REMEDIAL ACTION COMPLETION REPORT

Transcription

1 REMEDIAL ACTION COMPLETION REPORT PROJECT SITE: CIVIC CENTER REDEVELOPMENT SITE # 1 (FORMER MUSSELMAN LUMBER / PACKER ENGINEERING SITE) 28W 751 MOUNT STREET WARRENVILLE, DUPAGE COUNTY, ILLINOIS IEPA BOL # PREPARED FOR: CITY OF WARRENVILLE 3S 258 MANNING STREET WARRENVILLE, ILLINOIS PREPARED BY: V3 COMPANIES 7325 JANES AVENUE WOODRIDGE, ILLINOIS JULY 2014

2 This report has been prepared by V3 Companies (V3), on behalf of the Remediation Applicant, in conformance with the requirements of 35 IAC Section for the purpose of documenting the Remedial Action Completion Report at the Remediation Site. Prepared by: Kristine J. Wright Environmental Scientist Rachael K. Berthiaume, P.E, LEED AP Project Engineer Craig A. McCammack, P.G. Senior Project Manager Approved by: Keith R. Oswald, P.E. Director Environment & Geosciences Remedial Action Completion Report V3 Companies Page i

3 TABLE OF CONTENTS EXECUTIVE SUMMARY INTRODUCTION SITE BACKGROUND SITE DESCRIPTION AND HISTORY RECOGNIZED ENVIRONMENTAL CONDITIONS REC 1 Concrete Vault REC 2 Historical Site Operations and Fill REC 3 Petroleum Free Product Area REMEDIAL ACTIVITIES OFF-SITE REMEDIAL INVESTIGATION Residential Property Remedial Investigation Field Activities Field Observations Laboratory Analytical Results Findings and Conclusions Off-Site Remedial Investigation FREE PRODUCT REMOVAL ADDITIONAL SOIL DELINEATION NORTH PORTION OF CCRS#1 AREA SOIL REMEDIATION Excavation and Soil Removal CCRS#1 Property Excavation and Soil Removal Off-Site Residential Properties Total Remediation Amounts Verification Sampling and Backfill Removal of the Undocumented UST TACO EVALUATION (POST-REMEDIATION) BASELINE SITE TACO CONDITIONS TACO Subpart C Evaluation Free Product Determination Waste Determinations Subpart C PCBs Determination REC 1: CONCRETE VAULT TIER 1 EVALUATION TACO SUMMARY REC 2: HISTORICAL SITE OPERATIONS AND FILL Tier 1 Evaluation TACO Summary REC 3: PETROLEUM FREE-PRODUCT AREA Tier 1 Evaluation TACO Summary INDOOR INHALATION EVALUATION CONCLUSIONS LICENSED PROFESSIONAL ENGINEER AFFIRMATION Remedial Action Completion Report V3 Companies Page ii

4 LIST OF FIGURES Figure 1.1 Figure 2.1 Site Location Map Site Base Map Figure 3.1 Proposed Remediation Areas Figure 3.2 Remediation Excavation Limits and Verification Samples (REC 1 and REC 3) Figure 3.3 Remediation Excavation Limits and Verification Samples (Part of REC 2) Figure 3.4 Residential Property Soil Boring Location Map Figure 4.1 Site NFR Base Map LIST OF TABLES Table 1.1 Summary of Soil Results Remediation Verification Data Table 2.1 Soil Analytical Results (VOCs) Table 2.2 Soil Analytical Results (PAHs) Table 2.3 Soil Analytical Results (Inorganics) Table 2.4 Soil Analytical Results (Organics) Residential Property Table 2.5 Soil Gas Analytical Results (VOCs) APPENDICES Appendix A Photographic Documentation Appendix B Laboratory Analytical Results B.1 Laboratory Accreditation and Certification B.2 Laboratory Reports Appendix C Remediation Documentation C.1 Soil Waste Profile C.2 Solid and Liquid Disposal Manifests Non-Hazardous Special Waste Appendix D Appendix E Appendix F UST Removal Documentation Legal Description Soil Boring Logs Residential Properties Remedial Action Completion Report V3 Companies Page iii

5 EXECUTIVE SUMMARY V3 Companies (V3) prepared this Remedial Action Completion Report (RACR) on behalf of the City of Warrenville, the Remediation Applicant, for the remediation site referred to as Civic Center Redevelopment Site #1 (aka Former Musselman Site / Former Packer Engineering) (Site). The Site is located at 28W 715 Mount Street, at the southeast corner of Rockwell Street and Stafford Place, in Warrenville, Illinois (Figure 1.1). The RACR describes the remedial actions performed to address the environmental issues associated with historical site operations and a heating oil tank. Figure 2.1 depicts the site boundary. The subject of this RACR is to document the successful remediation of heating oil and VOC, SVOC/PAH impacts and including localized manganese concentrations. More specifically, the report summarizes the following: field activities performed; remedial action in accordance with the approved RAP; results of the post-remediation sampling data; and documentation of Tier 1 ROs. Based upon previous Site investigations, the following recognized environmental conditions (RECs) were defined for the Site: REC 1 Concrete Vault: Analytical results indicated the presence of chlorobenzene at a concentration exceeding TACO Tier 1 ROs, in soils within a concrete vault located on the southwest side of the property. - Chlorobenzene was present in soil at a concentration exceeding Tier 1 ROs for the soil construction worker inhalation exposure route and the soil component of the Class II groundwater ingestion route. - Concentrations of chlorobenzene collected from soil samples surrounding the vault were below Tier 1 ROs, indicating that the chlorobenzene impact to be confined to soils present inside of the concrete vault. REC 2 Historical Site Operations and Fill: Based on historical operations at the property, it is possible that potentially hazardous materials and petroleum products may have been used at the Site. In addition, the Site contains clay fill material that was likely imported during site grading activities prior to construction of the former buildings at the Site. - Methylene chloride was identified in one soil sample collected by V3 near the south side of the former building, within the Petroleum Free Product Area (REC 3). Despite its physical location in REC 3, the presence of methylene chloride is included under REC 2 because it is likely the result of historical manufacturing operations at the Site. - The concentration of methylene chloride exceeded the Tier 1 soil component of the Class II groundwater ingestion route. Field indications and laboratory analyses for nearby borings indicated that the extent of methylene chloride is limited to a small area at the eastern edge of the Petroleum Free Product Area (refer to REC 3 below). - Manganese in one fill soil sample collected from the west portion of the Site exceeded the Tier 1 RO for the residential ingestion exposure route. Remedial Action Completion Report V3 Companies Page 1

