09042_Scott Aviation_AWP_2015_11_06

November 6, 2015

Mr. Stuart Rixman Scott Figgie LLC
34407 DuPont Boulevard, Suite 6 Frankford, DE 19945
RE: Addendum to the 2014 Environmental Site Assessment Work Plan
City of Monroe Brownfields Property Redevelopment 310 West Crowell Street
Monroe, North Carolina
Dear Mr. Rixman:
AECOM Technical Services, Inc. (AECOM) has prepared this Addendum to the 2014 Environmental Site Assessment (ESA) Work Plan on behalf of Scott Figgie LLC in support of Brownfields
Development activities planned for the Former Scott Aviation Facility (the “Property”) located in Monroe, North Carolina. The Property (Figure 1) includes two areas divided by Crowell Street:
Parcel I (Building I and south area) and Parcel II (Building II and north area). This Work Plan Addendum presents follow-on investigation, sampling, and analytical laboratory test methods that
will be utilized during this event. The Property is slated for redevelopment by the City of Monroe. Building I and Building II have been razed and the building foundations remain intact.
PROJECT GOALS AND OBJECTIVES The objective of this project is to acquire the necessary data to address North Carolina Department
of Environmental Quality (NCDEQ; formerly North Carolina Department of Environment and Natural Resources [NCDENR]) concerns provided in the letter regarding “NCDENR Response to Phase II
Groundwater Investigation Report” dated September 3, 2015 (Attachment 1) and to conduct voluntary responsible party-driven activities to further define areas targeted for remediation.
The following activities are proposed as part of this Work Plan Addendum to address NCDEQ
concerns:
1. Parcel I
a. A focused receptor survey will be conducted to acquire information on off-site
properties and property owners in the vicinity of Parcel I.
b. Soil samples will be collected from three soil borings (SB35 through SB37) to
further define the extent of chlorinated volatile organic compounds (CVOCs) in the vicinity of SB03a.
c. One overburden groundwater monitoring well (MW-15) will be installed to confirm the presence/absence of CVOCs in overburden groundwater at the eastern end of
Parcel I.
d. Assuming an access request is successful, three off-site soil vapor points (SV03
through SV05) will be installed to the east of Parcel I and along the eastern edge of North Charlotte Avenue, to assess the presence/absence of CVOCs in soil vapor
east of Parcel I.
e. Assuming access requests are successful, three off-site soil vapor points (SV06
through SV08) will be installed west and south of the southwestern corner of
AECOM
10 Patewood Drive
Bldg. VI, Suite 500
Greenville, South Carolina 29615
www.aecom.com
864 234 3000 tel
864 234 3069 fax
Mr. Stuart Rixman
November 6, 2015
Page 2
Parcel I at the intersection of Jefferson Street and Crawford Avenue, to assess the
presence/absence of CVOCs in soil vapor southwest of Parcel I.
2. Parcel II
a. Three overburden groundwater monitoring wells (MW-12 through MW-14) will be installed in the northwestern area of Parcel II to assess the presence/absence of
overburden groundwater, to further define the extent of CVOCs in groundwater potentially cross-gradient and down-gradient from MW-1 and MW-6, and to verify
that offsite migration is not occurring along the northwestern boundary of Parcel II.
b. One surface water sample (SW01) will be collected (if surface water is present) at
the drainage ditch culvert located in the northwestern portion of Parcel II to assess the presence/absence of CVOCs in surface water.
The following activities are proposed as part of this Work Plan Addendum to address Voluntary Actions (Responsible Party-Driven):
1. A site reconnaissance will be conducted to verify the flow direction of surface water, if
present, in the drainage ditch at Parcel II and to acquire photo documentation of Parcel I and Parcel II.
2. The existing overburden and bedrock monitoring well network will be sampled concurrently with the newly installed monitoring wells, to measure current CVOC concentrations in
groundwater.
3. Microbial samples will be collected from monitoring wells MW-2 and MW-3 in Parcel I and
MW-1, MW-7, and MW-8 in Parcel II to assess the concentration and species of dehalococcoides (DHC) bacteria, if present.
4. Soil samples will be collected from three soil borings (SB38 through SB40) west of SB06c and along the western edge of Parcel I to further define CVOC concentrations in soil near
SB06c.
5. Soil samples will be collected from one soil boring (SB34) located between SB17 and SB18
in Parcel II, to provide better spatial resolution of CVOCs in soil within Geophysical Anomaly I.
NCDEQ and Voluntary Actions investigation activities are described separately within this Work Plan Addendum. The field investigation procedures and laboratory testing protocol described herein
were developed as a guide to meet these objectives. Data generated during this investigation will be evaluated, and if data gaps are present, follow-on investigation activities will be identified by the
project stakeholders. ADDENDUM WORK PLAN
AECOM will use this Work Plan Addendum as a guide for conducting the additional ESA activities. All field tasks will be performed in accordance with AECOM Standard Operating Procedures (SOPs)
and applicable state and federal guidance including, but not limited to, U.S. Environmental Protection Agency (EPA) SOPs for groundwater sampling (EPA, March 2013) and packaging,
marking, labeling, and shipping of environmental samples (EPA, April 2011). The Health and Safety Plan (HASP) that was developed for this site for the 2014 ESA field activities will be updated as
needed to include appropriate Task Hazard Analyses (THAs) associated with the work described herein. The HASP is an internal document to be utilized by AECOM field staff and AECOM
subcontractors; however, a copy of the HASP can be provided upon request. Work on this project will be performed under the direction of a Professional Geologist licensed in the State of North
Carolina.
Mr. Stuart Rixman
November 6, 2015
Page 3
MOBILIZATION AND SITE PREPARATION
Mobilization, utility locating, site preparation, and surveying activities will be conducted in accordance with the 2014 ESA Work Plan.
2015 ESA FIELD INVESTIGATION OVERVIEW

