R309-205-5. Inorganic Contaminants

Community, non-transient non-community, and transient non-community water systems shall conduct monitoring as specified to determine compliance with the maximum contaminant levels specified in R309-200-5 in accordance with this section.

(1) Monitoring shall be conducted as follows:

(a) 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) beginning in the compliance period starting January 1, 1993. 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.

(b) 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) beginning in the compliance period beginning January 1, 1993. 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 purposes of this paragraph, surface water systems include systems with a combination of surface and ground sources.)

(c) If a system draws water from more than one source and the sources are combined before distribution, the system shall 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).

(d) The frequency of monitoring for asbestos shall be in accordance with R309-205-5(2); the frequency of monitoring for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sodium, sulfate, thallium, and total dissolved solids shall be in accordance with R309-205-5(3); the frequency of monitoring for nitrate shall be in accordance with R309-205-5(4); the frequency of monitoring for nitrite shall be in accordance with R309-205-5(5).

(e) Confirmation samples:

(i) Where the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sulfate, thallium or total dissolved solids indicate an exceedance of the maximum contaminant level, the Director 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.

(ii) Where nitrate or nitrite sampling results indicate an exceedance of the maximum contaminant level, the system shall take a confirmation sample within 24 hours of the system's receipt of notification of the analytical results of the first sample. Systems unable to comply with the 24-hour sampling requirement shall immediately notify the consumers in the area served by the public water system source in accordance with R309-220-5. Systems exercising this option shall take and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample.

(iii) Procedures if the Secondary Standard for Fluoride is Exceeded Notification of State and/or Public.

If the result of an analysis indicates that the level of fluoride exceeds the Secondary Drinking Water Standard, the supplier of water shall give notice as required in R309-220-11.

(iv) The results of the initial and confirmation sample(s) taken for any contaminant, shall be averaged. The resulting average shall be used to determine the system's compliance in accordance with paragraph (1)(g) of this section. The Director has the discretion to delete results of obvious sampling errors.

(f) The Director may require more frequent monitoring than specified in paragraphs (2), (3), (4) and (5) of this section or may require confirmation samples for positive and negative results. The Director may also require an appropriate treatment process.

(g) Compliance with R309-200-5(1) shall be determined based on the analytical result(s) obtained at each sampling point.

(i) For systems which are conducting monitoring at a frequency greater than annual, compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sulfate, thallium and total dissolved solids is determined by a running annual average at each sampling point. If the average at any sampling point is greater than the MCL, then the system is out of compliance. If any one sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) shall be based on the total number of samples collected.

(ii) For systems which are monitoring annually, or less frequently, the system is out of compliance with the maximum contaminant levels for antimony, arsenic, asbestos, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sulfate, thallium and total dissolved solids if the level of a contaminant at any sampling point is greater than the MCL. If confirmation samples are required by the Director, the determination of compliance will be based on the annual average of the initial MCL exceedance and any Director required confirmation samples. If a system fails to collect the required number of samples, compliance (average concentration) shall be based on the total number of samples collected. If the average of the samples exceed the maximum contaminant levels then the water system shall provide public notice as required under R309-220.

(iii) Compliance with the maximum contaminant levels for nitrate and nitrite is determined based on one sample. If the levels of nitrate and/or nitrite exceed the MCLs in the initial sample, a confirmation sample is required in accordance with paragraph (1)(g)(ii) of this section, and compliance shall be determined based on the average of the initial and confirmation samples.

(iv) If a public water system has a distribution system separable from other parts of the distribution system with no interconnections, the Director may allow the system to give public notice to only the area served by that portion of the system which is out of compliance.

(h) Each public water system shall monitor at the time designated by the Director during each compliance period.

(2) The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in R309-200-5(1) shall be conducted as follows:

(a) Each community and non-transient non-community water system is required to monitor for asbestos during the first three-year compliance period of each nine-year compliance cycle beginning in the compliance period starting January 1, 1993.

(b) If the system believes it is not vulnerable to asbestos contamination in its source water, it may apply to the Director for a waiver of the monitoring requirement in paragraph (a) of this section. If the Director grants the waiver, the system is not required to monitor for asbestos.

(c) The Director may grant a waiver based on a consideration of the potential asbestos contamination of the water source.

(d) A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver shall monitor in accordance with the provisions of paragraph (a) of this section.

(e) A system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of R309-205-5(1).

(f) A system vulnerable to asbestos contamination due both to its source water supply and corrosion of asbestos-cement pipe as specified in R309-210-7 shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

(g) A system which exceeds the maximum contaminant levels as determined in R309-205-5(1)(g) shall monitor quarterly beginning in the next quarter after the violation occurred.

