Coast Guard Chief Warrant Officer David G. Williams Jr. pleaded guilty yesterday to making a false statement to investigators looking into the illegal discharge of 2,000 gallons of wastewater into Honolulu Harbor in March 2006.

Williams, who was responsible for engine maintenance on the Coast Guard cutter Rush, faces a maximum penalty of five years in prison and a $250,000 fine, according to Assistant U.S. Attorney William Shipley.

Sentencing is scheduled for Aug. 19 before U.S. District Judge J. Michael Seabright.

Williams was originally charged with obstruction of justice, but that count was dropped as part of a plea agreement reached with the U.S. Attorney's Office.

His lawyer, Deputy Public Defender Matthew Winter, would not comment on the case yesterday.

Bilge water, a combination of water, oil and other lubricants, was illegally dumped overboard from the cutter before the vessel left port for a training mission.

An anonymous tipster told state Health Department authorities about the illegal waste discharge, leading to a criminal investigation by the Coast Guard and Environmental Protection Agency.

Williams had told investigators he knew nothing about the dumping but admitted yesterday that it was a false statement.