Chemicals Research

Safe drinking water is the foundation of public health. The Safe Drinking Water Act of 1974 gave EPA the primary responsibility in the federal effort to protect the public's drinking water supply. The 1996 amendments to the Act required EPA to establish a Contaminant Candidate List (CCL), a list of drinking water contaminants to be considered for future regulation. The first CCL was finalized in 1998, and it included, among other contaminants, 50 chemicals. EPA must make a regulatory determination on a minimum of five contaminants every five years.

Availability of nationwide occurrence data is key to making a regulatory determination for the chemical contaminants under consideration. Under the Unregulated Contaminant Monitoring Regulations, monitoring for contaminants of interest is conducted at selected drinking water utilities, and chemical analyses are performed by the utilities or by commercial laboratories. EPA determines the extent of occurrence and the risk posed to the public via drinking water. This will ultimately lead to an appropriate EPA action for that chemical contaminant—regulation, guidance, or a decision not to regulate.

Emerging chemical contaminants are those of increasing regulatory interest. They may be currently unregulated or may be subject to new or revised regulatory standards. Characteristically, they occur at low levels, enter the aquatic environment from multiple sources, and are considered a long-term issue (not an issue that requires emergency action). Some of these chemicals may have harmful estrogenic (hormonal) effects on both wildlife and humans. No standardized biological test is available, and EPA does not currently have approved chemistry methods to detect many of these chemicals. Furthermore, the policies that address these emerging chemical contaminants are complicated because of different mandates from different agencies.

EPA’s research includes emerging chemical contaminants and focuses on:

• Suspected endocrine-disrupting chemicals (EDCs) and pharmaceuticals and personal care products that affect the environment and our drinking water
• The risks posed by the use of pesticides
• New disinfection by-products and chemicals on the CCL
• Cyanobacterial toxins
• Small systems
• Balancing the risks from microbial pathogens in our drinking water against the risks of creating disinfection by-products
• Developing the Treatability Database

Technical Contact:

Tom Speth (513) 569-7208