RUBIS ROBINSON ROAD FUEL RELEASE · Black & Veatch International (BVI) prepared this report for the Bahamas Environmental, Science, and Technology (BEST) Commission to provide an

RUBIS ROBINSON ROAD FUEL RELEASE B&V PROJECT NO. 181652

PREPARED FOR

Bahamas Environmental Science and Technology Commission 20 FEBRUARY 2014

®

®

©Bl

ack

& V

eatc

h Ho

ldin

g Co

mpa

ny 2

012.

All

right

s res

erve

d.

Bahamas Environmental Science and Technology Commission | RUBIS ROBINSON ROAD FUEL RELEASE

BLACK & VEATCH | Table of Contents i

1.1.1.1.1.1.1 Table of Contents 1 Introduction ....................................................................................................................... 1 2 Summary of Release and Initial Response Actions ............................................... 3 3 Summary of Environmental Impacts ......................................................................... 5

3.1 Extent of Free Product.................................................................................................... 5 3.2 Extent of Impacted Soil .................................................................................................. 5 3.3 Extent of Impacted Groundwater .............................................................................. 6 3.4 Vapor Intrusion Potential ............................................................................................. 7

4 Planned Future Actions .................................................................................................. 9 5 Stakeholder Interviews ............................................................................................... 10 6 Assessment of Risk ........................................................................................................ 13

6.1 CBL CSR Building ........................................................................................................... 13 6.2 CBL HEB Building .......................................................................................................... 15 6.3 Residential Exposure ................................................................................................... 15 6.3.1 Residential Risk from Groundwater Exposure ............................................. 15 6.3.3 Residential Risk from Migration of Soil Vapors ........................................... 17

7 Conclusions ...................................................................................................................... 18 7.1 Exposure issues .............................................................................................................. 18 7.2 Recommendations ........................................................................................................ 18

LIST OF FIGURES FROM DECEMBER 2013 CAR REPORT INCLUDED AS ATTACHMENT Figure 1 Site Layout/Vapor Sample Locations Map Figure 2 Surrounding Land Use Map Figure 3 Site Map Figure 8 Soil Assessment/UST Sampling Loccations Figure 10 Inferred Extent of Product (March 2013) Figure 11 Inferred Extent of Product (May 2013) Figure 12 Product Thickness (June 2012) Figure 14 Private Well Locations Figure 16 Inferred Extent of Dissolved Benzene (October 2013)

APPENDICES Appendix A CBL Fuel Release Timeline Appendix B CBL CSR Building Indoor Air Risk Assessment Appendix C Munroe Residence Risk Assessment


BLACK & VEATCH | Table of Contents ii

Acronyms and Abbreviations AS air sparging BEST Bahamas Environmental, Science, and Technology Commission BTEX benzene, toluene, ethylbenzene, and xylenes BVI Black & Veatch International CAR Contamination Assessment Report CBL Cable Bahamas Ltd. CSR CBL Customer/Service Retail building cy cubic yards DEHS Department of Environmental Health Services EMRAD Environmental Monitoring and Risk Assessment Division EPA U.S. Environmental Protection Agency FDEP Florida Department of Environmental Protection HEB CBL Head-End building LNAPL light non-aqueous phase liquid MEP multi-phase extraction point µg/L micrograms per liter µg/m3 micrograms per cubic meter ppm parts per million RAP Remediation Action Plan Rubis Rubis Bahamas, Ltd SVE soil vapor extraction UST underground storage tank VOC volatile organic compound


BLACK & VEATCH | Introduction 1

1 Introduction Black & Veatch International (BVI) prepared this report for the Bahamas Environmental, Science, and Technology (BEST) Commission to provide an overall assessment of the unleaded gasoline release that occurred at the Rubis Bahamas, Ltd (Rubis) Robinson Road gas station facility in late 2012/early 2013. The facility is at the southwest corner of the intersection of Robinson and Old Trail Roads in the Highbury Park area within Nassau on the New Providence Island in the Bahamas. The site is surrounded by commercial properties on the north, south, and west, and by a residential area to the east. Cable Bahamas Ltd. (CBL) occupies the adjacent properties to the west and south that house cable operations. The building to the west is the Customer/Service Retail (CSR) building, and the building to the south is the Head-End (HEB) building. Figures 1 and 2 show the layout and location of the site.

The primary goal of the assessment is to ensure that the actions taken by Rubis to address the release are appropriate to protect public health and adequately remediate the environment.

As part of this assessment, the following documents were reviewed to understand the nature of the release, associated environmental impacts, actions being taken to address the release, and stakeholder concerns:

Summary Report on Robinson Road Service Station Fuel Oil Spill, Environmental Monitoring and Risk Assessment Division (EMRAD) at the Department of Environmental Health Services (DEHS), Ministry of the Environment and Housing, March 8, 2013.

Letter to all residents neighboring the Texaco, Robinson Road Service Station from EMRAD DEHS, dated March 8, 2013.

Limited Site Assessment Report, Rubis Robinson Road, prepared by Arcadis for Rubis Bahamas, Ltd., dated March 27, 2013.

Action Plan for Cable Bahamas Facility, CSR Building, prepared by Arcadis for Rubis Bahamas, Ltd., dated June 28, 2013.

Letter from Ms. Lillian Russell, addressed to the Minister of the Environment and Housing, dated July 25, 2013.

Cable Bahamas Ltd. Environmental Analytical and Data Reports, compilation of data collected in January-March 2013, provided to BEST in a letter dated April 19, 2013.

Limited Site Assessment Report, Rubis Robinson Road, prepared by Arcadis for Rubis Bahamas, Ltd., dated August 27, 2013.

Guideline Document, Addressing Emergency and Non Emergency Fuel Oil Spills Cleanup, Inland, Draft for Review, EMRAD DHES, July 2011 Revision.

Contamination Assessment Report, Rubis Robinson Road, prepared by Arcadis for Rubis Bahamas, Ltd., dated December 11, 2013.

Remedial Action Plan, Rubis Robinson Road, prepared by Arcadis for Rubis Bahamas, Ltd., dated December 11, 2013.

Letter from Richard C. and Adrianne A. Munroe, addressed to the Director of the BEST Commission, dated December 19, 2013.


BLACK & VEATCH | Introduction 2

To complete this assessment, a site visit and interviews with Rubis and residential and business stakeholders were also conducted on November 14-16, 2013. A conference call was held with EMRAD DEHS on December 3, 2013.

The Commonwealth of The Bahamas has not promulgated any specific environmental laws associated with contamination liability and cleanup. However, EMRAD DEHS has a draft policy document that addresses appropriate response actions to be taken in the event of a fuel release. In addition, as reported by EMRAD/DEHS officials, the Department has reviewed and approved the remediation efforts by Rubis in accordance with DEHS protocol. The Department will continue to monitor site conditions to ensure the safety of the neighboring residents.

The following subsections summarize the information gathered during the site visit, review of provided documents and reports, discussions with Rubis and stakeholders, assessment of risk, and conclusions and recommendations. Figures presented at the end of the document and summary information contained herein were taken from the December 2013 Contamination Assessment Report (CAR) and Remediation Action Plan (RAP). These documents are assumed to supersede the preliminary information provided in the March and August assessment reports, some of which conflicts with the December report.


BLACK & VEATCH | Summary of Release and Initial Response Actions 3

2 Summary of Release and Initial Response Actions The release was reported to Rubis management on January 19, 2013. It was also reported that the leak was thought to have began on November 25, 2012. The release occurred in the riser pipe between the fuel tank and dispenser number 5. The equipment was repaired on January 21, 2013. All tanks and lines passed tightness testing following the repairs. Variance records show that approximately 24,000 gallons of unleaded gasoline were released.

On January 23, 2013, gasoline odors were noted by CBL personnel in the CSR building, and the building was evacuated. On January 24, two test pits were excavated by Environmental Response Concepts, Ltd, for CBL along the eastern property line between the CSR building and the Rubis property. CBL indicated that free product was observed in the test pits. Monitoring wells were installed in the test pits.

In response to the CBL notification of this finding to Rubis, they began an assessment and cleanup following Florida Administrative Code rules for emergency response. The response included excavating a trench parallel to the service station western property line on January 25. Free product was present in the trench. Seven borings were advanced; four contained product over 1 foot thick. Subsequent investigation activities included advancing additional borings to evaluate soil contamination and installing monitoring wells to evaluate groundwater contamination.

By January 31, 2013, DEHS EMRAD had been notified of the release and actions being taken, began providing guidance to Rubis, and had conducted a site visit.

Investigation locations were advanced both on the Rubis and adjacent properties. On February 8, Rubis closed the service station to expedite the remediation of impacted soil and groundwater, including the recovery of gasoline (free product) and soil vapor extraction (SVE) to treat impacted soil and groundwater.

Figure 3 shows the overall layout of the site.

Between January and November 2013, the following activities were conducted:

In late January/early February, an interceptor trench was constructed along the west property boundary to recover free product.

In January and February, test holes were advanced on the Rubis and adjacent properties to delineate the extent of free product impacts.

In February, a pilot scale SVE/multi-phase extraction point (MEP) system was constructed on the Rubis property and tested to gather data for design of CSR SVE system.

In early 2013, the quality of the air in the grates/sewer drains in the roadway along Robinson Road and at the east entrance on Old Trail Road were measured with a hand-held device that detects volatile organic compounds (VOCs). The highest detection was recorded in a grate located in the middle of Robinson Road at 32.8 parts per million (ppm).

Between February and May, monitoring and gasoline recovery wells were installed on and off site. Well locations are shown on Figure 3. On the site, 32 wells and an extraction trench were installed. Ten wells were installed on CBL property, and 16 wells were installed on private


BLACK & VEATCH | Summary of Release and Initial Response Actions 4

properties to the north and east of Robinson Road. After installation, a vacuum truck was used to recover product from selected wells both on the Rubis property and on private property north of Robinson Road.

In March, May, and October, groundwater samples were collected from monitoring wells located both on and off site. The results of the sampling efforts are reported in the December 2013 CAR.

In May, a survey of the number and location of private water wells was conducted within a 200-meter radius of the site. Fifty of the 55 private wells identified within this radius were sampled (Figure 14).

In June, an interim SVE system was constructed on site and began operation.

In July, wells along the property boundary between Rubis and the CBL HEB were included in the interim SVE system.

In August four underground storage tanks (USTs) and associated piping, located in the southeast corner of the property, were removed.

In August, additional SVE pilot testing was conducted to confirm the results of the February pilot test.

In August and September, test holes were advanced on site and soil samples were collected around the pumping station and from the UST removal area.

In August 2013, approximately 315 cubic yards (cy) of subsurface impacted soils were removed along with four USTs. An additional 135 cy of impacted soil were removed from dispenser area 5 on the Rubis property.

In September 2013, six soil gas monitoring points were installed along the northern boundary of the HEB property and samples collected to determine if site-related constituents were present and posed an indoor air inhalation risk to the CBL HEB.

In September/October 2013, soil gas, sub-slab, and indoor air samples were collected to assess the vapor intrusion potential on properties north of Robinson Road.

