Revisions to the Interim Enhanced Surface Water Treatment Rule (IESWTR), the Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1DBPR), and Revisions to State Primacy Requirements To Implement the Safe Drinking Water Act (SDWA) Amendments

This final action will make minor revisions to the Interim Enhanced Surface Water Treatment Rule (IESWTR) and the Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR) which were published December 16, 1998 and the Revisions to State Primacy Requirements to Implement Safe Drinking Water Act (SDWA) Amendments (Primacy Rule) published April 28, 1998. This final rule revises the compliance dates for the IESWTR and the Stage 1 DBPR so that they coincide with calendar quarters. This change will facilitate implementation of both rules. This action also extends the use of new analytical methods to compliance monitoring for long-standing drinking water regulations for total trihalomethanes. In addition, this document corrects typographical errors, replaces inadvertently deleted text, and clarifies some of the regulatory provisions found in the published rules. Lastly, this document contains minor corrections to the Primacy Rule. These regulations relate to the requirements and procedures for States to obtain primary enforcement authority (primacy) for the Public Water System Supervision (PWSS) program under the Safe Drinking Water Act as amended by the 1996 Amendments. At this time, EPA is not taking final action on the proposed changes to Sec. 141.130(a)(1) (consecutive systems) and to Sec. 141.174(b) (filtration sampling requirements). These changes will be considered in future rulemaking.