Harrison Bay State Park Sewer System


After decades of service, the Harrison Bay State Park sewage system was eventually faced with:

  • Inadequacy of the existing packaged treatment plant to handle increases in flows and loads.
  • Deterioration and failure of pumping equipment due to age and wear and tear.
  • Inability to meet increasingly stringent regulatory requirements.

The old wastewater collection system in the park consisted of a network of gravity sewers, constructed of vitrified clay.  There were also two sewage pump stations of the dry pit-wetwell underground canned variety.  Both of these pump stations were at the end of their service life and experienced frequent mechanical and electrical outages. This resulted in overflows directly into Chickamauga Lake near public recreation areas. Operating personnel were very reluctant to enter the stations due to their condition. Regulatory violations were inevitable.


CTI’s analysis showed that conveyance for off-site treatment was more cost-effective than other alternatives. CTI assisted park administration in obtaining permission from the Hamilton County Water and Wastewater Treatment Authority (WWTA) to connect to its system, which now conveys wastewater from the park to the City of Chattanooga’s Moccasin Bend Regional Wastewater Treatment Plant.

In a unique arrangement, the State of Tennessee provided funds to the WWTA in the form of a 100 percent grant.  These funds were used to replace the sewerage system within the park and connect to an existing force main on nearby State Highway 58.


Off-site sewers:

  • Duplex 135-gpm submersible pump station, appurtenances, site, and electrical work.
  • 7,400 LF of 4-inch PVC force main and connection to existing force main.

On-site improvements:

  • Simplex grinder pump installation at 10 sites.
  • Multiple pump installation at 7 sites.
  • 13,900 LF of 1.5- through 4-inch PVC low-pressure force main with appurtenances and electrical connections.


  • Computer hydraulic model
  • Master planning
  • Design, bidding, construction phase services
  • Permitting assistance (TDOT, storm water)
  • Grant administration assistance
Project Description

For many years the treatment plant and collection system served Harrison Bay State Park well. However, the plant was not designed to keep up with the increasing flows and loads generated by the camping and day use activities at this popular park.

Project Details
  • Client: State of Tennessee