Three decades of groundwater-quality data across the nation
National report summarizes 30 years of groundwater-quality data, including analysis of contaminants.
We have been sampling groundwater at decadal intervals in 82 regional groups of 20-30 wells (called networks) within the US since 1988. Each of the networks represent a geographic region, aquifer, and sometimes a specific land use. Certain contaminants such as chloride, dissolved solids, and nitrate are increasing in groundwater in many of these networks.
Out of the several hundred chemicals that are sampled in each well, we took a closer look at 28 to see if there were trends, or increases, in concentrations. Those included 6 pesticides, 6 volatile organic compounds, and 16 inorganic elements or compounds (trace elements, major ions, nutrients, and radionuclides).
This is the first time
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that results for the 28 chemicals have been summarized at the national level
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that a national summary has been published since 2012
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we've addressed factors affecting trends in groundwater-quality at the national level
Understanding the contaminants with significant increasing concentrations, and the locations and conditions under which they occur can help prioritize efforts to minimize contamination of groundwater resources.