12

DRAFT PROJECT CHARTER: Proposed 5-year monitoring plan for cyclic volatile 

methylsiloxane (cVMS) materials in surface sediment and aquatic biota of the Inner Oslofjord, 

Norway.

Date: 23February 2011

PROJECT NUMBER: 02/444/S040/07/xxx

STUDY AREA: Inner Oslofjord, Norway

TEST MATERIALS

Octamethylcyclotetrasiloxane (D4): CAS 556-67-2

Decamethylcyclopentasiloxane (D5): CAS 541-02-6

Dodecamethylcyclohexasiloxane (D6): CAS 540-97-6

Consideration should be given to making samples available for analysis of other materials such as 

legacy contaminants and metals. Results from such analyses may be used to increase the power to 

detect significant temporal changes in cVMS concentrations.

PURPOSE

Determine if concentrations of cyclic volatile methylsiloxane (cVMS) materials in surface sediment 

and aquatic biota are stable or changing following a decreasing or increasing temporal trend over the 

duration of the project.

OBJECTIVE

Conduct temporal trend analyses to determine if cVMS concentrations are stable or changing, based 

on detecting with 80% power (β=0.20) a statistically significant (α=0.05) annual rate of change of 

±6% per year over a 5 year period (net change of -27% to 34%). This is equivalent to detecting with 

65% power (β=0.35; α=0.05) an annual rate of change of ±5.0% per year over a 5 year period (net 

change of -23% to 28%). Detecting a change of ±6% per year with 80% power is less sensitive but 

statistically more robust than detecting a change of ±5% per year with 65% power. Established 

monitoring programs, for example the Northern Contaminants Program (NCP) of Canada and the 

Arctic Monitoring and Assessment Programme (AMAP) of Arctic Countries, are typically designed to 

detect with 80% power an annual rate of decrease of 5% per year over a 10 to 15 year period for a net 

decrease of 40 to 55% (UNEP 2004, 2007; EU 2010).

Any process or change in experimental design that decreases variability associated with cVMS 

concentrations in the samples will increase the power to detect a statistically significant trend or 

change in concentration. Specific procedures that will be implemented to reduce within-year and 

between-year variability are discussed in the appropriate sections that follow.

Project Duration 

The expected minimum project duration is 5 years, based on a temporal trend power analysis across a 

range of values for coefficient of variation (CV=20% to 50%). The power analysis was optimized to 

estimate the number of samples that would be needed to detect with 90% power an annual change in 

concentration of ±10% per year if samples were annually collected over a period of 3 to 10 years. 

Time-series monitoring programs are unlikely to detect changes with any confidence within a 

sampling period of less than five years unless the changes are very large (UNEP 2004, 2007; EU 

2010). It is expected that a period of 10-15 years would be required to detect changes in cVMS 

concentrations of 5% per year or less. 

Project duration was estimated on the basis of within-year variability of cVMS concentrations for a 

limited number of samples (n=3 to 6 samples per matrix) from previous monitoring programs in 

Oslofjord (Powell 2009, 2010). However, at least 4-5 years of monitoring are required to obtain 

reliable estimates of random within-year and between-year variation and other components of 
13

variance (UNEP 2004, 2007; EU 2010). Therefore, project duration and experimental design will be 

re-evaluated on an annual basis and modified as needed to maintain or improve upon the defined 

project objectives.

Sample Matrices to be Collected

Sediment (collected annually):

o 0-5 cm of surface sediment, sectioned into five 1-cm thick strata. Each stratum will be 

analyzed in order to minimize between-year variability (EU 2010) and to evaluate 

potential degradation within the sediment column. Power to detect a change in 

concentration in the surface stratum may be improved by treating concentrations in lower 

strata as covariates.

o Rates of sediment accumulation at the study area are on the order of 0.3 cm per year or 

less. As a result a 1 cm stratum of surface sediment will represent about 3 years or more 

of sediment accumulation. Collection of individual strata greater than 1 cm in thickness 

will not provide sufficient resolution to detect a significant change over the 5 year 

program.

o Sediment samples to be collected by sediment core and extruded to the desired thickness 

of 1 cm.

o Locations where sediment cores will be collected will be identified using a systematic 

random sampling design from along a transect (Gilbert 1987) that runs parallel to the 

predominant bottom current, extending from a known point source of wastewater release.

Biota (collected annually):

o Three target species are proposed for the monitoring program in the Inner Oslofjord:

1. Atlantic cod (Gadus morhua): age-2 fish (size-class about 46-55 cm total length; 

weight class generally > 1000 g fresh weight); represents a high trophic level 

predator species.

