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HomeMy WebLinkAboutSP202000006 Study Special Use Permit 2013-04-12Limited Phase II Investigation Report Scott's Ivy Exxon Site Charlottesville, Virginia C 0 am 00 c r. on am A 0 -I ANALYTICAL SERVICES, INC. Limited Phase II Investigation Report Scott's Ivy Exxon Site — 4260 Ivy Road Charlottesville, Virginia Prepared for: Mr. Scott Ramm Scott's Ivy Exxon 4260 Ivy Road Charlottesville, Virginia 22903 Prepared by: Analytical Services, Incorporated 402 N. West Street Culpeper, Virginia 22701 Date: April 12, 2013 Limited Phase II Investigation Report Scott's Ivy Exxon Site — 4260 Ivy Road Charlottesville, Virginia Prepared for: Mr. Scott Ramm Scott's Ivy Exxon 4260 Ivy Road Charlottesville, Virginia 22903 Prepared by: Analytical Services, Incorporated 402 N. West Street Culpeper, Virginia 22701 �/� Michael L. Maloy, CP Senior Geologist, P ` cipal Thomas P. Nelson, PG Hydrogeologist Date: April 12, 2013 r. Table of Contents 1.0 Introduction...........................................................................................................1 1.1 Summary of Phase I Environmental Site Assessment 2.0 Subsurface Investigation.......................................................................................2 2.1 Service Building 2.2 Residential Building and Adjoining Railroad 3.0 Document Review of Adjoining Leaking Underground Storage Tank Site ......... 6 K. 4.0 Above Ground Storage Tank Inventory ................................................................7 4W 5.0 Discussion of Findings..........................................................................................8 5.1 Soil Characterization 5.2 Soil and Groundwater Sampling 5.3 Adjoining Leaking Underground Storage Tank Site 5.4 AST Inventory 6.0 Conclusions ....................... ......................11 ............................................................ 7.0 Limitations..........................................................................................................12 8.0 References...........................................................................................................12 List of Figures Figure 1 Site Location Map Figure 2a Site Layout Map Figure 2b Boring Locations Map List of Tables Table 1 Summary of Soil Sample PID Readings Greater than 2 Parts Per Million Table 2 Soil Sampling Results �•• Table 3 Groundwater Sampling Results List of Appendices .• Appendix A Laboratory Analytical Results Appendix B Toddsbury of Ivy Virginia Department of Environmental Quality Documents im 400 Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 Om 4260 Ivy Road - Charlottesville. VA April 12 2013 1.0 Introduction Analytical Services, Inc. (ASI) is pleased to provide the following report documenting our findings during a limited investigation performed at the Scott's Ivy Exxon site located at 4260 Ivy Road in Charlottesville, Virginia. The investigation was performed at the request of our client, Mr. Scott Ramm, as part of the due diligence process for a future real estate transaction. The investigation consisted of a subsurface investigation at the site and a review of documents from an open leaking underground storage tank (LUST) site located within 100 feet of the Scott's Ivy Exxon site. The Scott's Ivy Exxon site is currently being operated as a gasoline and diesel fueling station and as an automotive repair shop. Two buildings are present at the site; the southern building is used as an automotive repair shop (service building) and the northern building is residential (residential building). Gasoline and diesel fueling dispensers are present to the south of the service building. The gasoline fueling island is supplied by two active underground storage tanks (USTs). According to the Virginia UST database, these tanks have capacities of 8,000 gallons and 12,000 gallons, and were installed in 1998. ' The diesel fueling dispenser is supplied by a 500-gallon aboveground storage tank (AST). The residential building is supplied by a heating oil UST of unknown capacity. A railroad runs along the northern boundary of the site. The subsurface investigation focused on the gasoline UST basin, an oil change pit, a diesel AST, an out -of -service hydraulic lift and the reported location of a used oil UST and kerosene UST near the northern side of the service building that may, or may not, have been previously removed (see Section 1.1). Your Locator, a private utility locating service, was used to supplement Miss Utility's clearance and line marking at the site. The private utility locator was also used to search the northern side of the service building for indications of the presence of potential USTs where the used oil UST and kerosene UST were reported to have previously existed. Additionally, the investigation addressed the existing residential structure which may have been used as a gasoline station prior to the 1950s. Investigation conducted at the residential structure included utilizing metal locating equipment to screen the yard area for the presence of metallic •.. anomalies, conducting soil borings and sampling, and assessing the subsurface near an existing heating oil UST. In addition shallow soils were sampled near the railroad that lies along the site's northern boundary. A Geoprobe® direct push drill rig, operated by Bedford Well Drilling, was utilized to collect soil cores and samples from near the UST basin, near the diesel AST, near the reported used oil tank and kerosene tank, and near the residential building. The subsurface investigation consisted of soil characterization, field screening of soil using a photoionization detector (PID), soil sampling, and laboratory analysis of the soil samples to provide a screening -level assessment of overburden soils for the presence of potential contaminants. A grab sample of groundwater was also collected from one boring located near the UST basin. A site location map has been provided as Figure 1 and site layout maps showing site features and sampling locations have been provided as Figures 2a and 2b. 0 0 Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 4260 Ivv Road - Charlottesville. VA April 12 2013 1.1 Summary of Phase I Environmental Site Assessment ASI completed a Phase I Environmental Site Assessment (ESA) of the Scott's Ivy Exxon site on February 28, 2013 (Analytical Services Inc. 2013). The ESA revealed that the site has been used as a gasoline station since at least the 1950s, and possibly longer. There have been two documented past releases from USTs at the site. The first release was reported in February 1997 (PC# 1997-5102) and the second release was reported in November 1998 (PC#1999-5133) following the removal of three 6,000-gallon gasoline USTs. A soil concentration of 85 milligrams per kilogram (mg/Kg) was documented in the vicinity of the UST basin during the investigation of PC41997-5102 and a soil concentration of 143.2 mg/Kg was documented in the vicinity of the UST basin during the investigation of PC# 1999-5133. Both releases have since been closed. The investigation also identified that four USTs have been removed from the ground in 00 the past. These tanks include three 6,000-gallon gasoline USTs and one 500-gallon kerosene UST according to Virginia UST database records. All three of the 6,000-gallon gasoline USTs were removed in October 1998 and the 500-gallon kerosene UST was "' reported to have been removed at an unknown date. The Phase I ESA revealed a correspondence dated March 7, 1997 between the Virginia r. Department of Environmental Quality (DEQ) and a former owner of the Scott's Ivy Exxon site, Mr. Roy Bailey, Jr. In the letter, the Virginia DEQ recommends the proper closure of two inactive USTs, a 250-gallon used oil tank and a 250-gallon kerosene tank. Although Mr. Roger Gibson, the current property owner, believes that these USTs were removed by Mr. Bailey, closure documentation within the Virginia DEQ's records was not found. ASI recommended that a Phase II ESA be completed to investigate potential impacts associated with: -historical use of petroleum storage tanks, oil change pit and hydraulic lift cylinder; -potentially existing waste oil and/or kerosene UST; -offsite release at Toddsbury of Ivy property -residence, heating oil UST and potential use as a former gasoline station -railroad In addition, ASI also recommended an inventory of ASTs at the Scotts Ivy Exxon site along with an estimate of aggregate AST storage volume. 2.0 Subsurface Investigation 2.1 Service Building On March 21, 2013, ASI personnel supervised the completion of five soil borings to a depth of 8-16 feet below ground surface (bgs) in the area of the service building. The borings were completed with a direct push Geoprobe® drill rig and were identified as 00 Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 4260 Ivv Road - Charlottesville, VA April 12 2013 Boring 1, 2, 3, 4, and 5 (Figure 2b). Additionally, ASI personnel used a hand -auger to bore to a depth of 5.3 feet bgs near the used oil UST. The hand-augered sample collected near the service building is identified as Service Building: Auger (Figure 2b). A soil sample was also collected in the service building, beneath the concrete building foundation in an oil -changing bay, and is identified as Sub -Slab (Figure 2b). Utility clearance was requested from Miss Utility and a private utility locator was also used to further screen the work area for underground utilities prior to drilling. .. Continuous sampling cores (48 inches in length) were extracted during drilling. The soil cores were visually inspected and logged by an ASI geologist. Soil samples were then collected at appropriate intervals, as determined by ASI personnel based on field observations, and placed in a sealable plastic bag. Each bagged sample was field - screened for the presence of volatile organic compound (VOC) vapors via a PID. Recorded PID readings that exceeded two parts per million (ppm) have been summarized in Table 1. Soil samples collected from selected borings were submitted for laboratory analysis. ASI personnel determined which samples to submit for laboratory analysis based on PID readings and boring proximity to site features of interest. The following samples collected from borings near the service building were submitted for laboratory analysis: (1) soil samples identified as Boring 1 and Boring 2 were submitted for analysis of total petroleum hydrocarbons- (TPH) gasoline range organics (GRO) via method 8015B. The sample collected from Boring 1 was a composite sample from depth intervals 8.0-10.0 feet bgs, 10.8-11.8 feet bgs, and 13.5-14.5 feet bgs, with the majority of the sample being collected from the 10.8-11.8 feet bgs interval. The Boring 2 sample was collected from the 7.0-8.0 feet bgs interval. (2) Soil sample identified as Boring 3 was submitted for analysis of TPH-GRO and TPH-diesel range organics (DRO) via method 8015B. This sample was collected from depth intervals 8.5-10.0 feet bgs and 10.5-12.0 feet bgs. (3) Soil sample identified as Boring 5 was submitted for analysis of oil and grease (O&G) r. via method 1664. This sample was collected from depth interval 4.0-8.0 feet bgs. (4) Soil sample identified as Sub -Slab was submitted for laboratory analysis of O&G via method 1664. This sample was collected from a depth of less than one foot below the «•• bottom of the concrete building foundation. In addition to the soil samples, a disposable bailer was used to collect a groundwater +.. sample from Boring 1. The groundwater sample, identified as Boring 1, was collected from an open borehole and submitted for analysis of benzene, toluene, ethylbenzene, and xylene (BTEX) via method 8021. While no measurable free product was observed in am Boring 1, the water did possess a petroleum odor. Table 2 summarizes the results of the TPH-GRO, TPH-DRO, and oil and grease m constituents detected in soil samples that were submitted for laboratory analysis, and Table, 3 summarizes the results of the BTEX constituents detected in the Boring 1 groundwater sample that was submitted for laboratory analysis. The tables include t, Virginia DEQ/Voluntary Remediation Program (VRP) screening levels for comparison 0 3 0 am Limited Phase H Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 4260 Ivv Road Charlottesville. VA April 12,2013 purposes. A copy of the laboratory report and chain -of -custody documentation provided OW by Phase Separation Science, Inc. has been included in Appendix A. 2.2 Residential Building and Adjoining Railroad .. Two soil borings were completed to depths of six and 12 feet bgs in the reported vicinity of the residential building at the site. The borings were identified as Borings 6 and 7 (Figure 2b). Additionally, one hand-augered boring was completed to a depth of 4.6 feet bgs in the vicinity of the residential building's heating oil tank and a second hand- augered boring was completed to a depth of less than one foot bgs within 10 feet of the railroad. The hand-augered borings were identified H.O. Tank: Auger and Railroad: Auger, respectively (Figure 2b). None of the soil samples from Boring 6, Boring 7, H.O. Tank: Auger, nor Railroad: Auger exceeded two ppm. VW Soil samples collected from selected borings were submitted for laboratory analysis. ASI personnel determined which samples to submit for laboratory analysis based on PID readings and boring proximity to site features of interest. The following samples OW collected from borings near the residential building were submitted for laboratory analysis: (1) soil sample identified as Boring 6 was submitted for analysis of TPH-GRO via method 8015B. This sample was collected from depth interval 4.0-6.0 feet bgs. (2) '•' Soil sample identified as H.O. Tank was submitted for analysis of TPH-DRO via method 8015B. This sample was a composite of material collected from the ground surface to a depth of 4.6 feet bgs. (3) Soil sample identified as Railroad was submitted for analysis of "" polychlorinated biphenyls (PCBs) via method 8082A. This sample was a composite of material collected from directly beneath the concrete building foundation to a depth of less than one foot beneath the bottom of the foundation. Table 2 summarizes the results of the TPH-GRO, TPH-DRO, and PCB constituents detected in these soil samples. Table 1 Summary of Soil Sample PID Readings Greater than 2 Parts Per Million Total PID$ Readings (ppm ) Soil Boring Boring sam le interval in feet below ground surface Identification Depth 6.5-8.0 7.0-8.0 8.0-10.0 10.8- 13.5- 14.5- (feet) feet feet feet 11.8 14.5 16.0 feet feet feet Boring 1 16 32.3 NS° 326 1,875 348 106 Boring 2 12 NS 22.3 NS NS NS NS Boring 3 12 No readings greater than 2 ppm in boring Boring 4 12 No readings greater than 2 ppm in boring Boring 5 8 No readings greater than 2 ppm in boring Boring 6 6 No readings greater than 2 ppm in boring Boring 7 12 No readings greater than 2 ppm in boring Service 5.3 No readings greater than 2 ppm in boring 0 .. am ., Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Egon Site ASI Project No. 3351 4260 Ivy Road - Charlottesville. VA April 12 2013 Buildin : Au er H.O. Tank: Auger 4.6 No readings greater than 2 ppm in boring Railroad: Auger <1 No readings greater than 2 ppin in boring Sub -Slab <1 No readings Zreatajhan 2 m in boring -rw = pnotoionization detector bppm = parts per million 'IS = sample not collected from this depth interval Table 2 Soil Sampling Results (Sampled March 21, 2013) TPH- TPH- Oil and Grease PCBs Boring Identification GROa DRO` (mF�gb) (mg/Kg) (mpg) (mg/Kg) Boring 1 1,300 NAe NA NA Boring 2 0.240 NA NA NA Boring 3 NA <5.3 NA NA Boring 5 NA NA <62 NA Boring 6 <0.130 NA NA NA H.O. Tank NA <4.8 NA NA <0.14 for all Railroad NA NA NA analyzed PCB constituents Sub -Slab NA NA <150 NA VDEQf Limit (mg/Kg) 100 None Provided Provided Provided ed VVRPg Tier III Screening Concentration: Soil None None 0.74 mg/Kg Restricted Commercial Provided Provided None Provided for Total /Industrial m /K PCBs meo maicates exceeaance in screening concentration value aTPH-GRO = total petroleum hydrocarbons -gasoline range organics bmg/Kg = milligrams per kilogram TPH-DRO = total petroleum hydrocarbons -diesel range organics dPCB = polychlorinated biphenyls eNA = sample not analyzed for this constituent wr fVDEQ = Virginia Department of Environmental Quality BVVRP = Virginia Voluntary Remediation Program "W w am Limited Phase H Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 am 4260 Iw Road - Charlottesville, VA April 12 2013 Table 3 w. Groundwater Sampling Results (Sampled March 21, 2013) Benzene, Toluene, Eth lbenzene, and X lene via Method 8021E Constituent Boring 1 Concentration (ltga'a) WRPb Tier III Commercial Groundwater Screening Level O g/L) Benzene 210 43.9 Toluene 180 8,050 Eth lbenzene 4,200 27.6 m, -X lenes 12,000 None Provided o-X lene 470 206 X lenes total 12,470 206 Red indicates exceedance in screening concentration value aµg/L = micrograms per liter bVVRP = Virginia Voluntary Remediation Program 3.0 Document Review of Adjoining Leaking Underground Storage Tank Site ,A„ Analytical Services, Inc. reviewed documents from the Toddsbury of Ivy LUST site (PC#01-6134), which is located less than 100 feet southwest of the Scott's Ivy Exxon site, at the intersection of Highway 250 and Ivy Depot Road, in Charlottesville, Virginia. low The documents were obtained from the DEQ via a freedom of information request. Based on the document review, the Toddsbury of Ivy site had been operating as a gasoline station since at least the early 1950's and contained three 3,000-gallon USTs at on the time of initial investigation. A Site Characterization Report (SCR) was completed by Jeffrey A. Sitler Environmental Service, Inc. (JAS), from Charlottesville, Virginia, in January 2002 (JAS 2002a) and an addendum to the SCR was completed in April 2002 Im (JAS 2002b) in response to an inconclusive pressure test to the piping lines at the site. Both of these reports are included in Appendix B. The SCR included the installation and sampling of four monitoring wells in the shallow groundwater system between November 2001 and February 2002. Groundwater levels were measured and groundwater samples were collected from these wells to determine groundwater flow direction, gradient, and contamination levels. It was determined that groundwater from the shallow aquifer flows in an east-southeast direction toward Little Ivy Creek, under a gradient of 0.01-0.03, and discharges into the creek. Laboratory analysis of the samples for TPH-GRO, BTEX, and methyl tert-butyl ether (MTBE) indicated elevated levels of benzene and highly elevated levels of MTBE in the immediate vicinity of the site's UST basin. Laboratory analysis also indicated elevated levels of MTBE in a monitoring well located 75 feet downgradient from the UST basin, although levels were two orders of magnitude less than the concentration measured in the 0 Ow Limited Phase II Investigation Analytical Services, Inca Scott's Ivy Exxon Site ASI Project No. 3351 am 4260 Ivy Road - Charlottesville. VA April 12 2013 immediate vicinity of the UST basin. Overall, the investigation showed that a release had we occurred at an unknown time from the site's USTs, and that although elevated levels of benzene and MTBE were present in the groundwater near the USTs, the lateral extent of the plumes was minimal. .. TPH-GRO, BTEX, and MTBE were monitored in the site's wells from February 2002 to March 2004. During this monitoring period, contaminants in the source area did not diminish appreciably and concentrations increased in the downgradient monitoring well. Also during this monitoring period, it was determined that the groundwater contamination plume had approximate dimensions of 75 feet in width by 125 feet in length. A request for a Corrective Action Plan (CAP) was then issued by the Virginia DEQ in March 2004, which was developed by JAS (JAS 2004) and is included in Appendix B. The final CAP consisted of conducting the following actions: (1) Removal of two of the site's three USTs and inactivate the third UST that is located beneath a building; (2) excavate contaminated soil in the vicinity of the UST basin; (3) install a groundwater pumping system to remove dissolved -phase contaminants from the shallow groundwater system, including the installation of a recovery well completed to a depth of 80 feet bgs into the fractured bedrock; (4) install a soil -vapor extraction (SVE) system in the vicinity of the source area to removed adsorbed -phase contaminants in the vadose zone and free - phase gasoline on the surface of the water table; and (5) quarterly monitoring of the site. low As of the most recent CAP monitoring report, dated February 28, 2013, TPH-GRO and BTEX levels were below laboratory detection limits in all of the monitoring wells. Additionally, MTBE levels were below laboratory detection limits in all of the site's wells except the 80-feet deep recovery well and the furthest downgradient monitoring well. Concentrations of MTBE in these wells were 4.9 micrograms per liter (µg/L) and 2.0 µg/L, respectively (JAS 2013). A copy of this report is included in Appendix B. on 4.0 Above Ground Storage Tank Inventory •r ASI performed an inventory of ASTs at the site in an attempt to determine if AST aggregate storage volume triggers Spill Prevention, Control, and Countermeasures Plan (SPCC) requirements for the site. The following ASTs were identified at the site: Exterior Tanks Diesel AST - 500 gallons .. Waste Oil AST (rectangular)-300 gallons Motor Oil 1 - 275 gallons Motor Oil 2 - 275 gallons Green Heating Oil AST - 275 gallons Red Heating Oil* - 275 gallons Subtotal 1,900 gallons «. No Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 Interior Tanks Pit Waste Oil 1 - 275 gallons w. Pit Waste Oil 2 - 275 gallons Subtotal 550 gallons .r. Total 2,450 gallons * reported to be out of service The existing aggregate volume for the site is deemed to be 2,450 gallons plus any existing 55-gallon drums that are onsite which contain oil. According to EPA personnel heating ASTs used for heating oil at commercial business locations are to be included within the sites aggregate AST storage. The aggregate AST volume was found to exceed the 1,320 gallon aggregate storage threshold for SPCC Plan requirements. 5.0 Discussion of Findings 5.1 Soil Characterization Similar geologic conditions were encountered in Borings 1 and 2, which were installed in close proximity to each other on the eastern portion of the site. A dark red colored, silty - clay layer was encountered in both borings from beneath the surface fill to a depth of approximately seven feet bgs. Beneath this layer was a light brown colored, silty -clay layer with a higher percentage of silt than in the overlying layer, and was present to a depth of 11 feet bgs. A fine- to coarse -grained, poorly sorted, angular, saturated sand layer was encountered at a depth of 11 feet in both borings, and was approximately one foot thick. Finally, interbedded sand and silty -clay layers were encountered from 12-16 feet bgs in Boring 1. The sand at this interval was fine- to coarse -grained, poorly sorted, angular, saturated, and contained gravels with a diameter of greater than one inch, and the silty -clay at this interval was light brown colored and soft, with moderate plasticity. The most prominent sand layer at the 12-16 feet bgs interval was encountered at 14.1-15.5 feet bgs, and the most prominent silty -clay layer was encountered at 12.0-13.5 feet bgs. �. It is likely that the geologic material observed in these borings from 7-16 feet bgs are fluvial deposits from a stream located approximately 150 feet east of the borings. Similar geologic conditions were encountered in Borings 3, 4, 5, 6, and 7. Dark red colored, silty -clay with some sand and gravel was encountered in Borings 3, 4, and 5 to a depth of 4-7 feet bsg. Highly weathered saprolite was encountered beneath this layer to .�. the total depth of these borings. Borings 6 and 7 encountered the same saprolite directly beneath the surface -fill material. .., The hand-augered borings showed similar geologic conditions as well. Dark red colored, silty -clay was encountered from beneath the surface -fill material to total augering depth in all of the augered borings. M am w. Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 aw 4260 Ivy Road - Charlottesville. VA April 12 2013 Soil collected from the Geoprobe® and hand-augered borings provided insight into 00 geologic conditions at the subject property. The borings indicate that unconsolidated overburden sediment is thickest in the vicinity of Borings 1 and 2, as evidenced by these borings not encountering the saprolite that was observed in all of the other Geoprobe® borings. The investigation also revealed that saprolite is within four feet of the surface �. throughout much of the subject property, as evidenced by the soil cores collected from Borings 3 through 7. The investigation revealed that the brown, silty -clay layers and sand layers observed in Borings 1 and 2, which appear to be of fluvial origin, pinch out "` before extending westward to the other borings. It is likely that these sand layers have the ability to transmit groundwater at a relatively fast flow rate. `"" 5.2 Soil and Groundwater Sampling Existin,z UST Basin Area Groundwater analytical results of a sample collected from Boring 1 indicate that concentrations of benzene, ethylbenzene, o-xylene, and total xylenes exceed Virginia VRP Tier III screening levels (Table 2). Additionally, soil analytical results of a sample collected from Boring 1 indicate that the concentration of TPH-GRO exceeds the Virginia DEQ UST reporting level for TPH (Table 3). None of concentrations of other analyzed constituents in the soil and groundwater samples collected from the site .. exceeded Virginia VRP or DEQ screening levels. Based on soil and groundwater sampling and analytical results generated from this limited Phase II Subsurface Investigation, the area in the vicinity of the UST basin has been impacted by a release of petroleum hydrocarbons. An elevated TPH concentration, found to be above the Virginia DEQ action level, was detected in soil at the site within the gasoline range (TPH-GRO). Additionally, concentrations of BTEX constituents were measured in groundwater from Boring 1 that exceeded Virginia VRP Tier III screening levels. It is likely that the source of this release is associated with either historical or current gasoline USTs used at the site. The existing UST tank pit is located in an apparent upgradient location and in close proximity to Boring 1. Further evidence toward the gasoline UST(s)/pit being the source of the release is that the TPH-GRO •. concentration measured in the Boring 2 soil sample, which is located in an apparent upgradient direction from the UST basin and Boring 1, contained a relatively low TPH- GRO concentration. The Virginia DEQ requires that a release of petroleum resulting in soil samples exhibiting TPH concentrations of greater than 100 mg/Kg be reported. Given that the ... TPH-GRO concentrations noted in soil sample Boring 1 is above 100 mg/Kg, a copy of this report should be submitted to the Virginia DEQ. „ Potential Used Oil UST and Kerosene UST During investigation of the area where both a used oil and kerosene tank had reportedly existed, no direct evidence of an existing buried tank was identified and no evidence of petroleum impact to soils within the areas investigated were found. A metal line does WO Limited Phase II Investigation Analytical Services, Inca Scott's Ivy Exxon Site ASI Project No. 3351 aw 4260 Ivy Road - Charlottesville. VA April 12 2013 exist from the oil change pit to the area north of the station, however, it abruptly appears pow to stop based on utility locating equipment readings. Diesel AST and Hydraulic Lift A single boring and soil sampling completed in close proximity to the diesel AST and the western most service bay did not yield any evidence of petroleum impacted soil. The out -of -service hydraulic lift should be accessed and any remaining hydraulic oil removed. Removal of the lift is recommended and at such time a better assessment of the soil conditions beneath the lift could be made. Residence and Railroad OW It remains unclear whether the existing building was used as a gasoline station. The existing porch on the structure has been built over deteriorating concrete steps that suggest the building has been in its current location for an extended period of time. The .m owner of the property had indicated that the building may have been moved to its present location and that the building may have once been closer to the road (Rt. 250). Two relatively small metallic anomalies were identified in the front (southern side) of the WO residential structure with utility locating equipment. A soil boring was completed near each area and no direct evidence of a tank or petroleum impact was identified. A soil boring was also completed adjacent to a heating oil UST that lies along the northern side of the residence. Again, no evidence of petroleum impact to soils was noted. A shallow boring was completed near the railroad track and screened with a PID. No am elevated PID readings were observed. The sample was submitted for analysis of PCBs and no detection was identified. 5.3 Ad'ot ining Leaking Underground Storage Tank Site ASI reviewed documents provided by the Virginia DEQ related to the Toddsbury of Ivy 1W LUST site, located on the southwestern adjoining property. The documents showed that a release had occurred from the site's gasoline USTs sometime prior to November 2001, resulting in a benzene and MTBE groundwater contamination plume. A CAP was m* implemented at the site in 2004 that consisted of UST removal/closure, contaminated soil excavation, installation of a groundwater pumping system and SVE system, and quarterly monitoring. The CAP actions have reduced concentrations of all contaminants of concern with the exception of MTBE to below laboratory detection limits. Concentrations of MTBE were detected at levels exceeding laboratory detection limits in two of the site's wells during the most recent sampling event, although both wells' concentrations were less than 5 µg/L. Additionally, site data from back to 2001 indicates that the site's groundwater contamination plume has a minimal lateral extent, and discharges to Little Ivy Creek. It is unlikely that contaminated groundwater from the Toddsbury of Ivy site has impacted groundwater at the Scott's Ivy Exxon site. Shallow groundwater at the Toddsbury of Ivy site has been documented to flow in an east-southeast direction, toward Little Ivy Creek. 10 0" Limited Phase II Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No.3351 4260 Ivy Road - Charlottesville, VA April 12 2013 Based on this information, it is likely that Scoff's Ivy Exxon is located hydraulically cross -gradient from the Toddsbury of Ivy site. Additionally, the maximum lateral extent of the Toddsbury of Ivy site's groundwater contaminant plume has been defined, as determined during site monitoring, and does not extend beneath the Scott's Ivy Exxon site. 5.4 AST Inventory Based on identified inventory of above ground storage tanks (ASTs) used at the site, and the apparent aggregate storage volume of the existing ASTs, the site does require a Tier 1 Spill Prevention, Control, and Countermeasures Plan (SPCC). 6.0 Conclusions ASI has performed a limited Phase II Subsurface Investigation to provide a screening level assessment of overburden soils and groundwater for the presence of potential contaminants that may be present at the Scott's Ivy Exxon site. The subsurface investigation focused on concerns identified within a Phase I ESA previously prepared for the site (ASI 2013). Based on soil and groundwater sampling and analytical results generated from this limited Phase II Subsurface Investigation, the area in the vicinity of the gasoline UST basin has been impacted by a release of petroleum hydrocarbons. An elevated concentration of TPH-GRO was measured in a soil sample collected from a boring located hydraulically downgradient from the UST basin, and elevated concentrations of BTEX constituents were measured in a groundwater sample collected from the same *" boring. The TPH-GRO concentration measured in the soil sample exceeded the Virginia DEQ UST reporting levels for TPH-GRO. Additionally, benzene, ethylbenzene, o- xylene, and total xylenes concentrations measured in the groundwater sample exceeded Virginia VRP Tier III screening levels. As such, a copy of this report should be submitted to the Virginia DEQ. 400 The results from this limited Phase II Subsurface Investigation are considered useful for screening purposes. However, additional subsurface investigation is recommended to characterize the nature and extent of the petroleum contaminant plume that exists in the tap area of the existing UST basin. Based on identified inventory of above ground storage tanks used at the site, and the a.• apparent aggregate storage volume of the existing ASTs, the site does require a Tier 1 Spill Prevention, Control, and Countermeasures Plan (SPCC). OW Limited subsurface investigation and sampling conducted at other areas of concern did not yield evidence of environmental impact at the time of this investigation and at the locations investigated. .. up 11 00. Limited Phase H Investigation Analytical Services, Inc. Scott's Ivy Exxon Site ASI Project No. 3351 am 4260 Ivy Road - Charlottesville, VA April 12 2013 7.0 Limitations The work performed in conjunction with this project, and the data developed, are intended as a description of available information at the sample locations indicated and the dates specified. Generally accepted industry standards were used in the preparation of this report. Laboratory data are intended to approximate actual conditions at the time of sampling. Results from future sampling and testing may vary significantly as a result of natural conditions, a changing environment, or the limits of analytical capabilities. This report does not warrant against future operations or conditions, nor does it warrant against operations or conditions present of a type or at a specific location not investigated. The limited sampling conducted was intended to approximate subsurface conditions by extrapolation between data points. Actual subsurface conditions may vary. ASI has based its recommendations on observable conditions and analytical results from an independent analytical laboratory, which is solely responsible for the accuracy of its methods and results. 8.0 References [ASI] Analytical Services, Inc. 2013. Phase I Environmental Site Assessment for the Scott's Ivy Exxon site, Charlottesville, Virginia. Report dated 2/28/2013. [JAS] Jeffrey A. Sitler Environmental Service, Inc. 2002a. Site Characterization Report am for Toddsbury of Ivy site (PC#01-6134). Submitted to Virginia Department of Environmental Quality, 01/03/2002. [JAS] Jeffrey A. Sitter Environmental Service, Inc. 2002b. Site Characterization Report Addendum for Toddsbury of Ivy site (PC#01-6134). Submitted to Virginia Department of Environmental Quality, 04/18/2002. [JAS] Jeffrey A. Sitler Environmental Service, Inc. 2004. Corrective Action Plan for Toddsbury of Ivy site (PC#01-6134). Submitted to Virginia Department of • Environmental Quality, 06/08/2004. [JAS] Jeffrey A. Sitler Environmental Service, Inc. 2013. CAPI Monitoring Report CAPI Val Subphase No. 24 for Toddsbury of Ivy site (PC#01-6134). Submitted to Virginia Department of Environmental Quality, 02/28/2013. am OW 12 "0 ow 0 m Figures Am e-� "m Appendix A Laboratory Analytical Results tm am Analytical Report for Analytical Services, Inc.(VA) Certificate of Analysis No.: 13032603 Project Manager: Mike Maloy Project Name: Scott's Ivy Exxon Project Location: Ivy, VA Project ID : 3351 ZO YEARS W THE S April 2, 2013 Phase Separation Science, Inc. 6630 Baltimore National Pike Baltimore, MD 21228 Phone: (410) 747-8770 Fax: (410) 788-8723 0 Page 1 of 8 Final 1.000 am 0 OFFICES: 6630 BALTIMORE NATIONAL PIKE ROUTE 40 WEST BALTIMORE, MD 21228 410-747-8770 800-932-9047 FAX 410-788-8723 April 2, 2013 Mike Maloy Analytical Services, Inc.(VA) 402 N West Street Culpepper, VA 22701 PHASE SEPARATION SCIENCE, INC. Reference: PSS Work Order(s) No: 13032603 aw Project Name: Scott's Ivy Exxon Project Location: Ivy, VA Project ID.: 3351 Dear Mike Maloy : This report includes the analytical results from the analyses performed on the samples received under the project name referenced above and identified with the Phase Separation Science (PSS) Work Order(s) numbered 13032603. All work reported herein has been performed in accordance with current NELAP standards, referenced methodologies, PSS Standard Operating Procedures and the PSS Quality Assurance Manual unless otherwise Joe noted in the Case Narrative Summary. PSS is limited in liability to the actual cost of the sample analysis done. PSS reserves the right to return any unused samples, extracts or related solutions. Otherwise, the samples are scheduled for disposal, without any further notice, on April 30, 2013. This includes any samples that were VM received with a request to be held but lacked a specific hold period. It is your responsibility to provide a written request defining a specific disposal date if additional storage is required. Upon receipt , the request will be acknowledged by PSS, thus extending the storage period. This report shall not be reproduced except in full, without the written approval of an authorized PSS representative. A copy of this report will be retained by PSS for at least 5 years, after which time it will be disposed of without further notice, unless prior arrangements have been made. We thank you for selecting Phase Separation Science, Inc. to serve your analytical needs. If you have any questions concerning this report, do not hesitate to contact us at 410-747-8770 or info@phaseonline.com. Sincerely, ( "e�j f / Dan Prucnal Laboratory Manager am Page 2 of 8 Final 1.000 - i0 Yf�Ry a9 T Sample Summary OFF Client Name: Analytical Services, Inc.(VA) o�p `°"_"� Project Name: Scott's Ivy Exxon Work Order Number(s): 13032603 Project ID: 3351 �. The following samples were received under chain of custody by Phase Separation Science (PSS) on 03/26/2013 at 10:30 am Lab Sample Id Sample Id Matrix Date/Time Collected 13032603-001 Boring 1 GROUND WATER 03/21/13 12:00 13032603-002 Boring 1 SOIL 03/21/13 12:00 13032603-003 Boring 3 SOIL 03/21/13 12:00 13032603-004 Boring 5 SOIL 03/21/13 12:00 13032603-005 Boring 6 SOIL 03/21/13 12:00 13032603-006 Boring 2 SOIL 03/21/13 12:00 13032603-007 H.O. Tank SOIL 03/21/13 12:00 13032603-008 Railroad SOIL 03/21/13 12:00 13032603-009 Sub -slab SOIL 03/21/13 12:00 +� Please reference the Chain of Custody and Sample Receipt Checklist for specific container counts and preservatives. Any sample conditions not in compliance with sample acceptance criteria are described in Case Narrative Summary. Notes: +•� 1. The presence of a common laboratory contaminant such as methylene chloride may be considered a possible laboratory artifact. Where observed, appropriate consideration of data should be taken. 2. The following analytical results are never reported on a dry weight basis: pH, flashpoint, moisture and paint filter test. 3. Drinking water samples collected for the purpose of compliance with SDWA may not be suitable for their intended use unless collected by a +�•� certified sampler [COMAR 26.08.05.07.C.2]. 4. The analyses of 1,2-dibromo-3-chloropropane (DBCP) and 1,2-dibromoethane (EDB) by EPA 524.2 and calcium, magnesium, sodium and iron by EPA 200.8 are not currently promulgated for use in testing to meet the Safe Drinking Water Act and as such cannot be used for compliance purposes. The listings of the current promulgated methods for testing in compliance with the Safe Drinking Water Act can be too found in the 40 CFR part 141.1, for the primary drinking water contaminates, and part 141.3, for the secondary drinking water contaminates. 5. The analyses of chlorine, pH, dissolved oxygen, temperature and sulfite for non -potable water samples tested for compliance for Virginia Pollution Discharge Elimination System (VDPES) permits and Virginia Pollutant Abatement (VPA) permits, have a maximum holding time of 15 minutes established by 40CFR136.3. Standard Flags/Abbreviations: 14W B A target analyte or common laboratory contaminant was identified in the method blank. Its presence indicates possible field or laboratory contamination. C Results Pending Final Confirmation. E The data exceeds the upper calibration limit; therefore, the concentration is reported as estimated. Fail The result exceeds the regulatory level for Toxicity Characteristic (TCLP) as cited in 40 CFR 261.24 Table 1. rr J The target analyte was positively identified below the reporting limit but greater than the LOD. LOD Limit of Detection. An estimate of the minimum amount of a substance that an analytical process can reliably detect. An LOD is analyte and matrix specific. ND Not Detected at or above the reporting limit. so RL PSS Reporting Limit. U Not detected. No Page 3 of 8 Final 1.000 Case Narrative Summary Client Name: Analytical Services, Inc.(VA) Project Name: Scott's Ivy Exxon MW Work Order Number(s): 13032603 Project ID: 3351 Any holding time exceedances, deviations from the method specifications, regulatory requirements or variations to the procedures outlined in the PSS Quality Assurance Manual are outlined below. Sample Receipt: All sample receipt conditions were acceptable. General Comments: Results reported on an as received basis for sample 'Sub -Slab'. NELAP accreditation was held for all analyses performed unless noted below. See www.phaseonline.com for complete PSS scope of accreditation. 0 0 Page 4 of 8 Final 1.000 OFFICES: 6630 BALTIMORE NATIONAL PIKE ROUTE 40 WEST BALTIMORE, MD 21228 410-747-8770 ..� 800-932-9047 FAX 410-788-8723 PHASE SEPARATION SCIENCE, INC. CERTIFICATE OF ANALYSIS No: 13032603 Analytical Services, Inc.(VA), Culpepper, VA April 2, 2013 Project Name: Scott's Ivy Exxon Project Location: Ivy, VA Project ID: 3351 Sample ID: Boring 1 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-001 Matrix: GROUND WATER Date/Time Received: 03/26/2013 10:30 BTEX Analytical Method: SW-846 8021B Preparation Method: 5030B r USEPA methods recommend that the appearance of detectable levels of the 8021E compounds below be confirmed when unfamiliar samples are analyzed. Result Units RL Flag Dil Prepared Analyzed Analyst Benzene 210 ug/L 25 25 03/27/13 03/27/1313:51 1035 fr Toluene 180 ug/L 25 25 03/27/13 03/27/1313:51 1035 Ethylbenzene 4,200 ug/L 25 25 03/27/13 03/27/1313:51 1035 m,p-Xylenes 12,000 ug/L 50 25 03/27/13 03/27/1313:51 1035 o-Xylene 470 ug/L 25 25 03/27/13 03/27/1313:51 1035 Sample ID: Boring 1 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-002 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 82 +� Total Petroleum Hydrocarbons-GRO Analytical Method: SW-846 8015C Preparation Method: 5030 Result Units RL Flag Dil Prepared Analyzed Analyst us TPH-GRO (Gasoline Range Organics) 1,300,000 ug/kg 12,000 100 03/27/13 03/27/13 20:30 1035 Sample ID: Boring 3 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-003 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 73 Total Petroleum Hydrocarbons - DRO Analytical Method: SW-846 8015 C Preparation Method: 3550 Result Units RL Flag Dil Prepared Analyzed Analyst ■,. TPH-DRO (Diesel Range Organics) ND mg/kg 5.3 1 03/26/13 03/26/13 21:20 1040 Total Petroleum Hydrocarbons-GRO Analytical Method: SW-846 8015C Preparation Method: 5030 Result Units RL Flag Dil Prepared Analyzed Analyst TPH-GRO (Gasoline Range Organics) ND ug/kg 130 1 03/27/13 03/27/13 17:46 1035 �. Sample ID: Boring 5 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-004 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 80 Oil and Grease Analytical Method: EPA 1664 A ■o Result Units RL Flag Dil Prepared Analyzed Analyst Oil & Grease, Total Recovered ND mg/kg 62 1 04/01/13 04/01/13 09:50 1028 U0 Page 5 of 8 .r Final 1.000 OFFICES: 6630 BALTIMORE NATIONAL PIKE ROUTE 40 WEST BALTIMORE, MD 21228 410-747-8770 800-932-9047 FAX 410-788-8723 Project Name: Scott's Ivy Exxon Project Location: Ivy, VA Project ID: 3351 w.. Sample ID: Boring 6 Matrix: SOIL Total Petroleum Hydrocarbons-GRO PHASE SEPARATION SCIENCE, INC. CERTIFICATE OF ANALYSIS No: 13032603 Analytical Services, Inc.(VA), Culpepper, VA April 2, 2013 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-005 Date/Time Received: 03/26/2013 10:30 % Solids: 77 Analytical Method: SW-846 8015C Preparation Method: 5030 Result Units RL Flag Dil Prepared Analyzed Analyst TPH-GRO (Gasoline Range Organics) ND ug/kg 130 1 03/27/13 03/27/13 18:13 1035 Sample ID: Boring 2 Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-006 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 75 Total Petroleum Hydrocarbons-GRO Analytical Method: SW-846 8015C Preparation Method: 5030 Result Units RL Flag Dil Prepared Analyzed Analyst TPH-GRO (Gasoline Range Organics) 240 ug/kg 130 1 03/27/13 03/27/13 18:41 1035 Sample ID: H.O. Tank Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-007 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 82 Total Petroleum Hydrocarbons - DRO Analytical Method: SW-846 8015 C Preparation Method: 3550 Result Units RL Flaq Dil Prepared Analyzed Analyst TPH-DRO (Diesel Range Organics) ND mg/kg 4.8 1 03/26/13 03/27/13 09:55 1040 Sample ID: Railroad Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-008 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 % Solids: 77 Polychlorinated Biphenyls Analytical Method: SW-846 8082 A Preparation Method: 3550 Clean up Method: SW846 3665A Result Units RL Flag Dil Prepared Analyzed Analyst PCB-1016 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 .. PCB-1221 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 PCB-1232 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 PCB-1242 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 �r PCB-1248 ND mg/kg 0.14 1 03/27/13 03127/1317:20 1029 PCB-1254 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 PCB-1260 ND mg/kg 0.14 1 03/27/13 03/27/1317:20 1029 e"" Sample ID: Sub -slab Date/Time Sampled: 03/21/2013 12:00 PSS Sample ID:13032603-009 Matrix: SOIL Date/Time Received: 03/26/2013 10:30 Oil and Grease Analytical Method: EPA 1664 A 8rr _Result Units RL Flag Dil Prepared Analyzed Analyst r Oil & Grease, Total Recovered ND mg/kg 150 1 04/01/13 04/01/13 09:50 1028 Page 6 of 8 Final 1.000 0 T 5 d 0 0 0 I 1 i 1 II I 11 II t i f f fl t 4" 1 1 11 — 11 yS+GAL cyF�/� SAMPLE CHAT N OF CUSTODWAGREEMENT FORM INC. www•phaseonline.com PHASE SEPARATION SCIENCE, email: info@phaseonline.com ' *CLIENT: AEI N;cc*OFFICEass {�Cti) SL° S Imo. LOC. G�lpe VA ` rIE braes il�i .., , 11 t!' 3 i;t PAGE I OF *PROJECT MGR: / ke- A4AD *PHONE NO.: (510) gag -500 atnx SW=SurfaceWtr es: . DW=Drinkin Wtr GW=GroundWtr WW=WasteWtr 0=0i1 S=Soil L=Li uid SOL=Solid A --Air WI=Wi e nqAA EMAIL: A•IA�0101Sr ( A01#C'am FAXNO.: ( ) No. C O SAMPL Used Anayi;isr *PROJECT NAME: 5co"S' TV EE?(XO PROJECT 3351 N TYPE rye k NO.: T C = tti! SITE LOCATION: TV)/, VA P.O. NO.: A E COMP G ' r 3 4, <; * 4 o y /y� SAMPLER(S): TPiN, ni � I" M 1 DW CERT NO.: S GRAB � y� � �Q �. � J+' *SAMPLE IDENTIFICATION *DATE *TIME MATRIX E S P (SAMPLE .�St �- REMARKS 3/771/13 M-00 See Codes GW :;L G x ja G x ,x -3 ,S G X X X fS V ., ' Bay. a i G N.o. T-A �s' 1 G a; I rs7aA C7 X G Relinquished By: 1) Date 3tas/1 Time y Received By: 5 *Requested TAT (One TAT per COC) E N ❑ 5-Day ❑3-Day 2-Day (iUpnf i ❑ Next Day ❑ Emeraencv ❑ Other Relinquished By: (2) UPS PS Date Time Received Data Deliverables Required: y/� �/ Q[ /W`/��'Jr�1 ��Q i �3 JKZ"F�D �}�� �j 3 ii %� J� /� 'V�U! COA OC SUMM CLIP LIKE OTHER , c:, ❑ / Relinquished By: (3) W� ate E Time Rece' ❑ ❑ i'Irii ed y: Special Instructions: Relinquished By: (4) Date Time Received By: DW COMPLIANCE? EDD FORMAT TYPE STATE RESULTS REPORTED TO: YES ❑ a 0 O a � OTHER snnn Raltirnnrp NnHnnsi Piirn . 0-4- An W-4. -in .�a:. �__ •�_____ .. .,..., y........ - . «v - k-r 1 vi I -r I -v I I v - tovv j waz-vv4 / . r-aX (47 U) /tsd-t$ /L.3 The client (Client Name), by signing, or having client's agent sign, this "Sample Chain of Custody/Agreement Form", agrees to pay for the above requested services per the latest version of the Service Brochure or PSS-provided quotation including any and all attorney's or other reasonable fees if collection becomes necessary. * = REQUIRED ryOYEARS Ae9 i$ P� F Phase Separation Science, Inc Sample Receipt Checklist Ftc��oNC-StnNo'p0 THE Work Order # 13032603 Client Name Analytical Services, Inc.(VA) Project Name Scott's Ivy Exxon Project Number 3351 Disposal Date 04/30/2013 Shipping Container(s) No. of Coolers 1 Custody Seal(s) Intact? Seal(s) Signed / Dated? No Documentation COC agrees with sample labels? 