Melton Hill Wastewater Treatment Plant Outfall Line

West Knox Utility District outgrew its previous 4 million gallon per day (MGD) wastewater treatment plant and was in need of an upgrade. In support of upgrading their facility to 6 MGD, Garney was hired to install more than 6,000 linear feet (LF) of 24-inch restrained joint ductile iron treated effluent pipeline.

Of the 6,225 LF of 24-inch pipeline, 3,250 LF was installed subaqueously out to the main channel of the Clinch River, where the diffuser was installed 60 feet deep. The pipe was installed in a drilled and shot trench with a minimum of three feet of cover on continuous grade across the bottom of the lake out to the main channel of the Clinch River. The scope included a 50-foot-long diffuser with six 10-inch duck bill valves installed on concrete supports anchored into rock in the main channel. 

In addition to the subaqueous marine installation, the project included a 600 LF hard rock directional drill under a creek using restrained joint ductile iron pipe.

The project team coordinated with many different agencies throughout the project, including the US Army Corps of Engineers, US Coast Guard, Tennessee Valley Authority (TVA), Tennessee Department of Environmental Conservation, Tennessee Wildlife Resources Agency, and local county agencies. 

By self-performing the marine work, including the diving, the team was able to completely control the quality and schedule of the project, completing it ahead of schedule and $580,000 under the original contract amount due to value engineering.