The city of Chattanooga on Thursday announced that its new wet weather equalization station, consisting of three large storage tanks that can hold up to 30 million gallons of wastewater, has effectively prevented untreated wastewater from overflowing into the Tennessee River during heavy rains since it became fully operational in June.
Officials said, "By protecting the river from contamination by tens of millions of gallons of raw sewage that would otherwise be overflowing into it every year, the new facility is helping preserve one of the region’s most important assets, while also satisfying the terms of the city’s consent decree."
Mayor Tim Kelly said, “The Tennessee River is literally and figuratively the essence of our sustainability - the source of our drinking water, our scenic beauty, and our recreation, as well as a major driver of our economic vitality.
That’s why this facility is so important for our future. By protecting our river, it will help preserve our future growth and prosperity, ensuring we can attract global talent and provide residents and visitors alike a cleaner, greener, more sustainable city for generations to come.”
The storage tanks are among a number of improvements Chattanooga has constructed in order to end the discharge of untreated sewage into the Tennessee River, said Mark Heinzer, interim director of the Moccasin Bend Environmental Campus.
He said, “On Aug. 10 of this year, when Chattanooga was hit with a 10-year rain event that flooded streets, parking lots, and buildings, one very important thing did not happen - not one gallon of untreated wastewater overflowed into the Tennessee River, thanks to the city’s new wet weather equalization station. Instead, 18 million gallons of wastewater and rainwater overflow was pumped into tanks and later slowly released into our treatment plant for purification. This represents a huge step forward in our work to preserve our outdoor resources and create a more sustainable future for our city, and I want to thank all of the talented, dedicated partners and teams who helped make it possible, including our Department of Public Works, Jacobs Engineering, Hazen and Sawyer, and Reeves Young Construction.”
Officials said in addition to the completion of the equalization station, the Department of Public Works has made significant progress in repairing and rehabilitating other parts of the city’s wastewater system since entering into the consent decree in 2013, including:
Rehabilitating 12 pump stations, with four more on the way in 2023.
Completing 12 capital projects to improve the Moccasin Bend Wastewater Treatment Plant
Inspecting and evaluating 284 miles of pipe and rehabilitating 73 miles of pipe, or about 25 percent of the system
Rehabilitating over 2,000 manholes
Cleaning approximately 1 million feet of pipe throughout the city annually
Officials said a consent decree "is simply an agreement between the federal government and local government meant to correct a violation of federal law to avoid costly litigation. In this case, Chattanooga’s old and inadequate sewer system, which combined both sewage and the city’s often torrential rainfall into one combined system, was repeatedly overflowing during heavy rains, causing nearly 100 million gallons of untreated wastewater to flow into the Tennessee River every year.
"The resulting contamination of the Tennessee River violated the federal Clean Water Act, and in response, the city entered into a consent decree with the Tennessee Department of Environment and Conservation and the EPA in 2013 to start rehabilitating and renewing its wastewater system.
"Chattanooga is approximately half way through its $1.1 billion, 17-year commitment under the consent decree, and the construction of the new equalization station marks a significant milestone in the city’s work."