Drinking Water Regulations

Interim Enhanced Surface Water Treatment Rule

IESWTR Reference Guide

Checklist for Producing Filter Profiles

Available on the eLibrary(opens in a new tab) (3800-FM-WSFR0004)
The Interim Enhanced Surface Water Treatment Rule (IESWTR) requires that public water systems report an obvious reason or produce a filter profile if any individual filter's turbidity exceeds certain trigger levels. Water system staff can use this checklist to help produce an accurate and usable filter profile.

Interpreting Filter Profiles

This is a PowerPoint presentation (PPT)(opens in a new tab) that gives specific guidance on interpreting filter profiles. Proper interpretation of filter profiles will help to identify causes of performance spikes.

IESWTR External Links

Pennsylvania's Final IESWTR(opens in a new tab) (PA Bulletin, Vol.31, No.29, Saturday, July 21, 2001)
This link will take you to the Environmental Quality Board's amendment to Chapter 109 Safe Drinking Water Regulations. The amendments pertain to filtration systems that serve at least 10,000 people and that use either surface water sources or groundwater sources that are under the direct influence of surface water (GUDI). The amendments establish: 2-log (99%) Cryptosporidium removal requirements; strengthened combined filter effluent turbidity performance standards and individual filter turbidity provisions; and disinfection benchmark provisions to assure continued levels of microbial protection while facilities take the necessary steps to comply with new disinfection byproduct standards. Also, the amendments include Cryptosporidium in the definition of ''GUDI.''

EPA's IESWTR Information(opens in a new tab)
This link will take you to EPA's Web site on the microbial and disinfection byproducts rules. You can view or download technical guidance manuals, look at slide presentations in the "Training Materials" section, obtain fact sheets, see the federal version of the rules, and learn more about ongoing microbial and disinfection byproducts rule-making efforts.