Current through Register Vol. 47, No. 11, December 11, 2024
Rule 567-43.7 - Lead and copper treatment techniques(1)Corrosion control treatment for lead and copper control.a. Applicability. Systems shall complete the applicable corrosion control treatment requirements by the deadlines specified in the following rules: (1) Large systems serving more than 50,000 persons. A large system (serving greater than 50,000 persons) shall complete the corrosion control treatment steps specified in 43.7(1)"d, " unless the system is deemed to have optimized corrosion control under 43.7(1)"b"(2) or (3).(2) Small and medium-size systems serving 50,000 or fewer persons. A small system (serving less than or equal to 3,300 persons) or a medium-size system (serving greater than 3,300 and less than or equal to 50,000 persons) shall complete the corrosion control treatment steps specified in 43.7(1)"e, " unless the system has optimized corrosion control under 43.7(1)"b" (1), (2), or (3).b. Determination that a system has optimized corrosion control. A public water supply system has optimized corrosion control and is not required to complete the applicable corrosion control treatment steps identified in this subrule if the system satisfies one of the criteria specified in subparagraphs 43.7(1) "b"(1) through (3). Any such system deemed to have optimized corrosion control under this paragraph and which has treatment in place shall continue to operate and maintain optimal corrosion control treatment and meet any requirements that the department determines appropriate to ensure optimal corrosion control treatment is maintained. (1) A small or medium-size water supply system has optimized corrosion control if the system meets the lead and copper action levels during each of two consecutive six-month monitoring periods, conducted in accordance with 567-paragraph 41.4(1)"c. "(2) Any public water supply system may be deemed to have optimized corrosion control treatment if the system demonstrates to the satisfaction of the department that it has conducted activities equivalent to the corrosion control steps applicable to such system under this subrule. If the department makes this determination, it shall provide the water supply system with written notice explaining the basis for its decision and shall specify the water quality control parameters representing optimal corrosion control in accordance with 43.7(2)"f. " Systems deemed to have optimized corrosion control under this paragraph shall operate in compliance with the department-designated optimal water quality control parameters in accordance with paragraph 43.7(1)"g" and continue to conduct lead and copper tap and water quality parameter sampling in accordance with 567-paragraph 41.4(1) "c"(4)"3" and 567-subparagraph 41.4(1)"d " (4), respectively. A system shall provide the department with the following information in order to support a determination under this paragraph: 1. The results of all test samples collected for each of the water quality parameters in 43.7(2)"c "(3);2. A report explaining the test methods used by the water system to evaluate the corrosion control treatments listed in 43.7(2)"c"(1) the results of all tests conducted, and the basis for the system's selection of optimal corrosion control treatment;3. A report explaining how corrosion control was installed and how it is being maintained to ensure minimal lead and copper concentrations at consumers' taps; and4. The results of tap water samples collected in accordance with 567-paragraph 41.4(1)"c" at least once every six months for one year after corrosion control has been installed.(3) Any water system has optimized corrosion control if it submits results of tap water monitoring conducted in accordance with 567-paragraph 41.4(1)"c" and source water monitoring conducted in accordance with 567-paragraph 41.4(1)"e" that demonstrate for two consecutive six-month monitoring periods that the difference between the 90th percentile tap water lead level computed under 567-subparagraph 41.4(1)"b" (3) and the highest source water lead concentration is less than the practical quantitation level for lead specified in 567-paragraph 41.4(1)"g. "1. Those systems whose highest source water lead level is below the method detection limit may also be deemed to have optimized corrosion control under this paragraph if the 90th percentile tap water lead level is less than or equal to the practical quantitation level for lead for two consecutive six-month monitoring periods.2. Any water system deemed to have optimized corrosion control in accordance with this paragraph shall continue monitoring for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of sites specified in 567-subparagraph 41.4(1) "c"(3) and collecting the samples at times and locations specified in 567-paragraph 41.4(1) "c"(4)"4," fourth bulleted paragraph.3. Any water system deemed to have optimized corrosion control pursuant to this paragraph shall notify the department in writing pursuant to 567-subparagraph 42.4(2)"a "(3) of any upcoming long-term change in treatment or the addition of a new source as described in 567-subparagraph 42.4(2)"a " (3). The department must review and approve the addition of a new source or long-term change in water treatment before it is implemented by the water system.4. Unless a system meets the copper action level, it is not deemed to have optimized corrosion control under this paragraph and shall implement corrosion control