DEQ's Northwest Region is responsible for carrying out environmental protection in the six northwest counties of Oregon: Clackamas, Clatsop, Columbia, Multnomah, Tillamook, and Washington.
- Columbia Steel
- Eagle Foundry Co.
- EcoLube Recovery
- Genentech
- Hydro Extrusion Portland, Inc.
- NEXT Renewable Fuels, LLC
- NW Metals: Columbia Boulevard Location
- Oil Re-Refining Company - Portland
- Orchid Orthopedics
- Owens-Brockway
- PCC SSBO
- PCC Structurals, Inc. Large Parts Campus
- QTS Investment Properties Hillsboro, LLC
- STACK Infrastructure (SI POR03, LLC)
- Stimson Lumber Company
- The Boeing Company
- Wolf Steel Foundry, Inc.
- Microchip Technology Incorporated
- Intel Corporation (Aloha Campus and Gordon Moore Park at Ronler Acres Campus)