Article of Interest

A Look Ahead...

New Water Contaminants Regulation on the Horizon

The Safe Drinking Water Act requires the United Sates Environmental Protection Agency (EPA) to publish a list of contaminants that are currently unregulated and known to occur in drinking water which may be candidates for regulation. The list is known as the Candidate Contaminant List (CCL). The most recent list, CCL 3, was published as a draft in October 2009. This publication begins a multi-year process of determining the validity of regulating these proposed compounds.

The CCL 3 list includes 104 chemical and 12 microbial contaminants. More specifically, the list includes 11  disinfection by-products, 9 hormones, 43 pesticides and degradates, 12 microbial pathogens and 3 cynotoxins. Cynotoxins are naturally produced or released from naturally occurring cynobacteria, a type of blue-green algae. Cynobacteria have been identified in some lakes and surface water bodies in New England. Anabena, a common blue-green algae found in New England, produces Anatoxin, one of the cynotoxins proposed for regulation.

In addition to the proposed list of new contaminants, 71 contaminants currently regulated under the Safe Drinking Water Act, including arsenic, will be reopened to the public and scientific community for consideration of a revised maximum contaminant level (MCL) for regulation. Arsenic is a common constituent in certain bedrock formations and in groundwater in many areas in New England. Arsenic is presently regulated with an MCL at 10 parts per billion (ppb). A lowering of this concentration will have a dramatic impact on groundwater supplies throughout New England. Arsenic is easily removed from groundwater using oxide coated media pressure filters, among other technologies.

If ultimately selected for regulation, many of these new contaminants are going to be important to drinking water systems and water sources in New England. In addition to cynobacteria byproducts and arsenic, NDMA (Nitrosodiethylamine) will be a concern to water systems using chloramination for primary disinfection. NDMA is a chloramination byproduct of rockets fuels. If your water system recently switched to chloramination as a strategy to control disinfection byproduct formation in your distribution system, you are encouraged to track this regulatory process.