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Office of Ground Water and Drinking Water

December 3, 2013

MEMORANDUM

SUBJECT: Basis for Expedited Approval of Online Standard Methods 

FROM: Glynda Smith, Chemist, Technical Support Center and Steve Wendelken, Chemist, Technical Support Center

TO: The Record

In the May 2013 expedited methods approval action (78 FR 32558, May 31, 2013), 22nd edition Standard Methods were reviewed for equivalency relative to the 

versions approved in the drinking water regulations. Documentation of the reviews is recorded in the memos entitled “Smith and Wendelken 2012b” and “Best 

2013” that are associated with the expedited action’s public docket (Docket ID EPA-HQ-OW-2013-0300). Unless noted, each of the following online versions has 

been compared to the 22nd edition version; if there are no changes, the edits in the online version are identical to those noted in the 22nd edition version and 

thus, the online version is equally as effective as the approved version as discussed in “Smith and Wendelken 2012b” and “Best 2013”.

# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

1 2550-00 2550-10 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 and thus the version in 

the 22nd edition version has been determined to be equally as effective as the approved online version. The online 

revision, Standard Method 2550-10, is identical to the version in the 22nd edition. Therefore, Standard Method 2550-

10 can be considered equally as effective as the approved method for the determination of temperature in drinking 

water.

2 3113 B-99 3113 B-10 In the evaluation of the 22nd edition methods, the 19th edition version was used as the basis for comparison. Since 

that time, Standard Methods Online has re-loaded Standard Method 3113 B-99 which 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, 
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# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

manganese, and silver. As a newer version, Standard Method 3113 B-99 was used for the comparative evaluation of 

Standard Method 3113 B-10. As with the 22nd edition evaluation, there are numerous technical edits:

 Under ¶ 3113 B.1, the following statement in the approved method has been deleted: “It <this method> is 

also applicable to analysis of bismuth, germanium, gold, iridium, mercury, tellurium, thallium, and vanadium, 

but precision and accuracy data are not yet available. “ Of these contaminants, only mercury and thallium 

have NPDWRs and neither specifies this method as an approved method for compliance monitoring. 

 Corrects an error in the preparation of the palladium nitrate modifier. In the approved method, the reagent 

prep. calls for 8.89 g Pd(NO3)2•(H2O) to obtain a 4000 mg Pd/L solution; that that actually yields a 3800 mg 

Pd/L solution. In the version under review, the reagent prep. calls for 9.34 g Pd(NO3)2•(H2O) which yields the 

correct 4000 mg Pd/L concentration.

 In the Sample Pretreatment section (¶ 4.a.1), “Dissolved metals” has been modified to “Dissolved metals and 

metals where sample turbidity is < 1 NTU”. It further states that nickel (as nickel nitrate) may be deleted if 

palladium is co-added during analysis.

 In ¶ 4.c (Instrument Calibration), the approved method calls for standard solutions to be prepared fresh daily. 

In the version under review, the calibration section has been modified to “Prepare standard solutions every 2 

weeks, or more frequently as needed if standard response indicates degradation of standard. A decrease in 

signal of more than 10% requires investigation and indicates the possible need for fresh standards”. This 

modification is in agreement with the standard solution preparation practice described in EPA Method 200.9, 

an approved graphite furnace AA method for the same contaminants.

 In the approved method, ¶ 4.c (Instrument Calibration) specifies analysis of standards in triplicate to verify 

method precision. In the version under review, this has been modified to analysis of standards in duplicate. 

This modification was checked against EPA Method 200.9; EPA Method 200.9 has no specification for the 

analysis of multiple standards.

 The version under review adds a cautionary note in ¶ 4.d.2 (Method of Standard Additions) that the addition 

of the known concentrations must yield results that fall within the linear range of the method.

 In the Quality Control section , the version under review adds the statement: “The QC practices considered to 

be an integral part of each method can be found 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 B10 is equally as effective as the approved version, Standard Method 3113 B-99.

3 5910 B-00 5910 B-11 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 the following editorial and technical revisions that are primarily associated with incorporating more quality 

control into the method:
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# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

 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.

 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-1is 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-1to 

0.005 to 0.950 cm-1for 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.
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# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

 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 22nd edition version of this method have been considerably strengthened 

relative to the approved version. The updated 2011 online version, Standard Method 5910 B-11, contains the same 

editorial and technical revisions detailed for the 22nd edition version. Therefore, Standard Method 5910 B-11 can be 

considered equally as effective as the approved method for the determination of UV absorption at 254 nm in drinking 

water.

4 6251 B-94 6251 B-07 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. Standard Method 

6251 B-07 is the current online version and it is identical to the 22nd edition version. Therefore, Standard Method 

6251 B-07 can be considered equally as effective as the approved method for the determination of HAA5 in drinking 

water.

5 EPA Method

515.4

6640 B-06 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 defines identical sample collection/handling protocols, sample preparation and derivatization steps, 

chromatographic conditions, and electron capture detection. Standard Method 6640 B in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater and EPA Method 515.4, Revision 1.0 specify the same quality 

control requirements and have the same method performance data. Standard Method 6640 B-06 is the current 

online version and it is identical to Method 6640 B in the 22nd edition version. Therefore, Standard Method 6640 B-06 

can be considered equally as effective as the approved method for the determination of Dalapon, 2,4-D, 2,4,5-TP 

(Silvex), Dinoseb, Pentachlorophenol, and Picloram in drinking water.

