WS-9507_44719_CA_FPR_20190318

EXECUTIVE SUMMARY
The Trindale Mini Mart site is located at 7619 N.C. Highway 62, Trinity, Randolph County, North
Carolina, 27370. The site is an active petroleum retail facility and convenience store, currently occupied
by Trindale Mini Mart. The site is located outside the city limits of Trinity and zoned commercial.
Reportedly, municipal water is available to all properties within 1,500-radius of the source area. The
former 3,000-gallon kerosene UST, dispenser and piping were removed on August 1, 2016. The current
UST system consists of three 8,000-gallon gasoline USTs associated dispensers and product piping. One
of the 8,000-gallon gasoline USTs is in temporary closure. A 3,000-gallon kerosene UST, one 4,000-
gallon gasoline UST, one 3,000-gallon gasoline UST and one 7,000-gallon fuel oil UST were removed in
1990. A release at the site was discovered during UST removal activities in August 2016. A Limited Site
Assessment (LSA) was completed in April 2017.

The receptor survey conducted in April 2017 identified eleven non-potable water supply wells (WSW-1
through WSW-11) within 1,500-foot radius of the source area. No potable water supply wells were
identified. One monitoring well (MW-1) was installed during LSA activities. A water sample was not
collected because of the presence of 0.10 feet of free product in the well. Risk classification for the
incident was determined to be intermediate due the presence of free product.

A free product evaluation was completed on MW-1 in August 2017. A free product thickness of 5.91 feet
was measured in MW-1 prior to the start of the free product evaluation activities. In November 2017, a 8-
hour AFVR event was conducted on MW-1 to recover free product from MW-1.

On February 14, 2019, a second 8-hour AFVR event was conducted on monitoring well MW-1 to recover
free product. Prior to the start of the AFVR event a free product thickness of 2.95 was measured in MW-
1 and no free product was measured in the well following the AFVR event. No free product was
observed in the tanker at the end of the event. A total of 435.60 gallons of petroleum impacted ground
water was removed during the event. Based on mass-removal calculations an additional 0.0353 pounds or
0.0056 gallons of vapor phase hydrocarbons were removed. No pre or post AFVR sampling of MW-1
was required because of the presence of free product before the event and the likelihood of free product in
MW-1 following the AFVR.

Based on this information, GRI recommends conducting a Comprehensive Site Assessment (CSA) at the
site to delineate the extent of free product and evaluate ground water quality. In addition, Aggressive

Fluid Vapor Recovery (AFVR) and/or Mobile Multi-Phase Extraction (MMPE) events should be
conducted on MW-1 in order to recover free product.

TABLE OF CONTENTS
1.0 SITE HISTORY AND CHARACTERIZATION ........................................................ 1
2.0 CURRENT SITE ASSESSMENT ................................................................................ 2
3.0 AGGRESSIVE FLUID VAPOR RECOVERY REPORT .......................................... 2
4.0 SUMMARY AND CONCLUSIONS ............................................................................ 3
5.0 LIMITATIONS ............................................................................................................ 3

FIGURES
Figure 1: Site Location Map
Figure 2: Site Vicinity Map
Figure 3: Site Map

TABLES

Table 1: Water Supply Well Information
Table 2: Well Construction & Gauging Information
Table 3: Free Product Recovery Results
Table 4: Free Product Recovery Event Information
Table 5: Free Product Recovery Cost Summary
Table 6: Ground Water Sample Analytical Results

APPENDIX
Appendix A: Hazmat Emergency Response and Remediation, Inc.’s AFVR report and Disposal
Manifest

1

1.0 SITE HISTORY AND CHARACTERIZATION
The Trindale Mini Mart site is located at 7619 N.C. Highway 62, Trinity, Randolph County, North
Carolina, 27370 (Figure 1). The site is an active petroleum retail facility and convenience store,
currently occupied by Trindale Mini Mart. The site is located outside the city limits of Trinity and zoned
commercial. The current UST system consists of three 8,000-gallon gasoline USTs associated dispensers
and product piping. One of the 8,000-gallon gasoline USTs is in temporary closure. A 3,000-gallon
kerosene UST, one 4,000-gallon gasoline UST, one 3,000-gallon gasoline UST and one 7,000-gallon fuel
oil UST were removed in 1990.

