On December 7, 2003, at 0100 Eastern Time, a sodium hypochlorite release occurred at the construction site of Covert Generating Company. At the time of the release, Stone & Webster Construction, Inc., of 26000 77th Street, Covert, Michigan was in charge of the site. The approximate release of sodium hypochlorite was 2023 pounds. Sodium hypochlorite is a CERCLA hazardous substance with a reportable quantity of 100 pounds. This release was 20.23 times the reportable quantity. The release was due to an inappropriate gasket at the flanged connection of cooling water piping. The gasket disintegrated and sodium hypochlorite was discharged directly to the soil. The NRC was called at 0900 Eastern time on December 7, 2003.