Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Surface Water Samples 

for D4

August 16, 2013

Silicones Environmental, Health and Safety Center 1

Synopsis: 

This testing standard provides guidelines for the collection and analysis of environmental samples for D4

in support of a Testing Program detailed in this Enforceable Consent Agreement (ECA). The purpose of 

the Testing Program is to “...develop environmental testing data for D4 in the vicinity of manufacturing 

and processing (including product formulating) sites and POTWs in the U.S. so that exposures and risks 

to sediment and aquatic organisms can be assessed.” This standard cites the requirements for the 

sampling of surface water as described in Section VII of the ECA and Appendices 1, 2, and 3, and 

identifies specific guidelines and references that will be used in the preparation of site-specific Sampling 

Plans for the collection and analysis of surface water samples, which will be included in a Study Plan for 

the Testing Program.

Requirements for sampling surface (receiving) waters: 

Per Appendix 1, Environmental Testing at D4 Direct Discharge Sites, Appendix 2, Environmental Testing 

for Indirect Discharge Sites, and Appendix 3, POTWs Not Receiving D4 from Industrial Facilities:

“Surface water shall be collected from the receiving water as close as possible to the release point from 

the treatment facility and measured for the concentration of D4, provided that adequate mixing of the 

discharge from the site with the receiving stream has occurred.”

Establishment of the location for surface water sample collection: 

At each site (i.e., POTW or direct discharge facility), surface water samples should be collected as close 

as possible to the discharge point provided adequate mixing of the discharge and receiving water has 

occurred. To satisfy these two requirements, surface water samples shall be collected at the end of the 

mixing zone at a point nearest the facility release point. 

Determination of a mixing zone is a facility-specific inquiry. For each facility, the mixing zone may have 

been established with the applicable wastewater permitting authority. The facility operator and 

permitting authority should be consulted, as appropriate, to determine if a mixing zone has been 

established. For cases in which the mixing zone is not known to the facility operator, it should be 

determined in the field using appropriate measurement or modeling techniques prior to the actual 

collection of samples. Methods for the analysis of mixing zones are presented in USEPA (1991, Section 

4.4 Mixing Zone Analyses) and USEPA (2006, Modeling Documents section, pp.9-13) (see Annexes 1 and 

2) and should be utilized, as appropriate. Each site-specific Sampling Plan shall include a discussion of 

the mixing zone in the receiving water, including the basis for the establishment of the specified zone. 
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Surface Water Samples 

for D4

August 16, 2013

Silicones Environmental, Health and Safety Center 2

Special considerations for the sampling and handling of water samples for D4: 

Cyclic volatile methyl siloxane (cVMS) materials, such as D4, are widely used in consumer products and 

may be present in personal care products, commercial products, and lubricants, and may be 

components of antifoams widely used in waste water treatment plants. To avoid the potential for 

sample contamination during collection, processing, storage, and analysis for D4 in environmental 

matrices, appropriate quality control measures should be implemented to the extent possible in the 

field. For example, field crew shall refrain from using any personal care products (e.g. , sun-block, sunscreen, hand lotion, antiperspirant, etc.) while preparing for or conducting any field activities to 

minimize the possibility for contamination with cVMS materials. Appropriate requirements for collecting 

and handling surface water samples that comply with the special considerations related to D4 are 

introduced below and shall be specified in the site-specific Sampling Plan. 

Collection of surface water samples for analysis of D4: 

On the day of field sampling at a given site, at the end of the established mixing zone, four (n=4) water 

samples (two for analysis of D4 and two for use in preparing field spikes) shall be collected from the 

center of the receiving water at mid-depth in accordance with the sample collection procedures set out 

in the site-specific Sampling Plan. The sample collection procedures will be based, as appropriate, on 

USEPA (1994, Section 7.3 Sample Collection) (see Annex 3). Specific requirements for sample bottle 

preparation, sample preservation, shipping and storage of the samples shall be based on Knoerr 2013, 

Sample Collection section, p. 8) (see Annex 4). All sample collection methods and sample handling 

procedures will be detailed in the site-specific Sampling Plans. 

During each sampling event at a given site, two field blanks, two field spikes, as well as a duplicate 

sample will be prepared as described below. Serving as field blanks, two samples of laboratory-grade 

water having very low or non-detectable concentrations of cVMS materials shall be taken into the field 

and processed like a field sample. The laboratory-grade water samples will be used to evaluate 

contamination bias resulting from collection, processing, transport, storage, and analysis of samples. 

