CORRECTIVE ACTION COMPLETION REPORT

Transcription

1 R E P O R T CORRECTIVE ACTION COMPLETION REPORT SHELL OIL PRODUCTS US SHELL SERVICE STATION # W. TALCOTT ROAD PARK RIDGE, ILLINOIS LUST INCIDENT NO Property of Shell Oil Products US Prepared for Equilon Enterprises, LLC. dba Shell Oil Products US 603 Diehl Road, Suite 103 Naperville, IL January South Wacker Drive Suite 500 Chicago, Illinois (312)

2 TABLE OF CONTENTS CORRECTIVE ACTION COMPLETION REPORT A. Site Identification. 1 B. Site Information...1 C. Remedial (Corrective) Action..2 D. Signatures...19 FIGURES: FIGURE 1: FIGURE 2: FIGURE 3: FIGURE 4: FIGURE 5: FIGURE 6: FIGURE 7: FIGURE 8: SITE LOCATION MAP LAND USE MAP BASE MAP WITH UTILITIES GROUNDWATER EQUIPOTENTIAL AND CONCENTRATION MAP SOIL ANALYTICAL RESULTS MAP AREAS SUBJECT TO INSTITUTIONAL CONTROL MODELED PLUME: MIGRATION TO GROUNDWATER PATHWAY MODELED PLUME: GROUNDWATER INGESTION PATHWAY TABLE: TABLE 1: TABLE 2: GROUNDWATER ELEVATIONS AND ANALYTICAL RESULTS SOIL ANALYTICAL RESULTS APPENDICES: APPENDIX A: IEPA LETTER DATED DECEMBER 13, 2006 APPENDIX B: SOIL BORING LOGS/MONITORING WELL CONSTRUCTION DIAGRAMS APPENDIX C: ZIRON MONITORING WELL REPORTS APPENDIX D: LABORATORY REPORTS APPENDIX E: ZIRON STANDARD OPERATING PROCEDURES APPENDIX F: VILLAGE OF PARK RIDGE LIMITED GROUNDWATER ORDINANCE (PROPOSED) APPENDIX G: IDOT HIGHWAY AUTHORITY AGREEMENT (PROPOSED) APPENDIX H: PROPERTY OWNER SUMMARY FORM APPENDIX I: TACO CALCULATIONS

3 The Agency is authorized to require this information under Section 4 and Title XVI of the Environmental Protection Act (415 ILCS 5/4, 5/ ). Failure to disclose this information may result in a civil penalty of not to exceed $50, for the violation and an additional civil penalty of not to exceed $10, for each day during which the violation continues (415 ILCS 5/42). Any person who knowingly makes a false material statement or representation in any label, manifest, record, report, permit, or license, or other document filed, maintained or used for the purpose of compliance with Title XVI commits a Class 4 felony. Any second or subsequent offense after conviction hereunder is a Class 3 felony (415 ILCS 5/57.17). This form has been approved by the Forms Management Center. A. Site Identification Illinois Environmental Protection Agency Leaking Underground Storage Tank Program Corrective Action Completion Report IEMA Incident # (6-digit) : IEPA LPC# (10-digit) : Site Name: Site Address (Not a P.O. Box) : 900 Talcott Road City: Park Ridge County: Cook Zip Code: B. Site Information 1. Has a High Priority Corrective Action Plan been approved? Yes No Date of approval letter: 12/13/ This completion report is being submitted pursuant to: a. 35 Ill. Adm. Code b. 35 Ill. Adm. Code (b) c. 35 Ill. Adm. Code d. 35 Ill. Adm. Code Method of remediation chosen: a. Soil The method of remediation proposed to address the extent of soil impact remaining at the site is Exposure Pathway Exclusion (Pathway Elimination) based on residential land use and pursuant to the Tiered Approach to Corrective Action Objectives (TACO) presented in 35 Illinois Administrative Code (IAC) Section 742. b. Groundwater The method of remediation selected to address the groundwater impact remaining at the site is Pathway Elimination pursuant to the TACO presented in 35 IAC Section Quantity of contaminated media remediated/recovered: a. Soil 0 yds3 b. Groundwater 0 gals c. Free Product Free product was not encountered at the site. 0 gals

4 C. Remedial (Corrective) Action 1. An executive summary that identifies the overall objectives of the corrective action and the technical approach utilized to meet those objectives. The summary shall contain the following information: Site Description: a. A brief description of the site, including but not limited to a description of the release, the applicable indicator contaminants, the contaminated media, and the extents of soil and groundwater contamination that exceeded the most stringent Tier 1 remediation objectives; The Shell Service Station (site) is located in the in the southeast quarter of the northwest quarter of Section 35, Township 41 North, Range 12 East, of the United States Geological Survey (USGS) 7.5-Minute Series Park Ridge, Illinois Quadrangle. The site is located within a mixed area of commercial and residential properties. The site, located at the northwest corner of the intersection between Cumberland Avenue and Talcott Road, is bordered to the north and west by residential properties. The site is bordered to the east by Cumberland Avenue with commercial properties beyond. Talcott Road borders the south property boundary with residential properties located beyond. Figure 1 presents a site location map. Figure 2 presents the surrounding land use. Current site features include three 10,000-gallon gasoline underground storage tanks (USTs), one 1,000-gallon used oil UST, three fuel dispenser islands, and a one-story auto service building that houses a convenience store. Former site features include one 1,000-gallon used oil UST (location of the existing used oil UST), which was removed in Figure 3 presents the current and former site features and location of utilities at the site. Description of the Release: On August 12, 2005, Remediation Unlimited, Inc. (RUI), with NESA & Associates, Inc. (NESA) oversight, advanced six soil borings (SB-1 through SB-6) using vacuum excavation and hand auger methods to advance the first five feet below ground level (bgl) of each soil boring to clear possible utilities. The soil borings were then completed to a maximum depth of 16 feet bgl using driven push methods. Soil samples collected during the assessment activities were submitted to an Illinois-accredited stationary laboratory for the analysis of the gasoline indicator contaminants consisting of: benzene, toluene, ethylbenzene, total xylenes (BTEX) and methyl tertiary butyl ether (MTBE) using United States Environmental Protection Agency (USEPA) Method SW B. A soil sample collected from soil boring SB-6, installed in the vicinity of the used oil UST, was submitted to an Illinoisaccredited stationary laboratory for the analysis of the following used oil indicator parameters (LUST Priority Pollutants) by using the respective USEPA Methods SW846: volatiles 8260, polynuclear aromatic (PNA) hydrocarbons 8270, base/neutrals 8270, metals 3050B and 7471A. Soil sample SB-2 (2) was analyzed for ph using USEPA Method SW Soil borings SB-1 through SB-5 were completed as monitoring wells MW-1 through MW-5 using hollow-stem auger methods. The wells were constructed of 2-inch inside diameter (ID) 2

