Derek R. Guthrie Water Quality Treatment Center (DRGWQTC)

The DRGWQTC was designed as a 15 million gallon per day preliminary and activated sludge treatment facility. There are no primary sedimentation facilities or sludge processing facilities at the DRGWQTC. Construction is scheduled to begin in April, 1999 to expand the capacity to 19.4 million gallons per day.

The raw influent wastewater flows through three coarse bar screens to the influent pump station. Four pumps life the raw wastewater to an aerated grit chamber. From the grit chamber, flow through the remainder of the plant is by gravity.

The secondary treatment facilities have the capacity to operate in either a complete mix or contact stabilization activated sludge process. Current operation is with the complete mix mode, utilizing two of the aeration basins. The wastewater flows from the aeration basins to three final settling tanks. Final settling tank effluent flows to chlorine contact basins for disinfection. Following chlorination/dechlorination, final effluent flows to the Ohio River.

Settled secondary sludge is wasted to temporary aerobic digesters. The temporary aerobic digesters are the two additional aeration basins that are not currently in service because of low influent organic loading and flow. Waste activated sludge is pumped to the Morris Forman Water Quality Treatment Center (approximately 12 miles) for further processing about once every week.

Odor Control
MSD recently completed installation of a $2+ Million project to control odors from the treatment plant. The project included installation of a carbon adsorber to treat sewage odors, a biofilter to treat the aeration basin influent channels and installation of fine bubble diffusers to reduce odors from the aeration basins. Provisions were also made to reduce noises from the plant. "Baseline" odor and noise testing (prior to construction of the new project) and follow-up odor and noise testing (after completion of the project) were performed.

• Plant odor testing completed after installation of the odor control equipment verified significant improvements in odor emissions. The carbon adsorber, biofilter and activated sludge diffusion odor control systems all performed excellently.
   
• Community odor surveys conducted in September, 2003 and again in May, 2004 revealed that the goals have been attained in are reducing frequency and intensity of odors in residential areas; and,
   
• The results from the testing yielded an overall reduction in odors of 87% and an overall reduction in hydrogen sulfide emission of 97% when compared to the baseline readings.

In addition, improvements were made to reduce noise levels from the treatment plant. A noise survey conducted in June 2004 indicated the following:

• Noise emissions from individual sources have been reduced by 10-14 decibels (dBA);
   
• Noise from plant at nearby residences have been reduced by 6 dBA;
   
• The water quality treatment center is determined to be inaudible relative to all other ambient noises, with the possible exception of a resident adjacent to the transformer; and,
   
• The noise consultant concluded that the plant is acceptably quiet.

A public meeting was held on June 29, 2004 to present the results of the odor and noise testing. To see the presentation, see "West County Treatment Plant Noise and Odor Control Project Update" (806K, ).

West County Local Limits

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