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Clean Water Act Analytical Methods

Approved CWA Chemical Test Methods

""The analytical methods promulgated under Clean Water Act section 304(h) are sometimes referred to as the "304(h)" or "Part 136" methods. The methods measure chemical and biological pollutants in media, such as wastewater, ambient water, sediment, and biosolids (sewage sludge). These various CWA methods are tested in a variety of labs and matrices.
 
In addition to 40 CFR Part 136 methods, some approved industry-specific methods are published or incorporated by reference at 40 CFR Parts 401 through 503.
 
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Approved Methods Listed by Method Number

Approved Inorganic Non-Metals Methods

Number Method Title
120.1 Conductance (Specific Conductance, μmhos, 25 °C) by Conductivity Meter
130.1 Hardness, Total (mg/L as CaCO3) (Colorimetric, Automated EDTA) by Spectrophotometer
150.2 pH, Continuous Monitoring (Electrometric) by pH Meter
160.4 Residue, Volatile (Gravimetric, Ignition at 550 °C) by Muffle Furnace
180.1 Turbidity by Nephelometry. Revision 2.0
300.0 Inorganic Anions by Ion Chromatography. Revision 2.1
300.1 Inorganic Anions in Drinking Water by Ion Chromatography. Revision 1.0
310.2 Alkalinity, Colorimetric, Automated Methyl Orange
335.4 Total Cyanide by Semi-Automated Colorimetry. Revision 1.0
350.1 Ammonia Nitrogen by Semi-Automated Colorimetry. Revision 2.0
351.1 Total Kjeldahl Nitrogen (Colorimetric, Automated Phenate) by Autoanalyzer
351.2 Total Kjeldahl Nitrogen by Semi-Automated Colorimetry. Revision 2.0
352.1 Nitrogen, Nitrate (Colorimetric, Brucine) by Spectrophotometer
353.2 Nitrate-Nitrite by Automated Colorimetry. Revision 2.0
365.1 Phosphorus by Semi-Automated Colorimetry. Revision 2.0
365.3 Phosphorus, All Forms, Colorimetric, Ascorbic Acid, Two Reagent
365.4 Phosphorus, Total, Colorimetric, Automated, Block Digester, Automated Analyzer II
375.2 Sulfate by Automated Colorimetry. Revision 2.0
410.3 Chemical Oxygen Demand (Titrimetric, High Level for Saline Waters) by Titration
410.4 Chemical Oxygen Demand by Semi-Automated Colorimetry. Revision 2.0
1627 Kinetic Test Method for the Prediction of Mine Drainage Quality
OIA-1677-09 Available Cyanide by Ligand Exchange and Flow Injection Analysis (FIA)
• Regulatory history

Approved Metals Methods

Number Method Title
200.2 Sample Preparation Procedure for Spectrochemical Determination of Total Recoverable Elements. Revision 2.8
200.5 Trace Elements in Drinking Water by Axially Viewed Inductively Coupled Plasma-Atomic Emission Spectrometry. Revision 4.2
200.7 Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry. Revision 4.4
200.8 Trace Elements in Water and Wastes by Inductively Coupled Plasma-Mass Spectrometry. Revision 5.4
200.9 Trace Elements by Stabilized Temperature Graphite Furnace Atomic Absorption Spectrometry. Revision 2.2
206.5 Arsenic, Sample Digestion Prior to Total Arsenic Analysis by Silver Diethyldithiocarbamate or Hydride Procedures
218.6 Dissolved Hexavalent Chromium in Drinking Water, Groundwater, and Industrial Wastewater by Ion Chromatography. Revision 3.3
• Regulatory history
231.2 Gold, Atomic Absorption, Furnace Technique
235.2 Iridium, Atomic Absorption, Furnace Technique
245.1 Mercury in Water by Cold Vapor Atomic Absorption Spectrometry. Revision 3.0
245.2 Mercury, Cold Vapor Technique, Automated
245.7 Mercury in Water by Cold Vapor Atomic Fluorescence Spectrometry. Revision 2.0
• Regulatory history
252.2 Osmium, Atomic Absorption, Furnace Technique
253.2 Palladium, Atomic Absorption, Furnace Technique
255.2 Platinum, Atomic Absorption, Furnace Technique
265.2 Rhodium, Atomic Absorption, Furnace Technique
267.2 Ruthenium, Atomic Absorption, Furnace Technique
279.2 Thallium, Atomic Absorption, Furnace Technique
283.2 Titanium, Atomic Absorption, Furnace Technique
289.2 Zinc, Atomic Absorption, Furnace Technique
1631E Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Fluorescence Spectrometry. Revision E
• Regulatory history

Approved Organic Methods

Number Method Title
420.1 Phenolics, Total Recoverable, Spectrophotometric, Manual 4-AAP With Distillation
420.4 Total Recoverable Phenolics by Semi-Automated Colorimetry. Revision 1.0
525.1 Organic Compounds in Drinking Water by Liquids-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry. Revision 2.2
525.2 Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass Spectrometry. Revision 2.0
601 Purgeable Halocarbons
602 Purgeable Aromatics
603 Acrolein and Acrylonitrile
604 Phenols
605 Benzidines
606 Phthalate Ester
607 Nitrosamines
608.1 Organochlorine Pesticides in Municipal and Industrial Wastewater
608.2 Certain Organochlorine Pesticides in Municipal and Industrial Wastewater
608.3 Organochlorine Pesticides and PCBs by GC/HSD (replaces Method 608)
609 Nitroaromatics and Isophorone
610 Polynuclear Aromatic Hydrocarbons
611 Haloethers
612 Chlorinated Hydrocarbons
613 2,3,7,8-Tetrachloro Dibenzo-p-Dioxin
614 Organophosphorus Pesticides in Municipal and Industrial Wastewater
614.1 Organophosphorus Pesticides in Municipal and Industrial Wastewater
615 Chlorinated Herbicides in Municipal and Industrial Wastewater
617 Organohalide Pesticides and PCBs in Municipal and Industrial Wastewater
619 Triazine Pesticides in Municipal and Industrial Wastewater
622 Organophosphorus Pesticides in Municipal and Industrial Wastewater
622.1 Thiophosphate Pesticides in Municipal and Industrial Wastewater
624.1 Purgeables by GC/MS (replaces Method 624)
625.1 Base/Neutrals and Acids by GC/MS (replaces Method 625)
• Validation of SPE Products & Associated Procedures with Method 625.1
632 Carbamate and Urea Pesticides in Municipal and Industrial Wastewater
1613B Tetra- through Octa-Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS. Revision B
• Regulatory History
1624B Volatile Organic Compounds by Isotope Dilution GC/MS
1625B Semivolatile Organic Compounds by Isotope Dilution GC/MS
1664A n-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated n-Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry. Revision A
• Regulatory history
1664B n-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated n-Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry. Revision B
• Regulatory history

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Approved Methods Listed by Analyte

The lists of approved methods at 40 CFR 136.3, with footnotes, are provided here as a reference. To download specific method publications, refer to the tables above.
 
  • Lists of methods by analyte; from 40 CFR 136.3
    • Table I B: Inorganics
    • Table I C: Non-pesticide organics
    • Table I D: Pesticides
    • Table I F: Pharmaceutical
    • Table I G: Pesticide active ingredients

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