| Business | Phone |
| Edenspace Systems Corp 3810 Concorde Pkwy 100, Chantilly 20151 | (703) 961-8700 |
| Engineers & Surveyors Inst 4460 Brookfield Cor Dr A, Chantilly 20151 | (703) 263-2232 |
| Greenhorne & O'Mara Inc 3635 Concorde Pkwy, Chantilly 20151 | (703) 263-1220 |
| Veraxx Engineering Corp 14221a Willard Rd, Chantilly 20151 | (703) 961-9535 |
| Protection Engineering Group 14150 Newbrook Dr, Chantilly 20151 | (703) 378-0037 |