2. Atlantic herring (Clupea harengus): age-0 fish (size-class generally < 15 cm total 

length); represents a low trophic level forage species for cod.

3. Northern shrimp (Pandalus borealis): represents a low trophic level forage 

species for cod.

o The proposed target species were selected because:

1. Trend analysis monitoring of biota should be based on target species that include 

(UNEP 2004; EU 2010):

A high trophic level predator species.

A low trophic level forage species near the base of the food chain of the 

predator species.

2. These species are representative of the pelagic zone food chain (Atlantic cod and 

Atlantic herring) and the demersal zone food chain (Atlantic cod and Northern 

shrimp) in the Inner Oslofjord food web (Powell 2010). Northern shrimp are the 

preferred forage for Atlantic cod in the Inner Oslofjord (Heggelund 2001). The 

importance of Atlantic herring to the diet of Atlantic cod in the Inner Oslofjord is 

not known. However, age-0 Atlantic herring are the preferred forage for Atlantic 

cod in the Barents Sea (Johnsen et al. 2004). 

3. These species are recommended for monitoring studies (UNEP 2004; EU 2010) 

and may be collected in sufficient numbers needed to meet the objectives of the 

experimental design.

4. Concentrations of cVMS materials in these species generally bracket the range in 

cVMS concentrations observed in the Inner Oslofjord (Powell 2010) and are at 

least 5 to 10 times the analytical method detection limits of 0.5 ng/g ww.

5. These species have a high ecological significance in the Oslofjord and are 

commercially important as a food resource.

o Biota will be collected from the inner Oslofjord at the CEMP stations used for the 

Norwegian Coordinated Environmental Monitoring Programme (Green et al. 2010).
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The within-year and between-year variability resulting from confounding factors associated with 

sample collection will be reduced by:

o Collecting samples from the same locations during the same timeframe (month or season) 

of every year;

o Collecting samples by the same field team (or under direction of the same team leader) 

using the same procedures every year;

o Collecting samples of the same size-class or age class every year;

o Selecting representative target species that can be collected every year in sufficient 

numbers required for the defined experimental design;

o Selecting representative target species that are expected to have concentrations at least 5

to 10 times the analytical method detection limit (MDL). For the cVMS materials MDL 

should be less than 0.5 ng/g ww and concentrations in the target species at least 2.5 to 5 

ng/g ww.

Frequency of Sample Collection and Sample Collection Times

Sediment (individual samples)

o Sediment cores will be collected from five locations (to be determined) in the Inner 

Oslofjord. Samples will be collected from locations along a transect that runs parallel to 

the predominant bottom current, extending from a known point source of wastewater 

release;

o Samples will consist of 0-5 cm of surface sediment sectioned into five 1-cm thick strata;

o Samples will be collected on an annual basis from the same locations (i.e., GPS 

coordinates) during the same month or season of each year (to be determined), including 

year-0 and year-5.

Biota (individual or pooled samples)

o Top predator species (Atlantic cod) and lower trophic level forage species (Atlantic 

herring and Northern shrimp) will be collected by trawl;

o Samples will be collected on an annual basis from the same areas during the same month 

or season of each year (to be determined), including year-0 and year-5;

o Samples will be field processed for species identification, total length, and fresh weight. 

Condition factors will be determined from the length and weight of each individual 

specimen;

o Atlantic cod (age-2 fish; size-class about 46-55 cm total length; weight class generally > 

1000 g fresh weight) will be retained as individual samples. Atlantic herring (age-0 fish; 

size-class generally < 15 cm total length) and Northern shrimp will be retained as pooled 

samples (n=3 to 5 pooled samples per species with n=10 to 20 individual specimens per 

pooled sample).

Number of Samples

A temporal trend power analysis was used to estimate the number of samples needed to detect with 

80% power (β=0.20) a statistically significant (α=0.05) annual rate of change of ±6% per year over a 

5 year period (net change of -27% to 34%). A constant coefficient of variation (CV) for 

concentrations of the cVMS materials was assumed for each collection interval (samples collected 

annually). Results from previous monitoring studies on the Oslofjord (Powell 2009, 2010) were used 

to estimate within-year CV values for annual mean whole-body lipid-equivalent concentrations in 

biota and annual mean organic carbon-equivalent concentrations in sediments. Concentrations of the 

cVMS materials were expressed on the basis of lipid content and organic carbon content to reduce the 

CV values used for each power analysis.