treatment pursuant to 43.7(1)"b "(3)"5."5. Any system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under this paragraph shall implement corrosion control treatment in accordance with the deadlines in paragraph 43.7(1)"e. " Any such large system shall adhere to the schedule specified in that paragraph for medium-size systems, with the time periods for completing each step being triggered by the date the system is no longer deemed to have optimized corrosion control under this paragraph.c. Requirements to recommence corrosion control steps. Any small or medium-size water system that is required to complete the corrosion control steps due to its exceedance of the lead or copper action level may cease completing the treatment steps whenever the system meets both action levels during each of two consecutive monitoring periods conducted pursuant to 567-paragraph 41.4(1)"c" and submits the results to the department. If any such water system thereafter exceeds the lead or copper action level during any monitoring period, the system shall recommence completion of the applicable treatment steps, beginning with the first treatment step which was not previously completed in its entirety. The department may require a system to repeat treatment steps previously completed by the system when it is determined by the department that this is necessary to implement properly the treatment requirements of this rule. The department will notify the system in writing of such a determination and explain the basis for its decision. The requirement for any small or medium-size system to implement corrosion control treatment steps in accordance with 43.7(1)"e" (including systems deemed to have optimized corrosion control under 43.7(1)"b" (1)) is triggered whenever any small or medium-size system exceeds the lead or copper action level.d. Treatment steps and deadlines for large systems. Except as provided in 43.7(1)"b" (2) or (3), large systems shall complete the following corrosion control treatment steps (described in the referenced portions of 43.7(1)"b", subrule 43.7(2), and 567-paragraphs 41.4(1)"c" and"d" by the dates indicated below.(1) Step 1. The system shall conduct initial monitoring pursuant to 567-paragraph 41.4(1) "c"(4)"l " and 567-subparagraph 41.4(1)"d"(2) during two consecutive six-month monitoring periods by January 1, 1993.(2) Step 2. The system shall complete corrosion control studies pursuant to 43.7(2)"c" by July 1, 1994.(3) Step 3. The department will designate optimal corrosion control treatment within six months of receiving the corrosion control study results (by January 1, 1995).(4) Step 4. The system shall install optimal corrosion control treatment by January 1, 1997.(5) Step 5. The system shall complete follow-up sampling pursuant to 567-paragraph 41.4(1) "c"(4)"2" and 567-subparagraph 41.4(1)"d"(3) by January 1, 1998.(6) Step 6. The department will review installation of treatment and designate optimal water quality control parameters pursuant to 43.7(2)"f" by July 1, 1998.(7) Step 7. The system shall operate in compliance with optimal water quality control parameters delineated by the department and continue to conduct tap sampling.e.Treatment steps and deadlines for small and medium-size systems. Except as provided in 43.7(2), small and medium-size systems shall complete the following corrosion control treatment steps (described in subrule 43.7(2) and 567-paragraphs 41.4(1)"c" and"d" by the indicated time periods listed below. (1) Step 1. The system shall conduct initial tap sampling pursuant to 567-paragraph 41.4(1)"c"(4)"l "and 567-subparagraph 41.4(1)"d"(2) until the system either exceeds the lead or copper action level or becomes eligible for reduced monitoring under 567-paragraph 41.4(1)"c" (4)"4." A system exceeding the lead or copper action level shall recommend optimal corrosion control treatment under 43.7(2)"a" within six months after the end of the monitoring period during which it exceeds one of the action levels.(2) Step 2. Within 12 months after the end of the monitoring period during which a system exceeds the lead or copper action level, the department may require the system to perform corrosion control studies under 43.7(2)"b. " If the system is not required to perform such studies, the department will specify optimal corrosion control treatment under 43.7(2) "d" as follows: for medium-size systems, within 18 months after the end of the monitoring period during which such system exceeds the lead or copper action level, and, for small systems, within 24 months after the end of the monitoring period during which such system exceeds the lead or copper action level.(3) Step 3. If a system is required to perform corrosion control studies under Step 2, the system shall complete the studies (under 43.7(2)"c")within 18 months after such studies are required to commence.(4) Step 4. If the system has performed corrosion control studies under Step 2, the department will designate optimal corrosion control treatment under 43.7(2)"d" within six months after completion of Step 3.(5) Step 5. The system shall install optimal corrosion control treatment under 43.7(2)"e " within 24 months after such treatment is designated.(6) Step 6. The system shall complete follow-up sampling pursuant to 567-paragraph 41.4(1) "c"(4)"2" and 567-subparagraph 41.4(1)"d"(3) within 36 months after optimal corrosion control treatment is designated.