section 1.0 1.0 site description and physical settingwell was not installed adjacent to mw-5 on the...

January 26, 2011 Mr. Chip Castle Executive Director Barre Housing Authority 4 Humbert Street Barre, Vermont 05641 Re: Supplemental Site Investigation Report Washington Street Apartments

14 Washington Street Barre, Vermont 05641 (SMS Site #93-1437) (Site or Property)

Dear Mr. Castle: Stone Environmental, Inc. (Stone) is pleased to submit this Supplemental Site Investigation Report which documents additional environmental activities completed at the above-referenced Site (Figures 1 and 2). Work was completed in accordance with the work plan and cost estimate dated March 7, 2010, which was prepared by Applied GeoSolutions, LLC (AGS), and subsequently approved by Mr. Matt Moran of the Vermont Department of Environmental Conservation (VT DEC) Waste Management Division (WMD). The overall purpose of the SSI was to further characterize the source(s), magnitude, and extent of petroleum-related constituents previously identified at the Site, and to better evaluate the impact and risk to sensitive receptors. This report is organized in the following manner:

Section 1.0 describes the Site location and physical setting; Section 2.0 provides background information on the Site; Section 3.0 discusses the work completed during this SSI; Section 4.0 presents the results of the investigation; Section 5.0 discusses an updated conceptual site model; and Section 6.0 provides conclusions and recommendations.

1.0 SITE DESCRIPTION AND PHYSICAL SETTING The Site is located in a mixed commercial/residential setting at 14 Washington Street in Barre, Vermont (Figures 1 and 2). The Property is bound to the north by Jefferson Street, to the east by the First Baptist Church, to the south by Washington Street, and to the west by the Aldrich Public Library. An apartment complex, with a footprint of about 8,400 ± ft2, is located on the Property. The balance of the Property is comprised primarily of asphalt and concrete surfaces. The building, and surrounding properties, is served by the municipal water and sewer. The Property is currently owned by the Barre Housing Authority. Prior to serving as an apartment complex, the on-Site building functioned as a hotel.

Mr. Chip Castle - 2 - January 26, 2011 The topography at the Site is generally flat. The nearest surface water body is the Stevens Branch of the Winooski River, which is located about 750 feet southeast of the Site at its closest point. 2.0 BACKGROUND Petroleum contamination was discovered at the Site in 1993 during the removal of a #2 heating oil underground storage tank (UST), which was located along the east side of the building. K-D Associates, Inc. completed subsequent investigations to determine the magnitude and extent of petroleum contamination at the Site. The initial investigation included the advancement of 18 soil borings in the vicinity of the former UST, with field screening of select soil samples using a photoionization detector (PID). These borings were followed by the installation of 11 monitoring wells (MW-1 through MW-11) across the Property, during multiple phases, to investigate the hydrogeology and ground water quality at the Site. Quarterly to semi-annual water quality monitoring was conducted on select monitoring wells between 1995 and 2000. Free-phase product, identified as #2 heating oil via petroleum fingerprinting, has historically been detected in monitoring well MW-3, which is located in the vicinity of the former heating oil UST. Through October 2000, free product was recovered from this well by manual bailing and absorbent pads. Between 1995 and 2000, benzene was consistently detected at concentrations above the Vermont Groundwater Enforcement Standard (VGES) of 5.0 micrograms per Liter (μg/L) in ground water samples collected from monitoring wells MW-4 and MW-9. Site monitoring ceased after October 2000. In spring 2008, the VT DEC contacted the Barre Housing Authority requesting that work resume on the project. The Barre Housing Authority subsequently retained AGS for assistance in this matter. AGS subsequently completed a supplemental site investigation (SSI), the results of which were documented in AGS’ report dated December 12, 2008. As part of the SSI, AGS conducted geophysical surveys on-Site (14 Washington Street) and off-Site at 30 Washington Street to determine whether out-of-service gasoline USTs depicted on Sanborn fire insurance maps remained in the ground. In addition, AGS supervised the installation of one (1) downgradient monitoring well (MW-12) and three (3) upgradient monitoring wells located at 30 Washington Street (MW-13, MW-14, and MW-15), and completed a Site-wide groundwater monitoring event. Pertinent findings from the SSI included the following:

Based on the results of the geophysical surveys, the gasoline USTs depicted on the Sanborn maps did not appear to remain in the ground at 14 or 30 Washington Street.

There may be at least three sources for the petroleum contamination identified at the Site: 1) the former #2 heating oil UST; 2) a former gasoline UST system believed to be located immediately north of the former heating oil UST; and 3) a former gasoline UST system located off-Site, on the property bordering the First Baptist Church to the east (14 Washington Street).

Mobile light non-aqueous phase liquid (LNAPL), released from the former #2 heating oil UST

system, continued to remain present within the smear zone in the vicinity of monitoring well MW-3. The extent of LNAPL was not well defined to the west. The dissolved-phase target VOC plume generated by the #2 oil appeared limited in magnitude and extent.

Mr. Chip Castle - 3 - January 26, 2011

Gasoline-related contamination was detected at monitoring wells MW-13 and MW-14, located in the southwest portion of the property at 30 Washington Street. It was presumed that this contamination is the result of the former gasoline UST system that was identified on the 1925 (revised 1949) Sanborn Map.

A gasoline-related dissolved-phase VOC plume has migrated beneath the First Baptist Church, and

onto the Washington Street Apartments’ Site. The downgradient extent and vertical distribution of the plume was not adequately characterized. Several target VOCs were detected above respective VGESs in monitoring wells MW-4, MW-9, MW-13, and MW-14 during the August 2008 monitoring event.

Vapor intrusion of petroleum VOCs to indoor air appeared to present the most significant potential exposure pathway to human receptors.

Given the results of the SSI, AGS recommended additional work to:

1. Define the extent of LNAPL associated with the former heating oil UST; 2. Investigate the potential for vapor intrusion at the Apartment Building; 3. Better characterize the downgradient extent of the dissolved-phase petroleum VOC plume; and 4. Further evaluate temporal changes in dissolved-VOC concentrations.

Based on discussions with Mr. Matt Moran of the VT DEC, it was determined that additional source-area characterization at 30 Washington Street and a vapor intrusion investigation at the First Baptist Church should not be undertaken by the Barre Housing Authority, and that these tasks will be the responsibility of the property owner of 30 Washington Street. This SSI presents the results of the additional investigation. 3.0 WORK COMPLETED 3.1 Sub-Slab Vapor / Indoor Air Monitoring On September 22, 2010 Stone completed compound-specific sub-slab vapor monitoring at eight (8) temporary vapor points within the basement of the apartment building at 14 Washington Street (TVP-01 through TVP-08) (Figure 2). Vapor samples were also collected from permanent vapor monitoring point VP-1 and monitoring well MW-3. An indoor air sample was collected in the basement-level laundry room. The purpose of the monitoring was to further evaluate vapor intrusion pathways to indoor air; this additional work was warranted due to the presence of free-phase #2 oil in close proximity to the building foundation, and historic elevated PID readings recorded at vapor points V-1 and V-2, located within the northern portion of the basement. At the temporary vapor points, the floor surface (comprised of concrete slab) was first penetrated with a 3/8-inch diameter drill bit. A section of ¼-inch I.D. Teflon-lined tubing was then inserted within the borehole, and the annulus was sealed at the surface with hydrated bentonite. At VP-1 and MW-3, a two-inch diameter PVC slip cap with a threaded hose barb (connected to ¼-inch I.D. Teflon-lined tubing) was placed on top of the well casing. The tubing was then connected to a 1-Liter Tedlar bag located within a vacuum chamber. The vacuum chamber was then closed to form an air-tight seal, and a diaphragm pump was utilized to evacuate atmospheric

Mr. Chip Castle - 4 - January 26, 2011 air from the vacuum chamber and create a negative pressure. Soil vapors from the vapor point then proportionally filled the Tedlar bag attached to the vapor point. The indoor air sample was collected in a similar manner using the vacuum chamber. Approximately three (3) tubing volumes were purged prior to sampling to ensure that vapors sampled were representative of the vapors contained within the vadose-zone pore space within the vicinity of the vapor point. Immediately after the samples were collected, the sample points were screened with a portable PID and O2 meter. After collection, samples were transported to Stone’s laboratory in Montpelier, Vermont for analysis of target VOCs by EPA Method 8260 using a TO-15 calibration standard. Stone is a National Environmental Laboratory Accreditation Program (NELAP) accredited laboratory for performing VOC analyses. The target list for VOCs included methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene, total xylenes, 1,2,4 trimethylbenzene, 1,3,5 trimethylbenzene, and naphthalene. For quality assurance / quality control (QA/QC) purposes, a field duplicate (from TPV-07), two (2) trip blanks, and an equipment blank were obtained and analyzed. 3.2 Soil Borings / Monitoring Well Installations On September 23, 2010, Stone installed eight (8) additional monitoring wells to better evaluate the potential source and distribution of petroleum constituents in the vicinity of the Site (Figure 2). A shallow water-table well was not installed adjacent to MW-5 on the west side of the on-Site building as proposed due to time constraints. Boring logs are presented in Appendix A. The screened intervals and placement rationale for the new monitoring wells are presented in Table 3-1 below. Table 3-1. Monitoring Well Construction Overview Well ID Screen Interval