Sediment: A minimum sample replication of n=5 samples/stratum/year would be required to 

detect with 80% power (β=0.20; α=0.05) an annual rate of change of ±6% per year in carbonequivalent concentration (CV=20%) over a 5 year period (net change of -27% to 34%).
15

Biota: A minimum sample replication of n=15 samples/species/year would be required to 

detect with 80% power (β=0.20; α=0.05) an annual rate of change of ±6% per year in wholebody lipid-equivalent concentration (CV=35%) over a 5 year period (net change of -27% to 

34%). For temporal trend studies of contaminants in fish, monitoring guidelines (UNEP 

2004) recommend that a minimum of 12 individual samples be collected each year. Atlantic 

cod (age-2 fish; size-class about 46-55 cm total length; weight class generally >1000 g fresh 

weight) will be retained as individual samples (n=15 to 20 individual specimens). Atlantic 

herring (age-0 fish; size-class < 15 cm total length) and Northern shrimp will be retained as 

pooled samples (n=3 to 5 pooled samples per species with n=10 to 20 individual specimens 

per pooled sample).

The numbers of samples to be collected were estimated on the basis of within-year variability 

of cVMS concentrations for a limited number of individual samples (n=3 to 6 samples per 

matrix) from previous monitoring programs in Oslofjord (Powell 2009, 2010). However, at 

least 4-5 years of monitoring are required to obtain reliable estimates of random within-year 

and between-year variation and other components of variance (UNEP 2004, 2007; EU 2010). 

Therefore, the numbers of samples to be collected will be re-evaluated and modified as 

needed on an annual basis to maintain or improve upon the project objectives.

Analysis of Samples 

Sediments and biota will be processed and analyzed following previously validated methods and 

QA procedures (Powell et. al. 2010).

Atlantic cod will be processed and analyzed as individual samples. Atlantic herring and Northern 

shrimp will be processed and analyzed as pooled samples (n=3 to 5 pooled samples per species 

with n=10 to 20 individual specimens per pooled sample). Except for Atlantic cod, all samples 

will be processed as whole-body homogenates. Atlantic cod will be processed without the head, 

which is expected to result in a much more homogeneous matrix that will reduce within-year 

variability for both cVMS concentration and lipid content.

In addition to analysis of cVMS, samples will be analyzed for lipid content (biota) or organic 

carbon content (sediments), water content, and the isotopic signatures of stable isotopes of carbon 

(

13C) and nitrogen ( 15N).

If samples will be analyzed by more than one facility then one laboratory must be responsible for 

processing and distributing the processed samples to the participating laboratories for analysis.

A standardized QA program, including the analysis of standard reference materials (SRMs) 

should be followed by all laboratories involved with the study.

Certified SRMs for cVMS materials do not presently exist and would need to be prepared for 

each matrix in sufficient mass for use over the duration of the monitoring program.

Measurement Basis:

o In order to meet the defined objective of the study, it is important that the within-year 

variability by species across samples be minimized. Therefore, temporal trend analyses 

of the biological data will be based on whole-body lipid equivalent concentrations of the 

cVMS materials. Temporal trend analyses of the sediment data will be based on organic 

carbon equivalent concentrations of the cVMS materials.

o All biota samples will be processed as whole-body homogenates except for Atlantic cod, 

which will be processed without the head. Processing the cod without the head is 

expected to result in a much more homogeneous matrix that will reduce within-year 

variability for both cVMS concentration and lipid content;

o Within species variation across samples is larger for cVMS concentrations in other 

matrices or for concentrations not expressed on the basis of lipid content or organic 
16

carbon content. For example, a mean coefficient of variation (CV) of 35% was obtained 

for whole-body lipid-equivalent concentrations across individual samples by species (n=3 

to 6 samples for each species) in the Oslofjord food web that was sampled in 2008 

(Powell 2010). In contrast, the mean CV value based on whole-body wet weight 

concentrations was about 65% (Powell 2010). Similarly, CV values based on lipidequivalent concentrations in cod liver were about 50% (Powell 2009).

The within-year and between-year variability resulting from confounding factors associated with 

sample analysis will be reduced by:

o Processing and analyzing samples by the same laboratory or laboratories using the same 

procedures every year;

o Analyzing sample matrices (e.g., whole-body) that minimize between-sample variability

o Analyzing sample matrices with concentrations that are at least 5 to 10 times the 

analytical method detection limit (MDL). For the cVMS materials MDL should be less 

than 0.5 ng/g ww and concentrations in the target species at least 2.5 to 5 ng/g ww.

o Analyzing pooled samples in order to increase sample replication without increasing the 

number of analyses.

o Consistent use of concentrations that are reported on a normalized basis (e.g., lipid 

weight) that minimizes the between-sample variability.

