Interim Enhanced Surface Water Treatment Rule

(1) General Requirements. (a) 310 CMR 22.20D establishes requirements for filtration and disinfection that are in addition to criteria established under 310 CMR 22.20A. The requirements of 310 CMR 22.20D apply to all public water supplies serving at least 10,000 people, beginning January 1, 2002 unless otherwise specified. 310 CMR 22.20D establishes or extends treatment technique requirements in lieu of maximum contaminant levels for the following contaminants: 1. Giardia lamblia; 2. Viruses; 3. Heterotrophic plate count bacteria; 4. Legionella; 5. Cryptosporidium; and 6. Turbidity. (b) Each supplier of water serving at least 10,000 people using a surface water source, or ground water source under the direct influence of surface water shall provide treatment of its source water that complies with the treatment technique requirements set forth in 310 CMR 22.20D in addition to the requirements identified in 310 CMR 22.20A. The treatment technique requirements set out in 310 CMR 22.20D consist of installing and properly operating water treatment processes which reliably achieve: 1. At least 99% (2-log) removal of Cryptosporidium between a point where water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer for filtered systems, or Cryptosporidium control under the watershed control plan for unfiltered systems. 2. Compliance with the profiling and benchmark requirements under the provisions of 310 CMR 22.20D(3). (c) A public water system subject to the requirements of 310 CMR 22.20D is deemed to be in compliance with the requirements of 310 CMR 22.20D(1)(a) and (b) if: 1. It meets the requirements for avoiding filtration in 310 CMR 22.20A(2) and 22.20D(2) and the disinfection requirements in 310 CMR 22.20A(3) and 22.20D(3); or, 2. It meets the applicable filtration requirements in either 310 CMR 22.20A(4) or 22.20D(4) and the disinfection requirements in 310 CMR 22.20A(3) and 22.20D(3). (d) A supplier of water is not permitted to construct uncovered finished water storage facilities. (e) A supplier of water that uses a surface water source or ground water source under the direct influence of surface water that did not conduct disinfection profiling under 310 CMR 22.20D(3)(b) because they served fewer than 10,000 persons when such monitoring was required, but serve more than 10,000 persons prior to January 14, 2005 must comply with 310 CMR 22.20D(1), (2) and (4) through (6). These systems must also consult with the Department to establish a disinfection benchmark. A supplier of water that decides to make a significant change to its disinfection practice, as described in 310 CMR 22.20D(3)(c)1.a. through e. must consult with the Department prior to making such change. (2) Criteria for Avoiding Filtration. 310 CMR 22.20D(2) establishes criteria for avoiding filtration for a supplier of water that uses a surface water source or a ground water source under the influence of surface water to serve a population of at least 10,000 people in addition to the requirements of 310 CMR 22.20A(2). Each supplier of water shall meet all of the following conditions: (a) Site-specific Conditions. In addition to site-specific conditions in 310 CMR 22.20A(2)(b), a supplier of water shall maintain the watershed control program under 310 CMR 22.20A(2)(b)5. to minimize the potential for contamination by Cryptosporidium oocysts in the source water. The watershed control program shall, for Cryptosporidium: 22.20D: continued 1. Identify watershed characteristics and activities which may have an adverse effect on source water quality; and, 2. Monitor the occurrence of activities that may have an adverse effect on source water quality. (b) During the onsite inspection conducted under the provisions of 310 CMR 22.20A(2)(b)(3), the Department will determine whether the watershed control program established under 310 CMR 22.20A(2)(b)5. is adequate to limit potential contamination by Cryptosporidium oocysts. (3) Disinfection Profiling and Benchmarking. 310 CMR 22.20D(3) establishes criteria that the Department will use to determine public water systems that are required to profile. A supplier of water subject to the requirements of 310 CMR 22.20D(3) had to determine its TTHM annual average using the procedure in 310 CMR 22.20D(3)(a) and its HAA5 annual average using the procedure of 310 CMR 22.20D(3)(b). The annual average is the arithmetic average of the quarterly averages of four consecutive quarters of monitoring. (a) Determination of Systems Required to Profile. 1. The TTHM annual average is the annual average determined during the same period as was used for the HAA5 annual average: a. A supplier of water who collected data under the provisions of the "Information Collection Rule"(ICR) was required to use the results of the samples collected during the last four quarters of required monitoring under the "disinfection byproduct and related monitoring" of the ICR. b. A supplier of water who used "grandfathered'' HAA5 occurrence data that met the provisions of 310 CMR 22.20D(3)(a)2.b. shall use TTHM data collected at the same time under the provisions of 310 CMR 22.07E. c. A supplier of water who used HAA5 occurrence data that met the provisions of 310 CMR 22.20D(3)(a)2.c.