Sociodemographic predictors of PFAS exposure among a combined sample of U.S. pregnant women: an Environmental influences on Child Health Outcomes (ECHO) public-use dataset analysis

Nature Portfolio (Springer Nature) | December 15th, 2025

Compared with White mothers, Black mothers had lower levels of PFOA (−23%; 95% CI −29%, −16%), PFOS (−9%; 95% CI −16%, −1%), and PFHxS (−23%; 95% CI −29%,

Compared with White mothers, Black mothers had lower levels of PFOA (−23%; 95% CI −29%, −16%), PFOS (−9%; 95% CI −16%, −1%), and PFHxS (−23%; 95% CI −29%, −14%) based on linear analysis, and lower detection of PFOSA, EtFOSAA, PFDoDA, and PFPeA and higher detection of PFBS and PFHxA based on logistic analysis. Compared with White mothers, Asian mothers had higher levels of PFNA ( + 26%; 95% CI 13%, 40%), PFDA ( + 60%, 95% CI 36%, 89%), and PFUnDA (+95%; 95% CI 63%, 134%) based on linear analysis and higher detection of PFPeA based on logistic regression. Greater weekly fish consumption was found to be a significant predictor of PFAS concentrations but did not attenuate associations with Asian race. Compared with non-Hispanic mothers, Hispanic mothers had lower levels of most of PFAS analytes studied. Higher levels of maternal education were associated with increased levels of most PFAS analytes.

Spectral characterization of dissolved organic matter in groundwater to assess mixing with oil-field water near selected oil fields, southern California

Science of The Total Environment (Elsevier) | September 16th, 2023

Status and Understanding of Groundwater Quality in the Klamath Mountains Study Unit, 2010: California GAMA Priority Basin Project

U.S. Geological Survey (USGS) | August 6th, 2014

Groundwater quality in the Klamath Mountains (KLAM) study unit was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and

Groundwater quality in the Klamath Mountains (KLAM) study unit was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in Del Norte, Humboldt, Shasta, Siskiyou, Tehama, and Trinity Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory. The GAMA Priority Basin Project was designed to provide a spatially unbiased, statistically robust assessment of the quality of untreated (raw) groundwater in the primary aquifer system. The assessment is based on water-quality data and explanatory factors for groundwater samples collected in 2010 by the USGS from 39 sites and on water-quality data from the California Department of Public Health (CDPH) water-quality database. The primary aquifer system was defined by the depth intervals of the wells listed in the CDPH water-quality database for the KLAM study unit. The quality of groundwater in the primary aquifer system may be different from that in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. This study included two types of assessments: (1) a status assessment, which characterized the status of the current quality of the groundwater resource by using data from samples analyzed for volatile organic compounds, pesticides, and naturally occurring inorganic constituents, such as major ions and trace elements, and (2) an understanding assessment, which evaluated the natural and human factors potentially affecting the groundwater quality. The assessments were intended to characterize the quality of groundwater resources in the primary aquifer system of the KLAM study unit, not the quality of treated drinking water delivered to consumers by water purveyors.

Status and understanding of groundwater quality in the Sacramento Metropolitan Domestic-Supply Aquifer study unit, 2017—California GAMA Priority Basin Project

U.S. Geological Survey (USGS) | May 26th, 2022

Groundwater quality in the Sacramento Metropolitan Domestic-Supply Aquifer study unit (SacMetro-DSA) was studied from August to November 2017 as part of the second phase

Groundwater quality in the Sacramento Metropolitan Domestic-Supply Aquifer study unit (SacMetro-DSA) was studied from August to November 2017 as part of the second phase of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in parts of Amador, Placer, Sacramento, and Sutter Counties, and the extent of the study unit was defined by the location of three California Department of Water Resources groundwater subbasins: the North American, the South American, and the Cosumnes. The SacMetro-DSA focused on groundwater resources used for domestic drinking-water supply, which generally correspond to shallower parts of aquifer systems than those of groundwater resources used for public drinking water supply in the same area. The assessments characterized the quality of untreated groundwater, not the quality of drinking water.

Status of California's Wadeable Perennial Streams (2000-2007)

California State Water Resources Control Board (SWRCB) | October 1st, 2011

The Surface Water Ambient Monitoring Program’s (SWAMP) Perennial Streams Assessment (PSA) surveys measure the ability of California’s perennial wadeable str

The Surface Water Ambient Monitoring Program’s (SWAMP) Perennial Streams Assessment (PSA) surveys measure the ability of California’s perennial wadeable streams (some 85,000 km) to support aquatic life. PSA surveys found half (50%) of the wadeable perennial stream length in California to be in relatively good biological condition, while about 22% is in very degraded biological condition. The statewide distribution of good, degraded and very degraded sites shows that most high quality streams in good biological condition are located in the mountainous regions of the state. Streams with the most degraded biology tend to be found in low-lying agricultural and urban areas in the central valley and parts of the coast.

