Lawmakers consider on-farm treatment of sewage sludge
SALEM — Sewage sludge already serves as fertilizer on Oregon farms but a proposed bill would also permit processing the waste within farm zones.
It's common for biosolids, also called human manure, to be treated at wastewater plants then applied to fields that aren't producing crops meant for human consumption.
Wayne Buma, who operates AAA Advanced Septic Cleaning in Southern Oregon, wanted to use waste from septic tanks in the same way but ran into troubles with Jackson County's government.
The county's objection wasn't based on sanitary issues, but rather Oregon's land use laws: It wasn't clear that sewage treatment is allowed on land zoned for "exclusive farm use."
"There is nothing new going on as far as the safety. All that has been approved," Buma told members of the House Agriculture Committee at a March 2 hearing.
Under House Bill 2179, the statute would clarify that on-farm biosolids treatment is allowed in farm zones as long as it's conducted with mobile units.
If on-farm biosolids treatment isn't allowed, Buma said he'd have to separately process the waste at the location of each septic tank, rather than collectively treat the material in a large tank at the site of application.
"Right now, it's bottle-necked," he said.
The treatment process described by Buma, which is permitted by Oregon's Department of Environmental Quality, is fairly straightforward.
Biosolids are filtered to remove plastic and other debris, then agriculture lime is mixed with the waste to make it alkaline and kill pathogens. The sterilized biosolids are then spread across a field with truck.
"It's a stable product, it's not a haz-mat material," Buma said of the lime that's integral to the process.
Legislators seemed amenable to HB 2179, with the committee's chair, Brian Clem, D-Salem, actually testifying in favor of the bill as a "no-brainer."
While Oregon's land use laws generally confine processing activities within "urban growth boundaries," that often involves increasing the "truck miles" required to transport materials, Clem said.
In this case, there is no construction of a permanent facility that would taken farmland out of production, he said.
"If it's not displacing farmland, I think it's good to have processing as close to the source of the material as possible," Clem said.