16 Del. Admin. Code § 4462-10.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 4462-10.0 - Lead (Pb) and Copper (Cu)

10.1 Unless otherwise indicated, each of the provisions of this section applies to CWSs and NTNCWSs. The requirements in Section 10.0 shall take effect November 9, 1992.

10.1.1 General Requirements: Applicability and effective dates.

10.1.1.1 The requirements of Section 10.0 constitute national primary drinking water regulations for lead and copper. Unless otherwise indicated, each of the provisions of this section applies to community water systems and non-transient, non-community water systems (hereinafter referred to as "water systems" or "systems").

10.1.1.2 Reserved

10.1.2 Scope. These regulations establish a treatment technique that includes requirements for corrosion control treatment, source water treatment, lead service line replacement, and public education. These requirements are triggered, in some cases, by lead and copper action levels measured in samples collected at consumer's taps.

10.1.3 Action Level:

10.1.3.1 The lead action level is exceeded if the concentration of lead in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with subsection 10.7 is greater than 0.015 mg/L (i.e., if the "90th percentile" lead level is greater than 0.015 mg/L).

10.1.3.2 The copper action level is exceeded if the concentration of copper in more than 10 percent of tap water samples collected during any monitoring period conducted in accordance with subsection 10.7 is greater than 1.3 mg/L (i.e., if the "90th percentile" copper level is greater than 1.3 mg/L).

10.1.3.3 The 90th percentile lead and copper levels shall be computed as follows:

10.1.3.3.1 The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken.

10.1.3.3.2 The number of samples taken during the monitoring period shall be multiplied by 0.9.

10.1.3.3.3 The contaminant concentration in the numbered sample yielded by the calculation in subsection 10.1.3.3.2 is the 90th percentile contaminant level.

10.1.3.3.4 For water systems serving fewer than 100 people that collect five samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations.

10.1.3.3.5 For a public water system that has been allowed by the Division to collect fewer than five samples in accordance with subsection 10.7.3 the sample result with the highest concentration is considered the 90th percentile value.

10.1.4 Corrosion Control Treatment Requirements:

10.1.4.1 All water systems shall install and operate optimal corrosion control treatment as defined in Section 2.0.

10.1.4.2 Any water system that complies with the applicable corrosion control treatment requirements specified by the Division under subsections 10.2 and 10.3 shall be deemed in compliance with each treatment requirement contained in subsection 10.1.4.1.

10.1.5 Source Water Treatment Requirements: Any system exceeding the lead or copper action level shall implement all applicable source water treatment requirements specified by the Division under subsection 10.4.

10.1.6 Lead Service Line Replacement: Any system exceeding the lead action level after implementation of applicable corrosion control and source water treatment requirements shall complete the lead service line replacement requirements contained in subsection 10.5.

10.1.7 Public Education Requirements: Pursuant to subsection 10.6, all water systems must provide a consumer notice of lead tap water monitoring results to persons served at the sites (taps) that are tested. Any system exceeding the lead action level shall implement the public education requirements contained in subsection 10.6.

10.1.8 Monitoring and Analytical Requirements: Tap water monitoring for lead and copper, monitoring for water quality parameters, source water monitoring for lead and copper, and analyses of the monitoring results under this section shall be completed in compliance with subsections 10.7, 10.8, 10.9 and 10.12.

10.1.9 Reporting Requirements: Systems shall report to the Division any information required by the treatment provisions of this section and subsection 10.10.

10.1.10 Recordkeeping Requirements: Systems shall maintain records in accordance with subsection 10.11.

10.1.11 Violation of National Primary Drinking Water Regulations:

10.1.11.1 Failure to comply with the applicable requirements of Section 10.0 including requirements established by the Division pursuant to these provisions, shall constitute a violation of the national primary drinking water regulations for lead and/or copper.

10.2 Applicability of Corrosion Control Treatment Steps for Small, Medium-Size and Large Water Systems:

10.2.1 Systems shall complete the applicable corrosion control treatment requirements described in subsection 10.3 by the deadlines established in this section.

10.2.1.1 A large system (serving >50,000 persons) shall complete the corrosion control treatment steps specified in subsection 10.2.4, unless it is deemed to have optimized corrosion control under subsection 10.2.2.2 or 10.2.2.3.

10.2.1.2 A small system (serving <3,300 persons) and a medium-size system (serving >3,300 and <50,000 persons) shall complete the corrosion control treatment steps specified in paragraph 10.2.5, unless it is deemed to have optimized corrosion control under subsections 10.2.2.1, 10.2.2.2 or 10.2.2.3.

10.2.2 A system is deemed to have optimized corrosion control and is not required to complete the applicable corrosion control treatment steps identified in this section if the system satisfies one of the following criteria specified in subsections 10.2.2.1 through 10.2.2.3. 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 Division determines appropriate to ensure that optimal corrosion control treatment is maintained.

10.2.2.1 A small or medium-size water system is deemed to have 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 subsection 10.7.

10.2.2.2 Any water system may be deemed by the Division to have optimized corrosion control treatment if the system demonstrates to the satisfaction of the Division that it has conducted activities equivalent to the corrosion control steps applicable to such system under this section. If the Division makes this determination, it shall provide the systems with written notice explaining the basis for its decision and shall specify the water quality control parameters representing optimal corrosion control in accordance with subsection 10.3.6. Water systems deemed to have optimized corrosion control under this paragraph shall operate in compliance with the Division-designated optimal water quality control parameters in accordance with subsection 10.3.7 and continue to conduct lead and copper tap and water quality parameter sampling in accordance with subsection 10.7.4.3 and subsection 10.8.4 respectively. A system shall provide the Division with the following information in order to support a determination under this paragraph.

10.2.2.2.1 The results of all test samples collected for each of the water quality parameters in subsection 10.3 .3.3.

10.2.2.2.2 A report explaining the test methods used by the water system to evaluate the corrosion control treatments listed in subsection 10.3.3.1, the results of all tests conducted, and the basis for the system's selection of optimal corrosion control treatment.

10.2.2.2.3 A report explaining how corrosion control has been installed and how it is being maintained to insure minimal lead and copper concentrations at consumer's taps; and

10.2.2.2.4 The results of tap water samples collected in accordance with subsection 10.7 at least once every six months for one year after corrosion control has been installed.

10.2.2.3 Any water system is deemed to have optimized corrosion control if it submits results of tap water monitoring conducted in accordance with subsection 10.7 and source water monitoring conducted in accordance with subsection 10.9 that demonstrates for two consecutive six-month monitoring periods that the difference between the 90th percentile tap water lead level computed under subsection 10.1.3.3, and the highest source water lead concentration, is less than the Practical Quantitation Level (PQL) for lead specified in subsection 10.12.

10.2.2.3.1 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.

10.2.2.3.2 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 subsection 10.7.3 and collect the samples at times and locations specified in subsection 10.7.4.4. Any such system that has not conducted a round of monitoring pursuant to subsection 10.7.4 since September 30, 1997, shall complete a round of monitoring pursuant to this paragraph no later than September 30, 2000.

10.2.2.3.3 Any water system deemed to have optimized corrosion control pursuant to this paragraph shall notify the Division in writing pursuant to subsection 10.10.1.3 of any upcoming long-term change in treatment or addition of a new source as described in that section. The Division 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. The Division may require any such system to conduct additional monitoring or to take other action the Division deems appropriate to ensure that such systems maintain minimal levels of corrosion in the distribution system.

10.2.2.3.4 As of July 12, 2001 a system is not deemed to have optimized corrosion control under this paragraph, and shall implement corrosion control treatment pursuant to subsection 10.2.2.3.5 unless it meets the copper action level.

10.2.2.3.5 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 subsection 10.2.5. Any such large system shall adhere to the schedule specified in that section for medium-sized 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 section.

10.2.3 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 subsection 10.7 and submits the results to the Division. If any such water system thereafter exceeds the lead or copper action level during any monitoring period, the system (or the Division, as the case may be) shall recommence completion of the applicable treatment steps, beginning with the first treatment step which was not previously completed in its entirety. The Division may require a system to repeat treatment steps previously completed by the system where the Division determines that this is necessary to properly implement the treatment requirements of this section. The Division shall 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 subsection 10.2.5 (including systems deemed to have optimized corrosion control under subsection 10.2.2.1) is triggered whenever any small or medium-size system exceeds the lead or copper action level.

10.2.4 Treatment Steps and Deadlines for Large Systems:

10.2.4.1 Except as provided in subsections 10.2.2.2 and 10.2.2.3, large systems shall complete the following corrosion control treatment steps (described in the referenced portions of subsections 10.3, 10.7 and 10.8 by the indicated dates.

Step 1: The system shall conduct two six month initial monitoring periods by January 1, 1993.

Step 2: The system shall complete corrosion control studies, subsection 10.3.3, in 18 months, by July 1, 1994.

Step 3: The Division shall designate optimal corrosion control treatment, subsection 10.3.4, in 6 months, by January 1, 1995.

Step 4: The system shall install optimal corrosion control treatment, subsection 10.3.5, in 24 months, by January 1, 1997.

Step 5: The system shall complete follow-up sampling, subsection 10.7.4.2 and subsection 10.8.3, in 12 months, by January 1, 1998

Step 6: The Division shall review installation of treatment and designate optimal water quality control parameters, subsection 10.3.6, in 6 months, by July 1, 1998.

Step 7: The system shall operate in compliance with the Division-specified optimal water quality control parameters, subsection 10.3 .7, and continue to conduct tap sampling, subsection 10.7.4 and subsection 10.8.4.

10.2.5 Treatment Steps and Deadlines for Small-and Medium-Size Systems:

10.2.5.1 Except as provided in subsection 10.2.2, small and medium-size systems shall complete the following corrosion control treatment steps (described in the referenced portions of subsections 10.3, 10.7 and 10.8 by the indicated time periods.

Step 1: The system shall conduct initial tap sampling, subsection 10.7.4.1 and subsection 10.8.2, until the system either exceeds the lead or copper action level or becomes eligible for reduced monitoring under subsection 10.7.4.4. A system exceeding the lead or copper action level shall recommend optimal corrosion control treatment, subsection 10.3.1, within six months after the end of the monitoring period during which it exceeds one of the action levels.

Step 2: Within 12 months after the end of the monitoring period during which a system exceeds the lead or copper action level, the Division may require the system to perform corrosion control studies (subsection 10.3.2). If the Division does not require the system to perform such studies, the Division shall specify optimal corrosion control treatment, (subsection 10.3.4) within the following time frames.

10.2.5.1.1 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.

10.2.5.1.2 For small systems, within 24 months after the end of the monitoring period during which such system exceeds the lead or copper action level.

Step 3: If the Division requires a system to perform corrosion control studies under step 2, the system shall complete the studies, subsection 10.3.3, within 18 months after the Division requires that such studies be conducted.

Step 4: If the system has performed corrosion control studies under step 2, the Division shall designate optimal corrosion control treatment, subsection 10.3.4, within 6 months after completion of step 3.

Step 5: The system shall install optimal corrosion control treatment, subsection 10.3.5, within 24 months after the Division designates optimal corrosion control treatment.

Step 6: The system shall complete follow-up sampling, subsection 10.7.4.2 and subsection 10.8.3, within 36 months after the Division designates optimal corrosion control treatment.

Step 7: The Division shall review the system's installation of treatment and designate optimal water quality control parameters, subsection 10.3.6, within 6 months after completion of Step 6.

