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.

In response to Ecology’s reissuance of the National Pollutant Discharge Elimination System (NPDES) Phase II Municipal Stormwater Permit, the City was required to update their Stormwater Management Manual (SWMM) to make Low Impact Development (LID) the preferred and commonly used approach to new and redevelopment. RKI provided on-call engineering services to assist with implementing the updated SWMM and provided development review support.

RKI updated the City’s Storm and Surface Water Engineering Standards to comply with National Pollutant Discharge Elimination System (NPDES) permit requirements, including new requirements for Low Impact Development (LID), and provided training for municipal staff and design professionals on how to use the new standards in the preparation and permit review of stormwater site plans.

RKI led the 2016 update of the County’s codes and engineering standards to meet requirements of the National Pollutant Discharge Elimination System (NPDES) Western Washington Phase II Municipal Stormwater Permit, including review and update of the County’s roadway, stormwater, subdivision, and landscape codes; update of the County’s Stormwater Design Manual; and development of outreach materials to educate designers on how to comply with the updated codes and standards.