Statistical Analysis

Data will be specifically analyzed to detect changes or trends in cVMS concentrations that may occur 

over the duration of the program (i.e., temporal trend analysis). Temporal trends will be evaluated 

using procedures described in various guidance documents (Gilbert 1987; UNEP 2004, 2007; OSPAR 

2008; EU 2010).

Contract

To be developed on a year by year basis.

Project Team

Team Leader: To be identified

Sample Collection: To be identified. It is proposed that samples be collected in cooperation 

with the Norwegian Institute for Water Research (NIVA). An industry representative (e.g., 

the Team Leader) should participate on every sample collection.

Sample Analysis: To be identified. It is proposed that cVMS analyses be conducted by one 

of the following laboratories:

o Dow Corning Corporation, Auburn, Michigan, USA

o Evonik Goldschmidt GmbH, Essen, Germany

Statistical Analysis and Database Management: To be identified.

References

EU. 2010. Guidance Document No: 25 Guidance on chemical monitoring of sediment and biota. 

Technical Report 2010.3991

Gilbert, R.O. 1987. Statistical Methods for Environmental Pollution Monitoring. Van Nostrand 

Reinhold, New York, NY. ISBN 0-442-23050-8.

Green, N.W., Schøyen, M., Øxnevad, S., Ruus, A., Berge, J.A., Høgåsen, T., Håvardstun, J., Rogne, 

Å.G., and Tveiten, L. 2010. Coordinated Environmental Monitoring Programme (CEMP). 

Levels, trends and effects of hazardous substances in fjords and coastal waters – 2008. 
17

(Norwegian State Pollution Monitoring Programme. Report no. 5867/2010. TA-no 

2566/2010, SPFO-report 1062/2010). NIVA O-29106, NIVA rapport, Lnr. 5867-2010, NIVA. 

Available at (as of 24 Jan 2011): http://www.klif.no/no/Tema/Miljoovervakning/Statligmiljoovervakning/Miljogifter-langs-norskekysten/Rapporter/Hazardous-substances-in-fjordsand-coastal-waters-2008--Levels-trends-and-effects--Long-term-monitoring-of-environmentalquality-in-Norwegian-coastal-waters/?attachment=true.

Heggelund, H.I. 2001. Diett og matinntak til torsk, Gadus morhua L., i Oslofjorden. M.sc. thesis. 

(Diet and feeding of cod, Gadus morhua L. in the Oslofjord). University of Oslo. In 

Norwegian.

Johnsen, G.O., Bogstad, B., Mehl, S. & Ulltang, Ø. 2004. Consumption of juvenile herring (Clupea 

harengus) by cod (Gadus morhua) in the Barents Sea: a new apprach to estimating 

consumption in piscivorous fish. Can. J. fish. Aquat. Sci. 61: 343-359.

OSPAR. 2008. CEMP Assessment Manual. Co-ordinated Environmental Monitoring Programme 

Assessment Manual for contaminants in sediment and biota. OSPAR Commission 

Publication Number No. 379/2008.

Powell, D.E. 2009. Cyclic volatile methylsiloxane materials (D3, D4, D5, and D6) in livers of 

Atlantic cod (Gadus morhua) from Oslofjord, Norway. Comparison and assessment of 

analytical methods utilized by Dow Corning Corporation, Evonik Goldschmidt, and the 

Norwegian Institute for Air Research. Final Report submitted to the Centre Européen des 

Silicones (CES). Dow Corning Corporation, technical report number 2009-I0000-60983.

Powell, D.E. 2010. Bioaccumulation and trophic transfer of cyclic volatile methylsiloxane (cVMS) 

materials in the aquatic marine food webs of the Inner and Outer Oslofjord, Norway. Final 

Report submitted to the Centre Européen des Silicones (CES). Dow Corning Corporation, 

technical report number 2010-I0000-62594.

UNEP. 2004. Guidance for a Global Monitoring Programme for Persistent Organic Pollutants, 1st

Edition. United Nations Environment Programme. UNEP Chemicals, Geneva, Switzerland.

UNEP. 2007. Draft Guidance on the Global Monitoring Plan for Persistent Organic Pollutants. 

United Nations Environment Programme. UNEP/POPS/COP.3/INF/14. 
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DRAFT PROJECT CHARTER: Proposed monitoring plan for cyclic volatile 

methylsiloxane (cVMS) materials in the influent, effluent, and sludge of a municipal wastewater

treatment plant.

