S.C. Code Regs. § § 61-58.10.F

Current through Register Vol. 48, No. 10, October 25, 2024

Section 61-58.10.F - Analytical and Monitoring Requirements

(1) Analytical requirements.

Only the analytical method(s) specified in this paragraph, or otherwise approved by EPA, may be used to demonstrate compliance with the requirements of R.61-58.10.C, R.61-58.10.D, and R.61-58.10.E. Measurements for pH, temperature, turbidity and residual disinfectant concentrations shall be conducted by a party approved by the Department. Measurements for total coliforms, fecal coliforms, and HPC shall be conducted by a laboratory certified by the Department or EPA to do such analysis. Until laboratory certification criteria are developed for the analysis of HPC and fecal coliforms, any laboratory certified for total coliform analysis by EPA is deemed certified for HPC and fecal coliform analysis. All procedures shall be performed in accordance with EPA-approved methods outlined in 40 CFR 141 (11-8-06 edition).

(a) Fecal coliform concentration--Method 908C (Fecal Coliform MPN Procedures), Method 908D (Estimation of Bacterial Density), or Method 909C (Fecal Coliform Membrane Filter Procedure), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(b) Total coliform concentration--Method 908A (Standard Total Coliform Multiple-Tube (MPN) Tests), Method 908B (Application of Tests to Routine Examinations), Method 908D (Estimation of Bacterial Density), Method 909A (Standard Total Coliform Membrane Filter Procedure), or Method 909B (Delayed-Incubation Total Coliform Procedure), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition; Minimal Medium ONPG-MUG Test, as set forth in the article "National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Escherichia coli from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method" (Edberg et al.), Applied and Environmental Microbiology, Volume 54, June 1988 (as amended under Erratum, Volume 54, December 1988). (Note: The Minimal Medium ONPG-MUG Test is sometimes referred to as the Autoanalysis Colilert System.) Systems may use a five-tube test or a ten-tube test.

(c) Heterotrophic Plate Count--Method 907A (Pour Plate Method), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(d) Turbidity--Method 214A (Nephelometric Method-Nephelometric Turbidity Units), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(e) Residual disinfectant concentration--Residual disinfectant concentrations for free chlorine and combined chlorine (chloramines) shall be measured by Method 408C (Amperometric Titration Method), Method 408D (DPD Ferrous Titrimetric Method), Method 408E (DPD Colorimetric Method), or Method 408F (Leuco Crystal Violet Method), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition. Residual disinfectant concentrations for free chlorine and combined chlorine may also be measured by using DPD colorimetric test kits if approved by the Department. Residual disinfectant concentrations for ozone must be measured by the Indigo Method as set forth in Bader, H., Hoigne, J., "Determination of Ozone in Water by the Indigo Method; A Submitted Standard Method"; Ozone Science and Engineering, Vol. 4, Pergamon Press Ltd., 1982, or automated methods which are calibrated in reference to the results obtained by the Indigo Method on a regular basis, if approved by the Department.

Residual disinfectant concentrations for chlorine dioxide shall be measured by Method 410B (Amperometric Method) or Method 410C (DPD Method), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(f) Temperature--Method 212 (Temperature), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(g) pH--Method 423 (pH Value), as set forth in Standard Methods for the Examination of Water and Wastewater, 1985, 16th edition.

(2) Monitoring requirements for systems that do not provide filtration.

A public water system that uses a surface water source and does not provide filtration treatment shall begin monitoring, as specified in this paragraph, beginning December 31, 1990, unless the Department has determined in writing that filtration is required, in which case the Department may specify alternative monitoring requirements, as appropriate, until filtration is in place. A public water system that uses a ground water source under the direct influence of surface water and does not provide filtration treatment shall begin monitoring as specified in this paragraph beginning December 31, 1990, or 6 months after the Department determines that the ground water source is under the direct influence of surface water, whichever is later, unless the Department has determined in writing that filtration is required, in which case the Department may specify alternative monitoring requirements, as appropriate, until filtration is in place.

(a) Fecal coliform or total coliform density measurements as required by R.61-58.10(C)(1)(a)(C)(1)(a)shall be performed on representative source water samples immediately prior to the first or only point of disinfectant application. The system shall sample for fecal or total coliforms at the following minimum frequency each week the system serves water to the public:

System size (persons served)	Samples/week [FN1]
<=500	1
501 to 3, 300 .......................	2
3,301 to 10, 000 ....................	3
10,001 to 25,000 ....................	4
>25,000 ..............................	5
[FN1] Must be taken on separate days.