Step 8: The system shall operate in compliance with the Division-designated optimal water quality control parameters, subsection 10.3 .7, and continue to conduct tap sampling, subsection 10.7.4.3 and subsection 10.8.4.

10.3 Description of Corrosion Control Treatment Requirements: Each System shall complete the corrosion control treatment requirements described below which are applicable to such systems under subsection 10.2.

10.3.1 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 subsection 10.3.3.1 which the system believes constitutes optimal corrosion control for that system. The Division may require the system to conduct additional water quality parameter monitoring in accordance with subsection 10.8.2 to assist the Division in reviewing the system's recommendation.

10.3.2 Division Decision to Require Studies of Corrosion Control Treatment (Applicable to Small and Medium-Size Systems): The Division may require any small or medium-size system that exceeds the lead or copper action level to perform corrosion control studies under subsection 10.3.3 to identify optimal corrosion control treatment for the system.

10.3.3 Performance of Corrosion Control Studies:

10.3.3.1 Any public water 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 for that system:

10.3.3.1.1 Alkalinity and pH adjustment;

10.3.3.1.2 Calcium hardness adjustment; and

10.3.3.1.3 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.

10.3.3.2 The water system shall evaluate each of the corrosion control treatments using either pipe ring/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.

10.3.3.3 The water system shall measure the following water quality parameters in any tests conducted under this paragraph before and after evaluating the corrosion control treatment listed above:

Lead;

Copper;

pH;

Alkalinity;

Calcium;

Conductivity;

Orthophosphate (when an inhibitor containing a phosphate compound is used);

Silicate (when an inhibitor containing a silicate compound is used);

Water temperature.

10.3.3.4 The water system shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and document such constraints with at least one of the following:

10.3.3.4.1 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; and/or

10.3.3.4.2 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.

10.3.3.5 The water system shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatments processes.

10.3.3.6 On the basis of an analysis of the data generated during each evaluation, the water system shall recommend to the Division in writing 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 specified in subsections 10.3.3.1 through 10.3.3.5.

10.3.4 Division Designation of Optimal Corrosion Control Treatment:

10.3.4.1 Based upon consideration of available information including, where applicable, studies performed under subsection 10.3.3 and a system's recommended treatment alternative, the Division shall either approve the corrosion control treatment option recommended by the system, or designate alternative corrosion control treatment(s) from among those listed in subsection 10.3.3.1. When designating optimal treatment the Division shall consider the effects that additional corrosion control treatment will have on water quality parameters and on other quality treatment processes.

10.3.4.2 The Division shall notify the system of its decision on optimal corrosion control treatment in writing and explain the basis for this determination within 6 months of receiving follow up samples. If the Division requests additional information to aid its review, the water system shall provide the information.

10.3.5 Installation of Optimal Corrosion Control: Each system shall properly install and operate throughout its distribution system the optimal corrosion control treatment designated by the Division under subsection 10.3.4.

10.3.6 Division Review of Treatment and Specification of Optimal Water Quality Control Parameters: The Division shall evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the water system and determine whether the system has properly installed and operated the optimal corrosion control treatment designated by the Division in subsection 10.3.4. Upon reviewing the results of tap water and water quality parameter monitoring by the system, both before and after the system installs optimal corrosion control treatment, the Division shall designate:

10.3.6.1 A minimum value or a range of values for pH measured at each entry point to the distribution system;

10.3.6.2 A minimum pH value measured in all tap samples. Such value shall be equal to or greater than 7.0 unless the Division determines that meeting a pH level of 7.0 is not technologically feasible or is not necessary for the system to optimize corrosion control;

10.3.6.3 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, that the Division determines is necessary to form a passivating film on the interior walls of the pipes of the distribution system;

10.3.6.4 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; and

10.3.6.5 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. The values for the applicable water quality control parameters listed above shall be those that the Division determines to reflect optimal corrosion control treatment for the system. The Division may designate values for additional water quality control parameters determined by the Division to reflect optimal corrosion control for the system. The Division shall notify the system in writing of these determinations and explain the basis for its decisions.

10.3.7 Continued Operation and Monitoring: All systems shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameter values at or above minimum values or within ranges designated by the Division under subsection 10.3.6 in accordance with this paragraph for all samples collected under subsection 10.8.4 through 10.8.6. Compliance with requirements of this paragraph shall be determined every six months, as specified under subsection 10.8.4. A water system is out of compliance with the requirements of this paragraph for a six-month period if it has excursions for any Division-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 Division. Daily values are calculated as follows. The Division has the discretion to delete results of obvious sampling errors from this calculation.

10.3.7.1 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 the results collected during the day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both. If EPA has approved an alternative formula under 40 CFR section 142.16 in the State's application for a program revision submitted pursuant to 40 CFR section 142.12, the Division's formula shall be used to aggregate multiple measurements taken at a sampling point for the water quality parameter.

10.3.7.2 On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value shall be that measurement.

10.3.7.3 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 sampling location.

10.3.8 Modification of Division's Corrosion Control Treatment Decision: Upon its own initiative, or in response to a request by the water system or other interested party, the Division may modify treatment determination. The requests in writing must explain why the change is appropriate and provide supporting documentation. The treatment may be changed when the Division determines that it is necessary for the water system to continue optimizing corrosion control. The Division's decision must be in writing and specify new treatment, explain the basis for its decision, and provide an implementation schedule for completing the treatment modifications.

10.3.9 EPA Treatment Decisions in Lieu of the Division's Decisions: The regional administrator may issue federal determinations in lieu of the Division's determinations when:

10.3.9.1 The Division fails to issue a determination in a timely manner.

10.3.9.2 The Division abuses its discretion in a substantial number of cases or in cases affecting large populations.

10.3.9.3 The technical basis of the Division's decision is indefensible in federal enforcement action(s).

10.4 Source Water Treatment Requirements: Systems shall complete the applicable source water monitoring and treatment requirements (described in the referenced portions of subsection 10.4.2, and in subsections 10.7 and 10.9 by the following deadlines:

10.4.1 Deadlines for Completing Source Water Treatment Steps:

Step 1: A system exceeding the lead or copper action level shall complete lead and copper source water monitoring (subsection 10.9 .2) and make a treatment recommendation to the Division (subsection 10.4.2.1) no later than 180 days after the end of the monitoring period during which the lead or copper action level was exceeded.

Step 2: The Division shall make a determination regarding source water treatment, subsection 10.4.2.2 within 6 months after submission of monitoring results under step 1.

Step 3: If the Division requires installation of source water treatment, the system shall install the treatment, subsection 10.4.2.3, within 24 months after completion of step 2.

Step 4: The system shall complete follow-up tap water monitoring, subsection 10.7.4.2, and source water monitoring, subsection 10.9 .3, within 36 months after completion of step 2.

Step 5: The Division shall review the system's installation and operation of source water treatment and specify maximum permissible source water levels for lead and copper, subsection 10.4.2.4, within 6 months after completion of step 4.

Step 6: The system shall operate in compliance with the Division-specified maximum permissible lead and copper source water levels, subsection 10.4.2.4, and continue source water monitoring, subsection 10.9 .4.

10.4.2 Description of Source Water Treatment Requirements:

10.4.2.1 System Treatment Recommendation: Any system which exceeds the lead or copper action level shall recommend in writing to the Division the installation and operation of one of the source water treatments listed in subsection 10.4.2.2. 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.

10.4.2.2 Division Determination Regarding Source Water Treatment: The Division shall complete an evaluation of the results of all source water samples submitted by the water system to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to users' taps. If the Division determines that treatment is needed, the Division shall either require installation and operation of the source water treatment recommended by the system (if any) 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 Division requests additional information to aid in its review, the water system shall provide the information by the date specified by the Division in its request. The Division shall notify the system in writing of its determination and set forth the basis for its decision.

10.4.2.3 Installation of Source Water Treatment: Each system shall properly install and operate the source water treatment designated by the Division under subsection 10.4 .2.2.

10.4.2.4 Division Review of Source Water Treatment and Specification of Maximum Permissible Source Water Levels: The Division shall review the source water samples taken by the water system both before and after the system installs source water treatment, and determine whether the system has properly installed and operated the source water treatment designated by the Division. Based upon its review, the Division shall designate the 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 Division shall notify the system in writing and explain the basis for its decision.

10.4.2.5 Continued Operation and Maintenance: Each water system shall maintain lead and copper levels below the maximum permissible concentrations designated by the Division at each sampling point monitored in accordance with subsection 10.9. 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 concentration designated by the Division.

10.4.2.6 Modification of Division Treatment Decisions: Upon its own initiative or in response to a request by a water system or other interested party, the Division may modify its determination of the source water treatment under subsection 10.4.2.2, or maximum permissible lead and copper concentrations for finished water entering the distribution system under subsection 10.4.2.4. A request for modification by a system or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The Division 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 shall be made in writing and set forth the new treatment requirements, explain the basis for the Division's decision and provide an implementation schedule for completing the treatment modifications.

10.4.2.7 EPA Treatment Decisions in Lieu of the Division's Decisions: The regional administrator may issue federal determinations in lieu of the Division's determination when:

10.4.2.7.1 The Division fails to issue a determination in a timely manner.

10.4.2.7.2 The Division abuses its discretion in a substantial number of cases or in cases affecting large populations.

10.4.2.7.3 The technical basis of the Division's decision is indefensible in federal enforcement action(s).

10.5 Lead Service Line Replacement Requirements:

10.5.1 Systems that fail to meet the lead action level in tap samples taken pursuant to subsection 10.7.4.2 after installing corrosion control and/or source water treatment (whichever sampling occurs later) shall replace lead service lines in accordance with the requirements of this section. If a system is in violation of subsections 10.2 or 10.4 for failure to install source water or corrosion control treatment, the Division may require the system to commence lead service line replacement under this section after the date by which the system was required to conduct monitoring under subsection 10.7.4.2 has passed.

10.5.1.1 A 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 systems 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 subsection 10.7.1 and relevant legal authorities (e.g., contracts, local ordinances) regarding the portion owned by the system. 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 under subsection 10.5.1. 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 Division has established an alternate monitoring period, then the end of the monitoring period will be the last day of that period.

10.5.1.2 Any water system resuming a lead service line replacement program after the cessation of its lead service line replacement program as allowed by subsection 10.5.6 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 subsection 10.5 .3. 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 (7 percent lead service line replacement is based on a 15-year replacement program, so, for example, systems resuming lead service line replacement after previously conducting two years of replacement would divide the updated inventory by 13). For those systems that have completed a 15-year lead service line replacement program, the Division will determine a schedule for replacing or retesting lines that were previously tested under the replacement program when the system re-exceeds the action level.

10.5.2 A 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 subsection 10.7.2.3, is less than or equal to 0.015 mg/L.

10.5.3 A water system shall replace the entire service line (up to the building inlet) unless it demonstrates to the satisfaction of the Division under subsection 10.5.4 that it controls less than the entire service line. In such cases, the system shall replace the portion of the line which the Division determines is under the system's control. The system shall notify the user served by the line that the system will replace the portion of the service line under its control and shall offer to replace the building owner's portion of the line, but is not required to bear the cost of replacing the building owner's portion of the line. For buildings where only a portion of the lead service line is replaced, the water system shall inform the resident(s) that the system will collect a first flush tap water sample after partial replacement of the service line is completed if the resident(s) so desire. In cases where the resident(s) accept the offer, the system shall collect the sample and report the results to the resident(s) within 14 days following partial lead service replacement.

