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 MCLsor HHBPs.
HBSLs were updated in order to:
- Provide benchmarks, when possible, for 267 new contaminants analyzed by the NAWQA Program.
- Replace HBSLs with new EPA chronic HHBPs, when available.
- Be consistent with new EPA policies by calculating both cancer and noncancer HBSLs for some contaminants.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology) and the USGS NAWQA Program.
Below are other science projects associated with this article.
National Water-Quality Assessment (NAWQA)
Water-Quality Benchmarks for Contaminants
Health-Based Screening Levels for Evaluating Water-Quality Data
- Overview
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 MCLsor HHBPs.
Sources/Usage: Public Domain.The HBSL database contains 777 contaminants currently or historically analyzed by the NAWQA Program. The database includes MCLs, HHBPs, or HBSLs for 351 contaminants. HBSLs are not available for the remaining 426 contaminants because of a lack of toxicity information. HBSLs were updated in order to:
- Provide benchmarks, when possible, for 267 new contaminants analyzed by the NAWQA Program.
- Replace HBSLs with new EPA chronic HHBPs, when available.
- Be consistent with new EPA policies by calculating both cancer and noncancer HBSLs for some contaminants.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology) and the USGS NAWQA Program.
- Science
Below are other science projects associated with this article.
National Water-Quality Assessment (NAWQA)
Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.Water-Quality Benchmarks for Contaminants
How does the water quality measure up? It all depends on what the water will be used for and what contaminants are of interest. Water-quality benchmarks are designed to protect drinking water, recreation, aquatic life, and wildlife. Here you’ll find links to some of the most widely used sets of water, sediment, and fish tissue benchmarks and general guidance about their interpretation.Health-Based Screening Levels for Evaluating Water-Quality Data
This searchable online database provides Health-Based Screening Levels (HBSLs) for hundreds of chemicals, including pesticides and degradates. HBSLs are non-enforceable benchmark concentrations of contaminants in water. These screening levels supplement federal drinking-water standards and guidelines.