In a 2015 article in The Georgia Operator titled, “A Multi-Faceted Approach to Odor Control for a 28.5 Mile Long Force Main,” the authors outlined the solutions to a particularly challenging set of problems faced by the Gwinnett County Department of Water Resources.
Upon startup of the 10-mile-long, 36-inch-diameter force main between the Alcovy River Pump Station and the F. Wayne Hill Water Reclamation Facility, Gwinnett County began receiving odor complaints along the pipeline. A preliminary odor investigation of the system indicated that while sulfide concentrations were increasing through the length of the force main and the existing odor control chemical feed was ineffective, there were indications that significant surges were occurring within the pipeline. A hydraulic and surge analysis showed that keeping the pipeline full during all operating scenarios could eliminate the foul air discharges at the problem air release valves and alleviate the odor complaints.
Among those solutions was the introduction of Thioguard technical-grade magnesium hydroxide to address H2S levels at key areas along the force main. The use of Thioguard also allowed the F. Wayne Hill Water Reclamation Facility to discontinue the addition of lime as an alkaline supplement.
Read the article here (begins on page 43).