The City of Bainbridge Island says as much as half-million gallons of raw sewage could have spilled into Eagle Harbor during a five-day period in late May and early June.
According to statement released by the city Friday, estimates on the total amount of sewage loss as a result of a ruptured sewage main on the north shore of the harbor ranges between 287,000 and 493,000 gallons. Initially, the city estimated that 140,000 gallons of sewage leaked into the harbor.
The city also believes the break could have begun as early as Thursday, May 28. Results of the pipe break were first noticed mid-afternoon on May 30 and the rupture was repaired in the early hours of June 2.
The revised estimates are based on an evaluation of flow records at the city wastewater treatment plant, said Lance Newkirk, the city’s deputy director of Operations and Maintenance of the Public Works Department.
“It’s important to recognize that this new information does not alter recent assessments which show that the harbor’s waters are now safe,” Newkirk said in a release.
On Wednesday, the Kitsap County Health District lifted the 10-day no-contact order for Eagle Harbor and surrounding waters from Yeomalt Point to Rockaway Beach.
John Kiess, water protection program manager with the health district, said his agency’s initial response would not have been different had the full scope of the spill been known.
“We took a very conservative approach with that ten day advisory,” Kiess said.
The no-contact order was issued on May 31, following the rupture of the sewer pipe in the harbor.
The latest test results from the water samples taken at Waterfront Park on Monday show 10 colony forming units or less of bacteria per 100 mL of water (10 cfu/100mL). Bacteria levels under 70 cfu/100mL are generally considered safe for humans.
The results back up earlier tests released on June 2, which showed little residual bacteria contamination in the harbor.
Shellfish harvesting along much of Bainbridge Island’s shores is still closed due to high levels of PSP, which are not related to the sewage spill.
Even given the new volume estimates, Kiess said it’s not surprising that tests showed low contamination. The conditions surrounding the spill were more important than the amount of sewage released, he said.
The leak occurred near the mouth of the harbor where there is relatively good water circulation. If the spill had been at the head of the bay, where the harbor flushes very slowly, it would have been a much greater concern, Kiess said.
The health district considered several other factors, including weather conditions, to calculate its response.
It’s still unclear whether the city will be fined by the state for violating clean water regulations.
Larry Altose, a spokesperson for the state Department of Ecology, said that no decision had been made on fines, but the incident was still under review.
– Tad Sooter, Sean Roach
