Dow Corning I NTERNAL 

# Environmental **Monitoring Proposal for**  **Certain Cyclic Siloxanes**  **– D4 & D5**  **Ma rch**  **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

1 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**o f 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 **MU NICIPA** **L 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

2  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 a pplies 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

3 ecological receptors .

## Generic D4/D5 Industrial **CSM**

4

## Generic POTWs CSM

5

## 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

6 • 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.

7  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 d ilution

8 • targeted sites in high population areas with low d ilution • considered sites that covered a geographic range with an emphasis on watersheds wi th high population density • predicted influent and effluent concentrations we re 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

d ata on historical effluent conditions (annual flow, D.O., temp, pH, SS, BOD) • Conduct site visits

9 • 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

10 

### • Sample Analysis Program  Method Validation for all matrices  Analyses 

### • Overall Schedule • Reporting

## Overview**o f 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 **MU NICIPA** **L 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

11  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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