| | | | | | | | | | | | | | |
| Name of Subsidiary | | Jurisdiction of Incorporation | | Ownership if Less Than 100% |
| ATG Environmental Holdco Limited | | United Kingdom | | |
| ATG Environmental Limited | | United Kingdom | | |
| ATG R&D Limited | | United Kingdom | | |
| ATG UV Technology Limited | | United Kingdom | | |
| Evoqua Finance LLC | | Delaware | | |
| Evoqua Pension Trustees Limited | | United Kingdom | | |
| Evoqua Treated Water Outsourcing LLC | | Delaware | | |
| Evoqua Water Technologies (Shanghai) Co., Ltd. | | China (Shanghai) | | |
| Evoqua Water Technologies Canada Ltd. | | Canada | | |
| Evoqua Water Technologies GmbH | | Germany | | |
| Evoqua Water Technologies India Private Limited | | India | | |
| Evoqua Water Technologies Ireland Limited | | Ireland | | |
| Evoqua Water Technologies Limited | | United Kingdom | | |
| Evoqua Water Technologies LLC | | Delaware | | |
| Evoqua Water Technologies Ltd. | | Canada | | |
| Evoqua Water Technologies Pte. Ltd. | | Singapore | | |
| Evoqua Water Technologies Pty. Ltd. | | Australia | | |
| EWT Holdings II Corp. | | Delaware | | |
| EWT Holdings III Corp. | | Delaware | | |
| Frontier Water Systems, LLC | | Delaware | | 68% |
| MAGNETO (Suzhou) special anodes Co., Ltd. | | China | | |
| MAGNETO international B.V. | | Netherlands | | |
| MAGNETO special anodes B.V. | | Netherlands | | |
| Neptune Benson, Inc. | | Delaware | | |
| Treated Water Outsourcing | | Delaware | | 50% |
| Water Technologies U.K. Ltd. | | United Kingdom | | |
| WTG Holdco Australia Pty. Ltd. | | Australia | | |
| WTG Holdco I LLC | | Delaware | | |
| WTG Holdings Cooperatief U.A. | | Netherlands | | |