| Business | Phone |
| Accelerate Environmental Hlth 7129 Southwest Fwy 115, Houston 77074 | (832) 264-7422 |
| Airflow Systems Southwest 14745 Memorial Dr 81, Houston 77079 | (281) 497-3386 |
| Applied Hydrology Assoc 1322 Space Park Dr A180, Houston 77058 | (281) 333-2241 |
| Aviles Engineering Corp 5790 Windfern Rd, Houston 77041 | (713) 895-7645 |
| Brown & Caldwell 1415 Louisiana St 2500, Houston 77002 | (713) 759-0999 |
| Erm Enviro-Clean 15810 Park Ten Pl 300, Houston 77084 | (281) 600-1200 |
| Irc North America Lp 10497 Town And Country Way, Houston 77024 | (713) 647-7929 |