The U.S. Environmental Protection Agency (USEPA) announced in mid-March that it will not develop regulations for nine of the 81contaminants listed on the Fifth Contaminant Candidate List (CCL5).
The Safe Drinking Water Act (SDWA) requires USEPA to make regulatory determinations every five years on at least five unregulated contaminants. USEPA used a three-phase process to identify which of the 81 contaminants are candidates for regulatory determinations. Most of the 81 CCL5 contaminants did not have adequate health or finished drinking water occurrence data to make a regulatory determination. USEPA prioritizes identifying contaminants known or substantially likely to occur at frequencies and levels of public health concern.
The regulatory agency will not propose or promulgate a national primary drinking water regulation for the following unregulated contaminants listed in the CCL5 because they are not commonly found in drinking water at levels or frequency of concern:
- 2-aminotoluene
- cylindrospermopsin
- ethoprop
- microcystins
- molybdenum
- permethrin
- profenofos
- tebuconazole
- tribufos
The CCL5 is considered a key indicator of contaminants that may be considered for inclusion in the Sixth Unregulated Contaminant Monitoring Rule (UCMR6). The upcoming UCMR6 is expected to include a combination of chemical contaminants and select microbial constituents.
To access additional information about the CCL5 regulatory determination, visit the USEPA website and the Federal Register.