(i) was required to use TTHM data collected at the same time under the provisions of 310 CMR 22.07(2) and 22.07E. 2. The HAA5 annual average is the annual average during the same period as was used for the TTHM annual average with the following provisions: a. A supplier of water who collected data under the Information Collection Rule shall have used the results of the samples collected during the last four quarters of required monitoring under the ICR. b. A supplier of water who collected four quarters of HAA5 occurrence data that met the routine monitoring sample number and location requirements for TTHMs in 310 CMR 22.07E(1), (2) and the handling and analytical method requirements of the ICR may use that data to determine whether the requirements of 310 CMR 22.20D(3) apply. c. A supplier of water who did not collect four quarters of HAA5 occurrence data that met the provisions of either 310 CMR 22.20D(3)(a)2.a. and b. by March 31, 1999 must either: (i) have conducted monitoring for HAA5 that met the routine monitoring sample number and location requirements for TTHM in 310 CMR 22.07(2) and 22.07E and the handling and analytical method requirements of 310 CMR 22.07E to determine the HAA5 annual average and whether the requirements of 310 CMR 22.07C(3) apply, which monitoring shall have been completed so that the applicability determination could be made no later than March 31, 2000; or, (ii) comply with all other provisions of 310 CMR 22.20D(3)(b)2. as if the HAA5 monitoring had been conducted and the results required compliance with 310 CMR 22.20D(3)(b). 3. The supplier of water may request the Department approve a more representative annual data set than the data set determined in 310 CMR 22.20D(3)(a)1. or 2. for the purpose of determining applicability of the requirements of 310 CMR 22.20D(3). A representative data set was to be determined based on the following: a. Whether the method of collection was in accordance with 310 CMR 22.07(2), 22.07E and 22.20D(3); b. Whether the annual set presented is representative of the plant's current and/or long-term disinfection practices. 4. The Department may require that a system use a more representative annual data set than the data set determined under 310 CMR 22.20D(3)(a)1. or 2. for the purpose of determining applicability of the requirements of 310 CMR 22.20D. 22.20D: continued 5. The supplier of water must have submitted data to the Department on the schedule as shown below: a. A supplier of water who collected TTHM and HAA5 data under the provisions of Information Collection Rule (ICR), as was required by 310 CMR 22.20D(3)(a)1.a. and 2.a., must have submitted the results of the samples collected during the last 12 months of required monitoring under the ICR not later than December 31, 1999. b. A supplier of water who collected four consecutive quarters of data that met the routine monitoring sample number and location for TTHM in 310 CMR 22.07A and 310 CMR 22.07E for handling and analytical method requirements, as was allowed by 310 CMR 22.20D(3)(a)1.b. and 2.b., must have submitted that data to the Department not later than April 16, 1999. Until the Department has approved the data, the system shall conduct monitoring for HAA5 using the monitoring requirements specified under 310 CMR 22.20D(3)(a) 2.c. c. A supplier of water who conducted monitoring for HAA5 using the monitoring requirements specified by 310 CMR 22.20D(3)(a)1.c. and 2.c.(i), must have submitted TTHM and HAA5 data not later than March 31, 2000. d. A supplier of water who elected to comply with all other provisions of 310 CMR 22.20D(3) as if the HAA5 monitoring had been conducted and the results required compliance with 310 CMR 22.20D(3)(a), as was allowed under 310 CMR 22.20D(3)(a)2.c.(i), must have notified the Department in writing of their election not later than March 31, 2000. e. If the supplier of water elected to request that the Department approve a more representative annual data set than the data set determined under 310 CMR 22.20D(3)(a)2.a., the system must have submitted this request in writing not later than March 31, 2000. 6. Any supplier of water having either a TTHM annual average greater than or equal to 0.064 mg/L or an HAA5 annual average greater than or equal to 0.048 mg/L during the period identified in 310 CMR 22.20D(3)(a)1. and 2. shall comply with 310 CMR 22.20D(3)(b). 7. An owner or operator of a consecutive systems was not required to develop a disinfection profile; however, they are required to meet the requirements of 310 CMR 22.07E. (b) Disinfection Profiling. 1. A supplier of water who meets the criteria in 310 CMR 22.20D(3)(a)6. shall develop a disinfection profile of their disinfection practice for a period of up to three years. 