Tenn. Comp. R. & Regs. 0400-45-01-.38 - STAGE 2 DISINFECTION BYPRODUCTS REQUIREMENTS (LRAA)

(1) General Requirements

(a) The requirements of this rule constitute national primary drinking water regulations. This rule establishes monitoring and other requirements for achieving compliance with maximum contaminant levels based on locational running annual averages (LRAA) for total trihalomethanes (TTHM) and haloacetic acids (five)(HAA5), and for achieving compliance with maximum residual disinfectant residuals for chlorine and chloramine for certain consecutive systems.

(b) Applicability. You are subject to these requirements if your system is a community water system or a nontransient noncommunity water system that uses a primary or residual disinfectant other than ultraviolet light or delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light.

(c) You must comply with the requirements in this rule on the schedule in the following table based on your system type.

If you are this type of system

You must comply with monitoring under this rule by:1

Systems that are not part of a combined distribution system and systems that serve the largest population in the combined distribution system

System serving 100,000 or more	April 1, 2012
System serving 50,000-99,999	October 1, 2012
System serving 10,000-49,999	October 1, 2013.
System serving less than 10,000	October1, 2013 if no Cryptosporidium monitoring is required under part (2)(a)4 of Rule 0400-45-01-.39 or October 1, 2014 if Cryptosporidium monitoring is required under part (2)(a)4 or (2)(a)6.

Other systems that are part of a combined distribution system

Consecutive system or wholesale system

-at the same time as the system with the earliest compliance date in the combined distribution system

¹The Department may grant up to an additional 24 months for compliance with MCLs and operational evaluaton levels if you require capital improvements to comply with an MCL.

1. Your monitoring frequency is specified in part (2)(a)2 of this rule.

(i) If you are required to conduct quarterly monitoring, you must begin monitoring in the first full calendar quarter that includes the compliance date in the table in this subparagraph.

(ii) If you are required to conduct monitoring at a frequency that is less than quarterly, you must begin monitoring in the calendar month recommended in the IDSE report prepared under paragraph (2) or (3) of Rule 0400-45-01-.37 or the calendar month identified in the (LRAA) monitoring plan developed under paragraph (3) of this rule no later than 12 months after the compliance date in this table.

2. If you are required to conduct quarterly monitoring, you must make compliance calculations at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter (or earlier if the LRAA calculated based on fewer than four quarters of data would cause the MCL to be exceeded regardless of the monitoring results of subsequent quarters). If you are required to conduct monitoring at a frequency that is less than quarterly, you must make compliance calculations beginning with the first compliance sample taken after the compliance date.

3. For the purpose of the schedule in this subparagraph, the Department may determine that the combined distribution system does not include certain consecutive systems based on factors such as receiving water from a wholesale system only on an emergency basis or receiving only a small percentage and small volume of water from a wholesale system. The Department may also determine that the combined distribution system does not include certain wholesale systems based on factors such as delivering water to a consecutive system only on an emergency basis or delivering only a small percentage and small volume of water to a consecutive system.

(d) Monitoring and compliance.

1. Systems required to monitor quarterly. To comply with LRAA MCLs, you must calculate LRAAs for TTHM and HAA5 using monitoring results collected under this rule and determine that each LRAA does not exceed the MCL. If you fail to complete four consecutive quarters of monitoring, you must calculate compliance with the MCL based on the average of the available data from the most recent four quarters. If you take more than one sample per quarter at a monitoring location, you must average all samples taken in the quarter at that location to determine a quarterly average to be used in the LRAA calculation.

2. Systems required to monitor yearly or less frequently. To determine compliance with LRAAs, you must determine that each sample taken is less than the MCL. If any sample exceeds the MCL, you must comply with the requirements of paragraph (6) of this rule. If no sample exceeds the MCL, the sample result for each monitoring location is considered the LRAA for that monitoring location.

(e) Violation. You are in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if you fail to monitor.

(2) Routine Monitoring

(a) Monitoring.

1. If you submitted an IDSE report, you must begin monitoring at the locations and months you have recommended in your IDSE report submitted under paragraph (6) of Rule 0400-45-01-.37 following the schedule in subparagraph (1)(c) of this rule, unless the Department requires other locations or additional locations after its review. If you submitted a 40/30 certification under paragraph (4) of Rule 0400-45-01-.37 or you qualified for a very small system waiver under paragraph (5) of Rule 0400-45-01-.37 or you are a nontransient noncommunity water system serving <10,000, you must monitor at the location(s) and dates identified in your monitoring plan in Rule 0400-45-01-.36, updated as required by paragraph (3) of this rule.

