Overview
In 2025, DEQ will lead an in-water sediment cleanup in the Columbia Slough. This page will provide construction updates, community event and meeting updates.
View the Story Map: Moore and Wright Islands Natural Area Sediments Cleanup
Background
For over 100 years, industrial, agricultural and urban development along the Columbia Slough resulted in contamination accumulating in the bottom of the slough. Contaminated slough sediments between Moore & Wright Islands and the former Pacific Carbide facility represent an in-water area that must be addressed as part of the Columbia Slough cleanup plan.
Pacific Carbide was developed in the 1940s and operated as a calcium carbide manufacturing plant until 1987. Prior to and during the 1970s, significant amounts of waste material entered the Columbia Slough through discharge pipes and from one or more catastrophic failures of the slough bank adjacent to the settling ponds.
In 2013, Pacific Carbide entered into an agreement with DEQ called a Consent Judgment to implement an upland soil cleanup remedy and pay into the Lower Columbia Slough settlement account to address the in-water sediment contamination.
Funding
In 2023, DEQ and Department of State Lands applied for and received a $1 million EPA Brownfield Cleanup Grant. In May 2024, DSL and DEQ entered into an Interagency Agreement to perform the work. DSL will administer and disburse Brownfield Grant funds. DEQ will manage day-to-day grant activities and the in-water cleanup.
In-water cleanup project
The in-water construction will begin in 2025.