Section 11-20-45.1 - Disinfectant residuals, disinfection byproducts, and disinfection byproduct precursors(a) General requirements(1) The requirements of this section constitute state primary drinking water regulations. (A) The regulations in this section establish criteria under which community water systems (CWSs) and nontransient, non-community water systems (NTNCWSs) which add a chemical disinfectant to the water in any part of the drinking water treatment process must modify their practices to meet MCLs and MRDLs in sections 11-20-4.1 and 11-20-7.5, respectively, and must meet the treatment technique requirements for disinfection byproduct precursors in subsection (f).(B) The regulations in this section establish criteria under which transient NCWSs that use chlorine dioxide as a disinfectant or oxidant must modify their practices to meet the MRDL for chlorine dioxide in section 11-20-7.5.(2) Compliance dates. (A) CWSs and NTNCWSs. Unless otherwise noted, systems must comply with the requirements of this section as follows. Public water systems with a surface water source or a GWUDI source serving 10,000 or more persons must comply with this section beginning January 1, 2002. Public water systems with a surface water source or a GWUDI source serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water must comply with this section beginning January 1, 2004.(B) Transient NCWSs. Public water systems with a surface water source or a GWUDI source serving 10,000 or more persons and using chlorine dioxide as a disinfectant or oxidant must comply with any requirements for chlorine dioxide in this section beginning January 1, 2002. Public water systems with a surface water source or a GWUDI source serving fewer than 10,000 persons and using chlorine dioxide as a disinfectant or oxidant and systems using only ground water not under the direct influence of surface water and using chlorine dioxide as a disinfectant or oxidant must comply with any requirements for chlorine dioxide in this section beginning January 1, 2004. (3) Each CWS and NTNCWS regulated under paragraph (1) must be operated by qualified personnel who meet the requirements specified by the director and are included in a state register of qualified operators.(4) Control of disinfectant residuals. Notwithstanding the MRDLs in section 11-20-7.5, systems may increase residual disinfectant levels in the distribution system of chlorine or chloramines (but not chlorine dioxide) to a level and for a time necessary to protect public health, i.e., to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross-connection events. (b) Analytical requirements. (1) General. (A) Systems must use only the analytical method(s) specified in this subsection, or their equivalent as approved by EPA, to demonstrate compliance with the requirements of this section and with the requirements of sections 11-20-45.2 and 11-20-45.3. These methods are effective for compliance monitoring beginning on February 16, 1999, unless a different effective date is specified in this section or by the director. (B) Documents on analytical methods incorporated by reference into this subsection per 5 U.S.C. 552(a) and 1 C.F.R. part 51 are listed in 40 C.F.R. § 141.131(a)(2). (2) Disinfection byproducts. (A) Systems must measure disinfection byproducts by the methods listed in 40 C.F.R. § 141.131(b)(1) or alternative methods listed in Appendix A to Title 40 Code of Federal Regulations, Part 141, Subpart C.(B) Analysis under this section for disinfection byproducts must be conducted by laboratories that have received certification by EPA or the director, except as specified under subparagraph (C). To receive certification to conduct analyses for the DBP contaminants in section 11-20-4.1(a), 11-20-45.2, and 11-20-45.3, and subsection (f), the laboratory must meet 40 C.F.R. § 141.131(b)(2) (i -iv).(C) A party approved by EPA or the director must measure daily chlorite samples at the entrance to the distribution system.(3) Disinfectant residuals. (A) Systems must measure residual disinfectant concentrations for free chlorine, combined chlorine (chloramines), and chlorine dioxide by the methods listed in 40 C.F.R. § 141.131(c)(1) or alternative methods listed in Appendix A to Title 40 Code of Federal Regulations, Part 141, Subpart C.(B) If approved by the director, systems may also measure residual disinfectant concentrations for chlorine, chloramines, and chlorine dioxide by using DPD colorimetric test kits.(C) A party approved by EPA or the director must measure residual disinfectant concentration.(4) Additional analytical methods. Systems required to analyze parameters not included in paragraphs (2) and (3) must use the following methods or alternative methods listed in Appendix A to Title 40 Code of Federal Regulations, Part 141, Subpart C. A party approved by EPA or the director must measure these parameters. (A) Alkalinity. All methods allowed in 40 C.F.R. § 141.89(a) for measuring alkalinity.(B) Bromide. EPA Method 300.0 or EPA Method 300.1, 317.0 Revision 2.0, 326.0, or ASTM D 6581-00.