ARSENIC: MOVING TOWARD A REGULATION

Currently, EPA is reviewing the arsenic standard so that communities that need to reduce arsenic in drinking water can proceed with confidence that the new standard is based on sound science and accurate cost and benefit analyses.

The Safe Drinking Water Act, as amended in 1996, required the U.S. Environmental Protection Agency to review current drinking-water standards for arsenic, propose a maximum contaminant level for arsenic by January 1, 2000, and issue a final regulation by January, 2001.

EPA published a new standard for arsenic in drinking water on January 22, 2001, that would require public water supplies to reduce arsenic to 10 ppb by 2006. EPA withdrew the standard in March 2001 for review. Many small communities will be affected by the drinking water standard for arsenic, making it especially important to ensure that the Safe Drinking Water Act provision allowing balancing of cost is based on accurate information.

While scientists agree that the previous standard of 50 parts per billion should be lowered, there is no consensus on a particular safe level. Independent review of the science behind the final standard will help clear up uncertainties that have been raised about the health benefits of reducing arsenic to 10 parts per billion in drinking water.

The state of New Hampshire has proposed an arsenic standard that mirrors that initially proposed and now under review by the EPA. The new state level will be 10 parts per billion. This will serve as an action level for private well owners and an enforceable regulatory level for public water supplies.