial conditions, the adoption of drip irrigation with water with less than 3 log E. coli CFU/100 mL proved to be safe, even for vegetables consumed raw, except for root crops such as onions and radishes that should not be irrigated with water having over 2 log E. coli CFU/100 mL. Treated wastewater had no adverse effect on vegetable quality compared to vegetables irrigated with other water sources. These results support efforts to update the Lebanese standards for water reuse in agriculture; standards proposed in 2011 by the FAO, and currently being reviewed by the Lebanese Institution of Standards. This research will inform a sustainable water management policy aimed at protecting the Litani River watershed by monitoring water quality.

Using farm animals for their natural capability of “recycling” food waste (FW) that is unfit for direct human consumption can support a circular economy as shown in the case of Sri Lanka’s Western Province. The reuse of organic residues including FW as animal feed is a traditional agricultural practice in Sri Lanka but is less studied within an urban FW context. A survey of piggeries using FW in and around the rapidly urbanizing city of Colombo showed that FW is a major feed source in the farms accounting for on average 82% of total feed. About 40% of the farms collected the FW mainly from hotels, restaurants, and institutional canteens. Urban FW is supplied to farmers free of charge when collected directly from the sources, although 26% of the farmers collected FW via intermediaries against a fee. As FW is collected daily, the restaurants appreciate the reliable service, the farmers the low-cost feed, and the municipality the reduced FW volumes to be collected. However, this triple-win situation encounters challenges such as (tourist related) seasonal low supply, which was exacerbated under the Covid-19 lockdown of food services. Another area of concern refers to biosafety. Although the large majority of interviewed farmers boil FW which contains raw meat or fish, there is a paucity of related guidelines and control. Given the benefits of FW use, it is worthwhile to explore how far these informal partnerships could be scaled without increasing transport costs for farmers, while introducing biosafety monitoring. For now, the regulatory environment is highly siloed and does not support material transitions across sector boundaries towards a circular economy.

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.

Globally, the use of untreated, often diluted, or partly treated wastewater in agriculture covers about 30 million ha, far exceeding the area under the planned use of well-treated (reclaimed) wastewater which has been estimated in this paper at around 1.0 million ha. This gap has likely increased over the last decade despite significant investments in treatment capacities, due to the even larger increases in population, water consumption, and wastewater generation. To minimize the human health risks from unsafe wastewater irrigation, the WHO’s related 2006 guidelines suggest a broader concept than the previous (1989) edition by emphasizing, especially for low-income countries, the importance of risk-reducing practices from ‘farm to fork’. This shift from relying on technical solutions to facilitating and monitoring human behaviour change is, however, challenging. Another challenge concerns local capacities for quantitative risk assessment and the determination of a risk reduction target. Being aware of these challenges, the WHO has invested in a sanitation safety planning manual which has helped to operationalize the rather academic 2006 guidelines, but without addressing key questions, e.g., on how to trigger, support, and sustain the expected behaviour change, as training alone is unlikely to increase the adoption of health-related practices. This review summarizes the perceived challenges and suggests several considerations for further editions or national adaptations of the WHO guidelines.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world’s rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Eighty percent of wastewater is left untreated or not reused, exacerbating the water quality challenge, especially in vulnerable communities. This Voices asks: how can we improve wastewater management and convert wastewater into a resource?

The impact of climate change on the availability of water affects all types of land use and sectors. This complexity calls for integrated water resources management and negotiations between sectors on the most important, cost-effective, and productive allocation of water where it is a limited resource. This reflection paper shows examples of adaptation efforts to water scarcity at a scale where gains in water productivity can be derived from intersectoral water reuse and wastewater–freshwater swaps, complementing other water scarcity coping strategies (water savings, long-distance transfer, and desalination). Wastewater treatment for reuse offers opportunities across scales as it allows, for example, donor regions to be compensated with reclaimed water for the release of freshwater for higher-value use, increasing overall economic water productivity in this way. In such water swaps, farmers are compensated with higher water volumes in exchange for higher quality. The reuse of water between sectors offers opportunities to (i) expand the traditional (agricultural) water productivity concept and (ii) significantly increase water productivity at the system level. While rural–urban water reallocation can help mitigate the impacts of climate change, compensating farmers with reclaimed water remains limited for the reasons discussed in the paper.

Agricultural waste represents untapped resources that can be used to produce large value added products with many potential industrial applications. On-farm food waste comprises of harvest and post-harvest waste amounting to 1.2 billion tons per annum and measures up to USD 370 million. Production of food products and other outputs (like biofuel and compost) help in reduction of on-farm food waste and provide livelihood opportunities for the rural households. This reports highlights some innovative approaches across four countries which lead to reduction to food waste. The report cover 6 cases located in Burkina Faso, India, Kenya and Vietnam. The two business models identified in Ouagadougou are – (i) Waka group, that repurpose mango residues in to sweet and bio-vinyl vinegar called MISSIM vinegar, and (ii) SOFAB-SA utilizes oilseeds (such as peanuts, cotton, and soybeans) with blue cheese bran or corn, salt, or any other micro-ingredient to produce feed for livestock. From India, two such case studies are included – (i) Sai Shubhada agro industries is located in Ahmednagar, (Maharashtra, India), and converts bagasse, [a pulpy and fibrous residue of the sugarcane processing] into organic jiggery, and (ii) Arogyasangini Oil Mill, Mill has embarked on the mission to reintroduce oil extracted from the safflower seeds. Nadanya Greens located in Mbale, (Vihiga, Kenya) is exploring the use of farm waste from livestock to produce feeds for fish reared through three fish ponds. Xuan Tien Agricultural Cooperative, located at Yen Chau (Son La province, Vietnam), converts mango which is otherwise wasted post-harvest.

Agricultural waste can be widely adopted to manufacture biogas or biofuel, which is obtained from biomass or agricultural wastes like molasses, bagasse slurries manure etc. Agricultural waste is mostly burned or left decomposing on the fields, where it has potential for polluting the environment and release greenhouse gases. Recovering energy helps to (i) reduce greenhouse emissions by reducing environmental pollution from unwanted biomasses otherwise being burnt in the field; (ii) improve energy efficiency in heating systems from renewable energy sources; (iii) introduce renewable energy by substituting carbon neutral biomass for hydro-carbons (coal, heavy oil and gas); and (iv) Recycle ash residues or slurry as a fertilizer. The present report covers four case studies from Kenya and Burkina Faso related to recovering energy from agrowaste. Biogas International Limited (BIL) is a public private venture in Kenya involved in collection of market waste and recovering biogas, compost, liquid bio fertilizer. The Dunga Beach biogas plant in Kenya turns the invasive water hyacinth (Eichhornia crassipes) on the shores of Lake Victoria to biogas energy, an alternative to charcoal burning for fish vendors at the beach. Keveye Girls is a boarding high school located in Vihiga County. Through consultations and interventions by the Department of Agriculture and Livestock at Vihiga County, Keveye Girls now converts cow dung into biogas, which is then used to power the school’s science laboratories and kitchen as an alternative to LPG gas and wood energy. Similar case studies exist in Burkina Faso. FasoBiogaz, an SME was founded by two Dutch entrepreneurs and supported by the Dutch government and is fully operated by a local team. FasoBiogaz operates the first industrial biogas plant connected to the SONABEL power grid and provides innovative resource recovery solutions producing 550 KW of power.

This study assessed the investment climate for circular bioeconomy in Kenya by reviewing the national policies, strategies and regulations, financing mechanisms, infrastructure and business environment. The study identified key gaps in these areas affecting waste management and entrepreneurship development in the circular bioeconomy sector. There are key developments at the policy level and some developments in entrepreneur promotion in resource recovery from different waste streams. The specific focus of the policies, strategies and regulations in the waste sector, lack of coordination of the relevant sectors in waste management, weak horizontal communication between sectors and implementation and compliance problems are main gaps in promoting circular bioeconomy. Absence of drastic changes in actual behaviour such as waste separation at source and lack of incentives in entrepreneurial development are also critical challenges. While addressing these gaps, the progresses identified need to be further scaled out to make waste management and circular bioeconomy in Kenya sustainable. Establishment of multiple stakeholder platforms involving key actors in the sector and enhancing awareness is important in promoting resource recovery and reuse. Promotion of incubator centres to enhance local capacity and foster uptake of resource recovery and reuse businesses is critical.

Agricultural waste represents untapped resources that can be used to produce large value added products with many potential industrial applications. The use of agricultural wastes as raw materials for various industrial applications can help to reduce production cost and contribute to environmental conservation. The business cases described in this report highlight innovative approaches to convert the growing amount of agricultural waste into eco-efficient and bio-based products which are essential components of Nature-based solutions.

Plastic usage increases year by year, and the growing trend is projected to continue. However as of 2017, only 9% of the 9 billion tons of plastic ever produced had been recycled leaving large amounts of plastics to contaminate the environment, resulting in important negative health and economic impacts. Curbing this trend is a major challenge that requires urgent and multifaceted action. Based on scientific and gray literature mainly published during the last 10 years, this review summarizes key solutions currently in use globally that have the potential to address at scale the plastic and microplastic contaminations from source to sea. They include technologies to control plastics in solid wastes (i.e. mechanical and chemical plastic recycling or incineration), in-stream (i.e. booms and clean-up boats, trash racks, and sea bins), and microplastics (i.e. stormwater, municipal wastewater and drinking water treatment), as well as general policy measures (i.e. measures to support the informal sector, bans, enforcement of levies, voluntary measures, extended producer responsibility, measures to enhance recycling and guidelines, standards and protocols to guide activities and interventions) to reduce use, reuse, and recycle plastics and microplastics in support of the technological options. The review discusses the effectiveness, capital expenditure, and operation and maintenance costs of the different technologies, the cost of implementation of policy measures, and the suitability of each solution under various conditions. This guidance is expected to help policymakers and practitioners address, in a sustainable and cost-efficient way, the plastic and microplastic management problem using technologies and policy instruments suitable in their local context.

The benefit of biochar as a soil fertility enhancer is well known and has been broadly investigated. Equally, many tropical and subtropical countries use wastewater for irrigation in urban agriculture. To assess the related health risks, we determined pathogen and heavy metal fate associated with biochar application and wastewater irrigation in the urban agriculture of northern Ghana. Rice (Oryza L.) husk biochar (20 t ha-1), N–P–K 15–15–15 fertilizer (212.5 kg ha-1), and their combinations were evaluated in a field-based experiment. Untreated wastewater and tap water served as irrigation water. Red amaranth (Amaranthus cruentus L.) was used as a test crop and was grown in wet (WS) and dry (DS) cropping seasons. Irrigation water, soil, and vegetables were analyzed for heavy metals, Escherichia coli, fecal coliform, helminth eggs, and Salmonella spp. Unlike the pathogens, analyzed heavy metals from irrigation water and soil were below the FAO/WHO permissible standard for agricultural activities. Wastewater irrigation caused E. coli concentrations ranging from 0.5 to 0.6 (WS) and from 0.7 to 0.8 (DS) log10 colony forming units per gram fresh weight (CFU gFW-1) on vegetables and from 1.7 to 2.1 (WS) and from 0.6 to 1.0 (DS) log10CFU per gram dry weight (gDW-1) in soil. Average log10CFU gFW-1 rates of 6.19 and 3.44 fecal coliform were found on vegetables, whereas in soil, 4.26 and 4.58 log10CFU gDW-1 were observed in WS and DS, respectively. Helminth egg populations were high in wastewater and were transferred to the crops and soil. Biochar did not affect bacteria contamination. Pathogen contamination on vegetables and in soil were directly linked to the irrigation water, with minimal or no difference observed from biochar application.

Wastewater-fed aquaculture has a long history, especially in Asia. This report examines three empirical cases of integrated wastewater treatment and aquaculture production. From an aquaculture entrepreneur’s perspective, the combination of fish farming and wastewater treatment in common waste stabilization ponds allows significant savings on capital (pond infrastructure) and running costs (wastewater supporting fish feed). On the other hand, the treatment plant owner will have the benefit of a partner taking over plant maintenance. Given the importance of food safety and related perceptions, the report is focusing on innovative business models where the marketed fish is not in direct contact with the treated wastewater, but only the brood stock or fish feed. The financial analysis of the presented systems shows profitable options for the fish farmer, operational and in part capital cost recovery for the treatment plant, and as the treatment plant operators can stop charging households a sanitation fee, eventually a triple-win situation for both partners and the served community.

Wastewater reuse is identified as strategic to help ameliorate scarcity in water-stressed regions around the world. However, to develop it, there is a need to better understand the social, institutional and technological contexts in which it takes place. This article develops a novel socio-technical framework to inform such an analysis and applies it to current wastewater reuse in Egypt. Our analysis highlights the different actors, management activities and practices that shape wastewater collection, transfer, treatment, discharge and/or reuse in different social, technological and environmental contexts in Egypt. It points out bottlenecks of current wastewater reuse policies and programmes.

A necessary extension of the concept of Resource Recovery and Reuse with an even higher priority is the prevention and reduction of waste. One concern, in particular, is food waste, which constitutes the largest share of human waste. Target 12.3 of the United Nations Sustainable Development Goals (SDGs) is to ‘halve per capita global food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses, by 2030’. For this report, over 400 businesses were analyzed to identify common approaches and business models to address the food waste challenge. The business models are presented under seven categories – measurement, redistribution, resell, value addition, responsible waste collection, resource recovery, and recycling – with a special focus on their application potential to the Global South.

Implementing a circular economy approach to sanitation requires knowledge of the costs to construct, operate and maintain resource-oriented systems. Yet the dearth of data on costs of urban sanitation in general, and resource-oriented systems in particular, limit opportunities to progress sustainable sanitation in low- and middle-income countries. This paper contributes empirical data on the life-cycle costs of a resource-oriented sanitation system in urban Sri Lanka, addressing a gap in evidence about how much it costs, and who pays, for a system that integrates fecal sludge management with nutrient capture and reuse. Costs across the system life-cycle were analyzed according to: (i) cost type; (ii) phases of the sanitation chain; and (iii) distribution between actors. Over a 25-year lifespan, the system had an annualized cost of USD 2.8/person or USD 11/m3 of septage treated. Revenue from co-compost sales covered reuse-related costs plus 8% of present value costs for other phases of the sanitation chain. Findings affirm both the potential for resource-oriented sanitation to generate revenue, and the need for substantial complementary investment in the overall system. The system was found to be reliant on household investment, yet financially viable from the service provider perspective with revenue from desludging services (89%) and co-compost sales (11%) that exceeded costs over the system lifespan and in most years. The analysis of total costs, financial perspectives, and reuse specifics contributes critical evidence to inform policy and planning that supports a purposeful and equitable transition towards circular economy approaches to sanitation.

