Since 2007, Gresham Smith has worked with the Port on evaluating, designing and optimizing needed upgrades to the PDX deicing system. The Port of Portland has stringent regulatory requirements for managing discharges of stormwater impacted by deicing chemicals from Portland International Airport (PDX). The Port also faced  a unique regulatory situation as it is limited on what it can discharge to its three primary outlets for stormwater — the Columbia Slough, the Columbia River and the local municipal wastewater treatment facility. These factors led to the need for a highly controlled and monitored deicer management system.

Gresham Smith has been a major contributor to the implementation of the significantly enhanced deicer management system, including leading development of the system concept during schematic design, providing high-end computer simulations using our GlyCASTTM deicer management software, and leading the design of an anaerobic fluidized bed reactor biological treatment system. Since the initial construction in 2012, Gresham Smith has designed an additional upgrade to the PDX deicer collection system through installation of 13 new online total organic carbon (TOC) monitors which are tied to the control system. The monitors separate clean and contaminated water and further segregate contaminated water into dilute and concentrated fractions to optimize storage and treatment efficiency. Gresham Smith’s work at PDX has improved the Port’s ability  to achieve compliance with its regulatory permits and provides a significant increase in flexibility for responding to Portland’s highly variable weather and deicing conditions.


Portland International Airport


Portland, Oregon

Project Type

Aviation, Stormwater




Project Contact

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Tim Arendt, P.E.
Tim Arendt, P.E.
Senior Environmental Engineer