Derek R. Guthrie Water Quality Treatment Center (DRGWQTC)

The DRGWQTC was originally designed as a 15 million gallon per day preliminary and activated sludge treatment facility. In 1999 it was expanded to treat 19.4 MGD.  It has been in service since 1986. The facility was upgraded to 30 MGD in 2005.  A wet weather treatment facility that can treat up to 200 Million Gallons per day in was  added 2012.  In 2017 the facility was rerated to 60 Million Gallons per day treatment.

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

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 a day.

MSD installed a project to control odors from the treatment plant. The project included installation of a carbon absorber 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.

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.

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.

West County Local Limits

Parameter Maximum Daily Concentration
Total Arsenic 0.57 mg/l
Total Cadmium 0.43 mg/l
Total Chromium 5.0 mg/l
Total Copper 3.8 mg/l
Total Lead 1.1 mg/l
Total Mercury 0.0015 mg/l
Total Nickel 4.1 mg/l
Total Silver 1.2 mg/l
Total Zinc 5.3 mg/l
Ammonia 50.0 mg/l
Cyanide, Amenable 1.2 mg/l
Oil & Grease (Hydrocarbon) 100.0 mg/l