40 C.F.R. § C app A to Subpart C of Part 141

Current through September 30, 2024
Appendix A to Subpart C of Part 141 - Alternative Testing Methods Approved for Analyses Under the Safe Drinking Water Act

Only the editions stated in the following table are approved.

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(3)

OrganismMethodologySM 21st Edition1SM 22nd Edition28SM Online3Other
Total ColiformsTotal Coliform Fermentation Technique9221 A, B9221 A, B9221 A,B-06
Total Coliform Membrane Filter Technique9222 A, B, C
Presence-Absence (P-A) Coliform Test9221 D
ONPG-MUG Test92239223 B9223 B-04
ColitagTMModified ColitagTM13
Tecta EC/TC33

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(5)

OrganismMethodologySM 22nd Edition28SM Online3
Fecal ColiformsFecal Coliform Procedure9221 E9221 E-06

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(6)

OrganismMethodologySM 20th
Edition6
SM 21st
Edition1
SM 22nd
Edition28
SM Online3Other
E.coliONPG-MUG Test9223 B9223 B9223 B9223 B-97, B-04
ColitagTMModified ColitagTM13
Tecta EC/TC33

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.23(k)(1)

ContaminantMethodologyEPA methodSM 21st
edition1
SM 22nd
edition28
SM 23rd
edition,49 SM
24th edition66
SM online3ASTM4Other
AlkalinityTitrimetric2320 B2320 B2320 BD1067-06 B, 11 B, 16 B
AntimonyHydride-Atomic AbsorptionD 3697-07, -12, -17
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
ArsenicAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 2972-08 C, -15 C
Hydride Atomic Absorption3114 B3114 B3114 B3114 B-09D 2972-08 B, -15 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
BariumInductively Coupled Plasma3120 B3120 B3120 B
Atomic Absorption; Direct3111 D3111 D3111 D
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
BerylliumInductively Coupled Plasma3120 B3120 B3120 B
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3645-08 B, -15 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CadmiumAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CalciumEDTA titrimetric3500-Ca B3500-Ca B3500-Ca BD 511-09, -14 A
Atomic Absorption; Direct Aspiration3111 B3111 B3111 BD 511-09, -14 B
Inductively Coupled Plasma3120 B3120 B3120 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Ion ChromatographyD 6919-09, -17
ChromiumInductively Coupled Plasma3120 B3120 B3120 B
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
CopperAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 1688-07, -12 C, 17 C
Atomic Absorption; Direct Aspiration3111 B3111 B3111 BD 1688-07, -12 A, 17 A
Inductively Coupled Plasma3120 B3120 B3120 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
ColorimetryHach Method 8026,35 Hach Method 10272.36
ConductivityConductance2510 B2510 B2510 BD 1125-14 A
CyanideManual Distillation with MgCl2 followed by:4500-CN-C4500-CN-C4500-CN-C4500-CN-C-99D 2036-06 A
Spectrophotometric, Amenable4500-CN-G4500-CN-G4500-CN-GD 2036-06 B
Spectrophotometric Manual4500-CN-E4500-CN-E4500-CN-ED2036-06 A
Selective Electrode4500-CN-F4500-CN-F4500-CN-F
Gas Chromatography/Mass Spectrometry HeadspaceME355.01.7
FluorideIon Chromatography4110 B4110 B4110 BD 4327-11, -17
Manual Distillation; Colorimetric SPADNS4500-F-B, D4500-F-B, D4500-F-B, D
Manual Electrode4500-F-C4500-F-C4500-F-CD 1179-04, 10 B, 16 B
Automated Alizarin4500-F-E4500-F-E4500-F-E
Arsenite-Free Colorimetric SPADNSHach SPADNS 2 Method 10225,22 Hach Method 10312.67
LeadAtomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3559-08 D, 15 D
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Differential Pulse Anodic Stripping VoltametryMethod 1001, Rev. 1.1.57
MagnesiumAtomic Absorption3111 B3111 B3111 BD 511-09, -14 B
Inductively Coupled Plasma3120 B3120 B3120 B
Complexation Titrimetric Methods3500-Mg B3500-Mg B3500-Mg BD 511-09, -14 A
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Ion ChromatographyD 6919-09, -17
MercuryManual, Cold Vapor3112 B3112 B3112 B3112 B-09D 3223-12, -17
NickelInductively Coupled Plasma3120 B3120 B3120 B
Atomic Absorption; Direct3111 B3111 B3111 B
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
NitrateIon Chromatography4110 B4110 B4110 BD 4327-11, -17
Automated Cadmium Reduction4500-NO3-F4500-NO3-F4500-NO3-F
Manual Cadmium Reduction4500-NO3- E4500-NO3- E4500-NO3- E
Ion Selective Electrode4500-NO3- D4500-NO3- D4500-NO3- D
Reduction/ColorimetricSystea Easy (1-Reagent),8 NECi Nitrate-Reductase.40
Colorimetric; DirectHach TNTplusTM 835/836 Method 10206.23
Capillary Ion ElectrophoresisD 6508-15
NitriteIon Chromatography4110 B4110 B4110 BD 4327-11, -17
Automated Cadmium Reduction4500-NO3-F4500-NO3-F4500-NO3-F
Manual Cadmium Reduction4500-NO3-E4500-NO3-E4500-NO3-E
Spectrophotometric4500-NO2-B4500-NO2-B4500-NO2-B
Reduction/ColorimetricSystea Easy (1-Reagent),8 NECi Nitrate-Reductase.40
Capillary Ion ElectrophoresisD 6508-15
Ortho-phosphateIon Chromatography4110 B4110 B4110 BD 4327-11, -17
Colorimetric, ascorbic acid, single reagent4500-P E4500-P E4500-P E4500-P E-99
Colorimetric, Automated, Ascorbic Acid4500-P F4500-P F4500-P F4500-P F-99Thermo Fisher Discrete Analyzer.41
Capillary Ion ElectrophoresisD 6508-15
pHElectrometric48 150.34500-H+ B4500-H+ B4500-H+ BD 1293-12, -18
SeleniumHydride-Atomic Absorption3114 B3114 B3114 B3114 B-09D 3859-08 A, -15 A
Atomic Absorption; Furnace3113 B3113 B3113 B3113 B-04, B-10D 3859-08 B, -15 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
SilicaColorimetricD859-05, 10, 16
Molybdosilicate4500-SiO2 C4500-SiO2 C4500-SiO2 C
Heteropoly blue4500-SiO2 D4500-SiO2 D4500-SiO2 D
Automated for Molybdate-reactive Silica4500-SiO2 E4500-SiO2 E4500-SiO2 E
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Inductively Coupled Plasma3120 B3120 B3120 B
SodiumAtomic Absorption; Direct Aspiration3111 B3111 B3111 B
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Ion ChromatographyD 6919-09, -17
TemperatureThermometric2550255025502550-10

