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Groundwater Quality

Every day, millions of gallons of groundwater are pumped to supply drinking water for almost one-half of the Nation’s population. Groundwater is also critical to agriculture, one of California's main economic drivers. The California Water Science Center studies aquifers throughout the state that are critical sources of groundwater used for public supply. This research informs us about the quality and availability of groundwater for drinking, where and why groundwater quality is degraded, and where groundwater quality is changing.

Filter Total Items: 42

Processes Controlling Riverbank Filtration of Pathogens in the Russian River Basin, Sonoma County, California

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...
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Processes Controlling Riverbank Filtration of Pathogens in the Russian River Basin, Sonoma County, California

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...
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San Gorgonio Pass Artificial Recharge Investigation

San Gorgonio Pass Water Agency (SGPWA) covers an area of 220 square miles in the mountain pass between the Upper Santa Ana River Basin to the west and the Coachella Valley to the east. Since 1961, when the SGPWA was formed, demand for ground water has increased with the increase in population within the agency boundaries. To prepare for future demands for water, the SGPWA has proposed to...
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San Gorgonio Pass Artificial Recharge Investigation

San Gorgonio Pass Water Agency (SGPWA) covers an area of 220 square miles in the mountain pass between the Upper Santa Ana River Basin to the west and the Coachella Valley to the east. Since 1961, when the SGPWA was formed, demand for ground water has increased with the increase in population within the agency boundaries. To prepare for future demands for water, the SGPWA has proposed to...
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Geohydrologic Study of the Central and West Coast Basins of Los Angeles County

Using the new information, along with the recently acquired seismic reflection data, USGS scientists and co-workers have been able to develop a much more detailed understanding of the stratigraphy and structure of the Central and West Coast Basins.
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Geohydrologic Study of the Central and West Coast Basins of Los Angeles County

Using the new information, along with the recently acquired seismic reflection data, USGS scientists and co-workers have been able to develop a much more detailed understanding of the stratigraphy and structure of the Central and West Coast Basins.
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Warren Subbasin Groundwater Recharge

The Hi Desert Water District (HDWD) provides water service to about 10,000 customers in the areas of Yucca Valley, Yucca Mesa, and some unincorporated areas of San Bernardino County. The study area is the 19 square mile Warren subbasin of the Morongo groundwater basin (approximately 100 miles east of Los Angeles, California).
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Warren Subbasin Groundwater Recharge

The Hi Desert Water District (HDWD) provides water service to about 10,000 customers in the areas of Yucca Valley, Yucca Mesa, and some unincorporated areas of San Bernardino County. The study area is the 19 square mile Warren subbasin of the Morongo groundwater basin (approximately 100 miles east of Los Angeles, California).
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Assessing the Feasibility of Artificial Recharge and Storage and the Effectiveness and Sustainability of Insitu Arsenic Removal in the North Buttes Area, Antelope Valley, California

Groundwater pumpage for agricultural and municipal supply has resulted in water-level declines of more than 200 ft in some parts of the Antelope Valley groundwater basin and land subsidence of more than 6 ft in some areas. Future urban growth, increased agricultural demand, and limits on the supply of imported water will continue to increase the demand for groundwater.
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Assessing the Feasibility of Artificial Recharge and Storage and the Effectiveness and Sustainability of Insitu Arsenic Removal in the North Buttes Area, Antelope Valley, California

Groundwater pumpage for agricultural and municipal supply has resulted in water-level declines of more than 200 ft in some parts of the Antelope Valley groundwater basin and land subsidence of more than 6 ft in some areas. Future urban growth, increased agricultural demand, and limits on the supply of imported water will continue to increase the demand for groundwater.
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Central Basin Groundwater Contamination Study

The Central and West Coast groundwater basins provide nearly a third of the water supply to 43 cities in southern Los Angeles County. Over 250,000 afy are pumped from the basins for municipal and industrial use. To properly manage the ground-water resource and to ensure its future availability, it is necessary to identify and manage threats to the drinking water aquifers from surface contamination...
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Central Basin Groundwater Contamination Study

The Central and West Coast groundwater basins provide nearly a third of the water supply to 43 cities in southern Los Angeles County. Over 250,000 afy are pumped from the basins for municipal and industrial use. To properly manage the ground-water resource and to ensure its future availability, it is necessary to identify and manage threats to the drinking water aquifers from surface contamination...
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Simulation of Water Resources Management in the Pajaro Valley