Strategic stream gauging network design for sustainable water management

Nature Portfolio (Springer Nature) | June 3rd, 2024

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compo

Stream gauging stations that monitor the flow of water in rivers and streams provide critical information to water managers, but biases and gaps in gauge placement, compounded by gauge deactivations, limit our ability to track river flows and address global water challenges. Here we introduce an approach for identifying gauging sites to efficiently fill gaps in monitoring coverage within river networks while also addressing water management priorities, including reservoir operations, biodiversity conservation and hydroclimatic monitoring. Applying this approach to gauges in California, United States, we found substantial gaps in the stream monitoring network. Hypothetically reconfiguring gauges to locations that maximize coverage and representation of management objectives highlights the current network’s biases. Through the strategic reactivation and placement of additional gauges, we demonstrate how stream gauging networks can be designed to support sustainable water management.

Strategy for In-Bay Fate Modeling to Support Contaminant and Sediment Management in San Francisco Bay

San Francisco Estuary Institute (SFEI) | August 15th, 2022

This report presents a strategy and multi-year workplan for modeling polychlorinated biphenyls (PCBs), contaminants of emerging concern (CECs), and sediment in San Franci

This report presents a strategy and multi-year workplan for modeling polychlorinated biphenyls (PCBs), contaminants of emerging concern (CECs), and sediment in San Francisco Bay (the Bay). Robust in-Bay fate modeling is needed to address priority management questions that have been identified for these constituents.

Strontium isotopes reveal ephemeral streams used for spawning and rearing by an imperiled potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi

Marine and Freshwater Research (CSIRO Publishing) | April 18th, 2019

Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was d

Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was developed to assess life stage linkages for the threatened potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi. Clear Lake hitch undertake migrations from Clear Lake (Lake County, CA, USA) into ephemeral tributary streams for spawning. An aqueous isoscape of strontium isotopic ratios (87Sr/86Sr) was constructed for Clear Lake and its watershed to trace natal origins and migration histories of adult recruits. Aqueous 87Sr/86Sr differentiated Clear Lake from 8 of 10 key tributaries and clustered into 5 strontium isotope groups (SIGs) with 100% classification success. Otolith 87Sr/86Sr showed all five groups contributed variably to the population. The age at which juveniles migrated from natal streams to Clear Lake ranged from 11 to 152 days (means.d.,4334 days) and was positively associated with the permanency of natal habitat. This information can be used by resource managers to develop conservation actions for Clear Lake hitch. This study demonstrates the utility of strontium isotopes in otoliths as a tool to identify important freshwater habitats occupied over the lifespan of an individual that would otherwise be challenging or impossible to trace with other methods.

Submittal of Report – Status Report on Implementation of the California Statewide Groundwater Elevation Monitoring Program Years 2012-2015

California Department of Water Resources (DWR) | April 1st, 2016

Senate Bill X7 6 (SBX7 6) (Chapter 1, Statutes of 2009) added provisions for groundwater monitoring to Division 6 of the Water Code (Water Code § 10920 et seq.). The bil

Senate Bill X7 6 (SBX7 6) (Chapter 1, Statutes of 2009) added provisions for groundwater monitoring to Division 6 of the Water Code (Water Code § 10920 et seq.). The bill authorized the Department of Water Resources (DWR) to establish permanent, locally managed, groundwater elevation monitoring and reporting for all 515 groundwater basins identified in DWR Bulletin 118, California’s Groundwater, as shown in Figure 1. Groundwater elevation data are foundational to improving the management and sustainability of California's groundwater resources. DWR developed the California Statewide Groundwater Elevation Monitoring (CASGEM) Program to implement SBX7 6. Water Code section 12924(c) requires DWR to report the status of the CASGEM Program to the Governor and Legislature by January 1, 2012, and thereafter in years ending in “5” or “0”. This report covers calendar years 2012 through 2015. The overall purpose of the CASGEM Program is to track seasonal and long-term groundwater elevation trends in groundwater basins statewide. The Water Code directs DWR to rely on, and build upon, the many established local agency groundwater monitoring and management efforts throughout the state. DWR works cooperatively with local agencies, referred to as CASGEM “Monitoring Entities,” to collect and maintain groundwater elevation data in a manner that is readily and widely available to the public. During 2010 and 2011, the first two years of the CASGEM Program, DWR focused its efforts on initiating the CASGEM Program and ensuring that Monitoring Entities would, by January 2012, be able to submit groundwater elevation data electronically.

Subsidence (2004-2009) in and near lakebeds of the Mojave River and Morongo groundwater basins, southwest Mojave Desert, California

U.S. Geological Survey (USGS) | July 1st, 2014