Drivers of Microbial Risk for Direct Potable Reuse and de Facto Reuse Treatment Schemes: The Impacts of Source Water Quality and Blending.

Although reclaimed water for potable applications has many potential benefits, it poses concerns for chemical and microbial risks to consumers. We present a quantitative microbial risk assessment (QMRA) Monte Carlo framework to compare a de facto water reuse scenario (treated wastewater-impacted surface water) with four hypothetical Direct Potable Reuse (DPR) scenarios for Norovirus, Cryptosporidium, and Salmonella. Consumer microbial risks of surface source water quality (impacted by 0-100% treated wastewater effluent) were assessed. Additionally, we assessed risks for different blending ratios (0-100% surface water blended into advanced-treated DPR water) when source surface water consisted of 50% wastewater effluent. De facto reuse risks exceeded the yearly 10-4 infections risk benchmark while all modeled DPR risks were significantly lower. Contamination with 1% or more wastewater effluent in the source water, and blending 1% or more wastewater-impacted surface water into the advanced-treated DPR water drove the risk closer to the 10-4 benchmark. We demonstrate that de facto reuse by itself, or as an input into DPR, drives microbial risks more so than the advanced-treated DPR water. When applied using location-specific inputs, this framework can contribute to project design and public awareness campaigns to build legitimacy for DPR

A framework for efficient wastewater treatment and recycling systems

Water reuse / Wastewater / Recycling / Pricing / Water allocation / Cost benefit analysis / Wastewater irrigation / Developing countries / Developed countries / Case studies

Chlorpyrifos Removal for Wastewater Reuse

Approximately 1.2 billion people around the world live in areas of physical water scarcity. This could increase to half of the world’s population by 2030 and could displace 24 to 700 million people unless steps are taken to ensure adequate water supply.1 Water scarcity is an escalating issue within the United States, specifically in Western inland states with arid climates. This scarcity is encouraging communities to investigate tertiary level municipal wastewater treatment, allowing for reuse of wastewater. Unfortunately, wastewater contains numerous contaminants that are not regulated by the Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA). Many of these contaminants are endocrine disrupting compounds (EDCs). According to the European Union Commission, an endocrine disruptor is “an exogenous substance that causes adverse health effects in an intact organism, or its progeny, in consequence to the induced changes in endocrine functions.”2 Many EDCs are not completely removed by standard secondary wastewater treatment methods. With the growing demand for potable water, as well as water for irrigation and agricultural purposes, communities are having to evaluate the potential health risks due to EDCs and other unregulated compounds. The Woo-Pig-Sewage team selected one unregulated contaminant, chlorpyrifos(CLP), to test. CLP is an organophosphate insecticide that is commonly used residentially and commercially. CLP has a long term impact asa cholinesterase inhibitor in humans.3 Using traditional biological methods, CLP, as well as other pesticides, are nearly impossible to remove.4 CLP is on the Fourth Unregulated Contaminant Monitoring Rule list produced by the EPA to provide a basis for future regulation.5 A bench scale unit utilizing ozone treatment (O3), ultraviolet radiation (UV), and granular activated carbon (GAC) was constructed to remove this contaminant from dopednanopure water. Ultimately, the selected technologies will be able to treat secondary wastewater effluent from the wastewater treatment plant (WWTP) in Tucumcari, New Mexico for direct or indirect aquifer reintroduction. Direct aquifer reintroduction would involveinjection of water to the existing aquifer, whileindirect aquifer introduction would consist of introducing treated effluent to an existing canal system. An oxidation process paired with UV and GAC filtration can be utilized to remove EDCs such as CLP and other unregulated contaminants from wastewater. O3is extremely effective at oxidizing bacteria as well as other organic molecules. UV is also a commonly used method to degrade organic compounds and is currently being used at the WWTP in Tucumcari, New Mexico and in Fayetteville, Arkansas. GAC is utilized to remove trace amounts of contaminants from wastewater streams, usually as a final treatment before the water is reintroduced to the environment. The WWTP in Rio Rancho, New Mexicocurrently plans to utilize GAC filtration in this manner. The Woo-Pig-Sewage team performed experiments to determine if the combination of O3, UV, and GAC could reduce CLP to a concentration below the minimum detection limit of 0.001ppm. To test the effectiveness of the bench scale, caffeine was used as an organic tracer. Bench scale results indicate that the proposed system is effective in the removal of caffeine and CLP from doped water samples. Caffeine concentrations were reduced to below the minimum detection limit of 0.05 ppm for samples with initial concentrations ranging from 0.1 ppm to 10 ppm. CLP was reduced to below the minimum detection limit of 0.001ppm from and initial concentration of 0.1 ppm. An industrial scale process was sized based on treating secondary effluent from the WWTP in Tucumcari, NM. The total cost was determined to be an additional $2.31 per 1000 gallons, assuming 0$4.95 per 1000 gallons for the existing treatment paired with the proposed system. While this adds a significant cost to the existing treatment at the WWTP in Tucumcari, plants with larger flow rates would see significantly less of an increase in the total cost per 1000 gallons. This can be seen from the comparison of the 144,000gallonper day (gpd) system with existing UV treatment and the 300,000gpdTucumcari system also utilizing UV treatment. The 144,000gpdsystem was estimated to cost about 60% more per 1000 gallons. However, if the Tucumcari WWTP is awarded a grant to cover 100% of the Fixed Capital Investment (FCI), the proposed system would only increase the cost per 1000 gallons by 38%. If the EPA determines that EDCs such as CLP must be removed from the effluent of WWTPs, a process such as the one proposed by the Woo-Pig-Sewage team will be necessary