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.24(e)(1)

ContaminantMethodologyEPA methodSM 21st edition1SM 22nd
edition,28 SM
23rd edition,49 SM
24th edition66
SM online3ASTM4Other
BenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Carbon tetrachloridePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
ChlorobenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichlorobenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,4-DichlorobenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichloroethanePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
cis-DichloroethylenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
trans-DichloroethylenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
DichloromethanePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2-DichloropropanePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
EthylbenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
StyrenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.429
TetrachloroethylenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,1,1-TrichloroethanePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
TrichloroethylenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
ToluenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,2,4-TrichlorobenzenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
1,1-DichloroethylenePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.429
1,1,2-TrichlorethanePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Vinyl chloridePurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
Xylenes (total)Purge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29
2,4-DGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06D 5317-20
2,4,5-TP (Silvex)Gas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06D 5317-20
AlachlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
AtrazineLiquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)536.25
Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3,24 523.26
Benzo(a)pyreneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
CarbofuranHigh-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection6610 B6610 B6610 B-04
Liquid Chromatography/Mass SpectrometryME 531.58
ChlordaneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
DalaponIon Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
Gas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06
Di(2-ethylhexyl)adipateSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Di(2-ethylhexyl)phthalateSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Dibromochloropropane (DBCP)Purge & Trap/Gas Chromatography/Mass Spectrometry524.3.9
DinosebGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06
EndrinSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Ethyl dibromide (EDB)Purge & Trap/Gas Chromatography/Mass Spectrometry524.3.9
GlyphosateHigh-Performance Liquid Chromatography (HPLC) with Post-Column Derivatization and Fluorescence Detection6651 B6651 B6651 B-00, B-05
HeptachlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Heptachlor EpoxideSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
HexachlorobenzeneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Hexachlorocyclo-pentadieneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
LindaneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
MethoxychlorSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
OxamylHigh-performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection6610 B6610 B6610 B-04
Liquid Chromatography/Mass SpectrometryME 531.58
PCBs (as Aroclors)Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
PentachlorophenolGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06D 5317-20
Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
PicloramGas Chromatography/Electron Capture Detection (GC/ECD)6640 B6640 B6640 B-01, B-06D 5317-20
SimazineLiquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)536.25
Solid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3,24 523.26
ToxapheneSolid Phase Extraction/Gas Chromatography/Mass Spectrometry (GC/MS)525.3.24
Total TrihalomethanesPurge & Trap/Gas Chromatography/Mass Spectrometry524.3,9 524.4.29

