Gremista gas trials

SHETLAND Islands Council has secured £120,000 of funding from Zero Waste Scotland to determine the levels of gas emanating from its Gremista landfill site in Lerwick.

Pumping trials will take place later this year via a number of extraction wells.

If there is enough gas coming from the site’s waste then council may flare it, vent it off or collect it for use in other ways such as to burn in an internal combustion engine.

However, SIC’s environmental services manager William Spence predicts there won’t be much gas on site as a lot of Shetland’s biodegradable waste is disposed of in the incinerator.

The funding is part of a nationwide initiative between Zero Waste Scotland and the Scottish Environment Protection Agency (SEPA) to support projects relating to landfill gas.

Spence said part of the Gremista site’s licence meant that the council needed to determine after a period of time how much gas comes off the landfill.

“I don’t expect us to have much gas, because most of our biodegradable waste is burned in the energy recovery plant,” he said.

“But it still has to be tested, and it was an opportunity for the council to get the funding.”

Between six and ten boreholes with a diameter of 30cm will be created around eight or ten metres below the ground. They will be then fitted with gas extraction wells.

Work will commence before the end of March and the testing will begin in the summer. A report will be presented to Zero Waste Scotland and SEPA by the autumn.

Landfill gas is typically primarily comprised of methane and carbon dioxide, while there are usually also small amounts of nitrogen and oxygen.