Abandonment of Water Supply Sources

(1) No supplier of water may remove a public water system source from service or abandon a public water system source without the prior written approval of the Department. The Department will not approve any such action unless the supplier of water demonstrates to the Department's satisfaction that such action will have no significant adverse impact upon the supplier of water's present and future ability to provide continuous adequate service to consumers under routine and emergency operating conditions, including emergencies concerning the contamination of sources of supply, failure of the distribution system and shortage of supply. (2) The supplier of water shall maintain each public water system source removed from service as an emergency source unless the Department approves its disposition in accordance with 310 CMR 22.24 or its abandonment in accordance with 310 CMR 22.25. All public water system groundwater sources approved for abandonment or permanent closure may continue to be used as non-public water system sources. The Department may require closure of certain groundwater sources in a manner that minimizes the potential for groundwater contamination and public health risk, by permanently preventing vertical movement of water within the borehole and annular space and eliminating all physical hazards at the ground surface associated with the well's construction or location. Proposals for permanent closure shall describe the closure method and materials to be used and shall be submitted to the Department for review and approval. 22.26 Ground Water Rule (1) General Requirements and Applicability. (a) Applicability. 310 CMR 22.26 applies to all Public Water Systems that use groundwater except that it does not apply to Public Water Systems that combine all of their groundwater with Surface Water or with Groundwater under the Direct Influence of Surface Water prior to treatment. For the purposes of 310 CMR 22.26, "groundwater system" is defined as any Public Water System meeting this applicability statement, including consecutive systems receiving finished groundwater. (b) General Requirements. Systems subject to 310 CMR 22.26 must comply with the following requirements: 1. Sanitary survey information requirements for all groundwater systems as described in 310 CMR 22.26(2). 2. Microbial source water monitoring requirements for groundwater systems that do not treat all of their groundwater to at least 99.99% (4-log) treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer as described in 310 CMR 22.26(3). 22.26: continued 3. Treatment Technique requirements, described in 310 CMR 22.26(4), that apply to groundwater systems that have fecally contaminated source waters, as determined by source water monitoring conducted under 310 CMR 22.26(3), or that have significant deficiencies that are identified by the Department. A groundwater system with fecally contaminated source water or with significant deficiencies subject to the Treatment Technique requirements of 310 CMR 22.26 must implement one or more of the following corrective action options: a. correct all significant deficiencies; b. provide an alternate source of water; c. eliminate the source of contamination; or d. provide treatment that reliably achieves at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer. 4. Groundwater systems that provide at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer are required to conduct compliance monitoring to demonstrate treatment effectiveness, as described in 310 CMR 22.26(4)(b). (c) Compliance Date. Groundwater systems must comply, unless otherwise noted, with the requirements of 310 CMR 22.26 beginning December 1, 2009. (2) Sanitary Surveys for Groundwater Systems. (a) Groundwater systems must provide the Department or its agents, at the Department's request, any existing information that will enable the Department to conduct a Sanitary Survey. (b) For the purposes of 310 CMR 22.26, a Sanitary Survey, as conducted by the Department or its agents, includes but is not limited to, an onsite review of the water source(s) (identifying sources of contamination by using results of source water assessments or other relevant information where available), facilities, equipment, operation, maintenance, and monitoring compliance of a Public Water System to evaluate the adequacy of the system, its sources and operations and the distribution of safe drinking water. (c) The Sanitary Survey must include a written evaluation of the applicable components listed in 310 CMR 22.26(2)(c)1. through 8.: 1. Source; 2. Treatment; 3. Distribution System; 4. Finished water storage; 5. Pumps, pump facilities, and controls; 6. Monitoring, reporting, and data verification; 7. System management and operation; and 8. Operator compliance with Department requirements. (3) Groundwater Source Microbial Monitoring and Analytical Methods. (a) Triggered Source Water Monitoring. 