A 3,000-gallon kerosene UST, dispenser and piping were removed on August 1, 2016. Soil samples were
collected during the initial abatement activities and summarized in the Initial Abatement Action Report
(IAAR) dated August 29, 2016. Concentrations of chemicals of concern that exceeded the soil-to-water
Maximum Contaminant Concentrations (MCCs) were reported in an over excavation soil sample
collected during the initial abatement activities. Therefore, a Limited Site Assessment (LSA) was
required to determine the risk of the site and if ground water contamination is present.

During LSA activities conducted in April 2017, a receptor survey was completed for this site.
Reportedly, municipal water is available to all properties within 1,500-radius of the source area. No
potable water supply wells and eleven non-potable water supply wells (WSW-1 through WSW-11) were
identified within 1,500-foot radius of the source area. One creek feature named Muddy Creek is located
approximately 1,300 feet northwest of the source area (Figure 2). Water supply well owner information
has been included as Table 1. The site does not lie within a designated wellhead protection area.

During LSA activities, two soil samples were collected during the advancement of the monitoring well
MW-1. Concentrations of contaminants that exceeded the soil-to-water MCCs and Residential Soil
Cleanup Levels (SCLs) were reported in the soil samples. Monitoring well MW-1 was not sampled
because free product was present in the well. A free product evaluation was completed on MW-1 in
August 2017. A free product thickness of 5.91 feet was measured in MW-1 prior to the start of the free
product evaluation activities. On November 22, 2017, a 8-hour Aggressive Fluid Vapor Recovery
(AFVR) event was conducted to recover free product from MW-1. Free product was measured in MW-1
with a thickness of 6.43 feet prior to the AFVR startup and 741 gallons of fluids were recovered. No
measurable free product was detected in the well after the event. The risk classification of the incident is
intermediate due the presence of free product. A Comprehensive Site Assessment (CSA) is currently

2

required to be completed at the site in order to delineate the free product, dissolved phase contaminant
concentrations in ground water and soil contamination at the site. A Site Map showing the location of the
monitoring well and the structures on-site has been included as Figure 3. Please refer to previous
submittals for further historical information regarding the site.

2.0 CURRENT SITE ASSESSMENT
The purpose of this report is to present the results of the AFVR event conducted at the Trindale Mini Mart
site. The activities were conducted in accordance with GRI Proposal Number 17-695 which was
submitted to NCDEQ on September 27, 2018, and approved as Task Authorization Number 44719-6 on
October 22, 2018. The current scope of work includes conducting an AFVR event to recover free product
at the site.

3.0 AGGRESSIVE FLUID VAPOR RECOVERY REPORT
On February 14, 2019, HAZMAT Emergency Response and Remediation, Inc. (HERR) conducted an
AFVR event on MW-1. The AFVR equipment included a 3,000-gallon capacity vacuum truck, flexible
vacuum hose, 1-inch diameter PVC stinger pipe and pipe fitting to connect to monitoring well MW-1.
The AFVR system provided 325 CFM at 25 inches of Hg.

Monitoring well MW-1 was gauged on February 14, 2019 prior to the event. Free product was measured
in MW-1 with a thickness of 2.95 feet prior to the AFVR startup. Monitoring well MW-1 was vacuumed
continuously for a total of 8 hours during the event. During the event, measurements of relative humidity,
temperature, vacuum, exhaust velocity, and off-gas concentrations were recorded at the discharge stack
every fifteen minutes for the first two hours, then every thirty minutes for the remaining six hours. At the
conclusion of the event, no measurable free product was observed in MW-1. A summary of well
construction and gauging data obtained before start up and at the conclusion of the AFVR event is
presented in Table 2. A copy of HERR’s AFVR report, field data sheet and data calculations have been
included as Appendix A.

