Ammonia leak undetected for two weeks at Dow

Charleston, W.Va.-Charleston emergency responders calculated that a leak of more than 3,000 pounds from an anhydrous ammonia tank at the Dow Chemical facility at Institute went undetected for two weeks for a number of reasons. “Sensors on the bottom of the tank never went off, so they didn’t know about the leak,” C.W. Sigman, Kanawha County fire coordinator, told Green Markets. Sigman added that it was a unit that was not in operation. “The safety valve was on top of the tank, and with the vapor density about half that of air [the leak] rose in the atmosphere and dissipated.” Dow spokesman Randy Fischback said the investigation was continuing, but that “we have determined it was coming from a pressure release device, but we don’t know the reason for that yet. It’s part of the investigation.” Fischback said it’s been determined that the tank was leaking about 11 pounds an hour between Feb. 4-16, but even when operators were troubleshooting they couldn’t detect anything at ground level. He said the anhydrous is used as part of the NOx abatement at the plant. Kanawha Metro 911 Shift Capt. Joe Coen explained to the press, “Operators had been looking at the inventory records and saw that the level in the gauges had been dropping for several days.” The ammonia leak occurred in Dow’s ethylene oxide catalyst unit located on Bayer CropScience property at the multi-company Institute site. On the same day, Dow informed Metro 911 officials of a leak of about 75 pounds of the chemical polyalkylene glycol, a liquid synthetic lubricant, that had occurred at the company’s South Charleston facility.