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Water: Long Term 2 Enhanced Surface Water Treatment Rule

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Are you trying to implement the LT2 rule? Do you have questions about the provisions of the rule? If so, this Web page should help you out!

You can also check out our Questions & Answers Database for answers to popular questions or submit a question.


Public Water System Guidance

EPA provides guidance documents to help states and public water systems implement the rules.

Quick Reference Guides to LT2 Rule
These documents provide a simple and straightforward description of the rule, critical deadlines and requirements for drinking water systems and states, and information on monitoring requirements.

Fact Sheets for LT2 Rule

Source Water Monitoring Guidance for Public Water Systems
Description: This guidance provides surface water systems, laboratories, states, tribes, and other primacy agencies with a review of the source water monitoring provisions. Surface water systems are required to conduct source water monitoring for Cryptosporidium, E. coli, and turbidity to assess the relative risk of the source water and determine additional treatment needs, if any. The source water monitoring guidance manual provides direction to the systems on how, where and when to monitor and how to report the data, and summarizes how the data can be evaluated and used to determine risk bin classification. It includes the information on guidance on grandfathering Cryptosporidium data.
Target Audience: Surface water systems, laboratories, States, Tribes, other primacy agencies

Bin Calculation Spreadsheets for Filtered Systems
The Bin Calculation Spreadsheets can be used by filtered Public Water Systems to calculate and report their bin calculation that is required under the LT2 rule when the PWS has completed its source water monitoring. There are three spreadsheets, one for each of the possible scenarios for sampling frequency:

Each spreadsheet contains an instruction sheet and two example calculations.

Microbial Laboratory Guidance
Description: The Microbial Laboratory Guidance manual provides information regarding analytical methods required for analysis of Cryptosporidium and E. coli samples under the LT2 rule, and other LT2 rule requirements for sample collection and analysis, analytical methods, recordkeeping and data reporting. It also provides information regarding laboratory quality control, the EPA Laboratory Quality Assurance Evaluation Program, and vendor suppliers.
Target Audience: Cryptosporidium and E. coli laboratories

Complying with the Long Term 2 Enhanced Surface Water Treatment Rule: Small Entity Compliance Guide (Revised April 2009)
Description: This guidance document is intended for small public water systems, as required by the Small Business Regulatory Enforcement Fairness Act of 1996. This guide contains a general introduction and background for the LT2 rule, describes the specific requirements of the LT2 rule, and provides information on how to comply with those requirements. [Note copies printed before April 2009 had an error in Appendix B and in Appendix C. The annual mean E.coli calculation in both examples uses more than 12 months of E.coli results. The annual mean should be calculated using 12 months of E.coli results.]
Target Audience: Small surface water systems.

Long Term 2 Enhanced Surface Water Treatment Rule: Toolbox Guidance Manual
Description: Surface water systems required to provide treatment under the LT2 rule can select from numerous “microbial toolbox” treatment options to meet treatment requirements. This manual provides general information on the LT2 regulation and treatment requirements. It also provides guidance on the selection, design, and operation of treatment and management strategies for each of the 15 treatment options in the LT2ESWTR “microbial toolbox” that can be used to comply with treatment requirements under the rule.
Target Audience: Surface water systems required to install treatment under the LT2 rule.

Ultraviolet Disinfection Guidance Manual Final
EPA 815-R-06-007, November 2006
Description: Surface water systems required to provide treatment under the LT2 rule can utilize ultraviolet disinfection as one of the “microbial toolbox” treatment options to meet treatment requirements. This manual provides background information on fundamentals of UV light, microbial response to UV light, and UV reactors. It also provides guidance on the selection, design, installation, testing, startup, operation, maintenance, monitoring, recording and reporting of ultraviolet disinfection to comply with treatment requirements under the rule.
Target Audience: Surface water systems required to install treatment under the LT2 rule

Ultraviolet Disinfection Guidance Manual Workbook
All material has been incorporated into the Ultraviolet Disinfection Guidance Manual listed above..

