code
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SewAge SPill
highlightS MSd heroeS
By neldA holder
The 400-pound stainless steel plate shot out of its casing, knocking steve sigman off the scaffolding. After crashing into a concrete wall and denting it, the massive plate landed on top of him as he lay curled up on the bare basement floor. Raw sewage poured out of the opening at a rate of roughly 300 gallons a minute. Soon, nearby manholes began overflowing into the French Broad River. All hell had broken loose on Riverside Drive. 8
The Metropolitan Sewerage District of Buncombe County collects and treats the wastewater from some 48,000 residences, 6,000 businesses and 22 industries within its service area. Each day, about 20 million gallons of sewage flows through some 900 miles of collection lines into the 60-mile complex of interceptors that deliver it to the basement of the pump station where the April 30 accident took place. There, three large pumps raise the sewage 30 feet above the intake level to begin the treatment process. Nearing the end of its 25-year useful life, the 1,500-pound pump No. 3 was slated for replacement. A contractor, Gilbert Engineering Co. of Statesville, had been hired to do the job, which included repacking the knife gate. In the open position, the sliding, inch-thick plate allows sewage to flow into the pump; when closed, it cuts off the flow. A dry run conducted by MSD staff clocked 48 minutes from the time all three pumps were turned off until backed up sewage would threaten an overflow. The repacking process would take approximately 25 minutes. The contractor was
JUNE 19 - JUNE 25, 2013 • mountainx.com
ProBleM SolVerS: MSd managers Peter weed, left, and ken Stines stand beside an inflow pump; the knife gate is above. Photos by Max cooper given those parameters and told to have MSD turn off all three pumps before any work began. But the signal to kill the pumps was never given. The contractor's three-man crew — Foreman don sigman and his two sons, Keith and steve — arrived at the three-story pump station around 7:15 a.m., accompanied by MSD inspector Mike schraven. Instead of notifying plant personnel to turn off the pumps, however, they simply went to work on repacking the gate. The effluent in the line to pump No. 3 was under considerable pressure; when the knife gate flew out, raw sewage rapidly spilled over the 30-by-50-foot basement floor. Keith and MSD staffer Bob Triplett got the plate off Steve’s chest and helped him up the
stairs. At Mission Hospital’s emergency room, they stapled a gash in Steve’s scalp and released him. Meanwhile, Schraven turned off the pumps. But that didn’t stanch the sewage spewing from the open slot in pump No. 3.
down Shit creek One backbone of MSD's operating strategy is an emergency procedure called “code red.” A code-red alarm quickly pulls together a team that assembles at the building where bypass pumps, various types of piping and other specialized equipment are carefully maintained and stored. "They know what their assignment is, what hoses and pumps they're supposed to get," explains Ken stines, director of system services maintenance. The code-red crew then scurries to the emergency site, ready to erect a bypass around the blockage, if necessary, until repairs can be made. "It's made a tremendous difference in our overall volume of spills," Stines reports. "Most