Safely managed waste reuse may be a sustainable way to protect human health and livelihoods in agrarian-based countries without adequate sewerage. The safe recovery and reuse of fecal sludge-derived fertilizer (FSF) has become an important policy discussion in low-income economies as a way to manage urban sanitation to benefit peri-urban agriculture. But what drives the user acceptance of composted fecal sludge? We develop a preference-ranking model to understand the attributes of FSF that contribute to its acceptance in Karnataka, India. We use this traditionally economic modeling method to uncover cultural practices and power disparities underlying the waste economy. We model farmowners and farmworkers separately, as the choice to use FSF as an employer versus as an employee is fundamentally different. We find that farmers who are willing to use FSF prefer to conceal its origins from their workers and from their own caste group. This is particularly the case for caste-adhering, vegetarian farmowners. We find that workers are open to using FSF if its attributes resemble cow manure, which they are comfortable handling. The waste economy in rural India remains shaped by caste hierarchies and practices, but these remain unacknowledged in policies promoting sustainable ‘business’ models for safe reuse. Current efforts under consideration toward formalizing the reuse sector should explicitly acknowledge caste practices in the waste economy, or they may perpetuate the size and scope of the caste-based informal sector.

Recycling of wastewater provides a substantial solution to the global issue of water scarcity and high water use in aquaculture. However, this sustainable way of wastewater use has not been given much attention and exploration. This study focused on the consumer preference for fish grown in treated wastewater as well as the effect of aeration on the growth performance and economic benefit of African catfish (Clarias gariepinus) grown in treated wastewater. Two hundred (200) respondents from two communities (Chirapatre and Gyinyase) near the wastewater treatment plant in Kumasi were interviewed to determine their willingness to accept and pay for African catfish grown in treated wastewater. For the growth trial, a total of 600 fish (of average initial weight 39.12g) were stocked in two maturation ponds with 4 h (3:00am–7:00am) of aeration daily. The trial lasted for 12 weeks and variables monitored included the survival, growth performance (weight gain, specific growth rate, and yield) and water quality. Fish cultured in non-aerated wastewater ponds (NWFPs) under similar conditions as in aerated wastewater-fed ponds (AWFPs) served as control. The results indicated most important considerations for consumers in their choice of fish to consume were in order of importance; food safety, freshness of fish, taste and packaging. The proximity of consumers to the treatment plant, the price of fish, religion, and age and whether or not they were fish consumers affected their willingness to pay for African catfish grown in the treated wastewater significantly. For the growth trial, dissolved oxygen concentrations in the aerated ponds were significantly higher than in the NWFPs and this led to more than a doubling of the growth rates in the African catfish grown in the AWFPs (189.10g 11.32) as compared to the NWFPs (90.70g 11.59). The pond aeration improved fish growth significantly (p lt; 0.0098). On economic benefit, the aerated system yielded profits of 618.83 (103.13) as compared to a loss of 104.99 (17.50), which was incurred in the non-aerated ponds. Education of the consumers on the process of wastewater treatment and establishment of food safety guidelines will therefore be recommended to increase consumer interest in consuming fish from the treated wastewater.

Large cities in developing countries are facing the challenge of rapid urban population growth, which results in increasing waste generation. In Nairobi, the solid waste situation is characterized by low coverage of collection, pollution from uncontrolled dumping, inefficient public services, unregulated and uncoordinated private sector operators and lack of key solid waste management infrastructure. About 3,121 tons of municipal solid waste (MSW) is generated daily, of which about 850 tons are collected and the remaining is burnt or dumped in unauthorized sites or landfilled in the Dandora dumpsite causing health and environmental problems. The recovery of nutrients from the organic content of MSW for reuse in agriculture has the potential to address the dual challenge of waste management and soil nutrient depletion. This study assessed the economic and environmental impact of decentralized composting business model in Nairobi based on a comparison with the baseline scenario using an indicator expressed in tons CO2 equivalent. The cost–benefit analysis was based on data collected from existing compost plants in Kenya. To assess the sensitivity of the results to variation in input variables, a simulation model was developed using the Monte Carlo method. The decentralized composting business model resulted in a net GHG emission saving of 1.21 tons CO2-eq/ton of compost, being both financially and economically feasible with more than 70% chance of economic success. Assessing the economic and environmental impact is an important tool for decision making and to ensure that the business model results in desired benefits to society.

Sustainable management of municipal solid waste (MSW) is a critical issue around the world, especially in South Asia where waste generation is expected to double by 2050. Closing the food-nutrient cycle through composting biodegradable MSW has the potential to meet human needs, including sanitation and food security, while protecting the environment. We use an interdisciplinary case study approach including systems thinking to assess Sri Lanka’s national MSW composting system, which primarily receives residential and commercial food waste. We embed quantitative compost quality analysis and interviews at 20 composting facilities within a broader qualitative assessment informed by ~60 stakeholders in total. This approach yields insights on how institutional, economic, social, and biophysical aspects of the system are interrelated, and how challenges and solutions can create undesirable and desirable cascading effects, respectively. Such dynamics can create risks of composting facility failure and unintended consequences, diminishing the chances of achieving a sustainable circular food–nutrient system. Compost quality, which was variable, plays a pivotal role within the system—a function of program design and implementation, as well as a determinant of value capture in a circular economy. We make several recommendations to inform future efforts to sustainably manage biodegradable MSW using composting, drawing on our case study of Sri Lanka and prior case studies from other nations. Key among these is the need for increased emphasis on compost product quality and markets in policy and program design and implementation. Targeted measures are needed to improve waste separation, boost compost quality, effectively use compost standards, encourage compost market development, ringfence the revenues generated at municipal compost plants, and identify efficient modes of compost distribution. Such measures require adequate space and infrastructure for composting, resource investment, local expertise to guide effective system management, strong links with the agriculture sector, and continued political support.

The use of food waste (FW) from food services as animal feed through informal agreements has been in practice for many years in Sri Lanka. However, data to show the scale of this practice are inadequate. This paper aims to study the extent of FW diverted to piggeries and the opportunities and challenges in reusing FW as animal feed. The data were collected via telephonic survey from 24 piggery farmers in the Western Province in May 2020. Results revealed that 50% of farmers were rearing 100-300 pigs. Farmers used FW as a major feed source to satisfy 82% of total feed requirement on an average. About 40% of the farmers collected the FW from multiple sources such as hotels, restaurants and canteens. Given that the piggery farms are located in peri-urban areas, the average distance traveled by the farmers is 38 km up and down which indicated the value of FW for them. FW was supplied mostly free of charge; however, 26% of the farmers pay LKR 2 to 40/kg when supplied by intermediaries. FW was collected daily, and the amount collected by the farmers varies 50 to 10000 kg/day depending on demand and supply, with 75% of farmers collected less than 1000 kg/day.

Little is known about the occurrence of emerging pollutants (EPs) in waters in the Middle East and North Africa (MENA) region despite the extensive use of low-quality water there. Available data dealing with the sources, occurrence and removal of EPs within the MENA region in different categories of water is collected, presented and analyzed in this literature review. According to the collected database, the occurrence and removal efficiency of EPs in the water matrix in the MENA region is available, respectively, for 13 and six countries of the 18 in total; no available data is registered for the rest. Altogether, 290 EPs have been observed in different water matrices across the MENA countries, stemming mainly from industrial effluents, agricultural practices, and discharge or reuse of treated wastewater (TWW). Pharmaceutical compounds figure among the most frequently reported compounds in wastewater, TWW, surface water, and drinking water. Nevertheless, pesticides are the most frequently detected pollutants in groundwater. Worryingly, 57 cases of EPs have been reported in different fresh and drinking waters, exceeding World Health Organization (WHO) and European Commission (EC) thresholds. Overall, pharmaceuticals, organic compounds, and pesticides are the most concerning EP groups. The review revealed the ineffectiveness of treatment processes used in the region to remove EPs. Negative removals of some EPs such as carbamazepine, erythromycin, and sulfamethoxazole were recorded, suggesting their possible accumulation or release during treatment. This underlines the need to set in place and strengthen control measures, treatment procedures, standards, and policies for such pollutants in the region.

This report examines social equality aspects related to resource recovery through solid waste composting and wastewater irrigation. The report shows that women are represented in greatest numbers at the base of the recycling chain, most often as informal waste pickers and as sorters of recyclables with limited access to resources and upward mobility. Despite a wide gender gap in the solid waste and sanitation sectors, women play a key role in both municipal waste reduction and food safety where irrigation water is unsafe. Analyzing the gender dimension is important for understanding household responses to recycling programs, differences between the formal and informal sectors as well as along the waste-to-resource value chain from collection to treatment and reuse. The report stresses the important role of women in household waste management, including waste segregation, and the power of women-dominated waste picker associations, where the informal sector plays an essential role alongside the formal sector.

In 2019, Sri Lanka introduced two policies that referred to food waste and the need to reduce it. To understand key stakeholders’ readiness in this context, this study analyzed the food waste perceptions of private and public sectors in Colombo (open markets, supermarkets, hotels, restaurants, canteens, food caterers and key authorities). Interviews were carried out with operational managers and public officials, as well as other stakeholders who have roles in food waste redistribution and reuse, such as NGOs and the livestock sector. So far, the food-waste-related policy recommendations lack an operational inter-institutional home which can build on measures, like standards, regulations and incentives. Thus, most food waste reduction initiatives are initiated by NGOs or by the private sector, e.g., by larger hotels and supermarket chains. These entities were ready to lead by example, based on the understanding that urban food waste is an internal (financial) management challenge. Among smaller local entities, food waste was perceived more as an external issue to be handled by the city’s waste collection services. Although perceptions varied between entities generating smaller or larger quantities of food waste, there was general agreement that suboptimal capacities and mechanisms to quantify, monitor and cost food waste generation appeared to be obstacles for in-depth awareness creation and action. There was significant interest in communication platforms for cross-sectoral learning, win/win collaborations with reliable collection (reuse) services that are currently operational, such as those provided by piggeries, as well as surplus redistribution initiatives if food safety and related liabilities can be addressed effectively.

This chapter documents and assesses available best practices and technologies that can be employed to mitigate the release of microplastics from textiles and tyres into the environment. The chapter follows a life-cycle approach, discussing options implementable at the design and manufacturing, use and end-of-life phases, as well as options for the end-of-pipe capture of microplastics.

In many parts of the world, wastewater irrigation has become a common practice because of freshwater scarcity and to increase resource reuse efficiency. Wastewater irrigation has positive impacts on livelihoods and at the same time, it has adverse impacts related to environmental pollution. Hydrochemical processes and groundwater behaviour need to be analyzed for a thorough understanding of the geochemical evolution in the wastewater irrigated systems. The current study focuses on a micro-watershed in the peri-urban Hyderabad of India, where farmers practice intensive wastewater irrigation. To evaluate the major factors that control groundwater geochemical processes, we analyzed the chemical composition of the wastewater used for irrigation and groundwater samples on a monthly basis for one hydrological year. The groundwater samples were collected in three settings of the watershed: wastewater irrigated area, groundwater irrigated area and upstream peri-urban area. The collected groundwater and wastewater samples were analyzed for major anions, cations and nutrients. We systematically investigated the anthropogenic influences and hydrogeochemical processes such as cation exchange, precipitation and dissolution of minerals using saturated indices, and freshwater-wastewater mixtures at the aquifer interface. Saturation indices of halite, gypsum and fluorite are exhibiting mineral dissolution and calcite and dolomite display mineral precipitation. Overall, the results suggest that the groundwater geochemistry of the watershed is largely controlled by long-term wastewater irrigation, local rainfall patterns and water-rock interactions. The study results can provide the basis for local decision-makers to develop sustainable groundwater management strategies and to control the aquifer pollution influenced by wastewater irrigation.

Globally, 50% of the population relies on on-site sanitation systems (OSS) such as septic tanks and pit latrines and is, hence, in need of Fecal Sludge Management (FSM) solutions. India is a classic example, given that its government built more than 100 million toilets with the majority relying on OSS. With 400 fecal sludge treatment plants (FSTPs) in various stages of planning, procurement and construction, this report comes at an opportune time to present findings on FSM business models already implemented across India. Interviews were conducted with a total of 105 Emptying and Transport (Eamp;T) operators in 72 towns and cities across 16 states in India, 22 representatives from municipalities that own emptying vehicles, 18 FSTP operators and more than 30 institutions. In addition, procurement tenders for Eamp;T and FSTPs in 13 states were analyzed. In total, 18 business models were identified, several with energy or nutrient recovery components. The analysis of Eamp;T operators revealed clear differences that steer a business towards success or failure. The majority of operators still dispose fecal sludge in an unsafe manner, due to the lack of official disposal or treatment sites. In comparison to sewer networks, the capital and operating costs (per capita) of FSTPs were significantly lower. The report provides evidence-based discussions on policies and recommendations for scaling and sustaining FSM.

We describe the technical feasibility of metagenomic water quality analysis using only portable equipment, for example mini-vacuum pumps and filtration units, mini-centrifuges, mini-PCR machines and the memory-stick sized MinION of Oxford Nanopore Technologies, for the library preparation and sequencing of 16S rRNA gene amplicons. Using this portable toolbox on site, we successfully characterized the microbiome of water samples collected from Birtley Sewage Treatment Plant, UK, and its environs. We also demonstrated the applicability of the portable metagenomics toolbox in a low-income country by surveying water samples from the Akaki River around Addis Ababa, Ethiopia. The 16S rRNA gene sequencing workflow, including DNA extraction, PCR amplification, sequencing library preparation, and sequencing was accomplished within one working day. The metagenomic data became available within 24e72 h, depending on internet speed. Metagenomic analysis clearly distinguished the microbiome of pristine samples from sewage influenced water samples. Metagenomic analysis identified the potential role of two bacterial genera not conventionally monitored, Arcobacter and Aeromonas, as predominant faecal pollution indicators/waterborne hazards. Subsequent quantitative PCR analysis validated the high Arcobacter butzleri abundances observed in the urban influenced Akaki River water samples by portable next generation sequencing with the MinION device. Overall, our field deployable metagenomics toolbox advances the capability of scientists to comprehensively monitor microbiomes anywhere in the world, including in the water, food and drinks industries, the health services, agriculture and beyond.