The results of the AFVR event indicate that a total of 435.60 gallons of fluids were removed during the
event. No free product was observed in the tanker at the end of the event. Based on 8 hours of operation,
the average fluid recovery rate was 54.45 gallons per hour. Based on mass-removal calculations,
approximately 0.0353 pounds or 0.0056 gallons of vapor phase hydrocarbons were removed. Based on 8

3

hours of operation, an average of 0.0007 gallons of vapor phase hydrocarbons was removed per hour by
the AFVR event. For the February 2019 AFVR event, the cost per gallon of recovered petroleum affected
ground water was $5.66. Summaries of free product recovery event data have been included in Tables 3
through 5. At the conclusion of the AFVR event, all wastewater was transported to a licensed facility for
disposal. A copy of disposal manifest has been included in Appendix A.

Pre and post AFVR ground water sampling activities were not required because of the presence of free
product prior to the AFVR and a likelihood that free product would be in the well during the post AFVR
sampling activities. A summary of ground water sample analytical results is presented in Table 6.

4.0 SUMMARY AND CONCLUSIONS
 A free product thickness was measured in extraction well MW-1 at 2.95 feet prior to the start of
the event.
 A total of 435.60 gallons of petroleum impacted ground water and free product was removed
during the February 14, 2019, 8-hour AFVR event conducted on MW-1. No free product was
observed in monitoring well MW-1 at the conclusion of the event.
 No measureable liquid phase hydrocarbons were recovered. Based on mass-removal calculations
an additional 0.0353 pounds or 0.0056 gallons of vapor phase hydrocarbons were removed at an
average rate of 0.0007 gallons per hour.
 Pre and post AFVR ground water sampling activities were not required because of the presence
of free product prior to the AFVR and a likelihood that free product would be in the well during
the post AFVR sampling activities
 Based on this information, the site should remain an intermediate risk site because of the
continuing presence of free product in MW-1. Free product recovery events should continue
until product is no longer measured in MW-1.
 GRI recommends conducting a Comprehensive Site Assessment (CSA) at the site to delineate the
extent of the free product plume and to evaluate ground water quality.
 Until a CSA can be conducted, GRI recommends conducting AFVR and/or MMPE events on
MW-1 to recover free product.

5.0 LIMITATIONS
This report has been prepared for the exclusive use of Angles, Inc. for specific application to the

4

referenced site in Randolph County, North Carolina. The assessment was conducted based on the scope
of work and level of effort specified by NCDEQ and with resources adequate only for that scope of work.
Our findings have been developed in accordance with generally accepted standards of geology and
hydrogeology practices in the State of North Carolina, available information, and our professional
judgment. No other warranty is expressed or implied.

The data that are presented in this report are indicative of conditions that existed at the precise locations
sampled and at the time the samples were collected. In addition, the data obtained from samples would be
interpreted as being meaningful with respect to parameters indicated in the laboratory report. No
additional information can logically be inferred from these data.

FIGURES
Copyright:© 2013 National Geographic Society, i-cubed
FIGURE 1SITE LOCATION MAPTRINDALE MINI MART7619 N.C. HIGHWAY 62TRINITY, RANDOLPH COUNTY,NORTH CAROLINAINCIDENT NO. 44719GRI PROJECT NO. 4236
PREPARED BY:GEOLOGICAL RESOURCES, INC.AUGUST 29, 201602,000 4,0001,000 Feet
SCALE: 1 INCH = 2,000 FEET
MAP CENTER LOCATIONLATITUDE: 35.903109° NLONGITUDE: 79.986786° W
`
SITE LOCATION
³
"J
"J
"J
"J
"J
"J
"J
"J
"J "J
"J
DJ
DJ
DJ
SITE
SEALY DR
TRINDALE RDNC HWY 62ROCKFORD DRT
RINIT
Y R
D OLD ENGLI
SH FARM RDOFFICE PKWYENGLISH FARM RD
ROCKFORD DR EXTUt Muddy Creek
WSW-9
WSW-8
WSW-7
WSW-6
WSW-5
WSW-4
WSW-3
WSW-1
WSW-11
WSW-10
7708757085
7708858110
7708669429
7708849043
7708756568
7708755108
7708755062
7708758200
7708853562
770875247077087550627708751519770875158277087533437708752035
770875514977087524267708668002
7708750718
WSW-2
1,500-FOOT RADIUS
250-FOOT RADIUS
1,000-FOOT RADIUS
FIGURE 2: SITE VICINITY MAPTRINDALE MINI MART7619 NC HIGHWAY 62TRINITY, RANDOLPH COUNTYNORTH CAROLINAINCIDENT NO. 44719GRI PROJECT NO. 4236
PREPARED BY:GEOLOGICAL RESOURCES, INC.MAY 24, 2017
³
0 300150Feet
1 inch = 300 feet
LEGEND
Subject Property
"J Water Supply Well
DJ Water Supply Well (Inactive)
streams
roads
Lakes
parcels
NOTE:THIS MAP IS BASED ON DATA FROM THERANDOLPH COUNTY, NC GIS WEBSITE.