(C) Total Organic Carbon (TOC). Standard Method 5310 B or 5310 B-00 (High-Temperature Combustion Method) or Standard Method 5310 C or 5310 C-00 (Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard Method 5310 D or 5310 D-00 (Wet-Oxidation Method) or EPA Method 415.3 Revision 1.1. Inorganic carbon must be removed from the samples prior to analysis. TOC samples may not be filtered prior to analysis. TOC samples must be acidified at the time of sample collection to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified TOC samples must be analyzed within twenty-eight days.(D) Specific Ultraviolet Absorbance (SUVA). SUVA is equal to the UV absorption at 254nm (UV254)(measured in m-1) divided by the dissolved organic carbon (DOC) concentration (measured as mg/L). In order to determine SUVA, it is necessary to separately measure UV254 and DOC. When determining SUVA, systems must use the methods stipulated in this subparagraph to measure DOC and the method stipulated in this subparagraph to measure UV254. SUVA must be determined on water prior to the addition of disinfectants/oxidants by the system. DOC and UV254 samples used to determine a SUVA value must be taken at the same time and at the same location. (i) Dissolved Organic Carbon (DOC). Standard Method 5310 B or 5310 B-00 (High-Temperature Combustion Method) or Standard Method 5310 C or 5310 C-00 (Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard Method 5310 D or 5310 D-00 (Wet-Oxidation Method) or EPA Method 415.3 Revision 1.1. DOC samples must be filtered through the 0.45 um pore diameter filter as soon as practical after sampling, not to exceed forty-eight hours. After filtration, DOC samples must be acidified to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified DOC samples must be analyzed within twenty-eight days of sample collection. Inorganic carbon must be removed from the samples prior to analysis. Water passed through the filter prior to filtration of the sample must serve as the filtered blank. This filtered blank must be analyzed using procedures identical to those used for analysis of the samples and must meet the following criteria: DOC less than 0.5 mg/L. (ii) Ultraviolet Absorption at 254 nm (UV254). Method 5910 B or 5910 B-00 (Ultraviolet Absorption Method) or EPA Method 415.3 Revision 1.1. UV absorption must be measured at 253.7 nm (may be rounded off to 254 nm). Prior to analysis, UV254 samples must be filtered through a 0.45 um pore-diameter filter. The pH of UV254 samples may not be adjusted. Samples must be analyzed as soon as practical after sampling, not to exceed forty-eight hours. (E) pH. All methods allowed in 40 C.F.R § 141.23(k)(1) for measuring pH.(F) Magnesium. All methods allowed in 40 C.F.R. § 141.23(k)(1) for measuring magnesium.(c) Monitoring requirements. (1) General requirements. (A) Systems must take all samples during normal operating conditions.(B) Systems may consider multiple wells drawing water from a single aquifer as one treatment plant for determining the minimum number of TTHM and HAA5 samples required, with director approval. Systems shall submit an evaluation report by a professional competent in the field of hydrogeology which proves with reasonable certainty that the affected wells are completed in, and drawing water from, the same aquifer, and that the water quality characteristics/chemistry of each well are enough alike to conclude that disinfection byproduct formation would be similar. Aquifer boundaries and designations shall be based on maps of the State Commission on Water Resource Management. (C) Failure to monitor in accordance with the monitoring plan required under paragraph (6) is a monitoring violation.(D) Failure to monitor will be treated as a violation for the entire period covered by the annual average where compliance is based on a running annual average of monthly or quarterly samples or averages and the system's failure to monitor makes it impossible to determine compliance with MCLs or MRDLs.(E) Systems may use only data collected under the provisions of this subsection or 40 C.F.R. subpart M to qualify for reduced monitoring. (2) Monitoring requirements for disinfection byproducts.(A) TTHMs and HAA5. (i) Routine monitoring. Systems must monitor at the frequency indicated in Appendix B entitled "Routine Monitoring Frequency For TTHM and HAA5 (HAR 11-20-45.1(c)(2)(A))", dated January 1, 2002, located at the end of this chapter and made a part of this section. (ii) Systems may reduce monitoring, except as otherwise provided, in accordance with Appendix C entitled "Reduced Monitoring Frequency For TTHM and HAA5 (HAR 11-20-45.1(c)(2)(B)) ", dated January 1, 2002, located at the end of this chapter and made a part of this section. (iii) Monitoring requirements for source water TOC. In order to qualify for reduced monitoring for TTHM and HAA5 under clause (ii), Subpart H systems not monitoring under the provisions of paragraph (c)(4) must take monthly TOC samples every thirty days at a location prior to any treatment, beginning April 1, 2008 or earlier, if specified by the director. In addition to meeting other criteria for reduced monitoring in clause (ii), the source water TOC running annual average must be <4.0 mg/L (based on the most recent four quarters of monitoring) on a continuing basis at each treatment plant to reduce or remain on reduced monitoring for TTHM and HAA5. Once qualified for reduced monitoring for TTHM and HAA5 under clause (ii), a system may reduce source water TOC monitoring to quarterly TOC samples taken every ninety days at a location prior to any treatment.