Section 22.07F - Definitions(1)Initial Distribution System Evaluations. (a)General Requirements. The requirements of 310 CMR 22.07F(1) through (6) establish monitoring and other requirements for identifying Stage 2 DBPR compliance monitoring locations under 310 CMR 22.07(F) for determining compliance with Maximum Contaminant Levels for Total Trihalomethanes (TTHM) and Haloacetic Acids (Five) (HAA5). The Supplier of Water must use an Initial Distribution System Evaluation (IDSE) to determine locations with representative high TTHM and HAA5 concentrations throughout their Distribution System. IDSEs are used in conjunction with, but separate from, compliance monitoring required by 310 CMR 22.07E, to identify and select compliance monitoring locations under 310 CMR 22.07F(6).(b)Applicability. For Community Water Systems that use a primary or residual Disinfectant other than ultraviolet light or deliver water that has been treated with a primary or residual Disinfectant other than ultraviolet light; or a Non-transient Non-community Water System that serves at least 10,000 people and 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)Schedule. 1. Each Supplier of Water must comply with the requirements of the schedule in the table in 310 CMR 22.20F(1)(c). TABLE 1 - 310 CMR 22.07F
INITIAL DISTRIBUTION SYSTEM EVALUATION SCHEDULE
If you serve this population | Supplier of water must submit their standard monitoring plan or system specific study plan1 or 40/30 certification2 to the Department by or receive very small system waiver from the Department | Supplier of water must complete their standard monitoring or system specific study by | Supplier of water must submit their IDSE report to the Department by3 |
Systems that are not part of a Combined Distribution System and systems that serve the largest population in the Combined Distribution System |
a. $100,000 | October 1, 2006 | September 30, 2008 | January 1, 2009 |
b. 50,000-99,999 | April 1, 2007 | March 31, 2009 | July 1, 2009 |
c. 10,000-49,999 | October 1, 2007 | September 30, 2009 | January 1, 2010 |
d. < 10,000 (CWS Only) | April 1, 2008 | March 31, 2010 | July 1, 2010 |
Other systems that are part of a Combined Distribution System |
e. Wholesale System or consecutive system | --at the same time as the system with the earliest compliance date in the Combined Distribution System | --at the same time as the system with the earliest compliance date in the Combined Distribution System | --at the same time as the system with the earliest compliance date in the Combined Distribution System |
1 If, within 12 months after the date identified in this column, the Department does not approve the Supplier of Water's plan or notify them that it has not yet completed its review, the Supplier of Water may consider the plan that was submitted as approved.
2 The Supplier of Water must implement that plan and they must complete standard monitoring or a system specific study no later than the date identified in the third column. The supplier of water must submit their 40/30 certification under 310 CMR 22.20F(4) by the date indicated.
3 If, within three months after the date identified in this column (nine months after the date identified in this column if the Supplier of Water must comply on the schedule in 310 CMR 22.07F(1)(c)1.c., the Department does not approve their IDSE report or notify them that it has not yet completed its review, the Supplier of Water may consider the report that was submitted as approved and must implement the recommended monitoring in 310 CMR 22.07F as required.
2. For the purpose of the schedule in 310 CMR 22.07F(1)(c)1., 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) The Supplier of Water must conduct standard monitoring that meets the requirements in 310 CMR 22.20F(2), or a system specific study that meets the requirements in 310 CMR 22.07F(3), or certify to the Department that they meet 40/30 certification criteria under 310 CMR 22.20F(4), or qualify for a very small system waiver under 310 CMR 22.07F(5). 1. The Supplier of Water must have taken the full complement of routine TTHM and HAA5 compliance samples required of a system with their population and source water under 310 CMR 22.07E (or they must have taken the full complement of reduced TTHM and HAA5 compliance samples required of a system with their population and source water under 310 CMR 22.07E if they meet reduced monitoring criteria under 310 CMR 22.07E) during the period specified in 310 CMR 22.07F(4)(a) to meet the 40/30 certification criteria in 310 CMR 22.07F(4). The Supplier of Water must have taken TTHM and HAA5 samples under 310 CMR 22.07E(6) and (7) to be eligible for the very small system waiver in 310 CMR 22.07F(5).2. If the Supplier of Water has not taken the required samples, they must conduct standard monitoring that meets the requirements in 310 CMR 22.07F(2), or a system specific study that meets the requirements in 310 CMR 22.07F(3).(e) The Supplier of Water must use only the analytical methods specified in 310 CMR 22.07E(6), or otherwise approved by EPA for monitoring under 310 CMR 22.07F, to demonstrate compliance with the requirements of 310 CMR 22.07F.(f) IDSE results will not be used for the purpose of determining compliance with MCLs in 310 CMR 22.07E(1).(2)Standard Monitoring.