1. General Requirements. A groundwater system must conduct triggered source water monitoring if the conditions identified in 310 CMR 22.26(3)(a)1.a. and b. exist. a. The system does not provide at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for each groundwater source; and b. The system is notified that a sample collected under 310 CMR 22.05(1)(a) is total coliform-positive and the sample is not invalidated under 310 CMR 22.05(3). 2. Sampling Requirements. A groundwater system must collect, within 24 hours of notification of the total coliform-positive sample, at least one groundwater source sample from each groundwater source in use at the time the total coliform-positive sample was collected, except as provided in 310 CMR 22.26(3)(a)2.b. a. The Department may extend the 24-hour time limit on a case-by-case basis if the system cannot collect the groundwater source water sample within 24 hours due to circumstances beyond its control. The system must contact the Department for pre-approval of the delay of sampling. In the case of an extension, the Department will specify in writing how much time the system has to collect the sample. 22.26: continued b. If approved by the Department, systems with more than one groundwater source may meet the requirements of 310 CMR 22.26(3)(a)2. by sampling a representative groundwater source or sources. Systems must submit for Department approval a triggered source water monitoring plan that identifies one or more groundwater sources that are representative of each monitoring site in the system's sample siting plan under 310 CMR 22.05(1) and that the system intends to use for representative sampling under 310 CMR 22.26(3). After December 1, 2009, a system that has not received written Department approval of their triggered source water monitoring plan, must collect triggered source water samples as required by 310 CMR 22.26(3)(a)2. until written approval is received. c. A groundwater system serving 1,000 people or fewer may use a repeat sample collected from a groundwater source to meet both the requirements of 310 CMR 22.05(2) and to satisfy the monitoring requirements of 310 CMR 22.26(3)(a)2. for that groundwater source: i. if E. coli is used as a fecal indicator for source water monitoring pursuant to 310 CMR 22.26(3)(a)3.; and ii. if the Department, pursuant to 310 CMR 22.05(1)(a)3.d.ii., has approved the use of a single sample for meeting both the triggered source water monitoring requirements in 310 CMR 22.26(3)(a) and the repeat monitoring requirements in 310 CMR 22.05(2). If the repeat sample collected for the groundwater source is E. coli positive, the system shall comply with 310 CMR 22.26(3)(a)4. d. A groundwater system may use a Raw Water sample collected to meet the requirements of 310 CMR 22.05(1) to satisfy the monitoring requirements of 310 CMR 22.26(3)(a)2. for that groundwater source only if: the Raw Water sample was collected on the same day as the distribution sample that tested total coliform-positive under 310 CMR 22.05(1) and triggered the requirements of 310 CMR 22.26(3)(a)2.; and the Raw Water sample was analyzed in accordance with 310 CMR 22.05(3)(b)1. and the analytical methods in 310 CMR 22.26(3)(c). If the Raw Water sample is total coliform-negative, no additional testing is required under 310 CMR 22.26 unless otherwise determined by the Department. 3. Fecal Indicator Requirement. a. All Non-transient Non-community Water Systems, all Transient Non-community Water Systems and each Community Water System serving 3,300 or fewer people shall use E. coli as the fecal indicator to comply with 310 CMR 22.26(3)(a). b. For Community Water Systems serving greater than 3,300 people: i. If E. coli is detected in samples collected under 310 CMR 22.05(1), the Community Water System shall use E. coli as the fecal indicator to comply with 310 CMR 22.26(3)(a). ii. If total coliform is detected in samples collected under 310 CMR 22.05(1) without the confirmation of E. coli, the Community Water System shall use enterococci as the fecal indicator to comply with 310 CMR 22.26(3)(a). c. Testing for additional fecal indicators may be required to further evaluate contamination at a groundwater source. 4. Additional Requirements. If the Department does not require corrective action under 310 CMR 22.26(4)(a)2. for a fecal indicator-positive source water sample collected under 310 CMR 22.26(3)(a)2. that is not invalidated under 310 CMR 22.26(3)(d), the system must collect five additional source water samples from the same source within 24 hours of being notified of the fecal indicator-positive sample. 