Peri-urban areas are characterized by multifunctional land-use patterns forming a mosaic of built-up and agricultural areas. They are critical for providing food and other agricultural products, livelihood opportunities and multiple ecosystem services, which makes them transformative where urban and rural spaces blend. We analyzed land use changes in a peri-urban micro-watershed in Southern India by using Google Earth data to understand the micro-level spatio-temporal dynamics. This study aims at understanding the peri-urban agriculture and landscape changes as related to the change in use of wastewater and groundwater for irrigation. The temporal dynamics of peri-urban system including the changes in built-up, paragrass, paddy rice and vegetable cultivation, groundwater and wastewater irrigated areas in the watershed were evaluated. The detected changes indicate that, as a consequence of urban pressures, agricultural landscapes are being converted into built-up areas and, at the same time, former barren land is converted to agricultural plots. The mapped land use data are used in landscape change modelling for predicting the peri-urban agricultural dynamics and the driving factors in the watershed. Combined with the mapping and modelling approaches for land use change analysis, our results form the basis for integrated resources management in the wastewater influenced peri-urban systems.

Based on primary data from fecal sludge (FS) treatment plants in three West African urban regions (Ouagadougou in Burkina Faso, Greater Accra in Ghana, and Grand Nokou in Benin), FS collection and treatment patterns were analyzed to identify possible scenarios for resource recovery (RR) through FS co-composting. FS collection was analyzed for up to 7 years, in part per day, month and season, as well as FS characteristics to understand peak flows, FS qualities and related variations to plan for appropriate RR technology and capacities. Overall, the FS volumes collected by vacuum trucks were not significantly affected by the calendar days, months or seasons. Commonly assumed increases during rainy months were, for example, only recorded in Ouagadougou. FS composition appeared highly variable with a pronounced difference in total solids between FS collected from households versus institutional sources, likely indicating that institutions are served more frequently. The analyzed treatment plants appear to be exploited beyond their capacity. RR for reuse can turn sludge disposal from a cost into a source of revenue with co-benefits for farmers and the environment, thereby reducing the pressure on tipping fees. The probability of the added co-compost production being financially viable on its own was estimated for all the study sites, indicating an earliest breakeven point after 5 to 8 years.

Climatic variability and change result in unreliable and uncertain water availability and contribute to water insecurity in Africa, particularly in arid and semi-arid areas and where water storage infrastructure is limited. Managed aquifer recharge (MAR), which comprises purposeful recharge and storage of surface runoff and treated wastewater in aquifers, serves various purposes, of which a prominent one is to provide a means to mitigate adverse impact of climate variability. Despite clear scope for this technology in Africa, the prevalence and range of MAR experiences in Africa have not been extensively examined. The objective of this article is provide an overview of MAR progress in Africa and to inform the potential for future use of this approach in the continent. Information on MAR from 52 cases in Africa listed in the Global MAR Portal and collated from relevant literature was analyzed. Cases were classified according to 13 key characteristics including objective of the MAR project, technology applied, biophysical conditions, and technical and management challenges. Results of the review indicate that: (i) the extent of MAR practice in Africa is relatively limited, (ii) the main objective of MAR in Africa is to secure and augment water supply and balance variability in supply and demand, (iii) the surface spreading/infiltration method is the most common MAR method, (iv) surface water is the main water source for MAR, and (v) the total annual recharge volume is about 158 Mm3 /year. MAR schemes exist in both urban and rural Africa, which exemplify the advancement of MAR implementation as well as its out scaling potential. Further, MAR schemes are most commonly found in areas of high inter-annual variability in water availability. If properly planned, implemented, managed, maintained and adapted to local conditions, MAR has large potential in securing water and increasing resilience in Africa. Ultimately, realizing the full potential of MAR in Africa will require undertaking hydrogeological and hydrological studies to determine feasibility of MAR, especially in geographic regions of high inter-annual climate variability and growing water demand. This, supported by increased research to gauge success of existing MAR projects and to address challenges, would help with future siting, design and implementation of MAR in Africa.

This article reviews the negative impact of anthropogenic changes on groundwater. The main changes in physical and geographical conditions that occur under the impact of anthropogenic pressures and that have the most significant influence on the state of groundwater, as well as a negative impaction the conditions of the formation of groundwater are: changes in the landscape caused by agricultural works, mining, construction of settlements, etc.; changes in the hydrographic network caused the construction of hydroelectric power facilities; changes in the composition of the atmospheric air; changes in the groundwater level regime, climatic conditions. The most significant factor of change in groundwater formation conditions is the progressive anthropogenic pollution of groundwater. It negatively influences the number of resources and their quality.

Investments in irrigation contribute to poverty reduction and enhance food security. This paper considers irrigation investments more broadly in the context of rural–urban linkages and thus examines rural irrigation schemes and peri-urban and urban agriculture using freshwater, groundwater and wastewater. We present case studies from East, West and Southern Africa, while focusing on the imperative of smallholders and of food security and nutrition. Evidence from Big Data and telecoupling show that, amid global change and sustainability issues, irrigation development strengthens connections between humans and nature with notable benefits to food security. Transforming investments to feed the future generation require priority investments in irrigation, solar energy for groundwater pumping, groundwater development policy, and integration of peri-urban and urban agriculture into food systems. Equally important will be no-regret interventions in wastewater reuse, water storage and groundwater buffer, micro-irrigation, and wholesale reconfiguration of farming systems, through anticipatory investments, to safeguard food security and sustainability into the distant future.

Urbanisation will be one of the 21st centuryapos;s most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. N50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

This chapter addresses the current state of water and climate finance, the costs of inaction versus the benefits of action, and several ways to access climate finance flows to improve water management as well as water supply and sanitation services, while synergistically mitigating and/or adapting to climate change.

This chapter focuses on the human health impacts associated with changes in water quality and quantity due to climate change. Trends in morbidity and mortality are examined in the context of health risks associated with climate change, and response options related to water supply and sanitation are presented.

This chapter establishes linkages between climate change and various aspects of water management. Adaptation and resilience-building options are presented with respect to water storage – including groundwater – and water supply and sanitation infrastructure, and unconventional water supply options are described. Mitigation options for water management systems are also presented.

Over the last decade, the International Water Management Institute (IWMI) has explored the use of fecal sludge (FS) in combination with other organic waste sources to optimize FS treatment and composting for the production of a safe organic fertilizer, which can – depending on demand – be enriched with crop nutrients or pelletized for volume reduction, delayed decomposition or easier application. Based on IWMI’s experience, this training manual has been compiled for plant managers and trainers to help ensure that staff involved in FS treatment and production, and application of an FS-based co-compost adopt best practices in all processes involved. The manual can be adapted to local needs as required. It also includes information on compost registration and certification, as well as guidelines for co-compost application in the field.

There is a proactive interest in recovering water, nutrients and energy from waste streams with the increase in municipal wastewater volumes and innovations in resource recovery. Based on the synthesis of wastewater data, this study provides insights into the global and regional “potential” of wastewater as water, nutrient and energy sources while acknowledging the limitations of current resource recovery opportunities and promoting efforts to fast-track highefficiency returns. The study estimates suggest that, currently, 380 billion m3 (m3 = 1,000 L) of wastewater are produced annually across the world which is a volume fivefold the volume of water passing through Niagara Falls annually. Wastewater production globally is expected to increase by 24% by 2030 and 51% by 2050 over the current level. Among major nutrients, 16.6 Tg (Tg = million metric ton) of nitrogen are embedded in wastewater produced worldwide annually; phosphorus stands at 3.0 Tg and potassium at 6.3 Tg. The full nutrient recovery from wastewater would offset 13.4% of the global demand for these nutrients in agriculture. Beyond nutrient recovery and economic gains, there are critical environmental benefits, such as minimizing eutrophication. At the energy front, the energy embedded in wastewater would be enough to provide electricity to 158 million households. These estimates and projections are based on the maximum theoretical amounts of water, nutrients and energy that exist in the reported municipal wastewater produced worldwide annually. Supporting resource recovery from wastewater will need a step-wise approach to address a range of constraints to deliver a high rate of return in direct support of Sustainable Development Goals (SDG) 6, 7 and 12, but also other Goals, including adaptation to climate change and efforts in advancing “netzero” energy processes towards a green economy.

In low- and middle-income countries, the management of fecal sludge from on-site sanitation systems has received little attention over many decades, resulting in insufficient or missing regulations to guide investments and management options. To address this gap, this report examines existing and emerging guidelines and regulations for fecal sludge management (FSM) along the sanitation service chain (user interface, containment, emptying, transport, treatment, valorization, reuse or disposal). It also draws empirical examples from guidelines across the globe to support policy-makers, planners, and sanitation and health officers, as well as consultants in low- and middle-income countries in the development and design of local and national FSM guidelines and regulations.

Fecal sludge (FS) contains a significant amount of plant nutrients. FS (treated/untreated) has been used as soil ameliorant in several countries. Use of FS-based compost on lettuce may meet reservations due to possible microbiological contamination. The objectives of this research are: (1) To determine the fertilizer value of different formulations of sawdust and fecal sludge compost (SDFS) pellets, and (2) to compare the effect of these SDFS formulations with poultry manure, commercial compost, mineral fertilizer, and non-fertilization on lettuce cultivation. The SDFS products were made by enriching, and pelletized with ammonium sulphate, mineral-NPK, or ammonium sulphate + muriate of potash + triple superphosphate. Lettuce was cultivated in a greenhouse and an open field. The result showed that the saleable fresh weight lettuce yield obtained from all SDFS pellets with/without enrichments were higher than those obtained from commercial compost, poultry manure, mineral fertilizer, or no fertilizer. Cultivation in the open field gave higher yields than those in the greenhouse. No helminth eggs were detected in composts or lettuces. Some fecal coliforms were detected in lettuces fertilized with almost all fertilizers tested, including NPK and non-fertilized control. A properly treated fecal sludge-based fertilizer can be a sustainable solution for lettuce production, which helps urban and peri-urban agriculture.

The Arab region needs a new generation of policies and investments in agricultural water. Agricultural water management has always posed challenges and opportunities in the Arab world. However, unprecedented and accelerating drivers such as climate change, population growth, and land degradation make agricultural water management a more urgent priority than ever before. In addition, as part of the 2030 UN Agenda for Sustainable Development, Arab countries have committed to work towards an ambitious set of development targets, the Sustainable Development Goals (SDGs). Unless the right policies and investments are put in place, it will be difficult to achieve the SDGs, including ending hunger and providing clean water and sanitation for all. This paper is part of an ongoing collaboration between the Food and Agriculture Organization of the United Nations (FAO) and the International Water Management Institute to foster dialogue on agricultural water policies and investments in the context of the FAO led Regional Water Scarcity initiative. The purpose of the paper is to frame the key challenges and opportunities in the sector – including emerging innovations in digital agriculture, water accounting, water supply and wastewater reuse – and to lay out broad strategic directions for action.

The Indus River Basin faces severe water quality degradation because of nutrient enrichment from human activities. Excessive nutrients in tributaries are transported to the river mouth, causing coastal eutrophication. This situation may worsen in the future because of population growth, economic development, and climate change. This study aims at a better understanding of the magnitude and sources of current (2010) and future (2050) river export of total dissolved nitrogen (TDN) by the Indus River at the sub-basin scale. To do this, we implemented the MARINA 1.0 model (Model to Assess River Inputs of Nutrients to seAs). The model inputs for human activities (e.g., agriculture, land use) were mainly from the GLOBIOM (Global Biosphere Management Model) and EPIC (Environmental Policy Integrated Model) models. Model inputs for hydrology were from the Community WATer Model (CWATM). For 2050, three scenarios combining Shared Socio-economic Pathways (SSPs 1, 2 and 3) and Representative Concentration Pathways (RCPs 2.6 and 6.0) were selected. A novelty of this study is the sub-basin analysis of future N export by the Indus River for SSPs and RCPs. Result shows that river export of TDN by the Indus River will increase by a factor of 1.6–2 between 2010 and 2050 under the three scenarios. N90% of the dissolved N exported by the Indus River is from midstream sub-basins. Human waste is expected to be the major source, and contributes by 66–70% to river export of TDN in 2050 depending on the scenarios. Another important source is agriculture, which contributes by 21–29% to dissolved inorganic N export in 2050. Thus a combined reduction in both diffuse and point sources in the midstream sub-basins can be effective to reduce coastal water pollution by nutrients at the river mouth of Indus.

This study applied a combined analytical hierarchy process (AHP) and goal programming (GP) model to assist decision makers in identifying and prioritizing key investment climate (IC) indicators for waste recycling and reuse enterprises in developing countries. Taking a sector based perspective, key IC criteria and indicators were identified and ranked through country stakeholder workshops in Ghana and Kenya. Three different key decision maker groups namely government agencies, private waste reuse enterprises and non-governmental organizations (NGOs) were involved in identifying and ranking of IC criteria and indicators. The IC criteria identified were policy and infrastructure, finance, business support and markets. A number of indicators across each of the criteria were also identified. By incorporating qualitative and quantitative assessments, criteria and indicator rankings are determined using the AHP and GP model. Model results for Ghana revealed that both the private sector and NGO group ranked finance as the most important criterion while markets was the most important criterion for the government organization group. In contrast, none of the stakeholder groups in Kenya ranked finance as the most important criterion. This indicates that reform priorities of waste reuse sector vary across countries depending on the country’s current situation. The approach adopted in this study enables the criteria and indicators for assessing sector specific investment climate to be clearly identified and the decision making problem to be structured systematically. The exercise can be extended to other countries to elicit priority ranking of IC criteria and indicators for waste reuse enterprises.

This study assesses the microbial and heavy metal distribution in African catfish (Clarias gariepinus) cultured in waste stabilization pond, and their subsequent suitability for human consumption. Treated wastewater-fed pond (WFP) was used in the culture of the fish with a non-wastewater fed pond (NWFP), fed with ground and rain water as control. Pond water, sediments and fish tissue (gill, liver, gut and skin) samples from both sources were analyzed for pathogens and heavy metal levels. Escherichia coli populations in the sediments and water from the WFP exceeded the maximum permissible limit by 2–3 log units as expected. Significantly higher levels of pathogen contamination were detected in the gut and skin of fish from the WFP than the NWFP. Heavy metal concentrations in all samples fell within the Food and Agricultural Organization (FAO)/World Health Organization (WHO) and National Oceanic and Atmospheric Administration (NOAA) permissible limits except for iron and cadmium. There were significantly higher heavy metal concentrations in gill and liver than the muscle. Even though iron recorded the highest concentrations in fish tissue, the concentrations (0.1–2.0 mg kg-1) were below the expected daily nutritional requirement (1–2 mg) for humans and pose no toxicological risk. However, catfish from WFP would require precautionary measures such as cooking/grilling prior to consumption to avoid pathogen infection.

Black soldier fly colonies can produce about 100 times more protein per year than chicken or soybeans, not to mention cattle, on the same area of land. The flies can directly feed on different types of organic wastes, leapfrogging closed loop processes within a circular food economy. Also, where no protein is needed, for example, to feed fish or pigs, the larvae can be processed into high-quality biodiesel. However, can this be done at scale? The answer is ‘Yes’. The report showcases some of the leading global businesses in Black Soldier Fly production.

