Contaminants

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.

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.

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.

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.

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop biological objectives for wadeable freshwater streams and rivers for the entire state.

Located in Santa Barbara County, California, the San Antonio Creek Groundwater Basin is a rural agricultural area that is reliant on local water supplies, predominantly groundwater. Because of the growth of irrigated agriculture in the area, water demands have increased significantly, taxing local groundwater supplies. Groundwater resources are also used to supply local inhabitants, as well as...

Malibu Lagoon and near-shore ocean water in Malibu, Calif. have concentrations of fecal indicator bacteria (FIB) that occasionally exceed public health standards for recreational water.

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...

The Sonoma County Water Agency (SCWA) supplies drinking water to municipalities and water districts in Sonoma and Marin Counties by diverting water from the alluvial aquifer underlying and adjacent to the Russian River. The U.S. Geological Survey, in cooperation with SCWA, is conducting an ongoing research program on water quality conditions in the Russian River and the physical and geochemical...

Pyrethroid insecticide use in California has been increasing in recent years. Pyrethroids are used in both agricultural and urban areas. They are of environmental concern because of their high toxicity to fish and invertebrates.

The primary purpose of the USGS portion of this proposed study is to evaluate if spectrophotometric and spectrofluorometric methods are useful for identifying organic sources of oxygen demand by analyzing water-quality samples (DO, BOD, Chl, SSC, Salinity, THg, MeHg) collected by other agencies and project participants. Sources to be evaluated include algal production, vegetation, soils, and...

The goals of the BLM suction dredging treatability study are to (1) assess the effectiveness of suction dredging in removing mercury from the environment and (2) assess potential impacts of suction dredging with regard to discharging mercury-contaminated suspended sediment to the aquatic environment.