| USEPA Region VII REAP: 2004 - 2009 |
Tetra Tech EC/PMRMA Subcontract: 2006 - 2011 |
| Indiana DEM: 1989 - 1992; 1997 to 2009 |
USACE/St. Louis, MO (Environmental Services): 1995 to 2009 |
| Illinois EPA SRAPL/CERCLA: 1986 to 2008 |
URS Group//PMRMA Subcontract: 1996 to 2006 |
| USACE/Honolulu, HI : 1997 - 1999 |
USACE/St. Louis, MO (Laboratory Services): 1992 to 2005 |
| USEPA CLP-SMO: 1991 - 1999 |
Region VII USEPA/EQM Subcontract:1999 to 2004 |
| USACE/Baltimore, MD : 1995 - 1998 |
Navy CLEAN/Halliburton NUS : 1995 - 2000 |
| USACE/Portland, OR : 1988- 1997 |
Jacobs Engineering Group/Alaska TERC:1996 - 1999 |
| CDM Federal Programs Corp.: 1992 - 1995 |
US Army Rocky Mountain Arsenal: 1992 - 1996 |
| USACE/Buffalo, NY: 1991-1994 |
USACE/Rock Island, IL: 1987 - 1992; Dallas, TX : 1991 - 1995 |