Mayor Tim Kelly: “This one is a win no matter how you look at it.” 

At yesterday’s monthly meeting of the Industrial Development Board, the City of Chattanooga unveiled plans to install a waste-to-energy system that will convert the city’s wastewater into a renewable energy source at its Moccasin Bend Environmental Campus (MBEC). Waste-to-energy systems convert the organic solids in wastewater into biogas that can be used to power on-site operations and be processed further to be sold as a natural gas substitute. The city is seeking to partner with the Industrial Development Board (IDB) to develop the Request for Proposal (RFP) and to award a contract to a design-build contractor to carry out the project, which it plans to be completed by December of 2028.  

“The turnaround at Moccasin Bend is nothing short of remarkable, and we’re excited to build on that momentum and to continue leading with strategic infrastructure investments like this one,” said Mayor Tim Kelly. “This facility upgrade will help address multiple challenges at once: Becoming a decentralized renewable energy generator means better resiliency and lower costs to operate the site; the new system will effectively double the efficiency of the process, which will help accommodate continued regional growth; it will also improve the quality and reduce the volume of beneficial use biosolid product, which means less odor and lower reuse costs; and by capturing and using the biogas as feedstock instead of flaring it, we’ll be taking better care of our environment and helping make Chattanooga an even better play to live, work, and play. This one is a win no matter how you look at it.”

Pursuant to Chattanooga’s Consent Decree and the Clear Chattanooga plan to improve the city’s wastewater system, the 2023 Clear Chattanooga Energy Audit recommends this process technology upgrade for solids treatment and generation of renewable energy. Improved capacity and lower operational costs resulting from the project will help MBEC maintain affordable sewer rates to promote economic development in Chattanooga and address a significant wastewater infrastructure vulnerability that will position the site to better accommodate regional growth.   The total capital investment for the project is estimated to be between $130-$150 million and will be funded through a combination of federal, state, and local sources, including the EPA’s Water Infrastructure Finance and Innovation Act (WIFIA), Tennessee’s Clean Water State Revolving Fund (SRF), and budget-allocated funding from the City of Chattanooga’s sewer system enterprise fund. 

“After years of project development, we are excited to finally push this into the next phase,” said Mark Heinzer, Administrator of the City of Chattanooga’s Wastewater Department. “We have successfully reduced our energy consumption by roughly 25% through the solar installation and our equalization basin project. This new system will add to that number considerably while increasing the site’s resiliency and benefiting the community as a whole.”

The city is seeking to partner with the IDB through a Memorandum of Understanding (MOU) for the design and construction of the waste-to-energy project, similar to the existing MOU governing the wet-weather storage facility installations associated with the Environmental and Economic Infrastructure Improvement Project (e2i2). After MBEC’s proposal to the IDB today, the IDB and the Chattanooga City Council would have to approve the MOU between the parties to further define roles and obligations. The IDB would then approve the RFP for advertisement, and a design-build contractor would be selected through a competitive bid process by a committee composed of City and IDB representatives.. The IDB would execute the contract, and the city would manage the project and provide routine updates to the IDB. 

The proposed design-build timeline calls for a contractor to be procured by spring of 2024, design pre-construction to occur for about a year, construction to begin in the spring of 2025, and for the project to be completed by the end of the year in 2028. 

About the Consent Decree

The City of Chattanooga entered a consent decree with the U.S. Environmental Protection Agency (EPA), the State of Tennessee and the Tennessee Clean Water Network (TCWN) on April 24, 2013. The overarching goal of the agreement is to significantly reduce, and where possible eliminate, sanitary sewer overflows and improve the overall operations of Chattanooga’s sewer system.

In the agreement, the City agreed to embark on a multi-year, $784 million program that includes major upgrades and revisions to several sections of the system including pipe replacement, upgrades to the Moccasin Bend Environmental Campus and operational audits across the board.

The agreement also included $800,000 to be spent on a Supplemental Environmental Project, $238,000 for a State environmental project and a $238,000 civil penalty paid to the United States. This agreement also serves as the settlement of a lawsuit filed by the U.S. Department of Justice on behalf of the EPA and the TCWN in 2010.