Code of Colorado Regulations
1000 - Department of Public Health and Environment
1002 - Water Quality Control Commission (1002 Series)
5 CCR 1002-11 - REGULATION NO. 11 - COLORADO PRIMARY DRINKING WATER REGULATIONS
Section 5 CCR 1002-11.16 - REVISED TOTAL COLIFORM RULE

(i) Sampling sites and a sample collection schedule that are representative of water throughout the distribution system. The supplier must collect total coliform samples according to the written sample siting plan. Monitoring locations may include a customer's premises, dedicated sampling station, or other designated compliance sampling site. The sample siting plan must include routine and repeat sample sites and any other sampling sites necessary to meet the requirements of 11.11.

(ii) Suppliers must identify repeat sample sites in the sample siting plan. Unless the requirements of 11.16(3)(a)(ii)(A) or 11.16(4)(a)(v)(A) are met, the supplier must collect at least one repeat total coliform sample at the site where the original total coliform-positive sample was collected, at least one repeat total coliform sample at a site within five service connections upstream from the site where the original total-coliform positive sample was collected, and at least one repeat total coliform sample at a site within five service connections downstream from the site where the original total-coliform positive sample was collected.

(iii) The Department may review, revise, and approve the written sample siting plan, as specified in 11.16(3). The supplier must demonstrate that the sample siting plan remains representative of the water quality in the distribution system.

(i) The supplier must collect total coliform samples at regular time intervals throughout the month, except:

(ii) The supplier may collect more samples than the minimum number of routine total coliform samples required as specified in Table 11.16-I as a tool to investigate potential problems in the distribution system.

(iii) If any of the sample results collected under 11.16(4) are total coliform-positive, the supplier must comply with the repeat monitoring requirements in 11.16(5) and E. coli analytical requirements in 11.16(4)(e).

(iv) The supplier is not required to submit special purpose samples, as defined in 11.2(5)(78) unless the sample result is E. coli-positive and is representative of water in the distribution system. The supplier must submit E. coli-positive special purpose sample results to the Department as specified in 11.35(2)(a).

(v) If an E. coli MCL violation occurs under 11.16(11) or if a coliform treatment technique is triggered under 11.16(8), the supplier must still collect at least the minimum number of required samples.

(vi) For groundwater systems, the supplier must collect triggered source water monitoring samples as specified in 11.11(4) in addition to repeat samples required in 11.16(5).

(i) For all public water systems, the supplier must collect the number of routine total coliform samples specified in Table 11.16-I each month except:

(ii) For public water systems that haul water, the water hauler must collect at least one total coliform sample from the outlet port of each tank or container each month that the tank or container is used to supply water to the public.

(iii) For hand-pumped wells, the supplier must collect at least one total coliform sample from each hand-pumped well each month that it supplies water to the public.

(iv) For the following public water systems, the supplier is not eligible for a quarterly sampling frequency as specified in 11.16(4)(b)(i)(A):

(v) The Department must perform a special monitoring evaluation during each sanitary survey to review the status of the system, including the distribution system, and determine whether the supplier is on an appropriate monitoring schedule.

(i) If the supplier is sampling quarterly, the supplier must increase the routine sampling frequency to monthly if any of the following events occur:

(ii) The supplier must begin the monthly sampling frequency in the month following the month that the event occurred under 11.16(4)(c)(i).

(iii) If the supplier is sampling monthly, the Department may allow the supplier to return to a routine quarterly sampling frequency if all of the following criteria are met:

(i) If the supplier is collecting total coliform samples on a quarterly frequency and one or more of the samples collected is total coliform-positive (with or without a Level 1 treatment technique trigger), the supplier must collect at least three additional routine samples during the following month.

(ii) If any of the additional routine sample results are total coliform-positive, the supplier must collect repeat samples as specified in 11.16(5).

(iii) The supplier must use the results of additional routine samples to determine whether an E. coli MCL violation of 11.16(10) has occurred or if a treatment technique requirement is triggered under 11.16(9).

(iv) If all three additional routine samples are total coliform-negative, the supplier may return to collecting one total coliform sample on a quarterly sampling frequency. The supplier must begin collecting the quarterly sampling frequency in the calendar quarter following the month that the three additional routine samples were required.

(i) If any routine sample under 11.16(4), repeat sample under 11.16(5), or special purpose sample result under 11.3(78) is E. coli-positive, the supplier must notify the Department no later than the end of the day that the supplier is notified of the sample result.

(i) If the supplier has a logistical problem beyond their control that prevents the supplier from collecting the repeat samples within the 24-hour limit, the Department may extend the 24hour limit on a case-by-case basis.

(ii) The Department shall not waive the requirement to collect repeat samples.