Date: 25 February 2011

PROJECT NUMBER: 02/444/S040/07/xxx

PROPOSED STUDY AREAS: Oslo, Norway

Tokyo, Japan

Toronto, Ontario, Canada

St. Paul, Minnesota, USA

TEST MATERIALS

Octamethylcyclotetrasiloxane (D4): CAS 556-67-2

Decamethylcyclopentasiloxane (D5): CAS 541-02-6

Dodecamethylcyclohexasiloxane (D6): CAS 540-97-6

PURPOSE

Determine representative concentrations of cVMS materials in the wastewater stream (influent, 

effluent, and sludge) of a municipal wastewater treatment plant. The data will be used to estimate 

mass loadings of the cVMS materials to the local environment and to detect any temporal trends 

associated with the mass loading. It is anticipated that results from this project will be used for 

environmental fate modelling and to provide a baseline for long-term environmental monitoring 

programs.

Guidelines and literature focusing on sampling of wastewater for pharmaceuticals and personal care 

products (PPCPs) are sparse and rarely cited. The objectives and experimental designs discussed in 

the remainder of this document were based on information obtained from available guidance 

documents for monitoring of wastewater (U.S. EPA 1982; Clesceri et al 1998; Ort et al 2010).

OBJECTIVES

The four basic factors which affect the quality of environmental data are sample collection, sample 

preservation, analyses, and recording. Improper actions in any one area may result in poor data from 

which poor judgments are certain. The objectives for the project were specifically defined to address 

these factors and were structured to transition three defined categories of wastewater studies--(i) 

method development, (ii) demonstrating presence or absence, and (iii) quantification of fate. Specific 

objectives for the project are to:

i. Phase 1: Method Development

Develop loss-free methods for collection, storage, and analysis of cVMS 

materials in wastewater samples (influent, effluent, and sludge).

Develop robust experimental designs that are appropriate for collection of 

samples from municipal wastewater treatment plants that may exhibit unique 

transport characteristics, highly dynamic flows, and variable loads of the cVMS 

materials.

Define and validate holding times that identify the maximum time allowed from 

the moment a sample is collected to when analysis of that sample must begin.

ii. Phase 2: Demonstrating Presence or Absence:

Implement results from Phase 1 and modify project duration and experimental 

designs as needed to maintain or improve upon the defined project objectives, or 

to account for unforeseen sample variability in terms of time and concentration.

Determine representative concentrations of cVMS materials in the wastewater 

stream (influent, effluent, and sludge) of a municipal wastewater treatment plant.
19

Determine the overall removal efficiency of cVMS materials in wastewater 

during the treatment process.

Determine diurnal cycle (i.e., short-term variability) of cVMS concentrations in 

the wastewater stream.

iii. Phase 3: Quantification of Fate:

Implement results from Phase 2 and modify project duration and experimental 

designs as needed to maintain or improve upon the defined project objectives, or 

to account for unforeseen sample variability in terms of time and concentration.

Determine seasonal and annual patterns or temporal trends associated with 

concentrations of cVMS materials in the wastewater stream (influent, effluent, 

and sludge).

Estimate mass loadings of cVMS materials to the local environment.

Determine any temporal trends associated with mass loadings of cVMS materials 

to the local environment.

Project Duration 

The expected minimum project duration is 1.5 years. Project duration was estimated based on the 

assumption that 0.5 years would be required for method development (i.e., Phase 1 of the project) and 

that a minimum of 1 year of sample collection would be required to detect seasonal trends (i.e., Phase 

3 of the project). Project duration and experimental design will be re-evaluated after each phase of 

the project and modified as needed to maintain or improve upon the defined project objectives, or to 

account for unforeseen sample variability in terms of time and concentration. Modifications may 

include revised estimates of the number of samples to be collected, the frequency of collection, and 

the desired power to detected changes over the duration of the project.

Experimental Design – Phase 1 (Method Development)

The four basic factors that affect the quality of environmental data are sample collection, sample 

preservation, analyses, and recording. For this project, it is expected that most of the effort associated 

with method development will be allocated to development of procedures for sample collection and 

preservation. It is anticipated that analytical methods and quality assurance and control (QA/QC) 

procedures developed for other matrices (e.g., water, sediment, soil, and biological tissues) may be 

directly applied and validated for analysis of cVMS materials in wastewater matrices (i.e., influent, 

effluent, and sludge).