6 REC 3 Petroleum Free Product Area: This REC consists of petroleum free product and naphthalene impacts to soil, resulting from the historical use of a heating oil aboveground storage tank (AST) formerly located within and along the south side of the former building, near the south Site boundary. Based on results of on-site and off-site subsurface investigations, visual observations and laboratory analytical results, the extent of the petroleum impacted area was initially delineated and measured in early 2010 to be approximately 30 feet by 80 feet in area. Off-site impacts were later identified prior to remediation, and a heating oil UST was identified during remediation. - Naphthalene was present in two soil samples, at concentrations exceeding Tier 1 ROs for the soil construction worker inhalation exposure route and the soil component of the Class II groundwater ingestion route, respectively. - Petroleum free product and related oily water were encountered during the CSI, in a shallow, thin soil layer. The product and oily water were pumped out of this soil layer and disposed during the related interim remedial measure. Minor amounts of oily water and soil staining remained due to the fact that this sort of response action is not 100 percent efficient. Contaminants of concern (COCs) at the Site: Soils contain two VOCs (chlorobenzene and methylene chloride), one SVOC (naphthalene) and one metal (manganese). In addition, potential free phase petroleum product may be present. Remedial Activities Remedial Actions (RAs) were conducted at the Site during November 2013 and April 2014 through May 2014 in accordance with the Remedial Action Plan. The proposed and final remediation areas are depicted in Figures 3.1 and 3.2, 3.3 respectively. Remedial measures within these areas included removing and disposing of soil that exceeded elevated concentrations of VOCs, PAHs, manganese and total petroleum hydrocarbons (TPH) / free product. Verification samples were collected along the sidewalls and bottom of excavations to compare to remediation goals. Remedial activities were performed under the supervision and direction of V3. As a brief overview, the areas of excavation are as follows: Off-Site Activities Remediation (removal and disposal) of oily soils in the petroleum remediation area were performed on the south-central portion of CCRS#1. Petroleum free product was encountered in a sand layer. Impacted soil was excavated in a generally triangular shape of approximately 560 square feet (approximately 70 feet long and 25 feet wide), and ranged between depths of 8 to 12 feet bgs. Soils were disposed at a landfill as non-hazardous special waste. The off-site properties are not part of the SRP Remediation Site and will not be included in the NFR Letter. REC 1 Concrete Vault (SB-5 Remediation Area) Chlorobenzene exceeding Tier 1 ROs was excavated and disposed off-site as non-hazardous special waste. A volume of soil measuring approximately 10 feet by 20 feet by 6 feet deep was removed and disposed. Refer to Figure 3.2. Remedial Action Completion Report V3 Companies Page 2

7 REC 2 Historical Site Operations and Fill (MP-GP-02, MP-GP-08 and MP-GP-305 Remediation Areas) Methylene chloride (MP-GP-08) and manganese (MP-GP-02) exceeding Tier 1 soil ROs were excavated and disposed off-site as non-hazardous special waste. Soil impacted by methylene chloride at MP-GP-08 was removed at the same time as impacted soils in REC 3. Impacted soils at the manganese area were excavated in an irregularly shaped area of approximately 2,450 square feet (about 35 feet wide and 70 feet long), to a depth of 6 feet below grade). Refer to Figure 3.3. REC 3 Petroleum Free Product Area (Free Product Remediation Area) Impacted soil containing naphthalene in excess of Tier 1 ROs is present in the Free Product Remediation Area (Figure 3.2), as is the soil layer which contained free product and oily water. Soils impacted at the Site petroleum area were excavated in an irregularly shaped area of nearly 7,800 square feet (about 130 feet long and 60 feet wide), to depths ranging from 4 17 feet) to the south property line. Excavated soils were disposed off-site as non-hazardous special waste. Free oil was not observed along any portions of the remediation excavation sidewalls or bottom of the Site. Additionally, no evidence of oil-saturated soils was observed based on field indicators (PID, visual, olfactory), and no evidence of free product was observed on storm water present in the remediation excavations. V3 sampled the excavation stormwater and compared results to General Use Surface Water Quality Standards (SWQS). Analytical results met the SWQS. All practically removable floating petroleum was removed using a vacuum truck prior to the remaining water being pumped out of the petroleum area. This remaining stormwater was filtered through four oil sorbent booms and a dewatering bag to capture sediment, before draining off-site. Water pumped from the manganese area was drained to the adjacent drainage swale. Remediation verification sampling was conducted during the implementation of the remedial actions to evaluate remediation goals. Figures 3.2, 3.3 and 3.4 summarize the completion of remediation activities. The excavations were backfilled with clean soils imported from several locations, and crushed concrete generated from the on-site building demolition. Import soils were analyzed prior to acceptance. Post-Remediation TACO Evaluation and Conclusion Verification sampling locations and results for SRP compliance are presented in Figures 3.2 and 3.3 and in Tables 2.1 to 2.3 and 2.5, illustrate that the remediation addressed the VOCs/BTEX, PAHs, and manganese concentrations in soil above Tier 1 ROs and TPH above soil attenuation limits. Based on the Tier 1 evaluations, the Site can qualify for an NFR determination under residential land use with no deed restrictions. A limited area of soils remains adjacent to the remediation excavation in REC 3 that may contain petroleum odors, but also may contain Site COCs at concentrations below Tier 1 ROs. These soils, if excavated in the future, can potentially be managed onsite in the same general area and depth (in accordance with SRP rules), or the soils will require off-site disposal. A base map for the Remediation Site Boundary is provided in Figure 4.1. A legal description is provided in Appendix E. Remedial Action Completion Report V3 Companies Page 3

