U.S. Geological Survey - Environmental Health
A U.S. Geological Survey USGS Health-Based Screening Level (HBSL) Web site includes human-health benchmarks for 351 contaminants (79 U.S. Environmental Protection Agency (EPA) Maximum Contaminant Levels (MCLs), 117 EPA Human Health Benchmarks for Pesticides (HHBPs), and 155 USGS HBSLs). The Web site also provides detailed toxicity information used to calculate HBSLs. A comprehensive update of the USGS HBSL database was completed in June 2014. HBSLs are non-enforceable water-quality benchmarks that can be used in conjunction with EPA MCLs and HHBPs to (1) determine whether contaminants found in surface water or groundwater sources of drinking water may indicate a potential human-health concern and (2) help prioritize monitoring efforts. HBSLs were developed by the USGS National Water-Quality Assessment (NAWQA) Program for contaminants without EPA MCLs or HHBPs.
HBSLs were updated in order to:
This study was funded by the USGS NAWQA Program.