Office of Ground Water and Drinking Water

January 19, 2012

MEMORANDUM

SUBJECT: Basis for Expedited Approval of Methods from Standard Methods and ASTM 

International

FROM: Glynda Smith

Standards and Risk Management Division, Technical Support Center

TO: The Record

This memorandum documents the reviews that were conducted on new versions of methods 

issued by Standard Methods and ASTM International. It provides the background information on why 

EPA is approving these methods using the expedited methods approval process. Each method is 

discussed individually below. 

Standard Methods

Standard Method 3112 B-09 published online at http://www.standardmethods.org.

The published online version, 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 analysis of mercury by cold-vapor 

atomic absorption spectroscopy. The updated version, 3112 B-09, contains only minor editorial changes 

relative to the approved version. Thus, the updated version is equally as effective as the approved 

version.

Standard Method 3125 published in the 21st edition of Standard Methods for the Analysis of Water and 

Wastewater.

The version published in the 20th edition of Standard Methods for the Analysis of Water and Wastewater

was used as the basis of comparison, because it is currently cited in the drinking water regulations at 40 

CFR 141.25(a) for the analysis of uranium. The version published in the 21st edition of Standard 

Methods is identical to the approved version. Thus, the 21st edition version is equally as effective as the 

version published in the 20th edition.

ASTM International

ASTM Method D 859-10

ASTM Method D 859-05 was approved for the analysis of silica in drinking water in the expedited 

methods approval action that was published on June 3, 2008 (73 FR 31616). In the June 2008 action, 

ASTM Method D 859-05 was compared against the approved version, ASTM Method D 859-00 which is 

cited in the drinking water regulations at 40 CFR 141.23 (k)(1). Only two minor editorial modifications 

have been added to ASTM Method D859-10 relative to the expedited version, ASTM Method D 859-05:

• Section 1 incorporates a statement indicating that SI units (the International System of Units -

abbreviated SI from French: Système International d'unités) are to be regarded as standard.

• Section 8.7 was modified to allow the use of commercially prepared standards.
The methods are otherwise identical with respect to sample collection and handling protocols, sample 

preparation, analytical procedure and calculation of silica concentration in the sample. The precision 

and bias are unchanged. Therefore, ASTM D 859-10 is equally as effective as ASTM Method D 859-05, 

and thus the approved method ASTM D859-00, for determining silica concentration in drinking water.

ASTM Method D 1179-10 B

ASTM Method D 1179-04 B was approved for the analysis of fluoride in drinking water in the expedited 

methods approval action that was published on June 3, 2008 (73 FR 31616). In the June 2008 action, 

ASTM Method D 1179-04 B was compared against the approved version, ASTM Method D 1179-99 B 

which is cited in the drinking water regulations at 40 CFR 141.23 (k)(1). The following changes have 

been made in ASTM Method D 1179-10 B relative to the expedited version, ASTM Method D 1179-04 B:

• Section 1 incorporates a statement indicating that SI units (the International System of Units –

abbreviated SI from French: Système International d'unités) are to be regarded as standard.

• Section 2 adds two guideline references: ASTM D 4127 (Terminology Used with Ion Selective 

Electrodes) and ASTM D 5810 (Guide for Spiking into Aqueous Samples).

• Simplified and clarified text in Section 4.2. Removed the statement: “Fluoride is monitored to 

assure that an optimum treatment level of 1.4 to 2.4 mg/L, depending on the corresponding 

range of ambient temperatures of 32 to 10 o

C, is maintained.” Replaced with the statement:

“Fluoride is monitored to assure that an optimum treatment level, usually near 1 mg/L, is 

maintained.”

• Expanded the Scope in Section 14.1 by adding: “Concentrated solutions of fluoroborate or 

fluoroboric acid, such as in electroplating wastes, should be distilled or tested using a 

fluoroborate ISE. Samples which contain aluminum, silica, or iron may require distillation. 

Anions such as chloride, bromide, iodide, sulfate, bicarbonate, nitrate, phosphate, and acetate 

typically do not interfere unless present at greater than 1% or more.” The cautions mentioned 

in the expanded scope have little bearing on drinking water samples. The threshold levels for 

aluminum and iron interference are significantly higher than the secondary MCLs cited at 40 CFR 

143.3.

• Expanded the Summary in Section 15 by adding: “The electrode is calibrated in known fluoride 

solutions, and the concentrations of unknowns are determined in solutions with the same 

background. Samples and standards should be measured at the same temperature. Standards 

and samples are diluted with an ionic strength adjustor that also minimizes possible 

interferences from hydroxide and low levels of aluminum and iron.” This summarizes 

information that is already in the Interference section.

• Section 11.1 allows the use of commercially prepared fluoride standard solutions.

• Calibration Section 19.3 now describes the use of electronic spreadsheets for plotting electrode 

potential versus fluoride concentration. (Earlier approved versions specified manually plotting 

the calibration data on semilogarithmic graph paper).

• Section 23.6.1 was modified to remove the statement, “Fluoride is not an analyte that can be 

feasibly spiked into samples.” With the availability of commercially prepared solutions, matrix 

spikes can be performed and the section has been revised to incorporate matrix spikes 

accordingly.

The methods are otherwise identical with respect to sample collection and handling protocols, 

sample preparation, and analytical procedure for determination of fluoride in the sample. The 

precision and bias are unchanged. Therefore, ASTM D 1179-10 B is equally as effective as ASTM 

Method D 1179-04 B, and thus the approved method ASTM D1179-99 B, for determining fluoride 

concentration in drinking water.
ASTM Method D 5673-10

ASTM Method D5673-05 was approved for the analysis of uranium in drinking water in the expedited 

methods approval action that was published on June 3, 2008 (73 FR 31616). In the June 2008 action, 

ASTM Method D 5673-05 was compared against the approved version, ASTM Method D 5673-03 which 

is cited in the drinking water regulations at 40 CFR 141.25(a). The following changes have been made in 

ASTM Method D 5673-10 relative to the expedited version, ASTM Method D 5673-05:

• Section 1 incorporates a statement indicating that SI units (the International System of Units –

abbreviated SI from French: Système International d'unités) are to be regarded as standard.

• In Section 4 a cross-reference mistake has been corrected.

• In the Purity of Reagents subsection of Section 8.1, the method deletes the option: “other 

grades may be used provided it is first ascertained that the reagent is of sufficient purity to 

permit its use without lessening the accuracy of the determination.”

• In the Purity of Water subsection of Section 8.2, the method adds the statement: “Other 

reagent water types may be used provided it is first ascertained that the water is of sufficiently 

high purity to permit its use without adversely affecting the bias and precision of the test 

method.”

The methods are otherwise identical with respect to sample collection and handling protocols, 

sample preparation, analytical procedure and calculation of uranium concentration in the sample. 

The precision and bias are unchanged. Therefore, ASTM D 5673-10 is equally as effective as ASTM 

Method D 5673-05, and thus the approved method ASTM D5673-03, for determining silica 

concentration in drinking water.