August 3, 2015 Mr. James Donaldson Waste Management ...Mr. James Donaldson - 2 - August 3, 2015 1.0 SITE DESCRIPTION AND PHYSICAL SETTING The Site is located in a mixed commercial/residential

2113 Stony Brook Road Northfield, VT 05663

(802) 485-9466

August 3, 2015 Mr. James Donaldson Vermont Department of Environmental Conservation Waste Management Division 1 National Life Drive – Davis 1 Montpelier, Vermont 05620-3704 Re: Semi-Annual Groundwater Monitoring Report – May 2015 Washington Street Apartments

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

Dear James: On behalf of the Barre Housing Authority, Vermont HydroGeo, LLC (VHG) is pleased to present the results of a semi-annual groundwater monitoring event completed at the above-referenced Site in May 2015 (Figures 1 and 2). This report also presents the results of free-phase product analysis on a sample collected from monitoring well MW-14. The groundwater monitoring was completed in accordance with the work plan and cost estimate dated September 17, 2014, which you approved via email with a Petroleum Cleanup Fund (PCF) budget tracking number of 13619. The fuel identification work was completed in accordance with a work plan and cost estimate dated March 18, 2015, which you approved via email with a PCF budget tracking number of 15625. 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 describes monitoring methods; Section 4.0 presents monitoring results; Section 5.0 discusses an updated conceptual site model; and Section 6.0 provides conclusions and recommendations.

Mr. James Donaldson - 2 - August 3, 2015 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. 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 groundwater quality at the Site. In addition, in October 1993, eight ambient air samples were collected within the on-Site building and the church using charcoal sorbent tubes; K-D Associates, Inc. reported that proper sampling procedures were followed and no volatile organic compounds (VOCs) were detected in any of the samples. 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 groundwater samples collected from monitoring wells MW-4 and MW-9.

Mr. James Donaldson - 3 - August 3, 2015 Site monitoring ceased after October 2000. In spring 2008, the Vermont Department of Environmental Conservation (VT DEC) contacted the Barre Housing Authority requesting that work resume on the project. The Barre Housing Authority subsequently retained Applied GeoSolutions, LLC (AGS) for assistance. Since 2008, a series of additional Site investigations were initiated to further characterize contaminant conditions and the risk to sensitive receptors. The results of these investigations have been documented in the following reports:

Supplemental Site Investigation Report. Applied GeoSolutions, LLC. December 12, 2008.

o Geophysical surveys were conducted 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 downgradient monitoring well (MW-12) and three upgradient monitoring wells located at 30 Washington Street (MW-13, MW-14, and MW-15), and completed a Site-wide groundwater monitoring event.

Additional Site Investigation Report. Stone Environmental, Inc. January 26, 2011.

o Nine sub-slab vapor samples were collected within the basement of the apartment building at 14 Washington Street from temporary vapor points TVP-01 through TVP-08 and permanent vapor point V-1 and analyzed for target petroleum VOCs via EPA Method 8260. One indoor air sample was collected from within the laundry room of on-Site building (basement level). Eight additional monitoring wells were installed at the Site, including shallow water-table monitoring wells MW-16, MW-17, MW-18S, MW-19S, MW-20S and deeply-screened monitoring wells MW-18D, MW-19D, and MW-20D, which were paired with shallow wells. Groundwater samples were collected from all the newly installed wells and most of the existing ones and analyzed for target petroleum VOCs via EPA Method 8260.

Supplemental Site Investigation Report. Vermont HydroGeo, LLC. January 29, 2013.

o An active soil gas survey was completed along the eastern exterior of the on-Site apartment building and the eastern exterior of First Baptist Church in order to: 1) further evaluate the potential source of elevated benzene concentrations previously detected in sub-slab soil gas beneath the on-Site apartment building; and 2) quantify target VOC concentrations in soil gas to better assess vapor intrusion (VI) pathways for the on-Site apartment building and the First Baptist Church. Five exterior soil gas sampling locations were monitored: two along

Mr. James Donaldson - 4 - August 3, 2015

the eastern side of the church (TPV-09 and TPV-10), and three along the eastern side of the on-Site apartment building (TPV-11, TPV-12, and TPV-13). Three indoor air samples were collected from within the basement of the apartment building (IA-01, IA-02, and IA-03) and one ambient outdoor air sample (OA-01) was obtained. In addition, groundwater samples were collected from select monitoring wells and analyzed for target petroleum VOCs via EPA Method 8260.

Following the 2013 SSI, a semi-annual monitoring and reporting program was implemented for select groundwater monitoring wells. In November 2014 and January 2015, VHG conducted a soil vapor extraction (SVE) pilot test in the vicinity of monitoring well MW-14 (which contains free-phase product) to: 1) determine the efficacy of SVE for mitigating the risk of vapor intrusion at the First Baptist Church and the office building at 30 Washington Street; 2) evaluate whether this remedial technology is suitable for removing free-phase product; and 3) obtain appropriate data to design a full-scale SVE system, should one be deemed necessary. The results of the pilot study were documented in VHG’s report dated March 11, 2015. In April 2015, VHG conducted an additional Site-wide VI assessment. The work included the collection of indoor air samples from the basements of the Washington Street Apartments (14 Washington Street), the office building at 30 Washington Street, and the First Baptist Church, located between the above two buildings. In addition, sub-slab vapor samples were collected from beneath the basements at 14 and 30 Washington Street. The results of the VI assessment were documented in VHG’s report dated May 12, 2015. 3.0 WORK COMPLETED Fuel Identification On April 16, 2015, VHG collected a sample of free-phase product from monitoring well MW-14 using a peristaltic pump and dedicated Teflon-lined polyethylene and silicone tubing. Following collection, the samples were placed in an ice-filled cooler and transported to Endyne, Inc. of Williston, Vermont for analysis of target petroleum VOCs by EPA Method 8260C and fuel identification via EPA Method 8015D. Target VOCs include Methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene, total xylenes, 1,2,4- trimethylbenzene (TMB), 1,3,5- TMB, and naphthalene.

