StacksVerified U.S. regulatory reference

40 CFR Part 141, Appendix A

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov

Only the editions stated in the following table are approved.

OrganismMethodologySM 21st Edition 1SM 22nd Edition 28SM Online 3Other
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
Colitag TM|| Modified Colitag TM 13
Tecta EC/TC 33
OrganismMethodologySM 22nd Edition 28SM Online 3
Fecal ColiformsFecal Coliform Procedure9221 E9221 E-06
OrganismMethodologySM 20thEdition 6SM 21stEdition 1SM 22ndEdition 28SM Online 3 | Other
E.coliONPG-MUG Test9223 B9223 B9223 B9223 B-97, B-04 |
Colitag TM||Modified Colitag TM 13
Tecta EC/TC 33 |
ContaminantMethodologyEPA methodSM 21stedition 1SM 22ndedition 28SM 23rdedition,49 SM24th edition 66 | SM online 3 | ASTM 4 | Other
AlkalinityTitrimetric| 2320 B2320 B2320 B| D1067-06 B, 11 B, 16 B |
AntimonyHydride—Atomic Absorption||| D 3697-07, -12, -17
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
ArsenicAtomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | D 2972-08 C, -15 C |
Hydride Atomic Absorption| 3114 B3114 B3114 B3114 B-09 | D 2972-08 B, -15 B |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
BariumInductively Coupled Plasma| 3120 B3120 B3120 B | |
Atomic Absorption; Direct| 3111 D3111 D3111 D | |
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
BerylliumInductively Coupled Plasma| 3120 B3120 B3120 B | |
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | D 3645-08 B, -15 B |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
CadmiumAtomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
CalciumEDTA titrimetric| 3500-Ca B3500-Ca B3500-Ca B| D 511-09, -14 A |
Atomic Absorption; Direct Aspiration| 3111 B3111 B3111 B| D 511-09, -14 B |
Inductively Coupled Plasma| 3120 B3120 B3120 B | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Ion Chromatography||| D 6919-09, -17
ChromiumInductively Coupled Plasma| 3120 B3120 B3120 B | |
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
CopperAtomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | D 1688-07, -12 C, 17 C |
Atomic Absorption; Direct Aspiration| 3111 B3111 B3111 B| D 1688-07, -12 A, 17 A |
Inductively Coupled Plasma| 3120 B3120 B3120 B | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Colorimetry|||Hach Method 8026,35 Hach Method 10272.36
ConductivityConductance| 2510 B2510 B2510 B| D 1125-14 A |
CyanideManual Distillation with MgCl2 followed by:| 4500-CN− C4500-CN− C4500-CN− C4500-CN− C-99 | D 2036-06 A |
Spectrophotometric, Amenable| 4500-CN− G4500-CN− G4500-CN− G| D 2036-06 B |
Spectrophotometric Manual| 4500-CN− E4500-CN− E4500-CN− E| D2036-06 A |
Selective Electrode| 4500-CN− F4500-CN− F4500-CN− F | |
Gas Chromatography/Mass Spectrometry Headspace|||ME355.01.7
FluorideIon Chromatography| 4110 B4110 B4110 B| D 4327-11, -17 |
Manual Distillation; Colorimetric SPADNS| 4500-F− B, D4500-F− B, D4500-F− B, D | |
Manual Electrode| 4500-F− C4500-F− C4500-F− C| D 1179-04, 10 B, 16 B |
Automated Alizarin| 4500-F− E4500-F− E4500-F− E | |
Arsenite-Free Colorimetric SPADNS|||Hach SPADNS 2 Method 10225,22 Hach Method 10312.67
LeadAtomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | D 3559-08 D, 15 D |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Differential Pulse Anodic Stripping Voltametry|||Method 1001, Rev. 1.1.57
MagnesiumAtomic Absorption| 3111 B3111 B3111 B| D 511-09, -14 B |
Inductively Coupled Plasma| 3120 B3120 B3120 B | |
Complexation Titrimetric Methods| 3500-Mg B3500-Mg B3500-Mg B| D 511-09, -14 A |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Ion Chromatography||| D 6919-09, -17
MercuryManual, Cold Vapor| 3112 B3112 B3112 B3112 B-09 | D 3223-12, -17 |
NickelInductively Coupled Plasma| 3120 B3120 B3120 B | |
Atomic Absorption; Direct| 3111 B3111 B3111 B | |
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
NitrateIon Chromatography| 4110 B4110 B4110 B| D 4327-11, -17 |
Automated Cadmium Reduction| 4500-NO3 − F4500-NO3 − F4500-NO3 − F | |
Manual Cadmium Reduction| 4500-NO3 − E4500-NO3 − E4500-NO3 − E | |
Ion Selective Electrode| 4500-NO3 − D4500-NO3 − D4500-NO3 − D | |
Reduction/Colorimetric|||Systea Easy (1-Reagent),8 NECi Nitrate-Reductase.40
Colorimetric; Direct|||Hach TNTplusTM 835/836 Method 10206.23
