SAN DIEGO, CA - (3-12-07) A sewage spill forced health officials to post signs warning of contaminated water. The spill happened on 55th Street near San Diego State University Monday morning. Authorities say 50,000 gallons of sewage flowed into a drainage channel that empties in the San Diego River. The signs were posted at the river were it empties into the ocean in Ocean Beach. They will remain until samples indicate it is safe for recreational use.