Also, one fecal or total coliform density measurement shall be made every day the system serves water to the public and the turbidity of the source water exceeds 1 NTU (these samples count towards the weekly coliform sampling requirements) unless the Department determines that the system, for logistical reasons outside the system's control, cannot have the sample analyzed within 30 hours of collection.

(b) Turbidity measurements as required by R.61-58.10 (C)(1)(b) shall be performed on representative grab samples of source water immediately prior to the first or only point of disinfectant application every four hours (or more frequently) that the system serves water to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a regular basis using a protocol approved by the Department.

(c) The total inactivation ratio for each day that the system is in operation shall be determined based on the CT_99.9 values in Table 1.1-1.6, 2.1 and 3.1 of this section, as appropriate. The parameters necessary to determine the total inactivation ratio shall be monitored as follows:

(i) The temperature of the disinfected water shall be measured at least once per day at each residual disinfectant concentration sampling point.

(ii) If the system uses chlorine, the pH of the disinfected water shall be measured at least once per day at each chlorine residual disinfectant concentration sampling point.

(iii) The disinfectant contact time(s) ("T") shall be determined for each day during peak hourly flow.

(iv) The residual disinfectant concentration(s) ("C") of the water before or at the first customer shall be measured each day during peak hourly flow.

(v) If a system uses a disinfectant other than chlorine, the system may demonstrate to the Department, through the use of a Department-approved protocol for on-site disinfection challenge studies or other information satisfactory to the Department, that CT_99.9 values other than those specified in Tables 2.1 and 3.1 in this section or other operational parameters are adequate to demonstrate that the system is achieving the minimum inactivation rates required by R.61-58.10(D)(1)(a)(D)(1)(a).

TABLE 1.1--CT VALUES (CT99-9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 0.5 ° C OR LOWER
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4.........................	137	163	195	237	277	329	390
0.6...........................	141	168	200	239	286	342	407
0.8...........................	145	172	205	246	295	354	422
1.0...........................	148	176	210	253	304	365	437
1.2...........................	152	180	215	259	313	37 6	451
1.4...........................	155	184	221	266	321	387	464
1.6...........................	157	189	226	273	329	397	477
1.8...........................	162	193	231	279	338	407	489
2.0...........................	165	197	236	286	346	417	500
2.2...........................	169	201	242	297	353	426	511
2.4...........................	172	205	247	298	361	435	522
2.6...........................	175	209	252	304	368	444	533
2.8...........................	178	213	257	310	375	452	543
3.0...........................	181	217	261	316	382	460	552
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.

TABLE 1.2--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 5.0 °C [FN1]
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4.........................	97	117	139	166	198	236	279
0.6...........................	100	120	143	171	204	244	291
0.8...........................	103	122	146	175	210	252	301
1.0...........................	105	125	149	179	216	260	312
1.2...........................	107	127	152	183	221	267	320
1.4...........................	109	130	155	187	227	274	329
1.6...........................	111	132	158	192	232	281	337
1.8...........................	114	135	162	196	238	287	345
2.0...........................	116	138	165	200	243	294	353
2.2...........................	118	140	169	204	248	300	361
2.4...........................	120	143	172	209	253	306	368
2.6...........................	122	146	175	213	258	312	375
2.8...........................	124	148	178	217	263	318	382
3.0...........................	126	151	182	221	268	324	389
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.

TABLE 1.3--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 10.0 °C [FN1]
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4.........................	73	88	104	125	149	177	209
0.6...........................	75	90	107	128	153	183	218
0.8...........................	78	92	110	131	158	189	226
1.0...........................	79	94	112	134	162	195	234
1.2...........................	80	95	114	137	166	200	240
1.4...........................	82	98	116	140	170	206	247
1.6...........................	83	99	119	144	174	211	253
1.8...........................	86	101	122	147	179	215	259
2.0...........................	87	104	124	150	182	221	265
2.2...........................	89	105	127	153	186	225	271
2.4...........................	90	107	129	157	190	230	276
2.6...........................	92	110	131	160	194	234	281
2.8...........................	93	111	134	163	197	239	287
3.0...........................	95	113	137	166	201	243	292
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.

TABLE 1.4--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 15.0 °C [FN1]
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4........................	49	59	70	83	99	118	140
0.6..........................	50	60	72	86	102	122	146
0.8..........................	52	61	73	88	105	126	151
1.0..........................	53	63	75	90	108	130	156
1.2..........................	54	64	76	92	111	134	160
1.4..........................	55	65	78	94	114	137	165
1.6..........................	56	66	79	96	116	141	169
1.8..........................	57	68	81	98	119	144	173
2.0..........................	58	69	83	100	122	147	177
2.2..........................	59	70	85	102	124	150	181
2.4..........................	60	72	86	105	127	153	184
2.6..........................	61	73	88	107	129	156	188
2.8..........................	62	74	89	109	132	159	191
3.0..........................	63	76	91	111	134	162	195
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99-9 value at the lower temperature, and at the higher pH.

