Md. Code Regs. 26.04.01.11-4

Current through Register Vol. 51, No. 22, November 1, 2024

Section 26.04.01.11-4 - Microbiological Contaminant Monitoring and Reporting Requirements

A. Applicability.

(1) This regulation applies to all public water systems.

(2) Suppliers of water shall comply with the provisions of this regulation beginning April 1, 2016, unless otherwise specified.

(3) Suppliers of water that fail to comply with the applicable requirements of 40 CFR §§ 141.851- 141.861, are in violation of the regulation.

B. Analytical Methods and Laboratory Certification.

(1) Analytical Methodology.

(a) The standard sample volume required for analysis, regardless of analytical method used, is 100 ml.

(b) The samples shall be analyzed for the presence or absence of total coliforms and E. coli; a determination of density is not required.

(c) The time from sample collection to initiation of test medium incubation may not exceed 30 hours. Suppliers are encouraged but not required to hold samples below 10 deg. C during transit.

(d) If drinking water having residual chlorine (measured as free, combined, or total chlorine) is to be analyzed, sufficient sodium thiosulfate (Na 2 S 2 O 3) shall be added to the sample bottle before sterilization to neutralize any residual chlorine in the water sample.

(e) Analyses shall be conducted for total coliform and E. coli analyses in accordance with an EPA approved analytical method, which is incorporated by reference.

(2) Laboratory certification. Suppliers shall have all compliance samples required under this regulation analyzed by a laboratory certified by the EPA, or the Approving Authority to analyze drinking water samples. The laboratory used by the supplier shall be certified for each method, and associated contaminants used for compliance monitoring analyses under this regulation.

C. General Monitoring Requirements for All Public Water Systems.

(1) Sample Siting Plans.

(a) No later than March 31, 2016, suppliers shall develop a written sample siting plan, which identifies sampling sites and includes a sample collection schedule and which shall be representative of water throughout the distribution system. These plans are subject to review by the Approving Authority and revision as needed. Suppliers shall collect total coliform samples according to the written sample siting plan. Monitoring required by this regulation may take place at a customer's premise, dedicated sampling station, or other designated compliance sampling location. Routine and repeat sample sites and any sampling points necessary to meet the requirements of Regulation .11-2 shall be included in the sampling plan.

(b) Suppliers shall collect samples at regular time intervals throughout the month, except that suppliers that use only ground water and serve 4,900 or fewer people may collect all required samples on a single day if they are taken from different sites.

(c) Suppliers shall take at least the minimum number of required samples even if the system has had an E. coli MCL violation or has exceeded the coliform treatment technique triggers in § 1(1) of this regulation.

(d) A supplier may conduct more compliance monitoring than is required by this regulation to investigate potential problems in the distribution system and use monitoring as a tool to assist in uncovering problems. A supplier may take more than the minimum number of required routine samples and shall include the results in calculating whether the coliform treatment technique trigger in § 1(1) (a) of this regulation has been exceeded if the samples are taken in accordance with the existing sample siting plan and are representative of water throughout the distribution system.

(e) Suppliers shall identify repeat monitoring locations in the sample siting plan according to the requirements of 40 CFR § 141.853(a) which is incorporated by reference.

(2) Special purpose samples. Special purpose samples, such as those taken to determine whether disinfection practices are sufficient following pipe placement, replacement, or repair, may not be used to determine whether the coliform treatment technique trigger has been exceeded. Repeat samples taken according to §H of this regulation are not considered special purpose samples, and shall be used to determine whether the coliform treatment technique trigger has been exceeded.

(3) Invalidation of total coliform samples. A total coliform-positive sample invalidated under this section does not count toward meeting the minimum monitoring requirements of this regulation.

