Located on a steep bluff above the Strait of Juan de Fuca, Port Angeles’s 3-cell landfill was closed under three regulatory statutes (WAC 173-301, 173-304, and 173-351). Aspect provides ongoing compliance and reporting to support all post-closure requirements. Analyzing geochemical data, we assess the groundwater and leachate monitoring program. We have addressed gas flare operations and maintenance, recommending strategies such as flow balancing and infrastructure improvements, and assisting with gas collection during relocation of a solid waste cell. We have also evaluated greenhouse gas emissions following EPA protocols.