Section 611.1059  Coliform Treatment Technique Triggers and Assessment Requirements for Protection Against Potential Fecal Contamination

a)         Treatment Technique Triggers.  A supplier must conduct assessments in accordance with subsection (b) after exceeding treatment technique triggers in subsections (a)(1) and (a)(2).

1)         Level 1 Treatment Technique Triggers

A)        For a supplier taking 40 or more samples per month, the supplier exceeds 5.0% total coliform-positive samples for the month.

B)        For a supplier taking fewer than 40 samples per month, the supplier has two or more total coliform-positive samples in the same month.

C)        The supplier fails to take every required repeat sample after any single total coliform-positive sample.

2)         Level 2 Treatment Technique Triggers

A)        An E. coli MCL violation, as specified in Section 611.1060(a).

B)        A second Level 1 trigger as defined in subsection (a)(1), within a rolling 12-month period, unless the Agency, by a SEP, has determined a likely reason that the samples that caused the first Level 1 treatment technique trigger were total coliform-positive and has established that the supplier has corrected the problem.

C)        For a supplier with approved annual monitoring, a Level 1 trigger in two consecutive years.

b)         Requirements for Assessments

1)         A supplier must ensure that Level 1 and Level 2 assessments are conducted in order to identify the possible presence of sanitary defects and defects in distribution system coliform monitoring practices.  Level 2 assessments must be conducted by parties approved by the Agency.

2)         When conducting assessments, the supplier must ensure that the assessor evaluates minimum elements that include review and identification of inadequacies in sample sites; sampling protocol; sample processing; atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality (including water storage); source and treatment considerations that bear on distributed water quality, where appropriate (e.g., small ground water systems); and existing water quality monitoring data.  The supplier must conduct the assessment consistent with any Agency directives that tailor specific assessment elements with respect to the size and type of the system and the size, type, and characteristics of the distribution system.

3)         Level 1 Assessments.  A supplier must conduct a Level 1 assessment consistent with Agency requirements if the supplier exceeds one of the treatment technique triggers in subsection (a)(1).

A)        The supplier must complete a Level 1 assessment as soon as practical after any trigger in subsection (a)(1).  In the completed assessment form, the supplier must describe sanitary defects detected, corrective actions completed, and a proposed timetable for any corrective actions not already completed.  The assessment form may also note that no sanitary defects were identified.  The supplier must submit the completed Level 1 assessment form to the Agency within 30 days after the supplier learns that it has exceeded a trigger.

B)        If the Agency reviews the completed Level 1 assessment and determines that the assessment is not sufficient (including any proposed timetable for any corrective actions not already completed), the Agency must consult with the supplier.  If the Agency, by a SEP, requires revisions after consultation, the supplier must submit a revised assessment form to the Agency on an agreed-upon schedule not to exceed 30 days from the date of the consultation.

C)        Upon completion and submission of the assessment form by the supplier, the Agency must determine if the supplier has identified a likely cause for the Level 1 trigger and, if so, establish that the supplier has corrected the problem, or has included a schedule acceptable to the Agency for correcting the problem.

4)         Level 2 Assessments.  A supplier must ensure that a Level 2 assessment consistent with Agency requirements is conducted if the supplier exceeds one of the treatment technique triggers in subsection (a)(2).  The supplier must comply with any expedited actions or additional actions required by the Agency, by a SEP, in the case of an E. coli MCL violation.

A)        The supplier must ensure that a Level 2 assessment is completed by the Agency or by a party approved by the Agency as soon as practical after any trigger in subsection (a)(2).  The supplier must submit a completed Level 2 assessment form to the Agency within 30 days after the supplier learns that it has exceeded a trigger.  The assessment form must describe sanitary defects detected, corrective actions completed, and a proposed timetable for any corrective actions not already completed.  The assessment form may also note that no sanitary defects were identified.

B)        The supplier may conduct Level 2 assessments if the supplier has staff or management with the certification or qualifications specified by the Agency unless otherwise directed by the Agency, by a SEP.

C)        If the Agency reviews the completed Level 2 assessment and determines that the assessment is not sufficient (including any proposed timetable for any corrective actions not already completed), the Agency must consult with the system.  If the Agency requires revisions after consultation, the supplier must submit a revised assessment form to the Agency on an agreed-upon schedule not to exceed 30 days.

D)        Upon completion and submission of the assessment form by the supplier, the Agency must determine if the system has identified a likely cause for the Level 2 trigger and determine whether the supplier has corrected the problem, or has included a schedule acceptable to the Agency for correcting the problem.

c)         Corrective Action.  A supplier must correct sanitary defects found through either Level 1 or 2 assessments conducted under subsection (b).  For corrections not completed by the time of submission of the assessment form, the supplier must complete the corrective actions in compliance with a timetable approved by the Agency, by a SEP, in consultation with the supplier.  The supplier must notify the Agency when each scheduled corrective action is completed.

d)         Consultation.  At any time during the assessment or corrective action phase, either the water supplier or the Agency may request a consultation with the other party to determine the appropriate actions to be taken.  The supplier may consult with the Agency on all relevant information that may impact on its ability to comply with a requirement of this Subpart AA, including the method of accomplishment, an appropriate timeframe, and other relevant information.

BOARD NOTE:  Derived from 40 CFR 141.859.

(Source:  Amended at 44 Ill. Reg. 6996, effective April 17, 2020)