Billions of people currently lack clean water and sanitation. By 2050 the global population will have grown to nearly 10 billion, over two-thirds of whom will live in urban areas. This Voices asks: what are the research and water-management priorities to ensure clean water and sanitation in the world’s cities?

Natural wetlands are green infrastructure systems that are energy-efficient for wastewater treatment and can be found in diverse geo-environmental settings around the world. Their structure and functions, which defines the treatment efficiencies are highly varied. Wetlands over shallow bedrock and geological lineaments (weak zones) have been known to contribute to groundwater contamination. However, not many studies have been performed to understand the structure in different geological settings to identify the efficiency determining factors. Therefore, it is important to investigate the geological suitability of the natural wetlands. We examined wastewater fed natural wetlands in diverse geological settings aiming at studying the depth, geo-stability, bio-chemical interactions, and hydrogeological attributes that improve the wastewater quality, within the Musi River basin, India. The integrated geophysical scans encompassing electrical resistivity tomography (ERT), hydrogeological test, bathymetric study and hydro-chemical analysis were carried out to explore the physical structure and hydro-dynamic processes in the wetlands. ERT investigations showed that, the depth to bedrock up to 20–25 m devoid of geo-fractures (lineaments) indicated the effective depth of saturated zone as a passable scope for potential bio-chemical interactions, implying the proportionality of the deep seated (deep bedrock) wetland to the pollutant removal efficiency. The lower order of electrical resistivity range 10–35 Om and hydraulic conductivity 2.938 md-1 acquired for saturated weathered zone were found catalyzing the bioremediation, sedimentation, adsorption, redox reactions and ion exchange processes. It caused the deep seated wetland removing nitrate 194.34 kgd-1 (97.18%); sulphate 333.75 kgd-1 (77.70%); phosphate 9.66 kgd-1 (82.53%); microbes 99.99%, BOD 80%, and COD 80% load with discharge 1408 m3d-1 of treated wastewater. Further, the strategies for designating the natural wetlands as wastewater treatment systems are also discussed in this paper.

This study reports and analyzes nutrient balances in experimental vegetable production systems of the two West African cities of Tamale (Ghana) and Ouagadougou (Burkina Faso) over a twoyear period comprising thirteen and eleven crops, respectively. Nutrient-use efficiency was also calculated. In Tamale and Ouagadougou, up to 2% (8 and 80 kg N ha–1) of annually applied fertilizer nitrogen were leached. While biochar application or wastewater irrigation on fertilized plots did not influence N leaching in both cities, P and K leaching, as determined with ion-absorbing resin cartridges, were reduced on biochar-amended plots in Tamale. Annual nutrient balances amounted to +362 kg N ha–1, +217 kg P ha–1, and –125 kg K ha–1 in Tamale, while Ouagadougou had balances of up to +692 kg N ha–1, +166 kg P ha–1, and –175 kg K ha–1 y–1. Under farmers’ practice of fertilization, agronomic nutrient-use efficiencies were generally higher in Tamale than in Ouagadougou, but declined in both cities during the last season. This was the result of the higher nutrient inputs in Ouagadougou compared to Tamale and relatively lower outputs. The high N and P surpluses and K deficits call for adjustments in local fertilization practices to enhance nutrient-use efficiency and prevent risks of eutrophication.

Groundwater quantity and quality may be affected by climate change through intricate direct and indirect mechanisms. At the same time, population growth and rapid urbanization have made groundwater an increasingly important source of water for multiple uses around the world, including southern Africa. The present study investigates the coupled human and natural system (CHANS) linking climate, sanitation, and groundwater quality in Ramotswa, a rapidly growing peri-urban area in the semi-arid southeastern Botswana, which relies on the transboundary Ramotswa aquifer for water supply. Analysis of long-term rainfall records indicated that droughts like the one in 2013–2016 are increasing in likelihood in the area due to climate change. Key informant interviews showed that due to the drought, people increasingly used pit latrines rather than flush toilets. Nitrate, fecal coliforms, and caffeine analyses of Ramotswa groundwater revealed that human waste leaching from pit latrines is the likely source of nitrate pollution. The results in conjunction indicate critical indirect linkages between climate change, sanitation, groundwater quality, and water security in the area. Improved sanitation, groundwater protection and remediation, and local water treatment would enhance reliable access to water, de-couple the community from reliance on surface water and associated water shortage risks, and help prevent transboundary tension over the shared aquifer.

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration. We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks.

The study is being carried out to investigate the potential for applying SAT in Xaysetha district, Lao PDR and investigation the most suitable site for SAT in Xaysetha district. The methodology was used MCDA, GIS, RRA and semistructured interview to rank SAT site and investigate the physical, social and economic factor at the most suitable site (Nonvay site). The results of SAT ranking indicated that Xaysetha district has a potential to construct up to 3 high suitable site, 8 moderate suitable sites, and 6 low suitable sites. On the other hand, the results of physical, social and economic assessment at Nonvay site represented that DO was exceeded the Lao National Environmental Standard, and the soil infiltration rate is about 24 mm/hour (0.58 m/day). The households around Nonvay site have their own land and they access to water use and have a relationship with 9 organizations. They product wastewater was estimate 150 liter/person/day. And the land available for SAT is worth to US$ 39 million.

Wastewater irrigation is a common livelihood practice in many parts of the developing world. With the continuous irrigation supply, groundwater systems in these regions perceive adverse impacts due to inadequate infrastructure to treat the wastewater. The current study area, Musi River irrigation system, is one such case study located in the peri-urban Hyderabad of South India. The Musi River water, which is used for irrigation, is composed of untreated and secondary treated wastewater from Hyderabad city. Kachiwani Singaram micro-watershed in the peri-urban Hyderabad is practicing wastewater irrigation for the last 40 years. The current quality of (untreated) wastewater used for irrigation is expected to have adverse impacts on the local aquifers, but detailed investigations are lacking. To elucidate the groundwater quality dynamics and seasonality of the wastewater irrigation impacts on the peri-urban agricultural system, we analyzed the groundwater quality on a monthly basis for one hydrological year in the wastewater and groundwater irrigated areas, which exist next to each other. The spatio-temporal variability of groundwater quality in the watershed was analyzed with respect to wastewater irrigation and seasonality using multivariate statistical analysis, multi-way modeling and self-organizing maps. This study indicates the significance of combining various statistical techniques for detailed evaluation of the groundwater processes in a wastewater irrigated agricultural system. The results suggest that concentrations of the major ionic substances increase after the monsoon season, especially in wastewater irrigated areas. Multi-way modeling identified the major polluted groundwaters to come from the wastewater irrigated parts of the watershed. Clusters of chemical variables identified by using self-organizing maps indicate that groundwater pollution is highly impacted by mineral interactions and long-term wastewater irrigation. The study recommends regular monitoring of water resources and development of sustainable management strategies to mitigate the aquifer pollution in wastewater irrigation systems.

Resource recovery and reuse (RRR) of domestic and agro-industrial waste has the potential to contribute to a number of financial, socioeconomic and environmental benefits. However, despite these benefits and an increasing political will, there remain significant barriers to build the required up-front capital which is discouraging private sector engagement. A systematic analysis and understanding of the enabling environment, public and private funding sources, risk-sharing mechanisms and pathways for cost recovery can help to identify opportunities to improve the viability of RRR solutions. This report looks at regulations and policies that remove disincentives for RRR, public and private funding sources for capital and operational costs, risk mitigation options through blending and structuring finance, and options for operational cost recovery.

This report is the result of the implementation of an assessment methodology for Colombo and its city region food system (CRFS). Colombo stands as a unique city in Sri Lanka due to the complexity of its socio-demographic profile and the diverse food items that arrive through multiple channels. The busy and complex lifestyle of its inhabitants, together with the floating population of the city, creates a high demand for catering services that supply prepared food for direct consumption. In addition, the Colombo Municipal Council (CMC) acts as the national hub for imported food items and the regional hub for vegetable and fruit. As a result, Colombo has one of the most complex food systems in Sri Lanka. The aims of the CRFS assessment include: to better understand the functioning the Colombo food system; to examine the current and future constraints on food security and safety, with respect to the challenges of urban growth, diversity, lifestyle and dynamics; to explore the sustainability and resilience of the Colombo CRFS; and to seek to improve the livelihoods of rural and urban dwellers now and in the future.

The safe recovery of nutrients from our waste streams allows us to address the challenges of waste management and soil nutrient depletion conjointly. Commercialization of waste-based organic fertilizers such as FortiferTM (fecal sludge-based co-compost) has the potential to generate significant benefits for developing economies via cost recovery for the sanitation sector and the provision of an alternative agricultural input for smallholder farmers. To guide future FortiferTM businesses, this report presents examples of detailed market assessments, based on farmers’ perceptions, attitudes and willingness-to-pay (WTP) for a pelletized and non-pelletized FortiferTM co-compost. The research was conducted in the Greater Accra and Western regions in Ghana, and in and around Kampala (Uganda), Bangalore (India), Hanoi (Vietnam), and Kurunegala (Sri Lanka). Cross-country analyses helped to understand the effects of market drivers and, where possible, capture lessons learned for knowledge sharing.

This Atlas summarizes recent advances in interdisciplinary approaches and research to address the different components of West African urban food systems, including urban and peri-urban agriculture. It thereby draws on the results of several major collaborative research projects and stakeholder consultations conducted in West Africa over the past two decades, and in particular on the UrbanFoodPlus project in Ghana and Burkina Faso (www.urbanfoodplus.org). The publication targets with its innovative design a broad range of stakeholders.

The use of wastewater to produce food crops particularly vegetables is very prevalent in Addis Ababa, Ethiopia. This practice may pose health risks to farm workers and consumers. Hence, the study was designed to evaluate farmers’ perceptions on irrigation water quality, health risks and health risk mitigation measures in four wastewater-irrigated urban vegetable farming sites in Addis Ababa. Data were collected on farm through 263 individual interviews and 12 focus group discussions. The findings showed that despite differences in levels of knowledge and awareness on health risks, farmers appear informed about the contamination of their irrigation water. The difference in perception to quality consideration of Akaki River/irrigation water is highlighted by the result of Kruskal–Wallis H test analysis which shows significant mean value (1.33) of positive perception toward the water quality by male than female farmers. Interestingly, significant difference (p lt; 0.05) in mean values of awareness toward problems of eating unwashed vegetables is also found between male and female farmers where females seemed to be more aware. Conversely, no significant difference was found in mean value of perception and awareness toward vegetables quality. Among the perceived health risks, skin problems were top-rated health risk while eye burn, sore feet and abdominal pains were rated low across the four farming sites. Although statistically not significant, perception toward consumption-related health risk differed with gender: females assigned relatively high mean score. Irrespective of the farming site and gender differences, the most accepted health risk reduction measures were health promotion programs and cessation of irrigation before harvesting. In view of crop restriction measures, females assigned significantly (p = 0.044) low mean score to planting non-food produce. Akaki-Addis farmers suitability perceptions of planting non-food produce and non-raw eaten crops were significantly (p lt; 0.001) higher than the other farming sites. Therefore, effective site and gender-specific educational programs have the potential for clarifying farmers and consumers’ risks and risk management perceptions and improving practical knowledge, which in turn may help identify adoption barriers, opportunities and incentives.

There is a strong link between gender and energy in view of food preparation and the acquisition of fuel, especially in rural areas. This is demonstrated in a range of case studies from East and West Africa, where biochar, human waste and other waste resources have been used to produce briquettes or biogas as additional high-quality fuel sources. The synthesis of the cases concludes that resource recovery and reuse for energy offers an alternative to conventional centralized grid projects which, while attractive to investors and large-scale enterprises, do not necessarily provide job opportunities for marginalized communities. Reusing locally available waste materials for energy production and as soil ameliorant (in the case of biochar) in small enterprises allows women and youth who lack business capital to begin modest, locally viable businesses. The case studies offer concrete examples of small-scale solutions to energy poverty that can make a significant difference to the lives of women and their communities.

Water and nutrition are linked in multiple ways, but few of these interlinkages are well understood. What is, for example, the exact relationship between water pollution and health or between water resource management and nutrition? Even less is known about the interactions across these various linkages. The importance of better understanding these connections has been highlighted as we pursue the United Nations Sustainable Development Goals (SDGs), which challenge mankind to meet both water security as well as food and nutrition security goals, while also improving water-based ecosystems. It has become increasingly clear that progress toward these goals can only be achieved if measures in the food and nutrition space (SDG 2) do not constrain progress on water (SDG 6) and if measures undertaken to support targets under one of these SGDs also support the outcomes of the other. This paper provides an overview of water–nutrition linkages as reflected in the SDGs, and it identifies key gaps in these linkages and suggests a way forward to support the achievement of both water and nutrition goals and targets.

To understand the full value of Resource Recovery and Reuse (RRR), a systematic assessment approach that balances complexity with practicality is required. This report highlights the methods available for quantifying and valuing social, environmental and economic costs and benefits of RRR, focusing on Cost-Benefit Analysis (CBA) as the primary framework. Rather than prescribing a standardized technique for conducting CBA for RRR, this report presents broad frameworks and several examples that can be catered to individual contexts. This results in a suggested eight-step process accompanied with suggested assessment techniques which have to be tailored to the type of question the assessment is meant to answer and related system boundaries.

Globally, more than 60% of the human population live without safely managed sanitation services or even lack access to basic sanitation facilities. In addition, most of the wastewater produced in the world is discharged without proper treatment. Integrated approaches are needed to address these issues and curb the resulting adverse impacts on public health and the environment, and associated societal economic losses. The UN 2030 SDG Agenda provides an important framework towards more sustainable sanitation development, in terms of both safe sanitation access and wastewater management. Innovative solutions that treat and enable productive safe use of water, and recovery of nutrients and organic matter from wastes resources are booming. Some examples of trends are decentralized solutions, separation of waste flows, low/or no-flushing toilets, and converting faecal sludge to energy. These alternative technologies show huge potential to address many development challenges, contributing to multiple SDGs, but achieving upscaling has proved to be a major challenge. A paradigm shift to ‘treatment for reuse’ instead of ‘treatment for disposal’ is already taking place in the wastewater sector. Nevertheless, a better understanding of driving forces and enabling environment, new organizational models based on more service-oriented sanitation provision, and highlighting potential multiple societal benefits to attract investments from new sectors, are identified areas that need further attention.

This chapter reviews the main pollutants from agriculture, its associated impacts, and offers some key pollution mitigation options. The chapter also discusses how agriculture can be a beneficial user of wastewater, and how the practice can become safe.