Mr. James Donaldson - 5 - August 3, 2015 Groundwater Monitoring VHG conducted groundwater monitoring at the Site on May 1, 2015. VHG collected groundwater samples for subsequent laboratory analysis from monitoring wells MW-3, MW-4, MW-9, MW-10, MW-13, MW-16, MW-17, MW-18S, MW-18D, MW-19S, and MW-19D. Prior to collecting groundwater samples, VHG obtained and recorded liquid-level measurements from select on-Site and off-Site monitoring wells. Liquid levels were manually measured to the nearest 0.01 foot using an electronic oil/water interface probe. Monitoring wells were purged and sampled in general accordance with United States Environmental Protection Agency (USEPA) Region I low-flow purging and sampling protocol using a peristaltic pump and dedicated Teflon-lined polyethylene and silicone tubing. A trip blank and duplicate sample (from MW-13) were acquired to evaluate quality assurance / quality control (QA/QC).

Following collection, all samples were placed in an ice-filled cooler and transported to Endyne, Inc. of Williston, Vermont for analysis of target petroleum VOCs by EPA Method 8021B. 4.0 MONITORING RESULTS

4.1 Liquid-Level Measurements During the May 2015 monitoring event, depth-to-water measurements in the flush-mounted overburden monitoring wells ranged from 10.21 feet below top-of-casing (BTOC) in monitoring well MW-19S to 13.45 feet BTOC in monitoring well MW-16. LNAPL was detected within monitoring well MW-14 at a thickness of 0.40 feet. LNAPL was not detected in any other monitoring well. Calculated relative groundwater elevations ranged from 83.84 feet at monitoring well MW-19D to 87.88 feet at monitoring well MW-13 (Table 4-1). On average, the groundwater elevations were about one foot higher than during the previous monitoring event in October 2014.


Table 4-1. Liquid-Level Monitoring Data: May 1, 2015

4.2 Quality Assurance / Quality Control During the April 2015 monitoring event, relative percent difference (RPD) values for individual VOCs from sample MW- and its field duplicate sample (Dup) ranged from 2.1 to 15 percent. The maximum acceptable RPD for water samples is 30 percent. No VOCs were detected in the trip blank.

4.3 Analytical Results

Groundwater laboratory analytical results are included in Table 4-2 and on Figure 4. Laboratory report forms are included in Appendix A. Time-series graphs for select monitoring wells are provided in Appendix B.

Well I.D.Top-of-Casing

Elevation (feet)

Depth-to-Product

(feet BTOC)

Depth-to-Water (feet BTOC)

Screen Interval (feet BTOC)

Apparent Product

Thickness (feet)

Corrected Depth-to-

water (feet BTOC)

Groundwater Elevation

(feet)

MW-3 98.25 -- 12.35 9-24 0.00 12.35 85.90

MW-4 97.89 -- 12.26 12.8-27.8 0.00 12.26 85.63

MW-8 98.13 -- 11.58 8-16 0.00 11.58 86.55

MW-9 98.50 -- 13.10 19-20 0.00 13.10 85.40

MW-10 98.69 -- 12.49 9-15 0.00 12.49 86.20

MW-13 98.79 -- 10.91 9.7-19.7 0.00 10.91 87.88

MW-14 99.43 13.05 13.45 9.7-19.7 0.40 13.10 86.33

MW-15 99.45 -- 12.45 9.8-19.8 0.00 12.45 87.00

MW-16 99.02 -- 13.45 10-20 0.00 13.45 85.57

MW-17 98.83 -- 13.36 8-18 0.00 13.36 85.47

MW-18S 98.91 -- 12.71 7.5-17.5 0.00 12.71 86.20

MW-18D 98.85 -- 13.41 16.9-21.9 0.00 13.41 85.44

MW-19S 96.39 -- 10.21 7.3-17.3 0.00 10.21 86.18

MW-19D 96.43 -- 12.59 19.3-24.3 0.00 12.59 83.84


Table 4-2: Groundwater Analytical Results: May 1, 2015

Notes: Concentrations reported in micrograms per Liter (µg/L). Shaded values exceed VGES. No target VOCs were detected in groundwater samples collected from monitoring wells MW-3, MW-10, or MW-19S.

Detectable total target VOC concentrations ranged from 3.5 µg/L in monitoring wells MW-18S to 44,618 µg/L in MW-13.

MTBE (MW-18D), benzene (MW-4, MW-9, MW-13, and MW-18D), toluene (MW-13), ethylbenzene (MW-13), total xylenes (MW-13), total TMBs (MW-4, MW-13, and MW-18D), and naphthalene (MW-4 and MW-18D) were detected at concentrations above respective VGESs.

Sample Location

MTBE Benzene Toluene Ethylbenzene Total

Xylenes Total TMBs

NaphthaleneTotal Target

VOCs

MW-3 ND<2.0 ND<1.0 ND<1.0 ND<1.0 ND<2.0 ND<1.0 ND<2.0 ND

MW-4 35.4 18.1 ND<10.0 454 567 1,088 149 2,312

MW-9 3.5 8.0 1.1 3.3 5.6 3.0 11.2 36

MW-10 ND<2.0 ND<1.0 ND<1.0 ND<1.0 ND<2.0 ND<1.0 ND<2.0 ND

MW-13 ND<400 510 21,700 3,710 15,900 2,798 ND<400 44,618

MW-16 ND<2.0 ND<1.0 ND<1.0 2.5 3.1 10.5 ND<2.0 16.1

MW-17 ND<2.0 ND<1.0 ND<1.0 2.4 ND<2.0 12.8 ND<2.0 15.2

MW-18S ND<20.0 ND<10.0 ND<10.0 ND<1.0 ND<2.0 3.5 ND<2.0 3.5

MW-18D 89.5 5.3 ND<10.0 219 55.8 961 30.0 1,361

MW-19S ND<2.0 ND<1.0 ND<1.0 ND<2.0 ND<2.0 ND<1.0 ND<2.0 ND

MW-19D 2.1 ND<1.0 ND<1.0 7.3 ND<2.0 ND<1.0 ND<2.0 9.4

QA/QC

MW-13 ND<400 510 21,700 3,710 15,900 2,798 ND<400 44,618

Dup ND<400 541 24,600 4,220 17,900 3,108 416 50,785

RPD -- 5.9 12.5 12.9 11.8 10.5 -- 12.9

Trip Blank ND<2.0 ND<2.0 ND<1.0 ND<2.0 ND<2.0 ND<2.0 ND<2.0 ND

VGES 40 5 1,000 700 10,000 350 20 --

Mr. James Donaldson - 8 - August 3, 2015 4.4 LNAPL Monitoring and Fuel Identification

LNAPL thickness monitoring data for monitoring wells MW-3 and MW-14 are provided in Tables 4-3, and Table 4-4, respectively.

