| Government |
| Advanced Chemical Systems (ACS) |
| Aeration Industries |
| Aero-Stream |
| Ameron |
| AquaChem |
| Aquarius Systems |
| Aquasensors |
| Aquifer Science & Technology |
| Arch Chemicals |
| Aries Industries |
| Badger Meter |
| Depuron |
| Donahue & Associates |
| Electrozone |
| EnviroCare |
| Fehr Graham |
| FPZ |
| Fristam Pumps |
| Great Lakes Bio Systems |
| ITT-Sanitaire |
| Johnson Controls |
| Key Engineering |
| Liquid Waste Technologies |
| Master Meter/Iroda |
| Mazzei Injectors |
| Meecopa |
| Pentair |
| Portapure |
| Racine Federated |
| Red Flint |
| Short Elliot Hendrickson (SEH) |
| Siemens (Envirex) |
| Siemens (Zimpro) |
| Spec Industries |
| Zenner |
