To: Jan Matuszko/DC/USEPA/US@EPA 

From: "Fick, Alyson" <afick@astm.org> 

Date: 08/14/2012 11:41AM 

Cc: "Morrissey, Len" <lmorriss@astm.org>, "Fick, Alyson" <afick@astm.org> 

Subject: D7575 EPA Questions from NODA - Task Group Response 

(See attached file: D7575 Task Group Response to EPA NODA Questions_Final.docx) 

Hi Jan, 

Attached, please find a working document that the D7575 TG has been developing to 

address the questions that you forwarded from the recent NODA. This continues to be 

an ongoing discussion at our D19 meetings but I thought that the information in the 

report might be useful as your staff is looking to address the issues brought up. If the 

EPA requires an official ASTM response to the questions, we will put this document 

through the necessary procedural process to make that happen. 

I wanted you to get this information prior to my going on maternity leave. If you need 

any additional information or would like to coordinate on these issues, you can work 

with Len while I’m out. He has been in the loop on our coordination efforts and will be 

glad to assist as needed until I return. 

Take care, 

Alyson 

Alyson Fick, MPA 

Manager, TCO Division 

ASTM International 

100 Barr Harbor Drive 

West Conshohocken, PA 19428 

Phone: 610-832-9710 

Fax: 610-832-9666 

afick@astm.org

 
To: "Fick, Alyson" <afick@astm.org> 

From: Jan Matuszko/DC/USEPA/US 

Date: 07/12/2012 11:52AM 

Subject: A few questions about ASTM D7575 

Hi Alyson, 

Per our conversation the other day, there are a few technical questions that were raised 

during the NODA comment period for which your input would be helpful. Please see the 

attachment. 

(See attached file: Questions for ASTM 71012.docx) 

Thanks! 

Jan 

++++++++++++++++++++ 

Jan Matuszko 

Branch Chief 

Engineering and Analytical Support Branch 

Engineering and Analysis Division (4303T) 

U.S. EPA 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

(202) 566-1035

Questions for ASTM on D7575 

Based on Public Comments 

1) Note 9 in the ASTM method mentions that contact mixing (i.e., a stand mixer) is acceptable 

EPA has always maintained that no contact should be made with the sample because the analyte 

may adhere to the contacting device (e.g., stir rod), which would change the sample integrity. 

What data does ASTM have to ensure that contact mixing does not have an impact on the 

analytical results? 

2) What data or literature does ASTM have to demonstrate that a 10 mL sample is truly 

representative of a 1L sample (aside from the comparability data already submitted to EPA)? 

3) How does D7575 compensate for extremely turbid samples? ASTM D7575 contains a 

cautionary statement that for certain samples this method may not be appropriate (e.g., because 

the samples contain high particulates). Is there a practical way for an analyst to make a 

determination before conducting an analysis using this method in a laboratory that receives a 

large amount of samples of different types? 
ASTM Committee D19 on WATER D7575 TASK GROUP:

RESPONSE TO UNITED STATES ENVIRONMENTAL PROTECTION 

AGENCY QUESTIONS DERIVED FROM 

NOTICE OF DATA AVAILABILITY COMMENTS

August 2012 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

PREFACE

 On December 14, 2011, the United States Environmental Protection Agency (EPA) 

published a Notice of Data Availability (NODA) in the Federal Register1, soliciting comments 

on new data received from ASTM D19 on Water D7575 Task Group and EPA’s consideration of 

approving ASTM Standard D7575-10 as an alternative choice for the determination of oil and 

grease in Clean Water programs. As published in the Method Update Rule – Notice of Data 

Availability Fact Sheet2

: 

[EPA described but did not propose the new ASTM method for oil and grease in 

the September 23, 2010 Federal Register notice. This method was not initially 

proposed because it uses a different extractant (a membrane rather than a 

solvent) and a different measurement technique (infrared absorption rather than 

gravimetry) from the extractant and measurement technique of currently 

approved methods for oil and grease... However, EPA is considering revising its 

regulatory requirements for oil and grease based on comments and additional 

data received on the new ASTM method for oil and grease (ASTM D7575-10). 