2. You must monitor at no fewer than the number of locations identified in this part.

Source water type	Population size category	Monitoring Frequency1	Distribution system monitoring location total permonitoring period2
Subpart H	<500	per year .............	2
	500-3,300	per quarter .............	2
	3,301-9,999	per quarter ..............	2
	10,000-49,999	per quarter ..............	4
	50,000- 249,999	per quarter ..............	8
	250,000-999,999	per quarter ..............	12
	1,000,000- 4,999,999	per quarter .............	16
	>5,000,000	per quarter	20
Ground Water	<500	per year	2
	500-9,999	per year	2
	10,000-99,999	per quarter	4
	100,000- 499,999	per quarter	6
	>500,000	per quarter	8

¹ All systems must monitor during month of highest DBP concentrations.

² Systems on quarterly monitoring must take dual sample sets every 90 days at each monitoring location, except for subpart H systems serving 500-3,300. Systems on annual monitoring and subpart H systems serving 500-3,300 are required to take individual TTHM and HAA5 samples (instead of a dual sample set) at the locations with the highest TTHM and HAA5 concentrations, respectively. Only one location with a dual sample set per monitoring period is needed if highest TTHM and HAA5 concentrations occur at the same location (and month, if monitored annually).

3. If you are an undisinfected system that begins using a disinfectant other than UV light after the dates in Rule 0400-45-01-.37 for complying with the Initial Distribution System Evaluation requirements, you must consult with the Department to identify compliance monitoring locations for LRAAs. You must then develop a monitoring plan under paragraph (3) of this rule that includes those monitoring locations.

(b) Analytical methods. You must use an approved method listed in Rule 0400-45-01-.14 for TTHM and HAA5 analyses. Analyses must be conducted by laboratories that have received certification by EPA or the Department as specified in Rule 0400-45-01-.14.

(3) LRAA monitoring plan.

(a)

1. You must develop and implement a monitoring plan to be kept on file for Department and public review. The monitoring plan must contain the elements in subpart (i) through (iv) of this part and be complete no later than the date you conduct your initial monitoring under this rule.

(i) Monitoring locations;

(ii) Monitoring dates;

(iii) Compliance calculation procedures; and

(iv) Monitoring plans for any other systems in the combined distribution system if the Department has reduced monitoring requirements under the State authority in 40 CFR 142.16(m).

2. If you were not required to submit an IDSE report under either paragraph (2) or (3) of Rule 0400-45-01-.37, and you do not have sufficient compliance monitoring locations under Rule 0400-45-01-.36 to identify the required number of LRAA compliance monitoring locations indicated in subparagraph (6)(b) of Rule 0400-45-01-.37, you must identify additional locations by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations have been identified. You must also provide the rationale for identifying the locations as having high levels of TTHM or HAA5. If you have more Rule 0400-45-01-.36 monitoring locations than required for LRAA compliance monitoring in subparagraph (6)(b) of Rule 0400-45-01-.37, you must identify which locations you will use for LRAA compliance monitoring by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of LRAA compliance monitoring locations have been identified.

(b) If you are a subpart H system serving > 3,300 people, you must submit a copy of your monitoring plan to the Department prior to the date you conduct your initial LRAA monitoring, unless your IDSE report submitted under Rule 0400-45-01-.37 contains all the information required by this paragraph.

(c) You may revise your monitoring plan to reflect changes in treatment, distribution system operations and layout (including new service areas), or other factors that may affect TTHM or HAA5 formation, or for Department-approved reasons, after consultation with the Department regarding the need for changes and the appropriateness of changes. If you change monitoring locations, you must replace existing compliance monitoring locations with the lowest LRAA with new locations that reflect the current distribution system locations with expected high TTHM or HAA5 levels. The Department may also require modifications in your monitoring plan. If you are a subpart H system serving > 3,300 people, you must submit a copy of your modified monitoring plan to the Department prior to the date you are required to comply with the revised monitoring plan.

(4) Reduced monitoring.

(a) You may reduce monitoring to the level specified in the table in this subparagraph any time the LRAA is less than or equal to 0.040 mg/L for TTHM and less than or equal to 0.030 mg/L for HAA5 at all monitoring locations. You may only use data collected under the provisions Rule 0400-45-01-.37 or this rule to qualify for reduced monitoring. In addition, the source water annual average TOC level, before any treatment, must be less than or equal to 4.0 mg/L at each treatment plant treating surface water or ground water under the direct influence of surface water, based on monitoring conducted under either subpart (6)(b)1(iii) or subparagraph (6)(d) of Rule 0400-45-01-.36.

