Surface Water Quality
Surface Water Quality
California's rivers and streams are a priceless resource. To understand the value of water quality, and to more effectively manage and protect the state's water resources, it's critical that we know the current status of water-quality conditions, and how and why those conditions have been changing over time. At the California Water Science Center, measuring the quality of surface water is one of the chief aims of its hydrological monitoring efforts.
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Quantification of Mercury Flux in Eroding Mining Debris, Yuba River Watershed, California
At two priority locations on BLM-administered land in the Yuba River watershed, the USGS has documented relatively rapid erosion of river bank material that consists of mercury (Hg)-laden sediment with a significant component of mining debris.
Pesticide Studies in the Sacramento/San Joaquin Delta and San Francisco Bay Estuary
The objectives of this specific study are to characterize the mixtures of current-use pesticides and pesticide degradates entering the Sacramento/San Joaquin Delta from its two main river sources over a period of 12 consecutive months.
Delta sediment measurements to support numerical modeling of turbidity
The purpose of the proposed work is to collect data that will support the development, calibration, and validation of numerical models of sediment transport and turbidity in the Sacramento-San Joaquin Delta.
Additional characterization of the impact of suction dredging, South Yuba River – Humbug Creek
The potential impacts of suction dredging on water quality remain largely undetermined, especially with regard to trace metals including Hg. Several State of California regulatory agencies have expressed concerns that suction dredging may cause deleterious impacts with regard to turbidity and Hg contamination in downstream areas.
Determination of Mercury Loads for Cache Creek Settling Basin Inflow and Outflows and Related Investigations
Mercury (Hg), a legacy pollutant from mining of mercury deposits in the Coast Ranges as well as gold deposits in the Sierra Nevada, has contaminated surface waters throughout northern California. Methylmercury (MeHg) is an organic form of Hg that bioaccumulates in food webs to elevated concentrations that threaten ecological health and human health through consumption of sport fish.
Suspended-Solids Concentrations in San Francisco Bay, California
Suspended solids are an important component of San Francisco Bay, California (USA) because they transport adsorbed toxic substances, provide habitat for benthic organisms, limit light availability and photosynthesis, and deposit in ports and waterways which require dredging. The U.S. Geological Survey has established a network of eight sites in San Francisco Bay at which suspended-solids...
San Francisco Bay Wetlands Priority Ecosystem Studies
The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
Impact of Climate Change on Future Suitability of the Sierra Nevada for Wolverines
The endeavor to ensure a viable population of the threatened wolverine to the mountains of California requires the characterization of suitable habitat.
Exploring: Reservoir Capacity And Sedimentation Of The Fena Valley Reservoir Guam
The Fena Valley Reservoir, located in southern Guam, is the primary source of water for the United States Naval Base Guam and nearby village residents. At full capacity, the reservoir surface area extends approximately 0.30 mi 2 , and drains a watershed area of about 5.88 mi 2 . After reservoir construction, periodic bathymetric surveys, coupled with sedimentation models, can be used to produce...
Trends in Dissolved Organic Carbon (DOC) in the Sacramento-San Joaquin Delta
Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water treatment process. The amount of DBPs that form is a function of both the amount and source of the DOC, both of...
The role of the alien clam Corbicula fluminea in the regulation of organic carbon in the San Joaquin River watershed
Sources and fate of various forms of organic carbon in the Sacramento-San Joaquin Delta (Delta) and San Joaquin River watershed are of concern because of the importance of identifying the sources of carbon contributing to the oxygen depletion zone on the San Joaquin River near the city of Stockton, the need to understand the causes of the low primary and secondary production in the Delta, and the...
Pathogen Total Maximum Daily Loads Modeling in the Chino Basin
The Santa Ana River in Southern California is the primary water supply for approximately 2 million people. The main constituent of regulatory concern is pathogens that have impaired the use of waters for the beneficial uses of warm freshwater habitat and noncontact water recreation. Pathogen loadings from the tributary watershed flows into lakes and streams leading into the Santa Ana River...