On behalf of the Port of Portland (Port), Geosyntec assisted with water quality assessments and stormwater master planning for the Portland International Airport (PDX), four major marine terminals, and two industrial parks in response to significant new stormwater permit requirements and other drivers, including deicing control, and the need for conveyance system assessments and upgrades. The Port holds industrial stormwater permits and is the co-permittee on the City of Portland's Municipal Separate Storm Sewer (MS4) permit. These permits obligate the Port to develop and implement plans to manage and monitor stormwater discharges from their drainage system. Furthermore, the MS4 permit required the Port to implement a stormwater retrofit strategy for currently developed areas identified as impacting water quality. The objective of the stormwater master plan (SWMP) was to develop a consolidated and coordinated plan to comply with current regulatory requirements while still meeting the level of service needs required by their tenants and the general public.
Geosyntec's Scope of Services
Geosyntec, on a team with Gresham, Smith and Partners (GS&P), led the water quality related assessments and planning at all of the facilities associated with this project including:
- Leading water quality data review
- Leading water quality modeling and coordinating with GS&P's hydraulic modeling efforts as necessary and appropriate for consistency
- Working with GS&P to assess water-quality related regulatory requirements, guidance, and pending regulations
- Assessing and providing recommendations on potential retrofit projects and BMPs, particularly how these affect water quality improvements and meeting MS4 permit requirements
- Providing support on stakeholder outreach including to the City of Portland and Oregon Department of Environmental Quality (ODEQ)
- Supporting development of water quality elements of the Port's stormwater design standards
- Assisting in document development
Geosyntec completed technical water quality assessments for PDX, all four marine terminals (T2, T4,T5, T6), and the two industrial parks (Rivergate and Swan Island/Mocks Bottom). Stormwater master plans were also developed for T4 and PDX. The SWMPs identify capital improvement projects to improve water quality, reduce flooding, and upgrade aging stormwater assets. A Stormwater Design Standards Manual was developed that provides guidance on water quality and quantity sizing, best management practice (BMP) selection and design, and checklists to ensure compliance with MS4 permit requirements.