|
||||||
|---|---|---|---|---|---|---|
| Home | 29 CFR | 40 CFR | 49 CFR | Federal Register | MSDS Search | Purchase CFR e-Books |
§141.74 Analytical and monitoring requirements.
(a) Analytical requirements. Only the analytical method(s) specified in this paragraph, or otherwise approved by EPA, may be used to demonstrate compliance with §§141.71, 141.72 and 141.73. Measurements for pH, turbidity, temperature and residual disinfectant concentrations must be conducted by a person approved by the State. Measurement for total coliforms, fecal coliforms and HPC must be conducted by a laboratory certified by the State or EPA to do such analysis. Until laboratory certification criteria are developed for the analysis of fecal coliforms and HPC, any laboratory certified for total coliforms analysis by the State or EPA is deemed certified for fecal coliforms and HPC analysis. The following procedures shall be conducted in accordance with the publications listed in the following section. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the methods published in Standard Methods for the Examination of Water and Wastewater may be obtained from the American Public Health Association et al., 1015 Fifteenth Street, NW., Washington, DC 20005; copies of the Minimal Medium ONPG-MUG Method as set forth in the article "National Field Evaluation of a Defined Substrate Method for the Simultaneous Enumeration of Total Coliforms and Esherichia coli from Drinking Water: Comparison with the Standard Multiple Tube Fermentation Method" (Edberg et al.), Applied and Environmental Microbiology, Volume 54, pp. 1595-1601, June 1988 (as amended under Erratum, Applied and Environmental Microbiology, Volume 54, p. 3197, December, 1988), may be obtained from the American Water Works Association Research Foundation, 6666 West Quincy Avenue, Denver, Colorado, 80235; and copies of the Indigo Method as set forth in the article "Determination of Ozone in Water by the Indigo Method" (Bader and Hoigne), may be obtained from Ozone Science & Engineering, Pergamon Press Ltd., Fairview Park, Elmsford, New York 10523. Copies may be inspected at the U.S. Environmental Protection Agency, Room EB15, 401 M St., SW., Washington, DC 20460 or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(1) Public water systems must conduct analysis of pH and temperature in accordance with one of the methods listed at §141.23(k)(1). Public water systems must conduct analysis of total coliforms, fecal coliforms, heterotrophic bacteria, and turbidity in accordance with one of the following analytical methods and by using analytical test procedures contained in Technical Notes on Drinking Water Methods, EPA-600/R-94-173, October 1994, which is available at NTIS PB95-104766.
------------------------------------------------------------------------
Organism Methodology Citation \1\
------------------------------------------------------------------------
Total Coliform \2\............. Total Coliform 9221 A, B, C
Fermentation
Technique [SU]3 4
5[/SU].
Total Coliform 9222 A, B, C
Membrane Filter
Technique \6\.
ONPG-MUG Test \7\. 9223
Fecal Coliforms \2\............ Fecal Coliform 9221 E
Procedure \8\.
Fecal Coliform 9222 D
Filter Procedure.
Heterotrophic bacteria \2\..... Pour Plate Method. 9215 B
SimPlate \11\.....
Turbidity...................... Nephelometric 2130 B
Method.
Nephelometric 180.1 \9\
Method.
Great Lakes Method 2 \10\
Instruments.
Hach FilterTrak... 10133 \12\
------------------------------------------------------------------------
The procedures shall be done in accordance with the documents listed
below. The incorporation by reference of the following documents
listed in footnotes 1, 6, 7 and 9-12 was approved by the Director of
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. Copies of the documents may be obtained from the sources listed
below. Information regarding obtaining these documents can be obtained
from the Safe Drinking Water Hotline at 800-426-4791. Documents may be
inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue,
NW., EPA West, Room B102, Washington DC 20460 (Telephone: 202-566-
2426); or at the Office of the Federal Register, 800 North Capitol
Street, NW., Suite 700, Washington, DC 20408.
\1\ Except where noted, all methods refer to Standard Methods for the
Examination of Water and Wastewater, 18th edition (1992), 19th edition
(1995), or 20th edition (1998), American Public Health Association,
1015 Fifteenth Street, NW., Washington, DC 20005. The cited methods
published in any of these three editions may be used.
\2\ The time from sample collection to initiation of analysis may not
exceed 8 hours. Systems must hold samples below 10 deg. C during
transit.
\3\ Lactose broth, as commercially available, may be used in lieu of
lauryl tryptose broth, if the system conducts at least 25 parallel
tests between this medium and lauryl tryptose broth using the water
normally tested, and this comparison demonstrates that the false-
positive rate and false-negative rate for total coliform, using
lactose broth, is less than 10 percent.
