- Atlantic Water Solutions — Atlantic Water Solutions is your best resource for water testing, and for effective treatment products.
- Bob J. Johnson & Associates, Inc. — Services include complete system design, fabrication and system construction, on-site installation, and service after the sale.
- Culligan — Recognized as the world leading innovator and provider of water softeners, water filters and purification systems to improve drinking water in the home and workplace
- Fremont Industries — Regional water treatment company based in Minnesota
- Hoover's Wastewater Treatment Company — A website containing a list of wastewater treatment companies, as well as related news and jobs
- Matt-Chlor — Water treatment specialists based in El Monte, CA
- Oiltrap — Industrial water treatment and recycling systems
- Olivers Ozone — A well water treatment company based in Texas
- Reynolds Water Conditioning — Specialists in water treatment systems for both well water and city water
- Talley Water Treatment Company — Well water and city water/municipally treated water treatment products and services
- The Keeler Company — Regional water treatment company based in Pennsylvania
- Water Treatment & Controls — The largest domestic factory authorized distributor and service center for SIEMENS/Wallace & Tiernan