Pesticides in the Nation’s Streams and Ground Water, 1992–2001

U.S. Geological Survey (USGS) | February 28th, 2006

This report is one of a series of publications, The Quality of Our Nation’s Waters, that describe major findings of the NAWQA Program on water-quality issues of regiona

This report is one of a series of publications, The Quality of Our Nation’s Waters, that describe major findings of the NAWQA Program on water-quality issues of regional and national concern. This report presents evaluations of pesticides in streams and ground water based on findings for the first decadal cycle of NAWQA. “Pesticides in the Nation’s Streams and Ground Water, 1992–2001” greatly expands the analysis of pesticides presented in “Nutrients and Pesticides,” which was the first report in the series and was based on early results from 1992 to 1995. About 1 billion pounds of conventional pesticides are used each year in the United States to control weeds, insects, and other pests. The use of pesticides has resulted in a range of benefits, including increased food production and reduction of insect-borne disease, but also raises questions about possible adverse effects on the environment, including water quality. The NAWQA assessment of pesticides provides the most comprehensive national-scale analysis to date of pesticide occurrence and concentrations in streams and ground water. NAWQA results show where, when, and why specific pesticides occur in streams and ground water across the Nation, and yield science-based implications for assessing and managing the quality of our water resources.

Petition for 2023 Drought Emergency Regulation or Other Emergency Action to Protect Nesting Birds, Water Quality, and other Public Trust Resources at Mono Lake

Mono Lake Committee | December 16th, 2022

PFAS in San Francisco Bay Water

San Francisco Estuary Institute (SFEI) | November 14th, 2022

Per- and polyfluoroalkyl substances (PFAS), a family of thousands of synthetic, fluorine-rich compounds commonly referred to as “forever chemicals,” are known for the

Per- and polyfluoroalkyl substances (PFAS), a family of thousands of synthetic, fluorine-rich compounds commonly referred to as “forever chemicals,” are known for their thermal stability, non-reactivity, and surfactant properties. These unique compounds have widespread uses across consumer, commercial, and industrial products, resulting in widespread occurrence in the environment and wildlife across the globe. This study analyzed ambient surface water in San Francisco Bay for 40 PFAS to discern the occurrence, fate, and potential risks to ecological and human health.

Phenomenological vs. biophysical models of thermal stress in aquatic eggs

Ecology Letters (Wiley) | January 1st, 2017

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between

Predicting species responses to climate change is a central challenge in ecology. These predictions are often based on lab-derived phenomenological relationships between temperature and fitness metrics. We tested one of these relationships using the embryonic stage of a Chinook salmon population. We parameterised the model with laboratory data, applied it to predict survival in the field, and found that it significantly underestimated field-derived estimates of thermal mortality. We used a biophysical model based on mass transfer theory to show that the discrepancy was due to the differences in water flow velocities between the lab and the field. This mechanistic approach provides testable predictions for how the thermal tolerance of embryos depends on egg size and flow velocity of the surrounding water. We found support for these predictions across more than 180 fish species, suggesting that flow and temperature mediated oxygen limitation is a general mechanism underlying the thermal tolerance of embryos.

Phytoplankton, and Related Water-Quality Constituents in the California Sacramento– San Joaquin Delta at the Landscape Scale: 2018 High Resolution Mapping Surveys

U.S. Geological Survey (USGS) | April 1st, 2024

This study examined the abundance and distribution of nutrients and phytoplankton in the tidal aquatic environments of the Sacramento–San Joaquin Delta (Delta) and Suis

This study examined the abundance and distribution of nutrients and phytoplankton in the tidal aquatic environments of the Sacramento–San Joaquin Delta (Delta) and Suisun Bay, comprising three spatial surveys conducted in May, July, and October of 2018 that used continuous underway high frequency sampling and measurements onboard a high-speed boat to characterize spatial variation across the extent of the Delta. The method used involves simultaneously collecting information about the concentration and spatial distribution of all major nutrient forms with analogous information about the major classes of phytoplankton and associated water-quality conditions. The results showed substantial variation across space and time, providing an unprecedented snapshot of the dynamic environmental processes that shape the ways nutrients interact with and affect aquatic habitats in the Delta.

Pilot Study Examining Spatial Differences in Water Quality Between Shoal and Channel Habitats

San Francisco Estuary Institute (SFEI) | August 1st, 2019

Under the umbrella of the Nutrient Management Strategy (NMS; www.sfbaynutrients.sfei.org), we are investigating relationships between the SFB’s elevated nutrient levels

Under the umbrella of the Nutrient Management Strategy (NMS; www.sfbaynutrients.sfei.org), we are investigating relationships between the SFB’s elevated nutrient levels and phytoplankton production, with the goal of identifying protective nutrient loads and effective nutrient management options. To address these goals, NMS work includes continued ship-based monitoring (in collaboration with USGS); augmenting that monitoring with high-frequency sensor data and intensive field studies; and developing coupled hydrodynamic-biogeochemical models -- calibrated using field observations -- to simulate water quality under a range of forcings.