(a) The Approving Authority may invalidate a total coliform-positive sample if the one of the following conditions are met:

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

(ii) The Approving Authority, on the basis of the results of repeat samples collected as required under §H of this regulation, determines that the total coliform-positive sample resulted from a domestic or other nondistribution system plumbing problem. The Approving Authority cannot invalidate a sample on the basis of repeat sample results unless all repeat sample (s) collected at the same tap as the original total coliform-positive sample are also total coliform-positive, and all repeat samples collected at a location other than the original tap are total coliform-negative; or

(iii) The Approving Authority has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition that does not reflect water quality in the distribution system. In this case, the supplier shall still collect all repeat samples required under §H of this regulation, and use them to determine whether a coliform treatment technique trigger in § 1 of this regulation has been exceeded.

(b) A laboratory shall invalidate a total coliform sample (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), produces a turbid culture in the absence of an acid reaction in the Presence-Absence (P-A) Coliform Test, or exhibits confluent growth or produces colonies too numerous to count with an analytical method using a membrane filter (e.g., Membrane Filter Technique). If a laboratory invalidates a sample because of such interference, the supplier shall collect another sample from the same location as the original sample within 24 hours of being notified of the interference problem, and have it analyzed for the presence of total coliforms. The supplier shall continue to re-sample within 24 hours and have the samples analyzed until it obtains a valid result. The Approving Authority may waive the 24-hour time limit on a case-by-case basis. Alternatively, the Approving Authority may implement criteria for waiving the 24-hoursampling time limit to use in lieu of case-by-case extensions.

D. Routine Monitoring Requirements for Noncommunity Water Systems Serving 1,000 or Fewer People Using Only Ground Water.

(1) General.

(a) This section applies to noncommunity water systems using only ground water (except ground water under the direct influence of surface water, as defined in Regulation .0 1 of this chapter) and serving 1,000 or fewer people.

(b) Following any total coliform-positive sample taken under the provisions of this section, suppliers shall comply with the repeat monitoring requirements and E. coli analytical requirements in §H of this regulation.

(c) Once all monitoring required by this section and §H of this regulation for a calendar month has been completed, suppliers shall determine whether any coliform treatment technique triggers specified in § 1 of this regulation have been exceeded. If any trigger has been exceeded, suppliers shall complete assessments as required by § 1 of this regulation.

(2) Monitoring frequency for total coliforms. Suppliers shall monitor each calendar quarter that the system provides water to the public, except for seasonal systems or as provided under subsections (3) - (8) and (10) of this section. Seasonal systems shall meet the monitoring requirements of subsection (9) of this section.

(3) Transition.

(a) Systems, including seasonal systems, shall continue to monitor according to the total coliform monitoring schedules under Regulation .11A(5) of this chapter that were in effect on March 31, 2016, unless any of the conditions for increased monitoring in subsection (6) of this section are triggered on or after April 1, 2016, or unless otherwise directed by the Approving Authority.

(b) Beginning April 1, 2016, the Approving Authority shall perform a special monitoring evaluation during each sanitary survey to review the status of the system, including the distribution system, to determine whether the system is on an appropriate monitoring schedule in accordance with 40 CFR § 141.853(c).

(4) Annual site visits. Beginning no later than January 1, 2017, systems on annual monitoring, including seasonal systems, shall have an initial and recurring annual site visit by the Approving Authority that is equivalent to a Level 2 assessment or an annual voluntary Level 2 assessment that meets the criteria in § 1(2) of this regulation in order to remain on annual monitoring.

(5) Criteria for annual monitoring. Beginning April 1, 2016, the Approving Authority may reduce the monitoring frequency for a well-operated ground water system from quarterly routine monitoring to no less than annual monitoring, if the system demonstrates that it meets the criteria for reduced monitoring in paragraphs (5) (a) - (c) of this section, except for a system that has been on increased monitoring under the provisions of subsection (6) of this section. A system on increased monitoring under subsection (6) of this section shall meet the provisions of subsection (7) of this section to go to quarterly monitoring and shall meet the provisions of subsection (8) of this section to go to annual monitoring.

