Mercury Contamination from Historical Gold Mining in California

U.S. Geological Survey (USGS) | October 31st, 2005

Methods of Analysis—Determination of Pesticides in Filtered Water and Suspended Sediment using Liquid Chromatography- and Gas Chromatography-Tandem Mass Spectrometry

U.S. Geological Survey (USGS) | January 31st, 2024

The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in en

The widespread application of pesticides in agricultural and urban areas leads to their presence in surface waters. Presence of these biologically active chemicals in environmental waters potentially has adverse effects on nontarget organisms. To better understand the environmental fate of these contaminants, a robust method to capture chemicals with wide-ranging physicochemical properties has been developed. The method was developed by the U.S. Geological Survey’s Organic Chemistry Research Laboratory to monitor pesticides, pesticide degradates, and other agrochemicals in environmental surface waters throughout the country. The analysis involves a multiresidue method to determine 183 pesticides and pesticide degradates in filtered water samples and 178 pesticides and pesticide degradates in paired suspended sediment samples. After the filtration of whole water, contaminants are individually measured in the filtered water and the collected suspended sediment. Filtered water is extracted via solid-phase extraction, whereas suspended sediment is extracted using an ultrasonication, solid-liquid extraction. Samples are analyzed by liquid chromatography-tandem mass spectrometry using an electrospray ionization source in positive and negative modes and analyzed by gas chromatography-tandem mass spectrometry using an advanced electron ionization source in positive mode. Instrument parameters were optimized for the highest sensitivity, and at least two transitions (quantifier and qualifier) were monitored for each analyte. Recoveries in test filtered water (n=9; 183 analytes) from the American River, California, and suspended sediment (n=9; 178 analytes) samples fortified at 15 nanograms per liter (ng/L) ranged from 70.1 to 121.0 and 71.1 to 117.0 percent in water and suspended sediment filter samples, respectively.

Microbial Water Quality at Minimally Human-Impacted Reference Beaches in Northern California

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

All of the coastal reference beaches that have been used by the State of California for quantifying “natural loads” of fecal indicator bacteria have been in Southern

All of the coastal reference beaches that have been used by the State of California for quantifying “natural loads” of fecal indicator bacteria have been in Southern California. None has been in the northern and central coastal regions of the State. To fill this information gap, this study assessed bacteria concentrations at coastal reference beaches in Northern California, investigated possible factors influencing the bacteria concentrations, and evaluated how these concentrations compare to results from the Southern California reference beaches. Reference beaches were defined as open beaches with breaking waves that receive runoff from undeveloped watersheds. The study beaches were selected to represent a variety of geographical conditions and watershed sizes in Northern California. Five reference beaches were sampled between January 2016 and September 2017 for a total of 25‐30 sampling events, including 10 wet weather events, 10 winter dry events, and 10 summer dry events. The number of samples collected was admittedly small for characterizing variable bacteria concentrations but was deemed sufficient for providing initial information relevant to management questions. At each beach, samples were collected from an ocean site in the surf zone and from a freshwater site in the watershed draining to the beach. Samples were analyzed for total coliform, fecal coliform, Escherichia coli (E. coli), enterococci (ocean sites only), as well as a human‐specific genetic marker (human Bacteroides HF183).

Microparticles, Microplastics, and PAHs in Bivalves in San Francisco Bay

San Francisco Estuary Institute (SFEI) | November 15th, 2019

Microplastic Monitoring and Science Strategy for San Francisco Bay

San Francisco Estuary Institute (SFEI) | February 1st, 2017

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a special study to measure microplastic in treated wastewater effluent and Bay surface water. Bay surface water appeared to have higher microplastic levels than other urban water bodies sampled in North America, such as the Great Lakes and Chesapeake Bay. Microbeads derived from personal care products and tiny fibers, a portion of which were likely derived from synthetic clothing, were recovered from all nine Bay sites. Tiny particles, primarily fibers, were also detected in treated effluent from Bay Area facilities; not all of these particles are known to be plastic. These findings received considerable media attention and catalyzed state and federal policy shifts. 