TABLES
Facility ID #: 00-0-0000018398
Well
No. PIN Well Owner Mailing Address Well Location Address Public Water
Connected
Well Use
(Potable/ Agriculture,
etc.)
Well
Depth
(ft BGS)
Type
of
Well
(Drilled/
Bored)
Well
Casing
Depth
(ft.
BGS)
Well
Screen
Interval
(x to y
ft. BGS)
Approximate
Distance
from
Source
Area of
Release (ft.)
WSW-1 7708753343 Thomas & Diane Harris Post Office Box 671
Trinity, NC 27370
107 Sealy Drive
Trinity, NC 27370 Yes Inactive
Non-potable UK UK UK UK 515' NW
WSW-2 7708752470 Cynthia Sink & Lamar
Gray
Post Office Box 57
Trinity, NC 27370
109 Sealy Drive
Trinity, NC 27370 Yes Unknown UK UK UK UK 600' NW
WSW-3 7708752426 Michael & Natasha Byrd 6469 Planters Place
Thomasville, NC 27360
111 Sealy Drive
Trinity, NC 27370 Yes Unknown UK UK UK UK 646' NW
WSW-4 7708751582 Steven Morris Reddeck 2414 Mt. Willing Road
Efland, NC 27243
113 Sealy Drive
Trinity, NC 27370 Yes Unknown UK UK UK UK 740' NW
WSW-5 7708751519 Langley Mitchel Ruth Post Office Box 78
Trinity, NC 27370
115 Sealy Drive
Trinity, NC 27370 Yes Unknown UK UK UK UK 850' NW
WSW-6 7708750718 Trinity Grange 794 6817 Fairview Church Road
Trinity, NC 27370
119 Sealy Drive
Trinity, NC 27370 Yes Unknown UK UK UK UK 1,130' NW
WSW-7 7708669429 J.L.Darr, Jr. & Henry
Darr
Post Office Box 7163
High Point, NC 27264 No Physical Address Yes Inactive
Non-potable UK UK UK UK 1,060' NW
WSW-8 7708668002 Raymond L. Foster 129 Sealy Drive
Trinity, NC 27370
129 Sealy Drive
Trinity, NC 27370 Yes Inactive
Non-potable UK UK UK UK 1,385' NW
WSW-9 7708756568 Henry L. Darr Post Office Box 7163
High Point, NC 27264 No Physical Address Yes Active
Non-potable UK UK UK UK 505' NE
WSW-10 7708853562 Johnny S. Jarrett 623 Trindale Road
Trinity, NC 27370
623 Trindale Road
Trinity, NC 27370 Yes Unknown UK UK UK UK 888' NE
WSW-11 7708849043 RUSTIXX, LLC 3002B Sherrill Avenue
Jamestown, NC 27282
12990 Trinity Road
Trinity, NC 27370 Yes Unknown UK UK UK UK 1,485' SE
Notes:
• Water supply wells are shown on Figure 2
• Ft. BGS : Feet below ground surface
• UK: Unknown
TABLE 1
WATER SUPPLY WELL INFORMATION
TRINDALE MINI MART (INCIDENT NO. 44719)
Date: 06/06/17
Page 1 of 1
Date: 02/04/19
04/26/17 31.11 0.10 Free Product
09/05/17 35.32 5.91 Free Product
11/22/17 37.43 6.43 Before AFVR
11/22/17 33.66 -After AFVR
02/14/19 24.75 2.95 Before AFVR
02/14/19 25.18 -After AFVR
Notes:
• *: Reference point for elevation measurements, assumed elevation 100.00 ft.
• ft BGS : feet below ground surface.
• NM: Not Measured.
NMNM4929 - 492904/26/17MW-1
Ground
Water
Elevation
(ft.)
Comments
TABLE 2
WELL CONSTRUCTION & GAUGING INFORMATION
TRINDALE MINI MART (INCIDENT NO. 44719)
Facility ID #: 00-0-0000018398
Well ID
Date
Installed
(mm/dd/yy)
Date Water
Level
Measured
(mm/dd/yy)
Well
Casing
Depth
(ft. BGS)
Screened
Interval