In November 2013, a deep monitoring well was installed to assess the vertical extent of groundwater impacts.


BLACK & VEATCH | Summary of Environmental Impacts 5

3 Summary of Environmental Impacts As a result of the investigations conducted by Rubis, environmental impacts to soil, groundwater, and indoor air were found on the site, adjacent CBL properties, and commercial and residential properties on the north side of Robinson Road. Both business and residential populations were impacted by the release, including evacuation of the CSR building west of the site and gasoline odors and sheen on private well water from residential properties north of the site.

The following sections summarize the environmental impacts based on the initial release of gasoline.

3.1 EXTENT OF FREE PRODUCT Based on the information presented in the December 2013 CAR, free product (i.e., gasoline) was initially present in private wells on residential properties on the north side of Robinson Road, within the site boundary to the east, to the south in wells along the CBL/Rubis property line, and to the west in offsite wells between the Rubis property and the CSR building. Gasoline is lighter than water, so it floats on top of groundwater.

Free product was observed in wells at the following thicknesses:

0.8 to 2.4 feet along the western portion of the Rubis property and in the northeast portion of CBL property

0.2 to 1.3 feet along the northern and eastern portions of the Rubis property.

0.25 to 1.7 feet north of the Rubis property and Robinson Road.

Remediation activities conducted since January 2013 to remove free product (using a vacuum truck, manually bailing, skimming, and operating the interim SVE system) has resulted in no measureable free product remaining in any monitoring or recovery wells since July 29, 2013. As stated in the December 2013 CAR, there is likely free product held up in the soil that has not entered the well system.

The CAR reported that approximately 7,173 gallons were recovered from the trench, wells, and SVE system to date. Figures 10, 11, and 12 show the extent of free product observed in March, May, and June 2013.

3.2 EXTENT OF IMPACTED SOIL Based on the initial findings from the interim remedial action activities and samples associated with the UST and piping removal in August 2013, a supplemental soil assessment was conducted to delineate the horizontal and vertical extent of impacted soil. Figure 8 shows the sample locations from the August/September 2013 investigation.

The investigation began near the source of contamination (fuel dispenser island) and proceeded outward in approximate 30-foot grid intervals to determine the horizontal extent of contamination. The investigation showed that impacts to soil and the highest contaminant concentrations were in the general area of the release. No evidence was observed that impacts from the release extended southeast along UST lines towards the UST pit (i.e., away from the dispensers).



Two deep borings were advanced in the fuel dispenser area to depths of 34.5 and 45 feet to determine the vertical extent of contamination. The borings were advanced below the extent of known contamination without casing off the contaminated zone, which may have resulted in “dragging” contamination deeper into the aquifer. Soil samples collected near the base of each boring contained gasoline-related chemicals; however, the concentrations were below Florida Department of Environmental Protection (FDEP) soil screening levels.

Soil sampling was conducted near well MW-28 and during removal of the USTs to determine the extent of soil contamination in the HEB area. Concentrations of petroleum-related contaminants were below the FDEP soil screening levels.

3.3 EXTENT OF IMPACTED GROUNDWATER The extent of contamination in groundwater was assessed during three sampling events in March 2013 (sampling onsite and offsite monitoring wells and two private wells), May 2013 (sampling 50 private wells), and October 2013 (sampling a subset of monitoring wells). Figure 16 shows the extent of benzene in the groundwater surrounding the site based on the combination of data from all sampling events. It also shows the well locations. Benzene is a common component of gasoline and other fuels, and based on its chemical properties, is a good indicator of the overall extent of a groundwater contaminant plume. The figure shows that offsite wells exceed both the U.S. Environmental Protection Agency (EPA) residential groundwater screening level of 0.39 µg/L and the FDEP groundwater target cleanup level of 1 µg/L. Four monitoring/private wells sampled in May 2013 on the north side of Robinson Road contained concentrations exceeding both the FDEP and EPA screening levels for benzene:

Munroe residence at 58 Grace Avenue. Well MW-44 contained 390 µg/L of benzene.

Evans residence adjacent to and west of the Munroe residence. Well MW-48 contained 69 µg/L of benzene.

Commercial property south of Munroe residence. Well MW-41 contained 9,900 µg/L of benzene.

Commercial property west of Evans residence. Well MW-45 contained 4,200 µg/L of benzene.

It should be noted that these wells were not sampled in October 2013.

Several private wells were decommissioned in May 2013. According to Rubis, no residences in the immediate area of the release are using well water for any purpose.

The deep monitoring well installed in the fuel dispenser area contained 51 µg/L of benzene in October 2013. This concentration is more than 50 times the FDEP level of 1 µg/L. The December 2013 CAR indicates that this contamination may be the result of “dragging” contamination deeper into the aquifer due to drilling methods.

A groundwater contaminant plume that appears to be separate from the contamination caused by the fuel dispenser release is located in the southeast corner of the Rubis property near the CBL HEB. In October 2013, well MW-52 contained 430 µg/L of benzene. Well MW-28 sampled in May 2013 contained 1,350 µg/L of benzene. Well MW-28 is located closer to the former UST area.



3.4 VAPOR INTRUSION POTENTIAL Vapor intrusion occurs when volatile chemicals migrate from contaminated groundwater or soil into an overlying building. Volatile chemicals can emit vapors (or gas) that may migrate through subsurface soils and into indoor air spaces of overlying buildings through crack or other openings in foundations. The presence of free product and elevated concentrations of volatile chemicals in groundwater near buildings represents a risk of vapor intrusion.

As documented in the December 2013 CAR, the potential for vapor intrusion was assessed for the CBL HEB and structures north of Robinson Road. The assessment consisted of two phases. During the first phase, soil gas samples were collected near potentially impacted structures. The second phase consisted of collecting soil gas samples directly below the foundations of structures and indoor air samples from the interior of the structures. The sampling and assessment were completed following standard EPA vapor intrusion protocol at a cancer risk level of 1x10-5 (risk of one person in 100,000 developing cancer), a hazard index of 1.0 (above this level, adverse non-carcinogenic health effects could occur), and using an attenuation factor of soil gas to indoor air of 0.03. EPA generally accepts risks between 1x10-4 and 1x10-6 and hazard indices less than 1.0. However, experience indicates that without indoor air data, a risk level of 1x10-6 should be evaluated. In addition, an attenuation factor of 0.1 is more generally accepted by EPA. The attenuation factor takes into account that chemicals will decrease in concentration as they move through soil gas and into a building. EPA also recommends that more than one round of sampling be conducted to assess the potential for indoor air risk.

For the CBL HEB, the December 2013 CAR reported a risk of 9x10-6 and a hazard index of 0.2 for the soil gas samples collected near the building. Therefore, the second phase of evaluation was not conducted because the calculated risk was less than 1x10-5 and 1.0. However, it should be noted that comparison of the benzene concentration in the six samples collected with the EPA industrial indoor air screening levels at an attenuation factor of 0.1, results in the four samples with detections exceeding the screening level at both 1x10-5 and 1x10-6 risk levels. The laboratory reporting limits for the other two samples also exceeded both screening levels.

Soil gas samples were collected from nine locations near the two commercial structures and the Munroe and Evans residences on the north side of Robinson Road. Risk calculations indicated a potential for indoor air risk for the two commercial structures and the Evans residence. As a result, indoor air and soil gas samples were collected below the foundations of one of the commercial buildings and the residence. Access to the other commercial building was not granted. It should be noted that only one of the soil gas samples collected near the Munroe residence can be compared with EPA residential screening levels because laboratory reporting limits were not sufficiently low. The reporting limits for benzene and other chemicals exceed the screening levels considering both the 0.03 attenuation factor used by Rubis as well as the more conservative 0.1 factor. This residence should have been included in the second phase of evaluation.

Several volatile chemicals were detected in the indoor air samples collected from the Evans residence including benzene and naphthalene. While no chemicals were detected in the soil gas samples collected from beneath the residence, the laboratory reporting limits were not sufficiently low to provide comparison with the indoor air sample results. The reporting limits for the indoor



air samples were three orders of magnitude lower than the limits for the soil gas samples. The 2013 CAR concludes that the pathway between soil gas and indoor air is incomplete and that there is no risk to the residents via this pathway to site contamination. Based on the reporting limit discrepancy, this conclusion is not appropriate.

Benzene and toluene were detected in soil gas below the foundation of the commercial building housing a convenience store. Benzene, toluene, ethylbenzene, xylenes, and naphthalene were detected in the indoor air samples collected from the convenience store. With the exception of naphthalene, all indoor air detections are below the non-residential EPA screening levels. The CAR suggests that the source of the naphthalene is from an indoor source; however, this cannot be confirmed because the reporting limits for the soil gas samples are not sufficiently low to compare with the indoor air data.

Using the maximum indoor air concentrations for the convenience store and Evans residence, the risk to building occupants was calculated and presented in the CAR:

Convenience store-hazard index of 0.1 and cancer risk of 1x10-6.

Evans residences-hazard index of 0.6 and cancer risk of 3x10-5.

These risks are within the EPA acceptable risk ranges; therefore, an unacceptable risk due vapor intrusion is not occurring. However, it cannot be concluded that the source of the measured indoor air concentrations is not related to the Rubis release. In addition, only one round of data were collected.


BLACK & VEATCH | Planned Future Actions 9

4 Planned Future Actions Based on information presented in December 2013 CAR and RAP documents, additional action is planned to continue to treat the groundwater impacted by the fuel release. Objectives of the cleanup effort are to expedite it by continuing to remove chemical mass from the subsurface and developing conditions in the groundwater to allow for the natural attenuation of contaminant concentrations to meet the FDEP groundwater cleanup target levels. The following specific items are delineated in the documents as planned ongoing/future actions:

Initiating the SVE systems for the CBL buildings and properties to the north of Robinson Road to minimize potential migration of vapors and to mitigate vapor intrusion concerns. Upgrading the onsite SVE system to include air sparging (AS) and additional SVE points. The system will be operated in four AS and two SVE zones to address onsite areas, as well as the north side of the CBL CSR and the northeast side of the CBL HEB.

Installing and operating a sub-slab depressurization system for the CBL CSR building (pending access from CBL).

Gauging free product levels in onsite and offsite wells to verify that levels do not increase.

Installing a monitoring well on the CBL HEB property to further define the groundwater plume near the southwestern corner of the site (pending access from CBL).

Re-sampling deep well DW-1.

Sampling groundwater to monitor progress in attaining remedial action objectives.

Quarterly and annual reports to document activities completed and status in attaining cleanup objectives.

The RAP indicates that once significant progress is made toward attaining cleanup objectives through active remediation, a post-active remediation monitoring program will be implemented to verify that impacts at the service station and surrounding properties are addressed.


BLACK & VEATCH | Stakeholder Interviews 10

5 Stakeholder Interviews BVI met with representatives from the following business and government entities during the November 2013 site visit:

Rubis

Arcadis

CBL

Department of Public Health, Ministry of Health

Water and Sewerage Corporation

The results of these discussions are presented herein. The information provided as a result of discussions with Rubis and Arcadis are incorporated into Sections 2.0 through 5.0.