(iv) Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the average of all samples taken in the year (for systems which must monitor quarterly) or the result of the sample (for systems which must monitor no more frequently than annually) is no more than 0.060 mg/L and 0.045 mg/L for TTHMs and HAA5, respectively. Systems that do not meet these levels must resume monitoring at the minimum frequency identified in Appendix B (minimum monitoring frequency column) in the quarter immediately following the monitoring period in which the system exceeds 0.060 mg/L and 0.045 mg/L for TTHMs and HAA5, respectively. For systems using only ground water not under the direct influence of surface water and serving fewer than 10,000 persons, if either the TTHM annual average is > 0.080 mg/L or the HAA5 annual average is > 0.060 mg/L, the system must go to the increased monitoring identified in Appendix B (sample location column) in the quarter immediately following the monitoring period in which the system exceeds 0.080 mg/L or 0.060 mg/L for TTHMs or HAA5 respectively. (v) Systems on increased monitoring may return to routine monitoring if, after at least one year of monitoring their TTHM annual average is <= 0.060 mg/L and their HAA5 annual average is <= 0.045 mg/L.(vi) The director may return a system to routine monitoring at the director's discretion.(B) Chlorite. Community and nontransient non-community water systems using chlorine dioxide, for disinfection or oxidation, must conduct monitoring for chlorite. (i) Routine daily monitoring. Systems must take daily samples at the entrance to the distribution system. For any daily sample that exceeds the chlorite MCL, the system must take additional samples in the distribution system the following day at the locations required by clause (iii) in addition to the sample required at the entrance to the distribution system. (ii) Routine monthly monitoring. Systems must take a three-sample set each month in the distribution system. The system must take one sample at each of the following locations: near the first customer, at a location representative of average residence time, and at a location reflecting maximum residence time in the distribution system. Any additional routine sampling must be conducted in the same manner (as three-sample sets, at the specified locations). The system may use the results of additional monitoring conducted under clause (iii) to meet the requirement for monitoring under this clause. (iii) Additional monitoring. On each day following a routine sample monitoring result that exceeds the chlorite MCL at the entrance to the distribution system, the system is required to take three chlorite distribution system samples at the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).(iv) Reduced monitoring at entrance to distribution system. Chlorite monitoring at the entrance to the distribution system required by clause (i) may not be reduced.(v) Reduced monitoring in distribution system. Chlorite monitoring in the distribution system required by clause (ii) may be reduced to one three-sample set per quarter after one year of monitoring where no individual chlorite sample taken in the distribution system under clause (ii) has exceeded the chlorite MCL and the system has not been required to conduct monitoring under clause (iii). The system may remain on the reduced monitoring schedule until either any of the three individual chlorite samples taken quarterly in the distribution system under clause (ii) exceeds the chlorite MCL or the system is required to conduct monitoring under clause (iii), at which time the system must revert to routine monitoring. (C) Bromate. (i) Routine monitoring. Community and nontransient non-community systems using ozone, for disinfection or oxidation, must take one sample per month for each treatment plant in the system using ozone. Systems must take samples monthly at the entrance to the distribution system while the ozonation system is operating under normal conditions.(ii) Reduced monitoring. Until March 31, 2009, systems required to analyze for bromate may reduce monitoring from monthly to quarterly, if the system's average source water bromide concentration is less than 0.05 mg/L based on representative monthly bromide measurements for one year. The system may remain on reduced bromate monitoring until the running annual average source water bromide concentration, computed quarterly, is equal to or greater than 0.05 mg/L based upon representative monthly measurements. If the running annual average source water bromide concentration is equal to or greater than 0.05 mg/L, the system must resume routine monitoring required by clause (i) in the following month. Beginning April 1, 2009, systems may no longer use the provisions of this clause to qualify for reduced monitoring. A system required to analyze for bromate may reduce monitoring from monthly to quarterly, if the system's running annual average bromate concentration is <=0.0025 mg/L based on monthly bromate measurements under clause (i) for the most recent four quarters, with samples analyzed using Method 317.0 Revision 2.0, 326.0 or 321.8. If the running annual average bromate concentration is >0.0025 mg/L, the system must resume routine monitoring required by clause (i). (3) Monitoring requirements for disinfectant residuals.