Mountlake Terrace updates sewer ILA with Lynnwood; new monitoring, protocol and per‑volume charge proposed

City wastewater staff presented a proposed update to the interlocal agreement (ILA) with the City of Lynnwood for emergency or planned overflow conveyance at the March 26 study session.

Background and changes: The original agreement dates to 1977 and was updated in 1982. Staff said current operational realities and modern monitoring justify a refresh. The revised ILA clarifies protocol for when Lynnwood will route overflow or maintenance flows into Mountlake Terrace’s conveyance system, sets clearer notification and operational steps, and uses a new cost calculation for treatment and conveyance to Edmonds based on measured volume. Staff cited a per‑volume charge calibrated using recent data at about $5 per CCF (where historical rates had been closer to $2 per CCF) and noted that Lynnwood has already signed the updated agreement.

Staff asked council to place the revised ILA on the consent calendar for a future meeting. Council members asked procedural questions about timing and whether Lynnwood’s council had already acted (staff said Lynnwood approved earlier in the sequence). The updated protocol also benefits both agencies by reducing environmental risk during emergencies and ensuring measured, billable interchange when the overflow pathway is used.

What happens next: Staff requested the item be placed on a near‑term consent agenda for council authorization; no council vote was taken at the study session.