Ground Water Rule Monitoring and Treatment Technique Requirements

PURPOSE: This rule sets standards for public water systems using ground water, including requirements for monitoring, treatment techniques, and corrective actions where significant deficiencies are found. The rule is based on the requirements in the federal Ground Water Rule found in subpart S of 40 CFR part 141, July 1, 2008. PUBLISHER’S NOTE: The secretary of state has determined that the publication of the entire text of the material which is incorporated by reference as a portion of this rule would be unduly cumbersome or expensive. This material as incorporated by reference in this rule shall be maintained by the agency at its headquarters and shall be made available to the public for inspection and copying at no more than the actual cost of reproduction. This note applies only to the reference material. The entire text of the rule is printed here. (1) General Requirements and Applicability. (A) Scope of this rule. The requirements of this rule constitute National Primary Drinking Water Regulations. (B) Applicability. This rule applies to all public water systems that use ground water except that it does not apply to public water systems that combine all of their ground water with surface water or with ground water under the direct influence of surface water prior to treatment. Also, it does not apply to ground water systems under the direct influence of surface water. For the purposes of this rule, ground water system is defined as any public water system meeting this applicability statement, including consecutive systems receiving finished ground water. (C) General Requirements. 1. Systems subject to this rule must comply with sanitary survey information requirements described in section (2) of this rule. 2. Wherever it is used in this rule, the term “4-log treatment of viruses” shall mean treatment to at least ninety-nine and ninetynine hundredths percent (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. 3. For the purposes of this rule, 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 are causing, or have the potential for causing, the introduction of contamination into the water delivered to consumers. 4. Systems subject to this rule must comply with microbial source water monitoring requirements for ground water systems that do not treat all of their ground water to at least ninety-nine and ninety-nine hundredths percent (99.99%) (4-log) treatment of viruses before or at the first customer as described in section (3) of this rule. 5. Systems subject to this rule must comply with treatment technique requirements, described in section (4) of this rule that apply to ground water systems that have fecally contaminated source waters, as determined by source water monitoring conducted under section (3) of this rule, or that have significant deficiencies that are identified by the department, or that are identified by the U.S. Environmental Protection Agency under section 1445 of the Safe Drinking Water Act. A ground water system with fecally contaminated source water or with significant deficiencies subject to the treatment technique requirements of this rule must implement one (1) or more of the following corrective action options under the direction and approval of the department: 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 before or at the first customer. 6. Ground water systems that are required by this rule to provide at least 4-log treatment of viruses before or at the first customer are required to conduct compliance monitoring to demonstrate treatment effectiveness, as described in subsection (4)(B) of this rule. 7. If requested by the department, ground water systems must provide any existing information that will enable the department to perform a hydrogeologic sensitivity assessment. For the purposes of this rule, a hydrogeologic sensitivity assessment is a determination of whether ground water systems obtain water from hydrogeologically sensitive settings. (2) Sanitary Surveys and Inspections for Ground Water Systems. (A) Ground water systems must provide, at the department’s request, any existing information that will enable the department to conduct a sanitary survey or inspection. (B) For the purposes of this rule, a sanitary survey includes, but is not limited to, an onsite review, under the supervision of an engineer, 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 in order to evaluate the adequacy of the system, its sources and operations, and the distribution of safe drinking water. (C) The sanitary survey or inspection must include an evaluation of the water system’s— 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) Ground Water Source Microbial Monitoring. (A) Triggered Source Water Monitoring. 1. General requirements. A ground water system must conduct triggered source water monitoring if the following conditions exist: A. The system does not provide at least 4-log treatment of viruses (using inactivation, removal, or a state-approved combination of 4-log virus inactivation and removal) before or at the first customer for each ground water source; and B. The system is notified that a sample collected under 10 CSR 60-4.022(4)-(7) is total coliform-positive and the sample is not invalidated under 10 CSR 60-4.022(3)(C). 