Discussion with John Gomez and Lester A. DeGregory of CBL and Philip E. Elson of Aerostar SES (CBL environmental consultant) provided the following information:

CBL has an access agreement with Rubis for investigation-related activities; however, the access agreement for remediation-related activities has not yet been resolved.

178 people worked in the CSR building before it was evacuated, up to 7 days per week.

An estimated 44,000 cable subscribers paid their monthly bills in the CSR building.

Issues with gasoline fumes in the CSR building occurred approximately 2 years ago whenever the tanks were refueled or when it rained. To alleviate the fumes, CBL turned off the air conditioning and vented the building. The building was evacuated on several occasions. Texaco measured VOCs in the building using a photoionization device (a common instrument used to measure total VOCs in air) in January 2013. The data were not shared with CBL, who stated that Texaco said the fumes were not gasoline-related. However, the vent stacks for the tanks were repositioned so as not to discharge near the CSR Building. (Note: The vent stacks were repositioned a number of years earlier to address complaints from the residents east of the facility who encountered gasoline fumes during tank refueling operations at the facility.) Records of reports of odors and fumes to Texaco and Rubis have been maintained by CBL.

In January 23 2013, the CSR building was evacuated. As a result of the exposure, two employees were sent to the hospital. One employee with severe asthma remains unable to return to work. The building remains unoccupied. Appendix A contains as timeline provided by CBL regarding the fuel spill, including three temporary evacuations in 2012.

In early 2013, CBL excavated a trench on their property to collect samples and collected indoor air samples from the CSR Building.

The environmental consultant (Aerostor SES) for CBL noted that both sporadic (acute) and continuous (chronic) exposures to employees have occurred. Sporadic exposure is associated with the refueling operations, and chronic exposure is associated with the gasoline release.

CBL has repeatedly asked for data and plans for addressing site-wide contamination from Rubis. They have only received an action plan associated with their property.



BVI spoke with Dr. Pearl McMillan and Dr. Smith of the Department of Public Health. Discussion provided the following information:

The Ministry is concerned with public health issues.

The Ministry has received no direct contact or complaints regarding the release at the Rubis Robinson Road facility.

The Ministry has not received any information or findings associated with the release at the Rubis Robinson Road facility.

The Ministry is not pleased with the lack of communication regarding the release at the Rubis Robinson Road facility.

BVI spoke with Dr Richard V. Cant, representing the Water and Sewerage Corporation. Discussion provided the following information:

Groundwater flow on New Providence Island is generally radial, from the center of the island towards the coastline. However. several fresh water lenses are documented in portions of the island which coincide with topographically elevated ridges and sufficient recharge to build up such a lens.

The site has two main aquifer units found in the Bahamas consisting of Holocene sand aquifers and the Lucayan Limestone aquifers. Several freshwater lenses are documented in the portion of the island coinciding with the site location.

BVI also met with four residential property owners:

Lillian Russell, who has lived in her home east of the Rubis facility along Old Trail Road for over 35 years.

Bemel and Barbara Holder, who have lived in their home southeast of the Rubis facility along old Trail Road since 1969.

Richard C. Munroe who has lived in his home northeast of the Rubis facility across Robinson Road along Gracie Avenue for over 40 years.

Kendrick Evans who lives in a home directly north of the Rubis facility across Robinson Road. He has leased a portion of his property to Rubis for installation of a SVE system to remediate gasoline-related contamination that has migrated across Robinson Road.

Ms. Russell, the Holders, and Mr. Munroe related great frustration with the lack of communication regarding the release at the Rubis facility, the actions being taken to address the contamination, and the findings associated with samples collected from their properties.

Based on discussions with Ms. Russell and the Holders, another release occurred at the facility approximately 20 years ago that resulted in contamination of their private wells. At that time, samples were collected from both residents’ wells and both were told that their well water was contaminated and they should use the government water supply. Both residents also observed gasoline on water in a trench excavated near the HEB south of the current Rubis facility. Neither property owner is aware of any cleanup action initiated as a result of this spill that occurred in the



early 1990s. Ms. Russell owner noted that the fruit on the Juju tree in her yard withered and died after this historic release occurred. Ms. Russell also noted that many people in the area have died of cancer, including her mother.

Mr. Munroe indicated that his family used water from their private well for cooking, washing, and bathing, but purchased water for drinking. Around January 10, 2013, they began noticing gasoline odors in the water and notified personnel on the Rubis facility. Thereafter, they discontinued use of well water at the advice of Rubis. The Munroe’s indicated their dissatisfaction regarding the lack of communications regarding the cleanup work and the status of their well water. Although their well and other wells installed by Rubis on their property have been sampled, they have not been provided the results of the testing.

Mr. Evans indicated that he switched from using well water to government water in May 2013. He stated that he never smelled any odors but a lot of other folks complained about it. He was told by Rubis that the SVE system on his property would be operated for 1 to 2 years.

A conference call was held between representatives of BEST, BVI, and Mr. Anthony Ryan of DEHS on December 3. The following information was obtained:

DEHS is concerned with the environment and public health and has been involved with the Rubis Robinson Road release since it occurred in early January 2013 and continues to be involved to date.

DEHS has directed Rubis to conduct the cleanup as delineated in the oil spill policy document, and has provided guidance regarding and approval of laboratories, work plans, reports, investigations, and interim remedial activities.

DEHS has been on site during many activities including, but not limited to, soil and groundwater sampling, removal of fuel tanks and piping, initial setup and operation of the MEP/SVE systems, private well survey, and sampling of private wells.

DEHS has communicated both verbally and in writing with property owners surrounding the Rubis facility. There is a currently an administrative restriction on DEHS communication with the public; however, DEHS continues to provide approvals and support to Rubis.

DEHS is not pleased with the lack of communication and cooperation regarding Rubis access to the CBL property west of the site to perform remedial activities.


BLACK & VEATCH | Assessment of Risk 13

6 Assessment of Risk Nearby residents, workers in both the CBL CSR and HEB buildings, and occupants and visitors to the commercial buildings on the north side of Robinson Road were potentially exposed to chemicals as a result of the Rubis release from its Robinson Road gas station. Two primary exposure pathways exist: contaminant migration through the groundwater to private wells and contaminant migration through soil gas into occupied structures.

An assessment following standard EPA human health risk assessment protocol and incorporating both EPA screening levels and FDEP groundwater cleanup target levels was completed. The EPA risk assessment process involves evaluating toxicity, assessing exposures, and characterizing risk. To evaluate potential health risks, both carcinogenic and non-carcinogenic health effects must be considered. The potential for producing carcinogenic effects is limited to substances that have been shown to be carcinogenic in animals and/or humans. Excessive exposure to all substances, carcinogens and non-carcinogens, can produce adverse non-carcinogenic effects.

To assess exposure, assumptions must be made regarding factors that contribute to risk, including length and duration of exposure, type of exposure (ingestion of water, showering, direct contact with skin), age group, ingestion/dermal contact rates, etc.

During risk characterization, the results of the exposure and toxicity assessments are integrated to determine the degree of potential carcinogenic and non-carcinogenic health risks posed to receptors. It should be noted that safety factors are built into each stage of risk assessment that typically result in a conservative estimate of risk. As mentioned previously, EPA generally accepts carcinogenic risks in the range of 1x10-6 to 1x10-4 and non-carcinogenic health effects under a hazard index of 1.0.

Additional detail regarding the EPA risk assessment process can be found at their main risk assessment web address http://www.epa.gov/oswer/riskassessment/risk_superfund.htm.

EPA has also developed screening levels based on standard default exposure assumptions at a carcinogenic risk level of 1x10-6 and a hazard index of 1.0. These levels provide easy comparison to chemical concentrations to determine if the concentration is above an acceptable risk level. Using screening levels does not allow evaluation of the cumulative effects of chemicals as does a standard risk assessment.

Equations used to develop risk-based screening levels (including exposure assumptions) and the risk-based screening tables can be found at the following web addresses:

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/equations.htm

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/index.htm

Exposure risks associated with the CBL CSR and HEB buildings and residents on the north side of Robinson Road were evaluated. The results of the assessment are provided in the following sections.

6.1 CBL CSR BUILDING As presented earlier in the report, the building was evacuated based on the presence of gasoline odors in the building subsequent to the Rubis release. Following evacuation, CBL measured the levels of total volatile organic compounds (VOCs) with a PID on January 23 and 24, and after

http://www.epa.gov/oswer/riskassessment/risk_superfund.htm�

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/equations.htm�

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/index.htm�



expansion joints were sealed along the foundation on January 26. Total VOCs measured in the building ranged as follows:

January 23-30 to 492 parts per million (ppm)

January 24-30 to 900 ppm

January 26-0 to 13.4 ppm

These results suggest that sealing the expansion joints decreased the overall concentration of VOCs entering the building. Additional measurements collected on nine days between January 30 and February 11 indicate that VOCs and hydrocarbon odors were still present in the building.

Indoor air samples for chemical analysis were collected by CBL’s contractor on five days in late January and early February 2013 from three locations inside the CSR as well as outside of the north end of the building. Benzene was detected in all building air samples at concentrations exceeding the EPA non-residential screening level (1.6 µg/m3 or 0.0005 ppm). Three of the five ambient air samples also exceeded the screening level. This suggests that occupants in the building before it was evacuated were exposed to concentrations of benzene exceeding an acceptable exposure level.

To determine overall risk, additional factors need to be considered including length and duration of exposure. CBL stated that the building was evacuated the same day that petroleum odors were first observed; however, it is possible that gasoline vapors were present in the building before they were perceived by occupants of the building. In addition, as noted on the time line in Appendix A, the building was temporarily evacuated twice in December 2012 and once in October 2012. The odor threshold for gasoline is in the range of 0.3 ppm, which is considerably higher than the EPA screening level. Considering that the leak may have occurred as early as November 25, and that although it would not be expected that free product or groundwater impacts would be immediately present in the area of the CSR, it is possible that gasoline vapors were entering the building before any odor was noted.

The following table outlines the assumptions made to complete a conservative assessment of the potential risk to the occupants of the CSR resulting from the November 2013 release at the adjacent Rubis facility:

EXPOSURE PARAMETER EXPOSURE ASSUMPTION Chemicals of concern Benzene, toluene, ethylbenzene, xylenes (BTEX) and

naphthalene at maximum concentration detected

Exposure frequency range 22, 46, 100 days based on time line in Appendix A

Exposure time Typical 12-hour work day

Exposure duration 1 year since exposure no longer exists

BTEX and naphthalene are the most likely chemicals to be present in the indoor air based on their presence in gasoline and higher volatility compared to other chemicals. Appendix B contains a table that summarizes the concentrations of BTEX and naphthalene detected in the CSR building.

The following table summarizes the risks determined during the assessment.



TYPE OF RISK 22 DAYS 46 DAYS 100 DAYS Carcinogenic risk 1.1 x 10-6 Acceptable 2.3x10-6 Acceptable 5.0x10-6 Acceptable

Non-carcinogenic hazard index

2.74 Not acceptable

5.73 Not acceptable

12.46 Not acceptable

While these risks are within the acceptable EPA levels for carcinogenic risk of 1x10-6 to 1x10-4, all exposures result in an unacceptable risk of incurring adverse non-carcinogenic health effects from the exposure that occurred in late 2012/early 2013 in the CBL CSR building. All hazard indices exceed 1.0.

