Revised Total Coliform Rule: What are the Requirements for My City?

EPA has issued a compliance order to all states requiring routine monitoring of Total Coliforms (TC) and E.coli (EC) levels in the public drinking water system. The mandate from EPA was revised and referred to as Revised Total Coliform Rule (RTCR) 78 FR 10269, February 13, 2013, Vol. 78, No. 30. The reason for the RTCR is to “increase public health protection through the reduction of potential pathways of entry for fecal contamination into distribution system”. (1)

The RTCR establishes a maximum contaminate level (MCL) for E.coli– set at zero—and uses E.coli and Total Coliforms to initiate a “find and fix” approach to address fecal contamination that could enter the distribution system of a city’s drinking water system. The operative word here is “could”. The mandate requires cities to identify potential sanitary sewer system problems, leaks, and other defects, and take action to correct them. The RTCR establishes required monitoring of the water distribution system to create reportable limits for microbial water quality for all potable water distribution networks; all Public Water Systems (PWSs). The intent of this regulation as further defined by EPA is as follows:

  • A decrease in the pathways by which fecal contamination can enter the drinking water distribution system.
  • Reduce the potential risk from all waterborne pathogens including bacteria, viruses, parasitic protozoa, and their associated illnesses that should be achieved through a reduction in fecal contamination. (1)

The deadline for compliance with the new RTCR is February 2016 when a PWS must have a written Siting Plan that identifies the systems sample collection schedule, sample sites, and establishes routine and repeat monitoring locations. Whether quarterly or annually, monitoring your city will need to identify additional monitoring locations in the sample plan. The Sample Siting Plan must be approved by the state agency (TCEQ) and may require revision as determined by the state. The new RTCR also sets the “frequency and timing of required microbial testing based on population served, public water system type and source water type: ground water or surface water”. (2) TCEQ has an established TC sampling protocol for public water systems.

How does this revised rule change or alter the city’s current monitoring program? Routine sampling throughout the month and a set schedule is common and each TC sample is tested for E.coli. What has changed is the notification policy should a sample test positive for TC and E.coli—the state must be notified the same day the city received notification. Additionally, repeat sampling is required from the same sample collection site. Within 24 hours of the positive notification three additional samples must be taken within five service connections upstream and downstream of the positive sample site. For TC+ samples that indicate TC contamination along with E. Coli violations in repeat sampling triggers the PWS to conduct a Level 1 Assessment that is a full evaluation of the sanitary sewer collection system and treatment to identify pathways for contamination to enter the PWS. (1) If any defects are found the PWS must make all necessary repairs to eliminate future contamination.

This will affect the overall operation of every PWS community, transient and non-transient system in Texas.

Level 1 Assessment triggers are as outlined below:

  • A PWS collecting fewer than 40 samples per month has two or more TC+ routine/ repeat samples in the same month.
  • A PWS collecting at least 40 samples per month with greater than 5.0 percent of the routine/repeat samples in the same month that are TC+.
  • A PWS fails to take every required repeat sample after any single TC+ sample. (1)

Level 2 assessments are triggered by any one of the following as set out by EPA:

  • A PWS incurs an E.coli MCL violation.
  • A PWS has a second Level 1 Assessment within a rolling 12-month period.
  • A PWS on state-approved annual monitoring has a Level 1 Assessment trigger in 2 consecutive years.

Level 2 Assessments are conducted by the state or an approved entity.

  • The PWS must insure that the Level 2 Assessment is conducted and appropriate documentation filed with the state at the completion of the assessment.
  • The PWS is responsible for all necessary findings and repairs indicated to prevent future contaminated samples.
  • Level 1 & 2 Assessments must be done within 30 days of a violation. (1)

A PWS will receive an E.coli MCL violation when there is any combination of an EC+ sample result with a routine/repeat TC+ or EC+ sample result:

E.coli MCL Violation Occurs with the Following Sample Result Combination

EPA Revised Total Coliform Rule: A Quick Reference Guide

The purpose of the revised rule in daily practice does not change much from the current TCEQ requirements. This will affect the overall operations of every PWS community, transient and non-transient system in Texas. The most dramatic effect this will have on PWS is identifying monitoring points in the distribution system that will allow a good assessment of the microbial condition of the PWS. Identifying old sanitary sewer collection piping in close proximity to the city’s distribution piping will now become extremely important. Documenting the types of pipe, (material, i.e. clay, concrete, etc.) in both systems along with the approximate age of the pipes will allow cities to make informed decisions on replacement for both sanitary sewers and water distribution piping.

One key area that will need to be addressed is public perception of a safe drinking water system. Public awareness will be heightened with this new rule and with this comes additional public scrutiny of the city’s operations. Monthly citizens water quality confidence reports will need to be monitored and full disclosure of any defects noted. Reporting and documentation of all repairs in both systems will need to be increased and communicated accordingly. Infrastructure improvements in treatment, handling and distribution will need to be a priority for cities in order to demonstrate a city’s water quality and safety to its citizens.

With EPA involved in the overall regulatory policing of this rule change, particular attention to sample sites, sample collection techniques and proper training for city personnel on sample collection is paramount. The costs of all of these changes will fall back to each PWS. Getting out in front with proper citizen information and education will make these changes smoother in transition.

Violations of the rule will most likely involve TCEQ and possibly EPA. Until the final enforcement is enacted and adopted by TCEQ, EPA could have a significant role in the enforcement process.


  1. Revised Total Coliform Rule: A quick Reference Guide, pgs. 1-3, EPA
  2. TCEQ, Coliform Sampling for Public Water Systems, August 2012, RG-421