Crew members clean equipment used in the Refugio oil spill response at a decontamination station in Ventura on Sunday. Crew members wear safety equipment to protect from hazardous materials and to prevent contaminants from leaving the decontamination zone. (Jonathan Klingenberg photo / U.S. Coast Guard)

As less oil is found on the water off the coast of southern Santa Barbara County — and more spill response vessels come out of it — cleanup crews are increasing efforts to decontaminate those boats at special stations in Ventura.

The number of booming boats decreased from eight to three Tuesday because spill response teams haven’t found oil on the water since last Wednesday, according to incident command for the May 19 Refugio oil spill.

Shoreline teams are continuing to clean oil from sand and rocks and have surveyed nearly 100 miles of coastline.

Three vessels, which will remain at sea until all cleanup operations are finished, are down from the 21 that kicked off efforts, recovering approximately 14,267 total gallons of oily water mix, incident command reported.

Boats exposed to oil have been traveling down to one of two Ventura decontamination stations — one on land and one in the water — and Santa Barbara Harbor received one request to handle decontamination locally.

Harbor operations manager Mick Kronman told Noozhawk the harbor hasn’t yet been able to handle decontaminating a boat, mostly due to space limitations on the launch ramp and concerns over whether oily contaminants could somehow flow into storm drains or back into the ocean.

A small 28-foot catamaran from the National Oceanic and Atmospheric Administration (NOAA) asked about a cleaning in Santa Barbara, but Kronman was hesitant to oblige.

“We haven’t decontaminated any boats in Santa Barbara Harbor, nor (do we) expect to,” he said. “This would all be on the contractor and those responsible for cleanup effort.”

Cleanup crews pressure-wash vessels that assisted in Refugio oil spill response near Santa Barbara. (Jonathan Klingenberg photo / U.S. Coast Guard)

Crew members wearing hazardous material safety equipment clean larger boats at a decontamination site at Port Hueneme south of Ventura in a process that involves removing debris, support equipment, skimmers and boom and cleaning oil pressure tanks, etc., said Petty Officer Kelly Parker in the command post’s joint information center.

Smaller vessels go to the Ventura Harbor Boatyard, where they are hoisted out of the water into a decontamination area on land for exterior and interior cleaning with high-pressure water and applied heat, as well as cleaning agents via rags, Parker said.

All contaminants are collected for disposal — vacuum trucks put leftover water into holding tanks — and the vessels can go back into the ocean after cleanliness has been verified by a unified command representative, a head of operations and the boat owner.

No specific timeframe is associated with the process, Parker said, noting Plains All American Pipeline, the oil company responsible for the spill, hires all decontamination contractors.

“None of the water is getting on to the land or back into the water itself,” he said.

So far, 17 vessels have gone through the decontamination process in the last two weeks.

Noozhawk staff writer Gina Potthoff can be reached at gpotthoff@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.