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Drinking Water Requirements for States and Public Water Systems

Long Term 1 Enhanced Surface Water Treatment Rule Documents

The Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) builds on the requirements of the Surface Water Treatment Rule (SWTR) and specifies treatment requirements to address Cryptosporidium and other microbial contaminants in public water systems serving less than 10,000 persons.

The rule balances the need for treatment with potential increases in disinfection by-products. The materials found on this page are intended to assist public water systems and states, respectively, in complying with and implementing the LT1ESWTR. 

SWTR/LT1 Monitoring Requirement Placards

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

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