Human Health Risk Assessment - Raytheon

DRAFT 

Human Health 

Risk Assessment 

Raytheon Company Facility 

St. Petersburg, Florida 

Prepared for: 

Florida Department of 

Environmental Protection 

On behalf of: 

Raytheon Company 

St. Petersburg, Florida 

Prepared by: 

ENVIRON International Corporation 

Tampa, Florida 

Date: 

May 2008

Contents 

Executive Summary 

i 

Human Health Risk Assessment 

DRAFT 

Page 

1 Introduction 3 

1.1 Overview 4 

1.2 Scope of the Risk Assessment 5 

1.3 Organization of the Risk Assessment Report 6 

2 Conceptual Site Model 7 

2.1 Setting 7 

2.2 Sources and Transport Mechanisms 7 

2.3 Potential Human Exposure Pathways and Receptors 8 

2.3.1 Potential On-Site Receptors 8 

2.3.2 Potential Off-Site Receptors 9 

3 Data Evaluation 10 

3.1 Identification of Constituents of Potential Concern 10 

3.1.1 Groundwater 11 

3.2 COPCs Detected in Air and Soil Vapor 13 

3.2.1 Soil Vapor Sampling 13 

3.2.2 Indoor Air Sampling 14 

3.2.3 Ambient Air Sampling 15 

3.2.4 Surface Water Sampling 15 

4 Exposure Assessment 16 

4.1 Identification of Complete Exposure Pathways 16 

4.1.1 On-Site 16 

4.1.2 Off-Site 17 

4.2 Estimating Exposure Point Concentrations 18 

4.2.1 On-Site Indoor Air 19 

4.2.2 Outdoor Air 19 

4.2.3 Groundwater 21 

4.2.4 Excavation Air 22 

4.2.5 Subsurface Soil 24 

4.2.6 Irrigation Water 24 

4.2.7 Homegrown Produce 26 

4.2.8 Surface Soil 27 

4.3 Quantification of Exposure 27 

4.3.1 On-Site Facility Worker 28 

4.3.2 On-Site Landscape Worker 29 

4.3.3 On-Site Trespasser 30 

4.3.4 On-Site Construction Worker 30 

4.3.5 On-Site Utility Worker 32

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4.3.6 Azalea Park Landscape/Maintenance Worker 33 

4.3.7 Azalea Park Ball Player and Recreation Center Employees 33 

4.3.8 Pinellas Trail User 33 

4.3.9 Apartment/Condo Complex Landscaper 34 

4.3.10 Apartment/Condo Resident 34 

4.3.11 Apartment/Condo Construction/Utility Worker 34 

4.3.12 Off-Site Residents 35 

5 Toxicity Assessment 41 

5.1 Toxicity Information for Carcinogenic Effects 42 

5.1.1 Oral and Dermal CSFs 42 

5.1.2 Inhalation Unit Risk Factors and CSFs 43 

5.2 Toxicity Information for Non-carcinogenic Effects 43 

5.2.1 Oral and Dermal RfDs 43 

5.2.2 Inhalation RfCs 43 

6 Risk Characterization 44 

6.1 Risk Summary 46 

6.1.1 On-Site Facility Worker 46 

6.1.2 On-Site Landscape Worker 47 

6.1.3 On-Site Trespasser 48 

6.1.4 On-Site Construction Worker 48 

6.1.5 On-Site Utility Worker 49 

6.1.6 Azalea Park Landscape/Maintenance Workers 50 

6.1.7 Azalea Park Ball Player and Visitor to Azalea Park Recreation Center 50 

6.1.8 Pinellas Trail User 50 

6.1.9 Apartment/Condo Complex Landscapers 51 

6.1.10 Apartment/Condo Complex Construction/Utility Worker 51 

6.1.11 Apartment/Condo Residents 52 

6.1.12 Off-Site Residents (other than Brandywine and Stone’s Throw) 52 

6.2 Comparison to RBSLs 52 

6.3 Potential Ecological Risks 54 

7 Uncertainty Analysis 55 

7.1 Site Characterization Data 55 

7.2 Exposure Assessment 56 

7.3 Toxicity Assessment 57 

8 Conclusions 58 

List of Tables 

Table 1. Constituents of Potential Concern in On-Site Groundwater 

Table 2. Constituents of Potential Concern in Off-Site Groundwater

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Table 3. Correlation between Indoor Air and Subslab Soil Vapor Concentrations 

Table 4. Summary of Ambient Air Sampling Data Collected at Azalea Park as Part of the National 

Air Toxics Trends Program 

Table 5. Estimated Exposure Point Concentrations 

Table 6. Summary of Exposure Factors 

Table 7. Physical and Chemical Properties of COPCs 

Table 8. Source and Derivation of Toxicity Values 

Table 9. Risk-Based Screening Levels (RBSLs) for Evaluating Potential Exposures to Irrigation Water 

List of Figures 

Figure 1. Potential Exposure Pathways Under Current Use Scenarios – On-Site Receptors 

Figure 2. Potential Exposure Pathways Under Current Use Scenarios – Off-Site Receptors 

List of Appendices 

Appendix A – Risk Spreadsheets

Executive Summary 

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DRAFT 

The purpose of this report is to evaluate the potential risks from exposure to Site-related 

constituents under current and likely future exposure conditions in conjunction with the SARA in 

support of an appropriate remediation plan to be submitted to the Florida Department of 

Environmental Protection (FDEP). The levels of exposure estimated in this report are based on 

extensive sampling data that has been collected to date and are summarized in the Site 

Assessment Report Addendum (SARA), prepared by ARCADIS, to which this report is attached. 

This risk assessment addresses Site occupants, outside workers and visitors, as well as 

residents surrounding the Site, who could be exposed to Site-related constituents. This report 

also includes a qualitative analysis of non-human receptors. 

To complete this type of an assessment, a series of health-protective assumptions about 

exposure characteristics must be made. The assumptions used in this assessment have been 

chosen to be health protective, and intentionally conservative, and therefore tend to 

overestimate the calculated non-cancer and theoretical excess cancer risks. 

Current and likely future on-Site receptors include workers at the facility who spend the majority 

of their time indoors, on-Site landscape workers who spend most of their time outdoors, contract 

workers who may be required to perform subsurface excavation activities to maintain existing 

underground utilities or support construction activities, and adolescent trespassers. 

The primary potentially complete exposure pathway for on-Site facility workers is the inhalation 

of constituents that have volatilized from shallow groundwater and entered indoor air. Only 

chemicals present at the surface of the groundwater are susceptible to volatilization to indoor 

air. 

For on-Site landscape workers and potential adolescent trespassers, the primary exposure 

pathway is inhalation of outdoor air. Because there are currently no irrigation wells on-Site and 

no planned excavation of soils to a depth below the water table, there is no direct exposure to 

on-Site groundwater for these receptors under current exposure scenarios. Some subsurface 

excavation may be required to maintain/upgrade existing utilities on-Site and commercial utility 

or construction workers could be exposed to COPCs via direct contact with subsurface soils and 

shallow groundwater, which may be found at 1.5 to 4 feet bgs. In addition, workers may be 

exposed to COPCs volatilized from exposed shallow groundwater during excavation. 

The potential area of impacted groundwater extends to the east beneath the Pinellas Trail, the 

Stone’s Throw Condominium Complex, and the Brandywine Apartments Complex as well as to 

the south and west beneath Azalea Park, the ball field area, and some residential properties. 

However, the impacted groundwater to the south and west is present below a clean water layer 

which prevents volatilization of COPCs from the water table and eliminates potential exposures 

to COPCs in deeper groundwater.

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In the off-Site areas above the deeper impacted groundwater, potential receptors include some 

area residents, construction workers, and users of the Pinellas Trail. 

Theoretical excess cancer and non-cancer risk estimates are calculated for individual COPCs 

for the complete exposure pathways associated with each assessed area using standard 

USEPA recommended approaches. These estimates provide a quantitative representation of 

the relationship between conservatively estimated exposures and potential toxic responses. 

Risk estimates are summarized for each receptor population in the tables below. These 

estimates characterize whether potential Site-related risks for individual receptors are in excess 

of the range considered to be de minimis by USEPA guidance (i.e. 10 -4 to 10 -6 for theoretical 

excess cancer risk and a hazard index of less than 1.0 for non-cancer risks). 

Potential Risk Ranges Under Current and Likely Future (a) Exposure 

Scenarios for Completed Pathways 

Potentially Exposed 

Non-Cancer 

Excess 

Population 

Hazard Quotient Cancer Risk 

On-Site Facility Worker 0.1 3 x 10 -6 

On-Site Landscape Worker 0.02 1 x 10 -6 

On-Site Construction Worker 0.1 9 x 10 -7 

On-Site Utility Worker 0.02 1 x 10 -6 

On-Site Trespasser 0.001 5 x 10 -8 

Pinellas Trail User 0.002 2 x 10 -9 

Offsite Apartment/Condo 

Construction/Utility Worker 

NA (b) 3 x 10 -9 

(a) Based on discussions with Raytheon, we have assumed that there will be future institutional controls associated 

with the Site. 

(b) No non-cancer toxicity reference values are available for 1,4-dioxane. 

In addition, because private irrigation well sampling is currently underway by ARCADIS, we 

have established risk-based screening levels (RBSLs) to facilitate evaluation of potential risks 

from exposure to COPCs in groundwater collected from individual private irrigation wells, 

RBSLs were developed for each potential exposure scenario associated with use of water from 

these private irrigation wells. Comparison of concentrations measured in irrigation wells to 

these RBSLs will be the first step in identifying any measures (e.g., providing an alternative 

irrigation water supply) that may be taken to prevent exposure. 

RBSLs are calculated concentrations of COPCs in environmental media that are developed by 

combining toxicity data with exposure factors that are intended to represent reasonable 

maximum exposure (RME) conditions and be protective of human health. The following is a

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table of the COPCs found off-Site in amounts in excess of FDEP GCTLs and their respective 

RBSL. 

Calculated RBSLs (µg/L) for Potential Exposures to 1,4-Dioxane, TCE and cis-1,2- 

DCE in Irrigation Water 

Exposure 

RBSL (µg/L) 

Pathway 1,4-Dioxane TCE cis-1,2-DCE 

Ingestion of Irrigation Water 670 670 10,200 

Dermal Contact while Gardening 29,900 650 31,300 

Inhalation During Lawn Irrigation 14,400 3,200 29,000 

Ingestion of Homegrown Produce 522 205 29,500 

Dermal Contact (Wading Pool Scenario) 2,320 416 6,360 

Dermal Contact (Sprinkler Scenario) 2110 410 9,860 

Based on the data received by us to date, there are no off-Site exceedences of the levels 

referenced above for the use of irrigation well water. Therefore, these data suggest that, based 

on the residential irrigation well sampling results to date, there is no health threat from exposure 

to irrigation water. 

There are uncertainties in any risk assessment. These uncertainties are primarily associated 

with lack of known human health effects directly attributable to constituents at concentrations 

encountered in the environment. Therefore, risk analyses rely on health protective 

(conservative) assumptions based on available studies and exposure scenarios. 

1 Introduction 

This report has been prepared on behalf of Raytheon Company (Raytheon) by ENVIRON 

International Corporation (ENVIRON) and contains an assessment of potential risks to human 

health and the environment from exposure to constituents of potential concern (COPCs) in 

groundwater and air at and near the Raytheon facility located at 1501 72 nd Street North, St. 

Petersburg, FL as shown in Figures 2-1 and 2-2 of the SARA (hereafter referred to as the 

“Facility” or “Site”). The report is being submitted as an addendum to the Site Assessment 

Report Addendum (“SARA”) 1 for the purpose of helping (i) to identify any mitigation measures 

that may be useful and (ii) in communicating potential risks to human health and the 

environment from Site-related constituents under current exposure conditions. 

1 Site Assessment Report Addendum; ARCADIS, May 30, 2008.

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Groundwater monitoring at the Facility has shown that COPCs that likely originated from historic 

manufacturing and storage activities have been detected in groundwater on-Site and beyond 

the Facility boundaries to the south, east and west. Surface soils in the vicinity of former 

processing and storage areas have been removed, but associated COPCs remain in 

groundwater and have been detected in on-Site soil vapor, monitoring wells (on and off-Site) 

and certain residential irrigation wells. COPCs in soil vapor are capable of entering indoor air 

environments or being released to outdoor air. COPCs in irrigation water may be brought to the 

land surface during residential use of groundwater for landscaping and irrigation of homegrown 

produce. Our evaluation of whether there are potential human health risks from exposures to 

these COPCs in groundwater, indoor and outdoor air, and homegrown produce is presented in 

this report. 

Potential human health and ecological risks are characterized based on COPC concentrations 

detected in groundwater, soil vapor and on-Site indoor air samples collected during the most 

recent rounds of monitoring beginning in 2007. These data are presented in detail in the SARA. 

Population groups (i.e., receptors) used to characterize potential exposures under current 

scenarios include indoor and outdoor workers at the Facility, construction and utility workers 

who may be involved in subsurface excavation activities, on-Site trespassers, 

maintenance/landscape workers on-Site, at the nearby Apartment/Condo Complex and at the 

public park adjacent to the Site (Azalea Park), ballplayers and visitors to the Azalea Recreation 

Center, users of the nearby Pinellas Trail and surrounding single and multi-family residents 

including residents of the Brandywine Apartments and Stone’s Throw Condominiums. 

1.1 Overview 

The Facility is located near the intersection of 22 nd Avenue North and 72 nd Street North in 

Pinellas County. Three buildings are located on-Site: Building A, Building E and Building M. 

Dating back to the late 1950’s, the Site has been used for general office use and various 

electronics manufacturing operations with activities such as soldering, vapor degreasing, 

painting and electroplating. In 1991, COPCs were first discovered by the County during an 

environmental site assessment of the then-proposed Pinellas Trail project. The source 

appeared be located near the northeast corner of Building M. Soils in this area were excavated 

to the water table to a depth of 1.5 to 2.0 feet below ground surface (bgs) in August, 1992. An 

additional potential source area, a former wastewater equalization vault located on the east side 

of Building M, was removed in 1994. Concentrations of chlorinated volatile organic chemicals 

(CVOCs), a vapor degreasing additive 1,4-dioxane, and miscellaneous other breakdown 

products and constituents are present in groundwater beneath the Site. 

The solvents and CVOCs are slightly soluble in water and 1,4-dioxane is miscible in water. 

These substances can be transported away from source areas by advection and dispersion 

processes in the general direction of groundwater flow. Recent groundwater monitoring in the 

area indicates that COPCs in groundwater have been detected off-Site to the east/northeast 

and to the south and west.

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COPCs with sufficient vapor pressure can volatilize from shallow groundwater and diffuse 

through overlying soils, eventually entering the atmosphere or indoor air. COPCs may also be 

brought to the land surface via pumping if an irrigation well is installed within the aquifer zone 

containing COPCs. 

The Facility is in the process of being vacated as employees move to new facilities in the area. 

It is anticipated that once the Facility is vacated it will be sold for re-use or redevelopment with 

appropriate mitigation measures and/or institutional controls. 

1.2 Scope of the Risk Assessment 

The purpose of this report is to evaluate the potential risks from exposure to Site-related 

constituents under current and likely future exposure conditions in conjunction with the SARA in 

support of an appropriate remediation plan to be submitted to the Florida Department of 

Environmental Protection (FDEP). As noted above, this risk assessment addresses Site 

occupants and visitors, as well as people surrounding the Site, who could be exposed to Siterelated 

COPCs. This report also includes a qualitative analysis of non-human receptors. 

To complete this type of an assessment, a series of health-protective assumptions about 

exposure characteristics must be made. The assumptions used in this assessment have been 

chosen to be health protective and intentionally conservative and therefore tend to overestimate 

the calculated non-cancer and theoretical excess cancer risks. For example, maximum 

concentrations detected in indoor air, soil vapor and groundwater have been used to estimate 

average potential exposures to the various receptor populations; off-Site residents are assumed 

to live in the same home for 30 years and spend all their time at home – not accounting for time 

away at school or at work; and potential non-cancer risks are evaluated separately for a child 

because potential exposures among children can be greater per unit body weight than potential 

exposures for adults. Per body weight basis, ingestion and inhalation rates for children yield 

greater daily exposures than for adults. Children also have a higher surface area to body 

weight ratios and behave differently than adults. These assumptions tend to overestimate 

potential risks to receptor populations. 

The level of exposure estimated in this report is based on extensive sampling data that has 

been collected to date and is summarized in the SARA which has been submitted to FDEP. 

The sampling of existing irrigation wells in the off-Site area is currently underway and more data 

is expected. To expedite evaluation of that data, we have calculated health-based screening 

levels for constituents in the irrigation water. Comparison of concentrations measured in 

irrigation wells to the risk-based screening levels will be the first step in identifying any 

measures (e.g., providing an alternative irrigation water supply) that may be taken to prevent 

exposure. 

Also, the numerical values used to represent toxicity are standard regulatory default values 

intentionally incorporating health protective safety factors. The use of this conservative 

approach provides a substantial margin of safety to ensure protection for individuals with 

different potential exposures and sensitivities under actual conditions of exposure.

1.3 Organization of the Risk Assessment Report 

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Following this introduction, a conceptual site model (CSM) is presented in Section 2.0. The 

CSM is a tool that identifies potentially complete exposure pathways to environmental media 

(e.g. soil, vapor, groundwater, etc.) associated with the Site and specifies the types of exposure 

scenarios relevant to include in the risk assessment. An evaluation of the environmental data 

used in the risk assessment and the identification of COPCs is presented in Section 3.0. An 

estimate of the types and magnitude of potential exposures to the COPCs detected on-Site and 

in the surrounding area is presented in Section 4.0. 

Toxicity factors for carcinogenic and/or non-carcinogenic effects of each of the COPCs are 

presented in Section 5.0 and theoretical cancer and potential non-cancer risk estimates are 

summarized in Section 6.0. A qualitative analysis of uncertainties in the data, exposure 

parameters, model assumptions and toxicity values are presented in Section 7.0. Finally, a 

summary of conclusions is provided in Section 8.0.

2 Conceptual Site Model 

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The purpose of the Conceptual Site Model (CSM) is to identify potentially complete exposure 

pathways to environmental media associated with the Site and to specify the types of exposure 

scenarios relevant to include in the risk analysis. The first step in constructing a CSM is to 

characterize the Site and surrounding area, including current and likely future land use 

scenarios. Source areas and transport mechanisms are then identified along with potential 

human receptors under current and likely future land use scenarios. 

Potential exposure pathways are determined to be complete when they contain the following 

four elements: 1) a recognized source area, 2) a mechanism of transport from the source area 

to an environmental medium, 3) a point of contact with the medium, and 4) a route of exposure 

at the point of contact (e.g., inhalation, ingestion, dermal contact). Completed exposure 

pathways identified in the CSM are then evaluated in the human health risk assessment. 

Exposure pathways are considered to be incomplete when one of the above elements is 

missing and there are no risks. Based on this lack of potential exposure, risks are not estimated 

for incomplete pathways. 

2.1 Setting 

As set forth above, the Site has been used historically for general office and electronics 

manufacturing purposes. Land use in the surrounding area includes commercial, residential, 

and recreational areas. The Site is adjacent to single-family residential areas to the south and 

southeast, the Brandywine Apartments and Stone’s Throw Condominiums to the east, 

commercial buildings to the north, and recreational areas including a park and ball field to the 

west. A recreational walking/biking trail, built along a former CSX railroad bed, extends along 

the eastern boundary of the Site. Additional residential areas can be found west of the park. 

Soils beneath the Site consist of fine to very fine-grained quartz sands from land surface to a 

depth of about 50 feet bgs. Groundwater in the shallow aquifer beneath the Site is encountered 

as high as 1.5 to 4.0 feet bgs and flows generally in a southwest direction. The shallow aquifer 

is not used as a source of potable water in the area; however, this aquifer remains classified as 

GII by the State of Florida, potentially potable groundwater. A well survey conducted in the area 

identified a number of irrigation wells within a ½ mile radius of the Site including a number of 

residential irrigation wells and irrigation wells at the Stone’s Throw Condominium and 

Brandywine Apartments complex. The City of St. Petersburg supplies all of its residents with 

potable municipally treated drinking water, and no potable wells were identified within a ½ mile 

radius of the Site. 

2.2 Sources and Transport Mechanisms 

Chlorinated volatile organic chemicals (CVOCs); hydrocarbons, (e.g., benzene, toluene, 

ethylbenzene, and xylenes); and oxygenated solvents (e.g., MEK, MIBK and acetone); and a 

vapor degreasing additive (1,4-dioxane) have been detected in groundwater beneath the Site. 

A number of the constituents were first detected when the County initiated a 1991

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environmental site assessment for the then-proposed Pinellas Trail project. Others were 

detected later on as part of ongoing site assessment activities. The primary source of COPCs 

was determined to be from an area located near the northeast corner of Building M. Soils in this 

area were excavated to the water table at a depth of 1.5 to 2.0 feet bgs in August, 1992. An 

additional potential source area, a former wastewater equalization vault located on the east side 

of Building M, was removed in 1994. 

The CVOCs and hydrocarbons are sparingly soluble in water while the oxygenated solvents are 

miscible in water. These chemicals are capable of being transported away from source areas 

by advection and dispersion processes in the general direction of groundwater flow. The most 

recent round of groundwater monitoring in the area was conducted in March-May 2008. These 

data indicate that COPCs in groundwater extend to the east beneath the Stone’s Throw 

Condominium complex and the Brandywine Apartments complex, and to the south and 

west/southwest beneath Azalea Park and the ball field area as well as under certain residential 

properties. The vertical and horizontal extent of COPCs present in the groundwater is detailed 

in the SARA. 

COPCs with sufficient volatility can volatilize from shallow impacted groundwater and diffuse 

through overlying soils, potentially entering the atmosphere or indoor air if a building is located 

above impacted groundwater. This process requires volatile COPCs to be present at the 

surface of the shallowest aquifer (i.e. at the water table); otherwise overlying unaffected 

groundwater impedes volatilization through the vadose zone. Based on the data received to 

date, volatile COPCs are present in source areas on-Site, but are not present in the shallow 

groundwater below off-Site residential areas. COPCs may also be brought to the land surface 

via pumping if an irrigation well is screened within the groundwater zone containing the COPCs. 

2.3 Potential Human Exposure Pathways and Receptors 

Potentially complete exposure pathways may be classified as primary or secondary. Primary 

exposure pathways are those that are expected to be the main contributors to risk analysis or 

are of particular concern to the goals of the particular risk assessment. Secondary exposure 

pathways may be complete, but are expected to contribute in relatively small proportions to 

overall potential risks. Primary and secondary exposure pathways for on-Site and off-Site 

receptors under current and likely future potential use scenarios are described below and 

presented in Figures 1 and 2. 

2.3.1 Potential On-Site Receptors 

Under current conditions, potential on-Site receptors include workers at the facility who spend 

the majority of their time indoors, on-Site landscape workers who spend most of their time 

outdoors, contract workers who may be required to perform subsurface excavation activities to 

maintain existing underground utilities or support construction activities, and adolescent 

trespassers. The primary potentially complete exposure pathway for on-Site facility workers is 

inhalation of constituents that have volatilized from shallow groundwater and entered indoor air.

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Only chemicals present at the surface of the groundwater are susceptible to volatilization to 

indoor air. 

For on-Site landscape workers and potential adolescent trespassers, the primary exposure 

pathway is inhalation of outdoor air. Because there are currently no irrigation wells on-Site and 

no planned excavation of soils to a depth below the water table, there is no direct exposure to 

on-Site groundwater for these receptors under current exposure scenarios. However, some 

subsurface excavation may be required to maintain/upgrade existing utilities on-Site and 

commercial utility or construction workers could be exposed to COPCs via direct contact with 

subsurface soils and shallow groundwater, which may be found at 1.5 to 4 feet bgs. In addition, 

workers may be exposed to COPCs volatilized from exposed shallow groundwater during 

excavation. 

2.3.2 Potential Off-Site Receptors 

The potential area of impacted groundwater extends to the east beneath the Pinellas Trail, the 

Stone’s Throw Condominium Complex, and the Brandywine Apartments Complex as well as to 

the south and west beneath Azalea Park, the ball field area, and some residential properties. 

However, the impacted groundwater to the south and west is present below a clean water layer 

which prevents volatilization of COPCs from the water table and eliminates potential exposures 

to COPCs in deeper groundwater. 

In the off-Site areas above the deeper impacted groundwater, potential receptors include some 

area residents, landscape workers, construction/utility workers, workers at the Azalea Park 

Recreation Center, ball players and users of the Pinellas Trail. The potential primary exposure 

pathways for area residents involve direct exposure to groundwater used for irrigation purposes 

via ingestion, dermal contact and inhalation. A recent well survey conducted in 2008 by 

ARCADIS identified a number of irrigation wells located within a ½ mile radius of the Site; 

consequently, residential use of groundwater for irrigation purposes is evaluated in this report. 

Potential exposures to surface soil and ingestion of homegrown produce are additional potential 

exposure pathways for residential receptors. Recreational use of irrigation water to fill a child’s 

wading pool or operate a sprinkler for children to play in has also been evaluated. 

Children and adults using the Pinellas Trail for recreational purposes could be exposed to 

COPCs volatilized from groundwater to outdoor air.

3 Data Evaluation 

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For the purpose of this Risk Assessment, all groundwater data collected during the most recent 

assessment activities (since March 2007) and presented in the SARA were used to identify 

COPCs at the Site. These data include samples collected from on-Site and off-Site monitoring 

wells as well as samples collected from temporary borings advanced with a direct-push rig using 

Cone Penetrometer Technology (CPT). Groundwater analytical data are presented in SARA 

Tables 8, 9 and 11, and groundwater sampling locations are shown in SARA Figures 3-1 and 3- 

2. Analytical data collected from private irrigation wells are presented separately in SARA Table 

11. As described in Section 3.1, COPCs were identified separately for on-Site and off-Site 

locations. 

Soil vapor and indoor air data were also collected at the Site. These data are presented in 

SARA Tables 12 and 13, respectively. SARA Table 12 also contains soil vapor results for a 

number of off-Site locations. Soil vapor sampling results are described in Section 3.2.1. Indoor 

air samples were only collected on-Site and are described in Section 3.2.2. A number of 

ambient air samples were also collected at the Site and in the surrounding area. These data 

are presented in SARA Table 13 and described in Section 3.2.3. On-Site and off-Site soil vapor 

and ambient air sampling locations are shown in SARA Figure 3-4. 

The purpose of the COPC selection process is to identify site-related constituents that are 

present in environmental media at concentrations which exceed typical background levels and 

may make non-negligible contributions to risk estimates. Constituents excluded as COPCs at 

the screening step are those where the maximum detected Site-related concentration is below 

the most stringent risk-based screening criterion or below typical background levels. 

3.1 Identification of Constituents of Potential Concern 

Constituents detected at least once in groundwater were considered for inclusion as COPCs. 

The list of detected chemicals was then evaluated based on the frequency of detection and a 

risk-based screening using the Florida Department of Environmental Protection (FDEP) riskbased 

Cleanup Target Level (CTL) for residential direct exposure to groundwater. If no CTL 

was available for a constituent, then the USEPA Region IX Preliminary Remediation Goal 

(PRG) was used in the risk-based screening step. Both the FDEP CTLs and the USEPA 

Region IX PRGs correspond to a 1x10 -6 (one in one million) risk level for potential carcinogens 

and a Hazard Quotient (HQ) of 1.0 for non-carcinogenic endpoints. In order to account for 

cumulative exposures to multiple COPCs, maximum concentrations for non-carcinogens were 

compared to an adjusted screening criteria corresponding to an HQ of 0.1. The cumulative 

impact of the sum of the HQs is the Hazard Index. Potential exposures are expected to be 

below the threshold required to produce non-cancer effects when the Hazard Index is below a 

value of 1.0. 

Constituents that are infrequently detected may represent sampling artifacts or localized 

conditions unrelated to former activities at the Site. According to FDEP guidance, a constituent 

may be eliminated from consideration at a site if it is detected: a) in only one out of 10 or more

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samples, or 5% or fewer out of 20 or more samples; and b) in low concentrations (no more than 

the default groundwater CTL); and c) there is no reason to believe that the contaminant may be 

present due to historical site activities (FDEP, 2005). 

Other factors used to evaluate constituents for selection as COPCs included whether or not the 

constituent is an essential element with nutritive value and whether or not the constituent is 

likely to be site related. 

