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Office of Ground Water and Drinking Water

November 26, 2012

MEMORANDUM

SUBJECT: Basis for Expedited Approval of Methods from the 22nd Edition of Standard Methods for 

the Examination of Water and Wastewater

FROM: Glynda Smith, Chemist, Technical Support Center

Steve Wendelken, Technical Support Center

TO: The Record

 This memo documents the reviews that were conducted on new versions of methods published in the 

22nd edition of Standard Methods for the Examination of Water and Wastewater. It provides the 

background information on why EPA is approving these methods using the expedited method approval 

process. Each method is discussed individually below:

(1) Standard Method 2120 B. The online version, Standard Method 2120 B-01, was used as the basis for 

comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for the 

determination of color. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 2020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(2) Standard Method 2130 B. The online version, Standard Method 2130 B-01, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(1) for 

the determination of turbidity. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 2020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(3) Standard Method 2150 B. The online version, Standard Method 2150 B-97, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for the 

determination of odor. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 2020. Thus, the 22nd edition 

version is equally as effective as the approved online version. 

(4) Standard Method 2320 B. The online version, Standard Method 2320 B-97, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of alkalinity. In Standard Methods for the Examination of Water and Wastewater, 

this method is linked with Standard Method 2310 B for the determination of acidity. In the approved 

method, both 2310 B and 2320 B separately list sodium thiosulfate in their respective Reagent sections 

to remove free chlorine residual. In the 22nd edition, Method 2320 B does not specify sodium 

thiosulfate as a reagent; rather, it references the titration procedure in Method 2310 B which specifies 

thiosulfate for the removal of residual free chlorine. It would be preferable if Standard Methods had not 

made this change. But since the specified chemistry remains the same (i.e., sodium thiosulfate remains 
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the reagent of choice for removing free chlorine residual), the modification is acceptable. Otherwise, 

only the editorial change adding reference to the quality control criteria in Section 2020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(5) Standard Method 2510 B. The online version, Standard Method 2510 B-97, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of conductivity. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 2020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(6) Standard Method 2540 C. The online version, Standard Method 2540 C-97, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for the 

determination of total dissolved solids. The version published in the 22nd edition of Standard Methods 

for the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 2020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(7) Standard Method 2550. The online version, Standard Method 2550-00, was used as the basis for 

comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the 

determination of temperature. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater contains the following minor technical revisions that are mainly 

associated with eliminating the use of mercury-filled glass thermometers to avoid breakage and release 

of toxic mercury into the environment:

• Adds the use of standard liquid-in-glass or electronic thermometers with analog or digital 

readouts;

• References the quality control criteria in Section 2020;

• Adds clarification in the calculations to indicate that all units are to be reported in terms of 

degrees (i.e., the determination of bulb “volume” is not intended to be a liquid volume); and,

• Adds the NIST Handbook 105-6 for checking tolerances

The methods have the same quality control requirements and method performance criteria. Therefore, 

Standard Method 2550 in the 22nd edition is equally as effective as the approved online version.

(8) Standard Method 3111 B. The online version, Standard Method 3111 B-99, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of calcium, magnesium, nickel, sodium , and copper, and again at 40 CFR 143.4(b) for 

the determination of iron, manganese, silver, and zinc. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 3020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(9) Standard Method 3111 D. The online version, Standard Method 3111 D-99, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of barium, and again at 40 CFR 143.4(b) for the determination of aluminum. The 

version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved online version with the minor editorial revision that references 

the quality control criteria in Section 3020. Thus, the 22nd edition version is equally as effective as the 

approved online version.
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(10) Standard Method 3112 B. The online version, Standard Method 3112 B-99, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of mercury. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 3020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(11) Standard Method 3113 B. The version approved in the 19th edition of Standard Methods for the 

Examination of Water and Wastewater was used as the basis for comparison because it is currently 

cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the determination of antimony, 

arsenic, barium, beryllium, cadmium, chromium, copper, lead, nickel, and selenium; and again at 40 CFR 

143.4(b) for the determination of aluminum, iron, manganese, and silver. Numerous technical edits 

have been made in the 22nd edition version of the method, including:

• The 22nd edition eliminates use of this method for the determinations of bismuth, germanium, 

gold, iridium, mercury, tellurium, thallium, and vanadium. Of these contaminants, only mercury 

and thallium have NPDWRs and neither specifies this method as an approved method for 

analysis. 