(a)Standard Monitoring Plan. The standard monitoring plan must comply with 310 CMR 22.07F(2)(a)1. through 4. The Supplier of Water must prepare and submit their standard monitoring plan to the Department according to the schedule in 310 CMR 22.07F(1)(c).1. The standard monitoring plan must include a schematic of the Supplier of Water's Distribution System (including Distribution System entry points and their sources, and storage facilities), with notes indicating locations and dates of all projected standard monitoring, and all projected compliance monitoring required under 310 CMR 22.07E.2. The standard monitoring plan must include justification of standard monitoring location selection and a summary of data relied on to justify standard monitoring location selection.3. The standard monitoring plan must specify the population served and system type (Surface Water or Groundwater under the Direct Influence of Surface Water or Groundwater).4. The Supplier of Water must retain a complete copy of their standard monitoring plan submitted under 310 CMR 22.07F(2)(a), including any Department modification of the standard monitoring plan, for as long as the Supplier of Water is required to retain their IDSE report under 310 CMR 22.07(2)(c)4.(b)Standard Monitoring.1. The Supplier of Water must monitor as indicated in the table in 310 CMR 22.07F(2)(b)1. The supplier must collect Dual Sample Sets at each monitoring location. One sample in the Dual Sample Set must be analyzed for TTHM. The other sample in the Dual Sample Set must be analyzed for HAA5. The Supplier of Water must conduct one monitoring period during the peak historical month for TTHM levels or HAA5 levels or the month of warmest water temperature. The Supplier of Water must review available compliance, study, or operational data to determine the peak historical month for TTHM or HAA5 levels or warmest water temperature. TABLE 2 - 310 CMR 22.07F
STANDARD MONITORING
Source water type | Population size category | Monitoring periods and frequency of sampling | Distribution System monitoring locations1 |
Total per monitoring period | Near entry points | Average residence Time | High TTHM locations | High HAA5 locations |
Surface Water and Groundwater under the Direct Influence of Surface Water | <500 consecutive systems | One (during peak historical month)2 | 2 | 1 | ......... | 1 |
<500 non-consecutive systems | ......... | 2 | ......... | ......... | 1 | 1 |
500-3,300 consecutive systems | Four (every 90 days) | 2 | 1 | ......... | 1 |
500-3,300 non-consecutive systems | ......... | 2 | ......... | ......... | 1 | 1 |
3,301-9,999 | ......... | 4 | ......... | 1 | 2 | 1 |
10,000-49,999 | Six (every 60 days) | 8 | 1 | 2 | 3 | 2 |
50,000-249,999 | ......... | 16 | 3 | 4 | 5 | 4 |
250,000-999,999 | ......... | 24 | 4 | 6 | 8 | 6 |
1,000,000-4,999,999 | ......... | 32 | 6 | 8 | 10 | 8 |
>=5,000,000 | ......... | 40 | 8 | 10 | 12 | 10 |
Groundwater | <500 consecutive systems | One (during peak historical month)2 | 2 | 1 | ......... | 1 |
<500 non-consecutive systems | ......... | 2 | ......... | ......... | 1 | 1 |
500-9,999 | Four (every 90 days) | 2 | ......... | ......... | 1 | 1 |
10,000-99,999 | ......... | 6 | 1 | 2 | 2 |
100,000-499,999 | ......... | 8 | 1 | 3 | 3 |
>=500,000 | ......... | 12 | 2 | 4 | 4 |
1 A Dual Sample Set (i.e., a TTHM and an HAA5 sample) must be taken at each monitoring location during each monitoring period.
2 The peak historical month is the month with the highest TTHM or HAA5 levels or the warmest water temperature.
2. The Supplier of Water must take samples at locations other than the existing monitoring locations required in 310 CMR 22.07E. Monitoring locations must be distributed throughout the Distribution System.3. If the number of entry points to the Distribution System is fewer than the specified number of entry point monitoring locations, excess entry point samples must be replaced equally at high TTHM and HAA5 locations. If there is an odd extra location number, the Supplier of Water must take a sample at a high TTHM location. If the number of entry points to the Distribution System is more than the specified number of entry point monitoring locations, the Supplier of Water must take samples at entry points to the Distribution System having the highest annual water flows.4. The Supplier of Water's monitoring under 310 CMR 22.07F(2)(b) may not be reduced under the provisions of 310 CMR 22.12.(c)IDSE Report. The Supplier of Water's IDSE report must include the elements required in 310 CMR 22.07F(2)(c)1. through 4. The Supplier of Water must submit their IDSE report to the Department according to the schedule in 310 CMR 22.07F(1)(c). 1. The Supplier of Water's IDSE report must include all TTHM and HAA5 analytical results from compliance monitoring under 310 CMR 22.07E and all standard monitoring conducted during the period of the IDSE as individual analytical results and LRAAs presented in a tabular or spreadsheet format acceptable to the Department. If changed from their standard monitoring plan submitted under 310 CMR 22.07F(2)(a), the Supplier of Water's report must also include a schematic of their Distribution System, the population served, and system type (Surface Water or Groundwater under the Direct Influence of Surface Water or Groundwater).2. The Supplier of Water's IDSE report must include an explanation of any deviations from their approved standard monitoring plan.3. The Supplier of Water must recommend and justify compliance monitoring locations under 310 CMR 22.07F and timing based on the protocol in 310 CMR 22.07F(6).4. The Supplier of Water must retain a complete copy of their IDSE report submitted under 310 CMR 22.07F(2)(c) for ten years after the date that they submitted their report. If the Department modifies the monitoring requirements of 310 CMR 22.07F that the Supplier of Water recommended in their IDSE report or if the Department approves alternative monitoring locations, the Supplier of Water must keep a copy of the Department's notification on file for ten years after the date of the Department's notification. The Supplier of Water must make the IDSE report and any Department notification available for review by the Department or the public.