Stage of Clean-up: Study Underway
Conditions at Proposal (July 27, 2000): The Willamette River originates within Oregon in the Cascade Mountain Range and flows approximately 187 miles north to its confluence with the Columbia River. The Lower Reach of the Willamette River from River Mile (RM) 0 to approximately RM 26.5 is a wide, shallow, slow moving segment that is tidally influenced with tidal reversals occurring during low flow periods as far upstream as RM 15. The river segment between RM 3 and RM 10 is the primary depositional area of the Willamette River system. The Lower Reach has been extensively dredged to maintain a 40-foot deep navigation channel from RM 0 to RM 14. This segment of the Lower Reach contains a highly industrialized area known as Portland Harbor, which contains a multitude of facilities and both private and municipal waste water outfalls. Up to 17 industrial operations have been identified as potential sources of contamination to Portland Harbor between RM 3.5 and RM 9.5; however, because not all sources of contamination to this river segment have been thoroughly investigated, the site is being evaluated as contaminated sediments with no identified source. In July 1997, the United States Army Corps of Engineers (USACE) collected surface sediment samples between RM 3.8 and RM 8.9 from Portland Harbor as part of a pre-dredging sediment quality study. More...