Ga. Comp. R. & Regs. R. 391-3-5-.21 - Inorganic Chemical Sampling and Analytical Requirements

(1) CWS and NTNCWS Monitoring. Community and non-transient, non-community water systems shall conduct monitoring to determine compliance with the maximum contaminant levels specified in Rule 391-3-5-.18 in accordance with this rule.

(2) TNCWS Monitoring. Transient, non-community water systems shall conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in Rule 391-3-5-.18 in accordance with this rule.

(3) Nitrate Monitoring for NCWS with Alternate Limit. The frequency of monitoring conducted to determine compliance with the maximum contaminant level for Nitrate as specified in Rule 391-3-5-.18(1)(b) shall be conducted as follows:

(a) Analyses for all non community water systems (NTNCWS and TNCWS) utilizing surface water sources shall be repeated at yearly intervals. Analyses for all non community water systems (NTNCWS and TNCWS) utilizing only ground water sources shall be repeated at three-year intervals.

(b) For any non community water system (NTNCWS and TNCWS) that the Director has granted an alternate nitrate MCL of 20 mg/l pursuant to Rule 391-3-5-.18(1)(b) the monitoring frequency shall be conducted at intervals determined by the Director.

(c) If the result of an analysis made pursuant to paragraph (3) of this Rule indicates that the level of Nitrate listed in Rule 391-3-5-.18(1)(b) exceeds the maximum contaminant level, the supplier of water shall report to the Division in writing within seven (7) days and initiate three additional analyses at the same sampling point within fourteen (14) days.

(d) When the average of four analyses made pursuant to paragraph (3)(c), rounded to the same number of significant figures as the maximum contaminant level for the substance in question, exceeds the maximum contaminant level, the supplier of water shall notify the Division pursuant to Rule 391-3-5-.30 and give notice to the public pursuant to Rule 391-3-5-.32. Monitoring after public notification shall be at a frequency designated by the Division and shall continue until the maximum contaminant level has not been exceeded in two successive samples or until a monitoring schedule as a condition to a permit, variance, exception or enforcement action shall become effective.

(e) If the four analyses are not made pursuant to paragraph (3)(c), the Division will use the analyses available to prepare compliance calculations pursuant to paragraph (3)(d).

(f) The Division has the authority to determine compliance or initiate enforcement action based upon analytical results and other information compiled by their sanctioned representatives or agencies.

(g) The provisions of paragraphs (3)(c) and (3)(d) not withstanding, compliance with maximum contaminant for nitrate shall be determined based on the mean of the two analyses. When a level exceeding the maximum contaminant level for nitrate is found, a second analysis shall be initiated within 24 hours and if the mean of the two analyses exceeds the maximum contamination level, the supplier of water shall report the findings to the Director pursuant to Rule 391-3-5-.30 and shall notify the public pursuant to Rule 391-3-5-.32.

(4) Inorganic Monitoring. Monitoring for inorganic chemicals 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 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. [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 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).

(d) The Division may reduce the total number of samples, which must be analyzed by allowing the use of compositing. Composite samples shall be collected and analyzed in accordance with 40 CFR, Part 141.23(a)(4) . In the case of arsenic, if a PWS supplies water to one or more other PWSs and the interconnection justifies treating them as a single system for monitoring purposes, then the PWSs receiving the supplied water may have their arsenic monitoring requirements modified.

(5) Asbestos Monitoring. The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos specified in Rule 391-3-5-.18 shall be conducted as follows:

(a) Community or non-transient, non-community water systems are 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 either asbestos contamination in its source water or due to corrosion of asbestos-cement pipe, or both, it may apply to the Division for a waiver of the monitoring requirements in paragraph (5)(a) above. If the waiver is granted by the Division, the system is not required to monitor.

(c) The Division may grant a waiver based on a consideration of the following factors:

1. Potential asbestos contamination of the water source.

2. The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.

(d) A waiver remains in effect until the completion of the three-year compliance period. Systems not receiving a waiver must monitor in accordance with the provisions of paragraph (5)(a).

(e) A system vulnerable to asbestos contamination due solely to corrosion of asbestos-cement pipe shall take one sample at a tap served by asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

(f) A system vulnerable to asbestos contamination due solely to source water shall monitor in accordance with the provision of paragraph (4).

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

(h) A system which exceeds the maximum contaminant levels as determined in Rule 391-3-5-.21(12) shall monitor quarterly beginning in the next quarter after the violation occurred.

(i) The Division may decrease the quarterly monitoring requirement to the frequency specified in paragraph (5)(a) provided the Division has determined that the system is reliably and consistently below the maximum contaminant level. In no case can the Division 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.

(j) If monitoring data collected after January 1, 1990 are generally consistent with the requirements of Rule 391-3-5-.21(5) then the Division may allow systems to use that data to satisfy the monitoring requirement for the initial compliance period beginning January 1, 1993.

(6) Other Inorganics Monitoring. The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in Rule 391-3-5-.18 for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium and thallium shall be as follows:

(a) Groundwater systems shall take one sample at each sampling point during each compliance period beginning in the compliance period starting January 1, 1993. Surface water systems (or combined surface/ground) shall take one sample annually at each sampling point beginning January 1, 1993.

(b) The system may apply to the Division for a waiver from the monitoring frequencies specified in paragraph (6)(a).

(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 Division 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. In the case of arsenic, new water systems are not eligible for a waiver until three rounds of monitoring have been completed.