(3)System Specific Studies. (a)System Specific Study Plan. The Supplier of Water's system specific study plan must be based on either existing monitoring results as required under 310 CMR 22.07F(3)(a)1. or modeling as required under 310 CMR 22.07F(3)(a)2. The Supplier of Water must prepare and submit their system specific study plan to the Department according to the schedule in 310 CMR 22.07F(1)(c). 1.Existing Monitoring Results. The Supplier of Water may comply by submitting monitoring results collected before they are required to begin monitoring under 310 CMR 22.07F(1)(c). The monitoring results and analysis must meet the criteria in 310 CMR 22.07F(3)(a)1.a and b. a.Minimum Requirements. i. TTHM and HAA5 results must be based on samples collected and analyzed in accordance with 310 CMR 22.07E(6). Samples must be collected no earlier than five years prior to the study plan submission date.ii. The monitoring locations and frequency must meet the conditions identified in 310 CMR 22.07F(3)(a)1.a.ii. Each location must be sampled once during the peak historical month for TTHM levels or HAA5 levels or the month of warmest water temperature for every 12 months of data submitted for that location. Monitoring results must include all monitoring results required under 310 CMR 22.07E plus additional monitoring results as necessary to meet minimum sample requirements. TABLE 3 - 310 CMR 22.07F
EXISTING MONITORING RESULTS REQUIRED
System Type | Population size category | Number of monitoring locations | Number of samples |
TTHM | HAA5 |
Surface and Groundwater under the Direct Influence of Surface Water | <500 | 3 | 3 | 3 |
500-3,300 | 3 | 9 | 9 |
3,301-9,999 | 6 | 36 | 36 |
10,000 - 49,999 | 12 | 72 | 72 |
50,000-249,999 | 24 | 144 | 144 |
250,000-999,999 | 36 | 216 | 216 |
1,000,000-4,999,999 | 48 | 288 | 288 |
>=5,000,000 | 60 | 360 | 360 |
Groundwater |
<500 | 3 | 3 | 3 |
500-9,999 | 3 | 9 | 9 |
10,000-99,999 | 12 | 48 | 48 |
100,000-499,999 | 18 | 72 | 72 |
>=500,000 | 24 | 96 | 96 |
b.Reporting Monitoring Results. The Supplier of Water must report the following information:i. The Supplier of Water must report previously collected monitoring results and certify that the reported monitoring results include all compliance and non-compliance results generated during the time period beginning with the first reported result and ending with the most recent results required under 310 CMR 22.07E.ii. The Supplier of Water must certify that the samples were representative of the entire Distribution System and that treatment, and Distribution System have not changed significantly since the samples were collected. iii. The Supplier of Water's system specific study plan must specify the population served and system type (Surface Water or Groundwater under the Direct Influence of Surface Water or Groundwater)iv. The Supplier of Water's system specific study plan must specify the population served and system type (Surface Water or Groundwater under the Direct Influence of Surface Water or Groundwater)v. The Supplier of Water must retain a complete copy of their system specific study plan submitted under 310 CMR 22.07F(3)(a)1., including any Department modification of their system specific study plan, for as long as they are required to retain their IDSE report under 310 CMR 22.07F(3)(b)7.vi. If the Supplier of Water submits previously collected data that fully meets the number of samples required under 310 CMR 22.07F(3)(a)1.a.ii. and the Department rejects some of the data, the Supplier of Water must either conduct additional monitoring to replace rejected data on a schedule the Department approves or conduct standard monitoring under 310 CMR 22.07F(2).2.Modeling. The Supplier of Water may comply through analysis of an extended period simulation hydraulic model. The extended period simulation hydraulic model and analysis must meet the criteria in 310 CMR 22.07F(3)(a)2. a.Minimum Requirements. i. The model must simulate 24-hour variation in demand and show a consistently repeating 24 hour pattern of residence time. ii. The model must represent the criteria listed in 310 CMR 22.07F(3)(a)2.a.ii.(A) through (I). (D) All 12-inch diameter and larger pipes;(E) All eight-inch and larger pipes that connect pressure zones, influence zones from different sources, storage facilities, major demand areas, pumps, and control valves, or are known or expected to be significant conveyors of water;(F) All six-inch and larger pipes that connect remote areas of a Distribution System to the main portion of the system;(G) All storage facilities with standard operations represented in the model; and(H) All active pump stations with controls represented in the model; and(I) All active control valves.iii. The model must be calibrated, or have calibration plans, for the current configuration of the Distribution System during the period of high TTHM formation potential. All storage facilities must be evaluated as part of the calibration process. All required calibration must be completed no later than 12 months after plan submission.b.Reporting Modeling. The Supplier of Water's system specific study plan must include the information in 310 CMR 22.07F(3)(a)2.b. i. Tabular or spreadsheet data demonstrating that the model meets requirements in 310 CMR 22.07F(3)(a)2.a.ii. ii. A description of all calibration activities undertaken, and if calibration is complete, a graph of predicted tank levels versus measured tank levels for the storage facility with the highest residence time in each pressure zone, and a time series graph of the residence time at the longest residence time storage facility in the Distribution System showing the predictions for the entire simulation period (i.e., from time zero until