There is a great potential to close the nutrient recycling loop, support a ‘circular economy’ and improve cost recovery within the waste sector and to create viable businesses via the conversion of waste to organic fertilizers. Successful commercialization of waste-based organic fertilizer businesses however largely depends on a sound market. We used a choice experiment to estimate farmers’ willingness-to-pay (WTP) for faecal sludge and municipal solid waste-based (FSM) compost in Kampala, Uganda and considered three attributes—fortification, pelletization and certification. Our results reveal that farmers are willing to pay for FSM compost and place a higher value on a ‘certified’ compost product. They are willing to pay US $0.4 per kg above the current market price for a similar certified product, which is 67 times higher than the cost of providing the attribute. Farmers are willing to pay US $0.127 per kg for ‘pelletized’ FSM compost, which is lower (0.57 times) than the cost of providing the attribute. On the other hand, farmers require US $0.089 per kg as a compensation to use ‘fortified’ FSM compost. We suggest that future FSM compost businesses focus on a ‘certified and pelletized’ FSM product as this product type has the highest production cost–WTP differential and for which future businesses can capture the highest percentage of the consumer surplus. The demand for FSM compost indicates the benefits that can accrue to farmers, businesses and the environment from the recycling of organic waste for agriculture.

A choice experiment was used to assess households’ willingness-to-pay (WTP) for informational attributes (sources of water used to rear sh, and certi cation) of sh products in Hanoi, Vietnam. The study showed that households’ purchasing decisions are in uenced by their access to information of food product attributes and ascribe an economic value to it. The results indicated that households are willing to pay 51% (USD 1.11 per kg) above the prevailing market price of sh for information to know if wastewater is used to rear the sh they consume. Similarly, they are willing to pay 20% above the prevailing market price of sh (USD 0.43 per kg) to know if freshwater is used as a rearing medium. It is important to note that the increased marginal WTP is for information on whether the sh they consume is raised in wastewater over freshwater. This supports the notion of households’ concern over the safety of consuming wastewater-raised sh. Households are also willing to pay 65% (USD 1.42 per kg) above the prevailing market price for certi ed sh. Based on the cost of sh certi cation and WTP estimates, we found a total economic bene t of USD 172 million for the implementation of a wastewater-raised sh business model in Hanoi. The demand for wastewater-raised sh is likely to be affected by households’ perception of certi cation by a trusted government agency, source of water used to raise the sh, age, income and household size.

When urban areas expand without concomitant increases in wastewater treatment capacity, vast quantities of wastewater are released to surface waters with little or no treatment. Downstream of many urban areas are large areas of irrigated croplands reliant on these same surface water sources. Case studies document the widespread use of untreated wastewater in irrigated agriculture, but due to the practical and political challenges of conducting a true census of this practice, its global extent is not well known except where reuse has been planned. This study used GIS-based modeling methods to develop the first spatially-explicit estimate of the global extent of irrigated croplands influenced by urban wastewater flows, including indirect wastewater use. These croplands were further classified by their likelihood of using poor quality water based on the spatial proximity of croplands to urban areas, urban wastewater return flow ratios, and proportion of wastewater treated. This study found that 65% (35.9 Mha) of downstream irrigated croplands were located in catchments with high levels of dependence on urban wastewater flows. These same catchments were home to 1.37 billion urban residents. Of these croplands, 29.3 Mha were located in countries with low levels of wastewater treatment and home to 885 million urban residents. These figures provide insight into the key role that water reuse plays in meeting the water and food needs of people around the world, and the need to invest in wastewater treatment to protect public health.

Co-composted dewatered faecal sludge (FS) with organic fractions of municipal solid waste (MSW) has a high potential to be used as an agricultural resource in Sri Lanka. In addition to options for cost recovery in waste management, closing the nutrient and carbon cycles between urban and rural areas, substitution of mineral fertilizers, reduced pollution. and the restoration of degraded arable land are possible with important benefits. Up to now little is known about the usage of FS-MSW as fertilizer and it needs to be studied in order to achieve a better understanding and generate application recommendations. The aim of these experiments has been to evaluate the possibility of substituting mineral fertilization. Two field experiments were conducted on sandy loam to assess the effects of MSW compost and FS-MSW co-compost, its pelletized forms, and mineral-enriched FS-MSW on crop growth. As a short-term crop Raphanus sativus “Beeralu rabu” (radish) was studied for 50 days in a randomized complete block design (RCDB). Results show that, under drought conditions, FS-MSW co-compost increased the yield significantly, while MSW and FS-MSW compost enabled the highest survival rate of the plants. Similarly, the second field trial with a long-term crop, Capsicum anuum “CA-8” (capsicum), was planted as RCBD, using the same treatments, for a cultivation period of 120 days. Results display that during a drought followed by water saturated soil conditions co-compost treatments achieved comparable yields and increased the survival rate significantly compared to the control, fertilized with urea, triple super phosphate, and muriate of potash. Cost-benefit analysis (CBA) revealed that pelletizing decreased the monetary benefits if only fertilizer value is considered. It can be concluded that, under drought and water stress, co-compost ensures comparable yields and enables more resistance, but might not be economical viable as a one-crop fertilizer. These findings need to be validated with further trials under different climate regimes and soils.

Nutrients and water found in domestic treated wastewater are valuable and can be reutilized in urban agriculture as a potential strategy to provide communities with access to fresh produce. In this paper, this proposition is examined by conducting a field study in the rapidly developing city of Hyderabad, India. Urban agriculture trade-offs in water use, energy use and GHG emissions, nutrient uptake, and crop pathogen quality are evaluated, and irrigation waters of varying qualities (treated wastewater, versus untreated water and groundwater) are compared. The results are counter-intuitive, and illustrate potential synergies and key constraints relating to the food–energy–water–health (FEW–health) nexus in developing cities. First, when the impact of GHG emissions from untreated wastewater diluted in surface streams is compared with the life cycle assessment of wastewater treatment with reuse in agriculture, the treatment-plus-reuse case yields a 33% reduction in life cycle system-wide GHG emissions. Second, despite water cycling benefits in urban agriculture, only lt;1% of the nutrients are able to be captured in urban agriculture, limited by the small proportion of effluent divertible to urban agriculture due to land constraints. Thus, water treatment plus reuse in urban farms can enhance GHG mitigation and also directly save groundwater; however, very large amounts of land are needed to extract nutrients from dilute effluents. Third, although energy use for wastewater treatment results in pathogen indicator organism concentrations in irrigation water to be reduced by 99.9% (three orders of magnitude) compared to the untreated case, crop pathogen content was reduced by much less, largely due to environmental contamination and farmer behavior and harvesting practices. The study uncovers key physical, environmental, and behavioral factors that constrain benefits achievable at the FEW-health nexus in urban areas.

Recovering nutrients, water and energy from domestic waste streams, including wastewater and faecal sludge, is slowly gaining momentum in low-income countries. Resource recovery and reuse (RRR) offers value beyond environmental benefits through cost recovery. An expected game changer in sanitation service provision is a business model where benefits accrued via RRR can support upstream sanitation services despite the multitude of private and public stakeholders involved from waste collection to treatment. This paper shows options of how resource recovery and reuse can be an incentive for the sustainable sanitation service chain, by recovering costs where revenue can feed back internally or using generated revenues from reuse to fill financial gaps across the service chain to complement other supporting mechanisms for making waste management more attractive.

Background: Wastewater irrigation for vegetable production is a highly prevalent practice in Addis Ababa and a number of articles have been published on wastewater-irrigated soils and vegetables contaminated with heavy metals. However, to the best of our knowledge, an insight into assessment of human health risks associated with the consumption of vegetable crops grown on wastewater-irrigated soils is non-existent in the city. Long-term effect of wastewater irrigation on the build-up of heavy metals in soils and selected vegetable crops in Addis Ababa urban vegetable farming sites (10) was evaluated. By calculating estimated daily intakes (EDIs) and target hazard quotients (THQs) of metals, health risk associated with the consumption of the analyzed vegetables was also evaluated.; Results: The heavy metal concentrations in irrigation water and soils did not exceed the recommended maximum limits (RMLs). Moreover, Cd, Co, Cr, Cu, Ni and Zn concentrations in all analyzed vegetables were lower than the RML standards. In contrast, Pb concentrations were 1.4–3.9 times higher. Results of two way ANOVA test showed that variation in metals concentrations were significant (p lt; 0.001) across farming site, vegetable type and site x vegetable interaction. The EDI and THQ values showed that there would be no potential health risk to local inhabitants due to intake of individual metal if one or more of the analyzed vegetables are consumed. Furthermore, total target hazard quotients (TTHQs) for the combined metals due to all analyzed vegetables were lower than 1, suggesting no potential health risk even to highly exposed local inhabitants.; Conclusions: There is a great respite that toxic metals like Pb and Cd have not posed potential health risk even after long term (more than 50 years) use of this water for irrigation. However, intermittent monitoring of the metals from irrigation water, in soil and crops may be required to follow/prevent their build-up in the food chain.

The chapter discusses how adopting a holistic methodology that acknowledges socio-logical factors, including community participation, public involvement, social perception, attitudes, gender roles and public acceptance, would lead to improvements in wastewater management practice. It highlights the social dimension as a tool, a lens through which wastewater management and reuse can take on new dimensions. In this way, this chapter aims to shift the focus from perceiving wastewater as a nuisance that needs disposal, toward a resource not to be wasted, which can contribute to food security, human and environmental health, access to energy as well as water security.

The study analyses dis-adoption of biogas technologies in Central Uganda. Biogas technology makes use of livestock waste, crop material and food waste to produce a flammable gas that can be used for cooking and lighting. Use of biogas technology has multiple benefits for the households since it reduces the need for fuelwood for cooking and also produces bio-slurry which is a valuable fertilizer. Despite efforts by Government and Non-Governmental Organizations to promote the biogas technology, the rate of its adoption of biogas technology was found to be low, estimated at 25.8% of its potential. A review of literature showed that the households that dis-adopted biogas technology, did so within a period of 4 years after its installation, yet the lifespan of using it is estimated at 25 years. There was need to examine the factors contributing to dis-adoption. Using cross sectional data collected from Luwero and Mpigi districts found in Central Uganda, a probit model was estimated. The findings showed that an increase in the family size, the number of cattle, number of pigs and the age of the household head reduced the likelihood of biogas technology dis-adoption. Other factors that contributed to dis-adoption included the failure to sustain cattle and pig production that are necessary for feedstock supply, reduced availability of family labor the and inability of the households to repair biogas digesters after malfunctioning. Based on the findings, it was concluded that long term use of biogas technology required improved management practices on the farm so as to sustain livestock production. It is also recommended that quality standards and socio-cultural factors be considered in the design of biogas digesters and end use devices.

The government of Bangladesh is increasingly paying attention to the safe collection and disposal of fecal sludge from pit latrines in rural areas. In this paper, we report on current sludge disposal practices from single-pit latrines, by conducting a survey of 1,091 households with pit latrines in a rural subdistrict of Bangladesh. Almost all households were using their pits, and 90% reported that hiring pit emptiers to empty the pit for reuse was the dominant pit management practice. However, 90% of households also reported that the sludge from these pits would be disposed of in the vicinity of their homes, by digging wide and shallow troughs in the soil to absorb the sludge. These results indicate an urgent need to design an organized service that safely transports fecal sludge away for treatment. The National Committee for Fecal Sludge Management, constituted by the government of Bangladesh, is using these results to design policy for sludge management.

Motivation: Proper management of fecal sludge has significant positive health and environmental externalities. Most research on managing onsite sanitation so far either simulates the costs of, or the welfare effects from, managing sludge in situ in pit latrines. Thus, designing management strategies for onsite rural sanitation is challenging, because the actual costs of transporting sludge for treatment, and sources for financing these transport costs, are not well understood.; Methods: In this paper we calculate the actual cost of sludge management from onsite latrines, and identify the contributions that latrine owners are willing to make to finance the costs. A spreadsheet-based model is used to identify a cost-effective transport option, and to calculate the cost per household. Then a double-bound contingent valuation method is used to elicit from pit-latrine owners their willingness-to-pay to have sludge transported away. This methodology is employed for the case of a rural subdistrict in Bangladesh called Bhaluka, a unit of administration at which sludge management services are being piloted by the Government of Bangladesh.; Results: The typical sludge accumulation rate in Bhaluka is calculated at 0.11 liters/person/day and a typical latrine will need to be emptied approximately once every 3 to 4 years. The costs of emptying and transport are high; approximately USD 13 per emptying event (circa 14% of average monthly income); household contributions could cover around 47% of this cost. However, if costs were spread over time, the service would cost USD 4 per year per household, or USD 0.31 per month per household—comparable to current expenditures of rural households on telecommunications.; Conclusion: This is one of few research papers that brings the costs of waste management together with financing of that cost, to provide evidence for an implementable solution. This framework can be used to identify cost effective sludge management options and private contributions towards that cost in other (context-specific) administrative areas where onsite sanitation is widespread.

Purpose: Faecal sludge (FS) has been co-composted with many organic solid wastes globally. Agricultural wastes, such as oil palm empty fruit bunches (EFB) and cocoa pod husks (CPH), have received very little research attention as far as combining with FS is concerned. This study aimed at co-composting these wastes at different ratios to produce safe compost for use as soilless medium for raising tomato transplants.; Methods: Dewatered FS (DFS) was mixed with shredded EFB and CPH at five different ratios: 1DFS:1EFB, 1DFS:1CPH, and DFS:EFB:CPH in ratios of 1:1:1, 2:1:1, and 2:2:1 and composted for 3 months. Select physicochemical parameters and pathogens were monitored every fortnightly and 3 weeks, respectively.; Results: Maximum temperatures obtained ranged 46.8–54.5 C. Though these temperatures were lower than sanitizing temperatures prescribed by USEPA, no E. coli was found in any of the piles at the end of composting. The ratio 2DFS:2EFB:1CPH was found to be the safest formulation and hence was used to grow tomato under greenhouse conditions. Tomato seeds were sown in three different growing media: 100% FS-based compost, 100% rice husk biochar, and 50% FS-based compost–50% rice husk biochar mix.; Conclusion: Results showed that FS-based compost was a suitable growing medium for tomato. Further studies into the optimal rate and frequency of application of compost teas on tomato are recommended.

Biogas (anaerobic digestion) technology is one of the most viable renewable energy technologies today. However, its economic efficiency depends on the investment costs, costs of operating the biogas plant and optimum methane production. Likewise the profit level also rests on its use directly for cooking or conversion into electricity. The present study assessed the economic potential for a 9000 m3 biogas plant, as an alternative to addressing energy and environmental challenges currently in Ghana. A cost-benefit analysis of the installation of biogas plant at University of Ghana (Legon Sewerage Treatment Plant) yielded positive net present values (NPV) at the prevailing discount rate of 23%. Further the results demonstrate that installation of the plant is capital intensive. Biogas used for cooking was by far the most viable option with a payback period (PBP) of 5 years. Sensitivity analysis also revealed cost of capital, plant and machinery as the most effective factors impacting on NPV and internal rate of return (IRR).

