Compilation of Rules and Regulations of the State of Georgia › Department 391 - RULES OF GEORGIA DEPARTMENT OF NATURAL RESOURCES › Chapter 391-3 - ENVIRONMENTAL PROTECTION › Subject 391-3-5 - RULES FOR SAFE DRINKING WATER › Rule 391-3-5-.24 - Disinfectant Residuals, Disinfection Byproducts, and Disinfection Byproduct Precursors Sampling, Analytical and Other Requirements

Current
				through Rules and Regulations filed through June 27, 2024
(1)
Purpose.
The purpose of this
				Rule is to provide for the procedures for establishing maximum contaminant
				levels, monitoring and other requirements for trihalomethanes, disinfectant
				residuals, disinfection byproducts, and disinfection byproduct
				precursors.
(2)
Variances.
Variances from the maximum contaminant level for total
				trihalomethanes shall be conducted in accordance with
				40 CFR §
										142.60.
(3)
Disinfectant Residuals,
				Disinfection Byproducts, and Disinfection Byproduct Precursors.
(a) Community water systems and
				non-transient, non-community water systems which add a chemical disinfectant to
				the water in any part of the drinking water treatment process must modify their
				practices to meet MCLs and MRDLs specified in subparagraph (7)(a) of Rule
				391-3-5-.18, and must meet the
				treatment technique requirements for disinfection byproduct precursors
				specified in paragraph (10).
(b)
				Transient non-community water systems that use chlorine dioxide as a
				disinfectant or oxidant must modify their practices to meet the MRDL for
				chlorine dioxide specified in subparagraph (7)(a) of Rule
				391-3-5-.18.
(c) Community Subpart H water systems and
				non-transient, non-community Subpart H water systems must comply with the
				requirements of this Rule, as specified in paragraphs (7)(b) and (7)(c) of Rule
				391-3-5-.18, respectively.
(d) Beginning January 1, 2002, transient
				non-community Subpart H water systems serving 10,000 or more persons and using
				chlorine dioxide as a disinfectant or oxidant must comply with the requirements
				for chlorine dioxide and chlorite in this Rule.
(e) Beginning January 1, 2004, transient
				non-community Subpart H water systems serving fewer than 10,000 people and
				using chlorine dioxide as a disinfectant or oxidant and systems using only
				ground water not under the direct influence of surface water and using chlorine
				dioxide as a disinfectant or oxidant must comply with the requirements for
				chlorine dioxide and chlorite in this Rule.
(f) Systems may increase residual
				disinfectant levels in the distribution system of chlorine or chloramines (but
				not chlorine dioxide) to a level and for a time necessary to protect public
				health, to address specific microbiological contamination problems caused by
				circumstances such as, but not limited to, distribution line breaks, storm
				run-off events, source water contamination events, or cross-connection
				events.
(g) Systems must use the
				analytical method(s) specified in
				40 CFR §
											141.131 to demonstrate compliance with the
				requirements of this Rule. The analytical requirements specified in
				40 CFR §
											141.131, which is hereby incorporated by
				reference, are required to demonstrate compliance with the requirements of
				Subpart L (Disinfectant Residuals, Disinfection ByProducts, and Disinfection
				ByProduct Precursors), Subpart U (Initial Distribution System Evaluations), and
				Subpart V (Stage 2 Disinfection ByProducts Requirements) of 40 CFR Part
				141.
(h) Monitoring Requirements.
				40 CFR §
											141.132, in its entirety, is hereby
				incorporated by reference. For compliance with the requirements of this Rule,
				the water systems must monitor the applicable parameters included in this Rule
				at the frequency specified in
				40 CFR §
											141.132. Failure to monitor will be treated
				as a violation for the entire period covered by the annual average where
				compliance is based on a running annual average of monthly or quarterly samples
				or averages and the system's failure to monitor makes it impossible to
				determine compliance with MCLs or MRDLs.
1.
				Systems must take all samples during normal operating conditions.
2. Systems may consider multiple wells
				drawing water from a single aquifer as one treatment plant for determining the
				minimum number of TTHM and HAA5 samples required, with the Division
				approval.
3. Systems may use only
				data collected under the provisions of this Rule to qualify for reduced
				monitoring.
4. Each system required
				to monitor under this Rule must develop and implement a monitoring plan. The
				plan must include at least the following elements: specific locations and
				schedules for collecting samples for any parameters included in this Rule; how
				the system will calculate compliance with MCLs, MRDLs, and treatment
				techniques; and if approved for monitoring as a consecutive system, or if
				providing water to a consecutive system, the sampling plan must reflect the
				entire distribution system.
(i) The system
				must maintain the plan and make it available for inspection by the Division and
				the general public no later than thirty (30) days following applicable
				compliance dates stated in paragraph (3)(c).
(ii) All Subpart H systems serving more than
				3,300 people must submit a copy of the monitoring plan to the Division no later
				than the date of the first report required under
				40 CFR §
													141.134.
(iii) The Division may require a monitoring
				plan to be submitted by any other system. The Division may also require changes
				in any plan elements.