10.5.3.1 At least 45 days prior to commencing with the partial replacement of a lead service line, the water system shall provide notice to the resident(s) of all buildings served by the line explaining that they may experience a temporary increase in lead levels in their drinking water, along with guidance on measures consumers can take to minimize their exposure to lead. The Division may allow the water system to provide notice under the previous sentence 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 a sample from each partially-replaced lead service line that is representative of the water in the service line for analysis of lead content, as prescribed under subsection 10.7.2.3, within 72 hours after 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 post-marked within three business days of receiving the results shall be considered "on time."

10.5.3.2 The water system shall provide the information required by subsection 10.5.3.1 to the residents of individual dwellings by mail or by other methods approved by the Division. In instances where multi-family dwellings are served by the line, the water system shall have the option to post the information at a conspicuous location.

10.5.4 A water system is presumed to control the entire lead service line (up to the building inlet) unless the system demonstrates to the satisfaction of the Division, in a letter submitted under subsection 10.10.5.4, that it does not have any of the following forms of control over the entire line (as defined by Division statutes, municipal ordinances, public service contracts or other applicable legal authority); authority to set standards for construction, repair, or maintenance of the line, authority to replace, repair, or maintain the service line, or ownership of the service line. The Division shall review the information supplied by the system and determine whether the system controls less than the entire service line, in such cases, shall determine the extent of the system's control. The Division's determination shall be in writing and explain the basis for its decision.

10.5.5 The Division shall require a system to replace lead service lines on a shorter schedule than that required by this section, taking into account the number of lead service lines in the system, where such a shorter replacement schedule is feasible. The Division shall make this determination in writing and notify the system of its finding within 6 months after the system is triggered into lead service line replacement based on monitoring referenced in subsection 10.5.1.

10.5.6 Any system may cease replacing lead service lines whenever first draw samples collected pursuant to subsection 10.7 .2.2 meet the lead action level during each of two consecutive monitoring periods and the system submits the results to the Division. If the first draw samples in any such water system thereafter exceeds the lead action level, the system shall recommence replacing lead service lines, pursuant to subsection 10.5.1.2.

10.5.7 To demonstrate compliance with subsections 10.5.1 through 10.5.4, a system shall report to the Division the information specified in subsection 10.10.5.

10.6 Public education and supplemental monitoring requirements. All water systems must deliver a consumer notice of lead tap water monitoring results to persons served by the water system at sites that are tested, as specified in subsection 10.6.4. A water system that exceeds the lead action level based on tap water samples collected in accordance with subsection 10.7 shall deliver the public education materials contained in subsection 10.6.1 in accordance with the requirements of subsection 10.6.2. Water systems that exceed the lead action level must sample the tap water of any customer who requests it in accordance with subsection 10.6.3.

10.6.1 Content of written public education materials.

10.6.1.1 Community water systems and non-transient non-community water systems. Water systems must include the following elements in printed materials (e.g., brochures and pamphlets) in the same order as listed below. In addition, language in subsections 10.6.1.1.1 through 10.6.1.1.2 and 10.6.1.1.6 must be included in the materials, exactly as written, except for the text in brackets in these sections for which the water system must include system-specific information. Any additional information presented by a water system must be consistent with the information below and be in plain language that can be understood by the general public. Water systems must submit all written public education materials to the Division prior to delivery. The Division may require the system to obtain approval of the content of written public materials prior to delivery.

10.6.1.1.1 IMPORTANT INFORMATION ABOUT LEAD IN YOUR DRINKING WATER [INSERT NAME OF WATER SYSTEM] found elevated levels of lead in drinking water in some homes/buildings. Lead can cause serious health problems, especially for pregnant women and young children. Please read the information closely to see what you can do to reduce lead in your drinking water.

10.6.1.1.2 Health effects of lead. Lead can cause serious health problems if too much enters your body from drinking water or other sources. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered IQ in children. Adults with kidney problems and high blood pressure can be affected by low levels of lead more than healthy adults. Lead is stored in the bones, and it can be released later in life. During pregnancy, the child receives lead from the mother's bones, which may affect development.

10.6.1.1.3 Sources of lead.

10.6.1.1.3.1 Explain what lead is.

10.6.1.1.3.2 Explain possible sources of lead in drinking water and how lead enters drinking water. Include information on home/building plumbing materials and service lines that may contain lead.

10.6.1.1.3.3 Discuss other important sources of lead exposure in addition to drinking water (e.g., paint).

10.6.1.1.4 Discuss the steps the consumer can take to reduce their exposure to lead in drinking water.

10.6.1.1.4.1 Encourage running the water to flush out the lead.

10.6.1.1.4.2 Explain the concerns with using hot water from the tap and specifically caution against use of hot water for preparing baby formula.

10.6.1.1.4.3 Explain that boiling water does not reduce lead levels.

10.6.1.1.4.4 Discuss other options consumers can take to reduce exposure to lead in drinking water, such as alternative sources or treatment of water.

10.6.1.1.4.5 Suggest that parents have their child's blood tested for lead.

10.6.1.1.5 Explain why there are elevated levels of lead in the system's drinking water (if known) and what the water system is doing to reduce the lead levels in homes/buildings in this area.

10.6.1.1.6 For more information, call us at [INSERT YOUR PHONE NUMBER] [(IF APPLICABLE), or visit our website at [INSERT YOUR WEBSITE HERE)]. For more information on reducing lead exposure around your home/building and the health effects of lead, visit EPA's Web site at http://www.epa.gov/lead or contact your health care provider.

10.6.1.2 Community water systems. In addition to including the elements specified in subsection 10.6.1.1 community water systems must:

10.6.1.2.1 Tell consumers how to get their water tested.

10.6.1.2.2 Discuss lead in plumbing components and the difference between low lead and lead free.

10.6.2 Delivery of public education material.

10.6.2.1 For public water systems serving a large proportion of non-English speaking consumers, as determined by the Division, the public education materials must contain information in the appropriate language(s) regarding the importance of the notice or contain a telephone number or address where persons served may contact the water system to obtain a translated copy of the public education materials or to request assistance in the appropriate language.

10.6.2.2 A community water system that exceeds the lead action level on the basis of tap water samples collected in accordance with subsection 10.7, and that is not already conducting public education tasks under this section, must conduct the public education tasks under this section within 60 days after the end of the monitoring period in which the exceedance occurred:

10.6.2.2.1 Deliver printed materials meeting the content requirements of subsection 10.6 .1 to all bill paying customers.

10.6.2.2.1.1 Contact customers who are most at risk by delivering education materials that meet the content requirements of subsection 10.6.1 to local public health agencies even if they are not located within the water system's service area, along with an informational notice that encourages distribution to all the organization's potentially affected customers or community water system's users. The water system must contact the local public health agencies directly by phone or in person. The local public health agencies may provide a specific list of additional community based organizations serving target populations, which may include organizations outside the service area of the water system. If such lists are provided, systems must deliver education materials that meet the content requirements of subsection 10.6.1 to all organizations on the provided lists.

10.6.2.2.1.2 Contact customers who are most at risk by delivering materials that meet the content requirements of subsection 10.6.1 to the following organizations listed in subsection 10.6.2.2.2.2.1 through 10.6.2.2.2.2.6 that are located within the water system's service area, along with an informational notice that encourages distribution to all the organization's potentially affected customers or community water system's users:

10.6.2.2.1.2.1 Public and private schools or school boards.

10.6.2.2.1.2.2 Women, Infants and Children (WIC) and Head Start Programs.

10.6.2.2.1.2.3 Public and private hospitals and medical clinics.

10.6.2.2.1.2.4 Pediatricians.

10.6.2.2.1.2.5 Family planning clinics.

10.6.2.2.1.2.6 Local welfare agencies.

10.6.2.2.1.3 Make a good faith effort to locate the following organizations within the service area and deliver materials that meet the content requirements of subsection 10.6.1 to them, along with an informational notice that encourages distribution to all potentially affected customers or users. The good faith effort to contact at-risk customers may include requesting a specific list of these organizations from the local public health agencies, even if the agencies are not located within the water system's service area:

10.6.2.2.1.3.1 Licensed childcare centers

10.6.2.2.1.3.2 Public and private preschools

10.6.2.2.1.3.3 Obstetricians-Gynecologists and Midwives.

10.6.2.2.2 [Reserved]

10.6.2.2.3 No less often than quarterly, provide information on or in each water bill as long as the system exceeds the action level for lead. The message on the water bill must include the following statement exactly as written except for the text in brackets for which the water system must include system-specific information: [INSERT NAME OF WATER SYSTEM] found high levels of lead in drinking water in some homes. Lead can cause serious health problems. For more information please call [INSERT NAME OF WATER SYSTEM] [or visit (INSERT YOUR WEBSITE HERE)] The message or delivery mechanism can be modified in consultation with the Division; specifically, the Division may allow a separate mailing of public education materials to customers if the water system cannot place the information on water bills.

10.6.2.2.4 Post material meeting the content requirements of subsection 10.6.1 on the water system's website if the system serves a population greater than 100,000.

10.6.2.2.5 Submit a press release to newspaper, television and radio stations.

10.6.2.2.6 In addition to subsections 10.6 .2.2.1 through 10.6.2.2.5, systems must implement at least three activities from one or more of the categories listed below. The educational content and selection of these activities must be determined in consultation with the Division.

10.6.2.2.6.1 Public Service Announcements.

10.6.2.2.6.2 Paid advertisements.

10.6.2.2.6.3 Public Area Information Displays.

10.6.2.2.6.4 Emails to customers.

10.6.2.2.6.5 Public meetings.

10.6.2.2.6.6 Household deliveries.

10.6.2.2.6.7 Targeted individual customer contact.

10.6.2.2.6.8 Direct material distribution to all multi-family homes and institutions.

10.6.2.2.6.9 Other methods approved by the Division.

10.6.2.2.7 For systems that are required to conduct monitoring annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the Division has established an alternative monitoring period, the last day of that period.

10.6.2.3 As long as a community water system exceeds the action level, it must repeat the activities pursuant to subsection 10.6.2.2 as described in subsections 10.6.2.3.1 through 10.6.2.3.4.

10.6.2.3.1 A community water system shall repeat the tasks contained in subsections 10.6.2.2.1, 10.6.2.2.2 and 10.6.2.2.6 every 12 months.

10.6.2.3.2 A community water system shall repeat the tasks contained in subsection 10.6.2.2.3 with every billing cycle.

10.6.2.3.3 A community water system serving a population greater than 100,000 shall post and retain material on a publicly accessible website pursuant to subsection 10.6.2.2.4.

10.6.2.3.4 The community water system shall repeat the task in subsection 10.6.2.2.5 twice every 12 months on a schedule agreed upon with the Division. The Division can allow activities in subsection 10.6.2.2 to extend beyond the 60-day requirement if needed for implementation purposes on a case-by-case basis; however, this extension must be approved in writing by the Division in advance of the 60-day deadline.

10.6.2.4 Within 60 days after the end of the monitoring period in which the exceedance occurred (unless it already is repeating public education tasks pursuant to subsection 10.6.2.5), a non-transient non-community water system shall deliver the public education materials specified by subsection 10.6.1 as follows:

10.6.2.4.1 Post informational posters on lead in drinking water in a public place or common area in each of the buildings served by the system; and

10.6.2.4.2 Distribute informational pamphlets and/or brochures on lead in drinking water to each person served by the non-transient non-community water system. The Division may allow the system to utilize electronic transmission in lieu of or combined with printed materials as long as it achieves at least the same coverage.

