FA-13884_13884_CA_CAP_20230412_NTCP

NEW TECHNOLOGY CLEANUP 
PLAN 

DUKE ENERGY PROGRESS, LLC 

WEATHERSPOON PLANT 
491 POWER PLANT ROAD 
LUMBERTON, ROBESON COUNTY, NORTH CAROLINA 

PREPARED FOR: 
DUKE ENERGY PROGRESS, LLC  
555A BREVARD ROAD 
ASHEVILLE, NORTH CAROLINA 28806 

SUBMITTED TO: 
DUKE ENERGY PROGRESS, LLC  
555A BREVARD ROAD 
ASHEVILLE, NORTH CAROLINA 28806 

WSP PROJECT 7812‐22‐0872 
APRIL 2023 

WSP USA ENVIRONMENT AND INFRASTRUCTURE INC. 
4021 STIRRUP CREEK DRIVE, SUITE 100 
DURHAM, NORTH CAROLINA 27703 
(919) 381‐9900 

WSP.COM

wsp.com
April 12, 2023 
Mr. Kenneth Currie  
Hydrogeologist II 
Division of Waste Management 
NCDEQ – Fayetteville Regional Office 
225 Green Street, Suite 714 
Fayetteville, North Carolina 28301 
Submitted by email: [e-mail]  

Subject: New Technology Cleanup Plan 
Weatherspoon Plant 
Lumberton, Robeson County, North Carolina 
 WSP Project: 7812‐22‐0872  

Dear Mr. Currie: 

On behalf of Duke Energy Progress, LLC, WSP USA Environment & Infrastructure Inc. (WSP) 
formerly Wood Environment & Infrastructure Solutions, Inc. is pleased to submit the 
enclosed New Technology Cleanup Plan for the subject site. Please let us know if you have 
questions or would like to discuss the project further. 

Sincerely, 

WSP USA Environment & Infrastructure Inc. 

Sheri Knox, PE, RSM                                                   Jay Bennett, PG, RSM  
V.P Senior Engineer        Senior PM/ V.P. Hydrogeologist 

New Technology Cleanup Plan
Project No. 7812-22-0872
Weatherspoon Plant
WSP
April 2023
Page iii
TABLE OF
CONTENTS
EXECUTIVE SUMMARY .................................................. 1 
1 INTRODUCTION ................................................. 3 
1.1 Release Information .......................................................... 3 
1.2 Site Information ................................................................ 4 
1.3 Other Releases .................................................................. 4 
2 SITE BACKGROUND ............................................ 5 
2.1 Summary of Assessment and Remediation ......................... 5 
2.1.1 2022 Annual Groundwater Monitoring and Remediation System Report 
Summary ............................................................................................. 8 
2.2 Geology and Hydrogeology ................................................ 9 
2.2.1 Regional Geology/Hydrogeology ............................................................. 9 
2.2.2 Site Geology/Hydrogeology .................................................................... 9 
2.3 NAPL and Dissolved Phase Impacts ................................... 10 
3 RISK CLASSIFICATION ........................................ 11 
3.1 Extent of Petroleum Constituents..................................... 11 
3.1.1 Soil .....................................................................................................11 
3.1.2 Groundwater .......................................................................................11 
3.2 Receptor Information ...................................................... 12 
3.2.1 Water Supply Wells ..............................................................................12 
3.2.2 Public Water Supply Wells ....................................................................13 
3.2.3 Surface Water .....................................................................................13 
3.2.4 Wellhead Protection Areas ...................................................................13 
3.3 Comparison to Risk Criteria .............................................. 13 
3.4 Future Site Use Considerations ......................................... 14 
3.4.1 Exposure to Impacted Soil .....................................................................14 
3.4.2 Exposure to Impacted Groundwater ......................................................14 
3.4.3 Exposure to Petroleum Vapor ...............................................................15 
3.5 Cleanup and Closure with Land Use Restrictions ............... 15 

