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. 

• Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) Implementation Turbidity Provisions - Technical Guidance Manual (PDF)(254 pp, 6 MB, About PDF) EPA 816-R-04-007, August 2004
• Long Term 1 Enhanced Surface Water Treatment Rule: A Quick Reference Guide (PDF)(2 pp, 298 K, About PDF) EPA 816-F-02-001
• Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR) Disinfection Profiling and Benchmarking Technical Guidance Manual (PDF)(210 pp, 4 MB, About PDF) EPA 816-R-03-004, May 2003 

SWTR/LT1 Monitoring Requirement Placards

• Systems Serving Less than 10,000 People Using Conventional or Direct Filtration (PDF)(1 pp, 40 K, About PDF) EPA 816-F-08-001, January 2008
• Systems Serving Less Than 10,000 People Using Slow Sand, Diatomaceous Earth, or Alternative Filtration (PDF)(1 pp, 40 K, About PDF) EPA 816-F-08-002, January 2008
• Unfiltered Systems Serving Less than 10,000 people (PDF)(1 pg, 41 K, About PDF) EPA 816-F-08-003, January 2008

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

Top of Page