Environmental Protection Agency (EPA) Seeks Advice on Perchlorate in Drinking Water Agency Issues Interim Health Advisory

Note: from Water Headlines for January 12, 2009. Water Headlines is a weekly online publication that announces publications, policies, and activities of the U.S. EPA's Office of Water.

The U.S. EPA is seeking advice from the National Academy of Sciences (NAS) before making a final determination on whether to issue a national regulation for perchlorate in drinking water.

The agency also is issuing an interim health advisory of 15 parts per billion (ppb) to assist state and local officials in addressing local contamination of perchlorate in drinking water and making a corresponding change to the factors it considers in cleaning up Superfund sites. States have the right to establish and enforce drinking water standards, and EPA encourages state-specific situations to be addressed at the local level. EPA expects to issue a final health advisory concurrent with the final regulatory determination for perchlorate.

"This is a sensible step for protecting public health and preserving regulatory options as the science of perchlorate is reviewed," said Benjamin H. Grumbles, EPA's assistant administrator for water.

On October 10, 2008, the agency issued a preliminary regulatory determination for public comment in the Federal Register. The notice described the agency's decision that there is not a "meaningful opportunity for health risk reduction" through a national drinking water regulation for perchlorate. The agency received more than 32,000 comments on the notice.

After considering public comments, as well as recommendations from EPA advisory groups and offices, EPA is asking the NAS to provide additional insight on various issues. Specifically, EPA is asking the NAS to evaluate its derivation of the Health Reference Level of 15 ppb, the use of modeling to evaluate impacts on infants and young children, and the implication of recent biomonitoring studies. The agency is also asking the NAS how it should consider the role of perchlorate relative to other iodide uptake inhibiting compounds and if there are other public health strategies to address this aspect of thyroid health.

EPA is replacing the existing preliminary remediation goal of 24.5 ppb with the interim health advisory value of 15 ppb. This goal will be used as a consideration when establishing cleanup levels for perchlorate at Superfund sites.

A regulatory determination is a formal decision by EPA as to whether it should initiate development of a national primary drinking water regulation for a specific contaminant under the Safe Drinking Water Act. EPA has drinking water regulations for more than 90 contaminants. Every five years, EPA develops a Contaminant Candidate List to consider for regulation and then makes regulatory determinations on some of the contaminants based on scientific information on health effects, occurrence in drinking water and the opportunity for risk reduction.

A health advisory provides technical guidance to federal, state, and other public health officials on health effects, analytical methods and treatment technologies associated with drinking water contamination. Health advisories also contain guidance values that are concentrations of a contaminant in drinking water that are likely to be without adverse health effects.

Perchlorate and Water Main Extension Project Update

(From October 2008)

The Town of Westford has been responding to perchlorate contamination issues in the area surrounding Snake Meadow Hill since 2004. The Town and Maine Drilling and Blasting have been identified as Potentially Responsible Parties in the Notice of Responsibility (NOR) issued in October 2007 by the Massachusetts Department of Environmental Protection (MassDEP).

Based upon well sample results and the MassDEP perchlorate limit of 2 parts per billion (ppb) for potable water, the perchlorate contamination has adversely impacted private wells and one of the Town's public water supply wells (Cote Well). In response to the observed perchlorate contamination, the Town has distributed bottled water for potable use to residents along Groton Road and installed emergency treatment for the Cote Well to allow limited use during peak water demand periods.

Currently, the Town is proceeding with the design and public bid of a water main extension along Groton Road, which will permanently service the most critically affected residents with perchlorate-contaminated private wells and eliminate the need for bottled water. It is anticipated that bid results will be received prior to Special Town Meeting (STM) scheduled for October 20, 2008, with construction starting this fall. The Town has requested a low interest loan for the water main construction costs under the DEP Drinking Water State Revolving Fund (DWSRF), which will significantly lower the overall projects costs.