\4\ Media should cover inverted tubes at least one-half to two-thirds
after the sample is added.
\5\ No requirement exists to run the completed phase on 10 percent of
all total coliform-positive confirmed tubes.
\6\ MI agar also may be used. Preparation and use of MI agar is set
forth in the article, ``New medium for the simultaneous detection of
total coliform and Escherichia coli in water'' by Brenner, K.P., et.
al., 1993, Appl. Environ. Microbiol. 59:3534-3544. Also available from
the Office of Water Resource Center (RC-4100T), 1200 Pennsylvania
Avenue, NW., Washington DC 20460, EPA/600/J-99/225. Verification of
colonies is not required.
\7\ The ONPG-MUG Test is also known as the Autoanalysis Colilert System.
\8\ A-1 Broth may be held up to three months in a tightly closed screw
cap tube at 4 deg. C.
\9\ ``Methods for the Determination of Inorganic Substances in
Environmental Samples'', EPA/600/R-93/100, August 1993. Available at
NTIS, PB94-121811.
\10\ GLI Method 2, ``Turbidity'', November 2, 1992, Great Lakes
Instruments, Inc., 8855 North 55th Street, Milwaukee, Wisconsin 53223.
\11\ A description of the SimPlate method, ``IDEXX SimPlate TM HPC Test
Method for Heterotrophs in Water'', November 2000, can be obtained
from IDEXX Laboratories, Inc., One IDEXX Drive, Westbrook, Maine
04092, telephone (800) 321-0207.
\12\ A description of the Hach FilterTrak Method 10133, ``Determination
of Turbidity by Laser Nephelometry'', January 2000, Revision 2.0, can
be obtained from; Hach Co., P.O. Box 389, Loveland, Colorado 80539-
0389. Phone: 800-227-4224.
(2) Public water systems must measure residual disinfectant concentrations
with one of the analytical methods in the following table. Except for the method
for ozone residuals, the disinfectant residual methods are contained in the
18th, 19th, and 20th editions of Standard Methods for the Examination of Water
and Wastewater, 1992, 1995, and 1998; the cited methods published in any of
these three editions may be used. The ozone method, 4500-O (b) 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 must begin monitoring, as specified in this
paragraph (b), beginning December 31, 1990, unless the State has determined that
filtration is required in writing pursuant to §1412(b)(7)(C)(iii), in which case
the State 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 must begin monitoring as specified in this paragraph (b) beginning
December 31, 1990, or 6 months after the State determines that the ground water
source is under the direct influence of surface water, whichever is later,
unless the State has determined that filtration is required in writing pursuant
to §1412(b)(7)(C)(iii), in which case the State may specify alternative
monitoring requirements, as appropriate, until filtration is in place.
(1) Fecal coliform or total coliform density measurements as required by
§141.71(a)(1) must be performed on representative source water samples
immediately prior to the first or only point of disinfectant application. The
system must sample for fecal or total coliforms at the following minimum
frequency each week the system serves water to the public: Also, one fecal or total coliform density measurement must 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
requirement) unless the State determines that the system, for logistical reasons
outside the system's control, cannot have the sample analyzed within 30 hours of
collection.
(2) Turbidity measurements as required by §141.71(a)(2) must 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 State.
(3) The total inactivation ratio for each day that the system is in operation
must be determined based on the CT (i) The temperature of the disinfected water must 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 must be
measured at least once per day at each chlorine residual disinfectant
concentration sampling point.
(iii) The disinfectant contact time(s) ("T") must 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 must be measured each day during peak hourly flow.
(v) If a system uses a disinfectant other than chlorine, the system may
demonstrate to the State, through the use of a State-approved protocol for
on-site disinfection challenge studies or other information satisfactory to the
State, that CT (4) The total inactivation ratio must 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 (B) Successive CTcalc/CT
------------------------------------------------------------------------
Residual Methodology Methods
------------------------------------------------------------------------
Free Chlorine................. Amperometric 4500-Cl D
Titration.
DPD Ferrous 4500-Cl F
Titrimetric.
DPD Colorimetric. 4500-Cl G
Syringaldazine 4500-Cl H
(FACTS).
Total Chlorine................ Amperometric 4500-Cl D
Titration.
Amperometric 4500-Cl E
Titration (low
level
measurement).
DPD Ferrous 4500-Cl F
Titrimetric.
DPD Colorimetric. 4500-Cl G
Iodometric 4500-Cl I
Electrode.