Recovering energy, nutrients and water from domestic and agro-waste streams is gaining momentum as a new agenda for promoting sustainable development in developing countries as waste management strategies shift focus from a disposal-oriented approach to a business-oriented approach. The latter approach emphasises value creation and revenue generation (Murray and Buckley, 2010). As most cities in developing countries struggle with the challenge of energy security, recovering energy from different waste streams offers dual benefits – improved waste management and provision of reliable energy to households, institutions and commercial entities.

Most cities in developing countries fail to treat their wastewater comprehensively. Consequently, farmers downstream use poor-quality water for irrigation. This practice implies risks for farmers, consumers and the environment. Conversely, this water supply supports the livelihood of these farmers and other stakeholders along the value chains. Linking safer options for wastewater management with irrigation could therefore be a win–win solution: removing the risks for society and maintaining the bene ts for farmers. However, in developing countries, the high investment costs for the required treatment are problematic and the willingness of farmers to pay for the water (cost recovery) is often questionable. Using a choice experiment, this paper gives insight into farmers’ preferences for wastewater use scenarios, quantifying their willingness to pay. The case study is Hyderabad, India. Farmers there prefer water treatment and are prepared to pay a surplus for this. Considering the costrecovery challenge, this information could be valuable for planning small on site wastewater treatment systems.

The main purpose of this paper is to estimate farmers’ preferences and their willingness to pay (WTP) for ecosystem services derived from four agricultural water management (AWM) and resource recovery and reuse (RRR) intervention options in Burkina Faso, using a choice experiment (CE). These include; small water infrastructure, drip irrigation, recovery of organic matter from waste, and treated wastewater. The design decisions relating to attribute selection, the level of attributes, alternatives and choice tasks were guided by literature, field visits, focus group discussions, expert input and an iterative process of the STATA software to generate an orthogonal main-effects CE design. The data used was generated from a random sample of 300 farm households in the Dano and Ouagadougou municipalities in Burkina Faso. Results from conditional logit, latent class logit and mixt logit models show that farmers have positive and significant preferences for drip irrigation, treated wastewater, and organic matter. However, they are WTP on average more for drip irrigation and organic matter for agricultural sustainability. In line with economic theory, the cost of an intervention reduces demand for a given intervention. These findings can provide policy makers with evidence for agricultural policy design to build farmers’ resilience in the Sahel.

Energy efficient wastewater treatment systems are the current environmental concerns which prompted for the applications of natural wetlands as efficient systems at urban areas. However, a detailed investigation is highly desired to determine the efficiency determining factors relevant to structure and functions of natural wetlands for enhanced wastewater treatment. In view of this the wastewater fed natural wetland is examined by hydro-geophysical means, to decipher i) the effective depth of physico-chemical and microbial reactions, ii) the saturated zone thickness, and iii) hydrogeological attributes enhancing the wastewater quality at Hyderabad city, India. The wetland has been scanned using electrical resistivity tomography (ERT) to decipher its physical structure, and hydrogeological and biogeochemical investigations are performed to understand the dynamics. The low electrical resistivity ( =10.5-34.0 O-m) and moderate hydraulic conductivity (K=2.938 m/d) acquired for saturated zone (10–15 m depth), are found the wastewater enhancing parameters in the wetlands. Geophysically derived laterally constrained inversion (LCI) models explore the maximum saturated zone of wetland up to 25 m as an effective depth for pollutant removal mechanisms. It implies the proportionality between depth to bed rock (confining layer) and wetland efficiency. Further, the bio-geochemical scanning determines the bioremediation, sedimentation, adsorption, redox reactions and ion exchange processes as wetland functions for removing nutrients (77-97%), BOD (78%), COD (76%), and microbes (99.5-99.9%) load with the discharge Q=1812 m3d-1 of treated wastewater. Further, the wetland efficiency integrated with engineered interventions help develop various NTS models with different application scenarios, that are i) constructed wetlands, ii) minimized community wetlands, and iii) single outlet system, suitable for urban, peri-urban and rural areas, respectively. The socio-economic assessment, and farmer-consumers and stakeholders survey suggest that to test and use of wetland systems implementation as a policy guideline under sustainable water management.

Background: In Addis Ababa, where irrigation water for vegetable production is commonly derived from the highly polluted Akaki river, information on microbial contamination of water and irrigated vegetable is scanty. An assessment was done to determine the microbiological quality of irrigation water and lettuce harvested from 10 urban farming sites of Addis Ababa. The efficacy of 5 lettuce washing methods were also assessed. A total of 210 lettuce and 90 irrigation water samples were analyzed for faecal coliform and helminth eggs population levels.; Results: The mean faecal coliform levels of irrigation water ranged from 4.29-5.61 log10 MPN 100 ml-1, while on lettuce, the concentrations ranged from 3.46-5.03 log10 MPN 100 g-1. Helminth eggs and larvae were detected in 80% of irrigation water and 61% of lettuce samples. Numbers ranged from 0.9-3.1 eggs 1000 ml-1 and 0.8-3.7 eggs 100 g-1 wet weight for irrigation water and lettuce, respectively. The helminth eggs identified included those of Ascaris lumbricoides, Hookworm, Enterobius vermicularis, Trichuris trichiura, Taenia and Strongloyides larvae. Ascaris lumbricoides and Hookworm were most prevalent in both irrigation water and lettuce samples. Compared with the WHO recommendations and international standards, the faecal coliform and helminth eggs levels in irrigation water and lettuce samples exceeded the recommended levels. Irrespective of the tested washing methods, faecal coliform and helminth eggs levels were somehow reduced. Among the washing methods, potable tap water washing - rinsing (2 min) followed by dipping in 15 000 ppm vinegar solution for a minute supported the highest faecal coliorm reduction of 1.7 log10 units, whereas lowest reduction of 0.8 log10 units was achieved for the same procedure without vinegar.; Conclusion: Compared with international standards, both faecal coliform and helminth eggs levels exceeded recommended thresholds in water and lettuce, but still in a potential risk range which can be easily mitigated if farmers and households are aware of the potential risk. Aside preventing occupational exposure, potential risk reduction programs should target households which have so far no guidance on how best to wash vegetables. The result of the present study suggest that the vinegar based washing methods are able to reduce faecal coliform towards low level while the physical washing with running water may help to substantially decrease potential risk of helminth parasitic infections.

Background: Faecal matter biochar offers an interesting value proposition where the pyrolysis process guaranties a 100% pathogen elimination, as well as significant reduction in transport and storage weight and volume. Therefore, to evaluate the effect of (1) biochar produced from dried faecal matter from household based septic tanks, and (2) N fertilizer, as well as their interaction on yield and nutrient status of lettuce (Lactuca sativa), lettuce was grown over two growing cycles under glasshouse on two contrasting soils amended once at the start with factorial combination of faecal matter biochar at four rates (0, 10, 20 and 30 t ha-1) with 0, 25 and 50 kg N ha-1 in randomized complete block design.; Results: For both soils, maximum fresh yields were recorded with biochar and combined application of biochar with N treatments. However, the greatest biochar addition effects (with or without N) with regard to relative yield were seen in less fertile sandy loam soil. We have also observed that faecal matter biochar application resulted in noticeable positive residual effects on lettuce yield and tissue nutrient concentrations in the 2nd growing cycle. For both soils, most nutrients analyzed (N, P, K, Mg, Cu and Zn) were within or marginally above optimum ranges for lettuce under biochar amendment.; Conclusions: The application of faecal matter biochar enhances yield and tissue nutrient concentrations of lettuce in two contrasting soils, suggesting that faecal matter biochar could be used as an effective fertilizer for lettuce production at least for two growing cycles. Moreover, the conversion of the faecal matter feedstock into charred product may offer additional waste management benefit as it offers an additional (microbiologically safe) product compared to the more common co-composting.

Groundwater quality is gaining more importance in groundwater management due to rapid growth in population, agriculture and industrial sectors worldwide. The goal of the present study is to evaluate the groundwater chemistry and to identify the geochemical processes governing the water chemistry in the shallow uncon ned and deeper con ned aquifers in the Eastern Ganges Basin using geochemical methods. Groundwater samples were analysed for major ions and metals (Fe, Mn, Zn, Cu, Pb and As). Shallow wells are found to have high pH, EC, TDS, Ca, Mg, Cl and SO4, and low HCO3/Cl ratio compared to the deep wells. However, the average concentration of Na, HCO3, NO 3, PO 4, F and Mn is not signi cantly varied with depth which indicates that the variation in the water chemistry between uncon ned and con ned aquifers is not only due to the natural processes but also indicates that surface contamination sources could have affected the water chemistry in the uncon ned aquifer. In the uncon ned aquifer, processes like wastewater in ltration, denitri cation, reverse ion exchange and mineral weathering govern the water chemistry. The water chemistry in the con ned aquifer is regulated by weathering of silicate and carbonate minerals and regional ow.

Recovering energy from waste offers dual benefits – a) improved waste management, and b) provision of reliable energy to households, institutions and commercial entities. In this report, we present a socioeconomic assessment of three energy business models (briquette manufacturing, on-site (public toilet) energy generation, and agro-waste electricity generation) based on feasibility studies carried out in the city of Kampala, Uganda. We assess the potential economic, environmental and social impacts of waste-to-energy business models taking into consideration a life cycle of emissions to provide decision makers with the overall costs and benefits of the models to society versus a business-as-usual scenario.

Phosphorus (P) is a critical, geographically concentrated, nonrenewable resource necessary to support global food production. In excess (e.g., due to runoff or wastewater discharges), P is also a primary cause of eutrophication. To reconcile the simultaneous shortage and overabundance of P, lost P flows must be recovered and reused, alongside improvements in P-use efficiency. While this motivation is increasingly being recognized, little P recovery is practiced today, as recovered P generally cannot compete with the relatively low cost of mined P. Therefore, P is often captured to prevent its release into the environment without beneficial recovery and reuse. However, additional incentives for P recovery emerge when accounting for the total value of P recovery. This article provides a comprehensive overview of the range of benefits of recovering P from waste streams, i.e., the total value of recovering P. This approach accounts for P products, as well as other assets that are associated with P and can be recovered in parallel, such as energy, nitrogen, metals and minerals, and water. Additionally, P recovery provides valuable services to society and the environment by protecting and improving environmental quality, enhancing efficiency of waste treatment facilities, and improving food security and social equity. The needs to make P recovery a reality are also discussed, including business models, bottlenecks, and policy and education strategies.

Groundwater quality receives increasing attention in water management in India. The purpose of this paper is to highlight the emerging issues of groundwater quality in the Ramganga Sub-Basin (RSB), a tributary joining the Ganga River from the northern plains, which extends over 30,839 Sq. km and covers 15 districts in both Uttarakhand and Uttar Pradesh. The groundwater in most of the districts of the RSB has high concentration of nitrate, iron, salinity and fluoride, which exceed the standards prescribed for drinking water by the Bureau of Indian Standards (BIS) and World Health Organization (WHO). Arsenic contamination in groundwater is an emerging issue in few groundwater development blocks. Moreover, groundwater with substantial hardness, high sulfate, and high manganese is emerging issue in some districts. Additionally, shallow aquifers have high concentration of ions. In the RSB, the quality of groundwater, especially in the shallow aquifers, is influenced by the contamination of poor quality surface water, due mainly to poor sanitation, improper disposable of domestic sewage water, manures and irrigation return flows. To reduce deterioration of water quality further, the RSB requires proper sanitation facilities, efficient usage of agrochemicals, as well as an awareness program of water-related disease.

Wastewater is increasingly regarded as a valuable resource, but to fully and safely exploit the potential, sound institutional arrangements governing its reuse are crucial. This article presents a case study of a self-managed irrigation scheme in Western Cape, South Africa, that uses treated effluent directly, formally and safely. By applying the Institutional Analysis and Development framework, the variables within the context, action arena and patterns of interaction that have enabled this outcome are systematically identified and evaluated. Key variables include: water scarcity; an effective policy and regulatory framework; public pollution prevention awareness; self-organization; and capital-intensive water use linked to profitable markets.

To assess the efficiency of seven treatments including biochars produced from dried faecal matter and manures as stabilizing agents of cadmium (Cd)-spiked soils, lettuce was grown in glasshouse on two contrasting soils. The soils used were moderately fertile silty loam and less fertile sandy loam and the applied treatments were 7 % w/w. The reduction of bioavailable Cd (ammonium nitrate extractable) and its phytoavailability for lettuce were used as assessment criteria in the evaluation of stabilization performance of each treatment. Moreover, the agronomic values of the treatments were also investigated. Ammonium nitrate extraction results indicated that faecal matter biochar, cow manure biochar and lime significantly reduced bioavailable Cd by 84–87, 65–68 and 82–91 %, respectively, as compared to the spiked controls. Unpredictably, coffee husk biochar induced significant increment of Cd in NH4NO3 extracts. The immobilization potential of faecal matter biochar and lime were superior than the other treatments. However, lime and egg shell promoted statistically lower yield and P, K and Zn concentrations response of lettuce plants compared to the biochar treatments. The lowest Cd and highest P tissue concentrations of lettuce plants were induced by faecal matter and cow manure biochar treatments in both soils. Additionally, the greatest Cd phytoavailability reduction for lettuce was induced by poultry litter and cow manure biochars in the silty loam soil. Our results indicate that faecal matter and animal manure biochars have shown great potential to promote Cd immobilization and lettuce growth response in heavily contaminated agricultural fields.

Biological treatment, composting, in particular, is a relatively simple, durable and inexpensive alternative for stabilizing and reducing biodegradable waste. Co-composting of different waste sources allows to enhance the compost nutrient value. In particular, integration of ‘biosolids’ from the sanitation sector as potential input material for co-composting would provide a solution for the much needed treatment of fecal sludge from on-site sanitation systems, and make use of its high nutrient content. This research paper elaborates in detail the main parameters that govern the co-composting process as well as factors that control the production of a safe and valuable quality compost. It further explains technological options to tailor the final product to crop and farmer needs.

Recycling and reuse of treated wastewater are an important part of the sanitation cycle and critical in an environment such as urban India with decreasing freshwater availability and increasing costs for delivering acceptable quality water, often from far distance. This report has been developed as a possible guidance document for the Indian government and gives substantial focus to the financial and economic benefits of wastewater recycling from the perspective of public spending. The report presents possible strategies for city and state planners and policymakers in view of the sanitation situation and the role of wastewater recycling in the larger cities in India (class I and II cities and towns with populations above 50,000), and focuses on recycling at the end of sewerage systems after treatment at sewage treatment plants.