the time it takes to for the model to reach a consistently repeating pattern of residence time). iii. Model output showing preliminary 24-hour average residence time predictions throughout the Distribution System. iv. Timing and number of samples representative of the Distribution System planned for at least one monitoring period of TTHM and HAA5 dual sample monitoring at a number of locations no less than would be required for the system under standard monitoring in 310 CMR 22.07F(2) during the historical month of high TTHM. These samples must be taken at locations other than existing compliance monitoring locations under 310 CMR 22.07E. v. Description of how all requirements will be completed no later than 12 months after the Supplier of Water submits their system specific study plan. vi. Schematic of the Supplier of Water's Distribution System (including Distribution System entry points and their sources, and storage facilities), with notes indicating the locations and dates of all completed system specific study monitoring (if calibration is complete) and all compliance monitoring required under 310 CMR 22.07E. vii. Population served and system type (Surface Water and Groundwater Under the Direct Influence of Surface Water or Groundwater). viii. The Supplier of Water must retain a complete copy of their system specific study plan submitted under 310 CMR 22.07F(3)(a)2., including any Department modification of the system specific study plan, for as long as the Supplier of Water is required to retain their IDSE report under 310 CMR 22.07F(3)(b)7. c. If the Supplier of Water submits a model that does not fully meet the requirements under 310 CMR 22.07F(3)(a)2., the Supplier of Water must correct the deficiencies and respond to Department inquiries concerning the model. If the Supplier of Water fails to correct deficiencies or respond to inquiries to the Department's satisfaction, they must conduct standard monitoring under 310 CMR 22.07F(2).(b)IDSE Report. The Supplier of Water's IDSE report must include the elements required in 310 CMR 22.07F(3)(b)1. through 6. The Supplier of Water must submit their IDSE report according to the schedule in 310 CMR 22.07F(1)(c).1. The Supplier of Water's IDSE report must include all TTHM and HAA5 analytical results from monitoring required under 310 CMR 22.07E and all system specific study monitoring conducted during the period of the system specific study presented in a tabular or spreadsheet format acceptable to the Department. If changed from the Supplier of Water's system specific study plan submitted under 310 CMR 22.07F(3)(a), their IDSE report must also include a schematic of their Distribution System, the population served, and system type (Surface Water and Groundwater under the Direct Influence of Surface Water or Groundwater).2. If the Supplier of Water used the modeling provision under 310 CMR 22.07F(3)(a)2., they must include final information for the elements described in 310 CMR 22.07F(3)(a)2.b., and a 24-hour time series graph of residence time for each compliance monitoring location selected in 310 CMR 22.07F.3. The Supplier of Water must recommend and justify compliance monitoring locations in 310 CMR 22.07F and timing based on the protocol in 310 CMR 22.07(6).4. The Supplier of Water's IDSE report must include an explanation of any deviations from their approved system specific study plan.5. The Supplier of Water's IDSE report must include the basis (analytical and modeling results) and justification they used to select the recommended monitoring locations in 310 CMR 22.07F(6).6. The Supplier of Water may submit their IDSE report in lieu of their system specific study plan on the schedule identified in 310 CMR 22.07F(1)(c) for submission of the system specific study plan if they believe that they have the necessary information by the time that the system specific study plan is due. If the Supplier of Water elects this approach, their IDSE report must also include all information required under 310 CMR 22.07F(3)(a).7. The Supplier of Water must retain a complete copy of their IDSE report submitted under 310 CMR 22.07F(3)(b) for ten years after the date that they submitted their IDSE report. If the Department modifies the monitoring requirements in 310 CMR 22.07F that the Supplier of Water recommended in their IDSE report or if the Department approves alternative monitoring locations, the Supplier of Water must keep a copy of the Department's notification on file for ten years after the date of the Department's notification. The Supplier of Water must make the IDSE report and any Department notification available for review by the Department or the public.(4)40/30 Certification. (a)Eligibility. The Supplier of Water is eligible for 40/30 certification if they had no TTHM or HAA5 monitoring violations under 310 CMR 22.07E and no individual sample exceeded 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 during an eight consecutive calendar quarter period beginning no earlier than the date specified in 310 CMR 22.07F(4)(a). TABLE 4 - 310 CMR 22.07F
40/30 CERTIFICATION SCHEDULE
If your 40/30 certification is due | Then your eligibility for 40/30 certification is based on eight consecutive calendar quarters of compliance monitoring results under 310 CMR 22.07E beginning no earlier than1 |
1. October 1, 2006 | January 2004 |
2. April 1, 2007 | January 2004 |
3. October 1, 2007 | January 2005 |
4. April 1, 2008 | January 2005 |
1 Unless the Supplier of Water is on reduced monitoring under 310 CMR 22.07E and was not required to monitor during the specified period. If they did not monitor during the specified period, they must base their eligibility on compliance samples taken during the 12 months preceding the specified period.