Microplastic Monitoring and Science Strategy for the San Francisco Bay

San Francisco Estuary Institute (SFEI) | February 7th, 2017

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducte

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a special study to measure microplastic in treated wastewater effluent and Bay surface water. Bay surface water appeared to have higher microplastic levels than other urban water bodies sampled in North America, such as the Great Lakes and Chesapeake Bay. Microbeads derived from personal care products and tiny fibers, a portion of which were likely derived from synthetic clothing, were recovered from all nine Bay sites. Tiny particles, primarily fibers, were also detected in treated effluent from Bay Area facilities; not all of these particles are known to be plastic. These findings received considerable media attention and catalyzed state and federal policy shifts. In 2016, the RMP authorized a special study to develop a strategy for continued study of microplastic in San Francisco Bay. To form this strategy, the RMP convened stakeholders to articulate management questions specific to microplastic pollution, and then conducted a one-day workshop that brought together stakeholders and microplastic experts to develop an understanding of the state of the science on this emerging contaminant, and determine consensus priorities for future work. The resulting strategy document provides: • an overview of microplastic science relevant to San Francisco Bay, • the management questions that will guide future work, • a summary of available sampling and analysis methods, and • a multi-year plan for studies that would provide answers to the management questions. The monitoring and management of both macro- and microplastic are issues that extend beyond the scope of the RMP. In this document, we seek to identify data gaps, next steps, and strategic partners who can help provide information and resources to inform management decisions. This Microplastic Strategy will be refined and adjusted in years to come based on advances in understanding and changes in the sources and management of plastic pollution.

Microplastic Strategy Update on behalf of the Regional Monitoring Program (RMP) for Water Quality in San Francisco Bay

San Francisco Estuary Institute (SFEI) | December 2nd, 2019

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) convened a Microplastic Workgroup (MPWG) in 2016 to discuss the issue, identify management information needs and management questions (MQs), and prioritize studies to provide information to answer these management questions. The MPWG meets annually to review on-going microplastic projects and to conduct strategic long-term planning in response to new information in this rapidly evolving field.

Microplastics from Tire Particles in San Francisco Bay

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

Microplastics in Lake Mead National Recreation Area

U.S. Geological Survey (USGS) | October 9th, 2019

  This dataset describes the quantity and morphology of microplastics in water, surficial sediment, sediment core, fish, and shellfish samples from Lake Mead Nation

  This dataset describes the quantity and morphology of microplastics in water, surficial sediment, sediment core, fish, and shellfish samples from Lake Mead National Recreation Area (Nevada/Arizona). Water and surficial sediment samples were collected once at 9 locations. A sediment core (33 cm long) was extracted from Las Vegas Bay to assess changes in microplastic deposition over time. Striped bass (Morone saxatilis), common carp (Cyprinus carpio), quagga mussels (Dreissena bugensis), and Asian clams (Corbicula fluminea) were sampled at a subset of locations to assess biological uptake of microplastics. Sampling and analysis methods are described in the Processing Steps section of the metadata. All samples were collected in March 2017 except the sediment core, which was collected in March 2018.  

Middle Santa Ana River Watershed TMDL Task Force

Santa Ana Watershed Project Authority (SAWPA) | July 5th, 2018

The Task Force is an 18-agency collaborative effort organized by the Santa Ana Watershed Project Authority. It was formed in January 2006 to coordinate water quality impr

The Task Force is an 18-agency collaborative effort organized by the Santa Ana Watershed Project Authority. It was formed in January 2006 to coordinate water quality improvement activities related to bacteria in the Middle Santa Ana River Watershed. The activities were designed to manage or eliminate sources of bacterial indicators in local waterbodies. The Task Force supports on-going source investigation efforts to identify major sources of bacterial indicators and to understand how to best address them. Task Force resources are allocated on a risk-reduction priority basis in order to achieve compliance where it will provide the greatest improvement in public health.