EE was picking up a load of slurry clay: he had left his truck & was at the base of steps leading to loadout office: where he slipped. The area was wet there was some algae under the steps, but not in the walking area, grating was also in place to prevent slips. He reported that he had slipped. He said that he was not hurt, other than his rear. We learned 10/11/05 he is off work.