(b)40/30 Certification.1. The Supplier of Water must certify to the Department that every individual compliance sample taken under 310 CMR 22.07E during the periods specified in 310 CMR 22.07F(4)(a) were <= 0.040 mg/L for TTHM and <= 0.030 mg/L for HAA5, and that they have not had any TTHM or HAA5 monitoring violations during the period specified in 310 CMR 22.07F(4)(a).2. The Department may require the Supplier of Water to submit compliance monitoring results, Distribution System schematics, and/or recommended compliance monitoring locations as required in 310 CMR 22.07F in addition to their certification. If the Supplier of Water fails to submit the requested information, the Department may require standard monitoring under 310 CMR 22.07F(2) or a system specific study under 310 CMR 22.07F(3).3. The Department may still require standard monitoring under 310 CMR 22.07F(2) or a system specific study under 310 CMR 22.07F(3) even if the Supplier of Water meets the criteria in 310 CMR 22.07F(4)(a).4. The Supplier of Water must retain a complete copy of their certification submitted under 310 CMR 22.07F(4)(b) for ten years after the date that they submitted their certification. The Supplier of Water must make the certification, all data upon which the certification is based, and any Department notification available for review by the Department or the public.(5)Very Small System Waivers.(a) If the Supplier of Water serves fewer than 500 people and it has taken TTHM and HAA5 samples under 310 CMR 22.07E, the Supplier of Water is not required to comply with 310 CMR 22.07F(1) unless the Department notifies the Supplier of Water that it must conduct standard monitoring under 310 CMR 22.07F(2) or a system specific study under 310 CMR 22.07F(3).(b) If the Supplier of Water has not taken TTHM and HAA5 samples under 310 CMR 22.07E or if the Department notifies the Supplier of Water that it must comply with 310 CMR 22.07F(1), the Supplier of Water must conduct standard monitoring under 310 CMR 22.07F(2) or a system specific study under 310 CMR 22.07F(3).(6)Compliance Monitoring Location Recommendations. (a) The Supplier of Water's IDSE report must include their recommendations and justification for where and during what month(s) TTHM and HAA5 monitoring required under 310 CMR 22.07F(8) should be conducted. They must base their recommendations on the criteria in 310 CMR 22.07F(6)(b) through (e).(b) The Supplier of Water must select the number of monitoring locations specified in the table in 310 CMR 22.07F(6)(b). The Supplier of Water will use these recommended locations as routine compliance monitoring locations under 310 CMR 22.07F, unless the Department requires different or additional locations. The Supplier of Water should distribute locations throughout the Distribution System to the extent possible. TABLE 5 - 310 CMR 22.07F
DISTRIBUTION SYSTEM MONITORING LOCATIONS
Distribution System monitoring location |
Source water type | Population size category | Monitoring frequency1 | Total per monitoring period2 | Highest TTHM locations | Highest HAA5 locations | Existing compliance locations under 310 CMR 22.07E |
Surface or Groundwater under the Direct Influence of Surface Water | <500 | Per year | 2 | 1 | 1 | ........... |
500-3,300 | Per quarter | 2 | 1 | 1 |
3,301-9,999 | Per quarter | 2 | 1 | 1 | ........... |
10,000-49,999 | Per quarter | 4 | 2 | 1 | 1 |
50,000-249,999 | Per quarter | 8 | 3 | 3 | 2 |
250,000-999,999 | Per quarter | 12 | 5 | 4 | 3 |
1,000,000-4,999,999 | Per quarter | 16 | 6 | 6 | 4 |
>=5,000,000 | Per quarter | 20 | 8 | 7 | 5 |
Groundwater |
<500 | Per year | 2 | 1 | 1 |
500-9,999 | Per year | 2 | 1 | 1 |
10,000-99,999 | Per quarter | 4 | 2 | 1 | 1 |
100,000-499,999 | Per quarter | 6 | 3 | 2 | 1 |
>=500,000 | Per quarter | 8 | 3 | 3 | 2 |
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 Surface Water and Groundwater under the Direct Influence of Surface Water systems serving 500-3,300. Groundwater systems serving 500 9,999 on annual monitoring must take Dual Sample Sets at each monitoring location. All other systems on annual monitoring and Surface Water and Groundwater under the Direct Influence of Surface Water 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. For systems serving fewer than 500 people, 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.