A table summarizing the risk calculations is included in Appendix B.

6.2 CBL HEB BUILDING The only data available to assess risk associated with occupants of the HEB are the soil gas data generated during the Rubis investigation. As indicated in Section 3.4, comparison of these data with more conservative screening levels (1x10-6 rather than 1x10-5) and consideration of a more widely accepted attenuation factor (0.1 rather than 0.03) suggest that the soil gas concentrations are at levels that if migration into the HEB building occurred, it would represent an unacceptable risk. Based on this, conducting the second phase of the vapor intrusion assessment is warranted. However, it should be noted that incorporating the more conservative attenuation factor in the risk assessment presented in the December 2013 CAR results in a carcinogenic risk of 2.9x10-5 and a hazard index of 0.6, which are still within acceptable ranges. Therefore, based on the data collected by Rubis to date, occupants of this building are not being exposed to unhealthy levels of chemicals in the building associated with the gasoline release.

6.3 RESIDENTIAL EXPOSURE The greatest potential for exposure is to the two residential properties located north of the Rubis facility on the north side of Robinson Road because exposure to chemical is possible through multiple pathways. Through interviews with the residents, the Munroe family was directly exposed to site-related contamination by January 10, 2013 from using impacted groundwater from their private well. There is also a potential for site-related chemicals to migrate into the residences through vapor intrusion.

Using applicable data from the December 2013 CAR, the following sections evaluate the risk associated with exposure to contaminated groundwater and chemicals through vapor intrusion.

6.3.1 Residential Risk from Groundwater Exposure The gasoline release occurred in November 2012; however, product levels were not measured in the private wells until March 2013 and samples were not collected from the private wells until May 2013. Therefore, it is difficult to assess when the private wells on the north side of Robinson Road were first impacted. Based on information provided in the December 2013 CAR, it takes between 6 and 21 days for groundwater near the release area to reach the private wells. This suggests that, in the absence of any fate and transport mechanisms limiting the migration of contamination, chemicals may have reached the wells as early as the end of November 2012. Because of fate and transport mechanisms, chemicals do not necessarily migrate at the same rate as the groundwater.



Predicting the movement of gasoline and contaminants in groundwater can be difficult. The Munroe family first began noticing a gasoline odor in their water on January 10, 2013. It is unclear whether, at this point, they refrained from using private well water or continued to use the water until the well was decommissioned in May 2013.

With limited information regarding the duration of exposure to impacted water from the private well, along with EPA default exposure assumptions for ingestion, dermal exposure, and inhalation, the following assumptions were made to assess the potential risk:

EXPOSURE PARAMETER EXPOSURE ASSUMPTION Chemicals of concern BTEX detected in well MW-44 (Munroe private well) in May 2013-

benzene (390 µg/L), toluene (2,600 µg/L), ethylbenzene (65 µg/L), and xylenes (2,900 µg/L)

Exposure frequency range 40-approximate days between release and first presence of odor in well, assuming migration duration of 6 days 90 days-approximate days between release and measurement of product levels in March 2013, assuming a migration duration of 21 days 160-approximate days based on release date and May 2013 well closure, assuming a migration duration of 21 days

Exposure population Adult only or adult and child combined

The tables in Appendix C include the standard EPA default exposure parameters, as well as the calculations to assess risk.

The following table summarizes the resultant carcinogenic and non-carcinogenic risks determined during the assessment. It should be noted that the assumption of 6 to 21 days for contamination to migrate from the initial release is conservative because it does not consider natural fate and transport processes that slow down the movement of contaminants in groundwater.

TYPE OF RISK 40 DAYS 90 DAYS 160 DAYS Adult: Carcinogenic risk

1.2 x 10-6 Acceptable 2.8x10-6 Acceptable 5.0x10-6 Acceptable

Adult: Non-carcinogenic hazard index

0.53 Acceptable 1.2 Not acceptable

2.1 Not acceptable

Adult/child: Carcinogenic risk

4.1 x 10-5 Acceptable 9.2x10-5 Acceptable 1.6x10-4 Not Acceptable

Adult/child: Non-carcinogenic hazard index

1.1 Not acceptable

2.5 Not acceptable

4.5 Not acceptable

All adult combined with child exposures and 2 of 3 adult only exposures result in an unacceptable risk of incurring adverse non-carcinogenic health effects from the exposure that occurred early in



2013. Only the calculated carcinogenic risk for 160 days of adult/child exposure to impacted groundwater results in an unacceptable risk.

6.3.3 Residential Risk from Migration of Soil Vapors As noted in Section 3.4, the analytical data for the soil gas samples collected near the Munroe residence were not reported with low enough laboratory reporting limits to compare with screening levels. The reporting limits exceed the EPA residential indoor air screening levels. The reporting limit for benzene and other chemicals exceed the screening levels (residential screening level for benzene is 0.31 µg/m3) considering both the 0.1 and 0.03 attenuation factors. Additional data would need to be collected to be able to make an assessment of the vapor intrusion risk at the Munroe residence. With the data provided in the 2013 CAR, the risk to the Munroe residents cannot be determined.

Near the Evans residence, soil gas samples contained concentrations of site-related chemicals above acceptable levels; therefore, soil gas samples were collected below the residence’s foundation as well as air samples from the interior of the structure. As indicated in Section 3.4, the detection limits for the soil gas samples were not low enough for comparison with the indoor air data. It should be noted, however, that the calculated risks associated with the one round of indoor air detections (hazard index of 0.6 and carcinogenic risk of 3x10-5) are within acceptable levels. Therefore, it appears that the Evans residents have not been adversely impacted by chemicals from the release. However, because the reporting limits were too high, it is not known the contribution of site-related contamination to the concentrations detected in the indoor air.

As noted in Section 3.4, the risks associated with the one round of indoor data collected from the convenience store on the north side of Robinson Road are also within acceptable levels (hazard index of 0.1 and cancer risk of 1x10-6). As with the Evans, it appears that the occupants of the convenience store have not been adversely impacted by chemicals from the release. However, because the reporting limits were too high, it is not known the contribution of site-related contamination to the concentrations detected in the indoor air.

Although the calculated indoor air risks associated with the Evans residence and the convenience store are within acceptable ranges and, therefore, the occupants are not at risk, the discrepancy of laboratory reporting limits for soil gas and indoor air does not allow a determination to whether or not site-related contamination is migrating into these structures. It is also prevents evaluating the risk associated with exposure to the Munroe residents.


BLACK & VEATCH | Conclusions 18

7 Conclusions Rubis responded to the gasoline release at their Robinson Road facility, including defining the extent of contamination on site, surveying and sampling private wells in the site area, and implementing interim responses to quickly begin recovering free product. However, the timing of their response in assessing impacts to offsite residential receptors could have been more expedited considering the product levels measured in monitoring wells on the north side of Robinson Road in March 2013. The Evans and Munroe private wells were not assessed for product or chemical contamination until May 2013. Although stated in the 2013 CAR that residents infrequently use private wells and only as a backup to the city water supply, discussions with both residents and BEST indicate that the use of these wells for potable water is actually routine.

The proposed remedial actions are appropriate to address groundwater contamination remaining in the site area with a few exceptions. Continued operation of the SVE/AS system on site and initiation of the SVE systems on the CBL CSR and the north side of Robinson Road should result in decreasing the mass of adsorbed contamination that remains in the subsurface (from free product moving with groundwater). Removal of this mass is critical to reducing the release of contaminants into groundwater and to allow natural processes to degrade the contaminants over time.

7.1 EXPOSURE ISSUES Based on the risk assessment, workers in the CBL CSR building were exposed to chemicals associated with gasoline before the building was evacuated in late January 23, and this exposure was likely above acceptable levels.

As suggested in Sections 3.4 and 6.0, the vapor intrusion assessment documented in the December 2013 CAR is not sufficient to ensure that the residential and commercial building occupants are not being exposed to contamination associated with the Rubis release. Although the calculated indoor air risks associated with the Evans residence and the convenience store are within acceptable ranges and, therefore, the occupants are not at risk, the discrepancy of laboratory reporting limits for soil gas and indoor air does not allow a determination to whether or not site-related contamination is migrating into these structures. Insufficient data are available to be able to assess the risk associated with the Munroe residence.

Considering the wide-spread use of private well water by the residences in the area, a conservative assessment of the risk associated with using this water on a daily basis in the Munroe residence for a duration between 40 and 160 days was completed. The assessment results in an unacceptable risk for multiple durations of exposure. With additional information from the Munroe family, a better estimate of the actual risk can be calculated.

7.2 RECOMMENDATIONS Based on the response actions completed to date associated with the release at the Rubis Robinson Road gas station, the following is recommended:

Rubis should be requested to provide the estimated duration for operation of the SVE systems to reduce contaminant mass sufficiently to allow groundwater contaminant concentrations to be


BLACK & VEATCH | Conclusions 19

reduced to below FDEP groundwater target cleanup levels in a reasonable time frame. A reasonable time frame of 5 years should be considered.

A number of wells in close proximity to residences and commercial buildings on the north side of Robinson Road have not been sampled since May 2013. These wells need to be sampled more frequently in conjunction with sampling onsite wells to provide an updated status of the extent and condition of the groundwater plume. The additional wells should include MW-41, MW-44, MW-45, and MW-48 at a minimum.

An additional monitoring well should be installed on the north side of the Munroe residence, considering the elevated levels of benzene detected in well MW-44 in May 2013. Wells MW-43 and MW-54 do not adequately define the extent of groundwater contamination to the northeast of the site.

Additional information should be obtained from the Munroe family to better estimate the risk associated with the exposure that occurred in early 2013, including number and age of occupants, estimated daily water use for various activities, and exact number of days well water continued to be used after odor was initially noted.

The isolated groundwater contamination at the southeast corner of the Rubis property that is likely the result of a historic release should be completely defined and measures implemented to reduce groundwater concentrations to FDEP groundwater target cleanup levels.

Either an additional round of soil gas samples should be collected near the Munroe residence or soil gas samples should be collected below the residence foundation along with indoor air samples. The reporting limits for the soil gas samples should be lower to provide comparison with the indoor air data and EPA screening levels. It is recommended that these data be collected prior to the startup of the SVE systems.

At least two additional rounds of soil gas and indoor air sampling should be conducted to evaluate whether site-related contamination is impacting the commercial buildings and residential homes. The reporting limits for the soil gas samples should be lower to provide comparison with the indoor air data and EPA screening levels. It is recommended that at least one round of data be collected prior to the startup of the SVE systems.

The potential for the migration of site-related contamination through soil gas to the residential buildings east of the Rubis property.

After initiating active operation of the SVE systems, a program should be developed to monitor the indoor air in the CBL CSR and HEB buildings to both determine when the CSR building can be re-occupied and to verify that occupants of either building are not being exposed to chemicals associated with the gasoline release. In addition, all reporting limits should be sufficiently low to provide comparison with EPA screening levels.