10.6.2.4.3 For systems that are required to conduct monitoring annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the Division has established an alternate monitoring period, the last day of that period.

10.6.2.5 A non-transient non-community water system shall repeat the tasks contained in subsection 10.6.2.4 at least once during each calendar year in which the system exceeds the lead action level. The Division can allow activities in subsection 10.6.2.4 to extend beyond the 60-day requirement if needed for implementation purposes on a case-by-case basis; however, this extension must be approved in writing by the Division in advance of the 60-day deadline.

10.6.2.6 A water system may discontinue delivery of public education materials if the system has met the lead action level during the most recent six-month monitoring period conducted pursuant to subsection 10.7. Such a system shall recommence public education in accordance with this section if it subsequently exceeds the lead action level during any monitoring period.

10.6.2.7 A community water system may apply to the Division, in writing (unless the Division has waived the requirement for prior Division approval), to use only the text specified in subsection 10.6 .1.1 in lieu of the text in subsections 10.6.1.1 and 10.6.1.2 and to perform the tasks listed in subsections 10.6.2.4 and 10.6.2.5 in lieu of the tasks listed in subsections 10.6.2.2 and 10.6.2.3 if:

10.6.2.7.1 The system is a facility, such as a prison or a hospital, where the population served is not capable of or is prevented from making improvements to plumbing or installing point of use treatment devices; and,

10.6.2.7.2 The system provides water as part of the cost of services provided and does not separately charge for water consumption.

10.6.2.8 A community water system serving 3,300 or fewer people may limit certain aspects of their public education programs as follows:

10.6.2.8.1 With respect to the requirements of subsection 10.6.2.2.6, a system serving 3,300 or fewer people must implement at least one of activities listed in that section.

10.6.2.8.2 With respect to the requirements of subsection 10.6.2.2.2, a system serving 3,300 or fewer people may limit the distribution of the public education materials required under that section to facilities and organizations served by the system that are most likely to be visited regularly by pregnant women and children.

10.6.2.8.3 With respect to the requirements of subsection 10.6.2.2.5, the Division may waive this requirement for systems serving 3,300 or fewer people as long as the system distributes notices to every household served by the system.

10.6.3 Supplemental monitoring and notification of results. A water system that fails to meet the lead action level on the basis of tap samples collected in accordance with section 10.7 shall offer to sample the tap water of any customer who requests it. The system is not required to pay for collecting or analyzing the sample, nor is the system required to collect and analyze the sample itself.

10.6.4 Notification of results.

10.6.4.1 Reporting requirement. All water systems must provide a notice of the individual tap results from the lead tap water monitoring carried out under the requirements of 107 to the persons served by the water system at the specific sample site from which the sample was taken (e.g., the occupants of the residence where the tap was tested).

10.6.4.2 Timing of notification. A water system must provide the consumer notice as soon as practical, but no later than 30 days after the system learns of the tap monitoring results.

10.6.4.3 Content. The consumer notice must include the results of the lead tap water monitoring for the tap that was tested, an explanation of the health effects of lead, list steps consumers can take to reduce exposure to lead in drinking water and contact information for the water utility. The notice must also provide the maximum contaminant level goal and the action level for lead and the definitions for those terms from subsection 6.3.3.

10.6.4.4 Delivery. The consumer notice must be provided to persons served at the tap that was tested, either by mail or by another method approved by the Division. For example, upon approval by the Division, a non-transient non-community water system could post the results on a bulletin board in the facility to allow users to review the information. The system must provide the notice to customers at sample taps tested, including consumers who do not receive water bills.

10.7 Monitoring Requirements for Lead and Copper in Tap Water:

10.7.1 Sample Site Location:

10.7.1.1 By the applicable date for commencement of monitoring under subsection 10.7.4.1, each water system shall complete a materials evaluation of its distribution system in order to identify a pool of targeted sampling sites that meets the requirements of this section, and which is sufficiently large enough to ensure that the water system can collect the number of lead and copper tap samples required in subsection 10.7 .3. All sites from which first draw samples are collected shall be selected from this pool of targeted sampling sites. Sampling sites may not include faucets that have point-of-use or point-of-entry treatment devices designed to remove inorganic contaminants.

10.7.1.2 A water system shall use the information on lead, copper, and galvanized steel that is required to collect under subsection 11.1.4 of these regulations (special monitoring for corrosivity characteristics) when conducting a materials evaluation. When an evaluation of the information collected pursuant to subsection 11.1.4 is insufficient to locate the requisite number of lead and copper sampling sites that meet the targeting criteria in subsection 10.7.1, the water system shall review the sources of information listed below in order to identify a sufficient number of sampling sites. In addition, the system shall seek to collect such information where possible in the course of its normal operations (e.g., checking service line materials when reading water meters or performing maintenance activities):

10.7.1.2.1 All plumbing codes, permits, and records in the files of the building department(s) which indicate the plumbing materials that are installed within publicly and privately owned structures connected to the distribution system;

10.7.1.2.2 All inspections and records of the distribution system that indicate the material composition of the service connections that connect a structure to the distribution system; and

10.7.1.2.3 All existing water quality information, which includes the results of all prior analyses of the system or individual structures connected to the system, indicating locations that may be particularly susceptible to high lead or copper concentrations.

10.7.1.3 The sampling sites selected for a community water system's sampling pool ("tier 1 sampling sites") shall consist of single family structures that:

10.7.1.3.1 Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or

10.7.1.3.2 Are served by a lead service line. When multiple-family residences comprise at least 20 percent of the structures served by a water system, the system may include these types of structures in its sampling pool.

10.7.1.4 Any community water system with insufficient tier 1 sampling sites shall complete its sampling pool with "tier 2 sampling sites", consisting of buildings, including multiple-family residences that:

10.7.1.4.1 Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or

10.7.1.4.2 Are served by a lead service line.

10.7.1.5 Any community water system with insufficient tier 1 and tier 2 sampling sites shall complete its sampling pool with "tier 3 sampling sites", consisting of single family structures that contain copper pipes with lead solder installed before 1983. A community water system with insufficient tier 1, tier 2, and tier 3 sampling sites shall complete its sampling pool with representative sites throughout the distribution system. For the purpose of this paragraph, a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the system.

10.7.1.6 The sampling sites selected for a non-transient non-community water system ("tier 1 sampling sites") shall consist of buildings that:

10.7.1.6.1 Contain copper pipes with lead solder installed after 1982 or contain lead pipes; and/or

10.7.1.6.2 Are served by a lead service line.

10.7.1.7 A non-transient non-community water system with insufficient tier 1 sites that meet the targeting criteria in subsection 10.7.1.6 shall complete its sampling pool with tier 2 sampling sites that contain copper pipes with lead solder installed before 1983. If additional sites are needed to complete the sampling pool, the non-transient non-community water system shall use representative sites throughout the distribution system. For the purpose of this paragraph, a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the water system.

10.7.1.8 Any water system whose distribution system contains lead service lines shall draw 50 percent of the samples it collects during each monitoring period from sites that contain lead pipes, or copper pipes with lead solder, and 50 percent of those samples from sites served by a lead service line. A water system that cannot identify a sufficient number of sampling sites served by a lead service line shall collect first-draw samples from all of the sites identified as being served by such lines.

10.7.2 Sample Collection Methods:

10.7.2.1 All tap samples for lead and copper collected in accordance with this section, with the exception of lead service line samples collected under subsection 10.5.3 and samples collected under subsection 10.7.2.5, shall be first draw samples.

10.7.2.2 Each first-draw tap sample for lead and copper shall be one liter in volume and have stood motionless in the plumbing system of each sampling site for at least six hours. First-draw samples from residential housing shall be collected from the cold-water kitchen tap or bathroom sink tap. First-draw samples from a non-residential building shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. Non-first-draw samples collected in lieu of first-draw samples pursuant to subsection 10.7.2.5 shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. First-draw samples may be collected by the system or the system may allow residents to collect first-draw samples after instructing the residents of the sampling procedures specified in this paragraph. To avoid problems of residents handling nitric acid, acidification of first-draw samples may be done up to 14 days after the sample is collected. After acidification to resolubilize the metals, the sample must stand in the original container for the time specified in the approved EPA method before the sample can be analyzed. If a system allows residents to perform sampling, the system may not challenge, based on the alleged errors in sample collection, the accuracy of sampling results.

10.7.2.3 Each service line sample shall be one liter in volume and have stood motionless in the lead service line for at least six hours. Lead service line samples shall be collected in one of the following three ways:

10.7.2.3.1 At the tap after flushing the volume of water between the tap and the lead service line. The volume of water shall be calculated based on the interior diameter and length of the pipe between the tap and the lead service line;

10.7.2.3.2 Tapping directly into the lead service line; or

10.7.2.3.3 If the sampling site is a building constructed as a single-family residence, allowing the water to run until there is a significant change in temperature which would be indicative of water that has been standing in the lead service line.

10.7.2.4 A water system shall collect each first-draw tap sample from the same sampling site from which it collected a previous sample. If, for any reason, the water system cannot gain entry to a sampling site in order to collect a follow-up tap sample, the system may collect the follow-up tap sample from the pool as long as the new site meets the same targeting criteria, and is within reasonable proximity of the original site.

10.7.2.5 A non-transient non-community water system, or a community water system that meets the criteria of subsection 10.6 .2.7 that does not have enough taps that can supply first-draw samples as defined in subsection 10.7.2.2, may apply to the Division in writing to substitute non-first-draw samples. Such systems must collect as many first-draw samples from appropriate taps as possible and identify sampling times and locations that would likely result in the longest standing time for the remaining sites. The Division has the discretion to waive the requirement for prior Division approval of non-first-draw sample sites selected by the system, either through regulation or written notification to the system.

10.7.2.6 Invalidation of lead and copper tap samples. A sample invalidated under this paragraph does not count toward determining lead or copper 90th percentile levels under subsection 10.1.3.3 or toward the minimum monitoring requirements of subsection 10.7.3.

10.7.2.6.1 The Division may invalidate a lead or copper tap sample at least if one of the following conditions is met.

10.7.2.6.1.1 The laboratory establishes that improper sample analysis caused erroneous results.

10.7.2.6.1.2 The Division determines that the sample was taken from a site that did not meet the site selection criteria of this section.

10.7.2.6.1.3 The sample container was damaged in transit.

10.7.2.6.1.4 There is substantial reason to believe that the sample was subject to tampering.

10.7.2.6.2 The system must report the results of all samples to the Division and all supporting documentation for samples the systems believes should be invalidated.

10.7.2.6.3 To invalidate a sample under subsection 10.7.2.6.1 the decision and the rationale for the decision must be documented in writing. The Division may not invalidate a sample solely on the grounds that a follow-up sample result is higher or lower than that of the original sample.

10.7.2.6.4 The system must collect replacement samples for any samples invalidated under this section if, after the invalidation of one or more samples, the system has too few samples to meet the minimum requirements of subsection 10.7.3. Any such replacement samples must be taken as soon as possible, but no later than 20 days after the date the Division invalidates the sample or by the end of the applicable monitoring period, whichever occurs later. Replacement samples taken after the end of the applicable monitoring period shall not also be used to meet the monitoring requirements of a subsequent monitoring period. The replacement samples shall be taken at the same locations as the invalidated samples or, if that is not possible, at locations other than those already used for sampling during the monitoring period.