Where modern heating and cooking fuels for domestic, institutional, commercial and industrial use are not readily available, briquettes made from biomass residues could contribute to the sustainable supply of energy. This study reviews the briquette making process, looking at the entire value chain starting from the type and characteristics of feedstock used for briquette making to the potential market for briquettes in developing countries. It also analyzes the role that gender plays in briquette production. Depending on the raw materials used and technologies applied during production, fuel briquettes come in different qualities and dimensions, and thus require appropriate targeting of different market segments. Key drivers of success in briquette production and marketing include ensuring consistent supply of raw materials with good energy qualities, appropriate technologies, and consistency in the quality and supply of the briquettes. Creating strong partnerships with key stakeholders, such as the municipality, financiers and other actors within the briquette value chain, and enabling policy are important drivers for the success of briquette businesses.

Safe emptying and disposal of fecal sludge from pit latrines in rural areas has become a priority for the Government of Bangladesh. In this paper, we calculate the volume and characterize the hazards of managing sludge to identify technologies for safely emptying rural single pits. In Bhaluka subdistrict, an estimated 15,000 m3 of sludge is produced annually. Physical, chemical, and microbial analysis of samples of sludge taken from pit latrines indicate that the sludge has a high moisture content of around 90%, a C:N ration of 10:1, and a helminth presence of 41 eggs/g. In a field test of alternative emptying technologies, simple pumps such as the gulper emerged as feasible for use in rural areas, due to the liquid nature of the sludge, narrow roads, and limited incomes of rural households. The results suggest that current practices of emptying liquid sludge manually without any protective equipment poses risks to those who handle sludge, and the process needs to be semi-mechanized with immediate effect. These results are being used by the Bangladesh government to design policy for sludge management. In the near future, an organized service that safely empties single pits and transports sludge for treatment needs to be urgently designed.

In response to changing urban food systems, short supply chains have been advocated to meet urban food needs while building more sustainable urban food systems. Despite an increasing interest in urban food supply and the flows of food from production to consumption, there is a lack of empirical studies and methodologies which systematically analyse the actual proportion and nutritional significance of local and regional food supplied to urban markets. The aim of this empirical study therefore was to compare the geographical sources supplying food to the urban population (“foodsheds”) in Tamale, Ghana and Ouagadougou, Burkina Faso, to record the supplied quantities and to assess the level of interaction between the sources and the respective city. The study was conducted over two years, covering the seasons of abundant and short supply, via traffic surveys on the access roads to the two cities, and in the Tamale markets, resulting altogether in more than 40,000 records of food flow. Results indicated that food sources were highly crop- and season-specific, ranging from one-dimensional to multi-dimensional foodsheds with diverse sources across seasons. Across the commodity-specific foodsheds, city region boundaries were established. Within the proposed city region a relatively large proportion of smallholders contributed to urban food supply, taking advantage of the proximity to urban markets. While food provided from within the city region offers certain place-based benefits, like the provision of fresh perishable crops, a larger geographical diversity of foodsheds appeared to enhance the resilience of urban food systems, such as against climate related production failures.

The study was carried out to assess the efficacy of a standard Biofil toilet digester with regard to its effluent quality and to evaluate the performance of new effluent polishing options being developed by BiofilCom. Infuent and effluent were collected from 18 standard Biofil digesters connected to full- flush toilets. Effluent from five pilot installations with improved effluent polishing options were also taken for analyses. Ten other Biofil installations were selected to assess the impact of digester effluent discharge on the surrounding soil. Pollutant concentrations in the Biofil effluent exceeded both Ghana EPA and WHO standards for discharge though pollutant removal efficiencies were high: 84% for biochemical oxygen demand, 86.1% for chemical oxygen demand and 82.4% for total suspended solids. Escherichia coli and total coliform levels were signi cantly reduced by 63% and 95.6%, respectively, and nutrients were the least removed from effluents. Generally, effluents from the majority of the pilot polishing options met most of the discharge standards. E. coli were present in the soil at all study sites, except one. Biofil digester effluent is discharged subsurface but comparing their effluent quality with standards for discharge into water courses is relevant especially in areas of frequent flooding and high water tables.

Tamale is the capital city of Ghana’s Northern Region. As the regional capital, Tamale is growing rapidly – the population has almost tripled to over 370,000 in the past 30 years, and the areal extent has increased up to sevenfold in the same period. Urban agriculture is an integral part of the food system, linked to resource management and spatial planning. In general one can say that backyard farming flourishes, but more formally organised production is threatened by urbanisation.

Wastewater irrigaon is not new in Maharashtra and the Government of Maharashtra as well as farmers are beginning to recognize its value as a drought response. This Highlight presents a synthesis of eld exploraons in 11 locaons in Maharashtra which cover the extent of wastewater irrigaon; economics of wastewater and freshwater use; farmersapos; preferences and percepons about wastewater; and how they are adapng to its use in agriculture.

Purpose: The purpose of this paper is to explore people’s perceptions, stated attitudes, and observed and reported behaviour to water and other environmental quality. Design/methodology/approach: The study adopted a mixed method approach. It employed a cross-sectional survey design. Ten communities were selected in Accra and its surrounding communities to indicate various levels of infrastructure provision and environmental quality. Four separate focus group discussions (FGDs) were carried out in each community, with a mixed group of older and young adult men and women, a group of men only, a group of women only, and a group of young adults only. Following the FGDs, further information was obtained through structured household questionnaire survey involving 443 respondents. Findings: Different ideas were employed to explain people’s perceptions of water quality. There were common ideas such as on health, history of water use, perceptions which affect water use, and management of community activities which affect water sources. These ideas which emerged from the focus groups helped participants to assign meaning to their environment. Reported behaviour was influenced by the ability to pay for services, their availability and the influence of shared community norms. Although citizen participation in water and environmental management decision making was very limited, community collective action can be harnessed to enhance water and other environmental management. Originality/value: Adopted an interdisciplinary approach that enabled explanations to phenomenon to emerge from the perspectives of the society rather than views being suggested to them. Thus, resulting in evidence-based issues for intervention.

On-site sanitation systems, such as septic tanks and pit latrines, are the predominant feature across rural and urban areas in most developing countries. However, their management is one of the most neglected sanitation challenges. While under the Millennium Development Goals (MDGs), the set-up of toilet systems received the most attention, business models for the sanitation service chain, including pit desludging, sludge transport, treatment and disposal or resource recovery, are only emerging. Based on the analysis of over 40 fecal sludge management (FSM) cases from Asia, Africa and Latin America, this report shows opportunities as well as bottlenecks that FSM is facing from an institutional and entrepreneurial perspective.

As in other cities of Sri Lanka, solid waste management has been a key problem in and concern for Balangoda Urban Council. Waste accumulations in the city have caused many problems, including unpleasant odours, contamination of water bodies, and contamination of paddy fields, giving rise to epidemic diseases such as Salmonella, typhoid fever, and diarrhoea. A Balangoda compost plant has been set up to process municipal solid waste into compost. The project started in 1999 as a city service to provide a solution to the solid waste problem, but converted into a business in later years. Integrated waste management in Balangoda now consists of a Municipal Solid Waste compost plant, septage treatment plant, plastic pelletiser and an open dump. In addition, as there is increasing awareness of environmental and health risks related to the use of agro-chemical fertilisers, demand for alternative – organic – fertilisers is increasing. As per the majority of the compost plants in the country, the Balangoda plants are located in semi-urban or rural areas, facilitating reuse of waste in agriculture, with farming areas located near the compost plants. The Balangoda system thus operationalises rural-urban linkages through the collection of urban food and organic waste and its recycling, sale, and reuse as compost for rural (and peri-urban) producers.

Fecal sludge (FS) contains significant amounts of plant nutrients and organic matter although it also contains pathogens. Therefore, FS can be used as fertilizer after proper sanitization. This study was designed to test dried fecal sludge (DFS)-based pellet fertilizers on maize cultivation. The DFS fertilizers were produced by composting, co-composting with sawdust, or irradiated by gamma-irradiation, and then nitrogen-enriched and pelletized using gelatinized or gamma-irradiated cassava starch. These DFS pellet fertilizers were compared to each other and to no-fertilization, mineral fertilizer, and agro-industrial waste compost. The fertilizer applications were 150 or 210 kgN/ha. Maize was cultivated in pots containing Cambisol and Ferric Lixisol growth media. The EC-SDFS-PG pellet (DFS + sawdust co-composted, enriched with nitrogen and pelletized) at a rate of 210 kgN/ha produced the highest maize yield (4.4 ton/ha) among all other treatments, while mineral fertilizer produced 3.9 ton/ha. It is concluded that the EC-SDFS-PG pellet produces similar or higher maize yields than mineral fertilizer and more than the agro-industrial compost in both growth media types.

During the past decades, many composting projects have been implemented with the assistance from various donor agencies to address the municipal solid waste (MSW) problem in developing countries, especially in urban areas. However, very few of these projects are sustainable and many were reported as failures, some even closed down and most ofexisting operations rely on heavy subsidies from the Government, foreign funding sources and Local Authorities (LAs). To enhance solid waste management (SWM) an initiative called quot;Pilisaruquot; project started in 2008 lead by the Central Environmental Authority (CEA) to develop the infrastructures of LAs for a better S WM system mainly focllsing on composting as an efficient low cost option for treatment of the organic waste fraction. However, the initial assessment of this initiative encountered many issues. Therefore, this study was proposed to identifY main lactors that affect the sustainability of municipal compost plants. The methods used to obtain data for this research comprise, sample survey that involved five selected compost plants operating under LAs in Sri Lanka; a specific lield survey that observed waste segregation activities: and a cl ients perception survey conducted in a super market in Colombo that aimed to assess customers perspective 011 buying and use ofcompost based Iquot;bod products. To supplement the findings ofthese investigations, a complementary literature revie\ and selected expert interviews were carried out with representative stakeholders. The research findings indicate that most of LAs do not have the needed expertise to design, implement and manage an integrated S WM system that allows efticient operation of compost plants according to recognized standards. Furthermore, it appears that 1110st ofthe compost plants do not manage it full-cost recovery of their Oamp;M cost with the main issues that users are not charged for the provided waste management services and .produced compost can not be marketed successfully, Besides, from the perspective of sustainable operation, need and provision offuture investment is unclear, especially for replacement to maintain an effective operation level. To overcome the emerging weaknesses of the Pilisaru project, it is recommended to provide a continuous capacity building programme for the LAs and involved stakeholders, supported by public awareness programs, especially lor enhanced waste segregation, marketing promotion for compost products as well as technical and financial assistance for relevant stakeholders that need support to perform their tasks in the SW value chain. Furthermore, it is envisioned to revisit the provided SWM policies and to add regulations that built on insights from best SWM practices in Sri Lanka but also from applicable international experiences from other developing countries. This should also include the production of quality compost that meets the fertilizer demands from an agriculture perspective. Lastly, th

Wastewater may be defined as the combination of liquid wastes discharged from domestic households, farms, institutions, and commercial and industrial establishments eventually mixed with groundwater, surface water, and stormwater. Wastewater is increasingly receiving global attention as it is seen as one of the alternative solutions to increasing global water scarcity. Indeed, wastewater is globally being reused in many applications including groundwater recharge, industrial reuse like for cooling, environmental and recreational uses, nonpotable urban uses, and indirect or direct potable reuse. However, agricultural irrigation and landscaping is by far the largest wastewater use sector. Indeed, millions of farmers worldwide are involved in wastewater irrigation activities. However, wastewater contains a variety of pollutants and contaminants, which may pose health risks if not well managed. These pollutants include salts, metals, metalloids, pathogens, residual drugs, organic compounds, endocrine disruptor compounds, and active residues of personal care products. The kind and extent of health risks depend on many factors including the types and levels of contaminants as well as regional risk relevance. In low-income countries, risks from pathogens receive the most attention. This is because people in these countries are most affected by diseases caused by poor sanitation such as diarrheal diseases and helminth infections, so high loads of pathogenic microorganisms are often found in wastewater systems. Focusing on low-income contexts, this chapter presents health risks posed by wastewater irrigation activities and some practical examples on how these risks could be managed.

Although wastewater has been increasingly used to grow a range of crops for income generation and livelihood resilience in urban and peri-urban areas, irrigation with untreated or partially treated wastewater may result in negative impacts on irrigated crops, soils, and groundwater along with implications for human and environmental health through chemical and microbial risks. With the potential for environmental risks due to concentrations above the maximum allowable levels, the major chemical constituent groups that need to be addressed in wastewater-irrigated environments are metals and metalloids, essential nutrients, salts and specific ionic species, and persistent organic pollutants. To avoid potential negative impacts, conventional wastewater treatment options, which can control the release of these contaminants into the environment, remain the key to protecting water quality for beneficial uses in agriculture, aquaculture, and agroforestry systems. Effective legislation, monitoring, and enforcement are also essential and often neglected management strategies. At the farm level, some low-cost irrigation, soil, and crop management options, discussed in this chapter, are available to reduce the risk from contaminants added through wastewater irrigation.

The paper investigates the current practices of the green economy, and challenges and opportunities in the Limpopo Province of South Africa. The paper is based on a baseline study designed to gather data from key informants in Limpopo provincial, district and local municipalities. Twenty-three key informants in the province were interviewed. Primary data collected from key informants was supplemented by secondary data from document reviews. Descriptive statistics were used to analyse data on the current practices of green economy, and challenges and opportunities in the province. Findings from the study suggest that there is generally significant awareness of the green economy concept across the provincial district and local municipalities in Limpopo Province. However, there are gaps in terms of information gathering, storage and sharing on green economy activities in the district municipalities, provincial and national departments. The main barriers constraining the implementation of green economy initiatives in the municipalities include lack of information; shortage of workers with full knowledge on green economy; shortage of training programmes on green economy; and costs of implementation. The main recommendations from this research include the need to improve awareness of green economy activities across all levels in the province, especially with communities’ need for evidence-based research to demonstrate the potential of green economy activities that can contribute to job creation and poverty reduction; and training of officials on how the green economy can contribute to addressing developmental challenges such as service delivery, job creation, local economic development and poverty reduction.

Wastewater constitutes an alternative water source for the irrigation sector. To fully benefit from it, and reduce possible adverse effects on public health and the environment, we need to look at the regulation of the practice. A prerequisite for this is an institutional analysis, and the points to consider are the institutional mandates. We used the city of Hyderabad, India, as a case study. There, irrigation with wastewater is not supported or recognized, but it happens in practice. It takes place in an indirect and unplanned way. Institutions fail at enforcing regulations, and little attention is given to formalization of the practice. With this article, we aim to untangle the institutional setup, and by doing so, identify the constraints surrounding development of a formal practice. Ultimately, we aim at contributing to the discussion on the agricultural use of wastewater.

