Owner: The City of Johnson City, Tennessee
Engineer: Smith Seckman Reid; Nashville, Tennessee
Contract Amount: $23.7 million
Year Completed: 2010
The Johnson City Regional Wastewater Treatment Plant was a difficult and complex project due to many site constraints. The project was phased in three stages.
The major civil elements of the project included: Drill, shoot and dispose of more than 125,000 cubic yards of rock; place more than 275,000 square feet of formed surface, pour and finish approximately 13,200 cubic yards of concrete, and furnish and install over 9,000 feet of DI and RCP pipe in sizes 4" through 48".
The major process elements of the project included headworks with two (2) rotary drum screens, an aerated grit and grease system with classifier and washer, two (2) oxidation ditches with 23 feet side water depth, one (1) 125 feet diameter, center feed final clarifier, construction of a three (3) cell deep bed tertiary filter, ultraviolet disinfection, step aerator for post aeration of effluent.
This project also included coarse bubble aeration for sludge holding, sludge dewatering for the waste activated sludge, on-site and off-site SCADA system that monitors and controls the treatment process and pump station in the collection system's seventeen (17) locations.
When the Owner opened bids for this project, W. Rogers Company was low with a bid of $27,413,000. This exceeded the Owners budget and after several Value Engineering proposals were introduced and considered, a change order was executed shortly after Contract award which reduced the project value by $3,711,462.