Residuals & Solid Waste > Project Case Study

Biosolids Compost Facility Evaluation

The Town has owned and operated a 15-bay agitated bin compost facility since 1994. The facility processes approximately 11,500 wet tons of municipal wastewater sludge from Merrimack and three other New Hampshire communities. 

While the debt service on the existing facility is not set to retire until 2015, corrosion of the facility from process air has started to take its toll on the building systems. In addition, the loss of tipping fee revenue from one community resulted in the need to evaluate facility upgrades as well as evaluate off-site sludge disposal alternatives.

Wright-Pierce conducted a detailed evaluation of all building systems and compiled a list of potential capital improvements necessary to extend the life of the facility. These were compared to the life-cycle costs of abandoning the compost facility and transitioning to off-site disposal. The cost per wet ton and net present value were calculated for each option for the Town's consideration.

The evaluation determined that abandoning the existing compost facility and transporting sludge to a landfill was the most cost efficient disposal plan.

Back To > Solid Waste Engineering Services