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.25(a)

ContaminantMethodologyEPA methodSM 21st edition1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition66ASTM4SM online3
Naturally Occurring:
Gross alpha and betaEvaporation900.0, Rev. 1.0507110 B7110 B
Liquid Scintillation7110 DD 7283-177110 D-17.
Gross alphaCoprecipitation7110 C7110 C
Radium 226Radon emanation903.1, Rev. 1.0537500-Ra C7500-Ra CD 3454-05, -18, D 3454-21
Radiochemical903.0, Rev. 1.0547500-Ra B7500-Ra BD 2460-07
Gamma Spectrometry7500-Ra E7500-Ra E-07.
Radium 228Radiochemical904.0, Rev. 1.0627500-Ra D7500-Ra D
Gamma Spectrometry7500-Ra E7500-Ra E-07.
UraniumRadiochemical7500-U B7500-U B
ICP-MS3125D 5673-05, 10, 16
Alpha spectrometry7500-U C7500-U CD 3972-09
Laser PhosphorimetryD 5174-07
Alpha Liquid Scintillation SpectrometryD 6239-09
Man-Made:
Radioactive CesiumRadiochemical7500-Cs B7500-Cs B
Gamma Ray Spectrometry71207120D 3649-06
Radioactive IodineRadiochemical7500-I B, 7500-I C, 7500-I D7500-I B, 7500-I C, 7500-I DD 3649-06
Gamma Ray Spectrometry71207120D 4785-08, -20
Radioactive Strontium 89, 90Radiochemical7500-Sr B7500-Sr B
TritiumLiquid Scintillation7500-3H B7500-3H BD 4107-08, -20
Gamma EmittersGamma Ray Spectrometry7120, 7500-Cs B, 7500-I B7120, 7500-Cs B, 7500-I BD 3649-06, D 4785-08, -20

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.74(a)(1)

OrganismMethodologySM 21st edition1SM 22nd
edition28
SM 23rd edition49SM 24th edition66SM online3Other
Total ColiformTotal Coliform Fermentation Technique9221 A, B, C9221 A, B, C9221 A, B, C9221 A, B, C9221 A, B, C-06
Total Coliform Membrane Filter Technique9222 A, B, C9222 A, B, C9222 A, B, C
ONPG-MUG Test92239223 B9223 B9223 B9223 B-04
Fecal ColiformsFecal Coliform Procedure9221 E9221 E9221 E9221 E9221 E-06
Fecal Coliform Filter Procedure9222 D9222 D9222 D9222 D9222 D-06
Heterotrophic bacteriaPour Plate Method9215 B9215 B9215 B9215 B-04
TurbidityNephelometric Method2130 B2130 B2130 B2130 BHach Method 8195, Rev. 3.0.52
Laser Nephelometry (on-line)Mitchell M5271,10 Mitchell M5331, Rev. 1.2,42 Lovibond PTV 6000.46
LED Nephelometry (on-line)Mitchell M5331,11 Mitchell M5331, Rev. 1.2,42 Lovibond PTV 2000,45 Yokogawa 820.68
LED Nephelometry (on-line)AMI Turbiwell,15 Lovibond PTV 1000.44
LED Nephelometry (portable)Orion AQ4500,12 Lovibond TB 3500,64 Lovibond TB 5000.65
Laser Nephelometry (portable)Lovibond TB 6000.63
360° NephelometryHach Method 10258, Rev. 1.0,39 Hach Method 10258, Rev. 2.0.51

Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.74(a)(2)

ResidualMethodologyEPA methodsSM 21st edition1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition66ASTM4Other
Free ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Indophenol ColorimetricHach Method 10241.34
Syringaldazine (FACTS)4500-Cl H4500-Cl H
On-line Chlorine AnalyzerEPA 334.0.16
Amperometric SensorChloroSense,17 ChloroSense, Rev. 1.1.59
Total ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
Amperometric Titration (Low level measurement)4500-Cl E4500-Cl E
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Indophenol Colorimetric127.55
Iodometric Electrode4500-Cl I4500-Cl I
On-line Chlorine AnalyzerEPA 334.0.16
Amperometric SensorChloroSense,17 ChloroSense, Rev. 1.1.59
Chlorine DioxideAmperometric Titration4500-ClO2 C4500-ClO2 C
Amperometric Titration4500-ClO2 E4500-ClO2 E
Amperometric SensorChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60
OzoneIndigo Method4500-O3 B4500-O3 B