(7) Step 7. The department will review the system's installation of treatment and designate optimal water quality control parameters pursuant to 43.7(2)"f" within six months after completion of Step 6.(8) Step 8. The system shall operate in compliance with the department-designated optimal water quality control parameters under 43.7(2)"f " (and continue to conduct tap sampling as per 567-paragraph 41.4(1)"c"(4)"3" and 567-subparagraph 41.4(1)"d" (4)).(2)Description of corrosion control treatment requirements. Each public water supply system shall complete the corrosion control treatment requirements described below which are applicable to such systems under 43.7(1). a. Public water supply system recommendation regarding corrosion control treatment. Based upon the results of lead and copper tap monitoring and water quality parameter monitoring, small and medium-size water systems exceeding the lead or copper action level shall recommend installation of one or more of the corrosion control treatments listed in 43.7(2)"c" which the system believes constitute optimal corrosion control for that system. The department may require the system to conduct additional water quality parameter monitoring in accordance with 567-subparagraph 41.4(1)"d"(2) to assist in reviewing the system's recommendation.b. Department decision to require studies of corrosion control treatment (applicable to small and medium-size systems). The department may require any small or medium-size system that exceeds the lead or copper action level to perform corrosion control studies under 43.7(2)"c" to identify optimal corrosion control treatment for the system.c. Performance of corrosion control studies.(1) Any public water supply system performing corrosion control studies shall evaluate the effectiveness of each of the following treatments and, if appropriate, combinations of the following treatments to identify the optimal corrosion control treatment: alkalinity and pH adjustment; calcium hardness adjustment; and the addition of a phosphate or silicate-based corrosion inhibitor at a concentration sufficient to maintain an effective residual concentration in all test tap samples.(2) The water system shall evaluate each of the corrosion control treatments using either pipe rig/loop tests, metal coupon tests, partial-system tests, or analyses based on documented analogous treatments with other systems of similar size, water chemistry and distribution system configuration.(3) The public water supply system shall measure the following water quality parameters in any tests conducted under this paragraph before and after evaluating the corrosion control treatments listed above:7. Orthophosphate (when an inhibitor containing a phosphate compound is used);8. Silicate (when an inhibitor containing a silicate compound is used);(4) The public water supply system shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and outline such constraints with the following: data and documentation showing that a particular corrosion control treatment has adversely affected other water treatment processes when used by another water system with comparable water quality characteristics; or data and documentation demonstrating that the water system has previously attempted to evaluate a particular corrosion control treatment and has found that the treatment is ineffective or adversely affects other water quality treatment processes.(5) The water system shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatment processes.(6) On the basis of an analysis of the data generated during each evaluation, the water system shall recommend in writing to the department the treatment option that the corrosion control studies indicate constitutes optimal corrosion control treatment for that system. The water system shall provide a rationale for its recommendation along with all supporting documentation required by 43.7(2)"c"(1) through (5).d. Department designation of optimal corrosion control treatment.(1) Based upon consideration of available information including, where applicable, studies performed under 43.7(2)"c" and a system's recommended treatment alternative, the department will either approve the corrosion control treatment option recommended by the public water supply system, or designate alternative corrosion control treatment(s) from among those listed in 43.7(2)"c." The department will consider the effects that additional corrosion control treatment will have on water quality parameters and on other water quality treatment processes (when designating optimal corrosion control treatment).(2) The department will notify the public water supply system of its decision on optimal corrosion control treatment in writing and explain the basis for this determination. If the department requests additional information to aid its review, the public water supply system shall provide the information.e. Installation of optimal corrosion control. Each public water supply system shall properly install and operate throughout its distribution system the optimal corrosion control treatment designated under 43.7(2) "d."f.Department review of treatment and specification of optimal water quality control parameters.