A communications program should be implemented to keep the surrounding businesses and residences up to date regarding the status of the cleanup. An initial public meeting would likely be well received by the community. This would provide an opportunity to explain the release, extent of contamination, response actions, and cleanup objectives, as well as allow the citizens to ask questions. The meeting could be followed up with a periodic newsletter to keep the community informed.


Figures


Appendix A


Appendix B

Concentrations of BTEX and Naphthalene Detected in Indoor and Ambient Air Samples Collected by Cable Bahamas

Call Center-SC1 Cash Room-SC2 Main Lobby-SC4 Ambient-SC3 Call Center-SC1 Cash Room-SC2 Main Lobby-SC4 Ambient-SC3 Call Center-SC1 Cash Room-SC2 Main Lobby-SC4 Ambient-SC31/30/2013 11 49 NA 2.6 5.1 530 Not sampled 13 15 110 Not sampled 0.992/1/2013 20 38 20 0.55 170 540 200 2 19 81 19 0.52/3/2013 5.8 33 19 0.5 33 270 110 0.5 8 63 15 0.52/21/2013 5.4 5.5 5.2 5.8 26 28 26 31 2.6 4.9 2.4 2.43/11/2013 2.7 5.8 2.5 0.62 3.3 5.1 2.9 2.1 ND 1 ND 0.5Average conc. 1/30-2/3 12.3 40.0 19.5 1.22 69.4 447 155 5.17 14.0 84.7 17.0 0.66EPA Industrial Screening Level 0.50 ppbv 5815 ppbv 1.13 ppbv

1.6 ug/m3 22000 ug/m3 4.9 ug/m3Maximum concentration 49.0 ppbv 540 ppbv 110 ppbv

156.5 ug/m3 2042.9 ug/m3 478 ug/m3Sources of Chemical (EPA and NIH) Additives to gasoline and diesel fuel Fingernail polish plastics

Many industrial solvents Glues/adhesives solventsVarious paint, lacquer, and varnish removers Lacquers rubber

Octane booster in gasoline plastic wrapPaintsPaint thinnersPrinting and leather tanning processesRubber and plastic cementsWood stains

http://water.epa.gov/drink/contaminants/basicinformation/ethylbenzene.cfm

http://www.nlm.nih.gov/medlineplus/ency/article/002829.htm

Concentration of Benzene in CBL CSR (ppbv)Sample Date

Concentration of Toluene in CBL CSR (ppbv) Concentration of Ethylbenzene in CBL CSR (ppbv)

http://water.epa.gov/drink/contaminants/basicinformation/ethylbenzene.cfm�


http://www.nlm.nih.gov/medlineplus/ency/article/002829.htm�


Concentrations of BTEX and Naphthalene Detected in Indoor and Ambient Air Samples Collected by Cable Bahamas

1/30/20132/1/20132/3/20132/21/20133/11/2013Average conc. 1/30-2/3EPA Industrial Screening Level

Maximum concentration

Sources of Chemical (EPA and NIH)

http://water.epa.gov/drink/contaminants/basicinformation/ethylbenzene.cfm

http://www.nlm.nih.gov/medlineplus/ency/article/002829.htm

Sample Date Call Center-SC1 Cash Room-SC2 Main Lobby-SC4 Ambient-SC3 Call Center-SC1 Cash Room-SC2 Main Lobby-SC4 Ambient-SC3129 1920 Not sampled 4.8 ND 0.6 Not sampled 0.5101 820 112 1 ND 0.84 ND ND51 650 93 1 ND ND ND ND

14.3 37.9 14.2 12.2 ND ND ND ND2.79 7.1 2.41 1 ND ND ND ND93.7 1130 102.5 2.27 ND 0.72 ND 0.50

101 ppbv 0.07 ppbv440 ug/m3 0.36 ug/m3

1920 ppbv 0.84 ppbv8338 ug/m3 4.40 ug/m3

Fingernail polish Moth repellentGlues/adhesives Toilet bowl deodorizersLacquers DyesOctane booster in gasoline InsecticidesPaintsPaint thinnersPrinting and leather tanning processesRubber and plastic cementsWood stains

Concentration of Naphthalene in CBL CSR (ppbv)Concentration of Total Xylenes in CBL CSR (ppbv)





Calculation of Indoor Air Risk Using Maximum Concentration Detected in Indoor Air

Benzene Toluene Ethylbenzene Xylenes Naphthalene Total RiskC, ug/m3 156.5 2043 477.7 8338 4.40ED, year 1 1 1 1 1EF, days 22 22 22 22 22ET, hours 12 12 12 12 12IUR 7.80E-06 NA 2.50E-06 NA 3.40E-05RfC 3.00E-02 5.00E+00 1.00E+00 1.00E-01 3.00E-03

THQ 0.16 0.01 0.01 2.51 0.04 2.74 Risk 5.26E-07 NA 5.14E-07 NA 6.44E-08 1.10E-06





10/12/2012 Reported odors to Rubis12/7/2012 Reported odors to Rubis1/23/2013 Evacuated building

24 October-4 weeks at 6 days/week30 November-5 weeks at 6 days/week24 Dec-4 weeks at 6 days/week22 Jan-3 weeks at 6 days/week + 4 days

100

46 Days of exposure from December evacuation (assumes October event due to fueling)22 Days of exposure (assumes October and December event due to fueling)

Maximum days of exposure from first notification (assumes gas vapors continued to enter building between October and December reporting events and January evacuation


Appendix C


Exposure Concentrations

Scenario Timeframe: Past ExposureMedium: GroundwaterExposure Medium: Groundwater/Water Vapor

Units ValueGroundwater Acenaphthene ug/L 0

Acenaphthylene ug/L 0Anthracene ug/L 0Arsenic ug/L 0Benzene ug/L 390Benzo(a)anthracene ug/L 0Benzo(a)pyrene ug/L 0Benzo(b)fluoranthene ug/L 0Benzo(g,h,i)perylene ug/L 0Benzo(k)fluoranthene ug/L 0Chrysene ug/L 0Dibenzo(a,h)anthracene ug/L 0Ethylbenzene ug/L 65Fluoranthene ug/L 0Fluorene ug/L 0Indeno(1,2,3-cd)pyrene ug/L 0Naphthalene ug/L 0o-Xylene ug/L 0Phenanthrene ug/L 0Pyrene ug/L 0Toluene ug/L 2600Total Xylenes ug/L 2900

Concentration detected in Munroe well in May 2013

TABLE A-EXPOSURE POINT CONCENTRATIONS

Exposure Point(s)Chemical of Concern

Exposure Point Concentration


Toxicity Data

CombinedChronic/ Uncertainty RfD:Target Organ(s)

Subchronic Value Units Value Units Primary Target Organ(s) Factors Source DateAcenaphthene chronic 6.00E-02 mg/kg-day 89% 6.00E-02 mg/kg-day liver 3000 IRIS 11/1/1990Acenaphthylene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 1/1/1991Anthracene chronic 3.00E-01 mg/kg-day 89% 3.00E-01 mg/kg-day NA 3000 IRIS 1/1/1991Arsenic chronic 3.00E-04 mg/kg-day 95% 3.00E-04 mg/kg-day skin 3 IRIS 6/1/1995Benzene chronic 4.00E-03 mg/kg-day 100% 4.00E-03 mg/kg-day lymphocytes 300 IRIS 4/17/2003Benzo(a)anthracene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Benzo(a)pyrene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 7/1/1992Benzo(b)fluoranthene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Benzo(ghi)perylene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 12/1/1990Benzo(k)fluoranthene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Cadmium chronic 0.0005 mg/kg-day 5.0% 2.50E-05 mg/kg-day proteinuria 10 IRIS 1/1/1991Chromium chronic 3.00E-03 mg/kg-day 2.10% 6.30E-05 mg/kg-day lungs 300 IRIS 6/25/2010Chrysene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Dibenzo(a,h)anthracene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Ethylbenzene chronic 1.00E-01 mg/kg-day 100% 1.00E-01 mg/kg-day liver, kidney 1000 IRIS 3/1/1991Fluoranthene chronic 4.00E-02 mg/kg-day 89% 4.00E-02 mg/kg-day kidney, liver, blood 3000 IRIS 12/1/1990Fluorene chronic 4.00E-02 mg/kg-day 89% 4.00E-02 mg/kg-day blood 3000 IRIS 12/1/1990Indeno(1,2,3-cd)pyrene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 3/1/1994Lead and Compounds NA NA mg/kg-day NA NA mg/kg-day developmental toxicity NA IRIS 6/25/2010Naphthalene chronic 2.00E-02 mg/kg-day 89% 2.00E-02 mg/kg-day body weight 3000 IRIS 9/17/1998Phenanthrene NA NA mg/kg-day NA NA mg/kg-day NA NA NA 12/1/1990Pyrene chronic 3.00E-02 mg/kg-day 89% 3.00E-02 mg/kg-day kidney 3000 IRIS 1/1/1991Toluene chronic 8.00E-02 mg/kg-day 100% 8.00E-02 mg/kg-day kidney, nasal epithelium 3000 IRIS 9/23/2005Total Xylenes chronic 2.00E-01 mg/kg-day 100% 2.00E-01 mg/kg-day body weight 1000 IRIS 2/21/2003

TABLE C1-NON-CANCER TOXICITY DATA -- ORAL/DERMAL

Absorbed RfD for DermalOral RfDOral Absorption

Efficiency for Dermal

Chemical of Potential Concern

Chronic/Subchronic Value Units Source Date

Acenaphthene NA NA mg/m3 NA NA EPA9 11/1/1990Acenaphthylene NA NA mg/m3 NA NA NA 1/1/1991Anthracene NA NA mg/m3 NA NA EPA9 1/1/1991Arsenic NA 1.50E-05 mg/m3 NA NA NA 6/1/1995Benzene chronic 3.0E-02 mg/m3 lymphocytes 300 IRIS 4/17/2003Benzo(a)anthracene NA NA mg/m3 NA NA NA 3/1/1994Benzo(a)pyrene NA NA mg/m3 NA NA NA 7/1/1992Benzo(b)fluoranthene NA NA mg/m3 NA NA NA 3/1/1994Benzo(ghi)perylene NA NA mg/m3 NA NA NA 12/1/1990Benzo(k)fluoranthene NA NA mg/m3 NA NA NA 3/1/1994Cadmium NA NA mg/m3 NA NA IRIS 1/1/1991Chromium chronic 1.00E-04 mg/m3 lungs 90 IRIS 6/25/2010Chrysene NA NA mg/m3 NA NA NA 3/1/1994Dibenzo(a,h)anthracene NA NA mg/m3 NA NA NA 3/1/1994Ethylbenzene chronic 1.0E+00 mg/m3 developmental toxicity 300 IRIS 3/1/1991Fluoranthene NA NA mg/m3 NA NA EPA9 12/1/1990Fluorene NA NA mg/m3 NA NA EPA9 12/1/1990Indeno(1,2,3-cd)pyrene NA NA mg/m3 NA NA NA 3/1/1994Lead and Compounds NA NA mg/m3 developmental toxicity NA IRIS 6/25/2010Naphthalene chronic 3.0E-03 mg/m3 nasal epithelium 3000 IRIS 9/17/1998Phenanthrene NA NA mg/m3 NA NA NA 12/1/1990Pyrene NA NA mg/m3 NA NA EPA9 1/1/1991Toluene chronic 5.0E+00 mg/m3 neurological effects 10 IRIS 9/23/2005Total Xylenes chronic 1.0E-01 mg/m3 motor coordination 300 IRIS 2/21/2003

