Corporate HQ: 

6725 Curran Street
McLean, VA 22101
Phone: (703) 847-0000
Fax: (703) 847-0867

Federal Services: 

3402 Wisconsin Avenue
Suite 5
Vicksburg, MS 39180
Phone: (601) 638-2128
Fax: (601) 638-1751

Laboratory: 

4444 Airpark Blvd.
Duluth, MN 55811
Phone: (218) 722-4040
Fax: (218) 722-2592

Sediment Quality: 

4444 Airpark Blvd.
Duluth, MN 55811
Telephone: (248) 342-8744

International Services: 

Kabul, Afghanistan