Two key hydrologic issues in all coastal aquifer systems are the delineation and the management of the renewable water resources. The proper development and management of the renewable resources helps to minimize ground-water mining of the lower aquifer systems, and minimizes overdraft and seawater intrusion of the upper aquifer system while maximizing the sustainable yield of the renewable water...
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Simulation of Water Resources Management in the Pajaro Valley

Two key hydrologic issues in all coastal aquifer systems are the delineation and the management of the renewable water resources. The proper development and management of the renewable resources helps to minimize ground-water mining of the lower aquifer systems, and minimizes overdraft and seawater intrusion of the upper aquifer system while maximizing the sustainable yield of the renewable water...
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California Oil, Gas, and Groundwater (COGG) Program

The USGS California Water Science Center is working in partnership with state and federal agencies to answer the following questions about oil and gas development and groundwater resources:
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California Oil, Gas, and Groundwater (COGG) Program

The USGS California Water Science Center is working in partnership with state and federal agencies to answer the following questions about oil and gas development and groundwater resources:
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Hydrogeologic Characterization of the Modesto Area Ground-Water Basin and Evaluation of Water Resource Management Alternatives

Strategies for managing local water supplies and ground-water quality are being formulated and evaluated by the Stanislaus-Tuolumne River Groundwater Basin Association (STRGBA).
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Hydrogeologic Characterization of the Modesto Area Ground-Water Basin and Evaluation of Water Resource Management Alternatives

Strategies for managing local water supplies and ground-water quality are being formulated and evaluated by the Stanislaus-Tuolumne River Groundwater Basin Association (STRGBA).
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Water-level Contour Map of the Antelope Valley Groundwater Basin and Interactive Website, 2014

The USGS has a long history of collecting water-level data in the Antelope Valley groundwater basin. Previous water-level contour maps for Antelope Valley were published by the USGS in cooperation with the Antelope Valley – East Kern Water Agency as Open-File Reports 80-1222, 86-498 and 98-4022 using water-level data collected in 1979, 1984 and 1996, respectively. An updated water-level contour...
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Water-level Contour Map of the Antelope Valley Groundwater Basin and Interactive Website, 2014

The USGS has a long history of collecting water-level data in the Antelope Valley groundwater basin. Previous water-level contour maps for Antelope Valley were published by the USGS in cooperation with the Antelope Valley – East Kern Water Agency as Open-File Reports 80-1222, 86-498 and 98-4022 using water-level data collected in 1979, 1984 and 1996, respectively. An updated water-level contour...
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Depth-Dependent groundwater flow, age, and chemistry in relation to solvent contamination in a production well, Tulare Lake basin, California

The Tulare Lake basin in the southern Central Valley of California is heavily dependent upon groundwater for drinking water supply but groundwater in this basin is threatened by a wide array of issues. Groundwater aquifers in the alluvial fan sediments derived from the Sierra Nevada on the eastern side of the Tulare Lake basin are highly productive aquifers that are vulnerable to contamination...
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Depth-Dependent groundwater flow, age, and chemistry in relation to solvent contamination in a production well, Tulare Lake basin, California

The Tulare Lake basin in the southern Central Valley of California is heavily dependent upon groundwater for drinking water supply but groundwater in this basin is threatened by a wide array of issues. Groundwater aquifers in the alluvial fan sediments derived from the Sierra Nevada on the eastern side of the Tulare Lake basin are highly productive aquifers that are vulnerable to contamination...
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Coordinated Pesticide Reconnaissance Study of Surface Waters in California

Pesticides are used throughout the State of California in both urban and agricultural settings and are routinely detected in surface water. Each year, new pesticides are introduced to the market and often become detected in surface water. It can take several years or more for routine monitoring programs to acquire the capability to detect new and understudied pesticides of concern because...
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Coordinated Pesticide Reconnaissance Study of Surface Waters in California

Pesticides are used throughout the State of California in both urban and agricultural settings and are routinely detected in surface water. Each year, new pesticides are introduced to the market and often become detected in surface water. It can take several years or more for routine monitoring programs to acquire the capability to detect new and understudied pesticides of concern because...
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