(c) The Supplier of Water must recommend compliance monitoring locations for 310 CMR 22.07F(6) based on standard monitoring results, system specific study results, and compliance monitoring results required under 310 CMR 22.07E. The Supplier of Water must follow the protocol in 310 CMR 22.07F(6)(c)1. through 8. If required to monitor at more than eight locations, the Supplier of Water must repeat the protocol as necessary. If the Supplier of Water does not have existing compliance monitoring results required under 310 CMR 22.07E or if they do not have enough existing compliance monitoring results required under 310 CMR 22.07E, they must repeat the protocol, skipping the provisions of 310 CMR 22.07F(6)(c)(3) and (7) as necessary, until they have identified the required total number of monitoring locations.1. Location with the highest TTHM LRAA not previously selected as a monitoring location under 310 CMR 22.07F.2. Location with the highest HAA5 LRAA not previously selected as a monitoring location under 310 CMR 22.07F.3. Existing average residence time compliance monitoring location (maximum residence time compliance monitoring location for groundwater systems) under 310 CMR 22.07E with the highest HAA5 LRAA not previously selected as a monitoring location under 310 CMR 22.07F.4. Location with the highest TTHM LRAA not previously selected as a monitoring location under 310 CMR 22.07F.5. Location with the highest TTHM LRAA not previously selected as a monitoring location under 310 CMR 22.07F.6. Location with the highest HAA5 LRAA not previously selected as a monitoring location under 310 CMR 22.07F.7. Existing average residence time compliance monitoring location (maximum residence time compliance monitoring location for groundwater systems) under 310 CMR 22.07E with the highest TTHM LRAA not previously selected as a monitoring location under 310 CMR 22.07F.8. Location with the highest HAA5 LRAA not previously selected as a monitoring location under 310 CMR 22.07F.(d) The Supplier of Water may recommend locations other than those specified in 310 CMR 22.07F(6)(c) if they include a rationale for selecting other locations. If the Department approves the alternate locations, they must monitor at these locations to determine compliance under 310 CMR 22.07F.(e) The Supplier of Water's recommended schedule must include monitoring required under 310 CMR 22.07F during the peak historical month for TTHM and HAA5 concentration, unless the Department approves another month. Once the Supplier of Water has identified the peak historical month, and if they are required to conduct routine monitoring at least quarterly, they must schedule compliance monitoring required under 310 CMR 22.07F at a regular frequency of every 90 days or fewer.(7)General Monitoring Requirements of Stage 2 Disinfection Byproducts Rule. (a)General. The requirements of 310 CMR 22.07F(7) through (16) establish 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. The Supplier of Water is subject to these requirements if their system is a Community Water System or a Non-transient Non-community 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)Schedule. The Supplier of Water must comply with the requirements in 310 CMR 22.07F(7) on the schedule in the following table based on their system type. TABLE 6 - 310 CMR 22.07F
MONITORING SCHEDULE
If you are this type of system | You must comply with monitoring required under 310 CMR 22.07F(7) by:1 |
Systems that are not part of a Combined Distribution System and systems that serve the largest population in the Combined Distribution System |
1. System serving >= 100,000 | April 1, 2012 |
2. System serving 50,000 99,999 | October 1, 2012 |
3. System serving 10,000 49,999 | October 1, 2013 |
4. System serving < 10,000 | October 1, 2013 if no Cryptosporidium monitoring is required under 310 CMR 22.20G(2)(a)4. or October 1, 2014 if Cryptosporidium monitoring is required under 310 CMR 22.20G(2)(a)4. or 310 CMR 22.20G(2)(a)6. |
Other systems that are part of a Combined Distribution System |
5. Consecutive system or Wholesale System | at the same time as the system with the earliest compliance date in the Combined Distribution System. |
1 The Department may grant up to an additional 24 months for compliance with MCLs and operational evaluation levels if the Supplier of Water requires capital improvements to comply with an MCL.
6. The Supplier of Water's monitoring frequency is specified in 310 CMR 22.07F(8)(a)2. a. If the Supplier of Water is required to conduct quarterly monitoring, they must begin monitoring in the first full calendar quarter that includes the compliance date in the table in 310 CMR 22.07F(7)(c).b. If the Supplier of Water is required to conduct monitoring at a frequency that is less than quarterly, they must begin monitoring in the calendar month recommended in the IDSE report prepared under 310 CMR 22.07F(2) or (3) or the calendar month identified in the monitoring plan developed under 310 CMR 22.07F(9) no later than 12 months after the compliance date in the table in 310 CMR 22.07F(7)(c).7. If the Supplier of Water is required to conduct quarterly monitoring, they 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 the Supplier of Water is required to conduct monitoring at a frequency that is less than quarterly, they must make compliance calculations beginning with the first compliance sample taken after the compliance date.8. For the purpose of the schedule in 310 CMR 22.07F(7)(c), 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 MCLs required by 310 CMR 22.07F listed in 310 CMR 22.07E(1), the Supplier of Water must calculate LRAAs for TTHM and HAA5 using monitoring results collected under 310 CMR 22.07F and determine that each LRAA does not exceed the MCL. If the Supplier of Water fails to complete four consecutive quarters of monitoring, they must calculate compliance with the MCL based on the average of the available data from the most recent four quarters. If the Supplier of Water takes more than one sample per quarter at a monitoring location, they 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 MCLs required by 310 CMR 22.07F listed in 310 CMR 22.07E(1), the Supplier of Water must determine that each sample taken is less than the MCL. If any sample exceeds the MCL, they must comply with the requirements of 310 CMR 22.07F(12). If no sample exceeds the MCL, the sample result for each monitoring location is considered the LRAA for that monitoring location.(e)Violation. The Supplier of Water is in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if they fail to monitor.(8)Routine Monitoring. (a)Monitoring. 1. If the water supplier submitted an IDSE report, they must begin monitoring at the locations and months they have recommended in their IDSE report submitted under 310 CMR 22.07F(6) following the schedule in 310 CMR 22.07F(7)(c), unless the Department requires other locations or additional locations after its review. If the Supplier of Water submitted a 40/30 certification under 310 CMR 22.07F(4) or they qualified for a very small system waiver under 310 CMR 22.07F(5) or they are a Non-transient Non-community Water System serving < 10,000, they must monitor at the location(s) and dates identified in their monitoring plan in 310 CMR 22.07E(7)(f) updated as required by 310 CMR 22.07F(9).2. The Supplier of Water must monitor at no fewer than the number of locations identified in 310 CMR 22.07F(8)(a)2. TABLE 7 - 310 CMR 22.07F
ROUTINE MONITORING FREQUENCY
Source Water Type | Population Size Category | Monitoring Frequency 1 | Distribution System monitoring location total per monitoring period 2 |
Surface Water and Groundwater under the Direct Influence of Surface Water | <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 |
Groundwater |
<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 systems using Surface Water or Groundwater under the Direct Influence of Surface Water systems and serving 500-3,300. Groundwater systems serving 500-9,999 on annual monitoring must take Dual Sample Sets at each monitoring location. All other systems on annual monitoring and systems using Surface Water or groundwater systems under the direct influence of surface water 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. For systems serving fewer than 500 people, 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.
