Munir A. Hanjra

Wastewater irrigation and environmental health: Implications for water governance and public policy

Climate change is a large-scale and emerging environmental risk. It challenges environmental health and the sustainability of global development. Wastewater irrigation can make a sterling contribution to reducing water demand, recycling nutrients, improving soil health and cutting the amount of pollutants discharged into the waterways. However, the resource must be carefully managed to protect the environment and public health. Actions promoting wastewater reuse are every where, yet the frameworks for the protection of human health and the environment are lacking in most developing countries. Global change drivers including climate change, population growth, urbanization, income growth, improvements in living standard, industrialization, and energy intensive lifestyle will all heighten water management challenges. Slowing productivity growth, falling investment in irrigation, loss of biodiversity, risks to public health, environmental health issues such as soil salinity, land degradation, land cover change and water quality issues add an additional layer of complexity. Against this backdrop, the potential for wastewater irrigation and its benefits and risks are examined. These include crop productivity, aquaculture, soil health, groundwater quality, environmental health, public health, infrastructure constraints, social concerns and risks, property values, social equity, and poverty reduction. It is argued that, wastewater reuse and nutrient capture can contribute towards climate change adaptation and mitigation. Benefits such as avoided freshwater pumping and energy savings, fertilizer savings, phosphorous capture and prevention of mineral fertilizer extraction from mines can reduce carbon footprint and earn carbon credits. Wastewater reuse in agriculture reduces the water footprint of food production on the environment; it also entails activities such as higher crop yields and changes in cropping patterns, which also reduce carbon footprint. However, there is a need to better integrate water reuse into core water governance frameworks in order to effectively address the challenges and harness the potential of this vital resource for environmental health protection. The paper also presents a blueprint for future water governance and public policies for the protection of environmental health.

Total Value of Phosphorus Recovery

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.

Improving Wheat Productivity in Pakistan: Econometric Analysis Using Panel Data from Chaj in the Upper Indus Basin

Abstract Increasing water scarcity, degradation of land and water resources, continuing low agricultural productivity, and increasing populations are posing the largest ever challenges for development of agricultural economies in many developing countries including Pakistan. Using panel data from irrigated settings in Chaj sub-basin of the Indus basin in Pakistani Punjab, we attempt to: (a) analyze the causes of low productivity; (b) disentangle factors (both land, water and other factors) contributing to productivity variations; and (c) identify limits and opportunities for narrowing productivity gaps and increasing overall wheat production, with a view to enhance food security for the poor. The results of the study indicate that locational inequities in distribution of canal water, use of groundwater of varying quality, differences in use of seed varieties, and other inputs lead to significant variations in wheat productivity. Key implications are that large gains in wheat productivity are possible by (a) improving the production environment at the tail-end through integrated water management practices; (b) adjusting the mix of canal and groundwater use; and (c) using technological interventions to improve the adoption of modern wheat varieties and dissemination of knowledge on planting dates and timings and application rates of inputs, especially water and fertilizer. Not only such interventions are economically, financially, and environmentally desirable, they are also pro-poor. What is needed is a strong political will and commitment.

Water Quality: Assessment of the Current Situation in Asia

The uncontrolled release of sewage, industrial wastes, and agricultural run-off continue to affect Asia. Although many Asian countries are getting closer to meeting the improved sanitation targets, much of the waste remains untreated. Comprehensive databases are rarely available and national data indicate that the water quality situation is serious. However, there are many signs of hope. Water quality monitoring efforts are improving and several countries now have systems in place that could guide other nations in the region. The efforts of basin agencies, such as the Mekong River Commission, could lead the way to transboundary or even regional assessments. Many regulatory and economic options are being tested for pollution control, but institutional and social challenges remain, in particular those related to population growth and the various ways in which it is affecting water quality across the region.

Environmental Risks and Cost-Effective Risk Management in Wastewater Use Systems

Wastewater use in agriculture has many potential benefits, yet it also poses environmental risks. In particular, the use of untreated or partially treated wastewater over the long run may result in negative impacts on irrigated crops, soils, and groundwater through the addition of excessive levels of metals and metalloids, nutrients, salts and specific ionic species, and micro- pollutants. The environmental risk reduction strategies for wastewater can be categorized into: (1) treatment of wastewater to a desired effluent quality; (2) on-farm wastewater treatment options; and (3) farm-based measures to reduce risks in areas irrigated by untreated or partially treated wastewater. However, the number of strategies that have been economically assessed and have proven to be cost-effective is rather limited, although all mention a positive impact. Despite limited examples, the economics of risk management reveal that cost-effective options for improving water quality by removing undesirable constituents are available at the treatment plant level and beyond.