8 1.0 INTRODUCTION On behalf of the City of Warrenville, the Remediation Applicant, V3 Companies, Ltd. (V3) is submitting this Remedial Action Completion Report (RACR) prepared in conformance with the requirements of 35 IAC Section for IEPA review and comment. The RACR documents the remedial actions performed to address environmental issues associated with historical operations and an undocumented heating oil underground storage tank (UST) formerly located at the Civic Center Redevelopment Site #1 (aka Former Musselman Site / Former Packer Engineering) (Site) in Warrenville, Illinois (Figure 1.1). Figure 2.1 shows the Remediation Site boundary and former site conditions. Based upon previous Site investigations and historical Site features, the following recognized environmental conditions (RECs) were initially defined for the Site in the Comprehensive Site Investigation / Remedial Objectives Report / Remedial Action Plan (CSI/ROR/RAP), dated July 2010 (refer to Figure 2.1, which depicts the RECs): REC 1 Concrete Vault and Pad: Analytical results from a Phase II ESA conducted by Aires indicated that the VOC chlorobenzene was present at a concentration exceeding TACO Tier 1 Soil Remediation Objectives, in soils within a concrete vault located on the southwest side of the property. In addition, a concrete pad of unknown use was observed north of the concrete vault on the west side of the property. Investigation findings indicated no environmental impact is associated with the concrete pad, and thus it is no longer included in REC 1. REC 2 Historical Site Operations and Fill: Based on historical operations at the property and the findings of previous investigations, potentially hazardous materials and petroleum products have been used at the manufacturing portion of the Site. In addition, the western portion of the Site contains clay fill material that was likely imported during site grading activities prior to construction of the former buildings at the Site. REC 3 Petroleum Free-Product Area: This REC consists of petroleum free product and naphthalene impacts to soil resulting from the historical use of a heating oil above ground storage tank (AST) formerly located within and along the south side of the former building, near the south Site boundary. [Note: The apparent presence of a heating oil AST in this area was based on anecdotal evidence. During removal of impacted soils from REC 3, an undocumented UST was discovered beneath the former building slab, to which the presence of the free product and impacted soils is attributed. This matter is discussed and resolved in subsequent sections of this report.] The implemented remedial action addressed soil impacts exceeding TACO Tier 1 remediation objectives (ROs) for residential land use within the three RECs. The implemented remedial action addressed the following: Performed remediation (excavate, transport and dispose) of those soils with VOC, SVOC/PAH, free product and manganese concentrations that are in excess of Tier 1 ROs, or are considered a Subpart C source material. The RACR has been prepared in general conformance with the requirements of 35 IAC Section , with institutional controls in accordance with 35 IAC Section Remedial Action Completion Report V3 Companies Page 4

9 2.0 SITE BACKGROUND 2.1 SITE DESCRIPTION AND HISTORY The Civic Center Redevelopment Site #1 (aka Former Musselman Site / Former Packer Engineering) (Site) is located at 28W 715 Mount Street, at the southeast corner of Rockwell Street and Stafford Place, Warrenville (Figure 1.1). The Site is located in a mixed-use commercial and residential area (Figure 2.1). The Site was previously occupied by a 51,000 square-foot slab on grade single story building (Figure 2.1) with sheet metal roof and attached two-story office building, which was constructed in 1951 and added onto in The structure consisted of a warehouse, and which in recent years was used to store vehicles and snow plowing equipment. Ralph White Racing, which assembled and built racecars, also occupied the building. The east side (office area) of the building was unoccupied. Prior to this, the Site was leased to Packard Engineering from , and prior to 2000 it was occupied by Musselman Lumber Company, a manufacturer of wood-framed windows and doors. The Site is currently unoccupied and used as a materials and equipment storage area for the City of Warrenville. Site buildings were demolished in 2008 and the building s concrete foundations and asphalt parking lots were removed in The intended reuse of the Site is residential with townhomes and single family homes. The Site will also contain landscaped areas, a detention pond and asphalt parking lots. The Site was enrolled in the Site Remediation Program (SRP) in October The RA and owner is the City of Warrenville. The purpose of the enrollment is to secure a comprehensive No Further Remediation (NFR) letter. Based upon historical Site operations, the SRP official Site name is Packer Engineering, related to the former tenant at the Site. The Site is also known as the Former Musselman Site. The CSI/ROR/RAP was submitted to the IEPA in July Amendments to the report were submitted as follows: V3 Amendment 1 / letter response (dated February 16, 2012) to IEPA January 10, 2011 letter for review of CSI/ROR/RAP; and V3 Amendment 2 / letter response (dated July 24, 2012) to IEPA June 22, 2012 letter for review of the CSI/ROR/RAP Amendment 1. IEPA approved the CSI/ROR/RAP and related Amendments in August Based upon the CSI/ROR/RAP, IEPA has approved the Site for residential land use with a Class II general resource groundwater classification. The approved RAP requires soil remediation only; there are no impacts to Site groundwater that exceed TACO Tier 1 Residential ROs, and thus no groundwater remediation is required. 2.2 RECOGNIZED ENVIRONMENTAL CONDITIONS The following RECs and site features are shown on Figure 3.1. Remedial Action Completion Report V3 Companies Page 5