Wastewater Reuse

Approximately 1.2 billion people around the world live in areas of physical water scarcity. This could increase to half of the world’s population by 2030 and could displace 24 to 700 million people unless steps are taken to ensure adequate water supply. Water scarcity is an escalating issue within the United States, specifically in Western inland states with arid climates. This scarcity is encouraging communities to investigate tertiary level municipal wastewater treatment, allowing for reuse of wastewater. Unfortunately, wastewater contains numerous contaminants that are not regulated by the Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA). Many of these contaminants are endocrine disrupting compounds (EDCs). According to the European Union Commission, an endocrine disruptor is an exogenous substance that causes adverse health effects in an intact organism, or its progeny, in consequence to the induced changes in endocrine functions. Many EDCs are not completely removed by standard secondary wastewater treatment methods. With the growing demand for potable water, as well as water for irrigation and agricultural purposes, communities are having to evaluate the potential health risks due to EDCs and other unregulated compounds. The Woo-Pig-Sewage team selected one unregulated contaminant, chlorpyrifos (CLP), to test. CLP is an organophosphate insecticide that is commonly used residentially and commercially. CLP has a long term impact as a cholinesterase inhibitor in humans. Using traditional biological methods, CLP, as well as other pesticides, are nearly impossible to remove. CLP is on the Fourth Unregulated Contaminant Monitoring Rule list produced by the EPA to provide a basis for future regulation. A bench scale unit utilizing ozone treatment (O3), ultraviolet radiation (UV), and granular activated carbon (GAC) was constructed to remove this contaminant from doped nanopure water. Ultimately, the selected technologies will be able to treat secondary wastewater effluent from the wastewater treatment plant (WWTP) in Tucumcari, New Mexico for direct or indirect aquifer reintroduction. Direct aquifer reintroduction would involve injection of water to the existing aquifer, while indirect aquifer introduction would consist of introducing treated effluent to an existing canal system. An oxidation process paired with UV and GAC filtration can be utilized to remove EDCs such as CLP and other unregulated contaminants from wastewater. O3 is extremely effective at oxidizing bacteria as well as other organic molecules. UV is also a commonly used method to degrade organic compounds and is currently being used at the WWTP in Tucumcari, New Mexico and in Fayetteville, Arkansas. GAC is utilized to remove trace amounts of contaminants from wastewater streams, usually as a final treatment before the water is reintroduced to the environment. The WWTP in Rio Rancho, New Mexico currently plans to utilize GAC filtration in this manner. The Woo-Pig-Sewage team performed experiments to determine if the combination of O3, UV, and GAC could reduce CLP to a concentration below the minimum detection limit of 0.001 ppm. To test the effectiveness of the bench scale, caffeine was used as an organic tracer. Bench scale results indicate that the proposed system is effective in the removal of caffeine and CLP from doped water samples. Caffeine concentrations were reduced to below the minimum detection limit of 0.05 ppm for samples with initial concentrations ranging from 0.1 ppm to 10 ppm. CLP was reduced to below the minimum detection limit of 0.001 ppm from and initial concentration of 0.1 ppm. An industrial scale process was sized based on treating secondary effluent from the WWTP in Tucumcari, NM. The total cost was determined to be an additional $2.31 per 1000 gallons, assuming 0$4.95 per 1000 gallons for the existing treatment paired with the proposed system. While this adds a significant cost to the existing treatment at the WWTP in Tucumcari, plants with larger flow rates would see significantly less of an increase in the total cost per 1000 gallons. This can be seen from the comparison of the 144,000 gallon per day (gpd) system with existing UV treatment and the 300,000 gpd Tucumcari system also utilizing UV treatment. The 144,000 gpd system was estimated to cost about 60% more per 1000 gallons. However, if the Tucumcari WWTP is awarded a grant to cover 100% of the Fixed Capital Investment (FCI), the proposed system would only increase the cost per 1000 gallons by 38%. If the EPA determines that EDCs such as CLP must be removed from the effluent of WWTPs, a process such as the one proposed by the Woo-Pig-Sewage team will be necessary