40 Chain of Custody Sample Container Appropriate for Specified Analysis? Intact? Labeled and Labels Legible? Total No. of Samples Received 9 Received By Rachel Davis Date Received 03/26/2013 10:30:00 AM Delivered By UPS Tracking No lzx097v3O395424104 Logged In By Rachel Davis Ice Present Temp (deg C) 2 Yes Temp Blank Present No Yes Sampler Name TPN, MLM MD DW Cert. No. N/A Yes Yes Custody Seal(s) Intact? Not Applicable Yes Seal(s) Signed / Dated Not Applicable Yes Yes Total No. of Containers Received 11 Preservation Metals (pH<2) N/A am Cyanides (pH>12) N/A Sulfide (pH>9) N/A TOC, COD, Phenols (ph<2) N/A TOX, TKN, NH3, Total Phos (pH<2) N/A VOC, BTEX (VOA Vials Rcvd Preserved) (pH<2) Yes Do VOA vials have zero headspace? Yes Comments: (Any "No" response must be detailed in the comments section below.) For any improper preservation conditions, list sample ID, preservative added (reagent ID number) below as well as documentation of any client notification as well as client instructions. Samples for pH, chlorine and dissolved oxygen should be analyzed as soon as possible, preferably in the field at the time of sampling. Samples which require thermal preservation shall be considered acceptable when received at a temperature above freezing to 6°C. Samples that are hand delivered on the day that they are collected may not meet these criteria but shall be considered acceptable if there is evidence that the chilling process has begun such as arrival on ice. r i Samples Inspected/Checklist Completed By: lAe�..() Oal'"l-i Date: 03/26/2013 rr Rachel Davis "W PM Review and Approval: Date: 03/26/2013 Amy Friedlander rr Printed: 0410212013 10:57 AM Page 8 of 8 Final 1.000 FIGURE Scott's Ivy Exxon 4260 Ivy Road Charlottesville, VA Legend ® Scott's Ivy Exxon Site N At • .. 0 1.5 3 6 Miles AKOANALYTICAL SERVICES, INC. ------ ASI Project # 3351 so Legend V'IU UKE La: SH'L LAYOUT MAP .. Q Property Boundary - Ivy Creek r. UST Basin • Domestic Well 0 75 150 300 Feet Scott's Ivy Exxon 4260 Ivy Road Charlottesville, VA • -.ANALYTICAL SERVICES, INC. ASI Project # 3351 I I -F1UUKL' 2b: BORING LOCATIONS MAP Scott's Ivy Exxon Legend 4260 Ivy Road Charlottesville, VA Property Boundary ® Boring N 0 75 150 300 Feet • AW-.ANALYTICAL SERVICES, INC. ASI Project # 3351 aw Appendix B Toddsbury of Ivy Virginia Department of Environmental Quality Documents "a .. Im SITE CHARACTERIZATION REPORT ADDENDUM D'Q-VALLEY TODDSBURY OF IVY 20E�2 Albemarle County JAN PC # 01-6134 FAC ID # (for DEQ use) Submitted to: Joel P. Maynard Valley Regional Office .. Department of Environmental Quality PO Box 3000 Harrisonburg, VA 22801-3000 (540)574-7800 Prepared for: Charlottesville Oil Company PO Box 6340 Charlottesville, Virginia 22906 (804)293-9107 Prepared by: Jeffrey A. Sitter Environmental Service, Inc. PO Box 6038 Charlottesville, Virginia 22906 .� (804)974-7080 fax(804)974-1657 January 3, 2002 n. SITE SUMMARY 0 0 YES Site currently developed NO Offsite drinking water wells potentially threatened YES Onsite drinking water well potentially threatened NO Surface water affected NO Surface water potentially threatened NO Liquid phase hydrocarbons on groundwater YES Dissolved phase present in groundwater above water quality standards NO Sump, basement, or utility affected NO Sump, basement, or utility potentially threatened NO Residual phase present that may leach into groundwater at concentrations of concern NO Residual phase levels in backfilled soils that merit abatement Site recommended for: One additional monitoring welt and Post -SCR Monitoring I Ouas0ury or ivy SCK - PC 01-6134 M 0 TABLE OF CONTENTS SITE SUMMARY ............... . "" TABLE OF CONTENTSaw ....... . 1.0 INTRODUCTION 1 1.1 SITE HISTORY . ....... . 1.2 SITE DESCRIPTION .................................................. 1 2.0 SITE ASSESSMENT . 7 2.1 SITE LOCATION AND DESCRIPTION ......... 8 2.2 RECEPTOR SURVEY 8 2.3 HISTORICAL RELEASES ........... 9 2.4 REGIONAL GEOLOGY ...... . 2.5 REGIONAL HYDROGEOLOGY ......... 9 9 2.6 RELEASE ASSESSMENT .............................. . . ' 2.6.1 Release Confirmation ............. 10 2.6.2 Investigative Methods ............... ................. ' ..' • • • . 10 2.6.2.1 Soil Borings/Monitoring Wells .......................... 12 2.6.2.2 Well Development and Elevation Survey .................. 13 2.6.2.3 Aquifer Test ......................................... 13 2.6.3 Groundwater Monitoring . 14 2.6.4 Groundwater Sampling and Analysis ............................. 14 ................ 2.7 LABORATORY ANALYTICAL RESULTS ............. ............... 14 2.7.1 Soil Analytical Results ........................................ 14 2.8 SITE GEOLOGY AND HYDROGEOLOGY ........ 21 2.10 CAUSE OF RELEASE ...................................... 23 2.11 NUMBER AND SIZE OF TANKS ..................................... 25 2.12 EXTENT OF HYDROCARBON CONTAMINATION ... 25 2.12.1 Liquid Phase Hydrocarbons (LPH) ............................. 25 2.12.2 Absorbed or Residual -Phase Contamination . 25 2.12.3 Dissolved -Phase Contamination ....... . ..... ....... 25 2.12.4 Vapor Phase...............................................26 3.0 RISK ASSESSMENT 26 .., 3.1 SITE DESCRIPTION ..................... ' ........................................... 26 3.1.1 Area Characteristics • • . • • 26 3.1.2 Nature and Extent of Contamination ....................... 27 3.1.3 Identif ying Contaminants of Concern (COC) ....................... 27 3.2 ENVIRONMENTAL FATE AND TRANSPORT OF GASOLINE ............ 28 3.3 EXPOSURE ASSESSMENT . 31 3.3.1 Potentially Exposed Human and Environmental Populations . 31 3.3.1.1 Potentially Exposed Human Populations ................... 31 3.3.1.2 Potentially Exposed Environmental Populations ............. 31 Toddsbury of Ivy SCR - PC 01-6134 ii 3.3.2 Exposure Pathways and Exposure Point Concentrations .............. 32 3.3.2.1 Water Consumption Pathway . .... , 32 3.3.2.2 Direct Contact Pathway ................................ . . • . • • . .. • . 34 3.3.2.3 Soil Ingestion Pathway ............................... . . 35 3.3.2.4 Inhalation Pathway . .... . 36 3.3.2.5 Environmental Receptor Pathway ........................ 36 3.3.2.6 Summary of Potentially Completed Exposure Pathways and Exposure Point Concentrations 36 3.4 RISK CHARACTERIZATION ......................................... 36 4.0 REMEDIATION ASSESSMENT ........................... 37 5.0 CONCLUSIONS AND RECOMMENDATIONS .......................... . 38 FIGURES Figure 1 - Site Location Topographic Map .............. 3 Figure 2 - Site Plan .................... ' .................... 4 aw Figure 3 - 1994 USGS Aerial Photograph 5 Figure 4 - Photograph of Toddsbury of Ivy .......... . . . . . . . . . 7 Figure 5 - Comparison of Ratios of BTE to Xylenes in Soil . 12 4. Figure 6 - Extent of Residual Soil Contamination as TPH-GRO 17 Figure 7 - Dissolved Benzene in Groundwater, ,ug/l, 11 /29/01 .... 19 Figure 8 - Dissolved MTBE in groundwater ....... , . . ... • . . . . . . . ' . . ' ' ' ' . ' 20 Figure 9 - Water Table Elevation as of 11/29/01 .............. . • . . . . • . . . • 22 Figure 10 - Comparison of Bear Water Table to Observed Water Table . 24 Figure 11 - Predicted MTBE in Onsite Water Well ................................... 34 TABLES .. Table 1. UST Information ... . Table 2. Soil Sampling Analytical Results .. . 7 11 MW Table 3. Groundwater Analytical Results .. ' .. ' ' ' ' ' ' ' • • • • . • • • Table 4. Maximum Contaminant Levels and Cancer Potential for Contaminants 1$ Observed in Soil and Groundwater at the Site .............. ..... , 28 wo Table 5. Environmental Data for Petroleum Compounds at 20C ........................ 30 .w LIST OF APPENDICES APPENDIX A- Boring/Well Logs ow APPENDIX B - Laboratory Analytical Reports APPENDIX C - Data for Analysis of BTEX Concentrations in Soil, Spreadsheets for Drain we Field Analysis, Spreadsheets for Pumped Concentration in Water Well Toddsbury of ivy SCR - PC 01-6134 ili 1.0 INTRODUCTION a„ Jeffrey A. Sitler Environmental Services, Inc., (JAS) was contracted by Charlottesville Oil Company, Rt. 250 West, Charlottesville, Virginia to prepare this Site Characterization Report or (SCR) for the property known as Toddsbury of Ivy Market located on US Route 250 in Ivy, Virginia, in Albemarle County, (the " Site" shown in Figure 1). The objectives of this SCR are to characterize the Site, determine environmental conditions at the „, Site, investigate the geology and hydrogeology in the vicinity of the Site, evaluate the risks associated with the contamination, and present remedial alternatives to mitigate the aw contamination at the Site if necessary. This SCR has been prepared following Department of Environmental Quality (DEQ) guidance. 1.1 SITE HISTORY The Site has been operated as a gas station since at least the early 1950's. Charlottesville Oil Company owns the three gasoline underground storage tanks (USTs) that are currently in service as shown in the site plan in Figure 2. There also is one unused kerosene (?) UST located at the northwest corner of the market building. Figure 3 shows the 1994 USGS aerial photograph for +- the area of the Site, and Figure 4 shows a ground -view photograph of the front of the Site looking southwest from Route 250. As a result of an inconclusive pressure test on the lines, on March 27, 2001, JAS completed four hand borings to a depth of four feet below the surface along the supply lines and pump island. Each soil sample was analyzed for total petroleum hydrocarbons -gasoline range organics (TPH- GRO, aka volatile TPH) by EPA Method 8015. The soil analysis indicates the following. S- !PH S-1 34.6 mg/kg S-2 BDL S-3 BDL S-4 68.6 mg/kg The soil samples from each hole did not have any strong gasoline fuel odors. These results indicated that significant leakage had not occurred from the i m at the Site. piping .. Toddsbury of Ivy SCR - PC 01-6134 l .Scale 0 500 ft Jeffrey A. Sitler - Date: Revised. Figure I - Site Location Environmental Services, Inc. Topographic Map PO Box 6038 ry Drawaby LRS Chwked by: Toddsbu of Ivy Charlottesville, VA 22906 (804)974-7080 - (804)974-1657 (FAX) File. Scale Toddsbury of Ivy SCR - PC 01-6134 2 W "M w .. Scale 0 200 ft Jeffrey A. Sider - Date: Revised: Figure 3 - 1444 USGS Aerial Environmental Services, Inc. Photograph PC Box 6038 Drawn by LRS Checked by: Charlottesville, VA 729W Toddsbury of Ivy (804)974-7080-(804)974-1657 (FAX) Toddsbury of Ivy SCR - PC 01-6134 4 ." w 00 Ow Y.. Toddsbury of ivy SCR - PC 01-6134 5 r-7 —, Table 1. UST Information UST Regulated I Contents I Type I UST/AST I Size Est. Age Status No. Gallons Years Super In I Yes Unleaded Steel UST 3,000 Unknown Service Gasoline Plus In 2 Yes Unleaded Steel UST 3,000 Unknown Service Gasoline Regular In 3 Yes Unleaded Steel UST 3,000 Unknown Service Gasoline Out of 4 No Kerosene Steel UST 550? Unknown Service prior to 1986 VW Mike Jones of Charlottesville Oil Company has hypothesized that the line test was affected by faulty foot valves at the end of the lines in the tanks. Subsequent to the soil sampling results, the am Department of Environmental Quality (DEQ) issued a directive to complete a Site Characterization Report (SCR) for the Site. An extension to January 18, 2002 for the SCR •• deadline was granted by Todd Pitsenberger on January 2, 2002. 1.2 SITE DESCRIPTION The Site is known as Toddsbury of Ivy and is located on the southeast corner of the intersection of State Route 786 and US Route 250 in the village of Ivy, Albemarle County, Virginia. The approximately rectangular Site has an area of about one-half acre with 200 feet fronting Route �- 250 and a 100-foot depth from Route 250 on the north side to a small stream on the south side. The Site contains a building that houses a small deli/grocery and storage rooms as shown in the -� photograph in Figure 4. The structure is a mixture of slab -on -grade and crawl space. The three in-service gasoline USTs are located at the east end of the building. 2.0 SITE ASSESSMENT 2.1 SITE LOCATION AND DESCRIPTION The Site is located in the central portion of Albemarle County. Topographically, the Site is at an elevation of about 535 feet above mean sea level with the ground surface on the Site being Toddsbury of Ivy SCR - PC 01-6134 6 m 0 relatively flat (Figure 1). The ground slopes imperceptibly to the south where runoff enters a small unnamed perennial tributary to Little Ivy Creek that flows along the southern boundary of the Site. The Site has its own private drinking water supply well located in the rear of the market near the southwest corner of the building. A private septic system is located in the rear on the east end of the property. Electric service is provided by Virginia Power via overhead cables, and telephone service is provided by Sprint via underground cables. 2.2 RECEPTOR SURVEY A preliminary receptor survey was performed for the Site to identify public and private water supply sources, i.e., wells, springs, and surface water intakes, within the immediate vicinity of the Site. In summary, there are no public water supply wells or public surface water intakes within more than one-half mile of the Site. However, there are private drinking water wells on adjoining properties. Surface Water 4M The local surface water drainage system is within the Rivanna River Basin. At the local scale, the runoff from the Site drains south into the small unnamed perennial tributary to Little Ivy Creek located along the southern boundary of the Site as shown in Figure 1. This tributary enters Little Ivy Creek within 100 feet of the Site. The Site is probably within both the 100- and 500- year flood plains. It is not believed that there are statutory wetlands on the Site. .. Water Supplies The residents and businesses in the area of the Site obtain drinking water from private water supply wells. There are no public water supplies in the area of the Site. The following lists the private water supply wells immediately adjacent to the Site. Toddsbury of Ivy, drilled well located about 100 feet southwest of the UST basin, unknown depth, sampled November 29, 2001 for the SCR. Ivy Nursery and US Post Office, located about 200 feet southwest of the UST basin, not sampled. Toddsbury of ivy SCR - PC O1-6134 7 ii r� Exxon Service Station, located on the opposite side of Route 250 about 200 feet northeast of the UST basin, not sampled. There are numerous businesses and residential water wells further from the Site that have not been listed. 2.3 HISTORICAL RELEASES Charlottesville Oil Company does not have any specific knowledge concerning historical releases at the Site. However, Mike Jones stated that since the USTs are 3,000 gallon capacities, there may have been times when a delivery caused overflow of product onto the ground. 2.4 REGIONAL GEOLOGY The Site is within the Blue Ridge Physiographic Province which was developed on metamorphic rocks of primarily gneiss and schist and covers the Commonwealth of Virginia from along Route 29 to the base of the Blue Ridge. The bedrock in the vicinity of the Site consists of the Middle Proterozoic -age porphyroblastic biotite-plagioclase augen gneiss, believed to be a metamorphosed igneous intrusion. The gneiss has been radiometrically dated at slightly more than one billion years old (Virginia Geologic Map -Expanded Explanation, Virginia Department of Mines, Minerals, and Energy,1993). Overlying the bedrock is saprolite, or weathered bedrock, that grades from nearly unweathered bedrock at depth up to completely weathered soil consisting of clay and silt at the surface. Typically, the thickness of the saprolite is thin to -•t nonexistent in stream valleys to more than 50 feet thick in upland areas. At the Site the unconsolidated soil was found to be 12 to15 feet thick where the auger drill met refusal on the bedrock surface. 2.5 REGIONAL HYDROGEOLOGY Groundwater occurs in both the unconsolidated soil and the underlying bedrock under unconfined conditions. Most of the rocks of the Blue Ridge province are not known as good aquifers. Drilled wells in the area generally have yields that range from two gallons per minute (gpm) to 20 gpm, with the average closer to three to five gpm with well depth ranging from 75 feet to 400 feet. In some cases, bored or hand dug wells have been utilized. These shallow wells rely on groundwater produced from the highly weathered bedrock at the bedrock-saprolite Toddsbury of Ivy SCR - PC 01-6134 8 M W" gradational interface. For the most part, the bedrock does not have appreciable primary porosity or permeability, but produces water from fractures, joints, and fault zones. Therefore, in order for a bedrock well to be successful, the well must intersect fractures and joints that are capable of yielding groundwater at rates and volumes required by the end user. The typical low yield produced by wells in the Blue Ridge has resulted in the development of public water supplies for larger towns and cities that are almost always developed from surface -water sources, such as the Rivanna Water and Sewer Authority for Charlottesville. Recharge to the groundwater in the Blue Ridge occurs over broad areas as a result of the infiltration of precipitation into the saprolite. The Virginia Department of Mines, Minerals, and Energy estimates that 15% of all precipitation infiltrates as recharge to groundwater. With an average rainfall of 47 inches (Charlottesville, 1961-1990), 7.0 inches of rainfall is recharged to the aquifer in an average year. The water table in the Blue Ridge generally mimics the topographic surface with the water table aw being closer to the surface in valleys than in uplands. The resulting groundwater flow is from the upland areas to streams and rivers, providing base flow when no stormwater runoff occurs. Based on the topography in the area of the Site, groundwater would be expected to flow to the south and east, ultimately discharging into either the small tributary on the south side of the Site or into Little Ivy Creek within 200 feet of the USTs to the east. -. 2.6 RELEASE ASSESSMENT 2.6.1 Release Confirmation One soil sample was collected from the south edge of the UST basin in MW-2 at a depth of eight feet. No soil samples were collected from the other two monitoring wells due to the absence of any gasoline odors. The laboratory report is provided in Appendix C and summarized in Table 2. The analysis of soil sample MW-2-8 had a TPH-GRO concentration of 1,060 mg/kg and benzene of 3,920 ,ug/kg. Figure 5 shows a comparison of the log benzene, log toluene, and log ethylbenzene plotted as dependent variables on the y-axis versus log xylenes on the x-axis. The data represents 12 soil analyses from nine sites around Charlottesville including the one sample from the Site Toddsbury of Ivy SCR - PC 01-6134 I" am 2. Soil Sampling Analytical Results Sample Volatile Benzene Toluene Ethyl- Xylenes MTBE l ID/Depth TPH- uglkg Ag/kg Benzene Ag/kg µg/kg GRO Ag/kg rTable m -2 MW-2-8 1,060 3,920 73,000 31,300 155,000BDL BDL - Below Detection Limit mg/kg - Milligrams Per Kilogram u - Micrograrris Per Kilogram F Benzene, Toluene, & Ethylbenzene Vs Xylenes in Soil 7 MW-2-8 ♦ Toluene 6 --�' ♦ Ethyl- m - ♦ '�� benzene 0 5 Benzene 0 0 C f � 4 c 0 U w m 3 � L 2 ---------------- 4.5 5 5.5 6 6.5 Xylene Concentration, log uglkg Linear Regression Data Benzene vs Xylenes B = 1.25 log {Xylene}-2.80 r = 0.95 Toluene vs Xylenes T = 1.12 log (Xylene)-1.01 r = 0.99 Ethylbenzene vs Xylenes E = 0.96 log {Xylenel-0.42 r = 0.99 Jeffrey A. Sitter - Date: Figure 5 - Comparison of Ratios Environmental Services, Inc. of BTE to Xylenes in Soil PO Box W38 Drawn by: LRS checked by: Charlottesville, VA 229DB (804)974-7080-(8041974-1657 (FAX) am WM Toddsbury of Ivy SCR - PC 01-6134 10 0 (MW-2-8). The straight lines in Figure 5 are the regression lines. The regression analyses indicated correlation coefficients of from 0.95 for benzene versus xylenes to 0.99 for the other two relationships. The eight other sites included in Figure 5 had leaking USTs with either free product present or very high concentrations. The ratios of benzene, toluene, and ethylbenzene to xylene in MW-2-8 relative to the other data indicate that the tank basin is the source of contamination similar to the other sites included in the data base. 2.6.2 Investigative Methods 2.6.2.1 Soil Borings/Monitoring Wells For the SCR, three soil borings/monitoring wells were installed at the Site in locations recommended by the DEQ and modified in the field due to utility and other restrictions. JAS and Certified Environmental Drilling, of Earlysville, Virginia, mobilized onsite on November 28, 2001 and installed the borings/monitoring wells by hollow -stem auger drill rig. All drilling was supervised by Lyle R. Silka, Virginia certified professional geologist, and was in accordance with standard health and safety practices. The total boring depths were 15 feet for MW-1 and MW-2, and 12 feet for MW-3. The borings were shallow due to refusal of the auger on the top of bedrock. Geologic samples were inspected at five-foot intervals for characterization of the geology and assessing the No„ presence of hydrocarbon contamination. Decontaminated drill stems were used for the borings. Each soil sample was logged for lithology, inspected for petroleum odors, examined for visual petroleum staining, and tested for total volatile hydrocarbon vapors. Boring logs are presented in Appendix A. One soil sample was collected from MW-2 at a depth of 8 feet where strong gasoline odor and staining were found. Since there was no odor or staining in either of the other two borings, no soil samples were collected from them. The soil sample was collected in a one laboratory -supplied four -ounce glass jar with Teflon septum. The container was labeled and stored on ice and delivered by overnight Federal Express to Maryland Spectral Services, Inc. in Baltimore, Maryland, for analysis of total petroleum hydrocarbons gasoline range organics (TPH- GRO) by EPA Method 5035/8015, and benzene, toluene, ethylbenzene, total xylenes (BTEX) and methyl -tertiary -butyl -ether (MTBE) by EPA Method 5035/8021. Section 2.7 presents a review of the analytical results. All samples collected for laboratory analysis were handled in accordance with standard chain -of -custody and quality assurance controls. Toddsbury of Ivy SCR - PC 01-6134 11 "M The soil borings were converted to monitoring wells using flush -threaded, two-inch diameter, schedule 40 PVC casing and 0.01-inch factory -slotted PVC screen with a threaded end cap. The wells were installed by assembling and lowering the PVC screen and blank casing into the open borehole to the total depth of the boring. A #2 filter sand was placed around the screen to a height of two feet above the screen, followed by a two -foot bentonite-chip seal that was hydrated in place. From the top of the bentonite seal to the surface, a cement grout mix was placed in the annulus around the casing. Each well was completed with a flush -mount, bolt -down, metal well protector set in concrete at the surface. A locking well cap and padlock were placed on each well casing. Monitoring well depths and screened intervals were selected in the field based on the depth at which groundwater was encountered in order to provide ample open screen above the water table to allow for seasonal fluctuations and allow sufficient screen below the water table to allow for groundwater sampling. The geologic logs of the borings/monitoring wells are presented in Appendix A. 2.6.2.2 Well Development and Elevation Survey Each monitoring well was purged of approximately three well volumes of water to develop the well and bring in fresh groundwater from the surrounding aquifer. The well purging was accomplished using a pre -cleaned plastic bailer. The relative elevation of the top of casing (TOC) for each monitoring well and the stream at the downstream sampling location was determined by surveying with a rod and transit. A local elevation datum was established for the TOC for MW-1 at 535 feet based on the 7.5 minute USGS topographic map. The horizontal position of the wells on the Site was determined relative to the building using a 200-foot fiberglass tape measure. Appendix A provides the elevation survey results. 2.6.2.3 Aquifer Test An aquifer test was not completed at the Site. The typical test consists of a single -well slug or recovery method that produces hydraulic conductivity estimates that are usually a factor of 10 too low because the single -well test is isolated to a small aquifer volume. Since there is a perennial stream next to the Site, the water table configuration was used to match predicted water table elevations produced by a drain -field analysis presented by Jacob Bear.' am Jacob Bear, 1979, Groundwater Hydraulics, McGraw-Hill, NY, page 180. Toddsbury of Ivy SCR - PC 01-6134 12 0 WAM 2.6.3 Groundwater Monitoring Data on the depth to the water table and thickness of LPH in each monitoring well were collected on the undisturbed water column in each monitoring well prior to purging and sampling the well. An electronic• oil/water interface probe capable of detecting both LPH and water to an accuracy of 0.01 feet was used. Also, the presence of LPH was checked by lowering a transparent plastic bailer into the water table to collect any LPH on the water table. 