3.1.1 Groundwater 

The selection process for determination of COPCs in groundwater was carried out separately 

for on-Site and off-Site areas. In on-Site areas, samples collected from the upper portion of the 

aquifer (0 – 20 feet bgs) were considered for determination of COPCs because only the upper 

layer (shallow aquifer) can act as a potential source of constituents volatilizing to indoor and 

outdoor air and because potential contact in a utility excavation scenario would only involve the 

upper layer of the aquifer. In off-Site areas where irrigation wells can provide a pathway for 

direct exposure to deeper groundwater, all groundwater samples collected off-Site, regardless 

of depth, were used to determine COPCs. The lists of all chemical constituents detected at 

least once in the upper layer of on-Site groundwater, and in off-Site groundwater regardless of 

depth, are provided in Tables 1 and 2 of this report. Included in each table, for each 

constituent, are: 

• the number of samples analyzed, 

• number of samples in which the COPC was detected, 

• the range of detection limits for samples where the COPC was not detected, 

• the calculated detection frequency, 

• the minimum, maximum and arithmetic average of the detected concentrations, 

• the risk-based screening values for direct contact under a residential exposure scenario, 

and 

• the basis for retaining or eliminating the constituent as a COPC. 

On-Site Groundwater. Of the 53 constituents detected at least once in the upper layer of on- 

Site groundwater, 24 were eliminated as COPCs because the maximum concentration detected 

did not exceed the screening criterion (equal to the FDEP CTL for potential carcinogens and 

one-tenth the CTL for non-carcinogens). Of the remaining 29 constituents, four (calcium, 

magnesium, potassium and sodium) were eliminated as COPCs because they are commonly 

detected in groundwater and considered to be essential dietary minerals with nutritive value 

(USEPA, 2000). 

Although a number of constituents were infrequently detected and are not considered to be siterelated 

constituents (i.e. 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2-dichloropropane,

12 


DRAFT 

4-methylphenol, methylene chloride, and tetrachloroethene), maximum concentrations exceed 

their respective CTL values and these constituents were retained as COPCs. 

The list of 25 COPCs are indicated below and in Table 1 and consist of chlorinated VOCs, 

miscellaneous solvents (acetone, carbon disulfide), hydrocarbons (e.g., toluene, ethylbenzene, 

xylenes, trimethylbenzenes and isopropylbenzene), phenols, and 1,4-dioxane. 

On-Site COPCS 

Chlorinated 

Miscellaneous 

VOCs 

Solvents 

1,1,1-trichloroethane acetone 

1,1,2-trichloroethane toluene 

1,1-dichloroethane ethylbenzene 

1,1-dichloroethene o-xylene 

chloroethane m, p-xylene 

chloroform carbon disulfide 

cis-1,2-dichloroethene isopropylbenzene 

1,2-dichloropropane 1,2,4-trimethylbenzene 

methylene chloride 1,3,5-trimethylbenzene 

tetrachloroethene 4-methylphenol 

trans-1,2-dichloroethene phenol 

trichloroethene 

vinyl chloride 

1,4-dioxane 

Off-Site Groundwater. Chlorinated VOCs and miscellaneous solvents were also detected in 

groundwater samples collected at off-Site locations. Constituents exceeding screening criteria 

are identified below and in Table 2. 

Off-Site COPCs 

Chlorinated 

Miscellaneous 

VOCs 

Solvents 

1,1-dichloroethane 1,2,4-trimethylbenzene 

1,1-dichloroethene 1,4-dioxane 

1,2-dichloroethane benzene 

cis-1,2-dichloroethene ethylbenzene 

methylene chloride isopropylbenzene 

trichloroethene toluene 

vinyl chloride o-xylene 

m, p-xylene

13 


DRAFT 

The list of COPCs identified in off-Site groundwater includes two constituents not identified as 

COPCs on-Site (benzene and 4-methyl-2-pentanone, also known as methyl isobutyl ketone or 

MIBK). However, because both benzene and MIBK have been detected in deep groundwater 

on-Site at concentrations exceeding groundwater CTLs (GCTLs), both constituents have been 

retained as off-Site COPCs. Chloromethane was detected in 4 of 413 samples collected off-Site 

at a maximum concentration of 3.3 µg/L, which exceeds the GCTL of 2.7 µg/L. However, 

because chloromethane was not detected on-Site, is commonly found in outdoor air and is 

unlikely to be Site-related, it was eliminated as a COPC. 

3.2 COPCs Detected in Air and Soil Vapor 

3.2.1 Soil Vapor Sampling 

To address potential exposures via soil vapor intrusion to indoor and outdoor air, soil vapor 

samples were collected from 9 on-Site and 20 off-Site locations and analyzed for volatile 

organic compounds (VOCs). 2 Soil vapor sampling results are presented in SARA Table 12 and 

soil vapor sampling locations are shown in SARA Figure 3-4. 

The primary constituents detected in soil vapor samples collected from beneath the buildings 

on-Site were CVOCs including trichloroethene (TCE), 1,1,1-trichloroethane (TCA) and their 

degradation products cis-1,2-dichloroethene (cis-1,2-DCE), trans-1,2-dichloroethene (trans-1,2- 

DCE), 1,1-dichloroethene (1,1-DCE) and 1,1-dichloroethane (1,1-DCA). None of these 

constituents were detected in soil vapor samples collected off-Site. Also detected on-Site, but 

at much lower concentrations, were a number of constituents commonly detected at low levels 

in outdoor air including toluene, xylenes, acetone, carbon disulfide, and MEK as well as 

chloroform and tetrachloroethene (PCE). 

The primary constituents detected in off-Site soil vapor samples were the BTEX chemicals 

(benzene, toluene, ethylbenzene and the xylenes), acetone, carbon disulfide, methyl ethyl 

ketone (MEK) and chloroform. The BTEX chemicals are found in gasoline and emitted in 

vehicle tailpipe emissions; consequently, they are widely distributed throughout the 

environment. Acetone and MEK are common solvents found in consumer products and 

routinely detected in outdoor air. Chloroform has been detected on-Site, but is also a drinking 

water disinfection byproduct commonly found in indoor air. Chloroform is also found in the 

reclaimed water supplied by the City of St. Petersburg, which Raytheon uses to irrigate the 

landscaping on-Site. Carbon disulfide is found naturally in ocean and coastal waters and also 

generated by bacteria in soil. 

2 

The target analyte list for soil vapor and indoor air samples differed from the target analyte list for groundwater 

samples and did not include the following COPCs: trimethylbenzenes, isopropylbenzene, phenol, 4-methylphenol 

and 1,2-dichloropropane.

14 


DRAFT 

Notably, no CVOCs were detected in off-Site soil vapor samples. This is consistent with the 

SARA characteristics of the groundwater impacted by chlorinated VOCs which is present at the 

water table near the on-Site source area but is only found at depth off-Site. In off-Site areas, a 

clean water layer generated by infiltration of rainwater has built up over the impacted 

groundwater area and limits volatilization of constituents from groundwater. However, in the on- 

Site source area where buildings and asphalt pavement prevent infiltration of rainwater, 

constituents are found near the surface of the water table. 

To further evaluate the possibility that soil vapor may be migrating off-Site, a second round of 

soil vapor samples were collected in April 2008 at 11 locations within the perimeter of the facility 

and 8 locations in Azalea Park. Soil vapor sampling locations are shown in SARA Figure 3-4; 

analytical results are provided in SARA Table 12. As indicated in SARA Table 12, one soil 

vapor sample contained 1,1-dichloroethane (1,1-DCA) and one sample contained 1,4-dioxane; 

all other COPCs detected in soil vapor were chloroform, common solvents (acetone and MEK) 

and gasoline constituents (toluene, ethylbenzene and xylenes) 3 . These additional soil vapor 

sampling data do not indicate the presence of a soil vapor plume migrating off-Site. Other than 

chloroform, which is present in the reclaimed water used to irrigate the park, no chlorinated 

VOCs were detected in soil vapor samples collected in Azalea Park. The only other chemicals 

detected in the park were the common solvents acetone, MEK and the common gasoline 

constituents, toluene and xylenes. 

3.2.2 Indoor Air Sampling 

Indoor air samples were collected from 8 locations within Building M, 3 locations within Building 

A, and 5 locations within Building E in November 2007. Sampling locations are shown in SARA 

Figure 3-4. Indoor air samples were analyzed for VOCs using a modified Method TO-15 and 

analytical data are reported in SARA Table 13. Only low levels of VOCs were detected in 

indoor air. At several locations, collocated soil vapor samples were collected from beneath the 

building slab and analyzed for the same suite of VOCs. In general, indoor air concentrations 

were uncorrelated to soil vapor levels. These data are shown in Table 3 of this report. As 

indicated in Table 3, indoor air levels for a number of constituents (acetone, carbon disulfide, 

MEK, toluene and xylene) were comparable to collocated subslab soil vapor concentrations. 

Constituents detected in indoor air at levels comparable to subslab soil vapor concentrations 

are likely originating from indoor sources. Indoor air concentrations for other constituents 

detected at much higher levels in soil vapor such as TCE, TCA and their degradation products 

(cis- and trans-1,2-DCE, 1,1-DCA and 1,1-DCE), may be attributed in part to the underlying soil 

vapor; however, concentrations detected in indoor air are low, indicating that soil vapor intrusion 

is not a significant exposure pathway for the three commercial buildings on-Site. 

3 Two non-COPC constituents commonly found in gasoline were also detected in one soil vapor sample 

(tetrahydrofuran and 2,2,4-trimethylpentane).

3.2.3 Ambient Air Sampling 

15 


DRAFT 

Four separate rounds of ambient air monitoring were conducted at the Site, in Azalea Park, and 

in the neighborhoods surrounding the Raytheon Facility. Ambient air monitoring locations are 

shown in Figure 3-4 of the SARA; analytical data are provided in SARA Table 13. The first 

round of ambient air samples were collected on December 4, 2007. After anomalous results 

were received in the first round of sampling, follow-up conversations with the analytical 

laboratory revealed that the Summa canisters were not 100% certified clean. As a result, a 

second round of sampling was conducted with 100% certified clean canisters on January 14, 

2008. This sampling event was followed by a focused, third round of sampling on February 22, 

2008 to further evaluate results obtained for one of the samples (AA-1). During the first two 

rounds of sampling, winds were blowing primarily from north to south. During the third round of 

sampling, winds were blowing primarily from the south/southwest. 

To evaluate the possibility that soil vapor originating on-Site may be diffusing through soil and 

entering outdoor air, a fourth round of ambient air monitoring was conducted. Ambient air 

monitors were set up at five locations surrounding the buildings on-Site (see Figure 3-4 of the 

SARA) and ambient air samples were collected over a period of approximately 8 hours on three 

separate days. Ambient air monitoring results are provided in Table 13 of the SARA. 

In addition to the four rounds of sampling described above, Pinellas County operates two 

ambient air monitoring stations as part of the National Air Toxics Trends (NATTS) program. 

One of the stations is located northwest of the Facility, adjacent to the tennis courts in Azalea 

Park. Summa canister samples are collected over a 24-hour period every six days and 

analyzed for VOCs using EPA Method TO-15. These data are summarized in Table 4 of this 

report and discussed in further detail in Section 7. 

3.2.4 Surface Water Sampling 

Four surface water samples were collected from the drainage canal along Farragut Drive North 

and analyzed for VOCs and 1,4-dioxane using EPA Methods 8260B and 8260C SIM/ID. One 

COPC (1,4-dioxane) was detected in all four samples at concentrations ranging from 5.4 to 8.9 

µg/L. These levels are well below the FDEP surface water criterion of 120 µg/L (FDEP, 2005), 

which is established based on protection of human health. FDEP does not have an ecological 

screening value for 1,4-dioxane; however, the USEPA Region V ecological screening level for 

1,4-dioxane is 22,000 µg/L. 4 Because all of the surface water sampling results for 1,4-dioxane 

were well below both human health and ecological screening criteria, this constituent does not 

represent a significant risk to human health or the environment via surface water discharges. 

The only other COPC detected was cis-1,2-DCE at concentration of 0.68 µg/L, which is well 

below the federal and state drinking water standard of 70 µg/L. 

4 http://www.epa.gov/reg5rcra/ca/ESL.pdf

4 Exposure Assessment 

16 


DRAFT 

The purpose of the exposure assessment is to characterize the types and magnitude of 

potential exposures to the COPCs detected at and near the Site. The results of the exposure 

assessment will be combined with toxicity information presented in Section 5.0 to characterize 

potential risks to receptors. Possible exposure to COPCs in irrigation water is a concern to 

residents in the surrounding neighborhoods. The sampling of irrigation wells is still underway. 

To support at least a preliminary evaluation of that sampling program as the results become 

available, we have calculated risk-based screening levels (RBSLs) to compare to the sampling 

results as they become available. Test results from the well sampling program can be 

compared to these screening levels as the first step in evaluating the significance of the test 

results. The exposure assumptions used in the risk assessment and in the calculation of the 

RBSLs are discussed in this chapter. 

4.1 Identification of Complete Exposure Pathways 

4.1.1 On-Site 

Under current conditions, potential on-Site receptors include workers at the Facility who spend 

the majority of their time indoors, on-Site landscape workers, construction and utility workers, 

and adolescent trespassers. The primary potentially complete exposure pathway for on-Site 

facility workers is inhalation of volatile constituents that have volatilized from shallow 

groundwater and entered indoor air. The constituents present at the surface of the groundwater 

(i.e. at the interface of the groundwater and the overlying vadose zone) have the potential for 

migration from the groundwater, through the vadose zone and into indoor air. 

For on-Site landscape workers and potential trespassers, the primary exposure pathway is 

inhalation of outdoor air. Because there are currently no irrigation wells on-Site, there is no 

direct exposure to on-Site groundwater under current exposure scenarios for trespassers and 

landscape workers. However, direct exposure to groundwater could occur for construction and 

utility workers involved in subsurface excavation activities to upgrade/maintain existing 

underground utilities or support construction activities. 

In summary, the following potential exposure pathways are assumed to be complete for on-Site 

receptors: 

On-Site Facility Worker 

• Inhalation of Indoor Air 

On-Site Landscaper Worker 

• Inhalation of Outdoor Air 

On-Site Trespasser


On-Site Construction Worker 


• Ingestion of Soil 

• Dermal Contact with Groundwater 

On-Site Utility Worker 




4.1.2 Off-Site 

17 


DRAFT 

In the off-Site areas surrounding the Facility which are above the suspected area of impacted 

groundwater, potential receptors include area residents and landscape workers who may be 

exposed to COPCs via direct contact with groundwater from an irrigation well. The potential 

primary exposure pathways for area residents are direct exposure to groundwater used for 

irrigation purposes via ingestion, dermal contact and inhalation. 

A recent well survey conducted in 2008 identified a number of irrigation wells located within a ½ 

mile radius of the Site; consequently, residential use of groundwater for irrigation purposes is a 

potentially complete exposure pathway for area residents. Potential exposures to surface soil 

and homegrown produce irrigated with groundwater are additional exposure pathways for 

residential receptors. Although most of the COPCs in groundwater are volatile and tend to be 

released to the atmosphere during irrigation as opposed to accumulating in plants and soil, 

uptake in plants is a potential transport pathway for COPCs. Therefore, we have included 

incidental ingestion of soil and ingestion of homegrown produce as potential exposure pathways 

for off-Site residents. We have also considered recreational use of irrigation water for wading 

(when used to fill a child’s wading pool), to operate a sprinkler for children to play in or to fill a 

swimming pool. 

Two COPCs, 1,4-dioxane and cis-1,2-DCE, have also been detected at low levels (below 

surface water cleanup criteria) in surface water samples collected from the drainage canal 

located along Farragut Drive North. Although access to the drainage ditch is generally difficult 

because of steep embankments, we have evaluated exposure to COPCs in surface water using 

a health protective wading pool scenario. 

Benzene and 1,4-dioxane were found at low levels (5.5 and 7.7 µg/L, respectively) in shallow 

groundwater collected off-Site east of the Facility at the Brandywine Apartment Complex. 

However, benzene was detected in only one shallow monitoring well (SMW-4) that, in prior 

sampling events, contained no benzene. Screening calculations indicate that, even if this

18 


DRAFT 

concentration is not an artifact, potential risks from exposure to benzene in indoor and outdoor 

air are negligible. 

In addition, only chemicals with Henry’s law constants greater than about 1 x 10 -5 atm-m 3 /mol 

are considered sufficiently volatile to enter the vapor phase in significant quantities (USEPA, 

2004a, 2004c). Note that 1,4-dioxane has a Henry’s law constant of 3 x 10 -6 atm-m 3 /mol (see 

Table 7) and, thus, has insufficient volatility to result in significant soil vapor or indoor air 

concentrations. Therefore, potential indoor and outdoor air exposure pathways for residents 

and landscapers at the Brandywine and Stone’s Throw Condominium Complex are incomplete. 

However, construction workers involved in subsurface excavation activities could be exposed to 

1,4-dioxane. 

Children and adults using the park facilities for recreational purposes are unlikely to be exposed 

to constituents volatilized from groundwater to outdoor air because the COPCs are present in 

the deeper groundwater zone off-Site and an overlying clean water layer prevents volatilization 

to indoor and outdoor air. Groundskeepers and landscape workers at the park are also 

protected from potential exposures to COPCs volatilizing to outdoor air by this clean water layer. 

However, because one area of the Pinellas Trail is located adjacent to the former on-Site 

source area, we evaluate potential risks to users of the Pinellas Trail from exposure to COPCs 

volatilizing from the former on-Site source area. In summary, the following exposure pathways 

are evaluated as complete exposure pathways for off-Site receptors: 

Off-Site Resident 

• Ingestion of Irrigation Water 

• Dermal Exposure to Irrigation Water 

• Dermal Exposure to Surface Water 

• Inhalation of Outdoor Air during Irrigation 

• Ingestion of Homegrown Produce 

• Incidental Ingestion of Soil 

Pinellas Trail User 


Apartment/Condo Construction Worker 



4.2 Estimating Exposure Point Concentrations 

In this section of the report, we present equations used to estimate exposure point 

concentrations (EPCs) in indoor air, outdoor air, groundwater, surface soil and homegrown

19 


DRAFT 

produce at the Site and in the surrounding area. An EPC is an upper bound (conservative) 

estimate of the concentration of a COPC in its transport medium (e.g., soil, groundwater, air) at 

the point of contact where exposure may occur. For soils, the EPC is typically represented by 

the 95% upper confidence limit of the arithmetic mean concentration based on an assumption of 

random exposure in an exposure area. However, for assessing potential exposures to 

groundwater from individual wells we look at levels detected in each individual well. For on-Site 

exposure to vapors potentially migrating through the vadose zone, we have used a healthprotective 

(conservative) screening approach in which we have assumed the presence of the 

highest level of each COPC detected anywhere is present at the same location. Estimated 

EPCs are provided in Table 5 of this report. The derivation of these values is described below. 

4.2.1 On-Site Indoor Air 

Potential risks to current facility workers were estimated based on the maximum concentration 

of any COPC detected in indoor air within Buildings A, E and M. Indoor air concentrations are 

provided in Table 13 of the SARA; estimated EPCs under current and reasonably foreseeable 

future exposure scenarios are provided in Table 5. 

In off-Site areas, soil vapor intrusion to indoor and outdoor air is an incomplete exposure 

pathway because an overlying clean water layer prevents volatilization. 

4.2.2 Outdoor Air 

In on-Site areas not covered by asphalt or buildings, the potential exists for COPCs in soil vapor 

or groundwater to volatilize to outdoor air. The process is expected to occur by diffusion and 

requires COPCs to be present in soil vapor or at the surface of the groundwater. Because the 

degree of mixing of COPCs volatilizing to outdoor air is expected to be much greater than the 

degree of mixing in indoor air, and because residents spend more time indoors than outdoors, 

inhalation of outdoor air is not expected to be a significant exposure pathway. 

Nevertheless, outdoor air concentrations were estimated by assuming a mass transfer rate from 

groundwater or soil vapor to outdoor air based on Fick’s first law of diffusion and then applying a 

dilution factor using a simple box model. According to Fick’s law of diffusion, mass transfer 

through an isotropic medium is proportional to the concentration gradient across the medium 

and the diffusion coefficient as described by equation (4-1). 

where: 

E 

( C C ) 

s gs Deff 

L 

− 

= (4-1) 

E = Rate of mass transfer through the soil column (mg/m 2 -s) 

Cs = Concentration in the soil vapor phase (mg/m 3 ) 

Cgs = Concentration at the ground surface (mg/m 3 )

Deff = Effective diffusion coefficient across the vadose zone (m 2 /s) 

L = Thickness of the vadose zone (m) 

20 


DRAFT 

The concentration of COPC in the soil vapor phase can be taken directly from off-Site soil vapor 

samples (Table 2) or estimated from the groundwater concentration using Henry’s Law. 

where : 

Cs gw 

H = Dimensionless Henry’s law constant 

Cgw = Concentration in groundwater (mg/L) 

CF = Conversion factor (1000 L/m 3 ) 

= H ⋅ C ⋅ CF 

(4-2) 

It is assumed that COPCs volatilizing from the ground surface are entrained immediately in the 

outdoor air so that concentrations at the ground surface are zero. This conservative 

assumption maximizes the estimated flux of chemicals from the subsurface; accordingly it is a 

health-protective assumption. 

A simple box model can be used to estimate ambient air concentrations from an area source. 

The model assumes that a box is constructed over the emission area and as COPCs volatilize 

from the ground surface, they are constrained within the box and diluted by the volume of air 

within the box. To be protective, it is assumed that the height of the box is equal to the 

breathing zone height (1.5 m). With these conservative assumptions, the outdoor air 

concentration is given by equation (4-3). 

where: 

C oa 

Coa = Outdoor air concentration (mg/m 3 ) 

E ⋅ x ⋅ f 

= (4-3) 

z ⋅ u 

x = Length of the box parallel to wind direction (m) 

f = Frequency that winds are blowing from the source area 

z = Mixing height (m) 

u = Average wind speed (m/s)

21 


DRAFT 

Combining equations (4-1) to (4-3) yields the following expression used to predict outdoor air 

concentrations from soil vapor (4-4) or groundwater (4-5) concentrations. 

C 

C 

oa 

oa 

Cs 

⋅ CF ⋅ Deff 

⋅ x ⋅ f 

= (4-4) 

L ⋅ z ⋅ u 

Cgw 

⋅ H ⋅ CF ⋅ Deff 

⋅ x ⋅ f 

= (4-5) 

L ⋅ z ⋅ u 

Note that the box model likely overestimates true outdoor air concentrations. One reason is that 

the box model assumes that the entire area within the box is emitting and that dilution is limited 

to the volume of the box rather than the open atmosphere. In contrast, for paved areas like the 

Pinellas Trail or the parking lots on-Site, emissions are limited to opening and cracks in the 

pavement. 

Upper bound estimates of EPCs in outdoor air for on-Site areas are reported in Table 5. These 

estimates were derived from the higher of the values derived from equations (4-4) and (4-5) and 

assume a vadose zone thickness of 1 meter, a box width of 10 meters, a box height of 1.5 

meters, a wind speed of 3.5 meters per second (average for St. Petersburg, FL), and a wind 

direction frequency of 50%. 

Measured levels of constituents in outdoor air were also obtained as part of the soil vapor 

sampling program. In addition, the county routinely collects 24-hour ambient air samples as 

part of the NATTS program. However, these data reflect potential contributions from multiple 

sources that are regional and typically found in urban environments. Ambient air sampling 

results are discussed in Section 7. 

4.2.3 Groundwater 

Direct exposure to groundwater could occur during subsurface excavation or via irrigation well 

pumping. Because no irrigation wells currently exist on-Site or in Azalea Park (both use 

reclaimed water from the City), direct exposure to irrigation water is not a reasonably 

foreseeable exposure scenario for these two areas. However, a utility worker could be exposed 

to shallow groundwater exposed during subsurface excavation activities. For the purpose of 

estimating potential exposures by a utility worker to COPCs in groundwater, the maximum 

concentration of each COPC detected in shallow groundwater 5 was selected as the EPC. 

5 

For the purpose of this risk assessment, all groundwater samples collected within the top 20 feet bgs were used to 

characterize potential exposures to shallow groundwater. This is a health-protective assumption that may result in an

4.2.4 Excavation Air 

22 


DRAFT 

Utility workers involved in subsurface excavation activities could also be exposed to COPC 

vapors released from the surface of the exposed groundwater during excavation. The model 

used to estimate emissions from the groundwater surface is based on a mass transfer approach 

that is governed by resistance to mass transfer in the liquid and vapor phase (for example, see 

Lyman et al, 1982). The basic emission rate equation is given in equation (4-6). 

where: 

E = Emission rate (g/m 2 - s) 

E = C ⋅ 

(4-6) 

w K ol 

Cw = Concentration in groundwater (g/m 3 ) 

Kol = Overall mass transfer coefficient (m/s) 

The overall mass transfer coefficient Kol can be calculated by the following relationship given in 

equation (4-7). 

where: 

1 

K 

ol 

kL = Liquid phase mass transfer coefficient (m/s) 

Keq = Air/water partition coefficient (unitless) 

kg = Vapor phase mass transfer coefficient (m/s) 

1 1 

= + 

(4-7) 

k K k 

The liquid phase mass transfer coefficient can be estimated using the simple empirical 

relationship shown in equation (4-8) 6 . 

where: 

l 

eq 

0. 

67 

−7 

2 ⎡ D ⎤ l 

2. 611x10 

⋅ u ⎢ ⎥ 

⎣ Dether 

⎦ 

g 

k = 

(4-8) 

L 

Dl = Diffusivity of COPC in water (cm 2 /s) 

Dether = Diffusivity of ether in water (8.5x10 -6 cm 2 /s) 

overestimate of potential risks. 

6 USEPA. 1987. Hazardous Waste Treatment, Storage and Disposal Facilities (TSDF) – Air Emission Models, 

Documentation. EPA-450/3-87-026.

u = Wind speed (m/s) 

23 


DRAFT 

The air/water partition coefficient used in this model is the dimensionless Henry’s Law constant, 

which varies with temperature, and is calculated according to equation (4-9). 

where: 

K eq 

H = Henry’s Law constant (atm-m 3 /mole) 

H 

= (4-9) 

R ⋅ T 

R = Ideal gas constant (8.206 x 10 -5 atm-m 3 /mole-K) 

T = Temperature in degrees Kelvin (K) 

The gas phase mass transfer coefficient in units of meters per second can be estimated from 

equation (4-10) based on the work of Mackay and Matsugu (1973) 7 . 

where: 

Scg = Schmidt number 

g 

−3 

0. 

78 −0. 

67 −0. 

11 

= 4. 

82x10 

⋅ u ⋅ ScG 

⋅ d e 

k (4-10) 

de = Effective diameter of the area emitting 

The Schmidt number is a dimensionless number that relates to the relative thickness of the 

surface boundary layer and is calculated according to equation (4-11). 

where: 

Sc 

g 

µ g 

= 

ρ ⋅ D 

µg = Viscosity of air (1.81 x 10 -4 g/cm-s) 

ρg = Density of air (1.2 x 10 -3 g/cm 3 ) 

Da = Diffusivity of COPC in air (cm 2 /s) 

The emission rate calculated from equation (4-6) is combined with the box model described by 

equation (4-3) to arrive at an upper bound estimate of outdoor air concentrations in the vicinity 

g 

a 

(4-11) 

7 D. Mackay and R.S. Matsugu. 1973. Evaporation rates of liquid hydrocarbon spills on land and water. Canadian J. 

Chem Eng. 51:434.

24 


DRAFT 

of the subsurface excavation. Estimated outdoor air concentrations in the vicinity of subsurface 

excavation activities are provided in Table 5. Note that worker protection evaluations 

administered under OSHA typically require air monitoring as opposed to this type of EPC 

estimation and that estimation of worker exposure in this scenario is not represented to be an 

alternative to complying with OSHA requirements. 

4.2.5 Subsurface Soil 

For the purpose of estimating potential exposures to construction or utility workers from 

incidental ingestion of soil, subsurface soil concentrations in contact with shallow groundwater 

were estimated assuming equilibrium partitioning with shallow groundwater according to 


where: 

C 

s 

C 

( θ + ρ K f ) 

w w b oc oc 

= (4-12) 

ρb 

Cs = Concentration in soil (mg/kg) 

Cw = Concentration in groundwater (mg/L) 

θw = Volumetric water content (0.39; unitless) 

ρb = Dry soil bulk density (1.62 kg/L) 

Koc = Organic carbon-water partition coefficient (L/kg) 

foc = Fraction of organic carbon in soil (0.01; unitless) 

Soil parameters were chosen to be consistent with a loamy sand. Subsurface soil EPCs are 

provided in Table 5. 