Source water type	Population size category	Monitoring Frequency1	Distribution system monitoring location per monitoring period
Subpart H	<500	per year .	monitoring may not be reduced
	500-3,300	per year	1 TTHM and 1 HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; 1 dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and quarter.
	3,301-9,999	per year	2 dual sample sets: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement.
	10,000-49,999	per quarter	2 dual sample sets at the locations with the highest TTHM and highest HAA5 LRAAs
	50,000- 249,999	per quarter	4 dual sample sets-at the locations with the two highest TTHM and two highest HAA5 LRAAs
	250,000- 999,999	per quarter	6 dual sample sets-at the locations with the three highest TTHM and three highest HAA5 LRAAs
	1,000,000- 4,999,999	per quarter	8 dual sample sets-at the locations with the four highest TTHM and four highest HAA5 LRAAs.
	>5,000,000	per quarter	10 dual sample sets-at the locations with the five highest TTHM and five highest HAA5 LRAAs
Ground Water	<500	every third year	1 TTHM and 1 HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; 1 dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and quarter.
	500-9,999	per year	1 TTHM and 1 HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; 1 dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and
			quarter
	10,000-99,999	per year	2 dual sample sets: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement.
	100,000- 499,999	per quarter	2 dual sample sets; at the locations with the highest TTHM and highest HAA5 LRAAs.
	>500,000	per quarter	4 dual sample sets at the locations with the two highest TTHM and two highest HAA5 LRAAs.

¹ Systems on quarterly monitoring must take dual sample sets every 90 days.

(b) You may remain on reduced monitoring as long as the TTHM LRAA is less than or equal to 0.040 mg/L and the HAA5 LRAA less than or equal to 0.030 mg/L at each monitoring location (for systems with quarterly reduced monitoring) or each TTHM sample is less than or equal to 0.060 mg/L and each HAA5 sample is less than or equal to 0.045 mg/L (for systems with annual or less frequent monitoring). In addition, the source water annual average TOC level, before any treatment, must be less than or equal to 4.0 mg/L at each treatment plant treating surface water or ground water under the direct influence of surface water, based on monitoring conducted under either subpart (6)(b)1(iii) or subparagraph (6)(d) of Rule 0400-45-01-.36.

(c) If the LRAA based on quarterly monitoring at any monitoring location exceeds either 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 or if the annual (or less frequent) sample at any location exceeds either 0.060 mg/L for TTHM or 0.045 mg/L for HAA5, or if the source water annual average TOC level, before any treatment, is >4.0 mg/L at any treatment plant treating surface water or ground water under the direct influence of surface water, you must resume routine monitoring under paragraph (2) of this rule or begin increased monitoring if paragraph (6) of this rule applies.

(d) The Department may return your system to routine monitoring at the Department's discretion.

(5) Additional requirements for consecutive systems.

(a) If you are a consecutive system that does not add a disinfectant but delivers water that has been treated with a primary or residual disinfectant other than ultraviolet light, you must comply with analytical and monitoring requirements for chlorine and chloramines in subparagraphs (5)(c) and (6)(c) of Rule 0400-45-01-.36 and the compliance requirements in part (7)(c)1 of Rule 0400-45-01-.36 beginning April 1, 2009, unless required earlier by the Department, and report monitoring results under subparagraph (8)(c) of Rule 0400-45-01-.36.

(6) Conditions requiring increased monitoring.

(a) If you are required to monitor at a particular location annually or less frequently than annually under paragraph (2) or (3) of this rule, you must increase monitoring to dual sample sets once per quarter (taken every 90 days) at all locations if a TTHM sample is >0.080 mg/L or a HAA5 sample is >0.060 mg/L at any location.

(b) You are in violation of the MCL when the LRAA exceeds the MCLs in paragraph (6) of Rule 0400-45-01-.06, calculated based on four consecutive quarters of monitoring (or the LRAA calculated based on fewer than four quarters of data if the MCL would be exceeded regardless of the monitoring results of subsequent quarters). You are in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if you fail to monitor.

(c) You may return to routine monitoring once you have conducted increased monitoring for at least four consecutive quarters and the LRAA for every monitoring location is less than or equal to 0.060 mg/L for TTHM and less than or equal to 0.045 mg/L for HAA5.

(7) Operational evaluation levels.

(a) You have exceeded the operational evaluation level at any monitoring location where the sum of the two previous quarters' TTHM results plus twice the current quarter's TTHM result, divided by 4 to determine an average, exceeds 0.080 mg/L, or where the sum of the two previous quarters' HAA5 results plus twice the current quarter's HAA5 result, divided by 4 to determine an average, exceeds 0.060 mg/L.