Capillary Ion Electrophoresis||| D 6508-15
NitriteIon Chromatography| 4110 B4110 B4110 B| D 4327-11, -17 |
Automated Cadmium Reduction| 4500-NO3 − F4500-NO3 − F4500-NO3 − F | |
Manual Cadmium Reduction| 4500-NO3 − E4500-NO3 − E4500-NO3 − E | |
Spectrophotometric| 4500-NO2 − B4500-NO2 − B4500-NO2 − B | |
Reduction/Colorimetric|||Systea Easy (1-Reagent),8 NECi Nitrate-Reductase.40
Capillary Ion Electrophoresis||| D 6508-15
Ortho-phosphateIon Chromatography| 4110 B4110 B4110 B| D 4327-11, -17 |
Colorimetric, ascorbic acid, single reagent| 4500-P E4500-P E4500-P E4500-P E-99 | |
Colorimetric, Automated, Ascorbic Acid| 4500-P F4500-P F4500-P F4500-P F-99 | | Thermo Fisher Discrete Analyzer.41
Capillary Ion Electrophoresis||| D 6508-15
pHElectrometric150.3 484500-H+ B4500-H+ B4500-H+ B | | D 1293-12, -18 |
SeleniumHydride-Atomic Absorption| 3114 B3114 B3114 B3114 B-09 | D 3859-08 A, -15 A |
Atomic Absorption; Furnace| 3113 B3113 B3113 B3113 B-04, B-10 | D 3859-08 B, -15 B |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
SilicaColorimetric||| D859-05, 10, 16
Molybdosilicate| 4500-SiO2 C4500-SiO2 C4500-SiO2 C | |
Heteropoly blue| 4500-SiO2 D4500-SiO2 D4500-SiO2 D | |
Automated for Molybdate-reactive Silica| 4500-SiO2 E4500-SiO2 E4500-SiO2 E | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Inductively Coupled Plasma| 3120 B3120 B3120 B | |
SodiumAtomic Absorption; Direct Aspiration| 3111 B3111 B3111 B | |
Axially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 | | |
Ion Chromatography||| D 6919-09, -17
TemperatureThermometric| 2550255025502550-10 | |
ContaminantMethodologyEPA methodSM 21st edition 1SM 22ndedition,28 SM23rd edition,49 SM24th edition 66SM online 3 | ASTM 4 | Other
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 Spectrometry524.3,9 524.4 29 | |
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 Spectrometry524.3,9 524.4 29 | |
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)53625 | |
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 detection| 6610 B6610 B6610 B-04 |
Liquid Chromatography/Mass Spectrometry||| ME 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)55714 | |
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 Detection| 6651 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 detection| 6610 B6610 B6610 B-04 |
Liquid Chromatography/Mass Spectrometry||| ME 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)53625 | |
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 | |
ContaminantMethodologyEPA methodSM 21st edition 1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition 66ASTM 4 | SM online 3
Naturally Occurring: |
Gross alpha and betaEvaporation900.0, Rev. 1.0 507110 B7110 B |
Liquid Scintillation|7110 DD 7283-177110 D-17.
Gross alphaCoprecipitation| 7110 C7110 C
Radium 226Radon emanation903.1, Rev. 1.0 537500-Ra C7500-Ra CD 3454-05, -18, D 3454-21 |
Radiochemical903.0, Rev. 1.0 547500-Ra B7500-Ra BD 2460-07 |
Gamma Spectrometry|7500-Ra E| 7500-Ra E-07.
Radium 228Radiochemical904.0, Rev. 1.0 627500-Ra D7500-Ra D |
Gamma Spectrometry|7500-Ra E| 7500-Ra E-07.
UraniumRadiochemical| 7500-U B7500-U B
ICP-MS| 3125| D 5673-05, 10, 16
Alpha spectrometry| 7500-U C7500-U CD 3972-09
Laser Phosphorimetry|| D 5174-07
Alpha Liquid Scintillation Spectrometry|| D 6239-09
Man-Made: |
Radioactive CesiumRadiochemical| 7500-Cs B7500-Cs B
Gamma Ray Spectrometry| 71207120D 3649-06
Radioactive IodineRadiochemical| 7500-I B, 7500-I C, 7500-I D7500-I B, 7500-I C, 7500-I DD 3649-06
Gamma Ray Spectrometry| 71207120D 4785-08, -20
Radioactive Strontium 89, 90Radiochemical| 7500-Sr B7500-Sr B
TritiumLiquid Scintillation| 7500-3 H B7500-3 H BD 4107-08, -20
Gamma EmittersGamma Ray Spectrometry| 7120, 7500-Cs B, 7500-I B7120, 7500-Cs B, 7500-I BD 3649-06, D 4785-08, -20
OrganismMethodologySM 21st edition 1SM 22ndedition 28SM 23rd edition 49SM 24th edition 66 | SM online 3 | Other
Total ColiformTotal Coliform Fermentation Technique9221 A, B, C9221 A, B, C9221 A, B, C9221 A, B, C | 9221 A, B, C-06 |
Total Coliform Membrane Filter Technique9222 A, B, C| 9222 A, B, C9222 A, B, C |
ONPG-MUG Test92239223 B9223 B9223 B | 9223 B-04 |
Fecal ColiformsFecal Coliform Procedure9221 E9221 E9221 E9221 E | 9221 E-06 |
Fecal Coliform Filter Procedure9222 D9222 D9222 D9222 D | 9222 D-06 |
