An estimated 4,000 to 7,000 gallons of diesel leaked from the Jarvis Street Diesel Plant, with some portion of it reaching Sitka Sound, though it's not yet clear how much. (KCAW graphic)

An estimated 4,000 to 7,000 gallons of diesel leaked from the Jarvis Street Diesel Plant, with some portion of it reaching Sitka Sound, though it’s not yet clear how much. (KCAW graphic)

A storage tank at Sitka’s Jarvis Street Diesel Plant failed over the weekend (8-15-15), spilling an estimated 4,000 to 7,000 gallons of diesel into Sitka Sound near the mouth of Indian River.

Teams from the city, state, and Coast Guard are working to contain and clean up the spill — and to find out what caused it.

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As of Sunday night, it wasn’t yet clear exactly how much diesel had actually made it into Sitka Sound.

The Jarvis Street Diesel Plant is owned by the city — it’s Sitka’s backup power station — and City Administrator Mark Gorman said the failed storage tank released about 30,000 gallons of diesel into a cement containment enclosure. Some portion of that — perhaps as much as 7,000 gallons — then leaked into the storm water system, which empties into the ocean at Eagle Beach.

Gorman said that though the release is near the mouth of Indian River, so far there’s no sign of diesel in the river itself, and the spill has been contained to Eagle Beach and the water near Cannon Island.

The Fire Department estimated that about 40 people from the city, the state Department of Environmental Conservation, the Coast Guard, and the National Park Service were on site Sunday, using boom and absorbent material to contain and soak up the spill. Speaking Sunday evening, Gorman said the efforts so far have had a visible impact.

“I was down at the impacted area this evening twice, and you can smell it in the air, but there’s no sheen on the water at this point in time, so it seems to be dispersing pretty rapidly,” Gorman said.

According to a press release from the city, the Fire Department first received a call around 11 a.m. Saturday (8-15-15) reporting a heavy smell of diesel near Eagle Beach. Assistant Fire Chief Al Stevens says the department found a small patch of diesel in the water, but couldn’t locate its source. He says responders thought it had perhaps come from a fishing vessel in the area, and contacted both the state and Coast Guard.

The city then received a second call on Sunday, reporting a sheen on the water near Cannon Island. This time, the Fire Department traced the spill to a storm drain on Sawmill Creek Road, and eventually followed it back to the Jarvis Street Diesel Plant.

Around 1 p.m. Sunday, The Fire Department initiated its Incident Command System, marshalling resources from the city, state, Coast Guard, and National Park Service. Stevens says the leak was stopped around 3:30 p.m. Sunday, and teams worked throughout the afternoon to mop up the spill. “It certainly is a big deal,” he said.

But Gorman added that diesel is much easier to clean up than, say, crude oil.

“Diesel is not [crude] oil,” Gorman said. “If this was an oil spill, I think the 7,000 gallons going into the Sound would be alarming. It’s not good to have diesel going into the sound, but diesel does evaporate and dissipate quite rapidly.”

It’s not yet clear why the tank failed, or how the diesel leaked out of the containment enclosure. The city, state and Coast Guard are all involved in that investigation.