Soil, groundwater, surface water, and soil vapor samples will be collected as part of this investigation. Proposed sample locations are provided in Figure 2 for Parcel I and in Figure 3 for
Parcel II. Sample collection procedures and methodologies are provided below for the media to be sampled:

• Soil Sampling: Geoprobe® utilizing Direct Push Technology (DPT) will be used to acquire environmental samples and to install groundwater monitoring wells and soil vapor points. The rig and drilling crew will work under the direction of AECOM professional staff. One discrete soil sample will be collected from up to three depth intervals at each proposed soil
boring: shallow (0-2 feet [ft]) below ground surface [bgs]), intermediate (2-10 ft bgs), and deep (i.e., at the top of competent rock; greater than 10 ft bgs). If the overburden soils are
less than 5 ft thick, only two soil sample intervals (shallow and intermediate) will be collected. Drilling, field classification, lithologic characterization, screening for volatile
vapors, equipment decontamination, and investigation derived waste (IDW) management will be conducted in accordance with the 2014 ESA Work Plan.
• Monitoring Well Installation and Groundwater Sampling: Monitoring well installation, development, and sampling will be conducted in accordance with the 2014 ESA Work Plan. Based on the results of the 2014 ESA field effort and the nature of the perched water table in the overburden soils, if 0-12 inches of water has not accumulated in a borehole slated for conversion into a monitoring well within 24 hours, the borehole will be considered “dry” and
abandoned.
• Surface Water Sampling: Surface water samples will be obtained by slowly submerging sample containers into the up-stream direction of the water in accordance with EPA and
AECOM standard SOPs. To avoid potential influences from surface water run-off, surface water samples will not be collected within 72 hours of a significant rain event (i.e., more
than 0.5 inches within a 24 hour period).
• Soil Vapor Sampling: Active soil vapor samples will be collected from approximately 5-6 ft
bgs over a 24 hour period using Summa canisters. Soil vapor wells will be constructed and soil vapor samples will be collected in general accordance with the Division of Waste
Management Vapor Intrusion Guidance (North Carolina Department of Environment and Natural Resources, April 2014). A helium leak test will be performed at each soil vapor sample location prior to sample collection. An enclosure will be placed over the top of the soil vapor point, above ground tubing, and tubing connections and then filled with helium gas. A vacuum will be applied to the tubing, thereby drawing soil vapor air as well as air potentially entering the tubing from loose connections or breaks. After the well has been purged, samples of the effluent air will be tested using a helium detector, and readings that exceed 10% helium will require troubleshooting. Helium leak test activities described above
will be conducted in general accordance with Collecting and Interpreting Soil Gas Samples from the Vadose Zone (American Petroleum Institute, 2005).
Mr. Stuart Rixman
November 6, 2015
Page 4
2015 ESA ANALYTICAL OVERVIEW
Samples for soil, groundwater/surface water, and soil vapor media will be analyzed for
contaminants of potential concern (COPCs) (the following CVOCs: 1,1,1-trichloroethane [TCA], 1,1-dichloroethene [DCE], 1,2-dichloroethane [DCA], tetrachloroethylene [PCE], trichloroethylene
[TCE], cis-1,2-DCE, and vinyl chloride [VC]) identified in the 2014 ESA Report. Soil, groundwater, and surface water samples will be analyzed by EPA SW-846 Method 8260B and soil vapor samples
will be analyzed using EPA Method TO-15. Microbial groundwater samples will be analyzed using RT-qPCR (reverse transcript quantitative polymerase chain reaction) and qPCR. Tables 1 through 3
summarize the sampling and analysis programs for soil, groundwater/surface water, and soil vapor investigations, respectively.
Pace Analytical® Services located in Huntersville, North Carolina will provide analytical testing
services for the air, water, and soil samples collected during this project. Microbial Insights located in Knoxville, Tennessee will provide analytical testing services for microbial samples collected
during this event. NCDEQ INVESTIGATION ACTIVITIES – Parcel I
Investigation activities described below were designed to address NCDEQ concerns at Parcel I. Focused Receptor Survey
A focused receptor survey will be conducted to acquire information on off-site properties and property owners in the vicinity of Parcel I. Records on property owners, contact information,
addresses, building construction specifications, water usage, etc., if available, will be collected from City of Monroe public databases, records at City Hall, and/or a windshield survey. Information will
