Assessing the lead solubility potential of untreated groundwater of the United States

Environmental Science & Technology
By: , and 

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Abstract

In the U.S., about 44 million people rely on self-supplied groundwater for drinking water. Because most self-supplied homeowners do not treat their water to control corrosion, drinking water can be susceptible to lead (Pb) contamination from metal plumbing. To assess the types and locations of susceptible groundwater, a geochemical reaction model that included pure Pb minerals and solid solutions of calcite (CaxPb1–xCO3) and apatite [CaxPb5-x(PO4)3(OH; Cl; F)] was developed to estimate the lead solubility potential (LSP) for over 8300 untreated groundwater samples collected from domestic and public-supply sites between 2000 and 2016 in the U.S. The LSP is the calculated amount of Pb metal that could dissolve at 25 °C before a Pb-bearing mineral precipitates. About 33% of untreated groundwater samples had LSP greater than 15 μg/L—the USEPA action level for dissolved plus particulate forms of Pb. Five percent of samples had high LSP (above 300 μg/L) and tended to occur in the eastern and southeastern U.S. Measured Pb concentrations above 15 μg/L were rarely detected (<1%) but always coincided with high LSP values. Future work will provide a better understanding of the relation between water chemistry, Pb-mineral formation, and dissolved Pb concentrations in tap water.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Assessing the lead solubility potential of untreated groundwater of the United States
Series title Environmental Science & Technology
DOI 10.1021/acs.est.8b04475
Volume 53
Issue 6
Year Published 2019
Language English
Publisher ACS Publications
Contributing office(s) National Research Program - Central Branch, National Water Quality Assessment Program, California Water Science Center
Description Article: 9 p.; Data Release
First page 3095
Last page 3103
Country United States