Since 2006, a landfill gas-to-energy project at the Ada County landfill has been generating electricity from methane gas — and generating more than $250,000 annually for the county.

The company that owns and operates the engines that convert gas from decomposing landfill materials into electricity on Tuesday filed a $30 million tort claim — a precursor to a lawsuit — against the county alleging breach of contract.

Hidden Hollow Energy LLC and Hidden Hollow Energy 2 LLC, subsidiaries of New York-based Fortistar, said in order to continue generating electricity, the company needs a long-term consistent supply of methane gas, a byproduct of decomposing trash, which the county has agreed to provide.

But in November 2011, the county entered a contract with Dynamis Energy in which the county agreed to deliver at least 408 tons of trash daily — about one-third of the landfill’s daily intake — to be gasified and converted to energy at Dynamis’ waste-to-energy facility. Dynamis has a contract to sell the electricity it generates to Idaho Power.

Hidden Hollow Energy claims the county’s contract with Dynamis conflicts with the county’s prior contract with Hidden Hollow Energy.

The waste diverted to Dynamis “would have generated the landfill gas already promised” to Hidden Hollow Energy,” according to the tort claim filed by Hidden Hollow Energy’s attorney, Stephen R. Thomas.

A tort claim is the first step to suing the county. The county has 90 days to respond to the claim. If there is no response or resolution, then Hidden Hollow Energy can file a lawsuit against the county.

Ada County and Thomas did not respond to requests for comment.

Cynthia Sewell: 377-6428, Twitter: @CynthiaSewell