By Janet Raloff
On Jan. 17, the Clinton administration issued a final rule lowering the amount of arsenic allowed in drinking water from 50 parts per billion to just 10 ppb. Many groundwater supplies around the world, including those from several hot spots in the United States, are naturally tainted with this carcinogenic element. In announcing the new limit, the Environmental Protection Agency noted that some 4,100 drinking-water systems serving 15 million people would be affected.
Upon taking office, the new Bush administration reviewed the change. On March 20, 3 days before the new limit was to go into effect, Christie Whitman, the new EPA administrator, announced she was delaying the rule’s implementation for 60 days. During this time, EPA will look for an alternative standard, she said.
“The standard should be less than 50 ppb, but the scientific indicators are unclear as to whether the standard needs to go as low as 10 ppb,” explains Whitman. EPA acknowledged last month that it had heard complaints about the cost of complying with Clinton’s rule from affected water utilities. EPA estimates that figure to be $200 million per year.
Whitman’s announcement came just days after a university study reported that arsenic is an endocrine disrupter that can impair hormone action at low exposures–ones potentially as low as 10 ppb in water (SN: 3/17/01, p. 164).