(x to y ft.
BGS)
Bottom
of Well
(ft. BGS)
Top of
Casing
Elevation*
(ft.)
Depth to
Water from
Top of
Casing
(ft)
Free Product
Thickness
(ft.)
Page 1 of 1
Date: 02/04/19
Method of Measurement:
Well ID Product Type
(gas, diesel, etc.)
Date of
Recovery
(mm/dd/yy)
Free Product
Recovery
Method*
Casing
Diameter
(inches)
Product Thickness
before Recovery
(feet)
Product Thickness
after Recovery
(feet)
Amount of Liquid
Recovered
(gallons)
Amount of
Product
Recovered
(gallons)
MW-1 Kerosene 09/05/17 Hand Bailing 2 5.19 2.89 4.00 4.00
MW-1 Kerosene 11/22/17 AFVR 2 6.43 0.00 741.00 0.00
MW-1 Kerosene 02/14/19 AFVR 2 2.95 0.00 435.60 0.00
Notes :
• *: Bailing, Skimming, Aggressive Fluid Vapor Recovery (AFVR), Mobile Multiphase Extraction (MMPE)
• Amount of Liquid Recovered (gallons) includes Total liquids (Water and Free Product) as indicated on Disposal Manifest.
• Amount of Product Recovered (in gallons) includes only the volume of free product in the tanker at the end of the event (based on Disposal Manifest
and/or Field Notes).
TABLE 3
FREE PRODUCT RECOVERY RESULTS
TRINDALE MINI MART (INCIDENT NO. 44719)
Interface probe at top-of-casing
Facility ID #: 00-0-0000018398
Parge 1 of 1
Date: 02/04/19
MW-1 09/05/17 Hand Bailing ------------4.00 4.00 4.00
MW-1 11/22/17 AFVR 1,143.86 152.29 583.29 0.25 741.00 0.00 0.25
MW-1 02/14/19 AFVR 118.24 66.71 84.23 0.01 435.60 0.00 0.01
0.26 1,180.60 4.00 4.26
Notes:
• *: Bailing, Skimming, Aggressive Fluid Vapor Recovery (AFVR), Mobile Multiphase Extraction (MMPE)
• Amount of Vaporized Product (in gallons) is based on Vapor Emissions Summary Sheet, = total emissions in pounds/6.25
• Amount of Liquid Recovered includes Total liquids (Water and Free Product) as indicated on Disposal Manifest.
• Amount of Product Recovered as Liquid includes only the volume of free product in the tanker at the end of the event (based on Disposal
Manifest and/or Field Notes).
• Total Amount of Product Recovered = Amount of Vaporized Product + Amount of Product Recovered as Liquid
• Total Fluids Removed = Amount of Vaporized Product + Amount of Liquid Recovered
• Information regarding historical free product recovery activities is not available.
Current Event 435.61 0.01
Total To Date 1,180.86 4.26
Totals
SUMMARY OF FLUID REMOVAL
Summary Total Fluids Removed (in gallons)Total Product Removed (in gallons)
Amount of
Liquid
Recovered
(gallons)
Amount of
Product
Recovered as
Liquid
(gallons)
Total Amount
of Product
Recovered
(gallons)
TABLE 4
FREE PRODUCT RECOVERY EVENT INFORMATION
TRINDALE MINI MART (INCIDENT NO. 44719)
Well ID Date
(mm/dd/yy)
Product
Recovery
Method*
Average
Effluent
Velocity
(ft/min)
Average
Effluent
Temperature
(°F)
Average
Effluent
Concentration
(ppm)
Amount of
Vaporized
Product
(gallons)
Facility ID #: 00-0-0000018398