2. Sampling requirements. A ground water system must collect, within twenty-four (24) hours of notification of the total coliform-positive sample, at least one (1) ground water source sample from each ground water source in use at the time the total coliformpositive sample was collected under 10 CSR 60-4.022(4)-(7) except as provided in subparagraph (3)(A)2.B. of this rule. A. The department may extend the twenty-four (24) hour time limit on a case-bycase basis if the system cannot collect the ground water source water sample within twenty-four (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. B. If approved by the department, systems with more than one (1) ground water source may meet the requirements of this subparagraph by sampling a representative ground water source or sources. If directed by the department, systems must submit for department approval a triggered source water monitoring plan that identifies one (1) or more ground water sources that are representative of each monitoring site in the system’s sample siting plan under 10 CSR 60-4.022(3) and that the system intends to use for representative sampling for triggered source water monitoring. C. A ground water system serving one thousand (1,000) or fewer people may use a repeat sample collected from a ground water source to meet both the requirements of 10 CSR 60-4.022 and to satisfy the monitoring requirements of paragraph (3)(A)2. of this rule for that ground water source only if the department approves the use of E. coli as a fecal indicator for source water monitoring under this subsection (3)(A) and approves the use of a single sample for meeting both the triggered source water monitoring requirements in this subsection (3)(A) and the repeat monitoring requirements in 10 CSR 604.022(8). If the repeat sample collected from the ground water source is E. coli positive, the system must comply with paragraph (3)(A)3. of this rule. 3. Additional requirements. If the department does not require corrective action under paragraph (4)(A)2. of this rule for a fecal indicator-positive source water sample collected under paragraph (3)(A)2. of this rule that is not invalidated under subsection (3)(D) of this rule, the system must collect five (5) additional source water samples from the same source within twenty-four (24) hours of being notified of the fecal indicator-positive sample. 4. Consecutive systems. In addition to the other requirements of this subsection (3)(A), a consecutive ground water system that has a total coliform-positive sample collected under 10 CSR 60-4.022(4)-(7) must notify the wholesale system(s) within twentyfour (24) hours of being notified of the total coliform-positive sample. 5. Wholesale systems. In addition to the other requirements of this subsection (3)(A), a wholesale ground water system that receives notice from a consecutive system it serves that a sample collected under 10 CSR 60-4.022(4)-(7) is total coliform-positive must, within twenty-four (24) hours of being notified, collect a sample from its ground water source(s) under paragraph (3)(A)2. of this rule and analyze it for a fecal indicator under subsection (3)(C) of this rule. If this sample is fecal indicator-positive, the system must notify all consecutive systems served by that ground water source of the fecal indicator source water positive within twenty-four (24) hours of being notified of the monitoring result and must meet the requirements of paragraph (3)(A)3. of this rule. 6. Exceptions to triggered source water monitoring requirements. A ground water system is not required to comply with the source water monitoring requirements of this subsection (3)(A) if either of the following conditions exists: A. The department determines, and documents in writing, that the total coliformpositive sample collected under 10 CSR 604.022(4)-(7) is caused by a distribution system deficiency; or B. The total coliform-positive sample collected under 10 CSR 60-4.022(4)-(7) is collected at a location that meets department criteria for distribution system conditions that will cause total coliform-positive samples. (B) Assessment Source Water Monitoring. If directed by the department, ground water systems must conduct assessment source water monitoring that meets department-determined requirements. A ground water system conducting assessment source water monitoring may use a triggered source water sample collected under paragraph (3)(A)2. of this rule to meet the requirements of this subsection. The department may require any combination of— 1. Collection of a total of twelve (12) ground water source samples that represent each month the system provides ground water to the public; 2. Collection of samples from each well unless the system obtains written department approval to conduct monitoring at one (1) or more wells within the ground water system that are representative of multiple wells used by that system and that draw water from the same hydrogeologic setting; 3. Collection of a standard sample volume of at least one hundred milliliters (100 mL) for fecal indicator analysis regardless of the fecal indicator or analytical method used; 4. Analysis of all ground water source samples using one (1) of the analytical methods listed in paragraph (3)(C)2. of this rule for the presence of E. coli, enterococci, or coliphage; 5. Collection of ground water source samples at a location prior to any treatment of the ground water source unless the department approves a sampling location after treatment; or 6. Collection of ground water source samples at the well itself unless the system’s configuration does not allow for sampling at the well itself and the department approves an alternate sampling location that is representative of the water quality of that well. (C) Analytical Methods. 1. A ground water system subject to the source water monitoring requirements of subsection (3)(A) of this rule must collect a standard sample volume of at least one hundred milliliters (100 mL) for fecal indicator analysis regardless of the fecal indicator or analytical method used. 2. A ground water system must analyze all ground water source samples collected under subsection (3)(A) of this rule using one (1) of the analytical methods listed in the Environmental Protection Agency’s Code of Federal Regulations, 40 CFR 141.402, published February 13, 2013. This document is incorporated by reference without any later amendments or modifications. To obtain a copy, contact the U.S. Government Printing Office at 732 North Capitol Street NW, Washington D.C., 20401, toll free at (866) 512-1800 or by visiting https://bookstore.gpo.gov. (D) Invalidation of a Fecal Indicator-Positive Ground Water Source Sample. 