(a) The system has a clean compliance history for a minimum of 12 months;

(b) The most recent sanitary survey shows that the system is free of sanitary defects or has corrected all identified sanitary defects, has a protected water source, and meets approved construction standards; and

(c) The Approving Authority has conducted an annual site visit within the last 12 months and the supplier has corrected all identified sanitary defects. The supplier may substitute a Level 2 assessment that meets the criteria in § 1(2) for the annual site visit.

(6) A system on quarterly or annual monitoring that experiences any of the events identified in paragraphs (6) (a) - (d) of this section shall begin monthly monitoring the month following the event. A system on annual monitoring that experiences an event identified in paragraphs (6)(e) of this section shall begin quarterly monitoring the quarter following the event. The supplier shall continue monthly or quarterly monitoring until the requirements in subsection (7) of this section for quarterly monitoring or subsection (8) of this section for annual monitoring are met. A system on monthly monitoring for reasons other than those identified in paragraphs (6) (a) - (d) of this section is not considered to be on increased monitoring for the purposes of subsections (7) and (8) of this section.

(a) The system triggers a Level 2 assessment or two Level 1 assessments under the provisions of § 1 of this regulation in a rolling 12-month period;

(b) The system has an E. coli MCL violation;

(c) The system has a coliform treatment technique violation;

(d) The system has two monitoring violations under this regulation, or one monitoring violation under this regulation and one Level 1 assessment under the provisions of § 1 of this regulation in a rolling 12-month period for a system on quarterly monitoring; or

(e) The system has one monitoring violation under this regulation for a system on annual monitoring.

(7) The Approving Authority may reduce the monitoring frequency for a system on monthly monitoring triggered under subsection (6) of this section to quarterly monitoring if the system meets the criteria in paragraphs (7) (a) and (7)(b) of this section.

(a) Within the last 12 months, the system shall have a completed sanitary survey or a site visit by the Approving Authority or by its designee or a voluntary Level 2 assessment by a party approved by the Approving Authority, be free of sanitary defects, and have a protected water source; and

(b) The system shall have a clean compliance history for a minimum of 12 months.

(8) The Approving Authority may reduce the monitoring frequency for a system on increased monitoring under subsection (6) of this section if the system meets the criteria in subsection (7) of this section plus the criteria in paragraphs (8) (a) and (8) (b) of this section.

(a) An annual site visit by the Approving Authority and correction of all identified sanitary defects. The supplier may substitute a voluntary Level 2 assessment by a party approved by the Approving Authority for the annual site visit in any given year.

(b) The supplier shall have in place or adopt one or more additional enhancements to the water system barriers to contamination in paragraphs (8)(b)(i) - (v) of this section:

(i) An approved cross connection control plan;

(ii) An operator certified by the Board of Waterworks and Waste Systems Operators or regular visits by a circuit rider certified by the Board of Waterworks and Waste Systems Operators;

(iii) Continuous disinfection entering the distribution system and a residual in the distribution system in accordance with criteria specified by the Approving Authority;

(iv) Demonstration of maintenance of at least a 4-log removal or inactivation of viruses as provided for under 40 CFR § 141.403(b)(3); or

(v) Other equivalent enhancements to water system barriers as approved by the Approving Authority.

(9) Seasonal Systems.

(a) Beginning April 1, 2016, all seasonal systems shall demonstrate completion of an approved start-up procedure, which may include a requirement for startup sampling prior to serving water to the public.

(b) Beginning April 1, 2016 a seasonal system shall monitor every month that it is in operation unless it meets the criteria in subparagraphs (9)(b)(i) - (iii) of this section to be eligible for monitoring less frequently than monthly, except as provided under subsection (3) of this section.

(i) Seasonal systems monitoring less frequently than monthly shall have an approved sample siting plan that designates the time period for monitoring based on site-specific considerations (e.g., during periods of highest demand or highest vulnerability to contamination). Seasonal systems shall collect compliance samples during this time period.