• This 22nd edition version corrects an error in the preparation of the palladium nitrate modifier. 

The approved 19th edition version calls for 8.89 g Pd(NO3)2•(H2O) to obtain a 4000 mg Pd/L 

solution; but that mass yield a 3800 mg Pd/L solution. The 22nd edition version changes the 

preparation to 9.34 g Pd(NO3)2•(H2O) which will yield the correct 4000 mg Pd/L concentration.

• The 22nd edition version includes metals with sample turbidities less than one NTU with 

dissolved metals and allows elimination of nickel (as nickel nitrate) as a modifier in 

arsenic/selenium analyses if palladium is co-added as the modifier during the analysis.

• In the approved method, standard solutions were required to be prepared fresh daily. The 22nd

edition version recommends preparation of standard solutions “every two weeks, or more 

frequently, as needed if standard response indicates degradation of standard.” This change is in 

agreement with the standard solution recommendations for EPA Method 200.9 which is also an 

approved graphite furnace atomic absorption method.

• In the approved method, standards are analyzed in triplicate. In the 22nd edition, standards are 

analyzed in duplicate. EPA Method 200.9 has no criteria for replicate analysis of standards. In

terms of waste generation of toxic metals, this change is reasonable.

• In the method of standard additions procedure, the 22nd edition version adds a cautionary note 

indicating that the procedure must yield results within the linear range of the method.

• The version published in the 22nd edition includes the editorial revision that references the 

quality control criteria in Section 3020.

The methods overall are the same with respect to sample collection/handling protocols, sample 

preparation, analytical techniques, and calculation of metal concentrations in drinking water. Therefore, 

Standard Method 3113 B in the 22nd edition is equally as effective as the approved 19th edition version.

(12) Standard Method 3114 B. The online version, Standard Method 3114 B-97, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 

the determination of arsenic and selenium. Technical edits have been made in the 22nd edition version 

of the method, including:

• The 22nd edition method adds expected performance in terms of detection level and optimum 

concentration range: “For both arsenic and selenium analyzed by atomization into a nitrogen-
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hydrogen flame after reduction, the method detection limit should be 2 μg/L, with an optimum 

concentration range of 2 – 20 μg/L. Lower detection limits can be expected with a quartz tube 

atomizer.”

• The version published in the 22nd edition includes the editorial revision that references the 

quality control criteria in Section 3020.

• The 22nd edition version revises the cautionary wording regarding addition of sodium 

borohydride.

• The approved method specifies six calibration standards encompassing the linear range of the 

instrument. The 22nd edition specifies three calibration standards plus a blank. This 

modification aligns with the requirements described in the EPA Manual for Certification of 

Laboratories Analyzing Drinking Water, 5th ed., Chapter IV, Section 7.2.3 which states”...a 

calibration curve covering the sample concentration range and all target analytes should be 

generated...the curve should be composed of three or more points.” In addition, EPA Method 

200.9, also approved for arsenic and selenium determination, calls for calibration with three or 

more concentrations within the useable linear dynamic range of the analyte. Since the change 

in the number of calibration concentration levels described in 3114 B of the 22nd edition is 

consistent with those specified in the laboratory certification manual and an approved EPA 

atomic absorption method, this change appears to be acceptable.

The methods overall are the same with respect to sample collection/handling protocols, sample 

preparation, analytical techniques, and calculation of arsenic and selenium concentrations in 

drinking water. Therefore, Standard Method 3114 B in the 22nd edition is equally as effective as the 

approved online version.

(13) Standard Method 3120. The online version, Standard Method 3120 B-99, was used as the basis for 

comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the 

determination of barium, beryllium, calcium, chromium, copper, magnesium, nickel, and silica, and 

again at 40 CFR 143.4(b) for the determination of aluminum, iron, manganese, silver, and zinc. The 

version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved online version with the minor editorial revision that references 

the quality control criteria in Section 3020. Thus, the 22nd edition version is equally as effective as the 

approved online version.

