Minnesota has been a maverick in that it did not adopt the federal hazardous waste exemption for chromated copper arsenate (CCA)-treated wood. Treated wood is classified as an industrial solid waste and must go into municipal solid waste (MSW) landfills, says Duane Duncanson, pollution control specialist with the Minnesota Pollution Control Agency, St. Paul.
“For the most part, I believe landfills are following this rule, and they’re doing their best to separate the waste,” Duncanson says. “But we do have a lot of incineration in the state as well, and if the average consumer puts treated wood from a house project into the trash, it could wind up in an MSW landfill or get burnt at a waste-to-energy (WTE) facility.”
Additionally, while state hazardous waste rules say all industrial waste, including treated wood, must be evaluated prior to disposal, Duncanson says this is not happening 100 percent of the time. “If every generator evaluated treated wood before disposal, this could add millions of dollars to disposal costs. Consequently, the state of Minnesota has not been enforcing what the rules say about treated wood.”
For the past several years, Duncanson says the state has been collecting information and analyzing studies — particularly the Florida research — with the hopes of making a concrete decision about whether the evaluation is necessary or not.
“We’re trying to address the evaluation issue where we’ll either change our rules so generators can legally not evaluate their loads,” Duncanson says, “or we’ll leave the evaluation rule in place and enforce it.” Minnesota also is watching Florida to determine the effects of burying the wood in MSW landfills or incinerating it, and to identify any beneficial reuse projects, Duncanson says.