EPA Administrator Gina McCarthy signed the proposed fourth Unregulated Contaminant Monitoring Rule (UCMR4) on November 30. Once finalized, the UCMR4 will require large public water systems to monitor for up to 30 chemical contaminants or contaminant groups between March 2018 and November 2020. The analytical data collected will be used to inform future drinking water regulatory development efforts.
In line with EPA’s recent emphasis on understanding algal blooms’ and resulting algal toxins’ potential impacts on drinking water, the proposed UCMR4 focuses heavily on cyanotoxin analyses. Ten of the 30 contaminants to be sampled under UCMR4 are cyanotoxins (either groups or particular congeners). Among the other 20 contaminants on the monitoring list are two metals, eight pesticides or pesticide manufacturing byproducts, three brominated haloacetic acid groups, three alcohols and 3 “other semi-volatile chemicals.” In addition, monitoring for four “indicators” – total organic carbon, bromide, temperature and pH – will be required.
Comments can be submitted on the proposed rule for 60 days following its publication in the Federal Register, which is expected in early December. EPA will also hold a public stakeholder webinar on the UCMR4 proposal on January 13, 2016 (1:00 p.m. - 4:30 p.m. ET) to “[d]iscuss the proposed UCMR4 monitoring requirements, analyte selection and rationales, analytical methods, laboratory approval process and other aspects of the proposed rule.”
Additional information on the UCMR4 proposal, including links to the draft Federal Register notice and webinar registration information for the public stakeholder meeting, is available through the Fourth Unregulated Contaminant Monitoring Rule webpage.