2.6.4 Groundwater Sampling and Analysis Groundwater samples were obtained from monitoring wells MW-1, -2, and -3, from the onsite water supply well, and from upstream and downstream locations on November 29, 2001. Each monitoring well was purged of approximately three well volumes of water using a separate pre - cleaned plastic bailer. The water supply well sample was collected from outside spigot in front of the market after letting the water run for about 15 minutes. The stream samples were obtained by collecting a sample directly from the flowing stream. Each water sample was placed into two laboratory -supplied 40-milliliter glass vials with Teflon septa in a manner to exclude all air from the vials. All sample bottles were labeled, placed on ice, and delivered via overnight Federal Express under standard chain -of -custody procedures to MSS. Water samples were analyzed for TPH-GRO, BTEX, and MTBE, except for the water supply sample that was analyzed for volatile organics by EPA Method 8260. The laboratory analytical results are discussed in Section 2.7.2. #W 2.7 LABORATORY ANALYTICAL RESULTS 2.7.1 Soil Analytical Results Table 2, above, presented the results of TPH-GRO, BTEX, and MTBE analyses of the soil sample collected from MW-2- The full laboratory report is presented in Appendix B. Figure 6 shows the estimated extent of residual -phase contamination as TPH-GRO and includes the analytical results from both the SCR and the line sampling study. 2.7.2 Groundwater Analytical Results The results of the groundwater analyses are summarized in Table 3 and reported in Appendix B. Figures 7 and 8 show the extent of dissolved benzene and MTBE, respectively. The full laboratory report is presented in Appendix B. Toddsbury of Ivy SCR - PC 01-6134 13 *.. US Ri 250 -3 N ND c 'BDL S-3 BDL ' BDL 3�F. ,•- BDL- ,t Toddebury of lay Market .......... —7,'`""- iBDL- -` Mw-1 ND Q WaLar Well r --E?rrrn-S- reom f ,~ `��+Tributary to Ivy Creek Scabs 25 ft ' Up Stream l- ixlevtan' .................................. r r 1 1 t t t t t t Table 3. Groundwater Analytical Results Well No. Date Sampled Water Depth feet LPH in TPH-GRO ug/l Benzene ug/l Toluene ug/l Ethyl- Benzene ug/l Xylenes ug/1 MTBE ug/l MW-1 11/29/01 6.59 0 BDL BDL BDL BDL BDL 18 MW-2 11/29/01 8.52 0 BDL 1480 1420 BDL 900 56400 MW-3 11/29/01 7.70 0 BDL BDL BDL BDL BDL BDL Onsite Water Well 11/29/01 0 BDL BDL BDL BDL BDL 3.3j Up Stream 11/29/01 BDL BDL BDL BDL BDL BDL Down Stream 11/29/01 12.66 BDL BDL BDL BDL BDL BDL Notes: ND - Not Determined BDL - Below Detection Limit j - Estimated value ug/kg - Micrograms Per Kilogram LPH - Liquid Petroleum Hydrocarbon NA - Not applicable Toddsbury of Ivy SCR - PC 01-6134 15 0 r C, 71 ------------------------------------------------------------------------------------- Benzene, ug f 1 N U:bBDL- ❑ ❑❑ ` ---^ i w - , ro 'J r`-� 51 F Tcd d eb ury of by Market ....... " 1450 --• ; i IuNI- 7 � BDL r,r Q Water Well BDLr i BDL --9vw�r-�'eom 'J BDL ................ . .... .....................- Tributary to Ivy Creek Scale Vp Stream_ D 25 R • IlyCfeYldlY -� - •-- -• ............... IrMt1wil ........................ .•-- •--- --•- ---- •--- ---- --•- ---- ---- ----.... .... .... .... .... .... .... •--•---...--.... .... ......--.... .... .... . US Rt 2' MTBE? ug/ 1 W#-3 0 13CL I- 00 --,,, CO y4` �� 4'`r,• I I d eb ury of arkuL r l 1 r 1 1 1 -1 1DDD r Q w ell 20 BDL N i -�ot�r-�Ire a m LL BILL °oa- °c.............................. r. ", t` -^r�.� Tribu#Ary t4 ltry Scale y , _ ,_. - ��- Creak 1pz UB Waam _ _ - `'may+ D 25 ft �•-• a. _ - � ro��evtdry y.--qua-...........................•--........--------...............--.........---------....--•----•-------------- ........................... Based on Figure 7 and 8, the dissolved contamination at the Site is primarily limited to the vicinity of the gasoline UST basin. Dissolved benzene was found at 1,480 µgli and MTBE was at 56,400 µg/1 in MW-2. However, MTBE was reported at 18 ,2g/1 in MW-1 and at an estimated 3.3 µg/l in the water supply well. 2.8 SITE GEOLOGY AND HYDROGEOLOGY The Site is underlain by 12 to 15 feet of red -brown clayey silt to silt soil with cobbles in the lower depths. It is not known whether the soil represents a saprolite or a reworked floodplain sediment. Underlying the soil is the well -indurated bedrock. The depth to the water table ranged from 6.5 to 8.5 feet below the surface. Thus, the shallow aquifer is from.5.5 to 6.5 feet thick in the vicinity of the monitoring wells. A water -table contour map is presented in Figure 9 that indicates the principal groundwater flow direction is to the southeast toward Little Ivy Creek. Since the small stream along the south side of the Site has continued to flow throughout the recent drought, the water table contours have been curved around to indicate that some groundwater flows into the small tributary. On the sampling date, the flow in the small tributary was low, estimated to be less than one gallon per minute. From Figure 9, the gradient toward Little Ivy Creek is about 0.03 under the market, but flattens out east of the store to an estimated 0.01. The change in gradient may be due to heterogeneities in aquifer permeability. 2.8.1 Hydraulic Conductivity and Groundwater Flow Velocity The hydraulic conductivity for the shallow aquifer was estimated by comparing the water table elevations in the stream and the monitoring wells to the predicted elevations based on the model presented by Jacob Bear.'- The Bear model estimates the seepage to parallel drains given uniform recharge and hydraulic conductivity. The uniform recharge was set at 0.0016 feet per day (7.0 inches per year). While the two -drain model assumption is not strictly adhered to in this situation with the tributary on the south flowing eastward into Little Ivy Creek on the east and uplands to the west and north, the extrapolated flow lines are relatively parallel through MW-1, MW-3, and Jacob Bear, 1979, Groundwater Hydraulics, McGraw-Hill, NY, page 180. I'oddsbury of Ivy SCR - PC 0I-6134 is I I 0 .USRt2 526 ,T 5 co ♦♦._ ♦♦._ ♦ ♦♦. MW-1 � 528,�F1 Water Well Toddebury of 575 _ —P— .............................................. Market 527 527 5N.7 N D 526.7 c ,•0mr-5braam c 526.57 1 Tributary to Ivy Greek Scale 25 R ' II�lC�Yid1V ........................................................................... 0 MW-2. If they are parallel, than, along that line, the water table should not be significantly am different from the modeled case. Two analyses are reported here: A predicted water table ff elevation that matches the observed water tables with a drain spacing ofi00 feet and 800 feet. x The results are presented in Figure 10. The estimated average hydraulic conductivity for the shallow aquifer is between 14 and 32 feet per day. Since the shallow aquifer is primarily within a silty soil, the effective porosity is estimated to be on the order of 0.2. With these parameter estimates, the groundwater velocity is estimated to be on the order of 1.6 to 2.1 feet per day, using the following equation: y, !< d C5'1 t v = Kiln, Equation (1) where v is the groundwater seepage velocity, (feet per day), K is the hydraulic conductivity (14 - 32 feet per day), V - _J . i is the hydraulic gradient (0.01 - 0.03 feet per foot), and ne is the -effective porosity,(0.2, dimensionless). ` wr Hai , , - : i }'�y, .I V ��„•,.es.� �.itf iUjS ti S.. ;h: 2.9 MATERIAL RELEASED Gasoline -range hydrocarbons have been confirmed in soil and groundwater samples from the Site. There is no information available concerning the amount of the release or the timing of the release. Since MTBE is present, the release occurred after 1978 when MTBE was first added to gasoline. Inspection of the GC chromatograms indicates that there are no late -eluting compounds that would be suggestive of kerosene or diesel contamination in the samples. Thus, based on these analyses, it appears that the contamination is limited to gasoline. 2.10 CAUSE OF RELEASE Field observations, including petroleum odors, and laboratory analysis of soil, revealed signs of gasoline contamination associated with the UST basin. Recent pressure testing indicated that the tanks were not leaking, and shallow soil samples did not indicate significant leakage from the supply lines. There may have been older tanks that leaked prior to the current tanks being installed, or overfilling of the tanks that resulted in the contamination. roddsbury of ivy SCR - PC 01-6134 20 ii .r .a. No Water Table Profile Per Bear Drainfield Model 535 Case 1: Drain Separation = 400 ft K = 14 ft/day a 530 MW 3 m u_ c ■ MW-1 m w 525 MW-2 Stream 520 0 100 200 300 400 Distance from Stream (Feet) Water Table Profile Per Bear Drainfield Model 535 _._. Case 2: Drain Separation = 800 ft K = 32 ft/day a 5W MW 3 U c ■ MW-1 w 525 - MW-2 Stream 520 -- 0 100 200 300 400 Distance from Stream (Feet) Jeffrey A. Sider - Date: Revised:..r_ Figure 10 - Comparison of Bear Environmental Services, Inc. Water Table to Observed Water PO Box 6= Chadoftesvtlte, va 22906 Drawn by: LRS Checked by: Table (804)974-7080-(804)974-1657(FAX) Fite: am Toddsbury of Ivy SCR - PC 01-6134 21 0 2.11 NUMBER AND SIZE OF TANKS The Site contained three regulated gasoline USTs and one unregulated abandoned kerosene UST with the characteristics shown in Table 1. The ages of the USTs are unknown. The kerosene UST appears to have a dispenser that is pre- 1950's vintage. 2.12 EXTENT OF HYDROCARBON CONTAMINATION 2.12.1 Liquid Phase Hydrocarbons (LPH) No LPH has been found at the Site in the monitoring wells or soil samples. Typically, where LPH is present, the individual dissolved gasoline components have been found at concentrations greater than 5,000 pg/l, although this is not a consistent indicator. Since the different gasoline components undergo varying rates of biodegradation and loss, samples can produce inconsistent results as to the indication of LPH. Thus, at the Site the BTEX components in MW-2 are well below 2,000 yg/l, but the MTBE component is at 56,400 4g/l. Based on the BTEX, LPH is not expected, but based on the MTBE in groundwater, at least some LPH should be expected, or was present at an earlier time and has since dissipated. 2.12.2 Absorbed or Residual -Phase Contamination �., Figure 6 above shows that the adsorbed -phase contamination as TPH-GRO appears to be highest in the vicinity of the gasoline tank basin. However, since the water table is at a depth of 8.5 feet . in MW-2, the water table is above the base of the tank basin. Therefore, there is no adsorbed soil contamination per se, since this phase of contamination typically is defined as residing above the water table. The contaminated soil in MW-2 is believed to have undergone anaerobic degradation. The soil had some gray coloring and a strong septic, or anaerobic odor. This fits with the high water table and high contamination levels that caused the low oxygen levels. A- 2.12.3 Dissolved -Phase Contamination Dissolved -phase contamination by gasoline components has been identified in MW-2, MW-1, and the water supply well. MW-2, adjacent to the UST tank basin, has the highest contamination levels in groundwater with: Benzene at 1,480 ug/l Toluene at 1,420 gg/l Ethylbenzene at BDL Total xylenes at 900 ug/1 Toddsbury of ivy SCR - PC 01-6134 22 0 MTBE at 56,400 pg/1 TPH-GRO at BDL MW-1 only had 18 ,ug/l of MTBE detected, and the water well only had 3.3 mg/1 of MTBE estimated. -• The extent of groundwater contamination is not clearly defined with the current data. The water table contour map in Figure 9 shows that the groundwater flow is toward the southeast, and the concentration contours in Figures 7 and 8 are dashed as uncertain to the southeast of MW-2. Since MW-1 and the water well had MTBE detected, there is a component of groundwater flow toward the water supply well. 2.12.4 Vapor Phase Some vapor -phase contamination was observed in the soil from MW-2 adjacent to the tank basin. However, the onsite building does not have any reported gasoline vapors and has no basement. There are no buried utilities onsite near the tank basin or dispenser island that could act as conduits for vapor migration. 3.0 RISK ASSESSMENT The risk assessment evaluates risks to human and environmental receptors posed by the release. In the risk assessment, where appropriate, potential and impacted receptors, including sensitive receptors, are identified; migration rates for the contaminants are estimated; and risks to individual receptors are determined. All potential pathways of exposure are evaluated, including ingestion, inhalation, and dermal contact. If there is determined to be a significant risk posed by the Site, remediation endpoints based upon site -specific risks are proposed. The overall goal of the risk assessment is to determine risks to receptors so that endpoints for corrective action may �., be defined on a scientific and defensible basis. 3.1 SITE DESCRIPTION 3.1.1 Area Characteristics Site geology consists of a thin soil less than 15 feet thick of predominantly silt with some clay in the upper region and some cobbles deeper that overlies a gneiss bedrock. The top of the well- roaasbury of Ivy SCR - PC 01-6134 23 w. u indurated bedrock occurs at between 12 and 15 feet of depth across the Site with the water table at a depth of from 6.5 to 8.5 feet below ground surface. Surface -water runoff and groundwater flow are toward the southeast and south. The Site has been a market and gasoline station for at least 50 years. Currently, there are three, 3,000-gallon gasoline USTs on the east end of the building and an abandoned kerosene (?) UST that may be 550 gallons on the west end. The market building is a mix of slab -on -grade and crawl space. The immediate area surrounding the Site is sparsely developed as commercial and residential land use interspersed with woodlands. Near the Site, the land use is commercial along Route 250. The residential homes are removed from the Site by several hundred feet and are either in the uplands or across the streams to the south and east. 3.1.2 Nature and Extent of Contamination The nature and extent of contamination due to the gasoline release at the Site is discussed in Section 2.12 and summarized as follows: ► Soil in the tank basin contains TPH-GRO at a concentration of at least 1,060 mg/kg as determined in MW-2-8. ► Since the water table is shallow and extends into the tank basin, the residual soil contamination appears to be limited to a thin zone between about five and eight feet. ► Groundwater contamination was detected in the onsite water supply well with benzene at 1,480 ,ug/1 and MTBE at 56,400 ug/l in MW-1. ► LPH has not been observed in the borings or in the monitoring wells or the onsite water supply well. 3.1.31dentifying Contaminants of Concern (COC) The Site has a gasoline release. Therefore, gasoline range organics are considered the only potential COCs. Of the more than 100 gasoline components, the BTEX compounds are generally of most concern due to their greater health threat, solubility and mobility. Benzene is a known human carcinogen, and the EPA has established a maximum contaminant level (MCL) for +` benzene of 5.0 ugn (0.005 mg/1) for drinking water. Table 4 lists the highest concentrations of too roaasbury of Ivy SCR - PC 01-6134 24 contaminants found in soil and compares the highest observed groundwater concentrations to drinking water MCLs and cancer rating. At the Site, only benzene exceeds an MCL, and MTBE exceeds an EPA health advisory. Therefore, risks associated with benzene, toluene, and MTBE will be addressed in this risk assessment. Table 4. Maximum Contaminant Levels and Cancer Potential for Contaminants Observed in Soil and Groundwater at the Site. Adsorbed/Dissolved Constituent Highest Observed Residual Concentration u Highest Observed Concentration in Groundwater u EPA Drinking Water MCL u 1 Reason for MCL Benzene 3,920 1,480 5 A Toluene 73,000 1,420 1,000 D Ethylbenzene 31,300 BDL 700 D Xylenes, Total 155,000 900 10,000 D MTBE BDL 56,400 40 H TPH 1,060,000 BDL NA NA NA = Not Analv7ed nr Not Annlirahle BDL = Below Detection Limit A = Classified as a human carcinogen, sufficient evidence in epidemiologic studies to support causal association between exposure and cancer. D = Cancer group not classifiable, inadequate or no human and animal evidence of carcinogenicity. H = EPA health advisory level for odor aesthetics, not cancer. 3.2 ENVIRONMENTAL FATE AND TRANSPORT OF GASOLINE Degradation. The BTEX compounds have both chemical and biological degradation pathways. The chemical degradation of aromatics by hydrolysis is the reaction of the aromatic molecule with water. Biological degradation involves the active breakdown of the compounds by enzymes excreted by microbes in the subsurface. In the course of normal life processes, bacteria accidentally cause the enzymatic breakdown of the BTEX compounds, reabsorb the broken molecules, and ultimately metabolize the organic carbon chains into the end products of carbon dioxide and water. Organic contaminants biodegrade on the order of 1,000 times faster in the presence of aerobic bacteria, i.e., dissolved oxygen must be present in the groundwater. For example, under aerobic conditions, the half life for benzene may be as short as 60 days. roddsbury of Ivy SCR - PC 01-6134 25 Volatility. With a vapor pressure of 5 to 15 millimeters of mercury, gasoline components readily volatilize, and transport in the vapor phase is potentially important. Gasoline vapors have a density that is greater than that of air and will tend to collect and diffuse into low areas, such as basements, sewers, and utility trenches. However, the Site does not have any basements or utility trenches that could act as vapor migration pathways. Attenuation. Gasoline components, having a lighter molecular weight and slight polarity, can be transported in the dissolved state fairly readily. Indicators of the compound' s mobility are its theoretical solubility in water, organic carbon partition coefficient (Koc) and oil/water partition coefficient (Kow). Koc is the ratio of the mass of a compound found adsorbed to the soil versus the mass dissolved in water at equilibrium. A high Koc means that the compound preferentially aw adheres to the soil solids. Kow is the ratio of the concentration of a compound in oil versus the concentration dissolved in water at equilibrium. A high Kow means that the compound preferentially dissolves into the oil more than the water. Thus, a compound with a high Koc and Kow has a low solubility in water, and as a consequence, is not very mobile in the water environment. If it is assumed that the adsorbed concentrations in MW-2-8 are at equilibrium with the dissolved concentrations in the MW-2 groundwater sample, then the partition coefficient K� can be estimated by: K. = C,.l Cg,t. Equation (2) where K,,,, is the organic carbon partition coefficient, C, is the concentration adsorbed to solids, C9W is the concentration dissolved in groundwater. With the Ka, estimated, the retardation coefficient, Rf can be estimated by: Rf = 1 + K,, fog. p.,177w Equation (3) where Rf is the retardation coefficient, dimensionless, K,C is the organic carbon partition coefficient, 1/kg, fa, is the fraction organic carbon, dimensionless, Uoddsbury of Ivy SCR - PC 01-6134 26 r_ p, is the bulk aquifer density, mg/kg, and %,, is the water filled porosity. Rf also is defined as: Rf = V. / v� Equation (4) where vH, is the velocity of groundwater, and v. is the velocity of the dissolved contaminant. Table 5 shows the results of these calculations for the data from MW-2. The Rf values in the last column indicate the velocity of the compound through the aquifer relative to the velocity of groundwater (from Equation 3). Thus, from Equation 4, MTBE moves at the same velocity as groundwater, benzene is indicated to move at 80% the velocity of groundwater, and xylene is estimated to move at just 6% that of groundwater. Table 5. Environmental Data for Petroleum Compounds at 20C. Compound Residual Concentration in MW-2 (uikg) Dissolved Concentration in MW-2 (ug/1) Calculated Organic Carbon Partition Coef. Koc 1/k Fuel/Water Partition Coef. Kow Calculated Retardation Factor for = l % Benzene 3,920 1,480 2.6 350 1.2 Toluene 73,000 1,420 51 1,250 5.5 Ethyl -benzene 31,300 400 78 4,500 7.8 Xylenes 155,000 900 172 4,110 16 MTBE 500 56,400 0 16 1.0 For example, the travel time for groundwater and MTBE from the tank basin to Little Ivy Creek No is estimated to be 200 feet divided by 2.1 feet per day, or 95 days. For benzene, with a retardation factor of 1.2, the travel time is estimated to be 114 days, and toluene, with a retardation factor of 5.5, the travel time would be 523 days. Toddsbury of Ivy SCR - PC 01-6134 27 3.3 EXPOSURE ASSESSMENT The exposure assessment uses information from the characterization of the site characterization and environmental fate and transport analysis to identify significant completed exposure pathways and to estimate actual or potential exposure point concentrations of identified COC. The results of the exposure assessment are used to determine the potential human health and environmental risks associated with the Site. 3.3.1 Potentially Exposed Human and Environmental Populations Both onsite and offsite residents can be considered potential receptors of the COCs released at the Site if there is a completed exposure pathway via ingestion of contaminated drinking water, contact with contaminated water or soil, or inhalation of vapors or contaminated dust. The potential exposure of environmental populations, i.e., biota, is via contamination of surface water. 3.3.1.1 Potentially Exposed Human Populations Both onsite workers and offsite workers and residents can be considered potential receptors of the COC released at the Site if there is a completed exposure pathway via ingestion of contaminated drinking water, contact with contaminated water or soil, or inhalation of vapors or contaminated dust. The results of the site investigation indicate that the groundwater flow direction is toward the southeast and south (see Section 2.8). All workers and residents within one-fourth mile radius are served by private water supply wells. There are no water supply wells •�, in the natural down -gradient direction from the contamination. However, the onsite water well and neighboring monitoring well contain MTBE. There are several up- and side -gradient water supply wells within 500 feet of the Site. Thus, potential exposure to human populations will be evaluated further. 