be acquired on properties located within the city block immediately south of Parcel I and potentially others areas adjacent to the Property. Soil Sampling near SB03a
Soil samples will be collected from three boreholes (SB35 through SB37) in the vicinity of SB03a to
address NCDEQ’s request to further define the extent of CVOCs in soil in this area. As reported in the 2014 ESA Report, PCE was detected at a significantly elevated concentration from 6-8 ft bgs at
SB03a. Three soil boreholes (SB35 through SB37) are proposed to the northeast, north, and west of SB03a, respectively. Groundwater and Off-site Soil Vapor Sampling in the Eastern Area One overburden monitoring well (MW-15) will be installed to confirm the presence/absence of
CVOCs in groundwater at the eastern end of Parcel I. Proposed monitoring well MW-15 is located near the northeastern corner of Parcel I, approximately 50 ft north-northeast of MW-5. As reported
in the 2014 ESA Report, groundwater was not present at MW-5, and saprolite/weathered rock groundwater at Parcel I appears to be present within localized perched zones and not hydraulically
connected. If shallow overburden groundwater is encountered in the borehole for MW-15, a monitoring well will be installed in overburden residual soils; otherwise, the borehole will be
abandoned and proposed monitoring well MW-15 will not be installed.
Assuming that access requests are successful, off-site soil vapor samples will be collected to the east of Parcel I along the eastern edge of North Charlotte Avenue to assess the presence/absence
of CVOCs in soil vapor east of Parcel I. Three soil vapor points (SV03 through SV05) will be installed in the City of Monroe’s easement.

Mr. Stuart Rixman
November 6, 2015
Page 5
Off-site Soil Vapor Sampling in the Southwestern Area
Assuming that access requests are successful, off-site soil vapor samples will be collected west and
south of the southwestern corner of Parcel I near the intersection of Jefferson Street and Crawford Avenue, to assess the presence/absence of CVOCs in soil vapor southwest of Parcel I. Soil vapor
points SV06 and SV07 will be installed south of Jefferson Street in the City of Monroe’s easement. Soil vapor point SV08 will be installed at the northwest corner from the intersection of Jefferson
Street and Crawford Avenue. NCDEQ INVESTIGATION ACTIVITIES – Parcel II
Investigation activities described below were designed to address NCDEQ concerns at Parcel II. Groundwater Sampling in the Northwest Area
Groundwater samples will be collected from three overburden monitoring wells (MW-12 through
MW-14) installed in the northwestern portion of Parcel II, to assess the presence/absence of overburden groundwater, to further define the extent of CVOCs in groundwater potentially cross-
gradient (northwest) and down-gradient (north) from MW-1 and MW-6, and to verify that offsite migration is not occurring along the northwestern boundary of Parcel II. Monitoring wells will be
installed to the top of competent bedrock. Monitoring well MW-12 is proposed in the wooded, low-lying area south of the drainage ditch and to the west of monitoring well MW-9; monitoring well MW-
13 is proposed along the western edge of the wooded, low-lying area, northwest of MW-6; and monitoring well MW-14 is proposed to the west-northwest of MW-1 and to the west of MW-6 along
the western edge of Parcel II. Surface Water Sampling in Drainage Ditch
A surface water sample (SW-1) will be collected from drainage ditch surface water, if present, to assess the presence/absence of CVOCs. The surface water sample will be collected near the
effluent discharge location for surface water in the drainage ditch (i.e. the stone culvert that routes drainage ditch surface water beneath a railroad track embankment towards Bearskin Creek located
approximately 200 ft north from the northwest corner of Parcel II). VOLUNTARY ACTION (RESPONSIBLE PARTY DRIVEN) INVESTIGATION ACTIVITIES
Site Reconnaissance
A site reconnaissance will be performed to verify the flow direction of surface water, if present, in the drainage ditch and to acquire additional photo-documentation of the Former Scott Aviation
Facility. Visual observations of surface water flow direction will be recorded in a log book and observations will be made on the northwestern and northeastern portion of Parcel II. Photographs
will be taken of Parcel I and II as to provide visual representation of surface features and topography.
Sampling of Existing Monitoring Well Network (Parcels I and II)
Groundwater samples will be collected from the 2014 ESA monitoring well network concurrently
with samples from the newly installed monitoring wells, to acquire current groundwater concentrations of CVOCs. This network is comprised of eleven existing overburden monitoring wells
(MW-1, MW-2, MW-3, MW-4, MW-5, MW-6, MW-7, MW-8, MW-9, MW-10, and MW-11) and eight existing bedrock aquifer monitoring wells (P-1, P-2, P-3, P-4, P-5, P-6, W-2A, and W-3A).