(ii) To be eligible for quarterly monitoring, the system shall meet the criteria in subsection (7) of this section.

(iii) To be eligible for annual monitoring, the system shall meet the criteria under subsection (8) of this section.

(c) The Approving Authority may exempt any seasonal system from some or all of the requirements for seasonal systems if the entire distribution system remains pressurized during the entire period that the system is not operating, except that systems that monitor less frequently than monthly shall monitor during the vulnerable period designated by the Approving Authority.

(10) Additional routine monitoring the month following a total coliform-positive sample. Suppliers collecting samples on a quarterly or annual frequency shall conduct additional routine monitoring the month following one or more total coliform-positive samples (with or without a Level 1 treatment technique trigger). Suppliers shall collect at least three routine samples during the next month, except that the Approving Authority may waive this requirement if the conditions of 40 CFR § 141.854(j) are met. Suppliers may either collect samples at regular time intervals throughout the month or may collect all required routine samples on a single day if samples are taken from different sites. Suppliers shall use the results of additional routine samples in coliform treatment technique trigger calculations under § 1 of this regulation.

E. Routine Monitoring Requirements for Community Water Systems Serving 1,000 or Fewer People Using Ground Water.

(1) General.

(a) This section applies to community water systems using only ground water (except ground water under the direct influence of surface water, as defined in Regulation .0 1 of this chapter) and serving 1,000 or fewer people.

(2) Monitoring frequency for total coliforms. The monitoring frequency for total coliforms is one sample/month, except as provided for under subsections (3) - (6) of this section.

(3) Transition.

(a) All suppliers shall continue to monitor according to the total coliform monitoring schedules under Regulation .11A(5) of this chapter that were in effect on March 31, 2016, unless any of the conditions in subsection (5) of this section are triggered on or after April 1, 2016, or unless otherwise directed by the Approving Authority.

(4) Criteria for reduced monitoring. The Approving Authority may reduce the monitoring frequency from monthly monitoring to no less than quarterly monitoring if the system is in compliance with operator certification provisions and demonstrates that it meets the criteria in paragraphs (4) (a) - (c) of this section. A system that loses its certified operator shall return to monthly monitoring the month following that loss.

(a) The system has a clean compliance history for a minimum of 12 months.

(b) The most recent sanitary survey shows the system is free of sanitary defects, or that the system is in compliance with an approved plan and schedule to correct the sanitary defects. The sanitary survey must also show that the system has a protected water source and meets approved construction standards.

(c) The system meets at least one of the following criteria:

(i) An annual site visit by the Approving Authority that is equivalent to a Level 2 assessment or an annual Level 2 assessment by a party approved by the Approving Authority and correction of all identified sanitary defects (or an approved plan and schedule to correct them and is in compliance with the plan and schedule).

(ii) An approved cross connection control plan.

(iii) Continuous disinfection entering the distribution system and a residual in the distribution system in accordance with criteria specified by the Approving Authority.

(iv) Demonstration of maintenance of at least a 4-log removal or inactivation of viruses as provided for under 40 CFR § 141.403(b)(3).

(v) Other equivalent enhancements to water system barriers as approved by the Approving Authority.

(5) Return to routine monthly monitoring requirements. Systems on quarterly monitoring that experience any of the events in paragraphs (5) (a) - (d) of this section shall begin monthly monitoring the month following the event. The supplier shall continue monthly monitoring until it meets the reduced monitoring requirements in subsection (4) of this section.

(a) The system triggers a Level 2 assessment or two Level 1 assessments in a rolling 12-month period.

(b) The system has an E. coli MCL violation.

(c) The system has a coliform treatment technique violation.

(d) The system has two monitoring violations under this regulation in a rolling 12-month period.