The analytical results for a sample are only as accurate as the quality of the sample itself. If the 

sample was improperly collected, the uncertainty associated with the analytical results will be high 

regardless of how accurate the analytical procedures are. Several studies (reviewed by Ort et al, 

2010) have demonstrated that the uncertainty associated with sampling wastewater can be very 

significant, and that insufficient emphasis is placed on development of methods that are appropriate 

for sample collection. As a result, the importance of short-term variations are ignored and 

inappropriate sampling procedures are employed that lead to over interpretation of the measured data 

and ultimately, wrong conclusions. Inappropriate sampling represents the major source of inaccuracy 

for monitoring studies on personal care products in wastewaters. However, sampling errors and 

sampling biases can be greatly reduced or eliminated by choosing an appropriate sampling mode and 

frequency. In addition, proper sampling maximizes the value of measured data for experimental 

assessment of fate in wastewaters and is required for formulation and validation of fate models.

It is anticipated that a combination of various sample types will be collected over the duration of the 

proposed project. As such, sample collection methods appropriate for cVMS materials should be 

developed for each sample type. Wastewater sampling is generally performed by one of two methods; 

grab sampling or composite sampling. Grab sampling consists of collecting a discrete sample at a 

specific point of time. As such, a grab sample reflects conditions only at the point in time that the 

sample was collected, and then only if the sample was properly collected. Composite sampling 

consists of a collection of numerous individual discrete samples taken at regular intervals over a 
20

period of time that are then pooled into a single composite sample. Sample to be collected may 

include any of the following sample types:

Grab Samples: A grab sample can only represent the composition of its source at the time 

and place of collection, and should not exceed a sampling time of 15 minutes. Because of 

widely varying flow and intermittent pulses of materials to the wastewater stream, a grab 

sample taken at one specific time will not be representative of conditions throughout the daily 

flow pattern. By definition, a single grab sample cannot be used to evaluate the long-term 

conditions of a wastewater stream. Grab samples must be collected at locations where the 

wastewater stream is well mixed and has sufficient velocity to keep the solids in suspension, 

while avoiding locations where the settling of solids occurs or floating debris is present.

The collection of a grab sample is appropriate when it is desired to:

o Characterize water quality at a particular time.

o Provide information about minimum and maximum concentrations.

o Allow collection of variable sample volumes.

o Corroborate composite samples.

Grab samples should be used when:

o The wastewater stream does not flow continuously.

o The characteristics of the wastewater stream are relatively constant.

o The parameters to be analyzed are likely to deteriorate rapidly or change with storage 

(for example, volatile organic compounds (e.g., VOCs).

o Information on maximum, minimum, or variability is desired.

o The history of water quality is to be established based on relatively short time 

intervals.

o The spatial variability for a parameter is to be determined.

Composite Samples: Individual samples that are taken and deposited in the same collection 

bottle. There are two methods that are most common to collecting composite samples. Timeproportional samples are taken at set increments of time. Flow- proportional samples are 

taken when a measured volume of water flows over the sensor of a flow meter. The preferred 

method is flow- proportional sampling, which gives the most representative sample. Without 

appropriate modifications, composite sampling is not valid for collection of samples when the 

parameter to be measured deteriorates rapidly (e.g., VOCs).

Composite samples should be used when:

o Determining average concentrations.

o Calculating mass/unit time loadings.

Volatile Organic Compound (VOCs) Grab Samples: These grab samples are collected in 

clean glass vials, usually containing a preservative, with Teflon-lined caps having a flexible 

septum. There must not be any air bubbles in the vial, so the cap must not have an air space 

under it. The vial must be filled until the liquid crowns and the cap screwed until the septum 

bulges. 

Grab Composite Samples: This procedure is not commonly used but is useful for such 

parameters as total oil and grease released to the sewer system in a 24-hour period. Individual 

samples are grabbed in the field and then composited in the lab or in the field for analysis. A 

variation of this sample type is the flow-proportional grab composite sample. Samples are 

grabbed in the usual manner but the flow level is recorded at the time of sampling. After all 

the predetermined times of sampling are done the composite is made with portions of each 

grab sample according to the amount of flow at the time of sampling.
21

Discrete Samples: Grab samples collected and used to monitor characteristics of the 

wastewater flow at certain times of the day, for certain parameters, such as during high or low 

pH, or during high or low flow events. Samples are taken in individual bottles at the time of 

the event and each sample is analyzed. This method can also be used for flow-proportional 

composite samples if the flow rate is recorded at the time of sampling.

Samples cannot be analyzed for cVMS concentrations on-site immediately after collection. 

