Contaminants
Contaminants
Contaminants can refer to the many different kinds of chemicals, including industrial pollutants, agricultural products, and household waste, that make it into lakes and rivers. Such chemicals can have a detrimental effect on the drinking water supply, as well as fish and other aquatic species. Contaminants have also been shown to bioaccumulate up the food web - putting even non-aquatic species at
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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...
Mercury
Mercury is a rare, dense metal, slightly more common than gold in the earth's crust. Mercury occurs in several different forms, the most important of which is methylmercury. Methylmercury is the form most readily incorporated into biological tissues and most toxic to humans. Methylmercury accumulates and biomagnifies in the food chain, reaching highest concentrations in predatory fish such as bass...
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...
Methylmercury cycling and export from agricultural and natural wetlands in the Yolo Bypass
The purpose of the work conducted by the USGS California Water Science Center is to help guide Yolo Wildlife Area management practices by identifying the relationships between management effects on dissolved organic matter properties and the resulting role of dissolved organic matter in mercury methylation and biotic uptake measured by the cooperating USGS scientists. The information gathered will...
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.
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...
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:
Delta Regional Monitoring Program: Current-use Pesticides
This study will utilize the unique analytical capabilities of the USGS Pesticide Fate Research Group (PFRG), Organic Chemistry Research Laboratory (OCRL) to assess the occurrence of a large suite of understudied, current-use pesticides and pesticide degradates in surface waters entering the Sacramento/San Joaquin Delta.
Evaluating coagulation techniques to reduce the transport of Hg from mine-affected and active geothermal Hg-source watersheds
Our objective is to determine the effectiveness of coagulation and adsorption techniques in removing mercury from contaminated surface waters of the Cache Creek watershed.