(6) Additional routine monitoring the month following a total coliform-positive sample. Suppliers collecting samples on a quarterly frequency shall conduct additional routine monitoring the month following one or more total coliform-positive samples (with or without a Level 1 treatment technique trigger). Suppliers shall collect at least three routine samples during the next month, except that the Approving Authority may waive this requirement if the conditions of paragraph (6) (a), (b), or (c) of this section are met. Suppliers may either collect samples at regular time intervals throughout the month or may collect all required routine samples on a single day if samples are taken from different sites. Suppliers shall use the results of additional routine samples in coliform treatment technique trigger calculations.

(a) The Approving Authority may waive the requirement to collect three routine samples the next month in which the system provides water to the public if the Approving Authority, or an agent approved by the Approving Authority, performs a site visit before the end of the next month in which the system provides water to the public. Although a sanitary survey need not be performed, the site visit shall be sufficiently detailed to allow the Approving Authority to determine whether additional monitoring and/or any corrective action is needed. The Approving Authority cannot approve an employee of the system to perform this site visit, even if the employee is an agent approved by the Approving Authority to perform sanitary surveys.

(b) The Approving Authority may waive the requirement to collect three routine samples the next month in which the system provides water to the public if the Approving Authority has determined why the sample was total coliform-positive and has established that the supplier has corrected the problem or will correct the problem before the end of the next month in which the supplier serves water to the public. In this case, the Approving Authority shall document this decision to waive the following month's additional monitoring requirement in writing, have it approved and signed by the supervisor of the Approving Authority official who recommends such a decision, and make this document available to the EPA and the public. The written documentation shall describe the specific cause of the total coliform-positive sample and what action the supplier has taken and/or will take to correct this problem.

(c) The Approving Authority may not waive the requirement to collect three additional routine samples the next month in which the supplier provides water to the public solely on the grounds that all repeat samples are total coliform-negative. If the Approving Authority determines that the supplier has corrected the contamination problem before the supplier takes the set of repeat samples required in 40 CFR § 141.858, and all repeat samples were total coliform-negative, the Approving Authority may waive the requirement for additional routine monitoring the next month.

F. Routine Monitoring Requirements for Subpart H Public Water Systems Serving 1,000 or Fewer People.

(1) General.

(a) This section applies to subpart H public water systems, as defined in Regulation .0 1 of this chapter, serving 1,000 or fewer people.

(c) Once all monitoring required by this section and §H of this regulation for a calendar month has been completed, suppliers shall determine whether any coliform treatment technique triggers specified in §1 of this regulation have been exceeded. If any trigger has been exceeded, suppliers shall complete assessments as required by §1 of this regulation.

(d) Seasonal Systems.

(i) Beginning April 1, 2016, all seasonal systems shall demonstrate completion of an approved start-up procedure, which may include a requirement for start-up sampling prior to serving water to the public.

(ii) The Approving Authority may exempt any seasonal system from some or all of the requirements for seasonal systems if the entire distribution system remains pressurized during the entire period that the system is not operating.

(2) Routine monitoring frequency for total coliforms. Subpart H systems of this regulation (including consecutive systems) shall monitor monthly. Systems may not reduce monitoring.

(3) Unfiltered Subpart H Systems. A subpart H system of this chapter that does not practice filtration in compliance with subparts H, P, T, and W of 40 CFR § 141 shall collect at least one total coliform sample near the first service connection each day the turbidity level of the source water, measured as specified in 40 CFR § 141.74(b)(2), exceeds 1 NTU. When one or more turbidity measurements in any day exceed 1 NTU, the supplier shall collect this coliform sample within 24 hours of the first exceedance, unless the Approving Authority determines that the supplier, for logistical reasons outside the supplier's control, cannot have the sample analyzed within 30 hours of collection and identifies an alternative sample collection schedule. Sample results from this coliform monitoring shall be included in determining whether the coliform treatment technique trigger in §1 of this regulation has been exceeded.