LNAPL (#2 oil) has not been detected in monitoring well MW-3 since the oleophilic “sock” was removed in January 2013.

Table 4-3: LNAPL Monitoring Data at MW-3.

Date

Depth-to-Product

(feet BTOC)

Depth-to-Water

(feet BTOC)

Apparent Product

Thickness (feet)

Comments

12/1/2012 12.90 13.18 0.28 12/19/2012 12.76 13.02 0.26 Installed oleophilic "sock". 1/4/2013 -- 12.90 0.00 Removed oil-saturated oleophilic "sock". 1/12/2013 -- 12.81 0.00 1/17/2013 -- 12.75 0.00 1/25/2013 -- 12.80 0.00 4/29/2013 -- 12.53 0.00 7/20/2013 -- 12.28 0.00

11/20/2013 -- 12.75 0.00 5/26/2014 -- 12.34 0.00 10/17/14 -- 12.91 0.00

5/1/15 -- 12.35 0.00

LNAPL was first detected in MW-14 during the November 2012 monitoring event, at a thickness of 0.81 feet. LNAPL has been present in this well during each of the subsequent monitoring events. On November 20, 2013, no LNAPL was detected with the interface probe; however, LNAPL was observed in the flow-through cell during purging. During the most recent monitoring event in May 2014, 0.45 feet of LNAPL was measured.


Table 4-4: LNAPL Monitoring Data at MW-14.

The fuel identification conducted on the sample of LNAPL collected confirmed the product resembles gasoline. Laboratory report forms are provided in Appendix A. 5.0 UPDATED CONCEPTUAL SITE MODEL

Geology / Hydrogeology 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 to 10 feet bgs. These materials appear to overlie native fluvial silt/clayey-silt deposits (with 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. The depth-to-water across the Site varies seasonally between about 11 to 14 feet bgs. Apparent shallow groundwater flow in the overburden aquifer is 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 3). The water-table gradient across the Site typically ranges from about 0.01 feet/foot to about 0.03 feet/foot.

DateDepth-to-Product

(feet BTOC)

Depth-to-Water (feet BTOC)

Apparent Product

Thickness (feet)

8/28/2008 -- 12.78 0.00

10/14/2010 -- 13.36 0.0011/11/2012 13.35 14.16 0.814/29/2013 12.23 12.91 0.6811/20/2013 -- 13.98 0.005/26/2014 12.51 13.39 0.8810/17/2014 13.40 14.49 1.094/16/2015 12.90 13.70 0.805/1/2015 13.05 13.45 0.40

Mr. James Donaldson - 10 - August 3, 2015 Hydraulic-head data from cluster wells MW-9/MW-10, MW-18S/MW-18D, and MW-19S/MW-19D indicate that vertical flow components within the overburden aquifer fluctuate both upward and downward. A buried stream channel (former Potash Brook) is located on the west side of the apartment building, flowing north to south. It is believed that the structure is a concrete box culvert. Leakage from the box culvert may recharge the shallow overburden aquifer and create the downward vertical groundwater flow component observed at cluster wells MW-19S/MW-19D. 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 features do not likely influence shallow groundwater flow. Contaminant Distribution/ Fate & Transport Based on available contaminant distribution and hydrogeologic data, and historic on-Site and off-Site operations, 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 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. Since the former on-Site gasoline and heating oil USTs appear to have been located in close proximity to each other, VHG has combined these apparent contaminant sources into one general area of concern (AOC #1) for discussion purposes. VHG has designated the former off-Site UST system at 30 Washington Street as AOC #2. Recent detections of MTBE in on-Site and off-Site monitoring wells suggest there may be an additional source(s) for petroleum contamination observed at the Site. 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 groundwater, and hydrocarbons are present in the vapor, sorbed, dissolved, and NAPL phases.

Mr. James Donaldson - 11 - August 3, 2015 Gasoline and #2 heating oil are comprised of hundreds of individual compounds. These compounds are typically readily sorbed to soil and organic matter, have a relatively low aqueous solubility, and are biodegradable under both aerobic and anaerobic conditions, although the rate of anaerobic biodegradation is one to two orders of magnitude lower than the rate of aerobic biodegradation. AOC #1 In AOC #1, mobile LNAPL released from the former #2 heating oil UST system had historically been present in monitoring well MW-3, which is located within the footprint of the former heating oil UST. On December 19, 2012, 0.26 feet of LNAPL was present in MW-3; this product was removed on January 4, 2013 using an oleophilic “sock”, and LNAPL has not been detected in the well during nine subsequent monitoring events completed to date. The horizontal extent of LNAPL (#2 oil) appears to have been confined to the vicinity of monitoring well MW-3. 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, but no measurable LNAPL has been detected in these wells to date. Dissolution of the #2 oil released at the Site has generated a dissolved-phase target VOC plume within the overburden aquifer (Figure 4). Monitoring wells MW-16, MW-18S, and MW-18D, located within the vicinity of the former heating oil UST system on the eastern side of the apartment building, have historically contained total TMBs and naphthalene at concentrations above the respective VGESs (Graphs 5, 7, and 8, Appendix B). In addition, MTBE has been detected above the VGES in MW-18D during the last six monitoring events, and in MW-18S during the November 2013 monitoring event. No VOCs have been detected at concentrations above the VGESs in downgradient monitoring wells located on the western side of the apartment building, suggesting the plume is relatively limited in extent. Based on apparent groundwater flow direction, it is possible that the heating-oil related plume co-mingles with the gasoline-related plume from AOC #2 beneath the apartment building downgradient of monitoring wells MW-9 and MW-10. Based on the analytical data available to date, total TMB and naphthalene concentrations appear to be stable or declining at monitoring wells MW-16 and MW-18D. At MW-18S, contaminant concentrations appear to vary widely in response to the water table elevation, with relatively high contaminant concentrations occurring under low water-table conditions; however, a decreasing trend in contaminant concentrations is beginning to develop in the low water table data set. Exposure pathways to human receptors from soil and groundwater contamination associated with AOC #1 do not currently appear to be complete, as impacted soils are relatively deep and covered with asphalt, and impacted groundwater at the Site is not used as a potable source. However, any future intrusive activities in this area may present a risk of exposure.