3.3.1.2 Potentially Exposed Environmental Populations im Potential for exposure of environmental populations, i.e., biota, is via contamination of surface water. The nearest perennial stream that would contain biota is either the tributary on the south side of the Site or Little Ivy Creek at the southeast side of the Site. Thus, potential exposure to environmental populations will be evaluated further. Toddsbury of Ivy SCR - PC 01-6134 28 3.3.2 Exposure Pathways and Exposure Point Concentrations For exposure to occur to a receptor, the contaminant must be able to reach a point where exposure may occur. If the exposure pathway is incomplete, no exposure and no health hazard can take place, and that pathway may be eliminated from further evaluation. The following evaluation considers each of the common exposure pathways typically occurring as a result of a �. release of petroleum hydrocarbons from a UST. ON 3.3.2.1 Water Consumption Pathway Based on available evidence, the onsite water supply well is up gradient of the source under natural conditions (see the water table contours in Figure 9). However, analysis of tap water from the onsite well found an estimated 3.3 µg/1 of MTBE. Therefore, it appears that the water well is able to reverse groundwater flow. This completed pathway is retained for further evaluation. The estimation of the exposure point concentration at the onsite water well is computed by using an analytical equation presented by Jacob Bear. The application of his analytical solution was first applied to modeling contaminant concentrations in a pumping well at a Superfund site.' The Lotus 1-2-3 spreadsheet showing the results of the calculation of the Bear model is presented in Appendix C. The Bear model assumes that a circular plume with radius, r, and thickness, h, having an average concentration, c, is drawn into a pumping well. As the contaminated plume is drawn in, it combines with fresh water from the other directions of radial flow to the well. The greatest concentration in the pumped water occurs when the center of mass of the circular plume reaches the well. For benzene, a plume radius of 25 feet is used based on Figure 7. For MTBE, a plume radius of o. 50 feet is assumed based on Figure 8. The thickness of each plume is 7.0 feet, and the distance from the center of the plume to the water well is 100 feet. The specific yield of the shallow im Bear, Jacob, 1979, Groundwater Hydraulics, McGraw-Hill, New York, pp. 290-292) 4 Silka, Lyle R., 1987, Predicting Plume Characteristics from Pumping Well Concentrations Using a One -Dimensional Analytical Solution, Proc. of the Conference on Northwestern Ground Water Issues, National Ground Water Association, Dublin, OH, pp. 329-347. am Toddsbury of Ivy SCR - PC O1-6134 29 aquifer is 0.2, and the average pumping rate is estimated to be 1.0 gpm (1,440 gallons per day). The average concentration in the benzene plume is estimated as the log average of the highest concentration to the lowest, i.e., 10Oog('.480Mgn)+1og(2.0µgn)}n_ for benzene, or 55 ,ug/l. The 2.0 gg/1 concentration replaces BDL and is the reported detection limit. For toluene, the log average plume concentration is 10('og(1•420jign)+ log(2.0' or 53 ,ug/l. For MTBE, the log average plume concentration is 10{log(56,400 ugn)+ log(4.0 µgA)}12' or 475 ,ug/l. The results of the Bear pumping well model are presented in Figure 10 for MTBE. The figure ft shows the solid curve with a peak of 4.0 ,ug/l at a time of 200 days that represents the approximation of a slug, or instantaneous source. The dashed line represents the case if the c source were constant and continuing. The horizontal dashed line implies that a steady state VV condition exists. Since the predicted peak is reached within less than one year, and the field evidence indicates that the contamination probably was in the subsurface for much longer than one year, than the MTBE concentration in the water well may be at an approximate steady state level. In order to match the observed 3.3 µg/1 in the water well, the average concentration in the cylindrical plume had to be reduced from 475 ,ug/1 to 24 ,ug/1. This reduction in the average ? plume concentration is equivalent to diluting the plume by a factor of 20 in the water well. This �V, corresponds to the well drawing from a saturated thickness that is 20 times thicker than the 7.0- foot thickness of the shallow aquifer used in the model, i.e., 140 feet. - k. The model for benzene predicts that, based on dilution alone, benzene will not be detectable in ■- the water well. Since the benzene model has a null result, there is no corresponding figure. Since toluene is at a slightly lower concentration than benzene, it also is predicted to remain undetectable in the water well. A spreadsheet for both the MTBE and benzene models are presented in Appendix C. As for neighboring water wells, the radial distance to these wells is greater than 100 feet. Therefore, adjustment of the above analysis would result in the prediction of no detectable contaminants in these more distant water supply wells also. r" Toddsbury of Ivy SCR - PC 01-6134 30 w MW 3.3.2.2 Direct Contact Pathway Direct contact of humans with contaminated water may be via exposure to contaminated surface 1 water such as during swimming or via contact with contaminated groundwater such as during showering. The closest point at which groundwater emerges, i.e., at a perennial stream, is either • in the small tributary about 75 feet south of the UST basin or Little Ivy Creek about 200 feet east of the UST basin. A conservative dilution rate for groundwater from the Site entering either the tributary or Little Ivy Creek can be estimated by the ratio of the area of contamination to the area of the upstream drainage basin. The contaminated area of the Site for benzene is estimated to be 0.04 acres (the area within the BDL contour in Figure 7). For MTBE, the contaminated area is Toddsbury of Ivy SCR - PC 01-6134 31 OW wo estimated to be 0.08 acres (the area within the BDL contour in Figure 8). The upstream area for the tributary is 430 acres, and the area for Little Ivy Creek is 760 acres. Thus, the dilution rate for the tributary is 430 acres divided by 0.04 acres, or 10,700. For Little Ivy Creek, the dilution rate is 760 acres divided by 0.08 acres, or 9,500. Without considering degradation and assuming that all contamination went to the tributary, the concentration for benzene in the tributary would be the 55 µg/l log average concentration developed in section 3.3.2.1 divided by 10,700, or BDL, and toluene would be diluted to 53 µg/1 divided by 9,500, or BDL. For MTBE, the concentration in the tributary would be the 475 49/1 divided by 10,700, or BDL. For Little Ivy Creek, benzene would be diluted to 55 µg/l divided by 9,500, or BDL, toluene would be diluted to 53 µg/1 divided by 9,500, or BDL, while MTBE would be diluted to 475 µg/l divided by 9,500, or BDL. Thus, both streams appear to have sufficient dilution to prevent contamination from becoming detectable even without accounting for degradation. As for direct contact via a water well, in the preceding section, it was shown that benzene is v unlikely to be detected in the onsite well. In addition, it is believed that MTBE is at an approximate steady-state value of about 3.3 µg/1 that is well below the 20 µg/1 advisory level c established for odor. Given these results, the direct contact pathway via contact with surface water or groundwater is insignificant and no potential exposure or health hazard is expected. �.• Therefore, the potential exposure via direct contact with surface- or groundwater is not retained for further evaluation. 3.3.2.3 Soil Ingestion Pathway .. The soil ingestion pathway is based on the direct ingestion, or exposure to fugitive dust, from contaminated surface soil. Since the contaminated soil is under the surface, potential exposure via direct ingestion of contaminated soil or fugitive dust by onsite workers is considered insignificant. The soil ingestion pathway is incomplete and no exposure or health hazard can occur. Therefore, this potential pathway is eliminated from further evaluation. wo Uft M. 32 Toddsbury of Ivy SCR - PC 01-6134 L:::] 3.3.2.4 Inhalation Pathway The inhalation pathway can occur from exposure to fugitive dusts and from inhalation of volatile COC. Since the contaminated soil is under the surface, potential exposure via inhalation of contaminated soil or fugitive dust by onsite workers is considered insignificant. The inhalation pathway is incomplete for fugitive dust and no exposure or health hazard can occur. The potential inhalation pathway via vapor entering buildings is minimized by the lack of vapor migration pathways. Therefore, the potential inhalation pathway via fugitive dust and vapor is eliminated from further evaluation. 3.3.2.5 Environmental Receptor Pathway The environmental receptor pathway is via exposure of aquatic biota to contaminated surface water. The environmental receptor pathway is considered potentially complete, but insignificant since the predicted dilution rates in the tributary and Little Ivy Creek would reduce contamination to undetectable concentrations according to the foregoing calculations (section 3.3.2.2). Therefore, based on only dilution, this potential pathway is eliminated from further evaluation. 3.3.2.6 Summary of Potentially Completed Exposure Pathways and Exposure Point Concentrations The potentially completed exposure pathway and exposure point concentrations are as follows: Ingestion of drinking water from the onsite water sugply. The benzene exposure point concentration at the water well is currently undetectable and is predicted to remain undetectable on the basis of dilution alone. The MTBE exposure point concentration is currently estimated at 3.3 µg/l and is predicted to remain at that level based on the assumption that it is at steady state. This MTBE level is well below the 20 /.4g/i advisory level for aesthetics (odor). 3.4 RISK CHARACTERIZATION The primary objective of characterizing risk is to integrate information into a complete evaluation of current and future human health risks and nonhuman impacts associated with " contaminants detected at the Site. The risk assessment evaluates the nature and degree of risk to Toddsbury of Ivy SCR - PC 01-6134 «. 33 on potential receptor populations. The following characterize the potential risks identified for the Site. ► No LPH has been observed at the Site, although MTBE has been detected at 56,400 fcg/l, a level usually associated with the presence of LPH. ► The residual soil contamination is minor, since the water table is so shallow. ► There is no significant risk of petroleum vapors migrating to the building. ► Dissolved benzene, toluene, and MTBE are the contaminants of concern present in the groundwater with the highest concentrations observed in MW-2 at 1,480, 1,420, and 56,400 jig/I, respectively. ► The onsite water supply well is contaminated with MTBE at an estimated 3.3 µg/l and is free of all other potential contaminants. ► While dissolved contaminants could migrate to the streams, predicted average dilution rates would render them undetectable. .w ► MTBE at 3.3 ,ug/l in the water well is believed to represent an approximate steady-state concentration and is not predicted to increase in the near future. No other dissolved contaminants are believed to present any potential threat to the onsite water well. ► There are no risks posed by inhalation, direct contact, or exposure of environmental receptors. ► There are no risks posed to offsite water wells. w 4.0 REMEDIATION ASSESSMENT An assessment of remediation alternatives is conducted if the risk assessment concludes that �. significant risks are presented by the contamination at the Site. Only MTBE has been detected in the onsite water well, and only MTBE is predicted to be detectable in the well into the future and .. even then at a similarly low concentration. MTBE does not have an MCL. EPA has established an advisory level for MTBE based solely on odor threshold of 20 to 40 µg/l. Therefore, it is recommended that a remediation assessment not be completed at this time. If the source characteristics remain constant, the MTBE concentration is predicted to remain at tow the current level. When the source diminishes or is removed, MTBE is predicted to require less than two years to purge out of the system. If the source increases its intensity, than the MTBE 0 Toddsbury of Ivy SCR - PC 01-6134 34 may begin to increase in the water well within 100 days. However, based on the observed concentration of MTBE of 56,400 ,ug/l, the current source intensity level is quite high. 5.0 CONCLUSIONS AND RECOMMENDATIONS The Site had a release of gasoline from the UST system that resulted in groundwater contamination with benzene, toluene, and MTBE. No LPH has been observed at the Site, even though the MTBE level is quite high. Groundwater flow is toward the southeast with discharge into Little Ivy Creek. Some groundwater from the Site also discharges into the small tributary on the south boundary of the Site. However, predicted dilution rates in the surface water would render contaminants undetectable. The potential exposure pathway is via the onsite water supply well. The well currently has 3.3 ,ug/1 MTBE but no other contaminants. The MTBE is predicted not to present any concern in the well into the future unless there is an intensification of the source. The other gasoline contaminants also are predicted not to present any concern for the water well at this time. The neighboring offsite water supply wells have remained uncontaminated and are predicted to remain so in the future. Since the water table contours indicate that the natural groundwater flow is toward the southeast, there is no down -gradient monitoring well. MW-2 represents a monitoring point for the immediate source area. MW-1 is near the water supply well up gradient of the source. MW-3 also is up gradient of the source and also provides confirmation that the pump island is not a source. It is recommended that one down -gradient monitoring well (MW-4) be installed to the southeast of MW-2 between MW-2 and Little Ivy Creek and that quarterly monitoring of the water supply well, MW-2, and the new MW-4 be conducted to provide confirmation for the predictive modeling. Toddsbury of Ivy SCR - PC 01-6134 35 APPENDIX A WELL DATA SPREADSHEET „ AND BORING/WELL LOGS Toddsbury of Ivy SCR - PC O1-6134 Toddsbury of Ivy Monitoring Well Data 01/03/02 w MW-1 MW-2 MW-3 Stream _ _ Installation Date 11 /28/01 1128/01 1128101 Heigth of Scope above TOC, ft 4. Height of Scope at Rod, ft 4.23 3.90 3.42 12.66 Total depth of well, ft 15.00 15.00 12.00 Elevation of TOC Relative Local Datum, ft 535.00 535.33 535.81 526.57 Water Table Depth below TOC, 3/3100, ft 6.59 8.52 7.70 12.66 swo Elevation of Water Table, ft 528.41 526.81 528.11 513.91 Toddsbury of Ivy SCR- PC 01-6134 am .. i. Boring/Well Log Project: Toddsbury of Ivy Log of Boring: MW-1 Location: Ivy, VA Date Drilled: 11/28/01 Ground Surface Elevation: 735 ft Drilling Method: Hollow Stem Auger Total Depth: 15 ft Drilling Company: Certified Environmental Drilling Geologist: Lyle R. Silka, CPG VA DEQ PC 01-6134 Weather: Cool, Partly Sunny Depth (ft) Sample Number Geologic Description 0-5 red -brown clayey silt, moist to dry, no gas odor 5-10 same, cobble layer, moist, no gas odor 10-15 same, moist to wet, no gas odor 15 total depth 2" casing set from 0 to 5 feet. 2" screen set from 5 to 15 feet. W Toddsbury of Ivy SCR - PC 01-6134 M BorinW%11 Log Project: Toddsbury of Ivy Log of Boring: MW-2 Location: Ivy, VA Date Drilled: 11/28/01 Ground Surface Elevation: 735 ft Drilling Method: Hollow Stem Auger Total Depth: 15 ft Drilling Company: Certified Environmental Drilling Geologist: Lyle R. Silka, CPG VA DEQ PC 01-6134 Weather: Cool, Partly Sunny Depth (ft) Sample Number Geologic Description 0-5 red -brown clayey silt, moist to dry, no gas odor 5-10 MW-2-8 same, cobble layer, moist to wet, no gas odor 10-15 same, wet, no gas odor 15 total depth 2" casing set from 0 to 5 feet. 2" screen set from 2 to 15 feet. Toddsbury of Ivy SCR - PC 01-6134 ago I= Boring/Well Log Project: Toddsbury of Ivy Log of Boring: MW-3 Location: Ivy, VA Date Drilled: 11/28/01 Ground Surface Elevation: 735 ft Drilling Method: Hollow Stem Auger Total Depth: 12 ft Drilling Company: Certified Environmental Drilling Geologist: Lyle R. Silka, CPG VA DEQ PC 01-6134 Weather: Cool, Partly Sunny Depth (ft) Sample Number Geologic Description 0-5 red -brown clayey silt, moist to dry, no gas odor 5-10 same, cobble layer, moist to wet, no gas odor 10-12 same, refusal at 12', wet, no gas odor 12 total depth 2" casing set from 0 to 2 feet. 2" screen set from 2 to 12 feet. Toddsbury of Ivy SCR - PC 01-6134 "W 0 APPENDIX B LABORATORY ANALYTICAL REPORTS Toddsbury of Ivy SCR - PC O1-6134 MARYLAND SPECTRAL SERVICES, INC. 1500 Caton Center Drive Baltimore, MD 21227 VOLATILE AROMATICS BY EPA METHODS 5030/8021 VOLATILE TPH BY EPA METHODS 5030/8015 tow CLIENT SAMPLE ID: MW-2-8 BBLK1205E1 TODDBURY-IVY LAB SAMPLE to: 01120402 METHOD BLANK WW SAMPLE DATE: 11/28/01 RECEIVED DATE: 12/04/01 ANALYSIS DATE: 12/05/01 12/05/01 FILE NAME: 120402D 1205BBLKEI ova INSTRUMENT to: GC-E GC-E % I40ISTURE: 24 N/A MATRIX: SOIL SOIL UNITS: UG/KG UG/KG bw DILUTION FACTOR: 2.0 1.0 VOLATILE COMPOUNDS ---------------------------------------------------------------------------------------------------- (Results reported on a dry -weight basis.) Benzene 3920 250 U Toluene 73000 250 U Ethylbenzene 31300 250 U Xylenes (total) 155000 500 U rr. Methyl-t-Butyl Ether 1320 U 500 U Volatile TPH 1060000 12500 U B - Detected in lab blank. U - Below reported quantitation level. J - Estimated value. VW UG/KG = Microgram per kilogram. ■w ' MARYLAND SPECTRAL SERVICES, INC. ow 1500 Caton Center Drive Baltimore, MD 21227 VOLATILE AROMATICS BY EPA METHODS 5030/8021 VOLATILE TPH BY EPA METHODS 5030/8015 ftw CLIENT SAMPLE ID: STREAM -UP STREAM -DOWN MW-1 MW-2 MW-3 TODDBURY-IVY TODDBURY-IVY TODDBURY-IVY TODDBURY-IVY TODDBURY-IVY BBLK1204E1 LAB SAMPLE ID: 01120403 01120404 01120405 01120406 01120407 METHOD BLANK SAMPLE DATE: 11/29/01 11/29/01 11/29/01 11/29/01 11/29/01 RECEIVED DATE: 12/04/01 12/04/01 12/04/01 12/04/01 12/04/01 ANALYSIS DATE: 12/04/01 12/04/01 12/04/01 12/04/01 12/04/01 12/04/01 FILE NAME: 120403 120404 120405 120406D 120407 120488LKE1 INSTRUMENT 1D: GC-E GC-E GC-E GC-E GC-E MATRIX: WATER WATER WATER WATER WATER WATER UNITS: DILUTION FACTOR: UG/L 1.0 UG/L UG/L UG/L UG/L UG/L ^�► VOLATILE COMPOUNDS 1.0 1.0 200 1.0 1.0 enzene Toluene ------------------------- 2.0 U ------------------------------------------ 2.0 U 2.0 U 1480 ----------------- 2.0 U 2.0 U Ethylbenzene 2.0 U 2.0 U 2.0 U 1420 2.0 U 2.0 U Xytenes (total) 2.0 U 4.0 U 2.0 U 2.0 U 400 U 2.0 U 2.0 u 4.0 U 4.0 U 900 4.0 U 4.0 U w. Methyt-t-Butyl Ether 4.0 U 4.0 U 18 56400 4.0 U 4.0 U Mm Volatile TPH 100 U 100 U 100 U 20000 U 100 U 100 U a+ moo B - Detected in Lab blank. U - Below reported quantitation level. J - Estimated value. ftw UG/L = Microgram per liter. A.. MARYLAND SPECTRAL SERVICES, INC. 1500 Caton Center Drive Baltimore, MD 21227 VOLATILE ORGANICS BY EPA GC/MS METHOD 8260 CLIENT SAMPLE ID: WS VOLK1205AI PAGE 1 OF 2 TODDBURY-IVY LAB SAMPLE ID: 01120408 METHOD BLANK SAMPLE DATE: 11/29/01 RECEIVED DATE: 12/04/01 ANALYSIS DATE: 12/05/01 12/05/01 FILE NAME: 120408 1205VBLKAI INSTRUMENT ID: MSA NSA +r MATRIX: WATER WATER UNITS: UG/L UG/L DILUTION FACTOR: 1.0 1.0 VOLATILE COMPOUNDS ----------------------------- Acetone 10 U '---- --- 10 U t-Amyl Methyl Ether (TAME) 5.0 U 5.0 U Benzene 5.0 U 5.0 U Bromobenzene 5.0 U 5.0 U Bromochloromethane 5.0 U 5.0 u Bromodichioromethane 5.0 U 5.0 U Bromoform 5.0 U 5.0 U Bromomethane 10 U 10 U tert-Butanol (TBA) 25 U 25 U 2-Butanone 10 U 10 U tert-Butylbenzene 5.0 U 5.0 U sec-Butylbenzene 5.0 U 5.0 U n-Butylbenzene 5.0 U 5.0 u +np Carbon Disulfide 5.0 U 5.0 U Carbon Tetrachloride 5.0 U 5.0 U Chlorobenzene 5.0 u 5.0 U +. Chtoroethene 10 U 10 U Chloroform 5.0 U 5.0 U Chtoromethane 10 U 10 U y 2-Chiorotoluene 5.0 U 5.0 U 4-Chiorotoluene 5.0 U 5.0 U 1,2-Dibromo-3-chloropropane 5.0 U 5.0 U Dibromochloromethane 5.0 U 5.0 U +r 1,2-Dibromoethane (EDB) 5.0 U 5.0 U Dibromomethane 5.0 U 5.0 U 1,3-Dichlorobenzene 5.0 U 5.0 U Nr 1,4-Dichlorobenzene 5.0 U 5.0 U 1,2-Dichlorobenzene 5.0 U 5.0 U Dichtorodiftuoromethane 5.0 U 5.0 U 1,2-Dichloroethane 5.0 U 5.0 U +.w 1,1-Dichloroethane 5.0 U 5.0 U trans-1,2-Dichloroethene 5.0 U 5.0 U cis-1,2-Dichloroethene 5.0 U 5.0 U 1,1-Dichloroethene 5.0 U 5.0 U 1,3-Dichloropropane 5.0 U 5.0 U 2,2-Dichloropropane 5.0 U 5.0 u 0 0 aw MARYLAND SPECTRAL SERVICES, INC. r... 1500 Caton Center Drive Baltimore, MD 21227 VOLATILE ORGANICS BY EPA GC/MS METHOD 8260 ,,. CLIENT SAMPLE ID: WS VBLK1205AI PAGE 2 OF 2 TODDBURY-IVY LAB SAMPLE ID: 01120408 METHOD BLANK SAMPLE DATE: 11/29/01 vNr RECEIVED DATE: 12/04/01 ANALYSIS DATE: 12/05/01 12/05/01 FILE NAME: 120408 1205V8LKAI INSTRUMENT ID: MSA MSA MATRIX: HATER WATER UNITS: UG/L UG/L DILUTION FACTOR: 1.0 1.0 VOLATILE COMPOUNDS -------------------------------- 1,2-Dichloropro a P� 5.0 "'" " '-'- trans-1,3-Dichloropropene 5.0 U 5.0 U cis-1,3-Dichloropropene 5.0 U 5.0 U 1,1-Dichloropropene 5.0 U 5.0 U Ethyl-t-Butyl Ether (ETBE) 5.0 U 5.0 U Ethytbenzene 5.0 U 5.0 U Hexachlorobutadiene 5.0 U 5.0 U 2-Nexanone 10 U 10 U Isopropyl Ether (DIPE) 5.0 U 5.0 U p-Isopropyl toluene 5.0 U 5.0 U Isopropylbenzene (Cunene) 5.0 U 5.0 U 4-Methyl-2-Pentanone 10 U 10 U r Methyl-t-Butyl Ether (MTBE) 3_3 J 5.0 U Methylene Chloride 5.0 U 5.0 U Naphthalene 5.0 U 5.0 U n-Propylbenzene 5.0 U 5.0 U Styrene 5.0 U 5.0 U 1,1,2,2-Tetrachloroethane 5.0 U 5.0 U 1,1,1,2-Tetrachtoroethane 5.0 U 5.0 U Tetrachtoroethene 5.0 U 5.0 U Toluene 5.0 U 5.0 U 1,2,3-Trichtorobenzene 5.0 U 5.0 U 1,2,4-Trichtorobenzene 5.0 U 5.0 u low 1,1,2-Trichtoroethane 5.0 U 5.0 U 1,1,1-Trichloroethane 5.0 U 5.0 U Trichloroethene 5.0 U 5.0 U Trichtorofluoromethane 5.0 U 5.0 U 1,2,3-Trichtoropropane 5.0 U 5.0 U 1,2,4-Trimethylbenzene 5.0 U 5.0 U 1,3,5-Trimethytbenzene 5.0 U 5.0 U �.r Vinyl Chloride 10 U 10 U o-Xytene 5.0 U 5.0 U w m+p-Xylenes 5.0 U 5.0 U B - Detected in Lab Blank. U - Below Reported Quantitation Level. J - Estimated Value. UG/L = Microgram per liter. aw "a f Company Name: AS Environmental Services, Inc. PO Box 6033 Charlottesville, VA 22906 Project Manager: Jeff Sitler tel (804)974-7080 fax 804 974-1657 no. of c o n t a i n e r Parameters CHAIN -OF CUSTODY RECORD T P H G R O EPA- 5035- goi5 T P H D R 4 EPA- 8015 M B T E X EPA- 5035- 1 8021 P A H EPA- 1 6270 M B T E X N EPA- 5035- 1 9021 Laboratory: Maryland Spectral Services, Inc. 1500 Caton Center Drive, Suite G Baltimore, Maryland 21227 (410) 247-7600 Project Name: cc- Project Number: Sampler(s): LRS Task Number: Date Time I Matrix ILL io UJ w- S3 SS c p { { /r (/ L� Federal Express Send report to: Lyle Silks 5709 Cedar Walk#402 Centreville, VA 20121 Fax summary of results to Lyle SIMA at (703)631-0726 (printed) ae- R. Silks (printed) Relinquished by: (signature) DaWrime � •vG1 t store- Li _ �_. Bill: (Prinked) (printed) ,r;j�.,, i� „w ow APPENDIX C DATA FOR ANALYSIS OF BTEX CONCENTRATIONS IN SOIL SPREADSHEETS FOR DRAIN FIELD ANALYSIS SPREADSHEETS FOR PUMPED CONCENTRATION IN WATER WELL Toddsbury of Ivy SCR - PC 01-6134 AW DATA FOR ANALYSIS OF BTEX CONCENTRATIONS IN SOIL BTEX Concentrations in Soil PC # Sample Benzene Toluene Ethyl- Xylenes MTBE benzene 9"' 67 99-5192 Equine MW-1-10 Ashley's MW-1-15 ug/kg 107,000 ug/kg 841,000 ug/kg 260,000 ug/kg 1,310,00 ug/kg 116 000 99-5158 Beaver Dam Gas-1 81,600 15,900 1,220,000 199,000 261,000 123,000 1,740,000 104,000 99-5158 99-5158 Beaver Dam Gas-2 Beaver Dam MW-1-15 42,400 403,000 253,000 527,00 1,040,000 BDL 17,200 w. 99-5159 Crozet MW-1-10 45,100 20,200 355,000 246,000 146,000 99,400 668,000 457,000 BDL 00-6036 99-5195 Jones SB-2-20 U's SB-1-10 23,100 170,000 67,200 314,000 NA BDL 99-5030 Midtown Pump-1 1,370 2,080 36,600 35,700 26,800 21,200 111,000 85,100 1,210 +■ 99-5060 01-6134 Stackhouse MW-4-10 Toddsbury MW-2-8 2,070 18,300 9,180 46,100 NA BDL 3,920 73,000 31,300 155,000 BDL N Average Std 11 31,340 11 327,055 11 118,007 11 586,655 59,603 33,515 362,416 95,165 532,286 _ 50.891 Log BTEX Concentrations in Soil to Xylene PC # Sample Est. Benzene Toluene Ethyl- Xylenes MTBE .� Age benzene 99-5067 Equine MW-1-10 yr 0 ug/kg 5.03 ug/kg ug/kg ug/kg ug/kg 99-5192 Ashley's MW-1-15 0 4.91 5.92 6.09 5.41 5.42 6.12 5.06 99-5158 Beaver Dam Gas-1 0 4.20 5.30 5.09 6.24 5.02 99-5158 Beaver Dam Gas-2 0 4.63 5.61 5.40 5.72 BDL 99-5158 Beaver Dam MW-1-15 0 4.65 5.55 5.16 6.02 4.24 99-5159 Crozet MW-1-10 0 4.31 5.39 5.00 5.82 5.66 BDL 00-6036 Jones SS-2-20 0 4.36 5.23 4.83 5.50 NA BDL 99-5195 99-5030 U's SB-1-10 Midtown Pump-1 0 0 3.14 4.56 4.43 5.05 3.08 99-5060 Stackhouse MW-4-10 0 3.32 3.32 4.55 4.26 4.33 4.93 NA 01-6134 Toddsbury MW-2-8 0 3.59 4.86 3.96 4.50 4.66 BDL 5.19 BDL N 4 Average 4.13 5.21 4.87 5.54 4.35 _ 0.65 0.56 0.48 0.49 0.80 Toddsbury of Ivy SCR - PC 01-6134 �.. �.. ..,,, DRAIN FIELD ANALYSIS AFTER BEAR (1979, P.180) - - -- INPUT RECHARGE (R) ON LEFT SIDE OF DRAIN ON RIGHT SIDE OF DRAIN DISTANCE BETWEEN DRAINS (L) HEIGHT OF DRAIN "0" (HO) HEIGHT OF DRAIN "1" (H1) HYDRAULIC CONDUCTIVITY (K) OUTPUT FLOW RATE TO DRAIN "0" FLOW RATE TO DRAIN "1" DISTANCE TO MAXIMUM HEIGHT OF WATER TABLE (HMAX) _ _ _ MODELER: LRS _ -. _ ... _._ ._ INPU UNITS - - - - - - 01/P4/01. 