(14) Standard Method 3500-Ca B. The online version, Standard Method 3500-Ca B-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of calcium. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 3020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(15) Standard Method 3500-Mg B. The online version, Standard Method 3500-Mg B-97, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of magnesium. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 3020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(16) Standard Method 4110 B. The online version, Standard Method 4110 B-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for 
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the determination of fluoride, nitrate, nitrite, and orthophosphate, and again at 40 CFR 143.4(b) for the 

determination of chloride and sulfate. The version published in the 22nd edition of Standard Methods 

for the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(17) Standard Method 4500-Cl D. The online version, Standard Method 4500-Cl D-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

for the determination of free and total chlorine, and again at 40 CFR 131(c)(1) for the determination of

free, total, and combined chlorine. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(18) Standard Method 4500-Cl E. The online version, Standard Method 4500-Cl E-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

and at 40 CFR 141.131(c)(1) for the determination of total chlorine. The version published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved 

online version with the minor editorial revision that references the quality control criteria in Section 

4020. Thus, the 22nd edition version is equally as effective as the approved online version.

(19) Standard Method 4500-Cl F. The online version, Standard Method 4500-Cl F-00, was used as the 

basis of comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

for the determination of free and total chlorine, and again at 40 CFR 131(c)(1) for the determination of 

free, total, and combined chlorine. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(20) Standard Method 4500-Cl G. The online version, Standard Method 4500-Cl G-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

for the determination of free and total chlorine, and again at 40 CFR 131(c)(1) for the determination of 

free, total, and combined chlorine. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(21) Standard Method 4500-Cl H. The online version, Standard Method 4500-Cl H-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

and at 40 CFR 141.131(c)(1) for the determination of free chlorine. The version published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved 

online version with the minor editorial revision that references the quality control criteria in Section 

4020. Thus, the 22nd edition version is equally as effective as the approved online version.

(22) Standard Method 4500-Cl I. The online version, Standard Method 4500-Cl I-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

and at 40 CFR 141.131(c)(1) for the determination of total chlorine. The version published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved 
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online version with the minor editorial revision that references the quality control criteria in Section 

4020. Thus, the 22nd edition version is equally as effective as the approved online version.

(23) Standard Method 4500-ClB. The online version, Standard Method 4500-ClB-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for 

the determination of chloride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version. Thus, the 22nd

edition version is equally as effective as the approved online version.

(24) Standard Method 4500-ClD. The online version, Standard Method 4500-ClD-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for 

the determination of chloride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(25) Standard Method 4500-ClO2 C. The online version, Standard Method 4500-ClO2 C-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.74(a)(2) for the determination of chlorine dioxide. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 4020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(26) Standard Method 4500-ClO2 E. The online version, Standard Method 4500-ClO2 E-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.74(a)(2) and at 40 CFR 141.131(c)(1) for the determination of chlorine dioxide. This method is also 

cited in the drinking water regulations at 40 CFR 141.131 (b)(1) for the determination of chlorite. The 

version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved online version with the minor editorial revision that references 

the quality control criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the 

approved online version. 

(27) Standard Method 4500-CNE. The online version, Standard Method 4500-CNE-99, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of free and total cyanide. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 4020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(28) Standard Method 4500-CNF. The online version, Standard Method 4500-CNF-99, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of free cyanide. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(29) Standard Method 4500-CNG. The online version, Standard Method 4500-CNG-99, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 
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141.23(k)(1) for the determination of free cyanide. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(30) Standard Method 4500-FB. The online version, Standard Method 4500-FB-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of fluoride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version. Thus, the 22nd

edition version is equally as effective as the approved online version.

(31) Standard Method 4500-FC. The online version, Standard Method 4500-FC-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of fluoride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(32) Standard Method 4500-FD. The online version, Standard Method 4500-FD-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of fluoride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(33) Standard Method 4500-FE. The online version, Standard Method 4500-FE-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of fluoride. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(34) Standard Method 4500-H+ B. The online version, Standard Method 4500-H+ B-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) 

for the determination of pH. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(35) Standard Method 4500-NO3

-

D. The online version, Standard Method 4500-NO3

-

D-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of nitrate. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(36) Standard Method 4500-NO3

-

E. The online version, Standard Method 4500-NO3

-

E-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 
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141.23(k)(1) for the determination of nitrate and nitrite. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 4020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(37) Standard Method 4500-NO3

-

F. The online version, Standard Method 4500-NO3

-

F-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of nitrate and nitrite. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 4020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(38) Standard Method 4500-NO2

-

B. The online version, Standard Method 4500-NO2

-

B-00, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of nitrite. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(39) Standard Method 4500-O3 B. The online version, Standard Method 4500-O3 B-97, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.74(a)(2) 

for the determination of residual ozone. The version published in the 22nd edition of Standard Methods 

for the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(40) Standard Method 4500-P E. The version published in the 19th edition of Standard Method for the 

Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the determination of orthophosphate. 

