Treadwell & Rollo, Inc.
- Comprehensive environmental, geotechnical, earthquake, and infrastructure consulting services. Based in California.
- http://www.treadwellrollo.net/

TWS Geologic Consulting
- Provides advise to the mining, mineral and utility industries through an accomplished geotechnical and procurement professional.
- http://www.ckfswebservices.com/tws/

Fred Snider Geology and Hydrology Expert Witness Services
- Bringing over 25 years experience in geology, hydrology, geophysics and geotechnical engineering to pre-litigation investigations, litigation support, expert witness services and consulting. Based in Greensboro, NC.
- http://fredsnider.com/

Géo-topics Sprl in Belgium
- Based in Belgium, firm provides expertise related to the extracting industry in the fields of survey, product characterization, quality management, expertise and training.
- http://www.geo-topics.be/EN/GT_Accueil.htm

Environmental Litigation Associates
- ELA offers technical litigation support and expert-witness testimony for both plaintiff and defendant cases. ELA was founded to provide experienced consultants and expert witnesses in the environmental sciences and engineering fields for the legal communi
- http://www.ela-iet.com/

CEC Energy Consultants
- Services for geologic evaluations, interim executive management, and raising joint venture capital. Tulsa, Oklahoma.
- http://www.cecenergyconsultants.com/

GeoTesting Express
- Massachusetts firm, providing geotechnical testing services on soils, rocks, solid waste and geosynthetic materials.
- http://www.geotest.com/

Geoforensics
- Forensic analyses and expert testimony related to water and soil aspects of criminal actions, groundwater and surface water contamination, environmental malpractice, consultant oversight, property transactions, and lake level problems. Based in Williamsto
- http://www.geoforensics.com/