0.0016 FT/DAY 0.0400 FT/DAY O0 FEET 0 FEET 0 FEET - 14 FT/DAY OUTPUT -0.320 GFD/LINEAL FT - 0.320 CFD/LINEAL FT 320 FEET "" HEIGHT ELEVATION DISTANCE OF HYDRAULIC OF (Fl) WATER GRADIENT WATER COMMENTS ,ow 10 TABLE TABLE _- -- (FT) 526 ",,,,' 0 0 10 10 0 526.0 526 20 1 0.0667 526.7 20 30 1 0.0264 526.9 30 1 0.0194 527.1 40 40 so 1 0.0156 527.3 ow' 50 1 0.0131 527.4 60 60 2 0.0113 527.5 70 70 2 0.0098 527.6 80 80 2 0.0086 527.7 ftw 90 90 2 0.0075 527.8 100 100 110 2 0.0066 527.9 526.8 N W-3- 110 2 0.0058 527.9 120 120 2 0.0050 528.0 to. 130 130 2 0.0043 528.0 140 140 2 0.0037 528.0 150 150 2 0.0031 528.1 160 160 2 0.0025 528.1 taw 170 170 180 2 0.0019 528.1 528.1 M180 W 3 190 190 2 2 0.0013 528.1 200 200 2 0.0008 528.1 210 210 0.0003 528.1 528.4 MW-1 220 2 2 -0.0003 528.1 230 230 2 -0.0008 528.1 240 240 2 -0.0013 528.1 r.. 250 -0.0019 528.1 -0.0025 528.1 250 2 -0.0031 528.0 270 270 280 2 -0.0037 528.0 280 290 290 2 -0.0043 528.0 om' 300 300 2 -0.0050 527.9 2 -0.0058 527.9 Kw Toddsbury of ivy SCR - PC 01-6134 aw I" .r DRAIN FIELD ANALYSIS AFTER BEA_ R (1979, P._ 180) _ INPUT - - - _ MODELER: LRS RECHARGE (R) ON LEFT SIDE OF DRAIN U INP _ UNITS 01AW0, ON RIGHT SIDE OF DRAIN 0.0016 FT/DAY DISTANCE BETWEEN DRAINS (L) 0.0016 FT/DAY HEIGHT OF DRAIN "0" (HO) 800 FEET HEIGHT OF DRAIN "l" (H1) 0 FEET HYDRAULIC CONDUCTIVITY (I) 0 FEET OUTPUT 32 FT/DAY FLOW RATE TO DRAIN "0""i-i---" OUTPUT FLOW RATE TO DRAIN "1" .639 CFD/LINEAL FT DISTANCE TO MAXIMUM HEIGHT 0 . NEAL FT OF WATER TABLE (HMAX) 400 00 FEET FEET HEIGHT ELEVATION DISTANCE OF HYDRAULIC OF (Fl) WATER GRADIENT WATER COMMENTS 10 TABLE TABLE (FT) 526 0 0 10 10 0 1 526.0 526 20 20 1 0.0628 526.6 30 30 0.0255 526.9 40 40 1 0.0191 527.1 50 50 1 0.0158 527.2 60 60 1 0.0136 527.4 70 70 1 0.0121 527.5 80 80 2 2 0.0108 527.6 90 90 2 0.0099 527.7 100 100 2 0.0090 527.8 110 110 2 0.0083 527,9 526.8 MW 3 120 120 2 0,0077 527.9 130 130 2 0.0072 528.0 140 140 2 0.0067 526.1 150 150 2 0.0063 528.1 160 160 2 0.0058 528.2 170 170 2 0.0055 528.3 180 180 2 0.0051 528.3 528.1 MW-3 190 190 2 0.0048 528.4 200 200 2 0,0045 528.4 210 210 2 0.0042 528.4 528.4 MW-1 220 220 3 0.0039 528.5 230 230 3 0.0037 528.5 0.0034 528.6 240 240 250 250 3 0.0032 528.6 260 260 3 3 0.0030 528.6 270 270 3 0.0027 528.6 280 280 3 0.0025 528.7 290 290 3 0.0023 528.7 300 300 3 0.0021 528.7 0.0019 528.7 Toddsbury of Ivy SCR - PC 01-6134 °-7 T PUMPING WELL (FROM BEAR, 1979, pp. 3enzene L.R. PLUME RADIUS 25 FEET DISTANCE, WELL TO PLUME CENTER 100 FEET SOURCE CONC. AQUIFER THICKNESS 7 FEET AREA = 3 ug/I SPECIFIC YIELD 0,200 1963 SQUARE FEET AVERAGE PUMPING RATE (gpm) 1.00 GPM Uo = 43982 CUBIC FEET RETARDATION FACTOR BIODEG HALFLIFE 10000 DAYS CUMMULATIVE PARAMETERS FOR BEAR'S EQUATION^ BIODEG RATE CONSERVATIVE 0.0001 PER DAY - TIME VOLUME PUMPED DAYS PUMPED PUMPED Observed CONC. WITH UpNo UUUo CF 6 CONC. Concentration BIODEGRADATIC 0.00E 66 0.00E+00 (Relative Cone.) ugn - ug11 3.00E+01 5.78E+03 1.31 E-01 6.25E-02 ERR ERR 6.00E+01 1.16E+04 2.63E-01 6.25E-02 ERR ERR ERI 9.00E+01 1.73E+04 3.94E-01 6.25E-02 ERR ERR ERI 1.20E+02 2.31E+04 5.25E-01 6.25E-02 ERR ERR 1.50E+02 2.89E+D4 6.57E-01 6.25E-02 5.76E-02 0 ERI 1.80E+02 3.47E+04 7.88E-01 6.25E-02 7.56E-02 0 2.10E+02 4. 04E+04 9.19E-01 6.25E-02 8.03E-02 p 2.40E+02 4.62E+04 1.05E+00 6.25E-02 7.84E-02 0 � 2.70E+02 5.20E+04 1.18E+00 6.25E-02 7.17E-02 0 3.00E+02 5.78E+04 1.31 E+00 6.25E-02 6.04E-02 0 � 3.30E+02 6,35E+04 1.44E+00 6.25E-02 4.28E-02 0 i 360E+02 6.93E+04 1.58E+00 6,25E-02 ERR ERR I 3.90E+02 7.51E+04 1.71E+00 6.25E-02 ERR ERR ERF 4.20E+02 8.09E+04 1.84E+00 6.25E-02 ERR ERR ERF 4.50E+02 8.66E+04 1.97E+00. 6.25E-02 ERR ERR ERF 4.80E+02 9.24E+04 2.10E+00 6,25E-02 ERR ERR 5.10E+02 9.82E+04 2.23E+00 6.25E-02 ERR ERR ERF 5.40E+02 1.04E+p5 2.36E+00 6.25E-02 ERR ERR ERR 5.70E+02 1.10E+05 2.49E+DD 6.25E-02 ERR ERR ERF 6.00E+02 1.16E+05 2.63E+DD 6.25E-02 ERR ERR ERR 6.30E+02 1.21 E+DS 2.76E+00 6.25E-02 ERR ERR ERR 6.60E+02 1.27E+05 2.89E+00 6.25E-02 ERR ERR ERR 6.90E+02 1.33E+05 3.02E+00 6.25E-02 ERR ERR ERR 7.20E+02 1.39E+05 3.15E+00 6.25E-02 ERR ERR ERR 7.50E+02 1.44E+D5 3.28E+00 6.25E-02 ERR ERR ERR 7.80E+02 1.50E+05 3.41E+00 6.25E-02 ERR ERR ERR 8.10E+02 1.56E+05 3.55E+00 6.25E-02 ERR ERR ERR 8.40E+02 1.62E+05 3.68E+00 6.25E-02 ERR ERR ERR 8.70E+02 1.67E+05 3.81 E+00 6.25E-02 ERR ERR ERR ERR Toddsbury of lvy SCR - PC 01-6134 c m" rrr CONCENTRATION AT PUMPING WELL (FROM BLAB, 1W9, p - 290-- -j - - " - MTBE L.R. SIl INPUT DATA - - - - - PLUME RADIUS ! DISTANCE, WELL TO PLUME CENTER 50 FEET AQUIFER THICKNESS 100 FEET SOURCE CONC. 24 ug/l SPECIFIC YIELD 7 FEET AREA = 7850 SQUARE FEET AVERAGE PUMPING RATE (gpm) 0.2DO Uo = 43982 CUBIC FEET RETARDATION FACTOR 1 DO GPM BIODEG HALFLIFE 10000 DAYS CUMMULATIVE 1 PARAMETERS FOR BE:AR'S EQUATION BIORATE 0.0001 PER DAY TIME VOLUME CONSENSE RVATIVE PUMPED DAYS PUMPED UWu-o UilUo PUMPED Observed CONC. WITH GF e CONC, Concentration BIODEGRADATION 0.00E+00 - 0.00E+00 - (Relative Conc ) --- ug/l 3.00E+01 5.78E+03 1.31E-01 2.50E-01 ERR ERR 6.00E+01 1.16E+04 2.63E-01 2.50E-01 4.91E-02 ERR 9.00E+01 1.73E+04 3.94E-01 2.50E-Ot 1.35E-01 1 3 1 1.20E+02 2.31 E+04 5.25E-01 2.50E-01 1.58E-01 4 3 1.50E+02 2.89E+04 6.57E-01 2.50E-01 1.65E-01 4 4 1.80E+02 3.47E+D4 7.88E-01 2.50E-01 1.66E-01 4 4 2.10E+02 4.04E+04 9.19E-01 2.SOE-01 1.64E-0i 4 4 2.40E+02 4.62E+04 1.05E+DO 2.50E-01 1.59E-01 4 4 2.70E+02 5.20E+04 1.18E+00 2.50E-01 1.52E-01 4 4 3.00E+02 5.78E+04 1.31E+00 2.SOE-01 1.43E-01 3 4 3.30E+02 6.35E+04 1.44E+0D 2.50E-01 1.34E-01 3 3 3.60E+02 6.93E+04 1,58E+0Q 2.50E-01 1.23E-01 3 3 3.90E+02 7.51 E+04 1.71 E+00 2.50E-01 1.11E-01 3 3 4.20E+02 8.09E+04 1.84E+ 00 2.50E-01 9.63E-D2 2 3 4.50E+02 8.66E+04 1.97E+00 2.50E-01 7.95E-02 2 2 4.80E+02 924E+ 04 2.10E+00 2.50E-01 5.78E-02 1 2 5.10E+02 9.82E+04 2,23E+00 2 50E-01 1.9BE-02 0 1 5.40E+02 1.04E+OS 2.36E+00 2.50E-01 ERR ERR D 5.70E+02 1.10E+D5 2.49E+00 2.50E-01 ERR ERR ERR 6.00E+02 1.16E+05 2.63E+00 2.50E-01 ERR ERR ERR 6.30E+02 1.21 E+05 2.76E+pQ 2.50E-01 ERR ERR ERR 6.60E+02 1.27E+05 2.89E+00 2.50E-01 ERR ERR ERR 6.90E+02 1.33E+05 3.02E+00 2.50E-01 ERR ERR 7.20E+02 1.39E+05 3.15E+00 2.50E-01 ERR ERR ERR 7.50E+02 1.44E+OS 3.28E+00 2.50E-01 ERR ERR ERR 7.80E+02 1.50E+05 3.41 E+00 2.50E-01 ERR ERR ERR 8.10E+02 1,56E+05 3.55E+p0 2.50E-01 ERR ERR ERR 840E+02 1.62E+05 3.68E+0o 2.50E-01 ERR ERR ERR 8.70E+02 1.67E+05 3.81E+00 2.50E-01 ERR ERR ERR ERR ERR Toddsbury of Ivy SCR - PC 01-6134 DEQ-VALLEY APR 2 2 2002 TO: FILE: SITE CHARACTERIZATION REPORT ADDENDU11W c. ; TODDSBURY OF IVt� S s Albemarle CountyBy. Y PC # 01-6134 - FAC ID # (for DEQ use) Submitted to: Joel P. Maynard Valley Regional Office Department of Environmental Quality PO Box 3000 Harrisonburg, VA 22801-3000 (540)574-7800 Prepared for: Charlottesville Oil Company PO Box 6340 Charlottesville, Virginia 22906 (804)293-9107 Prepared by: Jeffrey A. Sitler Environmental Service, Inc. PO Box 6038 Charlottesville, Virginia 22906 (804)974-7080 fax (804)974-1657 April 18, 2002 TABLE OF CONTENTS TABLE OF CONTENTS........................................................ i -- 1.0INTRODUCTION.......................................................... 1 2.0 MONITORING WELL INSTALLATION ....................................... 7 3.0 GROUNDWATER SAMPLING AND ANALYSIS ................................ 8 '" 4.0 GROUNDWATER FLOW DIRECTION ........................................ 8 5.0 LABORATORY ANALYTICAL RESULTS ..................................... 8 5.0 CONCLUSIONS AND RECOMMENDATIONS ................................ 13 FIGURES Figure 1 - Site Location Topographic Map .......................................... 3 Figure 2 - Site Plan............................................................ 4 Figure 3 - 1994 USGS Aerial Photograph ........................................... 6 Figure 4 - Water Table Elevation as of 03/14/02...................................... 9 Figure 5 - Benzene in Groundwater ............................................... 11 Figure 6 - MTBE in Groundwater ................................................ 12 TABLES wo Table 1. Groundwater Analytical Results .......................................... 10 LIST OF APPENDICES on APPENDIX A- Boring/Well Log APPENDIX B - Laboratory Analytical Reports VM Toddsbury of Ivy SCR Addendum - PC 01-6134 i 1.0 INTRODUCTION Jeffrey A. Sitter Environmental Services, Inc., (JAS) was contracted by Charlottesville Oil Company, Rt. 250 West, Charlottesville, Virginia to prepare this Site Characterization Report _ Addendum (SCRA) for the property known as Toddsbury of Ivy Market located on US Route 250 in Ivy, Virginia, in Albemarle County, (the " Site" shown in Figure 1). The objectives of this SCRA were to install a fourth monitoring well to the east of the tank basin in the down - gradient direction, sample the stream in the down -gradient direction under the Rt 250 bridge over Ivy Creek, and reevaluate the extent of contamination per a letter from Joel P. Maynard of the DEQ dated January 28, 2002. The Site has been operated as a gas station since at least the early 1950's. Charlottesville Oil Company owns the three gasoline underground storage tanks (USTs) that are currently in service as shown in the site plan in Figure 2. As a result of an inconclusive pressure test on the lines, soil sampling along the supply lines indicated potential petroleum releases. The DEQ-required Site Characterization Report (SCR) was submitted January 3, 2002. The SCR found the following: 1. No LPH has been observed at the Site, although MTBE has been detected at 56,400 µg/1, a level usually associated with the presence of LPH. 2. The residual soil contamination is minor, since the water table is so shallow. 3. There is no significant risk of petroleum vapors migrating to the building. ._ 4. Dissolved benzene, toluene, and MTBE are the contaminants of concern present in the groundwater with the highest concentrations observed in MW-2 at 1,480, 1,420, and 56,400 µg/1, respectively. 5. The onsite water supply well is contaminated with MTBE at an estimated 3.3 µg/1 and is free of all other potential contaminants. 6. While dissolved contaminants could migrate to the streams, predicted average ._ dilution rates would render them undetectable. 7. MTBE at 3.3 µg/1 in the water well is believed to represent an approximate steady-state concentration and is not predicted to increase in the near future. MW Toddsbury of Ivy SCR Addendum - PC 01-6134 2 Cy�^'1� ^ �'r �a� F'S+d .5d ��. fl.��^s'��y�-)'Y��K,L.��, � "�'a�,�2•=.�, A �}� .y�j_, f� .dim I y.r� '� 1 ,n .i� 9{� ��4�24x ..1w':F, :s .... y�i(t _ ..t: j ,�,fM1ti� L 'iD /�J��y'y�,.., f 1,r_,d-A•r� �,��,��5-� 5��g li�'���y.:s":f �' � •. i 'uti�p'�. .F4 '$�^ a D''�S".�.29 '{l'.. `� War r L.. Ty,f•�'l �y,xl. f�,y^ i � i ♦ A � s' � 1 � Jeffrey A. Sitter - Date: Revised: Figure 1 - Site Location Topographic Map EnvirPO Box onmental 017117ental Services, Inc. 38 D..b,: LRS chekealry: Toddsbury of Ivy Charlottesville, VA 22906 (6D4)974-7060-(604)974-1657(FAX) File: scale'. Toddsbury of Ivy SCR Addendum - PC 01-6134 3 r- A US Rt 250 G 4n crete Pump leland Broken hep h a ft & Gravel 0 Water Well Pipe Trench Tuddebury of Ivy Market Septic Tank Broken Aephaft & Gravel Plug 1 Super 10 Reg Unl _ Septic Field Mawed Orgau ,.............._.... ............. _ f ter`' r---�'Y Tributary to Ivy Greek Scala Scrub Brueh & Small Trev 0 2S ft bpcteYtdry 8. No other dissolved contaminants are believed to present any potential threat to the onsite water well. 9. There are no risks posed by inhalation, direct contact, or exposure of environmental receptors. 10. There are no risks posed to offsite water wells. Since the submission of the SCR, it was determined that the onsite water well was not used for drinking water. ,. The SCR determined that the water table gradient sloped to the east southeast, parallel with Rt 250, while the three monitoring wells were installed assuming the groundwater flow would be to the south. Therefore, as part of this SCRA, a fourth well was installed to the east southeast of the tank basin. In addition, the surface water sample was collected from the small unnamed tributary �. that flows along the southern boundary of the Site near the down -gradient end of the Site. However, the east southeast groundwater flow indicated that Little Ivy Creek may be the ••• recipient of contaminated groundwater leaving the Site. Therefore, as part of this SCRA, a surface water sample was collected from under the Rt 250 bridge. These relationships are shown -• on Figure 3. OM I Toddsbury of Ivy SCR Addendum - PC 01-6134 5 r ftm am No l'oddsbury of Ivy SCR Addendum - PC 01-6134 0 2.0 MONITORING WELL INSTALLATION For the SCRA, one monitoring well was installed at the Site in a location that would be down gradient of the tank basin per the water table contours developed in the SCR. JAS and Certified Environmental Drilling, of Earlysville, Virginia, mobilized onsite on February 12, 2002 and installed monitoring well MW-4 by hollow -stem auger drill rig. The drilling was supervised by Lyle R. Silka, Virginia certified professional geologist, and was in accordance with standard health and safety practices. The total boring depth was 20 feet. Geologic samples were inspected at five-foot intervals for characterization of the geology and assessing the presence of hydrocarbon contamination. Decontaminated drill stems were used for the boring. Each soil sample was logged for lithology, inspected for petroleum odors, examined for visual petroleum staining, and tested for total volatile hydrocarbon vapors. The boring log is presented in Appendix A. Since MW-4 was about 75 feet from the tank basin, no soil sample was collected. In addition, there was no odor or staining in the soil samples until the water table was reached at which depth a slight gasoline odor was encountered. The soil boring was converted to a monitoring well using flush -threaded, two-inch diameter, schedule 40 PVC casing and 0.01-inch factory -slotted PVC screen with a threaded end cap. The well was installed by assembling and lowering the PVC screen and blank casing into the open borehole to the total depth of the boring. A #2 filter sand was placed around the screen to a height of two feet above the screen, followed by a two -foot bentonite-chip seal that was hydrated in place. From the top of the bentonite seal to the surface, a cement grout mix was placed in the annulus around the casing. The well was completed with a flush -mount, bolt -down, metal well protector set in concrete at the surface. A locking well cap and padlock were placed on each well casing. Monitoring well depths and screened intervals were selected in the field based on the depth at which groundwater was encountered in order to provide ample open screen above the water table to allow for seasonal fluctuations and allow sufficient screen below the water table to allow for groundwater sampling. a, The monitoring well was purged of approximately three well volumes of water to develop the well and bring in fresh groundwater from the surrounding aquifer. The well purging was „m accomplished using a pre -cleaned plastic bailer. The relative elevation of the top of casing Toddsbury of Ivy SCR Addendum - PC 01-6134 7 0 (TOC) for MW-4 was determined by surveying with a rod and transit relative to MW-2. The horizontal position of the wells on the Site was determined relative to the building using a 200- foot fiberglass tape measure. Appendix A provides the elevation survey results. 3.0 GROUNDWATER SAMPLING AND ANALYSIS Groundwater samples were obtained from monitoring well MW-4 and Little Ivy Creek under the Rt 250 bridge on March 15, 2002. All four monitoring wells were checked for free product and depth to water with an electronic oil -water interface probe. Monitoring well MW-4 was purged of approximately three well volumes of water using a pre -cleaned plastic bailer. The stream sample was obtained by collecting a sample directly from the flowing stream along the west bank. Each water sample was placed into two laboratory -supplied 40-milliliter glass vials with Teflon septa in a manner to exclude all air from the vials. All sample bottles were labeled, placed on ice, and delivered via overnight Federal Express under standard chain -of -custody procedures to MSS. Water samples were analyzed for TPH-GRO, BTEX, and MTBE. The letter from Joel P. Maynard dated January 28, 2002 called for sampling and analysis of all four monitoring wells and the onsite water supply well. A mistake during field collection am erroneously omitted the sampling of MW-1, MW-2, MW-3, and the onsite water well. This SCRA thus combines the data for MW-4 and Little Ivy Creek with the data collected on November 29, 2001. 4.0 GROUNDWATER FLOW DIRECTION The results of the water table measurements are presented in Figure 4. The data for March 15, 2002 confirm the finding in the SCR that the groundwater flow is toward the east southeast at about the same gradient. 5.0 LABORATORY ANALYTICAL RESULTS The results of the groundwater analyses are summarized in Table 1 and reported in Appendix B. Figures 5 and 6 show the extent of dissolved benzene and MTBE, respectively. The full laboratory report is presented in Appendix B. w. Toddsbury of Ivy SCR Addendum - PC 01-6134 8 l ------------------------------------------------------------------------------------------------------------------ E z C "b '� N ti u3 y ti i ti L CO t� r4 t ; � '0 .tb 5 � 1 Un ti v I u6 M % EN h%? 3 r'-4 �, -•' � It a m1 cti( 1714 1 - --------•----•-- ,..--•---- ---- - fJf E is ID CL ID �� I. Jeffrey A. Sitter - Date: Raised: Figure 4 - Water Table Elevation Environmental Services, Inc. -' as of 03/14/02 PO Box 6038 Drawn by: LRS Checked by: Toddsbury of Ivy Charlottesville, VA 22906 (804)974-7080 - (804)974-1657 (FAX) Ivy, Virginia File: M Toddsbury of Ivy SCR Addendum - PC 01-6134 Table 1. Groundwater Analytical Results Well No. Date Sampled LPH in TPH-GRO µg/1 Benzene µg/I Toluene µg/l Etbyl- Benzene µg/l Xylenes µg/l MTBE µg/l MW-1 11/29/01 0 BDL BDL BDL BDL BDL 18 MW-2 11/29/01 0 BDL 1480 1420 BDL 900 56400 MW-3 11/29/01 0 BDL BDL BDL BDL BDL BDL MW-4 03/14/02 0 BDL BDL BDL BDL BDL 662 Onsite Water Well 11/29/01 0 BDL BDL BDL BDL BDL 3.3j Up Stream 11/29/01 BDL BDL BDL BDL BDL BDL Down Stream 11/29/01 BDL BDL BDL BDL BDL BDL Rt 250 Bridge 03/14/02 BDL BDL BDL BDL BDL BDL Notes: ND - Not Determined BDL - Below Detection Limit j - Estimated value µ g - Micrograms Per Kilogram LPH - Liquid Petroleum Hydrocarbon NA - Not applicable Toddsbury of Ivy SCR Addendum - PC O1-6134 10 Benzene, ugl � BDL DL .•kMW-4- BDL Tod deGury of (ay Markak -- -• ... �"'"`' W-1 0 BDL 0 Faker Well BDL BDL --6roam-�Iream BDLr ./1 ^f. • i•r'• -` %%............. Tributary to Ivy Crook Scale UBWe am _ l'�J•~ _ --�-'' O 25 14 imFavtdry Mtn Qn LLJ M e11 R Jeffrey A. Sitter - uue xr�ssea: Figure 6 - MTBE in Ground - Environmental Services, Inc. water, µg/1, 11/29/01 & 03/14/02 Po Box 60M °mw° by: LRS ce«xod by: Toddsbury of Ivy CharWnesvuie, VA 22906 (804)974-7080-(804)974-1657 (FAX) it Toddsbury of Ivy SCR Addendum - PC 01-6134 12 0 Based on Figures 5 and 6, the major dissolved contamination at the Site is limited to the vicinity of the gasoline UST basin. Dissolved benzene was found at 1,480 gg/1 and MTBE was at 56,400 µg/l in MW-2. By the time the contamination reaches MW-1 and the onsite water well, benzene becomes undetectable, and MTBE dropped to 18 ,ug/1 and an estimated 3.3 gg/l, respectively. Toward the east, benzene was not detected in MW-4, although MTBE was detected at 662 ,ug/l. However, none of the stream samples have any detectable contamination. These new data provide fairly conclusive data concerning the extent of groundwater contamination as depicted in Figures 5 and 6. 5.0 CONCLUSIONS AND RECOMMENDATIONS The conclusions from the SCR remain unchanged in the SCRA. The Site had a release of gasoline from the UST system that resulted in groundwater contamination with benzene, toluene, and MTBE. No LPH has been observed at the Site, even though the MTBE level is quite high in MW-2. Groundwater flow is toward the southeast with discharge into Little Ivy Creek. Some groundwater from the Site also discharges into the small tributary on the south boundary of the Site. However, as confirmed by the results of sampling, predicted dilution rates in the surface water would render contaminants undetectable. The potential exposure pathway is via the onsite water supply well. However, it has been determined that the well is not used for drinking water. The MTBE is predicted not to present any concern in the well into the future unless there is an intensification of the source. The other gasoline contaminants also are predicted not to present any concern for the water well at this time. It is recommended that quarterly monitoring be conducted for the four monitoring wells, the onsite water well, and the stream at the Rt 250 bridge to monitor the benzene and MTBE plumes. Toddsbury of Ivy SCR - PC 01-6134 KM WELL DATA SPREADSHEET AND BORING/WELL LOG FOR MW-4 Toddsbury of Ivy SCR - PC 01-6134 Fs Om Toddsbury of Ivy Monitoring Well Data _ OV17102 mW-1 _ MW-2 MW-3 Stream MW-4 Installation Data 11128N1 11128I01 11=101 02/12102 Heighh of Scope above TOC, ft 5.00 Height Of Scope at Rod, ft 4.23 3.90 3.42 12.66 5.57 Total deptrr of wax ft 15.00 15.07 12.09 20.09 Elevation of TOG Relative Local Datum. ft W5.00 535.33 535.81 526.67 534.76 Water Table Depth below TOC, I Ira 01, ft 6.50 8.52 7.70 -� 0.00 Elevatkm of water Table, ft _ 528.41 526.81 _ 528.11 526.57 Water Table Depth below TOC, 311MU0, ft 6.07 7.97 7.27 i49 Elevation of Water Table, ft 528.93 527.36 528.54 526.57 525.27 r Toddsbury of Ivy SCR - PC 01-6134 0 ^7 Boring/Well Log Project: Toddsbury of Ivy Log of Boring: MW-4 Location: Ivy, VA Date Drilled: 02/12/02 Ground Surface Elevation: 535 ft Drilling Method: Hollow Stem Auger Total Depth: 20 ft Drilling Company. Certified Environmental Drilling Geologist: Lyle R. Silka, CPG VA DEQ PC 01-6134 Weather: Warm and Sunny Depth (ft) Sample Number Geologic Description 0-5 red -brown clayey silt, moist to dry, no gas odor 5-10 same, cobble layer, moist, no gas odor 10-15 same, moist to wet, slight gas odor 15-20 same, moist to wet, slight gas odor 20 total depth 2" casing set from 0 to 5 feet. 2" screen set from 5 to 15 feet. Toddsbury of Ivy SCR - PC 01-6134 .. .. am sm APPENDIX B LABORATORY REPORT Toddsbury of Ivy SCR - PC 01-6134 MARYLAND SPECTRAL SERVICES, INC. 1500 Caton Center Drive Baltimore, MD 21227 �r VOLATILE AROMATICS BY EPA METHODS 5030/8021 VOLATILE TPH BY EPA METHODS 5030/8015 CLIENT SAMPLE 10: MW-4 STREAM BBLX032102 TODDSBMY-IVY TODDSBURY-IVY LAB SAMPLE ID: 02032012 02032013 METHOO BLANK SAMPLE DATE: 03/14/02 03/14/02 RECEIVED DATE: 03/20/02 03/20/02 rr ANALYSIS DATE; 03/21/02 03/21/02 03121/02 FILE NAME: 032012D 032013 0321BBLICO2 INSTRUMENT ID: GC-9 GC-D GC-0 MATRIX: WATER WATER WATER „w UNITS: UG/L UG/L UG/L DILUTION FACTOR: 2.0 1.0 1.0 VOLATILE COMPOUNDS ---------------------------------------------------------- Benzene ---------------------- 4.0 U 2.0 U ^------------ ---------------------- 2.0 U am Totuene 4.0 U 2.0 U 2.0 U Ethylbenzene 4.0 U 2.0 U 2.0 U Xytenes (totat) 8.0 U 4.0 U 4.0 U t' Methyl-t-Bvtyt Ether 662 4.0 U 4.0 U Volatile TPH 200 U 100 U 100 U I= ,w Toddsbury of Ivy SCR - PC 01-6134 I I I I ! f 1 1 I 1 I 1 1 J 1 1 1 Company Name: Project Manager: I S Environmental Services, Ire. Jeff Skler PO Box 603A ftel (804)974-7080 !fax Ciarlottesvgle, VA 22906 804 974-1657 Project Name: Project Number: - toejc(5bit., or —a, Sampler(s): Number: 'Task LRS i Date ; Time ; Matri Al no., Parameters i CHAIN -OF CUSTODY RECO. of T T M P M Laboratory: c P P B A B Maryland Spectral Services, Inc. o H H T H T 11500 Caton Center Drive, Suite G n E E Baltimore, Maryland 21227 t 4 D X X (410) 247-7600 a R R N i i o 0 I e 735. EPA 1 5035- EPA- S 35- Send report to: Lyle 3llka I, ��a �„ Federal Express PO Box 1283 (printed) (printed) Haymarket, VA 20168 Lyle IL Silka aab Funramaryefreswift to Lyle silks at 703) ReiinqukW by: (slgnatore) Datdfime ) Bill-. l�� S (printed) f (printed) CORRECTIVE ACTION PLAN . x " TODDSBURY OF IVY Albemarle County �y. PC # 01-6134 FAC ID # ((or VDEQ Use) Submitted to: Joel P. Maynard Valley Regional Office Department of Environmental Quality PO Box 3000 Harrisonburg, VA 22801-1.129 (540)574-7800 Prepared for: Charlottesville Oil Company PO Box 6340 Charlottesville, Virginia 22901 (434)293-9107 Prepared by: Jeffrey A. Sitler Environmental Service, Inc. PO Box 6038 Charlottesville, Virginia 22906 (434)974-7080 fax(434)974-1657 June 8, 2004 0 Toddsbury of Ivy Page ii Corrective Action Plan PC 01-6134 Section TABLE OF CONTENTS Page 1.0 INTRODUCTION.......................................................... 1 „ 1.1 Previous Investigations................................................ 1 1.2 Estimated Quantities of Contaminant in Each Phase .......................... 4 1.3 Previous Remedial Efforts ............................................. 7 1.4 CAP Objectives...................................................... 7 2.0 REMEDIAL DESIGN......................................................8 aw 2.1 Aquifer Characteristics................................................ 8 2.2 Zone of Capture ...................................................... 9 2.3 Water Quality Characteristics for Recovered Groundwater .................... 9 3.0 REMEDIATION SYSTEM DESIGN .......................................... 12 3.1 Remediation System Design ........................................... 12 .., 3.2 Water Treatment System .............................................. 12 3.3 Treated Groundwater Discharge ........................................ 12 3.4 Pumping Equipment .................................................. 14 4.0 SYSTEM OPERATION AND MONITORING .................................. 14 4.1 Operation Schedule .................................................. 14 ... 4.2 Numerical Remedial End Points ........................................ 15 4.3 Groundwater Discharge .............................................. 16 4.4 Schedule -Post-Operational........................................... 16 4.5 Implementation Schedule ............................................. 16 4.6 Reporting Requirements ................... I .......................... 