EMPLOYEE WAS ASSIGNED TO INSPECT THE BL2 DISCHARGE PIPELINE FOR LEAKS WHEN THE PUMPING SYSTEM WAS RESTARTED. WHEN CROSSING OVER THE PIPELINES, HE STEPPED OFF OF A 20"" PIPELINE ONTO A ROCK CAUSING HIM TO SLIP AND FALL DOWN TO THE GROUND ON HIS RIGHT LEG AND HIP. HE WAS PRESCRIBED PHYSICAL THERAPY ON JULY 19, 2004.