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 Stone Water District GSA Groundwater Sustainability Plan

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

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.

Nitrogen Tracking and Reporting Task Force: Final Report

California Department of Food and Agriculture (CDFA) | December 6th, 2013

Agriculture in California is highly diverse in terms of food production, crop management, ecosystems, and climate. Nitrogen fertilizer is essential for crop food producti

Agriculture in California is highly diverse in terms of food production, crop management, ecosystems, and climate. Nitrogen fertilizer is essential for crop food production. Nitrogen fertilizer use over several decades in California has led to nitrates in groundwater. Recognizing that nitrates from agricultural nitrogen fertilizing materials have entered some California groundwater systems used for drinking water, CDFA convened the Nitrogen Tracking and Reporting Task Force in 2013 as part of a multi-pronged administration effort to address nutrient management and water quality. This Task Force was charged with implementing Recommendation 11 of several recommendations made to the Legislature by the State Water Board: “CDFA, in coordination with the Water Boards, should convene a Task Force to identify intended outcomes and expected benefits of a nitrogen mass balance tracking system in nitrate high-risk areas. The Task Force should identify appropriate nitrogen tracking and reporting systems, and potential alternatives, that would provide meaningful and high quality data to help better protect groundwater quality.” This charge was achieved through several measures including, among others, understanding and discussing the pros and cons of existing nitrogen tracking and reporting systems, identifying desirable components or elements of existing systems and evaluating the variability and complexity of California agriculture in relation to where existing systems have been implemented. Through several meetings, presentations by subject matter experts and discussion, the Task Force members came to general agreement on several components of an effective nitrogen tracking and reporting system. The recommended system addresses eight key topics including: (1) System Structure; (2) Data Elements; (3) Roles, Responsibilities and Data Accessibility; (4) Benefits of Participation; (5) Verifiability; (6) Societal Benefits of the Recommended System; (7) Limitations and (8) System Phase-in. This report presents the Task Force’s discussions and recommendations including intended outcome and anticipated benefits of such a tracking and reporting system for nitrogen use.

North American diadromous fishes: Drivers of decline and potential for recovery in the Anthropocene

American Association for the Advancement of Science (AAAS) | January 28th, 2022

Diadromous fishes migrate between freshwater and marine habitats to complete their life cycle, a complexity that makes them vulnerable to the adverse effects of current

Diadromous fishes migrate between freshwater and marine habitats to complete their life cycle, a complexity that makes them vulnerable to the adverse effects of current and past human activities on land and in the oceans. Many North American species are critically endangered, and entire populations have been lost. Major factors driving declines include overfishing, pollution, water withdrawals, aquaculture, non-native species, habitat degradation, over-zealous application of hatcheries designed to mitigate effects of other factors, and effects of climate change. Perhaps, the most broadly tractable and effective factors affecting diadromous fishes are removals of the dams that prevent or hinder their migrations, alter their environment, and often favor non-native biotic communities. Future survival of many diadromous fish populations may depend on this.

North Bay Mercury Biosentinel Project 2016 - 2017

San Francisco Estuary Institute (SFEI) | March 1st, 2018

Concentrations of methylmercury throughout San Francisco Bay are high enough to warrant concern for the health of humans and wildlife. Large-scale tidal wetland restorat

Concentrations of methylmercury throughout San Francisco Bay are high enough to warrant concern for the health of humans and wildlife. Large-scale tidal wetland restoration is currently being implemented as a means of increasing populations of wildlife species of concern. There is concern that these restoration activities may lead to increased concentrations of methylmercury in the estuarine food web and exacerbate the existing methylmercury problem.

North Bay Selenium Monitoring Design

San Francisco Estuary Institute (SFEI) | December 3rd, 2018

The San Francisco Bay Regional Water Quality Control Board developed a Total Maximum Daily Load (TMDL) and implementation plan for selenium in North San Francisco Bay (N

The San Francisco Bay Regional Water Quality Control Board developed a Total Maximum Daily Load (TMDL) and implementation plan for selenium in North San Francisco Bay (NSFB). The TMDL is based on attainment of water column and fish tissue target concentrations protective of human health, aquatic life, and wildlife, and was approved by the U.S. Environmental Protection Agency (USEPA) in August 2016. The USEPA also published proposed aquatic life and aquatic-dependent wildlife criteria for selenium in the Bay and Delta in 2016. Subsequently, the San Francisco Water Board reached out to the Selenium Workgroup of the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) to consider the development and implementation of a robust selenium monitoring plan for the North Bay. A primary goal is to identify leading indicators of change to allow prompt management response to signs of increasing risk of impairment.

North Coast Regional Water Quality Control Board Fact Sheet

California State Water Resources Control Board (SWRCB) | March 1st, 2010

The North Coast Region receives more precipitation than any other part of California. Abundant in surface water and groundwater resources, the North Coast Regio

The North Coast Region receives more precipitation than any other part of California. Abundant in surface water and groundwater resources, the North Coast Region constitutes only about 12 percent of the area of California but produces about 40 percent of the annual runoff. Encompassing some 19,390 square miles, including 340 miles of coastline and remote wilderness, urban and agricultural areas, the North Coast Region is divided into two natural drainage basins—the Klamath River Basin and the North Coastal Basin.