New San Francisco Bay Contaminants Emerge

San Francisco Estuary Institute (SFEI) | July 2nd, 2020

 In 2016, the RMP launched a novel investigation to detect new or unexpected contaminants in Bay waters, as well as treated sewage (or wastewater) discharged to the Bay.

 In 2016, the RMP launched a novel investigation to detect new or unexpected contaminants in Bay waters, as well as treated sewage (or wastewater) discharged to the Bay. This study used non-targeted analysis, a powerful tool that provides a broad, open-ended view of thousands of synthetic and naturally-derived chemicals simultaneously. We identified hundreds of contaminants, and the results have opened our eyes to urban stormwater runoff as an important pathway for emerging contaminants to enter the Bay. 

New Sources for California’s Water Supply

State of California | March 1st, 2016

The Assembly Select Committee on Water Consumption and Alternative Sources was established in February 2015 to examine the strategies California could take to improve wat

The Assembly Select Committee on Water Consumption and Alternative Sources was established in February 2015 to examine the strategies California could take to improve water conservation and expand the portfolio of water sources. Given that California rose to the challenge of conservation, the committee turned its attention to alternative water source strategies such as stormwater capture, ocean desalination and water recycling, holding specific hearings to discuss the latter two in greater detail. This report is the culmination of several hearings held across the state on issues of water use and opportunities for expanding water sources. It includes summaries of expert testimony at those hearings, including illustrative slides from their presentations, as well as a list of key findings and recommendations compiled by committee staff and approved by the Chair. These findings and recommendations were not voted on by members of the Select Committee and may not reflect the view of each Select Committee member. This report is meant to provide knowledge regarding California’s drought, climate change future, and viability of water sourcing strategies including stormwater capture, water recycling and desalination. This knowledge will be essential in adapting California’s water infrastructure to climate changes and devising the most effective and environmentally friendly approach to endure the next California drought.

New Stone Water District Groundwater Sustainability Plan

New Stone Water District (NSWD) | December 23rd, 2019

This GSP covers about 4,200 acres in the northwestern area of the basin that is adjacent to the Chowchilla Bypass covering the New Stone Water District Groundwater Sustai

This GSP covers about 4,200 acres in the northwestern area of the basin that is adjacent to the Chowchilla Bypass covering the New Stone Water District Groundwater Sustainability Agency. The NSWD GSA is coterminous with the New Stone Water District (NSWD or District) boundary. The District is predominantly agriculture and consists of two landowners. The New Stone Water District Groundwater Sustainability Agency was created on December 22, 2016.

New Stone Water District GSA Groundwater Sustainability Plan

New Stone Water District (NSWD) | September 23rd, 2019

New Stone Water District Revised Groundwater Sustainability Plan

New Stone Water District (NSWD) | March 20th, 2023

New streams and springs after the 2014 Mw6.0 South Napa earthquake

Nature Portfolio (Springer Nature) | July 9th, 2015

Many streams and springs, which were dry or nearly dry before the 2014 Mw6.0 South Napa earthquake, started to flow after the earthquake. A United States Geologic

Many streams and springs, which were dry or nearly dry before the 2014 Mw6.0 South Napa earthquake, started to flow after the earthquake. A United States Geological Survey stream gauge also registered a coseismic increase in discharge. Public interest was heightened by a state of extreme drought in California. Since the new flows were not contaminated by pre-existing surface water, their composition allowed unambiguous identification of their origin. Following the earthquake we repeatedly surveyed the new flows, collecting data to test hypotheses about their origin. We show that the new flows originated from groundwater in nearby mountains released by the earthquake. The estimated total amount of new water is ∼106 m3, about 1/40 of the annual water use in the Napa–Sonoma area. Our model also makes a testable prediction of a post-seismic decrease of seismic velocity in the shallow crust of the affected region.

New water accounting reveals why the Colorado River no longer reaches the sea

Nature Portfolio (Springer Nature) | March 28th, 2024

New-generation pesticides are prevalent in California's Central Coast streams

Science of the Total Environment (Elsevier) | October 7th, 2021

Pesticides are widely recognized as important biological stressors in streams, especially in heavily developed urban and agricultural areas like the Central California Co

Pesticides are widely recognized as important biological stressors in streams, especially in heavily developed urban and agricultural areas like the Central California Coast region. We assessed occurrence and potential toxicity of pesticides in small streams in the region using two analytical methods: a broad-spectrum (223 compounds) method in use since 2012 and a newly developed method for 30 additional new-generation fungicides and insecticides. At least one pesticide compound was identified in 83 of the 85 streams sampled. About one-half (48%) of the 253 pesticides measured were detected at least once and 27 were detected in 10% or more of samples. Three of the top 4, and 6 of the top 10 most frequently detected compounds (chlorantraniliprole, dinotefuran, boscalid, thiamethoxam, clothianidin and the fluopicolide degradate 2,6-dichlorobenzamide) were analyzed by the new method. Pesticide mixtures were common, with two or more pesticide compounds detected in 81% of samples and 10 or more in 32% of samples. The pesticide count at a site was relatively consistent over the 6-week study. Four sites with mixed land-use in the lower basin (

Nitrate Implementation Measures Study (NIMS) Final Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 31st, 2016

This report summarizes the Nitrate Implementation Measures Study (NIMS) which addresses nitrate contamination in the groundwater basins underlying the floor of the Centra

This report summarizes the Nitrate Implementation Measures Study (NIMS) which addresses nitrate contamination in the groundwater basins underlying the floor of the Central Valley and appropriate implementation measures to mitigate nitrate contamination for these areas using a phased approach that includes providing safe drinking water, reducing or eliminating impacts to drinking water sources and implementing managed restoration activities where needed to restore beneficial uses in groundwater. These implementation measures will be incorporated into the SNMP. The findings from both the SSALTS and the NIMS will be used to guide discussions regarding the need for changes to the existing Basin Plan to facilitate salt disposal and mitigation measures for nitrate in a manner that is most beneficial to the region covered by the SNMP. 

Nitrogen Fertilizer Loading to Groundwater in the Central Valley

University of California, Davis (UC Davis) | October 31st, 2017

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and curr

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and current potential nitrogen loading to groundwater on irrigated and natural lands across the entire Central Valley of California using a nitrogen mass balance approach; assesses the long‐term implications for groundwater quality in the Central Valley (Sacramento Valley, San Joaquin Valley, and Tulare Lake Basin); evaluates potential best management practices to reduce groundwater nitrogen loading from irrigated lands; and provides a planning tool to better understand local and regional groundwater quality response to specific best management practices and policy/regulatory actions. The project complements other work to assess the vulnerability of Central Valley groundwater to nitrate contamination, sources of nitrate in groundwater, and how to reduce source loading.