After evaluating the new data, EPA finds that ASTM D7575-10 is a good standalone method for the measurement of oil and grease..., and it produces results 

that are generally very close results using Method 1664A for those matrices 

tested...] 

 

 On May 18, 2012, EPA published the Method Update Rule3

. In the Final Rule, EPA 

stated that it would, “Make a decision on the inclusion of the new method [ASTM D7575] once 

it reviews the public comments received in response to the NODA in a separate Federal Register 

notice.” As part of its diligence in reviewing the public comments solicited from the NODA, 

EPA on July 12, 20124 requested response from ASTM D19 on Water D7575 Task Group 

(D7575 Task Group) on three questions concerning contact mixing and representative sampling. 

The following document is the D7575 Task Group response to these questions. 

Comments regarding the content of this document should be addressed to the following:

Mr. Len Morrissey

Director, ASTM International

100 Barr Harbor Drive 

West Conshohocken, PA 

(610) 832-9719 

lmorriss@astm.org

 

1 Federal Register/Vol.76, No. 240/Wednesday, December 14, 2011/Proposed Rules

2 EPA-820-F-11-0150 3 Federal Register/Vol. 77, No. 97/Friday, May 18, 2012/Rules and Regulations 4 Communication from USEPA Jan Matuszko Branch Chief, Engineering and Analytical Support Branch, 

Engineering and Analysis Division to ASTM D19 Manager Alyson Fick July 12, 2012 including attached 

“Questions for ASTM 71212.docx” document.
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

3 

QUESTION 1

USEPA Statement:

Note 9 in the ASTM method mentions that contact mixing (i.e., a stand mixer) is 

acceptable. EPA has always maintained that no contact should be made with the sample 

because the analyte may adhere to the contacting device (e.g., stir rod), which would 

change the sample integrity. 

USEPA Question 1 – 

What data does ASTM have to ensure that contact mixing does not have an impact on the 

analytical results?

D7575 Task Group Response

 In many sections, D7575 references the procedures allowable in EPA Method 1664. 

Sections 6, 8, and 11 of the EPA reference method discusses, describes, and allows the use of 

contact mixing devices such as glass stirring rods and PFTE-coated stirring bars, etc. To address 

that contact mixing does not have an impact on the analytical results, ASTM Standard D7575 

instructs and guides the operator through the method to ensure analytical integrity and data 

quality. Specifically, in the following Sections: 

Section 6. Interferences

 6.1 Method interferences may be caused by contaminants in instrumentation, reagents, 

 glassware and other apparatus producing artifacts. Routine laboratory method blanks 

will demonstrate all these materials are free from interferences.

Section 14. Procedure 

 14.2 Sample pretreatment—If the sample to be tested is a grab sample, vigorously shake

 the sample bottle to sufficiently mix the sample. The sample bottle may require more 

 shaking if collected seven or more days prior to testing. It is up to the operator to ensure 

 the sample is homogeneous prior to proceeding with the measurement.

NOTE 9—For challenging samples it has been found that: A) vigorously shaking a 

sample bottle for up to 20 minutes with a paint shaker or an appropriate laboratory shaker 

 with sample container holder accessory and B) ultrasonic vibration using an ultrasonic 

 bath under the following suggested conditions [(a) bath is operating at a temperature of 

40 °C, (b) sample bottle cap(s) are sufficiently tightened (c) water level is sufficient to 

 fully submerge the sample bottle(s), (d) ultrasonic vibration for up to 20 minutes], are 

 sufficient to homogenize a sample that has been stationary for the maximum allowed 

 holding time of 28 days in the vast majority of cases. A sample processed very soon after 

taking the sample or created in the lab by spiking immediately before testing may require 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

4 

minimal shaking. If an inspection of the sample clearly indicates this amount of shaking 

has not sufficiently homogenized the sample (that is, stratification in the sample 

container), further homogenization by the same method or a different method may be 

required. In general it has been found that contact mixing (that is, ultrasonic 

homogenization, stand mixer, etc.) of the sample does not cause any interferences for the 

method. If the sample is known to be problematic, it may be ideal to collect the sample in 

a wide mouth jar to facilitate contact mixing.

