Page 1 of 14 Office of Ground Water and Drinking Water November 26, 2012

MEMORANDUM

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

22 nd 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 22 nd edition of Standard Methods for the Examination of Water and Wastewater is ident ical to the approved online version with the minor editorial revision that references the quality control criteria in Section 2020

. Thus, the 22 nd 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 22 nd edition of Standar d 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 22 nd 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 22 nd 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 22 nd 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 regulatio ns 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 23 20 B separately list sodium thiosulfate in their respective Reagent sections
to remove free chlorine residual. In the 22 nd edition, Method 2320 B does not specify sodium thiosulfate as a reagent; rather, it references the titration procedure in Method 231 0 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 remainsPage 2 of 14 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 22 nd
edition version is equally as effective as the approved online versio n.

(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 22 nd 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 22 nd 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 4 0 CFR 143.4(b) for the
determination of total dissolved solids. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version with the minor
editorial revision that re ferences the quality control criteria in Section 2020. Thus, the 22 nd 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 22 nd edition of Standard Methods for the Examination of Water and Wastewater contains the following m inor 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 :

• A dds 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 22 nd edition is equally as effective as the approved o nline 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, magne sium, 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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(9) Standard Method 3111 D. The online versio n, 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 22 nd 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 22 n d edition version is equally as effective as the approved online version.Page 3 of 14 (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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(11) S tandard M ethod 3113 B

. The version approved in the 19 th 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 22 nd edition version of the method, including:

• The 22 nd 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 m ethod for analysis.

• This 22 nd edition version corrects an error in the preparation of the palladium nitrate modifier. The approved 19 th edition version calls for 8.89 g Pd(NO 3 ) 2 •(H 2 O) to obtain a 4000 mg Pd/L solution; but that mass yield a 3800 mg Pd/L solution. The 22 nd edition version changes the preparation to 9.34 g Pd(NO 3 ) 2 •(H 2 O) which will yield the correct 4000 mg Pd/L concentration.

• The 22 nd edition version includes metals with sample turbidities less than one NTU with
dissolved metals and allo ws 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 22 nd

edition ver sion 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 22 nd 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 22 nd edition version adds a cautionary note indicating that the procedure must yield results within the linear range of the method.

• Th e version published in the 22 nd 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 22 nd edition is equally as effective as the approved 19 th edition version.

(12) S tandard M ethod 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 22 nd edition version of the method, including:

• The 22 nd 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

-Page 4 of 14 hydrogen flame after r eduction, 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 22 nd edition includes the editorial revision that references the quality control criteria in Section 3020.

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

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

instrume nt. The 22 nd 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, 5 th ed., Chapter IV, Section 7.2.3 which state s”...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, call s 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 22 nd edition is consistent with those specified in th e 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 calc ulation of arsenic and selenium concentrations in drinking water. Therefore, Standard Method 3114 B in the 22 nd edition is equally as effective as the approved online version.

(13) Standard Method 3120. The online version, Standard Method 3120 B

- 99, wa s 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 22 nd 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 22 nd 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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(15) Standard Method 3500

- Mg B. The onlin e 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 22 nd 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 22 nd
edition version is equally as effective as the a pproved 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) forPage 5 of 14 the determination of fluo ride, nitrate, nitrite, and orthophosphate, and again at 40 CFR 143.4(b) for the
determination of chloride and sulfate. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(17) Standard Method 4500

- Cl D. The online version, St andard 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 22 nd 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 22 nd 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 i s 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 22 nd

edition of Standard Methods for the Examination of Water and Wastewater is id entical to the approved online version with the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22 nd 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) f or the determination of free, total, and combined chlorine. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version with the minor
editorial revision that refere nces the quality control criteria in Section 4020. Thus, the 22 nd 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 compar ison 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 22 nd 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 22 nd 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 22 nd

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 22 nd 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 22 nd

edition of Standard Methods for the Exa mination of Water and Wastewater is identical to the approvedPage 6 of 14 online version with the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22 nd edition version is equally as effective as the approved online vers ion.

(23) Standard Method 4500

- Cl B. The online version, Standard Method 4500

- Cl 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 chloride. The vers ion published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version. Thus, the 22 nd
edition version is equally as effective as the approved online version.

(24) Standard Method 45 00

- Cl D. The online version, Standard Method 4500

- Cl D

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

(25) Standard Method 4500

- ClO 2 C. The online version, Standard Method 4500

- ClO 2 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 22 nd 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 qualit y control criteria in Section 4020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(26) Standard Method 4500

- ClO 2 E. The online version, Standard Method 4500

- ClO 2 E

- 00, was used as the basis for comparison becaus e 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 determinat ion of chlorite. The version published in the 22 nd 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 Sectio n 4020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(2 7 ) Standard Method 4500

- CN E. The online version, Standard Method 4500

- CN E

- 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 22 nd edition of Standard Methods for the Exami nation 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 22 nd edition version is equally as effective as the approved online versio n.

