A small amount of diesel fuel spilled into the south end of Lake Lanier on Wednesday after a construction crane slipped under water.

The incident occurred near the intersection of Buford Dam Road and Stewart Road in Gwinnett County, where a contractor is building a new discharge pipeline from the Hill wastewater treatment plant to the lake.

Lynn Smarr, acting water resources director for Gwinnett County, said the contractor crews were trying to move the crane onto a barge when an anchor cable came loose and the crane slid into the water.

When an oil slick appeared on the lake surface, Smarr said, the contractor halted construction, blocked off the area to keep boats away from the site, and reported the incident to the National Response Center and to the U.S. Army Corps of Engineers.

Oil booms were installed and absorbent material was used to contain the oil slick within an area of about 60 feet by 60 feet.

Tyler Richards, deputy director for Gwinnett's Water Resources Operation, said she didn't think the diesel fuel posed a threat to the water supply. But as a precaution, she said, the county has stopped using water intake pipes near the spill area "until the situation is stabilized and operations are back to normal at the construction site."