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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Continuous Monitoring of Water Quality and Suspended-Sediment Transport in the San Francisco Bay and Delta
Our group at the USGS continuously monitors suspended-sediment concentration (SSC), turbidity, dissolved oxygen, temperature, salinity, and water level at many sites throughout the San Francisco Bay (Bay) and the Sacramento-San Joaquin Rivers Delta (Delta). Our work began in 1988 to explore the spatial and temporal variability of water quality and sediment transport and to provide decision makers...
Pyrethroids
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.
Sedimentation in the Lower Laguna-Mark West Drainage
The Sonoma County Water Agency (SCWA) and the San Francisco District office of the U.S. Army Corps of Engineers (CORPS) have identified issues associated with sedimentation in the lower Laguna de Santa Rosa and Mark West Creek in Sonoma County. Human activities in the watershed over the last 200 years have accelerated erosion and sediment delivery to the Laguna reducing the water storage capacity...
Methylmercury and Low Dissolved Oxygen Events in Suisun Marsh
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...
Inundation Area '06 New Year's Flood in the Laguna-Mark West Drainage
The Laguna de Santa Rosa, located in Sonoma County, California, flows into Mark West Creek, which drains into the Russian River. The Laguna-Mark West drainage is the largest drainage contributing to the Russian River, encompassing approximately 21% of the total Russian River basin. Runoff from precipitation in headwater areas enters fast-flowing creeks that transport water and sediment downstream...
Assessment of environmental impacts of mercury treatability test using suction dredging, South Yuba River
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.
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...
Mercury and Dissolved Organic Matter in Delta Wetlands
Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar, metacinnabar...
Sources of Disinfection Byproduct-forming Material in the State Water Project
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 the amount and source of the DOC, both of which...
A Non-Point Source Of Contaminants To The Estuarine Food Web: Mobilized Particles From The Intertidal Zone
The San Francisco Bay and Sacramento-San Joaquin Delta (Bay-Delta) region is a highly urbanized and contaminated estuary with a valuable commercial and recreational fishery (Nichlos et al., 1986; SFEI, 2004). Many fish and birds in the San Francisco Estuary exhibit high levels of contaminants (metals and organic pollutants), which have been shown to affect their behavior and reproductive success...
Assessing the role of winter flooding on baseline greenhouse gas fluxes from corn fields in the Sacramento – San Joaquin Bay Delta
Understanding the magnitude and variability of baseline greenhouse gas (GHG) emissions from the Sacramento – San Joaquin Bay Delta is critical for current and future land management. For example, strategies that maximize carbon sequestration in soils and plants while minimizing unintended consequences such as GHG emissions are likely to produce both economic and environmental benefits for the...
Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses
The project is part of an overarching Interagency Ecological Program (IEP)/Department of Water Resources (DWR) study that is focused on understanding the processes by which the Yolo Bypass may provide a fall food web supply for the Cache Slough Complex and downstream regions of the Sacramento/San Joaquin Delta. Several studies conducted since 2011 have shown that phytoplankton blooms can be...