An ammonia leak at a facility at 514 Division St. on Madison’s east side forced an evacuation of the building and a response by the Madison Fire Department Hazardous Incident Team (HIT) on Wednesday. No illnesses or injuries were reported.
Engine Co. 3 was dispatched to the location for a potential ammonia release and requested the support of the MFD HIT. The building was evacuated prior to crews’ arrival; on-site personnel stated the building was evacuated after multiple ammonia sensors activated on the production floor.
The cause, quantity, and exact location of the leak were unknown. On-site personnel reported there was work being done on a specific silo, and they suspected the ammonia release originated from that silo. Supply to the silo was shut down prior to MFD HIT’s arrival, and on-site personnel had begun the work of ventilating the building.
When the HIT arrived on scene, they placed air monitors upwind of the building and confirmed that ammonia was not releasing horizontally into the residential neighborhood. No residential homes were evacuated.
An entry team went into the building with dedicated ammonia monitors and other equipment. Maintenance workers also activated the HVAC system to help with ventilation. The HVAC system was given 30 min to ventilate the space. Readings throughout the building continued to drop and remained at zero outside of the production floor.
A second entry into the building showed readings throughout the production floor that were mostly below the OSHA-permissible exposure limits, with the exception of ammonia readings near 200 ppm the presumed affected silo.
A third-party contractor arrived on scene to take over mitigation of the remainder of the incident. MFD HIT confirmed with the contractor the safe levels that must be achieved before anyone could resume work inside the building.
