The City of Omak is planning to replace the approximately 110,000 linear feet of aging concrete pipe that constitutes its sewer collection system. Approximately 95% of the city’s collection system is built with concrete pipe, from 50 to 80 years old, that has surpassed its useful life. The work will be done in five phases in the next 4 to 5 years using trenchless pipe bursting technology and open cut excavation. While the pipe bursting technology does not require excavation of the entire length of pipe being replaced, it does require replacement of manholes. In addition to replacing deteriorating pipe, a 400 foot length of new installation is proposed between Oak and Pine streets, south of Riverside Drive.
Plateau Archaeological Investigations conducted this cultural resource review of the overall project area to identify areas that may include sensitive historic properties, and conducted pedestrian survey and probing along the route of the proposed new sewer line installation.
During the project, Plateau determined that there are thirteen known archaeological sites, seven inventoried historic properties (two of which are eligible for inclusion on the National Register of Historic Places), and one Traditional Cultural Property within the city limits. In addition, there are 14 cultural resources are located within 1.0‐mi (1.6‐km). No new historic properties or archaeological sites were identified during this cultural resource survey.
Location: Okanogan County, Washington
