Durango Wastewater Treatment Plant Foils Energy Heist And Lowers Maintenance Costs

The Durango wastewater treatment facility is a traditional waste-activated system (WAS). The bio-solids are collected from secondary clarifiers, treated with flocculants and thickened before an anaerobic digestion. A centrifuge had been used for the thickening process which dewatered the WAS to a 8 to 10% consistency. Typical energy draw was in the range of 75 KW which was a big fraction of the plants total usage. Additionally, the centrifuges were requiring more maintenance than ever after 20+ years of operation. The service costs, spare parts and downtime were taking a considerable portion of the maintenance budget as well as operator time. Research was undertaken to determine alternate equipment or methods and a new set of chemical trials found flocculants with tighter solids formation. The Durango WWTP team ultimately decided on a rotary drum thickener to best meet their process needs.