The version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved version with the minor editorial revision that references the 

quality control criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the 

approved 19th edition version.

(41) Standard Method 4500-P F. The version published in the 19th edition of Standard Method for the 

Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the determination of orthophosphate. 

The version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved version with the minor editorial revision that references the 

quality control criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the 

approved 19th edition version.

(42) Standard Method 4500-SiO2 C. The online version, Standard Method 4500-SiO2 C-97, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of silica. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.
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(43) Standard Method 4500-SiO2 D. The online version, Standard Method 4500-SiO2 D-97, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of silica. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(44) Standard Method 4500-SiO2 E. The online version, Standard Method 4500-SiO2 E-97, was used as 

the basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 

141.23(k)(1) for the determination of silica. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(45) Standard Method 4500-SO4

2-

C. The version published in the 19th edition of Standard Method for 

the Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 143.4(b) for the determination of sulfate. The version 

published in the 22nd edition of Standard Methods for the Examination of Water and Wastewater is 

identical to the approved version with the minor editorial revision that references the quality control 

criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the approved 19th

edition version.

(46) Standard Method 4500-SO4

2-

D. The version published in the 19th edition of Standard Method for 

the Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 143.4(b) for the determination of sulfate. The version 

published in the 22nd edition of Standard Methods for the Examination of Water and Wastewater is 

identical to the approved version. Thus, the 22nd edition version is equally as effective as the approved 

19th edition version.

(47) Standard Method 4500-SO4

2-

E. The version published in the 19th edition of Standard Method for 

the Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 143.4(b) for the determination of sulfate. The version 

published in the 22nd edition of Standard Methods for the Examination of Water and Wastewater is 

identical to the approved version with the minor editorial revision that references the quality control 

criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the approved 19th

edition version.

(48) Standard Method 4500-SO4

2-

F. The version published in the 19th edition of Standard Method for 

the Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 143.4(b) for the determination of sulfate. The version 

published in the 22nd edition of Standard Methods for the Examination of Water and Wastewater is 

identical to the approved version with the minor editorial revision that references the quality control 

criteria in Section 4020. Thus, the 22nd edition version is equally as effective as the approved 19th

edition version.

(49) Standard Method 5310 B. The online version, Standard Method 5310 B-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.131(d)(3) for 
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the determination of total organic carbon (TOC) and at 40 CFR 141.131(d)(4)(i) for the determination of 

dissolved organic carbon (DOC). The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 5020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(50) Standard Method 5310 C. The online version, Standard Method 5310 C-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.131(d)(3) for 

the determination of total organic carbon (TOC) and at 40 CFR 141.131(d)(4)(i) for the determination of 

dissolved organic carbon (DOC). The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version. Thus, the 22nd

edition version is equally as effective as the approved online version.

(51) Standard Method 5310 D. The online version, Standard Method 5310 D-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.131(d)(3) for 

the determination of total organic carbon (TOC) and at 40 CFR 141.131(d)(4)(i) for the determination of 

dissolved organic carbon (DOC). The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version. Thus, the 22nd

edition version is equally as effective as the approved online version.

(52) Standard Method 5540 C. The online version, Standard Method 5540 C-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 143.4(b) for the 

determination of foaming agents. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 5020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(53) Standard Method 5910 B. The online version, Standard Method 5910 B-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.131(d)(4)(ii) 

for the determination of ultraviolet (UV) absorption at 254 nm. The version published in the 22nd edition 

of Standard Methods for the Examination of Water and Wastewater contains editorial and technical 

revisions that are primarily associated with incorporating more quality control into the method:

• In paragraph 1.a, several sentences have been edited to eliminate the use of passive voice. For 

example, the sentence “Samples are filtered to control variations in UV absorption caused by 

particles” has been revised to “Filter samples to control particle-related variations in UV 

absorption.”