5 Schedule 40 polyvinyl chloride (PVC) riser and slot PVC well screen. A coarse sand filter pack was placed around the well screen. On August 19, 2005, Ziron Environmental Services, Inc. (Ziron) performed groundwater monitoring and sampling on monitoring wells MW-1 through MW-5. The depth-to-water in each monitoring well was measured using an audible electronic interface probe. Monitoring wells MW-2, MW-3, and MW-4 were dry and therefore not sampled. Monitoring wells MW-1 and MW-5 were then developed by pumping and surging to remove fines that may have settled in the well. After a brief stabilization period, approximately three well volumes were purged from each well using an evacuation pump attached to dedicated tubing. Dedicated disposable polyethylene sampling bailers were then used to collect representative groundwater samples and to minimize the risk of cross-contamination between wells. Samples were immediately transferred to laboratory-supplied, hydrochloric acid-preserved, 40-milliliter vials, packed on ice, and shipped via overnight delivery service, under chain-ofcustody documentation, to an Illinois-accredited stationary laboratory for the laboratory analysis of BTEX and MTBE using USEPA Method SW B. Additionally, Ziron surveyed the top of casing elevation of monitoring wells MW-1 through MW-5 relative to an established site-specific benchmark. Based on the results of the site investigation activities, compounds of concern (COCs) were detected in soil and groundwater samples above Illinois Environmental Protection Agency (IEPA) Tier 1 Soil and Groundwater Remediation Objectives (SROs and GROs); therefore, a release of gasoline was reported to the Illinois Emergency Management Agency (IEMA) on September 13, 2005, and Leaking Underground Storage Tank (LUST) incident number was assigned. Contaminated Media: 1. Soil: Plate 1 of the Illinois State Geological Survey (ISGS), Circular 532 (Berg Circular), was referenced to determine the prevalent geology within the area of the site. Circular 532 classifies the area with an E rating. The description given for an E rating depicts the area geology as consisting of uniform, relatively impermeable silty or clayey till or other fine grained material more than 50 feet thick. The fine grained till generally has moderate to high attenuation capacities and low hydraulic conductivities. A soil investigation was conducted at the site in August 2005, May 2006, and May Based on the geology encountered during the site investigation activities, the geology beneath the site is generally consistent with the Berg Circular and comprised of the following: fill material containing gravel from below the surface cover to an average depth of 1.5 feet below ground level (bgl) across the site. Underlying the fill, a clay formation containing minor amounts of silt and gravel to the maximum depth explored of 16 feet bgl was encountered. Detailed soil boring and monitoring well construction logs are provided in Appendix B. 2. Groundwater: On November 24, 2007, February 16, June 16, and October 24, 2008, Ziron performed gauging and sampling activities on the site s monitoring wells. Depth-to-water 3

6 measurements were recorded by a Ziron technician using a standard measuring tape equipped with an electronic sensor. The depth-to-water measurements on October 24, 2008, ranged from 1.38 feet below top of casing (btoc) in monitoring wells MW-1 to feet btoc in monitoring well MW-7. The average depth-to-water measured at the site is 5.08 feet btoc. Based on the groundwater elevation measurements collected at the site on October 24, 2008 the generalized direction of groundwater flow across the site is towards the west, under a hydraulic gradient of ft/ft. The depth-to-water measurements are tabulated in Table 1, and the groundwater equipotential lines and flow direction (for the most recent event on October 24, 2008) are shown on Figure 4. The Ziron monitoring well reports are presented in Appendix C. An in-situ (bail-down) test was performed by Ziron on November 30, 2005, on monitoring wells MW-1 and MW-5 to measure the hydraulic conductivity of the water-bearing formation beneath the site. The bail-down test data collected in the field from monitoring wells MW-1 and MW-5 was analyzed using the Bouwer-Rice Method for analyzing aquifer parameters, and the resulting hydraulic conductivity measurements from monitoring well MW-1 and MW-5 are 2.53 x 10-6 and 1.77 x 10-6 centimeters per second (cm/s), respectively. The most conservative hydraulic conductivity measurement (MW-1: 2.53 x 10-6 cm/s) was then used to calculate an estimated groundwater yield of 2.53 gallons per day for the site. The bail-down test analysis data and the groundwater yield calculation and parameter values were provided to the IEPA in the Site Investigation Completion Report (SICR) dated July 7, A Class II groundwater demonstration was provided in the SICR dated July 7, 2006, and approved by the IEPA in the technical review letter dated July 19, Extent of Contamination Above Tier 1 Remediation Objectives: Soil Analytical Results (Tier 1 Evaluation): Soil BTEX and MTBE concentrations were compared with the following IEPA Tier I SROs for Residential Properties: Soil Component of the Groundwater Ingestion Exposure Pathway Soil Inhalation Exposure Pathway Soil Ingestion Exposure Pathway Site investigation results indicate that the extent of soil BTEX and MTBE impact above the Tier 1 Migration to Class II Groundwater SROs has been defined by the following soil borings: SB-12, SB-6, and SB-13 on-site to the north; SB-8 and SB-9 off-site to the south; SB-16 and SB-7 off-site to the east; and SB-10, SB-11, and SB-12 on-site to the west. The soil samples collected from soil borings GP-1 (3-4), GP-2 (4-5), GP-3 (4-5), SB-3 (4), and SB-4 (5) were collected at or below the static water table as shown by the depth to water measurements collected from monitoring wells MW-3, MW-4, and MW-5. Soil boring GP-1 is located next to MW-5 which had a depth to water measurement of 3.71 feet BTOC near the time the soil sample from GP-1 was collected from the 3-4 (bgl) foot interval. Soil boring GP-2 is located next to MW-4 which had a depth to water measurement of 4.05 feet 4