4.2.6 Irrigation Water 

A recent well survey conducted in 2008 identified a number of irrigation wells located within a ½ 

mile radius of the Site. If these irrigation wells are screened within the area of impacted 

groundwater, residents may be exposed to COPCs via dermal contact with irrigation water, 

inhalation of COPCs volatilized during irrigation and incidental ingestion. In addition, if residents 

are involved in gardening activities and irrigate their crops with well water, residents could be 

exposed to COPCs from incidental ingestion of surface soils during gardening and ingestion of 

homegrown produce. Recreational use of irrigation water to fill a child’s wading pool or operate 

a sprinkler for children to play in has also been evaluated. 

Potential outdoor air concentrations generated by volatilization of constituents during lawn 

irrigation were estimated by assuming an upper bound estimate of the fraction of COPCs 

volatilized to outdoor air. The fraction volatilized from groundwater during irrigation was 

estimated using the procedure described by McKone (1987) where the transfer efficiency from

25 


DRAFT 

water to air is estimated relative to the transfer efficiency for radon. This procedure assumes 

that the transfer efficiency is proportional to the overall mass transfer coefficient at the air/water 

boundary layer. The volatilized COPCs are released into a “box” and resulting outdoor air 

concentrations are estimated using equation (4-3). The emission rate of volatile COPCs into the 

box is calculated based on an assumed irrigation rate of one inch per hour applied over a 2500 

square foot area. This rate is consistent with recommended values provided by the University 

of Florida Institute of Food and Agricultural Sciences for Florida lawns. 8 The corresponding 

volume rate of water applied to the lawn is approximately 1.64 liters per second or 26 gallons 

per minute and the emission rate of volatile COPCs into the atmosphere is calculated according 

to equation (4-13). 

where: 

Eirr = Emission rate during irrigation (mg/m 2 -s) 

E 

irr 

Cirr 

⋅ ARirr 

⋅ f 

= (4-13) 

A 

Cirr = Concentration of constituent in irrigation water (mg/L) 

ARirr = Irrigation water application rate (L/s) 

f = Fraction volatilized to outdoor air (unitless) 

A = Area of lawn irrigated (m 2 ) 

and the fraction volatilized to outdoor air is chemical specific and calculated according to the 

equation below (McKone, 1987) 

where: 

f 

COPC 

= 

f 

Radon 

⎛ 2. 

5 

⎜ 

⎝ D 

⎛ 2. 

5 

⎜ 

⎝ D 

2 / 3 

w 

2 / 3 

w 

R T ⎞ 

+ 

Da 

H ⎟ 

2 / 3 

⎠ 

R T ⎞ 

+ 

Da 

H ⎟ 

2 / 3 

⎠ 

Radon 

COPC 

fCOPC = Fraction of COPC volatilized to outdoor air 

fRadon = Fraction of radon volatilized to outdoor air (assumed to be 100%) 

Da = Diffusivity in air (cm 2 /s) 

Dw = Diffusivity in water (cm 2 /s) 

8 http://polkfyn.ifas.ufl.edu/lawn_irrigation_guide.shtml 

(4-14)

R = Ideal gas constant (cm 3 -atm/mole-K) 

T = Temperature (K) 

4.2.7 Homegrown Produce 

26 


DRAFT 

For residents who maintain a home garden and irrigate their crops or trees with groundwater, 

potential exposures to COPCs may occur via ingestion of homegrown produce and incidental 

ingestion of soil while gardening. As previously mentioned, most of the COPCs present in off- 

Site groundwater are volatile constituents, which will tend to be released to outdoor air during 

irrigation rather than accumulate in soil or taken up by plants. 

COPC concentrations in homegrown produce were estimated for root vegetables and aboveground 

fruits and vegetables using empirical correlations with octanol-water partition coefficient 

(Kow) established by Briggs et al. (1982, 1983) and later updated by Ryan et al. (1988). The 

root concentration factor (RCF) is defined in equation (4-15) 

RCF 

and estimated according to equation (4-16). 

( mg / kg fresh weight) 

pore water ( mg / L) 

concentration 

in root 

= (4-15) 

concentration 

in soil 

0. 

77 log Kow −1. 

52 

RCF = 10 

+ 0. 

82 

(4-16) 

A stem concentration factor (SCF) derived by Briggs is used to estimate COPC concentrations 

in above-ground fruits and vegetables. The SCF is defined in equation (4-17) 

SCF 

and calculated according to equation (4-18). 

( mg / kg fresh weight) 

pore water ( mg / L) 

concentration 

in stem 

= (4-17) 

concentration 

in soil 

2 

−0. 

434( 

log Kow − 1. 

78) 

− 

= 

⋅ ⎜ 

2. 

44 

SCF 0. 

748 ⋅10 

⎟ 

(4-18) 

0. 

95 log Kow 2. 

05 

( 0. 

82 + 10 

) 

⎛ 

⎜ 

⎝ 

⎞ 

⎟ 

⎠

27 


DRAFT 

Because St Petersburg receives about 52 inches of rain per year 9 , we have assumed that the 

concentrations of COPCs in soil pore water are diluted by 50% compared to concentrations in 

irrigation water. This assumes that an equal amount of irrigation water (~50 inches per year) is 

applied to the home garden or trees. We have also assumed that some fraction volatilizes to 

outdoor air and is unavailable for plant uptake using equation (4-14). 

4.2.8 Surface Soil 

Surface soil concentrations resulting from irrigation of lawns and gardens were calculated 

assuming equilibrium partitioning with irrigation water according to equation (4-19). 

where: 

C 

s 

C 

( θ + ρ K f ) 

irr w b oc oc 

= (4-19) 

ρb 

Cs = Concentration in soil (mg/kg) 

θw = Volumetric water content (unitless) 

ρb = Dry soil bulk density (kg/L) 

Koc = Organic carbon-water partition coefficient (L/kg) 

foc = Fraction of organic carbon in soil (unitless) 

Soil parameters were chosen to be consistent with a loamy sand with a volumetric water content 

of 7.6% and soil bulk density of 1.62 kg/L (USEPA, 2004c). The fraction of organic carbon in 

the soil was assumed to be 1%. 

4.3 Quantification of Exposure 

For the purpose of quantitative risk assessment, dose is the estimation of exposure to 

constituents in specific environmental media. This risk assessment considers two types of 

dose: administered dose and absorbed dose. An administered dose is the amount of 

constituent (concentration) in material that is ingested, inhaled, or applied to the skin and is 

available for absorption. Absorbed dose is the amount of constituent actually crossing the 

absorption barrier (i.e., the amount absorbed). The type of dose estimate used in a risk 

assessment is dependent on the route of exposure. Typically, ingestion and inhalation 

pathways are evaluated with the administered dose, and exposure is quantified by multiplying 

exposure concentrations by an intake rate (i.e., ingestion or inhalation rate, respectively). On 

the other hand, dermal exposure is evaluated not for intake but for absorption of the constituent. 

9 Southeast Regional Climate Center http://www.sercc.com/cgi-bin/sercc/cliMAIN.pl?fl7886

28 


DRAFT 

For the dermal exposure route with constituents in soil, an absorbed dose is calculated from the 

product of exposure concentration (administered dose), dermal absorption factor, and exposed 

surface area. In the risk characterization stage, dose estimates are combined with toxicity 

criteria to estimate potential risk associated with exposure to COPCs. 

Doses are presented in this risk assessment as a daily dose rate per unit body weight (mg/kgday). 

The “Average Daily Dose” (ADD) and “Lifetime Average Daily Dose” (LADD) are the 

general parameters used to quantify exposure doses in site risk assessments. The ADD is 

used as a standard measure for characterizing long-term exposure pertaining to non-cancer 

effects. The LADD addresses exposures that may occur over varying durations, but are 

averaged over a 70-year human lifetime; these are used in estimating potential carcinogenic 

risks. The quantitative estimation of constituent intake involves the incorporation of numeric 

assumptions for a variety of exposure parameters. Exposure parameters were based primarily 

on factors provided in USEPA’s Exposure Factors Handbook, Vols. I-III (USEPA, 1997). Other 

sources include: 

• Florida Department of Environmental Regulation’s (FDEP’s) report on Development of 

Cleanup Target Levels (CTLs) for Chapter 62-777, F.A.C. (FDEP 2005), 

• USEPA’s Risk Assessment Guidance for Superfund (RAGS) document (USEPA, 1989, 

1991), 

• USEPA Supplemental Guidance to RAGS: Region 4 Human Health Risk Assessment 

Bulletins (USEPA, 2000), 

• USEPA’s RAGS Part E, Supplemental Guidance for Dermal Risk assessment (USEPA, 

2004d), 

• USEPA’s Child-Specific Exposure Factors Handbook (USEPA, 2002a), and 

• in a limited number of cases, on best professional judgment of the site-specific 

characteristics. 

The following subsections present the equations for calculating ADD and LADD for each of the 

exposure pathways evaluated in this risk assessment along with scenario-specific exposure 

parameters. Exposure factors assumed for each of the exposure scenarios are provided in 

Table 6; chemical-specific parameters are summarized in Table 7. Dose and risk calculations 

are provided in Appendix A. 

4.3.1 On-Site Facility Worker 

Inhalation of Indoor Air. On-Site facility workers may be exposed to COPCs via inhalation of 

indoor air. The average daily dose (ADD) from inhalation of COPCs is calculated using 


where: 

EPC 

x IR 

x ET x EF x ED 

a i 

ADD = (4-20) 

BW x ATn

EPCa = Exposure point concentration in air (mg/m 3 ) 

IRi = Inhalation rate (m 3 /hr) 

ET = Exposure time (hr/day) 

EF = Exposure frequency (days/year) 

ED = Exposure duration (years) 

BW = Body weight (kg) 

ATn = Averaging time for non-carcinogens (days) 

29 


DRAFT 

Exposure assumptions are summarized in Table 6. An inhalation rate of 0.83 m 3 /hr was 

assumed for indoor workers at the Facility. This value, which is equivalent to a daily inhalation 

rate 20 m 3 /day, is the value recommended by FDEP (2005) for workers. We have assumed the 

worker is exposed for 8 hours per day, 250 days per year (allowing for 2 weeks vacation) for 25 

years. 

For potential exposures to carcinogens, a lifetime average daily dose (LADD) is calculated as 

shown in equation (4-21). 

LADD 

ADD x ED 

= (4-21) 

70 years 

Dose and risk calculations for potential exposures to COPCs by on-Site facility workers via 

inhalation of indoor air are provided in Appendix A; Table A-1. 

4.3.2 On-Site Landscape Worker 

On-Site landscape workers spend the majority of their time outdoors and split their time 

between this Site (averaging approximately 150 days per year on-Site) and another Raytheon 

facility in the area. 

Inhalation of Outdoor Air. The ADD from inhalation of COPCs in outdoor air is calculated 

according to equation (4-20) where the EPC is the concentration of COPCs in outdoor air as 

described in section 4.2.2. The LADD is calculated using equation (4-21). Exposure point 

concentrations for on-Site outdoor air are reported in Table 5 and exposure factors are 

summarized in Table 6. We have assumed an inhalation rate of 1.5 m 3 /hr for outdoor air 

exposures based on data presented in USEPA’s Exposure Factors Handbook (EFH) for an 

outdoor worker participating in moderate activities. 

Dose and risk calculations for potential exposures to COPCs via inhalation of outdoor air by on- 

Site landscape workers are provided in Appendix A; Table A-2.

4.3.3 On-Site Trespasser 

30 


DRAFT 

Although the Site is fenced and site security ensures that access is limited, in accordance with 

USEPA Region 4 guidance, we have considered potential exposures to an adolescent 

trespasser. The adolescent trespasser scenario assumes that a child between the ages of 7 

and 16 spends an average of two hours per day, one day per week on site where potential 

exposure to constituents in outdoor air could occur via inhalation. The average daily dose from 

inhalation of outdoor air is calculated according to equation (4-20). EPCs are provided in Table 

5 and exposure factors are summarized in Table 6. We have assumed a body weight of 45 kg 

and an inhalation rate of 1.2 m 3 /hr based on data presented in USEPA’s Child-Specific 

Exposure Factors Handbook for a child participating in moderate activities (USEPA, 2002a). 

Dose and risk calculations for potential exposures to COPCs by on-Site trespassers via 

inhalation of outdoor air are provided in Appendix A; Table A-3. 

4.3.4 On-Site Construction Worker 

In the event that subsurface excavation is required to support potential future construction 

activities on-Site, a construction worker could be exposed to COPCs via dermal contact with 

exposed groundwater and saturated soils and inhalation of COPCs volatilized from the 

groundwater surface. The construction worker scenario also considers potential exposures to 

COPCs via incidental ingestion of subsurface soil. The construction scenario is modeled as a 

one-time event in which the excavation could remain open for as long as 20 days. However, we 

have assumed that incidental ingestion takes place over the entire construction event, which we 

have assumed could last as long as 6 months, even after the excavation has been covered. 

Dermal Contact with Groundwater. For the purpose of estimating potential risks to 

construction workers from dermal exposure to COPCs, it is assumed that a worker may be 

exposed to saturated soils and groundwater for 2 hours per day, 20 days per year for 1 year. It 

is assumed that the worker is wearing long pants, shoes and a short-sleeved shirt but the 

worker’s head, hands, and forearms could be exposed to saturated soil and groundwater. The 

dermally absorbed dose (DAD) of COPCs received from contact with saturated soils and 

groundwater was calculated following USEPA dermal risk assessment guidance for 

groundwater (USEPA, 2004d) where: 

and 

DA 

event 

DAD 

= 

DAevent 

⋅ EV ⋅ EF ⋅ ED ⋅ SA 

= (4-22) 

BW ⋅ AT 

6 ⋅τ 

event ⋅ tevent 

π 

2 ⋅ FA ⋅ K p ⋅ Cw 

if tevent ≤ t * (4-23) 

( ) ⎥ ⎥ 

⎡ 

2 

t 

⎛ 

⎞⎤ 

event 1 + 3B 

+ 3B 

= FA ⋅ K ⋅ ⎢ + ⎜ 

⎟ 

p Cw 

2 

⎜ 

2 ⎟ 

⎢⎣ 

1 + B ⎝ 1 + B ⎠⎦ 

DAevent τ event 

if tevent > t * (4-24)

where: 

DAD = Dermal absorbed dose (mg/kg-day) 

DAevent = Absorbed dose per event (mg/cm 2 -event) 

EV = Event frequency (events/day) 



SA = Exposed skin surface area (cm 2 ) 


AT = Averaging time (days) 

FA = Fraction absorbed water (dimensionless) 

Kp = Dermal permeability coefficient (cm/hr) 

Cw = Concentration of COPC in Irrigation water (mg/cm 3 ) 

τ event = Lag time per event (hr/event) 

tevent = Event duration (hr/event) 

31 


DRAFT 

B = Ratio of permeabilities through stratum corneum and viable epidermis 

(unitless) 

t* = Time to reach steady state (hr) 

The LADD is calculated using equation (4-21) with the exception that the ADD is replaced by 

the DAD. Exposure point concentrations for on-Site shallow groundwater are reported in Table 

5 and exposure factors are summarized in Table 6. Dose and risk calculations for potential 

exposures to COPCs via dermal contact with saturated soils and exposed groundwater by on- 

Site construction workers are provided in Appendix A; Table A-4. 

Incidental Ingestion of Soil. Some incidental ingestion of saturated soil may occur during 

subsurface excavation activities. The average daily dose (ADD) from ingestion of soil is 

calculated using equation (4-25). 

where: 

EPC 

x IR 

x ET x EF x ED 

s i 

ADD = (4-25) 

BW x ATn 

EPCs = Exposure point concentration in soil (mg/kg) 

IRs = Soil ingestion rate (kg/day) 



BW = Body weight (kg)

ATn = Averaging time for non-carcinogens (days) 

32 


DRAFT 

The LADD is calculated using equation (4-21). Subsurface soil concentrations were estimated 

using equation (4-19) and exposure point concentrations for subsurface soils on-Site are 

reported in Table 5. Soil parameters were chosen to be consistent with a loamy sand. 

Exposure factors are summarized in Table 6. We have assumed a soil ingestion rate of 330 

mg/day (0.00033kg/day) based on USEPA guidance (USEPA, 2002b). 

Dose and risk calculations for potential exposures to COPCs via incidental ingestion of 

subsurface soils by on-Site landscape/maintenance workers are provided in Appendix A; Table 

A-5. 

Inhalation of Air During Subsurface Excavation. Construction workers could also be 

exposed to COPCs volatilized from the surface of the exposed groundwater. The ADD received 

from inhalation of outdoor air is calculated according to equation (4-20) where the EPC is the 

concentration of COPCs in outdoor air as described in sections 4.2.4. The LADD is calculated 

using equation (4-21). Exposure point concentrations for on-Site outdoor air in the vicinity of 

subsurface excavation activities are reported in Table 5 and exposure factors are summarized 

in Table 6. 

Dose and risk calculations for potential exposures to COPCs via inhalation of outdoor air by on- 

Site landscape/maintenance workers involved in subsurface excavation activities are provided 

in Appendix A; Table A-6. 

4.3.5 On-Site Utility Worker 

Dermal Contact with Groundwater. For the purpose of estimating potential risks to utility 

workers involved in subsurface excavation activities, it is assumed that a construction/utility 

worker may be dermally exposed to saturated soil and groundwater for 2 hours per day, 8 days 

per year for 10 years. It is assumed that the worker is wearing long pants, shoes and a shortsleeved 

shirt but the worker’s head, hands, and forearms could be exposed to groundwater. The 

dermally absorbed dose of COPCs received from contact with groundwater is calculated using 

equations (4-22) through (4-24) and the LADD is calculated using equation (4-21) with the 

exception that the ADD is replaced by the DAD. Exposure point concentrations for on-Site 

shallow groundwater are reported in Table 5 and exposure factors for on-Site utility/construction 

workers are summarized in Table 6. 

Dose and risk calculations for potential exposures to COPCs via dermal contact with exposed 

groundwater by on-Site construction/utility workers are provided in Appendix A; Table A-7. 

Incidental Ingestion of Soil. Some incidental ingestion of soil may occur during subsurface 

excavation activities. The average daily dose (ADD) from ingestion of soil is calculated using 

equation (4-25). The LADD is calculated using equation (4-21). Subsurface soil concentrations 

were estimated using equation (4-19) and exposure point concentrations for subsurface soils 

on-Site are reported in Table 5. Soil parameters were chosen to be consistent with a loamy

33 


sand with a dry soil bulk density of 1.62 L/kg and a volumetric water content of 39% for 

saturated soils. Exposure factors are summarized in Table 6. 

DRAFT 

Dose calculations for potential exposures to COPCs via incidental ingestion of subsurface soil 

by on-Site construction/utility workers are provided in Appendix A; Table A-8. 

Inhalation of Air During Subsurface Excavation. If groundwater containing COPCs is 

exposed during the subsurface excavation activities, volatile constituents may be released to 

outdoor air. The ADD received from inhalation of outdoor air in the vicinity of the subsurface 

excavation is calculated according to equation (4-20) where the EPC is the concentration of 

COPCs in outdoor air as described in sections 4.2.5. The LADD is calculated using equation 

(4-21). Exposure point concentrations for on-Site outdoor air in the vicinity of subsurface 

excavation activities are reported in Table 5 and exposure factors for on-Site construction/utility 


Dose and risk calculations for potential exposures to COPCs via inhalation of outdoor air by 

construction/utility workers involved in subsurface excavation activities are provided in Appendix 

A; Table A-9. 

4.3.6 Azalea Park Landscape/Maintenance Worker 

Currently, the City of St. Petersburg maintains the ballfields and landscaping at Azalea Park 

using reclaimed water supplied by the City and there are no irrigation wells in use at the park. 

In addition, a clean water layer prevents potential volatilization of COPCs from underlying 

groundwater so no potential exposure pathways are complete for Azalea Park landscape 

workers. 

4.3.7 Azalea Park Ball Player and Recreation Center Employees 

Ballplayers and other individuals participating in recreational activities at the park could also be 

exposed to COPCs that have volatilized to outdoor air. However, as previously mentioned, a 

clean water layer prevents potential volatilization of COPCs from underlying groundwater so no 

potential exposure pathways are complete for Azalea Park ball players and workers/visitors to 

the Recreation Center. 

4.3.8 Pinellas Trail User 

Because areas of the Pinellas Trail are located adjacent to the former source area, we have 

evaluated potential risks to users of the Pinellas Trail from exposure to COPCs volatilized from 

nearby areas on-Site. In this scenario, we have assumed that an avid jogger pushes a stroller 

along the Pinellas trail an average of 200 days per year for 30 years. The jogger makes several 

passes along the boundary of the Site and is exposed to COPCs in outdoor air for a total of 0.25 

hours per day. For childhood exposures used to estimate the ADD for noncarcinogens, we 

assume that the child accompanies the parent initially in the stroller and then on bicycle. The 

ADD received under this scenario is calculated according to equation (4-20). The LADD for

34 


DRAFT 

potential carcinogens is not calculated based on the childhood exposure duration because the 

LADD is higher (i.e., more protective) based on the longer-term exposure scenario for the adult. 

EPCs are provided in Table 5 and exposure factors are summarized in Table 6. Because the 

Pinellas Trail is located immediately adjacent to the Site, we have used on-Site groundwater 

concentrations to estimate outdoor air levels on the Pinellas Trail. 

Dose and risk calculations for potential exposures to COPCs by users of the Pinellas Trail via 

inhalation of outdoor air are provided in Appendix A; Table A-10. 

4.3.9 Apartment/Condo Complex Landscaper 

The Brandywine Apartments and Stone’s Throw Condominium Complex are located east of the 

Pinellas Trail. There are two irrigation wells on the Brandywine property and a single irrigation 

well on the Stone’s Throw Condominium property. All three irrigation wells are more than 200 

feet deep and cased to a minimum depth of 100 feet. The irrigation well on the Stone’s Throw 

Condominium property has been sampled over the past several years and no COPCs have 

been detected above FDEP GCTLs. 10 

Because existing irrigation wells are screened in the unaffected Floridan aquifer, no potential 

exposure pathways are complete for landscape/maintenance workers at the Brandywine 

Apartments and Stone’s Throw Condominium Complex. The only COPC detected in shallow 

groundwater in this area is 1,4-dioxane; however, volatilization from groundwater is not 

considered to be a complete exposure pathway for this COPC. 

4.3.10 Apartment/Condo Resident 

Similarly, because a clean water layer prevents potential volatilization of COPCs from 

underlying groundwater, no potential exposure pathways are complete for residents of the 

Brandywine Apartments and Stone’s Throw Condominium Complex. 

4.3.11 Apartment/Condo Construction/Utility Worker 

Dermal Contact with Groundwater. For the purpose of estimating potential risks to utility 

workers involved in subsurface excavation activities, it is assumed that a construction/utility 

worker may be dermally exposed to saturated soil and groundwater for 2 hours per day, 8 days 

per year for 10 years. It is assumed that the worker is wearing long pants, shoes and a shortsleeved 

shirt but the worker’s head, hands, and forearms could be exposed to groundwater. The 

dermally absorbed dose of COPCs received from contact with groundwater is calculated using 

equations (4-22) through (4-24) and the LADD is calculated using equation (4-21) with the 

exception that the ADD is replaced by the DAD. Exposure point concentrations for off-Site 

10 1,4-dioxane was detected at a concentration of 1.9 µg/L in April, 2008 but was not detected in a second, follow-up 

sample from the same well.

35 


DRAFT 

shallow groundwater are reported in Table 5 and exposure factors for off-Site utility/construction 


Dose and risk calculations for potential exposures to COPCs via dermal contact with exposed 

groundwater by off-Site construction/utility workers are provided in Appendix A; Table A-11. 

Incidental Ingestion of Soil. Some incidental ingestion of soil may occur during subsurface 

excavation activities. The average daily dose (ADD) from ingestion of soil is calculated using 

equation (4-25). The LADD is calculated using equation (4-21). Subsurface soil concentrations 

were estimated using equation (4-19) and exposure point concentrations for subsurface soils 

off-Site are reported in Table 5. Soil parameters were chosen to be consistent with a loamy 

sand with a dry soil bulk density of 1.62 L/kg and a volumetric water content of 39% for 

saturated soils. Exposure point concentrations for off-Site soils are reported in Table 5 and 

exposure factors for off-Site utility/construction workers are summarized in Table 6. 

Dose and risk calculations for potential exposures to COPCs via incidental ingestion of 

subsurface soil by off-Site construction/utility workers are provided in Appendix A; Table A-12. 

Inhalation of Air During Subsurface Excavation. If groundwater containing COPCs is 

exposed during the subsurface excavation activities, volatile constituents may be released to 

outdoor air. The ADD received from inhalation of outdoor air in the vicinity of the subsurface 

excavation is calculated according to equation (4-20) where the EPC is the concentration of 

COPCs in outdoor air as described in sections 4.2.5. The LADD is calculated using equation 

(4-21). Exposure point concentrations for off-Site outdoor air in the vicinity of subsurface 

excavation activities are reported in Table 5 and exposure factors for off-Site construction/utility 


Dose and risk calculations for potential exposures to COPCs via inhalation of outdoor air by off- 

Site construction/utility workers involved in subsurface excavation activities are provided in 

Appendix A; Table A-13. 

4.3.12 Off-Site Residents 

In off-Site areas above the area of impacted groundwater, residents may be exposed to COPCs 

via direct exposure to groundwater used for irrigation purposes via ingestion, dermal contact 

and inhalation. Additional potential exposure pathways for residential receptors include 

exposures to surface soil and ingestion of homegrown produce irrigated with groundwater. 

Dermal contact with irrigation water used for recreational purposes (to operate a sprinkler or fill 

a child’s wading pool) is also evaluated along with potential exposures from dermal contact with 

surface water. Because a clean water layer prevents potential volatilization of COPCs from 

underlying groundwater, indoor and outdoor air exposure pathways are considered to be 

incomplete. 

Use of Irrigation Water. In off-Site areas, the existence of an irrigation well can facilitate direct 

contact with COPCs in groundwater. A recent well survey conducted in 2008 identified a

36 


DRAFT 

number of irrigation wells located within a ½ mile radius of the Site. A program to identify 

additional wells and to test water samples from the wells is currently underway. Results from 

several wells are available at the time this report is being prepared and results received to date 

are presented in Table 11 of the SARA. In order to facilitate evaluation of potential risks from 

exposure to COPCs in groundwater collected from individual private irrigation wells, Risk-Based 

Screening Levels (RBSLs) have been developed for each potential exposure scenario 

associated with use of water from the home irrigation wells. 

RBSLs are calculated concentrations of COPCs in environmental media that are developed by 

combining toxicity data with exposure factors that are intended to represent reasonable 

maximum exposure (RME) conditions and be protective of human health. Because there are a 

number of uncertainties inherent in the development of RBSLs due to modeling approaches, 

assumptions regarding exposure, and the toxicity of particular constituents, input assumptions 

are intentionally selected to be conservative and health protective. Upon receipt of data, COPC 

concentrations that fall below the RBSL are considered to not pose a threat to human health. 

For risk assessment purposes, potential effects of COPCs are separated into two categories: 

carcinogenic and non-carcinogenic effects. For the purpose of calculating RBSLs to evaluate 

potential exposures to COPCs in irrigation water, we have selected a target theoretical excess 

cancer risk of 1 x 10 -6 (equivalent to one in a million) and an HQ of 1.0 for non-cancer effects 

consistent with the inputs used by FDEP in their calculation of Cleanup Target Levels in state 

cleanup programs. These criteria are discussed in further detail in Section 6 of this report. 

Ingestion of Irrigation Water. For the purpose of evaluating potential exposures to COPCs 

from ingestion of irrigation water, it is assumed that a resident drinks on average 0.12 liters of 

water from the irrigation well per day (equivalent to 4 ounces per day), two days per month (24 

days per year) for 30 years. This scenario is intended to evaluate potential exposures to 

individuals who may be involved in gardening or landscaping and take an occasional drink from 

the garden hose. The RBSL to protect against potential exposures from ingestion of irrigation 

water is calculated according to equation (4-26) for carcinogenic effects and (4-27) for noncarcinogenic 

effects, which follow the approach specified by FDEP for calculating Cleanup 

Target Levels. 

where: 

RBSL 

RBSL 

Ing 

Ing 

Risk ⋅ BW ⋅ ATc 

⋅ CF 

, c = 

(4-26) 

IR ⋅ EF ⋅ ED ⋅CSF 

o 

HQ ⋅ BW ⋅ ATn 

⋅ CF ⋅ RfD 

, n = 

(4-27) 

IR ⋅ EF ⋅ ED 

o 

RBSLing,c = Risk-Based Screening Level for ingestion of irrigation water, 

carcinogenic effects (µg/L) 

RBSLing,n = Risk-Based Screening Level for ingestion of irrigation water,

non-carcinogenic effects (µg/L) 

Risk = Theoretical excess cancer risk (1 x 10 -6 ) 


ATc = Averaging time for carcinogenic effects (days) 

CF = Conversion factor (1000 µg/mg) 

IRo = Irrigation water ingestion rate (L/day) 



CSF = Cancer Slope Factor (Risk per mg/kg-day) 

HQ = Hazard Quotient (1.0) 

ATn = Averaging time for non-carcinogenic effects (days) 

37 


Exposure factors are summarized in Table 6; toxicity values are presented in Table 8; and 

calculated RBSLs are provided in Table 9. 

