OLYMPIA — Two Democrats in the Washington Senate introduced a bill Monday to refund cap-and-trade fuel surcharges to farmers and haulers of agricultural products.

Sen. Mark Mullet, D-Issaquah, said lawmakers promised cap-and-trade would not raise fuel prices for agriculture, but the Department of Ecology failed to keep the promise.

“They basically screwed it up,” he said. “We’re only running a bill to make Ecology do what they’re supposed to be doing.”

Cap-and-trade puts a fee on the consumption of fuels. Lawmakers exempted fuels used to grow and transport farm goods and directed Ecology to find a way to do it.

Ecology blames oil companies for misapplying the law. The oil industry faults Ecology for not writing rules to exempt the fuels.

Mullet said Ecology has passed the buck. “I met with Ecology the first week of session and asked, ‘What’s the plan?’ They didn’t plan to do anything,” he said.

“They’re doing everything they can to kill the bill,” Mullet said.

Ecology did not respond to a request for comment.

Senate and House Republicans previously introduced bills to provide refunds. The new bill enjoys sponsorship by majority Democrats.

Senate Environment and Energy Committee Chairman Joe Nguyen of Seattle co-sponsored the bill with Mullet.

“It was always our intention to exempt (farmers’) fuel … and this legislation affirms our commitment to them as we transition into a cleaner, greener economy,” Nguyen said in a statement.

Mullet’s and Nguyen’s legislation, Senate Bill 5766, directs Ecology to start taking applications for refunds by Jan. 1.

“I wish it was faster,” Mullet said. “They (Ecology) felt they were being pushed to do it by January. I don’t think they want to do anything.”

Farmers and haulers would have to document they bought fuel for agricultural uses. The bill calls for setting aside $50 million in cap-and-trade auction proceeds for refunds.

Refunds would be based on the current price of allowances sold at auctions. Every dollar would translate into a 0.8 cent a gallon.

Allowances sold for $48.50 at the first cap-and-trade auction in February. The reimbursement rate would be 38.8 cents a gallon if the bill were in effect today.

The bill also would forbid fuel suppliers or distributors from listing cap-and-trade surcharges on invoices. Mullet said the provision may need work. The idea is to create a standard formula to calculate refunds, he said.

Cap-and-trade taxes fuel consumption, but not in a transparent way. Ecology raised more than $299 million at the first cap-and-trade auction, but it’s unclear how much consumers will pay.

When lawmakers adopted cap-and-trade in 2021, they told Ecology to determine a method for exempting farm fuels from the tax.

The Mullet-Nguyen bill calls for setting up a work group to help Ecology figure out how to do it.