Office of Ground Water and Drinking Water

December 30, 2015

MEMORANDUM

SUBJECT: Basis for Expedited Approval of Methods from ASTM International

FROM: Glynda A. Smith, Chemist

Technical Support Center

TO: The Record

This memo documents the reviews that were conducted on new versions of methods issued by 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:

ASTM International Methods D 511-14 A and B (Method A is a complexometric titration technique; 

Method B is an atomic absorption spectrophotometric technique)

ASTM Methods D 511-09 A and B were approved for the determination of calcium and magnesium in 

drinking water in the expedited methods approval action that was published November 10, 2009 (74 FR 

57908). In that action, ASTM Methods D 511-09 A and B were compared to the approved versions, 

ASTM Methods D 511-03 A and B, which are cited in the drinking water regulations at 40 CFR 

141.23(k)(1). The record of this comparative evaluation is contained in the document titled “Basis for 

Expedited Approval of Updated ASTM Methods” in the docket associated with the expedited approval 

action (Docket ID: EPA-HQ-OW-2009-0707). The following changes have been made in the newest 

versions relative to the method versions approved in the 2009 action:

• Section 1.2 still specifies that SI units are the standard. However, it now makes allowance to 

include mathematical conversion to inch-pound units for informational purposes.

• Section 6.2 has been modified to allow pH adjustment of samples after they arrive in the 

laboratory rather than requiring field samplers to work with concentrated acids. This procedure 

is consistent with the sample handling instructions in other approved methods for calcium and 

magnesium, including EPA Method 200.7 (see Section 8.3 of the method).

• Section 11 has been modified to include filter paper information.

• Section 15.2.2 has been modified to clarify standardization of the titrant by using a mid-range 

concentration of calcium and magnesium.

• Sections 15 and 25 have been modified to identify that 20 samples constitute an analytical batch 

(the same specification used in EPA methods).

ASTM Methods D 511-14 A and B are identical to ASTM Methods D 511-09 A and B with respect to the 

sample preparation, analytical procedures, and calculation of calcium and magnesium concentrations in 

the samples. The precision and bias data are unchanged. Therefore, ASTM Methods D 511-14 A and B 

are equally as effective as D 511-09 A and B (and thus, D 511-03 A and B) for determining calcium and 

magnesium in drinking water.

ASTM International Method, D 1125-14 A
ASTM Method D 1125-95 A was used as the basis for comparison, because it is currently promulgated in 

the drinking water regulations at 40 CFR 141.23(k)(1) for determining conductivity in drinking water. The 

following changes have been made in the updated version:

• Section 1.4 was moved to 1.5 and a new Section 1.4 was added to note that SI units are the 

standard and will be used for all values in the method.

• Deleted Reference E 1 (Specification for ASTM Thermometers) and replaced it with Reference E 

2251 (Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids).

• Section 5.4 added describing interference associated with bubble formation on surface of 

conductivity cell electrodes and instructions for mitigating the issue.

• Added text to Section 6.1.1 describing the use of four-electrode conductivity cells.

• Section 6.2.4 modified to add the option to use hastelloy and stainless steel electrodes in 

addition to the monel, titanium and graphite electrodes.

• Section 9.1 modified to indicate that no mechanical cleaning should be attempted with platinum 

or graphite electrodes.

• Section 9.5 added describing electrode preparation for non-platinum based electrode materials.

• Section 25 (Quality Control) added to describe the types of QC analyses that must be included to 

verify that test results obtained using the method are valid and accurate.

ASTM Method D 1125-14 A is identical to the promulgated method with respect to sample preparation, 

analytical procedure and calculation of conductance in drinking water samples. The precision and bias 

data are unchanged. Therefore, ASTM Method D 1125-14 A is equally as effective as ASTM Method D 

1125-95 A for determining conductivity in drinking water.

ASTM International Method D 1253-14

ASTM Method D 1253-08 was approved for the determination of free, combined and total chlorine in 

drinking water in the expedited methods approval action that was published November 10, 2009 (74 FR 

57908). In that action, ASTM Method D 1253-08 was compared to the approved version, ASTM Method 

D 1253-03, which is cited in the drinking water regulations at 40 CFR 141.74(a)(2) and at 40 CFR 

141.131(c)(1) for determining free and total chlorine residual in water. It is also promulgated at 40 CFR 

141.131(c)(1) for determining combined chlorine in water. The record of this comparative evaluation is 

contained in the document titled “Basis for Expedited Approval of Updated ASTM Methods” in the 

docket associated with the expedited approval action (Docket ID: EPA-HQ-OW-2009-0707). The 

following changes have been made in the newest version relative to the method version that was 

approved in the 2009 action:

• Section 6.9 added describing oxidizing agents that can interfere and cause positive bias in test 

results.

• Section 7.1 updated to include digital instruments in addition to the older analog-based devices.

• Removed Figure 1 which provided a wiring diagram for an analog-based titrator. Replaced with a 

new Figure 1 that shows the titration plot of measured current vs. titrant volume and the 

titration endpoint analysts should observe.

