Naval Base Kitsap-Bremerton's public works department has discovered yet another sewage spill that leaked an estimated 450,000 gallons of wastewater from Puget Sound Naval Shipyard into Sinclair Inlet during a two-year period.
That breaks down to about 540 gallons each day.
The Navy became aware of a potential sewage spill Wednesday morning, after a monthly water testing sample indicated a spike above normal levels for bacteria, said Cmdr. Ben Leppard, public works officer for Naval Base Kitsap.
Further water testing and investigation pinpointed the source of the spill to two temporary trailers that were constructed on top of a multi-story building at Puget Sound Naval Shipyard in May 2016.
The pipes for the bathroom facilities, one in each trailer, were improperly connected to a stormwater system rather than the wastewater system, from where the sewage flowed through the underground pipes to an outfall and into Sinclair Inlet, Leppard said.
"There was volume coming from sinks, urinals and toilets, so that was the source," Leppard said.
Temporary facilities like that are commonplace at the shipyard, however most are just office space and don't contain bathroom facilities that require hookups to the shipyard's sewage system.
This particular sewage spill had gone undetected during the past two years because there weren't any obvious signs that pointed toward a problem, such as an odor emanating from the area.
"For two years, people were walking past and nobody smelled it, it didn't emanate, which I think is because the spill volume was what it was," Leppard said.
The estimated 450,000 gallon spill volume is the high end of the public works department's spill volume estimate, since usage of the trailers fluctuated.
"There's a little bit higher personnel loading in those trailers this summer as compared to other periods of time, so I would expect that if anything, it would be less than the number we've provided," Leppard said.
Health officials believe the spill doesn't pose a risk to public health, said John Kiess, environmental health director for Kitsap Public Health District.
"The impact of the spill is negligible at best because monitoring didn't even pick up bacteria level," Kiess said. "We don't believe there's been any public exposure to sewage."
Changes in reporting
After the last reported sewage spill, the Navy instituted some "enhanced testing protocols," that allows base officials to respond to a potential problem in a faster time frame.
"With this spill, and the last one, and the last one, it's an opportunity for continuous process improvement, and that's what led us to change our process last month," Leppard said. "It honestly allowed us to identify this in a matter of days, compared to what could've been a month or two more."
As soon as the sample came back with the result that indicated a problem, public works started trying to track down the source of the potential spill through the 30 miles of underground pipes on base rather than waiting for another month of testing to confirm that it might be occurring, as had been the procedure in the past.
"We did an immediate sample at that location again and we took a sample within our infrastructure at the nearest point upstream that's not tidally influenced, so what basically would be an accurate representation of our system as opposed to the interaction with the tides," Leppard said.
By the next morning, Leppard said they were able to conclusively trace the spill back to the two trailers in question.
"That's our standard. We're going to chase these," Leppard said. "At the end of the day, we are partners in this community, we live here too. We're going to make sure we do everything we can to maintain our standard of zero."
With the discovery of this most recent spill, the Navy plans to revisit all of the building and trailers that have been put in place on base within the past ten years to get "a full confirmation that things are going where they're supposed to be, such as the wastewater system is going into the wastewater system," Leppard said.