On Feb. 23, the U.S. EPA made available the final recommended aquatic life ambient water quality criteria for diazinon. This pesticide is traditionally used throughout the U.S. to control insects in agricultural areas, households and urban settings. While it became unlawful to sell diazinon for residential use in the U.S. after December 2004, it is still lawful to use diazinon properly for non-residential or agricultural uses. Mobile and moderately persistent in the environment, diazinon is frequently found in wastewater treatment plant effluent and storm water runoff in urban and agricultural areas.
The agency also made available the final recommended aquatic life ambient water quality criteria for nonylphenol. Produced in large quantities in the U.S., this organic chemical is toxic to aquatic life. It is often found in wastewater treatment plant effluent as a breakdown product from surfactants and detergents. The final criteria provide guidance to states and tribes (they have no binding legal effect), but they may form the basis for state water quality standards and become enforceable through NPDES permits or other environmental programs.
"This is an important addition to the Clean Water Act toolbox," saidBenjamin H. Grumbles, assistant administrator for Water. "EPA'sscientifically-based criteria for pesticides such as diazinon, and for
organic chemicals such as nonylphenol, help states and tribes set standards to protect watersheds, fish and wildlife."