Building on Chattanooga's successful achievement of 100% compliance with its consent decree—which included reducing inflow and infiltration and eliminating both chronic and West Bank sanitary sewer overflows—the Process Optimization & Wastewater Energy Recovery (POWER) project represents the city's next major leap forward. Designed to modernize aging infrastructure and secure the city’s environmental health and future growth capacity, the program is divided into two major capital investments.
The Liquid Process Upgrades, budgeted between $70 million and $80 million, focus on decommissioning the 1980s-era oxygen plant. This move will immediately save over $1 million in annual operating costs and reduce community impact. In its place, the city will rebuild the aeration system utilizing Integrated Fixed-Film Activated Sludge (IFAS) technology and additional blowers, creating a highly resilient, easy-to-operate system with significantly lower maintenance costs.
Concurrently, the Biosolids Process Upgrades, estimated between $130 million and $150 million, will fundamentally transform the campus's waste handling. This phase involves constructing four new digesters to replace 60-year-old infrastructure that currently meets only 40% of the plant's needs. By pairing these new digesters with a state-of-the-art methane recovery system and a biosolids drying and gasification facility, the campus will transition to Class A biosolids production. This upgrade not only eliminates odors and greenhouse gas emissions but also opens up new disposal options, reduces regulatory risk, and creates potential new revenue streams, all while generating energy that essentially pays for the recovery system itself.