Cooling Tower Pump Room - Water Treatment Chemicals
May 10, 2021
11
| Statement of Problem: The pump room design had insufficient containment for the two chemicals treating the cooling tower water. This led to a situation where if an accident were to happen and both drums were ruptured, the two incompatible chemicals could potentially mix and produce an adverse gaseous affect (chlorine gas). GM deemed this a Sentinel event on 2/24/16. When the mechanical subcontrator coordinated design of the cooling tower water chemical treatment system with the current GM chemical supplier, Chemtreat, the chemical supplier provided the schematic for their pumps/controller system and the number of drums, etc. The chemical treatment supplier did not identify the health hazard of the two chemicals mixing in open air. Further, the chemical treatment area was designed to mimick the chemical treatment in the old pump room, which did not have separate containment. The pump room was designed only as a secondary containment room, with a perimeter curb. Additionally, the chemicals changed from old pump room to new. Course of Action: Short term: CCC created a corrective action plan and built a temporary wall between the two chemicals and JEG provided spill containment pig containers for both chemicals in case of a leak. A temporary fance was placed and area was inspected daily. Long Term: CCC built a permanent 6" wide CMU wall between the two chemical drums/pumps and provided a concrete curb around each in case one were to have a leak. Additional PE containment barrels were purchased for spare chemical drums. An emergency shutoff button was added at the entrance door of the pump room to E-stop the chemical treatment system control panel in the event of an emergency. Lesson learned for Future Projects: The chemical supplier has to be more actively involved in the design of the chemical treatment system and the safety implications that the materials present. This is on of the resons why GM decided to no longer use Chemtreat for their chemical management services at the plant. |
