John S. Zogorski Julia E. Norman Patricia L. Toccalino 2005 To supplement existing Federal drinking-water standards and guidelines, thereby providing a basis for a more comprehensive evaluation of contaminant-occurrence data in a human-health context, USGS began a collaborative project in 1998 with USEPA, the New Jersey Department of Environmental Protection, and the Oregon Health & Science University to calculate non-enforceable health-based screening levels. Screening levels were calculated for contaminants that do not have Maximum Contaminant Level values using a consensus approach that entailed (1) standard USEPA Office of Water methodologies (equations) for establishing Lifetime Health Advisory (LHA) and Risk-Specific Dose (RSD) values for the protection of human health, and (2) existing USEPA human-health toxicity information. application/pdf 10.3133/fs20053059 en Geological Survey (U.S.) Health-Based Screening Levels and their Application to Water-Quality Data reports