Dow Corning INTERNAL

Environmental Monitoring Proposal for 

Certain Cyclic Siloxanes – D4 & D5

March 2012

Prepared by SEHSC, on behalf of its member companies:

Bluestar Silicones USA Corporation; Dow Corning Corporation; Evonik Goldschmidt 

Corporation; Milliken & Company; Momentive Performance Materials Inc.; Shin-Etsu 

Silicones of America, Inc.; and Wacker Chemical Corporation
Purpose/Basis for Proposed Monitoring Program

• Purpose:

 Provide additional information on the presence and concentration of D4 

and D5 in the environment and on sources of and pathways to the 

environmental concentrations of D4 and D5.

• Validate CSMs

• Basis:

 Generic Conceptual Site Models (CSMs) developed for D4 and D5: 

manufacturing, processing and formulating (MPF) facilities and 

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municipal wastewater treatment plants (WWTPs)

 Existing monitoring data

 Available science on the environmental properties of D4 and D5

 Agency feedback

 Consultation with ERM

 Existing international environmental monitoring program for D4 and D5
Overview of Proposed Monitoring Program

MPF MONITORING

• 4 Direct Discharge Sites:

 DCC Carrollton, KY

• D4/D5 M & F

 Momentive Waterford, NY

• D4/D5 M, P, F

 Momentive Sistersville, WV

• D4/D5 P

 Wacker Adrian, MI

• D4/D5 P & F

• Parameters:

 Effluent

MUNICIPAL WWTP MONITORING

• 5 Sites:

 Site #1 - Activated sludge, high 

population, low dilution, capped (for air)

 Site #2 – Activated sludge, high 

population, low dilution

 Site #3 – Oxidative ditch, high population, 

low dilution

 Site #4 – Trickling filter, high population, 

low dilution

 Site #5 – Lagoon, high population, low 

dilution

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 Effluent

 Surface water

 Sediment

 Fish

 Benthic species

• 2 monitoring events

dilution

• Parameters:

 Influent, Effluent

 Surface water

 Biosolids

 Sediment

 Fish

 Benthic species

 Air (Site #1)

• 2 monitoring events
Design of Proposed Monitoring Program

• What the CSMs Show...

 Only Potentially Complete Pathways are:

• Inhalation exposure resulting from dispersion in air (this 

pathway applies only to human receptors, because ecological 

receptors are not typically evaluated for inhalation exposure 

risk). 

• Exposures via sediment, including direct exposure for bottom 

dwelling biota and indirect exposure via the food chain to 

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ecological receptors.
Generic D4/D5 Industrial CSM

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Generic POTWs CSM

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Design of Proposed Monitoring Program

• What Recent Monitoring Results Show...

 Non-U.S. Studies

• Detectable concentrations of D4 and D5 are predominately found in air, 

WWTP influent, sludge and to a lesser extent sediments impacted by 

wastewater effluents 

• Detectable concentrations of D4 and D5 in sediments were variable 

and typically associated with high population areas

• Concentrations in Arctic samples were low to non-detect (ND) and only 

in areas of human impact

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• Austrian WWTP monitoring reported NDs in effluents

• In Japan, D4 and D5 were detectable in sediments heavily impacted by 

industrial and municipal wastewater 

• Canadian influent and effluent monitoring report detectable 

concentrations in effluent but scientific review indicates all D4 

concentrations and most D5 concentrations may be below detection

 U.S.

• Oregon Effluent concentrations at largest POTWs – all ND (n=90)

• Detectable concentrations in Lake Pepin sediment
Design of Proposed Monitoring Program

• Site Selection Process– Municipal WWTP Monitoring

 Developed and gained agreement for a set of parameters

 Ran EPA’s EFAST model to predict surface water concentration 

distributions and determine anticipated surface water 

concentrations.

 Ran ISTREEM to predict the geographic distribution of surface 

water concentrations to identify regional specificities of the 

program.

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 Delved into the detailed ISTREEM datasets (from EPA Needs 

Survey and ROUT) to begin the monitoring site selection process.

 Developed a preliminary list of potential monitoring sites.

 Reviewed a number of recent monitoring studies which provided 

additional insights.
Design of Proposed Monitoring Program

• Site Selection Process – Municipal WWTP Monitoring

 14,000 sewage treatment plants in the U.S. (EPA 2004 Needs 

Survey)

 Examine data on sites to produce a smaller list of sites that could 

be evaluated in more detail

 The list of sites was refined:

• sorted by treatment type

• targeted sites in high population areas with low dilution

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• targeted sites in high population areas with low dilution

• considered sites that covered a geographic range with an 

emphasis on watersheds with high population density

• predicted influent and effluent concentrations were examined 

and those with higher concentrations in effluent were given 

priority
Design of Proposed Monitoring Program

 Final Municipal WWTP Monitoring Site Selection

• Review WWTP’s NPDES permit (e.g., industrial inputs, compliance 

issues, changes in facility structure or operation, etc.)

• Determine which sites are capped/covered

• Check Google Earth and contact Plant Operator

• Obtain/review data on historical effluent conditions (annual flow, D.O., 

temp, pH, SS, BOD) 

• Conduct site visits

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• Obtain letter of cooperation/access
Environmental Monitoring Program - Key Tasks

• Selection and training of Contractor(s)

• Development of detailed Sampling Plan per Site

 Site description including maps, description of targeted WWTPs, 

sampling grids, and targeted locations of sediment and biota collections

 Access requirements

 Sampling Protocol

 QA/QC

 Monitoring Schedule per Site

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• Sample Analysis Program

 Method Validation for all matrices

 Analyses

• Overall Schedule

• Reporting
Overview of Proposed Monitoring Program

MPF MONITORING

• 4 Direct Discharge Sites:

 DCC Carrollton, KY

• D4/D5 M & F

 Momentive Waterford, NY

• D4/D5 M, P, F

 Momentive Sistersville, WV

• D4/D5 P

 Wacker Adrian, MI

• D4/D5 P & F

• Parameters:

 Effluent

MUNICIPAL WWTP MONITORING

• 5 Sites:

 Site #1 - Activated sludge, high 

population, low dilution, capped (for air)

 Site #2 – Activated sludge, high 

population, low dilution

 Site #3 – Oxidative ditch, high population, 

low dilution

 Site #4 – Trickling filter, high population, 

low dilution

 Site #5 – Lagoon, high population, low 

dilution

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 Effluent

 Surface water

 Sediment

 Fish

 Benthic species

• 2 monitoring events

dilution

• Parameters:

 Influent, Effluent

 Surface water

 Biosolids

 Sediment

 Fish

 Benthic species

 Air (Site #1)

• 2 monitoring events
Comments/Questions/Next Steps

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