(1) The department will evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the public water supply system and determine whether the system has properly installed and operated the optimal corrosion control treatment designated in 43.7(2)"d. " Upon reviewing the results of tap water and water quality parameter monitoring by the public water supply system, both before and after the system installs optimal corrosion control treatment, the department will designate the following: 1. A minimum value or a range of values for pH measured at each entry point to the distribution system;2. A minimum pH value, measured in all tap samples. Such value shall be equal to or greater than 7.0 unless meeting a pH level of 7.0 is not technologically feasible or is not necessary for the public water supply system to optimize corrosion control;3. If a corrosion inhibitor is used, a minimum concentration or a range of concentrations for the inhibitor, measured at each entry point to the distribution system and in all tap samples, necessary to form a passivating film on the interior walls of the pipes of the distribution system;4. If alkalinity is adjusted as part of optimal corrosion control treatment, a minimum concentration or a range of concentrations for alkalinity, measured at each entry point to the distribution system and in all tap samples; or5. If calcium carbonate stabilization is used as part of corrosion control, a minimum concentration or a range of concentrations for calcium, measured in all tap samples.(2) The values for the applicable water quality control parameters listed above shall be those which reflect optimal corrosion control treatment for the public water supply system. The department may designate values for additional water quality control parameters determined by the department to reflect optimal corrosion control for the system. The department will notify the system in writing of these determinations and explain the basis for its decisions.g. Continued operation with optimized corrosion control and water quality parameter monitoring compliance determination. All systems optimizing corrosion control shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameters at or above minimum values or within ranges designated by the department under paragraph 43.7(2)"f," in accordance with this paragraph for all samples collected under 567-subparagraphs 41.4(1)"d" (4) through (6). Compliance with the requirements of this paragraph shall be determined every six months, as specified under 567-subparagraph 41.4(1)"d" (4). A water system is out of compliance with the requirements of this paragraph for a six-month period if it has excursions for any department-specified parameter on more than nine days during the period. An excursion occurs whenever the daily value for one or more of the water quality parameters measured at a sampling location is below the minimum value or outside the range designated by the department. Daily values are calculated as follows. The department has the discretion to invalidate results of obvious sampling errors from this calculation. (1) On days when more than one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the average of all results collected during the day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both.(2) On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the result of that measurement.(3) On days when no measurement is collected for the water quality parameter at the sampling location, the daily value shall be the daily value calculated on the most recent day on which the water quality parameter was measured at the sample site.h. Modification of department treatment decisions. A determination of the optimal corrosion control treatment under 43.7(2)"d" or optimal water quality control parameters under 43.7(2)"f" may be modified. A request for modification by a public water supply system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify its determination when it concludes that such change is necessary to ensure that the public water supply system continues to optimize corrosion control treatment. A revised determination will be made in writing, which will set forth the new treatment requirements, explain the basis for the decision, and provide an implementation schedule for completing the treatment modifications.(3)Source water treatment requirements. Public water supply systems shall complete the applicable source water monitoring and treatment requirements, as described in the referenced portions of 43.7(3)"b, " and in 567-paragraphs 41.4(1)"c" and"e, " by the following deadlines. a. Deadlines for completing source water treatment steps.(1) Step 1. A public water supply system exceeding the lead or copper action level shall complete lead and copper source water monitoring under 567-subparagraph 41.4(1)"e "(2) and make a written treatment recommendation to the department no later than 180 days after the end of the monitoring period during which the lead or copper action level was exceeded. (2) Step 2. The department will make a determination regarding source water treatment pursuant to 43.7(3)"b" (2) within six months after submission of monitoring results under Step 1.(3) Step 3. If installation of source water treatment is required, the system shall install the treatment pursuant to 43.7(3)"b" (3) within 24 months after completion of Step 2.(4) Step 4. The public water supply system shall complete follow-up tap water monitoring under 567-paragraph 41.4(1) "c"(4)"2" and source water monitoring under 567-subparagraph 41.4(1)"e " (3) within 36 months after completion of Step 2.(5) Step 5. The department will review the system's installation and operation of source water treatment and specify maximum permissible source water levels under 43.7(3)"b" (4) within six months after completion of Step 4.