Analyses of Rotary Screw Trap Sampling of Migrating Juvenile Chinook Salmon in the Stanislaus River, 1996-2005

Delta Stewardship Council (Delta Council) | August 1st, 2006

Analysis of Potential Water-Supply Management Options, 2010-60, and Documentation of Revisions to the Model of the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

U.S. Geological Survey (USGS) | October 31st, 2014

The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional

The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional, finite-difference groundwater-flow model—the U.S. Geological Survey’s MOD-FLOW—of the aquifer system in the basin was updated and the initial input dataset was supplemented with groundwater withdrawal data for the period 2000–10. The updated model was then used to simulate four combinations, or scenarios, of groundwater withdrawal and recharge over the next 50 years (January 2011 through December 2060). The scenarios included combinations of continuing withdrawals from currently active production wells, supplementing any increases in demand with withdrawals from an inactive production well, reducing withdrawal amounts and rates, and reducing the discharge of treated wastewater to infiltration ponds that provide a recharge source to the underlying aquifer. Results of the simulations indicated that, depending on the scenario implemented, groundwater levels would rise (over the next 50 years) from 40 feet to as much as 65 feet in the northwestern part of the Irwin Basin, and from 5 feet to 10 feet in the southeastern part.

Annual Report Clean Water State Revolving Fund and the Water Quality, Supply, and Infrastructure Improvement Act of 2014 State Fiscal Year 2017-2018

California State Water Resources Control Board (SWRCB) | December 30th, 2018

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annua

The California State Water Resources Control Board (State Water Board), Division of Financial Assistance (DFA) presents the Clean Water State Revolving Fund (CWSRF) annual report for State Fiscal Year (SFY) 2017-18. The State Water Board provided approximately $707 million in new CWSRF financing to 44 projects in SFY 2017-18, which represent a wide variety of projects eligible under the CWSRF. This report describes how the State Water Board met the objectives identified in the SFY 2017-18 CWSRF Intended Use Plan (IUP). 

Annual Report of Activities October 1, 2013 to September 30, 2014, American River Group (ARG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

Annual Report of Activities Water Year 2018 Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | November 1st, 2018

Annual Report of Activities, October 1, 2013 to September 30, 2014, Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

Annual Report on the Colorado River Basin Salinity Control Program 2020

Colorado River Basin Salinity Control Advisory Council (CRBSCAC) | December 31st, 2020

Anthropogenic and geologic causes of anomalously high uranium concentrations in groundwater used for drinking water supply in the southeastern San Joaquin Valley, CA

Journal of Hydrology (Elsevier) | October 1st, 2019

Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where comp

Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where complex interactions of aquifer materials and anthropogenic alterations of the natural flow regime mobilize U. High concentrations (>30 µg/L) of U in the southeastern San Joaquin Valley, California, USA, have been detected in 24 percent of 257 domestic, irrigation, and public-supply wells sampled across an approximately 110,000 km2 area. In this study we evaluated mechanisms for mobilization of U in the San Joaquin Valley proposed in previous studies, confirming mobilization by HCO3 and refuting mobilization by NO3 and we refined our understanding of the geologic sources of U to the scale of individual alluvial fans. The location of high concentrations depends on the interactions of geological U sources from fluvial fans that originate in the Sierra Nevada to the east and seepage of irrigation water that contains high concentrations of HCO3 that leaches U from the sediments. In addition, interactions with PO4 from fertilized irrigated fields may sequester U in the aquifer. Principal component analysis of the data demonstrates that HCO3 and ions associated with high total dissolved solids in the aquifer and the percentage of agriculture near the well sampled are associated with high U concentrations. Nitrate concentrations do not appear to control release of U to the aquifer. Age dating of the groundwater and generally increasing U concentrations of the past 25  years in resampled wells where irrigation is prevalent suggests that high U concentrations are associated with younger water, indicating that irrigation of fields over the past 100  years has significantly contributed to increasing concentrations and mobilizing U. In some places, the groundwater is supersaturated with uranyl-containing minerals, as would be expected in roll front deposits. In general, the interaction of natural geological sources high in U, the anthropogenically driven addition of HCO3 and possibly phosphate fertilizer, control the location and concentration of U in each individual fluvial fan, but the addition of nitrate in fertilizer does not appear control the location of high U. These geochemical interactions are complex but can be used to determine controls on anomalously high U in alluvial aquifers.

Anthropogenic carbon and ocean pH: Oceanography

Nature Portfolio (Springer Nature) | September 25th, 2003

Most carbon dioxide released into the atmosphere as a result of the burning of fossil fuels will eventually be absorbed by the ocean1, with potentially adverse co

Most carbon dioxide released into the atmosphere as a result of the burning of fossil fuels will eventually be absorbed by the ocean1, with potentially adverse consequences for marine biota. Here we quantify the changes in ocean pH that may result from this continued release of CO2 and compare these with pH changes estimated from geological and historical records. We find that oceanic absorption of CO2 from fossil fuels may result in larger pH changes over the next several centuries than any inferred from the geological record of the past 300 million years, with the possible exception of those resulting from rare, extreme events such as bolide impacts or catastrophic methane hydrate degassing.

Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption

Nature Portfolio (Springer Nature) | September 24th, 2015

The ubiquity of anthropogenic debris in hundreds of species of wildlife and the toxicity of chemicals associated with it has begun to raise concerns regarding the presenc

The ubiquity of anthropogenic debris in hundreds of species of wildlife and the toxicity of chemicals associated with it has begun to raise concerns regarding the presence of anthropogenic debris in seafood. We assessed the presence of anthropogenic debris in fishes and shellfish on sale for human consumption. We sampled from markets in Makassar, Indonesia and from California, USA. All fish and shellfish were identified to species where possible. Anthropogenic debris was extracted from the digestive tracts of fish and whole shellfish using a 10% KOH solution and quantified under a dissecting microscope. In Indonesia, anthropogenic debris was found in 28% of individual fish and in 55% of all species. Similarly, in the USA, anthropogenic debris was found in 25% of individual fish and in 67% of all species. Anthropogenic debris was also found in 33% of individual shellfish sampled. All of the anthropogenic debris recovered from fish in Indonesia was plastic, whereas anthropogenic debris recovered from fish in the USA was primarily fibers. Variations in debris types likely reflect different sources and waste management strategies between countries. We report some of the first findings of plastic debris in fishes directly sold for human consumption raising concerns regarding human health.