See:
http://www.etcgroup.org/content/worlds-10-largest-water-companies World's 10 Largest Water Companies
Who they are, what they do and how much revenue they collected
Company (Headquarters) What they do Revenue 2009 (US$ million)
1. Veolia Environnement (France)
Water supply and mgmt., waste mgmt., energy and transport services
49,519
2. Suez Environnement (France)
Water supply, wastewater treatment, waste management
17,623
3. ITT Corporation (USA)
Water supply, treat wastewater, supply pumps etc. for handling toxic water
10,900
4. United Utilities (UK) (FY ending 3/31/2010)
Water supply and sewage treatment
3,894
5. Severn Trent (UK) (FY ending 3/31/2010)
Water supply and sewage
2,547
6. Thames Water (UK) (FY ending 3/31/2010)
Water supply and wastewater treatment
2,400
7. American Water Works Company (USA)
Water supply and wastewater mgmt
2,441
8. GE Water (USA)
Water treatment, wastewater treatment
2,500
9. Kurita Water Industries ( Japan) (FY ending 3/31/2010)
Water/wastewater treatment/reclamation, soil and groundwater remediation
1,926
10. Nalco Company (USA)
Water treatment (water-related revenue only)
1,628