(6) Step 6. The public water supply system shall operate in compliance with the specified maximum permissible lead and copper source water levels under 43.7(3)"b" (4) and continue source water monitoring pursuant to 567-subparagraph 41.4(1)"e " (4).b. Description of source water treatment requirements.(1) System treatment recommendation. Any system which exceeds the lead or copper action level shall recommend in writing to the department the installation and operation of one of the source water treatments listed in 43.7(3)"b "(2). A system may recommend that no treatment be installed based upon a demonstration that source water treatment is not necessary to minimize lead and copper levels at users' taps.(2) Source water treatment determinations. The department will complete an evaluation of the results of all source water samples submitted by the public water supply system to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to users' taps. If the department determines that treatment is needed, the department will require installation and operation of the source water treatment recommended by the public water supply system or require the installation and operation of another source water treatment from among the following: ion exchange, reverse osmosis, lime softening or coagulation/filtration. If the department requests additional information to aid in its review, the water system shall provide the information by the date specified in its request. The department will notify the system in writing of its determination and set forth the basis for its decision.(3) Installation of source water treatment. Public water supply systems shall properly install and operate the source water treatment designated by the department under 43.7(3)"b "(2). (4) Department review of source water treatment and specification of maximum permissible source water levels. The department will review the source water samples taken by the water supply system both before and after the system installs source water treatment and determine whether the public water supply system has properly installed and operated the designated source water treatment. Based upon its review, the department will designate maximum permissible lead and copper concentrations for finished water entering the distribution system. Such levels shall reflect the contaminant removal capability of the treatment (properly operated and maintained). The department will notify the public water supply system in writing and explain the basis for its decision.(5) Continued operation and maintenance. Each public water supply system shall maintain lead and copper levels below the maximum permissible concentrations designated by the department at each sampling point monitored in accordance with 567-paragraph 41.4(1)"e. " The system is out of compliance with this paragraph if the level of lead or copper at any sampling point is greater than the maximum permissible designated concentration.(6) Modification of source water treatment decisions. The department may modify its determination of the source water treatment under 43.7(3)"b " (6), or maximum permissible lead and copper concentrations for finished water entering the distribution system under 43.7(3)"b" (4). A request for modification by a public water supply system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify its determination where it concludes that such change is necessary to ensure that the system continues to minimize lead and copper concentrations in source water. A revised determination will be made in writing, set forth the new treatment requirements, explain the basis for the decision, and provide an implementation schedule for completing the treatment modifications.(4)Lead service line replacement requirements.a. Applicability. Public water supply systems that fail to meet the lead action level in tap samples taken pursuant to 567-paragraph 41.4(1) "c"(4)"2" after installing corrosion control or source water treatment (whichever sampling occurs later) shall replace lead service lines in accordance with the requirements of this subrule. If a system is in violation of 43.7(1) and 43.7(3) for failure to install source water or corrosion control treatment, the department may require the system to commence lead service line replacement under this subrule after the date by which the system was required to conduct monitoring under 567-paragraph 41.4(1) "c"(4)"2" has passed.b.Lead service line replacement schedule. A public water supply system shall replace annually at least 7 percent of the initial number of lead service lines in its distribution system. The initial number of lead service lines is the number of lead lines in place at the time the replacement program begins. The system shall identify the initial number of lead service lines in its distribution system, including an identification of the portion(s) owned by the system, based upon a materials evaluation, including the evaluation required under 567-subparagraph 41.4(1)"c"(1) and relevant legal authorities regarding the portion owned by the system such as contracts and local ordinances. (1) The first year of lead service line replacement shall begin on the first day following the end of the monitoring period in which the action level was exceeded in tap sampling referenced in 43.7(4)"a. " If monitoring is required annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs. If the department has established an alternate monitoring period, then the end of the monitoring period will be the last day of that period.