Provost & Pritchard has been working with Calgren on fighting air pollution by achieving a generation of renewable natural gas. Provost & Pritchard provided civil design services for a dairy digester at Schott Dairy for Calgren Dairy Fuels.

Site modifications included intercepting the flush water before the settling basins, pumping this water up to new manure screen separation and then gravity flowing over a sand settling lane before entering the new double HDPE lined digester pond.  After digestion the water is returned to the settling basins which then leads to the storage pond. Design services included replacing the flush gravity drain lines at the freestalls, pressure and gravity water transfer lines, concrete pits, sand lane, area grading, and the double lined pond.  We also provided liner construction quality assurance oversight and prepared the report to the Regional Water Quality Control Board (RWQCB) ensuring that the pond was constructed as designed and there will be no leakage to groundwater.