King County Wastewater Treatment Division (WTD) proposes to install Green Stormwater Infrastructure (GSI) facilities to the maximum extent practicable to reduce the gray infrastructure demands needed for full Combined Sewer Overflow (CSO) control at the University Regulator Station Overflow. RKI is serving as the Interagency Permitting Lead, responsible for planning and obtaining SDOT Street Improvement Permits and other required construction permits.

As part of its Plan to Protect Seattle’s Waterways, SPU committed to constructing green and/or gray infrastructure that will bring the Vine basin into compliance with Combined Sewer Overflow (CSO) regulatory requirements by the end of 2025. Serving as GSI Lead, RKI helped SPU develop and evaluate GSI options and select the preferred option to be advanced to final design and construction.

RKI is providing permit support, development review, engineering standards updates, and stormwater management planning for the Seattle-Tacoma International Airport (STIA) under the Port of Seattle’s Indefinite Delivery Indefinite Quantity (IDIQ) Environmental Review and Permitting Services contract. Recent tasks include development of the STIA LID Guideline for compliance with the Airport’s NPDES Individual Permit and Federal Aviation Administration requirements for commercial airport operations, planning for regional infiltration facilities, and assistance with Port policies and strategic goals.

The County Council requested a report from Road Services Division staff describing the location and condition of the County’s drainage trunk system within major road rights-of-way in unincorporated areas, the estimated accuracy of the resultant database, an analysis of the data to assess risks and impacts, and a prioritized program for maintenance. As Project Manager, RKI oversaw the condition and risk assessment of several thousand regional drainage assets and authored a strategic business plan to direct near- and long-term maintenance, repair, and renewal priorities.

The West Duwamish Combined Sewer Overflow (CSO) Control Project will control CSOs for King County’s West Michigan and Terminal-115 basins to the Washington State regulatory requirement of one-event per year on a rolling 20-year average. As Design Team Manager, RKI led the GSI alternatives analysis to identify and compare various combinations of grey and green technologies to achieve the control strategy and help protect the Duwamish River and Puget Sound.

RKI led the 2016 update of the City’s Stormwater Management Plan to address population growth, land use development, and requirements of the National Pollutant Discharge Elimination System (NPDES) Phase II Eastern Washington Permit. The plan characterizes existing drainage and water quality issues, identifies and prioritizes projects and programs that provide residents with the greatest value and protection, provides a financial plan and rate forecast, and helps the City prepare for possible future MS4 program audits.