(2) Any water system resuming a lead service line replacement program after the cessation of its lead service line replacement program as allowed by 43.7(4)"g" shall update its inventory of lead service lines to include those sites that were previously determined not to require replacement through the sampling provision under 43.7(4)"c. " The system will then divide the updated number of remaining lead service lines by the number of remaining years in the program to determine the number of lines that must be replaced per year. Seven percent lead service line replacement is based on a 15 -year replacement program. For example, systems resuming lead service line replacement after previously conducting two years of replacement would divide the updated inventory by 13.(3) For those systems that have completed a 15-year lead service line replacement program, the department will determine a schedule for replacing or retesting lines that were previously exempted through testing under 43.7(4)"c" from the replacement program when the system re-exceeds the action level.c. Exemption to lead service line replacement requirement. A public water supply system is not required to replace an individual lead service line if the lead concentration in all service line samples from that line, taken pursuant to 567-paragraph 41.4(1) "c"(2)"3," is less than or equal to 0.015 mg/L.d. Lead service line replacement requirements. A water system shall replace that portion of the lead service line that it owns. In cases where the system does not own the entire lead service line, the system shall notify the owner of the line, or the owner's authorized agent, that the system will replace the portion of the service line that it owns and shall offer to replace the owner's portion of the line. A system is not required to bear the cost of replacing the privately owned portion of the line, nor is it required to replace the privately owned portion of the line where the owner chooses not to pay the cost of replacing the privately owned portion of the line, or where replacing the privately owned portion would be precluded by state, local, or common law. A water system that does not replace the entire length of the service line shall complete the following tasks. (1) Notification of residents. At least 45 days prior to commencing with the partial replacement of a lead service line, the water system shall provide to the resident(s) of all buildings served by the line notice explaining that the resident(s) may experience a temporary increase of lead levels in their drinking water, along with guidance on measures consumers may take to minimize their exposure to lead. The department may allow the water system to provide this notice less than 45 days prior to commencing partial lead service line replacement where such replacement is in conjunction with emergency repairs. In addition, the water system shall inform the resident(s) served by the line that the system will, at the system's expense, collect from each partially replaced lead service line a sample that is representative of the water in the service line for analysis of lead content, as prescribed under 567-paragraph 41.4(1) "c"(2)"3," within 72 hours after the completion of the partial replacement of the service line. The system shall collect the sample and report the results of the analysis to the owner and the resident(s) served by the line within three business days of receiving the results. Mailed notices postmarked within three business days of receiving the results shall be considered "on time." (2) Notification methods. The water system shall provide the information required by subparagraph 43.7(4)"d " (1) to the residents of individual dwellings by mail or by other methods approved by the department. In instances where multifamily dwellings are served by the line, the water system shall have the option to post the information at a conspicuous location.e. Lead service line control -department review. Rescinded IAB 1/7/04, effective 2/11/04. f.Lead service line replacement schedule. The department may require a public water supply system to replace lead service lines on a shorter schedule than that required by this subrule, taking into account the number of lead service lines in the system, where such a shorter replacement schedule is feasible. The department will make this determination in writing and notify the system of its finding within six months after the system is triggered into lead service line replacement based on monitoring referenced in 43.7(4)"a. "g. Cessation of lead service line replacement. Any public water supply system may cease replacing lead service lines whenever first draw samples collected pursuant to 567-paragraph 41.4(1) "c"(2)"2" meet the lead action level during each of two consecutive monitoring periods and the system submits the results. If the first draw tap samples collected in any such water system thereafter exceed the lead action level, the system shall recommence replacing lead service lines, as detailed in 43.7(4)"b."h. Lead service line replacement reporting requirements. To demonstrate compliance with 43.7(4)"a" through"d, " a system shall report the information specified in 567-paragraph 42.4(2)"e. "Iowa Admin. Code r. 567-43.7
ARC 9915B, IAB 12/14/11, effective 1/18/12Amended by IAB April 11, 2018/Volume XL, Number 21, effective 5/16/2018