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

1. Reported concentrations from all previous monitoring;

2. The degree of variation in reported concentrations; and

3. 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 Division 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 Division or upon an application by the public water system. The public water system shall specify the basis for its request. The Division 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 paragraphs (3)(d) and (12) shall monitor quarterly beginning in the next quarter after the violation occurred.

(h) The Division may decrease the quarterly monitoring requirement to the frequencies specified in paragraphs (3)(a), (3)(b), (6)(a) and (6)(b) provided it has determined that the system is reliably and consistently below the maximum contaminant level. In no case can the Division 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.

(i) All new systems or systems that use a new source of water that begin operation after January 22, 2004 must demonstrate compliance with the MCL within a period of time specified by the Division. The system must also comply with the initial sampling frequencies specified by the Division to ensure a system can demonstrate compliance with the MCL. Routine and increased monitoring frequencies shall be conducted in accordance with the requirements in this paragraph.

(7) Nitrate Monitoring. The frequency of monitoring for nitrate shall be as follows: 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 Rule 391-3-5-.18.

(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 fifty percent (=50%) of the MCL. The Division 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 Division may allow a surface water system to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are less than fifty percent (50%) of the MCL. A surface water system shall return to quarterly monitoring if any one sample is greater than or equal to fifty percent (=50%) 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.

(8) Nitrite Monitoring. The frequency of monitoring for nitrite shall be as follows: 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 Rule 391-3-5-.18.

(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 fifty percent (<50%) of the MCL shall monitor at the frequency specified by the Division.

(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 fifty percent (>=50%) of the MCL. The Division 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.

(9) Confirmation samples.

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

(b) Where nitrate or nitrite sample 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 must immediately notify the customers served by the area served by the public water system in accordance with Rule 391-3-5-.32. Systems exercising this option must take and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample.

(c) If a Division-required confirmation sample is taken for any contaminant, then the results of the initial and confirmation sample shall be averaged. The resulting average shall be used to determine the system's compliance in accordance with paragraph (12).

(10) Increased Frequency of Monitoring. The Division may require more frequent monitoring than specified in paragraphs (5), (6), (7), and (8) or may require confirmation samples for positive and negative results at its discretion.

(11) Request for Increased Monitoring Frequency. Systems may apply to the Division to conduct more frequent monitoring than the minimum monitoring frequencies specified in this rule.

(12) Compliance Based on Analytical Results. Compliance with Rule 391-3-5-.18 (as appropriate) shall be determined based on the analytical result(s) obtained at each sampling point.

(a) 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 and thallium 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 single sample would cause the annual average to be exceeded, then the system is out of compliance immediately. Any sample below the detection limit shall be calculated at zero for the purpose of determining the annual average.

(b) 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 and thallium if the level of a contaminant at any sampling point is greater than the MCL. The Division may require one or more additional confirmation samples per paragraph (10). If a confirmation sample is required, the determination of compliance will be based on the annual average of the initial MCL exceedance and any state required confirmation sample(s).

(c) Compliance with the maximum contaminant levels for nitrate and nitrite is determined based on one sample if the levels of these contaminants are below the MCLs. If the levels of nitrate and/or nitrite exceed the MCLs in the initial sample, a confirmation sample is required in accordance with paragraph (9), and compliance shall be determined based on the average of the initial and confirmation samples.

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

(13) Monitor at Time Designed by Division. Each public water system shall monitor at the time designated by the Division during each compliance period.

(14) Analyses to Determine Compliance. All analyses conducted to determine compliance with paragraph (1)(a) of Rule 391-3-5-.18 and this Rule shall be in accordance with 40 CFR, Part 141.23(k) . Detection limits must be no less stringent than the detection limits presented in 40 CFR Part 141.23(a)(4) . Arsenic sampling results shall be reported to the nearest 0.001 mg/L.

(15) Certified Laboratories. Analysis under this rule shall only be conducted by laboratories that have received approval by EPA fulfilling the requirements listed in 40 CFR, Part 141.23(k)(3) or have received certification from the Division. Laboratories may conduct sample analysis under provisional certification until January 1, 1996.

(16) Treatment to Achieve Compliance. The best technology, treatment technique, or other means available for achieving compliance with the maximum contaminant level for inorganic contaminants identified in Rule 391-3-5-.18(1)(a) shall be in accordance with 40 CFR, Part 141.62(c).

Notes

Ga. Comp. R. & Regs. R. 391-3-5-.21

O.C.G.A. § 12-5-170 et seq.

Original Rule entitled "Inorganic Chemical Sampling and Analytical Requirements" adopted. F. July 5, 1977; eff. July 26, 1977, as specified by Rule 391-3-5-.47. Amended: F. July 15, 1983; eff. August 4, 1983. Repealed: New Rule of same title adopted. F. May 12, 1989; eff. June 1, 1989. Amended: F. Dec. 4, 1990; eff. Dec. 24, 1990. Repealed: New Rule of same title adopted. F. June 25, 1992; eff. July 15, 1992. Repealed: New Rule of same title adopted F. Mar. 10, 1994; eff. Mar. 30, 1994. Amended: F. Sept. 26, 1997; eff. Oct. 16, 1997. Amended: F. Dec. 10, 2002; eff. Dec. 30, 2002. Amended: F. Jan. 8, 2014; eff. Jan. 28, 2014. Amended: F. Apr. 22, 2021; eff. May 12, 2021.