Further, if there is observance of non-homogeneity [as outlined in ASTM D7575-10 Note

9.], and the operator determines a sample does not adequately homogenize using the 

conventional non-contact techniques (e.g. shaking, ultrasonic bath) and requires special 

treatment, then:

The operator may consider other contact homogenization techniques such as those 

described in EPA Method 1664 Revision A, using appropriate safeguards and 

consideration of data quality objectives. These procedures are described below: 

EPA 1664 Equipment: 

6.4 Equipment for sample extraction 

6.4.2 Glass stirring rod

6.7 Equipment for removal of adsorptive materials 

6.7.1 Magnetic stirrer 

6.7.2 PTFE-coated magnetic stirring bars

EPA 1664 Procedures: 

8.0 Sample Collection, Preservation, and Storage 

8.3 The high probability that extractable matter may adhere to sampling equipment and 

result in measurements that are biased low precludes the collection of composite samples 

for determination of oil and grease. ... Alternatively, samples can be collected in the field 

and composited in the laboratory. For example, collect four individual 250-mL samples 

over the course of a day. In the laboratory, pour each 250-mL sample into the separatory 

funnel, rinse each of the four bottles (and caps) sequentially with 30 mL of n-hexane, and 

use the 30 mL of n-hexane for the extraction (Section 11.3). 

11.2 pH verification 

11.2.1.1 Dip a glass stirring rod into the well mixed sample.

11.2.1.3 Rinse the stirring rod with a small portion of n-hexane that will be used for 

extraction (to ensure that no extractable material is lost on the stirring rod).

11.3 Extraction

11.3.5 Allow the organic phase to separate from the aqueous phase for a minimum of 10 

minutes. If an emulsion forms between the phases and the emulsion is greater than onethird the volume of the solvent layer, the laboratory must employ emulsion-breaking

techniques to complete the phase separation. The optimum technique depends upon the 

sample, but may include stirring... 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

5 

11.5 SGT-HEM Determination

11.5.3.2 Add a fluoropolymer-coated stirring bar to the flask and stir the solution on a 

magnetic stirrer for a minimum of 5 minutes.

With consideration to the above as it relates to contact homogenization, the operator 

should perform an equivalence testing study to ensure against impacting sample results 

(as per ASTM D7575 Section 2.2 Referenced Document EPA Method 1664 – see Section 

9.2.3). 

The operator should consider appropriate options based on the sample matrix. ASTM 

D7575 states that the method (as with all methods) may not be appropriate for all 

matrices and, in the case of concern, other alternative methods may be more appropriate. 

As was pointed out in the “ASTM International D19 Water and Orono Spectral Solutions, 

Inc. Response to United States Environmental Protection Agency Questions Concerning 

ASTM Standard D7575” in June of 2011: 

“to our knowledge, there is no single stand-alone method or Standard approved by 

USEPA and ASTM D19 that is completely robust to all NPDES regulated industries and 

discharge matrices for a given set of monitoring parameters. The USEPA is well aware of 

this gap in method robustness (deficiencies) and identifies and builds sufficient 

safeguards into method requirements for the laboratory and regulator who enforces the 

requirements of the method.” 

As an example, the method deficiencies and safeguards written in to ASTM D7575 

referenced document 2.2 ‘USEPA Method 1664, Revision A’, sections 1.3, 1.4, 1.7, 1.9, 

9.1, and Note of 11.2 point out the following: 

Method Deficiencies [this header added for clarity] 

Section 1.3 – [This method is not applicable to measurement of materials that volatilize 

at temperatures below approximately 85oC. Petroleum fuels from gasoline through #2 

fuel oil may be partially lost in the solvent removal process.] 

Section 1.4 – [Some crude oils and heavy oils contain significant percentage of materials 

that are not soluble in n-hexane. Accordingly, recoveries of these materials may be low.] 

Method Safeguards [this header added for clarity] 

Section 1.7 – [The laboratory is permitted to modify the method to overcome 

interferences or lower the cost of measurements, provided that all performance criteria 

in this method are met. The requirements for establishing method equivalency are given 

in Sections 9.1.2 and 9.2.3.] 