(ft BTOC) Placement Rationale

MW-16 MW-17 MW-18 (S) MW-18 (D) MW-19 (S) MW-19 (D) MW-20 (S) MW-20 (D)

10-20 8-18 7.5-17.5 16.9-21.9 7.3-17.3 19.3-24.3 6.4-16.4 17.4-22.4

Evaluate presence of #2 oil NAPL adjacent to building. Evaluate presence of #2 oil NAPL adjacent to building. Cluster wells; investigate elevated PID readings from borings B-4, B-7, and B-18; evaluate whether elevated benzene concentrations at MW-9 are related to on-Site or off-Site source(s); hydraulic control points. Cluster wells to monitor for #2 oil LNAPL (downgradient) and possible “diving” dissolved plume from on-Site and/or off-Site source; hydraulic control points. Cluster wells to monitor for #2 oil LNAPL (downgradient) and possible “diving” dissolved plume from on-Site source; hydraulic control points.

Note: BTOC = Below Top of Casing

Mr. Chip Castle - 5 - January 26, 2011 Borings were advanced by Stone using both a track-mounted Geoprobe® unit (model 6610 DT), and a truck-mounted rig (model A300) with direct-push capabilities. Soil samples were generally collected in continuous five-foot intervals, using the dual tube sampling technology. Soil samples were logged for texture and screened for the possible presence of VOCs using a properly calibrated portable PID (Ion Science Model 1000+). Monitoring wells were constructed of polyvinyl chloride (PVC) materials, using 1.0” diameter factory-slotted 0.010” screen and threaded well casing. In general, the annulus around the well screen was filled with #1 filter sand to at least 1 foot above the top of the well screen. The annulus was then backfilled with bentonite chips to within about two (2) feet of the ground surface, and hydrated. At monitoring well MW-20D, silt/clay swelled around the well screen; therefore, no sand pack was installed. Each well was finished about 0.3 feet bgs, plugged with an expansion cap, and protected with a flush-mounted road box. Prior to sampling, wells were developed to remove fine-grained sediment via a peristaltic pump and dedicated polyethylene tubing. At MW-20D, the well was filled with about five (5) feet of silt/clay at the start of well development; well development was abandoned after only removing about one (1) foot of sediment because the tubing clogged numerous times. On October 14th, the top-of-casing elevations of newly completed and previously existing monitoring wells were surveyed relative to a Site benchmark using an automatic level with a vertical accuracy of about +/- 0.01 feet. The horizontal locations of the newly installed monitoring wells and select existing wells were measured with a tape measure relative to known existing Site features. 3.3 Ground Water Monitoring On October 14, 2010, prior to ground water sampling, Stone obtained and recorded liquid level measurements in all on-Site and off-Site monitoring wells with the exception of monitoring wells MW-1 and MW-2, which could not be located. Liquid levels were manually measured to the nearest 0.01 foot using an electronic oil/water interface probe. During the synoptic round of liquid level measurements, wells were also inspected for signs of damage, tampering, etc.; Stone noted that the roadbox for monitoring well MW-8 is damaged and should be replaced. On October 14th, Stone collected ground water samples for subsequent laboratory analysis from monitoring wells MW-4, MW-5, MW-9, MW-10, MW-13, MW-14, MW-16, MW-17, MW-18S, MW-18D, MW-19S, MW-19D, and MW-20S; monitoring wells MW-12 and MW-15 were sampled on October 16th. Monitoring well MW-11 and MW-20D were not sampled as proposed; MW-11 was dry to a depth of 11.45 feet BTOC, and MW-20D was clogged with sediment. Samples were collected from monitoring wells MW-4, MW-5, MW-9, and MW-10 using dedicated bailers and drop lines; samples were collected from the other monitoring wells via a peristaltic pump with dedicated, Teflon-lined polyethylene and silicone tubing. With the exception of MW-9, at least three (3) well volumes were purged before samples were collected; MW-9 was purged dry prior to three (3) well volumes, and a sample was collected after the water level recovered to within about 90 percent of the initial static level. Stone acquired the following quality assurance / quality control (QA/QC) samples:

1 – Trip Blank; and


1 – Duplicate sample (from MW-14)

Following collection, all samples were placed in an ice-filled cooler and transported to Stone’s NELAP accredited laboratory in Montpelier, Vermont for analysis of target VOCs by EPA Method 8620B. 4.0 INVESTIGATION RESULTS

4.1 Soil Borings In general, soils encountered during the soil boring program consisted of varying percentages of sand, silt, and gravel (likely artificial fill) within the upper six (6) to seven (7) feet bgs in borings on the west side of the on-Site building (MW-19 and MW-20), and within about 12 to 14 feet bgs on the east side of the building, in the vicinity of the former heating oil and suspected gasoline USTs (MW-16, MW-17, and MW-18). These materials overlie native fluvial deposits generally comprised of interbedded fine to medium sand, silty-fine sand, silt, and clayey-silt layers (>1-inch thick), with occasional clay lenses (<1-inch thick). Bedrock was not encountered to a maximum exploratory depth of about 25 feet bgs. Near refusal was encountered at about 10 feet bgs at soil boring MW-17. Refusal was encountered at about 11 feet bgs at MW-18; relocating the boring about three (3) feet to the south enabled this depth to be penetrated. 4.2 Liquid-Level Measurements On October 14, 2010, depth-to-water measurements in the overburden monitoring wells ranged from 10.75 feet below top-of-casing (BTOC) in monitoring well MW-7 to 13.73 feet BTOC in monitoring well MW-16. LNAPL was present within monitoring well MW-3 at an apparent thickness of 0.27 feet. LNAPL was not detected in any other monitoring well; however, sheening was observed on the purge water for monitoring well MW-14. Calculated relative ground water elevations ranged from 83.36 feet at monitoring well MW-19D to 86.75 feet at monitoring well MW-15 (Table 4-1). The depth-to-water reading from MW-3 was corrected to account for the presence of LNAPL by multiplying the apparent product thickness by the specific gravity of heating oil (assumed to be 0.87), and subtracting the result from the measures depth-to-water value.

Mr. Chip Castle - 7 - January 26, 2011 Table 4-1. Liquid-Level Monitoring Data: October 14, 2010

Well I.D.

Top-of-Casing

Elevation (feet)

Depth-to-Product

(feet BTOC)

Depth-to-Water (feet

BTOC)

Apparent Product

Thickness (feet)

Corrected Depth-to-

Water (feet BTOC)

Ground Water Elevation

(feet)

MW-3 98.25 12.46 12.73 0.27 12.50 85.75 MW-4 97.89 -- 12.93 0.00 12.93 84.96 MW-5 96.16 -- 12.00 0.00 12.00 84.16 MW-6 95.72 -- 11.23 0.00 11.23 84.49 MW-7 96.48 -- 10.75 0.00 10.75 85.73 MW-8 98.13 -- 11.78 0.00 11.78 86.35 MW-9 98.50 -- 13.48 0.00 13.48 85.02

MW-10 98.69 -- 13.42 0.00 13.42 85.27 MW-11 97.99 -- >11.45 0.00 >11.45 <86.54 MW-12 96.21 -- 11.57 0.00 11.57 84.64 MW-13 98.79 -- 12.10 0.00 12.10 86.69 MW-14 99.43 -- 13.36 0.00 13.36 86.07 MW-15 99.45 -- 12.70 0.00 12.70 86.75 MW-16 99.02 -- 13.73 0.00 13.73 85.29 MW-17 98.83 -- 13.68 0.00 13.68 85.15

MW-18S 98.91 -- 13.65 0.00 13.65 85.26 MW-18D 98.85 -- 13.72 0.00 13.72 85.13 MW-19S 96.39 -- 11.91 0.00 11.91 84.48 MW-19D 96.43 -- 13.07 0.00 13.07 83.36 MW-20S 96.58 -- 12.05 0.00 12.05 84.53 MW-20D 96.57 -- 12.10 0.00 12.10 84.47

4.3 Quality Assurance / Quality Control

4.3.1 Soil Vapor Results for the quality control (QC) samples were as follows:

• Method Blanks, Trip Blanks, and the equipment blank were analyzed and they exhibited no detections.

