The U.S. Environmental Protection Agency ordered the Palmdale Water District of southern California to reduce the levels of disinfection byproducts from its drinking water system.
Twice this past summer, the water district--which serves approximately 90,000 customers--reported trihalomethane levels above the allowable federal limit. Trihalomethanes are formed when chlorine reacts with natural organic compounds during the treatment process to disinfect drinking water.
"Public drinking water systems have a responsibility to comply with national health-based drinking water standards," said Alexis Strauss, the U.S. EPA's water division director in the Pacific Southwest region. "Chemical byproducts in treated drinking water need to be monitored, reported and reduced to meet federal health standards."
The order requires the Palmdale Water District to notify the U.S. EPA of how it intends to stop trihalomethane violations within 30 days, and gives the water district until April 2004 to comply with disinfection provisions of the Safe Drinking Water Act.
The federal drinking water standard for trihalomethanes is 80 parts per billion; Palmdale's system-wide, annual average concentration reached approximately 85 ppb.
After many years of consumption, trihalomethanes may cause liver, kidney or central nervous system problems, and may increase the risk of cancer. The district has already begun reducing these levels and recent sampling indicates that system-wide trihalomethane levels are falling.
The U.S. EPA's action was taken because of an absence of state regulations for more stringent control of disinfectants and disinfection byproducts in drinking water. In 2002, the U.S. EPA began enforcing the new federal disinfectants and disinfection byproducts rule to protect public health from potentially harmful chemicals. This is the third action taken by the U.S. EPA in California under the new regulation.