The implications of drought and water conservation on the reuse of municipal wastewater: Recognizing impacts and identifying mitigation possibilities

Abstract

As water agencies continue to investigate opportunities to increase resilience and local water supply reliability in the face of drought and rising water scarcity, water conservation strategies and the reuse of treated municipal wastewater are garnering significant attention and adoption. Yet a simple water balance thought experiment illustrates that drought, and the conservation strategies that are often enacted in response to it, both likely limit the role reuse may play in improving local water supply reliability. For instance, as a particular drought progresses and agencies enact water conservation measures to cope with drought, influent flows likely decrease while influent pollution concentrations increase, particularly salinity, which adversely affects wastewater treatment plant (WWTP) costs and effluent quality and flow. Consequently, downstream uses of this effluent, whether to maintain streamflow and quality, groundwater recharge, or irrigation may be impacted. This is unfortunate since reuse is often heralded as a drought-proof mechanism to increase resilience. The objectives of this paper are two-fold. First, we illustrate-using a case study from Southern California during its most recent drought- how drought and water conservation strategies combine to reduce influent flow and quality and, subsequently, effluent flow and quality. Second, we use a recently developed regional water reuse decision support model (RWRM) to highlight cost-effective strategies that can be implemented to mitigate the impacts of drought on effluent water quality. While the solutions we identify cannot increase the flow of influent or effluent coming into or out of a treatment plant, they can improve the value of the remaining effluent in a cost-effective manner that takes into account the characteristics of its demand, whether it be for landscaping, golf courses, agricultural irrigation, or surface water augmentation.

Challenges on European Irrigation Governance: From Alternative Water Resources to Key Stakeholders’ Involvement

“…From the reviewed literature conducted in Tran QK (2017) [51], it has long been recognised that the main challenges to more effective water management are largely socio-institutional rather than technical, with institutional fragmentation, limited long-term strategic planning, lack of project demonstration, and inadequate community participation. Cognitive factors such as the Law of Contagion and the Law of Similarity may explain many of the cultural perceptions that people may have about alternative water resources [52].…”

Increasing Trends Towards Drinking Water Reclamation from Treated Wastewater

“…The analysis revealed that carefully planned potable water reuse projects should be able to provide a level of protection from waterborne illness and chemical contaminants comparable to (and, in some cases, better than) the level of protection the public experiences in many drinking water supplies across the nation. However, researchers [11] pointed out that the analysis was presented as an example and should not be used to endorse certain treatment schemes or to determine the risk at any particular site without site-specific analysis [7,9,11,33,[48][49][50][51][52][53].…”

Grass–Legume Forage Systems Effect on Phosphorus Removal from a Grassland Historically Irrigated with Reclaimed Wastewater

“…Therefore, alternative approaches must be sought and incorporated into traditional water management practices to ensure sustainable agricultural production from these water-scarce environments. One suitable and sustainable approach to agricultural production in water-scarce regions is the utilization of alternative water resources in the form of the large quantity of wastewater generated from municipalities [3][4][5][6][7][8][9]. The benefits of utilizing reclaimed wastewater are multiple, in that it provides a reliable year-round source of water for crop production [3], crop yield optimization through the provision of nutrients such as N, P, and K [9][10][11], reduced demand on fossil fuel for synthetic fertilizer production, minimize fertilizer input cost [3], increase crop farm profit margins [12], and enhance environmental conservation due to a reduction in synthetic fertilizer use [13].…”