GRW provided planning, design, bidding, permitting, and construction phase services to expand TriCo's water resource recovery facility (WRRF) from 3.05/15.3 MGD to 5.72/23.0 MGD average/peak flows. The existing treatment plant has gone through numerous expansions or upgrades, approximately every 3-4 years, since its original 0.35 MGD capacity in 1991. The moderate growth in the service area necessitated another expansion to meet system demands to Year 2030 and beyond. GRW worked closely with TriCo staff to complete the project which included design for the following major upgrades:
- New mechanical fine screens (perforated plate)
- New “Headcell” stacked-tray grit removal tanks and grit washing/classification
- Upgrade existing vertical loop reactors (4 tanks)
- Add new vertical loop reactor tanks (4 tanks)
- Biological phosphorus removal and total nitrogen removal treatment
- Blower aeration upgrades
- Add (3) 70’ diameter final clarifiers
- Demolition of existing (3) 40’ diameter clarifiers
- Add additional RAS/WAS pumping
- Ultraviolet disinfection system upgrades
- New non-potable water pump station
- Post aeration upgrades
- New 2,000 kW emergency generator
- SCADA system upgrades
- Stormwater treatment system
TriCo Regional Sewer Utility, headquartered in Zionsville, IN, serves more than 13,000 customers in the west half of Clay Township (Hamilton County), eastern edge of Zionsville (Boone County), and northwest edge of Indianapolis (Marion County). Since 2012, GRW has worked with TriCo to complete a variety of wastewater studies, sewer system designs, lift station, interceptor and forcemain improvement projects.