(h) The Director may decrease the quarterly monitoring requirement to the frequency specified in paragraph (a) of this section provided the Director has determined that the system is reliably and consistently below the maximum contaminant level. In no case can the Director make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface (or combined surface/ground) water system takes a minimum of four quarterly samples.

(i) If monitoring data collected after January 1, 1990 are generally consistent with the requirements of R309-205-5(2), then the Director may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.

(3) The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in R309-200-5(1). for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, sodium, sulfate, thallium and total dissolved solids shall be as follows:

(a) Each community and non-transient non-community groundwater system shall take one sample at each sampling point once every three years. Each community and non-transient non-community surface water system (or combined surface/ground) shall take one sample annually at each sampling point. Each transient non-community system shall take one sample for sulfate only at each sampling point once every three years for both groundwater and surface water systems.

(b) The system may apply to the Director for a waiver from the monitoring frequencies specified in paragraph (3)(a) of this section.

(c) A condition of the waiver shall require that a system shall take a minimum of one sample while the waiver is effective. The term during which the waiver is effective shall not exceed one compliance cycle (i.e., nine years).

(d) The Director may grant a waiver provided surface water systems have monitored annually for at least three years and groundwater systems have conducted a minimum of three rounds of monitoring. (At least one sample shall have been taken since January 1, 1990.) Both surface and groundwater systems shall demonstrate that all previous analytical results were less than the maximum contaminant level. Systems that use a new water source are not eligible for a waiver until three rounds of monitoring from the new source have been completed.

(e) In determining the appropriate reduced monitoring frequency, the Director shall consider:

(i) Reported concentrations from all previous monitoring;

(ii) The degree of variation in reported concentrations; and

(iii) Other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system's configuration, changes in the system's operating procedures, or changes in stream flows or characteristics.

(f) A decision by the Director to grant a waiver shall be made in writing and shall set forth the basis for the determination. The determination may be initiated by the Director or upon an application by the public water system. The public water system shall specify the basis for its request. The Director shall review and, where appropriate, revise its determination of the appropriate monitoring frequency when the system submits new monitoring data or when other data relevant to the system's appropriate monitoring frequency become available.

(g) Systems which exceed the maximum contaminant levels as calculated in R309-205-5(1)(g) of this section shall monitor quarterly beginning in the next quarter after the violation occurred.

(h) The Director may decrease the quarterly monitoring requirement to the frequencies specified in paragraphs (3)(a) and (b) of this section provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case can the Director make this determination unless a groundwater system takes a minimum of two quarterly samples and a surface water system takes a minimum of four quarterly samples.

(4) All public water systems (community; non-transient non-community; and transient non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrate in R309-200-5(1).

(a) Community and non-transient non-community water systems served by groundwater systems shall monitor annually beginning January 1, 1993; systems served by surface water shall monitor quarterly beginning January 1, 1993.

(b) For community and non-transient non-community water systems, the repeat monitoring frequency for ground water systems shall be quarterly for at least one year following any one sample in which the concentration is greater than or equal to 50 percent of the MCL. The Director may allow a groundwater system to reduce the sampling frequency to annually after four consecutive quarterly samples are reliably and consistently less than the MCL.

(c) For community and non-transient non-community water systems, the Director may allow a surface water system to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are less than 50 percent of the MCL. A surface water system shall return to quarterly monitoring if any one sample is greater than or equal to 50 percent of the MCL.

(d) Each transient non-community water system shall monitor annually beginning January 1, 1993.

(e) After the initial round of quarterly sampling is completed, each community and non-transient non-community system which is monitoring annually shall take subsequent samples during the quarter(s) which previously resulted in the highest analytical result.

(5) All public water systems (community; non-transient non-community; and transient non-community systems) shall monitor to determine compliance with the maximum contaminant level for nitrite in R309-200-5(1).

(a) All public water systems shall take one sample at each sampling point in the compliance period beginning January 1, 1993 and ending December 31, 1995.

(b) After the initial sample, systems where an analytical result for nitrite is less than 50 percent of the MCL shall monitor at the frequency specified by the Director.

(c) For community, non-transient non-community, and transient non-community water systems, the repeat monitoring frequency for any water system shall be quarterly for at least one year following any one sample in which the concentration is greater than or equal to 50 percent of the MCL. The Director may allow a system to reduce the sampling frequency to annually after determining the system is reliably and consistently less than the MCL.

(d) Systems which are monitoring annually shall take each subsequent sample during the quarter(s) which previously resulted in the highest analytical result.