6 6651 B, 20th

edition

6651 B-05 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. Standard Method 6651 B-05 is the current online version and it 

is identical to the 22nd edition version. Therefore, Standard Method 6651 B-05 can be considered equally as effective 

as the approved method for the determination of glyphosate in drinking water.

7 9215 B, 20th

ed.

9215 B-04 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 141.74(a)(1) 
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# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

for the determination of heterotrophic bacteria. The version of this method published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is similar to the approved version with some minor editorial 

revisions that do not impact the effectiveness of the method. The online version, 9215 B-04, is identical to the 22nd

edition version. Therefore, Standard Method 9215 B-04 can be considered equally as effective as the approved 

method for the determination of heterotrophic bacteria.

8 9221 A, 20th

ed.

9221 A-06 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 cited in the drinking water regulations at 40 CFR 141.21(f)(3) and at 40 

CFR 141.74(a)(1) for the determination of total coliform bacteria. The version of this method published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is similar to the approved version with 

some minor editorial revisions that do not impact the effectiveness of the method. The online version, 9221 A-06, is 

identical to the 22nd edition version. Therefore, Standard Method 9221 A-06 can be considered equally as effective as 

the approved method for the determination of total coliform bacteria.

9 9221 B, 20th

ed.

9221 B-06 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 cited in the drinking water regulations at 40 CFR 141.21(f)(3), 40 CFR 

141.74(a)(1), and more specifically, SM 9221 B.1, B.2 is cited at 40 CFR 141.852(a)(5) for the determination of total 

coliform bacteria. The version of this method published in the 22nd edition of Standard Methods for the Examination 

of Water and Wastewater is similar to the approved version with some minor editorial revisions that do not impact 

the effectiveness of the method. The online version, 9221 B-06, is identical to the 22nd edition version. Therefore, 

Standard Method 9221 B-06 can be considered equally as effective as the approved method for the determination of 

total coliform bacteria.

10 9221 C, 20th

ed.

9221 C-06 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 cited in the drinking water regulations at 40 CFR 141.74(a)(1)for the 

estimation of total and fecal coliform bacteria density. The version published in the 22nd edition of Standard Methods 

for the Examination of Water and Wastewater has editorial revisions along with modified Most Probable Number 

(MPN) tables which were developed with improved statistical approaches. The changes to the version of the method 

published in the 22nd edition of Standard Methods for the Examination of Water and Wastewater do not impact the 

effectiveness of the method. The online version, 9221 C-06, is identical to the 22nd edition version. Therefore, 

Standard Method 9221 C-06 can be considered equally as effective as the approved method for the estimation of total 

and fecal coliform bacteria density.

11 9221 E, 20th

ed.

9221 E-06 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 cited in the drinking water regulations at 40 CFR 141.21(f)(5) and 40 

CFR 141.74(a)(1) for the determination of fecal coliform bacteria . The version of this method published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is similar to the approved version with 

some minor editorial revisions that do not impact the effectiveness of the method. The online version, 9221 E-06 is 

identical to the 22nd edition version. Therefore, Standard Method 9221 E-06 can be considered equally as effective as 

the approved method for the determination of fecal coliform bacteria.
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# Approved

Method

Revised/Edited 

Online Version

Additional Revisions?

12 9221 F, 20th

ed.

9221 F-06 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 cited in the drinking water regulations at 40 CFR 141.402(c)(2) and, 

more specifically, 9221 F.1 is cited at 40 CFR 141.852(a)(5) for the determination of Escherichia coli. The version of this 

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

the approved version with some minor editorial revisions that do not impact the effectiveness of the method. The 

online version, 9221 F-06 is identical to the 22nd edition version. Therefore, Standard Method 9221 F-06 can be 

considered equally as effective as the approved method for the determination of Escherichia coli.

13 9222 D, 20th

ed.

9222 D-06 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 cited in the drinking water regulations at 40 CFR 141.74(a)(1) for the 

determination of fecal coliform bacteria. The version of this method published in the 22nd edition of Standard 

Methods for the Examination of Water and Wastewater is similar to the approved version with some minor editorial 

revisions that do not impact the effectiveness of the method. The online version, 9222 D-06 is identical to the 22nd

edition version. Therefore, Standard Method 9222 D-06 can be considered equally as effective as the approved 

method for the determination of fecal coliform bacteria.

14 9223 B, 20th

ed.

9223 B-04 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 cited in the drinking water regulations at 40 CFR 141.21(f)(3), 40 CFR 

141.852(a)(5), 40 CFR 141.74(a)(1) for the determination of total coliform bacteria, and at 40 CFR 141.402(c)(2) and at 

40 CFR 141.852(a)(5) for the determination of Escherichia coli. The version of this method published in the 22nd

edition of Standard Methods for the Examination of Water and Wastewater is similar to the approved version with 

some minor editorial revisions that do not impact the effectiveness of the method. The online version, 9223 B-04 is 

identical to the 22nd edition version. Therefore, Standard Method 9223 B-04 can be considered equally as effective as 

the approved method for the determination of total coliform bacteria and Escherichia coli.