The United States Environmental Protection Agency (“EPA”) published a final rule which is the Fourth Unregulated Contaminant Monitoring Rule (“Rule”) requiring public water systems to monitor 30 currently unregulated contaminants.

The Rule is promulgated pursuant to the Safe Drinking Water Act (“SDWA”).

The Rule identifies the analytical methods to support water system monitoring for a total of 30 chemical contaminants. They consist of:

  • 9 cyanotoxins
  • 1 cyanotoxin group
  • 2 metals
  • 8 pesticides plus one pesticide manufacturing byproduct
  • 3 brominated haloacetic acid disinfection byproduct groups
  • 3 alcohols
  • 3 semi volatile organic chemicals

The Rule applies to public water systems.

Public water systems are those systems that provide water for human consumption through pipes, or other constructed conveyances, to at least 15 service connections or that regularly serve an average of at least 25 individuals daily at least 60 days out of the year. It applies to all large community and non-transient non-community water systems serving more than 10,000 people. A community water system is a public water system that has at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.

Arkansas has been delegated primary enforcement responsibility for SDWA programs. The Arkansas Department of Health is the state agency that undertakes this responsibility.

A link to the final rule can be found here.