3. If the Supplier of Water is an undisinfected system that begins using a Disinfectant other than UV light after the dates in 310 CMR 22.07F(1) for complying with the Initial Distribution System Evaluation requirements, they must consult with the Department to identify compliance monitoring locations for 310 CMR 22.07F(8). The Supplier of Water must then develop a monitoring plan under 310 CMR 22.07F(9) that includes those monitoring locations. (b)Analytical Methods. The Supplier of Water must use an approved method listed in 310 CMR 22.07E(6) for TTHM and HAA5 analyses in 310 CMR 22.07F(8). Analyses must be conducted by laboratories that have received certification by EPA or the Department as specified in 310 CMR 22.07E(6). (9)Monitoring Plan. (a)1. The Supplier of Water 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 310 CMR 22.07F(9)(a)1.a. through d. and be completed no later than the date the Supplier of Water conducts their initial monitoring under 310 CMR 22.07F(8). c. Compliance calculation procedures; andd. Monitoring plans for any other systems in the Combined Distribution System if the Department has reduced monitoring requirements.2. If the Supplier of Water was not required to submit an IDSE report under either 310 CMR 22.07F(2) or (3), and they do not have sufficient monitoring locations required under 310 CMR 22.07E to identify the required number of compliance monitoring locations indicated in 310 CMR 22.07F(6)(b), they 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. They must also provide the rationale for identifying the locations as having high levels of TTHM or HAA5. If the Supplier of Water has more monitoring locations required under 310 CMR 22.07E than required for compliance monitoring in 310 CMR 22.07F(6)(b), they must identify which locations they will use for compliance monitoring under 310 CMR 22.07F(8) by alternating selection of locations representing high TTHM levels and high HAA5 levels until the required number of compliance monitoring locations under 310 CMR 22.07F(8) have been identified.(b) If the Supplier of Water is a Surface Water or a Groundwater under the Direct Influence of Surface Water serving > 3,300 people, they must submit a copy of their monitoring plan to the Department prior to the date they conduct their initial monitoring under 310 CMR 22.07F(8), unless their IDSE report submitted under 310 CMR 22.07F(2) contains all the information required by 310 CMR 22.07F(9).(c) The Supplier of Water may revise their 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 the Supplier of Water changes monitoring locations, they 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 their monitoring plan. If they are a Surface Water or Groundwater under the Direct Influence of Surface Water system serving > 3,300 people, they must submit a copy of their modified monitoring plan to the Department prior to the date they are required to comply with the revised monitoring plan.(10)Reduced Monitoring. (a) The Supplier of Water may reduce monitoring to the level specified in the table in 310 CMR 22.07F(10)(a) any time the LRAA is <= 0.040 mg/L for TTHM and <= 0.030mg/L for HAA5 at all monitoring locations. They may only use data collected under the provisions of 310 CMR 22.07E or 22.07F to qualify for reduced monitoring. In addition, the source water annual average TOC level, before any treatment, must be <= 4.0 mg/L at each treatment plant treating Surface Water or Groundwater Under the Direct Influence of Surface Water, based on monitoring conducted under 310 CMR 22.07E(7)(b)1.c. or (d). TABLE 8 - 310 CMR 22.07F
REDUCED MONITORNG FREQUENCY AND LOCATION
Source water type | Population size category | Monitoring frequency1 | Distribution System monitoring location per monitoring period |
Surface Water or Groundwater under the Influence of Surface Water | <500 | ................... | 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. |
Groundwater |
<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) The Supplier of Water may remain on reduced monitoring as long as the TTHM LRAA <= 0.040 mg/L and the HAA5 LRAA <= 0.030 mg/L at each monitoring location (for systems with quarterly reduced monitoring) or each TTHM sample <= 0.060 mg/L and each HAA5 sample <= 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 <= 4.0 mg/L at each treatment plant treating Surface Water or Groundwater under the Direct Influence of Surface Water, based on monitoring conducted under either 310 CMR 22.07E(7)(b)1.c. or (d).(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, >4.0 mg/L at any treatment plant treating Surface Water or Groundwater Under the Direct Influence of Surface Water, the Supplier of Water must resume routine monitoring under 310 CMR 22.07F(8) or begin increased monitoring if 310 CMR 22.07F(12) applies.(d) The Department may return the Supplier of Water to routine monitoring at the Department's discretion.(11)Additional Requirements for Consecutive Systems. If the Supplier of Water is 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, they must comply with analytical and monitoring requirements for chlorine and chloramines in 310 CMR 22.07E(6)(c) and (7)(c)1. and the compliance requirements in 310 CMR 22.07E(8)(c)1. beginning April 1, 2009, unless required earlier by the Department, and report monitoring results under 310 CMR 22.07E(9)(c).