10 2.2.1 REC 1 Concrete Vault This REC relates to the presence of chlorobenzene at a concentration exceeding TACO Tier 1 ROs, in soils within a concrete vault located on the southwest side of the property. Chlorobenzene was present in soil at a concentration exceeding Tier 1 ROs for the soil construction worker inhalation exposure route and the soil component of the Class II groundwater ingestion route. Concentrations of chlorobenzene collected from soil samples surrounding the vault were below Tier 1 ROs, indicating that the chlorobenzene impact was confined to soils present inside of the concrete vault. VOC-impacted soils in the concrete vault were mitigated by the remediation activities outlined in Section REC 2 Historical Site Operations and Fill This REC relates to the presence of one VOC (methylene chloride) and manganese concentrations in excess of Tier 1 soil ROs, as a result of former site operations and the historic placement of fill soil. Soil analytical results indicated the following: Methylene chloride was identified in one soil sample collected by V3 near the south side of the former building, within the Petroleum Free Product Area (REC 3). Despite its physical location in REC 3, the presence of methylene chloride is included under REC 2 because it is likely the result of historical manufacturing operations at the Site. The concentration of methylene chloride exceeded the Tier 1 soil component of the Class II groundwater ingestion route. Field indications and laboratory analyses for nearby borings indicated that the extent of methylene chloride is limited to a small area at the eastern edge of the Petroleum Free Product Area. Manganese in one fill soil sample collected from the west portion of the Site exceeded the Tier 1 RO for the residential ingestion exposure route. The VOC and manganese soil impacts from former site activities were mitigated by the remediation activities outlined in Section REC 3 Petroleum Free Product Area This REC consists of petroleum free product and naphthalene impacts to soil, resulting from the historical use of an apparent heating oil AST, which, based on anecdotal evidence, was formerly located within and along the south side of the former building, near the south Site boundary. [Note: During removal of impacted soils from REC 3, an undocumented heating oil UST was discovered, to which the presence of the free product and impacted soils in the remediation area is attributed. This matter is further addressed in subsequent sections of this report.] Based on results of on-site and off-site subsurface investigations, visual observations and laboratory analytical results, the extent of the petroleum impacted area was initially delineated and measured in early 2010 to be approximately 30 feet by 80 feet in area, and did not extend offsite to the south-adjacent residential properties (Figure 3.1). However, when removal of impacted soils began in November 2013, the presence of free product was observed to likely extend off site to the south and laterally on site more extensively than previously determined. Based on results of additional on-site and off-site subsurface Remedial Action Completion Report V3 Companies Page 6

11 investigations conducted in early 2013, the extent of the Petroleum Free Product Area was delineated and measured to be approximately 60 feet by 130 feet in area, and extended off site beneath the south-adjacent residential properties. For more information, refer to Figure 3.1 (attached) and discussions related to REC 3 in subsequent sections of the report below. Soil analytical results from the Petroleum Free Product Area indicated the following: Naphthalene was present in two soil samples, at concentrations exceeding Tier 1 ROs for the soil construction worker inhalation exposure route and the soil component of the Class II groundwater ingestion route, respectively. Petroleum free product and related oily water were encountered during the CSI, in a shallow, thin soil layer. The product and oily water were pumped out of this soil layer and disposed during the related interim remedial measure. Minor amounts of oily water and soil staining remained due to the fact that this sort of response action is not 100 percent efficient. The SVOC/PAH soil impacts and free product were mitigated by the remediation activities outlined in Sections 3.1 and 3.2. Remedial Action Completion Report V3 Companies Page 7