(i) If the system has only one service connection, the Department may allow the supplier to collect a larger volume repeat sample(s) in one or more sample containers of any size, as long as the total volume collected is at least 300 ml.

(i) Collect an additional repeat sample set as specified in 11.16(5)(a-d) for each site that had a total coliform-positive sample result.

(ii) Continue to collect additional repeat sample sets as specified in 11.16(5)(e)(i) until either:

(iii) If a trigger under 11.16(8) is exceeded as a result of a total coliform-positive routine sample, the supplier is required to conduct only one round of repeat monitoring for each total coliform-positive routine sample.

(i) No later than the 10th of the month following the month that the system began supplying water to the public, the supplier must submit the certification that start-up procedures were completed.

(i) The laboratory establishes that improper sample analysis caused the total coliform-

positive sample result.

(ii) Based on repeat sample results collected under 11.16(5), the Department determines that the total coliform-positive sample resulted from a domestic or other non-distribution system plumbing problem that is limited to the specific service connection from which the total coliform sample was collected. The Department shall not invalidate a total coliform-positive sample result on the basis of repeat sample results unless all repeat sample(s) collected at the same site as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected at a site other than the original site are total coliform-negative. The Department shall not invalidate a total coliform-positive sample result solely on the basis that all repeat sample results are total coliform-negative, or if the system has only one service connection.

(iii) The Department has substantial grounds to believe that a total coliform-positive sample result was due to a circumstance or condition that does not reflect water quality in the distribution system. If the Department makes this determination, the supplier must still collect the required number of repeat samples under 11.16(5) and use them to determine if a treatment technique is triggered as specified in 11.16(8). The Department must document the decision and supporting rationale for invalidating a total coliform-positive sample result in writing, have it approved and signed by a supervisor of the Department official who recommended the decision, and make this document available to the EPA and the public. The written documentation must state the specific cause of the total coliform-positive sample result and what action the supplier has taken, or will take, to correct the problem. The Department shall not invalidate a total coliform-positive sample result solely on the basis that all repeat sample results are total coliform-negative.

(iv) The laboratory shall invalidate a total coliform sample result (unless total coliforms are detected) if the sample produces a turbid culture in the absence of gas production using an analytical method where gas formation is examined (e.g., the Multiple-Tube Fermentation Technique), the sample produces a turbid culture in the absence of an acid reaction in the Presence-Absence (P-A) Coliform Test, or the sample exhibits confluent growth or produces colonies too numerous to count with an analytical method using a membrane filter (e.g., Membrane Filter Technique). If the laboratory invalidates a sample result because of such interferences, the supplier must collect a replacement total coliform sample from the same site as the invalidated sample no later than 24 hours after being notified of the invalidation, and have it analyzed for the presence of total coliforms. The supplier must continue to re-sample within 24 hours and have the samples analyzed for the presence of total coliforms until the supplier obtains a valid result. The Department may extend the 24-hour limit on a case-by-case basis.

(i) If the supplier collects greater than or equal to (>=) 40 samples per month, more than 5.0

percent of the samples collected for the month are total coliform-positive.

(ii) If the supplier collects less than (<) 40 samples per month, two or more samples collected for the monitoring period are total coliform-positive.

(iii) The supplier fails to collect all required repeat samples after any single total coliform-positive sample.

(i) An E. coli MCL violation occurs as specified in 11.16(11)(a).

(ii) A second treatment technique trigger for a Level 1 assessment, as specified in 11.16(8)(a), occurred within 12 consecutive months, except:

(i) To identify the possible presence of sanitary defects and defects in distribution system coliform sampling practices, the supplier must ensure that a Level 1 or Level 2 assessment is conducted.

(ii) The supplier must ensure that the assessor evaluates at least all of the following elements:

(iii) The supplier or the Department may request a consultation with the other party at any time during the assessment or corrective action phase. The consultation may be used to determine appropriate actions to be taken or to discuss relevant information that may impact the supplier's ability to comply with the requirements specified in 11.16(9).

(iv) If required by the Department, the supplier must ensure that the assessment is conducted consistent with any Department-specified modifications to assessment elements based on the size and type of the system and the size, type, and characteristics of the distribution system.

(v) The supplier must correct sanitary defects found through either Level 1 or Level 2

assessments, pursuant to 11.16(9)(b)(ii). If the supplier has not completed corrective action for any sanitary defect before the submission of the assessment form, the supplier, in consultation with the Department, must complete the corrective action(s) on a Department-approved schedule. The supplier must notify the Department when each scheduled corrective action is completed.

(i) If any treatment technique for a Level 1 assessment is triggered under 11.16(8)(a), the supplier must complete a Level 1 assessment, consistent with Department requirements, as soon as practical.