Section 1.9 – [Each laboratory [bold / underline added for emphasis] that uses this 

method must demonstrate [added for emphasis] the ability to generate acceptable results 

using the procedures in Section 9.2.] 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

6 

Section 9.1 – [Each laboratory that uses this method is required to operate a formal 

quality assurance program (Reference 16.8)... Laboratory performance is compared to 

established performance criteria to determine if the results of analyses meet performance 

characteristics of the method.] 

Section 11.2 Note – [NOTE: The procedure detailed below is for separatory funnel 

liquid-liquid extraction. Solid-phase extraction (SPE) may be used at the discretion of the 

discharger/generator and its laboratory. However, if SPE is used, it is the responsibility 

of discharger/generator and laboratory to assure [underline added for emphasis] that 

results produced are equivalent to results produced by the procedure below].” 

Proper operational practices, consideration, and techniques as outlined above will verify 

contact mixing performance (if so chosen) and ensure sample integrity. 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

7 

QUESTION 2

USEPA Question 2 – 

What data or literature does ASTM have to demonstrate that a 10 mL sample is truly 

representative of a 1L sample (aside from the comparability data already submitted to 

EPA)? 

D7575 Task Group Response

ASTM D19 D7575 Task Group follows the EPA direction and its data and 

documentation (EPA Method 1664, Revision B) which describes and demonstrates how a 

1L sample can be representative of a larger source of water. As an example, EPA sites in 

Method 1664, Revision B, Sections 1.7.15 and 4.5 the following: 

Section 1.7.15 

[Collection and analysis of a smaller sample volume is permitted provided all the quality 

control requirements of Section 9 are met. If smaller sample volumes are used, all QC 

and initial and ongoing demonstration of performance samples must use the same volume 

as the smaller volume samples. To achieve a proportionately smaller matrix spike at the 

recommended OPR concentration of 40 mg/L, i.e., spike 0.1 mL of the 4 mg/mL PAR 

standard for every 10 mL of proportionately smaller sample volume or fraction thereof. 

To report the most accurate HEM and SGT-HEM values in mg/L, subtract the smaller 

volume method blank value from the smaller volume sample value provided the recovery 

value of the smaller volume matrix spike is equal to or greater than the MDL for the 

modified method. Multiply this proportionately smaller sample value by the appropriate 

dilution factor and express the final sample result in mg/L. For example, if 4.4 mg/100 

mL was the result for the proportionately smaller sample and 0.6 mg/100mL was the 

result for the method blank, the reported concentration of the sample should be 38.0 

mg/L ([4.4 mg/100 mL – 0.6 mg/100 mL] x 10 = 38.0 mg/L). Additionally, all samples 

must be associated with an uncontaminated, 1-L method blank before the results may be 

reported for regulatory compliance purposes.] 

Section 4.5 

[Interferences extracted from samples will vary considerably from source to source, 

depending upon the diversity of the site being sampled. For those instances in which 

samples are thought to consist of complex matrices containing substances (such as 

particulates or detergents) that may interfere with the extraction procedure, a smaller 

sample may need to be collected for analysis.] 

ASTM Method D7575-10 provides similar guidance as in EPA Method 1664 for subsampling in Section 14, Note: 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

8 

Note 10 

[If the amount of particulate in the sample clogs the extractor and precludes processing a 

10 mL sample, repeat the procedure of Section 14 except using a smaller volume of 

sample; alternatively dilute the sample and re-run the analysis, making sure to account 

for the dilution in the final calculation of sample oil and grease concentration. It is 

recommended that a new MDL study be performed to determine the MDL and lower limit 

of the reporting range for processing a volume other than 10 mL. If performing multiple 

replicates on the same sample bottle, shake the bottle by hand for 10 seconds between 

syringe draws.]

Other than what has been demonstrated through the ASTM D19 D7575 Task Group 

round robin and NODA validation studies, the guidance in ASTM Standard D7575, and 

the guidance in EPA Method 1664, Revision A, ASTM D19 D7575 Task Group is not 

aware of a better way to demonstrate sample representativeness. 

