The Revised Total Coliform Rule

Greetings from the DEC Drinking Water Program!

As many of you are already probably aware, the EPA published revisions to the Total Coliform Rule, called the Revised Total Coliform Rule (RTCR), on February 13, 2013. This is one of the few drinking water rules that affect every public water system in the state, so we wanted to bring you up to date on the State’s efforts to adopt this very important microbial rule.

First, a brief history of the issues that have led to the revisions of the old Total Coliform Rule may be helpful.

EPA is required to review and revise, as appropriate, each National Primary Drinking Water Regulation no less than every six years. In 2003, EPA determined that it was appropriate to revise the Total Coliform Rule. The original TCR was published in 1989. Since then, a lot has been learned about the microbial quality of drinking water. This information allowed a new and improved rule to be developed that could address several major concerns.

The major concerns identified by the Six-Year Review process included the frequency and location of monitoring, follow-up monitoring after total-coliform-positive samples, the basis of the Maximum Contaminant Level (MCL), and even the use of total coliform as an indicator of water quality in the distribution system. The RTCR aims to increase public health protection through the reduction of potential pathways of entry for fecal contamination into the distribution system. The RTCR, like the TCR, applies to all public water systems.

During the rule revision process, the EPA convened a Microbials/Disinfection By-Products Advisory Committee to review existing data and findings from multiple groups associated with drinking water treatment and public health protection. Most of the findings of these groups were related to deficiencies in the distribution system which can lead to potential contamination problems. Also, data collected by the Centers for Disease Control indicate that most waterborne disease outbreaks are now associated with problems in the distribution system. The occurrence of waterborne disease outbreaks due to deficiencies in the distribution system have been steadily rising. During the 1981-1990 reporting period, fifteen percent of outbreaks were attributed to distribution system contamination. From 1991-2000, twenty-four percent of outbreaks were caused by distribution system problems. That is a significant increase which warranted a closer look at how we are monitoring water quality in the distribution system.

The RTCR links monitoring frequency to water quality and system performance.

The EPA believes that the RTCR will result in increased public health protection by putting more emphasis on maintaining water quality in the distribution system. This will mostly be accomplished by requiring routine monitoring, identifying potential problems, and requiring corrective action to fix problems in the system. The final RTCR retains the basic monitoring requirements of the original TCR; however, the RTCR links monitoring frequency to water quality and system performance by (1) providing criteria that well-operated systems must meet to qualify and stay on reduced monitoring; (2) requiring increased monitoring for high-risk small systems with an unacceptable compliance history; and (3) requiring some new monitoring requirements for seasonal systems such as campgrounds and state and national park systems. The RTCR also establishes a health goal, or maximum contaminant level goal (MCLG), and an MCL for E. coli and eliminates the MCLG and MCL for total coliforms, replacing the MCL with a treatment technique for coliforms that requires assessment and corrective action.

What does this mean for water systems?

One of the major changes in the RTCR is the establishment of two levels of formal assessment—called Level 1 Assessment and Level 2 Assessment—to identify the possible presence of sanitary defects in the distribution system which are triggered by positive coliform samples. Level 1 Assessments will be triggered by the following: (1) for a system collecting more than 40 samples a month, when more than 5 % of samples are total coliform positive; (2) for a system collecting fewer than 40 samples per month, when more than one sample is total coliform positive; and (3) if a system fails to collect any of the required repeat samples after a routine positive total coliform sample. EPA expects that most Level 1 Assessments will be conducted by the system operator or owner or a designated representative of the system, such as a consultant who routinely does work for the system. Level 1 Assessments must be conducted within 30 days of the triggering event unless the State agrees to a different schedule.

A Level 2 Assessment provides a more detailed examination of the system than the Level 1 Assessment through the use of more comprehensive investigation and review of the available information. A Level 2 Assessment is triggered for the following reasons: (1) The PWS has a violation of the E. coli MCL; or (2) the system triggers more than one Level 1 Assessment in a rolling 12-month period. The Level 2 Assessment will be conducted either by the State or by an individual approved by the State; the qualifications necessary to perform a Level 2 Assessment will be defined by the State as part of its primacy package for adopting the rule. Level 2 Assessments are required within 30 days of the triggering event.

Both the Level 1 and Level 2 Assessments may require corrective actions if sanitary defects are found. The EPA has issued guidance on corrective actions and we encourage you to review the current guidance to become familiar with the requirements.

Another major change in the RTCR is that seasonal systems must complete and certify that they have completed a State-approved start-up procedure at the beginning of each operating season. The start-up procedure is designed to reduce the risk of contamination associated with startup and shut down. The Drinking Water Program is currently working on establishing an approved start-up procedure that will be made available to systems before the rule’s compliance date.

The compliance date for RTCR is April 1, 2016.

The State plans to request a two-year extension from EPA for adopting this rule into the Drinking Water Regulations at 18 AAC 80. However, the RTCR requirements will kick in in 2016. The State and EPA have agreed that the State will be responsible for implementing the requirements of the rule even before we adopt it, with EPA handling RTCR enforcement until RTCR becomes effective in 18 AAC 80. Here are some of the things you can do now to help your system prepare to meet the new requirements of the RTCR:

  • Become familiar with the RTCR
  • Attend training as it becomes available
  • Review guidance documents as they are released
  • Review and update sample siting plans if necessary
  • Use available tools to better understand your distribution system
  • Evaluate your system for potential vulnerabilities
  • Review data management processes
  • Review your public notification protocols

Please contact your local DEC DWP Environmental Program Specialist if you have any questions specific to your system.

Contributed by Cindy Christian, DEC Drinking Water Program.

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