• Initial Calibration and Continuing Calibration Verification Samples were within acceptance

limits for the method.

• The parent sample, TVP-07, and its field duplicate sample TVP-07-FD, had a relative percent difference (RPD) of 51% for toluene. This RPD is slightly higher than the acceptable RPD range for soil gas (50%).


4.3.2 Ground Water Results for the QC samples (laboratory method blanks, laboratory control samples (LCS), initial calibration verification (ICV) samples, continuing calibration verification (CCV) samples and matrix spike and matrix spike duplicate (MS/MSD) samples) were all deemed to be within the QC tolerances, as specified in the SOPs for these analytical procedures, with the following exceptions:

• Surrogate recoveries were slightly outside of acceptance limits for three samples: MW-16, MW- 18D and DUP.

• The trip blank exhibited an estimated low-level toluene detection at 1.6 μg/L. Toluene was not detected in the laboratory method blanks.

The parent sample MW-14 and its field duplicate had an RPD within 18 percent for all detected compounds.

4.4 Contaminant Distribution 4.4.1 Soil Vapor Soil vapor laboratory results for target VOCs are summarized on Table 4-2. Benzene concentrations are also presented on Figure 3. The complete laboratory report is provided in Appendix B. The laboratory results were compared to the draft Vermont Soil Gas Screening Levels (VSGSLs), which are defined as 10 times the greater of either the Hazardous Ambient Air Standards (HAAS) from the VT DEC Air Pollution Control Regulations (April 2007), or the median annual “background” concentrations of select compounds measured during the Vermont Department of Health’s (VT DOH) study of indoor air quality at 60 residences throughout Vermont in 1993. Table 4-2. Summary of Soil Vapor Analytical Results: September 23, 2010

Sample Location

MTBE Benzene Toluene Ethyl-benzene

Total Xylenes

Total TMBs

Naph-thalene

O2

TPV-01 18U 16U 19U 22U 22U 25U 100U 13.8 TPV-02 18U 16U 47 22U 22U 25U 100U 14.6 TPV-03 18U 130 31 22U 22U 25U 100U 19.8 TPV-04 18U 19 68 22U 22U 25U 100U 19.3 TPV-05 18U 17 120 22U 22U 25U 100U 19.5 TPV-06 18U 16U 65 22U 22U 25U 100U 16.4 TPV-07 18U 16U 83 22U 22U 25U 100U 16.5 TPV-08 18U 16U 77 22U 22U 25U 100U 17.8 VP-01 18U 16U 130 22U 22U 25U 100U 20.1 MW-3 18U 16U 55 22U 151 780 220 20.9 VSGSL -- 4.9 3,000 1,000 1,000 98 3 --

Notes: - U = Not detected above reporting limit. - Concentrations reported in micrograms per cubic meter (μg/m3), except O2, which is reported as %.


As evident from Table 4-2, benzene exceeded the screening level of 4.9 μg/m3 at temporary sub-slab vapor points TPV-03, TPV-04, and TPV-05; at TPV-03, the benzene concentration was greater than 26x the screening level. Of note, the laboratory reporting limit for benzene was about 3x the screening level for benzene. Toluene was detected in each of the sub-slab samples, with the exception of TPV-01, at concentrations ranging from 31 μg/m3 at TPV-03 to 130 μg/m3 at VP-01, which were well below the screening level for toluene. No other target VOCs were detected in the sub-slab vapor samples; however, the laboratory detection limit for naphthalene was greater than the screening level for this compound. The vapor sample collected from monitoring well MW-3 contained detectable concentrations of total xylenes, total trimethylbenzenes (TMBs), and naphthalene, with total TMBs and naphthalene concentrations in excess of respective screening levels. Monitoring well MW-3 is located about 12 feet east of the apartment building; this well contained measurable LNAPL on top of the water table (about 12.5 feet bgs) at the time of sampling. Sub-slab vapor oxygen concentrations ranged from 13.8 % to 20.1%. O2 concentrations were lowest at vapor points TPV-1 and TPV-02. At monitoring well MW-3, an oxygen concentration of 20.9 % (equal to atmospheric) was recorded on the extracted soil vapor. 4.4.2 Indoor Air Toluene was detected at a concentration of 130 μg/m3 in the air sample collected within the basement laundry area of the apartment building (IA-01), which is below the HAAS of 300 μg/m3 for this compound. No other target VOCs were detected above laboratory reporting limits. However, the laboratory detection limit for benzene (16 μg/m3) was above the VT DOH median “background” value of 0.49 μg/m3 for this compound, and the laboratory detection limits for total TMBs (25 μg/m3) and naphthalene (100 μg/m3) were greater than the HAAS values of 9.8 μg/m3 and 0.3 μg/m3, respectively. 4.4.3 Field PID Screening Peak PID readings (per depth interval) obtained during the soil boring program are displayed in Table 4-3. PID readings are also provided on the soil boring logs (Appendix A).


Table 4-3. Peak PID Readings: September 23, 2010 Boring

Location Approximate

Depth Interval (ft bgs) Peak PID Reading

(ppmv)

MW-16

0.5-13 0.0 13-17 275 17-19 2,000 19-20 50

MW-17

0.5-7 <1 7-13 7

13-15.5 1,500 15.5-18 20

MW-18D

0-3 <1 3-8 20

8-13 <1 13-18 320 18-20 20 20-23 5

MW-19D 0-24 <1 24-25 5.1

MW-20D 0-25 <1

Black staining and petroleum sheening were observed on soils between about 13 to 19 feet bgs at MW-16, and between about 13 to 17 feet bgs at MW-17. Black staining was also observed at MW-18 between about 13 to 14 feet bgs.

4.4.4 Groundwater

Dissolved-phase analytical results are included in Table 4-4, and on Figure 3. Table 4-4 also includes results from the previous monitoring round in August 2008, where applicable. Laboratory report forms for the October 2010 event are included in Appendix B.


Table 4-4: Groundwater Analytical Results.

Sample Location Date MTBE Benzene Toluene

Ethyl-benzene

Total Xylenes

Total TMBs

Naph-thalene

Total Target VOCs

MW-4 08/29/08 ND<40.0 28.5 69.4 745 538 1,013 239 2,633 10/14/10 ND<2.0 11 10 390 197 920 160 1,688

MW-5 10/14/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND

MW-9 08/28/08 ND<20.0 301 42.4 776 102 375 95.5 1,692 10/14/10 ND<2.0 220 47 970 182 770 260 2,449

MW-10 10/14/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND MW-12 10/16/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND

MW-13 08/29/08 ND<1,000 4,260 27,700 4,780 18,900 4,950 ND<1,000 60,590 10/14/10 ND<240 1,900 28,000 E 6,700 29,200 10,700 ND<240 76,500

MW-14 08/29/08 ND<200 895 8,120 1,380 5,220 718 ND<200 16,333 10/14/10 ND<2.0 340 5,400 1,600 6,300 1,410 450 15,500

MW-15 08/29/08 ND<2.0 ND<1.0 ND<1.0 ND<1.0 ND<2.0 ND ND<2.0 ND 10/16/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND

MW-16 10/14/10 ND<2.0 ND<2.0 ND<2.0 38 55 332 25 450 MW-17 10/14/10 ND<2.0 ND<2.0 ND<2.0 32 12 179 3.0 226

MW-18S 10/14/10 ND<2.0 ND<2.0 1.9 J 47 195 67 17 328 MW-18D 10/14/10 ND<2.0 ND<2.0 ND<2.0 270 779 790 200 2,039 MW-19S 10/14/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND MW-19D 10/14/10 ND<2.0 3.2 1.0 J 45 ND<2.0 ND<2.0 2.1 51 MW-20S 10/14/10 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND

VGES -- 40 5.0 1,000 700 10,000 350 20 --

No target VOCs were detected in ground water samples collected from monitoring wells MW-5, MW-6, MW-10, MW-12 or MW-15. Detectable total target VOC concentrations ranged from 51 μg/L in deeply-screened cluster monitoring well MW-19D, located on the west side of the apartment building, to 76,500 μg/L in MW-13, which is located in the southwest corner of the parcel at 30 Washington Street. Target VOCs include MTBE, benzene, toluene, ethylbenzene, total xylenes, total trimethylbenzenes, and naphthalene. Benzene, toluene, ethylbenzene, total xylenes, total TMBs, and naphthalene were detected in one or more monitoring well at concentrations above the respective VGESs.