(b)

1. If you exceed the operational evaluation level, you must conduct an operational evaluation and submit a written report of the evaluation to the Department no later than 90 days after being notified of the analytical result that causes you to exceed the operational evaluation level. The written report must be made available to the public upon request.

2. Your operational evaluation must include an examination of system treatment and distribution operational practices, including storage tank operations, excess storage capacity, distribution system flushing, changes in sources or source water quality, and treatment changes or problems that may contribute to TTHM and HAA5 formation and what steps could be considered to minimize future exceedances.

(i) You may request and the Department may allow you to limit the scope of your evaluation if you are able to identify the cause of the operational evaluation level exceedance.

(ii) Your request to limit the scope of the evaluation does not extend the schedule in part 1 of this subparagraph for submitting the written report. The Department must approve this limited scope of evaluation in writing and you must keep that approval with the completed report.

(8) Requirements for remaining on reduced TTHM and HAA5 monitoring based on Rule 0400-45-01-.36 results.

(a) You may remain on reduced monitoring after the dates identified in subparagraph (1)(c) of this rule for compliance with this rule only if you qualify for a 40/30 certification under paragraph (4) of Rule 0400-45-01-.37 or have received a very small system waiver under paragraph (5) of Rule 0400-45-01-.37, plus you meet the reduced monitoring criteria in subparagraph (4)(a) of this rule, and you do not change or add monitoring locations from those used for compliance monitoring under Rule 0400-45-01-.36. If your monitoring locations under this rule differ from your monitoring locations under Rule 0400-45-01-.36 (subpart L), you may not remain on reduced monitoring after the dates identified in subparagraph (1)(c) of this rule for compliance with this rule.

(9) Requirements for remaining on increased TTHM and HAA5 monitoring based on Rule 0400-45-01-.36 results.

(a) If you were on increased monitoring under part (6)(b)1 of Rule 0400-45-01-.36, you must remain on increased monitoring until you qualify for a return to routine monitoring under subparagraph (6)(c) of this rule. You must conduct increased monitoring under paragraph (6) of this rule at the monitoring locations in the monitoring plan developed under paragraph (3) of this rule beginning at the date identified in subparagraph (1)(c) of this rule for compliance with this rule and remain on increased monitoring until you qualify for a return to routine monitoring under subparagraph (6)(c) of this rule.

(10) Reporting and Recordkeeping Requirements

(a) Reporting.

1. You must report the following information for each monitoring location to the Department within 10 days of the end of any quarter in which monitoring is required:

(i) Number of samples taken during the last quarter.

(ii) Date and results of each sample taken during the last quarter.

(iii) Arithmetic average of quarterly results for the last four quarters for each monitoring location (LRAA), beginning at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter. If the LRAA calculated based on fewer than four quarters of data would cause the MCL to be exceeded regardless of the monitoring results of subsequent quarters, you must report this information to the Department as part of the first report due following the compliance date or anytime thereafter that this determination is made. If you are required to conduct monitoring at a frequency that is less than quarterly, you must make compliance calculations beginning with the first compliance sample taken after the compliance date, unless you are required to conduct increased monitoring under paragraph (6) of this rule.

(iv) Whether, based on paragraph (6) of Rule 0400-45-01-.06 and this rule, the MCL was violated at any monitoring location.

(v) Any operational evaluation levels that were exceeded during the quarter and, if so, the location and date, and the calculated TTHM and HAA5 levels.

2. If you are a subpart H system seeking to qualify for or remain on reduced TTHM/HAA5 monitoring, you must report the following source water TOC information for each treatment plant that treats surface water or ground water under the direct influence of surface water to the Department within 10 days of the end of any quarter in which monitoring is required:

(i) The number of source water TOC samples taken each month during last quarter.

(ii) The date and result of each sample taken during last quarter.

(iii) The quarterly average of monthly samples taken during last quarter or the result of the quarterly sample.

(iv) The running annual average (RAA) of quarterly averages from the past four quarters.

(v) Whether the RAA exceeded 4.0 mg/L.

3. The Department may choose to perform calculations and determine whether the MCL was exceeded or the system is eligible for reduced monitoring in lieu of having the system report that information.

(b) Recordkeeping. You must retain any LRAA monitoring plans and your LRAA monitoring results as required by Rule 0400-45-01-.20.

Notes

Tenn. Comp. R. & Regs. 0400-45-01-.38

Original rule filed August 1, 2012; effective October 30, 2012. Rule was previously numbered 1200-05-01.

Authority: T.C.A. §§ 68-221-701 et seq. and 4-5-201 et seq.