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

Evaluation of extinction risk for stream fishes within an urban riverscape using population viability analysis

Aquatic Conservation: Marine and Freshwater Ecosystems (Wiley) | June 19th, 2024

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.

From wastewater treatment plants to decentralized resource factories

Nature Portfolio (Springer Nature) | June 10th, 2024

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.