Page 1 of 1
Date: 02/04/19
Wells
Included in
Event
Product
Recovery
Method*
Date of
Event
(mm/dd/yy)
Total Amount of Free
Product plus Ground
Water Recovered
(gallons)
Cost of Free
Product
Recovery
Event
Cost Per Gallon
(total liquids)
MW-1 Hand Bailing 09/05/17 4.00 $725.00 $181.25
MW-1 AFVR 11/22/17 741.25 $2,573.35 $3.47
MW-1 AFVR 02/14/19 435.61 $2,466.25 $5.66
1,180.86 $5,764.60 $4.88
Notes:
• *: Bailing, Skimming, Aggressive Fluid Vapor Recovery (AFVR), Mobile Multiphase Extraction (MMPE)
• Total Amount of Free Product Recovered = Amount of Vaporized Product + Amount of Product Recovered as Liquid
• Cost of Free Product Recovery Event includes supervision, travel, mileage, per diem, subcontractor costs, report preparation and project management.
TOTAL (to date)
TABLE 5
FREE PRODUCT RECOVERY COST SUMMARY
TRINDALE MINI MART (INCIDENT NO. 44719)
Comments
Cost per gallon for the event is based on a total volume of
4.00 gallons of free product.
Facility ID #: 00-0-0000018398
Cost per gallon for the event is based on a total volume of
435.61 gallons water and free product.
Cost per gallon for the event is based on a total volume of
741.25 gallons water and free product.
Page 1 of 1
Date: 02/04/19
Well ID
Date
Collected
(mm/dd/yy)
1 600 600 500 20 6 70 0.4 70 70 70 400 400 1 30 400 700 200 700 10,000 200
5,000 260,000 84,500 85,500 20,000 6,000 6,900 400 25,000 70,000 30,000 28,500 25,000 1,000 12,500 NE NE NE NE NE NE
04/26/17 FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP
02/14/19 FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP FP
Notes:
• Results reported in micrograms per liter (µg/l).
• < : Less than the method detection limit specified in the laboratory report.
• MAC: Maximum allowable concentrations as specified in T15A NCAC 2L.0202.
• GCL: Gross contamination level.
• FP: Free Product.
• NE: Not Established.
• Concentrations in bold face type exceeded the MACs.
• Concentrations in italic face type exceeded the GCLs.
• Refer to laboratory report for detected constituents that did not exceed the MACs, or for which no standard has been established.
MW-1
TABLE 6
SUMMARY OF GROUND WATER SAMPLE ANALYTICAL RESULTS
TRINDALE MINI MART (INCIDENT NO. 44719)
Facility ID #: 00-0-0000018398
Analytical Method EPA Method 6200B EPA Method 625 MADEP Method VPH MADEP Method VPH
Contaminant of Concern
BenzeneTolueneEthylbenzeneXylenesMTBENaphthalene1,2-DichloroethaneIsopropylbenzeneDi-isopropyl etherC19-C36 AliphaticsC11-C22 AromaticsMAC (µg/l)
GCL (µg/l)C9-C18 AliphaticsC5-C8 AliphaticsC9-C12 AliphaticsC9-C10 Aromaticsn-Propylbenzene1,2,4-Trimethylbenzene1,3,5-Trimethylbenzene1-Methylnaphthalene2-Methylnaphthalenen-ButylbenzenePage 1 of 1

APPENDIX

APPENDIX A
Hazmat Emergency Response and Remediation, Inc.’s AFVR report
And Disposal Manifest