- ACTenviro
- AECOM
- Anderson Environmental Contracting, LLC
- Alta Science and Engineering
- BB&A Environmental
- Blaine Tech Services Inc.
- Brooks Applied Labs
- Cascade Drilling/Technical Services
- Clarity Scientific, LLC
- Clarus Water Solutions
- Clean Air Engineering
- Clean Harbors
- CleanWay Environmental Partners, Inc.
- Clear Creek Systems, Inc.
- Clear Water Services, LLC
- Coast Pavement Services
- Confluence Environmental, Inc.
- DH Environmental, Inc.
- EA Engineering, Science, and Technology, Inc., PBC
- EDR
- ERIS - Environmental Risk Information Services
- Field Environmental Instruments
- GeoSearch
- Great Western Coatings
- Gregory Drilling, Inc.
- Gunderson
- Heritage Environmental Services, LLC
- Historical Information Gatherers, Inc.
- Holocene Drilling
- Holt Services, Inc.
- Ingenium Group
- Kennedy/Jenks Consultants
- Laboratory Data Consultants, Inc.
- Landau Associates
- Layfield USA Corp
- Montrose Air Quality Services
- MP Environmental Services, Inc.
- Northwest Linings & Geotextile Products
- NRC Environmental Services
- Olympic Environmental Equipment, LLC
- OneBeacon Insurance Group
- Pace National
- PBS Engineering & Environmental
- Pine Environmental
- PNE dba CCS
- Research Support Services, Inc.
- River City Environmental
- RJ Lee Group
- Seametrics
- SoilFreeze, Inc.
- SPECTRA Laboratories
- Stericycle Environmental Solutions
- Stoel Rives
- StormwateRx LLC
- TerraStryke Products LLC
- TRC Environmental
- Triverus, LLC
- TSI Inc.
- Unanet
- United Rentals Fluid Solutions
- Vista Analytical Laboratories
- Wapato Valley Mitigation & Conservation Bank
- WasteXpress Environmental
- WaterTectonics
- Whitney Equipment Company
- Willamette Cultural Resources Associates, Ltd.
- Willamette University, Atkinson Graduate School of Management
- Wood Environment & Infrastructure Solutions, Inc.
- Yellow Jacket Drilling Services LLC