RfC : Target Organ(s)

TABLE C2-NON-CANCER TOXICITY DATA -- INHALATION

Inhalation RfCChemical of Potential Concern

Primary Target Organ(s)

Combined Uncertainty Factors

Value Units Value Units Source DateAcenaphthene NA kg-day/mg NA NA kg-day/mg NA NA 11/1/1990Acenaphthylene NA kg-day/mg NA NA kg-day/mg NA NA 1/1/1991Anthracene NA kg-day/mg NA NA kg-day/mg NA NA 1/1/1991Arsenic 1.5E+00 kg-day/mg 95% 1.50E+00 kg-day/mg A IRIS 6/1/1995Benzene 5.5E-02 kg-day/mg 100% 5.50E-02 kg-day/mg A IRIS 4/17/2003Benzo(a)anthracene 7.3E-01 kg-day/mg 89% 7.30E-01 kg-day/mg B2 EPA9 3/1/1994Benzo(a)pyrene 7.3E+00 kg-day/mg 89% 7.30E+00 kg-day/mg B2 IRIS 7/1/1992Benzo(b)fluoranthene 7.3E-01 kg-day/mg 89% 7.30E-01 kg-day/mg B2 EPA9 3/1/1994Benzo(ghi)perylene NA kg-day/mg NA NA kg-day/mg D IRIS 12/1/1990Benzo(k)fluoranthene 7.3E-02 kg-day/mg 89% 7.30E-02 kg-day/mg B2 EPA9 3/1/1994Cadmium NA kg-day/mg NA NA kg-day/mg B1 IRIS 1/1/1991Chromium NA kg-day/mg 2.1% NA kg-day/mg A IRIS 6/25/2010Chrysene 7.3E-03 kg-day/mg 89% 7.30E-03 kg-day/mg B2 EPA9 3/1/1994Dibenzo(a,h)anthracene 7.3E+00 kg-day/mg 89% 7.30E+00 kg-day/mg B2 EPA9 3/1/1994Ethylbenzene 1.1E-02 kg-day/mg NA NA kg-day/mg NA NA 3/1/1991Fluoranthene NA kg-day/mg NA NA kg-day/mg D IRIS 12/1/1990Fluorene NA kg-day/mg NA NA kg-day/mg D IRIS 12/1/1990Indeno(1,2,3-cd)pyrene 7.3E-01 kg-day/mg 89% 7.30E-01 kg-day/mg B2 EPA9 3/1/1994Lead and Compounds NA kg-day/mg NA NA kg-day/mg B2 IRIS 6/25/2010Naphthalene NA kg-day/mg NA NA kg-day/mg C IRIS 9/17/1998Phenanthrene NA kg-day/mg NA NA kg-day/mg D IRIS 12/1/1990Pyrene NA kg-day/mg NA NA kg-day/mg D IRIS 1/1/1991Toluene NA kg-day/mg NA NA kg-day/mg NA NA 9/23/2005Total Xylenes NA kg-day/mg NA NA kg-day/mg NA NA 2/21/2003

Oral Absorption Efficiency for Dermal

(1)

Weight of Evidence/

Cancer Guideline

Description


TABLE D1-CANCER TOXICITY DATA -- ORAL/DERMAL

Oral Cancer Slope Factor

Absorbed Cancer Slope Factor Oral CSF

Inhalation Unit Risk Value Units Source Date

Acenaphthene NA (ug/m3)-1 NA NA 3/1/1994Acenaphthylene NA (ug/m3)-1 NA NA 7/1/1992Anthracene NA (ug/m3)-1 NA NA 3/1/1994Arsenic 4.3E-03 (ug/m3)-1 A EPA3 2/21/2003Benzene 7.8E-06 (ug/m3)-1 A EPA3 11/1/1990Benzo(a)anthracene 1.1E-04 (ug/m3)-1 B2 EPA3 12/1/1990Benzo(a)pyrene 1.1E-03 (ug/m3)-1 B2 EPA3 3/1/1994Benzo(b)fluoranthene 1.1E-04 (ug/m3)-1 B2 EPA3 3/1/1994Benzo(ghi)perylene NA (ug/m3)-1 D NA 3/1/1994Benzo(k)fluoranthene 1.1E-04 (ug/m3)-1 B2 EPA3 3/1/1991Cadmium 1.8E-03 (ug/m3)-1 B1 EPA3 1/1/1991Chromium (1) 8.4E-02 (ug/m3)-1 A EPA3 6/25/2010Chrysene 1.1E-05 (ug/m3)-1 B2 EPA3 12/1/1990Dibenzo(a,h)anthracene 1.2E-03 (ug/m3)-1 B2 EPA3 12/1/1990Ethylbenzene 2.5E-06 (ug/m3)-1 NA EPA3 1/1/1991Fluoranthene NA (ug/m3)-1 D NA 3/1/1994Fluorene NA (ug/m3)-1 D NA 9/17/1998Indeno(1,2,3-cd)pyrene 1.1E-04 (ug/m3)-1 B2 EPA3 12/1/1990Lead and Compounds NA (ug/m3)-1 B2 NA 6/25/2010Naphthalene 3.4E-05 (ug/m3)-1 C EPA3 1/1/1991Phenanthrene NA (ug/m3)-1 D NA 9/23/2005Pyrene NA (ug/m3)-1 D NA 6/1/1995Toluene NA (ug/m3)-1 NA NA 1/1/1991Total Xylenes NA (ug/m3)-1 NA NA 4/17/2003

(1) The IUR for hexavalent chromium was used for total chromium. Only hexavalent chromium is carcinogenic by the inhalation route of exposure.

TABLE D2-CANCER TOXICITY DATA -- INHALATION


Weight of Evidence/Cancer

Guideline Description

Unit Risk


Volatilization Factors

Chemical of ConcernH'

(unitless)KOC

(L/kg)Kd

(L/kg)Water,

Dw Air, Di

Apparent, Da

AcenaphthyleneArsenicBenzo(a)anthracene 4.91E-04 1.77E+05 1.06E+03 5.94E-06 5.09E-02 6.07E-13 4.98E+07Benzo(a)pyrene 1.87E-05 5.87E+05 3.52E+03 5.56E-06 4.76E-02 1.60E-13 9.70E+07Benzo(b)fluoranthene 2.69E-05 5.99E+05 3.60E+03 5.56E-06 4.76E-02 1.57E-13 9.79E+07Benzo(ghi)peryleneBenzo(k)fluoranthene 2.39E-05 5.87E+05 3.52E+03 5.56E-06 4.76E-02 1.60E-13 9.70E+07Chromium Dibenzo(a,h)anthracene 5.76E-06 1.91E+06 1.15E+04 5.21E-06 4.46E-02 4.31E-14 1.87E+08EthylbenzeneIndeno(1,2,3-cd)pyrene 1.42E-05 1.95E+06 1.17E+04 5.23E-06 4.48E-02 4.26E-14 1.88E+08LeadNaphthalene 1.80E-02 1.54E+03 9.26E+00 8.38E-06 6.05E-02 1.17E-10 3.59E+06Phenanthrene

Per EPA 1996:VF (m3/kg) Q/C x (3.14 X Da X T)1/2 /(2 x ρb x Da x 10000)

Da (cm2/s) [(θa10/3 DiH' + θw10/3Dw)/n2]/(ρbKd + θw + θaH')

Q/C (g/m2 s per kg/m3) 68.81T (s) 9.50E+08ρb (g/cm3) 1.5θa 0.28θw 0.15n 0.43Kd (cm3/g) Koc x foc

foc (g/g) 0.006

Diffusivity (cm2/sec) Volatilization Factor

(m3/kg)

VOLATILIZATION FACTORS (EPA 2012)


Adsorbed Dose-Adult

Kp

(cm/hr)B

(unitless)τevent

(hr) t* (hr)FA

(unitless) Adult-NCAge Adjusted Carcinogenic ug/cm3 ug/L

Acenaphthene -- -- -- -- -- -- -- 0.00 0Acenaphthylene -- -- -- -- -- -- -- 0.00 0Anthracene -- -- -- -- -- -- -- 0.00 0Arsenic -- -- -- -- -- -- -- 0.00 0Benzene 0.015 0.1 0.29 0.7 1 6.63E-03 6.63E-03 0.39 390Benzo(a)anthracene 0.47 2.8 2.03 8.53 1 -- -- 0.00 0Benzo(a)pyrene 0.7 4.3 2.69 11.67 1 -- -- 0.00 0Benzo(b)fluoranthene 0.7 4.3 2.77 12.03 1 -- -- 0.00 0Benzo(ghi)perylene -- -- -- -- -- -- -- 0.00 0Benzo(k)fluoranthene -- -- -- -- -- -- -- 0.00 0Chrysene 0.47 2.8 2.03 8.53 1 -- -- 0.00 0Dibenzo(a,h)anthracene 1.5 9.7 3.88 17.57 0.6 -- -- 0.00000 0Ethylbenzene 0.049 0.2 0.42 1.01 1 4.34E-03 -- 0.07 65Fluoranthene 0.22 1.2 1.45 5.68 1 -- -- 0.00 0Fluorene -- -- -- -- -- -- -- 0.00 0Indeno(1,2,3-cd)pyrene 1 6.7 3.78 16.83 0.6 -- -- 0.00 0Naphthalene 0.047 0.2 0.56 1.34 1 0.00E+00 -- 0.00 0Phenanthrene 0.14 0.7 1.06 4.11 1 -- -- 0.00 0Pyrene -- -- -- -- -- -- -- 0.00 0Toluene 0.031 0.1 0.35 0.84 1 -- -- 2.60 2600Xylene (total) 0.053 0.2 0.42 1.01 1 2.10E-01 -- 2.90 2900

CW

ABSORBED DOSE - GROUNDWATER

DAevent (ug/cm2-event)