5. Consecutive and Wholesale Systems. a. In addition to the other requirements of 310 CMR 22.26(3)(a), a consecutive groundwater system that has a total coliform-positive sample collected under 310 CMR 22.05(1) must notify the Wholesale System(s) within 24 hours of being notified of the total coliform-positive sample. b. In addition to the other requirements of 310 CMR 22.26(3)(a), a wholesale groundwater system must comply with 310 CMR 22.26(3)(a)5.b.i. and ii. 22.26: continued i. A wholesale groundwater system that receives notice from a consecutive system it serves that a sample collected under 310 CMR 22.05(1) is total coliform-positive must, within 24 hours of being notified, collect a sample from its groundwater source(s) under 310 CMR 22.26(3)(a)2. and analyze it for a fecal indicator under 310 CMR 22.26(3)(c). ii. If the sample collected under 310 CMR 22.26(3)(a)5.b.i. is fecal indicator-positive, the wholesale groundwater system must notify all consecutive systems served by that groundwater source of the fecal indicator source water positive within 24 hours of being notified of the groundwater source water sample monitoring result and must meet the requirements of 310 CMR 22.26(3)(a)4. 6. Exceptions to the Triggered Source Water Monitoring Requirements. A groundwater system is not required to comply with the source water monitoring requirements of 310 CMR 22.26(3)(a) if either of the following conditions exists: a. The Department determines, and documents in writing, that the total coliform-positive sample collected under 310 CMR 22.05(1) is caused by a Distribution System deficiency; or b. The total coliform-positive sample collected under 310 CMR 22.05(1)(a) is collected at a location that meets Department criteria for Distribution System conditions that will cause total coliform- positive samples. (b) Other Source Water Monitoring. 1. A groundwater system meeting the applicability requirements of 310 CMR 22.26(1)(a) that does not treat their groundwater to at least 99.99% (4-log) treatment of Viruses and conducts any type of source water monitoring under 310 CMR 22.00 or otherwise that includes analysis of total coliform, E. coli, enterococci, or coliphage is subject to the requirements of 310 CMR 22.26 if the source water sample analysis yields a positive result. The requirements of 310 CMR 22.26 apply only to the groundwater sources with positive source water sample results. A positive sample shall satisfy the monitoring requirements of 310 CMR 22.26(3)(a)2. If the source water sample is tested for total coliform, and the sample is total coliform-positive, the system must analyze that total coliform-positive culture medium for E. coli. E. coli shall serve as the fecal indicator under this condition. 2. The Department reserves the right to require additional source water monitoring for fecal indicators using analytical methods as defined under 310 CMR 22.26(3)(c) if circumstances warrant additional testing to determine system vulnerability. (c) Analytical Methods. 1. A groundwater system subject to the source water monitoring requirements of 310 CMR 22.26(3)(a) must collect a Standard Sample volume of at least 100 mL for fecal indicator analysis regardless of the fecal indicator or analytical methods used. 2. A groundwater system must analyze all groundwater source samples collected under 310 CMR 22.26(3)(a) and (b) using methods listed in the following table in 310 CMR 22.26(3)(c)2. for the presence of E. coli or enterococci as specified in 310 CMR 22.26(3)(a)3. The Department reserves the right to require coliphage analysis. 22.26: continued Analytical Methods for Source Water Monitoring Fecal Indicator Methodology Method Citation E.coli Colilert®3 Colisure®3 Colilert-18® Membrane Filter Method with MI Agar E*Colite Test5 NA-MUG SM 9223 B2 SM 9223 B2 SM 9223 B EPA Method 16044 SM 9222 G2 Enterococci Membrane Filter Technique Membrane Filter Technique Enterolert™ 7 SM 9230C2 EPA Method 16006 Coliphage Two-step Enrichment Presence-absence Procedure Single Agar Layer Procedure EPA Method 16018 EPA Method 16029 Analyses must be conducted in accordance with the documents listed below. Copies may be inspected at EPA's Drinking Water Docket, EPA West, 1301 Constitution Avenue, NW, EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-2426); or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/ code_of_federal_regulations/ibr_locations.html. The time from sample collection to initiation of analysis may not exceed 30 hours. The groundwater system is encouraged but is not required to hold samples below 10ºC during transit. Methods are described in Standard Methods for the Examination of Water and Wastewater 20 edition (1998) and th copies may be obtained from the American Public Health Association, 1015 Fifteenth Street, NW, Washington, DC 20005-2605. Medium is available through IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092 EPA Method 1604: Total Coliforms and Escherichia coli in Water by Membrane Filtration Using a Simultaneous Detection Technique (MI Medium); September 2002, EPA 821-R-02-024. Method is available at http://www.epa.gov/nerlcwww/1604sp02.