After putting a halt on the new arsenic MCL in March, drinking water in McLennan County, Texas, home to President George W. Bush's ranch, is reported to contain 40 percent more arsenic than would be allowed under the rule issued by the U.S. Environmental Protection Agency (EPA) in January. The proposed rule called for setting arsenic levels at 10 ppb down from the current 50 ppb originally set in 1942.
The arsenic rule, written under the Clinton administration and rejected by Bush, would slash the acceptable limits for this toxic chemical in drinking water by 80 percent. The current standard is five times higher than the World Health Organization's and the European Union's international standard.
In McLennan County, at least five communities report concentrations of arsenic higher than the 10 ppb standard. The EPA's new standard was issued after decades of regulatory development, public comment, debate, millions of dollars in EPA research and at least three missed statutory deadlines set by the 1974, 1986 and 1996 Safe Drinking Water Acts.
Arsenic occurs naturally in rocks and soil, water, air and plants and animals. The highest concentrations of arsenic occur in western states. It can be released into the environment through natural activities such as erosion and forest fires, or through human actions including in paints, metals, agriculture, mining and semiconductors.
Studies have linked long-term and short-term exposure to arsenic in drinking water to various health problems.