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.131(b)(1)

ContaminantMethodologyEPA methodASTM4SM online3SM 21st edition1SM 22nd
edition,28 SM
23rd edition,49
SM 24th
Edition66
Other
TTHMP & T/GC/MS524.3,9 524.4.29
HAA5LLE (diazomethane)/GC/ECD6251 B-076251 B6251 B
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
Two-Dimensional Ion Chromatography (IC) with Suppressed Conductivity DetectionThermo Fisher 557.1.47
BromateTwo-Dimensional Ion Chromatography (IC)302.018
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557.14
Chemically Suppressed Ion ChromatographyD 6581-08 A
Electrolytically Suppressed Ion ChromatographyD 6581-08 B
ChloriteChemically Suppressed Ion ChromatographyD 6581-08 A
Electrolytically Suppressed Ion ChromatographyD 6581-08 B
Chlorite-daily monitoring as prescribed in 40 CFR 141.132(b)(2)(i)(A) Amperometric Titration4500-ClO2 E4500-ClO2 E
Amperometric SensorChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60

Alternative Testing Methods for Disinfectant Residuals Listed at 40 CFR 141.131(c)(1)

ResidualMethodologySM 21st edition1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition66ASTM4Other
Free ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Indophenol ColorimetricHach Method 10241.34
Syringaldazine (FACTS)4500-Cl H4500-Cl H
Amperometric SensorChloroSense,17 ChloroSense, Rev. 1.1.59
On-line Chlorine AnalyzerEPA 334.0.16
Combined ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14.
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Total ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
[GREATER THAN]Low level Amperometric Titration4500-Cl E4500-Cl E
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl GHach Method 10260.31
Iodometric Electrode4500-Cl I4500-Cl I
Amperometric SensorChloroSense,17 ChloroSense, Rev. 1.1.59
On-line Chlorine AnalyzerEPA 334.0.16
Chlorine DioxideAmperometric Method II4500-ClO2 E4500-ClO2 E
Amperometric SensorChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60

Alternative Testing Methods for Parameters Listed at 40 CFR 141.131(d)

ParameterMethodologySM 21st edition1SM 22nd edition28SM 23rd edition49, SM 24th edition66SM online3EPAOther
Total Organic Carbon (TOC)High Temperature Combustion5310 B5310 B5310 B415.3, Rev 1.219
Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C415.3, Rev 1.219Hach Method 1026738.
Wet Oxidation5310 D5310 D415.3, Rev 1.219
Ozone OxidationHach Method 1026137.
Specific Ultraviolet Absorbance (SUVA)Calculation using DOC and UV254 data415.3, Rev 1.219
Dissolved Organic Carbon (DOC)High Temperature Combustion5310 B5310 B5310 B415.3, Rev 1.219
Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C415.3, Rev 1.219
Wet Oxidation5310 D5310 D415.3, Rev 1.219
Ultraviolet absorption at 254 nm (UV254)Spectrophotometry5910 B5910 B5910 B5910 B-11415.3, Rev 1.219

Alternative Testing Methods With MRL [LESS THAN EQUAL TO]0.0010 mg/L for Monitoring Listed at 40 CFR 141.132(b)(3)(ii)(B)

ContaminantMethodologyEPA method
BromateTwo-Dimensional Ion Chromatography (IC)302.018
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)55714

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.402(c)(2)

OrganismMethodologySM 20th edition6SM 21st edition1SM 22nd edition28SM 23rd edition49, SM 24th edition66SM online3Other
E. coliColilert9223 B9223 B9223 B9223 B-97, B-04
Colisure9223 B9223 B9223 B9223 B-97, B-04
Colilert-189223 B9223 B9223 B9223 B9223 B-97, B-04
Readycult®Readycult®.20
ColitagModified ColitagTM13, Modified Colitag TM, Version 2.0.61
Chromocult®Chromocult®.21
EC-MUG9221 F9221 F9221 F-06
NA-MUG9222 I
mColiBlue24 Test9222 J
Tecta EC/TC3343
RAPID'E.coli 256
EnterococciMultiple-Tube Technique9230 B9230 B-04
Membrane Filter Techniques9230 C
Fluorogenic Substrate Enterococcus Test (using Enterolert)9230 D
ColiphageTwo-Step Enrichment Presence-Absence ProcedureFast Phage.30