Chlorine Dioxide.............. Amperometric 4500-ClO[INF]2[/INF]
Titration. C
DPD Method....... 4500-ClO[INF]2[/INF]
D
Amperometric 4500-ClO[INF]2[/INF]
Titration. E
Ozone......................... Indigo Method.... 4500-O[INF]3[/INF] B
------------------------------------------------------------------------
------------------------------------------------------------------------
Samples/
System size (persons served) week\1\
------------------------------------------------------------------------
[lE]500...................................................... 1
501 to 3,300................................................. 2
3,301 to 10,000.............................................. 3
10,001 to 25,000............................................. 4
>25,000................................................... 5
------------------------------------------------------------------------
\1\ Must be taken on separate days.
Table 1.1_CT Values (CT[INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 0.5 °C or Lower \1\
----------------------------------------------------------------------------------------------------------------
pH
Residual (mg/l) ----------------------------------------------------
[lE]6.0 6.5 7.0 7.5 8.0 8.5 [lE]9.0
----------------------------------------------------------------------------------------------------------------
[lE]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........................................................ 152 180 215 259 313 376 451
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
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature and at the higher pH.
Table 1.2_CT Values (CT [INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 5.0 °C\1\
----------------------------------------------------------------------------------------------------------------
pH
Free residual (mg/l) ----------------------------------------------------
[lE]6.0 6.5 7.0 7.5 8.0 8.5 [lE]9.0
----------------------------------------------------------------------------------------------------------------
[lE]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
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature, and at the higher pH.
Table 1.3_CT Values (CT [INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 10.0 °C\1\
----------------------------------------------------------------------------------------------------------------
pH
Free residual (mg/l) ----------------------------------------------------
[lE]6.0 6.5 7.0 7.5 8.0 8.5 [lE]9.0
----------------------------------------------------------------------------------------------------------------
[lE]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
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature, and at the higher pH.
Table 1.4_CT Values (CT [INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 15.0 °C\1\
----------------------------------------------------------------------------------------------------------------
pH
Free residual (mg/l) ----------------------------------------------------
[lE]6.0 6.5 7.0 7.5 8.0 8.5 [lE]9.0
----------------------------------------------------------------------------------------------------------------
[lE]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
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature, and at the higher pH.
Table 1.5_CT Values (CT[INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 20 °C\1\
----------------------------------------------------------------------------------------------------------------
pH
--------------------------------------------------
Free residual (mg/l) [lE] [lE]
6.0 6.5 7.0 7.5 8.0 8.5 9.0
----------------------------------------------------------------------------------------------------------------
[lE] 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
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature, and at the higher pH.
Table 1.6_CT Values (CT[INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Free Chlorine
at 25 °C\1\ and Higher
----------------------------------------------------------------------------------------------------------------
pH
--------------------------------------------------
Free residual (mg/l) [lE] [lE]
6.0 6.5 7.0 7.5 8.0 8.5 9.0
----------------------------------------------------------------------------------------------------------------
[lE] 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 46 55 67 81 97
----------------------------------------------------------------------------------------------------------------
\1\ 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 CT[INF]99.9[/
INF] value at the lower temperature, and at the higher pH.
Table 2.1_CT Values (CT[INF]99.9[/INF]) for 99.9 Percent Inactivation of Giardia Lamblia Cysts by Chlorine
Dioxide and Ozone\1\
----------------------------------------------------------------------------------------------------------------
Temperature
-----------------------------------------------------------
< 1 5 10 15 20 >== 25
°C °C °C °C °C °C
----------------------------------------------------------------------------------------------------------------
Chlorine dioxide.................................... 63 26 23 19 15 11
Ozone............................................... 2.9 1.9 1.4 0.95 0.72 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 CT[INF]99.9[/INF]
value at the lower temperature for determining CT[INF]99.9[/INF] values between indicated temperatures.
Table 3.1_CT Values (CT [INF]99.9[/INF]) for 99.9 Percent Inactivation
of Giardia Lamblia Cysts By Chloramines\1\
------------------------------------------------------------------------
Temperature
-------------------------------------------------------------------------
< 1 20 °C
°C 5 °C 10 °C 15 °C 25 °C
------------------------------------------------------------------------
3,800 2,200 1,850 1,500 1,100 750
------------------------------------------------------------------------
\1\ 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 must demonstrate,
based on on-site studies or other information, as approved by the
State, 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 CT[INF]99.9[/INF] value at the lower temperature for
determining CT[INF]99.9[/INF] values between indicated temperatures.