5.0 UPDATED CONCEPTUAL SITE MODEL

Geology / Hydrogeology Based on a review of boring logs completed by K-D Associates, and the results of the soil boring program implemented by AGS and Stone, soil stratigraphy varies significantly across the areas of concern. In general, varying percentages of sand, silt, and gravel (artificial fill and/or native fluvial deposits) are present within the upper two (2) to 10 feet bgs. These materials appear to overlie native fluvial silt/clayey-silt deposits (with

Mr. Chip Castle - 12 - January 26, 2011 interbedded fine sands) within the northern and southern portions of the Site to depths of at least 20 to 25 feet bgs (the maximum depth of borings). The silt unit was not encountered at monitoring wells MW-4, MW-8, or MW-15; rather, fine to coarse stratified sands were present at these locations to depths of at least 20 to 28 feet bgs, respectively. These relatively coarse deposits may indicate the presence of a meandering former stream channel; hydraulic head and contaminant distribution data suggest the channel may traverse between MW-12 and MW-5 on the west side of the building. Bedrock has not been encountered across the Site to a maximum exploratory depth of about 28 feet bgs. On October 14, 2011, depth-to-water measurements in the overburden monitoring wells ranged from 10.75 feet below top-of-casing (BTOC) in monitoring well MW-7 to 13.73 feet BTOC in monitoring well MW-16. Apparent shallow ground water flow in the overburden aquifer was generally to the southwest within the northern portion of the Site, and to the northwest within the southern portion of the Site, with flow converging towards the apparent buried stream channel (Figure 4). The water-table gradient across the Site ranged from about 0.01 feet/foot to about 0.03 feet/foot. Hydraulic head data from cluster wells MW-9/MW-10 and MW-19S/MW-19D indicate there were vertical hydraulic gradients of 0.04 feet/foot and 0.11 feet/foot at these respective locations within the overburden aquifer, with a downward flow component. Several underground utilities are located within the investigation area, including sanitary sewer, water, and storm water lines. The invert elevations of these known utility corridors, as well as the foundation footings for the apartment building and church, are likely above the water table; as such, these utility corridors do not likely influence shallow ground water flow. Contaminant Distribution Based on available contaminant distribution and hydrogeologic data, and historic on-Site and off-Site operations, it appears that there may be at least three (3) sources for the petroleum contamination identified at the Site: 1) the former #2 heating oil UST; 2) a former gasoline UST system located immediately in the vicinity of the former heating oil UST; and 3) a former gasoline UST system located off-Site, on the property bordering the First Baptist Church to the east of the Site (30 Washington Street). The volume of the petroleum releases associated with these former UST systems is unknown. In general, once released to the subsurface, petroleum hydrocarbons (e.g. gasoline and #2 heating oil) can partition into four phases: 1) vapor (i.e. soil gas), 2) aqueous (dissolved in pore water), 3) sorbed (to soil minerals and organic matter), and 4) remain as NAPL, either residual or mobile. The phase partitioning and migration of petroleum hydrocarbons, once released to the subsurface, depends on several factors, including: the volume of the release, the physical and chemical properties of the individual hydrocarbon compounds, and the physical and chemical properties of the media that the hydrocarbons were released into. At the Washington Street Apartment Site, the petroleum releases have impacted soil and ground water, and hydrocarbons are present in the vapor, sorbed, dissolved, and NAPL phases. Mobile LNAPL, released from the former #2 heating oil UST system, remains present within the “smear zone” in the vicinity of monitoring well MW-3. The horizontal extent of mobile LNAPL appears to have been reasonably delineated, and is likely confined to the vicinity of monitoring well MW-3. While heavy sheening was observed on soils at borings MW-16 and MW-17, located downgradient of MW-3 in close proximity to the on-Site building, no mobile LNAPL was detected in these wells. Vertically, gross contaminant impact in the

Mr. Chip Castle - 13 - January 26, 2011 former UST area appears isolated to the “smear zone”, which likely extends from about 11 to 15 feet bgs (based on historic water-table fluctuations). An estimated volume of mobile LNAPL has not been calculated to date. A maximum apparent product thickness of 4.79 feet was present in MW-3 in March 1995. K-D Associates subsequently implemented manual and passive product recovery efforts at MW-3, and only a sheen was present in the well in October 2000. When AGS gauged the well in August 2008, 2.25 inches of free product were present; about 0.27 feet of apparent product thickness was measured by Stone on October 14, 2010. Since free-phase product remains in MW-3 15-plus years after its discovery, natural attenuation does not appear to be a viable remedial alternative for addressing the LNAPL. The dissolved-phase target VOC plume generated by the #2 oil appears limited in magnitude and extent, as the constituents of #2 oil generally have relatively low aqueous solubility. On October 31, 2000, when no LNAPL was present, total trimethylbenzenes and naphthalene were detected in a ground water sample from MW-3 at concentrations of 611 μg/L and 1,250 μg/L, respectively; no other target VOCs were detected. Given the close proximity of NAPL, these dissolved concentrations likely represented a “worst case” scenario for ground water impact from the #2 oil. In October 2010, samples collected from newly installed monitoring wells MW-16 and MW-17, located within 15 feet downgradient of MW-3, contained only relatively low concentrations of ethylbenzene, total xylenes, total TMBs, and naphthalene. In the early 1990s, K-D Associates completed 18 soil borings with PID screening in the vicinity of the former on-Site heating oil and gasoline USTs. These screening data, specifically from borings B-7, and B-13 through B-16, indicate the apparent presence of VOCs in the vadose zone and saturated zone upgradient of the former heating oil UST system, and suggest there may be another source for the contaminants. Given its proximity, the former gasoline UST system is a possible source. Releases could have occurred via leaks from the former UST and appurtenances (including the former fuel dispenser, the location of which is unknown), and/or spills associated with fueling. If releases of gasoline did occur in this area, the impact to ground water does not appear to be significant, and may be co-mingled with the dissolved-phase heating oil contamination. Gasoline-related contamination detected at monitoring wells MW-13 and MW-14, located in the southwest portion of the property at 30 Washington Street, appears to be related to the former gasoline UST system that was identified on the 1925 (revised 1949) Sanborn Map. Although the former USTs appear to have been removed, significant residual gasoline contamination likely remains present within the subsurface at this property. The upgradient boundary and vertical extent of the source-area contamination has not been defined. Based on apparent shallow ground water flow and available contaminant distribution, it appears that the dissolved-phase VOC plume has migrated from this source area, beneath the First Baptist Church, and onto the Washington Street Apartments’ Site. Offsite migration of the dissolved VOC plume from the source area appears strongly governed by the physical/chemical properties of the buried stream channel. It appears that the VOC impact at monitoring wells MW-4, MW-9, and MW-19D originates off-Site from 30 Washington Street. Data from cluster wells MW-9/MW-10 and MW-19S/MW-19D indicate the VOC plume is “diving” in this portion of the aquifer, and has migrated beneath the apartment building. There appears to be a “clean” water lense above this plume. Benzene, one of the more mobile and toxic target VOCs, appears to be present in ground water beneath the church at concentrations greater than 1,000 μg/L; based on the October 2010 data, the 1,000 μg/L benzene isopleth comprises an estimated area of at least 2,500 square feet downgradient of the source area. The downgradient extent of the benzene plume has not been completely delineated, either horizontally or vertically; however, based on the relatively low concentrations at MW-19D, the plume does not likely extend much beyond this well. In October 2010, detectable total target VOC

Mr. Chip Castle - 14 - January 26, 2011 concentrations ranged from 51 μg/L in deeply-screened cluster monitoring well MW-19D, located on the west side of the apartment building, to 76,500 μg/L in MW-13, which is located in the southwest corner of the parcel at 30 Washington Street. Benzene, toluene, ethylbenzene, total xylenes, total TMBs, and naphthalene were detected in one or more monitoring well at concentrations above the respective VGESs. Although benzene concentrations in MW-4 and MW-9 have fluctuated over time since monitoring commenced in 1995, an overall decreasing trend appears present from each data set. Therefore, monitored natural attenuation (MNA) may be a plausible remedial alternative for addressing the downgradient dissolved plume. There are insufficient monitoring data from other impacted monitoring wells at the Site to determine possible concentration trends. Given the gross contamination present within the source area at AOC #2, and the age of the release, more aggressive remediation may be appropriate within this source area. Vapor intrusion of petroleum VOCs to indoor air appears to present the most significant potential exposure pathway to human receptors. In September 2010, benzene was detected in sub-slab vapor beneath the apartment building at concentrations in excess of the screening level for this compound, with the highest concentration of 130 μg/m3 detected at TPVP-03. Toluene was detected in each of the sub-slab samples, with the exception of TPV-01, at concentrations ranging from 31 μg/m3 at TPV-03 to 130 μg/m3 at VP-01, which were well below the screening level for toluene. No other target VOCs were detected in the sub-slab vapor samples; however, the laboratory detection limit for naphthalene was greater than the screening level for this compound. Benzene was not detected in the indoor air sample collected from the basement; however, the laboratory detection limit for this compound (as well as for total TMBs and naphthalene) was above the VT DOH and/or HAAS concentrations. The source(s) of the elevated benzene concentrations in soil gas is not fully understood at this time; potential sources include releases from the former on-Site gasoline and heating oil USTs, the off-Site gasoline UST at 30 Washington Street, or a release or source yet to be identified. The heating oil contamination is a possible but unlikely source because benzene is typically only present in heating oil at trace concentrations, if at all, and benzene was not detected in sub-slab vapor samples collected closest to the heating oil LNAPL (TPV-01 and TPV-02). Although the dissolved-phase benzene plume that originates off-Site from 30 Washington Street is present under the apartment building, the plume is “diving” beneath a clean water lense in this portion of the aquifer; as such, phase partitioning of aqueous contamination to vapor should not be a significant concern. Residual gasoline contamination within the vadose zone, which is known to exist at 30 Washington Street and suspected to be present on-Site in the vicinity of the former gasoline UST system, is a more likely source for the elevated benzene concentrations detected in sub-slab vapor samples beneath the apartment building. Petroleum vapors could have migrated from these suspected source areas via diffusion and/or advection. Elevated PID readings up to 20 ppmv were detected on shallow soils between 3 to 8 feet bgs at soil boring MW-18D, which is located in relative close proximity to sub-slab vapor point TPV-03 (which contained benzene at 130 μg/m3). These soils may be a potential source; compound-specific analysis of soil gas in the vicinity of MW-18D would be required to confirm this possibility. Given its proximity to multiple potential contaminant sources, the First Baptist Church may be at risk of vapor intrusion from both the on-Site and off-Site petroleum releases.