(2 8 ) Standard Method 4500

- CN F. The online version, Standard Method 4500

- CN F

- 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. Th e version published in the 22 nd 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 2 2 nd
edition version is equally as effective as the approved online version.

( 29 ) Standard Method 4500

- CN G. The online version, Standard Method 4500

- CN G

- 99, was used as the basis for comparison because it is currently cited in the drinking water regu lations at 40 CFRPage 7 of 14 141.23(k)(1) for the determination of free cyanide. The version published in the 22 nd 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 22 nd
edition version is equally as effective as the approved online version.

(3 0 ) Standard Method 4500

- F B. The online version, Standard Method 4500

- F 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 fluoride. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identica l to the approved online version. Thus, the 22 nd
edition version is equally as effective as the approved online version.

(3 1 ) Standard Method 4500

- F C. The online version, Standard Method 4500

- F C

- 97, was used as the basis for comparison because it i s currently cited in the drinking water regulations at 40 CFR 141.23(k)(1) for the determination of fluoride. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online ver sion with the minor editorial revision that references the quality control criteria in Section 4020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(3 2 ) Standard Method 4500

- F D. The online version, Standard Met hod 4500

- F 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 fluoride. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(3 3 ) Standard Method 4500

- F E. The online version, Standard Method 4500

- F 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 determ ination of fluoride. The version published in the 22 nd 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 Se ction 4020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(3 4 ) 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 t he drinking water regulations at 40 CFR 141.23(k)(1) for the determination of pH. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version with the minor
editoria l revision that references the quality control criteria in Section 4020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(3 5 ) Standard Method 4500

- NO 3 - D. The online version, Standard Method 4500

- NO 3 - 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 22 nd 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 22 nd
edition version is equally as effective as the approved online version.

(3 6 ) Stand ard Method 4500

- NO 3 - E. The online version, Standard Method 4500

- NO 3 - E

- 00, was used as the basis for comparison because it is currently cited in the drinking water regulations at 40 CFRPage 8 of 14 141.23(k)(1) for the determination of nitrate and nitrite . The vers ion published in the 22 nd 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 22 nd ed ition version is equally as effective as the approved online version.

(3 7 ) Standard Method 4500

- NO 3 - F. The online version, Standard Method 4500

- NO 3 - 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 22 nd edition of Standard Methods for the Examinat ion 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 22 nd edition version is equally as effective as the approved online version.

(3 8) Standard Method 4500

- NO 2 - B. The online version, Standard Method 4500

- NO 2 - 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 vers ion published in the 22 nd 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 22 nd

ed ition version is equally as effective as the approved online version.

( 39 ) Standard Method 4500

- O 3 B. The online version, Standard Method 4500

- O 3 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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(4 0 ) Standard Method 4500

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

Examinat ion 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 22 nd 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 22 nd edition version is equally as effective as the approved 19 th e dition version.

(4 1 ) Standard Method 4500

- P F. The version published in the 19 th 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 22 nd edition of Standard Methods for the Examination of Water and

Wastewater is identical to the approved version with the minor editorial revision that referenc es the quality control criteria in Section 4020. Thus, the 22 nd edition version is equally as effective as the approved 19 th edition version.

(4 2 ) Standard Method 4500

- SiO 2 C. The online version, Standard Method 4500

- SiO 2 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 22 nd 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 22 nd
edition version is equally as effective as the approved online version

.Page 9 of 14 (4 3 ) Standa rd Method 4500

- SiO 2 D. The online version, Standard Method 4500

- SiO 2 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 22 nd 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 22 nd

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

(4 4 ) Standard Method 4500

- SiO 2 E. The online version, Standard Method 4500

- SiO 2 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 22 nd 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 22 nd
edition version is equally as effective as the approved online version.

(4 5 ) Standard Method 4500

- SO 4 2

- C. The version published in the 19 th edition of Standard Method for the Examination of Wate r and Wastewater was used as the basis for comparison, because it is currently cited in the drinking water regulations at 40 CFR 14 3.4(b) for the determination of sulfate. The version published in the 22 nd edition of Standard Methods for the Examination o f 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 22 nd edition version is equally as effective as the approved 19 th

edition version.

(4 6 ) Standard Method 4500

- SO 4 2

- D. The version published in the 19 th 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 14 3.4(b ) for the determination of sulfate. The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved version. Thus, the 22 nd edition version is equally as effective as the approved

19 th edition version.

