Title: Section 5-1.44 - Monitoring Requirements for Lead and Copper in Source Water

5-1.44 Monitoring Requirements for Lead and Copper in Source Water.

A water system that exceeds the lead or copper action level based on first draw tap water samples collected in accordance with section 5-1.42 shall collect lead and copper source water samples in accordance with the following requirements: 

(a) Sample Requirements. 

(1) Water systems shall take a minimum of one sample at every entry point to the distribution system which is representative of each source after treatment. The system shall collect each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. If a system draws water from more than one source and the sources are combined before distribution, the system shall sample at entry point(s) to be representative of normal operating conditions, when water is representative of all sources being used.

(2) The State may reduce the total number of samples which shall be analyzed by allowing the use of compositing. Compositing of samples shall be done by certified laboratory personnel. Composite samples from a maximum of five samples are allowed, provided that the method detection limit (MDL) for lead of 0.001 mg/L is achieved. 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:

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

(ii) 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.

(3) Where the results of sampling indicate an exceedance of State-specified maximum permissible source water levels established under section 5-1.45(a)(4), the State may require that one follow-up 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 State-required follow-up sample is taken for lead or copper, then the results of the initial and follow-up samples shall be averaged to determine compliance with the State-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 practical quantitation limit (PQL) shall either be considered as the measured value or be considered one-half the PQL.

(b) Standard Monitoring.

(1) Monitoring frequency after system exceeds tap water action level. Any system which exceeds the lead or copper action level shall collect one source water sample from each entry point to the distribution system no later than 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 State has established an alternate monitoring period, the last day of that period.

(2) Monitoring frequency after installation of source water treatment. Any system which installs source water treatment pursuant to section 5-1.45 shall collect an additional source water sample from each entry point to the distribution system during the two consecutive six-month monitoring periods immediately following the installation of treatment with the first monitoring period to begin either January 1 or July 1, whichever comes first.

(3) Monitoring frequency after State specifies maximum permissible source water levels or determines that source water treatment is not needed. 

(i) A system shall monitor at the frequency specified below in cases where the State specifies maximum permissible source water levels or determines that the system is not required to install source water treatment under section 5-1.45.

(a) A water system using only ground water shall collect samples once every three years with the first three year monitoring period to begin January 1 of the year in which the State determination is made under subdivision (b)(3)(i) of this section. Such systems shall collect samples once during each subsequent compliance period. Triennial samples shall be collected in the third calendar year.

(b) A water system using surface water (or a combination of surface and ground water) shall collect samples once during each calendar year with the first annual monitoring period to begin January 1 of the year in which the applicable State determination is made under subdivision (b)(3)(i) of this section.

(ii) 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 subdivision (b)(3)(i)(a) or (b) of this section.

(c) Reduced monitoring.

(1) A water system using only ground water may reduce the monitoring frequency for lead and copper in source water to once every nine-years provided that the samples are collected no later than every ninth calendar year and the system meets one of the following criteria:

(i) 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 State under section 5-1.45(a) during at least three consecutive years in which sampling was conducted under subdivision (b)(3)(i) of this section; or

(ii) The State has determined that source water treatment is not needed and the system demonstrates that 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 during at least three consecutive applicable monitoring periods in which sampling was conducted under subdivision (b)(3)(i) of this section. 

(2) A water system using surface water (or a combination of surface water and ground water) may reduce the monitoring frequency for lead and copper in source water to once during each nine-year compliance cycle provided that the samples are collected no later than every ninth calendar year and if the system meets one of the following criteria:

(i) 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 State for at least three consecutive years; or

(ii) The State 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.

(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 in accordance with subdivision (b)(2) or (3) of this section are below the maximum permissible lead and copper concentrations specified by the State.