2. A supplier of water shall monitor daily for a period of 12 consecutive calendar months to determine the total logs of inactivation for each day of operation, based on the CT values in 310 CMR 22.20A(5)(b): Tables 1.1 through 1.6, 2.1, and 3.1 and 310 CMR 22.20D(3): Tables C1 through C13, as appropriate, through the entire treatment plant. The supplier of water shall have begun this monitoring not later than April 1, 2000. As a minimum, the supplier of water using a single point of disinfectant application prior to entrance to the distribution system shall conduct monitoring in accordance with 310 CMR 22.20D(3)(b)2.a. through d. A supplier of water using a system with more than one point of disinfectant application shall conduct the monitoring in accordance with 310 CMR 22.20D(3)(b)2.a. through d. for each disinfection segment. The supplier of water shall monitor the parameters necessary to determine the total inactivation ratio, using analytical methods in 310 CMR 22.20A(5), as follows: a. The temperature of the disinfected water shall be measured once daily at each residual disinfectant concentration sampling point during peak hourly flow. b. If the system uses chlorine, the pH of the disinfected water shall be measured once daily at each chlorine residual disinfectant concentration sampling point during peak hourly flow. c. The disinfectant contact time(s) ("T") shall be determined for each day during peak hourly flow. d. The residual disinfectant concentration(s) ("C") of the water before or at the first customer and prior to each additional point of disinfection shall be measured daily during peak hourly flow. 22.20D: continued 3. In lieu of the monitoring conducted under the provisions of 310 CMR 22.20D(3)(b)2. to develop the disinfection profile, the supplier of water may have elected to meet the requirements of paragraph 310 CMR 22.20D(3)(b)3.a. In addition to the monitoring conducted under the of 310 CMR 22.20D(3)(b)2. to develop the disinfection profile, the system may elect to meet the requirements of 310 CMR 22.20D(3)(b)3.b. a. A supplier of water who has three years of existing operational data could have submitted that data, a profile generated using that data, and a request that the Department approve the use of that data in lieu of monitoring under the provisions of 310 CMR 22.20D(3)(b)2. not later than March 31, 2000. This data shall be representative of Giardia lamblia inactivation through the entire treatment plant and not just of certain treatment segments. Until the Department approves this request, the supplier of water is required to conduct monitoring under the provisions of 310 CMR 22.20D(3)(b)2. b. In addition to the disinfection profile generated under 310 CMR 22.20D(3)(b)2., a supplier of water who has existing operational data may use that data to develop a disinfection profile for additional years. The supplier of water may use these additional yearly disinfection profiles to develop a benchmark under the provisions of 310 CMR 22.20D(3)(c). The Department will determine whether these operational data are substantially equivalent to data collected under the provisions of 310 CMR 22.20D(3)(b)2. These data shall be representative of inactivation through the entire treatment plant, and not just of certain treatment segments. 4. The supplier of water shall calculate the total inactivation ratio as follows: a. If the supplier of water uses only one point of disinfectant application, the supplier of water may determine the total inactivation ratio for the disinfection segment based on either of the methods below: (i) Determine one inactivation ratio CTcalc/CT before or at the first customer during peak hourly flow; or, (ii) Determine successive CTcalc/CT values, representing sequential inactivation ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the supplier of water shall calculate the total inactivation ratio by determining CTcalc/CT for each sequence and then add the CTcalc/CT 99.9 values together: b. If the supplier of water uses more than one point of disinfectant application before the first customer, the supplier of water shall determine the CT value of each disinfection segment immediately prior to the next point of disinfectant application, or for the final segment, before or at the first customer, during peak hourly flow. The supplier of water shall calculate the CTcalc/CT value of each segment and S(CTcalc/CT ) using the method in 310 CMR 22.20D(3)(b)4.a. c. The supplier of water shall determine the total logs of inactivation (z) by multiplying the value calculated in 310 CMR 22.20D(b)4.a. or b. by 3.0 as shown below: 5. Each supplier of water who uses either chloramines or ozone for primary disinfection shall also calculate the logs of inactivation for Viruses using a method approved by the Department. 6. A supplier of water who uses mixed oxidants shall calculate the overall "CT" by finding the summation of the individual "CTs" of each disinfectant within the mix. 7. Each supplier of water shall retain the disinfection profile data in graphic form, as a spreadsheet, or in some other format acceptable to the Department for review as part of sanitary surveys conducted by the Department. 22.20D: continued (c) Disinfection Benchmarking. 1. Each supplier of water required to develop a disinfection profile under the provisions of 310 CMR 22.20D(a) and (b) who decides to make a significant change to a disinfection practice shall consult with the Department prior to making the change. A significant change to disinfection practice is any of the following: a. A change to the point of disinfection; b. A change to the disinfectant(s) used in the treatment plant; c. A change to the disinfection process; d. A physical modification(s) that directly or indirectly effects the detention time of any unit process; e. Any other modification identified by the Department. 