DRAFT 

Dermal Contact with Irrigation Water. For residents involved in home gardening activities, it 

is assumed that a resident is exposed to irrigation water on average for 1 hour per day, 1 day 

per week (50 days per year) for 30 years. During those two hours, it is assumed that the 

resident’s head, hands, feet, forearms and lower legs could be exposed to irrigation water. The 

RBSL to protect against potential exposures from dermal contact with irrigation water is 

calculated according to equation (4-28) for carcinogenic effects and (4-29) for non-carcinogenic 

effects. 

where: 

and 

RBSL 

RBSL 

Derm 

Derm 

F 


⋅ CF 

, c = 

(4-28) 

F ⋅ EV ⋅ SA ⋅ EF ⋅ ED ⋅CSF 



, n = 

(4-29) 

F ⋅ EV ⋅ SA ⋅ EF ⋅ ED 

= 

6 ⋅τ 

event ⋅ tevent 

π 

2 ⋅ FA ⋅ K p 

if tevent ≤ t * (4-30) 

( ) ⎥ ⎥ ⎡ 

2 

t 

⎛ 

⎞⎤ 

event 1 + 3B 

+ 3B 

= FA ⋅ K ⎢ + 2 

⎜ 

⎟ 2 

⎢⎣ 

1 + B ⎝ 1 + B ⎠⎦ 

F p τ event 

if tevent > t * (4-31) 

RBSLDerm,c = Risk-Based Screening Level for dermal contact with irrigation 

water, carcinogenic effects (µg/L)

38 


RBSLDerm,n = Risk-Based Screening Level for dermal contact with irrigation 

CF = 

water, non-carcinogenic effects (µg/L) 

Conversion factor (1000 µg/mg x 1000 cm 3 /L) 

F = Calculation factor (cm/event) 

and all other parameters are as previously described for equations (4-23) and (4-24). 



DRAFT 

Inhalation of COPCs Volatilized During Irrigation. Potential exposures to COPCs volatilized 

to outdoor air during lawn irrigation were estimated using a number of conservative, health 

protective assumptions. For example, it is assumed that an individual stands downwind of the 

area being irrigated and emissions are constrained to within the breathing zone. Estimation of 

outdoor air concentrations during lawn irrigation is described in Section 4.2.7; RBSLs are 

calculated according to equations (4-32) for carcinogenic effects and (4-33) for noncarcinogenic 

effects. 

where: 

RBSL 

RBSL 

IrrAir 

IrrAir 


⋅ CF 

, c = 

(4-32) 

IR ⋅ ET ⋅ EF ⋅ ED ⋅CSF 

i 



, n = 

(4-33) 

IR ⋅ ET ⋅ EF ⋅ ED 

i 

RBSLIrrAir,c = Risk-Based Screening Level for inhalation of outdoor during lawn 

irrigation, carcinogenic effects (µg/L) 

RBSLIrrAir,n = Risk-Based Screening Level for inhalation of outdoor during lawn 

CF = 

irrigation, non-carcinogenic effects (µg/L) 

Conversion factor (1000 µg/mg) 

IRi = Inhalation rate – outdoor air (m 3 /hr) 


calculated RBSLs are provided in Table 9.

39 


DRAFT 

Ingestion of Homegrown Produce. For residents who maintain a home garden and irrigate 

their crops and/or trees with groundwater, potential exposures to COPCs could occur via 

ingestion of homegrown produce. Potential concentrations of COPCs in homegrown produce 

have been estimated for root crops and crops grown above ground using equations presented 

in Section 4.2.8. RBSLs are calculated according to equations (4-34) for carcinogenic effects 

and (4-35) for non-carcinogenic effects. 

where: 

RBSL 

RBSL 

Crop 

Crop 

Risk ⋅ BW ⋅ AT ⋅ CF 

, c = 

(4-34) 

c 

( RCF ⋅ IR + SCF ⋅ IR ) ⋅ EF ⋅ ED ⋅ CSF 

p, 

r 

p, 

a 

HQ ⋅ BW ⋅ AT ⋅ CF ⋅ RfD 

, n = 

(4-35) 

n 

( RCF ⋅ IR + SCF ⋅ IR ) ⋅ EF ⋅ ED 

p, 

r 

RBSLCrop,c = Risk-Based Screening Level for ingestion of homegrown produce, 

p, 

a 


RBSLCrop,n = Risk-Based Screening Level for ingestion of homegrown produce, 

non-carcinogenic effects (µg/L) 

IRp,r = Ingestion rate for homegrown root crops (kg/day) 

IRp,a = Ingestion rate for above-ground homegrown crops (kg/day) 

RCF = Root crop concentration factor (L/kg) 

SCF = Above-ground crop concentration factor (L/kg) 

For the purpose of estimating potential exposures to COPCs in homegrown produce, it is 

assumed that an individual consumes homegrown produce 350 days per year for 30 years. 

Daily average ingestion rates were obtained for protected and exposed aboveground produce 

and belowground produce from USEPA’s Exposure Factors Handbook (USEPA, 1997). These 

values were derived from the 1987-1988 USDA National Food Consumption Survey and 

corrected for preparation and cooking losses as recommended by USEPA (1997). 



Ingestion of Soil. For residents involved in gardening activities, hand-to-mouth activity can 

result in incidental ingestion of soil. Because there are no garden soil data, we have estimated 

potential soil concentrations using equation (4-19) presented in Section 4.2.9. RBSLs are

40 


calculated according to equations (4-36) for carcinogenic effects and (4-37) for noncarcinogenic 

effects. 

where: 

RBSL 

RBSL 

Soil 

Soil 

DRAFT 


⋅ CF 

, c = 

(4-36) 

IR ⋅ EF ⋅ ED ⋅CSF 

s 



, n = 

(4-37) 

IR ⋅ EF ⋅ ED 

RBSLSoil,c = Risk-Based Screening Level for ingestion of soil, carcinogenic 

effects (µg/L) 

RBSLCrop,n = Risk-Based Screening Level for ingestion of soil, non- 


IRs = Soil ingestion rate (kg/day) 

Exposure factors are summarized in Table 6. Average soil ingestion rates of 120 mg/day for a 

resident and 200 mg/day for a child are values recommended by FDEP (2005). Toxicity values 

are presented in Table 8; and calculated RBSLs are provided in Table 9. 

Recreational Use of Irrigation Water. In order to evaluate potential risks from use of irrigation 

water for recreational purposes, we have included two additional exposure scenarios: dermal 

exposure to irrigation water used to fill a child’s wading pool, and dermal exposure to irrigation 

water used to operate a sprinkler. 

Child Wading Pool Scenario. The child wading pool scenario considers a child ages 1 

to 6 who plays in a small wading pool filled with irrigation water for 2 hours per day, 50 days per 

year (about once per week), for 6 years. During each play event, we have also assumed that 

some incidental ingestion of irrigation water takes place equivalent to 50 milliliters. RBSLs are 

calculated as previously described according to equations (4-26) through (4-29). 

Child Sprinkler Scenario. The sprinkler scenario considers a slightly older child, ages 

2 to 11 plays in the sprinkler one hour per day, 50 days per year (about once per week) for 10 

years. During each play event, we have again assumed that some incidental ingestion of 

irrigation water takes place equivalent to 50 milliliters. RBSLs are calculated as previously 

described according to equations (4-26) through (4-29). 

s

5 Toxicity Assessment 

41 


DRAFT 

The toxicity assessment provides a characterization of the relationship between a dose of a 

COPC and the potential occurrence of an adverse health effect. The purpose of toxicity 

assessment is to provide a quantitative estimate of the inherent toxicity of COPCs for use in risk 

characterization. In risk assessments, extrapolation of actual toxicity information from high 

doses to low doses is necessary since environmentally relevant exposure concentrations for 

humans are typically much lower than experimental or occupational exposure concentrations 

where adverse effects were observed. Also, extrapolation of results from laboratory animals to 

humans is typically required. 

For risk assessment purposes, potential effects of COPCs are separated into two categories: 

carcinogenic and non-carcinogenic effects. This division relates to current USEPA policy that 

the mechanisms of action for these endpoints differ in all cases. COPCs that are believed to be 

carcinogenic also are capable of producing non-cancer health effects. In these instances, 

potential health risks for these constituents are evaluated for both cancer and non-cancer health 

effects as described below. 

The USEPA generally assumes that carcinogens do not exhibit a response threshold (i.e., dose 

below which no effect occurs), while non-carcinogenic effects are universally recognized as 

threshold phenomena (USEPA, 1986). Recent scientific evidence clearly indicates that this 

assumption is an oversimplification of carcinogenic responses. A growing number of 

substances have been shown to elicit carcinogenic effects in experimental animals via 

mechanisms that are: (a) not relevant to human biological processes; or (b) are not expected to 

occur in humans at significantly lower, environmentally relevant doses (James and Saranko, 

2000). For the purposes of this risk assessment, alternate approaches to characterizing 

potential cancer risk are not being used. 

Toxicity factors used in the development of Florida Cleanup target Levels (FDEP, 2005) will be 

used as the primary source of toxicity values. In the event no value is given, USEPA’s 

Integrated Risk Information System (IRIS) will be used. For constituents having no IRIS values, 

other USEPA toxicity values will be used including provisional values developed by the National 

Center for Environmental Assessment (NCEA) and values used in USEPA Region 9 Preliminary 

Remediation Goals (PRG) table (USEPA, 2004e). 

If a COPC has no chronic toxicity values, then the toxicity value from a surrogate chemical that 

is related both chemically and toxicologically will be used. Sources and derivation of toxicity 

values used in the calculations for this risk assessment are summarized in Table 13. The 

following sections describe the approaches used to evaluate the toxicity of the COPCs 

associated with the Site.

42 


DRAFT 

5.1 Toxicity Information for Carcinogenic Effects 

USEPA uses a two-step process for evaluating potential carcinogenic effects. First, the 

available scientific data are reviewed to determine if there is an association between the 

substance and cancer in humans or experimental animals. Based on this review, the substance 

is assigned a weight-of-evidence classification reflecting the likelihood that the substance is a 

human carcinogen. Second, a cancer slope factor (CSF) or unit risk factor (URF) is calculated 

for substances considered to be known or probable human carcinogens. Substances are 

classified by USEPA (2003) as follows: 

• carcinogenic to humans, 

• likely to be carcinogenic to humans, 

• suggestive evidence of carcinogenic potential, 

• inadequate information to assess carcinogenic potential, and 

• not likely to be carcinogenic to humans. 

Hypothetical risk estimates for potential carcinogens are estimated quantitatively using CSFs, 

which represent the theoretical increased risk per milligram of constituent intake per kilogram 

body weight per day (mg/kg-day) -1 , or unit risk factors, which are the theoretical increased risk 

at a defined exposure concentration. CSFs or unit risk factors are used to estimate a theoretical 

upper-bound lifetime probability of an individual developing cancer as a result of a particular 

exposure to a potential carcinogen. 

CSFs are developed most commonly based on a linearized multi-stage model used to estimate 

the 95% Upper Confidence Limit (UCL) linear slope. USEPA’s Draft Final Guidelines for 

Carcinogen Risk Assessment (2003) recommended that the linearized multistage model be 

employed in the absence of adequate information to the contrary, and that, in general, models 

that incorporate low-dose linearity are preferred. The 95% UCL slope of the dose-response 

curve is subjected to various adjustments and an inter-species scaling factor is usually applied 

to derive a CSF or unit risk factor for humans. The modeled extrapolations (CSFs) are 

expected to provide estimates of the upper limits on carcinogenic potency. The actual risks 

associated with exposure to a potential carcinogen are not likely to exceed the risks estimated, 

and may be much lower or even zero according to USEPA (2003). 

5.1.1 Oral and Dermal CSFs 

USEPA has developed CSFs specific to the oral route of exposure. In accordance with USEPA 

guidance (1989), this risk assessment uses route-to-route extrapolation to estimate dermal 

CSFs from the oral CSFs in order to estimate the risk associated with dermal contact with 

irrigation water. This extrapolation is done by dividing the oral CSF by a constituent-specific 

oral absorption factor. This factor represents the relationship between an administered dose

43 


DRAFT 

and an absorbed dose for the oral route, essentially estimating the dose that enters a receptor’s 

circulation and elicits a toxic effect. 

5.1.2 Inhalation Unit Risk Factors and CSFs 

The USEPA has developed inhalation unit risk factors to estimate carcinogenic risk for 

inhalation routes of exposure. In this risk assessment, inhalation unit risks (per mg/m 3 ) were 

converted to inhalation CSFs (per mg/kg-day) assuming an inhalation rate of 20 m 3 /day and an 

average adult body weight of 70 kg. In the absence of CSFs or URFs specific to the inhalation 

route, route-to-route extrapolation of oral CSFs to inhalation CSFs was employed. 

5.2 Toxicity Information for Non-carcinogenic Effects 

Non-carcinogenic effects are considered to be threshold phenomena. Adverse effects are not 

expected at a range of exposures and resulting doses below the threshold dose. The threshold 

dose for a compound is usually estimated from the no observed adverse effect level (NOAEL) or 

the lowest observed adverse effect level (LOAEL), as determined from animal studies or human 

data. These threshold values are adjusted downward through the application of uncertainty 

factors to estimate a protective reference dose (RfD) or reference concentration (RfC). 

Potential non-carcinogenic effects resulting from human exposures are generally estimated 

quantitatively by comparing RfDs and RfCs to the exposure anticipated from the site. USEPA 

specifies that the RfD or RfC is an estimate of the daily maximum level of exposure to human 

populations (including sensitive sub-populations) that is likely to be without an appreciable risk 

of deleterious effects during a lifetime (USEPA, 1989). 

5.2.1 Oral and Dermal RfDs 

Oral reference doses are expressed in units of daily dose (mg/kg-day) and incorporate 

uncertainty factors to account for limitations in the quality or quantity of available data. The oral 

RfD provides a benchmark against which human intakes (via ingestion) are compared. Where 

environmental exposure results in a dose lower than the RfD, then there is no appreciable risk 

for non-cancer health effects. Non-carcinogenic toxicity criteria are typically only available for 

oral and inhalation exposures. In this risk assessment, dermal RfDs were extrapolated from the 

oral values using constituent-specific oral absorption factors. In contrast to the route-to-route 

extrapolation described for the carcinogenic toxicity criteria in the previous section, the dermal 

RfD is extrapolated from the oral RfD by multiplying the oral RfD by the oral absorption factor. 

5.2.2 Inhalation RfCs 

For inhalation exposures, USEPA has derived reference concentrations (RfCs) for substances 

that are more likely to be associated with adverse non-carcinogenic effects by the inhalation 

route of exposure (e.g., volatile or irritant substances). If the concentration of a constituent in air 

to which a human is exposed is lower than the RfC then there is no appreciable risk for noncancer 

health effects from that exposure. In this risk assessment, RfCs (mg/m 3 ) were converted 

to inhalation RfDs (mg/kg-day) using a daily inhalation rate of 20 m 3 /day and a body weight of 

70 kg. This conversion allows a cumulative dose from all routes of exposure to be calculated.

6 Risk Characterization 

44 


DRAFT 

This section provides a characterization of the potential risks estimated for identified exposure 

pathways. Risk characterization integrates the estimated exposure information for site 

receptors with the representations of the potential toxicity derived for each COPC. Using 

standard USEPA-recommended approaches, this integration yields quantitative estimates of 

theoretical excess cancer and non-cancer risk for site-related COPCs. These conservative 

estimates provide a quantitative representation of the risks associated with the protectively 

estimated exposures associated with the Site. 

Risk estimates are calculated for individual COPCs for the complete exposure pathways 

associated with each assessed area. Per USEPA guidance, risk characterization also includes 

combining COPC-specific risk estimates across complete exposure pathways to provide overall 

characterizations of potential site-related risks (i.e., cumulative risks across all exposure 

pathways). 

Theoretical Excess Cancer Risks. Theoretical excess cancer risks for receptors are 

expressed as an estimated upper-bound probability of additional lifetime cancer risk due to 

exposure to site-related constituents. Thus these estimates do not reflect a receptor’s overall 

risk of cancer but rather are an upper bound estimate of the incremental risk that could 

theoretically be attributed to exposure to site COPCs. 

Theoretical excess cancer risks are calculated for those COPCs identified as potential 

carcinogens by the USEPA. They are calculated for each COPC for each complete exposure 

pathway, by receptor. The upper-bound estimate of excess risk related to each COPC is 

calculated by multiplying the lifetime average daily dose estimated for that COPC by its 

corresponding route-specific cancer slope factor (USEPA, 1989). 

where: 

Riskex = theoretical excess lifetime cancer risk 

LADD = lifetime average daily dose 

CSF = cancer slope factor 

Risk ex = LADD x CSF 

(6-1) 

Overall theoretical excess cancer risks for complete pathways and receptors were estimated by 

summing all COPC-specific risk estimates. This form of summation incorporates the 

assumption that carcinogenic risks from multiple constituent exposures are additive. This health 

protective assumption ensures that excess lifetime cancer risks for each COPC, pathway and 

receptor risk estimates are theoretical upper-bound estimates (i.e., the actual risk is very 

unlikely to be higher and is expected to be much lower).

45 


DRAFT 

USEPA Superfund guidance (USEPA, 1991a) directs that risk managers consider excess 

cancer risks within the range of one-in-ten thousand (1 x 10 -4 ) and one-in-one million (1 x 10 -6 ) 

to be acceptable depending upon site-specific considerations. This range of risk is generally 

referred to as the “acceptable risk range” under the USEPA National Contingency Plan. Under 

this federal policy, regulators have discretion to require risk management measures. 

Incremental risks greater than 1 x10 -4 generally oblige regulators to require some form of risk 

management. In contrast, incremental risks less than 1 x 10 -6 are widely considered to be de 

miminis risks, not requiring management. A risk level of one in a million is often referred to as a 

“point of departure” or a level of risk where the estimated level of risk and its attendant exposure 

assumptions and estimated exposure concentrations are taken into account and the need for 

risk management is evaluated. In Florida, the risk level of 1 x 10 -6 is the target risk level used in 

setting health protective cleanup levels. 

Potential Non-cancer Risks. Potential non-cancer risks for individual COPCs are expressed 

as hazard quotients (HQs) (USEPA, 1989). HQs are calculated as the ratio of the estimated 

daily intake of each COPC to the corresponding route-specific RfD. HQs are calculated as 

follows: 

where: 

HQ 

ADD = average daily dose (mg/kg-day) 

RfD = reference dose (mg/kg-day) 

ADD 

= 

RfD 

When the average daily dose estimated from site-associated soil constituents exceeds the 

protective RfD, the HQ exceeds one. This typically is considered a circumstance requiring 

further evaluation since it indicates that exposure could be higher than the “no-effect” dose 

represented by the RfD. An HQ higher than one does not necessarily indicate a significant 

potential for non-cancer effects, however, since both the average daily dose and RfD are 

intended to be conservative estimations. An HQ higher than 1.0 suggests that further 

consideration should be given to the likelihood for potential non-cancer effects. 

When the HQ does not exceed 1.0, the average daily dose estimated from site-related soil 

constituents is not greater than the conservative RfD, indicating that exposure is expected to be 

below the threshold required to produce effects and the likelihood of realizing a non-cancer 

effect from that COPC is negligible. 

To summarize potential non-cancer risks for multiple COPCs across complete exposure 

pathways, and across receptors, HQs are summed to arrive at a Hazard Index (HI). The 

resulting HI serves as a conservative health protective summary of pathway and receptor risks, 

since summing all of the individual COPC HQs incorporates the assumption that their risks are 

all additive. In fact, different COPCs may act through different mechanisms and on different 

target organs. The overall HIs are useful for rapidly excluding pathways or receptors with 

(6-2)

46 


DRAFT 

negligible potential for non-cancer effects – where all the COPC HQs added together do not 

exceed an HI of one. 

6.1 Risk Summary 

Potential risks are summarized by receptor and exposure scenario in this section of the report. 

Theoretical excess cancer risks are calculated for those COPCs identified as carcinogens by 

the USEPA, for each complete exposure pathway, by receptor. Overall theoretical excess 

cancer risks are estimated by summing all COPC-specific risk estimates for each receptor type. 

Potential non-cancer risks for individual COPCs are reported as HQs and summed across 

complete exposure pathways for each receptor type as an overall hazard index. 

6.1.1 On-Site Facility Worker 

Potential risks to on-Site facility workers are summarized below; COPC-specific risks are 

provided in Appendix A; Table A-1. As described in Section 4.2.1, potential risks to current 

facility workers were estimated based on the maximum concentration of each of the COPCs 

detected in indoor air within Buildings A, E and M. 

Potential Risks to On-Site Facility Workers 

Exposure 

Non-Cancer 

Excess 

Pathway 


Inhalation of Indoor Air 1 x 10 -1 3 x 10 -6 

Total Excess Cancer Risk 3 x 10 -6 

Hazard Index 1 x 10 -1 

The cumulative theoretical excess cancer risk is calculated to be 3 x 10 -6 , which is at the low 

end of the range of risks (10 -4 to 10 -6 ) that is considered to be acceptable by USEPA. As 

indicated in Table A-1, the majority of the risk is attributed to exposure to benzene and 

chloroform. Both are ubiquitous chemicals in the environment and the concentrations detected 

in indoor air on-Site are similar to typical indoor air levels. Therefore, these concentrations do 

not necessarily result from volatilization of on-Site COPCs. 

Chloroform was detected at a maximum concentration of 0.001 mg/m 3 in one sample collected 

from within Building M. The average concentration of chloroform detected in all three buildings 

on-Site was 0.00033 mg/m 3 . These levels are similar to typical indoor air concentrations. The 

Agency for Toxic Substances and Disease Registry (ATSDR) reports that typical median indoor 

air concentrations range from 0.001 to 0.02 mg/m3 (ATSDR, 1997). The primary source of 

chloroform in indoor air is chlorinated tap water (ATSDR, 1997). Chloroform represents a

47 


DRAFT 

significant fraction of total trihalomethanes in drinking water and total trihalomethanes detected 

in drinking water provided by the City of St. Petersburg range from 0.0093 to 0.0165 mg/L 11 . 

Benzene is a component of gasoline and is released to the atmosphere in automobile exhaust. 

The maximum concentration detected in indoor air at the Site was 0.0016 mg/m 3 . This is within 

the range of benzene concentrations detected in outdoor air on-Site and in samples collected at 

Azalea Park by Pinellas County as part of the National Air Toxics Trends (NATTS) program. 

For example, over the past three years of monitoring, benzene concentrations detected by 

Pinellas County ranged from 0.00019 to 0.00283 mg/m 3 at Azalea Park and 0.00017 to 0.00474 

mg/m 3 at the Skyview Elementary Monitoring Station (see Table 4). Thus, indoor air benzene 

concentrations are within the range of concentrations detected in outdoor air. 

Non-cancer risk estimates for on-Site facility workers are below a hazard index of one (HI = 

0.1), indicating that exposures are below levels that could result in adverse health effects. 

6.1.2 On-Site Landscape Worker 

Potential risks to on-Site landscape workers are summarized below; COPC-specific risks are 

provided in Appendix A; Table A-2. On-Site maintenance workers are assumed to spend on 

average 150 days per year at the Site performing landscaping and general maintenance 

activities. Potential risks from exposure to outdoor air are based on estimated values as 

described in Section 4.2.2. 

Potential Risks to On-Site Landscape Workers 

Exposure 

Non-Cancer 

Excess 

Pathway 


Inhalation of Outdoor Air 1 x 10 -2 1 x 10 -6 


Hazard Index 1 x10 -2 

The cumulative theoretical excess cancer risk for on-Site maintenance workers is calculated to 

be 1 x 10 -6 and the non-cancer hazard index is 0.01. Both risk estimates are similar to the 

values calculated for the on-Site facility worker. The theoretical excess cancer risk is at the low 

end of the range of risks (10 -4 to 10 -6 ) that is considered to be acceptable by USEPA and the 

hazard index is below 1.0, indicating that exposures are below levels that could result in 

adverse health effects. 

Potential risks from exposure to outdoor air are based on modeled outdoor air concentrations 

derived from maximum groundwater or soil vapor concentrations detected on-Site. Because the 

highest concentrations of COPCs in groundwater and soil vapor are located beneath the 

11 http://www.dep.state.fl.us/water/drinkingwater/chemdata.htm

48 


DRAFT 

existing buildings on-Site, the risk estimates presented above more accurately reflect potential 

future conditions if the existing buildings are removed. Current risks from exposure to outdoor 

air are expected to be much lower because existing buildings prevent volatilization to outdoor 

air in the areas with the highest groundwater and soil vapor concentrations. 

6.1.3 On-Site Trespasser 

Potential risks to on-Site trespassers are summarized below; COPC-specific risks are provided 

in Appendix A; Table A-3. Potential risks from exposure to outdoor air are based on estimated 

outdoor air levels assuming volatilization from the most concentrated part of the area of 

impacted groundwater. Because this area is located beneath the existing buildings on-Site, 

current risks are expected to be much lower than those reported below. 

Potential Risks to On-Site Trespassers 

Exposure 

Non-Cancer 

Excess 

Pathway 





The cumulative theoretical excess cancer risk estimate based on modeled outdoor air 

concentrations is 5 x 10 -8 . This value is well below the range of risks that is considered to be 

acceptable by USEPA and below the FDEP criterion of 1 x 10 -6 . Similarly, non-cancer risk 

estimates are many times below a hazard index of one (HI = 0.001), supporting the conclusion 

that exposures are substantially below levels that could result in adverse health effects. 

6.1.4 On-Site Construction Worker 

Potential risks to on-Site construction workers are summarized below; COPC-specific risks are 

provided in Appendix A; Tables A-4, A-5 and A-6. Potential risks to on-Site construction 

workers assume that a worker may be dermally exposed to groundwater for 2 hours per day, 20 

days per year (4 weeks) over a six month (125-day) construction event. Dermal exposure to 

groundwater, incidental ingestion of saturated soils, and inhalation of COPCs volatilized from 

groundwater is assumed to take place during the 20 days when the excavation is open. Once 

the excavation is closed, it is assumed that these exposure pathways are no longer complete.

Potential Risks to On-Site Construction Workers 

Exposure 

Pathway 

49 

Non-Cancer 

Hazard Quotient 


Excess 

Cancer Risk 


Dermal Contact with Groundwater 9 x 10 -2 8 x 10 -7 

Ingestion of Subsurface Soil 2 x 10 -2 5 x 10 -8 



DRAFT 

The cumulative theoretical excess cancer risk estimate based on modeled outdoor air 

concentrations is 9 x 10 -7 . This value is below the range of risks (10 -4 to 10 -6 ) used by USEPA 

as a point of departure for concluding that risks are unacceptable. Similarly, non-cancer risk 

estimates are below a hazard index of 1.0 (HI = 0.1), supporting the conclusion that exposures 

are below levels that could result in adverse health effects. 

6.1.5 On-Site Utility Worker 

Potential risks to on-Site utility workers are summarized below; COPC-specific risks are 

provided in Appendix A; Tables A-7, A-8 and A-9. Potential risks to on-Site utility workers 

assume that a worker may be dermally exposed to groundwater for 2 hours per day, 8 days per 

year (2 days per event and 4 events per year) over a period of 10 years. 

Potential Risks to On-Site Utility Workers 

Exposure 

Pathway 

Non-Cancer 


Excess 



Dermal Contact with Groundwater 1 x 10 -2 1 x 10 -6 

Ingestion of Subsurface Soil 3 x 10 -3 8 x 10 -8 



The cumulative theoretical excess cancer risk estimate is 1 x 10 -6 . This value is at the lower 

end of the range of risks (10 -4 to 10 -6 ) considered to be acceptable by USEPA. Similarly, noncancer 

risk estimates are below a hazard index of 1.0 (HI = 0.02), supporting the conclusion that 

exposures are below levels that could result in adverse health effects.

6.1.6 Azalea Park Landscape/Maintenance Workers 

50 


DRAFT 

Currently, the City of St. Petersburg maintains the ballfields and landscaping at Azalea Park 

using reclaimed water supplied by the City and there are no irrigation wells in use at the park. 

In addition, a shallow clean water layer prevents potential volatilization of COPCs from 

underlying groundwater so no potential exposure pathways are complete for Azalea Park 

landscape workers. 