(ii) No later than 30 days after learning of a treatment technique trigger for a Level 1

assessment, the supplier must submit for review a completed Level 1 assessment form. In the completed form, the supplier must state whether sanitary defects were identified and if so, describe all of the following:

(iii) If the Department reviews the Level 1 assessment form and determines that the assessment is not sufficient or the assessment form is not complete (including any proposed schedule for any corrective actions not already completed), the Department shall consult with the supplier. If the Department requires revisions after consultation, the supplier must submit a revised assessment form to the Department on an agreed-upon date no later than 30 days from the date of the consultation.

(iv) Upon completion and submission of the assessment form by the supplier, the

Department shall determine if the supplier identified the likely reason(s) for the Level 1 trigger. If the supplier identified the likely reason(s) for the treatment technique trigger, the Department shall determine if the supplier corrected the problem or included a Department-approved schedule for correcting the problem.

(i) If any treatment technique for a Level 2 assessment is triggered under 11.16(8)(b), the supplier must ensure that a Level 2 assessment is conducted as soon as practical. The supplier must ensure that the Level 2 assessment, consistent with Department requirements, is completed by the Department or Department-approved party.

(ii) The supplier must comply with any expedited actions or additional actions required by the

Department in the case of an E. coli violation.

(iii) No later than 30 days after learning of a Level 2 treatment technique trigger exceedance, the supplier must submit for review a completed Level 2 assessment form. The supplier must state whether sanitary defects were identified and if so, describe all of the following:

(iv) If the Department reviews the Level 2 assessment form and determines that the assessment was not sufficient or the assessment form is not complete (including any proposed schedule for any corrective actions not already completed), the Department shall consult with the supplier. If the Department requires revisions after consultation, the supplier must submit a revised assessment form to the Department on an agreed-upon schedule no later than 30 days from the date of the consultation.

(v) Upon completion and submission of the assessment form by the supplier, the Department shall determine if the supplier identified the likely reason(s) for the Level 2 treatment technique trigger. If the supplier identified the likely reason(s) for the treatment technique trigger, the Department shall determine if the supplier corrected the problem or included a Department-approved schedule for correcting the problem.

(i) A repeat sample is E. coli-positive following a total coliform-positive routine sample.

(ii) A repeat sample is total coliform-positive following an E. coli-positive routine sample.

(iii) The supplier fails to collect all required repeat samples following an E. coli-positive routine sample.

(iv) The supplier fails to analyze a total coliform-positive repeat sample for E. coli.

(v) If a repeat sample collected at the monitoring location for triggered source water monitoring is E. coli-positive. The supplier must also comply with 11.11(4)(d). If a supplier collects more than one repeat sample at the monitoring location for triggered source water monitoring, the supplier may reduce the number of additional source water samples required under 11.11(4) by the number of repeat samples collected at that location that were not E. coli-positive.

(vi) If a supplier collects more than one repeat sample at the triggered source water monitoring location under 11.11(4), and more than one repeat sample is E. coli-positive, the supplier has violated the E. coli MCL and must also comply with 11.11(6).

(vii) If all of the repeat samples collected at the triggered source water monitoring location are E. coli negative and a repeat sample collected other than the one for triggered source water monitoring is E. coli-positive, the supplier has violated the E. coli MCL under 11.16(11)(a) and the supplier is not required to comply with 11.11(4)(d).

(i) A treatment technique was triggered under 11.16(8) and the supplier failed to conduct the required assessment or corrective action(s) within the timeframe as specified in 11.16(9).

(ii) For seasonal systems, the supplier fails to complete Department-approved start-up procedures before supplying water to the public.

(i) Failure to collect every required routine or additional routine sample in the supplier's compliance period.

(ii) Failure to analyze for E. coli following a total coliform-positive routine sample.

(i) Failure to submit monitoring results or a completed assessment form after a supplier conducts the required monitoring or assessment in a timely manner.

(ii) Failure to notify the Department following an E. coli-positive sample as required by 11.16(4)(e)(i) in a timely manner.

(iii) For seasonal systems, failure to submit certification of completion of Department-approved start-up procedures.

(i) Notify the Department no later than the end of the day that the supplier learns of the violation. If the supplier learns of the violation after the Department is closed, the supplier must contact the Department's 24 Hour Environmental Release/Incident report line (i.e., after-hours phone line).

(ii) Distribute Tier 1 public notice as specified in 11.33.

(i) Notify the Department no later than the end of the next business day after the supplier learns of the violation.

(ii) Distribute Tier 2 public notice as specified in 11.33.

(i) Notify the Department within 10 days after the system discovers the violation.

(ii) Conduct Tier 3 public notice as specified in 11.33.