Pilot Study of Contaminants of Emerging Concern (CECs) in the Russian River Watershed: Lessons Learned

San Francisco Estuary Institute (SFEI) | December 21st, 2017

Contaminants of emerging concern (CECs) can be defined as any chemicals that are not regulated or commonly monitored but have the potential to enter the environment and c

Contaminants of emerging concern (CECs) can be defined as any chemicals that are not regulated or commonly monitored but have the potential to enter the environment and cause adverse ecological or human health impacts. Determining which of the thousands of chemicals in commerce are CECs and whether or not they may be a problem is a formidable challenge. For most chemicals in use, a number of limitations prevent researchers from measuring their presence and assessing their potential risks. It is therefore difficult to monitor and manage CECs.  In response, scientists and managers recently completed a Pilot Study Design1 for monitoring CECs in aquatic ecosystems throughout California. The Russian River watershed (RRW) study was the first regional implementation of this Pilot Study Design. The collected data provide useful information for both the Russian River region and the implementation of the monitoring framework in other areas.  The primary objective of this study was to investigate the occurrence of high priority CECs in receiving water, sediment, and fish tissue within the RRW to address the management question: 

Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California

California State Water Resources Control Board (SWRCB) | March 17th, 2005

This state policy for water quality control (Policy), adopted by the State Water Resources Control Board on March 2, 2000 and effective by May 22, 2000 (See “Note” be

This state policy for water quality control (Policy), adopted by the State Water Resources Control Board on March 2, 2000 and effective by May 22, 2000 (See “Note” below), applies to discharges of toxic pollutants into the *inland surface waters, *enclosed bays, and *estuaries of California subject to regulation under the State's Porter-Cologne Water Quality Control Act (Division 7 of the Water Code) and the federal Clean Water Act (CWA). Such regulation may occur through the issuance of National Pollutant Discharge Elimination System (NPDES) permits, or other relevant regulatory approaches. The goal of this Policy is to establish a standardized approach for permitting discharges of toxic pollutants to non-*ocean surface waters in a manner that promotes statewide consistency. As such, this Policy is a tool to be used in conjunction with watershed management approaches and, where appropriate, the development of Total Maximum Daily Loads (TMDLs) to ensure achievement of water quality standards (i.e., water quality criteria or objectives, and the beneficial uses they are intended to protect, as well as the State and federal antidegradation policies). This Policy establishes: (1) implementation provisions for priority pollutant criteria promulgated by the U.S. Environmental Protection Agency (U.S. EPA) through the National Toxics Rule (NTR) (promulgated on December 22, 1992 and amended on May 4, 1995) and through the California Toxics Rule (CTR), and for priority pollutant objectives established by Regional Water Quality Control Boards (RWQCBs) in their water quality control plans (basin plans); (2) monitoring requirements for 2,3,7,8-TCDD equivalents; and (3) chronic toxicity control provisions. In addition, this Policy includes special provisions for certain types of discharges and factors that could affect the application of other provisions in this Policy.

Policy for Maintaining Instream Flows in Northern California Streams

California State Water Resources Control Board (SWRCB) | September 28th, 2010

The State Water Resources Control Board (State Water Board or Board) adopted this state policy for water quality control on May 4, 2010. This policy is also known as the

The State Water Resources Control Board (State Water Board or Board) adopted this state policy for water quality control on May 4, 2010. This policy is also known as the North Coast Instream Flow Policy. It applies to applications to appropriate water, small domestic use and livestock stockpond registrations, and water right petitions. Water Code section 1259.4, which was added by Assembly Bill 2121 (Stats. 2004, ch. 943, § 3), requires the State Water Board to adopt principles and guidelines for maintaining instream flows in northern California coastal streams as part of state policy for water quality control, for the purposes of water right administration. This policy implements Water Code section 1259.4. The geographic scope of this policy, referred to as the policy area, extends to five counties—Marin, Sonoma, and portions of Napa, Mendocino, and Humboldt counties— and encompasses (1) coastal streams from the Mattole River (originating in Humboldt County) to San Francisco, and (2) coastal streams entering northern San Pablo Bay. This policy focuses on measures that protect native fish populations, with a particular focus on anadromous salmonids (e.g., steelhead trout, coho salmon, and chinook salmon) and their habitat. Beginning in 1996, the National Marine Fisheries Services (NMFS) and the California Department of Fish and Game (DFG) listed steelhead trout, coho salmon, and chinook salmon as “threatened” under the federal Endangered Species Act (ESA) and the California Endangered Species Act (CESA), respectively. In 2005, the coho salmon’s status was upgraded from threatened to “endangered” on both the ESA and the CESA lists. This policy establishes principles and guidelines for maintaining instream flows for the protection of fishery resources. It does not specify the terms and conditions that will be incorporated into water right permits, licenses, and registrations. It prescribes protective measures regarding the season of diversion, minimum bypass flow, and maximum cumulative diversion. Applicants may choose to implement the policy principles through the regionally protective criteria or site-specific studies. Site-specific studies may be conducted to develop alternative site-specific protective criteria. The policy also limits construction of new onstream dams and contains measures to ensure that approval of new onstream dams does not adversely affect instream flows needed for fishery resources. The policy provides for a watershed-based approach to evaluate the effects of multiple diversions on instream flows within a watershed as an alternative to evaluating water diversion projects on an individual basis. Enforcement requirements contained in this policy include a framework for compliance assurance, prioritization of enforcement cases, and descriptions of enforcement actions. The policy contains guidelines for evaluating whether a proposed water diversion, in combination with existing diversions in a watershed, may affect instream flows needed for the protection of fishery resources.

Policy for Water Quality Control for Recycled Water (Recycled Water Policy)

California State Water Resources Control Board (SWRCB) | June 21st, 2013

The purpose of this Policy is to increase the use of recycled water from municipal wastewater sources that meets the definition in Water Code section 13050(n), in a manne

The purpose of this Policy is to increase the use of recycled water from municipal wastewater sources that meets the definition in Water Code section 13050(n), in a manner that implements state and federal water quality laws. The State Water Board expects to develop additional policies to encourage the use of stormwater, encourage water conservation, encourage the conjunctive use of surface and groundwater, and improve the use of local water supplies. When used in compliance with this Policy, Title 22 and all applicable state and federal water quality laws, the State Water Board finds that recycled water is safe for approved uses, and strongly supports recycled water as a safe alternative to potable water for such approved uses.