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-.23 - Coliform Sampling

Current through Rules and Regulations filed
				through June 27, 2024
(1)
Routine Coliform Monitoring.
(a) Public water systems must collect total
				coliform samples at sites which are representative of water throughout the
				distribution system according to a written sample siting plan. These plans are
				subject to Division review and revision.
(b) The minimum residential population of a
				community water system shall be determined by a mathematical calculation of the
				total number of active residential service connections multiplied by Georgia's
				average population per household, as published in the most recent Federal
				Census Bureau Statistics. Multiple residential units served by a single
				connection (master meter) shall be included in the determination of population
				for a water system. The minimum monitoring frequency for total coliforms for
				community water systems is based on the population served by the system, as
				follows:
Population
								Served
Minimum Number of Samples per
								Month
25 to
								1,0001
1
1,001 to 2,500
2
2,501 to 3,300
3
3,301 to 4,100
4
4,101 to 4,900
5
4,901 to 5,800
6
5,801 to 6,700
7
6,701 to 7,600
8
7,601 to 8,500
9
8,501 to 12,900
10
12,901 to 17,200
15
17,201 to 21,500
20
21,501 to 25,000
25
25,001 to 33,000
30
33,001 to 41,000
40
41,001 to 50,000
50
50,001 to 59,000
60
59,001 to 70,000
70
70,001 to 83,000
80
83,001 to 96,000
90
96,001 to 130,000
100
130,001 to 220,000
120
220,001 to 320,000
150
320,001 to 450,000
180
450,001 to 600,000
210
600,001 to 780,000
240
780,001 to 970,000
270
970,001 to 1,230,000
300
1,230,001 to 1,520,000
330
1,520,001 to 1,850,000
360
1,850,001 to 2,270,000
390
2,270,001 to 3,020,000
420
3,020,001 to 3,960,000
450
3,960,001 or more
480
1Includes public water systems
				  which have at least 15 service connections, but serve fewer than 25
				  persons.
If a community water system serving 25 to 1,000 persons has
				  no history of total coliform contamination in its current configuration and a
				  sanitary survey conducted in the past five years shows that the system is
				  supplied solely by a protected ground water source and is free of sanitary
				  defects, the Division may reduce the monitoring frequency specified above,
				  except that in no case shall it be reduced to less than one sample per
				  quarter.
(c) The monitoring
				frequency for total coliform for non-community water systems is as follows:
1. A non-community water system using only
				ground water (except ground water under the direct influence of surface water)
				and serving 1,000 persons or fewer must monitor each calendar quarter that the
				system provides water to the public, except that the Division may adjust this
				monitoring frequency in writing, if a sanitary survey shows that the system is
				free of sanitary defects.
2. A
				non-community water system using only ground water (except ground water under
				the direct influence of surface water) and serving more than 1,000 persons
				during any month must monitor at the same frequency as a like-sized community
				water system, except that the Division may adjust this monitoring frequency, in
				writing for any month the system serves 1,000 persons or fewer.
3. A non-community water system using surface
				water, in total or in part, must monitor at the same frequency as a like-sized
				community water system, regardless of the number of persons it
				serves.
4. A non-community water
				system using ground water under the direct influence of surface water must
				monitor at the same frequency as a like-sized community water system. The
				system must begin monitoring at this frequency beginning six months after the
				Division determines that the ground water is under the direct influence of
				surface water.
(d) The
				public water system must collect samples at regular time intervals throughout
				the month, except that a system which uses only ground water (except ground
				water under the direct influence of surface water), and serves 4,900 persons or
				fewer, may collect all required samples on a single day if they are taken from
				different sites.
(e) Special
				purpose samples, such as those taken to determine whether disinfection
				practices are sufficient following pipe placement, replacement, or repair,
				shall not be used to determine compliance with the MCL for total coliforms.
				Repeat samples are not considered special purpose samples, and must be used to
				determine compliance with the MCL for total coliforms.