Stellar J built two concrete digesters and support facilities for the City of Portland, Oregon.  Work included forming and placing 11,000 cubic yards of concrete, with 500,000 pounds of rebar, and included free span concrete roofs weighing 5,500,000 pounds each. Support facilities included a filter room, an office, a laboratory, a soda ash room, new electrical and controls, HVAC, and mechanical systems needed to produce and deliver biogas to produce electricity, heat and renewable natural gas.