The City of Osage Beach shares a wastewater treatment plant (WWTP) with the City of Lake Ozark, the Lake Ozark/Osage Beach Wastewater Treatment Plant, located on the Osage River in Miller County. The WWTP is operated by a private company, Alliance Water Resources, Inc., and both Cities share in the cost of the facility proportionately based on flow.
The Lake Ozark/Osage Beach Joint Sewer Board administers the structure, processes, equipment, and arrangements necessary to treat and discharge wastewater at the WWTP. The Board is composed of eight (8) members, four (4) from each City. The Mayor and City Administrator from each City are members by virtue of office and the Board of Aldermen from each city appoints the remaining members for three (3) year terms.