TABLE 1.5--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 20.0 °C [FN1]
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4.........................	36	44	52	62	74	89	105
0.6...........................	38	45	54	64	77	92	109
0.8...........................	39	46	55	66	79	95	113
1.0...........................	39	47	56	67	81	98	117
1.2...........................	40	48	57	69	83	100	120
1.4...........................	41	49	58	70	85	103	123
1.6...........................	42	50	59	72	87	105	126
1.8...........................	43	51	61	74	89	108	129
2.0...........................	44	52	62	75	91	110	132
2.2...........................	44	53	63	77	93	113	135
2.4...........................	45	54	65	78	95	115	138
2.6...........................	46	55	66	80	97	117	141
2.8...........................	47	56	67	81	99	119	143
3.0...........................	47	57	68	83	101	122	146
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.

TABLE 1.6--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY FREE CHLORINE AT 25.0°C [FN1] AND HIGHER.
pH
Free Residual (mg/l)	<=6.0	6.5	7.0	7.5	8.0	8.5	<=9.0
<=0.4.........................	24	29	35	42	50	59	70
0.6...........................	25	30	36	43	51	61	73
0.8...........................	26	31	37	44	53	63	75
1.0...........................	26	31	37	45	54	65	78
1.2...........................	27	32	38	46	55	67	80
1.4...........................	27	33	39	47	57	69	82
1.6...........................	28	33	40	48	58	70	84
1.8...........................	29	34	41	49	60	72	86
2.0...........................	29	35	41	50	61	74	88
2.2...........................	30	35	42	51	62	75	90
2.4...........................	30	36	43	52	63	77	92
2.6...........................	31	37	44	53	65	78	94
2.8...........................	31	37	45	54	66	80	96
3.0...........................	32	38	4 6	55	67	81	97
[FN1] These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.

TABLE 2.1--CT VALUES (CT 99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY CHLORINE DIOXIDE AND OZONE
Temperature
<=1°C	5° C	10° C	15° C	20° C	<=25° C
Chlorine dioxide .... Ozone ........	63 2.9	26 1.9	23 1.4	19 0.95	15 0.72	11 0.48
1 These CT values achieve greater than 99-99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature for determining CT99.9 values between indicated temperatures.

TABLE 3.1--CT VALUES (CT99.9) FOR 99.9 PERCENT INACTIVATION OF GIARDIA LAMBLIA CYSTS BY CHLORAMINES [FN1]
Temperature
<1° C	5° C	10° C	15° C	20° C	25° C
3,800	2,200	1,850	1,500	1,100	750
[FN1] These values are for pH values of 6 to 9. These CT values may be assumed to achieve greater than 99.99 percent inactivation of viruses only if chlorine is added and mixed in the water prior to the addition of ammonia. If this condition is not met, the system shall demonstrate, based on on-site studies or other information, as approved by the Department, that the system is achieving at least 99.99 percent inactivation of viruses. CT values between the indicated temperatures may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature for determining CT99.9 values between indicated temperatures.

(d) The total inactivation ratio shall be calculated as follows:

(i) If the system uses only one point of disinfectant application, the system may determine the total inactivation ratio based on either of the following two methods:

(A) One inactivation ratio (CTcalc/CT_99.9) is determined before or at the first customer during peak hourly flow and if the CTcalc/CT_99.9 >= the 99.9 percent Giardia lamblia inactivation requirement has been achieved; or

(B) Successive CTcalc/CT_99.9 values, representing sequential inactivation ratios, are determined between the point of disinfectant application and a point before or at the first customer during peak hourly flow. Under this alternative, the following method shall be used to calculate the total inactivation ratio:

Step 1: Determine CTcalc for each / CT_99.9 sequence.

Step 2: Add the CTcalc values together / CT_99.9

Sigma (CTcalc) / CT_99.9

Step 3: If Sigma CTcalc >= 1.0, / CT_99.9

the 99.9 percent Giardia lamblia inactivation requirement has been achieved.

(ii) If the system uses more than one point of disinfectant application before or at the first customer, the system shall determine the CT value of each disinfection sequence immediately prior to the next point of disinfectant application during peak hourly flow. The CTcalc/CT_99.9 value of each sequence and

Sigma CTcalc / CT_99.9

shall be calculated using the method in paragraph (2)(d)(i)(B) of this section to determine if the system is in compliance with R.61-58.10(D)(1)(D)(1).

