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: 

Pixley Irrigation District Groundwater Sustainability Plan

Pixley Irrigation District Groundwater Sustainability Agency (PIDGSA) | January 21st, 2020

Plan of Development Sacramento-San Joaquin Delta

Interagency Delta Committee (IDC) | January 20th, 1965

Policy Considerations for Managing Agricultural Nitrogen to Reduce Groundwater Contamination in California

California Roundtable on Agriculture and the Environment (CRAE) | May 28th, 2013

Recent research, including “The California Nitrogen Assessment”1 and the UC Davis Report for the SWRCB SBX2 1 Report to the Legislature2, has produced an important co

Recent research, including “The California Nitrogen Assessment”1 and the UC Davis Report for the SWRCB SBX2 1 Report to the Legislature2, has produced an important collection of data about how nitrogen compounds move in the environment. Members of the California Roundtable on Agriculture and the Environment (CRAE) share an interest in meaningfully addressing water quality challenges while maintaining a healthy and prosperous agriculture sector. Because of the serious health concerns associated with nitrate in groundwater, CRAE members agree that the immediate goal should be to find cost-effective solutions to cleaning up drinking water supplies or providing safe alternate sources of drinking water to affected communities. We support ongoing efforts, such as the governor’s Drinking Water Task Force, to address this important issue. While CRAE’s ultimate interest is in addressing the full range of water quality challenges related to agriculture—from drinking water to legacy issues, groundwater to surface water, and nitrate to Total Maximum Daily Loads (TMDLs)—and supporting improved nutrient management broadly speaking, the group has chosen to focus specifically on the longer-term challenge of reducing nitrate loading in groundwater from agricultural sources. Recognizing that a range of research and policy processes to address the harmful impacts of excess reactive nitrogen-based compounds in the environment are ongoing, CRAE stakeholders agreed that a focus on preventing further contamination of groundwater from nitrate is an area where CRAE has a unique opportunity to contribute. Furthermore, we anticipate that approaches to reduce nitrate loading that adhere to the considerations below will simultaneously improve other challenges, including air quality, energy use, and climate change. Nitrate contamination is projected to increase in the coming years as legacy contributions work their way through the soil profile. The short-term remediation of groundwater basins is so costly as to be practically impossible. Therefore, CRAE has concentrated on intermediate and longer-term groundwater quality issues by helping to find practical solutions to groundwater quality challenges. Reflecting our membership composition, our focus is on the contribution of agricultural sources of nitrate in particular. CRAE has compiled the following set of key facts on our state of knowledge about nitrogen management and a set of considerations to inform related policy and programs focused on improving water quality.

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 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.

Pollutants of concern (POC) loads monitoring progress report, water years (WYs) 2012, 2013, and 2014

San Francisco Estuary Institute (SFEI) | July 1st, 2016

The San Francisco Regional Water Quality Control Board (Water Board) has determined that San Francisco Bay is impaired by mercury and PCBs due to threats to wildlife and

The San Francisco Regional Water Quality Control Board (Water Board) has determined that San Francisco Bay is impaired by mercury and PCBs due to threats to wildlife and human consumers of fish from the Bay. These contaminants persist in the environment and accumulate in aquatic food webs (SFRWRCB 2006; SFRWRCB, 2008). The Water Board has identified urban runoff from local watersheds as a pathway for pollutants of concern into the Bay, including mercury and PCBs. The Municipal Regional Stormwater Permit (MRP; SFRWRCB, 2009) contains several provisions requiring studies to measure local watershed loads of suspended sediment (SS), total organic carbon (TOC), polychlorinated biphenyl (PCB), total mercury (HgT), total methylmercury (MeHgT), nitrate-N (NO3), phosphate-P (PO4), and total phosphorus (TP) (provision C.8.e), as well as other pollutants covered under provision C.14. (e.g. legacy pesticides, PBDEs, and selenium).

Pollutants of concern (POC) reconnaissance monitoring final progress report, water year (WY) 2015

San Francisco Estuary Institute (SFEI) | June 6th, 2016

The San Francisco Bay mercury and PCB TMDLs called for implementation of control measures to reduce PCB and mercury loads entering the Bay via stormwater. Subsequently,

The San Francisco Bay mercury and PCB TMDLs called for implementation of control measures to reduce PCB and mercury loads entering the Bay via stormwater. Subsequently, the San Francisco Bay Regional Water Quality Control Board (Regional Water Board) issued the first combined Municipal Regional Stormwater Permit (MRP). This first MRP contained provisions aimed at improving information on stormwater pollutant loads in selected watersheds (Provision C.8.) and piloted a number of management techniques to reduce PCB and Hg loading entering the Bay from smaller urbanized tributaries (Provisions C.11. and C.12.). In November 2015, the Regional Water Board issued the second MRP. “MRP 2.0” places an increased focus on finding watersheds, sources areas, and source properties that are potentially more polluted and are therefore more likely to be cost effective areas for addressing load reduction requirements through implementation of control measures. To support this increased focus, a stormwater characterization monitoring program was developed and implemented beginning in Water Year (WY) 2015. This same design is being implemented in the winter of WY 2016 by the RMP, the San Mateo Countywide Water Pollution Prevention Program and the Santa Clara Valley Urban Runoff Pollution Prevention Program. In addition, the RMP is piloting a project to explore the use of alternative un-manned “remote” suspended sediment samplers. During WY 2015, composite stormwater samples were collected from 20 watershed locations. At three of these locations, data were also collected using two remote suspended sediment sampler devices, both of which are designed to enhance settling and capture of suspended sediment particles from the water column. This report summarizes and provides a preliminary interpretation of data collected during WY 2015. The data collected is contributing to a broader effort to identify potential management areas. The report is designed to be updated in subsequent years as more data are collected.