17 4.7 Waste Disposal.....................................................17 .. 4.8 Public Notification.................................................. 17 4.9 Contingency Plan...................................................17 am o. Toddsbury of Ivy Page iii Corrective Action Plan PC 01-6134 List of Figures Figure 1 - Site location on topographic map ......................................... 2 Figure 2 - 1994 USGS Aerial Photograph ........................................... 3 Figure 3 - Benzene in groundwater Toddsbury of Ivy .................................. 5 Figure 4 - Estimation of Gasoline in Groundwater .................................... 6 Figure 5 - Estimated TPH-GRO Concentration in MW-2 Discharge ..................... 1 I Figure 6 - Zone of Capture after Two Years and Seepage Hose Location .................. 13 List of Tables Table 2. Estimated Radius of Capture per Two -Inch Well .............................. 9 Table 3. Highest Observed Concentrations at Proposed Recovery Wells and Predicted Discharge and Treated Discharge Concentrations ....................................... 9 Table 4. Operation Schedule .................................................... 14 Table 5. Monitoring Schedule ................................................... 15 List of Appendices Appendix A CAP Summary Worksheet Appendix B Public Notice No fts .. Toddsbury of [vy Page I Corrective Action Plan PC 01-6134 1.0 INTRODUCTION Jeffrey A. Sider Environmental Services, Inc., (JAS) was contracted by Charlottesville Oil Company, to prepare a Corrective Action Plan (CAP) for the property known as Toddsbury of Ivy Market located on US Route 250 in Ivy, Virginia, in Albemarle County as shown in Figure 1. Figure 2 is an enlargement of the 1996 USGS aerial photograph for the vicinity of the Site. This CAP has been prepared based on information provided in the Site Characterization Report (SCR) dated January 3, 2002, SCR Addendum (SCRA) dated April 18, 2002, and seven post -SCR monitoring reports. This CAP is designed to address the issues identified in the March 10, 2004 letter addressed to Mr. Mike Jones of Charlottesville Oil Company from Joel P. Maynard, Senior Geologist with the Virginia Department of Environmental Quality's (DEQ) Valley Regional Office in Harrisonburg, Virginia. 1.1 Previous Investigations The following is a summary of the findings for the Site: l . High concentrations of MBTEX are present in the shallow groundwater, emanating from the region of the gasoline tank basin and migrating eastward and discharging into Little Ivy Creek. For the latest monitoring event, benzene was 4,400 µg/l, and MTBE was 3,980 yg/l. 2. Free product has been observed near the source in the form of sheen and drops in MW-2. Based on those observations and the high dissolved concentrations, it is hypothesized that there is a lens of free product located near the tank basin or just down gradient. 3. The onsite water supply well has remained contaminated with a low concentration of MTBE that has hovered around 4.0 Mg/l. 4. In 3.5 years of monitoring, the dissolved concentrations in the source area have not ... diminished appreciably and concentrations have increased down gradient. .M Ow Toddsbury of Ivy Corrective Action Plan PC 01-6134 Page 2 err � �✓ S `; , � - � ��.. } (/ /yJ 622 OWN No aw l . r, f • � �,� A 1 x-� -.i � tea..^—� Ow am A NOW *. Jeffrey A. Sitter - Date: Revised: Figure I - Site location on VAN Environmental Services, Inc. topographic map PO Sax 6038 Drawn by: LRS checked by: Toddsbury of Ivy Charlottesville, VA 22906 (804)974.7080•(804)974-1657(FAX) No am Toddsbury GMR Page 17 Maryland Analytical Chemistry Services ..1 _ Services Services Gi7Baltimore AnalyticalResults 1FOOCatonItimor I}rSu121G �IID 212:? rr 410 :4' 1600 Project: Toddsbury of Ivy TM-r.mrltpeetraLcom 17EL-IP ID 460040 Project Number: N/A ]AS Environmental Services Project Manager: Jeff Sider- P.O. Box 6038 Report Issued: 0 26/13 18:11 Charlottesville VA, 22M CLIENT SAMPLE ID: MW-2 MW-4 MW-6 WW urn LAS SAMPLE ID: 3022102-01 3022102-02 3022102-03 3022102-04 SAMPLE DATE: 02i19113 02A9113 02119113 02119,1113 RECEIVED DATE: 02/21/13 02/21113 02121113 02121(13 MATRIX Unrts Nonpotable Wafter Nonpotable Wafter Nonpoteble Water Potable Water ttw VOLATILE ORGANICS BY EPA METHOD 8021B (Water) Benzene ugfL <;2.0 <.2.0 {2.0 Toluene ug(L <:2.0 <2.0 <2.0 ar Ethylbenzene ug, L <:2.0 <2.0 <2.0 Xylenes, Total ug; L <AC .4.0 <4.0 Methyl tert-butyl ether (MTSE) ug; L <.2.0 2.0 4.9 w ro Unnamed Tributary �� •� j.,» �,_ ...K � .. • is i ... � f < -� - � ' 'M ` '.(11 =�.. Little Ivy Creek t Stream Sa mging Location .. ZD 0 Toddsbury of Ivy Page 4 Corrective Action Plan PC 01-6134 1.2 Estimated Quantities of Contaminant in Each Phase Liquid Phase. There is a hypothesized layer of liquid, or free -phase gasoline floating on the water table. The layer of gasoline may be less than one-fourth inch thick, but probably is thicker than a sheen. The area with free -phase gasoline probably is less than 20 to 30 feet across. In order to create the observed plume of dissolved gasoline, it is estimated that the liquid phase originally contained on the order of 50 gallons of gasoline. This estimate is based on the fact that the release has been losing an estimated 2.0 gallons of gasoline per year (see "Dissolved Phase" section below). Thus, if the release is 20 years old, the source would have involved at least 40 gallons. In the SCR, it was concluded that if the source disappeared, it would take two years for MTBE to flush out of the shallow aquifer. The SCR was published more than two years ago and MTBE is still at a relatively high concentration. However, with the continuous flushing of contamination out of the aquifer, the current liquid phase probably contains on the order of five or ten gallons of gasoline. , Adsorbed Phase. There is a thin unsaturated zone that is about seven feet thick that may have gasoline adsorbed and suspended within the pore space. This adsorbed contamination is limited to the immediate vicinity of the tank basin and to the area of the liquid -phase gasoline. It is estimated that the adsorbed phase contains on the order of five gallons of gasoline. l� Dissolved Phase. There is a plume of contaminated groundwater with an approximate width of 75 feet and a length of 125 feet. The highest TPH-GRO concentration was reported in April of 2003 at 64.2 mg/l (64,200 µg/1). Figure 3 shows the extent of the dissolved plume in the groundwater as dissolved benzene concentration contours. Figure 4 shows the worksheet used to estimate the log average concentration, volume of the plume, and volume of gasoline dissolved in the plume. The gasoline dissolved in the plume is estimated to be 1.3 gallons. An estimate of the volume of gasoline moving through the groundwater each year is estimated using the Darcy groundwater flow equation (q=KAi), where K is the average hydraulic conductivity of 23 feet per day, A is the aquifer cross - sectional area to groundwater flow in the plume of 75 feet wide by 10 feet thick, and i is the average hydraulic gradient of 0.2. dim AW am WO IIIr am wr xr am ili No "Ok Toddsbury of Ivy Page 5 Corrective Action Plan PC 0 1 -6134 M Ell d i % CO 0 3901 7878 7ff7L % W C[3 C13 03 F r % M 103 CC ................... ............ j M Jeffrey A. Sider - Date Revised: Figure 3 - Benzene in Environmental Services, Inc. groundwater PO Box SMS Drawn by: LRS Checked by; Toddsbury of Ivy Charloftesydia, VA 22WS (804)974-70B0- (804)974-1657 (FAX) am ANN MONO Mr aNO VON ". No AW am Mr MOM 01111 am No am WO am Toddsbury of Ivy Corrective Action Plan PC 0 1 -6134 Estimation of the Volume of Dissolved Fuel in Plume Page 6 Parameter Value Unit Maximum Concentration TPH-GRO 64.2 mg/I Log Max Conc 1.81 Minimum Concentration 0.1 mg/I Log Min Conc -1.00 Log Average Conc 2.5 mg/I Area of Plume 9375 feet Thickness of Plume 30 feet Volume of Aquifer 281,250 cubic feet Porosity 0.25 Volume of Plume 525,938 gallon Volume of Contaminant in Plume 1.33 gallon Area of Plume 9,375 square feet Recharge 0.58 feet per year Volume of Recharge 5,469 cubic feet 40,906 gallons Contaminated Water to Recharge 13 hydraulic gradient 0.02 hydraulic conductivity 23 feet per day vertical cross section to flow 750 sq feet groundwater flow volume 345 cfd 125,925 cfy 941,919 gallons gas removed by groundwater flow 2 gallons per year Jeffrey A. Sitter - Date Revised: Figure 4 - Estimation of Gasoline Environmental Services, Inc. — in Groundwater PO Box 6038 Drawn by: LRS Checked by: Charlottesville, VA 22906 (804)974-7080 - (804)974-1657 (FAX) Toddsbury of Ivy Page 7 Corrective Action Plan ., PC 01-6134 At the bottom of Figure 4, these values produce an estimate of two gallons of gasoline moving through the shallow aquifer each year. Thus, there is a source of gasoline that adds two gallons of gasoline per year to the shallow aquifer. The gasoline contamination has been estimated to be distributed amongst the three phases as am summarized in the following table. Based on this analysis, it is apparent that the primary source of contamination has been the free -phase gasoline. Table 1. Distribution of Gasoline Amongst Three Phases. Phase Original Volume in Gallons Current Volume in Gallons Original Percent of Total Free Phase 50 5 81 Adsorbed Phase 10 5 16 Dissolved Phase 2 2 3 Total 62 12 100 1.3 Previous Remedial Efforts No remediation activities have been conducted at the Site. 1.4 CAP Objectives aw This CAP is designed to address the dissolved -phase plume, any free -phase gasoline floating on the water table, and, as a spinoff, the adsorbed -phase gasoline associated with the free -phase gasoline. The following objectives are proposed for the CAP. 1. Develop a zone of capture that will encompass contaminated groundwater in the area of MW-2 and MW-4 to accelerate the removal of free -phase gasoline. 0 Toddsbury of Ivy Page 8 Corrective Action Plan PC 0 1 -6134 2. Reduce the concentration of MTBE in the onsite water well to below the detection limit. The CAP has been prepared in accordance with VR680-13-02 and guidance documents published by the DEQ. Section 2.0 discusses the hydrogeology and remedial design. Section 3.0 details the selected remedial design for the Site. Schedules for operations and monitoring, numerical end points, waste disposal, and reporting requirements are described in Section 4.0. The CAP Summary Worksheet is presented in Appendix A, and a copy of the Public Notice is included in Appendix B. 2.0 REMEDIAL DESIGN The remedial design is for a total fluids pumping system installed in MW-2 and MW-4 that pumps 120 gallons per day. 2.1 Aquifer Characteristics The Site is underlain by 12 to 15 feet of red -brown clayey silt to silt soil with cobbles in the lower depths. It is not known whether the soil represents a saprolite or a reworked floodplain sediment. `" Underlying the soil is indurated bedrock. At MW-2, the depth to the water table has remained close to 7.0 feet below the surface. During drilling of MW-2, hard bedrock was encountered at 15 feet. Thus, the shallow aquifer is eight feet thick in the vicinity of MW-2. The SCR estimate for hydraulic conductivity was between 14 and 32 feet per day. The result of the pumping test on M W-2 indicated a hydraulic conductivity of 1.0 feet per day. Pumping of MW-2 was able to achieve 60 gallons per day. The natural groundwater flow direction is eastward with discharge in Little Ivy Creek. Under natural conditions, the contamination remains in the shallow groundwater, since the area is in the discharge zone with upward flowing groundwater. However, the onsite water well that is completed in the fractured bedrock creates downward flow lines when it is pumping. Even so, there is relatively little contamination in the fractured bedrock due to the fact that the bedrock contains so little pore space, OW on the order of a few percent. Since the free -phase gasoline floats on the water table, no free -phase gasoline will occur in the deeper fractured aquifer. En Toddsbury of Ivy Page 9 Corrective Action Plan PC 01-6134 2.2 Zone of Capture The zone of capture for pumping the two-inch diameter monitoring wells will have the estimated values over time shown in Table 2. These estimates use an aquifer porosity of 20% and a pumping rate of 60 gallons per day. Table 2. Estimated Radius of Capture per Two -Inch Well Time, days Radius, feet Volume pumped, gallons 60 10 3600 180 18 10800 365 26 21900 730 36 43800 2.3 Water Quality Characteristics for Recovered Groundwater Since there is a significant plume of dissolved gasoline near MW-2, it is predicted that MW-2 will produce water having maximum dissolved concentrations that approach those shown in Table 2. These concentrations were observed during the pump test on MW-2 completed in mid-2003. MW-4 •- produces groundwater with somewhat less concentration than MW-2 as shown in Table 2. Table 3. Highest Observed Concentrations at Proposed Recovery Wells and Predicted Discharge and Treated Discharge Concentrations Well TPH-GRO Benzene Toluene Ethyl- Xylenes MTBE No. Mg/1 Mg/1 gg/1 Benzene ug/1 ug/I 'Ug/I MW-2 95,300 4,500 1,950 470 2,780 89,500 MW4 1 3,120 992 42 275 552 6,700 wo Toddsbury of Ivy Page 10 Corrective Action Plan PC 01-6134 The estimation of concentrations in the discharge from the groundwater recovery system has been evaluated by using an analytical solution developed by Jacob Bear. 12 The Bear model, as modified by Silka, assumes that the well is pumping from an isotropic homogeneous aquifer and draws in a "" cylindrical plume of a specified radius and thickness with its center initially at a certain distance from the pumping well. The Bear model also assumes that the source is not continuous. The cylindrical plume can be assigned a thickness of uniform concentration, and the well can draw groundwater from a different aquifer thickness. The Lotus 1-2-3 spreadsheet showing the results of the calculation of the Bear model is presented in the appendix. The input parameters for the Bear model are: 1. Plume uniform concentration of each constituent is estimated as the following log +� average: 1 of Ilog(highest concentration)+log(detection limit),' 2] The highest concentration of TPH-GRO in MW-2 is 90,000 pg/l. The lowest concentration is the detection limit of 100 /,cg/l for TPH-GRO. 2. Plume radius is 50 feet when only MW-2 is pumping and 25 feet when both MW-2 and MW-4 are pumping. 3. Plume thickness is 7.0 feet. 4. Distance from the center of the plume to the onsite well is 25 feet. 5. Aquifer thickness (the saturated length of the water well) is assumed to be 7.0 feet. 6. Specific yield is 0.2. 7. Average pumping rate is 60 gpd per well. 5. Retardation factor is 1.2. This is conservative since 90% of the TPH-GRO is attributable to MTBE and the weighted average retardation factor is 1.1. 6. No biodegradation. 1 Bear, Jacob, 1979, Groundwater Hydraulics, McGraw-Hill, New York, pp. 290-292) 2 Silka, Lyle R., 1987, Predicting Plume Characteristics from Pumping Well Concentrations Using a One -Dimensional Analytical Solution, Proc. of the Conference on Northwestern Groundwater Issues, National Ground Water Association, Dublin, OH, pp. 329-347. n M Toddsbury of Ivy Page 11 Corrective Action Plan PC 01-6134 Figure 5 shows the results of the model prediction for the concentrations in MW-2 when either MW- 2 is the only pumped well or when both MW-2 and MW-4 are pumped together. It is predicted that pumping from both wells accelerates the cleanup of the aquifer by more than a factor of two. This figure assumes that the free -phase gasoline ceases to be a source quickly. lox" 10 L 0 Predicted TPH-GRO in Recovered Groundwater Pumping onlyfrom MW-2 Pumping from MW-2 and MW-4 2 a 0 a 10 12 I ELAPSED TIME ffmm) 1 Jeffrey A. Sitler - Date: Revised: Figure 5 - Estimated TPH-GRO Environmental Services, Inc. Concentration in MW-2 PO Box 6038 Dre.vn by: LRS checked by: Discharge for Two Cases Charlottesville, VA 22906 (8(X)974-7080-(804)974-1657 (FAX) 0 Toddsbury of Ivy Page 12 Corrective Action Plan PC O1-6134 3.0 REMEDIATION SYSTEM DESIGN 3.1 Remediation System Design The remediation system has the following objectives. I. Recover free -phase gasoline from the water table. ll. Prevent further migration of contaminated groundwater. III. Recover dissolved -phase gasoline from groundwater. IV. Reduce dissolved contamination in the onsite water well to below detection limits. 3.2 Water Treatment System Discharge from the recovery system will be pumped to a 300-gallon polytank. The tank will be fitted with a 110-volt aerator that puts out about 7.0 efm through a large air diffuser. With a pumping rate of 120 gallons per day, the residence time in the holding tank will be approximately 24 hours. This system has been found to attain up to 90% removal of volatile organics. The tank will be fitted with a passive drain that will allow water from the bottom of the tank to drain out to a seepage hose. The drain will have an anti -syphon device. As water is pumped into the tank, when the water level in the tank reaches the outflow level of the drain, the water from the bottom of the tank will flow out the tank. In this manner, any free -phase gasoline that is collected in the tank will be trapped within the tank and cannot be discharged. The discharge of the water on the ground will allow natural biodegradation and evaporation to further treat the water. The seepage hose will be moved around to prevent water logging and also to prevent the infiltration of the water to reduce the effective growth of the zone of capture. 3.3 Treated Groundwater Discharge Groundwater from the aerated holding tank will be passively drained to an infiltration hose that will overly the plume of contaminated groundwater. The discharge will be through a 50-foot-long, three - fourth -inch diameter seepage hose. Figure 6 shows the location of the seepage hose along the fence "N line next to MW-2 and MW-4. 717 Toddsbury of ivy Corrective Action Plan PC 01-6134 n Page 13 0 Toddsbury of Ivy Page 14 Corrective Action Plan PC 01-6134 3.4 Pumping Equipment The monitoring wells will be pumped using Weldon air -diaphragm pumps capable of pumping between 1.0 and 10 gpm. The air -diaphragm pumps are driven by compressed air from a small electric air compressor. The air -diaphragm pumps are equipped with Viton diaphragms designed for pumping gasoline. The holding tank, pumps, and air compressor will be mounted on a small trailer behind the fence next to the MW-2 and MW-4. The pumps will have an intake hose run out to each well where a fitting will attach the hose to the two-inch PVC well casing. A riser will be inserted into each well to pump in groundwater from near the bottom of each well to maximize drawdown. The two pumps will be installed inside a weatherproof box on the trailer. Electrical service will be obtained from the existing service in the market by running a contractor -grade 12- AWG UL extension cord from the market to the trailer. 4.0 SYSTEM OPERATION AND MONITORING 4.1 Operation Schedule The operation schedule has been developed to ensure continuous system operation, verify compliance with applicable discharge requirements, and track system efficiency and effectiveness. Table 4 summarizes the operation schedule for the system components to be implemented at the Site. Table 4. Operation Schedule Component Estimated Operation Comments Monitor production for significant Free -phase gasoline and 4.5 years decline and determine necessary groundwater recovery operation change. Monitor operation, replace air Groundwater Treatment 4.5 years compressors as needed. The monitoring schedule is shown in Table 5. Routine monitoring of system performance and compliance with requirements will ensure that the system is operating at optimum effectiveness. M Toddsbury of Ivy Page 15 Corrective Action Plan PC 01-6134 Table 5. Monitoring Schedule Component Estimated Operation Comments Free -phase gasoline Semi-monthly check Record accumulated volume recovery Groundwater recovery Semi-monthly check Confirm flow rates, record total volume pumped Quarterly sampling of Effluent water analysis to include effluent. BTEX + MTBE (8020) and TPH-GRO (8015). Groundwater Treatment Semi-monthly check Check aeration tank for iron or biofouling. Clean out sediment as needed. Check anti -syphon passive drain for proper functioning Quarterly sampling of Water analysis to include BTEX + monitoring wells and MTBE (8020) and TPH-GRO (8015). water supplysHpply wells 4.2 Numerical Remedial End Points The groundwater remediation program is designed to remediate the Site and decrease contaminant concentrations over time. The longer the remediation is conducted, the greater the decrease of contaminants in groundwater. While the MCL for benzene is 5.0 ug/l, the Commonwealth of Virginia has a zero -tolerance policy for gasoline contaminants, especially benzene, in drinking water. However, it is questionable whether zero concentration is achievable within a reasonable time frame and cost. In addition, it is often the case that a remediation system will reach a point of diminishing return when the concentrations will reach a plateau where there are no further decreases in concentration (asymptotic concentration). This plateau occurs when the amount of contaminants being added to the groundwater equals the amount of contaminants being removed by the recovery wells. The sources of the contaminants being added to the groundwater include contaminants adsorbed to the soil particles that are gradually released to the groundwater, and contaminated groundwater caught in less permeable soil or aquifer zones that slowly is released to the groundwater flowing through the higher permeability fractures (this is referred to as "dual porosity"). In addition, concentrations in pumped water may 0 r Toddsbury of Ivy Page 16 Corrective Action Plan Wn PC 0 1 -6134 approach asymptotes, but upon resting, the concentrations may recover again. Thus, the achievable end point for the remediation system is difficult to determine in advance. However, the goal of the remediation system is to achieve the MCLs. _ 4.3 Groundwater Discharge A total of 120 gpd of treated groundwater will be discharged from the system. The discharge of treated groundwater will be made to the seepage hose located over the groundwater plume. Therefore, no direct discharge to surface water will occur from the treatment system, and no discharge permit is required. -- 4.4 Schedule -Post-Operational After the proposed numerical end points have been achieved for six consecutive months, the remediation system will be shut down and taken off-line. Groundwater monitoring will be continued on a quarterly basis for one year following the remediation system shut -down. Groundwater samples from all monitoring wells and previously contaminated water supply wells will be analyzed for BTEX plus MTBE. The remediation system will be reactivated if the numerical end points are exceeded at any time during the post -operational phase. The remediation system will be dismantled after the numerical end points have been achieved for four consecutive quarters. 4.5 Implementation Schedule The main elements of CAP implementation are: mobilization of the system to the site, system start-up and break-in period, monitoring and maintenance, and post -operational monitoring. It is expected that the remediation system can be in operation within 90 days of DEQ authorization. The break-in period is expected to last approximately four weeks. The remediation system is '"� expected to operate for up to 4.5 years. M" Toddsbury of Ivy Corrective Action Plan PC 01-6134 Page 17 4.6 Reporting Requirements Quarterly monitoring reports will be submitted to the DEQ that will include treatment system sampling analysis results, system flow rates and efficiency, and cumulative recovery data for free -phase gasoline and total groundwater pumped. The fourth quarterly report of each year will also be the annual report that will include an evaluation of CAP effectiveness and its progress in achieving the numerical end points. 4.7 Waste Disposal No wastes are anticipated to be developed during CAP construction. During operation, if free - phase gasoline is collected, the RECO Biotechnology vacuum truck will be scheduled as required to remove the gasoline for recycling. 