U.S. Environmental Protection Agency Administrator Christie Whitman announced on March 20 that EPA will propose to withdraw the pending arsenic standard for drinking water that was issued on January 22. The rule would have reduced the acceptable level of arsenic in water from 50 parts per billion to 10 ppb.
EPA will seek independent reviews of both the science behind the standard and of the estimates of the costs to communities of implementing the rule. A final decision on withdrawal is expected after the public has an opportunity to comment.
"I want to be sure that the conclusions about arsenic in the rule are supported by the best available science. When the federal government imposes costs on communities-especially small communities-we should be sure the facts support imposing the federal standard," Whitman explained.
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.
"It is clear that arsenic, while naturally occurring, is something that needs to be regulated. Certainly 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," said Whitman.
EPA asked for a 60-day extension of the effective date of the pending arsenic standard for drinking water, and expects to release a timetable for review within the next few weeks.
Arsenic is an element that occurs naturally in several parts of the country. The highest concentrations of arsenic occur mostly in the Western states, particularly in the Southwest. At unsafe levels, arsenic causes cancer and other diseases.