Section 392. Coliform treatment technique triggers and assessment requirements  


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  • A. Assessments shall be conducted in accordance with subsections C, D, and E of this section after exceeding treatment technique triggers.

    B. Treatment technique triggers.

    1. Level 1 treatment technique triggers:

    a. For owners required to collect 40 or more samples per month, the number of total coliform-positive samples exceeds 5.0% of the number of samples collected for the month.

    b. For owners required to collect fewer than 40 samples per month, when there are two or more total coliform-positive samples in the same month.

    c. The owner fails to collect every required repeat sample after any single total coliform-positive sample.

    2. Level 2 treatment technique triggers:

    a. An E. coli PMCL violation, as specified in 12VAC5-590-380 B 2.

    b. A second Level 1 trigger occurs within a rolling 12-month period, unless the commissioner has determined a likely reason for the first Level 1 treatment technique trigger and that the owner has corrected the problem.

    C. Assessment requirements.

    1. Level 1 and 2 assessments shall be conducted in order to identify the possible presence of sanitary defects and defects in the distribution system coliform monitoring practices. The owner shall be responsible for conducting Level 1 assessments. Level 2 assessments shall be conducted by the commissioner.

    2. When conducting Level 1 and Level 2 assessments, the assessor shall include:

    a. A review and identification of inadequacies in sample sites, sampling protocol, and sample processing;

    b. A review of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired;

    c. Evaluation of changes in distribution system maintenance and operation that could affect distributed water quality, including water storage;

    d. Evaluation of source and treatment considerations that impact distributed water quality; and

    e. Evaluation of existing water quality monitoring data.

    3. Level 1 assessment.

    a. The owner shall complete the assessment and document the assessment on the Waterworks Level 1 Assessment form. The owner shall submit the assessment form, as soon as practical, but within 30 days after the owner learns that a trigger in subdivision B 1 of this section has been exceeded.

    b. If the commissioner reviews the completed Level 1 assessment and determines that the assessment is not sufficient, including any proposed timetable for any corrective actions, the commissioner shall consult with the owner. If the commissioner requires revisions after the consultation, the owner shall submit a revised assessment form to the appropriate ODW field office on an agreed upon schedule not to exceed 30 days from the date of consultation.

    c. Upon completion and submission of the assessment form by the owner, the commissioner shall determine if the owner has identified a likely cause for the Level 1 trigger and, if so, confirm that the owner has corrected the problem or has included a schedule acceptable to the commissioner for correcting the problem.

    4. Level 2 assessment.

    a. ODW will complete the assessment and document the assessment on the Waterworks Level 2 Assessment form. ODW staff will consult with the owner during the assessment and complete the assessment within 30 days upon learning a waterworks has exceeded any trigger in subdivision B 2 of this section.

    b. The commissioner will send to the owner the completed assessment form, which will describe any detected sanitary defects, corrective actions completed or needed and, if needed, a timetable to complete corrective actions. The owner will return the form within seven days with signature that indicates concurrence with the listed actions needed and timetable to complete the corrective actions. If the owner does not concur with either an action or timetable to complete a corrective action, the owner shall notify the commissioner, complete consultation with the commissioner, and develop a revised corrective action schedule. The owner shall submit the revised schedule to the commissioner for review and approval within 30 days of the date of the consultation.

    D. Corrective actions.

    1. The owner shall correct sanitary defects found through either Level 1 or 2 assessment conducted under subsection C of this section.

    2. The owner shall complete the corrective action or corrective actions in compliance with the timetable approved by the commissioner in consultation with the owner. The owner shall notify the appropriate ODW field office no later than seven days after each scheduled corrective action is completed.

    E. Consultation.

    1. At any time during the assessment or corrective action phase, either the owner or the commissioner may request a consultation with the other party to determine the appropriate actions to be taken.

    2. The owner may consult with the commissioner on all relevant information that may impact the ability to comply with subsection D of this section.

    F. Violations. Failure to conduct the required assessment or corrective actions in accordance with subsections C and D of this section, after exceeding a treatment technique trigger specified in subsection B of this section, is a treatment technique violation. The owner shall provide public notification as required under Tier 2 conditions specified in 12VAC5-590-540.

Historical Notes

Derived from Volume 33, Issue 03, eff. November 2, 2016.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.