SAFE REUSE OF TREATED WASTEWATER AND SLUDGE IN DECENTRALIZED SYSTEM

The unsafe water and solid reuse from decentralized wastewater treatment plant still occur due to the lack of improved and effective water management. This paper has aims to provide research findings of main management aspect of decentralized wastewater treatment plant with water reuse orientation. The scope of analysis includes wastewater treatment process performance evaluation, health risk, water reuse constraints and community motivation. The decentralized wastewater system had been designed as green technology in some settlements areas, which have low maintenance, low sludge production, and have high potential of water reuse for non potable water demand. According to the treatment schemes for water reuse system, the management is affected by treatment performance, proper maintenance, environmental condition and community motivation. The treated water quality according to water reuse standard of USEPA can be a source for agriculture or non-potable water demand and reduce contamination of water sources. Achievement of the effective wastewater management system could provide non-potable water source to fulfill 50-65% of clean water demand according water reuse standards. There are some constraints of wastewater reuse that were minimized through some steps to enhance wastewater system towards safe water and solid reuse

Wastewater reuse status in the Gaza Strip, Palestine

Groundwater is the only significant source of water in the Gaza Strip. Currently, special attention has been paid to improve the water resource situation in the regional level. Reuse of wastewater could be one of the main options to develop the water resource in the region. This strategy will lead to reducing the gap of water deficit between supply and demand. The limited reliable data on existing situation and absence of clearly defined reuse policy for wastewater based on economic and health basis make the reuse of wastewater dream more than a reality in Gaza Strip. The paper provides adequate data on wastewater reuse planning. It evaluates the status of wastewater quality and quantity, treatment faculties and reuse applications. In the same time, the paper gives some regional experiences and recommendations for future management of wastewater reuse

Towards Sustainable Wastewater Reuse in the Middle East and North Africa

Water has a precious value, and each drop must be accounted for in water scarce regions such as the Middle East and North Africa. Therefore, wastewater has to be reclassified as a renewable water resource rather than as waste. This helps in augmenting water availability, and at the same time in preventing environmental pollution. Utilization of this resource requires collection, treatment, and use of all generated wastewater. Although reuse of wastewater is recognized in most water-scarce countries, the reuse of wastewater is still very low. This paper analyzes the major components of a sustainable wastewater reuse scheme. It also reviews the different methods that are frequently used to quantify and report progress and achievements in wastewater reuse. The paper also introduces an alternative yardstick named by the author as the Wastewater Reuse Index (WRI) that has a value between 0-100; WRI is calculated by dividing the amounts of wastewater being actually reused by the total amounts of wastewater generated at country level. WRI enables water resource managers and policymakers to put a figure on the gap between achievements at different junctures. Moreover, WRI recognizes water saving efforts such as low water consumption and reducing losses; thus, WRI highlights the way forward for improving the reuse efficiency as an integral part of water resources management. The paper highlights the major barriers to extensive reuse of the reclaimed wastewater in the MNEA countries

reuse study of sustainable wastewater in agroforestry domain of marrakesh city

The current work aims to perform a feasibility study of sustainable urban wastewater reuse in agroforestry domain of Marrakesh city in order to assess the environmental and the sustainability of urban wastewater reuse in agroforestry irrigation. To this end, wastewater physicochemical characteristics from Marrakesh full-scale wastewater treatment plant, soil physicochemical analysis and climate analysis were investigated. Finally, treated urban wastewater potential production in Marrakesh WWTP and challenge related to its reuse are provided. The obtained results of the present study reveals the feasibility of this practice in Marrakesh region. Regarding the actual situation, climate analysis highlight that the local climatic conditions is an ultimate challenge for water resources; soil analysis reveals a loss of soil fertility due to the decline in soil organic matter. To face this condition, treated urban wastewater reuse is a sustainable and promising strategy to face water scarcity, enhance soil fertility, preserve natural resources, develop local products and improve living conditions of agriculture and farmers. Keywords: Urban wastewater, Physicochemical analysis, Wastewater reuse, Climate analysis, Arid climate, Marrakes

Land Use and Water Management in Israel- Economic and environmental analysis of sustainable reuse of wastewater in agriculture

We will analyze land use and water management issues in Israel by focusing on wastewater irrigation. Irrigation with treated effluents has become an important water source in Israel due to scarcity of natural water resources. Treated wastewater reuse serves as source of water and nutrients and assists with wastewater discard. Wastewater also carries pollutants including micro and macro organic and inorganic matter and its treatment and use should adapt to sustainability criteria. Wastewater treatment processes can decrease pollutants levels, while salinity is not influenced unless combining relatively expensive desalination processes. Advantages of using wastewater in irrigation include: supporting agricultural production, highly reliable supply, low cost water source, solution for effluent disposal and saving of chemical fertilizers. Disadvantages include quality problems as related to human health, damage to crops, contamination of groundwater, problems related to irrigation system, increased water requirement and need for continuous follow up and control. The higher is the treatment level, the higher are the treatment costs but the environmental potential hazards are lower. Regarding sustainable use we will assess advantages and disadvantages of treating and irrigating with treated effluents. We will focus on the economic and environmental analysis of sustainable reuse of wastewater in agriculture regarding its impact on groundwater, soil and society.