G. Routine Monitoring Requirements for Public Water Systems Serving More Than 1,000 People.

(1) General.

(a) This section applies to public water systems serving more than 1,000 persons.

(c) Once all monitoring required by this section and §H of this regulation for a calendar month has been completed, suppliers shall determine whether any coliform treatment technique triggers specified in §1 of this regulation have been exceeded. If any trigger has been exceeded, suppliers shall complete assessments as required by §1 of this regulation.

(d) Seasonal Systems.

(i) Beginning April 1, 2016, all seasonal systems shall demonstrate completion of a Approving Authority-approved start-up procedure, which may include a requirement for start-up sampling prior to serving water to the public.

(2) Monitoring frequency for total coliforms. The monitoring frequency for total coliforms is based on the population served by the system, as follows:

Population served	Minimum number of samples per month
1,001 to 2,500	2
2,501 to 3,300	3
3,301 to 4,100	4
4,101 to 4,900	5
4,901 to 5,800	6
5,801 to 6,700	7
6,701 to 7,600	8
7,601 to 8,500	9
8,501 to 12,900	10
12,901 to 17,200	15
17,201 to 21,500	20
21,501 to 25,000	25
25,001 to 33,000	30
33,001 to 41,000	40
41,001 to 50,000	50
50,001 to 59,000	60
59,001 to 70,000	70
70,001 to 83,000	80
83,001 to 96,000	90
96,001 to 130,000	100
130,001 to 220,000	120
220,001 to 320,000	150
320,001 to 450,000	180
450,001 to 600,000	210
600,001 to 780,000	240
780,001 to 970,000	270
970,001 to 1,230,000	300
1,230,001 to 1,520,000	330
1,520,001 to 1,850,000	360
1,850,001 to 2,270,000	390
2,270,001 to 3,020,000	420
3,020,001 to 3,960,000	450
3,960,001 or more	480
Total Coliform Monitoring Frequency for Public Water Systems Serving More Than 1,000 People

(3) Unfiltered Subpart H Systems. A subpart H system of this part that does not practice filtration in compliance with subparts H, P, T, and W of 40 CFR 141 shall collect at least one total coliform sample near the first service connection each day the turbidity level of the source water, measured as specified in § 141.74(b)(2), exceeds 1 NTU. When one or more turbidity measurements in any day exceed 1 NTU, the supplier shall collect this coliform sample within 24 hours of the first exceedance, unless the Approving Authority determines that the supplier, for logistical reasons outside the supplier's control, cannot have the sample analyzed within 30 hours of collection and identifies an alternative sample collection schedule. Sample results from this coliform monitoring shall be included in determining whether the coliform treatment technique trigger in §1 of this regulation has been exceeded.

(4) Reduced monitoring. Suppliers may not reduce monitoring, except for noncommunity water systems using only ground water (and not ground water under the direct influence of surface water) serving 1,000 or fewer people in some months and more than 1,000 persons in other months. In months when more than 1,000 persons are served, the suppliers shall monitor at the frequency specified in subsection (1) of this section. In months when 1,000 or fewer people are served, the Approving Authority may reduce the monitoring frequency, in writing, to a frequency allowed under §D of this regulation for a similarly situated system that always serves 1,000 or fewer people, taking into account the provisions in §D(1) - (7).

H. Repeat Monitoring and E. coli Requirements

(1) Repeat Monitoring.

(a) If a sample taken under §§D - G of this regulation is total coliform-positive, the supplier shall collect a set of repeat samples within 24 hours of being notified of the positive result. The supplier shall collect no fewer than three repeat samples for each total coliform-positive sample found. The Approving Authority may extend the 24-hour limit on a case-by-case basis if the supplier has a logistical problem in collecting the repeat samples within 24 hours that is beyond its control. Alternatively, the Approving Authority may implement criteria for the supplier to use in lieu of case-by-case extensions. In the case of an extension, the Approving Authority shall specify how much time the supplier has to collect the repeat samples. The Approving Authority cannot waive the requirement for a supplier to collect repeat samples in paragraphs (a) - (c) of this section.