Mr. James Donaldson - 12 - August 3, 2015 Partitioning from the petroleum released in AOC #1 has generated a vapor-phase plume with select target VOCs present at concentrations in excess of the VT DEC soil gas screening values. However, multiple phases of investigation have led to the conclusion that the vapor intrusion exposure pathway does not appear to be complete, as documented in previous reports. Finally, 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 identified in AOC #1. 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. However, if releases of gasoline did occur in this area, the impact to groundwater does not appear to be significant, and it may be co-mingled with the dissolved-phase heating oil contamination. AOC #2 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 gasoline contamination remains present within the subsurface at this property. LNAPL (as gasoline) has routinely been detected in monitoring well MW-14, and LNAPL was recorded at a thickness of 0.45 feet during the most recent monitoring event in April 2015. Gross contamination (e.g. PID readings >1,000 ppm v/v on soils) within the investigated portion of this area is present between about 8 to 20 feet bgs. The upgradient boundary of the source-area contamination has not been defined. Based on apparent shallow groundwater flow and available contaminant distribution data, 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. The VOC impact at monitoring wells MW-4, MW-9, and MW-19D likely originates from 30 Washington Street. Data from cluster wells MW-9/MW-10 and MW-19S/MW-19D suggest the VOC plume is “diving” in this portion of the aquifer, and has migrated beneath the apartment building. There appears to be a relatively “clean” water lense above the plume in this portion of the Site. The downgradient extent of the VOC plume has been reasonably delineated, and the plume does not likely extend much beyond MW-19D. During the most recent monitoring event in May 2014, detectable total target VOC concentrations ranged from 97.6 µg/L in

Mr. James Donaldson - 13 - August 3, 2015 deeply-screened cluster monitoring well MW-19D, located on the west side of the apartment building, to 25,877 µg/L in MW-14, which is located in the southwest corner of the parcel at 30 Washington Street. MTBE, benzene, toluene, ethylbenzene, total TMBs, and naphthalene were detected in one or more monitoring well impacted by AOC #2 at concentrations above the respective VGESs. Although total dissolved VOC concentrations in MW-4 and MW-9 have fluctuated over time since monitoring commenced in 1995, an overall decreasing trend appears evident from each data set (Graphs 1 and 2, Appendix B). Within the source area, total VOC and benzene concentrations have fluctuated up and down in MW-13 over the eight monitoring events completed at this well to date (Graph 3, Appendix B); concentrations may vary in response to fluctuations of the water table within the smear zone. Partitioning from the petroleum released in AOC #2 has generated a vapor-phase plume with select target VOCs present at concentrations in excess of the VT DEC soil gas screening values. However, multiple phases of investigation have led to the conclusion that the vapor intrusion exposure pathway does not appear to be complete, as documented in previous reports. Monitored natural attenuation (MNA) appears to be a plausible remedial alternative for addressing the downgradient dissolved plume associated with AOC #2. However, the presence of mobile LNAPL in MW-14 warrants some form of active remediation.

MTBE Source(s) During the November 2012 monitoring event, MTBE was detected in groundwater at the Site for the first time since monitoring commenced in 1995. MTBE concentrations in monitoring wells MW-9 and MW-18D exceeded the VGES for this compound of 40 µg/L, while MTBE was detected in downgradient monitoring well MW-19D at a concentration of 5.0 µg/L. Since that time, MTBE has been detected in several other monitoring wells, and has consistently exceeded its VGES in monitoring well MW-18D. During the May 2014 event, MTBE was detected for the first time in monitoring well MW-13, which is located upgradient of the Site; however, laboratory detection limits during previous monitoring events were elevated due to the presence of other high level contamination, so it is possible that MTBE was present at this location previously. MTBE is an octane-enhancing additive of gasoline that came into wide-spread use circa 1979. Since the removal of the former on-Site gasoline UST is believed to have been taken out of service prior to 1979, and MTBE was not previously detected in on-Site monitoring wells, the release of MTBE that has been detected in monitoring wells within and near AOC#1 appears to have occurred relatively recently. While the source of the MTBE is not known at this time,

Mr. James Donaldson - 14 - August 3, 2015 it is possible that it is attributed to parking lot runoff that may have leaked from the storm water catch basin that is located hydraulically upgradient of monitoring wells MW-9 and MW-18D. It is not clear when the gasoline USTs at 30 Washington Street were removed. If they were removed after 1979, these former USTs may be the source for the MTBE detected in MW-13. If the USTs were removed before 1979, the MTBE detected in MW-13 must be attributed to another unknown release. 6.0 CONCLUSIONS AND RECOMMENDATIONS Based on the results of the October 2014 monitoring event and historic Site data, VHG has drawn the following conclusions:

There appears to be multiple sources for the petroleum contamination identified at the Site, including: 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 (30 Washington Street). The former on-Site gasoline and heating oil USTs appear to have been located in close proximity to each other, and are combined into one general area of concern (AOC #1); if a release did occur from the former on-Site gasoline UST system, the impact is overshadowed by the release from the former heating oil UST. The former off-Site UST system at 30 Washington Street is designated as AOC #2. Recent detections of MTBE suggest there may be additional sources for petroleum contamination observed at the Site.

LNAPL released from the former #2 heating oil UST system has historically been present in monitoring well MW-3, which is located within the footprint of the former heating oil UST. However, no LNAPL has been detected in this well since January 2013.

Dissolution of the #2 oil released at the Site in AOC #1 has generated a dissolved-

phase target VOC plume within the overburden aquifer that appears to be relatively limited in extent. Monitoring wells MW-16, MW-18S, and MW-18D, located within the vicinity of the former heating oil UST system on the eastern side of the apartment building, have historically contained total TMBs and naphthalene at concentrations above the respective VGESs. MTBE has recently been detected above the VGES in MW-18S and MW-18D; the source of MTBE in these wells may be related to parking lot runoff. During the May 2015 monitoring event, total TMBs, naphthalene, and MTBE were detected in monitoring well MW-18D at concentrations above the VGESs; MTBE also exceeded the VGES at MW-18D. Based on the limited analytical data


available to date, total TMB and naphthalene concentrations appear to be stable or declining at monitoring wells MW-16 and MW-18D. At MW-18S, contaminant concentrations appear to vary widely in response to the water table elevation, with relatively high contaminant concentrations occurring under low water-table conditions; however, a decreasing trend in contaminant concentrations is beginning to develop in the low water table data set. At this time, continued MNA appears to be a viable remedial alternative for addressing the dissolved plumes associated with AOC #1.

