Health advisory level (HAL)s are developed when a chemical is found in drinking water and no regulatory standard (MCL) exists for the chemical. The HAL concentration of a chemical in drinking water is a value that, based on the available data, is virtually certain not to cause adverse human health effects if consumed over a lifetime. HALs provide guidance for the public and the Department of Environmental Protection (DEP) on the potential for these chemicals to cause harm to humans.

The maximum contaminant level (MCL) is a standard established by the U.S. Environmental Protection Agency, under the Safe Drinking Water Act. It represents an acceptable level of a chemical under specified conditions that ensures the safety of a public drinking water supply. MCLs are used by DEP to regulate theย  level of chemicals allowed in drinking water.


Chemical Fact Sheets

Following are fact sheets with information on selected chemicals.