COMMISSION AGENDA – Action Item No. 6e Page 3 of 5
Meeting Date: October 13, 2020
Template revised June 27, 2019 (Diversity in Contracting).
and land stewardship requirements through alternative means such as in-house field crews,
existing contractors, or alternative contracting with other organizations.
Scope of Work
Maintenance services to be completed under this ILA may include: selective vegetation trimming,
replacement plantings in areas of high mortality or low vigor, planting in areas of low density or
cover, weed management, soil amendment, installation of rodent guards, troubleshooting
existing irrigation systems, supporting existing monitoring efforts and other natural resource
maintenance services. Under this ILA, the WCC would provide crew management services, labor
and plants.
Natural resource maintenance services performed under this agreement will primarily be
performed at SEA wetland mitigation sites in compliance with existing permits. Due in large part
to WCC support, the mitigation sites initially constructed are maturing so maintenance needs on
these sites will continue to decline over the period of this agreement. In addition to routine site
maintenance, roadways may need to be decommissioned at the Auburn mitigation site and will
be re-vegetated through this ILA.
Other work not required by existing permits will include: 1) Vegetation plantings at the former
Tyee Golf Course may be needed to improve upland habitat while reducing bird attractants which
pose a hazard to Airport operations; 2) Fish and wildlife habitat sites located in Elliott Bay and
the Duwamish Waterway may require assistance to maintain and improve riparian and marsh
vegetation conditions; and 3) Other natural resource services may be performed on Aviation and
Seaport properties including those located along Elliott Bay and the Duwamish Waterway.
Key Scope Items:
• As mitigation for impacts related to the construction of the Third Runway and other 1997
Master Plan Updates (MPU) projects, the Port created, restored and enhanced over 164
acres of wetlands and wetland buffers. The 401 and 404 permits require that these
wetlands and buffers meet stringent performance standards for plant survival, density
and overall function for a period of 15 years. Due to the staggered construction dates of
the mitigation sites (Des Moines Nursery, Tyee Golf Course, Williams property, and Lora
Lake were constructed between 2012-2020) several sites will require higher levels of
maintenance until they become more established. This period will end between 2022 and
2027. In order to meet these requirements, the Port must perform regular plant
maintenance including vegetation trimming, replacement of dead plants, weed
management, soil amendment application and grazing protection.
• In addition to the Airport’s 1997 MPU wetland mitigation sites, there are other natural
resource sites on seaport and aviation properties. The Port has implemented significant
environmental restoration, cleanup and habitat enhancement projects as part of its
capital improvement programs and ongoing operations and management of Port
facilities. Two major projects would be the Lora Lake conversion to wetland habitat and