EPA reduced public health risks from arsenic this week by establishing a new arsenic standard for the nation''s drinking water at 10 parts per billion (ppb), down from the current 50 ppb level.
All 54,000 community water systems, serving 254 million people will be subject to the new standard.
However, EPA estimates that roughly 5 percent, or 3,000 community water systems serving 13 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.
EPA estimates that approximately 1,100 of these systems serving 2 million people will need to take corrective action.
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 standard, according to the agency.
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.
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 data on arsenic and recommended that EPA lower the standard as soon as possible.
EPA estimates that 90 percent of households served by systems needing treatment will have annual costs of $60 or less per household.
The American Water Works Association (AWWA) is concerned that the rule''s massive compliance costs may stymie its public health benefits to the nation.
The new standard reduces the existing standard by 80 percent, but at a cost of $600 million annually and $5 billion in capital outlays that some communities may have trouble financing.
"AWWA has long supported a stronger arsenic standard," said AWWA Executive Director Jack Hoffbuhr. "Water utilities, ratepayers and Congress must now work to ensure that the tougher standard can be implemented in every community impacted by it."
AWWA said that complying with the new standard could cost individual ratepayers in the desert Southwest, Midwest and New England as much as $2,000 a year.
To ease this burden, the association said it is going to initiate efforts in Congress to "procure adequate federal assistance for those communities hit hardest by the requirements of the new rule."
"The rule strengthens public health protection, but at a significant cost," said Hoffbuhr. "With some help from Congress, communities will be able to find the financial balance necessary to promote the health of their residents."
by Virginia Sutcliffe