Ecology, working with a Steering Committee of Eastern Washington Phase II National Pollutant Discharge Elimination System (NPDES) permittees, completed a 2019 update of the Stormwater Management Manual for Eastern Washington. RKI helped incorporate the latest advances in design, construction, and maintenance techniques for conventional and Low Impact Development stormwater BMPs into the manual and provided team facilitation and public outreach, helping to gather and incorporate necessary inputs for successful use of the manual.

This project installed and will monitor permeable pavement for durability, water quality (influent and effluent), and infiltration rates. RKI assisted the City of Spokane with research on successful monitoring practices and lessons learned by other jurisdictions and provided design review and recommendations for final design, construction, monitoring, operation and maintenance.

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.

Following on our work with Kitsap County Department of Community Development to update the County’s codes, Road Standards, and Stormwater Design Manual to meet regulatory requirements of the NPDES permit, RKI provided training for Capital Improvement Project (CIP) Inspectors on how to apply the updated codes and standards in managing construction of roadway CIPs.