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW, Washington, D.C. 20460. A description of the E*Colite Test, Charm E*Colite Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichia coli in Drinking Water, January 9, 1998, is available from Charm Sciences, Inc, 659 Andover St., Lawrence, MA 01843-1032 or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW, Washington, DC 20460. EPA Method 1600: Enterococci in Water by Membrane Filtration Using membrane-Enterococcus Indoxyl-[beta]-D-Glucoside Agar (mEI) EPA 821-R-02-022 (September 2002) is an approved variation of Standard Method 9230C. The method is available at http://www.epa.gov/nerlcwww/1600sp02.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW, Washington, DC 20460. The holding time and temperature for groundwater samples are specified in footnote , rather than as specified in Section 8 of EPA Method 1600. DEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine 04092. Preparation and use of the medium is set forth in the article Evaluation of Enterolert for Enumeration of Enterococci in Recreational Waters, by Budnick, G.E., Howard, R.T., and Mayo, D.R., 1996, Applied and Environmental Microbiology, 62:3881- 3884. EPA Method 1601: Male-specific (F+) and Somatic Coliphage in Water by Two-step Enrichment Procedure; April 2001, EPA 821-R-01-030. Method is available at http://www.epa.gov/nerlcwww/1601ap01.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW, Washington, DC 20460. EPA Method 1602: Male-specific (F+) and Somatic Coliphage in Water by Single Agar Layer (SAL) Procedure; April 2001, EPA 821-R-01-029. Method is available at http://www.epa.gov/nerlcwww/1602ap01.pdf or from EPA's Water Resource Center (RC-4100T), 1200 Pennsylvania Avenue, NW, Washington, DC 20460. (d) Invalidation of a Fecal Indicator-positive Groundwater Source Sample. 1. A groundwater system may obtain Department invalidation of a fecal indicator-positive groundwater source sample collected under 310 CMR 22.26(3)(a) only under the conditions specified in 310 CMR 22.26(3)(d)1.a. and b. a. The system provides the Department with written notice from the laboratory that improper sample analysis occurred; or 22.26: continued b. The Department determines and documents in writing that there is substantial evidence that a fecal indicator-positive groundwater source sample is not related to source water quality. 2. If the Department invalidates a fecal indicator-positive groundwater source sample, the groundwater system must collect another source water sample under 310 CMR 22.26(3)(a) within 24 hours of being notified by the Department of its invalidation decision and have it analyzed for the same fecal indicator using the analytical methods in 310 CMR 22.26(3)(c). The Department may extend the 24-hour time limit on a case-by-case basis if the system cannot collect the source water sample within 24 hours due to circumstances beyond its control. In the case of an extension, the Department will specify how much time the system has to collect the sample. (e) Sampling Location. 1. Any groundwater source sample required under 310 CMR 22.26(3)(a) must be collected at a location prior to any treatment of the groundwater source. All systems are required to maintain a Raw Water source water sample tap in accordance with 310 CMR 22.05(1)(a)1. 2. If the system's configuration does not allow for sampling at the well itself, the system may collect a sample at a Department-approved location to meet the requirements of 310 CMR 22.26(3)(a) if the sample is representative of the water quality of that well. Approval must be received in writing. (f) New Sources. A groundwater system that plans to place a new groundwater source into service after November 30, 2009, must conduct source water monitoring in accordance with Chapter 4 of the Massachusetts Guidelines for Public Water Systems and may have to meet the requirements of 310 CMR 22.26(3)(b) if the Department determines additional testing is required. (g) Public Notification. A groundwater system with a groundwater source sample collected under 310 CMR 22.26(3)(a) or (b) that is fecal indicator-positive and that is not invalidated under 310 CMR 22.26(3)(d), including consecutive systems served by the groundwater source, must conduct public notification under 310 CMR 22.16. (h) Monitoring Violations. Failure to meet the requirements of 310 CMR 22.26(3)(a) through (f) is a monitoring violation and requires the groundwater system to report each failure to the Department pursuant to 310 CMR 22.15(1), and provide public notification under 310 CMR 22.16. (i) Department Notification. The Supplier of Water shall notify the Department by the end of the day that it is notified of a fecal indicator-positive source water test result. If the Supplier of Water receives such notification outside of the Department's regular business hours, then it shall provide notification to the Department by calling the Department's Emergency notification telephone number and using any other electronic reporting tool designated by the Department, or other Department designated telephone numbers. (4) Treatment Technique Requirements for Groundwater Systems. (a) Groundwater systems with significant deficiencies or source water fecal contamination. 