• Sections 8.3 and 8.4 modified to allow the use of commercially prepared pH buffer solutions.

• Section 9.1 added the recommendation to use only glass containers that have been pretreated 

to eliminate chlorine demand.

• Section 10.2.2 updated to incorporate titration procedure for digital instruments. 

• Section 13.2.4 added specifying analysis of a continuing calibration blank and continuing 

calibration verification check at a 10% frequency. Acceptance criteria specifying that the results 

must be within + 15% of the known concentration also included. 
• Section 13.6 revised to incorporate a procedure for preparing matrix spike QC checks, 

calculations, and acceptance criteria (recoveries must be within + 20%).

ASTM Method 1253-14 is identical to Method D 1253-08 with respect to sample collection, sample 

preparation, analytical procedure and calculation of chlorine residual (free, total and combined) 

concentrations in the sample. The QC specifications have been expanded and the method allows the use 

of the more robust digital instruments. The precision and bias data are unchanged. Therefore, ASTM 

Method D 1253-14 is equally as effective as ASTM Method D 1253-08 (and thus, ASTM Method D 1253-

03) for determining free, total and combined chlorine residual in drinking water.

ASTM International Methods D 1688-12 A and C (Method A is a direct atomic absorption 

spectrophotometric technique; Method C is a graphite furnace atomic absorption technique)

ASTM Methods D 1688-07 A and C were approved for the determination of copper in drinking water in 

the expedited methods approval action that was published November 10, 2009 (74 FR 57908). In that 

action, ASTM Methods D 1688-07 A and C were compared to the approved versions, ASTM Methods D 

1688-02 A and C which are cited in the drinking water regulations at 40 CFR 141.23(k)(1). The record of 

this comparative evaluation is contained in the document titled “Basis for Expedited Approval of 

Updated ASTM Methods” in the docket associated with the expedited approval action (Docket ID: EPAHQ-OW-2009-0707). The following changes have been made in the newest versions relative to the 

method versions approved in the 2009 action:

• Section 1.2 still specifies that SI units are standard; however, it now makes allowance for the use 

of inch-pound units.

• Removed Reference D 1192 which has been withdrawn and not superseded by an alternate 

reference.

• Section 6.2 has been modified to allow pH adjustment of samples after they arrive in the 

laboratory rather than requiring field samplers to work with concentrated acids. This procedure 

is consistent with the sample handling instructions in other approved methods for copper, 

including EPA Methods 200.7 and 200.9 (see Section 8.3 of the methods).

• Sections 13.3 and 31.4 have been modified to allow the use of block digestion systems in place 

of requiring sample digestion in a water bath. Regulation of temperature can be more readily 

controlled in block digesters.

• Section 34.2.4 added recommending analysis of a continuing calibration blank and continuing 

calibration verification check at a 10% frequency.

ASTM Methods D 1688-12 A and C are identical to ASTM Methods D 1688-07 A and C with respect to the 

sample preparation, analytical procedures, and directions for calculating copper concentrations in 

samples. The precision and bias data are unchanged. Therefore, ASTM Methods D 1688-12 A and C are

equally as effective as ASTM Methods D 1688-07 A and C (and thus, ASTM Methods D 1688-02 A and C) 

for determining copper in drinking water.

ASTM International Method D 3697-12

ASTM Method D 3697-07 was approved for the determination of antimony in drinking water in the 

expedited methods approval action that was published November 10, 2009 (74 FR 57908). In that 

action, ASTM Method D 3697-07 was compared to the approved version, ASTM Method D 3697-02 

which is cited in the drinking water regulations at 40 CFR 141.23(k)(1). The record of this comparative 

evaluation is contained in the document titled “Basis for Expedited Approval of Updated ASTM 

Methods” in the docket associated with the expedited approval action (Docket ID: EPA-HQ-OW-2009-

0707). The following changes have been made in the newest version relative to the method version that 

was approved in the 2009 action:
• Section 1.4 was moved to Section 1.5 and a new Section 1.4 was added specifying the use of SI 

units, but making allowance for the use of inch-pound units.

• Section 9.2 has been modified to allow pH adjustment of samples after they arrive in the 

laboratory rather than requiring field samplers to work with concentrated acids. This procedure 

is consistent with the sample handling instructions in other approved methods for antimony, 

including EPA Method 200.9 (see Section 8.3 of the method).

• Section 11.3 has been modified to allow the use of block digestion systems in place of 

evaporating samples on a hot plate. Regulation of temperature can be more readily controlled 

in block digesters.

ASTM Method D 3697-12 is identical to ASTM Method D 3697-07 with respect to the sample 

preparation, analytical procedures, and directions for calculating antimony concentrations in samples. 

The precision and bias data are unchanged. Therefore, ASTM Method D 3697-12 is equally as effective 

as ASTM Method D 3697-07 (and thus, ASTM Method D 3697-02) for determining antimony in drinking 

water.