Significant gasoline-related contamination is present within the subsurface at 30 Washington Street which appears to be related to a former gasoline UST system on this property (AOC #2). Gasoline (as LNAPL) was present in monitoring well MW-14 during the May 2015 at a thickness of 0.45 feet. The upgradient boundary of the source-area contamination has not been reasonable defined. The dissolved-phase VOC impact at monitoring wells MW-4, MW-9, and MW-19D likely originates from AOC #2, although there may be some co-mingling with contamination from AOC #1. The VOC plume is “diving” in this portion of the aquifer, and has migrated beneath the church and the apartment building at 14 Washington Street. The downgradient extent of the plume appears to have been reasonably delineated, and does not likely extend much beyond MW-19D. During the most recent monitoring event in May 2015, detectable total target VOC concentrations ranged from 3.5 µg/L in monitoring well MW-18S to 44,618 µg/L in MW-14. Benzene, toluene, ethylbenzene, total TMBs, and total xylenes were detected in one or more monitoring well impacted by AOC #2 at concentrations above the respective VGESs. MNA appears appropriate for addressing the downgradient dissolved plume associated with AOC #2. However, active remediation appears prudent to remove LNAPL near MW-14.

Partitioning from the petroleum released in AOC #1 and AOC #2 has generated vapor-phase plumes with select target VOCs present at concentrations in excess of the VT DEC soil gas screening values. However, multiple phases of investigation have led to the conclusion that the vapor intrusion exposure pathway does not appear to be complete, as documented in previous reports.

The free-phase product present in monitoring well MW-14 was confirmed by laboratory analysis to resemble gasoline.

Given the above conclusions, VHG offers the following recommendations:

Groundwater monitoring of select monitoring wells should continue on a semi-annual basis to track temporal changes in water quality. The next monitoring event should occur in fall 2015, and include monitoring wells MW-3, MW-4, MW-9, MW-10, MW-


13, MW-14, MW-16, MW-17, MW-18S, MW-18D, MW-19S, and MW-19D. Samples should be analyzed for target VOCs via US EPA Method 8021B. In addition, monitoring wells MW-13, MW-4, and MW-9 should be analyzed for ethylene dibromide via EPA Method 8011 (alternatively, these well could be analyzed for target VOCs and ethylene dibromide via EPA Method 8260 with selected ion monitoring (SIM), which may provide a cost savings). Following the fall 2015 monitoring event, assuming contaminant concentrations are comparable or lower than previous results, the monitoring frequency should be reduced to annually, with events occurring in the fall when groundwater elevations across the Site are typically relatively low, and the highest contaminant concentrations are generally observed.

Free-phase product in monitoring well MW-14 should be recovered on a periodic basis with a peristaltic pump.

SVE should be conducted at SVE-1 to assist in recovery of free-phase product near MW-14 until the granular activated carbon drum utilized for the SVE pilot test is spent.

************************************************************************************** Please do not hesitate to contact me if you have any questions. Yours truly, Vermont HydroGeo, LLC Eric J. Swiech, P.G. Principal Hydrogeologist Phone / 802-485-9466 E-Mail / [email protected] cc: Mr. Chip Castle, Barre Housing Authority Mr. Rick Davis, Property Owner (30 Washington Street)

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

Laboratory Report

WSAPROJECT:

DATE RECEIVED:

WORK ORDER:

DATE REPORTED:

100905

Vermont HydroGeo

2113 Stony Brook Rd

Northfield, VT 05663

Atten: Eric Swiech SAMPLER:

May 01, 2015

1504-06977

Eric

April 17, 2015

Enclosed please find the results of the analyses performed for the samples referenced on the attached chain of custody. All required method quality control elements including instrument calibration were performed in accordance with method requirements and determined to be acceptable unless otherwise noted.

The column labeled Lab/Tech in the accompanying report denotes the laboratory facility where the testing was performed and the technician who conducted the assay. A "W" designates the Williston, VT lab under NELAC certification ELAP 11263; "R" designates the Lebanon, NH facility under certification NH 2037 and “N” the Plattsburgh, NY lab under certification ELAP 11892. “Sub” indicates the testing was performed by a subcontracted laboratory. The accreditation status of the subcontracted lab is referenced in the corresponding NELAC and Qual fields.

The NELAC column also denotes the accreditation status of each laboratory for each reported parameter. “A” indicates the referenced laboratory is NELAC accredited for the parameter reported. “N” indicates the laboratory is not accredited. “U” indicates that NELAC does not offer accreditation for that parameter in that specific matrix. Test results denoted with an “A” meet all National Environmental Laboratory Accreditation Program requirements except where denoted by pertinent data qualifiers. Test results are representative of the samples as they were received at the laboratory

Endyne, Inc. warrants, to the best of its knowledge and belief, the accuracy of the analytical

test results contained in this report, but makes no other warranty, expressed or implied, especially no warranties of merchantability or fitness for a particular purpose.

Page 1 of 2

Reviewed by:

Harry B. Locker, Ph.D.

Laboratory Director

ELAP 11263

160 James Brown Dr., Williston, VT 05495

Ph 802-879-4333 Fax 802-879-7103

www.endynelabs.com

NH2037

56 Etna Road, Lebanon, NH 03766

Ph 603-678-4891 Fax 603-678-4893

Laboratory Report

Vermont HydroGeo

Page 2 of 2

CLIENT:PROJECT: WSA

WORK ORDER:DATE RECEIVED

1504-0697704/17/2015

DATE REPORTED: 05/01/2015

001 Date Sampled: 4/16/15Site: MW-14 Time: 12:50

Analysis Date/TimeMethodParameter Result NELACLab/TechUnits Qual.