COPC


Absorbed Dose-Adult/Child

Kp

(cm/hr)B

(unitless)τevent

(hr) t* (hr)FA

(unitless) Adult-NC Child-NCAge Adjusted Carcinogenic

Adjusted

Mutagenic ug/cm3 ug/LAcenaphthene -- -- -- -- -- -- -- -- -- 0.00 0Acenaphthylene -- -- -- -- -- -- -- -- -- 0.00 0Anthracene -- -- -- -- -- -- -- -- -- 0.00 0Arsenic -- -- -- -- -- -- -- -- -- 0.00 0Benzene 0.015 0.1 0.29 0.7 1 6.63E-03 1.62E-02 7.74E-03 -- 0.39 390Benzo(a)anthracene 0.47 2.8 2.03 8.53 1 -- -- -- 0.00E+00 0.00 0Benzo(a)pyrene 0.7 4.3 2.69 11.67 1 -- -- -- 0.00E+00 0.00 0Benzo(b)fluoranthene 0.7 4.3 2.77 12.03 1 -- -- -- 0.00E+00 0.00 0Benzo(ghi)perylene -- -- -- -- -- -- -- -- -- 0.00 0Benzo(k)fluoranthene -- -- -- -- -- -- -- -- -- 0.00 0Chrysene 0.47 2.8 2.03 8.53 1 -- -- -- 0.00E+00 0.00 0Dibenzo(a,h)anthracene 1.5 9.7 3.88 17.57 0.6 -- -- -- 0.00E+00 0.00000 0Ethylbenzene 0.049 0.2 0.42 1.01 1 4.34E-03 5.71E-03 -- -- 0.07 65Fluoranthene 0.22 1.2 1.45 5.68 1 -- -- -- -- 0.00 0Fluorene -- -- -- -- -- -- -- -- -- 0.00 0Indeno(1,2,3-cd)pyrene 1 6.7 3.78 16.83 0.6 -- -- -- 0.00E+00 0.00 0Naphthalene 0.047 0.2 0.56 1.34 1 0.00E+00 0.00E+00 -- 0.00E+00 0.00 0o-Xylene 0.00 0Phenanthrene 0.14 0.7 1.06 4.11 1 -- -- -- -- 0.00 0Pyrene -- -- -- -- -- -- -- -- -- 0.00 0Toluene 0.031 0.1 0.35 0.84 1 -- -- -- -- 2.60 2600Xylene (total) 0.053 0.2 0.42 1.01 1 2.10E-01 2.75E-01 -- -- 2.90 2900

CW

ABSORBED DOSE - GROUNDWATER

DAevent (ug/cm2-event)

COPC


Exposure Parameter and Risk Calculation-Adult, 40-Day Exposure Frequency

Scenario Timeframe: PastMedium: GroundwaterExposure Medium: Groundwater

Receptor Receptor Exposure Parameter Rationale/ Intake Equation/

Exposure Route Population Age Point Code Parameter Definition Value Units Reference Model NameIngestion Resident Private Well CW Chemical Concentration in Groundwater Table A mg/L Ingestion of Carcinogenic Contaminants in Groundwater:

Use/Tap Water IRWA Ingestion Rate of Water 2 L/day EPA 1997aCR = CW x EF x ED x SFO x IR x 1/AT x 1/365

EF Exposure Frequency 40 days/year EPA 1991aEDR Exposure Duration (NC) 1 years EPA 1991aSFo Oral Cancer Slope Factor Table D1 (mg/kg-d)-1 EPA 2002 Ingestion of Non-Carcinogenic Contaminants in Groundwater:

RfDSC Oral Reference Dose Table C1 mg/kg-d EPA 2002 THQ = CW x EF x EDR x IRWA x 1/RfD x 1/BW x 1/AT x 1/365

BWA Body Weight 70 kg EPA 1991aAT Averaging Time (C) 70 years EPA 1991a

Averaging Time (NC) 1 years EPA 1991a Dermal Resident Private Well

Use/Tap Water CW Chemical Concentration in Water Table A mg/L

Dermal Adsorption of Carcinogenic Contaminants in Groundwater:

FA Fraction Absorbed Water Chemical Specific EPA 2004a CR = DA-event x SFABS x ED x EV x EF x SA x 1/BWA x 1/ATC x

1/365 x 1/1000 Kp Permeability Constant Chemical Specific cm/hr EPA 2004a

SAA Skin Surface Area, SA16-30 18,000 cm2 EPA 2004a Dermal Adsorption of Non-Carcinogenic Contaminants in

Groundwater:THQ = DA-event x 1/RfDabs x EV x ED x EF x SA x 1/BW x 1/ATNC x 1/365 x 1/1000

τevent Chemical Specific Chemical Specific hours/event EPA 2004a ETA Event Duration Adult, ET16-30 0.58 hours/event EPA 2004a For organic compounds:

B Ratio of permeability coefficient of a compound through the stratum corneum relative to its permeability coefficient across the viable epidermis

Chemical Specific EPA 2004a DA-event = 2 x FA x Kp x CW x SQRT(6 x τevent x ET x 1/π)

EV Event Frequency 1 events/day EPA 2004a or, if ET>t*, then

EF Exposure Frequency 40 days/year EPA 2004a DA-event = FA x Kp x CW x ((ET/(1+B)) + 2 x τevent x ((1+(3 x B) + (3 x B2))/(1+B)2))

EDA Exposure Duration 1 years EPA 1991a

Adult

Adult

TABLE B-VALUES USED FOR DAILY INTAKE CALCULATIONS



Exposure Route Population Age Point Code Parameter Definition Value Units Reference Model Name


CF Volumetric Conversion Factor for Water 0.001 L/cm3 For inorganic analytes:

BWA Body Weight 70 kg EPA 2004a DA-event = Kp x CW x CF x t-event ATC Averaging Time (C) 70 years EPA 2004a

ATNC Averaging Time (NC) 1 years EPA 2004a Inhalation Resident Water Vapors

from CW Chemical Concentration in Groundwater Table A mg/L Inhalation of Carcinogenic Volatile Contaminants in Groundwater:

Showerhead K Volatilization Factor 0.5 L/m3 EPA 2009 ET Exposure Time 1 hours/day EPA 2009 CR = CW x EF x EDR x ET x 1/24 x IUR x K x 1/AT x 1/365 x 1000

EF Exposure Frequency 40 days/year EPA 2009ED Exposure Duration (C) 0-30 years EPA 2009

EDR Exposure Duration (C) 1 years EPA 2009Exposure Duration (NC) 1 years EPA 2009 Inhalation of Non-Carcinogenic Volatile Contaminants in

IUR Inhalation Unit Risk Table D2 (ug/m3)-1 Groundwater:RfC Inhalation Reference Concentration Table C2 mg/m3 THQ = CW x EF x EDR x ET x 1/24 x 1/RfC x K x 1/AT x 1/365AT Averaging Time (C) 70 years EPA 2009

Averaging Time (NC) 1 years EPA 2009

Adult

Scenario Timeframe: Past .Receptor Population: Offsite ResidentReceptor Age: Adult/Child

Non-Cancer Hazard Calculations

Value Units Value Units Cancer Risk Value Units Value UnitsIngestion Acenaphthene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 0.00E+00 (mg/kg-day)-1 6.00E-02 mg/kg-day 0.00E+00

Acenaphthylene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NAAnthracene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 3.00E-01 mg/kg-day NA

Arsenic 0.00 mg/L 0.0E+00 mg/kg-day 1.5E+00 (mg/kg-day)-1 0.00E+00 0.00E+00 (mg/kg-day)-1 3.00E-04 mg/kg-day 0.00E+00Benzene 0.39 mg/L 1.7E-05 mg/kg-day 5.5E-02 (mg/kg-day)-1 9.59E-07 1.22E-03 (mg/kg-day)-1 4.00E-03 mg/kg-day 3.05E-01

Benzo(a)anthracene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-01 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NABenzo(a)pyrene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E+00 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NA

Benzo(b)fluoranthene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-01 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NABenzo(ghi)perylene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NA

Benzo(k)fluoranthene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-02 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NAChrysene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-03 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NA

Dibenzo(a,h)anthracene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E+00 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NAEthylbenzene 0.07 mg/L 2.9E-06 mg/kg-day 1.1E-02 (mg/kg-day)-1 3.20E-08 2.04E-04 (mg/kg-day)-1 1.00E-01 mg/kg-day 2.04E-03Fluoranthene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 4.00E-02 mg/kg-day NA

Fluorene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 4.00E-02 mg/kg-day NAIndeno(1,2,3-cd)pyrene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-01 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NA

Naphthalene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 0.00E+00 (mg/kg-day)-1 2.00E-02 mg/kg-day 0.00E+00Phenanthrene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NA

Pyrene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 0.00E+00 (mg/kg-day)-1 3.00E-02 mg/kg-day 0.00E+00Toluene 2.60 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 8.00E-02 mg/kg-day NA

Xylene (total) 2.90 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 9.08E-03 (mg/kg-day)-1 2.00E-01 mg/kg-day 4.54E-029.9E-07 3.5E-019.9E-07 3.5E-019.9E-07 3.5E-01

EPCSF/IURIntake Concentration Intake Concentration

Exp. Route Total

Exposure RouteChemical of Potential

Concern

TABLE E-CALCULATION OF CHEMICAL CANCER RISKS AND NON-CANCER HAZARDS

Exposure MediumMedium

Exposure Point

Cancer Risk Calculations

Value UnitsHazard

Quotient

RfD/RfC

Ground Water

Ground Water

Private Well Use

Exposure Point TotalExposure Medium Total



Value Units Value Units Cancer Risk Value Units Value Units



Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC

Acenaphthene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 6.00E-02 mg/kg-day NAAcenaphthylene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NA

Anthracene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 3.00E-01 mg/kg-day NAArsenic 0.00 mg/L NA mg/kg-day 1.5E+00 (mg/kg-day)-1 NA NA (mg/kg-day)-1 3.00E-04 mg/kg-day NABenzene 0.39 mg/L 2.7E-06 mg/kg-day 5.5E-02 (mg/kg-day)-1 1.47E-07 1.9E-04 (mg/kg-day)-1 4.00E-03 mg/kg-day 4.67E-02



Benzo(k)fluoranthene 0.00 mg/L NA mg/kg-day 7.3E-02 (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NAChrysene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E-03 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NA

Dibenzo(a,h)anthracene 0.00 mg/L 0.0E+00 mg/kg-day 7.3E+00 (mg/kg-day)-1 0.00E+00 NA (mg/kg-day)-1 NA mg/kg-day NAEthylbenzene 0.07 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 1.2E-04 (mg/kg-day)-1 1.00E-01 mg/kg-day 1.22E-03Fluoranthene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 4.00E-02 mg/kg-day NA


Naphthalene 0.00 mg/L 0.0E+00 mg/kg-day NA (mg/kg-day)-1 NA 0.0E+00 (mg/kg-day)-1 2.00E-02 mg/kg-day 0.00E+00Phenanthrene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 NA mg/kg-day NA

Pyrene 0.00 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 3.00E-02 mg/kg-day NAToluene 2.60 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA NA (mg/kg-day)-1 8.00E-02 mg/kg-day NA


Ground Water

Ground Water

Private Well Use

Exp. Route TotalExposure Point Total

Exposure Medium Total

Dermal Adsorption






Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC

Acenaphthene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NAAcenaphthylene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NA

Anthracene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NAArsenic 0.00 mg/L NA ug/m3 4.3E-03 (ug/m3)-1 NA NA (mg/m3)-1 1.50E-05 mg/m3 NABenzene 0.39 mg/L 1.3E-02 ug/m3 7.8E-06 (ug/m3)-1 9.92E-08 8.9E-04 (mg/m3)-1 3.00E-02 mg/m3 2.97E-02