10.7.3 Number of Samples: Water systems shall collect at least one sample during each monitoring period specified in subsection 10.7.4 from the number of sites listed in the second column below ("standard monitoring"). A system conducting reduced monitoring under subsection 10.7.4.4 shall collect one sample from the number of sites specified in the third column ("reduced monitoring") below during each monitoring period specified in subsection 10.7.4.4. Such reduced monitoring sites shall be representative of the sites required for standard monitoring. A public water system that has fewer than five drinking water taps, that can be used for human consumption meeting the sample site criteria of subsection 10.7 .1 to reach the required number of sample sites listed in subsection 10.7.3, must collect at least one sample from each tap and then must collect additional samples from those taps on different days during the monitoring period to meet the required number of sites. Alternatively the Division may allow these public water systems to collect a number of samples less than the number of sites specified in subsection 10.7.3, provided that 100 percent of all taps that can be used for human consumption are sampled. The Division must approve this reduction of the minimum number of samples in writing based on a request from the system or onsite verification by the Division. The Division may specify sampling locations when a system is conducting reduced monitoring. The table is as follows:

System Size (No. people served)	No. of sites (Standard monitoring)	No. of sites (Reduced monitoring)
>100,000	100	50
10,001-100,000	60	30
3,301-10,000	40	20
501-3,300	20	10
101-500	10	5
<100	5	5

10.7.4 Timing of Monitoring:

10.7.4.1 Initial Tap Sampling: The first six-month monitoring period for small, medium-size and large systems shall begin on the following dates:

System Size (No. people served)	First six-month monitoring period begins on
>50,000	January 1, 1992
3,301-50,000	July 1, 1992
<3,300	July 1, 1993

10.7.4.1.1 All large systems shall monitor during two consecutive six-month periods.

10.7.4.1.2 All small and medium-size systems shall monitor during each six-month monitoring period until:

10.7.4.1.2.1 The system exceeds the lead or copper action level and is therefore required to implement the corrosion control treatment requirements under subsection 10.2 in which case the system shall continue monitoring in accordance with subsection 10.7.4.2, or

10.7.4.1.2.2 The system meets the lead and copper action levels during two consecutive six-month monitoring periods, in which case the system may reduce monitoring in accordance with subsection 10.7.4.4.

10.7.4.2 Monitoring after Installation of Corrosion Control and Source Water Treatment:

10.7.4.2.1 Any large system which installs optimal corrosion control treatment pursuant to subsection 10.2.4 Step 4 shall monitor during two consecutive six-month periods by the date specified in subsection 10.2.4 Step 5.

10.7.4.2.2 Any small or medium-size system which installs optimal corrosion control treatment pursuant to subsection 10.2 .5 Step 5 shall monitor during two consecutive six-month periods by the date specified in subsection 10.2.5 Step 6.

10.7.4.2.3 Any system which installs source water treatment pursuant to subsection 10.4.1 Step 3 shall monitor during two consecutive six-month periods by the date specified in subsection 10.4.1 Step 4.

10.7.4.3 Monitoring after Division specifies Water Quality Parameter Values for Optimal Corrosion Control: After the Division specifies the values for water quality control parameters under subsection 10.3.6, the system shall monitor during each subsequent six-month monitoring period, with the first monitoring period to begin on the date the Division specifies the optimal values under subsection 10.3.6.

10.7.4.4 Reduced Monitoring:

10.7.4.4.1 A small or medium-size water system that meets the lead and copper action levels during each of two consecutive six-month monitoring periods may reduce the number of samples in accordance with subsection 10.7.3, and reduce the frequency of sampling to once per year. A small or medium water system collecting fewer than five samples as specified in subsection 10.7.3, that meets the lead and copper action levels during each of two consecutive six-month monitoring periods may reduce the frequency of sampling to once per year. In no case can the system reduce the number of samples required below the minimum of one sample per available tap. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period.

10.7.4.4.2 Any water system that meets the lead action level and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the Division under subsection 10.3.6 during each of two consecutive six-month monitoring periods may reduce the frequency of monitoring to once per year and to reduce the number of lead and copper samples in accordance with subsection 10.7.3 if it receives written approval from the Division. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period. The Division shall review monitoring, treatment and other relevant information submitted by the water system in accordance with subsection 10.10, and shall notify the system in writing when it determines the system is eligible to commence reduced monitoring pursuant to this paragraph. The Division shall review, and where appropriate, revise its determination when the system submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available.

10.7.4.4.3 A small or medium-size water system that meets the lead and copper action levels during three consecutive years of monitoring may reduce the frequency of monitoring for lead and copper from annually to once every three years. Any water system that meets the lead action level and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the Division under subsection 10.3.6 during three consecutive years of monitoring may reduce the frequency of monitoring from annually to once every three years if it receives written approval from the Division. Samples collected once every three years shall be collected no later than every third calendar year. The Division shall review monitoring, treatment and other relevant information submitted by the water system in accordance with subsection 10.10 and shall notify the system in writing when it determines the system is eligible to reduce the frequency of monitoring to once every three years. The Division shall review, and where appropriate, revise its determination when the system submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available.

10.7.4.4.4 A water system that reduces the number and frequency of sampling shall collect these samples from sites included in the pool of targeted sampling sites identified in subsection 10.7 .1. Systems sampling annually or less frequently shall conduct the lead and copper tap sampling during the months of June, July, August or September unless the Division has approved a different sampling period in accordance with subsection 10.7.4.4.4.1.

10.7.4.4.4.1 The Division, at its discretion, may approve a different period for conducting the lead and copper tap sampling for systems collecting a reduced number of samples. Such a period shall be no longer than four consecutive months and must represent a time of normal operation where the highest levels of lead are most likely to occur. For a non-transient non-community water system that does not operate during the months of June through September, and for which the period of normal operation where the highest levels of lead are most likely to occur is not known, the Division shall designate a period that represents a time of normal operation for the system. This sampling shall begin during the period approved or designated by the Division in the calendar year immediately following the end of the second consecutive six-month monitoring period for systems initiating annual monitoring and during the three-year period following the end of the third consecutive calendar year of annual monitoring for systems initiating triennial monitoring.

10.7.4.4.4.2 Systems monitoring annually, that have been collecting samples during the months of June through September and that receive Division approval to alter their sample collection period under subsection 10.7.4.4.4.1, must collect their next round of samples during a time period that ends no later than 21 months after the previous round of sampling. Systems monitoring triennially that have been collecting samples during the months of June through September, and receive Division approval to alter the sampling collection period as per subsection 10.7.4.4.4.1, must collect their next round of samples during a time period that ends no later than 45 months after the previous round of sampling. Subsequent rounds of sampling must be collected annually or triennially, as required by this subsection. Small systems with waivers, granted pursuant to subsection 10.7.6, that have been collecting samples during the months of June through September and receive Division approval to alter their sample collection period under subsection 10.7.4.4.4.1 must collect their next round of samples before the end of the 9-year period.

10.7.4.4.5 Any water system that demonstrates for two consecutive 6-month monitoring periods that the tap water lead level computed under subsection 10.1.3.3 is less than or equal to 0.005 mg/L and the tap water copper level computed under subsection 10.1.3.3 is less than or equal to 0.65 mg/L may reduce the number of samples in accordance with subsection 10.7.3 and reduce the frequency of sampling to once every three calendar years.

10.7.4.4.6 Return to standard monitoring after failure to meet action levels or operate within specified water quality parameters.

10.7.4.4.6.1 A small or medium-size water system subject to reduced monitoring that exceeds the lead or copper action levels shall resume sampling in accordance with subsection 10.1.3.3 and collect the number of samples specified for standard monitoring under subsection 10.7.3. Such a system shall also conduct water quality parameter monitoring in accordance with subsections 10.8.2, 10.8.3 or 10.8.4 (as appropriate) during the monitoring period in which it exceeded the action level. Any such system may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in subsection 10.7.3 after it has completed two subsequent consecutive 6-month rounds of monitoring that meet the requirements of subsection 10.7.4.4.1 and/or may resume triennial monitoring for lead and copper at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either subsection 10.7.4.4.3 or 10.7.4.4.5.

10.7.4.4.6.2 Any water system subject to reduced monitoring frequency that fails to meet the lead action level during any four-month monitoring period or that fails to operate at or above the minimum value or within the range of values for the water quality control parameters specified by the Division under subsection 10.3.6 for more than nine days in any 6-month period specified in subsection 10.8.4 shall conduct tap water sampling for lead and copper at the frequency specified in subsection 10.7.4.3, collect the number of samples specified for standard monitoring under subsection 10.7.3, and shall resume monitoring for water quality parameters within the distribution system in accordance with subsection 10.8 .4. This standard tap water sampling shall begin no later than the six-month period beginning January 1 of the calendar year following the lead action level exceedance or water quality parameter excursion. Such a system may resume reduced monitoring for lead and copper at the tap and for water quality parameters within the distribution system under the following conditions:

10.7.4.4.6.2.1 The system may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in subsection 10.7.3 after it has completed two subsequent 6-month rounds of monitoring that meet the criteria of subsection 10.7.4.4.2 and the system has received written approval from the Division that it is appropriate to resume reduced monitoring on the annual frequency. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period.

10.7.4.4.6.2.2 The system may resume triennial monitoring for lead and copper at the tap at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either subsections 10.7.4.4.3 or 10.7.4.4.5 and the system has received written approval from the Division that it is appropriate to resume triennial monitoring.

10.7.4.4.6.2.3 The system may reduce the number of water quality parameter tap water samples required in accordance with subsection 10.8.5.1 and the frequency with which it collects such samples in accordance with subsection 10.8.5.2. Such a system may not resume triennial monitoring for water quality parameters at the tap until it demonstrates, in accordance with the requirements of subsection 10.8.5.2, that it has re-qualified for triennial monitoring.

10.7.4.4.7 Any water system subject to a reduced monitoring frequency under subsection 10.7.4.4 shall notify the Division in writing in accordance with subsection 10.10.1.3 of any upcoming long-term change in treatment or addition of a new source as described in that section. The Division 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. The Division may require the system to resume sampling in accordance with subsection 10.7.4.3 and collect the number of samples specified for standard monitoring under subsection 10.7.3 or take other appropriate steps such as increased water quality parameter monitoring or re-evaluation of its corrosion control treatment given the potentially different water quality considerations.

10.7.5 Additional Monitoring by Systems: The results of any monitoring conducted in addition to the minimum requirements of this subsection shall be considered by the system and the Division in making any determinations (i.e., calculating the 90th percentile lead or copper level) under this section.

10.7.6 Monitoring Waivers for Small Systems: Any small system that meets the criteria of this paragraph may apply to the Division to reduce the frequency of monitoring for lead and copper under this section to once every nine years (i.e., a "full waiver") if it meets all of the materials criteria specified in section 10.7.6.1 and all of the monitoring criteria specified in subsection 10.7.6.2. If Division regulations permit, any small system that meets the criteria in subsections 10.7.6.1 and 10.7.6.2 only for lead, or only for copper, may apply to the Division for a waiver to reduce the frequency of tap water monitoring to once every nine years for that contaminant only (i.e., a "partial waiver").

10.7.6.1 Materials Criteria: The system must demonstrate that its distribution system and service lines and all drinking water supply plumbing, including plumbing conveying drinking water within all residences and buildings connected to the system, are free of lead-containing materials and/or copper-containing materials, as those terms are defined in this paragraph, as follows:

10.7.6.1.1 Lead. To qualify for a full waiver, or a waiver of the tap water monitoring requirements for lead (i.e., a "lead waiver"), the water system must provide certification and supporting documentation to the Division that the system is free of all lead-containing materials as follows:

10.7.6.1.1.1 It contains no plastic pipe which contain lead plasticizers, or plastic service lines which contain lead plasticizers; and

10.7.6.1.1.2 It is free of lead service lines, lead pipes, lead soldered pipe joints, and leaded brass or bronze alloy fittings and fixtures, unless such fittings and fixtures meet the specifications of any standard established pursuant to 42 U.S.C. 300g- 6(e) (Safe Drinking Water Act section 1417(e)).

