EPA Seeks Comment on Preliminary Perchlorate Drinking Water Decision
October 21, 2008 // Published as a news service by IHS
The U.S. Environmental Protection Agency (EPA) seeks comments on its preliminary determination not to regulate perchlorate in drinking water at a national level after it 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, said the EPA.
One of the analyses that the EPA considered for this preliminary determination is a physiologically-based pharmacokinetic (PBPK) model that predicts radioactive iodide uptake (RAIU) inhibition in the thyroid for various sub-populations and drinking water concentrations, according to the "Drinking Water: Preliminary Regulatory Determination on Perchlorate" Federal Register notice.
The Federal Register Notice can be found at http://www.epa.gov/fedrgstr/EPA-WATER/2008/October/Day-10/w24042.htm.
While less than 1% of the drinking water sources have perchlorate levels above the health reference level, the EPA said it will work with states and localities to ensure public health is protected.
States have the right to establish and enforce drinking water standards and the EPA encourages state-specific situations to be addressed at the local level. The EPA plans to issue a health advisory at the time it issues its final regulatory determination for perchlorate, to assist states with their local response, said the EPA.
A regulatory determination is a formal decision by the 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.
The EPA has drinking water regulations for more than 90 contaminants. Every five years, the 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, said the EPA.
Source: U.S. Environmental Protection Agency (EPA).