• In paragraph 1.a, the sentence “Adjustment of pH before filtration is optional” has been 

replaced and expanded by the sentence “The sample’s pH should be adjusted before filtration; 

however, certain organic constituents (e.g., humic substances) may be lost to filters, suspended 

particles, or vessel walls at lower pH values. When filtering samples for SUVA determination, do 

not adjust pH before filtration.” These instructions relating to SUVA (specific UV absorption) 

determination are taken directly from the specifications in the regulations at 40 CFR 

141.131(d)(4)(ii). These instructions are repeated in paragraphs 1.d and 4.b.

• In paragraph 1.b, “UV-absorbing organics other than those of interest” has been added to the 

list of potential interferences.

• In paragraph 1.c, the statement “Dilute high-strength samples to fall within the determined 

range” has been added. This is consistent with the QC specification defined in EPA methods that 

prohibits extrapolation beyond the calibrated range.
Page 11 of 14

• Adds a new paragraph 1.d which details preparation of sample collection vessels, sampling, 

shipping conditions, and storage of collected samples.

• In paragraph 2.b, additional optional filters are listed for removing gross particulates, such as 

polyether sulfone (PES) and hydrophilic polypropylene (HPP). Includes instructions for handling 

highly turbid samples such as would be expected in some wastewater samples.

• In paragraph 3.a, the specification for organic-free water has been changed from “reagent 

water...containing less that 0.05 mg DOC/L” to “reagent water containing less than 0.010 cm-1 of 

UV-absorbing compounds. For optimum performance, reagent water of less than 0.0045 cm-1 is 

recommended.” Since the method is based on determination of UV absorption, it is reasonable 

to base the background specification on UV absorption as well, rather than a different physical 

parameter.

• In paragraph 4.a, there is a minor change in the suggested UV absorbance range from 0.005 to 

0.900 cm-1 to 0.005 to 0.950 cm-1 for determining an appropriate sample volume. This is not a 

method criterion, but rather a suggested range.

• In paragraph 6, several additions have been made to the method Quality Control. A revision has 

been added that references the QC criteria in Section 5020 and instructs the analyst to also 

follow all QC described within the method.

• Paragraph 6.b adds the specification for duplicate analyses, determination of the relative 

percent difference (RPD), and RPD limits: for UV values > 0.045 cm-1 , the RPD limit is < 10%; for 

UV values < 0.045 cm-1

, the RPD limit is < 20%.

• Adds a new paragraph, 6.d, which adds the specification for including filter blanks with each 

batch of filtered samples.

• Adds a new paragraph 6.e, which adds the option of checking filtrate turbidities if a UV value or 

calculated SUVA seems unusually high.

• Paragraph 6.f adds a QC check for the spectrometer by preparation and addition of at least one 

KHP standard in the range of interest with each analytical batch.

The quality control requirements in the new version of this method have been considerably 

strengthened relative to the approved version. As a result, Standard Method 5910 B in the 22nd edition 

is equally as effective (if not more so) as the approved online version.

(54) Standard Method 6251 B. The online version, Standard Method 6251 B-94, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.131(b)(1) for 

the determination of HAA5 (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, 

monobromoacetic acid, and dibromoacetic acid). The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 6020. Thus, the 22nd

edition version is equally as effective as the approved online version. 

(55) Standard Method 6610 B. EPA Method 531.2 was used as the basis for comparison because it is 

currently cited in the drinking water regulations at 40 CFR 141.24(e)(1) for the determination of 

carbofuran and oxamyl. Standard Method 6610 B was developed directly from EPA Method 531.2, and 

thus describes the same sample collection/handling protocols, sample preparation, and analysis steps. 

There are only two technical differences between Standard Method 6610 B and the approved method:

• EPA Method 531.2 specifies preparation of 0.075 N NaOH as the hydrolysis reagent, while 

Standard Method 6610 B specifies 0.05 N NaOH. Verification of the calculations reveals that the 

level specified in EPA Method 531.2 is incorrect – dilution of 4 mL of 50% NaOH (w/w) to 1000 
Page 12 of 14

mLs results in a solution that is 0.05 N, not 0.075 N. Therefore, the concentration listed in 

Standard Method 6610 B is correct.

• EPA Method 531.2 allows the use of a coil temperature range of 80 to 100 o

C in the post-column 

reaction system. Standard Method 6610 B restricts the range to 80 to 95 o

C. But, EPA Method 

531.2 contains a cautionary note indicating that if the temperature is allowed to exceed 95 o

C, a 

back pressure must be maintained to prevent boiling of the post-column eluent. By restricting 

the upper operating temperature, Standard Method 6610 B prevents analysts from dealing with 

those issues.

