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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.

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Sustainable Groundwater Management

In 2014, the State of California adopted historic legislation to help manage its groundwater, the Sustainable Groundwater Management Act (SGMA) . According to the act, local Groundwater Sustainability Agencies (GSAs) must be formed for all high and medium priority basins in the state. These GSAs must develop and implement Groundwater Sustainability Plans (GSPs) for managing and using groundwater...
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Sustainable Groundwater Management

In 2014, the State of California adopted historic legislation to help manage its groundwater, the Sustainable Groundwater Management Act (SGMA) . According to the act, local Groundwater Sustainability Agencies (GSAs) must be formed for all high and medium priority basins in the state. These GSAs must develop and implement Groundwater Sustainability Plans (GSPs) for managing and using groundwater...
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Evaluation of the groundwater resources of the Petaluma Valley

The city of Petaluma, located in the Petaluma Valley and home to about 12 percent of the population of Sonoma County, faces growth in population and demand for water. Water supply is provided primarily by water delivered via aqueduct from the Russian River; however, groundwater is a vital supplemental source of water for the city of Petaluma and is the primary source of supply for domestic and...
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Evaluation of the groundwater resources of the Petaluma Valley

The city of Petaluma, located in the Petaluma Valley and home to about 12 percent of the population of Sonoma County, faces growth in population and demand for water. Water supply is provided primarily by water delivered via aqueduct from the Russian River; however, groundwater is a vital supplemental source of water for the city of Petaluma and is the primary source of supply for domestic and...
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Relation of Groundwater Age to Herbicide Concentration Trends in Fresno and Tulare Counties, California

The California Department of Pesticide Regulation (DPR) has been monitoring pesticide concentrations in about 70 domestic drinking water wells located in vulnerable areas of Fresno and Tulare Counties for approximately 15 years. A recent analysis of the monitoring data indicated that there were decreases in simazine, diuron, and bromacil concentrations in many wells during 2000-2010.
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Relation of Groundwater Age to Herbicide Concentration Trends in Fresno and Tulare Counties, California

The California Department of Pesticide Regulation (DPR) has been monitoring pesticide concentrations in about 70 domestic drinking water wells located in vulnerable areas of Fresno and Tulare Counties for approximately 15 years. A recent analysis of the monitoring data indicated that there were decreases in simazine, diuron, and bromacil concentrations in many wells during 2000-2010.
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Evaluation of water resources in Chuckwalla Valley, Riverside County, California

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...
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Evaluation of water resources in Chuckwalla Valley, Riverside County, California

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...
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Optimization of Operation of Yuma Area Drainage and Regulatory Wells - Pilot Project

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.
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Optimization of Operation of Yuma Area Drainage and Regulatory Wells - Pilot Project

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.
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Determining the fate and transport of septic-tank effluent in the southern area of Warren subbasin, California

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.
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Determining the fate and transport of septic-tank effluent in the southern area of Warren subbasin, California

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.
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Sonoma Valley Surface Water/Groundwater-Flow Model

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.
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Sonoma Valley Surface Water/Groundwater-Flow Model

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.
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Water-Level, Water-Quality and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins

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...
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Water-Level, Water-Quality and Land-Subsidence Studies in the Mojave River and Morongo Groundwater Basins

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...
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Assessing the Feasibility of Artificial Recharge and Storage and the Effectiveness and Sustainability of Insitu Arsenic Removal in the Antelope Valley, California

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...
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Assessing the Feasibility of Artificial Recharge and Storage and the Effectiveness and Sustainability of Insitu Arsenic Removal in the Antelope Valley, California

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...
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Statistical Evaluation of Factors Affecting Occurrence of Organic Constituents from Fuels in Public-Supply Wells in Southern California

Biofuels, including ethanol, are expected to provide a greater contribution to the fuel supply in the United States. Research in the past decade has shown that ethanol in gasoline can cause plumes of benzene in groundwater to be larger than they would otherwise be.
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Statistical Evaluation of Factors Affecting Occurrence of Organic Constituents from Fuels in Public-Supply Wells in Southern California

Biofuels, including ethanol, are expected to provide a greater contribution to the fuel supply in the United States. Research in the past decade has shown that ethanol in gasoline can cause plumes of benzene in groundwater to be larger than they would otherwise be.
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Water-resources study of Fort Irwin National Training Center

The U.S. Army at Fort Irwin National Training Center (NTC) obtains all of its potable water supply from Irwin, Langford, and Bicycle Basins within the base boundaries. Groundwater pumping, since as early as 1941, has resulted in water-level declines in all of these basins and the disposal of treated wastewater in the Irwin Basin has resulted in elevated nitrate concentrations in some wells in...
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Water-resources study of Fort Irwin National Training Center

The U.S. Army at Fort Irwin National Training Center (NTC) obtains all of its potable water supply from Irwin, Langford, and Bicycle Basins within the base boundaries. Groundwater pumping, since as early as 1941, has resulted in water-level declines in all of these basins and the disposal of treated wastewater in the Irwin Basin has resulted in elevated nitrate concentrations in some wells in...
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San Antonio Creek Water Availability

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...
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San Antonio Creek Water Availability

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...
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