Mr. Chip Castle - 15 - January 26, 2011 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of this SSI, and a review of historic Site data, Stone has drawn the following conclusions:

There may be at least three (3) sources for the petroleum contamination identified at the Site: 1) the former #2 heating oil UST; 2) a former gasoline UST system believed to have been located immediately north of the former heating oil UST; and 3) a former gasoline UST system located off-Site, on the property bordering the First Baptist Church to the east. The volume of the petroleum releases associated with these former UST systems is unknown.

Vapor intrusion of petroleum VOCs to indoor air appears to present the most significant potential

exposure pathway to human receptors. Benzene was detected in sub-slab vapor beneath the apartment building at concentrations in excess of the screening level for this compound, with the highest concentration of 130 μg/m3 detected at TPVP-03. Benzene was not detected in the indoor air sample collected from the basement; however, the laboratory detection limit for this compound (as well as for total TMBs and naphthalene) was above the VT DOH and/or HAAS concentrations. Additional indoor air testing appears warranted.

The source of the elevated benzene concentrations in soil gas is not fully understood at this time; potential sources include releases from the former on-Site gasoline and heating oil USTs, the off-Site gasoline UST at 30 Washington Street, or a release or source yet to be identified. Residual gasoline contamination within the vadose zone ,which is known to exist at 30 Washington Street and suspected to be present on-Site in the vicinity of the former gasoline UST system, is the most probable source for the elevated benzene concentrations detected in sub-slab vapor samples beneath the apartment building. Given its proximity to multiple potential contaminant sources, the First Baptist Church may also be at risk of vapor intrusion from both the on-Site and off-Site petroleum releases. Additional investigation should be implemented to determine whether vapor intrusion pathways are complete at the First Baptist Church.

Mobile LNAPL, released from the former #2 heating oil UST system, remains within the smear zone in the vicinity of monitoring well MW-3. The extent of mobile LNAPL is reasonably defined, and does not appear to extend beneath the apartment building; however, residual LNAPL is present immediately adjacent to the apartment building. On October 14, 2010, 0.27 feet of apparent product thickness was present within MW-3. Since free-phase product remains in this well over 15 years since its discovery, natural attenuation does not appear to be a viable remedial alternative for addressing the LNAPL. The dissolved-phase target VOC plume generated by the #2 oil appears limited in magnitude and extent.

Given the available data, it appears that the VOC impact at monitoring wells MW-4, MW-9, and MW-19D originates off-Site from 30 Washington Street. Data from cluster wells MW-9/MW-10 and MW-19S/MW-19D indicate the VOC plume is “diving” in this portion of the aquifer, and has migrated beneath the apartment building. There appears to be a “clean” water lense above this plume. The downgradient extent of the benzene plume has not been completely delineated, either horizontally or vertically; however, based on the relatively low concentrations at MW-19D, the plume does not likely extend much beyond this well.


In October 2010, detectable total target VOC concentrations ranged from 51 μg/L in deeply-screened cluster monitoring well MW-19D, located on the west side of the apartment building, to 76,500 μg/L in MW-13, which is located in the southwest corner of the parcel at 30 Washington Street. One or more target VOCs were detected above respective VGESs in monitoring wells MW-4, MW-9, MW-13, MW-14, MW-16, and MW-18D during the October 2010 monitoring event.

Given the above conclusions, Stone offers the following recommendations:

Indoor air samples should be collected within the basement of the apartment building to further evaluate whether the vapor intrusion pathway is complete. Samples should be analyzed for VOCs via EPA Method TO-15.

Sub-slab soil gas sampling with compound-specific laboratory analysis should be conducted at the First Baptist Church to determine if this structure is at risk of vapor intrusion from the on-Site and/or off-Site petroleum releases. This phase of work may be followed by indoor air sampling/analysis depending on the soil gas results.

Manual product recovery via bailing and/or the use of absorbent “socks” should be initiated on a routine basis at monitoring well MW-3.

Semi-annual monitoring of the Site monitoring well network should be initiated, with samples being analyzed for target VOCs via EPA Method 8021B.

The roadbox for monitoring well MW-8 should be repaired. **************************************************************************************

Mr. Chip Castle - 17 - January 26, 2011 Stone appreciates the opportunity to assist you on this project. Please do not hesitate to contact me f you have any questions. Yours truly, Stone Environmental, Inc. Eric J. Swiech, P.G. Senior Hydrogeologist / Director of Consulting Services Direct Phone / 802-229-6432 E-Mail / [email protected] cc: Mr. Matt Moran, VT DEC Figure 1 Site Location Map Figure 2 Site Plan Figure 3 Contaminant Distribution Map: Fall 2010 Figure 4 Water-Table Contour Map: October 14, 2010 Appendix A Boring Logs Appendix B Laboratory Reports

FIGURES

Copyright (C) 1997, Maptech, Inc.

Name: BARRE EASTDate: 7/7/2008Scale: 1 inch equals 2000 feet

Location: 044° 11' 52.25" N 072° 29' 53.69" W NAD 27Caption: Figure 1. Site Location Map

SITESITESITESITESITESITE

Magnetic Declination

16° W

SCALE 1:24000

0 1 MILES

0 1000 YARDS

0 1 KILOMETER

APPENDIX A

Site Name: WSA Client: BHA Permit No.: NA

Location: 14 Washington St., Barre, VT Drilling Dates: 9/23/2010

Project: Field Log By: Eric Swiech

Driller: Mike Jordan Company: SEI Drilling Method: A300 w/ Direct Push Hammer

5-foot dual-tube sampler

Latitude: Longitude: Borehole Diam. (in.): 3.25"

State Plane Coordinate Feet (North): Outer Casing: NA

State Plane Coordinate Feet (East): Well Diameter (inches) 1

Outer Casing (OC) Elevation (feet): NA Casing Length (feet): See Below

Inner Casing (IC) Elevation (feet): NA Screen Length (feet): See Below

Ground Elevation (feet): NA Screen Slot Size: 10

Datum: MSL Sand Pack: #1

Notes: Flush-mounted roadbox

Depth (feet) PID Response (ppm) Recovery Sample IDs0.5-3' RUN

1 Brn f-c Sand, some f Gravel, little Silt (FILL). Moist.0.0 31"

2

33-8' RUN

4 0-6": Drk brn f-c Sand, some Gravel, little Silt (FILL). Moist.6-17": Brn-orange m SAND. Dry.

5 17-22": Brn-tan f-c SAND, little Gravel. Dry.22-31": Brn f(+)-c(-) SAND, little Silt and Gravel. Dry. 0 24"

6

7

88-13' RUN

9

100 40"

11

12

1313-18' RUN

14 0-11": As above. Wet @ 7" + black staining (strong petro odors) 275

15 2340"

16 37-40": Blk m-c SAND, srong odors. 7

17 2000

1818-20' RUN 1500

19 0-3":As above. 20"3-20": Gryish-brn SILT w/ interbedded f Sand lenses/layers. No odors. 50

20 25

Drilling Log

MW-16

Description

E.O.B. @ 20'. Set MW-16 @ 20' bgs, w/ 10' of 10-slot screen. #1 sand to 9' bgs, hydrated bentonite chips to 2' bgs.

