Water Quality

The Chuckwalla Valley in the southern Mojave Desert in California has been selected as an area with high potential for solar energy development. Six large-scale solar energy projects are currently approved or proposed in this basin, the largest number of solar projects in any one basin in California. Water needs associated with proposed solar energy projects within the basin have generated...

The Leviathan Mine, located in Alpine County is one of the worst sites in California for acid mine drainage. The site is on the National Priority List for CERCLA (Superfund) (U.S. EPA, 2011) and U.S. EPA is working with ARCO/BP (the Responsible Party) on designing and implementing site remediation. The USGS did research there during the 1980s on geochemistry (e.g., Nordstrom and Ball, 1986). The...

Reclamation's Yuma Area Office (YAO) operates 50 plus drainage wells and 21 regulatory wells to control groundwater levels in low-lying flood plain areas and to supply a significant portion of the Colorado River water the United States (US) is required by treaty to deliver to Mexico.

Residents and businesses in Yucca Valley, CA rely currently on septic tanks to treat their wastewater. The local water district, Hi-Desert Water District (HDWD), is planning to construct a sewer system and wastewater treatment plant, initially serving the West, Midwest, Mideast, Northeast, and East hydrogeologic units of the Warren subbasin.

Sonoma County faces potential changes in surface-water availability, including potential impacts on water quality in response to changing land use, increasing population, and climate change.

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. The population of the Mojave River and Morongo groundwater basins has grown rapidly during the last several decades, increasing from an estimated population of almost 273,000 in 1990 (Mojave Water Agency, 2004) to more than 453,000 in...

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.

This study will use the release-recapture information derived from the 2012 receiver array to populate a mark-recapture model based on a Cormack-Jolly-Seber model in combination with a route-specific survival model of Skalski et al. (2002) to derive maximum likelihood estimates and standard errors of reach specific survival and entrainment rates at important junctions, similar to what was used in...

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.

Project Update - 8/2/2011: Water having an arsenic concentration of 30 micrograms per liter was infiltrated from a test pond beginning in December, 2010. After water moved downward through the unsaturated zone, arsenic concentrations in Lysimeters as deep as 110 ft beneath the pond were about 2 micrograms per liter. Laboratory column experiments show similar changes in arsenic concentrations in...

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.