At 7:15 a.m. on May 10, 2017, vapor phase anhydrous ammonia was released in an uncontrolled manner from a high-pressure line. The release took place when an employee drilled a 5/32-inch diameter pilot hole into a 3-inch schedule 40 seamless steel pipe containing anhydrous ammonia. The pilot hole was drilled as a starter hole for a ?-inch diameter pipe connection for a new auto-purger. No injuries or illness resulted from the incident. No harm to any employee occurred.