Mr. Stuart Rixman
November 6, 2015
Page 6
Microbial Study (Parcels I and II)
Microbial samples will be collected from overburden monitoring wells with elevated CVOC
concentrations, to determine if bacterial enzymes (DHC species) capable of degrading chlorinated ethenes under aerobic conditions via co-metabolism are active (based on the presence of RNA)
and their concentrations. Samples will be collected from monitoring wells MW-2 and MW-3 in Parcel I and MW-1, MW-7, and MW-8 in Parcel II using a Microbial Insights Bio-Trap® Sampler or
other passive adsorbent sampler. Each sampler will be deployed after the monitoring wells are sampled for CVOCs. Each sampler will be placed into the saturated screen zone of each well and
allowed to incubate for 30 to 60 days before retrieval.
Soil Sampling near SB06a at Parcel I
Soil samples will be acquired from three boreholes (SB38 through SB40) to be advanced along the western edge of Parcel I to further define the extent of CVOC in soil in the vicinity of SB06c. As
reported in the 2014 ESA Report, PCE was detected at an elevated concentration from 0-2 ft bgs at SB06c. Three soil boreholes (SB38 through SB40) are proposed to the northwest, west, and
southwest of SB06c, respectively, along the eastern edge of Crawford Avenue.
Soil Sampling between SB17 and SB18 at Parcel II
One borehole (SB34) will be advanced between SB17 and SB18 to provide better spatial resolution of CVOCs in soil downgradient of the Former Building II Hazardous Waste Storage Building, within
Geophysical Anomaly I.
DATA EVALUATION
Definitive soil, groundwater, surface water, and soil gas data will be collected as part of NCDEQ and Voluntary Action investigation activities. Upon receipt of the analytical results from the
analytical laboratory, an EPA Level III data validation will be conducted and Data Validation Reports (DVRs) that describe the quality control and quality assurance verification process will be prepared.
The 2015 ESA findings will be combined with historical data to verify that the project objectives have been met and to update the Conceptual Site Model (CSM) for the Former Scott Aviation
Facility.
REPORTING
Upon completion of the field activities, an Environmental Site Assessment Report Addendum will be prepared. This report will include a description of the additional ESA activities, a summary and
evaluation of analytical data, an updated CSM, copies of field forms, photographs, analytical data packages, and DVRs. The City of Monroe will submit the Environmental Site Assessment Report Addendum to NCDEQ.
SCHEDULE
We expect that field activities will be completed within 45 days of approval of this Work Plan. The project duration (from Work Plan approval through report submittal) is not expected to exceed four
months.
Mr. Stuart Rixman
November 6, 2015
Page 7
Sincerely,
AECOM Technical Services, Inc.