(A) Chlorine and chloramines. (i) Routine monitoring. Beginning April 1, 2016, community and non-transient non-community water systems that use chlorine or chloramines must measure the residual disinfectant level in the distribution system at the same point in the distribution system and at the same time as total coliforms are sampled, as specified in sections 11-20-9.1(d) and (e). Public water systems which filter either a surface water source or a GWUDI source may use the results of residual disinfectant concentration sampling conducted under section 11-20-46(d)(2)(B)(iii), in lieu of taking separate samples. (ii) Reduced monitoring. Monitoring may not be reduced.(B) Chlorine dioxide. (i) Routine monitoring. Community, nontransient non-community, and transient non-community water systems that use chlorine dioxide for disinfection or oxidation must take daily samples at the entrance to the distribution system. For any daily sample that exceeds the MRDL, the system must take samples in the distribution system the following day at the locations required by clause (ii), in addition to the sample required at the entrance to the distribution system.(ii) Additional monitoring. On each day following a routine sample monitoring result that exceeds the MRDL, a system covered by this paragraph is required to take three chlorine dioxide distribution system samples. If chlorine dioxide or chloramines are used to maintain a disinfectant residual in the distribution system, or if chlorine is used to maintain a disinfectant residual in the distribution system and there are no disinfection addition points after the entrance to the distribution system (i.e., no booster chlorination), the system must take three samples as close to the first customer as possible, at intervals of at least six hours. If chlorine is used to maintain a disinfectant residual in the distribution system and there are one or more disinfection addition points after the entrance to the distribution system (i.e., booster chlorination), the system must take one sample at each of the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system). All sampling locations shall be approved by the director. (iii) Reduced monitoring. Chlorine dioxide monitoring may not be reduced.(4) Monitoring requirements for disinfection byproduct precursors(DBPP). (A) Routine monitoring. Public water systems with a surface water source or a GWUDI source which use conventional filtration treatment (as defined in section 11-20-2) must monitor each treatment plant for TOC no later than the point of combined filter effluent turbidity monitoring and representative of the treated water. All systems required to monitor under this subparagraph must also monitor for TOC in the source water prior to any treatment at the same time as monitoring for TOC in the treated water. These samples (source water and treated water) are referred to as paired samples. At the same time as the source water sample is taken, all affected systems must monitor for alkalinity in the source water prior to any treatment. Systems must take one paired sample and one source water alkalinity sample per month per plant at a time representative of normal operating conditions and influent water quality. (B) Reduced monitoring. Public water systems with a surface water source or a GWUDI source with an average treated water TOC of less than 2.0 mg/L for two consecutive years, or less than 1.0 mg/L for one year, may reduce monitoring for both TOC and alkalinity to one paired sample and one source water alkalinity sample per plant per quarter. The system must revert to routine monitoring in the month following the quarter when the annual average treated water TOC is equal to or greater than 2.0 mg/L. (5) Bromide. Systems required to analyze for bromate may reduce bromate monitoring from monthly to once per quarter, if the system demonstrates that the average source water bromide concentration is less than 0.05 mg/L based upon representative monthly measurements for one year. The system must continue bromide monitoring to remain on reduced bromate monitoring.(6) Monitoring plans. Each system required to monitor under this subsection must develop and implement a monitoring plan. The system must maintain the plan and make it available for inspection by the director and the general public no later than thirty days following the applicable compliance dates in subsection (a)(2). All public water systems with a surface water source or a GWUDI source serving more than 3,300 people must submit a copy of the monitoring plan to the director no later than the date of the first report required under subsection (e). The director may also require the plan to be submitted by any other system. After review, the director may require changes in any plan elements. The plan must include at least the following elements:(A) Specific locations and schedules for collecting samples for any parameters included in this section.(B) How the system will calculate compliance with MCLs, MRDLs, and treatment techniques.