MOUNT VERNON — The full-scale mock disaster drill planned for May 6 in Knox and Licking counties has been canceled in Knox County.

Chris Menapace, Mount Vernon assistant fire chief who led the design team for the exercise, said that due to the hazmat incident April 20 near Fredericktown, it was decided the disaster drill could overtax participating agencies.

“We decided as a design team that it was inappropriate to tax the resources of the county’s first responders financially and with personal time constraints,” Menapace said.

The drill was to have involved about 100 firefighters from both counties, who would have participated in a scenario that had similar components to the actual hazmat incident April 20 on Ohio 13, when a tanker filled with 41,000 pounds of anhydrous ammonia overturned. Because so many agencies participated, the incident can be submitted to the state for the same credit as the May 6 exercise.

“During the after-action review of the incident, deficiencies as well as successes were identified, and we have no reason to believe that either of those categories would have changed in two weeks,” Menapace said regarding the decision not to conduct the exercise.

Brian Hess, interim EMA director for Knox County, said he discussed the decision to cancel the exercise with other county EMA directors, including Jeff Walker of Licking County.

Licking County will go forward with its portion of the exercise, according to Hess, with some Knox County departments participating. Only the Knox County portion of the exercise is canceled.

Hess said the state EMA has looked over the evaluations of the hazmat incident last week.

“The state evaluator who looks over our evaluation forms and determines if we get credit or not recommended we use the incident in place of the exercise,” Hess said Tuesday afternoon.

The areas of evaluation include communication, incident command and use of resources. Hess said the results of the evaluations will be made public this week.