10.7.6.1.2 Copper. To qualify for a full waiver, or a waiver of the tap water monitoring requirements for copper (i.e., a "copper waiver"), the water system must provide certification and supporting documentation to the Division that the system contains no copper pipes or copper service lines.

10.7.6.2 Monitoring Criteria for Waiver Issuance: The system must have completed at least one six-month round of standard tap water monitoring for lead and copper at sites approved by the Division and from the number of sites required by subsection 10.7.3 and demonstrate that the 90th percentile levels for any and all rounds of monitoring conducted since the system became free of all lead-containing and/or copper-containing materials, as appropriate, meet the following criteria.

10.7.6.2.1 Lead levels. To qualify for a full waiver, or a lead waiver, the system must demonstrate that the 90th percentile lead level does not exceed 0.005 mg/L.

10.7.6.2.2 Copper levels. To qualify for a full waiver, or a copper waiver, the system must demonstrate that the 90th percentile copper level does not exceed 0.65 mg/L.

10.7.6.3 Division Approval of Waiver Application: The Division shall notify the system of its waiver determination, in writing, setting forth the basis of its decision and any condition of the waiver. As a condition of the waiver, the Division may require the system to perform specific activities (e.g., limited monitoring, periodic outreach to customers to remind them to avoid installation of materials that void the waiver) to avoid the risk of lead or copper concentration of concern in tap water. The small system must continue monitoring for lead and copper at the tap as required by subsections 10.7.4.1 through 10.7.4.4, as appropriate, until it receives written notification from the Division that the waiver has been approved.

10.7.6.4 Monitoring frequency for systems with waivers.

10.7.6.4.1 A system with a full waiver must conduct tap water monitoring for lead and copper in accordance with subsection 10.7.4.4.4 at the reduced number of sampling sites identified in subsection 10.7.3 at least once every nine years and provide the materials certification specified in subsection 10.7.6.1 for both lead and copper to the Division along with the monitoring results. Samples collected every nine years shall be collected no later than every ninth calendar year.

10.7.6.4.2 A system with a partial waiver must conduct tap water monitoring for the waived contaminant in accordance with subsection 10.4.4.4 at the reduced number of sample sites specified in subsection 10.7.3 at least once every nine years and provide the materials certification specified in subsection 10.7.6.1 pertaining to the waived contaminant along with the monitoring results. Such a system also must continue to monitor for the non-waived contaminant in accordance with subsections 10.7 .4.1 through 10.7.4.4, as appropriate.

10.7.6.4.3 Any water system with a full or partial waiver shall notify the Division in writing in accordance with subsection 10.10.1.3 of any upcoming long-term change in treatment or addition of a new source, as described in that subsection. The Division 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. The Division has the authority to require the system to modify waiver conditions (e.g., require re-certification that the system is free of lead-containing and/or copper-containing materials or require additional round(s) of monitoring), if it deems such modifications are necessary to address treatment or source water changes at the system.

10.7.6.4.4 If a system with a full or partial waiver becomes aware that it is no longer free of lead-containing or copper-containing materials, as appropriate, (e.g., as a result of new construction or repairs), the system shall notify the Division in writing no later than 60 days after becoming aware of such a change.

10.7.6.5 Continued Eligibility: If the system continues to satisfy the requirements of subsection 10.7.6.4, the waiver will be renewed automatically, unless any of the conditions listed in subsections 10.7.6.5.1 through 10.7.6.5.3 occurs. A system whose waiver has been revoked may re-apply for a waiver at such time as it again meets the appropriate materials and monitoring criteria of subsections 10.7.6.1 and 10.7.6.2.

10.7.6.5.1 A system with a full waiver or a lead waiver no longer satisfies the materials criteria of subsection 10.7.6.1.1 or has a 90th percentile level greater than 0.005 mg/L.

10.7.6.5.2 A system with a full waiver or a copper waiver no longer satisfies the materials criteria of subsection 10.7.6.1.2 or has a 90th percentile copper level greater than 0.65 mg/L.

10.7.6.5.3 The Division notifies the system, in writing, that the waiver has been revoked, setting forth the basis of its decision.

10.7.6.6 Requirements Following Waiver Revocation: A system whose full or partial waiver has been revoked by the Division is subject to the corrosion control treatment and lead and copper tap water monitoring requirements, as follows:

10.7.6.6.1 If the system exceeds the lead and/or copper action level, the system must implement corrosion control treatment in accordance with the deadlines specified in subsection 10.2.5, and any other applicable requirements of this subsection.

10.7.6.6.2 If the system meets both the lead and copper action level, the system must monitor for lead and copper at the tap no less frequently than once every three years using the reduced number of sample sites specified in subsection 10.7.3.

10.7.6.7 Pre-existing Waivers: Small system waivers approved by the Division in writing prior to April 11, 2000 shall remain in effect under the following conditions:

10.7.6.7.1 If the system has demonstrated that it is both free of lead-containing and copper-containing materials, as required by subsection 10.7.6.1 and that its 90th percentile lead levels and 90th percentile copper levels meet the criteria of subsection 10.7.6.2, the waiver remains in effect so long as the system continues to meet the waiver eligibility criteria of subsection 10.7.6.5. The first round of tap monitoring conducted pursuant to subsection 10.7.6.4 shall be completed no later than nine years after the last time the system has monitored for lead and copper at the tap.

10.7.6.7.2 If the system has met the materials criteria of subsection 10.7.6.1 but has not met the monitoring criteria of subsection 10.7.6.2, the system shall conduct a round of monitoring for lead and copper at the tap demonstrating that it meets the criteria of subsection 10.7.6.2, no later than September 30, 2003. Thereafter, the waiver shall remain in effect as long as the system meets the continued eligibility criteria of subsection 10.7.6.5. The first round of tap water monitoring conducted pursuant to subsection 10.7.6.4 shall be completed no later than nine years after the round of monitoring conducted pursuant to subsection 10.7.6.2.

10.8 Monitoring Requirements for Water Quality Parameters: All large water systems and all small and medium-size systems that exceed the lead or copper action level shall monitor water quality parameters in addition to lead and copper in accordance with this subsection. The requirements of this section are summarized in the table at the end of this section.

10.8.1 General Requirements:

10.8.1.1 Sample Collection Methods:

10.8.1.1.1 Tap samples shall be representative of water quality throughout the distribution system taking into account the number of persons served, the different sources of water, the different treatment methods employed by the system, and seasonal variability. Tap sampling under this section is not required to be conducted at taps targeted for lead and copper sampling under subsection 10.7.1. (NOTE: Systems may find it convenient to conduct tap sampling for water quality parameters at sites used for coliform sampling under Section 5.0.)

10.8.1.1.2 Samples collected at the entry point(s) to the distribution system shall be from locations representative of each source after treatment. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

10.8.1.2 Number of Samples:

10.8.1.2.1 Systems shall collect two tap samples for applicable water quality parameters during each monitoring period specified under subsections 10.8.2 and 10.8.5 from the following number of sites:

System Size (No. people served)	No. sites for water quality parameters
>100,000	25
10,001-100,000	10
3,301-10,000	3
501-3,300	2
101-500	1
<100	1

10.8.1.2.2 Except as provided in subsection 10.8.3.3, systems shall collect two samples for each applicable water quality parameter at each entry point to the distribution system during each monitoring period specified in subsection 10.8.2. During each monitoring period specified in subsections 10.8.3 through 10.8.5, systems shall collect one sample for each applicable water quality parameter at each entry point to the distribution system.

10.8.2 Initial Sampling: All large water systems shall measure the applicable water quality parameters as specified below at taps and at each entry point to the distribution system during each six-month monitoring period specified in subsection 10.7.4.1. All small and medium-size systems shall measure the applicable water quality parameters at the locations specified below during each six-month monitoring period specified in subsection 10.7.4.1 during which the system exceeds the lead or copper action levels.

10.8.2.1 At taps:

pH;

Alkalinity;

Orthophosphate, when an inhibitor containing a phosphate compound is used;

Silica, when an inhibitor containing a silicate compound is used;

Calcium;

Conductivity; and

Water Temperature.

10.8.2.2 At each entry point to the distribution system, all of the applicable parameters listed in subsection 10.8 .2.1.

10.8.3 Monitoring after Installation of Corrosion Control: Any large system which installs optimal corrosion control treatment pursuant to subsection 10.2.4 Step 4 shall measure the water quality parameters at the locations and frequencies specified below during each six-month monitoring period specified in subsection 10.7 .4.2.1. Any small or medium-size system which installs optimal corrosion control treatment shall conduct such monitoring during each six-month monitoring period specified in subsection 10.7.4.2.2 in which the system exceeds the lead or copper action level.

10.8.3.1 At taps two samples for:

pH;

Alkalinity;

Orthophosphate, when an inhibitor containing a phosphate compound is used;

Silica, when an inhibitor containing a silicate compound is used;

Calcium, when calcium carbonate stabilization is used as part of corrosion control.

10.8.3.2 Except as provided in subsection 10.8.3.3 at each entry point to the distribution system, one sample every two weeks (bi-weekly) for:

pH;

When alkalinity is adjusted as part of optimal corrosion control, a reading of the dosage rate of the chemical used to adjust alkalinity, and the alkalinity concentration; and

When a corrosion inhibitor is used as part of optimal corrosion control, a reading of the dosage rate of the inhibitor used, and the concentration of orthophosphate or silica (whichever is applicable).

10.8.3.3 Any groundwater system can limit entry point sampling described in subsection 10.8.3.2 to those entry points that are representative of water quality and treatment conditions throughout the system. If water from untreated groundwater sources mixes with water from treated groundwater sources, the system must monitor for water quality parameters both at representative entry points receiving treatment and representative points receiving no treatment. Prior to the start of any monitoring under this paragraph, the system shall provide to the Division written information identifying the selected entry points and documentation, including information on seasonal variability, sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

10.8.4 Monitoring after Division Specifies Water Quality Parameter Values for Optimal Corrosion Control: After the Division specifies the values for applicable water quality control parameters reflecting optimal corrosion control treatment under subsection 10.3.6, all large systems shall measure the applicable water quality parameters in accordance with subsection 10.8.3 and determine compliance with the requirements of subsection 10.3.7 every six months with the first six-month period to begin on either January 1 or July 1, whichever comes first, after the Division specifies the optimal values under subsection 10.3.6. Any small or medium-size system shall conduct such monitoring during each six-month period specified in this paragraph in which the system exceeds the lead or copper action level. For any such small and medium-size system that is subject to a reduced monitoring frequency pursuant to subsection 10.7.4.4 at the time of the action level exceedance, the start of the applicable six-month period under this paragraph shall coincide with the start of the applicable monitoring period under subsection 10.7.4.4. Compliance with the Division-designated optimal water quality parameter values shall be determined as specified under subsection 10.3.7.

10.8.5 Reduced Monitoring:

10.8.5.1 Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment during each of two consecutive six-month monitoring periods under subsection 10.8.4 shall continue monitoring at the entry point(s) to the distribution system as specified in subsection 10.8.3.2. Such system may collect two tap samples for applicable water quality parameters from the following reduced number of sites during each six-month monitoring period.