(C) If approved for monitoring as a consecutive system, or if providing water to a consecutive system, under the provisions of section 11-20-16, the sampling plan must reflect the entire distribution system.(d) Compliance requirements. (1) General requirements. (A) Where compliance is based on a running annual average of monthly or quarterly samples or averages and the system fails to monitor for TTHM, HAA5, or bromate, this failure to monitor will be treated as a monitoring violation for the entire period covered by the annual average. Where compliance is based on a running annual average of monthly or quarterly samples or averages and the system's failure to monitor makes it impossible to determine compliance with MRDLs for chlorine and chloramines, this failure to monitor will be treated as a monitoring violation for the entire period covered by the annual average. (B) All samples taken and analyzed under the provisions of this section must be included in determining compliance, even if that number is greater than the minimum required.(C) If, during the first year of monitoring under subsection (c), any individual quarter's average will cause the running annual average of that system to exceed the MCL for total trihalomethanes, haloacetic acids (five), or bromate; or the MRDL for chlorine or chloramine, the system is out of compliance at the end of that quarter.(2) Disinfection byproducts. (A) TTHMs and HAA5. (i) For systems monitoring quarterly, compliance with MCLs in section 11-20-4.1 must be based on a running annual arithmetic average, computed quarterly, of quarterly arithmetic averages of all samples collected by the system as prescribed by subsections (c)(2)(A).(ii) For systems monitoring less frequently than quarterly, systems demonstrate MCL compliance if the average of samples taken that year under the provisions of subsection (c)(2)(A) does not exceed the MCLs in section 11-20.4.1. If the average of these samples exceeds the MCL, the system must increase monitoring to once per quarter per treatment plant and such a system is not in violation of the MCL until it has completed one year of quarterly monitoring, unless the result of fewer than four quarters of monitoring will cause the running annual average to exceed the MCL, in which case the system is in violation at the end of that quarter. Systems required to increase monitoring frequency to quarterly monitoring must calculate compliance by including the sample which triggered the increased monitoring plus the following three quarters of monitoring. (iii) If the running annual arithmetic average of quarterly averages covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to section 11-20-18 or 40 C.F.R. § 141.202, whichever is effective for your system, in addition to reporting to the director pursuant to subsection (e).(iv) If a PWS fails to complete four consecutive quarters of monitoring (e.g., when the PWS has not been operating for four quarters), compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data. (B) Bromate. Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly samples (or, for months in which the system takes more than one sample, the average of all samples taken during the month) collected by the system as prescribed by subsection (c)(2)(C). If the average of samples covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to section 11-20-18, in addition to reporting to the director pursuant to subsection (e). If a PWS fails to complete twelve consecutive months of monitoring, compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data.(C) Chlorite. Compliance must be based on an arithmetic average of each three sample set taken in the distribution system as prescribed by subsection (c)(2)(B)(ii) and (iii). If the arithmetic average of any three sample set exceeds the MCL, the system is in violation of the MCL and must notify the public pursuant to section 11-20-18, in addition to reporting to the director pursuant to subsection (e).(3) Disinfectant residuals. (A) Chlorine and chloramines. (i) Compliance must be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system under subsection (c)(3)(A). If the average covering any consecutive four-quarter period exceeds the MRDL, the system is in violation of the MRDL and must notify the public pursuant to section 11-20-18, in addition to reporting to the director pursuant to subsection (e). (ii) In cases where systems switch between the use of chlorine and chloramines for residual disinfection during the year, compliance must be determined by including together all monitoring results of both chlorine and chloramines in calculating compliance. Reports submitted pursuant to subsection (e) must clearly indicate which residual disinfectant was analyzed for each sample. (B) Chlorine dioxide.