7 BTOC near the time the soil sample from GP-2 was collected from the 4-5 foot (bgl) interval. Soil boring GP-3 is located next to MW-3 which had a depth to water measurement of 3.45 feet BTOC near the time the soil sample from GP-3 was collected from the 4-5 foot (bgl) interval. Soil samples SB-3 (4) and SB-4 (5) were collected during the installation of monitoring wells MW-3 and MW-4, respectively. The average depth to water measurements from MW-3 (3.8 feet BTOC) and MW-4 (4.8 feet BTOC) demonstrate that the soil samples collected from SB-3 (4) and SB-4 (5) were collected from below the static water table. Based on the information presented above, the BTEX and MTBE concentrations in soil samples GP-1, GP-2, GP-3, SB-3, and SB-4 are not representative of the BTEX and MTBE concentrations within the unsaturated zone. Risk Based Corrective Action (RBCA) will be utilized to determine the furthest extent of potential groundwater impact. The soil analytical results for BTEX and MTBE are summarized in Table 2. Soil sampling locations and corresponding BTEX and MTBE concentrations are presented on Figure 5. Laboratory reports from the recent site assessment activities are provided in Appendix D. Groundwater Analytical Results (Tier 1 Evaluation): The chemical analytical data for the groundwater samples were compared with the IEPA Tier 1 GROs for Class II groundwater. These cleanup objectives are provided in 35 IAC Section 742. Appendix B, Table E. The results of the site investigation activities indicate that the extent of groundwater BTEX and MTBE impact above Tier 1 GROs for Class II groundwater has been defined by the following monitoring wells: MW-1 and MW-11 to the north; MW-7 and MW-8 to the south; MW-1, MW-2 and MW-3 to the east; and MW-9, MW-10 and MW-11 to the west. Concentrations of BTEX and MTBE in groundwater are summarized in Table 1. Monitoring well locations and the corresponding BTEX and MTBE concentrations are presented on Figure 4. Laboratory reports for the recent groundwater sampling events are provided in Appendix D. b. The major components (e.g., treatment, containment, removal) of the corrective action; The major component of the corrective action is Pathway Elimination pursuant to the TACO presented in 35 IAC Section 742. c. The scope of the problems corrected or mitigated by the corrective action; and Soil and groundwater impact above Tier I SROs remaining at the site are addressed in the corrective action. d. The anticipated post-corrective action uses of the site and areas immediately adjacent to the site; The anticipated post-corrective action use of the site will be to remain as a retail gasoline station. There are no anticipated changes in the current uses of the areas adjacent to the site upon the completion of corrective action. 5

8 2. A description of the corrective action activities conducted including: Soil Investigation: a. A narrative description of the field activities conducted as part of corrective action On May 12, 2008, CS Drilling with URS Corporation (URS) oversight, advanced five soil borings (GP-1 through GP-5) on site as part of a Phase II Environmental Site Assessment (ESA) in preparation for the sale of the property. The soil borings were advanced to a maximum depth of 10 feet bgl using vacuum excavator, hand auger, and driven push methods. Soil samples collected during the assessment activities were submitted to an Illinois-accredited stationary laboratory (SPL: Houston, TX) for the analysis of BTEX and MTBE using USEPA Method SW B. The analytical laboratory reports are provided in Appendix D. Soil sampling performed by URS was conducted following standard industry practice and the sampling procedures established in ASTM Method E An air-knife was utilized to advance the first 5 feet of each soil boring to reduce the risk of damaging subsurface utilities that may be present. During the airknifing activities only, a soil sample was collected at one-foot intervals, utilizing a decontaminated steel hand auger. After reaching a depth of 5 feet, a direct-push drilling unit was utilized to collect soil samples. A portion of each soil sample was placed into a re-sealable plastic bag and allowed to volatilize to screen for the presence of VOCs utilizing a 10.6 ev photo-ionization detector (PID). The soil sample was logged by a field geologist and recorded on a field boring log along with the PID readings and any visual indications of product saturation and/or staining. At each sampling interval above the water table, a soil sample was collected in a glass jar and placed into a cooler with ice. The soil interval exhibiting the highest PID reading and/or visual/olfactory signs of impact was then preserved in the field using USEPA Method SW Soil samples were collected and preserved based on these field observations as well as professional knowledge of contaminant migration through soils. Groundwater Investigation: On November 24, 2007, February 16, June 16, and October 24, 2008, Ziron performed gauging and sampling activities on the sites monitoring wells. Ziron personnel performed groundwater sampling of the sites monitoring wells as reported by the Ziron standard operating procedures provided in Appendix E. The samples collected by Ziron personnel were submitted to an Illinois-accredited stationary laboratory (Test America: Nashville, TN for samples collected on November 24, 2007 and Xenco Laboratories: Houston, TX for samples collected on February 16, June 16, and October 24, 2008) for the laboratory analysis of BTEX and MTBE using USEPA Method SW B. Groundwater analytical results are summarized in Table 1 and shown on Figure 4. The laboratory chemical analytical reports for groundwater samples are presented in Appendix D. 6

