Advanced Treatment Units
- BioMicrobics Inc. & SeptiTech (subsidiary; Maine)
- Delta Treatment Systems, LLC
- Ecoflo - Premier Tech Water and Environment
- ECOPOD by Delta
- Eljen Corporation
- Enviro-Aire by Delta
- Howden
- Infiltrator Water Technologies, LLC
- Jet, Inc.
- Norweco, Inc.
- Orenco Systems, Inc.
- Presby Environmental
- Whitewater by Delta