Revised Total Coliform Rule
Beginning April 1, 2016, the Federal Revised Total Coliform Rule (rTCR) will become effective. The revisions include the new Coliform Treatment Technique requirement replacing the Total Coliform MCL, and a new E.coli MCL regulatory limit. The Revised Total Coliform Rule establishes a “Find-and-fix” approach for investigating and correcting causes of coliform problems within water distribution systems. California will be revising its version of the Total Coliform Rule in Title 22; however, the draft regulations will not be adopted in time to correspond with the Federal rule requirements. Beginning April 1, 2016, all public water systems will need to comply with California’s existing Total Coliform Rule and the new requirements in the federal rTCR, until California can complete the regulatory adoption process for the rTCR.
Under the headings below, you will find guidance and forms to help comply with California’s current TCR and the new federal RTCR during this interim period. A two-page summary table of both rules is also provided at the link below to help illustrate how compliance with the current TCR and the federal rTCR can be achieved. This webpage will be updated with news on California’s rTCR regulation adoption process as it is available.
Draft Revised Total Coliform Regulations
- VIDEO: Revised Total Coliform Workshop Presentation in Sacramento - March 29, 2017
- Draft CA Revised Total Coliform Regulations - February 3, 2017
- Revised Total Coliform Rule Workshop Presentation - (PowerPoint)
- RTCR Workshops Public Notice
Bacteriological Sample Siting Plans
Existing bacteriological sample siting plans will comply with the new Federal rTCR requirements provided the plans:
- Identify repeat sample locations for each routine sample location
- Identify triggered source sampling needed to comply with the Groundwater Rule
- Identify the sample schedule and rotation plan among sampling sites for collection of routine, repeat and triggered source sampling
If your existing plan does not include the additional requirements above, please submit a new plan to your local regulating agency (DDW District Office or County Environmental Health Office). A sample bacteriological sample siting plan will be available soon.
Routine and Repeat Sampling
Routine sampling frequency and number of required samples remain the same for all water systems. Within 24 hours following a total coliform-positive sample result, water systems shall continue to collect a repeat sample set of 3 samples (4 samples for systems which collect only one routine sample per month). Water systems which collect fewer than five routine samples per month must continue to collect five routine samples in the month following a total coliform-positive sample result. All routine and repeat samples must be collected according to the approved bacteriological sample siting plan above.
Total Coliform MCL Exceedances / Level 1 Assessment
|If a water system collects...||Total Coliform MCL Exceedance|
|...Less than 40 routine and repeat samples per month||More than 1 TC-positive sample in a month|
|...40 or more routine and repeat samples per month||More than 5.0% TC-positive samples in a month|
Under the Federal rTCR, a water system which exceeds the current Total Coliform MCL (see table above) must also conduct a Level 1 Assessment. The completed assessment must be submitted to the local regulating agency (DDW District Office or County Health Office) within 30 days of the exceedance. The Level 1 Assessment will require water systems to identify a possible cause to the total coliform positive samples and corrective actions taken/needed. Failure to complete the corrective actions will be a violation of the Coliform Treatment Technique in the Federal rTCR.
Templates for the Level 1 Assessment for different types of water systems are available below:
- Level 1 Assessment for simple water systems (well, pressure tank, no treatment/chlorination)
- Level 1 Assessment for most groundwater systems (wells, storage/pressure tanks, chlorination)
- Level 1 Assessment for water systems with a surface water treatment plant
- Level 1 Assessment for groundwater systems with chemical removal treatment
- Level 1 Assessment for transient, non-community water systems
Public notification (Tier 2) will be required within 30 days of the exceedance and a template will be available soon.
E.coli MCL Exceedances / Level 2 Assessment
E.Coli MCL Exceedances
1. E.coli-positive repeat sample following TC-positive routine sample
2. TC-positive repeat sample following an E.coli positive routine sample
3. Failure to collect all required repeat samples following a E.coli-positive routine sample
4. Failure to test for E.coli when any repeat sample is TC-positive
Acute Total Coliform MCL (Section 64426.1, Title 22, CCR)
E.coli MCL (Federal rTCR) - NEW
Under the Federal rTCR, a water system exceeds the E.coli MCL under the existing Acute Total Coliform MCL conditions in Title 22 (see table above) In addition, the Federal rTCR adds two new conditions to the E.coli MCL for failing to collect all required repeat samples following a E.coli positive routine sample and failing to test for E.coli after a total coliform positive repeat sample. The water system must notify the local regulating agency (DDW District Office or County Environmental Health Office) by the end of the business day to schedule a Level 2 assessment. Similar to the Level 1 assessment, the Level 2 Assessment will require the water system to identify a possible cause to the total coliform positive samples and corrective actions taken/needed. However, the Level 2 Assessment will be performed by the local regulating agency. Failure to return the assessment or complete the corrective actions will be a violation of the Coliform Treatment Technique in the Federal rTCR.
Public notification (Tier 1) will be required within 24 hours of the exceedance and a template will be available soon.
Seasonal Water Systems
Non-community water systems which do not operate on a year-round basis (e.g. starts-up and shut down at the beginning and end of each operating season) must have an approved, written start-up procedure to comply with the Federal rTCR requirements. Seasonal water systems are required to follow this start-up procedure which includes:
- an inspection of water system components,
- disinfection and flushing,
- coliform and chlorine residual monitoring,
- use of certified distribution operators to perform 1-3 above,
- notification to local regulating agency (DDW District Office or County Environmental Health Office) upon start-up.
Monthly Coliform Reporting
All water systems are required to report results of coliform monitoring monthly by the 10th day of the following month. A revised monthly summary form and instructions are available below.
- USEPA Revised Total Coliform Rule Information
- Revised Total Coliform Rule Analytical Methods (ELAP webpage)
Regulatory Agency Contact Information
(Page last updated 5/31/18)
Drinking Water Resources
Water is a precious resource in California, and maintaining its quality is of utmost importance to safeguard the health of the public and the environment.