Chattanooga Selects Archer Western-Stantec Team for Major Wastewater Upgrades

Archer Western and Stantec will lead Chattanooga, Tenn.’s effort to improve wastewater services at its Moccasin Bend Environmental Campus on the Tennessee River, together with plans for the world’s largest membrane-aerated biofilm reactor. 

The crew will design-build Part 1 of a Class A Course of Optimization for Wastewater Vitality Restoration (POWER) venture and wastewater therapy plant upgrades on the web site, the place town has put in infrastructure to assist power, water and value financial savings, together with photo voltaic electrical energy era. Archer Western Building will likely be lead contractor for the venture, with Stantec main design and engineering. The ability is anticipated to be operational in December 2028. 

In an announcement, Stantec and Archer Western say the progressive design-build venture is anticipated to include a thermal hydrolysis course of (THP) facility, anaerobic digestion upgrades and conversion of a high-purity oxygen facility to a membrane aerated biofilm reactor (MABR). 

Waste-to-energy programs convert the natural solids in wastewater into biogas, which is used on-site to energy operations and to be additional processed and bought as a pure gasoline substitute. 

Upon completion, in accordance with the announcement, the power would be the world’s largest MABR facility, described as an energy-efficient, intensified nutrient removing course of that may enable Chattanooga to make the most of present tanks whereas assembly future nutrient limits in effluent discharged from the Moccasin Bend web site.

It is going to produce Class A biosolids that can be utilized as a soil additive in close by farms, and biogas that will likely be reused to generate steam, with extra producing energy for the power.

To satisfy town’s sustainability and operational targets, the biosolids portion will combine the THP facility throughout the present biosolids therapy course of, enhancing anaerobic digestion and biogas manufacturing whereas lowering the amount of biosolids for disposal. 

The venture was unveiled in September 2023 at a gathering of town’s Industrial Growth Board, with Mark Heinzer, Chattanooga’s wastewater administrator, telling the board that the venture may value $130 million to $150 million. 

He stated town at the moment hauls away as much as 15 truckloads per day of Class B biosolids, which should be taken at the least 50 miles away to be utilized. 

Based on minutes from that meeting, 49% of the venture is being funded by way of a $186-million federal Water Infrastructure Finance and Innovation Act (WIFIA) mortgage authorised in 2022 that’s being cut up amongst three different initiatives as properly, carrying a Dec. 31, 2028 deadline. 

Heinzer advised the board that the leftover gasoline might be put again into the grid for renewable power credit or can energy autos, anticipating $4 million per 12 months within the sale of renewable power credit. In complete, he stated it represents a financial savings of as much as $9 million for town yearly.

Chattanooga Mayor Tim Kelly stated in a subsequent launch that the power improve will assist town decentralize its renewable power era efforts and double the wastewater system’s effectivity to higher cope with continued progress within the area. 

Parts of town’s wastewater infrastructure system are reaching the top of their helpful lives, town says, contributing to failures throughout heavy rains and sanitary sewer overflows.

The venture is a part of town’s Clear Chattanooga effort, a community-wide plan to lower the variety of sewer overflows to satisfy an April 2013 consent decree settlement with the EPA, state of Tennessee and Tennessee Clear Water community following a lawsuit alleging town had violated the Clear Water Act.

The consent decree settlement features a dedication from Chattanooga to spend $784 million on a multi-year program together with main upgrades, system revisions, pipe alternative and extra.

Chattanooga has accomplished evaluations on 1.3 million ft of pipe, resulting in the alternative or rehabilitation of 300,000 ft to date, and has constructed three equalization stations to briefly retailer overflow wastewater, including a capability of 30 million gallons to the system.