Membrane Filtration Guidance Manual
Description: Surface water systems required to provide treatment under the LT2 rule can utilize membrane filtration as one of the “microbial toolbox” treatment options to meet treatment requirements. This manual is designed to provide surface water systems with an overview of membrane filtration and information regarding: requirements for membrane filtration under the LT2 rule; membrane filtration system design and operation; membrane filtration testing requirements; and startup and implementation considerations.
Target Audience: Surface water systems required to install treatment under the LT2 rule.

Simultaneous Compliance Guidance Manual for Stage 2 Rules
EPA 815-R-07-017, May 2007
Description: This manual discusses the issues that systems will face as they evaluate and implement changes necessary to comply with the Stage 2 DBPR and the LT2ESWTR, while still being required to comply with earlier rules such as the Total Coliform Rule and Lead and Copper Rule. Some of the changes that systems may make can have compliance or operational consequences if not properly designed, implemented, and monitored. This manual builds on a similar manual developed for the Stage 1 rules, incorporating new research and case studies, and is presented in a more user-friendly manner. EPA has developed this guidance manual to provide systems and states with information on operational and capital changes and approaches to enable systems to evaluate different compliance strategies and technologies.
Target audience: Public water systems making treatment and operational changes to comply, states.

Low-pressure Membrane Filtration for Pathogen Removal: Application, Implementation, and Regulatory Issues
Final guidance released in 2001.
Description: This report summarizes the state of membrane filtration in 2000 as applied for pathogen removal. The results of the study summarized in this report were used to support the development of the regulatory framework and guidance for membrane filtration under the LT2 rule.
Target audience: Public water systems and states.

State Guidance

The Long Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule) State Implementation Guidance

Training

If you are implementing the LT2 rule and are interested in trainings please visit the EPA's microbial and disinfection byproducts training site for a list of trainings, webcasts, and other training opportunities available.

  • Training Modules For the Long Term 2 Enhanced Surface Water Treatment Rule
    On-line training modules have been developed to provide additional guidance and instruction to utility and laboratory personnel on LT2 sample collection and analysis. These training modules are meant to complement and expand on the guidance manuals developed for the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR or LT2 rule).

    The following training modules require the use of the Flash player plug-in.
    If you do not have Flash installed, you can visit Adobe's Web site to download and install the plug-in for your browser. Get the Flash player. Exit EPA Disclaimer

  • Download the zip file on to your computer then unzip it to your desired location and open the index.html file to start the training.
    1. LT2 Training Module - Basic Microscopy (17M ZIP File)
      This module is designed to assist analysts in the proper use and maintenance of a microscope as used to detect Cryptosporidium and Giardia in Method 1623.

    2. On-line Sample Collection Training Module (58M ZIP File)
      This module is designed to help utility staff and others that will collect samples under the LT2 rule. The module details the sampling procedures for bulk sample collection and field filtration, and provides instruction on proper sample packing and shipping.

    3. On-line Microscopy Training Module (13M ZIP File)
      This module is designed to help analysts properly identify and characterize Cryptosporidium and Giardia using Method 1622/1623. The module includes characterization by FITC, DAPI, and DIC of positive control organisms and interfering organisms.

    4. Immunomagnetic Separation Training Module (26M ZIP File)
      This module details the immunomagnetic separation (IMS) procedure used in EPA Method 1622/1623 to separate Cryptosporidium oocysts and Giardia cysts from extraneous debris in a water sample.

  • LT2: Cryptosporidium & E. coli Sample Collection Recommendations Pocket Guide
    The following links contain a 'Pocket Reference' version of the Cryptosporidium & E. coli sample collection module.
    Select the first link to view a printable version of the pocket guide for use with 8.5" x 11" paper.
    Select the second link for a viewable version of the water-resistant pocket guide (can be scaled up to print on any size paper).
    Copies of the water-resistant color pocket guide can be ordered by using its document number [817-K-06-002] and contacting the National Service Center for Environmental Publications at 1-800-490-9198.

Point of Contact List
In various places in guidance it is suggested that systems contact EPA or the state. Regardless of whether EPA or the state would be doing certain reviews, certain states have indicated still being the point of contact for questions/interactions with systems. In order to provide clarity about who to contact, the following is a point of contact list. This list will be updated periodically as our implementation relationship with states evolve.

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