Facilities Must Meet Requirements Beginning January 2006
New federal drinking water standards designed to lower the levels of arsenic in drinking water take effect Jan. 23, 2006, for Pennsylvania's public water systems, Environmental Protection Secretary Kathleen A. McGinty said. The federal law lowers the maximum contaminant level (MCL) for arsenic from 0.050 milligrams per liter (mg/L), or 50 ppb, to 0.010 mg/L, or 10 ppb.
"The department has been working aggressively to make sure drinking water suppliers understand the federal requirements and have in place the mechanisms they need to meet the new standard," McGinty said. "Ensuring a smooth transition will strengthen public confidence in the systems that supply our public drinking water."
The Pennsylvania Department of Environmental Protection (DEP) outreach efforts have been ongoing for years as the new standards were being developed and finalized. The U.S. Environmental Protection Agency (EPA) adopted the new standard for arsenic in drinking water Jan. 22, 2001. The rule became effective Feb. 22, 2002. The date by which systems must begin complying with the new standard is Jan. 23, 2006. DEP incorporates by reference federal MCLs as state MCLs.
DEP has been working with community water suppliers and nontransient, noncommunity public water suppliers -- those that serve water to at least 25 of the same people for more than six months in a year, but not year-round -- to help bring their operations into compliance ahead of the effective date.
The department sent letters to all public water system operators in July informing them of the change, and DEP staff members have been in direct contact with systems identified as having arsenic levels above 0.010 mg/L in past monitoring. According to historical information, about 90 of a total of 3,340 systems (or about 3%) have arsenic levels above 0.010 mg/L.
Efforts were made to inform these systems about various grants and other programs available to offset the costs of installing treatment, such as DEP's Growing Greener grants for innovative technologies and the Pennsylvania Infrastructure Development Authority's funding, and about EPA's Arsenic Treatment Technology Research Demonstrations and Environmental Technology Verification (ETV) Program.
Initial compliance monitoring for arsenic will begin after the Jan. 23
effective date for the new MCL. State regulations require water systems in violation of the MCL to issue public notification and conduct more frequent monitoring as interim measures until treatment is provided to reduce the arsenic levels or a new source is brought on line.
Some studies have linked long-term exposure to high levels of arsenic in drinking water to cancer of the bladder and lungs. Short-term exposure to high doses of arsenic can cause other adverse health effects, but such effects are unlikely to occur from Pennsylvania's public water supplies that are in compliance with the existing arsenic standard of 0.050 mg/L.
EPA set the current standard of 0.050 mg/L in 1975, based on a Public Health Service standard originally established in 1942. A March 1999 report by the National Academy of Sciences concluded standards should be strengthened further to protect public health.