6.1.7 Azalea Park Ball Player and Visitor to Azalea Park Recreation Center 

Ballplayers and other individuals participating in recreational activities at the park could also be 

exposed to COPCs that have volatilized to outdoor air. However, as previously mentioned, a 

shallow clean water layer prevents potential volatilization of COPCs from underlying 

groundwater so no potential exposure pathways are complete for Azalea Park ball players and 

workers/visitors to the Recreation Center. 

6.1.8 Pinellas Trail User 

Potential risks calculated for a frequent user of the Pinellas Trail are summarized below; COPCspecific 

risks are provided in Appendix A; Table A-10. The primary exposure pathway is 

inhalation of outdoor air. To be conservative, we have use onsite outdoor air concentrations for 

evaluating potential risks to Pinellas Trail users. 

Potential Risks to Pinellas Trail Users 

Exposure 

Non-Cancer 

Excess 

Pathway 





Under current exposures, the theoretical excess cancer risk is 2 x 10 -7 . This value is well below 

the range of risks (10 -4 to 10 -6 ) considered to be acceptable by USEPA and below the FDEP 

criterion of 1 x 10 -6 . Similarly, non-cancer risk estimates are many times below an HI of 1.0, 

supporting the conclusion that exposures are substantially below levels that could result in 


Note that potential risks to users of the Pinellas Trail are based on modeled outdoor air 

concentrations derived from maximum groundwater or soil vapor concentrations detected on- 

Site. Because the highest concentrations of COPCs in groundwater and soil vapor are located 

beneath the existing buildings on-Site, the risk estimates presented above more accurately 

reflect potential future conditions if the existing buildings are removed. Current risks from 

exposure to outdoor air are expected to be much lower because existing buildings prevent

51 


volatilization to outdoor air in the areas with the highest groundwater and soil vapor 

concentrations. 

DRAFT 

6.1.9 Apartment/Condo Complex Landscapers 

There are two irrigation wells on the Brandywine property and a single irrigation well on the 

Stone’s Throw Condominium property. All three irrigation wells are more than 200 feet deep 

and cased to a minimum depth of 100 feet. Because existing irrigation wells are screened in 

the unaffected Floridan aquifer, no potential exposure pathways are complete for 

landscape/maintenance workers at the Brandywine Apartments and Stone’s Throw 

Condominium Complex. The only COPCs detected in shallow groundwater in this area are 

benzene and 1,4-dioxane; however, volatilization from groundwater is not considered to be a 

complete exposure pathway for this COPC and benzene was detected in only one shallow 

monitoring well (SMW-4) that, in prior sampling events, contained no benzene. Screening 

calculations indicate that, even if this concentration is not an artifact, potential risks from 

exposure to benzene in indoor and outdoor air are negligible. 

6.1.10 Apartment/Condo Complex Construction/Utility Worker 

Potential risks to apartment/condo construction/utility workers are summarized below; COPCspecific 

risks are provided in Appendix A; Tables A-11, A-12 and A-13. Potential risks to off- 

Site utility workers assume that a worker may be dermally exposed to groundwater for 2 hours 

per day, 8 days per year (2 days per event and 4 events per year) over a period of 10 years. 

The only COPC present in shallow groundwater is 1,4-dioxane at a maximum concentration of 

7.7 µg/L. 

Potential Risks to Off-Site Apartment/Condo Construction/Utility Workers 

Exposure 

Pathway 

Non-Cancer 


Excess 


Inhalation of Outdoor Air NA 12 1 x 10 -12 

Dermal Contact with Groundwater NA 3 x 10 -9 

Ingestion of Subsurface Soil NA 1 x 10 -14 


Hazard Index NA 

The cumulative theoretical excess cancer risk estimates based on modeled outdoor air 

concentrations is 3 x 10 -9 . This value is well below the range of risks (10 -4 to 10 -6 ) considered to 

be acceptable by USEPA and below the FDEP criterion of 1 x 10 -6 . No non-cancer Hazard 

12 There is no reference dose available for 1,4-dioxane.

52 


DRAFT 

Index has been calculated because there are no non-cancer toxicity reference values available 

for 1,4-dioxane. 

6.1.11 Apartment/Condo Residents 

Because a clean water layer prevents potential volatilization of COPCs from underlying 

groundwater, no potential exposure pathways are complete for residents of the Brandywine 

Apartments and Stone’s Throw Condominium Complex. The only COPCs detected in shallow 

groundwater in this area are benzene and 1,4-dioxane; however, volatilization from groundwater 

is not considered to be a complete exposure pathway for 1,4-dioxane and benzene was 

detected in only one shallow monitoring well (SMW-4) that, in prior sampling events, contained 

no benzene. Screening calculations indicate that, even if this concentration is not an artifact, 

potential risks from exposure to benzene in indoor and outdoor air are negligible. 

6.1.12 Off-Site Residents (other than Brandywine and Stone’s Throw) 

Because a clean water layer prevents potential volatilization of COPCs from underlying 

groundwater, no potential indoor and outdoor air exposure pathways are complete for offsite 

residents. Potential risks from exposure to COPCs in irrigation water to off-Site residents are 

summarized in Section 6.2. As previously indicated, potential risks from exposure to COPCs in 

irrigation water are treated differently, using an RBSL approach, so that potential risks can be 

evaluated separately based on individual irrigation well sampling results. 

6.2 Comparison to RBSLs 

A risk-based screening level approach is used to evaluate potential risks from exposure to 

COPCs in irrigation water because sampling of the irrigation wells is an ongoing process. As 

previously described, RBSLs are COPC concentrations that are intended to represent 

reasonable maximum exposure (RME) conditions and be protective of human health and/or the 

environment. COPC concentrations that fall below the RBSL are considered not to pose a 

threat to human health. If the concentration of COPC detected in an irrigation well exceeds the 

RBSL, then further characterization of the potential exposure is warranted. 

As indicated in Table 11 of the SARA, the only Site-related COPCs detected above GCTLs thus 

far in off-Site irrigation wells are 1,4-dioxane, TCE and cis-1,2-DCE at maximum concentrations 

of 32, 65 and 77 µg/L, respectively. The RBSLs calculated to protect against potential 

exposures to these three COPCs from ingestion of irrigation water are summarized below. As a 

matter of reference, a complete list of RBSLs for all COPCs is provided in Table 9.

53 


DRAFT 

Calculated RBSLs (µg/L) for Potential Exposures to 1,4-Dioxane, TCE and cis-1,2- 

DCE in Irrigation Water 

Exposure 

RBSL (µg/L) 

Pathway 1,4-Dioxane TCE cis-1,2-DCE 

Ingestion of Irrigation Water 670 670 10,200 

Dermal Contact while Gardening 29,900 650 31,300 

Inhalation during Lawn Irrigation 14,400 3,200 29,000 

Ingestion of Homegrown Produce 522 205 29,500 

Dermal Contact (Wading Pool Scenario) 2,320 416 6,360 

Dermal Contact (Sprinkler Scenario) 2110 410 9,860 

Ingestion of Irrigation Water. For the purpose of evaluating potential exposures to COPCs 

from ingestion of irrigation water, it is assumed that a resident drinks on average 0.12 liters per 

day (equivalent to 4 ounces per day), two days per month (24 days per year) for 30 years. This 

scenario is intended to evaluate potential exposures to individuals who may be involved in 

gardening or landscaping and take a drink from the garden hose. As indicated above, 

maximum concentrations detected in residential irrigation wells to-date indicate that an 

occasional sip from the irrigation well does not pose a health threat from COPCs. 

Dermal Contact while Gardening. Potential dermal exposure to COPCs may occur for 

residents using irrigation water during home gardening activities. Under this scenario, it is 

assumed that a resident is exposed to irrigation water on average for 1 hours per day, 1 day per 

week (50 days per year) for 30 years. During this hour, it is assumed that the resident’s head, 

hands, feet, forearms and lower legs could be exposed to irrigation water. The calculated 

RBSLs for 1,4-dioxane, TCE and cis-1,2-DCE are 29900, 650 and 31300 µg/L, respectively, 

which are well above maximum concentrations detected to date in residential irrigation wells. 

Inhalation of COPCs during Lawn Irrigation. The lawn irrigation scenario assumes that the 

resident is standing downwind during lawn irrigation for one hour per day, 50 days per year, for 

30 years. As shown in the table above, calculated RBSLs to protect against potential 

exposures to COPCs from inhalation during lawn irrigation are well above maximum 

concentrations detected in residential wells. 

Ingestion of Homegrown Produce. Under this scenario we have assumed that a resident 

ingests 237 grams per day (about ½ pound per day; 183 pounds per year) for 30 years. These 

estimates were obtained from USEPA’s Exposure Factors Handbook and are based on a 7-day 

USDA survey of consumers of homegrown produce living in the South (USEPA, 1997). 

Maximum concentrations detected in residential irrigation wells to-date are all below RBSLs that 

have been calculated based on the plant uptake model presented by Ryan et al. (1988).

54 


DRAFT 

Recreational Use of Irrigation Water. In order to evaluate potential risks from use of irrigation 

water for recreational purposes, we have included two additional exposure scenarios: dermal 

exposure to irrigation water used to fill a child’s wading pool, and dermal exposure to irrigation 

water used to operate a sprinkler. The child wading pool scenario considers children ages 1 to 

6 who play in a small wading pool filled with irrigation water for 2 hours per day, 50 days per 

year (about once per week), for 6 years. The sprinkler scenario considers slightly older 

children, ages 2 to 11 play in the sprinkler one hour per day, 50 days per year (about once per 

week) for 10 years. During each play event, we have again assumed that some incidental 

ingestion of irrigation water takes place equivalent to 50 milliliters and children are exposed via 

inhalation as well. RBSLs calculated for these two scenarios are well above maximum 

concentrations of COPCs detected in residential irrigation wells. 

These calculations also indicate that there is no threat to health under lesser exposure 

scenarios such as walking barefoot across a freshly watered lawn or playing on the lawn after 

watering. We also considered a swimming pool scenario in which a resident swims for 1 hour 

per day, 100 days per year for 30 years. The calculated RBSLs for 1,4-dioxane, TCE and cis- 

1,2-DCE are 680, 88 and 7,260 µg/L, respectively, which are all above maximum concentrations 

detected to date in residential irrigation wells. Note that these RBSLs do not account for 

volatilization of COPCs during filling and from the pool surface. 

Surface Water Contact. The potential risk from exposure to 1,4-dioxane detected in the 

surface water drainage canal along Farragut Drive North was evaluated assuming a child is 

dermally exposed to the maximum detected concentration (0.009 mg/L) by wading in the canal 

for 2 hours per day, one day per week, for 10 years. Under this scenario, the potential risk from 

dermal contact with 1,4-dioxane is 5 x 10 -10 , which is well below any level of concern. 

6.3 Potential Ecological Risks 

The only COPCs detected in the surface water drainage canal along Farragut Drive North were 

1,4-dioxane at a maximum concentration of 8.9 µg/L and cis-1,2-DCE at 0.68 µg/L. The 

concentration of 1,4-dioxane is well below the FDEP surface water cleanup target levels of 120 

µg/L, which is developed based on the protection of human health (ingestion of fish). USEPA 

Region V lists an Ecological Screening Level (ESL) for 1,4-dioxane of 22,000 µg/L. 13 USEPA 

Region 4 lists acute and chronic surface water toxicity screening values for cis-1,2-DCE of 606 

and 24.4 µg/L, respectively. 14 

Pet Exposure Scenario. Toxicity reference values for evaluating potential risks to pets from 

exposure to irrigation water used for drinking water purposes are lacking. To be protective, 

irrigation water concentrations should be compared to human risk standards, and in those 

cases where irrigation water is found to be in excess of the FDEP drinking water standards, 

pets should be supplied with an alternative potable water source (i.e. tap water). 

13 http://www.epa.gov/reg5rcra/ca/ESL.pdf 

14 http://www.epa.gov/region4/waste/ots/ecolbul.htm#tbl1

7 Uncertainty Analysis 

55 


DRAFT 

Uncertainties are inherent in quantitative risk assessment due to the use of environmental 

sampling results, modeling approaches, assumptions regarding exposure, and the toxicity of 

particular constituents. This risk assessment has incorporated site-specific information where 

feasible, in order to reduce the uncertainty associated with those assumptions. Analysis of the 

critical areas of uncertainty in risk assessment provides context for better understanding the 

assessment conclusions by identifying the uncertainties expected to most significantly affect the 

results. 

7.1 Site Characterization Data 

A large amount of data has been collected to characterize the nature and extent of constituents 

present in environmental media at the Site and in the surrounding area, yet some uncertainties 

remain and where they do, upper bound estimates have been used so as not to understate any 

potential risk. 

Indoor and Ambient Air Concentrations Represent a Snapshot in Time. Indoor air samples 

were collected from the three main buildings on-Site over a limited number of days. Although 

these data were collected during the winter when soil vapor intrusion is expected to be greatest, 

they represent a snapshot in time and may not be representative of concentrations present at 

other times of the year under different ventilation conditions. To be conservative and account 

for expected variability in indoor air conditions, exposure point concentrations in indoor air are 

based on maximum detected COPC concentrations. 

Calculated Risks to On-Site Facility Workers May Reflect Exposures to Non-Site Sources. 

Potential risks from exposure to COPCs in indoor air may reflect a significant contribution from 

non-Site sources (e.g. chloroform from drinking water and benzene from automobiles) because 

risks are based on measured values. Indoor air is constantly being replaced by outdoor air and 

constituents typically present in outdoor air will also be detected in indoor air. In addition 

common solvents in cleaning products and disinfection byproducts in drinking water can be a 

source of volatiles in indoor air (Rappaport and Kupper, 2004). Thus potential risks to on-Site 

facility workers, which are based on measured indoor air concentrations, may reflect 

contributions from non-Site sources. 

Measured Ambient Air Concentrations Reflect Contributions from Many Sources. 

Ambient air samples collected at the Site and in the surrounding neighborhoods reflect potential 

contributions from multiple sources. For example, emissions from automobiles are a significant 

source of benzene in outdoor air and day to day concentrations can vary significantly due to 

changes in local traffic conditions (Batterman et al., 2002). PCE is also commonly found in 

outdoor air due to its widespread use as a drycleaning agent. A comparison of ambient air 

concentrations detected at the Pinellas County Skyview Elementary monitoring station indicates 

that alternative sources exist for most of the COPCs at this Site (see Table 8). TCE is a COPC 

at the Site; however, according to the 2000 Air Toxics Inventory for Pinellas County, Florida 

(Pinellas County Environmental Management, 2003), there are other emission sources in the

56 


DRAFT 

area that as of the time of the inventory continued to emit this constituent in amounts up to 7.87 

tons per year. 

TCE was detected at low levels (1.2 µg/m 3 ) in two samples collected on-Site northeast and 

northwest of Building M on November 20, 2007 with winds out of the northeast. TCE was also 

detected in six of six ambient air samples collected off-Site to the south and southeast of the 

facility on December 4, 2007 when winds were blowing steadily out of the north at 3 to 6 miles 

per hour. Concentrations ranged from 9 to16 µg/m 3 . However no TCE was detected in followup 

samples collected from the same area on January 14, 2008 when winds were blowing out of 

the north, and no TCE was detected in ambient air samples collected on-Site over three days of 

sampling in April, 2008 when winds were blowing out of the north and east. TCE was detected 

in only one other sample, which was collected near the Azalea Park Recreation Center. 

TCE concentrations detected in Azalea Park over the past three years (2005, 2006 and 2007) 

ranged from non-detect to 0.16 µg/m 3 (see Table 8). These data reflect 24-hour average 

concentrations recorded every 6 days over the past three years (from 2005 to 2007) and 

provide a more representative indication of average conditions in the park near the tennis 

courts. 

For comparison, the maximum concentration of TCE estimated in outdoor air on-Site is 0.14 

µg/m 3 . This value was used as the average exposure point concentration for estimating 

potential long-term exposures to on-Site maintenance workers, on-Site trespassers and users of 

the Pinellas Trail. Similarly, the estimated outdoor air concentration generated during lawn 

irrigation with groundwater containing 0.046 mg/L TCE 15 is 0.7 µg/m 3 . When converted to a 24hour 

average basis, this estimated value falls within the range of values detected in Azalea Park 

by Pinellas County. 

Cone Penetrometer Samples May Overestimate Well Concentrations. Groundwater 

concentrations in samples collected using Cone Penetrometer Technology (CPT) may 

overestimate irrigation and monitoring well concentrations because CPT samples are collected 

from narrow, discrete zones in the aquifer (immediately surrounding the probe tip) whereas 

wells are typically screened over a much wider zone (five to ten feet, or open borehole) that 

allows for dilution with cleaner water. Use of these data may result in an overestimation of 

potential risks to on-Site workers from exposure to groundwater. 

7.2 Exposure Assessment 

Under the standard approach to exposure assessment recommended by the USEPA, if a 

constituent is found to be present at a site, it is generally assumed that exposure to that 

substance will occur. The human health risk assessment attempts to make use of Site-specific 

exposure information where available. Uncertainties associated with the exposure assessment 

include calculation of exposure point concentrations and selection of exposure parameters. 

15 The highest concentration of TCE detected in off-Site groundwater as of May 23, 2008 is 0.065 mg/L.

57 


DRAFT 

Use of Maximum Detected Concentrations. The maximum detected concentration of a 

constituent was used as the exposure point concentration (EPC) or used to estimate the EPC. 

Use of the maximum detected concentration is a highly conservative estimate of exposure 

which, when combined with a number of upper percentile exposure assumptions, leads to a 

very conservative estimate of potential risk. This was the case for all constituents detected in 

groundwater, soil vapor and indoor air. 

Use of Default Exposure Factors. Although effort has been taken to apply Site-specific and 

receptor-specific exposure factors, for those with limited data, FDEP and USEPA defaults were 

used. These recommended defaults are also based on limited data and are chosen to 

represent conservative estimates. For example, it is assumed that residents are exposed to 

indoor air for 22 hours per day, 350 days per year for 30 years – neglecting time away from 

home at work or at school. We have also conservatively assumed that residents ingest up to 

one half of a pound of homegrown produce every day, 350 days per year for 30 years. 

Use of Health Protective Assumptions. In order to arrive at an upper bound estimate of 

potential risks associated with use of irrigation water we have used a number of conservative, 

health protective assumptions. We have assumed that residents are standing outdoors, 

downwind of lawn irrigation activities each time the lawn is watered. We have also assumed 

that residents take a drink from the hose, once every two weeks for 30 years. Use of these 

assumptions increases the overall uncertainty associated with estimates of COPC intake. The 

intentional conservatism makes it unlikely that exposures are underestimated. 

7.3 Toxicity Assessment 

The toxicity information used in the health risk assessment is a substantial source of 

uncertainty. The uncertainties specific to the toxicity assessment are associated with: (1) the 

toxicity studies that form the basis for the toxicity values recommended by USEPA and (2) the 

lack of sufficient toxicity data to develop toxicity values for certain substances. 

USEPA Toxicity Values. The toxicity values (i.e., RfDs and CSFs) used in this risk 

assessment were developed by the USEPA and FDEP for regulatory purposes and are 

intended to represent upper-bound estimates of potential toxicity. For example, most of the 

RfDs incorporate large uncertainty factors are intended to lie well below the true threshold for 

toxicity in humans. While this helps ensure the protectiveness of decisions based on the RfD, it 

should be recognized that a dosage exceeding the RfD (i.e., a HQ > 1.0) does not necessarily 

indicate the likelihood for toxicity. Similarly, the CSFs developed by the USEPA incorporate a 

number of conservative choices in risk extrapolation. These include the assumption of a linear, 

non-threshold dose-response relationship for cancer, interpretation of animal carcinogenicity 

data, and dose-metrics for extrapolation of results from rodents to humans. As a result, cancer 

risk estimates using these values reflect conservative upper bound estimates of risk associated 

with specific exposures. 

In summary, there are uncertainties in any risk assessment. These uncertainties are primarily 

associated with lack of known human health effects directly attributable to constituents at 

concentrations encountered in the environment. Therefore, risk analyses rely on health 

protective (conservative) assumptions based on available studies and exposure scenarios.

8 Conclusions 

58 


DRAFT 

A risk assessment was completed for potential exposures to Site-related COPCs in 

groundwater, soil and indoor and outdoor air at and near the Site. Potential human health risks 

were characterized based on COPC concentrations detected during the most recent rounds of 

groundwater monitoring conducted from March 2007 through May 2008. Exposure pathways 

were evaluated for current and likely future exposures to COPCs in groundwater, soil and indoor 

and outdoor air. Potential receptors included on-Site and off-Site workers, trespassers, off-Site 

residents and individuals involved in recreational activities along the Pinellas Trail. 

In addition, RBSLs were developed for a number of potentially complete exposure pathways 

involving residential use of irrigation water. Potentially complete exposure pathways include 

ingestion of irrigation water, ingestion of homegrown produce, dermal contact with irrigation 

water while gardening and during recreational use, and inhalation of COPCs volatilized from 

irrigation water to outdoor air during lawn irrigation. 

Calculated non-cancer and theoretical excess cancer risk estimates for the potential exposure 

pathways evaluated in this report support the following conclusions: 

• The cumulative theoretical excess cancer risk to on-Site facility workers is calculated to 

be 3 x 10 -6 , which is at the lower end of the range of risks that is considered to be 

acceptable by USEPA. It should be noted that these risks are based in part on COPCs 

that may not be associated with subsurface conditions or historic site uses (i.e. benzene 

and chloroform). Measured indoor air levels are well below OSHA standards governing 

worker safety. Non-cancer risk estimates for on-Site facility workers are below a hazard 

index of one (HI = 0.1) indicating that exposures are below levels that could result in 


• The cumulative theoretical excess cancer risk for on-Site landscape workers is 

calculated to be 1 x 10 -6 , which is at the low end of the range of risks that is considered 

to be acceptable by USEPA and the non-cancer hazard index is 0.01. Both risk 

estimates are similar to the values calculated for the on-Site facility worker. The 

theoretical excess cancer risk and the hazard index is below 1.0, indicating that 

exposures are below levels that could result in adverse health effects. 

• The cumulative theoretical excess cancer risk to on-Site trespassers is 5 x 10 -8 which is 

well below the range of risks that is considered to be acceptable by USEPA and below 

the FDEP criterion of 1 x 10 -6 . Similarly, non-cancer risk estimates are many times 

below a hazard index of one (HI = 0.001), supporting the conclusion that exposures are 

substantially below levels that could result in adverse health effects. 

• Potential risks to on-Site construction and utility workers is 9x10 -7 and 1x10 -6 , 

respectively, which are within or below the range of risks that is considered to be 

acceptable by USEPA. Similarly, non-cancer risk estimates are below a hazard index of


1.0 supporting the conclusion that exposures are below levels that could result in 


59 

DRAFT 

• The cumulative theoretical excess cancer risk to off-Site construction workers is 3 x 10 -9 

which is well below the range of risks that is considered to be acceptable by USEPA 

and below the FDEP criterion of 1 x 10 -6 . 

• At Azalea Park, no potential exposure pathways are complete for 

landscape/maintenance workers, individuals involved in recreational activities, or 

Recreation Center workers because there are no irrigation wells in use at the park and 

because a shallow clean water layer prevents potential volatilization of COPCs from 

underlying groundwater. 

• No potential exposure pathways are complete for residents of the Brandywine 

Apartments and Stone’s Throw Condominiums because existing irrigation wells are 

screened in the unaffected Floridan aquifer and the only COPC detected in the shallow 

aquifer on these properties is 1,4-dioxane, which is miscible and exhibits low volatility in 

water and therefore does not present a health threat from volatilization to indoor and 

outdoor air. 

In addition, no COPC concentrations detected in residential irrigation wells to-date 

exceeded RBSLs for any of the potentially complete exposure pathways involving use of 

irrigation water. These data suggest that based on residential irrigation well data collected 

to date, there is no significant health threat from exposure to irrigation water.

References 

60 


DRAFT 

Agency for Toxic Substances & Disease Registry (ATSDR). 1997. Toxicological Profile for 

Chloroform. 

ARCADIS Geraghty and Miller, 1998. Contamination Assessment Report, Raytheon E-Systems 

Facility, 1501 72 nd Street North, St. Petersburg Florida, OGC Case No. 93-4374. 

ATSDR. 2004. Draft Toxicological Profile for 1,4-Dioxane. US Department of Health and 

Human Services, Public Health Service, Agency for Toxic Substances and Disease 

Registry. September. 

Batterman, S.A., C-Y Peng and J. Braun. 2002. Levels and composition of volatile organic 

compounds on commuting routes in Detroit, Michigan. Atmospheric Environment 36: 6015- 

6030. 

Briggs, G.G., R.H. Bromilow and A.A. Evans. 1982. Relationships between lipophilicity and 

root uptake and translocation of non-ionised chemicals by barley. Pesticide Science 

13:495-504. 

Briggs, G.G., R.H. Bromilow, A.A. Evans and M. Williams. 1983. Relationships between 

lipophilicity and the distribution of non-ionised chemicals in barley shoots following uptake 

by roots. Pesticide Science 14: 492-500. 

FDEP. 2005. Technical Report: Development of Cleanup Target Levels (CTLs) for Chapter 62- 

777, F.A.C. Prepared for Division of Waste Management by Center for Environmental & 

Human Toxicology, University of Florida, Gainesville, FL. February. 

Fitzpatrick, N.A. and J.J. Fitzgerald. 1996. An evaluation of vapor intrusion into buildings 

through a study of field data. Paper presented at the 11 th annual Conference on 

Contaminated Soils, University of Massachusetts at Amherst, October. 

Hers, I., R. Zapf-Gilje, L. Li, and J. Atwater. 2001. The use of indoor air measurements to 

evaluate intrusion of subsurface VOC vapors into buildings. J. Air & Waste Manage. Assoc. 

51: 1318-1331. 

James, R.C. and C.J. Saranko. 2000. Carcinogenesis. In: Principles of Toxicology: 

Environmental and Industrial Applications, 2nd Edition. (Williams, P.L, James, R.C., and 

Roberts, S.M., eds), New York: John Wiley and Sons. 

Jury, W.A., D. Russo, G. Streile, and H. El Abd. Evaluation of volatilization of organic chemicals 

residing below the soil surface. Water Resources Research 26(1): 13-20. 

Klaassen, C.D., ed. 1996. Casarett and Doull's Toxicology: The Basic Science of Poisons, 3rd 

edition. Casarett and Doull, eds. MacMillan Publishing, New York.

61 


DRAFT 

Lyman, W.J., W.F. Reehl, and D.H. Rosenblatt. 1990. Handbook of Chemical Property 

Estimation Methods: Environmental Behavior of Organic Compounds. American Chemical 

Society, Washington, DC. 

Mackay, D. and R.S. Matsugu. 1973. Evaporation rates of liquid hydrocarbon spills on land 

and water. Canadian J. Chem Eng. 51:434. 

McKone, T.E. 1987. Human exposure to volatile organic compounds in household tap water: 

The indoor inhalation pathway. Environmental Science & Technology 21(12):1194 – 1201. 

Nazaroff, W.W. 1992. Radon transport from soil to air. Reviews of Geophysics 30(2): 137-160. 

Pinellas County Environmental Management. 2003. 2000 Air Toxics inventory for Pinellas 

County, Florida. August. 

Rappaport, S.M. and L.L. Kupper. 2004. Variability of environmental exposures to volatile 

organic compounds. Journal of Exposure Analysis and Environmental Epidemiology 14:92- 

107. 

Ryan, J.A., R.M. Bell, J.M. Davidson and G.A. O’Connor. 1988. Plant uptake of non-ionic 

organic chemicals from soils. Chemosphere 17: 2299-2323. 

USEPA. 1986. Guidelines for Carcinogenic Risk Assessment. Federal Register. 51:33992. 

USEPA. 1987. Hazardous Waste Treatment, Storage and Disposal Facilities (TSDF) – Air 

Emission Models, Documentation. EPA-450/3-87-026. 

USEPA. 1989. Risk Assessment Guidance for Superfund – Volume I. Human Health 

Evaluation Manual (Part A). Interim Final. EPA/540/1-89/002. 

USEPA. 1991a. Risk Assessment Guidance for Superfund. Volume I. Part B. Development of 

Risk-Based Remediation Goals. Office of Emergency and Remedial Response. OSWER 

Directive 9285.7-018. 

USEPA. 1991b. Role of the Baseline Risk Assessment in Superfund Remedy Selection 

Decisions. OSWER Directive 9355.0-30. 

USEPA. 1996b. Proposed Guidelines for Carcinogen Risk Assessment. Office of Research and 

Development. EPA/600/P-92/003C. April. 

USEPA. 1997. Exposure Factors Handbook – Volume I – General Factors. Update to 

EPA/600/8-89/043. Office of Research and Development, National Center for 

Environmental Assessment. Washington, DC. August. 

