McPHERSON, Kan. — McPherson Fire Chief Chad Mayberry gave City Commissioners an overview Tuesday on the December 2nd incident where a semi hauling hydrochloric acid overturned at the US 56/Old81 Bypass intersection. The semi was going north on the bypass, K-153 for that section, and after stopping was turning west onto US 56 when a cargo trailer laid over.
When the first emergency personnel arrived, they noticed a vapor coming from the trailer, at which time the scene was isolated. The driver was able to provide a bill of lading which indicated there were ten 300-gallon totes of a 31.45 percent concentration hydrochloric acid in the trailer.
One tote was punctured when the trailer was pierced by the “Conway Gate” at the northwest corner of the intersection from which about 300 gallons spilled, and another had a lead from the plug on a small bung that leaked about 20 gallons of product.
The leaking product led to a chemical reaction with the aluminum trailer, producing a hydrogen gas cloud. Diesel fuel also leaked from a saddle tank on the semi tractor, which was also cleaned up.
While the actual activation zone was only around 150 feet, extended further north due to prevailing winds, the road closings required made it seem like a larger area was evacuated. “You can’t just shut down a road 150 feet from an intersection. You got to go back further to get your traffic flow, and get your detour routes set up, so you end up with a larger zone for traffic management purposes,” chief Mayberry explained.
One storm drain was affected, but that only went to a culvert that was partly blocked on one end. Mainly diesel fuel leaked into that drain.