(4 7 ) Standard Method 4500

- SO 4 2

- E. The version published in the 19 th 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 reg ulations at 40 CFR 14 3.4(b) for the determination of sulfate. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved 19 th

edition version

.

(4 8 ) Standard Method 4500

- SO 4 2

- F. The version published in the 19 th 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 22 nd edition of Standard Methods fo r 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 22 nd edition version is equally as effective as the approved 19 th

edit ion 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) forPage 10 of 14 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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(5 0 ) Standard Method 5310 C. The online version, Standard Method 5310 C

- 0 0, 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 ca rbon (DOC). The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version . Thus, the 22 nd
edition version is equally as effective as the approved online version.

(5 1 ) 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 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version. Thus, the 22 nd

edit ion version is equally as effective as the approved online version.

(5 2 ) 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 CF R 143.4(b) for the determination of foaming agents. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(5 3 ) Standard Method 5910 B. The online version, Standard Method 5910 B

- 00, was used as the basis for comparison because i t 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 22 nd edition
of Standard Methods for the Examination of Water and Wastewater co ntains 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 sam ples 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 interferen ce s.

• 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 • Add s a new par agraph 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) an d 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 reas onable 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 ins tructs 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 i f 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 n ew version of this method have been considerably strengthened relative to the approved version. As a result, Standard Method 5910 B in the 22 nd edition is equally as effective (if not more so) as the approved online version.

(5 4 ) 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, trichlo roacetic acid, monobromoacetic acid, and dibromoacetic acid) . The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version with
the minor editorial revision that refe rences the quality control criteria in Section 6 020. Thus, the 22 nd
edition version is equally as effective as the approved online version.

(5 5 ) Standard Method 6610 B. EPA Method 531.2 was used as the basis for comparison because it is currently cite d 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 prepar ation, 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 NaO H. 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 1000Page 12 of 14 mLs results in a solution that is 0.05 N, not 0.075 N. Therefore, the concentration listed in
Standard Meth od 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 t hat 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.

St andard 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 22 nd edition is equally as effective as the approved method, EPA Method 531.2.

(5 6 ) 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, Pent achlorophenol, 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 22 nd edition is equally as effective as the approved method, EPA Method 515.4, Revision 1.0.

(5 7 ) Standard Method 6651 B. The version published in the 20 th edition of Standard Methods for the Examination of Water and Wastewater was used as the basis for com parison, 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 22 nd 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 22 nd edition version is equally as effective as the approved 20 th edition version.

(5 8 ) Standard Method 7110 B. The online ve rsion, 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 22 nd 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 7 020. Thus, the 22 nd
edition version is equally as effectiv e 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 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(6 0 ) Standard Method 7120. The online version, Standard Method 7120

- 97, was used as the basis for comparison because it is currently cited in the dr inking water regulations at 40 CFR 141.25(a) for the
determination of gamma emitters . The version published in the 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identical to the approved online version with the minorPage 13 of 14 edit orial revision that references the quality control criteria in Section 7020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(6 1 ) Standard Method 7500

- Cs B. The online version, Standard Method 7500

- Cs B

- 00, was us ed 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 22 nd 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 22 nd
edition version is equally as effective as the approved online version.

(6 2 ) Standard M ethod 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 i n the 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(6 3 ) 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 22 nd 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 22 nd
edition version is equally as effective as the approved online version.

(6 4 ) Standard Method 7500

- I C. The online version, Standard Method 7500

- I C

- 00, was used as the
basis for co mparison 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 22 nd edition of Standard Methods for the Examination of Water and Wastewater is identica l to the approved online version with the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22 nd
edition version is equally as effective as the approved online version.

(6 5 ) 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 22 nd edit ion 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 22 nd
edition version is equally as ef fective as the approved online version.

(6 6 ) 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 de termination of radium

- 226. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved online version.

(6 7 ) 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 cite d in the drinking water regulations at 40 CFR 141.25(a)
for the determination of radium

- 226. The version published in the 22 nd edition of Standard Methods forPage 14 of 14 the Examination of Water and Wastewater is identical to the approved online version with the min or editorial revision that references the quality control criteria in Section 7020. Thus, the 22 nd edition version is equally as effective as the approved online version.

(6 8 ) 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 22 nd edition of Standard Methods for the Examination of Water and W astewater is identical to the approved online version with the minor editorial revision that references the quality control criteria in Section 7020. Thus, the 22 nd edition version is equally as effective as the approved online version.

( 69 ) Standard Me thod 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 22 nd 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 22 nd editi on version is equally as effective as the approved online version.

(7 0 ) 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 22 nd edition of Stan dard 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 22 nd edition version is equally as effective as the approved online version.

(7 1 ) 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 o f uranium. The version published in the 22 nd 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 22 nd edition version is equally as effective as the approved online version.