Abstract: At approximately 10:30 a.m. on March 29, 2002, Employee #1 was working with his coworkers cleaning out settling basin tanks that had quit working properly because the connecting pipes between them were clogged with solids. Water was generated from the lime slack, to treat it for public use. Small amounts of water dripped into a small metal dumpster and overflowed into a greater pit, 2 ft by 2 ft, that was connected to a settling basin (2 ft by 5 ft by 2ft deep) via a 4 in. pipe. This settling basin is connected to another settling area (2 ft diameter by 2 ft deep) that had a manhole cover. The settling areas were 2 ft below the surface (road and sidewalk). Employee #1 was closing up the job pulling the 2 ft by 5 ft steel cover back onto the settling basin with a metal handheld hook. As he was pulling the cover to adjust it properly, the hook slipped out of the hole on the cover as he stepped back, his right leg went into the open manhole. He broke his left hip.