What are Maximum Contaminant Levels (MCLs) and Health-Based Screening Levels (HBSLs) and how do they differ?
A USEPA MCL is a legally enforceable, Federal standard for public water supplies that sets the maximum permissible level of a contaminant in water that is delivered to any user of a public water system. MCLs are set as close as feasible to the maximum level of a contaminant in drinking water at which no known or anticipated adverse effects on human health would occur, taking into account the best available technology, treatment techniques, cost considerations, expert judgment, and public comments. MCLs are not enforceable for water from domestic wells. HBSLs are non-enforceable guidelines based on health effects alone and do not consider cost and technical limitations. HBSLs were developed for those contaminants for which Federal standards (MCLs) have not been established. HBSLs were developed by the USGS in collaboration with USEPA and others using standard USEPA methods for establishing drinking-water guidelines for the protection of human health. The most current, USEPA peer-reviewe
Related Questions
- What are Health-Based Screening Levels (HBSLs), and how are they different from existing USEPA drinking-water guidelines?
- What are Maximum Contaminant Levels (MCLs) and Health-Based Screening Levels (HBSLs) and how do they differ?
- How do the three levels of protection (Maximum, Medium, Minimum) differ?
