Construction Value
The Project
RK&K provided planning through construction phase services to implement the most cost effective, reliable, and proven approach to transform Harrisonburg-Rockingham Regional Sewer Authority’s (HRRSA) North River Wastewater Treatment Facility biosolids from Class B to Class A exceptional quality for beneficial reuse. RK&K worked closely with HRRSA to develop a sustainable biosolids management program that included:
- Thermal drying to produce dried granular product, increase storage capacity, and reduce hauling costs
- Biogas utilization, heat recovery, and increased co-digestion of poultry dissolved air flotation solids
- Market analysis to reuse the new Class A product as a soil amendment
The design was completed in four months to secure funding through the Virginia Clean Water Revolving Loan Fund program. The project included a new screw press dewatering system, cake conveyance system, biosolids dryer system in a new building, heat recovery system, and biogas handling upgrades. The screw press had a capacity of 1,000 dry lbs. per hour. The dryer system was pre-selected through an evaluated bid. The indirect paddle dryer has a design evaporative capacity of 4,100 lbs. of water per hour. Site constraints dictated that the new dryer building be located underneath of an existing biosolids storage pavilion. The dryer system was commissioned in 2019 and has been operating 24 hours every day with only three-four days of downtime per month for maintenance. To date, HRRSA is drying all of its dewatered cake with biogas and has not required supplemental propane. The project was a gold medal winner in Virginia’s 2020 Governor’s Environmental Excellence Awards competition.