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.704(b)

OrganismMethodologySM 20th edition6
E. coliMembrane Filtration, Two Step9222 D/9222 G

Alternative Testing Methods for Contaminants Listed at 40 CFR 141.852(a)(5)

OrganismMethodology categoryMethodSM 20th, 21st editions16SM 22nd edition28SM 23rd edition49, SM 24th edition66SM online3
Total ColiformsLactose Fermentation MethodsStandard Total Coliform Fermentation Technique9221 B.1, B.29221 B.1, B.2, B.3, B.49221 B.1, B.2-06.
Presence-Absence (P-A) Coliform Test9221 D.1, D.2, D.3
Membrane Filtration MethodsStandard Total Coliform Membrane Filter Procedure using Endo Media9222 B, C
Simultaneous Detection of Total Coliforms and E. coli by Dual Chromogen Membrane Filter Procedure (using mColiBlue24 medium)9222 J
Simultaneous Detection of Total Coliform Bacteria and Escherichia coli Using RAPID'E.coli (REC2) in Drinking Water56
Enzyme Substrate MethodsColilert®9223 B9223 B9223 B-04.
Colisure®9223 B9223 B9223 B-04.
Colilert-189223 B9223 B9223 B9223 B-04.
Tecta EC/TC3343
Modified ColitagTM, Version 2.061
Escherichia coliEscherichia coli Procedure (following Lactose Fermentation Methods)EC-MUG medium9221 F.19221 F.19221 F.1-06.
Escherichia coli Partitioning Methods (following Membrane Filtration Methods)EC broth with MUG (EC-MUG)9222 H
NA-MUG medium9222 I
Simultaneous Detection of Total Coliforms and E. coli by Dual Chromogen Membrane Filter ProceduremColiBlue24 medium9222 J
Membrane Filtration MethodSimultaneous Detection of Total Coliform Bacteria and Escherichia coli Using RAPID'E.coli (REC2) in Drinking Water56
Enzyme Substrate MethodsColilert®9223 B9223 B9223 B-04.
Colisure®9223 B9223 B9223 B-04.
Colilert-189223 B9223 B9223 B9223 B-04.
Tecta EC/TC3343
Modified ColitagTM, Version 2.061

Alternative Testing Methods for Contaminants Listed at 40 CFR 143.4(b)

ContaminantMethodologyEPA methodASTM4SM 21st edition1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition66SM online3
AluminumAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Atomic Absorption; Direct3111 D3111 D
Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma3120 B3120 B
ChlorideSilver Nitrate TitrationD 512-04 B, 12 B4500-Cl-B4500-Cl-B
Ion ChromatographyD 4327-11, -174110 B4110 B
Potentiometric Titration4500-Cl-D4500-Cl-D
ColorVisual Comparison2120 B2120 B
Foaming AgentsMethylene Blue Active Substances (MBAS)5540 C5540 C
IronAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Atomic Absorption; Direct3111 B3111 B
Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10
Inductively Coupled Plasma3120 B3120 B
ManganeseAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Atomic Absorption; Direct3111 B3111 B
Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma3120 B3120 B
OdorThreshold Odor Test2150 B2150 B
SilverAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Atomic Absorption; Direct3111 B3111 B
Atomic Absorption; Furnace3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma3120 B3120 B
SulfateIon ChromatographyD 4327-11, -174110 B4110 B
Gravimetric with ignition of residue 4500-SO42-C 4500-SO42-C 4500-SO42-C-97.
Gravimetric with drying of residue 4500-SO42-D 4500-SO42-D 4500-SO42-D-97.
Turbidimetric methodD 516-07, 11, 16 4500-SO42-E 4500-SO42-E 4500-SO42-E-97.
Automated methylthymol blue method 4500-SO42-F 4500-SO42-F 4500-SO42-F-97.
Total Dissolved SolidsTotal Dissolved Solids Dried at 180 deg C2540 C2540 C
ZincAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.22
Atomic Absorption; Direct Aspiration3111 B3111 B
Inductively Coupled Plasma3120 B3120 B

1Standard Methods for the Examination of Water and Wastewater, 21st edition (2005). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

2 EPA Method 200.5, Revision 4.2. "Determination of Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry." 2003. EPA/600/R-06/115. (Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.)

3 Standard Methods Online are available at http://www.standardmethods.org. The year in which each method was approved by the Standard Methods Committee is designated by the last two digits in the method number. The methods listed are the only online versions that may be used.