(b) The supplier shall collect all repeat samples on the same day, except that the Approving Authority may allow a supplier with a single service connection to collect the required set of repeat samples over a 3-day period or 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.

(c) The supplier shall collect an additional set of repeat samples in the manner specified in paragraphs (a) - (c) of this section if one or more repeat samples in the current set of repeat samples is total coliform-positive. The supplier shall collect the additional set of repeat samples within 24 hours of being notified of the positive result, unless the Approving Authority extends the limit as provided in paragraph (a) of this section. The supplier shall continue to collect additional sets of repeat samples until either total coliforms are not detected in one complete set of repeat samples or the supplier determines that a coliform treatment technique trigger specified in § 1(1) has been exceeded as a result of a repeat sample being total coliform-positive and notifies the Approving Authority. If a trigger identified in §1 is exceeded as a result of a routine sample being total coliform-positive, suppliers are required to conduct only one round of repeat monitoring for each total coliform-positive routine sample.

(d) After a supplier collects a routine sample and before it learns the results of the analysis of that sample, if it collects another routine sample (s) from within five adjacent service connections of the initial sample, and the initial sample, after analysis, is found to contain total coliforms, then the supplier may count the subsequent sample (s) as a repeat sample instead of as a routine sample.

(e) Results of all routine and repeat samples taken under §§D-G of this regulation not invalidated by the Approving Authority shall be used to determine whether a coliform treatment technique trigger specified in §1 of this regulation has been exceeded.

(2) Escherichia coli (E. coli) Testing.

(a) If any routine or repeat sample is total coliform-positive, the supplier shall analyze that total coliform-positive culture medium to determine if E. coli are present. If E. coli are present, the supplier shall notify the Approving Authority by the end of the day when the supplier is notified of the test result, unless the supplier is notified of the result after the Approving Authority office is closed and the Approving Authority does not have either an after-hours phone line or an alternative notification procedure, in which case the supplier shall notify the Approving Authority before the end of the next business day.

(b) The Approving Authority has the discretion to allow a supplier, on a case-by-case basis, to forgo E. coli testing on a total coliform-positive sample if that supplier assumes that the total coliform-positive sample is E. coli-positive. Accordingly, the supplier shall notify the Approving Authority as specified in paragraph (2) (a) of this section and the provisions of 40 CFR § 141.63(c) apply.

I. Coliform Treatment Technique Triggers and Assessment Requirements for Protection Against Potential Fecal Contamination

(1) Treatment Technique Triggers. Suppliers shall conduct assessments in accordance with subsection (2) of this section after exceeding treatment technique triggers in paragraphs (l)(a) and (1) (b) of this section.

(a) Level 1 Treatment Technique Triggers.

(i) For suppliers taking 40 or more samples per month, the system exceeds 5.0% total coliform-positive samples for the month.

(ii) For suppliers taking fewer than 40 samples per month, the system has two or more total coliform-positive samples in the same month.

(iii) The system fails to take every required repeat sample after any single total coliform-positive sample.

(b) Level 2 treatment technique triggers.

(i) An E. coli MCL violation, as specified in 40 CFR § 141.860(a).

(ii) A second Level 1 trigger as defined in paragraph (l)(a) of this section, within a rolling 12-month period, unless the Approving Authority 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.

(iii) For systems with approved annual monitoring, a Level 1 trigger in 2 consecutive years.

(2) Requirements for assessments.

(a) Suppliers shall ensure that Level 1 and 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 shall be conducted by parties approved by the Approving Authority.

(b) When conducting assessments, suppliers shall 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 shall conduct the assessment consistent with any Approving Authority 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 shall conduct a Level 1 assessment consistent with Approving Authority requirements if the system exceeds one of the treatment technique triggers in paragraph (1) (a) of this section.