9 Not Applicable. b. A narrative description of the remedial actions implemented at the site and the performance of each remedial technology utilized; c. Documentation of sampling activities; The following list sources of documentation provided for sampling activities: i) Sample Collection Information; Sample collection information is provided in the previously submitted reports and in Section C.2.a. ii) Sample Preservation and Shipment Information; Sample preservation and shipment information is provided in the previously submitted reports and in Section C.2.a. iii) Analytical Procedure Information; Analytical procedure information is provided in the previously submitted reports and in Appendix D. iv) Analytical Results, Chain of Custody, and Control, and Laboratory Certification; Analytical results, chain of custody, and control, and laboratory certification are provided in the previously submitted reports and in Appendix D. v) Field and Lab blanks Lab blanks are provided in the previously submitted reports and in Appendix D. vi) Tables comparing analytical results to remediation objectives approved for the site; Groundwater and soil analytical results for BTEX/MTBE are summarized and compared to the remediation objectives in Table 1 and Table 2, respectively. d. Soil boring logs and monitoring well construction diagrams. Soil boring and monitoring well construction diagrams are provided in Appendix B. 3. A narrative description of any special conditions relied upon as part of corrective action including: a) Engineered barriers utilized; i) type of barrier; and An asphalt or concrete engineered barrier of at least 3-inches in thickness will be maintained on site to eliminate the risks associated with soil impact exceeding the soil inhalation exposure route in accordance with 35 IAC Section and will be recorded to the deed of the property. ii) map showing location(s) and dimension(s) of barrier(s); The location and dimension of the engineered barrier is presented on Figure 6. 7

10 b) Institutional controls utilized: i) copy of fully executed institutional control(s); and The following institutional controls will be utilized to exclude the Soil Inhalation, Soil Component of the Groundwater Ingestion, and Groundwater Ingestion Pathways from further evaluation: On site: Village of Park Ridge Limited Groundwater Ordinance (proposed) On site: Engineered Barrier Off site: Village of Park Ridge Limited Groundwater Ordinance (proposed) Off site: Illinois Department of Transportation (IDOT) Highway Authority Agreement (HAA) (proposed) A copy of the Village of Park Ridge Limited Groundwater Ordinance (proposed) that prohibits the installation and/or use of wells as a potable water source is provided in Appendix F. A copy of the HAA (proposed) between Shell and the IDOT is provided in Appendix G. The Owner/Operator Property Summary Form, which indicates the property owners approval of the institutional controls, is included as Appendix H. ii) map showing location(s) of controls; Figure 6 presents the area subject to the executed institutional controls. c) Other conditions, if any, necessary for protection of human health and safety and the environment that are related to the issuance of a No Further Remediation Letter; and Based on the Tier 2 evaluation presented in Section C.9 and the executed institutional controls, there are no other conditions necessary for the protection of human health and safety. d) Any information required regarding off-site access; Not applicable. 4. An analysis of the effectiveness of the corrective action that compares the confirmation sampling results to the remediation objectives approved for the site; Concentrations of benzene in soil sample SB-15 are above the calculated Tier 2 SRO (5.98 mg/kg) for the Soil Inhalation Exposure Pathway; therefore, an engineered barrier will be utilized to eliminate the Soil Inhalation Exposure Pathway. Concentrations of benzene in soil samples SB-3, SB-5 and SB-15 are above the calculated Tier 2 SRO (benzene = 1.3 mg/kg for Class II groundwater) for the Soil Component of the Groundwater Ingestion Exposure Pathway. However, the Village of Park Ridge has a limited groundwater ordinance (proposed) which prohibits the use and/or installation of potable water supply wells. The Village of Park Ridge limited groundwater ordinance (proposed) will be utilized to eliminate the Soil Component of the Groundwater Ingestion Exposure Pathway. The RBCA R26 equation will be used to determine the extent that potential groundwater impact, from contaminated soil leaching to groundwater, may migrate. The TACO Tier 2 evaluation is presented in Section C.9. 8

11 5. A conclusion that identifies the success in meeting the remediation objectives approved for the site; Based on the results of the Tier 2 evaluation and the executed institutional controls, the Soil Inhalation, Soil Ingestion, Soil Component of the Groundwater Ingestion, and Groundwater Ingestion Exposure Pathways have been effectively eliminated. The TACO Tier 2 evaluation is presented in section C Appendices containing references and data sources; The appendices containing references and data sources are listed in the Table of Contents. 7. The water supply well survey: a. Map(s) showing locations of community water supply wells and other potable wells and the setback zone for each well; The well search results found that there are no public, private and/or commercial water supply wells within 2,500 feet of the site. The well search records were provided in the SICR dated July 7, b. Map(s) showing regulated recharge areas and wellhead protection areas; The IEPA Source Water Assessment Program (SWAP) database indicates that there are no regulated recharge areas within a one-mile radius of the site. The database indicates there are no wellhead protection areas within a one-mile radius of the site. The well search records were provided in the SICR dated July 7, c. Map(s) showing the current extent of groundwater contamination exceeding the most stringent Tier 1 remediation objectives; Figure 4 shows the current extent of groundwater contamination above the Tier 1 GROs. d. Map(s) showing the modeled extent of groundwater contamination exceeding the most stringent Tier 1 remediation objectives; Figure 7 and Figure 8 present the source dimensions used for Equation R26. Figure 7 and Figure 8 present the results of Equation R26 for migration to groundwater and groundwater ingestion pathways, respectively. e. Table(s) listing the setback zones for each community water supply well and other potable water supply wells; Not applicable. The well search results found that there are no public, private and/or commercial water supply wells within 2,500 feet of the site. The well search records were provided in the SICR dated July 7, f. A narrative identifying each entity contacted to identify potable water supply wells, the name and title of each person contacted, and any field observations associated with any wells identified; and Well searches were conducted through the Illinois State Water Survey (ISWS), the ISGS, the IEPA Division of Public Water Supply, the DPWS SWAP, and Environmental Data Resources, Inc. (EDR) to determine if there are any public, private and/or commercial wells located within 2,500 feet of the site. The well search results found that there are no public, 9

