The Environmental Protection Agency (EPA) is proposing revisions to the 1989 Total Coliform Rule (TCR), a national primary drinking water regulation (NPDWR). The purpose of the TCR is to protect public health by ensuring the integrity of the drinking water distribution system and monitoring for the presence of microbial contamination. EPA anticipates greater public health protection under the proposed revised requirements, which are based on recommendations by a federal advisory committee.
Under the proposed Revised Total Coliform Rule (RTCR) (USEPA 20 10b), a public water system (PWS) that is vulnerable to microbial contamination (as indicated by its monitoring results) 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. Under the proposed RTCR, EPA uses total coliform (TC) as indicators of the integrity of the distribution system, and E. coli as an indicator of the presence of fecal contamination.
The purpose of performing assessments is to enhance public health protection by identifying the presence of "sanitary defects" (defects that could provide a pathway of entry for microbial contamination into the distribution system or that are indicative of a failure or imminent failure in a barrier that is already in place). Sampling results can trigger an assessment designed to take a closer look at the system and to identify whether one or more sanitary defects are present.
MassDEP Assessment Initiative
MassDEP is taking a proactive approach to the RTCR by implementing the Level 1 Assessment prior to EPA's promulgation of the new rule. This initiative is intended to assist the PWS in evaluating deficiencies that may lead to the presence of total coliform in the distribution system and will help to identify the source of the contamination, correct problems that may compromise public health, and help to prevent future violations.
Assessment and Corrective Action
Under the current TCR assessment and corrective action (if necessary) are recommended if PWS has a total coliform maximum contaminant level (MCL) violation. The PWS should conduct a Level 1 assessment if it exceeds any of the following triggers:
- for systems taking ≥ 40 samples per month, the PWS exceeds 5.0% TC+ samples for the month; or
- for systems taking < 40 samples per month, the PWS has >1 TC+ samples for the month; or
- PWS fails to take every required repeat sample after any single routine TC+ sample.
Level 1 Assessment
The Level 1 assessment consists of an examination of the system's source water, treatment, distribution system, and relevant operational practices. While the Level 1 assessment is intended to be a relatively simple assessment, it should be conducted thoroughly enough to capture the possibility that there may be multiple sanitary defects. Systems should complete the entire assessment form, even if they believe they understand the apparent cause, to ensure they have a holistic picture of the overall integrity of their system and do not inadvertently overlook a sanitary defect. Ideally, a well-performed Level 1 assessment will prevent most systems from developing conditions that lead to a Level 2 assessment.
Who Can Perform a Level 1 Assessment?
The Level 1 Assessment is a self-assessment. This assessment is intended for the PWS to review general water system infrastructure, operating and sampling protocols in response to a total coliform bacteria MCL violation, and should be completed by a knowledgeable representative of the water system. A Level 1 assessment should be conducted or managed by a responsible party of the PWS. This should be someone familiar enough with the system to answer the questions in the Level 1 Assessment form or to gather correct information from others who work for the system. Having the PWS responsible for having the assessment conducted also serves to strengthen the PWS's capacity to ensure that barriers to contamination are in place and are effective in the future.
Public Water Systems conducting a Level 1 Assessment must fully complete the Coliform Bacteria Level 1 Assessment Form . The PWS will provide MassDEP with a completed Level 1 Assessment form within 30 days after determination of exceeding a Level 1 Assessment trigger; the Level 1 Assessment trigger is a Total Coliform Maximum Contaminant Level (TCR MCL) violation. In an effort to ensure that the certified operator is aware of the violation and participates in the Level 1 Assessment, both the certified operator and the responsible party filling out the Level 1 Assessment form (if different than the certified operator) must sign the document.
Since the form cannot cover all possible situations or distribution system configurations Assessors should use professional judgment in the application of the forms to their system and provide additional information t support conclusions, if warranted.
The Level 1 Assessment form may be used in lieu of ATTACHMENT H COLIFORM VIOLATION EVALUATION SURVEY which is part of Guidelines and Policies for Public Water Systems Appendix O, HANDBOOK FOR WATER SUPPLY EMERGENCIES.
To complete this form electronically, click on the gray boxes and type in your responses. For printed forms, write in your responses. All forms must be completely filled out and returned to the MassDEP office where the system is located (Find Your Region ).
If you have any questions on Level 1 assessment requirements please contact the Drinking Water Program at 617-292-5770 or by email at Program.Director-DWP@state.ma.us.
If you are a small system serving less than 10,000 users and you need technical assistance, call the Massachusetts Rural Water Association at 866-451-8099 or email email@example.com, or contact the appropriate MassDEP staff:
CERO: Paula Caron, 508-767-2719
NERO: Jim Persky, 978-694-3227
SERO: Karen Dube, 508-946-2720
WERO: Rick Larson, 413-755-2207
Boston: Anita Wolovick, 617-292-5920
For an in-depth explanation of the Level 1 Assessment refer to EPA's "Proposed Revised Total Coliform Rule Assessments and Corrective Actions Guidance Manual" at http://water.epa.gov/lawsregs/rulesregs/sdwa/tcr/regulation.cfm#draft.