1. The Treatment Technique requirements of 310 CMR 22.26(4) must be met by groundwater systems when a Significant Deficiency is identified or when a groundwater source sample collected under 310 CMR 22.26(3)(a)4. is fecal indicator-positive. 2. If directed by the Department, a groundwater system with a groundwater source sample collected under 310 CMR 22.26(3)(a)2., 5., or (b) that is fecal indicator positive must comply with the Treatment Technique requirements of 310 CMR 22.26(4). 3. When a Significant Deficiency is identified at a surface or Groundwater Under the Direct Influence of Surface Water Public Water System that uses both Groundwater and Surface Water or Groundwater under the Direct Influence of Surface Water, the system must comply with provisions of 310 CMR 22.26(4) except in cases where the Department determines that the Significant Deficiency is in a portion of the Distribution System that is served solely by Surface Water or Groundwater under the Direct Influence of Surface Water. 22.26: continued 4. Unless the Department directs the groundwater system to implement a specific corrective action, the groundwater system must consult with the Department regarding the appropriate corrective action within 30 days of receiving written notice from the Department of a Significant Deficiency, written notice from a laboratory that a groundwater source sample collected under 310 CMR 22.26(3)(a)4. was found to be fecal-indicator-positive, or direction from the Department that a fecal indicator-positive sample collected under 310 CMR 22.26(3)(a)2., 5., or (b) requires corrective action. For the purposes of 310 CMR 22.26, significant deficiencies include, but are not limited to, defects in design, operation, or maintenance, or a failure or malfunction of the sources, treatment, storage, or Distribution System that the Department determines to be causing, or have potential for causing, the introduction of contamination into the water delivered to consumers. 5. Within 120 days (or earlier if directed by the Department) of receiving written notification from the Department of a Significant Deficiency, written notice from a laboratory that a groundwater source sample collected under 310 CMR 22.26(3)(a)4. was found to be fecal indicator-positive, or direction from the Department that a fecal indicator-positive sample collected under 310 CMR 22.26(3)(a)2., 5., or (b) requires corrective action, the groundwater system must either: a. Have completed corrective action in accordance with applicable Department plan review processes or other Department guidance or direction, if any, including Department-specified interim measures; or b. Be in compliance with a Department-approved corrective action plan and schedule subject to the conditions specified in 310 CMR 22.26(4)(a)5.b.i. and ii. i. Any subsequent modifications to a Department-approved corrective action plan and schedule must also be approved by the Department. ii. If the Department specifies interim measures for protection of the public health pending Department approval of the corrective action plan and schedule or pending completion of the corrective action plan, the system must comply with these interim measures as well as with any schedule specified by the Department. iii. Corrective action plans submitted under 310 CMR 22.05(4) or 22.26(4) may be considered for purposes of 310 CMR 22.26(4)(a)5., as appropriate. 6. Corrective Action Alternatives. Groundwater systems that meet the conditions of 310 CMR 22.26(4)(a)1. or 2. must implement one or more of the following corrective action alternatives: a. Correct all significant deficiencies; b. Provide an alternate source of water; c. Eliminate the source of contamination; or d. Provide treatment that reliably achieves at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for the groundwater source. (b) Compliance Monitoring. 1. Existing Groundwater Sources. A groundwater system that is not required to meet the source water monitoring requirements of 310 CMR 22.26 for any groundwater source because it provides at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for any groundwater source before December 1, 2009, must notify the Department in writing that it provides at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for the specified groundwater source and begin compliance monitoring in accordance with 310 CMR 22.26(4)(b)3. by December 1, 2009. Notification to the Department must include engineering, operational, or other information that the Department requests to evaluate the submission. If the system subsequently discontinues 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for a groundwater source, the system must conduct groundwater source monitoring as required 310 CMR 22.26(3). 