Vt Petroleum List

Complete 4/30/15 SJMW APrep EPA 5035A High Level EPA 5035A-H

< 1,400 mg/Kg 4/30/15 SJMW AMethyl-t-butyl ether (MTBE) EPA 8260C

784 mg/Kg 4/30/15 SJMW ABenzene EPA 8260C

38,000 mg/Kg 4/30/15 SJMW AToluene EPA 8260C

14,700 mg/Kg 4/30/15 SJMW AEthylbenzene EPA 8260C

71,100 mg/Kg 4/30/15 SJMW AXylenes, Total EPA 8260C

10,700 mg/Kg 4/30/15 SJMW A1,3,5-Trimethylbenzene EPA 8260C

33,400 mg/Kg 4/30/15 SJMW A1,2,4-Trimethylbenzene EPA 8260C

4,460 mg/Kg 4/30/15 SJMW ANaphthalene EPA 8260C

91 % 4/30/15 SJMW USurr. 1 (Dibromofluoromethane) EPA 8260C

99 % 4/30/15 SJMW USurr. 2 (Toluene d8) EPA 8260C

101 % 4/30/15 SJMW USurr. 3 (4-Bromofluorobenzene) EPA 8260C

>10 4/30/15 SJMW UUnidentified Peaks EPA 8260C

C8-C12 4/29/15 FAAW UHydrocarbon Range EPA 8015D

Gasoline 4/29/15 FAAW UFuel Identification EPA 8015D

Laboratory Report

WSAPROJECT:

DATE RECEIVED:

WORK ORDER:

DATE REPORTED:

100905Vermont HydroGeo

2113 Stony Brook Rd

Northfield, VT 05663

Atten: Eric Swiech SAMPLER:

May 18, 2015

1505-07846

Eric

May 04, 2015

Reviewed by:

Harry B. Locker, Ph.D.

Laboratory Director

Enclosed please find the results of the analyses performed for the samples referenced on the attached chain of custody. All required method quality control elements including instrument calibration were performed in accordance with method requirements and determined to be acceptable unless otherwise noted.

The column labeled Lab/Tech in the accompanying report denotes the laboratory facility where the testing was performed and the technician who conducted the assay. A "W" designates the Williston, VT lab under NELAC certification ELAP 11263; "R" designates the Lebanon, NH facility under certification NH 2037 and “N” the Plattsburgh, NY lab under certification ELAP 11892. “Sub” indicates the testing was performed by a subcontracted laboratory. The accreditation status of the subcontracted lab is referenced in the corresponding NELAC and Qual fields.

The NELAC column also denotes the accreditation status of each laboratory for each reported parameter. “A” indicates the referenced laboratory is NELAC accredited for the parameter reported. “N” indicates the laboratory is not accredited. “U” indicates that NELAC does not offer accreditation for that parameter in that specific matrix. Test results denoted with an “A” meet all National Environmental Laboratory Accreditation Program requirements except where denoted by pertinent data qualifiers. Test results are representative of the samples as they were received at the laboratory

Endyne, Inc. warrants, to the best of its knowledge and belief, the accuracy of the analytical

test results contained in this report, but makes no other warranty, expressed or implied, especially no warranties of merchantability or fitness for a particular purpose.

160 James Brown Dr., Williston, VT 05495

Ph 802-879-4333 Fax 802-879-7103 ELAP 11263

www.endynelabs.com

NH203756 Etna Road, Lebanon, NH 03766

Ph 603-678-4891 Fax 603-678-4893

Laboratory Report

Vermont HydroGeo

Page 2 of 4

CLIENT:PROJECT: WSA

WORK ORDER:DATE RECEIVED:

1505-0784605/04/2015

5/18/2015REPORT DATE:

