Paint residues in tap water? Federal regulators want to know.
City of Seattle
EPA’s proposal would require facilities
like Seattle Public Utilities' water
quality laboratory to test for 28
To that end, the Environmental Protection Agency is proposing additional monitoring of tap water for unregulated contaminants.
The EPA’s proposed “Revisions to the Unregulated Contaminant Monitoring Regulation (UCMR 3) for Public Water Systems,” issued March 3, would establish monitoring of 28 chemical contaminants and two viruses in public drinking water.
Although the contaminants are called “unregulated,” the 1996 amendments to the Safe Drinking Water Act require the EPA to establish criteria for a program to monitor unregulated contaminants and to publish a list of contaminants to be monitored every five years. The current proposal would be the third UCMR cycle (UCMR 3).
Under the proposal, all Public Water Systems (PWSs) serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people would be required to monitor for 28 contaminants during a 12-month period from January 2013 through December 2015.
EPA would also select 800 representative PWSs serving 1,000 or fewer people. Of particular concern are PWSs in areas with karst or fractured bedrock, as well as in non-community water systems. These PWSs would monitor for two viruses (enteroviruses and noroviruses) twice during a 12-month period from January 2013 through December 2015.
The list of proposed contaminants includes these Volatile Organic Compounds:
• 1,2,3-Trichloropropane (1,2,3-TCP), used historically as a paint and varnish remover, cleaning and degreasing agent, cleaning and maintenance solvent, and more currently as a chemical intermediate;
• 1,1-Dichloroethene, used in piping, coating for steel pipes, and adhesive applications, as well as many consumer plastics, packaging and flame-retardant fabrics;
• n-Propylbenzene, a member of the alkyl aromatic family of hydrocarbons, which also includes toluene (methylbenzene), xylenes, ethylbenzene, and cumene. n-Propylbenzene occurs as a natural constituent in petroleum and bituminous coal and is used to make other chemicals, and textile dyeing and printing; and
• Sec-butylbenzene, used as solvent.
The list also includes the synthetic organic compound 1,4-Dioxane, used in the formulation of inks, coatings, and adhesives. 1,4-Dioxane is used primarily as a solvent in paints, varnishes, lacquers and consumer cosmetics, cleaners and detergents.
Also targeted are several metals, including:
• Cobalt, used in pigments; and
• Molybdenum, used in corrosion inhibitors for coatings as well as in catalysts, polymer compounding, and high-performance lubricant formulations.
Focus on PFCs
A major focus of the initiative is perfluorinated chemicals, a family of toxic industrial chemicals found widely in consumer products. The list includes six perfluorochemicals (PFCs) used in a wide variety of stain-repellent textile coatings, non-stick cookware, and water and grease-resistant coatings.
The chemicals are believed to contaminate the environment through unregulated industrial discharges, coating residues that wear and wash off consumer goods, and leaching of perfluorochemical materials disposed in landfills, according to the nonprofit Environmental Working Group.
The EPA’s proposal does not include monitoring Hexavalent Chromium (chromium-6), which has drawn increasing concern and regulation worldwide. Hexavalent Chromium has many industrial applications, including chromate pigments in dyes and paints; chromates added as anticorrosive agents to paints, primers and other surface coatings; and chromic acid electroplated onto metal parts to provide a decorative or protective coating.
“EPA is aware of potential concerns about chromium-6 occurrence in public water supplies,” the agency said. However, the agency noted that it issued a directive in December for water utilities to develop monitoring and sampling programs for Hexavalent Chromium, in the wake of a study that found the toxic chemical in most of the water supplies tested.
EPA left open the possibility that Chromium-6 could still be added to the UCMR 3 list, if public comment demands it. Public comments on the proposal will be accepted through May 5.