22.26: continued 2. New Groundwater Sources. A groundwater system that places a groundwater source in service after November 30, 2009, that is not required to meet the source water monitoring requirements of 310 CMR 22.26 because the system provides at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for the groundwater source must comply with the requirements of 310 CMR 22.26(4)(b)2.a. through c. a. The system must notify the Department in writing that it provides at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for the groundwater source. Notification to the Department must include engineering, operational, or other information that the Department requests to evaluate the submission. b. The system must conduct compliance monitoring as required under 310 CMR 22.26(4)(b)3. within 30 days of placing the source in service. c. The system must conduct groundwater source monitoring under 310 CMR 22.26(3) if the system subsequently discontinues 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for the groundwater source. 3. Monitoring Requirements. A groundwater system subject to the requirements of 310 CMR 22.26(4)(a) or (b)1. or 2. must monitor the effectiveness and reliability of treatment for that groundwater source before or at the first customer as follows: a. Chemical Disinfection. i. Groundwater Systems Serving Greater than 3,300 People. A groundwater system that serves greater than 3,300 people must continuously monitor the Residual Disinfectant Concentration using analytical methods specified in 310 CMR 22.20A(5)(a)2. at a location approved by the Department and must record the lowest Residual Disinfectant Concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Department-determined Residual Disinfectant Concentration every day the groundwater system serves water from the groundwater source to the public. If there is a failure in the continuous monitoring equipment, the groundwater system must conduct grab sampling every four hours until the continuous monitoring equipment is returned to service. The system must resume continuous residual Disinfectant monitoring within 14 days. ii. Groundwater Systems Serving 3,300 or Fewer People. A groundwater system that serves 3,300 or fewer people must monitor the Residual Disinfectant Concentration using analytical methods specified in 310 CMR 22.20A(5)(a)2. at a location approved by the Department and record the residual Disinfection concentration each day that water from the groundwater source is served to the public. The groundwater system must maintain the Department-determined Residual Disinfectant Concentration every day the groundwater system serves water from the groundwater source to the public. The groundwater system must take a daily grab sample during the hour of peak flow or at another time specified by the Department. If any daily grab sample measurement falls below the Department-determined Residual Disinfectant Concentration, the groundwater system must take follow-up samples every four hours until the Residual Disinfectant Concentration is restored to the Department-determined level. Alternatively, a groundwater system that serves 3,300 or fewer people may monitor continuously and meet the requirements of 310 CMR 22.26(4)(b)3.a.i. b. Membrane Filtration. A groundwater system that uses Membrane Filtration to meet the requirements of 310 CMR 22.26 must monitor the Membrane Filtration process in accordance with all Department-specified monitoring requirements and must operate the Membrane Filtration in accordance with all Department-specified compliance requirements. A groundwater system that uses Membrane Filtration is in compliance with the requirement to achieve at least 4-log removal of Viruses when: i. The membrane has an absolute molecular weight cut-off (MWCO), or an alternate parameter that describes the exclusion characteristics of the membrane, that can reliably achieve at least 4-log removal of Viruses; 22.26: continued ii. The membrane process is operated in accordance with Department-specified compliance requirements; and iii. The integrity of the membrane is intact. c. Alternative Treatment. A groundwater system that uses a Department-approved alternative treatment to meet the requirements of 310 CMR 22.26 by providing at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer must: i. Monitor the alternative treatment in accordance with all Department-specified monitoring requirements; and ii. Operate the alternative treatment in accordance with all compliance requirements that the Department determines to be necessary to achieve at least 4-log treatment of Viruses. (c) Discontinuing Treatment. A groundwater system may discontinue 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for a groundwater source if the Department determines and documents in writing that 4-log treatment of Viruses is no longer necessary for that groundwater source. A system that discontinues 4-log treatment of Viruses is subject to the source water monitoring and analytical methods requirements of 310 CMR 22.26(3). (d) Failure to meet the monitoring requirements of 310 CMR 22.26(4)(b) is a monitoring violation and requires the groundwater system to provide public notification under 310 CMR 22.16(4). (5) Treatment Technique Violations for Groundwater Systems. (a) A groundwater system