Pima County Logo
  • Increase font size
  • Decrease font size
  • Print
  • RSS
  • Converting biogas to save money and go green: It’s not just hot air

    Feb 04, 2014 | Read More News
    Share this page
    You probably don’t spend a lot of time thinking about byproducts produced during the treatment of wastewater.none

    But the Pima County Board of Supervisors is now moving toward converting a waste product left over from the treatment of sludge and turning it into a beneficial, natural gas-like commodity that can generate revenue for the County while improving the environment.

    The Board of Supervisors Tuesday authorized the Regional Wastewater Reclamation Department to enter into negotiations with Anaergia Inc. and Grannus Biogas to construct, own and operate a biogas facility adjacent to the Tres Rios Water Reclamation Facility, located at 7102 N. Casa Grand Highway.

    No sludge is processed at the Agua Nueva plant, 2947 W. Calle Agua Nueva, so no biogas can be generated there.

    Two big environmental positives will come from converting the biogas, which is composed primarily of methane and carbon dioxide and is currently being burned off in a flare. Those gases contribute to global warming when released directly into the atmosphere. Not only is converting it better for air quality, but it also produces a renewable energy source that can reduce the nation’s dependence on fossil fuel.

    Under the agreement, the County will provide the digester gas that the developer will clean to a natural gas pipeline quality and sell on the open market. The County will collect lease payments on the land and will be paid a commission on gross sales, with revenues used to offset a portion of the plant operations and management costs. The contract will be for 15 years, with the option of one five-year extension.

    “The County has been very successful in leveraging the ingenuity of the private sector through several public-private partnerships,” said Pima County Administrator Chuck Huckelberry. “This particular project has the advantage of not only benefiting Pima County ratepayers, but also making sure we’re doing our part to address concerns over global climate change and its effect on human health and the environment.”

    The Regional Wastewater Reclamation Department anticipates that the biogas facility will be in operation by the end of 2015.