Nestled in the Great Smoky Mountains, Pigeon Forge, TN receives approximately 10 million visitors annually and is looking to expand its tourism with future growth and development.  With a daily population that can vary from 6,000 permanent residents to 50,000 residents and visitors, such widely varying flows can wreak havoc on treatment processes that function best under steady state conditions. The City needed a treatment process that could absorb these fluctuations while minimizing reductions in treatment. To accommodate the fluctuation in visitors each season, as well as the permanent residents, the City recognized the existing water treatment plant had reached capacity and would need to be expanded. The new wastewater treatment plant is able to process six million gallons per day, which meets the City’s current needs and will accommodate their future growth.

The new wastewater treatment plant also serves the community as an educational tool for local students, exposing them to the importance of wastewater treatment and the means by which it’s done.

With impending permit limitations changing, the project was expedited to ensure completion within the existing specifications imposed by TDEC. SSR designed sequencing batch reactors to provide plant operators a high degree of flexibility to treat very low nutrient levels, even at varying influent flows. To meet this challenge, SSR designed biological nutrient removal (BNS) into the sequencing batch reactors to enable the system to remove nutrients to low levels. This system was the most cost-effective way to reduce nutrients. A chemical feed system was also designed for low levels of phosphorus removal to ensure the City’s needs were met. In addition, the high quality effluent from the plant will improve the health of the receiving stream that is used recreationally by both residents and visitors.

Located in close proximity to the surrounding community, issues such as odor control and architectural features became important project requirements. SSR worked closely with the project team incorporate innovative odor control measures and architectural features to help this facility blend seamlessly into its surroundings. For example, odor control systems were provided at the influent pump station and headworks building, both of which have potential generate odors. In addition, SSR designed a pre-thickened aerobic digestion system utilizing membrane thickeners. This innovative aerobic process minimizes the potential of offensive odors being generated during the digestion process, while also providing better digestion in a smaller footprint.