National Recommended Water Quality Criteria (U.S.)

Surface and groundwater data are often compared to criteria established under Section 304 of the Clean Water Act. The CWA criteria are used as guidelines for actual Water Quality Standards established by states and tribes. There is a separate set of Water Quality Criteria established under the CWA for the protection of human health and aquatic life. And, for the protection of human health, two sets of criteria have been established, one which assumes that humans only route of exposure is fish consumption and the a more stringent criteria that assumes human exposure through both fish consumption and drinking the water.