BIRMINGHAM — In Water Technology’s April Professor POU/POE, Technical Editor Dr. Joseph Cotruvo writes about the U.S. Environmental Protection Agency’s proposed Contaminant Candidate List 4 (CCL 4).

In the article, Cotruvo explains that the Safe Drinking Water Act (SDWA) requires EPA to publish a list every five years of unregulated drinking water contaminants that may pose risks, and this list is subsequently used to help make decisions of whether to regulate at lease five contaminants as national primary drinking water regulations and also as a basis for candidate selection for Unregulated Contaminant Monitoring Rules (UCMRs).

The proposal for CCL 4 was issued on Feb. 4, states Cotruvo, and many CCL 3 substances were carried forward to CCL 4.

Cotruvo notes CCL 4 contains 12 microbes and 100 chemicals and includes two antibiotics, three halogenated volatile organic compounds (VOCs), four metals, five nitrosamines, seven hormones, 39 pesticides or their metabolites and several solvents or other industrial chemicals.

Cotruvo also lists nonylphenol, manages and cyanotoxins as additions to CCL 4, adding that cyanotoxins are of high-priority interest because they can occur during algal blooms, and short-term exposure guidance is needed to assist state and local decision-makers.

In the article, Cotruvo continues by offering appropriate deletions from CCL 4 as well as the history behind prior CCLs.

According to Cotruvo, when it comes to looking for information to make decisions about contaminants of concern and potential upcoming regulations, Health Advisories over CCLs and UCMRs are probably the best choice.

“Health Advisories are probably the most efficient and effective means for providing information that states and water suppliers need to respond to detections of the numerous less nationally significant contaminants and short-term incidents, and that is why they were developed 35 years ago,” says Cotruvo.

You can find the entire April Professor POU/POE on CCL 4 here.