Biosolids Management Master Plan and Facility Upgrades

City of Provo, 
Utah

Biosolids Management Master Plan and Facility Upgrades

Service Type: 
Project Highlights: 
  • Beneficial reuse options focusing on full use of Provo’s biosolids in a composting program.
  • Digester-mixing improvements.
  • Design of a centrifuge dewatering facility.
Provo’s compost facility
Carollo has completed a biosolids master plan and recommended equipment for expansion of Provo’s compost facility.

Provo City selected Carollo to complete a biosolids master plan with beneficial reuse options focusing on full use of Provo’s biosolids in a composting program. The master plan study included evaluating digestermixing improvements and biosolids dewatering alternatives.

Composting alternatives included developing physical siting and layout of the composting facility and determining the quantity of bulking agent required to fully utilize Provo’s biosolids. The study team projected revenues from the composting operation and determined capital and operations and maintenance (O&M) costs.

Digester mixing alternatives included pump mixing, mechanical draft tubes, and various gas mixing options. The team prepared capital and O&M cost estimates for each alternative. Rehabilitating the existing gasmixing system provided the least expensive alternative. Rehabilitation included replacing the existing reciprocating compressors with stainless steel liquid ring compressors and providing stainless steel gas piping.

Following an evaluation of biosolids dewatering options, the team selected centrifuges based on project capital and O&M costs and other non-economic considerations. Carollo provided design and construction management services for the new dewatering facility and digester mixing improvements. Carollo prepared a prepurchase specification with an evaluated bid for competitive procurement of the centrifuge. Carollo also designed a new dewatering building which included an elevated centrifuge platform, polymer feed facilities, shaftless screw conveyors for dewatered cake transport, and an enclosed truck loading bay with a cake storage hopper.