001 Date Sampled: 5/1/15Site: MW-16 5/8/15 RGTWAnalysis Date:10:42

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter

TEST METHOD: EPA 8021B

< 2.0 NMethyl-t-butyl ether (MTBE) ug/L < 1.0 NBenzene ug/L

< 1.0 NToluene ug/L 2.5 NEthylbenzene ug/L

3.1 NXylenes, Total ug/L 1.7 N1,3,5-Trimethylbenzene ug/L

8.8 N1,2,4-Trimethylbenzene ug/L < 2.0 NNaphthalene ug/L

84 NSurr. 1 (Bromobenzene) % >10 NUnidentified Peaks


QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter



< 1.0 NToluene ug/L < 1.0 NEthylbenzene ug/L

< 2.0 NXylenes, Total ug/L < 1.0 N1,3,5-Trimethylbenzene ug/L

< 1.0 N1,2,4-Trimethylbenzene ug/L < 2.0 NNaphthalene ug/L



QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter




< 2.0 NXylenes, Total ug/L 5.1 N1,3,5-Trimethylbenzene ug/L



004 Date Sampled: 5/1/15Site: MW-18S 5/11/15 RGTWAnalysis Date:12:04

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter




< 2.0 NXylenes, Total ug/L 1.0 N1,3,5-Trimethylbenzene ug/L



005 Date Sampled: 5/1/15Site: MW-18D 5/12/15 RGTWAnalysis Date:12:28

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter


89.5 NMethyl-t-butyl ether (MTBE) ug/L 5.3 NBenzene ug/L

< 10.0 NToluene ug/L 219 NEthylbenzene ug/L

55.8 NXylenes, Total ug/L 468 N1,3,5-Trimethylbenzene ug/L

493 N1,2,4-Trimethylbenzene ug/L 30.0 NNaphthalene ug/L


Laboratory Report

Vermont HydroGeo

Page 3 of 4

CLIENT:PROJECT: WSA


1505-0784605/04/2015



QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter






88 NSurr. 1 (Bromobenzene) % 0 NUnidentified Peaks


QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter



1.1 NToluene ug/L 3.3 NEthylbenzene ug/L

5.6 NXylenes, Total ug/L < 1.0 N1,3,5-Trimethylbenzene ug/L

3.0 N1,2,4-Trimethylbenzene ug/L 11.2 NNaphthalene ug/L



QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter



< 10.0 NToluene ug/L 454 NEthylbenzene ug/L

567 NXylenes, Total ug/L 242 N1,3,5-Trimethylbenzene ug/L

846 N1,2,4-Trimethylbenzene ug/L 149 NNaphthalene ug/L


009 Date Sampled: 5/1/15Site: MW-19D 5/11/15 RGTWAnalysis Date:14:05

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter


2.1 NMethyl-t-butyl ether (MTBE) ug/L < 1.0 NBenzene ug/L





010 Date Sampled: 5/1/15Site: MW-19S 5/11/15 RGTWAnalysis Date:14:30

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter







Laboratory Report

Vermont HydroGeo

Page 4 of 4

CLIENT:PROJECT: WSA


1505-0784605/04/2015



QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter


< 400 NMethyl-t-butyl ether (MTBE) ug/L 510 NBenzene ug/L

21,700 NToluene ug/L 3,710 NEthylbenzene ug/L

15,900 NXylenes, Total ug/L 688 N1,3,5-Trimethylbenzene ug/L

2,110 N1,2,4-Trimethylbenzene ug/L < 400 NNaphthalene ug/L

81 NSurr. 1 (Bromobenzene) % > 10 NUnidentified Peaks

012 Date Sampled: 5/1/15Site: Dup 5/12/15 RGTWAnalysis Date:10:42

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter


< 400 NMethyl-t-butyl ether (MTBE) ug/L 541 NBenzene ug/L

24,600 NToluene ug/L 4,220 NEthylbenzene ug/L

17,900 NXylenes, Total ug/L 758 N1,3,5-Trimethylbenzene ug/L

2,350 N1,2,4-Trimethylbenzene ug/L 416 NNaphthalene ug/L


013 Date Sampled: 5/1/15Site: TB 5/11/15 RGTWAnalysis Date:10:42

QualNelac

Result

UnitResult

Result

ParameterQualNelac

Result

UnitResult

Result

Parameter







Report Summary of Qualifiers and Notes

Samples were received at the laboratory with a temperature of 14.1 degrees Celsius. Samples must be received in a

cooler with sufficient ice to attain a temperature of 6 degrees Celsius or below. Samples must not be frozen.

APPENDIX B

Graph 1. MW-4VOC Concentrations in Groundwater Over Time

Washington Street ApartmentsBarre, Vermont

Date Total BTEX MTBE Benzene TolueneEthyl

benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

01/95 8,670 ND<25 1,340 650 2,500 4,180 -- -- --07/95 6,605 ND<500 1,330 265 2,360 2,650 -- -- --12/95 10,619 ND<500 1,230 549 3,190 5,650 -- -- --03/96 5,403 ND<200 1,220 143 2,320 1,720 -- -- --08/96 1,257 ND<20 835 93 ND<20 329 -- -- --02/97 1,759 ND<200 1,280 110 42 327 -- -- --02/97 764 ND<200 628 38 44 54 -- -- --02/98 1,123 ND<100 517 35 11 560 -- -- --10/98 5,082 ND<200 105 127 1,940 2,910 -- -- --02/99 2,462 ND<200 488 36 1,020 918 -- -- --08/99 3,165 ND<200 502 27 1,820 816 -- -- --04/00 2,619 ND<200 364 43 1,220 992 -- -- --10/00 1,071 ND<100 577 31 182 281 -- -- --

08/28/08 1,381 ND<40.0 28.5 69.4 745 538 1,013 239 85.9010/14/10 608 ND<2.0 11 10 390 197 920 160 84.9611/12/12 546 ND<40.0 23.6 ND<20.0 522 ND<40.0 2,001 263 84.6504/24/13 1,309 ND<20.0 ND<5.0 ND<10.0 393 916 1,197 290 85.3911/20/13 581 21.4 13.3 ND<10.0 448 120 1,260 198 84.6305/28/14 1,797 35.6 ND<10.0 ND<10.0 577 1,220 1,200 150 85.5610/17/14 1,080 ND<40.0 34.1 ND<20.0 588 458 1,453 194 84.4805/01/15 1,039 35.4 18.1 ND<10.0 454 567 1,088 149 85.63

VGES --- 40 5 1,000 700 10,000 350.0 20 ----

Notes: Results reported in micrograms per liter (µg/L)ND- None detected at indicated detection limit.VGES - Vermont Groundwater Enforcement StandardsMTBE - Methyl tert-butyl etherTotal TMBs = Trimethylbenzenes (1,2,4 trimethylbenzene and 1,3,5 trimethylbenzene)Shaded areas denote VGES exceedance.

82

83

84

85

86

1

10

100

1,000

10,000

100,000

9/23/94 6/19/97 3/15/00 12/10/02 9/5/05 6/1/08 2/26/11 11/22/13 8/18/16

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nce

ntr

atio

n (

µg

/L)

Date

Benzene Total BTEX Naph-thalene Ground-water Elevation

Vermont HydroGeo, LLC WSA_Water Quality Results




benzeneXylenes Total TMBs

Naph-thalene

Ground-water

Elevation

07/95 7,301 ND<500 2,660 2,490 251 1,900 -- -- --08/96 598 ND<50 519 25 ND<5 54 -- -- --02/97 9,713 ND<500 4,480 473 2,260 2,500 -- -- --09/97 2,021 ND<500 1,270 118 95 538 -- -- --02/98 5,676 ND<500 3,320 717 429 1,210 -- -- --10/98 3,387 ND<200 1,480 106 848 953 -- -- --02/99 4,463 ND<200 2,270 210 933 1,050 -- -- --08/99 7,840 ND<500 3,200 1,480 1,500 1,660 -- -- --02/00 10,541 ND<500 3,400 3,070 571 3,500 -- -- --10/00 2,652 ND<100 820 784 318 730 -- -- --

08/28/08 1,221 ND<20.0 301 42.4 776 102 375 95.5 85.5710/14/10 1,419 ND<2.0 220 47 970 182 770 260 85.0211/12/12 1,302 43.4 138 33.5 1,020 110 717 272 84.8504/24/13 193 4.4 23.8 3.3 156 9.5 32.6 10.0 85.2011/20/13 636 14.3 59.8 12.0 505 59.6 148.7 87.1 84.7805/26/14 33 3.6 18.8 1.8 8.3 3.9 9.2 5.4 85.3510/17/14 631 11.1 65.1 10.5 520 35.7 26.1 62.5 84.6805/01/15 18 3.5 8.0 1.1 3.3 5.6 3.0 11.2 85.40

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


82

83

84

85

86

1

10

100

1,000

10,000

100,000

09/94 06/97 03/00 12/02 09/05 06/08 02/11 11/13 08/16

Gro

un

dw

ate

r E

leva

tio

n (

fee

t)

Co

nc

en

tra

tio

n (

µg

/L)

Date






benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

08/29/08 55,640 ND<1,000 4,260 27,700 4,780 18,900 4,950 ND<1,000 87.5110/14/10 66,600 ND<240 1,900 28,800 6,700 29,200 10,700 ND<240 86.6911/12/12 45,520 ND<1,000 900 26,300 3,420 14,900 2,696 ND<1,000 86.4404/29/13 21,356 ND<200 226 11,300 2,320 7,510 1,443 255 88.1811/20/13 46,950 ND<400 1,210 27,600 3,340 14,800 2,170 ND<400 86.4605/26/14 19,921 202 131 8,320 2,430 9,040 2,191 236 87.6010/17/14 23,660 122 1,090 12,200 2,330 8,040 1,787 308 86.0905/01/15 41,820 ND<400 510 21,700 3,710 15,900 2,798 ND<400 87.88