1. A ground water system may obtain department invalidation of a fecal indicatorpositive ground water source sample collected under subsection (3)(A) of this rule only under the following conditions: A. The system provides the department with written notice from the laboratory that improper sample analysis occurred; or B. The department determines and documents in writing that there is substantial evidence that a fecal indicator-positive ground water source sample is not related to source water quality. 2. If the department invalidates a fecal indicator-positive ground water source sample, the ground water system must collect another source water sample under subsection (3)(A) of this rule within twenty-four (24) hours of being notified by the department of its invalidation decision and have it analyzed for the same fecal indicator listed in 40 CFR 141.402. The department may extend the twenty-four (24)-hour time limit on a case-by-case basis if the system cannot collect the source water sample within twenty-four (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 ground water source sample required under subsection (3)(A) of this rule must be collected at a location prior to any treatment of the ground water source unless the department approves a sampling location after treatment. 2. If the system’s configuration does not allow for sampling at the well itself, the system may collect a sample at a departmentapproved location to meet the requirements of subsection (3)(A) of this rule if the sample is representative of the water quality of that well. (F) New Sources. If directed by the department, a ground water system that places a new ground water source into service after November 30, 2009, must conduct assessment source water monitoring under subsection (3)(B) of this rule. If directed by the department, the system must begin monitoring before the ground water source is used to provide water to the public. (G) Public Notification. A ground water system with a ground water source sample collected under subsection (3)(A) or (3)(B) of this rule that is fecal indicator-positive and that is not invalidated under subsection (3)(D) of this rule, including consecutive systems served by the ground water source, must conduct Tier 1 public notification under 10 CSR 60-8.010. (H) Monitoring Violations. Failure to meet the requirements of subsections (3)(A)–(F) of this rule is a monitoring violation and requires the ground water system to provide Tier 3 public notification under 10 CSR 608.010. (4) Treatment Technique Requirements. (A) Ground Water Systems with Significant Deficiencies or Source Water Fecal Contamination. 1. The treatment technique requirements of this rule must be met by ground water systems when a significant deficiency is identified or when a ground water source sample collected under paragraph (3)(A)3. of this rule is fecal indicator-positive. 2. If directed by the department, a ground water system with a ground water source sample collected under paragraph (3)(A)3., paragraph (3)(A)4., or subsection (3)(B) that is fecal indicator-positive must comply with the treatment technique requirements of this section (4). 3. When a significant deficiency is identified at a public water system that uses both ground water and surface water or ground water under the direct influence of surface water, the system must comply with provisions of this subsection (4)(A) 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 ground water under the direct influence of surface water. 4. Unless the department directs the ground water system to implement a specific corrective action, the ground water system must consult with the department regarding the appropriate corrective action within thirty (30) days of receiving written notice from the department of a significant deficiency, written notice from a laboratory that a ground water source sample collected under paragraph (3)(A)3. of this rule was found to be fecal indicator-positive, or direction from the department that a fecal indicator-positive sample collected under paragraph (3)(A)2., paragraph (3)(A)4., or subsection (3)(B) of this rule requires corrective action. For the purposes of this rule, 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 are causing, or have potential for causing, the introduction of contamination into the water delivered to consumers. Such significant deficiencies may include, but may not be limited to, the following: A. For the source, any improperly constructed, sealed, or inadequately screened opening in the well head; B. For treatment— (I) Failure to perform and record the results of sufficient analyses to maintain control of treatment process or water quality; (II) Systems required to provide 4log virus inactivation or removal that do not meet disinfection concentration and detention time requirements; or (III) Systems that are required to disinfect that do not have standby redundant disinfection facilities; C. For distribution systems— (I) The existence of a known unprotected cross-connection; (II) Widespread or persistent low pressure events as defined in 10 CSR 604.080(8); (III) Submerged automatic air release valves or uncapped manual air release valves; or (IV) Failure to properly disinfect new or newly-repaired water mains; D. For finished water storage— (I) The existence of any unprotected, inadequately protected, or improperly constructed opening in a storage facility; or (II) Evidence that the water in the storage facility has been contaminated (for example, feathers or nesting materials in an overflow pipe or positive bacteria samples); E. For pumps or pump facilities and controls, repeated or persistent low pressures caused by pump or pump control problems or inadequate pump capacity; F. For monitoring, reporting, or data verification— (I) Falsification of monitoring or reporting records; or (II) Failure to maintain system records required under 10 CSR 60-9.010; G. For water system management or operations, failure to address significant deficiencies listed in the most recent inspection or sanitary survey report; and H. For operator compliance— (I) Lack of properly certified chief operator in responsible charge of the treatment facility as required under 10 CSR 6014.010(4); or (II) Lack of properly certified chief operator in responsible charge of the distribution facility as required under 10 CSR 6014.010(4). 5. Within one hundred twenty (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 ground water source sample collected under paragraph (3)(A)3. of this rule was found to be fecal indicator-positive, or direction from the department that a fecal indicator-positive sample collected under paragraph (3)(A)2., paragraph (3)(A)4., or subsection (3)(B) of this rule requires corrective action, the ground water 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 following conditions: (I) Any subsequent modifications to a department-approved corrective action plan and schedule must be approved by the department; and (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. 6. Corrective action alternatives. Ground water systems that meet the conditions of paragraph (4)(A)1. or (4)(A)2. of this rule must implement one (1) or more of the following corrective action alternatives under the direction and approval of the department: 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 before or at the first customer for the ground water source. 7. Special notice to the public of significant deficiencies or source water fecal contamination. A. In addition to the applicable public notification requirements of 10 CSR 608.010, a community ground water system that receives notice from the department of a significant deficiency or notification of a fecal indicator-positive ground water source sample that is not invalidated by the department under subsection (3)(D) of this rule must inform the public served by the water system under 10 CSR 60-8.030(2)(H)6. of the fecal indicator-positive source sample or of any significant deficiency that has not been corrected. The system must continue to inform the public annually until the significant deficiency is corrected or the fecal contamination in the ground water source is determined by the department to be corrected under paragraph (4)(A)5. of this rule. B. In addition to the applicable public notification requirements of 10 CSR 608.010, a non-community ground water system that receives notice from the department of a significant deficiency must inform the public served by the water system in a manner approved by the department of any significant deficiency that has not been corrected within twelve (12) months of being notified by the department, or earlier if directed by the department. The system must continue to inform the public annually until the significant deficiency is corrected. (I) The information must include: (a) The nature of the significant deficiency and the date the significant deficiency was identified by the department; (b) The department-approved plan and schedule for correction of the significant deficiency, including interim measures, progress to date, and any interim measures completed; and (c) For systems with a large proportion of non-English speaking consumers, as determined by the department, information in the appropriate language(s) regarding the importance of the notice or a telephone number or address where consumers may contact the system to obtain a translated copy of the notice or assistance in the appropriate language. (II) If directed by the department, a noncommunity water system with significant deficiencies that have been corrected must inform its customers of the significant deficiencies, how the deficiencies were corrected, and the dates of correction. (B) Compliance Monitoring. 1. Existing ground water sources. A ground water system that is not required to meet the source water monitoring requirements of this rule for any ground water source because it provides at least 4-log treatment of viruses before or at the first customer for any ground water source before December 1, 2009, must notify the department in writing that it provides at least 4-log treatment of viruses before or at the first customer for the specified ground water source and begin compliance monitoring in accordance with paragraph (4)(B)3. of this rule 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 before or at the first customer for a ground water source, the system must conduct ground water source monitoring as required under section (3) of this rule. 2. New ground water sources. A ground water system that places a ground water source in service after November 30, 2009, that is not required to meet the source water monitoring requirements of this rule because the system provides at least 4-log treatment of viruses before or at the first customer for the ground water source must comply with the following: A. The system must notify the department in writing that it provides at least 4-log treatment of viruses before or at the first customer for the ground water 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 paragraph (4)(B)3. of this rule within thirty (30) days of placing the source in service; and C. The system must conduct ground water source monitoring under section (3) of this rule if the system subsequently discontinues 4-log treatment of viruses before or at the first customer for the ground water source. 