Heterotrophic bacteriaPour Plate Method9215 B9215 B9215 B| 9215 B-04 |
TurbidityNephelometric Method2130 B2130 B2130 B2130 B | | Hach 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° Nephelometry||| Hach Method 10258, Rev. 1.0,39 Hach Method 10258, Rev. 2.0.51
ResidualMethodologyEPA methodsSM 21st edition 1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition 66ASTM 4 | Other
Free ChlorineAmperometric Titration| 4500-Cl D4500-Cl DD 1253-08, -14
DPD Ferrous Titrimetric| 4500-Cl F4500-Cl F
DPD Colorimetric| 4500-Cl G4500-Cl G| Hach Method 10260.31
Indophenol Colorimetric||Hach Method 10241.34
Syringaldazine (FACTS)| 4500-Cl H4500-Cl H
On-line Chlorine AnalyzerEPA 334.0.16 |
Amperometric Sensor||ChloroSense,17 ChloroSense, Rev. 1.1.59
Total ChlorineAmperometric Titration| 4500-Cl D4500-Cl DD 1253-08, -14
Amperometric Titration (Low level measurement)| 4500-Cl E4500-Cl E
DPD Ferrous Titrimetric| 4500-Cl F4500-Cl F
DPD Colorimetric| 4500-Cl G4500-Cl G| Hach Method 10260.31
Indophenol Colorimetric12755 |
Iodometric Electrode| 4500-Cl I4500-Cl I
On-line Chlorine AnalyzerEPA 334.0.16 |
Amperometric Sensor||ChloroSense,17 ChloroSense, Rev. 1.1.59
Chlorine DioxideAmperometric Titration| 4500-ClO2 C4500-ClO2 C
Amperometric Titration| 4500-ClO2 E4500-ClO2 E
Amperometric Sensor||ChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60
OzoneIndigo Method| 4500-O3 B4500-O3 B
ContaminantMethodologyEPA methodASTM 4SM online 3SM 21st edition 1 | SM 22ndedition,28 SM23rd edition,49SM 24thEdition 66 | Other
TTHMP&T/GC/MS524.3,9 524.4.29 | |
HAA5LLE (diazomethane)/GC/ECD|6251 B-076251 B6251 B |
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)55714 | |
Two-Dimensional Ion Chromatography (IC) with Suppressed Conductivity Detection||| Thermo Fisher 557.1.47
BromateTwo-Dimensional Ion Chromatography (IC)30218 | |
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)55714 | |
Chemically Suppressed Ion Chromatography| D 6581-08 A |
Electrolytically Suppressed Ion Chromatography| D 6581-08 B |
ChloriteChemically Suppressed Ion Chromatography| D 6581-08 A |
Electrolytically Suppressed Ion Chromatography| D 6581-08 B |
Chlorite—daily monitoring as prescribed in 40 CFR 141.132(b)(2)(i)(A)Amperometric Titration|| 4500-ClO2 E4500-ClO2 E
Amperometric Sensor||| ChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60
ResidualMethodologySM 21st edition 1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition 66ASTM 4Other
Free ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl G| Hach Method 10260.31
Indophenol Colorimetric|| Hach Method 10241.34
Syringaldazine (FACTS)4500-Cl H4500-Cl H
Amperometric Sensor|| ChloroSense,17 ChloroSense, Rev. 1.1.59
On-line Chlorine Analyzer|| EPA 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 G| Hach Method 10260.31
Total ChlorineAmperometric Titration4500-Cl D4500-Cl DD 1253-08, -14
Low level Amperometric Titration4500-Cl E4500-Cl E
DPD Ferrous Titrimetric4500-Cl F4500-Cl F
DPD Colorimetric4500-Cl G4500-Cl G| Hach Method 10260.31
Iodometric Electrode4500-Cl I4500-Cl I
Amperometric Sensor|| ChloroSense,17 ChloroSense, Rev. 1.1.59
On-line Chlorine Analyzer|| EPA 334.0.16
Chlorine DioxideAmperometric Method II4500-ClO2 E4500-ClO2 E
Amperometric Sensor|| ChlordioX Plus,32 ChlordioX Plus, Rev. 1.1.60
ResidualMethodologyMethod
Free ChlorineTest StripsMethod D99-003 5
ParameterMethodologySM 21st edition 1SM 22nd edition 28SM 23rd edition 49, SM 24th edition 66SM online 3 | EPA | Other
Total Organic Carbon (TOC)High Temperature Combustion5310 B5310 B5310 B| 415.3, Rev 1.2 19 |
Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C| 415.3, Rev 1.2 19 | Hach Method 10267 38.
Wet Oxidation5310 D5310 D|415.3, Rev 1.2 19 |
Ozone Oxidation||| Hach Method 10261 37.
Specific Ultraviolet Absorbance (SUVA)Calculation using DOC and UV254 data||415.3, Rev 1.2 19
Dissolved Organic Carbon (DOC)High Temperature Combustion5310 B5310 B5310 B| 415.3, Rev 1.2 19 |
Persulfate-Ultraviolet or Heated Persulfate Oxidation5310 C5310 C5310 C| 415.3, Rev 1.2 19 |
Wet Oxidation5310 D5310 D|415.3, Rev 1.2 19 |
Ultraviolet absorption at 254 nm (UV254)Spectrophotometry5910 B5910 B5910 B5910 B-11 | 415.3, Rev 1.2 19 |
ContaminantMethodologyEPA method
BromateTwo-Dimensional Ion Chromatography (IC)302.0 18
Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS)557 14
OrganismMethodologySM 20th edition 6SM 21st edition 1SM 22nd edition 28SM 23rd edition 49, SM 24th edition 66 | SM online 3 | Other
E. coliColilert| 9223 B9223 B9223 B9223 B-97, B-04 |
Colisure| 9223 B9223 B9223 B9223 B-97, B-04 |
Colilert-189223 B9223 B9223 B9223 B | 9223 B-97, B-04 |
Readycult®||| Readycult®.20
Colitag||| Modified ColitagTM 13, Modified Colitag TM, Version 2.0.61
Chromocult®||| Chromocult®.21
EC-MUG|9221 F9221 F9221 F-06 |
NA-MUG|| 9222 I
mColiBlue24 Test|| 9222 J
Tecta EC/TC 33 43 | |
RAPID'E.coli 2 56 | |
EnterococciMultiple-Tube Technique|| 9230 B9230 B-04
Membrane Filter Techniques|| 9230 C
Fluorogenic Substrate Enterococcus Test (using Enterolert)|| 9230 D
ColiphageTwo-Step Enrichment Presence-Absence Procedure||| Fast Phage.30
OrganismMethodologyEPA Method
CryptosporidiumFiltration/Immunomagnetic Separation/Immunofluorescence Assay Microscopy1623.1 27
OrganismMethodologySM 20th edition 6
E. coliMembrane Filtration, Two Step9222 D/9222 G
OrganismMethodology categoryMethodSM 20th, 21st editions 1 6SM 22nd edition 28SM 23rd edition 49, SM 24th edition 66 | SM online 3
Total ColiformsLactose Fermentation MethodsStandard Total Coliform Fermentation Technique| 9221 B.1, B.29221 B.1, B.2, B.3, B.49221 B.1, B.2-06.
Presence-Absence (P-A) Coliform Test|9221 D.1, D.2, D.3
Membrane Filtration MethodsStandard Total Coliform Membrane Filter Procedure using Endo Media|9222 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 Water 56 |
Enzyme Substrate MethodsColilert®| 9223 B9223 B9223 B-04.
Colisure®| 9223 B9223 B9223 B-04.
Colilert-189223 B9223 B9223 B | 9223 B-04.
Tecta EC/TC 33 43 |
Modified ColitagTM, Version 2.0 61 |
Escherichia coliEscherichia coli Procedure (following Lactose Fermentation Methods)EC-MUG medium| 9221 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 medium|9222 I
Simultaneous Detection of Total Coliforms and E. coli by Dual Chromogen Membrane Filter ProceduremColiBlue24 medium|9222 J
Membrane Filtration MethodSimultaneous Detection of Total Coliform Bacteria and Escherichia coli Using RAPID'E.coli (REC2) in Drinking Water 56 |
Enzyme Substrate MethodsColilert®| 9223 B9223 B9223 B-04.
Colisure®| 9223 B9223 B9223 B-04.
Colilert-189223 B9223 B9223 B | 9223 B-04.
Tecta EC/TC 33 43 |
Modified ColitagTM, Version 2.0 61 |
ContaminantMethodologyEPA methodASTM 4SM 21st edition 1SM 22nd edition,28 SM 23rd edition,49 SM 24th edition 66 | SM online 3
AluminumAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 |
Atomic Absorption; Direct|3111 D3111 D
Atomic Absorption; Furnace|3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma|3120 B3120 B
ChlorideSilver Nitrate Titration| D 512-04 B, 12 B4500-Cl− B4500-Cl− B
Ion Chromatography| D 4327-11, -174110 B4110 B
Potentiometric Titration|4500-Cl− D4500-Cl− D
ColorVisual Comparison|2120 B2120 B
Foaming AgentsMethylene Blue Active Substances (MBAS)|5540 C5540 C
IronAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 |
Atomic Absorption; Direct|3111 B3111 B
Atomic Absorption; Furnace|3113 B3113 B3113 B-04, B-10
Inductively Coupled Plasma|3120 B3120 B
ManganeseAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 |
Atomic Absorption; Direct|3111 B3111 B
Atomic Absorption; Furnace|3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma|3120 B3120 B
OdorThreshold Odor Test|2150 B2150 B
SilverAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 |
Atomic Absorption; Direct|3111 B3111 B
Atomic Absorption; Furnace|3113 B3113 B3113 B-04, B-10.
Inductively Coupled Plasma|3120 B3120 B
SulfateIon Chromatography| D 4327-11, -174110 B4110 B
Gravimetric with ignition of residue|4500-SO4 2 − C4500-SO4 2 − C4500-SO4 2 − C-97.
Gravimetric with drying of residue|4500-SO4 2 − D4500-SO4 2 − D4500-SO4 2 − D-97.
Turbidimetric method| D 516-07, 11, 164500-SO4 2 − E4500-SO4 2 − E4500-SO4 2 − E-97.
Automated methylthymol blue method|4500-SO4 2 − F4500-SO4 2 − F4500-SO4 2 − F-97.
Total Dissolved SolidsTotal Dissolved Solids Dried at 180 deg C|2540 C2540 C
ZincAxially viewed inductively coupled plasma-atomic emission spectrometry (AVICP-AES)200.5, Revision 4.2 2 |
Atomic Absorption; Direct Aspiration|3111 B3111 B
Inductively Coupled Plasma|3120 B3120 B

