The U.S. Environmental Protection Agency today reduced public health risks from arsenic in the nation's drinking water. The agency is establishing a new arsenic standard for drinking water at 10 parts per billion (ppb), down from the current 50 ppb level. Today's action will provide additional protection to at least 13 million Americans from cancer and other health problems.
All 54,000 community water systems, serving 254 million people will be subject to the new standard. However, EPA estimates that roughly five percent, or 3,000, community water systems serving l3 million people, will need to take corrective action to lower current arsenic levels in their drinking water. The standard will also apply, for the first time, to 20,000 water systems that serve people only part of the year, such as schools, churches, and factories. Approximately 1,100 of these systems, serving two million people will need to take corrective action. Most of the systems affected by the new standard serve fewer than 10,000 people.
Water systems in western states and parts of the Midwest and New England that depend on underground sources of drinking water will be affected most by the new standard.
In general, arsenic can contaminate drinking water through natural processes, such as erosion of rocks and minerals. Arsenic can also contaminate drinking water when used for industrial purposes. Arsenic is found at higher levels in underground sources of drinking water than in surface waters, such as lakes, reservoirs, and rivers.
The earlier 50 ppb arsenic standard for drinking water was set by EPA in 1975, based on a Public Health Service standard originally set in 1942. In March 1999, the National Academy of Sciences (NAS) completed a review of updated scientific data on arsenic and recommended that EPA lower the standard as soon as possible. Although the NAS did not recommend a specific numeric level, its recommendation formed the basis for EPA's new standard.
EPA estimates that 90 percent of households served by systems needing treatment will have annual costs of $60 or less per household. Financial and technical assistance is available to help small systems address the costs of this rule, primarily through the drinking water state revolving fund established under the Clinton-Gore Administration that has provided $3.6 billion to drinking water systems since 1997. In addition to financial assistance, compliance period extensions of up to 9 years (resulting in a total compliance period of 14 years) are available to small systems through an exemption process.
Additional information on the new standard is available at
http://www.epa.gov/safewater, under "What's New" or from EPA's drinking water hotline at 800-426-4791.
