Inorganic Constituent and Ancillary Data for Evaluation of Lithium in Groundwater in the United States, 1991-2018
Dates
Publication Date
2020-12-28
Start Date
1991
End Date
2018
Citation
Lindsey, B.D., Belitz, K., Cravotta, C.A. III, Toccalino, P.L., and Dubrovsky, N.M., 2020, Inorganic Constituent and Ancillary Data for Evaluation of Lithium in Groundwater in the United States, 1991-2018: U.S. Geological Survey data release, https://doi.org/10.5066/P9GCGY5K.
Summary
Lithium concentrations in untreated groundwater from 1,464 public-supply wells, 1,676 domestic-supply wells, and 1,560 monitoring wells distributed across 33 principal aquifers in the United States were evaluated for spatial variations and possible explanatory factors. For context, lithium concentrations are compared to a drinking-water only threshold (60 micrograms per liter) and a Health-Based Screening Level (HBSL, 10 micrograms per liter). These thresholds were exceeded in 9% and 45% of samples from public-supply wells and in 6% and 37% from domestic-supply wells, respectively. Exceedances were most frequent for arid regions and older groundwater. Groundwater lithium concentrations were highest in unconsolidated clastic aquifers [...]
Summary
Lithium concentrations in untreated groundwater from 1,464 public-supply wells, 1,676 domestic-supply wells, and 1,560 monitoring wells distributed across 33 principal aquifers in the United States were evaluated for spatial variations and possible explanatory factors. For context, lithium concentrations are compared to a drinking-water only threshold (60 micrograms per liter) and a Health-Based Screening Level (HBSL, 10 micrograms per liter). These thresholds were exceeded in 9% and 45% of samples from public-supply wells and in 6% and 37% from domestic-supply wells, respectively. Exceedances were most frequent for arid regions and older groundwater. Groundwater lithium concentrations were highest in unconsolidated clastic aquifers and sandstones and lowest in carbonate-rock aquifers, consistent with differences in lithium abundance among lithologies. Groundwater from unconsolidated clastic aquifers of the western region exhibited the highest concentrations owing to the small volume of recharge, extensive evaporation, mineral dissolution, cation exchange, and mixing with geothermal waters or brines. Geochemical models indicate cation exchange and mixing with saline groundwaters as major contributing factors. Of the public-supply wells in the unconsolidated clastic High Plains aquifer, 24% exceeded the drinking-water only threshold and 86% exceeded the HBSL. Other unconsolidated clastic aquifers in the arid west had comparable exceedances. Multiple lines of evidence indicate natural sources for the lithium concentrations.
Describe the occurrence of lithium in groundwater used as a source of drinking water in the United States and explain the factors that lead to high concentrations of lithium.