Revised Total Coliform Rule (RTCR)

Information and resources to help Public Water Systems maintain compliance with the Revised Total Coliform Rule (RTCR).

The Environmental Protection Agency (EPA) published the Revised Total Coliform Rule (RTCR) in the Federal Register on February 13, 2013, and minor corrections on February 26, 2014. The RTCR is the revision to the 1989 Total Coliform Rule (TCR) and is intended to improve public health protection.
The RTCR applies to all public water systems (PWS) and introduced changes in how coliforms are monitored and how positive samples are managed. Compliance started on April 1, 2016.

What is Total Coliform?

Total coliforms are a group of bacteria found in soil, plants, water, and in human and animal waste that are harmless (with a few exceptions) to humans. While they may not be harmful on their own, they operate as a useful indicator for the presence of other potentially harmful microorganisms in drinking water. These harmful microorganisms may include a variety of bacteria, parasites, viruses, and other pathogens that may cause health problems to humans if ingested. Monitoring levels of total coliform in drinking water leads to a better understanding of the effectiveness of water treatment methods and the reliability of the distribution system.

Total Coliform Rule (TCR)

The Total Coliform Rule (TCR) is a National Primary Drinking Water Regulation (NPDWR), which was published in 1989 and became effective in 1990. The rule set both a health goal, known as a Maximum Contaminant Level Goal (MCLG), and legal limits, known as Maximum Contaminant Levels (MCLs), for the presence of total coliforms in drinking water.

The MCLG for total coliforms is set at zero, while the MCL is based on the positive sample tests for total coliforms, or for total coliforms and Escherichia coli (E. coli) or fecal coliforms.

The purpose of the 1989 TCR was to protect public health by ensuring the integrity of the drinking water distribution system and monitoring for the presence of microbial contamination.

The rule required all public water systems (PWSs) to monitor for the presence of total coliforms in the distribution system at a frequency proportional to the number of people served.

Revised Total Coliform Rule (RTCR)

While the TCR focused on violations exceeding total coliform limits, the RTCR focuses on identifying and correcting the cause of these exceeded limits through required assessments. With that, the revisions focus more on protecting public health and proactive prevention of microbial contamination. Some of the main differences include the integration of Level 1 and Level 2 assessments when bacteria are detected, system evaluations, and designating E. coli as a trigger for Maximum Contaminant Level (MCL) violations.

Massachusetts has adopted the RTCR into 310 CMR 22.00: The Massachusetts Drinking Water Regulations which are available here.

Key provisions of the RTCR include:

• Setting a maximum contaminant level goal (MCLG) and maximum contaminant level (MCL) for E. coli for protection against potential fecal contamination.
• Setting a total coliform treatment technique (TT) requirement.
• Requirements for monitoring total coliforms and E. coli according to a sample siting plan and schedule specific to the PWS.
• Provisions allowing PWSs to transition to the RTCR using their existing TCR monitoring frequency, including PWSs on reduced monitoring under the TCR.
• Requirements for seasonal systems (such as Non-Community Water Systems not operated on a year-round basis) to monitor and certify the completion of a MassDEP DWP approved start-up procedures.
• Requirements for assessments and corrective action when monitoring results show that PWSs may be vulnerable to contamination.
• Public notification (PN) requirements for violations.
• Specific language for Community PWS to include in their Consumer Confidence Reports (CCRs) when they must conduct an assessment or if they incur an E. coli MCL violation.

Public Health Information and Guidelines

A public health order is a preventive measure to protect public health from waterborne disease or contamination. MassDEP issues different types of orders, depending on the severity of the problem; boil orders are issued if excess levels of bacteria or other contamination are found by a PWS during routine testing. For more information on water boil orders and other public health orders please see our webpage: Drinking Water Boil Orders and Public Health Orders 

Public Notification

Multiple Public Notice templates, including Tier 1 and Tier 2 RTCR Templates, are available for PWS use on the Public Notification Forms and Templates webpage. 

Guidance for People with Severely Weakened Immune Systems

Individuals with severely weakened immune systems are recommended by the EPA/Centers for Disease Control and Prevention (CDC) to take extra caution regarding their drinking water. The most effective way to ensure your drinking water is save from waterborne pathogens is by boiling your water for at least one minute as outlined in MassDEP’s boil order guidelines. For more information on recommended precautions for immunocompromised individuals please see the following document:

• A joint EPA and CDC guidance document for people who are immunocompromised
• Spanish version - “Guía Para Individuos Con El Sistema Inmunológico Severamente Debilitado”

Coliform Bacteria Level 1 Assessment

Under the RTCR, a PWS that is vulnerable to microbial contamination is required to conduct an assessment and corrective action of the system to identify and correct any sanitary defects in the distribution system or treatment processes. The PWS should conduct a Level 1 assessment if it exceeds certain triggers related to positive total coliform samples collected during routine sampling. Learn more about Coliform Bacteria Level 1 Assessments by visiting the MassDEP DWP Resources below:

Coliform Bacteria Level 2 Assessment

The RTCR requires all PWSs to complete a Level 2 Assessment in response to the triggers identified in the Massachusetts Drinking Water Regulations. The purpose of the Level 2 Assessment is to identify the possible presence of sanitary defects and defects in distribution system coliform monitoring practices.  Learn more about Coliform Bacteria Level 2 Assessments by visiting the MassDEP DWP Resources below.

Seasonal Start-Up Procedure for Non-Community Systems

The RTCR requires seasonal water suppliers to implement a “State-approved start-up procedure.” This requirement was put in place to provide additional public health protection by offsetting an increased contamination risk in water systems where piping and other system components are depressurized. Learn more about Seasonal Start-Ups for Non-Community Systems by visiting the MassDEP DWP resources below.

Revised Total Coliform Rule Sampling Resources

• EPA RTCR Sampling Resources
• RTCR Placards
• RTCR Sample Siting Plan with Template Manual
• Fact Sheet: Repeat Monitoring Requirements
• Fact Sheet: Requirements for Small Systems on Monthly Monitoring
• Fact Sheet: Requirements for Small Systems on Quarterly Monitoring
• Checklist: Items to be Discovered & Addressed upon Discovery of Coliform Bacteria