Beginning July 1, 2021, the California 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
Under the headings below, you will find guidance and forms to help comply with the RTCR requirements.
Existing bacteriological sample siting plans may comply with the new State RTCR requirements provided the plans:
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 Local Primacy Agency , e.g. County Environmental Health Office). Guidance for creating a bacteriological sample siting plan is available from your local regulating agency. A template bacteriological sample siting plan for small water systems is available below.
Table 64423-A lists the required number of routine samples per month based on population served or number of service connections. Within 24 hours following a total coliform-positive sample result, water systems shall continue to collect a repeat sample set of 3 samples. All routine and repeat samples must be collected according to the approved bacteriological sample siting plan above.
| If a water system collects. | Level 1 Assessment is required within 30 days if. |
|---|---|
| . 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 |
| …a sample that is total coliform positive | Fails to collect all required repeat samples |
Under the RTCR, a water system which exceeds one of the trigger levels in the table above must conduct a Level 1 Assessment within 30 days. The completed assessment must be submitted to the local regulating agency (DDW District Office or County Health Office) within 30 days of exceeding the trigger level. 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 conduct or submit a completed assessment, or failure to complete the corrective actions is a violation of the Coliform Treatment Technique in the RTCR.
Templates for the Level 1 Assessment for different types of water systems are available below:
Under the RTCR, a water system exceeds the E.coli MCL when any of the four trigger levels above are met. In addition, the State 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 E.coli 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 is a violation of the Coliform Treatment Technique in the RTCR.
Public notification (Tier 1) will be required within 24 hours of the E.coli MCL exceedance and a template is available.
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 State RTCR requirements. Seasonal water systems are required to follow this start-up procedure which includes:
Water systems are required to issue a Tier 1 Public Notice to all customers within 24 hours of learning of an E.coli MCL exceedance.
Water systems are required to issue a Tier 2 Public Notice to all customers within 30 days for the following violations of the Coliform Treatment Technique requirements.
Templates for these Tier 1 and Tier 2 Public Notices is available on the Templates for Public Notification webpage.
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.
Pre-Rulemaking Workshops
In February 2017, the State Water Board released a draft of the planned regulation text and held six public workshops throughout California to receive input on the rule. The California version of the RTCR will follow many of the federal requirements, with some exceptions as indicated in the workshops.