1 

### • SEHSC is committed to science

- based risk assessment and responsible environmental stewardship



### • SEHSC Proposal based upon sound

- science with substantial justification

o Number of sites is not primary driver for proposal

o Proposal supported by accepted environmental risk assessment methods
o Detailed member facility release assessments



### o Development of Conceptual Site Models

o Environmental consultant justification for monitoring program

• Agency sampling & analysis plan may have omitted critical elements

• Power analysis to determine adequate sample numbers

• Essential field and laboratory quality control samples

• Control for loss and contamination

• Stability and sample integrity

• Validation and use of the appropriate analytical methods

• SEHSC is committed to working with the agency to address information “gaps”. 

## SEHSC D4/D5 Monitoring Proposal

– Discussion Elements2 

# • Methodologies for assessing risk should be 

# consistent for new and existing chemicals.

o Greater transparency would foster cooperation 

# and be a greater incentive for product innovation. SEHSC D4/D5 Monitoring Proposal

– Discussion Elements3 

## SEHSC Municipal Wastewater Treatment Plant (POTW) Monitoring Proposal Overview

5 POTW Sites

 Site #1

– Activated sludge, high population, low dilution, capped (for air)  Site #2

– Activated sludge, high population, low dilution  Site #3

– Activated sludge, high population, low dilution  Site #4

– Lagoon , Activated sludge, high population, low dilution  Site #5

– Lagoon, high population, low dilution

Monitoring Parameters

 Influent, Effluent  Surface Water  Bio
- solids  Sediment  Fish  Benthic Species  Air (Site #1)  2 Monitoring Events4 

## SEHSC Manufacturer, Processor, Formulator (MPF) Monitoring Proposal Overview

Monitoring Parameters

 Effluent

 Surface Water

 Sediment

 Fish

 Benthic Species

 2 Monitoring Events Dow Corning Carrollton, KY D4/D5 M & F Wacker Adrian, MI D4/D5 P & F Momentive Waterford, NY D4/D5 M, P, F

Momentive Sistersville, WV D4/D5 P5  EPA’s proposal presumes that D4 and D5 require risk management without having conducted a risk assessment first. To the contrary, an appropriate risk assessment should include the following:

o Risk

- based decision

- making is a two tier process where the potential environmental risks associated with a material are systematically evaluated through a risk assessment followed by a separate process for risk management, if necessary.

o Risk management should be considered only after risk is identified. The nature and magnitude of the risk should inform the risk management activities, including selection of the most practical risk management instrument.

o A practically designed and efficient monitoring proposal facilitates a determination first of whether risk management is needed before implementing the much more significant effort of determining how to manage risk.

 The Agency has not provided a scientific justification for conducting a national exposure assessment prior to a screening level risk assessment.

o Conducting a screening level risk assessment is consistent with EPA risk assessment guidance and will better focus resources.

o Monitoring 5 POTWs and 4 direct discharge sites will provide a sufficient dataset for conducting a worst

- case environmental assessment of D4 and D5.

o If no risk is identified with a worst

- case assessment additional data collection is not warranted. 

# D4 / D5 ECA Development Points6 

# D4 / D5 ECA Development Points (cont’d)

 Data from SEHSC member indirect discharge facilities will not provide relevant information on environmental compartment exposures.

o POTW monitoring provides relevant data for understanding environmental exposure in support of a screening level risk assessment.



##  The full value of available monitoring data has not been considered for informing the development of a D4/D5 monitoring program.

o Reasonable justification has not been provided to dismiss the utility of non

- US monitoring data for informing a US assessment of potential risk.

o While the Canadian monitoring study does include data for lagoons, the study is not exclusively focused on lagoons.



### o Industry’s on

- going voluntary international monitoring program, which includes sites in the US, provides additional data that inform the overall assessment of environmental exposure and potential risk from D4 and D5. Results will be available to the EPA and other regulatory bodies around the world.7 

# D4 and D5 Risk Assessment

• There has been extensive research on the environmental fate and effects of D4 in recent years.



## • The environmental fate of a chemical compound is determined by its basic physicochemical characteristics and their relationship to other physicochemical characteristics of the environment:  binding to organic carbon, lipid content of organisms, and 

## concentrations of inorganic ions, such as sulfide and calcium.  This has allowed the EPA and the “EPA’s” of other countries to utilize toxicity threshold data from around the world to develop their own water and sediment quality criteria.

• There is no scientific reason why D4 and D5 should be treated otherwise.

• These two chemicals are not toxic at concentrations below their solubility, which means they are not toxic at the maximum concentrations that could exist in the environment.

• The “worst case scenario” for environmental risk associated with D4 and 

### D5 is the presence of these chemicals at concentrations near their solubility and at these concentrations there will be no environmental risk.8 

# D4 and D5 Risk Assessment

• D4 and D5 behave differently than other compounds that are similar in molecular weight and size.  These characteristics result in unique distributions in the environment and 

### explain their lack of toxicity and risk.  These chemicals readily partition into air, no matter where they are discharged into the environment. In the air compartment they readily degrade.



## • Given the 30+ years of use of these chemicals it can be assumed they 

## are at a relative steady state in the environment.  Even if they were not, they cannot accumulate at concentration in aquatic systems that are above their solubility.  In addition, degradation of these compounds in aquatic ecosystems and their metabolism within organisms further prevents concentrations that would 

### present a risk.  Their strong partitioning to organic carbon is reflected by their sometimes elevated concentrations in sediments which are the compartment of greatest exposures to benthic organisms.

• Nevertheless, these exposures would not exist above D4 and D5 solubility limits and are not toxic.