Wet Well Condition Assessment

The City of Mercer Island identified the need to upgrade 17 lakefront sewer lift stations to support long-term wastewater service. Built between 1955 and 1965, the Lakeline Sewer System conveys wastewater around the island to the regional interceptor system. Many of the lift stations are located along the Lake Washington shoreline, including in side yards and on waterfront docks, which required a careful, low-impact approach.
RH2 completed a visual condition assessment of the lift station wet wells, coordinated with scheduled maintenance to improve access and minimize impacts to nearby properties. The assessment evaluated concrete structures, piping, and odor control systems, with condition scores and criticality ratings assigned to each facility.

The results are now guiding Mercer Island’s maintenance priorities and long-term capital planning, giving City staff clear, actionable information to manage risk and plan investments. Projects like this reflect RH2’s hands-on, collaborative approach to solving complex infrastructure challenges in real-world settings.