The proposed water main extension is a significant step in addressing the most urgent issues related to the perchlorate contamination. However, the construction of this water main extension and the approval of "emergency" DWSRF funds are contingent upon approval of the local appropriation at STM. The Town encourages residents to attend Selectmen's meeting prior to STM to learn more and comment about this project. Residents should also understand that according to Massachusetts General Law Chapter 21E, Section 5(e), MassDEP has the legal authority to complete the project and subsequently charge the Town up to three times the actual cost. We encourage your attendance at STM at the Abbot Elementary School, Monday, October 20, 2008 at 7:30 p.m.

EPA Seeks Comment on Preliminary Perchlorate Drinking Water Decision

(From the U.S. EPA Office of Water's Water Headlines for October 6, 2008, Benjamin H. Grumbles, Assistant Administrator for Water. Water Headlines is a weekly online publication that announces publications, policies, and activities of the U.S. Environmental Protection Agency's Office of Water.)

The EPA conducted extensive review of scientific data related to the health effects of exposure to perchlorate from drinking water and other sources and found that in more than 99% of public drinking water systems, perchlorate was not at levels of public health concern. Therefore, based on the Safe Water Drinking Act criteria, the agency determined there is not a "meaningful opportunity for health risk reduction" through a national drinking water regulation.

The agency is seeking comment on its preliminary determination not to regulate perchlorate in drinking water at a national level. EPA will make a final determination for perchlorate after considering information provided in the 30-day public comment period.

While fewer than one percent of the drinking water sources have perchlorate levels above the health reference level, EPA is committed to working with states and localities to ensure public health is protected. States have the right to establish and enforce drinking water standards and EPA encourages state-specific situations to be addressed at the local level. EPA intends to issue a health advisory at the time it issues its final regulatory determination for perchlorate, to assist states with their local response.

A regulatory determination is a formal decision by EPA as to whether it should initiate development of a national primary drinking water regulation for a specific contaminant under the Safe Drinking Water Act. EPA has drinking water regulations for more than 90 contaminants. Every five years, EPA develops a Contaminant Candidate List of contaminants to consider for regulation and then makes regulatory determinations on some of the contaminants based on scientific information on health effects, occurrence in drinking water and the opportunity for risk reduction.

A health advisory provides technical guidance to federal, state, and other public health officials on health effects, analytical methods and treatment technologies associated with drinking water contamination. Health advisories also contain guidance values that are concentrations of a contaminant in drinking water that are likely to be without adverse health effects.

View additional information on Drinking Water Regulatory Determinations.

New Perchlorate Regulations Established

On July 28, 2006, Massachusetts became the first state in the nation to promulgate drinking water and waste site cleanup standards for the chemical perchlorate, setting the standard at 2 parts per billion (ppb). The new regulations require most public water systems to regularly test for perchlorate. The regulations were adopted to protect public health, including sensitive populations such as pregnant women, nursing mothers, infants and individuals with low levels of thyroid hormones. Perchlorate has been found to interfere with thyroid function, which could lead to impaired development and metabolism.

Perchlorate is a chemical that can be found in blasting agents, fireworks, military munitions, and other manufacturing processes. Since perchlorate was first detected in the aquifer under Bourne, MA in 2002, the chemical has been detected in 10 other public water systems across Massachusetts, including Westford's Cote Well in July 2004.

The Westford Water Department received final approval from the Massachusetts Department of Environmental Protection (MassDEP) to operate a treatment system for the Cote Well on May 22, 2006. The Cote Well had been shut down since July 2004. The treatment system treats the well's water to below 1 ppb of perchlorate, one-half of the new standard of 2 ppb. The treatment system consists of two high flow pressure vessels that use a perchlorate-selective resin to filter out the chemical.

Besides the requirement for regular testing, the new regulations also require parties responsible for perchlorate contamination to notify MassDEP of the contamination and conduct appropriate environmental assessment and cleanup, and for all drinking water supplies to contain no more than 2 ppb of perchlorate. Since the Cote Well was placed back online, no perchlorate has been detected in any sample from the Cote Well.