Assessing the finance and economics of resource recovery and reuse solutions across scales

The recovery and reuse of wastewater can contribute to reducing poverty, improving food security, improving nutrition and health, and managing natural resources more sustainability to protect ecosystems and build climate resilient communities. Reusing wastewater generates both private and public benefits, yet care must be taken to minimize environmental harm and risks to human health. Assessing the costs and benefits of wastewater use is challenging for decision making. Financial analysis of wastewater and other reuse options can underpin decision making from a business standpoint, and economic analysis provides the information needed to support public policy decisions. In this chapter, we provide a framework for assessing the finance and economics of wastewater and other reuse options. We examine several components of resource recovery and reuse, including water reuse, energy recovery, and nutrient capture from wastewater as well as fecal sludge and biosolids. We describe the cost-savings and partial cost-recovery made possible by wastewater use and we discuss value propositions for possible business models. Many water reuse solutions do not achieve financial cost recovery but are viable from an economic perspective. However, public agencies can enhance revenue streams by supporting more than water recovery and/or by targeting high-end users.

Structured analysis of seepage losses in irrigation supply channels for cost-effective investments: case studies from the southern Murray-Darling Basin of Australia

Much of inland Australia has been in perpetual drought since 1997 except during 2010 when above average rainfall occurred. It has been the worst drought since 1788 when European settlement began. Water scarcity poses a serious threat to the sustainability of the irrigated agriculture in major irrigation systems across the Murray-Darling Basin (MDB). There is a need for water-saving measures and a structured approach to assess water loss in earthen supply channels. This paper presents such an approach to assess and reduce seepage losses for improving irrigation efficiencies. Main elements of this approach are the following: field measurements, hydrologic modelling, potential options for seepage reduction, economic analysis and financing water-saving investments. Using data from two irrigation systems in the southern MDB, a case is made for reducing seepage water losses in irrigation supply channels in a cost-effective manner using low-cost technologies. Increasing the level of security for investments in water-saving programs provides incentives to key stakeholders to achieve water-saving targets. Considering the value of water recovered from reducing seepage loss at irrigation system level, this study demonstrates how reducing just one component (seepage) from the total water losses in irrigation systems can help improve water supplies as well as the environmental flows. Potential options for financing infrastructure improvement for saving irrigation water are proposed and discussed.

Business Models and Economic Approaches for Nutrient Recovery from Wastewater and Fecal Sludge

Plant nutrient recovery from wastewater and fecal sludge is high on the development agenda, driven by the need to feed the global population, the discussion around peak phosphorous, increasing fertilizer prices and stricter regulations for safeguarding the environment from pollution. With a shift in thinking from nutrient removal to nutrient recovery, new public-private partnerships are developing to capture nutrients from the waste streams for reuse in agriculture. The prospects for cost recovery from capturing phosphorous are significant, if savings in wastewater treatment and sludge disposal costs are considered, as so far the phosphate recovery costs still result in prices higher than those of phosphate rock, unless niche markets are targeted. The chapter differentiates between nutrient recovery options commonly seen in sewered and non-sewered (on-site) sanitation systems, looking at wastewater, fecal sludge, biosolids and urine. To date, nutrient recovery from wastewater is driven more by the treatment sector and its challenges or by changing regulations, rather than by market demand for alternative fertilizers.

Cost-benefit analysis and ideas for cost sharing of groundwater irrigation: evidence from north-eastern Ethiopia

The government of Ethiopia has invested in groundwater development for smallholder irrigation in the Raya Valley and Kobo Valley, north-eastern Ethiopia, where the hydrogeological potential is large but not fully developed. A cost-benefit analysis shows that investment in deep groundwater irrigation development is viable at a 9.5% discount rate in 75% of the wells. Assuming full cost recovery of capital investment, the annual payment rates (annuity) that irrigation users should pay over the wells’ service life (25 years) were estimated. It is recommended that future investment be based on cost sharing rather than full cost recovery to facilitate uptake and address financial realities.

Business Models and Economic Approaches Supporting Water Reuse

Water reuse has significant environmental benefits that include mitigating water scarcity, and offering opportunities for revenue generation, especially if more resources than water are recovered, or if treatment can deliver water of potable quality. Options for achieving cost recovery or cost savings range from the promotion of greywater use at household or community level, to inter- and intra-sectoral water swaps, the replenishment of natural resources, on-site value creation through treatment related aquaculture, and reclaimed water sales for different purposes. Value might also be derived from emerging models of water hedging for future reuse markets. A key element of the business model approach is the move toward operational cost-recovery at minimum and profit maximization at best. Although cost recovery is typically low in wastewater use projects and treatment is primarily a ‘social business model,’ several empirical examples highlight opportunities for enhancing the business character of wastewater use by pursuing different value propositions and innovative mechanisms to achieve overall system sustainability.