Metrics for assessing the quality of groundwater used for public supply, CA, USA: Equivalent-population and area

Environmental Science & Technology
By: , and 

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Abstract

Data from 11 000 public supply wells in 87 study areas were used to assess the quality of nearly all of the groundwater used for public supply in California. Two metrics were developed for quantifying groundwater quality: area with high concentrations (km2 or proportion) and equivalent-population relying upon groundwater with high concentrations (number of people or proportion). Concentrations are considered high if they are above a human-health benchmark. When expressed as proportions, the metrics are area-weighted and population-weighted detection frequencies. On a statewide-scale, about 20% of the groundwater used for public supply has high concentrations for one or more constituents (23% by area and 18% by equivalent-population). On the basis of both area and equivalent-population, trace elements are more prevalent at high concentrations than either nitrate or organic compounds at the statewide-scale, in eight of nine hydrogeologic provinces, and in about three-quarters of the study areas. At a statewide-scale, nitrate is more prevalent than organic compounds based on area, but not on the basis of equivalent-population. The approach developed for this paper, unlike many studies, recognizes the importance of appropriately weighting information when changing scales, and is broadly applicable to other areas.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Metrics for assessing the quality of groundwater used for public supply, CA, USA: Equivalent-population and area
Series title Environmental Science & Technology
DOI 10.1021/acs.est.5b00265
Volume 49
Issue 14
Year Published 2019
Language English
Publisher American Chemical Society
Contributing office(s) WMA - Earth System Processes Division
Description 9 p.
First page 8830
Last page 8838
Country United States
State California