2. Each supplier of water who proposes to modify its disinfection practice shall calculate the disinfection benchmark using the following procedure: a. For each year of profiling data collected and calculated under 310 CMR 22.20D(3)(b), the supplier of water shall determine the lowest average monthly Giardia lamblia inactivation in each year of profiling data. The supplier of water shall determine the average Giardia lamblia inactivation for each calendar month for each year of profiling data by dividing the sum of daily Giardia lamblia of inactivation by the number of values calculated for that month. b. The disinfection benchmark is the lowest monthly average value (for systems with one year of profiling data) or average of lowest monthly average values (for systems with more than one year of profiling data) of the monthly logs of Giardia lamblia inactivation in each year of profiling data. 3. Each supplier of water who uses either chloramines or ozone for primary disinfection shall also calculate the disinfection benchmark for Viruses using a method approved by the Department. 4. Each supplier of water shall submit the information required in 310 CMR 22.20D(3)(c) and the information required in 310 CMR 22.20D(3)(c)4.a. through c. to the Department as part of the consultation process including: a. A description of the proposed change b. The disinfection profile for Giardia lamblia (and, if necessary, Viruses) under 310 CMR 22.20D(3)(b) and benchmark as required by 310 CMR 22.20D(3)(c)2.; and c. An analysis of how the proposed change will affect the current levels of disinfection. (4) Filtration. Each supplier of water using a system subject to the requirements of 310 CMR 22.20D that does not meet all of the criteria of 310 CMR 22.20D(2) and the criteria in 310 CMR 22.20A(2) for avoiding filtration shall provide treatment consisting of both disinfection, as specified in 310 CMR 22.20A(3)(b), and filtration treatment that complies with the requirements of 310 CMR 22.20A(4)(b) or (c) and 22.20D(4)(a) or (b) and by December 31, 2001. (a) Conventional Filtration Treatment or Direct Filtration. 1. Each supplier of water using conventional filtration or direct filtration, shall maintain a turbidity level in representative samples of a system's filtered water of less than or equal to 0.3 NTU in at least 95% of the measurements taken each month, measured as specified in 310 CMR 22.20A(5)(a) and (c). 2. Each supplier of water must maintain a turbidity level of representative samples of a system's filtered water that at no time exceed one NTU, measured as specified in 310 CMR 22.20A(5)(a) and (c). 3. A supplier of water who uses lime softening may acidify representative samples prior to analysis in accordance with a protocol approved by the Department. (b) Filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration. 1. A supplier of water may use a filtration technology not listed in 310 CMR 22.20A(4)(b) or (c) or 22.20D(4)(a) if the supplier of water demonstrates to the Department, using pilot plant studies or other means, that the alternative filtration technology, in combination with disinfection treatment that meets the requirements of 310 CMR 22.20A(3)(b), consistently achieves 99.9% removal and/or inactivation of Giardia lamblia cysts and 99.99% removal and/or inactivation of Viruses, and 99% removal of Cryptosporidium oocysts, and the Department approves the use of the filtration technology. For each approval, the supplier of water shall maintain the turbidity level of representative samples of the system's filtered water at less than or equal to 0.3 NTU at least 95% of the time and that the system shall not exceed one NTU at any time. 22.20D: continued 2. The performance standards of slow sand filters and diatomateous earth filters are the same as indicated in 310 CMR 22.20A. (5) Monitoring Requirements for Systems Using Filtration Treatment. (a) In addition to monitoring required by 310 CMR 22.20A(5), a supplier of water who relies upon a public water system subject to the requirements of 310 CMR 22.20D that provides conventional filtration treatment or direct filtration shall conduct continuous monitoring of turbidity for each individual filter using an approved method in 310 CMR 22.20A(5)(a), and shall calibrate turbidimeters using the procedure specified by the manufacturer. The supplier of watershall record the results of individual filter monitoring every 15 minutes. (b) If there is a failure in the continuous turbidity monitoring equipment, the supplier of water shall conduct grab sampling every four hours in lieu of continuous monitoring, but for no more than five working days following the failure of the equipment. (6) Reporting and Recordkeeping Requirements. In addition to the reporting and recordkeeping requirements in 310 CMR 22.20A(6), a supplier of water who is subject to the requirements of 310 CMR 22.20D who provides conventional filtration treatment or direct filtration shall report monthly to the Department the information specified in 310 CMR 22.20D(6)(a) and (b) beginning January 1, 2002. In addition to the reporting and recordkeeping requirements in 310 CMR 22.20A(6), a supplier of water who is subject to the requirements of 310 CMR 22.20D that provides filtration approved under 310 CMR 22.20D(4)(b) shall report monthly to the Department the information specified in 310 CMR 22.20D(6)(a) beginning January 1, 2002. This reporting in 310 CMR 22.20D(6)(a) is in lieu of the reporting specified in 310 CMR 22.20A(6). (a) The supplier of water shall report turbidity measurements as required by 310 CMR 22.20D(4) within ten days after the end of each month the system serves water to the public. Information that shall be reported to the Department includes: 1. The total number of filtered water turbidity measurements taken during the month. 