4 Available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 or http://astm.org. The methods listed are the only alternative versions that may be used.

5 Method D99-003, Revision 3.0. "Free Chlorine Species (HOCl- and OCl-) by Test Strip," November 21, 2003. Available from Industrial Test Systems, Inc., 1875 Langston St., Rock Hill, SC 29730.

6Standard Methods for the Examination of Water and Wastewater, 20th edition (1998). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

7 Method ME355.01, Revision 1.0. "Determination of Cyanide in Drinking Water by GC/MS Headspace," May 26, 2009. Available at https://www.nemi.gov or from James Eaton, H & E Testing Laboratory, 221 State Street, Augusta, ME 04333. (207) 287-2727.

8 Systea Easy (1-Reagent). "Systea Easy (1-Reagent) Nitrate Method," February 4, 2009. Available at https://www.nemi.gov or from Systea Scientific, LLC., 900 Jorie Blvd., Suite 35, Oak Brook, IL 60523.

9 EPA Method 524.3, Version 1.0. "Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry," June 2009. EPA 815-B-09-009. Available at https://www.nemi.gov.

10 Mitchell Method M5271, Revision 1.1. "Determination of Turbidity by Laser Nephelometry," March 5, 2009. Available at https://www.nemi.gov or from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

11 Mitchell Method M5331, Revision 1.1. "Determination of Turbidity by LED Nephelometry," March 5, 2009. Available at https://www.nemi.gov or from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

12 Orion Method AQ4500, Revision 1.0. "Determination of Turbidity by LED Nephelometry," May 8, 2009. Available at https://www.nemi.gov or from Thermo Scientific, 166 Cummings Center, Beverly, MA 01915, http://www.thermo.com.

13 Modified ColitagTM Method. "Modified ColitagTM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water (ATP D05-0035)," August 28, 2009. Available at https://www.nemi.gov or from CPI International, 5580 Skylane Boulevard, Santa Rosa, CA 95403.

14 EPA Method 557. "Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)," September 2009. EPA 815-B-09-012. Available at https://www.nemi.gov.

15 AMI Turbiwell, "Continuous Measurement of Turbidity Using a SWAN AMI Turbiwell Turbidimeter," August 2009. Available at https://www.nemi.gov or from Markus Bernasconi, SWAN Analytische Instrumente AG, Studbachstrasse 13, CH-8340 Hinwil, Switzerland.

16 EPA Method 334.0. "Determination of Residual Chlorine in Drinking Water Using an On-line Chlorine Analyzer," September 2009. EPA 815-B-09-013. Available at https://www.nemi.gov.

17 ChloroSense. "Measurement of Free and Total Chlorine in Drinking Water by Palintest ChloroSense," August 2009. Available at https://www.nemi.gov or from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018.

18 EPA Method 302.0. "Determination of Bromate in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection," September 2009. EPA 815-B-09-014. Available at https://www.nemi.gov.

19 EPA 415.3, Revision 1.2. "Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water," September 2009. EPA/600/R-09/122. Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.

20 Readycult® Method, "Readycult® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichia coli in Finished Waters," January, 2007. Version 1.1. Available from EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.

21 Chromocult® Method, "Chromocult® Coliform Agar Presence/Absence Membrane Filter Test Method for Detection and Identification of Coliform Bacteria and Escherichia coli in Finished Waters," November, 2000. Version 1.0. EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821.

22 Hach Company. "Hach Company SPADNS 2 (Arsenite-Free) Fluoride Method 10225-Spectrophotometric Measurement of Fluoride in Water and Wastewater," January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.

23 Hach Company. "Hach Company TNTplusTM 835/836 Nitrate Method 10206-Spectrophotometric Measurement of Nitrate in Water and Wastewater," January 2011. 5600 Lindbergh Drive, P.O. Box 389, Loveland, Colorado 80539.

24 EPA Method 525.3. "Determination of Semivolatile Organic Chemicals in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS)," February 2012. EPA/600/R-12/010. Available at http://www.epa.gov/water-research/epa-drinking-water-research-methods.