12 private and/or commercial water supply wells within 2,500 feet of the site. Based on the above mentioned information the site is not located within the minimum set back zone of a potable water supply well, pursuant to 35 IAC Section Results from the water supply well search were provided in the SICR dated July 7, g. A certification from a Licensed Professional Engineer of Licensed Professional Geologist that the survey was conducted in accordance with the requirements and that the documentation submitted includes the information obtained as a result of the survey (Certification of this report satisfies this requirement). A certification from a Licensed Professional Engineer that the survey was conducted in accordance with the requirements and that documentation submitted includes information obtained as a result of the survey is provided in Section D. 8. Site maps meeting the requirements of 35 Ill. Adm. Code (a) or Figures 1 through Figure 8 meet the requirements of 35 IAC Development of Tier 2 or 3 remediation objectives, if applicable: a. Equations used; In order to address the Tier 1 exceedances discussed in Section C.1a of this report, sitespecific remediation objectives were developed by using Tier 2 procedures provided in TACO, pursuant to 35 IAC Section Appendix C, Table A. The following is a summary of equations used for the development of Tier 2 remediation objectives for the Soil Inhalation, Soil Component of the Groundwater Ingestion (Soil Migration to Groundwater), and Groundwater Ingestion Pathways. Pathway Soil Inhalation Pathway Soil Migration to Groundwater Pathway Groundwater Ingestion Pathway Scenario Residential Residential Class I Groundwater Contaminant of Concern Benzene Benzene and Ethylbenzene Benzene and MTBE Equations Used SSL Equations S6 and S26 SSL Equations S18 and S28 RBCA Equations R12, R14, R20, R24, and R26 RBCA Equation R26 b. Discussion of how input variables were determined; The default input variables for the Soil Screening Level (SSL) equations are provided in 35 IAC Section ; Appendix C Table B. The default input variables for the RBCA equations are provided in 35 IAC Section ; Appendix C Table D. Site specific input variables for the SSL and RBCA equations were collected from the site during the previous site investigation activities and presented in the SICR dated July 7, 2006 and the Corrective Action Plan dated October 17,

13 c. Map(s) depicting distances used in equation; and The distances used in the Tier 2 Groundwater Migration evaluation are shown on Figure 7 and Figure 8. d. Calculations; and Prior to conducting an exposure pathway exclusion evaluation, the following site-specific physical soil characteristics were assessed consistent with the requirements of 35 IAC Section 742: 1. Whether or not the concentration of any organic contaminants exceeded the attenuation capacity of the soil. The soil samples with the highest sum of concentrations of BTEX in soil from above and below three (3) feet of ground surface were compared in the following table to site-specific natural attenuation capacity values pursuant to 35 IAC Section Sample ID Sample Depth (in feet) Sum of BTEX Concentrations (mg/kg) Site-Specific Attenuation Capacity (mg/kg) SB ,900 SB ,500 mg/kg = milligrams per kilogram Site-Specific attenuation capacities were calculated using foc values of g/g (SB-12 at 2) and g/g (SB-12 at 4) and converting them into mg/kg. Based on these results, the site-specific soil attenuation capacity values have not been exceeded at the site. 2. Whether or not the organic contaminants exceeded the soil saturation limit. The following table compares the default soil saturation limit (C sat ) presented in 35 IAC Section 742, Appendix A, Table A, with the highest concentrations of BTEX detected in soil samples collected at the site. Concentrations are listed in mg/kg. Benzene Toluene Ethylbenzene Xylenes C sat * Highest IC Concentrations for soil samples collected above water table * C sat values are from 35 IAC Section 742, Appendix A, Table A. These results demonstrate that the maximum concentration for benzene, toluene, ethylbenzene, and total xylenes detected in soil samples collected within the unsaturated zone do not exceed the default C sat values. 11

14 3. Whether or not the soils exhibited any characteristics of reactivity for hazardous waste. Subsurface soil at the site is impacted with residual amounts of unleaded gasoline; therefore, reactive hazardous waste would not be generated. 4. The ph of the soil. Subsurface soil at the site is impacted with residual amounts of unleaded gasoline; therefore, no impact is likely to have occurred which exhibit corrosive or caustic characteristics. TACO EXPOSURE PATHWAY EXCLUSION EVALUATION: Consistent with the procedures provided in 35 IAC Section 742, the following exposure pathways have been evaluated based on residential land use of the site: Soil Ingestion Exposure Pathway Soil Inhalation Exposure Pathway Soil Component of the Groundwater Ingestion Exposure Pathway Groundwater Ingestion Exposure Pathway Tier 2 Soil Ingestion Exposure Pathway Evaluation Based on the Tier 1 evaluation, the concentrations of BTEX from soil samples collected at the site were not detected above Tier 1 Residential Soil Ingestion Exposure Pathway SROs; therefore, the soil ingestion exposure pathway is excluded from further consideration as an environmental concern. Tier 2 Soil Residential Inhalation Exposure Pathway Evaluation (Benzene): Concentrations of benzene in soil samples SB-3, SB-5, and SB-15 are above the Residential Soil Inhalation Pathway SRO. Therefore, a site-specific benzene SRO was developed by using the Tier 2 procedures provided in TACO, pursuant to 35 IAC Section ; Appendix C, Table A. TACO provides the following Equation (S6) to develop site-specific SROs for the residential inhalation pathway: URF d TR ATc 365 yr ug mg EF ED 1 1, 000 VF The following descriptions are given for each of the parameters in the equation above: VF = Mass Limit Volatilization Factor (m 3 /kg) (Equation S26) TR = Target Cancer Risk (default residential value) = 10-6 URF = Inhalation Unit Risk Factor (benzene: IRIS/HEAST) = 7.8x10-6 (ug/m 3 ) -1 ATc = Averaging Time for Carcinogens = 70 yrs EF = Exposure Frequency (default residential value) = 350 d/yr ED = Exposure Duration for Inhalation of Carcinogens (default value) = 30 yrs 12