Depending on location of the study area, the samples will be shipped to Evonik Goldschmidt GmbH 

(Essen, Germany) or to Dow Corning Corporation (Auburn, Michigan, USA) for analysis. Therefore, 

in conjunction with the development of methods for sample collection, appropriate methods for 

sample preservation must also be developed and validated for each sample type. For the cVMS 

materials, the purpose of sample preservation should be to prevent volatile loss and to minimize 

degradation until the sample can be analyzed.

Holding times for each sample type will also need to be identified and validated, based on the method 

of preservation. The holding time is the maximum time allowed from the moment a sample is 

collected to when analysis on that sample must begin. All samples must be analyzed within the 

validated holding time for the analytical results to be considered acceptable. A validated holding time 

in conjunction with proper sample preservation is required to retain the integrity of the sample and 

ensure that accurate results are obtained. It is anticipated that a minimum holding time of 72 hours 

will be required for this project.

Experimental Design – Phase 2 (Demonstrating Presence or Absence)

The experimental design for Phase 2 of the project will be developed based on the results obtained 

from Phase 1 of the project. The focus of the Phase 2 experimental design will be on identification of 

sample collection intervals and sample collection frequency. Inappropriate sampling (in terms of 

collection procedures, intervals, and frequency) represents the major source of inaccuracy for 

monitoring studies on personal care products in wastewaters (Ort et al, 2010).

Short-term variations in the composition of the wastewater stream resulting from widely varying flow 

and intermittent pulses of materials may confound interpretation of the measured data and lead to 

incorrect and misleading conclusions. Consequently, sampling intervals and frequency are crucial 

parameters for monitoring compounds in the wastewater stream that are released through the use and 

disposal of personal care products. Sampling intervals should be selected on the basis of the expected 

frequency of changes, which may vary from as little as 5 min to as long as 1 h or more. Because of 

analytical costs, high sampling frequencies may become prohibitive. However, low sampling 

frequencies increase random uncertainty, which leads to systematic overestimations or 

underestimations of concentrations and loads in the wastewater stream. Sampling intervals and 

frequencies for monitoring a wastewater stream can only be determined after detailed preliminary

work that involves a high sampling frequency is completed.

It is anticipated that large diurnal variations will be observed for concentrations of cVMS materials in 

the wastewater stream that are associated with intermittent “wastewater pulses” or discharges to the 

sewer. At the source, these pulses may last a few seconds (toilet flushes) to minutes (emptying a 

bathtub or pumping water out of washing machines, etc.). Depending on hydraulic conditions and 

flow distances, the number of wastewater pulses that contain the cVMS materials will depend on the 

number of people in the catchment and the frequency that personal care products containing the 

cVMS materials are used. If only a few such wastewater pulses are expected over the course of a day 

a high sampling frequency is necessary to capture these pulses.

It is assumed that major pulses of cVMS materials in the wastewater stream will occur twice a day, 

with much smaller pulses intermittently occurring in between the major pulses. Major pulses of 

cVMS materials are anticipated to occur during weekday mornings in association with the morning 

activities of individuals preparing for the workday. Major pulses of cVMS materials, but of smaller 

magnitude, are also anticipated to occur during the early evening in association with recreational 
22

activities after the workday. It is also anticipated that the major pulses of cVMS materials may be 

associated with seasonal cycles that are primarily related to temperature and daylight hours. 

Based on these assumptions it is anticipated that discrete grab samples collected at 1-hour intervals 

over a 24-hour period will initially be used to identify presence of cVMS materials in the wastewater 

stream. Ideally, this sampling routine should be conducted over a number of consecutive days rather 

than non-consecutive days (Ort et al 2010). Results from the analysis of these samples may also be 

used to identify any diurnal cycles that may influence cVMS concentrations in the waste stream. 

Repeated sampling over a longer period would be required to determine weekly and seasonal 

variations. Results may also be used to estimate the number of samples and frequency of collection 

for Phase 3 of the project.

Experimental Design – Phase 3 (Quantification of Fate)

The experimental design for Phase 3 of the project will be developed based on the results obtained 

from Phase 2 of the project. The focus of the Phase 3 experimental design will be identification of 

seasonal and annual patterns or temporal trends associated with concentrations of cVMS materials in 

the wastewater stream. Results from Phase 3 of the project will be used to estimate mass loadings of 

cVMS materials to the local environment.