System Size (No. people served)	Reduced no. of sites for water quality parameters
>100,000	10
10,001-100,000	7
3,301-10,000	3
501-3,300	2
101-500	1
<100	1

10.8.5.2 Frequency of monitoring

10.8.5.2.1 Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Division under subsection 10.3.6 during three consecutive years of monitoring may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in subsection 10.8.5.1 from every six months to annually. This sampling begins during the calendar year immediately following the end of the monitoring period in which the third consecutive year of six-month monitoring occurs. Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Division under subsection 10.3.6, during three consecutive years of annual monitoring under this paragraph may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in subsection 10.8.5.1 from annually to every three years. This sampling begins no later than the third calendar year following the end of the monitoring period in which the third consecutive year of monitoring occurs.

10.8.5.2.2 A water system may reduce the frequency with which it collects tap samples for applicable water quality parameters specified in subsection 10.8.5.1 to every three years if it demonstrates during two consecutive monitoring periods that its tap water lead level at the 90th percentile is less than or equal to the PQL (Practical Quantitation Level) for lead specified in subsection 10.12, that its tap water copper level at the 90th percentile is less than or equal to 0.65 mg/L for copper in subsection 10.1.3.2, and that it also has maintained the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Division under subsection 10.3.6. Monitoring conducted every three years shall be done no later than every third calendar year.

10.8.5.3 A water system that conducts sampling annually shall collect these samples evenly throughout the year so as to reflect seasonal variability.

10.8.5.4 Any water system subject to reduced monitoring frequency that fails to operate within the range of values for the water quality parameters specified by the Division under subsection 10.3.6 for more than nine days in any six-month period specified in subsection 10.3.7 shall resume distribution system tap water sampling in accordance with the number and frequency requirements in subsection 10.8.4. Such a system may resume annual monitoring for water quality parameters at the tap at the reduced number of sites specified in subsection 10.8.5.1 after it has completed two subsequent consecutive six-month rounds of monitoring that meet the criteria of that section and/or may resume triennial monitoring for water quality parameters at the tap at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either subsections 10.8.5.2.1 or 10.8.5.2.2.

10.8.6 Additional Monitoring by Systems: The results of any monitoring conducted in addition to the minimum requirements of this section shall be considered by the system and the Division in making any determinations (i.e., determining concentrations of water quality parameters) under this section or subsection 10.3.

Summary of monitoring requirements for water quality parameters¹

Monitoring	Parameters2	Location	Frequency
Initial monitoring	pH, alkalinity, orthophosphate or silica3, calcium, conductivity, temperature	Taps and at entry point(s) to the distribution system.	Every 6 months.
After installation of corrosion control	pH, alkalinity, orthophosphate or silica3, calcium4. pH, alkalinity, dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5.	Taps Entry point(s) to the distribution system6.	Every 6 months. No less frequently than every two weeks.
After the Division specifies parameter values for optimal corrosion control.	pH, alkalinity, orthophosphate or silica3, calcium4. pH, alkalinity, dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5.	Taps Entry point(s) to the distribution system6.	Every 6 months. No less frequently than every two weeks.
Reduced monitoring	pH, alkalinity, orthophosphate or silica3, calcium4. pH, alkalinity, dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5.	Taps Entry point(s) to the distribution system6.	Every 6 months, annually7 or every 3 years8; at reduced number of sites. No less frequently than every two weeks.

¹ Table is for illustrative purposes; consult the text of this section for precise regulatory requirements.

² Small and medium-size systems have to monitor for water quality parameters only during monitoring periods in which the system exceeds the lead or copper action level.

³ Orthophosphate must be measured only when an inhibitor containing a phosphate compound is used. Silica must be measured only when an inhibitor containing silicate compound is used.

⁴ Calcium must be measured only when calcium carbonate stabilization is used as part of corrosion control.

⁵ Inhibitor dosage rates and inhibitor residual concentrations (orthophosphate or silica) must be measured only when an inhibitor is used.

⁶ Groundwater systems may limit monitoring to representative locations throughout the system.

⁷ Water systems may reduce frequency of monitoring for water quality parameters at the tap from every 6 months to annually if they have maintained the range of values for water quality parameters reflecting optimal corrosion control during three consecutive years of monitoring.

⁸ Water systems may further reduce the frequency of monitoring for water quality parameters at the tap from annually to once every three years if they have maintained the range of values for water quality parameters reflecting optimal corrosion control during three consecutive years of annual monitoring. Water systems may accelerate to triennial monitoring for water quality parameters at the tap if they have maintained 90th percentile lead levels less than or equal to 0.005 mg/L, 90th percentile copper levels less than or equal to 0.65 mg/L, and the range of water quality parameters designated by the Division under subsection 10.3.6 as representing optimal corrosion control during two consecutive six-month monitoring periods.

10.9 Monitoring Requirements for Lead and Copper in Source Water:

10.9.1 Sample Location Collection Methods, and Number of samples:

10.9.1.1 A water system that fails to meet the lead or copper action level on the basis of tap samples collected in accordance with subsection 10.7 shall collect lead and copper source water samples in accordance with the requirements regarding sample location, number of samples, and collection methods:

10.9.1.1.1 Groundwater systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each well after treatment (hereafter called a sampling point). The system shall take one sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant.

10.9.1.1.2 Surface water systems shall take a minimum of one sample at every entry point to the distribution system after any application of treatment or in the distribution system at a point which is representative of each source after treatment (hereafter called a sampling point). The system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. NOTE: For the purpose of this paragraph, surface water systems include systems with a combination of surface and groundwater sources.

10.9.1.1.3 If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

10.9.1.1.4 The Division may reduce the total number of samples which must be analyzed by allowing the use of compositing. Compositing of samples must be done by certified laboratory personnel. Composite samples from a maximum of five samples are allowed, provided that if the lead concentration in the composite sample is greater than or equal to 0.001 mg/L or the copper concentration is greater than or equal to 0.160 mg/L, then either:

10.9.1.1.4.1 A follow-up sample shall be taken and analyzed within 14 days at each sampling point included in the composite; or

10.9.1.1.4.2 If duplicates of or sufficient quantities from the original samples from each sampling point used in the composite are available, the system may use these instead of resampling.

10.9.1.2 Where the results of sampling indicate an exceedance of maximum permissible source water levels established under subsection 10.4.2.4, the Division may require that one additional sample be collected as soon as possible after the initial sample was taken (but not to exceed two weeks) at the same sampling point. If a Division-required confirmation sample is taken for lead or copper, then the results of the initial and confirmation sample shall be averaged in determining compliance with the Division-specified maximum permissible levels. Any sample value below the detection limit shall be considered to be zero. Any value above the detection limit but below the PQL shall either be considered as the measure value or be considered one-half the PQL.

10.9.2 Monitoring Frequency after System Exceeds Tap Water Action Level: Any system which exceeds the lead or copper action level at the tap shall collect one source water sample from each entry point to the distribution system within six months after the end of the monitoring period during which the lead or copper action level was exceeded. For monitoring periods that are annual or less frequent, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or if the Division has established an alternate monitoring period, the last day of that period.

10.9.3 Monitoring Frequency after Installation of Source Water Treatment: Any system which installs source water treatment pursuant to subsection 10.4.1 Step 3 shall collect an additional source water sample from each entry point to the distribution system during two consecutive six-month monitoring periods by the deadline specified in subsection 10.4.1 Step 4.

10.9.4 Monitoring Frequency after Division Specifies Maximum Permissible Source Water Levels or Determines that Source Water Treatment is not Needed:

10.9.4.1 A system shall monitor at the frequency specified below in cases where the Division specifies maximum permissible source water levels under subsection 10.4.2.4 or determines that the system is not required to install source water treatment under subsection 10.4.2.2.

10.9.4.1.1 A water system using only groundwater shall collect samples once during the three-year compliance period (as that term is defined in section 1.0) in effect when the applicable Division determination under section 10.9.4.1 is made. Such systems shall collect samples once during each subsequent compliance period. Triennial samples shall be collected every third calendar year.

10.9.4.1.2 A water system using surface water (or a combination of surface and groundwater) shall collect samples once during each calendar year, the first annual monitoring period to begin during the year in which the applicable Division determination is made under subsection 10.9 .4.1.

10.9.4.2 A system is not required to conduct source water sampling for lead and/or copper if the system meets the action level for the specific contaminant in tap water samples during the entire source water sampling period applicable to the system under subsection 10.9.4.1.1 or 10.9.4.1.2.

10.9.5 Reduced Monitoring Frequency:

10.9.5.1 A water system using only groundwater may reduce the monitoring frequency for lead and copper in source water to once during each nine-year compliance cycle (as that term is defined in section 1.0) provided that the samples are collected no later than every ninth calendar year and if the system meets one of the following criteria:

10.9.5.1.1 The system demonstrates that finished drinking water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the Division in subsection 10.4.2.4 during at least three consecutive compliance periods under subsection 10.9.4.1; or

10.9.5.1.2 The Division has determined that source water treatment is not needed and the system demonstrates that, during at least three consecutive compliance periods in which sampling was conducted under subsection 10.9.4.1, the concentration of lead in source water was less than or equal to 0.005 mg/L and the concentration of copper in source water was less than or equal to 0.65 mg/L.

10.9.5.2 A water system using surface water (or a combination of surface and ground water) may reduce the monitoring frequency in subsection 10.9.4.1 to once during each nine-year compliance cycle (as that term is defined in section 1.0) provided that the samples are collected no later than every ninth calendar year and if the system meets one of the following criteria:

10.9.5.2.1 The system demonstrates that finished drinking water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the Division in subsection 10.4.2.4 during at least three consecutive years; or

10.9.5.2.2 The Division has determined that source water treatment is not needed and the system demonstrates that, during at least three consecutive years, the concentration of lead in source water was less than or equal to 0.005 mg/L and the concentration of copper in source water was less than or equal to 0.65 mg/L.

10.9.5.3 A water system that uses a new source of water is not eligible for reduced monitoring for lead and/or copper until concentrations in samples collected from the new source during three consecutive monitoring periods are below the maximum permissible lead and copper concentrations specified by the Division in subsection 10.4.1 Step 5.

10.10 Reporting Requirements: All water systems shall report all of the following information to the Division in accordance with this section.

10.10.1 Reporting Requirements for Tap Water Monitoring for Lead and Copper and for Water Quality Parameter Monitoring:

10.10.1.1 Except as provided in subsection 10.10.1.1.8, a water system shall report the information specified below for all tap water samples specified in 10.7 and for all water quality parameter samples specified in subsection 10.8 within the first 10 days following the end of each applicable monitoring period specified in subsections 10.7, and 10.8, (i.e., every six-months, annually, every 3 years or every 9 years). For monitoring periods with a duration less than six months, the end of the monitoring period is the last date samples can be collected during the period specified in subsections 10.7 and 10.8.