Standard Method 6610 B and EPA Method 531.2 specify the same quality control requirements and 

have the same method performance data. Therefore, Standard Method 6610 B in the 22nd edition is 

equally as effective as the approved method, EPA Method 531.2.

(56) Standard Method 6640 B. EPA Method 515.4, Revision 1.0 was used as the basis for comparison 

because it is currently cited in the drinking water regulations at 40 CFR 141.24(e)(1) for the 

determination of Dalapon, 2,4-D, 2,4,5-TP (Silvex), Dinoseb, Pentachlorophenol, and Picloram. Standard 

Method 6640 B was developed directly from EPA Method 515.4, Revision 1.0 and thus describes the 

identical sample collection/handling protocols, sample preparation and derivatization steps, 

chromatographic conditions, and electron capture detection. Standard Method 6640 B and EPA Method 

515.4, Revision 1.0 specify the same quality control requirements and have the same method 

performance data. Therefore, Standard Method 6640 B in the 22nd edition is equally as effective as the 

approved method, EPA Method 515.4, Revision 1.0.

(57) Standard Method 6651 B. The version published in the 20th edition of Standard Methods for the 

Examination of Water and Wastewater was used as the basis for comparison, because it is currently 

cited in the drinking water regulations at 40 CFR 141.24(e)(1) for the determination of glyphosate. The 

version published in the 22nd edition of Standard Methods for the Examination of Water and 

Wastewater is identical to the approved version with the minor editorial revision that references the 

quality control criteria in Section 6020. Thus, the 22nd edition version is equally as effective as the 

approved 20th edition version.

(58) Standard Method 7110 B. The online version, Standard Method 7110 B-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) for the 

determination of gross alpha and beta activity. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(59) Standard Method 7110 C. The online version, Standard Method 7110 C-00, was used as the basis 

for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) for the 

determination of gross alpha activity. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(60) Standard Method 7120. The online version, Standard Method 7120-97, was used as the basis for 

comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) for the 

determination of gamma emitters. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 
Page 13 of 14

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(61) Standard Method 7500-Cs B. The online version, Standard Method 7500-Cs B-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radioactive cesium. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(62) Standard Method 7500-

3

H B. The online version, Standard Method 7500-

3

H B-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of tritium activity. The version published in the 22nd edition of Standard Methods 

for the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(63) Standard Method 7500-I B. The online version, Standard Method 7500-I B-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radioactive iodine. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(64) Standard Method 7500-I C. The online version, Standard Method 7500-I C-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radioactive iodine. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(65) Standard Method 7500-I D. The online version, Standard Method 7500-I D-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radioactive iodine. The version published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is identical to the approved online version with 

the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd

edition version is equally as effective as the approved online version.

(66) Standard Method 7500-Ra B. The online version, Standard Method 7500-Ra B-01, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radium-226. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(67) Standard Method 7500-Ra C. The online version, Standard Method 7500-Ra C-01, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radium-226. The version published in the 22nd edition of Standard Methods for 
Page 14 of 14

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(68) Standard Method 7500-Ra D. The online version, Standard Method 7500-Ra D-01, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of radium-228. The version published in the 22nd edition of Standard Methods for 

the Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(69) Standard Method 7500-Sr B. The online version, Standard Method 7500-Sr B-01, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of strontium-89 and strontium-90. The version published in the 22nd edition of 

Standard Methods for the Examination of Water and Wastewater is identical to the approved online 

version with the minor editorial revision that references the quality control criteria in Section 7020. 

Thus, the 22nd edition version is equally as effective as the approved online version.

(70) Standard Method 7500-U B. The online version, Standard Method 7500-U B-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of uranium. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.

(71) Standard Method 7500-U C. The online version, Standard Method 7500-U C-00, was used as the 

basis for comparison because it is currently cited in the drinking water regulations at 40 CFR 141.25(a) 

for the determination of uranium. The version published in the 22nd edition of Standard Methods for the 

Examination of Water and Wastewater is identical to the approved online version with the minor 

editorial revision that references the quality control criteria in Section 7020. Thus, the 22nd edition 

version is equally as effective as the approved online version.