(iii) Although not required, the total percent inactivation for a system with one or more points of residual disinfectant concentration monitoring may be calculated by solving the following equation:

Percent inactivation = 100 - 100 / 10z

where z = 3 X Sigma CTcalc / CT_99.9

(e) The residual disinfectant concentration of the water entering the distribution system shall be monitored continuously, and the lowest value shall be recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every 4 hours may be conducted in lieu of continuous monitoring, but for no more than 5 working days following the failure of the equipment, and systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing basis at the frequencies prescribed below:

System size by population	Samples/day [FN1]
<=500 ...........................................	1
501 to 1,000 ..................................	2
1,001 to 2,500 ..................................	3
2,501 to 3,300 ..................................	4
[FN1] The day's samples cannot be taken at the same time. The sampling intervals are subject to Department review and approval.
If at any time the residual disinfectant concentration falls below 0.2 mg/l in a system using grab sampling in lieu of continuous monitoring, the system shall take a grab sample every 4 hours until the residual concentration is equal to or greater than 0.2 mg/l.

(f)

(i) Until March 31, 2016, the residual disinfectant concentration shall be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in R.61-58.5.G. Beginning April 1, 2016, the residual disinfectant concentration shall be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in R.61-58.17.E through R.61-58.17.I. The Department may allow a public water system which uses both a surface water source or a ground water source under the direct influence of surface water, and a ground water source, to take disinfectant residual samples at points other than the total coliform sampling points if the Department determines that such points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as heterotrophic plate count (HPC) as specified in R.61-58.10.F(1), may be measured in lieu of residual disinfectant concentration.

(ii) If the Department determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by paragraph (1)(c) of this section and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (2)(f)(i) of this section do not apply to that system.

(3) Monitoring requirements for systems using filtration treatment.

A public water system that uses a surface water source or a ground water source under the influence of surface water and provides filtration treatment shall monitor in accordance with this paragraph beginning June 29, 1993, or when filtration is installed, whichever is later.

(a) Turbidity measurements as required by R.61-58.10(E)(E)shall be performed on representative samples of the system's filtered water every four hours (or more frequently) that the system serves water to the public. A public water system may substitute continuous turbidity monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a regular basis using a protocol approved by the Department. For any systems using slow sand filtration or filtration treatment other than conventional treatment, direct filtration, or diatomaceous earth filtration, the Department may reduce the sampling frequency to once per day if it determines that less frequent monitoring is sufficient to indicate effective filtration performance. For systems serving 500 or fewer persons, the Department may reduce the turbidity sampling frequency to once per day, regardless of the type of filtration treatment used if the Department determines that less frequent monitoring is sufficient to indicate effective filtration performance.

(b) The residual disinfectant concentration of the water entering the distribution system shall be monitored continuously, and the lowest value shall be recorded each day, except that if there is a failure in the continuous monitoring equipment, grab sampling every 4 hours may be conducted in lieu of continuous monitoring, but for no more than 5 working days following the failure of the equipment, and systems serving 3,300 or fewer persons may take grab samples in lieu of providing continuous monitoring on an ongoing basis at the frequencies each day prescribed below:

System size by population	Samples/day [FN1]
<=500 .................................................	1
501 to 1,000 ..............................	2
1,001 to 2,500 ..................................	3
2,501 to 3,300 ..................................	4
[FN1] The day's samples cannot be taken at the same time. The sampling intervals are subject to Department review and approval.
If at any time the residual disinfectant concentration falls below 0.2 mg/l in a system using grab sampling in lieu of continuous monitoring, the system shall take a grab sample every 4 hours until the residual disinfectant concentration is equal to or greater than 0.2 mg/l.

(c)

(i) Until March 31, 2016, the residual disinfectant concentration shall be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in R.61-68.5.G. Beginning April 1, 2016, the residual disinfectant concentration shall be measured at least at the same points in the distribution system and at the same time as total coliforms are sampled, as specified in R.61-58.17.E through R.61-58.17.I. The Department may allow a public water system which uses both a surface water source or a ground water source under the direct influence of surface water, and a ground water source to take disinfectant residual samples at points other than the total coliform sampling points if the Department determines that such points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as heterotrophic plate count (HPC) as specified in R.61-58.10.F(1), may be measured in lieu of residual disinfectant concentration.

(ii) If the Department determines, based on site-specific considerations, that a system has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions specified by paragraph (1)(c) of this section and that the system is providing adequate disinfection in the distribution system, the requirements of paragraph (3)(c)(i) of this section do not apply to that system.

S.C. Code Regs. § 61-58.10.F

Amended by State Register Volume 38, Issue No. 9, eff. 9/26/2014.