2. The number and percentage of filtered water turbidity measurements taken during the month which are less than or equal to the turbidity limits specified in 310 CMR 22.20D(4)(a) or (b). 3. The date and value of any turbidity measurements taken during the month which exceed one NTU for systems using conventional filtration treatment or direct filtration, or exceed the maximum level set by the Department in 310 CMR 22.20D(4)(b). (b) The supplier of water shall maintain the results of individual filter monitoring taken as required in 310 CMR 22.20D(5) for at least three years. Each supplier of water shall report that individual filter turbidity monitoring was conducted in accordance with 310 CMR 22.20D(5) within ten days after the end of each month the system serves water to the public. Each supplier of water shall report individual filter turbidity measurement results taken under 310 CMR 22.20D(5) within ten days after the end of each month the system serves water to the public only if measurements demonstrate one or more of the conditions in 310 CMR 22.20D(6)(b)1. through 3. Each supplier of water who uses lime softening may apply to the Department for alternative exceedance levels for the levels specified in 310 CMR 22.20D(6)(b)1. through 4. if the supplier can demonstrate that higher turbidity levels in individual filters are due to lime carryover only and not due to degraded filter performance. A supplier of water shall report the filter number, the turbidity measurement, and the date(s) on which an exceedance occurred for any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart. In addition, the supplier of water shall either produce a filter profile for the filter within seven days of the exceedance (if the supplier is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance. 1. For any individual filter that has a measured turbidity level of greater than 0.5 NTU in two consecutive measurements taken 15 minutes apart at the end of the first four hours of continuous filter operation after the filter has been backwashed or otherwise taken offline, the supplier of water shall report the filter number, the turbidity, and the date(s) on which the exceedance occurred. In addition, the supplier of water shall either produce a filter profile for the filter within seven days of the exceedance (if the system is not able to identify an obvious reason for the abnormal filter performance) and report that the profile has been produced or report the obvious reason for the exceedance. 22.20D: continued 2. For any individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each of three consecutive months, the supplier of water shall report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the supplier of water shall conduct a self-assessment of the filter within 14 days of the exceedance and report that the self-assessment was conducted. The self-assessment shall consist of at least the following components: assessment of filter performance; development of a filter profile; identification and prioritization of factors limiting filter performance; assessment of the applicability of corrections; and preparation of a filter self-assessment report. 3. For any individual filter that has a measured turbidity level of greater than 2.0 NTU in two consecutive measurements taken 15 minutes apart at any time in each of two consecutive months, the supplier of water shall report the filter number, the turbidity measurement, and the date(s) on which the exceedance occurred. In addition, the supplier of water shall arrange for the Department to conduct a Comprehensive Performance Evaluation no later than 30 days following the exceedance and have the evaluation completed no later than 90 days following the exceedance. (c) Additional Reporting Requirements. 1. If at any at time the turbidity exceeds one NTU in representative samples of filtered water in a system using conventional treatment or direct filtration, the supplier of water shall inform the Department as soon as possible, but not later than the end of the next business day. 2. If at any at time the turbidity exceeds one NTU in representative samples of filtered water in a system using filtration technologies other than conventional filtration treatment, direct filtration, slow sand filtration, or diatomaceous earth filtration, the supplier of water shall inform the Department as soon as possible, but not later than the end of the next business day.