PID readings obtained w/ Ion Science Model 1000+ (10.6 eV lamp)

Drk Brn f-c SAND, some f-c gravel/cobbles, little Silt (with couple pockets of f SAND). Dry. Loose.

11-37": Lt Brn f SAND, some Silt with interbedded f Sand lenses. Wet, no odors, except black staining/sheening/strong petro odor in f-m SAND lense @ 31".

WSA_Boring Logs.xlsx - MW-16















1<1 29"

2

33-8' RUN

4 As above. Dry.<1

539"

6

72.6

88-13' RUN

9 7

10 10-12"; Brn wood/branch & organic matter.13-16": Olive Silt. With interbedded f Sand. Wet. 16"

11

12 0

1313-18' RUN

14 1500

15400 58"

16

17 20

18 53

19

20

F Sand, and Silt w/ interbedded f Sand lenses/layers. Black staining and heavy sheening from .

E.O.B. @ 18'. Set MW-17 @ 18' bgs, w/ 10' of 10-slot screen. #1 sand to 6.75' bgs, hydrated bentonite chips to 2' bgs.


F-c Sand, some f Gravel, little Silt. Loose (FILL). Moist. Grey to 7", brn from 7-29".

Drilling Log

MW-17

Description

0-10": white/lt grey pulverized concrete?

WSA_Boring Logs.xlsx - MW-17















1<1 30"

2

33-8' RUN

4 As above. Dry. 6

5 440"

6 20

7 7

8 28-13' RUN

9

10<1 30"

24-30": Rock fragments (granite and phylite) w/ f-c Sandand organic debris

Drilling Log

MW-18 (S,D)

Description

F-c Sand, some f Gravel, little Silt. Loose (FILL). Moist.

0-24": As above.

<1 3011

12

1313-18' RUN

14 0-4"; As above w/ black staining/odors. Wet. 320

1528"

16 19-28":Olive f Sand, and Silt w/ f Sand lenses. 10

17190

1818-23' RUN 20

19As above. 11

20 36"2

215

222

23Soil log for MW-18D displayed above. Soil boring for MW-18S completed 2' north of MW-18D.Set MW-18S @ 18' bgs, w/ 10' of 10-slot screen. #1 sand to 7' bgs, hydrated bentonite chips to 2' bgs.Set MW-18D @ 23' bgs, w/ 5' of 10-slot screen. #1 sand to 17' bgs, hydrated bentonite chips to 2' bgs.

4-19": Olive Silt w/ few f Sand lenses.


debris.

WSA_Boring Logs.xlsx - MW-18S &D



Project: Field Log By: Lee Rosberg

Driller: Mike Jordan Company: SEI Drilling Method: Geoprobe 6610 DT











1<1 1.9'

2 0.2-1.4': Loamy f Sand, organics. Mottles common. Dry.1.4-1.6': Asphalt/fill material.

3 organics. Mottles

4

55-10' RUN

6 0-1.9': F-vf SAND, lt brn, mottles common, organics (1.7-1.9').

72.7-3.2': Silt w/ some f Sand. Iron staining @ 2.8-2.9'. Brn. Moist. <1 3.2'

8

9

1010-15' RUN

11 0-4.3': Lt brn to geenish grey SILT, some vf Sand. Wet.

1.9-2.7': Poorly sorted SAND, some Gravel (up to 1.5"), dry becoming moist.

4.3-5': vf-f SAND, lt brn. Wet.

Drilling Log

MW-19 (S,D)

Description

0-0.2': Organic material, dark brn loamy f Sand. Dry.

12<1 5'

13

14

1515-18' RUN

16 Silt, and vf Sand, w/ interbedded clay lenses. <1 5'

17

1818-20' RUN

19 As above. <1 3.2'

2020-25' RUN 0

21 As above.0

220 5'

230

24 3.2

25 5.1Soil log for MW-19S displayed from 0-20', MW-19D for 20-25'. Soil boring for MW-19S completed 2' east of MW-19D.Set MW-19S @ 19.7' bgs, w/ 10' of 10-slot screen. #1 sand to 9' bgs, hydrated bentonite chips to 1' bgs.Set MW-19D @ 24.5' bgs, w/ 5' of 10-slot screen. #1 sand to 18.5' bgs, hydrated bentonite chips to 6' bgs.PID readings obtained w/ Ion Science Model 1000+ (10.6 eV lamp)

4.3 5 : vf f SAND, lt brn. Wet.




Project: Field Log By: Lee Rosberg

Driller: Mike Jordan Company: SEI Drilling Method: Geoprobe 6610 DT











1<1 1.8'

2

3 0.4-0.7':Vf Sand, some Gravel.0.7-1.5': Brn gravelly reworked till.

4 1.5-1.8': Brn sand and Gravel.

55-10' RUN

6

71.1-4': Lt Brn Silt, some f Sand. Wet. <1 4'

8

9

1010-15' RUN

11 0-4': Lt brn to geenish grey SILT, some vf Sand and clay lenses. Wet.

12<1 5'

13

14

1515-20' RUN

16 Silt, and vf Sand, some interbedded clay lenses. Wet. <1 5'

17

18

19

2020-25' RUN 0

21 As above.0

220 5'

230

24 3.2

25 5.1Soil log for MW-20S displayed from 0-20', MW-20D for 20-25'. Set MW-20S @ 17.7' bgs, w/ 10' of 10-slot screen. #1 sand to 7' bgs, hydrated bentonite chips to 1' bgs.Set MW-20D @ 22.4' bgs, w/ 5' of 10-slot screen. No sand pack due to heave. Bentonite chips from 15' to 6' bgs.

4-5': vf-f SAND, some Silt. Wet.


0-0.4' Asphalt

Drilling Log

MW-20 (S,D)

Description

0-1.1': Poorly sorted m SAND, and Gravel. Dry


APPENDIX B

Final Data Report for Laboratory Services PREP AR ED FOR STONE E NVIRONMENTAL

S ITE ID : W ASHINGTON STREET AP AR TMEN TS, B ARRE, VT

Stone Project ID 102402-R

REPORT DATE: October 29, 2010

Prepared for: Prepared by:

Stone Environmental, Inc. Stone Environmental, Inc.

Eric Swiech 535 Stone Cutters Way

535 Stone Cutters Way Montpelier, VT 05602 Montpelier, VT 05602

Tel. / 802.229.4541 Tel. / 802.229.4541

Fax / 802.229.5417 Fax / 802.229 5417

E-Mail / [email protected] E-Mail / [email protected]

1 of 25

2 of 25

Table of Contents Page

NARRATIVE ................................................................................................................................. 4

SAMPLE LOGIN RECORDS AND SAMPLE WEIGHTS SUMMARY TABLE ..............................6

LABORATORY ANALYTICAL RESULTS ....................................................................................10

3 of 25

STONE ENVIRONMENTAL, INC. LABORATORY

NARRATIVE

October 29, 2010

This data package presents the analytical results for the soil gas samples analyzed at the Stone Environmental fixed laboratory facility in Montpelier, VT on September 22, 2010. Samples were collected at the Washington Street Apartments Site in Barre, VT on September 22, 2010.

Soil gas samples were collected in tedlar bags. After receipt, samples were stored at the laboratory and analyzed within 24 hours of collection. Samples were analyzed by EPA SW846 Method 8260 (gas chromatography/mass spectrometry (GC/MS)) with solid phase microextration technique for volatile organic compounds (VOCs).

The analytical results associated with the samples presented in this test report were generated under a quality system that adheres to requirements specified in the National Environmental Laboratory Accreditation Conference (NELAC) standards. Results for the quality control (QC) samples were as follows:

• Method Blanks and Trip Blanks were analyzed and they exhibited no detections.

• Initial Calibration and Continuing Calibration Verification Samples were within acceptance limits for the method.

• The parent sample, TVP-07, and its field duplicate sample, TVP-07-FD, had a relative percent difference (RPD) of 51% for toluene. This RPD is slightly higher than the acceptable RPD range for soil gas (50%).

