Kauai County is looking to use methane gas generated by landfills to fuel buses and garbage trucks.

Mayor Bernard Carvalho wants to build the island’s first biogas collection system, and the Kauai County Council approved $5 million in funding for the county to begin construction.

The funding was part of the county budget that will be sent to Carvalho in the first week of June for his approval.

The gas collection system is planned for the Kekaha Landfill.

The goal of the project is to provide biogas to the county’s bus and waste fleet, said Ben Sullivan, Kauai County energy and substainability manager.

"One of the challenges we have always had with our Kauai Bus was we would see increased ridership at the time oil prices would go up. At that same moment we would be in a position where we would have to cut service," Sullivan said. "If oil prices go up, you are going to see a jump in demand for the buses. We saw this project as a way to stabilize that and make fuel more reliable."

Once the collection system is in place, Kauai County will test the quantity and quality of the available gas for six months. After that the county would begin the second phase of the system: cleaning and compressing the gas. The gas would then be used as fuel for county buses.

The buses the county currently uses are not designed for running on methane gas, but the county changes buses every five years and plans to phase in new buses that would run on the biogas.

Sullivan said the collection system was originally proposed to avoid methane emissions due to an Environmental Protection Agency requirement, but the county decided to go one step further.

"We’ve always known we would need to collect the gas from the landfill," Sullivan said. "There is an EPA requirement — once the landfill gets to a certain size, you need to collect the gas. You have to collect it because it is a potent greenhouse gas and you don’t want to let it up in the environment. Our expectations are there is more than enough capacity there to power the entire bus fleet for Kauai."

The county’s buses and garbage trucks use less than 600 gallons of diesel per day. The Kekaha Landfill could produce the equivalent of approximately 1,000 gallons of diesel fuel per day, according to a Renewable Natural Gas Resource Feasibility Study by Cornerstone Environmental released in January.

"Abundant solar energy has allowed the county to generate significant amounts of renewable electricity. Biogas offers a similar potential for homegrown, renewable energy for the transportation sector in the form of compressed natural gas vehicle fuel," the study said.

Kauai County said construction of the collection system will be complete by December 2016.

Mark Glick, administrator of the State Energy Office, said the use of alternative fuels is one of several strategies the energy office is considering to help reduce petroleum consumption in Hawaii’s transportation sector.

Imported oil supplies 90 percent of Hawaii’s energy needs, according to the State Energy Office of the Department of Business, Economic Development and Tourism.

The transportation sector accounts for two-thirds of the state’s energy consumption.

"Our dependence on oil threatens both our economic and energy security. Simply stated, our current way of meeting our energy needs is not sustainable," Glick said.

Sullivan said the gas collection facility will help cut Kauai County’s dependence on oil.

"We feel we have a specific liability with oil on the transportation side and see this as a good first step," Sullivan said.