M. Evelyn Rogers, PE Project Manager
Attachments: Figure 1 – Site Location Map Figure 2 – 2015 ESA Sample Location Map Parcel I
Figure 3 – 2015 ESA Sample Location Map Parcel II Table 1 – Soil Sampling and Analysis Summary
Table 2 – Groundwater and Surface Water Sampling and Analysis Summary Table 3 – Soil Vapor Sampling and Analysis Summary
Attachment 1 - NCDENR letter, Response to Phase II Groundwater Investigation Report, Sept 3, 2015

FIGURES

TABLES

Table 1
Soil Sampling and Analysis Summary
Former Scott Aviation Facility
Monroe, North Carolina
Sample Identification Depth Interval VOCs1
(8260B)
Parcel I – Soil Sampling near SB03a
SB35-S (XX)Shallow X
SB35-I (XX)Intermediate X
SB35-D (XX)Deep X
SB36-S (XX)Shallow X
SB-36-S (XX)-a Shallow X
SB-36-S (XX)-d Shallow X
SB-36-S (XX)-ms/msd Shallow X
SB36-I (XX)Intermediate X
SB36-D (XX)Deep X
SB37-S (XX)Shallow X
SB37-I (XX)Intermediate X
SB37-D (XX)Deep X
Parcel I – Soil Sampling near SB06a
SB38-S (XX)Shallow X
SB38-I (XX)Intermediate X
SB38D (XX)Deep X
SB39-S (XX)Shallow X
SB39-I (XX)Intermediate X
SB39-D (XX)Deep X
SB40-S (XX)Shallow X
SB40-I (XX)Intermediate X
SB40-D (XX)Deep X
SB34-S (XX)Shallow X
SB34-I (XX)Intermediate X
SB34-D (XX)Deep X
Notes:
-a - Indicates a field duplicate sample
-d - Indicates a equipment rinsate sample
-ms/msd - Indicates a matrix spike/matrix spike duplicate sample
VOC - Volatile Organic Compound
1 - 1,1,1-TCA; 1,1-DCE; 1,2-DCA; PCE; TCE; cis-1,2-DCE; VC
Parcel I – Soil Sampling between SB17 and SB18
Page 1 of 1 November 2015
Table 2
Groundwater and Surface Water Sampling and Analysis Summary
Former Scott Aviation Facility
Monroe, North Carolina
Sample Identification Depth
Interval VOCs 1
(8260B)
Microbial
Sampler
(RT-qPCR and
qPCR)
Existing Overburden Wells
MW-1 Shallow X XMW-2 Shallow X X
MW-3 Shallow X X
MW-3-a Shallow X --
MW-3-d Shallow X --
MW-3-ms/msd Shallow X --
MW-4 Shallow X --
MW-5 Shallow X --
MW-6 Shallow X --
MW-7 Shallow X X
MW-7-a Shallow X --
MW-8 Shallow X X
MW-9 Shallow X --
MW-10 Shallow X --
MW-11 Shallow X --
New Overburden Wells*
MW-12 NA X --
MW-13 NA X --
MW-14 NA X --
MW-15 NA X --
P-1 Shallow X --
P-2 Shallow X --
P-3 Shallow X --
P-4 Shallow X --
P-5 Shallow X --
P-6 Deep X --
W-2A --X --
W-3A --X --
Surface Water
SW-1 --X --
Notes:
-a - Indicates a field duplicate sample
-d - Indicates a equipment rinsate sample
-ms/msd - Indicates a matrix spike/matrix spike duplicate sample
VOC - Volatile Organic Compound
1 - 1,1,1-TCA; 1,1-DCE; 1,2-DCA; PCE; TCE; cis-1,2-DCE; VC
-- = not applicable/unknown
* - Overburden monitoring wells to be installed if groundwater is encountered
during drilling.
Existing Bedrock Wells
Page 1 of 1 November 2015
Table 3
Soil Gas Sampling and Analysis Summary
Former Scott Aviation Facility
Monroe, North Carolina
Sample Identification Depth Interval
(feet bgs)VOCs (Method TO-15)
Parcel I – Off-site Soil Vapor Sampling in the Eastern Area
SV03-X 5 to 6 X
SV04-X 5 to 6 X
SV04-X-a 5 to 6 X
SV05-X 5 to 6 X
Parcel I – Off-site Soil Vapor Sampling in the Southwestern Area
SV06-X 5 to 6 X
SV07-X 5 to 6 X
SV08-X 5 to 6 X
Notes:
-a - Indicates a field duplicate sample
VOC - Volatile Organic Compound
bgs - below ground surface
File]Page 1 of 1 November 2015

ATTACHMENT 1