12 3.0 REMEDIAL ACTIVITIES Remedial Actions (RAs) were conducted at the Site during November 2013 and April 2014 through May The RAs were conducted in accordance with IEPA s August 2012 approval of the RAP (July 2010, as amended February 16, 2012 and July 24, 2012). The proposed remediation areas are shown in Figure 3.1 and the actual excavated areas are depicted in Figures 3.2 and 3.3. RAs within these areas included soil removal and placement of on-site and import soils and crushed concrete backfill. Robinette Demolition, Inc. (Robinette) of Oakbrook Terrace, Illinois was retained as the remediation contractor to excavate, transport, and dispose of impacted materials. All soils considered for import to the Remediation Site and off-site residential properties were first sampled and chemically analyzed for a comprehensive list of compounds. Results were compared to the most stringent TACO Tier 1 ROs for residential land use. Only soils that met these ROs were imported to the Site and used to backfill the remediation excavations. Subsequent to completion of remediation activities, the Remediation Site surface was restored by reconstructing the south slope from the off-site residential properties and drainage swale along the south side of the property, and smooth grading the remainder of the Remediation Site to match the adjacent grade and surface flow. Remediation verification sampling was conducted by V3 during the implementation of the RAs, utilizing industry-accepted field methods and protocols. Verification sample locations are shown on Figures 3.2 and 3.3, and are discussed in the following sections. Test America Laboratory, Inc., located in University Park, Illinois, analyzed the verification soil samples. First Environmental Laboratories, Inc. (Naperville, Illinois) and STAT Analysis Corporation, Inc. (Chicago, Illinois) analyzed the import soil samples. Chemical analyses were performed in accordance with 35 IAC Part 186 / NELAC standards using EPA SW-846 methods, in accordance with SRP and TACO requirements. All of the laboratories are NELAP accredited (see Appendix B.1). Verification soil analytical results are summarized in Tables 2.1 through Table 2.4. The laboratory analytical reports are presented in Appendix B OFF-SITE REMEDIAL INVESTIGATION Remediation (removal and disposal) of oily soils in the petroleum remediation area on the south-central portion of CCRS#1 began in November Petroleum free product was encountered in an approximate 12-inch thick sand layer, which was generally present in the 4 6 feet depth interval. Based on V3 s findings from previous off-site investigations, the sand layer extends southward beneath two adjacent residential properties. During soil removal work at CCRS#1, the sand layer was exposed along the south Site boundary adjacent to the off-site residential properties. Petroleum free product was observed seeping from the sand at the Site boundary and into the remediation excavation. Based on field observations, V3 concluded it likely that oil-impacted soils extend off-site beneath the two residential properties. The off-site properties are not part of the SRP Remediation Site and will not be included in the NFR Letter. Remedial Action Completion Report V3 Companies Page 8

13 3.1.1 Residential Property Remedial Investigation Subsurface investigations on the two adjacent residential properties were performed to assess the extent of apparent petroleum free product in soils beneath the properties. An initial investigation was performed in December 2013 to make a general assessment of subsurface conditions and the presence of oily soils. This was followed by a second investigation in February 2014, the purpose being to delineate the extent of petroleum-impacted soils encountered in the December investigation, in order to evaluate potential remediation alternatives and costs. A total of 14 Geoprobe soil borings were advanced along and near the property line (Figure 3.4). Soils were classified and screened in the field for VOCs utilizing a photoionization detector (PID). A total of 13 soil samples were collected for laboratory analysis of benzene, toluene, ethyl benzene and xylenes (BTEX) and polynuclear aromatic hydrocarbons (PAHs). Field activities and laboratory analytical results are discussed below Field Activities Six soil borings (MP-GP-405 through MP-GP-410) were advanced by Johnson Probing on December 4, 2013, to assess the extent of oily soils onto the residential properties. An additional eight soil borings (MP-GP-501 through MP-GP-508) were advanced on February 12, 2014, to visually and analytically delineate the extent of petroleum free product and petroleumimpacted soils on the residential property that would be considered for remediation. Soil boring locations are shown on Figure 3.4. Borings were advanced 12 to 16 feet below the ground surface (bgs) using direct push Geoprobe soil sampling methods. Soil samples were collected continuously using new 2-inch diameter, 5-feet long clear plastic liners. Field activities were performed under the supervision of V3 s site geologist. Soil boring logs for the residential investigations are provided in Appendix F Field Observations The following summarizes the subsurface conditions encountered during the field investigations. Refer to Figure 3.4 for boring locations: Geological conditions were similar to those observed and discussed in Sections of the July 2010 CSIR/ROR/RAP. Note: The residential properties are topographically several feet higher in elevation than the adjacent CCRS#1 property, and thus, the oily sand layer is several feet deeper on the residential properties, compared to the CCRS#1 property. Elevated PID readings, slight to strong petroleum odors, heavy oil staining and free product were observed in the interstices of soils from approximately 6-10 feet bgs in borings MP-GP-405, MP-GP-407 and MP-GP-501. Lower level PID readings and significantly less petroleum hydrocarbon staining and odors were observed from the same depth interval in nearby borings MP-GP-406, MP- GP-408 and MP-GP-502. Remedial Action Completion Report V3 Companies Page 9

14 No petroleum odors, staining or elevated PID readings were observed in the remaining borings. Groundwater was encountered at approximately 8-11 feet bgs; groundwater samples were not collected for chemical analysis during the investigations Laboratory Analytical Results A total of 13 soil samples were collected and analyzed for BTEX and PAHs. Samples MP-GP- 405(9-10), MP-GP-407(9-10), MP-GP-501(7-8) and MP-GP-501(8-9) contain Tier 1 residential and/or construction worker RO exceedances of benzene, xylenes and seven PAHs. The exposure pathways of concern are ingestion, inhalation and the soil component of the groundwater ingestion routes. The limits of petroleum impacted soils exceeding Tier 1 Residential soil ROs are shown on Figure 3.4. Analytical results are summarized in Table 2.4. Remediation of free product and impacted soils are described below in Sections 3.2 and Findings and Conclusions Off-Site Remedial Investigation The two subsurface investigations performed on the residential properties resulted in the following: The lateral and vertical extents of soils exceeding Tier 1 Residential soil ROs, and requiring remediation, were delineated on the residential properties. The potential exists for petroleum-impacted soils in excess of Tier 1 Residential ROs to be present beneath the northeast corner of the Existing Building (garage) shown on Figure 3.4. The need to remediate impacted soils near to and possibly beneath the northeast corner of the garage will be determined at the time of soil remediation. Based on effectiveness, certainty, time constraints, regulatory criteria and technical feasibility, the City of Warrenville chose to address impacted soils on the residential properties by excavating and disposing them concurrently with the remediation activities on CCRS# FREE PRODUCT REMOVAL During soil remediation work (which commenced November 22, 2013), petroleum free product was encountered in soils at the Petroleum Free Product Area and also seeping from off-site soils at the south property boundary (from the residential properties). A small temporary sump pit was excavated southeast of former monitoring well MP-MW-03 (Figure 2.1) to collect oil seeping from the oily sand layer, where it was removed by a vacuum truck. Free product and impacted soil removal activities at the Site were halted due to inclement weather (snow and sub-freezing temperatures) on November 26, Site remediation work recommenced in April 2014 after winter snow and ice had melted, which resulted in the accumulation of storm water in the Petroleum Free Product Area excavation. Free product and associated oily water had to first be removed from the excavation before the remaining storm water and impacted soils could be removed from the Site and residential properties. Stormwater removal from the remediation excavations is discussed further in Section Remedial Action Completion Report V3 Companies Page 10