1 Standard 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.

6 Standard 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.

28 Standard 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.

49 Standard 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.

66 Standard 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.

69 e-sens, Inc. “e-sens, Inc. Automated Micro Chlorine Detection (AMCD) Method for the Determination of Residual Free and Total Chlorine in Water.” December 2023. Available from e-sens, Inc., 630 Komas Dr., Ste 235, Salt Lake City, Utah 84108.

70 EPA Method 537.1, Version 1.0. “Determination of Selected Per- and Polyfluorinated Alkyl Substances (PFAS) in Drinking Water by Solid Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS).” November 2018. EPA/600/R-18/352. Approved as alternative testing method to support initial PFAS monitoring (for monitoring-frequency determinations) until April 26, 2027 as described at 40 CFR 141.902(b)(1) [Monitoring requirements for PFAS—Initial monitoring]. Available at the National Service Center for Environmental Publications at https://www.epa.gov/nscep.

[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; 90 FR 4660, Jan. 16, 2025]

Editorial Note:At 90 FR 4660, Jan. 16, 2025, appendix A to subpart C of part 141 was amended in part by revising the entries for “Free Chlorine” and “Total Chlorine” in the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.74(a)(2)”, revising the entries for “Free Chlorine” and “Total Chlorine” in the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.131(c)(1)”, and adding the table entitled “Alternative Testing Methods for Contaminants Listed at 40 CFR 141.901(b)(1)”. However, the amendments could not be incorporated due to errors in the amendatory instruction that misidentified the tables.