Winner – Sustainable

OCEP Siemers LLC – Renewable Natural Gas Digester

Location: Newton
Owner: Siemers Holsteins INC.
Concrete Supplier: Carew Concrete & Supply Co., Inc.
Technology Provider: BIOFerm
Engineer: Applied Technologies, Inc.
Contractor:  JP TANK INC.

The Siemer’s Farm decided to build 100% carbon neutral. The over 5000 herd of cows operation is on its way to being completely self-sustainable and is one of the first farms in Wisconsin to achieve this goal.

The two tanks were constructed with concrete except for the rubber membrane roof.  The gas created in the digesters keeps the rubber roof freely inflated.  The 765-yard foundation slabs were poured 24 inches thick. These bases were poured with a 5000 air entrained plus super plasticizer and 3% Xypex in the mix to waterproof the concrete.

The concrete poured on the site was a 5,000-psi NRCS mix. It was pumped into place with 26-foot high walls and a tank diameter of 96 feet. The total amount of concrete on the job was 1,570 yards.

In the last two years, the contractor has built 8 digesters at farms throughout Wisconsin. The demand is huge for this sustainable energy. They are looking to build 13 additional digesters in 2023.