Two of the surface water samples shall be spiked in the field with a known amount of D4, then 

processed like field samples. The field-spiked surface water samples will be used to evaluate loss of 

cVMS during collection, processing, transport, storage, and analysis of samples, and to evaluate 

analytical bias. One of the surface water samples shall be split into duplicate samples. The duplicate field 

samples shall be processed and analyzed as individual samples for D4. Duplicate samples are used to 

evaluate between-sample variability or precision. Specific requirements for preparation, processing, and 

analysis of field blanks, field spikes, and duplicate samples) shall be detailed in the Study Plan and the 

Quality Assurance Project Plan (QAPP).
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Surface Water Samples 

for D4

August 16, 2013

Silicones Environmental, Health and Safety Center 3

During the time of collection of surface water samples, two separate sample bottles shall be prepared 

for analysis of total organic carbon (TOC). The TOC analyses shall follow procedures equivalent to AHPA 

1999 Part 5310, Total Organic Carbon (TOC) (see Annex 5).

Analysis of surface water samples for D4: 

All water samples shall be analyzed for D4 at a commercial testing laboratory. The commercial 

laboratory will validate a method for the analysis of D4 in the surface water samples that shall be 

adapted from the analytical method specified in Knoerr (2013) (see Annex 4). The specific level of 

detection shall be based on the Practical Quantitation Limit (PQL) (USEPA 1985 and APHA 1999, Part 

1030C, see Annexes 6 and 7). The PQL is in turn based on the matrix-specific Method Detection Limit 

(MDL). These terms are defined as follows:

Practical Quantitation Limit (PQL): Minimum concentration of a constituent in a sample that can be 

measured among laboratories within specified limits during routine laboratory operations. The PQL 

is proposed because different laboratories may produce different MDLs even though they may be 

using the same analytical procedures, instruments and sample matrices. The PQL is typically defined 

as 5 to 10 times the MDL.

Method Detection Limit (MDL): Concentration of a constituent in a sample, that when processed 

through the complete analytical method, can be measured and reported with 99% probability that it 

is greater than 0 or statistically different from a blank. The MDL is a measure of a methods ability to 

quantify a constituent in a sample matrix.

During method development, the Knoerr (2013) analytical method for D4 achieved an average matrixspecific Method Detection Limit (MDL) of 0.037 μg/L. For use at the commercial laboratory, the targeted 

PQL for D4 in aqueous matrices shall be calculated as 5 times the Knoerr (2013) MDL. Therefore, when 

rounded to one significant figure, the PQL for D4 in aqueous matrices shall be 0.20 μg/L.

Compliance with Good Laboratory Practices:

Sample collection, handling, and transfer activities should be conducted in accordance with GLP 

requirements, as applicable. The analytical laboratory conducting the analyses of D4 shall be a GLP 

certified facility and all analytical work shall be conducted in accordance with GLP requirements. The 

QAPP shall be prepared according to USEPA guidance and shall include information on all field and 

laboratory quality control measures to be followed. 
Testing Standard for the Collection, Sample Handling, Transfer and Analysis of Surface Water Samples 

for D4

August 16, 2013

Silicones Environmental, Health and Safety Center 4

Annex 1 – USEPA 1991. Technical Support Document for Water Quality-based Toxics Control, Section 

4.4: Mixing Zone Analyses. EPA 505-290-001. U.S. Environmental Protection Agency, Office of Water, 

Washington, DC.

Annex 2 – USEPA 2006. Compilation of EPA Mixing Zone Documents, Modeling Documents, pp. 9-13. 

EPA 823-R-06-003, July, 2006.

Annex 3 – USEPA 1994. Surface Water Sampling, Section 7.3 Sample Collection. U.S. Environmental 

Protection Agency, SOP#: 2013, 11/17/94, REV. #: 0.0 

Annex 4 – Knoerr SM, Durham JA. 2013. NON REGULATED STUDY: Development of Collection, Storage 

and Analysis Procedures for the Quantification of D4, D5, and D6 in Waste Water Treatment Plant 

Effluent and Surface Water Samples. Dow Corning Corporation, HES Study No. 11936-108, April 18, 

2013.

Annex 5 – AHPA 1999. Standard Methods for the Examination of Water and Wastewater, Part 5310 C. 

Total Organic Carbon (TOC). American Public Health Association, American Water Works Association, 

Water Environment Federation.

Annex 6 – USEPA 1985. National primary water drinking standards: synthetic organics, inorganics, and 

bacteriologicals. 40 CFR Part 141; Federal Register 50: No. 219, November 13. 1985.

Annex 7 – APHA 1999. Standard Methods for the Examination of Water and Wastewater, Part 1030 C. 

Method Detection Level, Section 2 Determining Detection Levels. American Public Health Association, 

American Water Works Association, Water Environment Federation.