(a) The supplier shall complete a Level 1 assessment as soon as practical after any trigger in paragraph (l)(a) of this section. In the completed assessment form, the supplier shall 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 shall submit the completed Level 1 assessment form to the Approving Authority within 30 days after the supplier learns that it has exceeded a trigger.

(b) If the Approving Authority 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 Approving Authority shall consult with the supplier. If the Approving Authority requires revisions after consultation, the supplier shall submit a revised assessment form to the Approving Authority 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 Approving Authority shall determine if the supplier has identified a likely cause for the Level 1 trigger and, if so, establish if the supplier has corrected the problem, or has included a schedule acceptable to the Approving Authority for correcting the problem.

(4) Level 2 Assessments. A supplier shall ensure that a Level 2 assessment consistent with Approving Authority requirements is conducted if the supplier exceeds one of the treatment technique triggers in paragraph (I) (b) of this section. The supplier shall comply with any expedited actions or additional actions required by the Approving Authority in the case of an E. coli MCL violation.

(a) The supplier shall ensure that a Level 2 assessment is completed as soon as practical after any trigger in paragraph (I) (b) of this section. The supplier shall submit a completed Level 2 assessment form to the Approving Authority within 30 days after the supplier learns that it has exceeded a trigger. The assessment form shall 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 Approving Authority unless otherwise directed by the Approving Authority.

(c) If the Approving Authority 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 Approving Authority shall consult with the supplier. If the Approving Authority requires revisions after consultation, the supplier shall submit a revised assessment form to the Approving Authority on an agreed-upon schedule not to exceed 30 days.

(d) Upon completion and submission of the assessment form by the supplier, the Approving Authority shall determine if the supplier 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 Approving Authority for correcting the problem.

(5) Corrective Action. Suppliers shall correct sanitary defects found through either Level 1 or 2 assessments conducted under subsection (2) of this section. For corrections not completed by the time of submission of the assessment form, the supplier shall complete the corrective action(s) in compliance with a timetable approved by the Approving Authority in consultation with the supplier. The supplier shall notify the Approving Authority when each scheduled corrective action is completed.

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

J. Violations of the Revised Total Coliform Rule.

(1) E. coli MCL Violation. A system is in violation of the MCL for E. coli when any of the conditions identified in paragraphs (I) (a) - (d) of this section occur:

(a) The system has an E. coli-positive repeat sample following a total coliform-positive routine sample;

(b) The system has a total coliform-positive repeat sample following an E. coli-positive routine sample;

(c) The system fails to take all required repeat samples following an E. coli-positive routine sample; or

(d) The system fails to test for E. coli when any repeat sample tests positive for total coliform.

(2) Treatment Technique Violation.

(a) A treatment technique violation occurs when a system exceeds a treatment technique trigger specified in § 1(1) of this regulation and then fails to conduct the required assessment or corrective actions within the time frame specified in § 1(2) and (3) of this regulation.

(b) A treatment technique violation occurs when a seasonal system fails to complete an Approving Authority-approved start-up procedure prior to serving water to the public.

(3) Monitoring Violations.

(a) Failure to take every required routine or additional routine sample in a compliance period is a monitoring violation.

(b) Failure to analyze for E. coli following a total coliform-positive routine sample is a monitoring violation.

(4) Reporting Violations.

(a) Failure to submit a monitoring report or completed assessment form after a system properly conducts monitoring or assessment in a timely manner is a reporting violation.

(b) Failure to notify the Approving Authority following an E. coli-positive sample as required by 40 CFR § 141.858 (b)(1) in a timely manner is a reporting violation.

(c) Failure to submit certification of completion of Approving Authority-approved start-up procedure by a seasonal system is a reporting violation.

Md. Code Regs. 26.04.01.11-4

Regulation .11-4 adopted effective 43:17 Md. R. 957, eff. 8/29/2016