The Surface Water Treatment Rule (SWTR) established minimum treatment requirements for public water systems using surface water as supply source. 

The document provides guidance on treatment methods and required monitoring to meet SWTR requirements. The guidance can be used in evaluating existing treatment processes or in considering new treatment processes or changes in treatment operation to meet SWTR treatment requirements.

For more information, please see the Surface Water Treatment Rules page.

• Guidance Manual for Compliance with the Filtration and Disinfection Requirements (PDF)(580 pp, 26 MB, March 1991)