Benzo(ghi)perylene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NAEthylbenzene 0.07 mg/L 2.1E-03 ug/m3 2.5E-06 (ug/m3)-1 5.30E-09 1.5E-04 (mg/m3)-1 1.00E+00 mg/m3 1.48E-04Fluoranthene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NA

Fluorene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NANaphthalene 0.00 mg/L 0.0E+00 ug/m3 3.4E-05 (ug/m3)-1 0.00E+00 0.0E+00 (mg/m3)-1 3.00E-03 mg/m3 0.00E+00

Phenanthrene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NAPyrene 0.00 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 NA mg/m3 NA

Toluene 2.60 mg/L NA ug/m3 NA (ug/m3)-1 NA NA (mg/m3)-1 5.00E+00 mg/m3 NAXylene (total) 2.90 mg/L NA ug/m3 NA (ug/m3)-1 NA 6.6E-03 (mg/m3)-1 1.00E-01 mg/m3 6.62E-02

1.0E-07 9.6E-021.0E-07 9.6E-02

Exposure Medium Total 1.0E-07 9.6E-02Total Receptor Risk/Hazard 1.2E-06 5.3E-01

Exposure Point TotalExp. Route Total

Air Water Vapors

Ground Water

Inhalation























Adult

Adult















Adult














Ground Water

Ground Water

Private Well Use




Exposure Point


Value UnitsHazard

Quotient

RfD/RfCSF/IURIntake Concentration Intake Concentration

Exp. Route Total


Concern

EPC






Exposure Point


Value UnitsHazard

Quotient



Concern

EPC











Dermal Adsorption

Ground Water

Ground Water

Private Well Use








Exposure Point


Value UnitsHazard

Quotient



Concern

EPC







2.4E-07 2.2E-012.4E-07 2.2E-01

Exposure Medium Total 2.4E-07 2.2E-01Total Receptor Risk/Hazard 2.8E-06 1.2E+00

Air Water Vapors

Ground Water

Inhalation
























Adult

Adult















Adult





Arsenic 0.00 mg/L 0.0E+00 mg/kg-day 1.5E+00 (mg/kg-day)-1 0.00E+00 0.00E+00 (mg/kg-day)-1 3.00E-04 mg/kg-day 0.00E+00Benzene 0.39 mg/L 7.0E-05 mg/kg-day 5.5E-02 (mg/kg-day)-1 3.84E-06 4.88E-03 (mg/kg-day)-1 4.00E-03 mg/kg-day 1.22E+00








Xylene (total) 2.90 mg/L NA mg/kg-day NA (mg/kg-day)-1 NA 3.63E-02 (mg/kg-day)-1 2.00E-01 mg/kg-day 1.82E-014.0E-06 1.4E+004.0E-06 1.4E+004.0E-06 1.4E+00


Exp. Route Total


Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC

Ground Water

Ground Water

Private Well Use







Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC











Ground Water

Ground Water

Private Well Use



Dermal Adsorption






Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC







4.2E-07 3.8E-014.2E-07 3.8E-01



Air Water Vapors

Ground Water

Inhalation


Exposure Parameter and Risk Calculation-Adult/Child, 40-Day Exposure Frequency



Exposure Route Population Age Point Code Parameter Definition Value Units Reference Model NameIngestion Resident Private Well CW Chemical Concentration in Groundwater Table A mg/L Ingestion of Carcinogenic/Mutagenic Contaminants in

Use/Tap Water IRWA Ingestion Rate of Water 2 L/day EPA 1997a (Adult/Child Age-Adjusted):IRWC Ingestion Rate of Water 1 L/day EPA 1997 CR = CW x EF x SFO x IFW x 1/AT x 1/365

EF Exposure Frequency 40 days/year EPA 1991a CR = CW x EF x SF x IFWM x 1/AT x 1/365EDR Exposure Duration (NC) 1 years EPA 1991aEDC Exposure Duration (C) 24 years EPA 1991a IFW = (EDC x IRWC x 1/BWC) + (EDR-EDC) x IRWA x 1/BWA

Exposure Duration (mutagenic) 0-6 years EPA 2012a IFWM = (ED0-2 x IRWC x 10 x 1/BWC) + (ED2-6 x IRWC x 3 x 1/BWC) + IFW Age-Adjusted Water Ingestion Rate (C) 1.086 L-year/kg-day (ED6-16 x IRWA x 3 x 1/BWA) + (ED16-30 x IRWA x 1 x 1/BWA)

IFWM Age-Adjusted Water Ingestion Rate (mutagenic)

3.39 L-year/kg-day

SFo Oral Cancer Slope Factor Table D1(mg/kg-d)-1 EPA 2002

Ingestion of Non-Carcinogenic Contaminants in Groundwater (Child Pathway Only):

RfDSC Oral Reference Dose Table C1 mg/kg-d EPA 2002 THQ = CW x EF x EDR x IRWA x 1/RfD x 1/BWC x 1/AT x 1/365

BWC Body Weight 15 kg EPA 1991aBWA Body Weight 70 kg EPA 1991aAT Averaging Time (C) 70 years EPA 1991a

Averaging Time (NC, Child) 1 years EPA 1991a Dermal Resident Private Well

Use/Tap Water CW Chemical Concentration in Water Table A mg/L Dermal Adsorption of Carcinogenic/Mutagenic Contaminants in

Groundwater (Adult/Child Age-Adjusted): FA Fraction Absorbed Water Chemical Specific EPA 2004a CR = DA-event x SFABS x DFW x 1/ATC x 1/365 x 1/1000 Kp Permeability Constant Chemical Specific cm/hr EPA 2004a ET = (ETC x EDC + ETA x EDA)/(EDC + EDA) SAA Skin Surface Area, SA16-30 18,000 cm2 EPA 2004a

SAC Skin Surface Area, SA0-2, SA2-6, SA6-16 6,600 cm2 EPA 2004a CR = DA-event x SFABS x DFWM x 1/ATC x 1/365 x 1/1000 τevent Chemical Specific Chemical Specific hours/event EPA 2004a ETM = [(ET0-2 x ED0-2) + (ET2-6 x ED2-6) +(ET6-16 x ED6-16) + ETA Event Duration Adult, ET16-30 0.58 hours/event EPA 2004a (ET16-30 x ED16-30)]/(ED0-2 +ED2-6 + ED6-16 + ED6-16)

ETC Event Duration Child, ET0-2, ET2-6, ET6-1 1 hours/event EPA 2004a ET Adjusted Event Duration for Carcinogenic

Exposures0.79 hours/event DFW = (EVC x EDC x EFC x SAC x 1/BWC) + (EVA x EDA x EFA x

SAA x 1/BWA)ETM Adjusted Event Duration for Mutagenic

Exposures0.80 hours/event DFWM = (EV0-2 x EF0-2 x ED0-2 x SA0-2 x 1/BW0-2 x 10) +(EV2-

6 x EF2-6 x ED2-6 x SA2-6 x 1/BW2-6 x 3) + (EV6-16 x EF6-16


Chemical Specific EPA 2004a x ED6-16 x SA6-16 x 1/BW6-16 x 3) + (EV16-30 x EF16-30 x ED16-30 x SA16-30 x 1/BW16-30 x 1)

Adult/Child-Carcinogenic

Exposure; Child-Non-

carcinogenic Exposure









Dermal Resident EV Event Frequency 1 events/day EPA 2004a For organic compounds: EF Exposure Frequency 40 days/year EPA 2004a DA-event = 2 x FA x Kp x CW x SQRT(6 x τevent x ET x 1/π) EDA Exposure Duration, ED6-16 1 years EPA 1991a or, if ET>t*, then

EDC Exposure Duration, ED0-2=2, ED2-6=4, ED6-16=10

1 years EPA 1991a DA-event = FA x Kp x CW x ((ET/(1+B)) + 2 x τevent x ((1+(3 x B) + (3 x B2))/(1+B)2))


BWA Body Weight 70 kg EPA 2004a DA-event = Kp x CW x CF x t-event BWC Body Weight 15 kg EPA 2004a Dermal Adsorption of Non-Carcinogenic Contaminants in

Groundwater (Child Pathway Only):

ATC Averaging Time (C) 70 years EPA 2004a THQ = DA-event x 1/RfDabs x EVC x EDC x EFC x SAC x 1/BWC x

1/ATNC x 1/365 x 1/1000 ATNC Averaging Time (NC, Child) 1 years EPA 2004a

Inhalation Resident Water Vapors from

CW Chemical Concentration in Groundwater Table A mg/L Inhalation of Carcinogenic/Mutagenic Volatile Contaminants in

Showerhead K Volatilization Factor 0.5 L/m3 EPA 2009 Groundwater (Adult/Child Age-Adjusted): ET Exposure Time 1 hours/day EPA 2009 CR = CW x EF x EDR x ET x 1/24 x IUR x K x 1/AT x 1/365 x 1000

EF Exposure Frequency 40 days/year EPA 2009 CR = CW x EF x [(ED0-2 x IUR x 10) + (ED2-6 x IUR x 3) + (ED6-16 x ED Exposure Duration (C) 0-30 years EPA 2009 IUR x 3) + (ED16-30 x IUR x 1)] x ET x K x 1/24 x 1/AT x 1/365 x 1000


IUR Inhalation Unit Risk Table D2 (ug/m3)-1 Groundwater (Child Pathway Only):RfC Inhalation Reference Concentration Table C2 mg/m3 THQ = CW x EF x EDR x ET x 1/24 x 1/RfC x K x 1/AT x 1/365AT Averaging Time (C) 70 years EPA 2009








Private Well Use/Tap Water














Ground Water

Ground Water

Private Well Use




Exposure Point


Value UnitsHazard

Quotient


Exp. Route Total


Concern

EPC






Exposure Point


Value UnitsHazard

Quotient



Concern

EPC











Dermal Adsorption

Ground Water

Ground Water

Private Well Use








Exposure Point


Value UnitsHazard

Quotient



Concern

EPC







1.0E-07 9.6E-021.0E-07 9.6E-02


Air Water Vapors

Ground Water

Inhalation











3.39 L-year/kg-day































































Exp. Route Total


Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC

Ground Water

Ground Water

Private Well Use







Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC











Ground Water

Ground Water

Private Well Use



Dermal Adsorption






Concern



Exposure Point


Value UnitsHazard

Quotient

RfD/RfC







2.4E-07 2.2E-012.4E-07 2.2E-01



Air Water Vapors

Ground Water

Inhalation










3.39 L-year/kg-day






























































Ground Water

Ground Water

Private Well Use




Exposure Point


Value UnitsHazard

Quotient


Exp. Route Total


Concern

EPC






Exposure Point


Value UnitsHazard

Quotient



Concern

EPC











Dermal Adsorption

Ground Water

Ground Water

Private Well Use








Exposure Point


Value UnitsHazard

Quotient



Concern

EPC







4.2E-07 3.8E-014.2E-07 3.8E-01


Air Water Vapors

Ground Water

Inhalation


Documents

RUBIS ROBINSON ROAD FUEL RELEASE · Black & Veatch International (BVI) prepared this report for the Bahamas Environmental, Science, and Technology (BEST) Commission to provide an