Contributions of recycled wastewater to clean water and sanitation Sustainable Development Goals

Clean Water | April 30th, 2020

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbani

Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbanisation are increasing the number of users and uses of water, making water resources scarcer and more polluted. Changes in rainfall patterns threaten to worsen these effects in many areas. Water scarcity, due to physical lack or pollution, has become one of the most pressing issues globally, a matter of human, economic and environmental insecurity. Wastewater, whose value had not been appreciated until recently, is increasingly recognised as a potential ‘new’ source of clean water for potable and non-potable uses, resulting in social, environmental and economic benefits. This paper discusses the potential of recycled wastewater (also known as reused water) to become a significant source of safe water for drinking purposes and improved sanitation in support of the Sustainable Development Goals.

Cultivating effective utility-regulator relationships around innovation: Lessons from four case studies in the U.S. municipal wastewater sector

PLOS | August 26th, 2022

Regulation is critical for protecting public and environmental health but is often perceived as a barrier to innovation in the U.S. municipal wastewater sector. Before a

Regulation is critical for protecting public and environmental health but is often perceived as a barrier to innovation in the U.S. municipal wastewater sector. Before a wastewater utility can implement a new technology, it must navigate applicable regulatory processes and obtain necessary approvals, often including obtaining an updated wastewater discharge permit. While all regulatory processes involve interactions between regulators and regulated entities, innovative projects may require them to engage in new ways, heightening the importance of the relationships between them. We investigated four case studies to examine how regulatory relationships affect municipal wastewater utilities’ efforts to adopt new technologies. Through cross-case analysis, we identified five interconnected characteristics of regulatory relationships that appear to facilitate innovation, and whose absence could impede it: clarity, capacity building, continuity, trust, and bounded flexibility. Appropriately applied bounded flexibility—such as using regulatory discretion to tailor permits to reflect the particular risks, benefits, and information needs of the technology at issue—may be key for enabling socially and environmentally beneficial innovation. Yet all five characteristics play important and mutually reinforcing roles in supporting innovation. By cultivating these characteristics in their relationships, both utilities and regulators can take responsibility for enabling appropriate implementation of innovative technologies. However, some parties, particularly small and under-resourced utilities, may find cultivating these characteristics difficult. Therefore, sector-wide support for effective utility-regulator relationships, including coordinated regulatory and funding programs targeted to meet small utilities’ needs, may be needed to bring beneficial innovation within reach for many wastewater utilities and the communities they serve.

Estuary News, December 2014

San Francisco Estuary Partnership (SFEP) | December 15th, 2014

Estuary News, December 2018

San Francisco Estuary Partnership (SFEP) | December 15th, 2018

Estuary News, June 2018

San Francisco Estuary Partnership (SFEP) | June 15th, 2018

Estuary News, March 2020

San Francisco Estuary Partnership (SFEP) | March 15th, 2020

Estuary News, September 2020

San Francisco Estuary Partnership (SFEP) | September 15th, 2020

Evaluating effects of urban water use efficiency standards (AB 1668- SB 606) on urban retail water suppliers, wastewater management agencies, and urban landscapes (trees and urban parklands)*

California State Water Resources Control Board (SWRCB) | January 15th, 2022

Click here for the companion draft chapter on trees and parkland

Click here for the companion draft chapter on trees and parkland

Formation and prevention of pipe scale from acid mine drainage at iron Mountain and Leviathan Mines, California, USA

Applied Geochemistry (Elsevier) | April 1st, 2020

Pipelines carrying acid mine drainage (AMD) to treatment plants commonly form pipe scale, an Fe(III)-rich precipitate that forms inside the pipelines and requires periodi

Pipelines carrying acid mine drainage (AMD) to treatment plants commonly form pipe scale, an Fe(III)-rich precipitate that forms inside the pipelines and requires periodic and costly cleanout and maintenance. Pipelines at Iron Mountain Mine (IMM) and Leviathan Mine (LM) in California carry acidic water from mine sources to a treatment plant and have developed pipe scale. Samples of scale and AMD were collected from both mine sites for mineralogical, microbiological, and chemical analysis. The scale mineralogy was primarily schwertmannite with minor amounts of poorly crystalline goethite. Although the bulk composition of the scale was similar along the length of the pipeline at IMM, the number of iron-oxidizing bacteria and concentrations of associated trace elements decreased along the flow path inside the pipeline. Laboratory batch experiments with unfiltered AMD from IMM and LM showed that Fe(II) oxidation was driven by microbial activity when the pH was <5. A remediation strategy of decreasing the pH to <2.2 was tested through geochemical modeling and laboratory experiments. These experiments indicated that scale formation could be prevented by decreasing the pH, which could be achieved at IMM by mixing source waters. However, the presence of Fe(III)-rich scale in a pipeline buffers the pH to higher values that may affect the efficacy of this remedial approach.

Groundwater Quality of the Lucerne Valley Groundwater Basin, California

U.S. Geological Survey (USGS) | July 7th, 2022

Anthropogenic activities, including groundwater withdrawals, return flow from irrigated agriculture, and treated wastewater-effluent disposal have the potential to affect

Anthropogenic activities, including groundwater withdrawals, return flow from irrigated agriculture, and treated wastewater-effluent disposal have the potential to affect groundwater quality in the Lucerne Valley groundwater basin, located in the southwest Mojave Desert. Questions regarding the current state and potential future of groundwater quality in this basin were addressed by (1) considering groundwater data from and findings of historical water-quality studies, (2) evaluating recent (1990–2021) U.S. Geological Survey water-quality and geochemical-tracer data, and (3) assessing groundwater-quality results from samples collected in 2021 to better understand the transport of applied treated wastewater effluent in the subsurface and associated effects of this practice on water quality. As observed by previous studies, differences in groundwater quality existed among the upper, middle, and lower aquifers of the Lucerne Valley groundwater basin, with the lower aquifer characterized by high dissolved-solid content relative to the middle and upper aquifers. Stable and radioisotope tracers indicate that most of the groundwater sampled in the basin was recharged during cooler, wetter climate conditions than those of the present day (2022). Analyses of the 2021 samples collected to examine the subsurface transport of applied treated wastewater effluent were not conclusive but indicate that water from applied treated wastewater effluent is currently (2022) limited to the upper aquifer and likely to remain so given the extensive confining unit below the upper aquifer.