4.8 Public Notification The adjacent landowners will be made aware of the CAP by being provided with a public notice statement. The public notice will not be published in the local paper. A copy of the statement is included in Appendix B. 4.9 Contingency Plan ®p In the event that proposed numerical end points cannot be achieved using the chosen technology, a contingency plan will be activated. The plan will be based on site -specific conditions and may am include actions such as installing additional recovery points or changing recovery rates through flow and pumping schedule adjustments. The remediation system components including pump +.w and air stripping system have been oversized to provide at least a 100 percent increase in designed flow requirements. This expansion capability should enable the system to comply with the contingency requirements. M APPENDIX A CAP Summary Worksheet n 0 CAP Summary Worksheet Proposed Post Oper. Close Proposed Proposed Monitoring to Achieve Endpoints Monitoring Site Phase of Cleanup System or Contamination Endpoints Shutdown Reactivate System Sampling Schedule to Schedule to Sampling Post Oper. Sampling Frequency Method of Achieve Maintain Frequency Monitoring Location & Type Analysis Endpoints End pints & Type Schedule 0.01 ft MW-2 Quarterly, NA NA NA Quarterly, 12 months Free Product - for 6 months MW-4 probe and grab Gasoline if encountered bailer Dissolved Asymptotic MW-1 Quarterly, BTEX/MTBE 4.5 years 6 months Quarterly, 12 months Product Endpoints M W-2 grab by EPA 8020 grab in GW - M W-3 TPH-GRO BTEX & MTBE MW-4 by TPH-GRO Stream EPA 8015 WS For VDEQ Use: Comments: Reviewed by: Date: 0 APPENDIX B Public Notice cm PUBLIC NOTICE PROPOSAL TO CLEANUP AN UNDERGROUND STORAGE TANK (UST) SITE Released June 10, 2004 There has been a release of petroleum from an underground storage tank system at: Toddsbury of Ivy Market Rt 250 West Ivy, VA Albemarle County The Department of Environmental Quality (DEQ) is requiring Charlottesville Oil Company, the owner of the underground storage tanks that were involved in the release, to develop a Corrective Action Plan to address cleanup of gasoline contamination at the Site. The corrective action will consist of the pumping and treatment of contaminated groundwater. If you have any questions regarding the cleanup, please contact: Lyle R. Silka Jeffrey A. Sitler Environmental Services Inc. PO Box 6038 Charlottesville, VA 22906 (703)216-2490 The Corrective Action Plan was submitted to the Valley Regional Office of the DEQ on June 10, 2004. If you would like to review or discuss the proposed Corrective Action Plan with the staff of the DEQ, please feel free to contact Mr. Joel P. Maynard (540)574-7800. The DEQ Valley Regional Office will consider written comments regarding the proposed Corrective Action Plan until July 31, 2004 and may decide to hold a public meeting if there is significant public interest. Written comments should be sent to the DEQ at the address listed below. The DEQ requests that all written comments reference the tracking number for this case; PC# 01-6134. Joel P. Maynard Storage Tank Program o Department of Environmental Quality PO Box 3000 Harrisonburg, VA 22801 CAPI Monitoring Report CAPI Subphase No. 24 Toddsbury of Ivy 4297 Ivy Road Ivy, Virginia 22945 Albemarle County .. PC 2001-6134 FAC ID # (for DEQ use) Submitted to: David A. Fitt Valley Regional Office Department of Environmental Quality PO Box 3000 •• Harrisonburg, VA 22801 (540)574-7800 Prepared for: Charlottesville Oil Company w. PO Box 6340 Charlottesville, Virginia 22906 (434)293-9107 am Prepared by: Jeffrey A. Sitler Environmental Service, Inc. PO Box 6038 Charlottesville, Virginia 22906 (434)974-7080 fax (434)974-1657 February 28, 2013 w" ,, Jeffrey A. Sitter - Environmental Services, Inc. PO Box 6038 Charlottesville, VA 22906 em (434)974-7080 Fax (434)974-1657 February 28, 2013 David A. Fitt Department of Environmental Quality Now PO Box 3000 Harrisonburg, VA 22801 RE: Toddsbury of Ivy CAPI Subphase No. 24 Quarterly Groundwater Monitoring Report PC 01-6134 Dear David: No This report is for the latest quarterly monitoring event completed at the subject Site and covers the O&M period from December 16, 2012 to February 28, 2013. Figure 1 shows the topographic ,V map with the Site location indicated. Groundwater Monitoring. On February 19, 2013, Brian Silka went to the Site to complete quarterly sampling. Monitoring wells MW-1 through MW-4 were opened and the depth to water measured. The water -table elevation worksheet is included in Appendix A. For this event, only ., MW-2, 4, 6 were sampled. The groundwater samples were analyzed for benzene, toluene, ethylbenzene, xylenes, naphthalene, and MTBE by EPA Method 8021B. Usually, the analysis has been limited to MBTEX, but naphthalene was inadvertently left on the chain of custody form. The water well was sampled and analyzed for volatile organics by EPA Method 8260B. Table 1, at the end of this report, presents a summary of all groundwater analyses to date. The lab report for this quarterly sampling event is presented in Appendix B. Figure 2 shows the water -table contours for this event. Overall, the interpreted groundwater flow direction has not changed significantly since the beginning of investigations at the Site in 2001. Last fall, only the recovery well MW-6 had any MBTEX contamination with BEXM. For this quarter, MW-6 had only MTBE at 4.9 µg/l. For this quarter, MW-4 had 2.0 µg/1 MTBE. MW-2 1"` was free of detectable MBTEX. Only a figure for the extent of dissolved MTBE is presented (Figure 3). M AM Toddsbury GMR Page 3 Source Area Recovery The four -inch diameter MW-6 is an 80-foot deep recovery well located about 10 feet east of MW-2. MW-6 pumps from the depth interval 10 to 80 feet. Thus, it pumps from both the shallow zone above the bedrock surface (at 13 feet of depth at MW-6) and the deeper fractured bedrock zone. MW-6 began pumping on June 1, 2009. "0 ITI CD N CD CD CD c o' 0 CD CD H 0 0 1� Todclsbur-yWaterTable Elevation Contours u� �saso �- 1 t 0 on { P11h�4 � f JQ--. • 52 11 %nlc T 1'&Mrinet................` y f r,VV-z{ YVicer I 530 rr 524 '! 528 527 r — N ey - r� r �htrlstAid irf6u Q 25 r� Todd-sbury GMR Page 5 M j2 a A WIM Pigure 3. Extent of dissolved MTBE in the groundwater for this event. Toddsbury GMR Page 6 Concentration Trends MW-2/MW-5. The shallow groundwater from MW-2 had the highest concentrations historically, with MTBE at 56,400 µg/l and benzene at 11,500 µg/1 in 2001 and 2002. Even with the historically high concentrations in MW-2, measurable free product has not been observed, and a sheen was seen only once in 2005. After a period of two years with MTBE at between 10 and 20 µg/l, MTBE has not been detected for the last two quarters. Toddsbury of Ivy MTBE and Benzene Versus Time in MW,21MWs 100000 10000 c o� 1000 c 0 a+ R C v 100 C O U 10 1 Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Dec-06 Dec-07 Dec-00 Dec-09 Dec-10 Dec-11 Dec-12 Dec-13 r igure 4. MTBE and benzene concentrations versus time in MW-2/MW-5. Now KM Toddsbury GMR Page 7 Down gradient (MW-4). Down gradient of the source area at MW-4, MTBE has been following an overall decreasing trend since 2003, even before remediation began, as shown in the graph in Figure 5. This may be related to groundwater migrating eastward through MW-4. However, since MW-6 began pumping, MTBE in MW-4 increased for a short period, then began a steep downward trend. MTBE was not detected for the summer and fall events, but was 2.0 µg/l for this event. The BTEX compounds have been virtually absent from MW-4 since early 2010. Toddsbury of Ivy Benzene & MTBE Versus Time at MW-4 10000 1000 8. e 0 •R 1 00 a c 0 U 10 Benzene Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Dec-06 Dec-07 Dec-08 Dec-09 Dec-10 Dec-11 Dec-12 Dec-13 rigure 5. Benzene and MTBE versus time at MW-4. Toddsbury GMR Page 8 Stream Bank. The groundwater quality at the stream bank was below detection from August w. 2008 through November of 2010 (the last sample analyzed). Fi pgore 6 shows the change in MTBE concentration in the stream bank sample over time. The stream bank groundwater, and, ®� by association, the stream, are no longer at risk from contaminated groundwater. 1000 1 Toddsbury of lay MTBE WPM Time at Stream Bank MTBE Dec-01 Dec-03 Dec-05 Dec-07 Dec-09 Dec-11 r igure d. ivi 1 bh concentration versus time at the Stream Bank. Toddsbury GMR Page 9 MW-6. The trends for MTBE and benzene in the recovery well, MW-6, are shown in Figure 7. MTBE showed a relatively consistent decrease over time from the startup of MW-6. 10000 1 L-- Dec-07 Toddsbury of Ivy Benzene & MTBE Versus Time at Recovery Well MW-6 MW-6 Startup MTBE Benzene Dec-08 Dec-09 Dec-10 Dec-11 Dec-12 Figure 7. Benzene and MTBE versus time at MW-6. MTBE and benzene have had three peaks since startup of MW-6 pumping. All three peaks have occurred in the January 2010, February 2011, and May 2012 for benzene, while the peaks for MTBE have been in April 2010, and May of 2011 and 2012. These peaks coincide with the normal groundwater recharge season. Since one of the gasoline USTs was left in the ground, because it was under the building, the annual recharge events may be causing residual gasoline from in and around that remaining gasoline UST to be flushed into the groundwater. Toddsbury GMR Page 10 Onsite Water Well. The well water samples had been less than 2.0 µg/l from November of 2009, and less than 1.0 µg/1 for eight out of the nine quarters and the last six straight leading to aw May of 2012. As with the spikes in MTBE witnessed in MW-2, 4 and 6, the well water had a small spike in August of 3.7 µg/l. MTBE was not detected in the water well for the last two OM events. �] Toddsbury of Ivy MTBE Versus Time in Water Well 50 MW_s 40 Startup c 30 e 0 •R V M n 20 C O U 10 NEW MTBE D Dec-01 Dec-02 Dec-03 Dec-04 Dec-05 Dec-06 Dec-07 Dec-00 Dec-09 Dec-10 Dec-11 Dec-12 Dec-13 rigure zs. M 1 BL versus time in the onsite water well. MTBE cleanup is predicted to be much quicker after MW-6 startup than before. 0 Toddsbury GMR Page 11 CAPI Performance. The well water was virtually clean from January of 2010 through February of 2012. Now that the spike of 2012 appears to have passed through, the well water is expected to remain clean. . NM Figure 9 shows the comparison of the current plume interpretation to the historical "highest" MTBE plume. With MTBE detected only in MW-6, the MTBE plume is reduced to the immediate area around MW-6. low Conclusions and Recommendations. The pumping of MW-6 has reduced the MTBE to a low ,ftp concentration and may have reduced BTEX to undetectable levels. The next sampling event in May may confirm whether another spike in MTBE or other contaminant occurs as a result of the seasonal groundwater recharge. Please do not hesitate to contact me if I can be of further service in this matter. Sincerely, 1� Lye R. Silka, CPG enclosures 0 FE Toddsbury GMR Page 12 Toddsbury - Highest MTBE in Groundwater Ever UftM. • <2 _ _._. BDL j \ 100 I 1000 0 10000 / b • 670D� f 440 1 rVY •MW-2 j 10000 '� •� MW-11000... .. i BDL— Q sods UP Stream _ _ 0 25ft Toddsbury - Current MTBE in Groundwater MN�3 • ,2 L7 M a b DV ... To"*Wya(NyMtiW 2 4Mt uwe wy C"* a a) <2 � ` I TWO, l Sala up S"M ' 0 k Q (1) r Figure 9. Comparison of the MTBE plume based on the highest concentrations ever observed (top) to the current MTBE plume (bottom). w Toddsbury GMR Page 13 APPENDIX A WATER TABLE DATA WORKSHEET LABORATORY REPORT 0 Toddsbury GMR Page 14 WATER TABLE DATA WORKSHEET Toddsbury of Ivy - Monitoring Well Data MW-1 MW-2 MW-3 Stream MW-4 MW-5 MW6 Installation Date 110/2001 11/2812001 11/28/2001 02112/2002 09106/2005 12/2912008 Heigth of Scope above TOG; ft Height of Scope at Rod, ft 4.23 3.90 3.42 12.66 5.00 5.57 Total depth of well, ft 15.00 15.00 12 00 20.00 16.00 80.00 Elevation of TOG Relative Local Datum, ft 535.00 535.33 535.81 526.57 534.76 Elevation of Water Table, ft 531.04 528.42 531Al 526.57 527.77 ... Water Table Depth below TOG,11111110, ft 5.83 6.10 6.97 9.52 Elevation of Water Table, ft 529.17 528.62 528.84 526.57 525.24 8.21 Water Table Depth below TOG, 2124111, ft 5.68 6.33 6.82 9.17 Elevation of Water Table, ft 529.32 528.39 528.99 526.57 525.59 Pumping 4W Water Table Depth below TOG, 5/1oil 1, ft 4.44 7.81 5.49 7.98 Elevation of Water Table, ft 530.56 626.91 530.32 526.57 526.78 Pumping Water Table Depth below TOG, 8/17111, ft 4.01 5.96 5.20 9.68 Elevation of Water Table, ft �.. 530.99 52V6 530.61 526.57 525.08 Pumping Water Table Depth below TOG, 11/21111; ft 4.11 5.66 5.00 9.41 Elevation of Water Table, It 530.89 529.06 530.81 526.57 525.35 Pumping Water Table Depth below TOG, 2113/12, ft 4.78 5.22 5.79 8.12 Elevation of Water Table, It 530.22 529.50 530.02 526.57 526.64 Pumping Water Table Depth below TOG, 5123112, ft 5.53 8.20 6.56 8.93 Elevation of Water Table, ft 529.47 526.52 529.25 526.57 525.83 Pumping Water Table Depth below TOG, 8127112, ft 6.25 8.90 7.21 9.59 Elevation of Water Table, ft 528.75 525.82 528.60 526.57 525.17 Pumping Water Table Depth below TOG,12/4/12, ft 5.83 8.49 6.85 9.14 Elevation of Water Table, ft 529.17 526.23 528.96 526.57 525.62 Pumping Water Table Depth below TOG, 2119113, ft ... 4.92 7.25 5.99 8.65 Elevation of Water Table, It 530.08 527.47 529.83 526.57 526.11 Pumping +.. C- MW r.r Toddsbury GMR Page 15 Maryland Ana[yical Chemistry Services ..e Services Analytical Results 1-00Caton center nrSetweG Baltimore 31D 21:17 Projec6 Toddsbury of Ivy 410.247 4600 xmcndspectm1cam �" Project Number: N/A iELAP M 4 0U0 3A5 Enwiionmentl Services Pr*rt Mar>ager: 3eff SMer P.O. Box 6038 Reportlssuedt 02/26/13 19:11 titarlattesvilk- VA, 22906 aw CLIEHT9AMPLEID. Flt"f-2 K -4 W-6 VAV LAB SAMPLE ID: 3022102-01 3022102-02 3022102-03 30222102-04 SAMPLE DATE: O2/14r13 02/191i3 02419f13 02/19?7.3 RECEIVED DATE: OV21/13 02/21JA 02f21J13 02/21V13 Y1y MATRIX Units Nonxteble Water KvWteble Weer Nonpatable water Potable Vlater VOLATILE ORGANICS BY EPA METHOD 8260B (GC/MS) (Water) Aoftre t>/L tert An4 alCOW (TAA) 4L <10.0 am le t-Arryl met rf 1 et+- (TAME) <20.0 Benzene u; Jl ugX <5.0R,arrobenzene &'[flgcftt�tnrret;;en? ?L ue <5,0 ➢iaa Br't3rtlrldE:lllar�Gmethd'1e f tts. L <5.4 B mgFa mL <5.00 ugJL <5.0Brtrmmetr'at� Boanol (TBA) ujJL <5.0tent ar 2-Qrtatow- (PR) LgIL <13.0 nBrtylbauene n,,L <10.0 .50 Z. Sutflae r<ene ugJL tett Btrylbe¢ene 4L rw'r Carbon dsulfide t,?L <5,0 Cethontetrachlaide usfL <:5.0 CNom�er¢ene u2,+1 <5.0 Chloroahane ug?L <5,4 <5,0 Now CJowa n Gnlotvmethere u;JL 2-Chlo,oro -A <5.0 <5.0luwx 4-Chlo,otoluene 4L w Di6tomodibromethane �+1 <:5.0 1,2-Dibtamo-3-6loropopane ;?L <5.0 <5,4 1,2-DibiDmDethane(EDB) uq?L Dibromoro-thete Lg1 <5.0 'r. 1,2-Didtlwobenzere u2. L <5.0 13-Dichlorobe-eene tr,?L <5.0<5.0 1,4-0icHorobenze-e tr?L Dichlorodifl,,ommtha-re a+L <5.0 <3.0 Aw 1.I-Didtivicet�wrre t�1L 1,2-Diddaoet an- tnr,l <5.0 1. WYcli oroetirzre aJl <3.0 ds•1.20chlxrethene ugJL <,5.0 t,0 ansl,2-Dichlo oetfr_ne t �dL `S ,ter 0ichlorcfluunnte$wne Kk <5.0 <:5.0 7 "W 0 Toddsbury GMR Page 16 Maryland Analytical Chemistry Services S(Drvices Analytical Results HOD CatoaLmmteG 9allimerert IMID 21227, Project: Toddsbury of Ivy 416-2r-7600 wmsmdspedraLcom wr Project Number; NIA ]AS Ehvltrmmerttal Setuices TTUP ID 1660l0 Project hlanaget; )eff Sider P.D. eox 6035 Reoott Lnuedr 02126I1310:11 Charlattesville VA, 22906 CLIENT SAMPLE ID: W-2 KOWA 14W-6 W.V LAB SAMPLE M. 3022102-01 3D32102-02 3422102-03 3D22102-D4 SAMPLE DATE: 02114;13 4t? IVO 0191'_3 0214?"l RECEIVED DATE: 0$r21A3 0� J21J_3 02/21i0 (P,12iJ13 rrt MATRUC Urns l bnpaeble Water honpDmNe Meter Wnp calve W"— Potable Warer VOLATILE ORGANICS BY EPA METHOD 82608 (GC/MS) (owdinued) 1,24)ichlo-opropane uj?L 13achloroptopane u;?L <SA �.0 2,2achlompropane ug?L <:a.0 1.1-DichloTpropme ugiL <:5.0 ds-1,3-DichbWropere tr,JL <.5,0 trarr,1.3-Dichlomprapene tr?L AM Diisoaopyiether (DIPE) upA <5.0 Ethyl tertbugd ether (EiEE) tr;,+L <3.0 EthAbetzete ug?L <:5,0 Hexachloo'tutndie a tr?L <5,0 rr, 2-Heunose u;JL <10.4 Isop-oWlbe-xert-_ (Curren-) LgA <:5,0 4-Isop'opyita ene ua?L <:5.0 Methyl te.-b:Ryl ether (WU) u;/L <:5.0 •"w 4•Medtyi-2•pente•rone ug?L <10.0 Meth*ne chbaide uiJL <10.0 Naphdulene- W.-IL <5,0 n-Prop*d enzene u3JL <5.0 ow Styrene tr?L <i,4 1,U2-Teaechiaoetha-r tq+L <10 1,1.2.2-Teuachbvethdro LS?L <5.0 Teodchlo,cethene WX <5,0 am' Toluene tr,•JL <3.0 U,-Trr--dxobenzane u; L <S.0 1,2 4 Tric ,lacbenz ne tJL <5.0 1,1,1 T ic�daoethere UCA <5,0 Wo 1,1.2-T1chbvedrd-e LVIL <5.0 Tr¢hbnriMne LrtL <:5.0 TrichImkoranvthane (RBtn IS) Lq,`L <5,0 1143-Trkhlaop opane u;JL <5.0 rwt 1.24-Trimeth}ibe-we w L <5.0 1,3,5-Trimethylberae-c uy?L <;5.0 vilyl chlo�xe u;JL <.5,0 o-Xyierr- W.L <:5,0 a+r m- & p-Xyletes ugJL <5.0 M= Toddsbury GMR Page 18 IN= .41;T i cm C2.1 o tu to m i Ia3' Via, 10, Ell, 'C, 11 14 C'A k �w Toddsbury GMR Page 19 0 r APPENDIX B ANALYTICAL DATA SUMMARY Toddsbury GMR Page 20 Groundwater Analytical Results Well Date TPH-GRO Benzene Toluene Ethyl- Xylenes MTBE No. Sampled µg/l µg/1 µg/l Benzene µg/l µg/l µg/l MW-1 11/29/01 BDL BDL BDL BDL BDL 18 06/26/02 BDL BDL BDL BDL BDL BDL 09/19/02 BDL BDL BDL BDL BDL 22 01/09/03 BDL BDL BDL BDL BDL BDL 04/09/03 BDL BDL BDL BDL BDL BDL 07/24/03 BDL BDL BDL BDL BDL BDL 10/23/03 BDL BDL BDL BDL BDL BDL 02/05/04 BDL BDL BDL BDL BDL BDL 09/06/05 BDL BDL BDL BDL BDL BDL 12/27/05 BDL BDL BDL BDL BDL BDL 04/26/06 BDL BDL BDL BDL BDL BDL 06/27/06 BDL BDL BDL BDL BDL BDL 10/09/06 ND BDL BDL BDL BDL BDL 12/27/06 ND BDL BDL BDL BDL BDL 03/07/07 ND BDL BDL BDL BDL BDL 05/29/07 ND BDL BDL BDL BDL BDL 08/09/07 ND BDL BDL BDL BDL BDL 12/04/07 ND BDL BDL BDL BDL BDL 02/18/08 ND BDL BDL BDL BDL BDL 05/07/08 ND BDL BDL BDL BDL BDL 08/15/08 ND BDL BDL BDL BDL BDL 12/29/08 ND BDL BDL BDL BDL BDL 04/04/09 ND BDL BDL BDL BDL BDL 06/19/09 ND BDL BDL BDL BDL BDL 09/29/09 ND BDL BDL BDL BDL BDL 01/20/10 ND BDL BDL BDL BDL BDL 04/15/10 ND BDL BDL BDL BDL BDL 07/21/10 ND BDL BDL BDL BDL BDL 11/11/10 ND BDL BDL BDL BDL BDL +r Toddsbury GMR Page 21 Well Date No. Sampled 4~ MW-2 11/29/01 06/26/02 .w 09/19/02 O1/09/03 04/09/03 07/16/03 10/23/03 02/05/04 09/06/05 12/27/05 04/26/06 06/27/06 10/09/06 12/27/06 r` 03/07/07 05/29/07 08/09/07 low 12/04/07 02/18/08 02/24/08 05/07/08 08/15/08 04/04/09 06/19/09 01/20/10 04/15/10 07/21/10 11/11/10 02/24/11 05/16/11 08/17/11 11/21/11 02/13/12 05/23/12 08/27/12 12/04/12 02/19/13 TPH-GRO Benzene Toluene Ethyl- Xylenes MTBE µgn µgn µgn Benzene It µgn µgn BDL 1,480 1,420 BDL 900 56,400 57,100 11,500 18,200 2,580 10,700 18,900 38,500 9,600 8,000 2,130 9,120 16,600 56,500 8,800 17,000 3,040 14,000 5,600 64,200 7,140 19,000 3,070 15,300 1,790 9,950 2,170 1,950 470 1,750 22,400 32,300 4,080 11,200 1,660 7,480 7,000 31,600 4,400 8,560 2,020 7,560 3,980 40,200 3,300 5,280 3,210 14,600 723 16,800 1,770 1,710 1,250 5,430 497 5,750 775 850 415 2,060 305 ND 175 BDL BDL BDL 17,800 ND BDL BDL BDL BDL 144 ND 267 508 288 1,090 112 ND BDL BDL BDL BDL BDL ND BDL BDL BDL BDL 5,630 ND 110 BDL 60 168 7,760 ND BDL BDL BDL BDL BDL ND BDL BDL BDL BDL 5,980 ND 458 118 261 725 2,320 ND ND ND ND ND ND ND BDL BDL BDL BDL 4,470 ND 112 26 90 222 79 ND 3.2 7.2 5.2 26 543 ND BDL BDL BDL BDL 3.3 ND BDL 3.8 3.6 14 BDL ND BDL BDL BDL BDL BDL ND BDL BDL BDL BDL 9.3 ND BDL BDL BDL BDL BDL ND BDL BDL BDL BDL 17 ND BDL BDL BDL BDL 11 ND BDL BDL BDL BDL 18 ND BDL BDL BDL BDL 12 ND 6.7 7.9 BDL 5.7 16.4 ND BDL BDL 10 BDL 18.5 ND BDL BDL BDL BDL BDL ND BDL BDL BDL BDL BDL Toddsbury GMR Page 22 Well7jDate— SamplNo. MW-3 11/29/01 06/26/02 09/19/02 O1/09/03 04/09/03 07/24/03 10/23/03 02/05/04 09/06/05 12/27/05 04/26/06 06/27/06 10/09/06 12/27/06 03/07/07 05/29/07 08/09/07 12/04/07 02/18/08 05/07/08 08/15/08 12/29/08 04/04/09 06/19/09 09/29/09 O1/20/10 04/15/10 07/21/10 11/11/10 TPH-GRO Benzene µg/l µg/l BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 103 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL ND BDL Toluene µg/] BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL Ethyl - Benzene µgn BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL Xylenes µgn BDL BDL BDL BDL BDL 6.3 BDL BDL BDL BDL BDL BDL BDL 4.4 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL MTBE µg/l 18 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL Am MAO 7 Toddsbury GMR Page 23 Well Date No. Sampled MW-4 03/14/02 06/26/02 09/19/02 01/09/03 04/09/03 07/24/03 10/23/03 02/05/04 09/06/05 12/27/05 04/26/06 06/27/06 10/09/06 12/27/06 03/07/07 05/29/07 08/09/07 12/04/07 02/18/08 05/07/08 08/15/08 12/29/08 04/04/09 06/19/09 09/29/09 O1/20/10 04/15/10 07/21/10 11/11/10 02/24/11 05/16/11 08/17/11 11/21/11 02/13/12 05/23/12 08/27/12 12/04/12 02/19/13 TPH-GRO µgn Benzene µgn Toluene µgn Ethyl- Benzene µgn Xylenes µgn BDL BDL BDL BDL BDL BDL 30 BDL BDL BDL BDL BDL BDL BDL BDL 1,120 320 20 42 98 2,280 76 6.2 7.6 21 3,120 929 42 275 552 BDL 675 BDL 167 122 2,200 992 BDL 124 BDL 282 BDL BDL BDL BDL 2,110 116 46 41 315 466 6.4 4 4 21 ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND 199 313 139 449 ND 187 34 81 336 ND 146 BDL BDL 55 ND BDL BDL 2.9 BDL ND BDL BDL BDL 14 ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL 2.6 BDL ND BDL BDL 2.5 BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND 1.0 BDL BDL 5.7 ND 40 26 229 337 ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL 15 6 ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL ND BDL BDL BDL BDL MTBE µg/1 662 1,730 1,330 758 142 4,950 4,670 6,700 534 1,940 562 260 47 439 848 1,520 185 63 76 77 66 22 24 9.4 11 12 16 9.5 1.9 5.2 BDL BDL 6 9 3.4 BDL BDL 2.0 Toddsbury GMR Page 24 Well Date TPH-GRO Benzene Toluene Ethyl- XH No. Sampled µg/l µg/l µg/l Benzene µgQMW-5 09/06/05 32,800 1,150 8,680 1,610 24,700 1,470 8,520 1,180 ,99012/27/05 73004/26/06 6,560 366 1,770 362 13002/18/08 BDL BDL BDL BDL 950MW-6 12/29/08 ND 99 1,420 1,880 53004/04/09 ND 21 356 723 DL06/19/09 ND BDL 14 5.4 298 09/29/09 ND 11 26 79 189 92 01/20/10 ND 23 27 73 206 56 04/15/10 � 9.4 9.1 44 101 58 07/21/10 ND 3.9 4.6 55 91 11/11/10 ND 1.6 2.2 24 36 34 02/24/11 ND 11 4 20 37 12 05/16/11 ND BDL BDL BDL 18 22 08/17/11 ND 11 BDL 19 24 33 11/21/11 ND 5 BDL 13 32 27 02/13/12 � 15 BDL 17 23 13 05/23/12 ND 63 7.3 74 89 22 08/27/12 ND 16.3 BDL 31.3 30.5 27 11.4 12/04/12 ND 4 BDL BDL BDL 6.5 02/19/13 ND BDL BDL BDL BDL 4.9 Discharge 06/19/09 ND BDL BDL 5 4 to Trench 09/29/09 ND BDL BDL DL BDL BDL 3.2 01/20/10 ND 3.4 2.9 BDL 15 12 04/15/10 � BDL BDL 2.1 5.1 18 07/21/10 ND BDL BDL BDL BDL 15 7.8 11/11/10 � 1.2 BDL 11 29 15 Toddsbuiy GMR Page 25 Well Date No. Sampled Onsite 11/29/01 Water 01/31/02 ..r Well 09/20/02 O1/09/03 04/09/03 07/24/03c 10/23/03 02/05/04 ,w 09/06/05 12/27/05 04/26/06 06/27/06 10/09/06 12/27/06 03/07/07 05/29/07 08/09/07 11 /15/07c 12/04/07 02/18/08 .. 05/07/08 05/15/08c 08/15/08 11/15/08 12/29/08 04/04/09 ` 05/04/09c 06/19/09 11/18/09c 01/20/10 04/15/10 05/25/10c "" 11/11/10 02/24/11 05/16/11 05/24/11 08/17/11 08/23/11 we 11/21/11 02/03/12 08/27/12 08/27/12 12/04/12 02/19/13 TPH-( Benzene Toluene Ethyl- Xylenes MTBE µg µb/, lib/, Benzene µg/, µg/, µg/, BDL BDL BDL BDL 3.3 j BDL BDL BDL BDL 2.3 j BDL BDL BDL BDL 6.9 BDL BDL BDL BDL 4.0 BDL BDL BDL BDL 4.4 BDL BDL BDL BDL 4.0 BDL BDL BDL BDL 4.0 BDL BDL BDL BDL BDL BDL BDL BDL BDL 45.0 BDL BDL BDL BDL 14.0 BDL BDL BDL BDL 14.0 BDL BDL BDL BDL 35 BDL BDL BDL BDL 17.0 BDL BDL BDL BDL 6.7 BDL BDL BDL BDL 5.9 BDL BDL BDL BDL 18.0 BDL BDL BDL BDL 25.0 BDL BDL BDL BDL 9.5 BDL BDL BDL BDL 13 BDL BDL BDL BDL 10 BDL BDL BDL BDL 68 BDL BDL BDL BDL 7.9 BDL BDL BDL BDL 13 BDL BDL BDL BDL BDL BDL BDL BDL .0 7 BDL BDL 5 16 .3 2.6 BDL BDL BDL BDL 3.9 B BDL BDL BDL BDL BDL BDL BDL BDL 1.3 1.7 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 1.2 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 0.9 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL 4.9 BDL 1.7 BDL 3.4 3.3 BDL 1.0 BDL 3.7 BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL am Toddsbury GMR Page 26 Well Date TPH-GRO Benzene Toluene Ethyl- Xylenes MTBE No. Sampled µg/l µg/l 99/1 Benzene µgQ µg n µgn Up 11/29/O1 BDL BDL BDL BDL BDL BDL Stream BDL BDL BDL BDL BDL Down 11/29/O1 BDL Stream BDL BDL BDL BDL 5 Bank 04/09/03 BDL 10/23/03 BDL BDL BDL BDL BDL BDL 02/05/04 BDL BDL BDL BDL BDL 278 09/06/05 100 BDL BDL BDL BDL 112 112 12/27/05 BDL BDL BDL BDL BDL 440 04/26/06 BDL BDL BDL BDL BDL 313 313 06/27/06 ND BDL BDL BDL BDL 134 10/09/06 ND BDL BDL BDL BDL 20 12/27/06 ND BDL BDL BDL BDL BDL 03/07/07 ND BDL BDL BDL BDL BDL 05/29/07 ND BDL BDL BDL BDL BDL 08/09/07 ND BDL BDL BDL BDL BDL 12/04/07 ND BDL BDL BDL BDL 5.8 02/18/08 ND BDL; BDL BDL 5.8 2.5 05/07/08 ND BDL BDL BDL BDL 13 08/15/08 ND BDL BDL BDL BDL BDL 12/29/08 ND BDL BDL BDL BDL BDL 04/04/09 ND BDL BDL BDL BDL BDL 06/19/09 ND BDL BDL BDL BDL BDL 09/29/09 ND BDL BDL BDL BDL BDL 01/20/10 ND BDL BDL BDL BDL BDL 04/15/10 ND BDL BDL BDL BDL BDL 07/21/10 ND BDL BDL BDL BDL BDL 11/11/10 ND BDL BDL BDL BDL BDL Rt 250 03/14/02 BDL BDL BDL BDL BDL BDL Bridge 06/26/02 BDL BDL BDL BDL BDL 09/19/02 BDL BDL BDL BDL BDL BDL BDL O1/09/03 BDL BDL BDL BDL BDL BDL Notes: ND- Not Determined BDL- Below Detection Limit µ9/1- Micrograms per liter j-Estimated value LPH- Liquid Petroleum Hydrocarbon NA- Not applicable c- Culligan raw, untreated drinking water RECEIVED F73 1 8 7 "' COMMUNITY DEVELOPMENT cz a" am �.z