25 EPA Method 536. "Determination of Triazine Pesticides and their Degradates in Drinking Water by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS)," October 2007. EPA 815-B-07-002. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

26 EPA Method 523. "Determination of Triazine Pesticides and their Degradates in Drinking Water by Gas Chromatography/Mass Spectrometry (GC/MS)," February 2011. EPA 815-R-11-002. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

27 EPA Method 1623.1. "Cryptosporidium and Giardia in Water by Filtration/IMS/FA," 2012. EPA-816-R-12-001. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

28Standard Methods for the Examination of Water and Wastewater, 22nd edition (2012). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

29 EPA Method 524.4, Version 1.0. "Measurement of Purgeable Organic Compounds in Water by Gas Chromatography/Mass Spectrometry using Nitrogen Purge Gas." May 2013. EPA 815-R-13-002. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

30 Charm Sciences Inc. "Fast Phage Test Procedure. Presence/Absence for Coliphage in Ground Water with Same Day Positive Prediction". Version 009. November 2012. 659 Andover Street, Lawrence, MA 01843. Available at www.charmsciences.com.

31 Hach Company. "Hach Method 10260-Determination of Chlorinated Oxidants (Free and Total) in Water Using Disposable Planar Reagent-filled Cuvettes and Mesofluidic Channel Colorimetry," April 2013. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

32 ChlordioX Plus. "Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors," November 2013.

Available from Palintest Ltd, 1455 Jamike Avenue (Suite 100), Erlanger, KY 41018.

33 Tecta EC/TC. "TechtaTM EC/TC Medium and TechtaTM Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water," version 1.0, May 2014. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.

34 Hach Company. "Hach Method 10241-Spectrophotometric Measurement of Free Chlorine (Cl2) in Drinking Water," November 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

35 Hach Company. "Hach Method 8026-Spectrophotometric Measurement of Copper in Finished Drinking Water," December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

36 Hach Company. "Hach Method 10272-Spectrophotometric Measurement of Copper in Finished Drinking Water," December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

37 Hach Company. "Hach Method 10261-Total Organic Carbon in Finished Drinking Water by Catalyzed Ozone Hydroxyl Radical Oxidation Infrared Analysis," December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

38 Hach Company. "Hach Method 10267-Spectrophotometric Measurement of Total Organic Carbon (TOC) in Finished Drinking Water," December 2015. Revision 1.2. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

39 Hach Company. "Hach Method 10258-Determination of Turbidity by 360° Nephelometry," January 2016. Revision 1.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

40 Nitrate Elimination Company Inc. (NECi). "Method for Nitrate Reductase Nitrate-Nitrogen Analysis of Drinking Water," February 2016. Superior Enzymes Inc., 334 Hecla Street, Lake Linden, Michigan 49945.

41 Thermo Fisher. "Thermo Fisher Scientific Drinking Water Orthophosphate Method for Thermo Scientific Gallery Discrete Analyzer," February 2016. Revision 5. Thermo Fisher Scientific, Ratastie 2, 01620 Vantaa, Finland.

42 Mitchell Method M5331, Revision 1.2. "Determination of Turbidity by LED or Laser Nephelometry," February 2016. Available from Leck Mitchell, Ph.D., PE, 656 Independence Valley Dr., Grand Junction, CO 81507.

43 Tecta EC/TC. "TectaTM EC/TC Medium and the TectaTM Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water," version 2.0, March 2017. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2.

44 Lovibond PTV 1000. "Continuous Measurement of Drinking Water Turbidity using a Lovibond PTV 1000 White Light LED Turbidimeter," December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

45 Lovibond PTV 2000. "Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 2000 660-nm LED Turbidimeter," December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

46 Lovibond PTV 6000. "Continuous Measurement of Drinking Water Turbidity Using a Lovibond PTV 6000 Laser Turbidimeter," December 2016. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

47 Thermo Fisher. "Thermo Fisher method 557.1: Determination of Haloacetic Acids in Drinking Water using Two-Dimensional Ion Chromatography with Suppressed Conductivity Detection," January 2017. Version 1.0. Available from Thermo Fisher Scientific, 490 Lakeside Dr., Sunnyvale, CA 94085 (Richard.jack@thermofisher.com).

48 EPA Method 150.3. "Determination of pH in Drinking Water," February 2017. EPA 815-B-17-001. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

49Standard Methods for the Examination of Water and Wastewater, 23rd edition (2017). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

50 EPA Method 900.0, Rev. 1.0. "Determination of Gross Alpha and Gross Beta in Drinking Water," February 2018. EPA 815-B-18-002. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

51 Hach Company. "Hach Method 10258-Determination of Turbidity by 360° Nephelometry." March 2018. Revision 2.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

52 Hach Company. "Hach Method 8195-Determination of Turbidity by Nephelometry." March 2018. Revision 3.0. 5600 Lindbergh Drive, P.O. Box 389, Loveland, CO 80539.