15 SSL Equation S26 (Section 742: Appendix C, Table A) VF M L Q C T M L b 7 s yr cm 3 d 10 6 s m 3 The following descriptions are given for each of the parameters in the equation above: VF M-L = Mass Limit Volatilization Factor (m 3 /kg) T M-L = Exposure Interval for Mass-Limit Volatilization Factor = 30 yr Q/C = Inverse of the mean concentration at the center of a square source Default value for ½ acre lot = (g/m 2 -s)/(kg/m 3 ) d S = Depth of Source (default) = m (10) b = Dry Soil Bulk Density (Site Specific) = 1.58 g/cm 3 Based on the above referenced parameter values and computations, the site-specific Tier 2 Soil Residential Inhalation Pathway SRO value calculated for benzene is 5.98 mg/kg. The TACO equation calculations are provided in Appendix I. The concentrations of benzene in soil sample location SB-15 is above the site-specific Tier 2 SRO; therefore, an engineered barrier (i.e. asphalt/concrete cap) will be maintained as an institutional control, pursuant to 35 IAC Section A signed Owner/Operator Property Summary Form, indicating the property owners approval of the proposed institutional control, is provided in Appendix H. To address concentrations of benzene in soil sample SB-15 above the calculated Tier 2 SRO for the Soil Inhalation Exposure Pathway, Shell will utilize a HAA with IDOT to eliminate the Soil Inhalation Exposure Pathway as an environmental concern. The area covered under the proposed institutional controls is presented on Figure 6. Tier 2 Soil Component of the Groundwater Ingestion Exposure Pathway Evaluation: Concentrations of benzene and ethylbenzene in soil exceed the Tier 1 Migration to Class I Groundwater SRO. To address the concentrations of benzene and ethylbenzene above the Tier 1 SRO that will remain beneath the site, a Tier 2 evaluation was conducted to calculate a site-specific Tier 2 SROs for benzene and ethylbenzene using SSL Equation S28 provided in 35 IAC Section 742.Appendix C, Table A. SSL Equation S28: C w I M L ED M L b ds Cw = Target Soil Leachate Concentration (mg/l) (Equation S18) I M-L = Infiltration Rate for Migration to Groundwater Mass-Limit = 0.18 m/yr ED M-L = Exposure Duration for Migration to Groundwater Mass-Limit = 70 yr b = Dry Soil Bulk Density: site-specific: 1.58 g/cm 3 13

16 d s = Depth of Source: default: m SSL Equation S18 (Section 742: Appendix C, Table A) C w Cw DF GWobj = Target Soil Leachate Concentration (Class II Groundwater) Benzene Toluene Ethylbenzene Xylenes MTBE = 0.5 mg/l = 50 mg/l = 20 mg/l = 200 mg/l = 1.4 mg/l DF = Dilution Factor (default) = 20 GW obj = GRO (Chemical-Specific - Class II Groundwater) Benzene Toluene Ethylbenzene Xylenes MTBE = mg/l = 2.5 mg/l = 1.0 mg/l = 10 mg/l = 0.07 mg/l Based on the SSL equation S28 demonstrations presented above, the site-specific Tier 2 Migration to Class II Groundwater SROs are as follows: Benzene = 1.3 mg/kg Toluene = mg/kg Ethylbenzene = 52.3 mg/kg Xylenes = mg/kg MTBE = 3.7 mg/kg The SSL equation S28 parameter values and calculations are provided in Appendix I. Concentrations of benzene and ethylbenzene in soil exceed the site-specific Tier 2 SROs. As a result, an additional Tier 2 evaluation was conducted to determine the potential for concentrations of benzene and ethylbenzene in soil to leach to groundwater. The Tier 2 evaluation was completed for each of the Tier 2 exceedances using the following RBCA equations and parameters. Equation R12 (Section 742: Appendix C, Table B): Equation R12 calculates a value for the maximum potential groundwater concentration as a result of impacted soil leaching to groundwater (mg/l). GW source = Soil Concentration at the Source * LF sw LF sw = Leaching Factor: (mg/l water )/(mg/kg soil ): Calculated value 14

17 Equation R14 (Section 742: Appendix C, Table B): LF sw k s H cm kg L g ws s s as 3 1 U gw I W gw s = Soil bulk density: kg/l: Site Specific value: 1.58 ws = Volumetric water content in vadose zone soils: cm 3 water/cm 3 soil: Default value: 0.3 k s = Soil-Water Sorption Coefficient: cm 3 water/g soil : calculated value: Benzene = 1.97 Ethylbenzene = H' = Henrys Law Constant: Default value: Benzene: Ethylbenzene: as = Volumetric air content in vadose zone soils: cm 3 air/cm 3 soil: Default value: 0.13 U gw = Groundwater Darcy Velocity: cm/yr: Site-specific: 2.23 gw = Groundwater Mixing Zone Thickness: cm: Default Value: 200 I = Infiltration rate: cm/yr: Default: 30 W = Width of source area parallel to direction of groundwater movement: cm: = 3600 cm (measured from SB-1 to SB-10) Equation R20 (Section 742: Appendix C, Table B): K oc k K f s oc oc = Organic Carbon Partition Coefficient: cm 3 /g or L/kg: Default value Benzene = 58.9 Ethylbenzene = 363 f oc = Fraction of organic carbon: g/g: Site-Specific value: Equation R24 (Section 742: Appendix C, Table B): U K i gw K = Hydraulic Conductivity: cm/yr: Site-specific: 79.8 i = Hydraulic Gradient: cm/cm: Site-specific: (from October 2008 sampling event) Equation R26 (Section 742: Appendix C, Table B): The TACO guidance document provides the following equation (R26) to predict the potential future migration of potentially impacted groundwater as a result of soil concentrations leaching to groundwater: C ( x ) C source exp 2 X x U x erf S w erf 4 y X 2 S d z X 15