3. Monitoring requirements. A ground water system subject to the requirements of subsection (4)(A), or paragraph (4)(B)1. or (4)(B)2. of this rule must monitor the effectiveness and reliability of treatment for that ground water source before or at the first customer as follows: A. Chemical disinfection. (I) A ground water system that serves greater than three thousand three hundred (3,300) people must continuously monitor the residual disinfectant concentration using analytical methods specified in 10 CSR 60-5.010(5) at a location approved by the department and must record the lowest residual disinfectant concentration each day that water from the ground water source is served to the public. The ground water system must maintain the department-determined residual disinfectant concentration every day the ground water system serves water from the ground water source to the public. If there is a failure in the continuous monitoring equipment, the ground water system must conduct grab sampling every four (4) hours until the continuous monitoring equipment is returned to service. The system must resume continuous residual disinfectant monitoring within fourteen (14) days. (II) A ground water system that serves three thousand three hundred (3,300) or fewer people must monitor the residual disinfectant concentration using analytical methods specified in 10 CSR 60-5.010(5) at a location approved by the department and record the residual disinfection concentration each day that water from the ground water source is served to the public. The ground water system must maintain the departmentdetermined residual disinfectant concentration every day the ground water system serves water from the ground water source to the public. The ground water 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 ground water system must take follow-up samples every four (4) hours until the residual disinfectant concentration is restored to the department-determined level. Alternatively, a ground water system that serves three thousand three hundred (3,300) or fewer people may monitor continuously and meet the requirements in part (I) of this subparagraph (4)(B)3.A. B. Membrane filtration. A ground water system that uses membrane filtration to meet the requirements of this rule 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. The department will consider the manufacturer’s recommendations and guidelines as well as standard industry practices in setting monitoring and compliance requirements. A ground water 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, or an alternate parameter that describes the exclusion characteristics of the membrane, that can reliably achieve at least 4-log removal of viruses; (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 ground water system that uses a department-approved alternative treatment to meet the requirements of this rule by providing at least 4-log treatment of viruses before or at the first customer must monitor the alternative treatment in accordance with all department-specified monitoring requirements and 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. The department will consider the manufacturer’s recommendations and guidelines as well as standard industry practices in setting monitoring and compliance requirements for the approved alternative treatment. (C) Discontinuing Treatment. A ground water system may discontinue 4-log treatment of viruses before or at the first customer for a ground water source if the department determines and documents in writing that 4log treatment of viruses is no longer necessary for that ground water source. A system that discontinues 4-log treatment of viruses is subject to the source water monitoring and analytical methods requirements of section (3) of this rule. (D) Failure to meet the monitoring requirements of this section is a monitoring violation and requires the ground water system to provide public notification under section 10 CSR 60-8.010(4) (Tier 3 notice). (5) Treatment Technique Violations for Ground Water Systems. (A) A ground water system with a significant deficiency is in violation of the treatment technique requirement if, within one hundred twenty (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 ground water source sample under subsection (3)(D) of this rule, a ground water system is in violation of the treatment technique requirement if, within one hundred twenty (120) days (or earlier if directed by the department) of meeting the conditions of paragraph (4)(A)1. or (4)(A)2. of this rule, 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 ground water system subject to the requirements of paragraph (4)(B)3. of this rule that fails to maintain at least 4-log treatment of viruses before or at the first customer for a ground water source is in violation of the treatment technique requirement if the failure is not corrected within four (4) hours of determining the system is not maintaining at least 4-log treatment of viruses before or at the first customer. (D) Ground water system must give public notification under section 10 CSR 60-8.010(3) (Tier 2 notice) for the treatment technique violations specified in this section. (6) Reporting Requirements. Reporting requirements are in 10 CSR 60-7.010 Reporting Requirements. (7) Record-Keeping Requirements. Recordkeeping requirements are in 10 CSR 60-9.010 Requirements for Maintaining Public Water System Records. AUTHORITY: section 640.100, RSMo 2016.* Original rule filed April 14, 2010, effective Dec. 30, 2010. Amended: Filed Aug. 12, 2015, effective March 30, 2016. Amended: Filed June 13, 2018, effective Feb. 28, 2019. *Original authority: 640.100, RSMo 1939, amended 1978, 1981, 1982, 1988, 1989, 1992, 1993, 1995, 1996, 1998, 1999, 2002, 2006, 2012, 2014.