Current through Register Vol. 54, No. 45, November 9, 2024
Section 109.1102 - Action levels and treatment technique requirements(a)Action levels for lead and copper.(1) The lead action level is 0.015 mg/L.(2) The copper action level is 1.3 mg/L.(3) An action level is exceeded when the concentration of a contaminant in more than 10% of tap water samples collected during a monitoring period conducted in accordance with § 109.1103 (relating to monitoring requirements) is greater than the action level.(4) The 90th percentile lead and copper levels shall be computed as follows: (i) 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.(ii) The number of samples taken during the monitoring period shall be multiplied by 0.9.(iii) The contaminant concentration in the numbered sample yielded by the calculation in subparagraph (ii) is the 90th percentile contaminant level.(iv) For water systems that collect five samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations.(v) Interpolation shall be used to compute the 90th percentile when the numbered sample indicated in subparagraph (iii) is not a whole number.(b)Treatment technique requirement for corrosion control.(1)Optimal corrosion control treatment. A community water system or nontransient noncommunity water system shall provide optimal corrosion control treatment which minimizes the lead and copper concentrations at users' taps while ensuring that the treatment does not cause the system to violate a primary MCL. Water systems deemed to have optimized corrosion control treatment under this subsection shall operate in compliance with Department designated water quality parameters and continue to conduct lead and copper tap monitoring. A system may achieve optimal corrosion control treatment in one of the following ways:(i) A small or medium water system is deemed to have optimized corrosion control if the system does not exceed either the lead or copper action level during each of two consecutive 6-month monitoring periods conducted in accordance with § 109.1103. If the system thereafter exceeds an action level during a monitoring period, the system shall complete applicable compliance activities under paragraph (2). The Department may require a system repeat compliance activities previously completed when the Department determines that this is necessary for the system to achieve optimal corrosion control treatment.(ii) A water system is deemed to have optimized corrosion control if the system demonstrates to the Department that for two consecutive 6-month monitoring periods conducted in accordance with § 109.1103 that the system does not exceed a lead or copper action level and the difference between the 90th percentile tap water lead level and the highest source water lead concentration is less than 0.005 mg/L, which is the Practical Quantitation Level for lead. (A) To make this demonstration, the system shall collect one sample for lead from each entry point during a monitoring period prior to initiation of construction or modification of corrosion control treatment facilities. If the system thereafter exceeds an action level during a monitoring period, the system shall complete applicable compliance activities under paragraph (2). The Department may require a system to repeat compliance activities previously completed when the Department determines that this is necessary for the system to achieve optimal corrosion control treatment.(B) A water system deemed to have optimized corrosion control in accordance with this subparagraph shall continue monitoring for lead and copper at the tap no less frequently than once every 3-calendar years using the reduced number of sites specified in § 109.1103(e), and collecting the samples at times and locations specified in § 109.1103(e)(1)(iii).(iii) A system is deemed to have optimized corrosion control if the system installs new corrosion control treatment facilities or modifies existing treatment in accordance with paragraph (2) and operates in compliance with water quality parameter performance requirements specified by the Department in a permit issued under § 109.1105(c) (relating to permit requirements).(2)Corrosion control treatment compliance schedule. A system shall comply with the following schedule unless the system achieves optimal corrosion control treatment under paragraph (1)(i) or (ii) prior to initiation of construction or modification of corrosion control treatment facilities.(i) An existing large water system shall:(A) Submit a corrosion control treatment feasibility study that complies with paragraph (3) by June 30, 1994.(B) Submit a permit application for construction or modification of corrosion control treatment facilities by March 31, 1995.(C) Initiate construction or modification of corrosion control treatment facilities by December 31, 1995.(D) Complete construction or modification of corrosion control treatment facilities and begin operation of these facilities by January 1, 1997.(E) Submit a request for a Department designation of optimal corrosion control treatment performance requirements by January 31, 1998.(ii) A large water system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under paragraph (1), or any medium or small water system that exceeds an action level shall:(A) Submit a corrosion control treatment feasibility study that complies with paragraph (3) within 18 months of the end of the monitoring period in which the action level was exceeded.(B) Submit a permit application or otherwise comply with the permit application requirements under § 109.1105(b) for construction or modification of corrosion control treatment facilities within 30 months of the end of the monitoring period in which the action level was exceeded.(C) Initiate construction or modification of corrosion control treatment facilities within 48 months of the end of the monitoring period in which the action level was exceeded.(D) Complete construction or modification of corrosion control treatment facilities and begin operation of these facilities within 60 months of the end of the monitoring period in which the action level was exceeded.(E) Submit a request for Department designation of optimal corrosion control treatment performance requirements within 30 days of the end of the second follow-up monitoring period required under § 109.1103(c)(1)(ii) following completion of construction or modification of corrosion control treatment facilities.(3)Corrosion control treatment feasibility study. The system shall prepare and submit a corrosion control treatment feasibility study to the Department by the applicable deadline established in paragraph (2). The purpose of this study is to identify corrosion control priorities, evaluate viable corrosion control approaches and select the optimal corrosion control treatment. As a minimum, the system shall include the information required in a basic study described in subparagraph (i). The Department may require a water supplier to conduct demonstration testing if the Department determines that a basic study is insufficient to determine optimal corrosion control treatment. Demonstration testing may also be required when a system continues to exceed an action level after corrosion control treatment has been installed. (i) The basic study shall include the following information: (A) A sample site location plan prepared in accordance with § 109.1103 (g).