Washington Department of Ecology 7/27/2023

Page 2 of 46State of Washington Department of Ecology Agreement No: Project Title: Recipient Name: WQC-2023-EverPW-00118 Regional Stormwater Facility Planning City of Everett Stormwater facilities constructed in the City of Everett prior to 2010 do not meet current water quality treatment and flow control standards. Most development within the City was built with limited mitigation for stormwater impacts and does not meet the National Pollutant Discharge Elimination System (NPDES) MS4 permit requirements for runoff treatment and flow control. There are currently multiple receiving waters within City limits that have Category 5 303(d) water quality impairments. Regional facilities will allow the RECIPIENT to accommodate future growth and mitigate stormwater from existing development. The RECIPIENT will select regional facility sites that have a direct connection to the highest priority receiving waters. The receiving waters will be prioritized using a process developed during the planning stage of this project. The RECIPIENT will identify suitable locations for regional stormwater facilities using information gathered during the Surface Water Comprehensive Plan (SWCP) and Stormwater Management Action Plan (SMAP) Receiving Water Conditions Assessment planning processes . The RECIPIENT will draft an Assessment Approach Memorandum which will develop a framework and tools to rate regional facility alternatives, and will include consideration of cost, operations and maintenance, treatment efficiency, and siting requirements. The RECIPIENT will review existing geotechnical data and stormwater facilities and will conduct an evaluation of the drainage basins to determine primary pollutant sources and connectivity to impaired receiving waters. The RECIPIENT will then rank and select at least five alternative regional facilities to bring to conceptual design. The RECIPIENT will prepare a Regional Facilities Report which will inform the development of a Conceptual Design Report to include estimated size, descriptive summaries, and cost estimates for the selected regional facilities for water quality treatment and flow control. Overall Goal: This project will help protect and restore water quality in Washington state by reducing stormwater impacts from existing infrastructure and development. Template Version 12/10/2020 DocuSign Envelope ID: 2DF45A90-96AE-464E-848B-4CA1529CAE01