Here we go again. “More than 100,000 gallons of coal slurry poured into an eastern Kanawha County stream Tuesday in what officials were calling a ‘significant spill’ from a Patriot Coal processing facility,” http://www.wvgazette.com/News/201402110032.
Another crew working with poison one valve away from the drinking water supply bobbled the job. I particularly liked the article’s characterization of "serious ecological consequences" by the Secretary of the Department of Ecological Protection: "When this much coal slurry goes into the stream, it wipes the stream out," he said.
This spill was not polyethylene glycol, like the other West Virginia event in recent weeks. This one was coal slurry, loaded with heavy metals and organic coal byproducts. Fortunately the spill was downstream of the drinking water pickup for the area, by about a mile.
The Secretary went on to explain that there was an alarm in place to alert workers of the valve failure that caused the spill, but the alarm failed, too. Okay, readers, what do we know about simultaneous, independent equipment failures? Mostly we know they don’t happen. The math model for the likelihood of two simultaneous failures is the product of the probabilities of the failures, as in 1 in 1,000 X 1 in 1,000 = 1 in 1,000,000.
Those of us who have worked in control rooms know that operators usually have the ability to silence alarms. Sadly, they often have to do so in poorly maintained plants so they can hear themselves think and talk in the control room. Poorly maintained facilities typically have lots of alarms going off.
Patriot's assertion that there was a simultaneous failure of the valve and alarm system is most unlikely. More likely, they ignored the alarm when it failed weeks or months ago. Or perhaps they ignored it long enough for 100,000 gallons to flow into the river when it worked as designed and signaled the valve failure. Alarms do not fail silently; they're designed to go out screaming.
This spill, the third slurry spill in the area in the last three years, is the result of a training failure that prevented instant, accurate response to the alarm, whenever it sounded. It is also the result of reliability and maintenance failures that prevented the prediction and avoidance of a critical valve failure before it caused a major leak.
Are there training or maintenance time bombs around your plant waiting to damage the environment and make you look incompetent? Anyone who drinks the water in your neighborhood would appreciate your finding and disarming them. So would anyone doing business or trying to sell real estate around you. Just ask the folks in the beautiful state of West Virginia.
Read Stanton McGroarty's monthly column Strategic Maintenance.