SEATTLE — A new report from Washington State Ferries revealed the Walla Walla ferry ran aground in April due to contaminated fuel, caused by bacterial and fungal growth that overwhelmed the vessel’s fuel filtration system.
The ferry was intentionally grounded near Bainbridge Island on April 15 after the vessel lost propelling force and steering controls when contaminated fuel caused generators to fail.
“This water contamination resulted in gross bacterial and fungal growth to the extent that the fuel filtration system was overcome, and the ship's service diesel and vital generator engines could not function,” according to the report.
Filters of two of the vessel’s service diesel generators were contaminated with “black sludge,” according to the report. Engineers sampled 13 sites and five were microscopically examined, showing bacterial fungal growth.
The Walla Walla has multiple engines, generators and fuel tanks but it was just one fuel tank that was contaminated. Both the main generator and the backup generator failed.
The black water-based sludge was found in the vessel’s two-day fuel tanks supplying fuel to the main generator.
Sludges clogged the active fuel filter for the first diesel generator, becoming unstable and failing. The backup generator and the main generator were not functioning, causing the vessel to lose forward motion.
The source of the water contamination, which was found to be fresh water and air in the fuel tank, triggered the Alfa Laval Fuel Centrifugal filter, which separates liquids from liquids or solid particles from liquids.
Washington State Ferries is now using more biocide to limit bacterial and fungal growth, according to Ian Sterling, public information officer for WSF. The agency has also cleaned the fuel system and sealed off air sources of the tank.
In addition, training and procedures on monitoring the fuel system have been implemented, Sterling said.
The Walla Walla was stranded along the Rich Passage near Bainbridge Island on April 15. The vessel, traveling from Bremerton to Seattle, ran aground, meaning it was lying on or touching the ground under shallow water.
It was successfully re-floated during high tide overnight and brought safely to Bremerton with tugs assisting.
The report also noted that there were no injuries or fatalities to any passengers or the 15 crew members on board.
Due to crowd control difficulties, there was not an accurate passenger count taken onboard at any time during the grounding, the report notes. As passengers disembarked, an accurate count of 596 people was recorded.