(B) A summary of lead and copper and water quality parameter monitoring results performed in accordance with § 109.1103. These results shall be evaluated considering the location of sample sites within the distribution system and used as the basis for considering corrosion control treatment options.(C) An evaluation of source water contributions and the need for source water treatment.(D) A desktop evaluation of alkalinity and pH adjustment, calcium hardness adjustment and corrosion inhibitor addition or a combination of these treatments. The evaluation shall include analyses based on documented analogous treatments with other systems of similar size, water chemistry and distribution system configuration. If source water treatment is needed to achieve optimal corrosion control, the water supplier shall evaluate the source water treatments specified in paragraph (4).(E) An identification of chemical, physical or regulatory constraints on the use of a particular corrosion control treatment, such as its adverse effects on other treatment processes or the ability of wastewater facilities to comply with applicable statutes or regulations.(F) A recommendation of optimal corrosion control treatment, including source water treatment, if applicable, for the system based on the supporting documentation specified in clauses (A)-(E). When a system has multiple sources, it may be necessary for the system to provide different corrosion control treatment for different sources.(G) Recommended water quality parameter performance requirements for the selected corrosion control treatment.(H) A proposed schedule for completion of the remaining corrosion control treatment compliance steps in accordance with paragraph (2), including, but not limited to, treatment design and permit application submittal, financing and construction, and initiation of operation.(ii) A demonstration study shall include the evaluation of corrosion control treatments using pipe rig/loop tests, metal coupon tests or partial system tests.(4)Source water treatment. A system that must reduce the concentration of lead or copper in its source water to achieve optimal corrosion control shall provide source water treatment. (i) A system which exceeds either the lead or copper action level shall conduct initial source water monitoring in accordance with § 109.1103(a)(3). The water supplier shall use the results of this monitoring along with the results of lead and copper tap and water quality parameter monitoring to determine corrosion control treatment priorities including the need for source water treatment as part of the corrosion control feasibility study required under paragraph (3).(ii) If source water treatment needs to be evaluated, the water supplier shall evaluate treatments including ion exchange, reverse osmosis, lime softening and coagulation/filtration. The water supplier shall recommend a source water treatment along with the recommendation for optimal corrosion control treatment. The water supplier shall include recommended source water treatment performance requirements for the selected treatment.(iii) If, after review of the feasibility study, the Department determines that source water treatment is necessary as part of a system's overall approach to achieving optimal corrosion control, the water supplier shall provide source water treatment under the compliance schedule established in paragraph (2) for corrosion control treatment. The Department may require the water supplier to provide source water treatment for lead on an earlier schedule if the Department determines that lead in the source water presents an imminent hazard to the public health.(iv) Following the installation of source water treatment, the water supplier shall conduct source water monitoring in accordance with § 109.1103(c)(3). Based on the results of this monitoring and lead and copper tap and water quality parameter monitoring, the Department will establish source water treatment performance requirements when water quality parameter performance requirements are established for the system under paragraph (5).(5)Water quality parameter performance requirements. The Department will designate optimal corrosion control treatment water quality parameter performance requirements for large water systems by June 30, 1998, and for medium or small water systems within 18 months after the system completes construction or modification of corrosion control treatment, if the water supplier submits a request for Department designation of performance requirements within the time frames established in paragraph (2) and the request contains the information specified in § 109.1107(a)(3)(v) (relating to system management responsibilities). The performance requirements will be specified in the amended operation permit issued in accordance with § 109.1105(c). A system shall maintain the designated water quality parameter performance requirements at or above minimum values or within specified ranges designated by the Department. The Department may designate values for additional water quality parameters if the Department determines these requirements are necessary to assure optimal corrosion control treatment. Depending on the type of corrosion control treatment, the performance requirements will be designated as follows: (i) A minimum value or range of values for pH measured at each entry point to the distribution system.(ii) A minimum pH value measured in distribution system samples.(iii) If a corrosion inhibitor is used, a minimum concentration or range for the inhibitor necessary to form a passivating film on the interior walls of the distribution system pipes. The inhibitor concentration is measured at each entry point and in all distribution system samples.(iv) If alkalinity is adjusted as part of optimal corrosion control treatment, a minimum concentration or range of concentrations for alkalinity measured at each entry point and in distribution system samples.(v) If calcium carbonate stabilization is used as part of optimal corrosion control treatment, a minimum concentration or range of concentrations for calcium measured in distribution system samples.The provisions of this §109.1102 amended August 9, 2002, effective 8/10/2002, 32 Pa.B. 3894; amended May 22, 2009, effective 5/23/2009, 39 Pa.B. 2661; corrected August 29, 2009, effective 8/1/2009, 39 Pa.B. 5119; amended December 17, 2010, effective 12/18/2010, 40 Pa.B. 7212. This section cited in 25 Pa. Code § 109.810 (relating to reporting and notification requirements); 25 Pa. Code § 109.901 (relating to requirements for a variance); 25 Pa. Code § 109.903 (relating to requirements for an exemption); 25 Pa. Code § 109.1103 (relating to monitoring requirements); 25 Pa. Code § 109.1104 (relating to public education and notification); 25 Pa. Code § 109.1105 (relating to permit requirements); 25 Pa. Code § 109.1107 (relating to system management responsibilities); and 25 Pa. Code § 109.1108 (relating to fees).