USEPA. 2000. Supplemental Guidance to RAGS: Region 4 Bulletins, Human Health Risk 

Assessment Bulletins. EPA Region 4, originally published November 1995, Website version 

last updated May 2000: http://www.epa.gov/region4/waste/ots/healtbul.htm.


USEPA. 2002a. Child-Specific Exposure Factors Handbook. Interim Report. September. 

EPA-600-P-00-002B. 

62 

DRAFT 

USEPA. 2002b. Supplemental Guidance for Developing Soil Screening Levels for Superfund 

Sites. Office of Emergency and Remedial Response. OSWER 9355.4-24. December. 

USEPA. 2003. Draft Final Guidelines for Carcinogenic Risk Assessment. EPA/630/P-03/001A, 

NCEA-F-0644A www.epa.gov/ncea/raf/cancer2003.htm 

USEPA. 2004a. Johnson & Ettinger (1991) Model for Subsurface Vapor Intrusion Into 

Buildings. 

USEPA. 2004b. An Examination of EPA Risk Assessment Principles and Practices. Staff 

paper prepared for the U.S. Environmental Protection Agency by Members of the Risk 

Assessment Task Force. Office of the Science Advisor, Washington, DC. March. 

USEPA. 2004c. User’s Guide for Evaluating Subsurface Vapor Intrusion into Buildings. 

Prepared by Environmental Quality Management, Inc. for USEPA Office of Emergency and 

Remedial Response, Washington, DC. February. 

USEPA. 2004d. Risk Assessment Guidance for Superfund – Volume I: Human Health 

Evaluation Manual (Part E, Supplemental Guidance for Dermal Risk Assessment) Final. 

Office of Superfund Remediation and Technology Innovation. Washington, DC. July. 

EPA/540/R/99/005 OSWER 9285.7-02EP, PB99-963312. 

USEPA. 2004e. Region IX PRG Table. http://www.epa.gov/region09/waste/sfund/prg/ .

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Tables

DRAFT 

Table 1. Constituents of Potential Concern in On-Site Groundwater 

Constituent Carcinogen? 

Number of 

Samples 

Number of 

Detects 

Detection 

Frequency 

(%) 

Range of 

Detection 

Limits 

Min of Detected 

Concentrations 

Max of Detected 


Mean of Detected 

Concentrations GCTL 

Detection 

Frequency > 

5% 

Max Above 

Screening 

Criterion? 

Retain as 

COPC? 


Basis for Elimination as 

COPC 

1,1,1-Trichloroethane N 61 13 21.3 1 - 10 2.5 4900 643 200 Yes Yes Yes 

1,1,2-Trichloroethane Y 61 3 4.9 1 - 25 0.96 130 45.8 5 No Yes Yes 

1,1-Dichloroethane N 61 27 44.3 1 1 2300 291 70 Yes Yes Yes 

1,1-Dichloroethene N 61 24 39.3 1 0.53 2300 363 7 Yes Yes Yes 

1,2,4-Trimethylbenzene N 57 3 5.3 1 - 50 1.5 31 11.6 12 Yes Yes Yes 

1,2-Dichloropropane Y 61 1 1.6 1 - 50 160 160 160 5 No Yes Yes 


1,4-Dichlorobenzene Y 64 2 3.1 1 - 50 9.7 53 31.35 75 No No No A, B 

1,4-Dioxane Y 62 14 22.6 1 - 50 0.8 100 26.5 3.2 Yes Yes Yes 

4-Methyphenol N 3 1 33.3 10 4.6 4.6 4.6 3.5 Yes Yes No 

Acenaphthene N 3 1 33.3 2 1.1 1.1 1.1 20 Yes No No B 

Acetone N 57 2 3.5 20 - 500 19 890 454.5 6300 No Yes Yes 

Organic Benzene Y 61 2 3.3 1 - 50 0.56 0.85 0.71 1 No No No A, B 

Constituents Carbon Disulfide N 57 7 12.3 1 - 50 1.2 16 7.1 700 Yes No Yes 

(µg/L) Chlorobenzene N 61 1 1.6 1 - 50 1 1 1 100 No No No A, B 

Chloroethane Y 61 5 8.2 5 - 250 4.7 180 63.7 12 Yes Yes Yes 

Chloroform Y 61 8 13.1 1 - 10 1.1 2600 387 70 Yes Yes Yes 

cis-1,2-Dichloroethene N 61 26 42.6 1 1.1 1200 246 70 Yes Yes Yes 

Ethylbenzene N 61 11 18.0 1 - 10 1.3 390 74.1 30 Yes Yes Yes 

Fluorene N 3 1 33.3 2 1.1 1.1 1.1 280 Yes No No B 

Isopropylbenzene N 57 4 7.0 1 - 50 0.29 48 12.9 0.8 Yes Yes Yes 

m-Dichlorobenzene N 64 2 3.1 1 - 50 6.9 19 12.9 210 No No No A, B 

Methylene chloride Y 61 2 3.3 5 - 250 22 30 26 5 No Yes Yes 

m-Xylene & p-Xylene N 61 13 21.3 2 - 10 0.72 1400 196 20 Yes Yes Yes 

N-Propylbenzene N 57 1 1.8 1 - 50 2.3 2.3 2.3 240 No No No A, B 

o-Xylene N 61 12 19.7 1 - 10 0.61 440 71.3 20 Yes Yes Yes 

Phenol N 3 1 33.3 10 8.4 8.4 8.4 10 Yes Yes Yes 

Tetrachloroethene Y 61 2 3.3 1 - 50 1.4 77 39.2 3 No Yes Yes 

Toluene N 61 10 16.4 1 - 10 1.1 4700 868 40 Yes Yes Yes 

trans-1,2-Dichloroethene N 61 14 23.0 1 - 50 0.62 110 13.6 100 Yes Yes Yes 

Trichloroethene Y 61 28 45.9 1 0.6 810 138 3 Yes Yes Yes 

Trichlorofluoromethane N 61 2 3.3 5 - 250 6.1 6.3 6.2 2100 No No No A, B 

Vinyl chloride Y 61 27 44.3 1 0.72 1800 274 1 Yes Yes Yes 

Aluminum N 3 3 100.0 NA 0.24 0.46 0.343333333 200 Yes No No B 

Arsenic (total) Y 3 1 33.3 0.01 0.0063 0.0063 0.0063 10 Yes No No B 

Barium N 3 3 100.0 NA 0.02 0.034 0.029 2000 Yes No No B 

Boron N 3 3 100.0 NA 0.11 0.22 0.156666667 1400 Yes No No B 

Calcium N 3 3 100.0 NA 96 180 135 NA Yes NA No C 

Chromium N 3 2 66.7 0.01 0.0033 0.0092 0.00625 100 Yes No No B 

Inorganic Cobalt N 3 1 33.3 0.01 0.002 0.002 0.002 140 Yes No No B 

Constituents Copper (total) N 3 1 33.3 0.02 0.083 0.083 0.083 1000 Yes No No B 

(mg/L) Iron N 3 3 100.0 NA 0.065 2.4 1.028333333 300 Yes No No B 

Lead N 3 1 33.3 0.005 0.0019 0.0019 0.0019 15 Yes No No B 

Magnesium N 3 3 100.0 NA 7.1 39 22.4 NA Yes NA No C 

Manganese N 3 3 100.0 NA 0.018 0.1 0.05 50 Yes No No B 

Molybdenum N 3 1 33.3 0.01 0.013 0.013 0.013 35 Yes No No B 

Potassium N 3 3 100.0 NA 3.5 29 16 NA Yes NA No C 

Silver N 3 1 33.3 0.01 0.0036 0.0036 0.0036 100 Yes No No B 

Sodium N 3 3 100.0 NA 38 400 226 160 Yes Yes No C 

Strontium N 3 3 100.0 NA 0.47 1.6 0.99 4200 Yes No No B 

Titanium N 3 2 66.7 0.01 0.0012 0.0019 0.00155 28000 Yes No No B 

Vanadium N 3 1 33.3 0.01 0.02 0.02 0.02 49 Yes No No B 

Zinc (total) N 3 2 66.7 0.02 0.089 0.12 0.1045 5000 Yes No No B 

Notes: A Constituent is infrequently detected 

B Maximum concentration is below screening level 

C Constituent is an essential dietary mineral with nutritive value 

ENVIRON Page 1 of 1

DRAFT 

Table 2. Constituents of Potential Concern in Off-Site Groundwater 

Constituent Carcinogen? 

Number of 

Samples 

Number of 

Detects 

Detection 

Frequency 

(%) 

Range of 

Detection 

Limits 

Min of Detected 


Max of Detected 


Mean of 

Detected 

Concentrations GCTL 

Detection 

Frequency > 

5% 

Max Above 

Screening 

Criteria? 


Retain as 

COPC? Basis for Elimination as COPC 

1,1-Dichloroethane N 413 34 8.2 1 - 250 0.55 450 44.6 70 Yes Yes Yes 

1,1-Dichloroethene N 413 25 6.1 1 - 450 0.5 450 44.3 7 Yes Yes Yes 


1,2-Dichloroethane Y 413 2 0.5 1 - 250 3.3 17 10.2 3 No Yes Yes 

1,3,5-Trimethylbenzene N 405 10 2.5 1 - 250 1.2 1.6 1.4 12 No Yes No A 

1,4-Dioxane Y 415 143 34.5 1 - 3 0.62 1400 79.0 3.2 Yes Yes Yes 

2-Butanone (MEK) N 405 2 0.5 10 - 2500 11 14 12.5 4200 No No No A, B 

4-Methyl-2-pentanone (MIBK) N 405 2 0.5 10 - 2500 20 160 90.0 560 No Yes No A, B 

Acetone N 405 17 4.2 10 - 5000 9.9 82 21.9 6300 No No No B 

Benzene Y 413 30 7.3 1 - 250 0.55 9.7 2.1 1 Yes Yes Yes 

Carbon Disulfide N 405 30 7.4 1 - 250 0.9 3.9 1.8 700 Yes No No B 

Chloroform Y 413 2 0.5 1 - 250 1.2 2.6 1.9 70 No No No A, B 

chloromethane Y 413 4 1.0 4 - 1000 1.8 3.3 2.6 2.7 No Yes No A, C 

cis-1,2-Dichloroethene N 413 62 15.0 1 - 10 0.68 1300 90.8 70 Yes Yes Yes 

Ethylbenzene N 413 27 6.5 1 - 250 0.65 4.8 2.2 30 Yes Yes Yes 

Isopropylbenzene N 405 4 1.0 1 - 250 1 1.1 1.1 0.8 No Yes Yes 

Methyl tert-butyl ether N 413 4 1.0 1 - 250 0.66 2.2 1.2 20 No Yes No A, B 

Methylene chloride Y 413 8 1.9 4 - 1300 4.1 10 6.0 5 No Yes Yes 

m-Xylene & p-Xylene N 413 27 6.5 2 - 500 1.5 14 5.4 20 Yes Yes Yes 

N-Propylbenzene N 405 1 0.2 1 - 250 1.3 1.3 1.3 240 No No No A, B 

o-Xylene N 413 24 5.8 1 - 250 0.88 6.8 2.8 20 Yes Yes Yes 

Toluene N 413 47 11.4 1 - 250 0.54 84 7.0 40 Yes Yes Yes 

trans-1,2-Dichloroethene N 413 12 2.9 1 - 250 0.5 23 4.7 100 No Yes No A, B 

Trichloroethene Y 413 55 13.3 1 - 10 0.59 18000 775.0 3 Yes Yes Yes 

Vinyl chloride Y 413 27 6.5 1 - 100 0.71 660 80.8 1 Yes Yes Yes 

Notes: A Constituent is infrequently detected 

B Maximum concentration is below GCTL 

C Constituent is unlikely to be site-related 

ENVIRON Page 1 of 1

DRAFT 

Table 3. Comparison Between Indoor Air and Subslab Soil Vapor Concentrations 

Detected in Buildings Onsite 

Soil Vapor Indoor Air 

Concentration (µg/m3) 

Building ID Sample ID Sample ID Constituent Indoor Air Soil Vapor 

Bldg E SV-21 0711339A-06A Acetone 51 29 

Bldg E SV-65 0711339A-04A Acetone 49 17 

Bldg E SV-21 0711339A-06A Toluene 11 11 

Bldg E SV-21 0711339A-06A Methyl Ethyl Ketone 8.4 5.2 

Bldg E SV-64 0711462A-20A Methyl Ethyl Ketone 3.9 4.3 

Bldg E SV-21 0711339A-06A m,p-Xylene 3.4 4.9 

Bldg M SV-4 0711339A-01A Trichloroethene 3.2 280000 

Bldg M SV-7 0711339A-07A Trichloroethene 1.9 43000 

Bldg M SV-4 0711339A-01A cis-1,2-Dichloroethene 1.7 68000 

Bldg E SV-65 0711339A-04A 1,1,1-Trichloroethane 1.5 10 

Bldg M SV-7 0711339A-07A cis-1,2-Dichloroethene 1.3 200000 

Bldg E SV-64 0711462A-20A Chlorofrom 1 8.5 

Bldg M SV-62 0711339A-08AA 1,1,1-Trichloroethane 0.96 24000 

Bldg M SV-62 0711339A-08A 1,1,1-Trichloroethane 0.96 23000 


Bldg E SV-64 0711462A-20A Tetrachloroethene 0.91 17 


Bldg E SV-64 0711462A-20A 1,1,1-Trichloroethane 0.73 8.5 

Bldg E SV-64 0711462A-20A Trichloroethene 0.72 38 

Bldg M SV-6 0711339A-02A Tetrachloroethene 0.64 7.6 

Bldg E SV-21 0711339A-06A Chlorofrom 0.64 6.2 

Bldg M SV-7 0711339A-07A trans-1,2-Dichloroethe 0.61 20000 

Bldg E SV-21 0711339A-06A Tetrachloroethene 0.61 8.2 

Bldg M SV-4 0711339A-01A trans-1,2-Dichloroethe 0.6 17000 

Bldg M SV-6 0711339A-02A Carbon Disulfide 0.48 4.8 

Bldg E SV-19 0711339A-03A 1,1,1-Trichloroethane 0.41 11 

Bldg M SV-4 0711339A-01A 1,1-Dichloroethene 0.38 2100 

Bldg M SV-4 0711339A-01A 1,1-Dichloroethane 0.34 6200 

Bldg M SV-62 0711339A-08AA 1,1-Dichloroethene 0.33 520 




Bldg M SV-6 0711339A-02A 1,1-Dichloroethane 0.29 4.9 

Bldg M SV-62 0711339A-08AA 1,1-Dichloroethane 0.28 1100 


Bldg M SV-62 0711339A-08AA Chlorofrom 0.25 92 

Bldg M SV-62 0711339A-08A Chlorofrom 0.25 92 

Bldg M SV-6 0711339A-02A Chlorofrom 0.18 5.5 

ENVIRON Page 1 of 1 

Human Health Risk Assessment

DRAFT 


Table 4. Summary of Ambient Air Sampling Data Collected at Azalea Park and Skyview Elementary as part of 

the National Air Toxics Trends (NATTS) Program 2005-2007 

Azalea Park 

Skyview Elementary 

Min Median Max Min Median Max 

Constituent 

Count (µg/m3) (µg/m3) (µg/m3) Count (µg/m3) (µg/m3) (µg/m3) 

Freon-12 168 1.61 2.71 3.72 518 1.01 2.67 4.08 

chloromethane 177 0.94 1.28 2.02 545 0.89 1.31 2.96 

Freon 114 177 0.00 0.14 0.36 545 0.00 0.14 0.78 

Vinyl chloride 177 0.00 0.00 0.05 545 0.00 0.00 0.05 

1,3-butadiene 177 0.01 0.11 0.74 545 0.02 0.13 1.12 

bromomethane 177 0.00 0.08 0.95 545 0.00 0.08 0.72 

chloroethane 177 0.00 0.03 0.13 545 0.00 0.03 0.13 

Freon 11 176 0.78 1.57 11.65 541 1.13 1.62 11.48 

Acrylonitrile 177 0.05 0.24 0.66 545 0.00 0.20 0.79 

1,1-dichloroethene 177 0.00 0.00 0.08 545 0.00 0.00 0.12 

Methylene chloride 177 0.17 0.30 1.91 545 0.16 0.33 1.49 

Freon 113 176 0.39 0.62 1.32 541 0.00 0.62 1.32 

1,1-dichloroethane 177 0.00 0.00 0.08 545 0.00 0.00 0.12 

cis-1,2-dichloroethene 177 0.00 0.00 0.10 545 0.00 0.00 0.12 

chloroform 177 0.00 0.15 2.63 545 0.00 0.15 0.60 

1,2-dichloroethane 177 0.00 0.05 0.12 545 0.00 0.07 0.21 

1,1,1-trichloroethane 177 0.06 0.11 15.81 545 0.00 0.11 0.28 

Benzene 177 0.19 0.65 2.83 545 0.17 0.84 4.74 

Carbontetrachloride 177 0.32 0.54 0.77 545 0.32 0.55 0.77 

1,2-dichloropropane 177 0.00 0.00 0.09 545 0.00 0.00 0.09 

Trichloroethene 177 0.00 0.00 0.16 545 0.00 0.00 0.33 

cis 1,3-dichloropropene 177 0.00 0.00 0.09 545 0.00 0.00 0.09 

trans 1,3-dichloropropene 177 0.00 0.00 0.19 545 0.00 0.00 0.09 

1,1,2-Trichloroethane 177 0.00 0.00 0.17 545 0.00 0.00 0.19 

Toluene 177 0.28 1.69 58.94 545 0.41 2.64 18.39 

1,2-Dibromoethane 177 0.00 0.00 0.16 545 0.00 0.00 0.16 

Tetrachloroethene 176 0.00 0.14 0.76 543 0.00 0.16 2.21 

Chlorobenzene 177 0.00 0.00 0.11 545 0.00 0.00 0.09 

Ethyl benzene 177 0.04 0.26 1.28 545 0.06 0.40 2.60 

m/p Xylene 177 0.11 0.79 4.24 545 0.13 1.19 8.74 

styrene 177 0.00 0.13 1.59 545 0.00 0.22 4.68 

o-Xylene 177 0.00 0.28 1.32 545 0.08 0.42 2.87 

1,1,2,2-Tetrachloroethane 177 0.00 0.00 0.14 545 0.00 0.00 0.14 

1,3,5-Trimethylbenzene 177 0.00 0.11 0.60 545 0.00 0.15 1.05 

1,2,4-Trimethylbenzene 174 0.07 0.44 2.25 537 0.10 0.60 4.65 

1,3-Dichlorobenzene 177 0.00 0.00 0.12 545 0.00 0.00 0.18 



1,2,4-Trichlorobenzene 165 0.00 0.00 0.27 509 0.00 0.00 1.60 

Hexachlorobutadiene 163 0.00 0.00 0.26 503 0.00 0.00 1.89 

ENVIRON Page 1 of 1

DRAFT 

Table 5. Estimated Exposure Point Concentrations 


Indoor Air Outdoor Air Excavation Air Subsurface Soil Shallow GW Excavation Air Subsurface Soil Shallow GW 

Carcinogens (mg/m 3 ) (mg/m 3 ) (mg/m 3 ) (mg/kg) (mg/L) (mg/m 3 Onsite Offsite 

) (mg/kg) (mg/L) 

benzene 1.6E-03 3.8E-08 2.8E-06 1.2E+00 8.5E-04 0.0E+00 0.0E+00 0.0E+00 

chloroethane 0.0E+00 6.9E-05 6.7E-04 5.0E-01 1.8E-01 0.0E+00 0.0E+00 0.0E+00 

chloroform 1.0E-03 8.2E-05 8.8E-03 8.3E+01 2.6E+00 0.0E+00 0.0E+00 0.0E+00 

1,2-dichloroethane 0.0E+00 0.0E+00 0.0E+00 1.5E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 

1,2-dichloropropane 0.0E+00 2.1E-06 4.9E-04 1.1E-01 1.6E-01 0.0E+00 0.0E+00 0.0E+00 

1,4-dioxane 0.0E+00 7.2E-12 7.4E-05 7.7E+01 1.0E-01 7.7E-07 2.8E-04 7.7E-03 

methylene chloride 1.3E-03 6.4E-07 1.1E-04 3.2E+01 3.0E-02 0.0E+00 0.0E+00 0.0E+00 

tetrachloroethene 8.9E-04 1.3E-05 2.3E-04 1.4E-01 7.7E-02 0.0E+00 0.0E+00 0.0E+00 

1,1,2-trichloroethane 0.0E+00 1.7E-07 4.0E-04 9.6E-02 1.3E-01 0.0E+00 0.0E+00 0.0E+00 

trichloroethene 3.2E-03 4.8E-05 2.6E-03 2.9E+02 8.1E-01 0.0E+00 0.0E+00 0.0E+00 


NonCarcinogens 

0.0E+00 2.8E-03 7.0E-03 1.3E+01 1.8E+00 0.0E+00 0.0E+00 0.0E+00 

acetone 5.6E-02 1.3E-08 2.7E-03 1.4E+01 8.9E-01 0.0E+00 0.0E+00 0.0E+00 

benzene 1.6E-03 3.8E-08 2.8E-06 1.2E+00 8.5E-04 0.0E+00 0.0E+00 0.0E+00 

carbon disulfide 2.1E-03 2.1E-05 5.4E-05 7.7E-01 1.6E-02 0.0E+00 0.0E+00 0.0E+00 

chloroethane 0.0E+00 6.9E-05 6.7E-04 5.0E-01 1.8E-01 0.0E+00 0.0E+00 0.0E+00 

chloroform 1.0E-03 8.2E-05 8.8E-03 8.3E+01 2.6E+00 0.0E+00 0.0E+00 0.0E+00 

1,1-dichloroethane 4.5E-04 1.3E-04 8.1E-03 2.0E+01 2.3E+00 0.0E+00 0.0E+00 0.0E+00 

1,2-dichloroethane 0.0E+00 0.0E+00 0.0E+00 1.5E+00 0.0E+00 0.0E+00 0.0E+00 0.0E+00 

1,1-dichloroethene 9.2E-04 1.8E-03 8.0E-03 5.1E+01 2.3E+00 0.0E+00 0.0E+00 0.0E+00 

cis-1,2-dichloroethene 1.7E-03 4.0E-05 4.4E-03 7.1E+01 1.2E+00 0.0E+00 0.0E+00 0.0E+00 

trans-1,2-dichloroethene 7.2E-04 1.2E-05 4.2E-04 2.2E-01 1.1E-01 0.0E+00 0.0E+00 0.0E+00 

1,2-dichloropropane 0.0E+00 2.1E-06 4.9E-04 1.1E-01 1.6E-01 0.0E+00 0.0E+00 0.0E+00 

1,4-dioxane 0.0E+00 7.2E-12 7.4E-05 7.7E+01 1.0E-01 0.0E+00 0.0E+00 0.0E+00 

ethylbenzene 1.8E-03 6.4E-06 1.1E-03 1.5E+00 3.9E-01 0.0E+00 0.0E+00 0.0E+00 

isopropylbenzene 0.0E+00 2.6E-06 1.3E-04 1.2E-01 4.8E-02 0.0E+00 0.0E+00 0.0E+00 

methyl ethyl ketone 1.3E-02 0.0E+00 0.0E+00 1.2E+01 0.0E+00 0.0E+00 0.0E+00 0.0E+00 

methyl isobutyl ketone 1.2E-03 0.0E+00 0.0E+00 2.1E+01 0.0E+00 0.0E+00 0.0E+00 0.0E+00 

methylene chloride 1.3E-03 6.4E-07 1.1E-04 3.2E+01 3.0E-02 0.0E+00 0.0E+00 0.0E+00 

4-methylphenol 0.0E+00 3.8E-14 1.2E-06 5.3E-03 4.6E-03 0.0E+00 0.0E+00 0.0E+00 

phenol 0.0E+00 3.9E-09 9.9E-07 4.4E-03 8.4E-03 0.0E+00 0.0E+00 0.0E+00 

tetrachloroethene 8.9E-04 1.3E-05 2.3E-04 1.4E-01 7.7E-02 0.0E+00 0.0E+00 0.0E+00 

toluene 7.5E-01 1.2E-04 1.4E-02 4.7E+01 4.7E+00 0.0E+00 0.0E+00 0.0E+00 

1,1,1-trichloroethane 1.0E-03 1.0E-03 1.5E-02 2.9E+01 4.9E+00 0.0E+00 0.0E+00 0.0E+00 

1,1,2-trichloroethane 0.0E+00 1.7E-07 4.0E-04 9.6E-02 1.3E-01 0.0E+00 0.0E+00 0.0E+00 

trichloroethene 3.2E-03 4.8E-05 2.6E-03 2.9E+02 8.1E-01 0.0E+00 0.0E+00 0.0E+00 

1,2,4-trimethylbenzene 0.0E+00 2.7E-08 8.4E-05 1.2E+00 3.1E-02 0.0E+00 0.0E+00 0.0E+00 

1,3,5-trimethylbenzene 0.0E+00 4.2E-07 1.5E-04 4.7E-01 5.6E-02 0.0E+00 0.0E+00 0.0E+00 

xylenes 1.2E-02 2.2E-05 5.3E-03 7.9E+00 1.8E+00 0.0E+00 0.0E+00 0.0E+00 

vinyl chloride 0.0E+00 2.8E-03 7.0E-03 1.3E+01 1.8E+00 0.0E+00 0.0E+00 0.0E+00 

ENVIRON Page 1 of 1

DRAFT 

Receptor Population Value Source 

IRia,w 3 

Inhalation rate (m /hr) 0.83 FDEP (2005); equivalent to 20 m 3 /day 

ET Exposure Time (hr/day) 8 Assumes 8-hour work day 

EF 

ED 

Exposure frequency (day/yr) 

Exposure duration (yr) 

250 

25 

FDEP (2005); default assumption 


BWw Body weight (kg) 76.1 FDEP (2005); value for workers (derived from NHANES III data) 

AT Averaging time (days) 9,125 FDEP (2005); default assumption (AT = ED) 

IRoa,w 3 

Inhalation rate – outdoors (m /hr) 1.5 EFH - outdoor worker - moderate activities 

ET Exposure time – outdoors (hr/day) 8 Assumes 8-hour work day 

EF 

ED 

Exposure frequency – outdoors (day/yr) 


150 

25 

Site-specific employee info 


BW Body weight (kg) 76.1 FDEP (2005); value for workers (derived from NHANES III data) 


IRi 3 

Inhalation rate (m /hr) 1.2 Child EFH – moderate activities 

ET Exposure time (hr/day) 2 Assumed value 

EF 

ED 

Exposure frequency (day/yr) 


52 

10 

Assumes 1 day per week 

Child exposure from age 7-16; USEPA (2000) 

BW Body weight (kg) 45 USEPA (2000) 

AT Averaging time (days) 3,650 USEPA (2000) 

IRioa 3 

Inhalation rate – outdoors, aggregate resident (m /hr) 1.5 EFH - moderate activites (child +adult) 

IRoa 3 

Inhalation rate – outdoors, child (m /hr) 1.2 Child EFH – moderate activities 

IRs Soil ingestion rate – aggregate resident (kg/day) 0.00012 FDEP (2005) 

IRs Soil ingestion rate – child (kg/day) 0.0002 FDEP (2005) 

IRw Ingestion rate – irrigation water, aggregate res (L/day) 0.12 Assumed value; (equivalent to 4 ounces) 

IRw Ingestion rate - irrigation water, child (L/day) 0.12 Assumed value; (equivalent to 4 ounces) 

IRp,a Ingestion rate – above-ground crops, aggregate resident (kg/day) 0.208 

IRp,a Ingestion rate – above-ground crops, child 0.067 

IRp,r Ingestion rate - root crops, aggregate resident (kg/day) 0.029 

IRp,r Ingestion rate – root crops, child (kg/day) 0.0094 

EF Exposure frequency – irrigation water (day/yr) 50 Assumed value 

EF Exposure frequency (day/yr) 350 FDEP (2005); default value 

ED Exposure duration – aggregate resident (yr) 30 FDEP (2005); default value 

ED Exposure duration – child (yr) 6 FDEP (2005); default value 

SA Exposed skin surface area – aggregate res (cm 2 ) 4,810 FDEP (2005); value for residents (derived from NHANES III data) 

SA Exposed skin surface area – child (cm 2 Table 6. Summary of Exposure Factors 

Exposure Factor 

On-Site Facility Worker 

On-Site Landscape Worker 

On-Site Trespasser 

derived from EFH Tables 13-61, 13-62, 13-63, 13-64 and 13-65 (South 

Region; P-50; corrected for cooking and paring lossess (Tables 13-6 and 

13-7). (RCF and SCF calculated according to Ryan et al., 1988) 

Off-Site Resident 

) 2,960 FDEP (2005); value for residents (derived from NHANES III data) 

BWar Body weight – aggregate resident (kg) 51.9 FDEP (2005); value for residents (derived from NHANES III data) 

BWc Body weight – child (kg) 16.8 FDEP (2005); value for residents (derived from NHANES III data) 

ATar Averaging time – aggregate resident (days) 10,950 FDEP (2005); default assumption (AT = ED) 

ATc Averaging time – child (days) 2,190 FDEP (2005); default assumption (AT = ED) 

IRoa 3 

Inhalation rate – outdoor air (m /hr) 1.5 EFH - Outdoor Worker - moderate activities 

IRs Soil ingestion rate (kg/day) 0.00033 USEPA (2002) - outdoor worker 

EF Exposure frequency - dermal contact with groundwater (day/yr) 20 Assumed to occur during 20 days of open excavation activities 

On-Site Construction ED Exposure duration (yr) 1 Assumed value 

Worker 

ET Exposure Time – dermal contact (hr/day) 2 Assumed value 

SA Exposed skin surface area (cm2) 3,500 FDEP (2005); value for workers (derived from NHANES III data) 




DRAFT 

Table 6. Summary of Exposure Factors 

Receptor Population Exposure Factor 

Value Source 

Child Wading Pool 

Scenario 

Swimming Pool Scenario 

Child Sprinkler 

Scenario 

On-Site and Off-Site Utility 

Worker 

AT Averaging time (days) 365 FDEP (2005); default assumption (AT = ED) 

SA Exposed skin surface area – child (cm 2 ) 6,912 FDEP (2005); entire body exposed (derived from NHANES III data) 

IR w Ingestion rate - irrigation water, child (L/day) 0.05 Assumed value 


EF Exposure frequency (day/yr) 50 Assumed value 

ED Exposure duration (yr) 6 Assumes child exposure from age 1 - 6 

BW Body weight (kg) 16.8 FDEP (2005); ages 1 - 6 (derived from NHANES III data) 











IR oa Inhalation rate – outdoor air (m 3 /hr) 1.20 Child EFH – moderate activities 






IR oa Inhalation rate – outdoor air (m 3 /hr) 1.5 EFH - Outdoor Worker - moderate activities 

IR s Soil ingestion rate – outdoor worker (kg/day) 0.00033 USEPA (2002) 

EF Exposure frequency (day/yr) 8 Assumed value (2 days every 3 months) 

ED Exposure duration (yr) 10 Assumed value 

ET Exposure Time – dermal contact (hr/day) 2 Assumed value 

SA Exposed skin surface area (cm2) 3,500 FDEP (2005); value for workers (derived from NHANES III data) 



Notes: FDEP (2005) - Technical Report: Development of Cleanup Target Levels (CTLs) for Chapter 62-777, F.A.C. Prepared for Division of Waste Management 

EFH - USEPA. 1997. Exposure Factors Handbook – Volume I – General Factors. Update to EPA/600/8-89/043. Office of Research and Development, 

USEPA (2000) - Supplemental Guidance to RAGS: Region 4 Bulletins, Human Health Risk Assessment Bulletins. EPA Region 4, originally published 

Child EFH (2002) - Child-Specific Exposure Factors Handbook. Interim Report. September. EPA-600-P-00-002B 

USEPA (2005) - Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities. Office of solid Waste and Emergency Response. 

