On 05/25/10, a mechanic replaced the MXWM domestic water pump. He stood up to reach for a pipe wrench & felt a sharp pain in his back. Evaluation by the plant Dr. was a pulled muscle. Injury was classified as a FAC. On 08/04/10, MRI revealed emp. has a herniated disc. Emp. will receive further evaluation. On 08/11/10, this case was re-classified as an OER-RWC.