Lake Oswego council approves long-term IGA with Portland to develop replacement wastewater plant

Lake Oswego — The City Council on Tuesday voted unanimously to adopt Resolution 25-49, authorizing a 2025 intergovernmental agreement (IGA) with the City of Portland to design, construct, operate and maintain a replacement wastewater treatment plant.

The council approved the measure after a staff presentation from Stefan Broadus, director of special projects, who described the IGA as a continuation of past cost‑sharing arrangements and a framework for a long‑term partnership. "This tries to continue this overarching theme of a fair and equitable cost share," Broadus said, explaining that development costs will be based on recent flow share and operations and maintenance (O&M) will be billed on actual flow contributions.

Why it matters: Lake Oswego will lead development of the new plant while Portland will be a financial participant under the agreement. The IGA spells out three main cost buckets — land acquisition (with a Portland not‑to‑exceed cap set by earlier council actions), development (design and construction, apportioned by recent flow share) and O&M (billed on actual ongoing flow). Broadus told the council the 1984 IGA will remain in effect until the existing plant is decommissioned; the 2025 IGA governs the new plant’s design and operation.

Key fiscal and schedule points: Broadus said the city closed a WIFIA loan in August and expects contractor proposals in March, with negotiations through the fall and construction extending for two to three years. He told the council the project team would plug contractor cost figures into the city’s rate model when they arrive: "I'll start getting some numbers flowing in in February, and then their proposal in March," Broadus said.

Decommissioning and remediation: Councilors asked who would pay to decommission and to remediate the old plant site. Broadus clarified that decommissioning costs are shared under the IGA, while demolition and remediation of the old facility would be borne by Lake Oswego because Portland plans to transfer the parcels to Lake Oswego for $1 after the new plant is commissioned.

Next steps: Broadus said the presented IGA provides structural formulas for future billing and that staff will return with contractor cost estimates and proposed amendments that insert the specific numbers. He also reported reciprocal staff work with Portland and said Portland’s administrator was expected to sign the agreement before year‑end.

Council action: Councilor Winland moved to adopt the resolution; Councilor Corrigan seconded. The motion passed by voice vote, 6-0.

What’s next: Staff will amend the IGA with concrete cost figures once contractor estimates are available, and the project will proceed through procurement and construction phases outlined in the staff schedule.