Ryan et al., 1988. Plant uptake of non-ionic organic chemicals from soils. Chemosphere 17(12): 2299-2323. 

USEPA (2002) Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites. Office of Emergency and Remedial Response. 



DRAFT 

Table 7. Physical and Chemical Properties of COPCs 


MW H H' Di Dw Koc Kd log Kow Kp * S DA VF SAT kg kl Kol 

(g/mol) (atm-m 3 /mol) (dimensionless) (cm 2 /s) (cm 2 /s) (cm 3 /g) (cm 3 /g) (cm/hr) (mg/L-water) (cm 2 /s) (m 3 /kg) (mg/kg) (cm/hr) (cm/hr) (cm/hr) 

Acetone 58.0 3.9E-05 1.6E-03 1.2E-01 1.1E-05 5.8E-01 3.5E-03 -0.24 5.2E-04 1.0E+06 9.9E-05 1.2E+04 1.0E+05 1.7E+03 1.7E+01 2.3E+00 

Benzene 78.1 5.6E-03 2.3E-01 8.8E-02 9.8E-06 5.9E+01 3.5E-01 2.13 1.5E-02 1.8E+03 2.1E-03 2.6E+03 8.7E+02 1.4E+03 1.5E+01 1.4E+01 

carbon disulfide 76.0 3.0E-02 1.2E+00 1.0E-01 1.0E-05 4.6E+01 2.7E-01 2.24 1.8E-02 1.2E+03 1.1E-02 1.1E+03 7.2E+02 1.5E+03 1.5E+01 1.5E+01 

chloroethane 65.0 1.1E-02 4.5E-01 1.0E-01 1.2E-05 1.5E+01 8.8E-02 1.43 6.0E-03 5.7E+03 8.9E-03 1.3E+03 1.6E+03 1.6E+03 1.6E+01 1.6E+01 

chloroform 119.0 3.7E-03 1.5E-01 1.0E-01 1.0E-05 4.0E+01 2.4E-01 1.97 6.8E-03 7.9E+03 2.2E-03 2.6E+03 2.9E+03 1.2E+03 1.2E+01 1.1E+01 

1,1-dichloroethane 99.0 5.6E-03 2.3E-01 7.4E-02 1.1E-05 3.2E+01 1.9E-01 1.79 6.7E-03 5.1E+03 2.7E-03 2.3E+03 1.7E+03 1.3E+03 1.3E+01 1.3E+01 

1,2-dichloroethane 99.0 9.8E-04 4.0E-02 1.0E-01 9.9E-06 1.7E+01 1.0E-01 1.48 4.2E-03 8.5E+03 1.0E-03 3.8E+03 1.8E+03 1.3E+03 1.3E+01 1.1E+01 

1,1-dichloroethene 97.0 2.6E-02 1.1E+00 9.0E-02 1.0E-05 5.9E+01 3.5E-01 2.13 1.2E-02 2.3E+03 7.6E-03 1.4E+03 1.5E+03 1.3E+03 1.3E+01 1.3E+01 

cis-1,2-dichloroethene 97.0 4.1E-03 1.7E-01 7.4E-02 1.1E-05 3.6E+01 2.1E-01 1.86 7.7E-03 3.5E+03 1.8E-03 2.8E+03 1.2E+03 1.3E+03 1.3E+01 1.3E+01 

trans-1,2-dichloroethene 97.0 9.4E-03 3.8E-01 7.1E-02 1.2E-05 5.3E+01 3.2E-01 1.86 7.7E-03 6.3E+03 2.9E-03 2.2E+03 3.1E+03 1.3E+03 1.3E+01 1.3E+01 

1,2-dichloropropane 113.0 2.8E-03 1.1E-01 7.8E-02 8.7E-06 4.4E+01 2.6E-01 2.00 7.7E-03 2.8E+03 1.2E-03 3.4E+03 1.1E+03 1.2E+03 1.2E+01 1.1E+01 

1,4-dioxane 88.1 3.00E-06 1.2E-04 8.7E-02 9.3E-06 3.5E+00 -0.27 3.4E-04 miscible 6.1E-06 4.8E+04 1.4E+03 1.4E+01 1.6E-01 

ethylbenzene 106.2 7.9E-03 3.2E-01 7.5E-02 7.8E-06 3.6E+02 2.2E+00 3.15 4.8E-02 1.7E+02 5.3E-04 5.2E+03 4.0E+02 1.2E+03 1.3E+01 1.2E+01 

isopropylbenzene 120.0 1.2E-02 4.7E-01 7.5E-02 7.1E-06 2.2E+02 1.3E+00 1.95 6.5E-03 6.1E+01 1.2E-03 3.4E+03 3.2E+01 1.2E+03 1.2E+01 1.2E+01 

methyl ethyl ketone 72.0 2.7E-05 1.1E-03 9.0E-02 9.8E-06 4.5E+00 2.7E-02 0.29 9.7E-04 2.7E+05 4.1E-05 1.9E+04 3.4E+04 1.5E+03 1.6E+01 1.5E+00 

methyl isobutyl ketone 100.0 1.4E-04 5.7E-03 7.5E-02 7.8E-06 1.3E+02 8.0E-01 1.31 3.2E-03 1.9E+04 2.5E-05 2.4E+04 1.7E+04 1.3E+03 1.3E+01 4.7E+00 

methylene chloride 85.0 2.2E-03 9.0E-02 1.0E-01 1.2E-05 1.2E+01 7.0E-02 1.25 3.5E-03 1.3E+04 2.5E-03 2.4E+03 2.5E+03 1.4E+03 1.4E+01 1.3E+01 

4-methylphenol 108.1 1.0E-06 4.1E-05 7.4E-02 8.3E-06 9.1E+01 1.95 7.6E-03 2.1E-06 1.2E+03 1.3E+01 5.0E-02 

phenol 94.1 4.0E-07 1.6E-05 8.2E-02 9.1E-06 2.9E+01 1.46 4.3E-03 8.3E+04 1.3E-06 1.1E+05 1.3E+03 1.4E+01 2.1E-02 

tetrachloroethene 165.8 1.8E-02 7.5E-01 7.2E-02 8.2E-06 1.6E+02 9.3E-01 3.40 3.3E-02 2.0E+02 2.4E-03 2.4E+03 2.3E+02 9.9E+02 1.0E+01 1.0E+01 

toluene 92.0 6.6E-03 2.7E-01 8.7E-02 8.6E-06 1.8E+02 1.1E+00 2.73 3.1E-02 5.3E+02 9.8E-04 3.8E+03 6.5E+02 1.3E+03 1.4E+01 1.3E+01 

1,1,1-trichloroethane 133.0 1.7E-02 7.1E-01 7.8E-02 8.8E-06 1.1E+02 6.6E-01 2.49 1.3E-02 1.3E+03 3.2E-03 2.1E+03 1.2E+03 1.1E+03 1.2E+01 1.1E+01 

1,1,2-trichloroethane 133.0 9.1E-04 3.7E-02 7.8E-02 8.8E-06 5.0E+01 3.0E-01 2.05 6.4E-03 4.4E+03 3.7E-04 6.2E+03 1.8E+03 1.1E+03 1.2E+01 9.0E+00 

trichloroethene 131.0 1.0E-02 4.2E-01 7.9E-02 9.1E-06 1.7E+02 1.0E+00 2.42 1.2E-02 1.1E+03 1.5E-03 3.1E+03 1.3E+03 1.1E+03 1.2E+01 1.1E+01 

1,2,4-trimethylbenzene 120.0 5.7E-03 2.3E-01 7.5E-02 7.1E-06 3.7E+03 2.2E+01 3.78 1.1E-01 5.7E+01 4.0E-05 1.9E+04 1.3E+03 1.2E+03 1.2E+01 1.2E+01 

1,3,5-trimethylbenzene 120.0 7.7E-03 3.2E-01 7.5E-02 7.1E-06 8.2E+02 4.9E+00 3.42 6.1E-02 4.8E+01 2.4E-04 7.7E+03 2.4E+02 1.2E+03 1.2E+01 1.2E+01 

xylenes 106.0 7.3E-03 3.0E-01 7.0E-02 7.8E-06 4.1E+02 2.4E+00 3.20 5.2E-02 1.6E+02 4.2E-04 5.9E+03 4.2E+02 1.2E+03 1.3E+01 1.2E+01 

vinyl chloride 63.0 2.7E-02 1.1E+00 1.1E-01 1.2E-05 1.9E+01 1.1E-01 1.36 5.6E-03 2.8E+03 1.5E-02 9.9E+02 1.2E+03 1.6E+03 1.7E+01 1.7E+01 

data obtained from Region IX PRG table unless otherwise noted MW molecular weight DA effective diffusion coefficient 

log Kow for acetone and MIBK obtained from http://www.arb.ca.gov/db/solvents/all_cmpds.htm H Henry's Law Constant VF soil volatilization factor 

* estimated from USEPA Equation 3.8 in Dermal Guidance (2004) H' dimensionless Henry's Law Constant SAT Saturated soil concentration 

log Kow obtained from USEPA Dermal Guidance (2004) Di diffusivity in air kg gas phase mass transfer coefficient 

MW, H and Koc for 1,4-dioxane obtained from Environmental Claims Journal 16:69-79 (2004) Dw diffusivity in water kl liquid phase mass transfer coefficient 

Note: H' = 41 * H Koc organic carbon/water partition coefficient Kol overall mass transfer coefficient 

Kow for 1,2,4-trimethylbenzene obtained from SRC ChemFate database (http://www.syrres.com/esc/chemfate.htm) Kd soil/water partition coefficient 

Kow for 1,3,5-trimethylbenzene obtained from HSDB (http://toxnet.nlm.nih.gov) Kow octanol/water partition coefficient 

Data for phenol obtained from USEPA's Soil Screening Guidance Technical Background Document Kp skin permeabiity coefficient 

Data for 2-methylphenol from Soil Screening Guidance used as a surrogate for 4-methylphenol S solubility in water 

ENVIRON Page 1 of 1

DRAFT 

Table 8. Source and Derivation of Toxicity Values 

COPCs in Indoor Air 

Skin 

Absorption 

Source 

GI Absorption 

Source 

Cancer Class 

Source 

IUR 1/(ug/m3) 

Source 

CSFo 

1/(mg/kg-day) 

Source 

CSFi 

1/(mg/kg-day) 

Source 

CSFd 

1/(mg/kg-day) 

Carcinogens 

benzene 0.9 A A I 7.80E-06 I 5.50E-02 I 2.73E-02 E 6.11E-02 E 

chloroethane 1 R NA NA 2.90E-03 N 2.90E-03 E 2.90E-03 E 

chloroform 1 A B2 I 2.30E-05 I NA 8.05E-02 E NA 

1,2-dichloroethane 1 A B2 H 2.60E-05 I 9.10E-02 I 9.10E-02 E 9.10E-02 E 

1,2-dichloropropane 1 A B2 H NA 6.80E-02 H 6.80E-02 E 6.80E-02 E 

1,4-dioxane 0.1 9 1 R B2 I NA 1.10E-02 I 1.10E-02 E 1.10E-02 E 

methylene chloride 1 A B2 I 4.70E-07 I 7.50E-03 I 1.65E-03 E 7.50E-03 E 

tetrachloroethene 1 A NA NA 5.20E-02 N 2.00E-03 N 5.20E-02 E 

1,1,2-trichloroethane 0.81 A C I 1.60E-05 I 5.70E-02 I 5.60E-02 E 7.04E-02 E 

trichloroethene 0.945 A B2 H NA 1.10E-02 N 6.00E-03 N 1.16E-02 E 

vinyl chloride 0.875 A A I 4.40E-06 I 7.20E-01 I 1.54E-02 E 8.23E-01 E 

Skin 

Absorption 

Source 

GI Absorption 

Source 

Critical Effect 

Source 

RfC 

(mg/m3) 

Source 

RfDo 

(mg/kg-day) 

Source 

RfDi 

(mg/kg-day) 

Source 

RfDd 

(mg/kg-day) 


acetone 1 R Kidney, Liver, Neuro NA 9.00E-01 I 9.00E-01 E 9.00E-01 E 

benzene 0.9 A Blood 3.00E-02 I 4.00E-03 I 8.57E-03 E 3.60E-03 E 

carbon disulfide 1 R Development, Neuro 7.00E-01 I 1.00E-01 I 2.00E-01 E 1.00E-01 E 

chloroethane 1 R Developmental 1.00E+01 I 4.00E-01 N 2.86E+00 E 4.00E-01 E 

chloroform 1 A Liver NA 1.00E-02 I 1.40E-02 N 1.00E-02 E 

1,1-dichloroethane 1 R Kidney 5.00E-01 H 1.00E-01 H 1.43E-01 E 1.00E-01 E 

1,2-dichloroethane 1 A None Specified NA 3.00E-02 N 3.00E-02 E 3.00E-02 E 

1,1-dichloroethene 1 A Liver 2.00E-01 I 5.00E-02 I 5.71E-02 E 5.00E-02 E 

cis-1,2-dichloroethene 1 R Blood NA 1.00E-02 H 1.00E-02 E 1.00E-02 E 

trans-1,2-dichloroethene 1 R Blood, Liver NA 2.00E-02 I 2.00E-02 E 2.00E-02 E 

1,2-dichloropropane 1 A Nasal 4.00E-03 I 1.10E-03 9 1.14E-03 E 1.10E-03 E 

1,4-dioxane 0.1 9 1 R NA NA NA NA 

ethylbenzene 1 R Develop, Kidney, Liver 1.00E+00 I 1.00E-01 I 2.86E-01 E 1.00E-01 E 

isopropylbenzene 1 R Adrenals, Kidney 4.00E-01 I 1.00E-01 I 1.14E-01 E 1.00E-01 E 

methyl ethyl ketone 1 R Developmental 5.00E+00 I 6.00E-01 I 1.43E+00 E 6.00E-01 E 

methyl isobutyl ketone 1 R Kidney, Liver 3.00E+00 I 8.00E-02 H 8.57E-01 E 8.00E-02 E 

methylene chloride 1 A Liver 3.00E+00 H 6.00E-02 I 8.57E-01 E 6.00E-02 E 

4-methylphenol 0.745 A Neuro, Respiratory NA 5.00E-03 H 3.73E-03 E 3.73E-03 E 

phenol 1 A Developmental NA 3.00E-01 I 3.00E-01 E 3.00E-01 E 

tetrachloroethene 1 A Liver NA 1.00E-02 I 1.40E-01 N 1.00E-02 E 

toluene 1 R Kidney, Liver, Neuro 5.00E+00 I 8.00E-02 I 1.43E+00 E 8.00E-02 E 

1,1,1-trichloroethane 1 HS NA 2.80E-01 N 2.86E-01 N 2.80E-01 E 

1,1,2-trichloroethane 0.81 A Liver NA 4.00E-03 I 3.24E-03 E 3.24E-03 E 

trichloroethene 0.945 A NA 6.00E-03 N 5.67E-03 E 5.67E-03 E 

1,2,4-trimethylbenzene 1 R NA 5.00E-02 N 1.70E-03 N 5.00E-02 E 

1,3,5-trimethylbenzene 1 R NA 5.00E-02 N 1.70E-03 N 5.00E-02 E 

xylenes 0.895 A Neurological 1.00E-01 I 2.00E-01 I 2.86E-02 E 1.79E-01 E 

vinyl chloride 0.875 A Liver 1.00E-01 I 3.00E-03 I 2.86E-02 E 2.63E-03 E 

I = IRIS 

E = Extrapolated 

A = ATSDR 

N = NCEA 

R = RAGS-E 

H = HAL (USEPA's 2002 Edition of the Drinking Water Standards and Health Advisories) 

HE = HEAST 

HS = HSDB 

T = TPHCWG 

9 = Region 9 PRG Table 



Source 

Source

DRAFT 

Table 9. Risk-Based Screening Levels (RBSLs) for Evaluating Potential Exposures to Residential Irrigation Water 

Constituent Ingestion Dermal Contact 

RBSL (µg/L) 

Inhalation during Ingestion of Dermal Contact Dermal Contact 

while Gardening while Gardening Lawn Irrigation Homegrown Produce (Wading Pool) (Sprinkler) 

acetone 919,800 49,611,496 7,808,787 4,625,973 1,877,444 2,414,509 

benzene 134 131 1,342 64 78 82 

carbon disulfide 102,200 150,675 1,249,281 145,266 34,375 60,787 

chloroethane 2,540 7,128 11,333 3,616 3,239 2,996 

chloroform 10,220 31,493 450 18,216 6,492 849 

1,1-dichloroethane 102,200 353,227 867,589 242,714 69,555 110,585 

1,2-dichloroethane 81 275 407 62 122 107 

1,1-dichloroethene 51,100 104,055 347,791 89,972 23,218 37,918 

cis-1,2-dichloroethene 10,220 31,315 57,940 29,478 6,357 9,863 

trans-1,2-dichloroethene 20,440 62,629 111,541 77,712 12,714 19,643 

1,2-dichloropropane 108 189 584 45 104 98 

1,4-dioxane 670 29,927 28,804 522 2,315 2,114 

ethylbenzene 102,200 47,115 2,110,120 34,115 13,072 21,976 

isopropylbenzene 102,200 326,750 897,870 104,157 66,782 105,508 

methyl ethyl ketone 613,200 16,696,416 16,472,371 1,431,937 1,098,322 1,677,188 

methyl isobutyl ketone 81,760 589,378 7,294,344 117,929 88,633 147,718 

methylene chloride 982 4,263 19,920 1,616 1,675 1,651 

4-methylphenol 5,110 11,273 628,828 1,958 2,465 4,321 

phenol 306,600 1,686,022 116,143,165 167,088 282,112 483,225 

tetrachloroethene 142 41 20,567 13 31 31 

toluene 81,760 65,000 9,900,752 50,121 16,549 29,235 

1,1,1-trichloroethane 286,160 437,898 1,946,500 237,887 106,924 170,998 

1,1,2-trichloroethane 129 192 718 50 113 105 

trichloroethene 670 654 6,403 205 416 410 

1,2,4-trimethylbenzene 51,100 10,125 13,378 7,955 2,967 3,977 

1,3,5-trimethylbenzene 51,100 17,498 13,366 11,415 4,949 5,952 

xylenes 204,400 78,027 211,084 64,642 21,927 33,258 

vinyl chloride 10 27 2,038 23 13 14 




DRAFT 

Figures

DRAFT 

Primary Primary Secondary Secondary 

Source Release Mechanism 

Source Release Mechanism 

Ground 

Water 

Plume 

Drafted by: 

Volatilization 

through Vadose 

Zone 

Contact with Soil 

Legend 

pathway 

� principal pathway for quantitative evaluation 

o pathway for qualitative evaluation 

-- incomplete pathway 

Date: 5/30/08 

Indoor Air 

Outdoor Air 

(vapor) 

Digging Trench Groundwater in 

Trench 

Subsurface Soil 


Excavation 

Activities 

Media 

Affected 

Indoor Air 

Outdoor Air 

Outdoor Air 

(trench) 

Exposure Facility Onsite Construction Utility 

Route Worker Landscaper Worker Worker Tresspasser 

Inhalation � -- -- -- -- 

Inhalation -- � o o � 

Inhalation -- -- � � -- 

` Groundwater 

Dermal Absorption -- -- � � -- 

(trench) 

Soil 

Ingestion -- -- � � -- 

Dermal Absorption -- -- o o -- 

Inhalation -- -- o o -- 

Potential Exposure Pathways Under Current Use Scenarios – 

On-Site Receptors 

Raytheon Company Facility, St Petersburg, FL 

Onsite Receptors 

FIGURE 

1

DRAFT 

Primary Primary Secondary Secondary 

Media 

Source Release Mechanism Source Release Mechanism Affected 

Ground 

Water 

Plume 


Pumping Well 

Groundwater 

Migration 

Indoor Air 

Outdoor Air 

(vapor) 

Irrigation Water 

Surface Water 

Digging Trench Groundwater in 

Trench 

Subsurface Soil 

Deposition 

Plant Uptake 


Excavation 

Activities 

Surface Soil 

Homegrown 

Produce 

Offsite Receptors 

Exposure Offsite Construction Other 

Route Resident † 

Worker Offsite* 

Inhalation -- -- -- 

Inhalation -- -- -- 

Inhalation � -- -- 

Ingestion � -- 

Dermal Absorption � -- 


Dermal Absorption o -- 

Inhalation o -- 



Dermal Absorption � -- 

Inhalation -- � -- 

` Groundwater 

Dermal Absorption -- � -- 

(trench) 

Ingestion -- � -- 

Dermal Absorption -- o -- 

Inhalation -- o -- 

Legend Notes 

pathway 

† 

Offsite resident includes children exposed to irrigation water in a wading pool or by sprinklers. 

� principal pathway for quantitative evaluation * Other offsite receptors include: Pinellas Trail users, Azalea Park ball players, Workers at the Azalea 

o pathway for qualitative evaluation Park recreation center, Azalea Park Groundskeepers, and Apartment/Condominium landscapers 

-- incomplete pathway 

FIGURE 

Potential Exposure Pathways Under Current 

Use Scenarios – Off-Site Receptors 2 

Drawn By: Date: 5/30/08 Raytheon Company Facility, St Petersburg, FL 

Indoor Air 

Outdoor Air 

(vapor intrusion) 

Outdoor Air 

(irrigation) 

Irrigation Water 

Surface Water 

Outdoor Air 

(trench) 

Soil 

2512243G


DRAFT 

Appendix A: 

Dose and Risk Spreadsheets

DRAFT 

Table A-1. Dose and Risk Calculations for Potential Current/Future Exposures to COPCs via Inhalation of Indoor Air 

Based on Measured Indoor Air Levels. Facility Worker - Raytheon Facility - St. Petersburg, FL 


CSFi RfDi C air ADD LADD Hazard Excess Cancer 

COPC (mg/kg-day)-1 (mg/kg-day) (mg/m 3 ) (mg/kg-day) (mg/kg-day) Quotient Risk 

Carcinogens 

benzene 2.7E-02 0.0016 9.6E-05 3.4E-05 9.E-07 

chloroethane 2.9E-03 0 0.0E+00 0.0E+00 0.E+00 

chloroform 8.1E-02 0.001 6.0E-05 2.1E-05 2.E-06 

1,2-dichloroethane 9.1E-02 0 0.0E+00 0.0E+00 0.E+00 

1,2-dichloropropane 6.8E-02 0 0.0E+00 0.0E+00 0.E+00 

1,4-dioxane 1.1E-02 0 0.0E+00 0.0E+00 0.E+00 

methylene chloride 1.6E-03 0.0013 7.8E-05 2.8E-05 5.E-08 

tetrachloroethene 2.0E-03 0.00089 5.3E-05 1.9E-05 4.E-08 

1,1,2-trichloroethane 5.6E-02 0 0.0E+00 0.0E+00 0.E+00 

trichloroethene 6.0E-03 0.0032 1.9E-04 6.8E-05 4.E-07 

vinyl chloride 1.5E-02 0 0.0E+00 0.0E+00 0.E+00 


acetone 9.0E-01 0.056 3.3E-03 4.E-03 

benzene 8.6E-03 0.0016 9.6E-05 1.E-02 

carbon disulfide 2.0E-01 0.0021 1.3E-04 6.E-04 

chloroethane 2.9E+00 0 0.0E+00 0.E+00 

chloroform 1.4E-02 0.001 6.0E-05 4.E-03 

1,1-dichloroethane 1.4E-01 0.00045 2.7E-05 2.E-04 

1,2-dichloroethane 3.0E-02 0 0.0E+00 0.E+00 

1,1-dichloroethene 5.7E-02 0.00092 5.5E-05 1.E-03 

cis-1,2-dichloroethene 1.0E-02 0.0017 1.0E-04 1.E-02 

trans-1,2-dichloroethene 2.0E-02 0.00072 4.3E-05 2.E-03 

1,2-dichloropropane 1.1E-03 0 0.0E+00 0.E+00 

1,4-dioxane NA 0 0.0E+00 

ethylbenzene 2.9E-01 0.0018 1.1E-04 4.E-04 

isopropylbenzene 1.1E-01 0 0.0E+00 0.E+00 

methyl ethyl ketone 1.4E+00 0.013 7.8E-04 5.E-04 

methyl isobutyl ketone 8.6E-01 0.0012 7.2E-05 8.E-05 

methylene chloride 8.6E-01 0.0013 7.8E-05 9.E-05 

4-methylphenol 3.7E-03 0 0.0E+00 0.E+00 

phenol 3.0E-01 0 0.0E+00 0.E+00 

tetrachloroethene 1.4E-01 0.00089 5.3E-05 4.E-04 

toluene 1.4E+00 0.75 4.5E-02 3.E-02 

1,1,1-trichloroethane 2.9E-01 0.001 6.0E-05 2.E-04 

1,1,2-trichloroethane 3.2E-03 0 

trichloroethene 5.7E-03 0.0032 1.9E-04 3.E-02 

1,2,4-trimethylbenzene 1.7E-03 0 0.0E+00 0.E+00 

1,3,5-trimethylbenzene 1.7E-03 0 0.0E+00 0.E+00 

xylenes 2.9E-02 0.0116 6.9E-04 2.E-02 

vinyl chloride 2.9E-02 0 0.0E+00 0.E+00 

Totals 1.E-01 3.E-06 

ADD 

= 

C 

LADD 

air 

× IRi 

× ET × EF × ED 

BW × AT 

ADD × ED 

70 


= 

C air Indoor Air Concentration chemical -specific mg/m 3 

IRi Inhalation Rate 0.83 m 3 /hr 

ET Exposure Time 8 hr/day 

EF Exposure Frequency 250 days/year 

ED Exposure Duration 25 year 

BW Body weight 76.1 kg 

AT Averaging Time 9,125 days

DRAFT 

Table A-2. Dose and Risk Calculations for Potential Current/Future Exposures to COPCs via Inhalation of Outdoor Air 