(12)Conditions Requiring Increased Monitoring. (a) If the Supplier of Water is required to monitor at a particular location annually or less frequently than annually under 310 CMR 22.07F(8) or (10), they 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) The Supplier of Water is in violation of the MCL when the LRAA exceeds the Stage 2 Disinfection Byproducts MCLs in 310 CMR 22.07E(1), 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). The Supplier of Water is in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if they fail to monitor.(c) The Supplier of Water may return to routine monitoring once they have conducted increased monitoring for at least four consecutive quarters and the LRAA for every monitoring location is <= 0.060 mg/L for TTHM and <= 0.045 mg/L for HAA5.(13)Operational Evaluation Levels.(a) The Supplier of Water has 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 four 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 four to determine an average, exceeds 0.060 mg/L.(b)1. If the Supplier of Water exceeds the operational evaluation level, they 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 them to exceed the operational evaluation level. The written report must be made available to the public upon request.2. The Supplier of Water's 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 exceedences.a. The Supplier of Water may request and the Department may allow them to limit the scope of their evaluation if they are able to identify the cause of the operational evaluation level exceedance.b. The Supplier of Water's request to limit the scope of the evaluation does not extend the schedule in 310 CMR 22.07F(13)(b)1. for submitting the written report. The Department must approve this limited scope of evaluation in writing and the Supplier of Water must keep that approval with the completed report.(14)Requirements for Remaining on Reduced TTHM and HAA5 Monitoring Based on Results Required under 310 CMR 22.07E. The Supplier of Water may remain on reduced monitoring after the dates identified in 310 CMR 22.07F(7)(c) for compliance with 310 CMR 22.07F(14) only if they qualify for a 40/30 certification under 310 CMR 22.07F(4) or have received a very small system waiver under 310 CMR 22.07F(5), plus they meet the reduced monitoring criteria in 310 CMR 22.07F(10)(a), and they do not change or add monitoring locations from those used for compliance monitoring under 310 CMR 22.07E. If the Supplier of Water's monitoring locations under 310 CMR 22.07F differ from their monitoring locations under 310 CMR 22.07E, they may not remain on reduced monitoring after the dates identified in 310 CMR 22.07F(7)(c) for compliance with 310 CMR 22.07F.(15) Requirements for Remaining on Increased TTHM and HAA5 Monitoring Based on Results Required under 310 CMR 22.07E. If the Supplier of Water was on increased monitoring under 310 CMR 22.07E(7)(b)1., they must remain on increased monitoring until they qualify for a return to routine monitoring under 310 CMR 22.07F(12)(c). The Supplier of Water must conduct increased monitoring under 310 CMR 22.07F(12) at the monitoring locations in the monitoring plan developed under 310 CMR 22.07F(9) beginning at the date identified in 310 CMR 22.07F(7)(c) for compliance with 310 CMR 22.07F and remain on increased monitoring until they qualify for a return to routine monitoring under 310 CMR 22.07F(12)(c).(16)Reporting and Recordkeeping Requirements. (a)Reporting. 1. The Supplier of Water must report the following information for each monitoring location to the Department within ten days of the end of any quarter in which monitoring is required:a. Number of samples taken during the last quarter.b. Date and results of each sample taken during the last quarter.c. 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, they 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 the Supplier of Water is required to conduct monitoring at a frequency that is less than quarterly, they must make compliance calculations beginning with the first compliance sample taken after the compliance date, unless they are required to conduct increased monitoring under 310 CMR 22.07F(12).d. Whether, based on 310 CMR 22.07E(1) and 22.07F, the MCL was violated at any monitoring location.e. 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 the Supplier of Water is a Surface Water or Groundwater under the Direct Influence of Surface Water system seeking to qualify for or remain on reduced TTHM/HAA5 monitoring, they must report the following source water TOC information for each treatment plant that treats Surface Water or Groundwater under the Direct Influence of Surface Water to the Department within ten days of the end of any quarter in which monitoring is required: a. The number of source water TOC samples taken each month during last quarter.b. The date and result of each sample taken during last quarter.c. The quarterly average of monthly samples taken during last quarter or the result of the quarterly sample.d. The Running Annual Average (RAA) of quarterly averages from the past four quarters.e. 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. The Supplier of Water must retain any monitoring plans required under 310 CMR 22.07F and their monitoring results as required by 310 CMR 22.07E(8).Amended by Mass Register Issue 1309, eff. 3/25/2016.Amended by Mass Register Issue 1419, eff. 6/12/2020.Amended by Mass Register Issue 1427, eff. 10/2/2020.Amended by Mass Register Issue 1430, eff. 10/2/2020.