Finally, it should be noted that with ASTM Standard D7575, multiple representative 

aliquots can be obtained from a single collected sample for processing and analysis. 

Whereas with EPA Method 1664, Revision A, unless multiple 1-L samples are collected 

and composited, only one full 1-L sample can be processed and analyzed. 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

9 

QUESTION 3

USEPA Question 3 – Part 1

How does D7575 compensate for extremely turbid samples? 

D7575 Task Group Response

ASTM Standard D7575 addresses turbid samples in two specific Notes: 

Note 2 

[It is important to note that the partition of solid matter on to the extractor does not 

preclude IR measurement; in the majority of cases there is sufficient IR throughput to still 

perform the measurement as described herein. This is the case with most metal-oxide 

materials (that is, clay or sand) and biological material (that is, algae or cellulose). 

There may of course be samples encountered wherein the solid matter is not sufficiently 

IR transmitting; one example may be a sample containing a large concentration of metal 

particulate. In these instances an alternative measurement technique may be necessary.] 

Note 10 

[If the amount of particulate in the sample obstructs the extractor and precludes 

processing a 10 mL sample, repeat the procedure of Section 14 except using a smaller 

volume of sample; alternatively dilute the sample and re-run the analysis, making sure to 

account for the dilution in the final calculation of sample oil and grease concentration...] 

USEPA Question 3 – Part 2

ASTM D7575 contains a cautionary statement that for certain samples this method may 

not be appropriate (e.g., because the samples contain high particulates). Is there a 

practical way for an analyst to make a determination before conducting an analysis using 

this method in a laboratory that receives a large amount of samples of different types? 

D7575 Task Group Response

The practical way to determine if there is a matrix issue prior to actual sample analysis is 

through the homogenization step in the ASTM Standard D7575 procedure. Should 

homogenization of the sample aliquot fail (i.e. high particulate matter), it may be 

determined that ASTM Standard D7575 is not be appropriate for that specific matrix and 

that the alternative EPA Method 1664 need be employed.

As a note, homogenization and sample extraction failures are an exception to the number 

of different matrices that were tested in the ASTM D19 D7575 Task Group round robin 

and NODA validation studies. The vast majority of sample matrices tested with this 

method experienced no failures and produced equally effective results to that of the 
ASTM D19 D7575 TASK GROUP TO UNITED STATES ENVIRONMENTAL PROTECTION AGENCY QUESTIONS 

DERIVED FROM NOTICE OF DATA AVAILABILITY COMMENTS

10

reference method. An added benefit to ASTM Standard D7575 is that the method allows 

volume corrections to be made if the entire 10 mL aliquot cannot be processed. If this is 

due to pressure, the user will see indications such as failure of the syringe, or stalling of 

the syringe pump. If failure of the device itself occurs, the companion Standard 

Operating Procedure5 guides and instructs the user through the sample preparation 

process, as described below: 

Standard Operating Procedure

[NOTE: While the sample is being processed, watch carefully for leaking in the syringe. 

This is an indication that Extractor membrane has clogged and is no longer processing 

sample. In some cases the pressure from the Extractor will become great enough to stall 

the syringe pump. If the syringe pump is unable to process the entire 10 mL volume 

through the extractor, record the total volume that has been processed, and proceed with 

drying. A correction will be made to the measured value to accommodate for this loss of 

volume. If another analysis of this matrix is necessary, the syringed pump should be 

stopped before the point that it stalled, and this volume should be recorded...] 

Similarly, as cited in Section 11.3.5 of the EPA Method 1664, Revision A, “an analyst is 

expected to use judgment to identify if an emulsion has formed in the two-phase system, 

and determine the proper way of breaking it. In any instance that the end user is not 

familiar with the sample, or is unsure of the accuracy of the volume correction procedure, 

they are advised to show equivalency using matrix spikes...” 

 

 

5 Standard Operating Procedure for: ASTM D7575 “Standard Test Method for Solvent-Free Membrane Recoverable 

Oil and Grease by Infrared Determination”