BANGOR — Shellfish harvesting on Hood Canal, closed because of an oily bilge-water spill in mid-February, reopened in most areas Feb. 28.

The Bangor shoreline remains closed, according to state Health Department spokesman Mark Toy. As of Feb. 26, there was still “a little” oily bilge water running off the pier where a pump had failed, Toy said. The failed pump caused an estimated 2,000 gallons of oily bilge water to spill into Hood Canal.

The spill occurred Feb. 11 during a transfer of oily bilge water from a ship docked at Naval Base Kitsap — Bangor, according to base public affairs officer Tom Danaher. The bilge water had petroleum products in it. The spill reached the Hood Canal Bridge, leaving a sheen that was visible over a nine-mile stretch of the waterway.

Samples from the closed and advisory areas in Hood Canal were taken to the National Oceanic and Atmospheric Administration, which gave all but the Bangor shoreline a “pass,” allowing the areas to reopen. Detailed reports were not available March 3.

The Navy reported the spill to the state Department of Ecology at 1:15 p.m. Feb. 11, according to Ecology spokeswoman Joye Redfield-Wilder.

“A system failure in the pier-side transfer system” caused an overflow that spilled onto the pier and into Hood Canal, Danaher reported. “Pumping ceased, a containment boom was employed and trained Port Operations personnel began clean up using vacuum trucks and absorbent pads until sunset.”

According to an investigation into the system failure and the environmental impact, the spill was caused by an electrical failure with the pump system. No impacts to wildlife — other than shellfish harvesting — were reported.