The Challenge

The Draper Approach

Results Realized

The Challenge

Since 1985, the Richard B. Russell Dam hydro project has used pure oxygen distributed in the reservoir to meet water quality requirements of 6 mg/L in the hydropower releases. The project uses $500,000 to $1 million worth of oxygen each year to maintain these dissolved oxygen levels. The oxygen transfer efficiency of the original diffuser system had decreased over the years along with increased maintenance costs.

In light of this increased cost, the US Army Corps of Engineers, Savannah District, decided to replace the diffuser system with a line diffuser system that was developed for the Tennessee Valley Authority.

The Draper Approach

A team was formed to carry out the replacement, with Draper & Associates providing project management, TVA providing oxygen facility modifications and diffuser installation labor, and Mobley Engineering providing engineering for the diffuser installation. Draper & Associates developed, and maintained, a Primavera schedule of activities, monitored actual progress against this schedule, facilitated a bi-weekly Progress Meeting, and prepared and distributed a report following each meeting. A unique feature of this engagement was the electronic distribution of reports and meeting minutes, and periodic teleconferences among Project Team members with the attendant savings in time and travel expenses.

Results Realized

The replacement diffuser design has ten lines, each 4,000 feet long extending along the old river channel upstream of the Richard B. Russell dam. The oxygen is distributed along the full length of each of these lines during operation, thus spreading the oxygen over a much larger area to achieve higher oxygen transfer efficiencies that should reduce oxygen expenditures.

Experience at TVA and other utilities has shown that the maintenance costs for the line diffusers are small. The installation of the diffusers at Richard B. Russell was completed in September 2001. Some preliminary testing was performed that compares the new system with the old. This presentation will include information on the installation of the diffusers and some preliminary test results.