(i) Acute violations. Compliance must be based on consecutive daily samples collected by the system under subsection (c)(3)(B). If any daily sample taken at the entrance to the distribution system exceeds the MRDL, and on the following day one (or more) of the three samples taken in the distribution system exceed the MRDL, the system is in violation of the MRDL and must take immediate corrective action to lower the level of chlorine dioxide below the MRDL and must notify the public pursuant to the procedures for acute health risks in section 11-20-18(b)(2)(D) in addition to reporting to the director pursuant to subsection (e). Failure to take samples in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system will also be considered an MRDL violation and the system must notify the public of the violation in accordance with the provisions for acute violations in section 11-20-18(b)(2)(D) in addition to reporting to the director pursuant to subsection (e). (ii) Nonacute violations. Compliance must be based on consecutive daily samples collected by the system under subsection (c)(3)(B). If any two consecutive daily samples taken at the entrance to the distribution system exceed the MRDL and all distribution system samples taken are below the MRDL, the system is in violation of the MRDL and must take corrective action to lower the level of chlorine dioxide below the MRDL at the point of sampling and will notify the public pursuant to the procedures for nonacute health risks in section 11-20-18 in addition to reporting to the director pursuant to subsection (e). Failure to monitor at the entrance to the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system is also an MRDL violation and the system must notify the public of the violation in accordance with the provisions for nonacute violations under section 11-20-18 in addition to reporting to the director pursuant to subsection (e). (4) Disinfection byproduct precursors (DBPP). Compliance must be determined as specified by subsection (f)(3). Systems may begin monitoring to determine whether Step 1 TOC removals can be met twelve months prior to the compliance date for the system. This monitoring is not required and failure to monitor during this period is not a violation. However, any system that does not monitor during this period, and then determines in the first twelve months after the compliance date that it is not able to meet the Step 1 requirements in subsection (f)(2)(B) and must therefore apply for alternate minimum TOC removal (Step 2) requirements, is not eligible for retroactive approval of alternate minimum TOC removal (Step 2) requirements as allowed pursuant to subsection (f)(2)(C) and is in violation of a treatment technique under subsection (f). Systems may apply for alternate minimum TOC removal (Step 2) requirements any time after the compliance date. For systems required to meet Step 1 TOC removals, if the value calculated under subsection (f)(3)(A)(iv) is less than 1.00, the system is in violation of the treatment technique requirements and must notify the public pursuant to section 11-20-18, in addition to reporting to the director pursuant to subsection (e). (e) Reporting and record keeping requirements. (1) Systems required to sample quarterly or more frequently, pursuant to this subsection shall report to the director within ten days after the end of each quarter in which samples were collected, notwithstanding the provisions of section 11-20-17. Systems required to sample less frequently than quarterly must report to the director within ten days after the end of each monitoring period in which samples were collected.(2) Disinfection byproducts. Systems must report the information specified in Appendix D entitled "Reporting Requirements For Disinfection Byproducts (HAR 11-20-45.1(e)(2) ) ", dated January 1, 2002, located at the end of this chapter and made a part of this section.(3) Disinfectants. Systems must report the information specified in Appendix E entitled "Reporting Requirements For Disinfection Residuals (HAR 11-20-45.1(e)(3) ) ", dated January 1, 2002, located at the end of this chapter and made a part of this section.(4) Disinfection byproduct precursors and enhanced coagulation or enhanced softening. Systems must report the information specified in Appendix F entitled "Reporting Requirements For Disinfection Byproduct Precursors and Enhanced Coagulation or Enhanced Softening (HAR 11-20-45.1(e)(4) ) ", dated January 1, 2002, located at the end of this chapter and made a part of this section.(f) Treatment technique for control of disinfection byproduct (DBP) precursors. (1) Applicability.(A) Public water systems with a surface water source or a GWUDI source using conventional filtration treatment (as defined in section 11-20-2) must operate with enhanced coagulation or enhanced softening to achieve the TOC per cent removal levels specified in paragraph (2) unless the system meets at least one of the alternative compliance criteria listed in subparagraphs (B) or (C).(B) Alternative compliance criteria for enhanced coagulation and enhanced softening systems. Public water systems with a surface water source or a GWUDI source using conventional filtration treatment may use the alternative compliance criteria in this subparagraph to comply with this subsection in lieu of complying with paragraph (2). Systems shall still comply with monitoring requirements in subsection (c)(4). (i) The system's source water TOC level, measured according to subsection (b)(4)(C), is less than 2.0 mg/L, calculated quarterly as a running annual average. (ii) The system's treated water TOC level, measured according to subsection (b)(4)(C), is less than 2.0 mg/L, calculated quarterly as a running annual average. (iii) The system's source water TOC level, measured according