15 The sump pit was excavated deeper to more effectively collect free product seeping from oily soils around the excavation and prevent movement of product and oily water out of the remediation excavation. A vacuum truck was called out multiple times during April May 2014 to skim off and dispose free product as it accumulated, along with related oily water, until no more could be practicably removed. Approximately 20,900 gallons of a combination of free product and oily water were removed from the remediation excavation during this project, which was disposed by North Branch Environmental. This total does not include the UST contents (discussed below in Section 3.5). Subsequent to removal of free product and oily water from the sump pit, a soil sample [MP-EX1-35(17)] was collected from the bottom of the sump, and was submitted to the laboratory for BTEX, PAHs and TPH analysis. Analytical results met Tier 1 Residential ROs (refer to Table 2.1 and 2.2). 3.3 ADDITIONAL SOIL DELINEATION NORTH PORTION OF CCRS#1 AREA Because free product and impacted soils extended laterally at the Site more extensively than had previously been determined in 2010, additional field delineation work was performed across the northern portion of the Petroleum Free Product Area. Test pits and soil borings were used to establish the new lateral and vertical extents of oily and impacted soils. On November 26, 2013, two exploratory test pits were excavated in the petroleum area by Robinette, under the direction of V3. A backhoe was used to visually assess the northern extent of free product and the vertical depth range of impacted soils. The first test pit was excavated approximately 10 feet north of the source area (35 feet north of the property line). The new extent of oily / impacted soils is shown on Figure 3.2. The depth interval of apparent impacts, based on visual and field screening methods, was observed to be 3 6 feet bgs. A test pit was excavated approximately 20 feet north of the source area (45 feet north of the property line). No free product was observed in the sandy-silty-clayey soils. However, strong petroleum odors were noted at approximately 4 6 feet bgs. A soil sample was collected [MP-TP-01(6)] at 6 feet deep and was analyzed for BTEX. Results met Tier 1 Residential ROs. Refer to Figure 3.2 for sample location and Table 2.1 for sample results. In addition to the test pits, Johnson Probing advanced six soil borings on February 12, 2014, under the direction of V3. Borings were advanced across the northern portion of the petroleum area to visually delineate the vertical and horizontal extents of free product and oily soils. No soil samples were collected. Based on visual observations from test pits and soil borings, the northern extent of free product and oily soil was determined, allowing remediation activities to resume. 3.4 SOIL REMEDIATION The specific areas of soil that were removed and disposed were discussed above in Section 2.2, and are shown on Figures 3.1 to 3.3: REC 1 Concrete Vault Remediation Area (boring SB-5). REC 2 (a portion of it) Historical Site Operations (methylene chloride at boring MP-GP- 08). Remedial Action Completion Report V3 Companies Page 11

16 REC 2 (a portion of it) Fill Remediation Area (manganese at borings MP-GP-02, MP- GP-202, and MP-GP-305). REC 3 Petroleum Free Product Remediation Area (including the off-site residential properties). The remedial plan consisted of the following elements: Excavation and Soil Removal Verification Sampling Excavation and Soil Removal CCRS#1 Property Soils were excavated from the three remediation areas by Robinette using a backhoe. Soils were either loaded directly into trucks or stockpiled over plastic and covered, for later haul-off and disposal, as a non-hazardous special waste. In addition, concrete debris from the demolition of the vault was temporarily stockpiled and later hauled off and disposed as a nonhazardous special waste. Photographs of remediation activities are presented in Appendix A. Concrete Vault REC 1 Soils impacted at the concrete vault (EX-2) were excavated in a rectangular-shaped area of 200 square feet (10 feet by 20 feet), to a depth of 6 feet below grade. Methylene Chloride Part of REC 2 Methylene chloride was identified in one soil sample collected by V3 near the south side of the former building, within the Petroleum Free Product Area (REC 3). Despite its physical location in REC 3, the presence of methylene chloride is included under REC 2 because it is likely the result of historical manufacturing operations at the Site. Soils impacted with methylene chloride were excavated and disposed along with petroleum-impacted soils, all of which were located in the REC 3 area. Manganese Impact Area Part of REC 2 Impacted soils at the manganese area were excavated in an irregularly shaped area of approximately 2,450 square feet (about 35 feet wide and 70 feet long), to a depth of 6 feet below grade). Petroleum Area REC 3 Soils impacted at the Site petroleum area were excavated in an irregularly shaped area of nearly 7,800 square feet (about 130 feet long and 60 feet wide), to depths ranging from 4 17 feet), on the CCRS#1 property. For excavation dimensions related to the residential properties, refer to Section Free oil was not observed along any portions of the remediation excavation sidewalls or bottom of the Site. During the cleanup work, the groundwater monitoring well located next to the concrete vault (MP-MW-01) and the well that was located in the petroleum area (MP-MW-03) were removed due to their proximity to the remediation excavations. Refer to Figure 2.1 for the well locations. Stormwater In April and May of 2014, water was present in all three remediation excavation areas as a result of heavy snow melt and spring rains. V3 sampled the stormwater and compared results to General Use Surface Water Quality Standards (SWQS). Analytical results met the SWQS, so Remedial Action Completion Report V3 Companies Page 12