10.10.1.1.1 The results of all tap samples for lead and copper including the location of each site and the criteria under subsections 10.7.1.3, 10.7.1.4, 10.7.1.5, 10.7.1.6 or 10.7.1.7 under which the site was selected for the system's sampling pool;

10.10.1.1.2 Documentation for each tap water lead or copper sample for which the water system requests invalidation pursuant to subsection 10.7.6.2;

10.10.1.1.3 Reserved

10.10.1.1.4 The 90th percentile lead and copper concentrations measured from among all lead and copper tap water samples collected during each monitoring period (calculated in accordance with subsection 10.1.1.3) unless the Division calculates the 90th percentile lead and copper levels under subsection 10.10.8;

10.10.1.1.5 With the exception of initial tap sampling conducted pursuant to subsection 10.7.4.1 the system shall designate any site which was not sampled during previous monitoring periods, and include an explanation of why sampling sites have changed;

10.10.1.1.6 The results of all tap samples for pH, and where applicable, alkalinity, calcium, conductivity, temperature, and orthophosphate or silica collected under subsections 10.8.2 through 10.8.5.

10.10.1.1.7 The results of all samples collected at the entry point(s) to the distribution system for applicable water quality parameters under subsections 10.8.2 through 10.8.5.

10.10.1.1.8 A water system shall report the results of all water quality parameter samples collected under subsections 10.8.3 through 10.8.6 during each six-month monitoring period specified in subsection 10.8.4 within the first ten days following the end of the monitoring period unless the Division has specified a more frequent reporting requirement.

10.10.1.2 For a non-transient non-community water system, or a community water system meeting the criteria of subsection 10.6.2.7, that does not have enough taps that can provide first-draw samples, the system must either:

10.10.1.2.1 Provide written documentation to the Division identifying standing times and locations for enough non-first-draw samples to make up its sampling pool under subsection 10.7.2.5 by the start of the first applicable monitoring period under subsection 10.7.4 that commences after April 11, 2000, unless the Division has waived prior Division approval of non-first-draw sample sites selected by the system pursuant to subsection 10.7.2.5; or

10.10.1.2.2 If the Division has waived prior approval of non-first-draw sample sites selected by the system, identify, in writing, each site that did not meet the six-hour minimum standing time and the length of standing time for that particular substitute sample collected pursuant to subsection 10.7.2.5 and include this information with the lead and copper tap sample results required to be submitted pursuant to subsection 10.10 .1.1.1.

10.10.1.3 At a time specified by the Division, or if no specific time is designated by the Division, then as early as possible prior to the addition of a new source or any long-term change in water treatment, a water system deemed to have optimized corrosion control under subsection 10.2.2.3, a water system subject to reduced monitoring pursuant to subsection 10.7.4.4, or a water system subject to a monitoring waiver pursuant to subsection 10.7.7, shall submit written documentation to the Division describing the change or addition. The Division must review and approve the addition of the new source or long-term change in treatment before it is implemented by the water system. Examples of long-term treatment changes include the addition of a new treatment process or modification of an existing treatment process. Examples of modifications include switching secondary disinfectants, switching coagulants (e.g., orthophosphate to blended phosphate), switching corrosion inhibitor products (e.g., alum to ferric chloride). Long-term changes can include dose changes to existing chemicals if the system is planning long-term changes to its finished pH or residual inhibitor concentration. Long-term treatment changes would not include chemical dose fluctuations associated with daily raw water quality changes.

10.10.1.4 Any small system applying for a monitoring waiver under subsection 10.7.6, or subject to a waiver granted pursuant to subsection 10.7.6.3, shall provide the following information to the Division in writing by the specified deadline:

10.10.1.4.1 By the start of the first applicable monitoring period in subsection 10.7.4, any small water system applying for a monitoring waiver shall provide the documentation required to demonstrate that it meets the waiver criteria of subsections 10.7.6.1 and 10.7.6.2.

10.10.1.4.2 No later than nine years after the monitoring previously conducted pursuant to subsection 10.7.6.2 or subsection 10.7.6.4.1, each small system desiring to maintain its monitoring waiver shall provide the information required by subsections 10.7 .6.4.1 and 10.7.6.4.2.

10.10.1.4.3 No later than 60 days after it becomes aware that it is no longer free of lead-containing and/or copper-containing material, as appropriate, each small system with a monitoring waiver shall provide written notification to the Division, setting forth the circumstances resulting in the lead-containing and/or copper-containing materials being introduced into the system and what corrective action, if any, the system plans to remove these materials.

10.10.1.4.4 By October 10, 2003, any small system with a waiver granted prior to April 11, 2000 and that has not previously met the requirements of subsection 10.7.6.2 shall provide the information required by that section.

10.10.1.5 Each groundwater system that limits water quality parameter monitoring to a subset of entry points under subsection 10.8.3.3 shall provide, by the commencement of such monitoring, written correspondence to the Division that identifies the selected entry points and includes the information sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

10.10.2 Source Water Monitoring Reporting Requirements:

10.10.2.1 A water system shall report the sampling results for all source water samples collected in accordance with subsection 10.9 within the first 10 days following the end of each source water monitoring period (i.e., annually, per compliance period, per compliance cycle) specified in subsection 10.9.

10.10.2.2 With the exception of the first round of source water sampling conducted pursuant to subsection 10.9.2, the system shall specify any site which was not sampled during previous monitoring periods, and include an explanation of why the sampling point has changed.

10.10.3 Corrosion Control Treatment Reporting Requirements: By the applicable dates under subsection 10.2, systems shall report the following information:

10.10.3.1 For systems demonstrating that they have already optimized corrosion control, information required in subsections 10.2.2.2 or 10.2.2.3;

10.10.3.2 For systems required to optimize corrosion control, their recommendation regarding optimal corrosion control treatment under subsections 10.3 .1;

10.10.3.3 For systems required to evaluate the effectiveness of corrosion control treatments under subsection 10.3.3, the information required by that paragraph; and

10.10.3.4 For systems required to install optimal corrosion control designated by the Division under subsection 10.3.4, a letter certifying that the system has completed installing that treatment.

10.10.4 Source Water Treatment Reporting Requirements: By the applicable dates in subsections 10.4, systems shall provide the following information to the Division:

10.10.4.1 If required under subsection 10.4.2.1 their recommendation regarding source water treatment; and

10.10.4.2 For systems required to install source water treatment under subsection 10.4.2.2, a letter certifying that the system has completed installing the treatment designated by the Division within 24 months after the Division designated the treatment.

10.10.5 Lead Service Line Replacement Reporting Requirements: Systems shall report the following information to the Division to demonstrate compliance with the requirements of subsection 10.5 :

10.10.5.1 No later than 12 months after the end of the monitoring period in which a system exceeds the lead action level in sampling referred to in subsection 10.5 .1, the system must submit written documentation to the Division of the material evaluation conducted as required in subsection 10.7.1, identify the initial number of lead service lines in its distribution system at the time the system exceeds the lead action level, and provide the system's schedule for annually replacing at least 7 percent of the initial number of lead service lines in its distribution system.

10.10.5.2 No later than 12 months after the end of the monitoring period in which a system exceeds the lead action level in sampling referred to in subsection 10.5.1, and every 12 months thereafter, the system shall demonstrate to the Division in writing that the system has either:

10.10.5.2.1 Replaced in the previous 12 months at least 7 percent of the initial lead service lines (or a greater number of lines specified by the Division under subsection 10.5.5 in its distribution system; or

10.10.5.2.2 Conducted sampling which demonstrates that the lead concentration in all service lines samples from an individual line(s), taken pursuant to subsection 10.7.2.3, is less than or equal to 0.015 mg/L. In such cases, the total number of lines replaced and/or which meet the criteria in subsection 10.5.3 shall equal at least 7 percent of the initial number of lead lines identified under subsection 10.10.5.1 (or the percentage specified by the Division under subsection 10.5.5.

10.10.5.3 The annual letter submitted to the Division under subsection 10.10.5.2 shall contain the following information:

10.10.5.3.1 The number of lead service lines scheduled to be replaced during the previous year of the system's replacement schedule;

10.10.5.3.2 The number and location of each lead service line replaced during the previous year of the system's replacement schedule; and

10.10.5.3.3 If measured, the water lead concentration and location of each lead service line sampled, the sampling method, and the date of sampling.

10.10.5.4 Any system which collects lead service line samples following partial lead service line replacement required by subsection 10.5 shall report the results to the Division within the first ten days of the month following the month in which the system receives the laboratory results, or as specified by the Division. The Division, at its discretion may eliminate this requirement to report these monitoring results. Systems shall also report any additional information as specified by the Division, and in a time and manner prescribed by the Division, to verify that all partial lead service line replacement activities have taken place.

10.10.6 Public Education Program Reporting Requirements:

10.10.6.1 Any water system that is subject to the public education requirements in subsection 10.6 shall, within ten days after the end of each period in which the system is required to perform public education tasks in accordance with subsection 10.6.2, send written documentation to the Division that contains:

10.10.6.1.1 A demonstration that the system has delivered the public education materials that meet the content requirements in subsection 10.6.1 and the delivery requirements in subsection 10.6.2; and

10.10.6.1.2 A list of all newspapers, radio stations, television stations, and facilities and organizations to which the system delivered public education materials during the period in which the system was required to perform public education tasks.

10.10.6.2 Unless required by the Division, a system that previously has submitted the information required in subsection 10.10.6.1.2 need not resubmit the information required by subsection 10.10.6.1.2, as long as there have been no changes in the distribution list and the system certifies that the public education materials were distributed to the same list submitted previously.

10.10.6.3 No later than 3 months following the end of the monitoring period, each system must mail a sample copy of the consumer notification of tap results to the Division along with a certification that the notification has been distributed in a manner consistent with the requirements of subsection 10.6.4.

10.10.7 Reporting of Additional Monitoring Data: Any system which collects sampling data in addition to that required by this section shall report the results to the Division within the first ten days following the end of the applicable monitoring period under subsections 10.7, 10.8 and 10.9 during which the samples are collected.

10.10.8 Reporting of the 90th percentile lead and copper concentrations where the Division calculates a system's 90th percentile concentrations. A water system is not required to report the 90th percentile lead and copper concentrations measured from among all lead and copper tap water samples collected during each monitoring period, as required by subsection 10.10.1.1.4 if:

10.10.8.1 The Division has previously notified the water system that it will calculate the water system's 90th percentile lead and copper concentrations, based on the lead and copper tap results submitted pursuant to subsection 10.10.8.2.1, and has specified a date before the end of the applicable monitoring period by which the system must provide the results of lead and copper tap water samples;

10.10.8.2 The system has provided the following information to the Division by the date specified in subsection 10.10.8.1:

10.10.8.2.1 The results of all tap samples for lead and copper including the location of each site and the criteria under subsections 10.7.1.3, 10.7.1.4, 10.7.1.5, 10.7.1.6 and/or 10.7.1.7 under which the site was selected for the system's sampling pool, pursuant to subsection 10.10.1.1.1; and

10.10.8.2.2 An identification of sampling sites utilized during the current monitoring period that were not sampled during previous monitoring periods, and an explanation why sampling sites have changed; and

10.10.8.3 The Division has provided the results of the 90th percentile lead and copper calculations, in writing, to the water system before the end of the monitoring period.

10.11 Recordkeeping Requirements: Any system subject to the requirements of this section shall retain on its premises original records of all sampling data and analyses, reports, surveys, letters, evaluations, schedules, Division determinations, and any other information required by subsections 10.2 through 10.9. Each water system shall retain the records required by this section for no fewer than 12 years.

10.12 Analytical Methodology: Analysis for compliance with this section shall be conducted in accordance with 40 CFR 141.89. Copies may be obtained from the Office of Drinking Water.

16 Del. Admin. Code § 4462-10.0

20 DE Reg. 555(1/1/2017)
20 DE Reg. 808(4/1/2017)
24 DE Reg. 794(2/1/2021) (Final)
24 DE Reg. 904( 4/1/2021) (Errata)