to subsection (b)(4)(C), is less than 4.0 mg/L, calculated quarterly as a running annual average; the source water alkalinity, measured according to subsection (b)(4)(A), is greater than 60 mg/L (as CaCO3), calculated quarterly as a running annual average; and either the TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively; or prior to the effective date for compliance in subsection (a)(2), the system has made a clear and irrevocable financial commitment not later than the effective date for compliance in subsection (a)(2) to use technologies that will limit the levels of TTHMs and HAA5 to no more than 0.040 mg/L and 0.030 mg/L, respectively. Systems must submit evidence of a clear and irrevocable financial commitment, in addition to a schedule containing milestones and periodic progress reports for installation and operation of appropriate technologies, to the director for approval not later than the effective date for compliance in subsection (a)(2). These technologies must be installed and operating not later than June 30, 2005. Failure to install and operate these technologies by the date in the approved schedule will constitute a violation of National Primary Drinking Water Regulations. (iv) The TTHM and HAA5 running annual averages are no greater than 0.040 mg/L and 0.030 mg/L, respectively, and the system uses only chlorine for primary disinfection and maintenance of a residual in the distribution system. (v) The system's source water SUVA, prior to any treatment and measured monthly according to subsection (b)(4)(D), is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average. (vi) The system's finished water SUVA, measured monthly according to subsection (b)(4)(D), is less than or equal to 2.0 L/mg-m, calculated quarterly as a running annual average. (C) Additional alternative compliance criteria for softening systems. Systems practicing enhanced softening that cannot achieve the TOC removals required by paragraph (2)(B) may use the alternative compliance criteria in this subparagraph in lieu of complying with paragraph (2). Systems must still comply with monitoring requirements in subsection (c)(4).(i) Softening that results in lowering the treated water alkalinity to less than 60 mg/L (as CaCO3), measured monthly according to subsection (b)(4)(A) and calculated quarterly as a running annual average. (ii) Softening that results in removing at least 10 mg/L of magnesium hardness (as CaCO3), measured monthly according to subparagraph (b)(4)(F) and calculated quarterly as an annual running average.(2) Enhanced coagulation and enhanced softening performance requirements. (A) Systems must achieve the per cent reduction of TOC specified in subparagraph (B) between the source water and the combined filter effluent, unless the director approves a system's request for alternate minimum TOC removal (Step 2) requirements under subparagraph (C).(B) Required Step 1 TOC reductions, indicated in the following table, are based upon specified source water parameters measured in accordance with subsection (b)(4). Systems practicing softening are required to meet the Step 1 TOC reductions in the far-right column (source water alkalinity greater than 120 mg/L) for the specified source water TOC: Step 1 Required Removal of TOC By Enhanced Coagulation and Enhanced Softening for Subpart H Systems Using Conventional Treatment
| Source-water alkalinity, mg/L as CaCO3 |
Source-water TOC, mg/L | 0-60 | >60-120 | >120 |
>2.0-4.0 | 35.0% | 25.0% | 15.0% |
>4.0-8.0 | 45.0% | 35.0% | 25.0% |
>8.0 | 50.0% | 40.0% | 30.0% |
(C) Public water systems with a surface water source or a GWUDI source using conventional treatment systems that cannot achieve the Step 1 TOC removals required by subparagraph (B) due to water quality parameters or operational constraints must apply to the State, within three months of failure to achieve the TOC removals required by subparagraph (B), for approval of alternative minimum TOC (Step 2) removal requirements submitted by the system. If the director approves the alternative minimum TOC removal (Step 2) requirements, the director may make those requirements retroactive for the purposes of determining compliance. Until the director approves the alternate minimum TOC removal (Step 2) requirements, the system must meet the Step 1 TOC removals contained in subparagraph (B).(D) Alternate minimum TOC removal (Step 2) requirements. Applications made to the director by enhanced coagulation systems for approval of alternative minimum TOC removal (Step 2) requirements under subparagraph (C) must include, as a minimum, results of bench- or pilot-scale testing conducted under clause (i). The submitted bench-or pilot-scale testing must be used to determine the alternate enhanced coagulation level. (i) Alternate enhanced coagulation level is defined as coagulation at a coagulant dose and pH as determined by the method described in this subparagraph such that an incremental addition of 10 mg/L of alum (or equivalent amount of ferric salt) results in a TOC removal of less than or equal to 0.3 mg/L. The per cent removal of TOC at this point on the "TOC removal versus coagulant dose" curve is then defined as the minimum TOC removal required for the system. Once approved by the director, this minimum requirement supersedes the minimum TOC removal required by the table in subparagraph (B). This requirement will be effective until such time as the director approves a new value based on the results of a new bench- and pilot-scale test. Failure to achieve State-set alternative minimum TOC removal levels is a violation of National Primary Drinking Water Regulations. (ii) Bench- or pilot-scale testing of enhanced coagulation must be conducted by using representative water samples and adding 10 mg/L increments of alum (or equivalent amounts of ferric salt) until the pH is reduced to a level less than or equal to the enhanced coagulation Step 2 target pH shown in the following table: Enhanced Coagulation Step 2 Target pH |