17 the City instructed Robinette to pump the water out of the excavations using best management practices. All practically removable floating petroleum was removed using a vacuum truck prior to the remaining water being pumped out of the petroleum area. The water was pumped to the onsite swale located just east of the petroleum area, and was filtered through four oil sorbent booms and a dewatering bag to capture sediment, before draining off-site to the east. Water pumped from the manganese area was drained to the adjacent drainage swale. Photo documentation the three areas and their dewatering methods are presented in Appendix A Excavation and Soil Removal Off-Site Residential Properties On May 27, 2014, Robinette began soil removal work on the residential properties, under the direction of a V3 Environmental Professional. A vacuum truck from North Branch Environmental was initially used to remove a minor accumulation of free product and standing water in the CCRS#1 excavation. Robinette built a soil bridge across the partially open CCRS#1 excavation, using clean imported soils, to access the residential properties with a large excavator. Next, Robinette removed approximately seven feet of clean overburden soil from within the remediation limits on the residential properties (refer to Figure 3.4). These soils were temporarily stockpiled on uncontaminated areas of the CCRS#1 property (outside of the remediation areas), and were ultimately used to backfill the excavation on the residential properties. Oily / impacted soils were typically encountered from approximately 7 to 12 feet bgs. Contaminated soils were removed and stockpiled over plastic on the CCRS#1 property, and covered with plastic, pending haul-off and disposal. Impacted soil on the residential property was excavated in a generally triangular shape of approximately 560 square feet (approximately 70 feet long and 25 feet wide), and ranged between depths of 8 to 12 feet bgs (Figure 3.2). All of the soils that were visually impacted were removed, except near the northeast corner of the garage (Figure 3.4), which was oilstained, but impractical to remove due to the proximity of the garage. Free product was not observed along any portions of the remediation excavation sidewalls or bottom on the residential properties Total Remediation Amounts A total of 3, tons of soil was excavated and delivered to Orchard Hills Landfill in Davis Junction, Illinois, for disposal. At Orchard Hills, the loads were received, weighed, and visually inspected. Manifest documents are provided in Appendix C Verification Sampling and Backfill Verification sidewall and bottom samples were collected approximately every 20 feet of lateral separation. Refer to Figures 3.2 and 3.3 for verification sample locations. Analytical results are summarized in Tables 2.1 to 2.3. Refer to the TACO Tier 1 data evaluation in Section 4.0 (below) for analytical results and the evaluation of applicable exposure routes. Remedial Action Completion Report V3 Companies Page 13

18 Concrete Vault REC 1 A total of four sidewall samples [MP-EX2-01(4-6), MP-EX2-02(4-6), MP-EX2-03(4-6) and MP- EX2-GP-04(4-6)] and one bottom sample [MP-EX2-05(6)] were collected and analyzed for VOCs. Methylene Chloride Part of REC 2 Methylene Chloride was detected in excess of Tier 1 Class II soil to groundwater RO at boring location MP-GP-08, which is physically located in REC 3. As indicated above, the presence of methylene chloride is included under REC 2 because it is likely the result of historical manufacturing operations at the Site. Verification samples MP-EX1-03(4-6) and MP-EX1-04(4-6) were collected adjacent to this location and analyzed for VOCs. Manganese Area Part of REC 2 A total of 26 sidewall and bottom verification samples (MP-EX3-01 to MP-EX3-26) were collected and analyzed for one or more of the following: manganese, ph and SPLP manganese. Petroleum Area (REC 3) A total of 40 sidewall and bottom samples (MP-EX1-01 to MP-EX1-35, MP-EX1-43, MP-EX1-44 and MP-TP-01) were collected and analyzed for one or more of the following: BTEX, PAHs and TPH. Out of the 40 soil samples, six of them (MP-EX1-22 to MP-EX1-27) were collected for the UST excavation discussed below in Section 3.5. To demonstrate that all free product was removed to the maximum extent practical, TPH results were compared to the default soil saturation limit (2,000 mg/kg) below 1 meter. Additionally, the demonstration was completed when no evidence of oil-saturated soils was observed based on field indicators (PID, visual, olfactory), and no evidence of free product was observed on storm water present in the remediation excavations. Residential (Offsite) Properties Five verification sidewall samples [MP-EX-36(8) and MP-GP-37(9) to MP-GP-42(9)] and three bottom samples [MP-GP-36(8), MP-GP-38(12) and MP-GP-45(12)] were collected from the petroleum area on the residential property. The eight samples were analyzed for BTEX and PNAs, and five of the eight samples were also analyzed for TPH. Remediation Excavation Backfill Activities Following excavation and removal of impacted soils, and verification that the remaining soils meet Tier 1 Residential ROs, clean soils imported from several locations, and crushed concrete generated from the on-site building demolition, were used to backfill the excavations. Soils being considered for import to the CCRS#1 Remediation Site were chemically analyzed for a comprehensive list of compounds, and the analytical results must meet the most stringent TACO Tier 1 Remediation Objectives for residential land use. Typically, one sample was collected and analyzed for every 500 cubic yards of import. Grab samples were collected from potential stockpiled import sources, and a track-mounted Geoprobe drill rig was used to collect in-situ soil samples at potential in-ground import sources. Detected soil concentrations were compared to the ROs specified in the State of Illinois 35 Illinois Administrative Code (IAC), Part 742 Tiered Approach to Corrective Action Objectives (TACO) for residential properties. Analytical data for import soil samples were reviewed by V3 and approved for use at the Site prior to importing the fill. Only soils that met the most stringent Remedial Action Completion Report V3 Companies Page 14

