Engineering a Change

In 2004, in anticipation of a U.S. Environmental Protection Agency (EPA) Consent Decree, the Knoxville Utilities Board (KUB) was faced with the need for a wastewater collection system improvement program to reduce the occurrence of sanitary sewer overflows, increase wastewater collection system capacity, and improve surface water quality in Knoxville.

In order to reduce the occurrence of Knoxville’s sewer system overflows, Gresham Smith joined KUB’s PACE 10 Program to provide project management, design and construction phase services for six wastewater equalization basins. The basins are a key component of the 10-year, $530 million overflow reduction program, and range in size from 3.25 to 9.0 mg. Gresham Smith provided overall project management and site suitability studies on each site and has played a major role in the conceptual and final designs of all six basins.

The basins, at an approximate cost of $83 million, were designed and constructed on an expedited project schedule. Each equalization basin includes a circular or rectangular reinforced concrete basin, pumping station using submersible pumps, flow diversion structure, odor control systems designed for intermittent operation, and grinder screens.