with a Significant Deficiency is in violation of the Treatment Technique requirement if, within 120 days (or earlier if directed by the Department) of receiving written notice from the Department of the Significant Deficiency, the system: 1. Does not complete corrective action in accordance with any applicable Department plan review processes or other Department guidance and direction, including Department specified interim actions and measures, or 2. Is not in compliance with a Department-approved corrective action plan and schedule. (b) Unless the Department invalidates a fecal indicator-positive groundwater source sample under 310 CMR 22.26(3)(d), a groundwater system is in violation of the Treatment Technique requirement if, within 120 days (or earlier if directed by the Department of meeting the conditions of 310 CMR 22.26(4)(a)1. or 2., the system: 1. Does not complete corrective action in accordance with any applicable Department plan review processes or other Department guidance and direction, including Department-specified interim measures, or 2. Is not in compliance with a Department-approved corrective action plan and schedule. (c) A groundwater system subject to the requirements of 310 CMR 22.26(4)(b)3. that fails to maintain at least 4-log treatment of Viruses (using inactivation, removal, or a Department-approved combination of 4-log Virus inactivation and removal) before or at the first customer for a groundwater source is in violation of the Treatment Technique requirement if the failure is not corrected within four hours of determining the system is not maintaining at least 4-log treatment of Viruses before or at the first customer. (d) Groundwater system must give public notification under 310 CMR 22.16 for the Treatment Technique violations specified in 310 CMR 22.26(5)(a) through (c). (6) Reporting and Recordkeeping for Groundwater Systems. (a) Reporting. In addition to the requirements of 310 CMR 22.15, a groundwater system regulated under 310 CMR 22.26 must provide the following information to the Department: 22.26: continued 1. A groundwater system conducting compliance monitoring under 310 CMR 22.26(4)(b) must notify the Department any time the system fails to meet any Department-specified requirements including, but not limited to, minimum Residual Disinfectant Concentration, membrane operating criteria or membrane integrity, and alternative treatment operating criteria, if operation in accordance with the criteria or requirements is not restored within four hours. The groundwater system must notify the Department as soon as possible, but in no case later than the end of the next business day. 2. After completing any corrective action under 310 CMR 22.26(4)(a), a groundwater system must notify the Department within 30 days of completion of the corrective action. 3. If a groundwater system subject to the requirements of 310 CMR 22.26(3)(a) does not conduct source water monitoring under 310 CMR 22.26(3)(a)6.b., the system must provide documentation to the Department within 30 days of the total coliform-positive sample that it met the Department criteria. (b) Recordkeeping. In addition to the requirements of 310 CMR 22.17, a groundwater system regulated under 310 CMR 22.26 must maintain the following information in its records: 1. Documentation of Corrective Actions. Documentation shall be kept for a period of not less than ten years. 2. Documentation of notice to the public as required under 310 CMR 22.16A(8). Documentation shall be kept for a period of not less than three years. 3. Records of decisions under 310 CMR 22.26(3)(a)6.b. and records of invalidation of fecal indicator-positive groundwater source samples under 310 CMR 22.26(3)(d). Documentation shall be kept for a period of not less than five years. 4. For consecutive systems, documentation of notification to the Wholesale System(s) of total-coliform positive samples that are not invalidated under 310 CMR 22.05(3). Documentation shall be kept for a period of not less than five years. 5. For systems, including Wholesale Systems, that are required to perform compliance monitoring under 310 CMR 22.26(4)(b): a. Records of the Department-specified minimum Disinfectant residual. Documentation shall be kept for a period of not less than ten years. b. Records of the lowest daily Residual Disinfectant Concentration and records of the date and duration of any failure to maintain the Department-prescribed minimum Residual Disinfectant Concentration for a period of more than four hours. Documentation shall be kept for a period of not less than five years. c. Records of Department-specified compliance requirements for Membrane Filtration and of parameters specified by the Department for Department-approved alternative treatment and records of the date and duration of any failure to meet the membrane operating, membrane integrity, or alternative treatment operating requirements for more than four hours. Documentation shall be kept for a period of not less than five years.