53 EPA Method 903.1, Rev. 1.0. "Radium-226 in Drinking Water Radon Emanation Technique." January 2021. EPA 815-B-21-003. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

54 EPA Method 903.0, Rev. 1.0. "Alpha-Emitting Radium Isotopes in Drinking Water." January 2021. EPA 815-B-21-002. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

55 EPA Method 127. "Determination of Monochloramine Concentration in Drinking Water." January 2021. EPA 815-B-21-004. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

56 Bio-Rad. "Simultaneous Detection of Total Coliform Bacteria and Escherichia coli using RAPID'E. coli 2 (REC2) in Drinking Water." May 2020. Bio-Rad Laboratories, 2000 Nobel Drive, Hercules, California 94547.

57 Method 1001, Rev. 1.1. "Lead in Drinking Water by Differential Pulse Anodic Stripping Voltammetry." May 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.

58 ME 531, Version 1.0. "Measurement of N-Methylcarbamoyloximes and N-Methylcarbamates in Drinking Water by LC-MS/MS. September 2019. Maine Health Environmental Testing Laboratory, 221 State Street, Augusta, ME 04330.

59 ChloroSense, Rev. 1.1. "Free and Total Chlorine in Drinking Water by Amperometry using Disposable Sensors." February 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.

60 ChlordioX Plus, Rev. 1.1. "Chlorine Dioxide and Chlorite in Drinking Water by Amperometry using Disposable Sensors." February 2020. Palintest Ltd, 400 Corporate Circle, Suite J, Golden, CO 80401.

61 Modified ColitagTM, Version 2.0. "Modified ColitagTM Test Method for the Simultaneous Determination of Total Coliforms and E. coli in Water." June 2020. Neogen Corporation, 620 Lesher Place, Lansing, MI 48912.

62 EPA Method 904.0, Rev. 1.0. "Radium-228 in Drinking Water." March 2022. EPA 815-B-22-003. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

63 Lovibond TB 6000. "Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond Portable Laser Turbidimeter." May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

64 Lovibond TB 3500. "Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond White Light LED Portable Turbidimeter." May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

65 Lovibond TB 5000. "Measurement of Drinking Water Turbidity of a Captured Sample using a Lovibond 660-nm LED Portable Turbidimeter." May 2021. Revision 1.0. Available from Tintometer, Inc., 6456 Parkland Drive, Sarasota, FL 34243.

66Standard Methods for the Examination of Water and Wastewater, 24th edition (2023). Available from American Public Health Association, 800 I Street NW, Washington, DC 20001-3710.

67 Hach Company. "Hach Method 10312-Spectrophotometric Measurement of Fluoride in Finished Drinking Water Aluminum-Chromeazurol S complex (AL-CAS) Using Planar Reagent-filled Cuvettes". August 2022. Revision 1.0. 5600 Lindbergh Drive, Loveland, Colorado 80539.

68 Yokogawa Electric Corporation. "Yokogawa Method 820-Measurement of Turbidity in Drinking Water by Right Angle Scattered Light Turbidity Analyzer". November 2022. Revision 1.0. 2-9-32 Nakamachi, Musashino-shi, Tokyo, Japan 180-8750.

40 C.F.R. C app A to Subpart C of Part 141

74 FR 38353, Aug. 3, 2009, as amended at 74 FR 57914, Nov. 10, 2009; 74 FR 63069, Dec. 2, 2009; 75 FR 32299, June 8, 2010; 76 FR 37018, June 24, 2011; 77 FR 38527, June 28, 2012; 78 FR 32565, May 31, 2013; 78 FR 37463, June 21, 2013; 79 FR 35086, June 19, 2014; 79 FR 36428, June 27, 2014; 81 FR 46844, July 19, 2016; 82 FR 34867, July 27, 2017; 83 FR 51644, Oct. 12, 2018; 83 FR 54676, Oct. 31, 2018; 86 FR 28284, May 26, 2021; 86 FR 29526, June 2, 2021; 87 FR 50579, Aug. 17, 2022; 89 FR 5780, Jan. 30, 2024; 89 FR 7624, Feb. 5, 2024
81 FR 46844, 7/19/2016; 82 FR 34867, 7/27/2017; 83 FR 51644, 10/12/2018; 83 FR 54676, 10/31/2018; 86 FR 28284, 5/26/2021; 86 FR 29526, 6/2/2021; 87 FR 50579, 8/17/2022; 89 FR 5779, 1/30/2024; 89 FR 7624, Not Available