19 TACO Tier 1 Soil ROs for residential land use were imported and used to fill the remediation excavation. Refer to Appendix B.2 for import soils lab results. 3.5 Removal of the Undocumented UST During soil removal activities in the Petroleum Free Product Area, an undocumented heating oil UST was encountered within the remediation area. The approximate location of the tank is shown on Figure 3.2. Refer to Appendix A for photo-documentation of the tank removal and Appendix D for the tank removal permit, waste disposal manifest, tank destruction certificate, and OSFM records. Following is a description of the tank removal. On April 22, 2014, a 6,000-gallon pre-1974 heating oil UST was encountered within the northern portion of the Petroleum Free Product Area. Robinette obtained the removal permit from the Office of the State Fire Marshall (OSFM), and removed the tank on May 15, 2014, in the presence of OSFM Storage Tank Safety Specialist, Mr. Bruce Billman. The tank appeared to be filled with an oil and water mixture, which was pumped out using a vacuum truck prior to removing the tank. Approximately 3,000 gallons of oil and water were pumped out of the tank and disposed by North Branch Environmental. Once removed, it was apparent that the tank was in poor condition, having significant corrosion and numerous holes. Soils surrounding the tank were observed to be impacted with petroleum hydrocarbons, indicating that the leaking tank was the source of free product and impacted soils that are the subject of this remedial action. The final tank excavation dimensions were approximately 13 feet x 25 feet x 12 feet deep. Four sidewall samples [MP-EX1-22(9), MP-EX1-24(10.5), MP-EX1-26(10.5) and MP-EX1-27(10.5)] and two bottom samples [MP-EX1-23(12) and MP-EX1-25(12)] were collected from between 9 and 12 feet bgs. The samples were submitted to the laboratory and analyzed for one or more of the following: BTEX, PAHs and Total Petroleum Hydrocarbons (TPH). Refer to Figure 3.2 for verification sample locations and Table 2.1 and Table 2.2 for a summary of the laboratory results. On behalf of the City of Warrenville, V3 called the release into the Illinois Environmental Management Agency (IEMA), which applied Incident #H to the leaking tank. The incident will be transferred from the IEPA LUST Program to the SRP program for closure. The evaluation of verification sample analytical results is provided below in Section 4.4. Remedial Action Completion Report V3 Companies Page 15

20 4.0 TACO EVALUATION (POST-REMEDIATION) This section presents a discussion of recognized environmental conditions (RECs), COCs above Tier 1 ROs, exposure pathways, and the results of the Tier 1 evaluation completed for the Site. The TACO evaluation provided in the following sections is intended to reflect the completion of the remedial measures. Tables 1.1 to 2.5 provide the compliance data used in this post-remediation TACO evaluation and summarizes COC concentrations for detected compounds. The data set used for the postremediation compliance evaluation included verification sampling results from each remediation area. The TACO evaluation is discussed in the following sections. 4.1 BASELINE SITE TACO CONDITIONS The results of the remediation verification were the basis for these TACO evaluations. The site COCs include select PAHs, VOCs/BTEX, TPH and manganese (total and SPLP) in soil. The applicable land use designation for the Site is residential with a construction worker scenario. Soil results were compared to Tier 1 Class II standards TACO Subpart C Evaluation The following sections discuss the additional data as related to the exposure route evaluation required by 35 IAC 742, Subpart C. After the completion of remedial measures described in Section 3.0, the compliance data have identified no conditions which, when assessed pursuant to the criteria listed at 35 IAC Section : a) through f) could be viewed as a Subpart C source Free Product Determination An evaluation of soil attenuation capacity, soil saturation limit, and soil observations for the Site indicates that free product is no longer present within soils. Free product was observed within the REC 3 excavation and the soils have been removed until free product was not present. The default F oc of 2,000 mg/kg was used for evaluation of TPH results against soil attenuation capacity for the verification sampling of the REC 3: Petroleum Free Product Area. The TPH values on-site within the sidewalls and bottom samples range between 30 mg/kg and 370 mg/kg, below the F oc, indicating the Site soils are below the soil attenuation capacity. At the off-site residential properties (not part of the SRP Site), one TPH sample [MP-EX1-41 (9 )] was collected next to the residential garage and did not meet the default TPH. However, no free-flowing petroleum product was observed anywhere along the excavation sidewall. The garage area will be further investigated to delineate impacted soils beneath the northeast corner of the structure, and will be considered for remediation at a later time. [Note: The residential properties are not part of the Remediation Site or the NFR letter.] Waste Determinations Based on the remedial activities and post-remediation data at the Site, Remedial Action Completion Report V3 Companies Page 16