Alkalinity (mg/L as CaCO3) | Target pH |
0-60 | 5.5 |
>60-120 | 6.3 |
>120-240 | 7.0 |
>240 5.5 | 7.5 |
(iii) For waters with alkalinities of less than 60 mg/L for which addition of small amounts of alum or equivalent addition of iron coagulant drives the pH below 5.5 before significant TOC removal occurs, the system must add necessary chemicals to maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3 mg/L per 10 mg/L alum added (or equivalent addition of iron coagulant) is reached.(iv) The system may operate at any coagulant dose or pH necessary (consistent with other NPDWRs) to achieve the minimum TOC per cent removal approved under subparagraph (C).(v) If the TOC removal is consistently less than 0.3 mg/L of TOC per 10 mg/L of incremental alum dose at all dosages of alum (or equivalent addition of iron coagulant), the water is deemed to contain TOC not amenable to enhanced coagulation. The system may then apply to the director for a waiver of enhanced coagulation requirements.(3) Compliance calculations. (A) Public water systems with a surface water source or a GWUDI source other than those identified in paragraphs (1)(B) and (1)(C) must comply with requirements contained in paragraph (2)(B) or (2)(C), whichever is applicable. Systems must calculate compliance quarterly, beginning after the system has collected twelve months of data, by determining an annual average using the following method: (i) Determine actual monthly TOC per cent removal, equal to: (1-(treated water TOC/source water TOC)) x 100(ii) Determine the required monthly TOC per cent removal (from either the table in paragraph (2)(B) or from paragraph (2)(C)).(iii) Divide the value in clause (i) by the value in clause (ii).(iv) Add together the results of clause (iii) for the last twelve months and divide by twelve.(v) If the value calculated in clause (iv) is less than 1.00, the system is not in compliance with the TOC per cent removal requirements. (B) Systems may use the provisions in this subparagraph in lieu of the calculations in subparagraph (A) to determine compliance with TOC per cent removal requirements. (i) In any month that the system's treated or source water TOC level, measured according to subsection (b)(4)(C), is less than 2.0 mg/L, the system may assign a monthly value of 1.0 in lieu of the value calculated in subparagraph (A)(iii) when calculating compliance under the provisions of subparagraph (A).(ii) In any month that a system practicing softening removes at least 10 mg/L of magnesium hardness (as CaCO3), the system may assign a monthly value of 1.0 in lieu of the value calculated in subparagraph (A)(iii) when calculating compliance under the provisions of subparagraph (A).(iii) In any month that the system's source water SUVA, prior to any treatment and measured according to subsection (b)(4)(D), is less than or equal to 2.0 L/mg-m, the system may assign a monthly value of 1.0 in lieu of the value calculated in subparagraph (A)(iii) when calculating compliance under the provisions of subparagraph (A).(iv) In any month that the system's finished water SUVA, measured according to subsection (b)(4)(D), is less than or equal to 2.0 L/mg-m, the system may assign a monthly value of 1.0 in lieu of the value calculated in subparagraph (A)(iii) when calculating compliance under the provisions of subparagraph (A).(v) In any month that a system practicing enhanced softening lowers alkalinity below 60 mg/L (as CaCO3), the system may assign a monthly value of 1.0 in lieu of the value calculated in subparagraph (A)(iii) when calculating compliance under the provisions of subparagraph (A).(C) Public water systems with a surface water source or a GWUDI source using conventional filtration treatment may also comply with the requirements of this subsection by meeting the criteria in paragraphs (1)(B) or (1)(C).(4) Treatment technique requirements for DBP precursors. The Administrator identifies the following as treatment techniques to control the level of disinfection byproduct precursors in drinking water treatment and distribution systems: for public water systems with a surface water source or a GWUDI source using conventional treatment, enhanced coagulation or enhanced softening. Haw. Code R. § 11-20-45.1
[Eff and comp 11/30/02; am and compiled 12/16/05; am and comp 11/28/11; comp MAY 02 2014 ] (Auth: HRS §§ 340E-2, 340E-9) (Imp: HRS §§ 340E-2, 340E-9; 42 U.S.C. §§300 f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-4, 300j-9, 300j-11; 40 C.F.R. §141.130, § 141.131, § 141.132, § 141.133, § 141.134, § 141.135,)