18 The parameters in the equation presented above are described below. X = Distance from the planar source to the location of concern, along the centerline of the plume: cm: C source = The maximum potential concentration in groundwater that could occur at the source of the contamination as a result of soil leaching to groundwater was calculated using the TACO Equation R12. Based on the results of the R12 calculations, the maximum potential groundwater concentrations as a result of soil leaching to groundwater equals: x = Longitudinal dispersivity (i.e., Equation R16) = X * 0.10 y = Transverse dispersivity (i.e., Equation R17) = x /3 z = Vertical dispersivity (i.e., Equation R18) = x /20 U = specific discharge (i.e., Equation R19) = (K * I)/ T K = Hydraulic Conductivity = cm/day (site-specific measurement) i = Hydraulic Gradient = cm/cm (site specific measurement) T = Total Soil Porosity = 0.43 (Default value) = First order degradation constant: (Appendix C, Table E) Benzene = Ethylbenzene = S w = Source width (horizontal) of planar source perpendicular to groundwater flow (cm): = 4572 cm (measured from SB-8 to SB-12) S d = Source width (vertical) depth of planar source in the z direction, perpendicular to groundwater flow = 200 cm (default value) Based on the maximum potential groundwater concentration as calculated using Equation R12, the following parameter values and the R26 calculations are provided: Sample ID Potential Benzene Concentration (ug/l) Cx X (cm) X (feet) SB-3 (4) SB-5 (2) 1, SB-15 (2) 3, Sample ID Potential Ethylbenzene Concentration (ug/l) Cx X (cm) X (feet) GP-5 (2-3) 15, The following institutional controls will be utilized to exclude the Soil Component of the Groundwater Ingestion Pathway from further evaluation: 16

19 On Site: Village of Park Ridge Limited Groundwater Ordinance (proposed) Off Site: Village of Park Ridge Limited Groundwater Ordinance (proposed) The furthest modeled extent of potential groundwater impact from benzene is presented on Figure 7. Based on the R12 and R26 calculations, it is clear that there is no immediate or long-term threat of benzene concentrations in groundwater migrating past the compliance points determined by the furthest extent of the institutional controls. The parameter values and results of the TACO analysis are provided in Appendix I. A copy of the Village of Park Ridge Limited Groundwater Ordinance (proposed) that prohibits the installation and/or use of wells as a potable water source is provided in Appendix F. Tier 2 Groundwater Ingestion Exposure Pathway Evaluation: To evaluate the potential future migration of impacted groundwater with benzene and MTBE, a Tier 2 evaluation was performed. The evaluation was conducted to determine the potential impacts using the following equations in accordance with the TACO procedures presented in 35 IAC Section (d): Equation R26 (Section 742: Appendix C, Table B): The TACO guidance document provides the following equation (R26) to predict the potential future migration of impacted groundwater: C ( x ) C source exp 2 X x U x erf S w erf 4 y X 2 S d z X C source = GW source : The maximum concentration in groundwater that is detected at the source of the contamination as a result of the release. Based on the results of the R26 calculations, the groundwater concentration detected at the sites potential migration is: C source = Maximum concentrations of benzene and MTBE above Tier 1 GROs from the groundwater sampling events conducted x = Longitudinal dispersivity (i.e., Equation R16) = X * 0.10 y = Transverse dispersivity (i.e., Equation R17) = x /3 z = Vertical dispersivity (i.e., Equation R18) = x /20 U = specific discharge (i.e., Equation R19) = (K * I)/ T K = Hydraulic Conductivity = cm/day (site-specific measurement) i = Hydraulic Gradient = cm/cm (site specific measurement) T = Total Soil Porosity = 0.43 (Default value) = First order degradation constant for benzene = MTBE = S w = Source width (horizontal) of planar source perpendicular to groundwater flow: = 2,408.0 cm (measured from MW-3 to MW-10) 17

20 S d = Source width (vertical) depth of planar source in the z direction, perpendicular to groundwater flow = 200 cm (default value) Cx = Groundwater remedial objective X = Distance to compliance Based on the groundwater concentrations and the above referenced parameter values, the results of the Equation R26 calculations indicate: Well ID Benzene Concentration (ug/l) Cx X (cm) X (feet) MW-4 2, MW-5 1, Well ID MTBE Concentration (ug/l) Cx X (cm) X (feet) MW , The following institutional controls will be utilized to exclude the Groundwater Ingestion Pathway from further evaluation: On Site: Village of Park Ridge Limited Groundwater Ordinance (proposed) Off Site: Village of Park Ridge Limited Groundwater Ordinance (proposed) The furthest modeled extent of groundwater impact from benzene and MTBE is presented in Figure 8. Based on the R26 calculations, it is clear that there is no immediate or long-term threat of benzene and MTBE concentrations in groundwater migrating past the compliance points determined by the furthest extent of the institutional controls. The parameter values and results of the TACO analysis are provided in Appendix I. A copy of the Village of Park Ridge Limited Groundwater Ordinance (proposed) that prohibits the installation and/or use of wells as a potable water source is provided in Appendix F. 10. Property Owner Summary form. The property owner summary form is provided in Appendix H. 18

