Underwater Release Challenges EPA

In 1990, the Continental Steel Quarry Site in Kokomo, Indiana, presented the Superfund emergency response program with a new challenge: conducting a large-scale underwater emergency response action as the first initiative in the long-term cleanup of the site. The EPA Environmental Response Team (ERT) visually surveyed the quarry pond with an underwater remotely operated vehicle (ROV). The ROV is equipped with a tracking and detection system that assists in locating underwater objects in areas of limited visibility. The survey team found hundreds of hazardous substance containers. Samples of the pond water revealed that it contained many hazardous substances that had altered the pH level. No life remained in the pond because of the extremely toxic levels of these chemicals. The quarry area was bordered on three sides by residential property. Wildlife had been seen traveling across the site and contamination was seeping through the pond bottom to underground water supplies.

The EPA On-Scene Coordinator (OSC) had three objectives: 1) removing the containers without releasing more of the substances into the water; 2) removing the hazardous substances already in the pond; and 3) dealing with the difficulties and safety concerns in conducting this emergency response action underwater. To minimize the amount of hazardous substance further released into the pond, responders worked underwater, placing the containers in overpacks (larger containers). Equipment modifications were made and specific safety procedures were followed to ensure diver safety. To clean up the pond, responders drained all the water, treated it, and returned it to the pond.