It is anticipated that the flow rate of the wastewater stream will vary significantly over time during the 

course of a day when sampling takes place. Therefore, flow-proportional composite sampling would 

be used if appropriate methods can be developed (i.e., Phase 1). Flow-proportional composite 

sampling is the only sampling mode that correctly weights the individual subsamples, which are 

combined to form a composite sample, and analyzed to obtain an average concentration. If 

appropriate methods cannot be developed for composite sampling, then flow-proportional grab 

sampling may be used. If concentrations of the cVMS materials in the wastewater stream were 

relatively constant over the course of a day (as demonstrated from the Phase 2 results), a grab sample 

would be equal to the average concentration in a flow-proportional composite sample. However, to 

demonstrate that concentrations of the cVMS materials were relatively constant would require a large 

number of grab samples to be collected at very short intervals (1-5 min over several hours) during the 

Phase 2 program.

Sample Matrices to be Collected

Wastewater influent, effluent, and sludge (collectively referred to as the wastewater stream) of a 

municipal wastewater treatment plant will be collected and analyzed for this project. Sludge is the 

mud-like residual material generated during the wastewater treatment process that consists of organic 

and inorganic solids present in raw sewage. Sludge should not be confused with bio-solids, which are 

processed and treated sludges. Samples will be collected from locations specified by the facility 

operator or by individuals having experience with the facility being monitored.

Frequency of Sample Collection and Sample Collection Times

The frequency of sample collection will be based on results from Phase 1 and Phase 2 of the project.

Number of Samples

The number of sample to be collected will be determined by the type of samples collected (grab vs 

composite), by the sampling mode used to collect the samples (continuous vs discrete), and on results 

from Phase 1 and Phase 2 of the project.

Analysis of Samples 

Analytical methods and quality assurance and control (QA/QC) procedures will developed as part of 

Phase 1 of the project. It is anticipated that analytical methods and QA/QC procedures developed for 

other matrices (e.g., water, sediment, soil, and biological tissues) may be directly applied and 

validated for analysis of cVMS materials in the wastewater matrices (i.e., influent, effluent, and 

sludge).
23

Statistical Analysis

Data will be specifically analyzed to detect changes or trends in cVMS concentrations that may occur 

over the short-term and long-term for the duration of the program. Temporal trends will be evaluated 

using procedures described in various guidance documents (Gilbert 1987; UNEP 2004, 2007; OSPAR 

2008; EU 2010).

Contract

To be developed on a semi-annual basis, and re-evaluated after completion of Phase 1 and Phase 2 of 

the project.

Project Team

Team Leader: To be identified. The Team Leader should work closely with the facility 

operator where the monitoring study is conducted.

Sample Collection: To be identified. It is proposed that samples be collected by individuals 

having substantial experience with monitoring wastewater treatment facilities. The 

individuals should also be experienced with development of experimental designs for 

monitoring wastewater treatment facilities. An industry representative (e.g., the Team 

Leader) should participate on initial sample collections.

Sample Analysis: To be identified. It is proposed that cVMS analyses be conducted by one 

of the following laboratories:

o Dow Corning Corporation, Auburn, Michigan, USA

o Evonik Goldschmidt GmbH, Essen, Germany

Statistical Analysis and Database Management: To be identified.

References

Clesceri, L.S.; Greenberg, A.E.; Eaton, A D. 1998. Standard Methods for the Examination of Water 

and Wastewater; American Public Health Association: Washington, DC; Vol. 20, ISBN 

0875532357.

EU. 2010. Guidance Document No: 25 Guidance on chemical monitoring of sediment and biota. 

Technical Report 2010.3991

Gilbert, R.O. 1987. Statistical Methods for Environmental Pollution Monitoring. Van Nostrand 

Reinhold, New York, NY. ISBN 0-442-23050-8.

Ort , C.; Lawrence, M.G.; Rieckermann, J.; Joss, A. 2010. Sampling for pharmaceuticals and 

personal ccare products (PPCPs) and illicit drugs in wastyewater systems: are your 

conclusions valid? A critical review. Environmental Science and Technology 44: 6024–

6035.

OSPAR. 2008. CEMP Assessment Manual. Co-ordinated Environmental Monitoring Programme 

Assessment Manual for contaminants in sediment and biota. OSPAR Commission 

Publication Number No. 379/2008.

UNEP. 2004. Guidance for a Global Monitoring Programme for Persistent Organic Pollutants, 1st

Edition. United Nations Environment Programme. UNEP Chemicals, Geneva, Switzerland.

UNEP. 2007. Draft Guidance on the Global Monitoring Plan for Persistent Organic Pollutants. 

United Nations Environment Programme. UNEP/POPS/COP.3/INF/14. 
24

U.S. EPA 1982. Handbook for Sampling and Sample Preservation of Water and Wastewater; 600/4-

82-029; Environmental Monitoring and Support Laboratory.