21 D. Signatures All plans, budgets, and reports must be signed by the owner or operator and list the owner s or operator s full name, address, and telephone number. UST Owner or Operator Name: Shell Oil Products US Contact: John R. Robbins Address: 603 Diehl Road, Suite 103 City: Naperville State: Illinois ZIP Code: Phone: (630) Signature: Date: Consultant Company: URS Corporation - Chicago Contact: Stephen W. Bates, M.S. Address: 100 South Wacker Drive City: Chicago State: Illinois ZIP Code: Phone: (312) Signature: Date: I certify under penalty of law that all activities that are the subject of this plan were conducted under my supervision or were conducted under the supervision of another Licensed Professional Engineer and reviewed by me; that this plan and all attachments were prepared under my supervision; that, to the best of my knowledge and belief, the work described in this plan has been completed in accordance with the Environmental Protection Act [415 ILCS 5], 35 Ill. Adm. Code 734, and generally accepted standards and practices of my profession; and that the information presented is accurate and complete. I am aware there are significant penalties for submitting false statements or representations to the Illinois EPA, including but not limited to fines, imprisonment, or both as provided in Sections 44 and of the Environmental Protection Act [415 ILCS 5/44 and 57.17]. Licensed Professional Engineer Name: Robin Semer, P.E. Company: URS Corporation - Chicago Address: 100 South Wacker Drive City: Chicago State: Illinois ZIP Code: Phone: (312) Ill. Registration No.: License Expiration Date: Signature: Date: L.P.E. Seal 19

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31 Corrective Action Completion Report IEMA No TABLES

32 Table 1 GROUNDWATER ELEVATIONS AND ANALYTICAL RESULTS 900 Talcott Road, Park Ridge, Illinois Monitoring Well Identification Date Depth to Groundwater Top of Well Casing Groundwater Elevation Benzene Toluene Ethylbenzene Xylenes Elevation (TOC) (TOC) (feet) (ug/l) (ug/l) (ug/l) (ug/l) (feet) (feet) Tier 1 GRO for Class I Groundwater Tier 1 GRO for Class II Groundwater MW-1 MW-1 MW-1 MW-1 MW-1 MW-1 MW-2 MW-2 MW-2 MW-2 MW-2 MW-2 MW-2 MW-3 MW-3 MW-3 MW-3 MW-3 MW-3 MW-3 MW-4 MW-4 MW-4 MW-4 MW-4 MW-4 MW-4 MW-5 MW-5 MW-5 MW-5 MW-5 MW-5 MW-5 MW-6 MW-6 MW-6 MW-6 MW-6 MW-7 MW-7 MW-7 MW-7 MW-7 11/30/2005 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 8/19/ /30/2005 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 8/19/ /30/2005 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 8/19/ /30/2005 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 8/19/ /30/2005 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 6/1/ /24/2007 2/16/2008 6/16/ /24/ NA NA NA NA NA NA NA NA NA NA MTBE (ug/l) 5 1, , ,500 1,000 10, < Dry Well <2 < Dry Well < Dry Well <2 Ziron reported well was destroyed <2 Unable to Locate under snow pile <5 <5 < <25 17 <5 <5 <5 <5

33 Table 1 GROUNDWATER ELEVATIONS AND ANALYTICAL RESULTS 900 Talcott Road, Park Ridge, Illinois Monitoring Well Identification Date Depth to Groundwater Top of Well Casing Groundwater Elevation Benzene Toluene Ethylbenzene Xylenes Elevation (TOC) (TOC) (feet) (ug/l) (ug/l) (ug/l) (ug/l) (feet) (feet) Tier 1 GRO for Class I Groundwater Tier 1 GRO for Class II Groundwater MW-8 MW-8 MW-8 MW-8 MW-8 MW-9 MW-9 MW-9 MW-9 MW-9 MW-10 MW-10 MW-10 MW-10 MW-10 MW-11 MW-11 MW-11 MW-11 MW-11 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 6/1/ /24/2007 2/16/2008 6/16/ /24/2008 6/1/ /24/2007 2/16/2008 6/16/ /24/ NS = Not Sampled Bold = Exceeded Tier 1 GROs for Class I groundwater GRO = Groundwater Remediation Objective = Not detected above laboratory limits TOC = Top of Casing NM = Not Measured ug/l = micrograms per liter NA NA NA NA NA NA MTBE (ug/l) 5 1, , ,500 1,000 10, <2 Insufficient volume of groundwater Unable to Locate under snow pile Blockage in well prevented sample from being collected Insufficient volume of groundwater < < < Unable to Locate under snow pile <5 <5 < Unable to Locate under snow pile <5 <5

34 Table 2 SOIL ANALYTICAL RESULTS Shell Service Station # Talcott Road, Park Ridge, Illinois Benzene (mg/kg) Toluene (mg/kg) Ethylbenzene (mg/kg) Xylenes (mg/kg) MTBE (mg/kg) Tier 1 - SRO - Migration to Class I Groundwater Tier 1 - SRO - Migration to Class II Groundwater Tier 1 - SRO - Residential - Inhalation Tier 1 - SRO - Residential - Ingestion 12 16,000 7, , < < < < < <2.4 < < < < < <0.004 <0.004 <0.004 <0.005 <0.004 <0.005 < < < <0.36 <0.099 < <0.075 < <2.4 < Boring # SB-1 SB-2 SB-3 SB-4 SB-5 SB-6 SB-7 SB-8 SB-9 SB-10 SB-11 SB-12 SB-12 SB-13 SB-14 SB-15 SB-16 GP-1 GP-2 GP-3 GP-4 GP-5 Date 8/12/2005 8/12/2005 8/12/2005 8/12/2005 8/12/2005 8/12/2005 5/4/2006 5/4/2006 5/4/2006 5/5/2006 5/5/2006 5/5/2006 5/5/2006 5/5/2006 5/4/2006 5/5/2006 5/5/2006 5/12/2008 5/12/2008 5/12/2008 5/12/2008 5/12/2008 Depth (Feet) Notes: mg/kg = milligram per kilogram = Concentration not detected above laboratory method limit. SRO = soil remediation objective Bold = Analytical result is above the Tier 1 SRO for Class I groundwater MTBE = Methyl Tert Butyl Ether Shaded samples were collected at or below the static water table based on depth to water measurements collected across the site.

35 Corrective Action Completion Report IEMA No APPENDIX A IEPA LETTER DATED DECEMBER 13, 2006

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