Concrete torched in Sonoma County fires being recycled for roadbeds
Marta May lives in Bloomfield and is used to seeing trucks coming and going from the Stony Point Rock Quarry west of Cotati.
But never has she seen anything like the procession of heavy-duty dump trucks recently waiting to deliver their seemingly endless loads of rubble to the facility.
“There’s millions of them,” May said after passing the long line of trucks along Stony Point Road late last month.
Equally amazing is what they are leaving behind: a mountain of concrete chunks 30 feet high, the remains of hundreds of driveways and foundations cleared from some of the 5,100 residential properties in Sonoma County destroyed in October’s fires.
“It’s huge and it keeps getting bigger, and you wonder how much bigger that it can get,” May said.
The activity around the quarry is just one more reminder of the unprecedented scale of the fires, which scorched 137 square miles in Sonoma County, killed 24 people, and triggered the largest wildfire cleanup in the state history.
While tens of thousands of tons of ash and debris from destroyed homes is being deposited into the Sonoma County landfill, raising concerns about its future capacity, by contrast the concrete heading into the quarry will be recycled, said Mark Soiland, president of the Soiland Company, which owns the quarry.
Until recently, the quarry was receiving about 300 truckloads per day of concrete from contractors clearing home sites under the management of the U.S. Army Corps of Engineers, Soiland said.
By late last week, 234,000 tons of debris had been removed from 923 properties in Coffey Park, Fountaingrove and Larkfield-Wikiup by contractors working for the Corps.
The Corps estimates about a million tons ultimately will be cleared from burned out properties, much of it heading to landfills, while the balance - mostly concrete, metal and wood - can be salvaged and recycled.
The concrete heading to the Stony Point Road quarry will have its rebar removed before being ground into ¾-inch chunks and sold as road base, mostly for building projects in Sonoma County. Building activity is particularly brisk in Rohnert Park and Petaluma, Soiland said.
The demand for that product is strong, but at the moment the supply far exceeds the demand or the quarry’s capacity to process it, Soiland said. So in the meantime, it’s being stockpiled. After stripping out the rebar, excavators and front loaders are stacking the chunks into towering piles of broken concrete.
“We flew a drone over it recently and estimate that we have 41,000 tons in here,” Soiland said.
The quarry has plenty of additional capacity, and Soiland expects a significant percentage of the total concrete from the cleanup to pass through his facility. The amount already is enough, he said, to supply its customers’ anticipated road base needs for about three years.
The material is considered clean and there are no restrictions on its reuse, according to the Corps. Tests for asbestos have all come back negative, said Patrick Bloodgood, a Corps spokesman.
Part of the reason for the huge queue outside the Stony Point Road facility were rains last month that briefly halted some of the work by contractors, creating a backlog of material they needed to get through, Soiland said.
Another reason is the Corps, because it’s footing the bill, requires its own officials to be on site monitoring and manually tracking the intake of the material, Soiland said, a process that takes extra time.
“Each transaction has double the effort,” he said.
Many of trucks are not even full, Soiland said, because the cleanup crews haven’t been able to clear multiple sites at once. That process is expected to get more efficient as it continues, he said.
Soiland charges a few dollars a ton to dump the material at the site, and then sells it after it’s ground up for about $8 per ton. But the operating costs are huge, he said. He spent an extra $35,000 on fuel for equipment alone in the first weeks, he said.
The volume of trucks to Stony Point has tapered off as one of the contractors doing the first phase of the Corps cleanup, ECC, winds down its work. Private contractors continue to bring a significant volume of material to the quarry, he said.
A large volume is also going to a property in Windsor operated by Pacific Recycling Solutions, a sister company to C&S Waste Solutions, the Ukiah company that bid unsuccessfully for Windsor’s garbage contract.
Concrete and metal is being stockpiled on about 5 acres of the 30-acre industrial site, home of the former Standard Structures, said Kristyn Byrne, company spokeswoman.
At present the company doesn’t have a way to crush the concrete into the road base product that will be needed, but it’s exploring how to do that, perhaps through a partnership, when the material is most needed during the spring construction seasons, Byrne said.
“What we agree to do is take it,” she said. “What happens next is still undetermined.”