Onsite Landscape/Maintenance Worker - Raytheon Facility - St. Petersburg, FL 

CSFi RfDi C oa ADD LADD Hazard Excess Cancer 


Carcinogens 

benzene 2.7E-02 3.83E-08 2.5E-09 8.9E-10 2.E-11 

chloroethane 2.9E-03 6.88E-05 4.5E-06 1.6E-06 5.E-09 

chloroform 8.1E-02 8.19E-05 5.3E-06 1.9E-06 2.E-07 

1,2-dichloroethane 9.1E-02 0.00E+00 0.0E+00 0.0E+00 0.E+00 

1,2-dichloropropane 6.8E-02 2.11E-06 1.4E-07 4.9E-08 3.E-09 

1,4-dioxane 1.1E-02 7.20E-12 4.7E-13 1.7E-13 2.E-15 

methylene chloride 1.6E-03 6.43E-07 4.2E-08 1.5E-08 2.E-11 

tetrachloroethene 2.0E-03 1.32E-05 8.6E-07 3.1E-07 6.E-10 

1,1,2-trichloroethane 5.6E-02 1.71E-07 1.1E-08 4.0E-09 2.E-10 

trichloroethene 6.0E-03 4.76E-05 3.1E-06 1.1E-06 7.E-09 

vinyl chloride 1.5E-02 2.75E-03 1.8E-04 6.4E-05 1.E-06 


acetone 9.0E-01 1.34E-08 8.7E-10 1.E-09 

benzene 8.6E-03 3.83E-08 2.5E-09 3.E-07 

carbon disulfide 2.0E-01 2.08E-05 1.3E-06 7.E-06 

chloroethane 2.9E+00 6.88E-05 4.5E-06 2.E-06 

chloroform 1.4E-02 8.19E-05 5.3E-06 4.E-04 

1,1-dichloroethane 1.4E-01 1.34E-04 8.7E-06 6.E-05 

1,2-dichloroethane 3.0E-02 0.00E+00 0.0E+00 0.E+00 

1,1-dichloroethene 5.7E-02 1.78E-03 1.2E-04 2.E-03 

cis-1,2-dichloroethene 1.0E-02 4.04E-05 2.6E-06 3.E-04 

trans-1,2-dichloroethene 2.0E-02 1.16E-05 7.5E-07 4.E-05 

1,2-dichloropropane 1.1E-03 2.11E-06 1.4E-07 1.E-04 

1,4-dioxane NA 7.20E-12 4.7E-13 

ethylbenzene 2.9E-01 6.40E-06 4.1E-07 1.E-06 

isopropylbenzene 1.1E-01 2.64E-06 1.7E-07 1.E-06 

methyl ethyl ketone 1.4E+00 0.00E+00 0.0E+00 0.E+00 

methyl isobutyl ketone 8.6E-01 0.00E+00 0.0E+00 0.E+00 

methylene chloride 8.6E-01 6.43E-07 4.2E-08 5.E-08 

4-methylphenol 3.7E-03 3.79E-14 2.5E-15 7.E-13 

phenol 3.0E-01 3.87E-09 2.5E-10 8.E-10 

tetrachloroethene 1.4E-01 1.32E-05 8.6E-07 6.E-06 

toluene 1.4E+00 1.20E-04 7.7E-06 5.E-06 

1,1,1-trichloroethane 2.9E-01 1.05E-03 6.8E-05 2.E-04 

1,1,2-trichloroethane 3.2E-03 1.71E-07 

trichloroethene 5.7E-03 4.76E-05 3.1E-06 5.E-04 

1,2,4-trimethylbenzene 1.7E-03 2.72E-08 1.8E-09 1.E-06 


xylenes 2.9E-02 2.20E-05 1.4E-06 5.E-05 

vinyl chloride 2.9E-02 2.75E-03 1.8E-04 6.E-03 

Totals 1.E-02 1.E-06 

ADD = 

Coa 

× IRi 

× ET × EF × ED 

BW × AT 

LADD = 

ADD × ED 

70 


C oa Outdoor Air Concentration chemical -specific mg/m 3 

IR i Inhalation Rate 1.5 m 3 /hr 





AT Averaging Time 9,125 days 


DRAFT 

Table A-3. Dose and Risk Calculations for Potential Exposures to COPCs via Inhalation of Outdoor Air 

Onsite Trespasser - Raytheon Facility - St. Petersburg, FL 



Carcinogens 

benzene 2.7E-02 3.8E-08 2.9E-10 4.2E-11 1.E-12 





1,4-dioxane 1.1E-02 7.2E-12 5.5E-14 7.8E-15 9.E-17 







acetone 9.0E-01 1.3E-08 1.0E-10 1.E-10 

benzene 8.6E-03 3.8E-08 2.9E-10 3.E-08 










1,4-dioxane NA 7.2E-12 5.5E-14 







phenol 3.0E-01 3.9E-09 2.9E-11 1.E-10 


toluene 1.4E+00 1.2E-04 9.1E-07 6.E-07 






xylenes 2.9E-02 2.2E-05 1.7E-07 6.E-06 


Totals 1.E-03 5.E-08 

ADD = 

C oa × IR i × ET × EF × ED 

BW × AT 

LADD = 

ADD × ED 

70 


Coa Outdoor Air Concentration chemical -specific mg/m 3 

Iri Inhalation Rate 1.2 m 3 /hr 




BW Body weight 45 kg 



DRAFT 

CSFd RfDd DA event C w DAD LADD Hazard Excess Cancer 

COPC (mg/kg-day)-1 (mg/kg-day) (mg/cm 2 -event) (mg/cm 3 ) (mg/kg-day) (mg/kg-day) Quotient Risk 

Carcinogens 

benzene 6.1E-02 3.1E-08 0.00000085 7.9E-08 1.1E-09 7.E-11 

chloroethane 2.9E-03 2.7E-06 0.00018 6.7E-06 9.6E-08 3.E-10 

chloroform NA 5.2E-05 0.0026 1.3E-04 1.9E-06 

1,2-dichloroethane 9.1E-02 0.0E+00 0 0.0E+00 0.0E+00 0.E+00 

1,2-dichloropropane 6.8E-02 3.5E-06 0.00016 8.9E-06 1.3E-07 9.E-09 

1,4-dioxane 1.1E-02 9.0E-08 0.0001 2.3E-07 3.2E-09 4.E-11 

methylene chloride 7.5E-03 2.8E-07 0.00003 7.0E-07 1.0E-08 7.E-11 

tetrachloroethene 5.2E-02 9.3E-06 0.000077 2.3E-05 3.4E-07 2.E-08 

1,1,2-trichloroethane 7.0E-02 2.6E-06 0.00013 6.6E-06 9.5E-08 7.E-09 

trichloroethene 1.2E-02 2.9E-05 0.00081 7.3E-05 1.0E-06 1.E-08 

vinyl chloride 8.2E-01 2.4E-05 0.0018 6.2E-05 8.8E-07 7.E-07 


acetone 9.0E-01 1.1E-06 0.00089 2.9E-06 3.E-06 

benzene 3.6E-03 3.1E-08 0.00000085 7.9E-08 2.E-05 

carbon disulfide 1.0E-01 7.1E-07 0.000016 1.8E-06 2.E-05 

chloroethane 4.0E-01 2.7E-06 0.00018 6.7E-06 2.E-05 

chloroform 1.0E-02 5.2E-05 0.0026 1.3E-04 1.E-02 

1,1-dichloroethane 1.0E-01 4.2E-05 0.0023 1.1E-04 1.E-03 

1,2-dichloroethane 3.0E-02 0.0E+00 0 0.0E+00 0.E+00 

1,1-dichloroethene 5.0E-02 7.1E-05 0.0023 1.8E-04 4.E-03 

cis-1,2-dichloroethene 1.0E-02 2.5E-05 0.0012 6.3E-05 6.E-03 

trans-1,2-dichloroethene 2.0E-02 2.3E-06 0.00011 5.7E-06 3.E-04 

1,2-dichloropropane 1.1E-03 3.5E-06 0.00016 8.9E-06 8.E-03 

1,4-dioxane NA 9.0E-08 0.0001 2.3E-07 

ethylbenzene 1.0E-01 5.0E-05 0.00039 1.3E-04 1.E-03 

isopropylbenzene 1.0E-01 9.3E-07 0.000048 2.3E-06 2.E-05 

methyl ethyl ketone 6.0E-01 0.0E+00 0 0.0E+00 0.E+00 

methyl isobutyl ketone 8.0E-02 0.0E+00 0 0.0E+00 0.E+00 

methylene chloride 6.0E-02 2.8E-07 0.00003 7.0E-07 1.E-05 

4-methylphenol 3.7E-03 9.9E-08 0.0000046 2.5E-07 7.E-05 

phenol 3.0E-01 9.8E-08 0.0000084 2.5E-07 8.E-07 

tetrachloroethene 1.0E-02 9.3E-06 0.000077 2.3E-05 2.E-03 

toluene 8.0E-02 3.7E-04 0.0047 9.3E-04 1.E-02 

1,1,1-trichloroethane 2.8E-01 1.9E-04 0.0049 4.8E-04 2.E-03 


trichloroethene 5.7E-03 2.9E-05 0.00081 7.3E-05 1.E-02 

1,2,4-trimethylbenzene 5.0E-02 9.0E-06 0.000031 2.3E-05 5.E-04 


xylenes 1.8E-01 2.5E-04 0.00184 6.4E-04 4.E-03 

vinyl chloride 2.6E-03 2.4E-05 0.0018 6.2E-05 2.E-02 

Totals 9.E-02 8.E-07 

DAD 

= 

LADD 

see text for definition of DA event 

Table A-4. Dose and Risk Calculations for Potential Exposures to COPCs via Dermal Exposure to Groundwater 

Onsite Construction Worker - Raytheon Facility - St. Petersburg, FL 

DA 

event 

= 

x SA × EV × EF × ED 

CF × BW × AT 

DAD× 

ED 

70 


Worker 

Cw Irrigation Water Concentration chemical -specific mg/L 

SA Exposed skin surface area 3,500 cm2 


EF Exposure Frequency 20 day/yr 

ED Exposure Duration 1 years 

CF Conversion Factor 1000 cm 3 /L 


AT Averaging Time 365 days 


DRAFT 

Table A-5. Dose and Risk Calculations for Potential Exposures to COPCs via Incidental Ingestion of Soil 

Onsite Construction Worker - Raytheon Facility - St. Petersburg, FL 

CSFo RfDo Cs ADD LADD Hazard 

Excess 

Cancer 

COPC (mg/kg-day)-1 (mg/kg-day) (mg/kg) (mg/kg-day) (mg/kg-day) Quotient Risk 

Carcinogens 

benzene 5.5E-02 1.16E+00 2.8E-07 3.9E-09 2.E-10 


chloroform NA 8.30E+01 2.0E-05 2.8E-07 

1,2-dichloroethane 9.1E-02 1.53E+00 3.6E-07 5.2E-09 5.E-10 


1,4-dioxane 1.1E-02 7.71E+01 1.8E-05 2.6E-07 3.E-09 

methylene chloride 7.5E-03 3.18E+01 7.6E-06 1.1E-07 8.E-10 



trichloroethene 1.1E-02 2.85E+02 6.8E-05 9.7E-07 1.E-08 



7.2E-01 1.32E+01 3.1E-06 4.5E-08 3.E-08 

acetone 9.0E-01 1.38E+01 3.3E-06 4.E-06 

benzene 4.0E-03 1.16E+00 2.8E-07 7.E-05 


chloroethane 4.0E-01 5.04E-01 1.2E-07 3.E-07 

chloroform 1.0E-02 8.30E+01 2.0E-05 2.E-03 

1,1-dichloroethane 1.0E-01 2.00E+01 4.8E-06 5.E-05 


1,1-dichloroethene 5.0E-02 5.14E+01 1.2E-05 2.E-04 

cis-1,2-dichloroethene 1.0E-02 7.15E+01 1.7E-05 2.E-03 



1,4-dioxane NA 7.71E+01 1.8E-05 

ethylbenzene 1.0E-01 1.51E+00 3.6E-07 4.E-06 


methyl ethyl ketone 6.0E-01 1.17E+01 2.8E-06 5.E-06 

methyl isobutyl ketone 8.0E-02 2.05E+01 4.9E-06 6.E-05 

methylene chloride 6.0E-02 3.18E+01 7.6E-06 1.E-04 


phenol 3.0E-01 4.44E-03 1.1E-09 4.E-09 


toluene 8.0E-02 4.74E+01 1.1E-05 1.E-04 

1,1,1-trichloroethane 2.8E-01 2.95E+01 7.0E-06 3.E-05 


trichloroethene 6.0E-03 2.85E+02 6.8E-05 1.E-02 

1,2,4-trimethylbenzene 5.0E-02 1.15E+00 2.7E-07 5.E-06 


xylenes 2.0E-01 7.93E+00 1.9E-06 9.E-06 

vinyl chloride 3.0E-03 1.32E+01 3.1E-06 1.E-03 

Totals 2.E-02 5.E-08 

ADD = 

C s × IR s × EF × ED 

BW × AT 

LADD = 

ADD × ED 

70 


Worker 

Cw Soil Conc. chemical -specific mg/kg 

Irs Soil Ingestion Rate 0.00033 kg/day 






DRAFT 


During Subsurfcae Excavation Activities - Onsite Construction Worker - Raytheon Facility - St. Petersburg, FL 



Carcinogens 

benzene 2.7E-02 2.84E-06 2.5E-08 3.5E-10 1.E-11 





1,4-dioxane 1.1E-02 7.40E-05 6.4E-07 9.1E-09 1.E-10 







acetone 9.0E-01 2.67E-03 2.3E-05 3.E-05 

benzene 8.6E-03 2.84E-06 2.5E-08 3.E-06 










1,4-dioxane NA 7.40E-05 6.4E-07 







phenol 3.0E-01 9.87E-07 8.5E-09 3.E-08 


toluene 1.4E+00 1.44E-02 1.2E-04 9.E-05 






xylenes 2.9E-02 5.28E-03 4.6E-05 2.E-03 


Totals 3.E-02 1.E-07 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Worker 

Coa Outdoor Air Concentration chem-specific mg/m 3 








DRAFT 



Carcinogens 

benzene 6.1E-02 3.1E-08 0.00000085 1.3E-08 1.8E-09 1.E-10 

chloroethane 2.9E-03 2.7E-06 0.00018 1.1E-06 1.5E-07 4.E-10 

chloroform NA 5.2E-05 0.0026 2.1E-05 3.0E-06 

1,2-dichloroethane 9.1E-02 0.0E+00 0 0.0E+00 0.0E+00 0.E+00 

1,2-dichloropropane 6.8E-02 3.5E-06 0.00016 1.4E-06 2.0E-07 1.E-08 

1,4-dioxane 1.1E-02 9.0E-08 0.0001 3.6E-08 5.2E-09 6.E-11 

methylene chloride 7.5E-03 2.8E-07 0.00003 1.1E-07 1.6E-08 1.E-10 

tetrachloroethene 5.2E-02 9.3E-06 0.000077 3.8E-06 5.4E-07 3.E-08 

1,1,2-trichloroethane 7.0E-02 2.6E-06 0.00013 1.1E-06 1.5E-07 1.E-08 

trichloroethene 1.2E-02 2.9E-05 0.00081 1.2E-05 1.7E-06 2.E-08 

vinyl chloride 8.2E-01 2.4E-05 0.0018 9.9E-06 1.4E-06 1.E-06 


acetone 9.0E-01 1.1E-06 0.00089 4.6E-07 5.E-07 

benzene 3.6E-03 3.1E-08 0.00000085 1.3E-08 4.E-06 

carbon disulfide 1.0E-01 7.1E-07 0.000016 2.9E-07 3.E-06 

chloroethane 4.0E-01 2.7E-06 0.00018 1.1E-06 3.E-06 

chloroform 1.0E-02 5.2E-05 0.0026 2.1E-05 2.E-03 

1,1-dichloroethane 1.0E-01 4.2E-05 0.0023 1.7E-05 2.E-04 

1,2-dichloroethane 3.0E-02 0.0E+00 0 0.0E+00 0.E+00 

1,1-dichloroethene 5.0E-02 7.1E-05 0.0023 2.9E-05 6.E-04 

cis-1,2-dichloroethene 1.0E-02 2.5E-05 0.0012 1.0E-05 1.E-03 

trans-1,2-dichloroethene 2.0E-02 2.3E-06 0.00011 9.2E-07 5.E-05 

1,2-dichloropropane 1.1E-03 3.5E-06 0.00016 1.4E-06 1.E-03 

1,4-dioxane NA 9.0E-08 0.0001 3.6E-08 

ethylbenzene 1.0E-01 5.0E-05 0.00039 2.0E-05 2.E-04 

isopropylbenzene 1.0E-01 9.3E-07 0.000048 3.7E-07 4.E-06 

methyl ethyl ketone 6.0E-01 0.0E+00 0 0.0E+00 0.E+00 

methyl isobutyl ketone 8.0E-02 0.0E+00 0 0.0E+00 0.E+00 

methylene chloride 6.0E-02 2.8E-07 0.00003 1.1E-07 2.E-06 

4-methylphenol 3.7E-03 9.9E-08 0.0000046 4.0E-08 1.E-05 

phenol 3.0E-01 9.8E-08 0.0000084 3.9E-08 1.E-07 

tetrachloroethene 1.0E-02 9.3E-06 0.000077 3.8E-06 4.E-04 

toluene 8.0E-02 3.7E-04 0.0047 1.5E-04 2.E-03 



trichloroethene 5.7E-03 2.9E-05 0.00081 1.2E-05 2.E-03 



xylenes 1.8E-01 2.5E-04 0.00184 1.0E-04 6.E-04 

vinyl chloride 2.6E-03 2.4E-05 0.0018 9.9E-06 4.E-03 

Totals 1.E-02 1.E-06 

DAD 

= 

LADD 



Onsite Utility Worker - Raytheon Facility - St. Petersburg, FL 

DA 

event 

= 



DAD× 

ED 

70 


Worker 










DRAFT 


Onsite Utility Worker - Raytheon Facility - St. Petersburg, FL 


Excess 

Cancer 


Carcinogens 

benzene 5.5E-02 1.16E+00 4.4E-08 6.3E-09 3.E-10 


chloroform NA 8.30E+01 3.2E-06 4.5E-07 

1,2-dichloroethane 9.1E-02 1.53E+00 5.8E-08 8.3E-09 8.E-10 


1,4-dioxane 1.1E-02 7.71E+01 2.9E-06 4.2E-07 5.E-09 

methylene chloride 7.5E-03 3.18E+01 1.2E-06 1.7E-07 1.E-09 



trichloroethene 1.1E-02 2.85E+02 1.1E-05 1.5E-06 2.E-08 



7.2E-01 1.32E+01 5.0E-07 7.2E-08 5.E-08 

acetone 9.0E-01 1.38E+01 5.2E-07 6.E-07 

benzene 4.0E-03 1.16E+00 4.4E-08 1.E-05 


chloroethane 4.0E-01 5.04E-01 1.9E-08 5.E-08 

chloroform 1.0E-02 8.30E+01 3.2E-06 3.E-04 



1,1-dichloroethene 5.0E-02 5.14E+01 2.0E-06 4.E-05 

cis-1,2-dichloroethene 1.0E-02 7.15E+01 2.7E-06 3.E-04 



1,4-dioxane NA 7.71E+01 2.9E-06 

ethylbenzene 1.0E-01 1.51E+00 5.7E-08 6.E-07 


methyl ethyl ketone 6.0E-01 1.17E+01 4.5E-07 7.E-07 

methyl isobutyl ketone 8.0E-02 2.05E+01 7.8E-07 1.E-05 

methylene chloride 6.0E-02 3.18E+01 1.2E-06 2.E-05 


phenol 3.0E-01 4.44E-03 1.7E-10 6.E-10 


toluene 8.0E-02 4.74E+01 1.8E-06 2.E-05 

1,1,1-trichloroethane 2.8E-01 2.95E+01 1.1E-06 4.E-06 


trichloroethene 6.0E-03 2.85E+02 1.1E-05 2.E-03 

1,2,4-trimethylbenzene 5.0E-02 1.15E+00 4.4E-08 9.E-07 


xylenes 2.0E-01 7.93E+00 3.0E-07 2.E-06 

vinyl chloride 3.0E-03 1.32E+01 5.0E-07 2.E-04 

Totals 3.E-03 8.E-08 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Worker 








DRAFT 


During Subsurfcae Excavation Activities - Onsite Utility Worker - Raytheon Facility - St. Petersburg, FL 



Carcinogens 

benzene 2.7E-02 2.84E-06 9.8E-10 1.4E-10 4.E-12 





1,4-dioxane 1.1E-02 7.40E-05 2.6E-08 3.7E-09 4.E-11 







acetone 9.0E-01 2.67E-03 9.2E-07 1.E-06 

benzene 8.6E-03 2.84E-06 9.8E-10 1.E-07 










1,4-dioxane NA 7.40E-05 2.6E-08 







phenol 3.0E-01 9.87E-07 3.4E-10 1.E-09 


toluene 1.4E+00 1.44E-02 5.0E-06 3.E-06 






xylenes 2.9E-02 5.28E-03 1.8E-06 6.E-05 


Totals 1.E-03 4.E-08 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Worker 









DRAFT 

Table A-10. Dose and Risk Calculations for Current Exposures to COPCs via Inhalation of Outdoor Air 

Pinellas Trail Jogger - Raytheon Facility - St. Petersburg, FL 



Carcinogens 

benzene 2.7E-02 3.8E-08 3.2E-10 1.4E-10 4.E-12 





1,4-dioxane 1.1E-02 7.2E-12 6.1E-14 2.6E-14 3.E-16 







acetone 9.0E-01 1.3E-08 1.3E-10 1.E-10 

benzene 8.6E-03 3.8E-08 3.8E-10 4.E-08 










1,4-dioxane NA 7.2E-12 7.0E-14 







phenol 3.0E-01 3.9E-09 3.8E-11 1.E-10 


toluene 1.4E+00 1.2E-04 1.2E-06 8.E-07 






xylenes 2.9E-02 2.2E-05 2.2E-07 8.E-06 


Totals 2.E-03 2.E-07 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Adult Child 

Coa Indoor Air Concentration mg/m 3 

Iri Inhalation Rate 3.2 1.2 m 3 /hr 

ET Exposure Time 0.25 0.25 hr/day 

EF Exposure Frequency 200 200 days/year 

ED Exposure Duration 30 6 year 

BW Body weight 51.9 16.8 kg 

AT Averaging Time 10,950 2,190 days 


DRAFT 



Carcinogens 

benzene 6.1E-02 0.0E+00 0.0E+00 0.0E+00 0.E+00 

chloroethane 2.9E-03 0.0E+00 0.0E+00 0.0E+00 0.E+00 

chloroform NA 0.0E+00 0.0E+00 0.0E+00 


1,2-dichloropropane 6.8E-02 0.0E+00 0.0E+00 0.0E+00 0.E+00 

1,4-dioxane 1.1E-02 6.9E-06 0.0077 1.7E-05 2.5E-07 3.E-09 

methylene chloride 7.5E-03 0.0E+00 0.0E+00 0.0E+00 0.E+00 

tetrachloroethene 5.2E-02 0.0E+00 0.0E+00 0.0E+00 0.E+00 

1,1,2-trichloroethane 7.0E-02 0.0E+00 0.0E+00 0.0E+00 0.E+00 

trichloroethene 1.2E-02 0.0E+00 0.0E+00 0.0E+00 0.E+00 

vinyl chloride 8.2E-01 0.0E+00 0.0E+00 0.0E+00 0.E+00 


acetone 9.0E-01 0.0E+00 0.0E+00 0.E+00 

benzene 3.6E-03 0.0E+00 0.0E+00 0.E+00 

carbon disulfide 1.0E-01 0.0E+00 0.0E+00 0.E+00 

chloroethane 4.0E-01 0.0E+00 0.0E+00 0.E+00 

chloroform 1.0E-02 0.0E+00 0.0E+00 0.E+00 



1,1-dichloroethene 5.0E-02 0.0E+00 0.0E+00 0.E+00 

cis-1,2-dichloroethene 1.0E-02 0.0E+00 0.0E+00 0.E+00 

trans-1,2-dichloroethene 2.0E-02 0.0E+00 0.0E+00 0.E+00 

1,2-dichloropropane 1.1E-03 0.0E+00 0.0E+00 0.E+00 

1,4-dioxane NA 0.0E+00 0.0E+00 

ethylbenzene 1.0E-01 0.0E+00 0.0E+00 0.E+00 

isopropylbenzene 1.0E-01 0.0E+00 0.0E+00 0.E+00 

methyl ethyl ketone 6.0E-01 0.0E+00 0.0E+00 0.E+00 


methylene chloride 6.0E-02 0.0E+00 0.0E+00 0.E+00 

4-methylphenol 3.7E-03 0.0E+00 0.0E+00 0.E+00 

phenol 3.0E-01 0.0E+00 0.0E+00 0.E+00 

tetrachloroethene 1.0E-02 0.0E+00 0.0E+00 0.E+00 

toluene 8.0E-02 0.0E+00 0.0E+00 0.E+00 

1,1,1-trichloroethane 2.8E-01 0.0E+00 0.0E+00 0.E+00 


trichloroethene 5.7E-03 0.0E+00 0.0E+00 0.E+00 

1,2,4-trimethylbenzene 5.0E-02 0.0E+00 0.0E+00 0.E+00 


xylenes 1.8E-01 0.0E+00 0.0E+00 0.E+00 

vinyl chloride 2.6E-03 0.0E+00 0.0E+00 0.E+00 

Totals 0.E+00 3.E-09 

DAD 

= 



Off-Site Construction/Utility Worker - Raytheon Facility - St. Petersburg, FL 

LADD 

DA 

event 

= 



DAD× 

ED 

70 


Worker 










DRAFT 


Off-Site Construction/Utility Worker - Raytheon Facility - St. Petersburg, FL 


Excess 

Cancer 


Carcinogens 

benzene 5.5E-02 0.00E+00 0.0E+00 0.0E+00 0.E+00 


chloroform NA 0.00E+00 0.0E+00 0.0E+00 



1,4-dioxane 1.1E-02 2.80E-04 6.7E-11 9.5E-13 1.E-14 







7.2E-01 0.00E+00 0.0E+00 0.0E+00 0.E+00 

acetone 9.0E-01 0.00E+00 0.0E+00 0.E+00 

benzene 4.0E-03 0.00E+00 0.0E+00 0.E+00 


chloroethane 4.0E-01 0.00E+00 0.0E+00 0.E+00 








1,4-dioxane NA 0.00E+00 0.0E+00 



methyl ethyl ketone 6.0E-01 0.00E+00 0.0E+00 0.E+00 




phenol 3.0E-01 0.00E+00 0.0E+00 0.E+00 


toluene 8.0E-02 0.00E+00 0.0E+00 0.E+00 






xylenes 2.0E-01 0.00E+00 0.0E+00 0.E+00 


Totals 0.E+00 1.E-14 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Worker 








DRAFT 


During Subsurface Excavation Activities - Off-Site Construction/Utility Worker - Raytheon Facility - St. Petersburg, FL 



Carcinogens 

benzene 2.7E-02 0.00E+00 0.0E+00 0.0E+00 0.E+00 


chloroform 8.1E-02 0.00E+00 0.0E+00 0.0E+00 0.E+00 



1,4-dioxane 1.1E-02 7.70E-07 6.7E-09 9.5E-11 1.E-12 





vinyl chloride 1.5E-02 0.00E+00 0.0E+00 0.0E+00 0.E+00 


acetone 9.0E-01 0.00E+00 0.0E+00 0.E+00 

benzene 8.6E-03 0.00E+00 0.0E+00 0.E+00 


chloroethane 2.9E+00 0.00E+00 0.0E+00 0.E+00 








1,4-dioxane NA 0.00E+00 0.0E+00 







phenol 3.0E-01 0.00E+00 0.0E+00 0.E+00 


toluene 1.4E+00 0.00E+00 0.0E+00 0.E+00 






xylenes 2.9E-02 0.00E+00 0.0E+00 0.E+00 


Totals 0.E+00 1.E-12 

ADD = 


BW × AT 

LADD = 

ADD × ED 

70 


Worker

Human Health Risk Assessment - Raytheon

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