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


86

87

88

89

90

91

92

1

10

100

1,000

10,000

100,000

12/31/07 12/30/09 12/31/11 12/30/13 12/31/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date






benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

08/29/08 15,615 ND<200 895 8,120 1,380 5,220 718 ND<200 86.6510/14/10 13,640 ND<2.0 340 5,400 1,600 6,300 1,410 450 86.0711/20/13 49,090 ND<400 2,260 26,200 3,430 17,200 4,110 1,340 85.45

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


84

85

86

87

88

1

10

100

1,000

10,000

100,000

08/06/07 06/01/08 03/28/09 01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date






benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

10/14/10 93 ND<2.0 ND<2.0 ND<2.0 38 55 332 25 85.2911/12/12 236 ND<20.0 ND<10.0 ND<1.0 23.2 213 530 64.1 85.1604/24/13 30 7.9 ND<2.0 ND<2.0 16.9 13 114 11.7 85.3511/20/13 19 3.1 ND<2.0 ND<2.0 11.0 8.0 65.9 3.4 85.0405/28/14 15 4.9 ND<1.0 ND<1.0 9.4 5.5 43.0 2.5 85.5310/17/14 9 ND<2.0 ND<1.0 ND<1.0 5.4 3.5 26.4 ND<2.0 84.8605/01/15 6 ND<2.0 ND<1.0 ND<1.0 2.5 3.1 10.5 ND<2.0 85.57

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


84

85

86

87

88

1

10

100

1,000

01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14 12/27/14 10/23/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date






benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

10/14/10 43.8 ND<2.0 ND<2.0 ND<2.0 32 12 179 3.0 85.1511/12/12 23.2 ND<2.0 ND<1.0 ND<1.0 23.2 ND<2.0 4.2 ND<2.0 84.9704/24/13 34.1 2.0 ND<1.0 ND<1.0 30.8 3.3 17.5 5.2 85.2511/20/13 69.6 3.5 ND<1.0 ND<1.0 66.3 3.3 15.0 ND<2.0 84.9005/26/14 1.1 ND<2.0 ND<1.0 ND<1.0 1.1 ND<2.0 1.3 ND<2.0 85.4210/17/14 32.9 ND<2.0 ND<1.0 1.8 28.9 2.2 ND<1.0 ND<2.0 84.7105/01/15 2.4 ND<2.0 ND<1.0 ND<1.0 2.4 ND<2.0 12.8 ND<2.0 85.47

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


84

85

86

87

88

1

10

100

01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14 12/27/14 10/23/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date



Graph 7. MW-18SVOC Concentrations in Groundwater Over Time



benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

10/14/10 244 ND<2.0 ND<2.0 1.9 47 195 67 17 85.2611/12/12 2,061 ND<100 ND<50.0 ND<50.0 491 1,570 2,117 294 84.7604/24/13 ND ND<2.0 ND<1.0 ND<1.0 ND<1.0 ND<2.0 8.9 ND<2.0 85.9611/20/13 1,081 41.3 2.2 5.4 406 667 711 131 84.8105/26/14 ND ND<2.0 ND<1.0 ND<1.0 ND<2.0 ND<2.0 1.5 ND<2.0 86.2610/17/14 618 ND<20.0 ND<10.0 ND<10.0 267 351 353 53.8 84.6105/01/15 0 ND<20.0 ND<10.0 ND<10.0 ND<1.0 ND<2.0 3.5 ND<2.0 86.20

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


84

85

86

87

88

1

10

100

1,000

10,000

01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14 12/27/14 10/23/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date



Graph 8. MW-18DVOC Concentrations in Groundwater Over Time



benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

10/14/10 1,049 ND<2.0 ND<2.0 ND<2.0 270 779 790 200 85.1311/12/12 425 99.6 ND<1.0 ND<20.0 260 165 1,731 156 84.9604/24/13 460 94.0 ND<10.0 ND<10.0 247 213 1,346 264 85.2111/20/13 318 98.9 ND<10.0 ND<10.0 224 94.2 1,129 69.1 84.8305/26/14 343 118 ND<10.0 ND<10.0 271 71.9 1,014 46.1 85.3510/17/14 299 107 ND<5.0 8.3 243 47.3 1,006 31.3 84.6805/01/15 280 89.5 5.3 ND<10.0 219 55.8 961 30.0 85.44

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


84

85

86

87

88

1

10

100

1,000

10,000

01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14 12/27/14 10/23/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date



Graph 9. MW-19DVOC Concentrations in Groundwater Over Time



benzeneXylenes

Total TMBs

Naph-thalene

Ground-water

Elevation

10/14/10 48.2 ND<2.0 3.2 1.0 J 45 ND<2.0 ND<2.0 2.1 83.3611/12/12 21.1 5.0 1.5 ND<1.0 19.6 ND<2.0 ND<2.0 ND<2.0 83.3704/24/13 1.3 ND<2.0 ND<1.0 ND<1.0 1.3 ND<2.0 ND<2.0 ND<2.0 83.4411/20/13 18.3 4.5 1.3 ND<1.0 17.0 ND<2.0 ND<2.0 ND<2.0 83.4105/26/14 15.3 3.5 1.0 ND<1.0 14.3 ND<2.0 ND<1.0 ND<2.0 83.5710/17/14 97.6 ND<5.0 ND<5.0 53.6 44.0 ND<10.0 ND<1.0 ND<2.0 83.0405/01/15 7.3 2.1 ND<1.0 ND<1.0 7.3 ND<2.0 ND<1.0 ND<2.0 83.84

VGES --- 40 5 1,000 700 10,000 350.0 20 ----


80

81

82

83

84

1

10

100

01/22/10 11/18/10 09/14/11 07/10/12 05/06/13 03/02/14 12/27/14 10/23/15

Gro

un

dw

ater

Ele

vati

on

(fe

et)

Co

nc

en

tra

tio

n (

µg

/L)

Date



Documents

August 3, 2015 Mr. James Donaldson Waste Management ...Mr. James Donaldson - 2 - August 3, 2015 1.0 SITE DESCRIPTION AND PHYSICAL SETTING The Site is located in a mixed commercial/residential