What happened on the creek?
The timeline and severity of an oil spill into Big Chico Creek are under scrutiny following an equipment malfunction at a Caltrans project site
People hoping to cool off in Sycamore Pool in Lower Bidwell Park’s One-Mile Recreation Area in the late afternoon of Tuesday, Sept. 27, were met by signs reading “Pool closed—Stay out.”
The next day, at 4:30 p.m., an oily sheen was still visible on the surface of the creek upstream, under Highway 99 next to the footbridge. This is where hydraulic fluid—purported to be approximately 1 gallon of the stuff—was spilled from a Caterpillar excavator used to drive in sheet piles as part of the recently launched Caltrans upgrade of Highway 99.
Barriers of booms and straw wattles also were visible here, as were six metal drums labeled “nonhazardous waste” and countless baby-wipes-like sheets laid on the water’s surface to soak up the petroleum-based fluid that hit the water after the excavator—run by Rancho Cordova-based Viking Construction Co. Inc.—reportedly malfunctioned.
“It looks like more than a gallon,” said Chico resident Joanne Skeen, shaking her head as she stood on the bridge last Wednesday afternoon watching small patches of fluid slipping past containment devices and floating downstream.
The pool reopened on Friday, Sept. 30, after the city and Butte County Environmental Health determined that water conditions were safe. However, proper protocols for dealing with the spill apparently were not followed, and the amount of fluid and time of the spill are questionable.
“I got the call just after 4 o’clock on Tuesday,” said Dan Efseaff, the city of Chico’s parks and natural resources manager. “We heard that the incident happened just before 3 [p.m.].”
Efseaff said Denice Britton, the city’s urban-forest manager, received a call from Caltrans that “a small amount of fluid” had spilled onto the creek’s bank and into the creek. “She called me after she got word, so it was at least an hour before we heard anything about it.”
John P. Quiggle, Viking’s project manager, explained that one of the lines on the vibrating hammer attached to the excavator sprang a leak. The leak was noticed, Quiggle said, “when the water started collecting the oil—10 to 12 seconds after the spill.” He said the excavator was shut off “immediately.” He placed the time of the accident at “about 3:30 p.m. on Tuesday.”
But at least one park user says the spill happened much earlier.
“The timeline that the city gave for the spill is wrong,” said Anna Marie Cooper, who has lived in Chico since 1975 and walks in the park every morning.
Cooper said she called the city before 9:30 a.m. on Tuesday (Sept. 27) and spoke with “a woman named Betty” to report a “rainbow sheen” of oil floating on the surface of Sycamore Pool.
According to an email from city administrative analyst Annalisa Dillard, Betty Brown, an office assistant in the Finance Department, “received a call while she was working in the Building Dept. on Sept. 27th between 8:30 and 9:30. The caller wanted to report an oil spill at One-Mile Pool located on the right hand side of the new restroom. … Betty transferred the caller directly to the General Services Department.”
Cooper disputes that, saying she simply left a message with Brown reporting the spill.
As for the gallon said to have been spilled, Cooper responded, “That’s a joke.”
On Sept. 29, two days after the spill, she again saw oil floating in Sycamore Pool, “so obviously that means that it had not been contained.” The next day, Cooper says she saw a dead mouse floating in the water.
It also appears that the response to the spill, once it was noticed, was not adequate.
Caltrans called out a hazardous-materials cleanup team from the Chico unit of Seattle-based NRC Environmental Services, which “came out onsite just after 5 on Tuesday,” said Efseaff.
But that did not fit protocol. Instead of calling Britton and NRC, Efseaff said, Caltrans should have called the Chico Fire Department first, then the city’s General Services Department, then the California Emergency Management Agency, “to activate the [response] system.”
According to the material-safety data sheet provided to Efseaff, the fluid—an Exxon Mobil product called Cat HYDO Advanced 10—contains zinc dithiophosphate. “Excessive exposure may result in eye, skin or respiratory irritation,” advises the data sheet. Chemical-trading website Guidechem.com describes zinc dithiophosphate as being “moderately toxic by ingestion.” As for containment in case of a spill in water, the data sheet states: “Confine the spill immediately with booms.”
Since Viking’s measures to contain the spill—wattles and absorbent sweep (the name for the “baby-wipes” sheets)—were focused on the pile-driving site, Efseaff “suggested to Caltrans that they establish containment at the One-Mile dam and just above Sycamore Pool.” Viking had no booms—which absorb oil but not water, unlike wattles, which absorb both and thus can sink below the surface—on hand.
As for the amount of hydraulic fluid spilled from the machine, which holds “approximately 50 gallons,” Viking’s Quiggle said it was “hard to call. We were guessing it was about a gallon.”
The excavator has since been switched over to a “vegetable bio-oil” hydraulic fluid, called Cat Bio HYDO Advanced, he said.
“We had it hauled down to Peterson Tractor [in south Chico] and they flushed the whole hydraulic system and ran 50 gallons of bio-hydraulic oil to get rid of anything, then added 50 more gallons of bio-oil,” Quiggle said.
“In 35 years [of working in construction], this is the first time I’ve seen anything like this happening,” he said. “It was horrible. … If this happened again, we have oil-absorbent booms on site now, and plenty of sweep. … We weren’t equipped for having that type of thing happen in water.”