Uncoated, ungalvanized rebar and other construction deficiencies led to the collapse of a massive wastewater containment wall that unleashed millions of gallons of raw sewage, killing two Tennessee men and contaminating a river in April, authorities have concluded.
|Workers comb the debris of a collapsed wastewater equalization basin wall in Gatlinburg, TN.|
John Eslinger, 53, and Don Storey, 44, employees of Veolia Water North America, died in the accident at the Gatlinburg (TN) Wastewater Treatment Plant. Veolia operates the Gatlinburg facility and about 200 others nationwide.
The accident occurred about 9 a.m. April 5 when the 40-foot-high, 18-inch-thick concrete east wall of the 1.5-million-gallon basin abruptly separated and collapsed onto the facility’s flow control building.
Storey, an operator, and Eslinger, lead operator, were working inside the building, making adjustments to the effluent flow valve and performing other duties to adjust high flow levels inside the basin. At the time, the basin contained 1.3 million gallons of sewage, 25.5 feet deep.
No Citations Issued
In a report released Thursday (Oct. 27), the Occupational Safety and Health Administration said it would not issue any citations against Veolia. Both the engineering and construction companies that designed and built the plant are out of business.
Both the basin and flow control building were designed by Flynt Engineering Company and built by Crowder Construction Company. The structures were completed in 1996; both companies later went out of business.
Cracks and Displacement
According to OSHA’s five-page report, plant personnel discovered cracks and lateral displacement/bowing of the basin’s north wall and walkway in 1997. Buttresses were installed to correct the problems in that wall. Nevertheless, deeper construction flaws apparently affected other walls as well.
State, company and federal inspectors assigned to the accident investigation included Mahammad Ayub, PE, SE, director of the Office of Engineering for federal OSHA. According to the final OSHA report, Ayub concluded:
• “The cause of the failure was a deficiency in the concrete wall construction. Walls were cast in a manner that produced a cold joint between the east wall, which fell, and the three orthogonal interior intersection walls.
“The intersecting walls were critical to the structural integrity of the east wall. The cold smooth joint facilitated the leakage of the acidic waste water across the joint and, as a result, corroded the rebar splice couplers over a number of years.”
• “The contractor used splicing couplers instead of dowels, as required by the original drawings.” The formation of the cold joint accelerated corrosion of the coupler, and the rebars were not threaded to the length required inside the coupler.
• The couplers failed gradually over the life of the basin, affecting support of the intersecting walls.
• The rebar and couplers “were neither galvanized nor epoxy-coated, which could have prolonged the life of the basin.”
Veolia Water issued this statement Friday:
“The Tennessee Occupational Health and Safety Administration (TOSHA) has issued its final report and detailed findings relating to the April 5th wastewater equalization basin wall collapse at the Gatlinburg Wastewater Treatment Facility. The report states that Veolia Water was in compliance with all TOSHA/OSHA employee safety standards and that no citations will be issued.
“Employee safety is central to our operations and company culture—reflected by the company’s safety record that is 1.5 times better than the national average for OSHA Recordable Incident Rate and three times better for Lost-Time Incidence Rate.
“Although the findings from TOSHA reinforce our emphasis on employee safety, it does not dismiss the fact that two Veolia Water employees perished in this tragic accident and company employees continue to mourn their deaths.
“Veolia Water will continue to work closely and cooperate fully with all local, state and federal agencies, regarding this accident.”
‘Some Day This Would Happen’
Eslinger’s wife, Brenda, told a local TV station after the accident that her husband had expressed concern years ago about the basin’s construction, saying the basin “was cracked and that it was a danger.” Eslinger, who had worked at the plant 26 years, “was afraid some day this would happen," his wife said.
In May, the Environmental Protection Agency announced that it would not issue any fines in the accident, which “bypassed” four million gallons of sludge into the Little Pigeon River over 36 hours. Tennessee’s Department of Environment and Conservation approved the bypass.
Civil lawsuits in the case are pending.