4 of 25

5 of 25

SAMPLE LOGIN RECORDS

6 of 25

7 of 25

8 of 25

Login Summary

LabID LocationID Matrix SampleName SampleCode Quantity CollectedBy CollectedDate CollectedTime CollectionMethod ReceivedBy ReceivedDate ReceivedTime ReceivedTemp Comments LabID_ParentSEI‐115 Bag Blank Soil Gas Bag Blank Normal Sample 1 LJR 9/22/2010 7:10 AM Grab DMKC 9/22/2010 7:10 AM N/ASEI‐110 IA‐01 Soil Gas IA‐01 Normal Sample 1 LJR 9/22/2010 12:15 PM Grab DMKC 9/22/2010 2:05 PM N/ASEI‐112 MW‐3 Soil Gas MW‐3 Normal Sample 1 LJR 9/22/2010 1:20 PM Grab DMKC 9/22/2010 2:05 PM N/ASEI‐106 TB‐01 Soil Gas TB‐01 Normal Sample 1 LJR 9/22/2010 7:10 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐113 TB‐02 Soil Gas TB‐02 Normal Sample 1 LJR 9/22/2010 7:10 AM Grab DMKC 9/22/2010 2:05 PM N/ASEI‐101 TVP‐01 Soil Gas TVP‐01 Normal Sample 1 LJR 9/22/2010 9:13 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐102 TVP‐02 Soil Gas TVP‐02 Normal Sample 1 LJR 9/22/2010 9:41 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐103 TVP‐03 Soil Gas TVP‐03 Normal Sample 1 LJR 9/22/2010 10:04 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐104 TVP‐04 Soil Gas TVP‐04 Normal Sample 1 LJR 9/22/2010 10:22 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐105 TVP‐05 Soil Gas TVP‐05 Normal Sample 1 LJR 9/22/2010 10:45 AM Grab DMKC 9/22/2010 11:24 AM N/ASEI‐114 TVP‐06 Soil Gas TVP‐06 Normal Sample 1 LJR 9/22/2010 11:13 AM Grab DMKC 9/22/2010 2:05 PM N/ASEI‐107 TVP‐07 Soil Gas TVP‐07 Normal Sample 1 LJR 9/22/2010 11:28 AM Grab DMKC 9/22/2010 2:05 PM N/A SEI‐107SEI‐107‐FD TVP‐07 Soil Gas TVP‐07‐FD Field Duplicate 1 LJR 9/22/2010 11:34:00 AM Grab DMKC 9/22/2010 2:05 PM N/A SEI‐107SEI‐109 TVP‐08 Soil Gas TVP‐08 Normal Sample 1 LJR 9/22/2010 12:00 PM Grab DMKC 9/22/2010 2:05 PM N/ASEI‐111 VP‐1 Soil Gas VP‐1 Normal Sample 1 LJR 9/22/2010 12:50 PM Grab DMKC 9/22/2010 2:05 PM N/A

Stone Environmental, Inc. Stone Environmental, Inc. Page 1 of 19 of 25

LABORATORY ANALYTICAL RESULTS

10 of 25

Onsite Laboratory Results Mobile Laboratory 2

Client: Barre Housing Authority Report Date:

Location: Barre, VT Date(s) Sampled:

Project ID: Washington Street Apartments Date(s) Analyzed:

SEI Project No.: 10-2402-R Test Method: SW8260B

Matrix: SG Results Given as: ug/m3

Location ID: TB-01

Sample NameCAS #

TB-01

Analysis Date 9/22/2010 N

tert-Butyl-methyl ether 1634-04-4 18 U

Benzene 71-43-2 16 U

Toluene 108-88-3 19 U

Ethylbenzene 100-41-4 22 U

m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U

1,2,4-Trimethylbenzene 95-63-6 25 U


Naphthalene 91-20-3 100 U

10/29/2010All of the tests results were performed in accordance with the NELAC standards and meet all NELAC requirements for parameters for which accreditation is required or available. The reports were completed according to contract specific reporting requirements. Any exceptions to the NELAC standard requirements are noted and the data has been qualified accordingly.

9/22/2010

9/22/2010

U = Not detected above the specified reporting limit.J = Estimated value.E = Estimated value, marginally above the calibration levels.D = Sample analyzed at a dilution.N = Normal sample.EB = Equipment BlankB = Indicates blank contamination.


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Location ID: TB-02

Sample NameCAS #

TB-02




Toluene 108-88-3 19 U


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-01

Sample NameCAS #

TVP-01




Toluene 108-88-3 19 U


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-02

Sample NameCAS #

TVP-02




Toluene 108-88-3 47


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-03

Sample NameCAS #

TVP-03



Benzene 71-43-2 130

Toluene 108-88-3 31


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-04

Sample NameCAS #

TVP-04



Benzene 71-43-2 19

Toluene 108-88-3 68


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-05

Sample NameCAS #

TVP-05



Benzene 71-43-2 17

Toluene 108-88-3 120


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-06

Sample NameCAS #

TVP-06




Toluene 108-88-3 65


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: TVP-07

Sample NameCAS #

TVP-07-FD TVP-07

Analysis Date 9/22/2010 FD 9/22/2010 N

tert-Butyl-methyl ether 1634-04-4 18 U 18 U

Benzene 71-43-2 16 U 16 U

Toluene 108-88-3 50 83

Ethylbenzene 100-41-4 22 U 22 U

m,p-Xylenes 136777612 22 U 22 U

o-Xylene 95-47-6 22 U 22 U

1,2,4-Trimethylbenzene 95-63-6 25 U 25 U

1,3,5-Trimethylbenzene 108-67-8 25 U 25 U

Naphthalene 91-20-3 100 U 100 U


9/22/2010

9/22/2010



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Location ID: TVP-08

Sample NameCAS #

TVP-08




Toluene 108-88-3 77


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: IA-01

Sample NameCAS #

IA-01




Toluene 108-88-3 130


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: MW-3

Sample NameCAS #

MW-3




Toluene 108-88-3 55


m,p-Xylenes 136777612 72

o-Xylene 95-47-6 79

1,2,4-Trimethylbenzene 95-63-6 260


Naphthalene 91-20-3 220


9/22/2010

9/22/2010



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Location ID: VP-1

Sample NameCAS #

VP-1




Toluene 108-88-3 130


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Location ID: Bag Blank

Sample NameCAS #

Bag Blank




Toluene 108-88-3 19 U


m,p-Xylenes 136777612 22 U

o-Xylene 95-47-6 22 U





9/22/2010

9/22/2010



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Field Duplicate Analyses ReportStone Environmental Project Number: 10-2402-R

RPD

NANA51NANANANANANA

Sample IDLab IDSample DateDate Analyzed

Test Method: SW8260

Results Given as: ug/L

TVP-07 TVP-07-FDSEI-107 SEI-107-FD

9/22/2010 9/22/20109/22/2010 9/22/2010

tert-Butyl-methyl ether 5.0 U 5.0 U

Benzene 5.0 U 5.0 U

Toluene 22 13Ethylbenzene 5.0 U 5.0 U

m,p-Xylenes 5.0 U 5.0 U

o-Xylene 5.0 U 5.0 U

1,2,4-Trimethylbenzene 5.0 U 5.0 U

1,3,5-Trimethylbenzene 5.0 U 5.0 U

Naphthalene 20 U 20 U

U = Not detected above the specified reporting limit.J = Estimated value.E = Estimated value, marginally above the calibration levels.* = Percent Recovery outside QC Limits

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Final Data Report for Laboratory Services PREP AR ED FOR STONE E NVIRONMENTAL

S ITE ID : W ASHINGTON STREET AP AR TMEN TS, B ARRE, VT

Stone Project ID 102402-R

REPORT DATE: November 1, 2010

Prepared for: Prepared by:

Stone Environmental, Inc. Stone Environmental, Inc.

Eric Swiech 535 Stone Cutters Way

535 Stone Cutters Way Montpelier, VT 05602 Montpelier, VT 05602

Tel. / 802.229.4541 Tel. / 802.229.4541

Fax / 802.229.5417 Fax / 802.229 5417

E-Mail / [email protected] E-Mail / [email protected]

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Table of Contents Page

NARRATIVE .................................................................................................................................4

SAMPLE LOGIN RECORDS AND SAMPLE WEIGHTS SUMMARY TABLE ..............................6

LABORATORY ANALYTICAL RESULTS ....................................................................................10

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STONE ENVIRONMENTAL, INC. LABORATORY

NARRATIVE

November 1, 2010

This data package presents the analytical results for the groundwater samples analyzed at the Stone Environmental fixed laboratory facility in Montpelier, VT on October 26-27, 2010. Samples were collected at the Washington Street Apartments Site in Barre, VT on October 14-20, 2010.

After receipt, samples were stored in a refrigerator at the laboratory and were analyzed within 14 days of collection. Samples were analyzed by EPA SW846 Method 8260 (gas chromatography/mass spectrometry (GC/MS)) with solid phase microextration technique for volatile organic compounds (VOCs).

The analytical results associated with the samples presented in this test report were generated under a quality system that adheres to requirements specified in the National Environmental Laboratory Accreditation Conference (NELAC) standards. Results for the quality control (QC) samples (laboratory method blanks, laboratory control samples (LCS), initial calibration verification (ICV) samples, continuing calibration verification (CCV) samples and matrix spike and matrix spike duplicate (MS/MSD) samples) were all deemed to be within the QC tolerances, as specified in the SOPs for these analytical procedures, with the following exceptions:

• Surrogate recoveries were slightly outside of acceptance limits for three samples: MW-16, MW-18D and DUP.