This paper presents an application of integrated methodological approach for identifying cost-effective combinations of agri-environmental measures to achieve water quality targets. The methodological approach involves linking hydro-chemical modelling with economic costs of mitigation measures. The utility of the approach was explored for the River Dee catchment in North East Scotland, examining the cost-effectiveness of mitigation measures for nitrogen (N) and phosphorus (P) pollutants. In-stream nitrate concentration was modelled using the STREAM-N and phosphorus using INCA-P model. Both models were first run for baseline conditions and then their effectiveness for changes in land management was simulated. Costs were based on farm income foregone, capital and operational expenditures. The costs and effects data were integrated using ‘Risk Solver Platform’ optimization in excel to produce the most cost-effective combination of measures by which target nutrient reductions could be attained at a minimum economic cost. The analysis identified different combination of measures as most costeffective for the two pollutants. An important aspect of this paper is integration of model-based effectiveness estimates with economic cost of measures for cost-effectiveness analysis of land and water management options. The methodological approach developed is not limited to the two pollutants and the selected agri-environmental measures considered in the paper; the approach can be adapted to the cost-effectiveness analysis of any catchment-scale environmental management options.

As in other developing countries, solid waste management (SWM) remains a crucial environmental issue in the Philippines. In the year 2000, the Philippine Congress released a new waste management legislation, the Philippine Ecological Solid Waste Management Act of 2000 (Republic Act 9003). This law mandates Local Governments to implement suited measures for waste avoidance, materials recovery and recycling in order to reduce waste disposal and to enhance residual waste management through alternative technologies or sanitary landfills. The total municipal waste generation in the country is estimated at more than 25 Mio tons/year, with organic waste components representing the main fraction with around 50% in cities and up to 70% in rural areas. Although RA 9003 mandates a waste diversion rate of at least 25 % to be realized by municipalities in 2006, most of them fail to implement the waste legislation properly mainly due to budget limitations, lack of know-how and conflicting interests that delay priority setting and political decision-making. In this context, the Philippine government entered into a bilateral official development program with the German government provided through the Deutsche Gesellschaft fr Internationale Zusammenarbeit GmbH (GIZ) through its development program Solid Waste Management for Local Government Units (SWM4LGUs) during the time period 2005-2012. As part of this program an in-depth and year-long analysis of main factors that relate to success and failures in municipal SWM was conducted. As main outcome of this development program, the National Solid Waste Management Commission integrated these experiences and developed the new National Solid Waste Management Strategy for the years 2012 to 2016 in order to facilitate implementation of RA 9003.

To establish and operate reliable Solid Waste Management (SWM) systems, efficient technologies, stable organizational structures, skilled personnel, sound operational management and appropriate financing concepts are required. In order to sustain such systems, the implementation of suited legal framework conditions and economical instruments are considered as key success factors. Proper financial management allows to determine the real costs of SWM and to design local policies that provide the needed mechanisms to conduct Solid Waste Management on community level and to formulate rules and user fees that are not only acceptable by residents and users but likewise secure participation of stakeholders and transparency for the public [1, 3]. As in other developing countries, financing SWM remains a severe issue also in the Philippines. Cost recovery is an important requirement for sustainable waste management, but it does not always correspond with political priorities, the willingness of the population or the capacities of the administration to implement it. Fees to cover SWM costs are either not asked for, or existing fee mechanism are not effectively implemented or being utilized by the authorities in charge. However, policies that address cost recovery will directly affect the capacity and willingness of service recipients to pay as well as the maximum level of refinancing that can be achieved. The lower the level of cost recovery, the higher the resulting risk of poor services rendered or ultimately service interruptions. Hence, sustainable financing of SWM by local means is imperative. In Bayawan City, Philippines the local government recognized the opportunities arising with establishing a new SWM system as required by national waste legislation [5]. During SWM planning various issues surfaced that were taken up by the local authorities to design apos;taylor-madeapos; new local policies that integrate cost recovery mechanism through user fees and revenues for material recovery. Main positive effects of cost recovery resulted from introduction of a prepaid sticker system that requests to pre-pay a fee for collection of residual waste and bio-waste. Besides, the introduction of an environmental fee claimed with the regular water bill propelled cost recovery from initial 3% to more than 15% of annual SWM budget after only 3 years operation of the new system whereas income for the latter is mainly used for cleaning of septic tanks and processing of recovered sludge at the newly established municipal waste management center. Results of this case underline that enhancing SWM systems is possible also in developing countries with innovative technologies and approaches that integrate local conditions and provide suited mechanism to enhance motivation and ownership of local decision-makers and users likewise [2-4].

In many urban and peri-urban areas of India, wastewater is under-recognized as a major water resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha) in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability for agriculture and challenges in potential irrigated area development towards wastewater use. This integrated approach showed that the change in the total irrigated area was marginal over the decade, whereas the built-up area within the watershed boundaries doubled and there was a distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters of the water used and was largely derived from wastewater. The remainder was groundwater from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the wastewater was of value, although they were also interested to pay modest amounts for additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was attributed to increased profitability due to the high urban demand. The unutilised scrubland within the watershed has the potential for irrigation development, but the major constraints appear to be unavailability of labour and high land values rather than water availability. The study provides evidence to support the view that the opportunistic use of wastewater and irrigation practices, in general, will continue even under highly evolving peri-urban conditions, to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for agriculture, with flow-on benefits including improved public health and protection of ecosystem services.

Risk assessments related to use of water and safety of fresh produce originate from both water and food microbiology studies. Although the set-up and methodology of risk assessment in these 2 disciplines may differ, analysis of the current literature reveals some common outcomes. Most of these studies from the water perspective focus on enteric virus risks, largely because of their anticipated high concentrations in untreated wastewater and their resistance to common wastewater treatments. Risk assessment studies from the food perspective, instead, focus mainly on bacterial pathogens such as Salmonella and pathogenic Escherichia coli. Few site-specific data points were available for most of these microbial risk assessments, meaning that many assumptions were necessary, which are repeated in many studies. Specific parameters lacking hard data included rates of pathogen transfer from irrigation water to crops, pathogen penetration, and survival in or on food crops. Data on these factors have been investigated over the last decade and this should improve the reliability of future microbial risk estimates. However, the sheer number of different foodstuffs and pathogens, combined with water sources and irrigation practices, means that developing risk models that can span the breadth of fresh produce safety will be a considerable challenge. The new approach using microbial risk assessment is objective and evidence-based and leads to more flexibility and enables more tailored risk management practices and guidelines. Drawbacks are, however, capacity and knowledge to perform the microbial risk assessment and the need for data and preferably data of the specific region.

Effective facilitation enables farmer-based water user organizations to analyse contextual issues, identify causal links, formulate clear challenges, develop partnerships with stakeholders, and innovate and implement solutions. However, facilitation is often provided by international partners, such as advanced research institutions or non-governmental organisations (NGOs). The reliance on external consultants to facilitate innovation and change processes creates risks for sustainability. This article provides an overview of a capacity development initiative for facilitation of change in the agriculture water sector in Africa. It focuses on the case study of the Improved Management for Agricultural Water in East and Southern Africa (IMAWESA) network’s learning alliance on facilitating community engagement. The IMAWESA learning alliance sought to build competency on facilitation methods and tools at national and sub-national levels within and across agricultural water management projects. The paper primarily seeks to address questions related to the sustainability of facilitated processes and the effectiveness of capacity development methods to train facilitators and thus strengthen local facilitation.

Accessibility to abundant sources of high-quality water is integral to the production of safe and wholesome fresh produce. However, access to safe water is becoming increasingly difficult in many parts of the world, and this can lead to the production of fresh produce contaminated with pathogenic microorganisms, resulting in increased risk of human disease. Water, an important raw material in the fresh produce chain, is used in considerable amounts in many operations, including irrigation and application of pesticides and fertilizers, but also as a transport medium and for cooling and washing in postharvest practices. In several reported outbreaks related to uncooked fruit and vegetable products, water has been identified as a likely source of the outbreak. The present study, initiated by the ILSI Europe Emerging Microbiological Issues Task Force in collaboration with 8 other ILSI branches and support of WHO/FAO, was undertaken to review the status of, and provide suggestions for, consideration by different stakeholders on water and sanitation and its impact on food safety and public health. A limited number of guidelines and regulations on water quality for agricultural production are available, and many of them are still heavily based on microbial standards and (debated) parameters such as fecal coliforms. Data gaps have been identified with regard to baseline studies of microbial pathogens in water sources in many regions, the need for agreement on methods and microbial parameters to be used in assessing water quality, the fate of pathogens in water, and their transfer and persistence on irrigated/processed produce.

The reuse of treated wastewater for aquaculture has been practiced in several countries and has a potential to create a viable fish farming business in low income countries. However, wastewater aquaculture practices which satisfy health and hygiene guidelines and standards will not be viable if consumers are unwilling to purchase fish reared in treated wastewater. In this study we investigate consumers’ preference and willingness to pay for fish farmed in treated wastewater in Ghana. A consumer survey was conducted in Kumasi. We utilize a dichotomous-choice contingent valuation methodology to estimate willingness to pay for fresh Tilapia and smoked Catfish farmed in treated wastewater and analyze factors that affect consumer choice. Consumers in the survey ranked price, size and quality of fish measured by taste and freshness as the most important product attributes influencing their decision prior to purchasing fish. Source of fish is among the least important product attributes influencing consumers’ decision. Results indicate that surveyed consumers generally accept fish reared in treated wastewater if lower prices are offered. Socioeconomic factors such as household income, education and family size significantly determine consumers’ willingness to pay. Furthermore, results indicate that households with children are more likely to pay for smoked Catfish compared to fresh Tilapia indicating that postharvest processing of fish might be perceived as safer and thus increases consumers’ willingness to pay for smoked Catfish. The results of this study provide better understanding of fish consumers’ buying behavior and their perceptions of and attitude towards fish reared in treated wastewater. Moreover, results can contribute to identifying key product attributes that need to be targeted for improvement if sales of fish farmed in treated wastewater is to be achieved.

When flowing through Hyderabad, the capital of Telangana, India, the Musi River picks up (partially) treated and untreated sewage from the city. Downstream of the city, farmers use this water for the irrigation of rice and vegetables. Treatment of the river water before it is used for irrigation would address the resulting risks for health and the environment. To keep the costs and operational efforts low for the farmers, the use of constructed wetlands is viewed as a suitable option. Towards this end, the paper investigates the interests and perceptions of government stakeholders and farmers on the treatment of wastewater for irrigation and further explores the consumer willingness to pay a higher price for cleaner produced vegetables. Full cost recovery from farmers and consumers cannot be expected, if mass scale treatment of irrigation water is implemented. Instead, both consumers and farmers would expect that the government supports treatment of irrigation water. Most stakeholders associated with the government weigh health and environment so high, that these criteria outweigh cost concerns. They also support the banning of irrigation with polluted water. However, fining farmers for using untreated river water would penalize them for pollution caused by others. Therefore public funding of irrigation water treatment is recommended.

Thirsty and hungry cities are posing significant challenges for the urban-rural interface ranging from food security to inter-sectoral water allocation. Not only is the supply of resources to urban centres a growing challenge in low-income countries, but even more is the urban return flow, as investments in waste management and sanitation, ie the ‘ultimate food waste’, are not able to keep pace with population growth. And where polluted water is used in irrigation to feed the cities, food safety is becoming a crucial component of food security. Most affected by resource competition and pollution are the urban and peri-urban farming systems which are often driven by the informal sector. Urban waste is not only a challenge but also offers opportunities. It is in this interface between agriculture and sanitation where the CGIAR operates through its research programme on Water, Land and Ecosystems (WLE), addressing both the challenges and opportunities of urbanisation: by exploring novel perspectives and solutions to respond to changing population dynamics, resource demands, centralised water and nutrient flows, and ecosystem services under pressure.

To assess the current situation of municipal solid waste (MSW) composting opportunities and potential acceptance of nutrient enriched pelletized compost in Sri Lanka,two field surveys were conductednationwide and in Kurunegala (Northwestern) area, respectively. Due to the low nutrient content of MSW compost, it qualifies mostly as a conditioner of the soil’s physical properties. As a result the compost so far produced across the country has received limitedattention. The surveys indicated that if the nutrient levels are in­creased, 74% of the farmers surveyed are willing to use thecompost. The percentage willing to use compost was similar among farmers of the three most common crops; coconut, paddy and vegetables,ranging from 72 to 77%. Using the land use pattern, the crop cultivation databases and the willingness to use (WTU) results, the potential demand for compost was estimated.As per the results, in the urban context of Kaluthara,a 160% larger capacity plant (present input capacity 38 t/day)would be needed to satisfy market demand within a 10 km radiusof theplant. For the Attanagalla plant (present capacity 10 t/day) within a rural setting, all compost could be absorbed within 2 km.

With increasing change of traditional diets, and the emergence of new supply and marketing chains, urban food consumers in low-income countries are faced with multiple food safety challenges, among which microbial contamination and pesticides are key concerns for fruits and vegetables sold on urban markets in West Africa. Although consumers have a genuine interest in healthy food, and are willing to pay premiums, their interpretation of food quality and risks deviates from scientific health risk assessments and does not translate into recommended risk mitigation behavior. To safeguard public health, alternative measures are needed to support consumers’ risk awareness and decision making. The review looked at common and less-common options to trigger and support behavioral change, including safety labeling (certification), corporate social responsibility models, incentive systems and social marketing of safe practices, to address potential food safety risks from farming in urban and peri-urban areas. Overall, it appears that regulatory measures for risk management, including certifications, will be – for now – less effective in the West African setup due to low educational levels in view of chemical and microbial risk, diverse and often informal food chains, poor safety supporting infrastructure and weak institutional capacities for compliance monitoring.

The report summarizes key results from surveys carried out on urban and peri-urban agriculture (UPA) in Tamale (Ghana) and Ouagadougou (Burkina Faso) in 2013. The aim was to provide a broad overview of the state of UPA in the study cities and a basis for future research endeavors. The randomized sampling approach used aerial photography to identify 10 sites in different categories of farm in each city. Farmers provided information on their cropping and livestock-rearing activities. There were similarities between the cities, but the differences in the expression of UPA in Tamale and Ouagadougou were more intriguing, as in farm sizes, crops grown and livestock ownership. Farmers were particularly concerned about diminishing access to land in Tamale, where sales by chiefs to private investors were accelerating. In Ouagadougou, formal reallocation of land to homeowners by the state had similarly decreased available farmland. Water availability was a universal concern, and the quality of water used for irrigation was potentially more questionable in Ouagadougou than in Tamale. The results point to the need for further work on uncontaminated, perennial water sources and soil fertility management, alongside focuses on commercialization of animal production, and the legal, political and institutional context of UPA in different West African cities.