AWWA WQTC52785

In the spring of 2000, the US Environmental Protection Agency proposed a newmaximum contaminant level (MCL) for arsenic in drinking water. The Agencyproposed a standard of 5 ug/L and invited comment on alternative levels of 3, 10,and 20 ug/L. As required by law, the EPA provided a national cost impact andbenefits analysis for the proposed rule. One of the important considerations of acost benefit analysis for rule development is having adequate occurrence data.Occurrence data for the rule making process was gathered from a myriad of sourcesand included national surveys, USGS, and state compliance records. Extensivehistorical data compiled by the Tampa Water Department of Tampa, Florida,indicates that arsenic occurrence may be seasonal in surface water supplies andthat the very low level MCL's proposed by the EPA may represent a treatmentconsideration for surface water facilities. This paper presents raw and finishedwater arsenic levels for Tampa, Florida, from 1992 through 2000. Includes tables, figure.