• The trip blank exhibited an estimated low-level toluene detection at 1.6 ug/L. Toluene was not detected in the laboratory method blanks.

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SAMPLE LOGIN RECORDS

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LabID LocationID Depth Matrix SampleName SampleCode Quantity CollectedBy CollectedDate CollectedTime CollectionMethod ReceivedBy ReceivedDate ReceivedTime ReceivedTemp Comments LabID_ParentSEI-13 DUP 000.00 Groundwater DUP Normal Sample 1 ES 10/14/2010 12:00 AM Grab dc 10/20/2010 1:36 PM N/ASEI-17 MW-10 000.00 Groundwater MW-10 Normal Sample 1 ES 10/14/2010 1:52 PM Grab dc 10/20/2010 1:36 PM N/ASEI-14 MW-12 000.00 Groundwater MW-12 Normal Sample 1 ES 10/16/2010 3:55 PM Grab dc 10/20/2010 1:36 PM N/ASEI-4 MW-13 000.00 Groundwater MW-13 Normal Sample 1 ES 10/14/2010 4:25 PM Grab dc 10/20/2010 1:36 PM N/ASEI-5 MW-14 000.00 Groundwater MW-14 Normal Sample 1 ES 10/14/2010 4:05 PM Grab dc 10/20/2010 1:36 PM N/ASEI-15 MW-15 000.00 Groundwater MW-15 Normal Sample 1 ES 10/16/2010 4:10 PM Grab dc 10/20/2010 1:36 PM N/ASEI-6 MW-16 000.00 Groundwater MW-16 Normal Sample 4 ES 10/14/2010 12:45 PM Grab dc 10/20/2010 1:36 PM N/ASEI-7 MW-17 000.00 Groundwater MW-17 Normal Sample 1 ES 10/14/2010 12:00 PM Grab dc 10/20/2010 1:36 PM N/ASEI-9 MW-18D 000.00 Groundwater MW-18D Normal Sample 1 ES 10/14/2010 1:50 PM Grab dc 10/20/2010 1:36 PM N/ASEI-8 MW-18S 000.00 Groundwater MW-18S Normal Sample 1 ES 10/14/2010 1:20 PM Grab dc 10/20/2010 1:36 PM N/ASEI-11 MW-19D 000.00 Groundwater MW-19D Normal Sample 1 ES 10/14/2010 3:05 PM Grab dc 10/20/2010 1:36 PM N/ASEI-10 MW-19S 000.00 Groundwater MW-19S Normal Sample 1 ES 10/14/2010 2:40 PM Grab dc 10/20/2010 1:36 PM N/A SEI-10SEI-10-MS MW-19S 000.00 Groundwater MW-19S-MS Matrix Spike 1 ES 10/14/2010 2:40 PM Grab dc 10/20/2010 1:36 PM N/A SEI-10SEI-10-MSD MW-19S 000.00 Groundwater MW-19S-MSD Matrix Spike Duplicate 1 ES 10/14/2010 2:40 PM Grab dc 10/20/2010 1:36 PM N/A SEI-10SEI-12 MW-20S 000.00 Groundwater MW-20S Normal Sample 1 ES 10/14/2010 3:35 PM Grab dc 10/20/2010 1:36 PM N/ASEI-1 MW-4 000.00 Groundwater MW-4 Normal Sample 2 ES 10/14/2010 12:47 PM Grab dc 10/20/2010 1:36 PM 4.5SEI-2 MW-5 000.00 Groundwater MW-5 Normal Sample 2 ES 10/14/2010 1:02 PM Grab dc 10/20/2010 1:36 PM 4.5SEI-3 MW-9 000.00 Groundwater MW-9 Normal Sample 2 ES 10/14/2010 12:35 PM Grab dc 10/20/2010 1:36 PM N/ASEI-16 Trip Blank 000.00 Groundwater Trip Blank Trip Blank 1 ES 10/20/2010 2:20 PM Grab dc 10/20/2010 1:36 PM N/A

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LABORATORY ANALYTICAL RESULTS

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Matrix: GW Results Given as: ug/L

Location ID: MW-4

Sample Name CAS # MW-4


tert-Butyl-methyl ether 1634-04-4 2.0 U

Benzene 71-43-2 11

Toluene 108-88-3 10

Ethylbenzene 100-41-4 390

m,p-Xylenes 136777612 150

o-Xylene 95-47-6 47




Bromofluorobenzene (SS) 460-00-4 124 %


10/14/2010

10/27/2010



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Location ID: MW-5




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U

Ethylbenzene 100-41-4 2.0 U

m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U

1,2,4-Trimethylbenzene 95-63-6 2.0 U


Naphthalene 91-20-3 2.0 U



10/14/2010

10/26/2010



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Location ID: MW-9




Benzene 71-43-2 220

Toluene 108-88-3 47


m,p-Xylenes 136777612 170

o-Xylene 95-47-6 12






10/14/2010

10/27/2010



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Location ID: MW-10




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/14/2010

10/26/2010



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Location ID: MW-12




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/16/2010

10/27/2010



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Location ID: MW-13




Benzene 71-43-2 1900

Toluene 108-88-3 28000 E


m,p-Xylenes 136777612 20000

o-Xylene 95-47-6 9200




Bromofluorobenzene (SS) 460-00-4 116 D


10/14/2010

10/27/2010



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Location ID: MW-14




Benzene 71-43-2 340

Toluene 108-88-3 5400


m,p-Xylenes 136777612 4100

o-Xylene 95-47-6 2200






10/14/2010

10/27/2010



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Location ID: MW-15




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/16/2010

10/27/2010



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Location ID: MW-16




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 46

o-Xylene 95-47-6 9.0






10/14/2010

10/27/2010



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Location ID: MW-17




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 3.0

o-Xylene 95-47-6 8.8



Naphthalene 91-20-3 3.0



10/14/2010

10/27/2010



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Location ID: MW-18S

Sample Name CAS # MW-18S



Benzene 71-43-2 2.0 U

Toluene 108-88-3 1.9 J


m,p-Xylenes 136777612 190

o-Xylene 95-47-6 5.4






10/14/2010

10/27/2010



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Location ID: MW-18D

Sample Name CAS # MW-18D



Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 750

o-Xylene 95-47-6 29






10/14/2010

10/27/2010



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Location ID: MW-19S




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/14/2010

10/27/2010



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Location ID: MW-19D

Sample Name CAS # MW-19D



Benzene 71-43-2 3.2

Toluene 108-88-3 1.0 J


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U



Naphthalene 91-20-3 2.1



10/14/2010

10/27/2010



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Location ID: MW-20S




Benzene 71-43-2 2.0 U

Toluene 108-88-3 2.0 U


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/14/2010

10/27/2010



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Location ID: DUP

Sample Name CAS # DUP



Benzene 71-43-2 380

Toluene 108-88-3 6100


m,p-Xylenes 136777612 4700

o-Xylene 95-47-6 2400






10/14/2010

10/27/2010



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Location ID: Trip Blank

Sample Name CAS # Trip Blank

Analysis Date 10/27/2010 TB


Benzene 71-43-2 2.0 U

Toluene 108-88-3 1.6 J


m,p-Xylenes 136777612 2.0 U

o-Xylene 95-47-6 2.0 U






10/20/2010

10/27/2010



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Stone Environmental Inc. Project Number: 102402 Laboratory Matrix Spike/Matrix Spike Duplicate Analyses Summary Sheet

MW-19S

10/14/2010

10/27/2010

Sample ID:

Sample Date:

Analysis Date:

Analyte

OriginalConc.(ug/L)

MSConc. (ug/L)

MS% Recovery

MSD% Recovery

MSDConc. (ug/L)

RPD < 30

QC Limits(% Recovery)

Spike Amount (ug/L):

SW8260BMethod:

20 20

tert-Butyl-methyl ether 2.0 U 22 110 21 105 5 70 - 130Benzene 2.0 U 20 100 19 95 5 70 - 130Toluene 2.0 U 21 105 20 100 5 70 - 130Ethylbenzene 2.0 U 21 105 19 95 10 70 - 130m,p-Xylenes 2.0 U 42 105 38 95 10 70 - 130o-Xylene 2.0 U 21 105 19 95 10 70 - 1301,2,4-Trimethylbenzene 2.0 U 21 105 19 95 10 70 - 1301,3,5-Trimethylbenzene 2.0 U 21 105 19 95 10 70 - 130Naphthalene 2.0 U 20 100 19 95 5 70 - 130

U = Not detected above the specified reporting limit.J = Estimated value.E = Estimated value, marginally above the calibration levels.* = Percent Recovery outside QC Limits

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section 1.0 1.0 site description and physical settingwell was not installed adjacent to mw-5 on the...

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