Page iv

4 CURRENT REMEDIATION SYSTEM EFFECTIVENESS
...................................................................... 17 
5 SYSTEM SHUTDOWN TESTING ........................... 18 
6 PROPOSED REMEDIATION TECHNOLOGY ........... 19 
6.1 Phase 1 – Phase Separated Product Recovery ................... 19 
6.1.1 Operation ...........................................................................................19 
6.1.2 Maintenance .......................................................................................20 
6.2 Phase 2 – In‐Situ SEAR Evaluation ..................................... 20 
6.2.1 Step 1 – SEAR Bench Study ....................................................................20 
6.2.2 Step 2 – SEAR Field Pilot Study ..............................................................21 
6.2.3 Step 3 – SEAR Full‐Scale Design .............................................................21 
7 REPORTING AND SCHEDULE .............................. 22 
8 REFERENCES .................................................... 23 

FIGURES 
FIGURE 1: SITE LOCATION MAP 
FIGURE 2: SITE MAP 
FIGURE 3: GEOTECH SIPPER SCHEMATIC  

APPENDICES 

APPENDIX A WSP STANDARD OPERATING PROCEDURES 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

1
EXECUTIVE SUMMARY 
This New Technology Cleanup Plan (NTCP) has been prepared for the Duke Energy Progress, LLC (Duke Energy) 
Weatherspoon Plant. If successful, this NTCP will be used to supplement the current Corrective Action Plan 
(CAP). The Duke Energy Weatherspoon Plant Site (Site) consists of a 500,000‐gallon Aboveground Storage Tank 
(AST) and an area downgradient and to the southeast, between the AST and a railroad spur that Duke Energy 
has owned the Site since 1949. The AST was installed in 1969. The AST is currently in operation at the Site. The 
AST contains #2 fuel oil. In addition to the 500,000‐gallon AST, a second, 250,000‐gallon #2 fuel oil, operational 
AST is located upgradient and to the northwest of the Site. This NTCP provides a summary of current Site 
conditions, cleanup objectives and risk‐ranking criteria, Corrective Action (CA) activities performed to date, and 
a recommendation of the most appropriate remedial approach for progressing the Site towards closure. 
Petroleum impacts in shallow groundwater exist at the Weatherspoon Plant as a result of a leak, discovered on 
March 16, 1995, due to corrosion of the steel bottom of the 500,000‐gallon AST. Approximately 153,600 
gallons of No. 2 fuel oil was released. The subject incident (#13884) is currently classified as intermediate risk 
due to the presence of light non‐aqueous phase liquid (LNAPL). Based on information reported in the CAP an 
estimated 40,000 gallons of No. 2 fuel oil were recovered as part of initial recovery efforts. These recovery 
activities involved the use of temporary recovery sumps that were later replaced by permanent recovery and 
drawdown wells. An underground drip line is installed around the perimeter of the site. Additional 
recovery/drawdown wells were installed in 2008, bringing the Site total to six recovery/drawdown wells.  
Assessment and remedial activities conducted at the Site between November 2015 and May 2018 were 
submitted in a report prepared by Catlin Engineers and Scientists (Catlin) to the North Carolina Department of 
Environmental Quality (NCDEQ) on June 15, 2018. These activities included recovery well cleaning and long 
term LNAPL recovery evaluation. In their report, Catlin indicated that with aggressive well maintenance 
practices, LNAPL recovery could be enhanced. However, the long‐term success of these efforts would be 
limited because of excessive biofouling and mineralization in the vicinity of the recovery wells and aquifer 
matrix. 
WSP USA Environment & Infrastructure Inc. (WSP) has determined based on an evaluation of the LNAPL recovery 
system that a significant reduction in recovery has been observed since installation with recovery becoming 
asymptotic over the past several years. As such, other remedial technologies/approaches will be necessary to 
achieve long term LNAPL removal objectives. Based on previous assessments performed at the Site, LNAPL 
remains within the subsurface beneath the concrete secondary containment, and pump and treat technology may 
be ineffective, in the long term. Hence, efforts to remove low to de‐minimis levels of LNAPL from the shallow 
groundwater table appear to be unattainable without major system modification or a more effective in‐situ 
remediation technology to expedite transition into a monitored natural attenuation (MNA) phase and Site closure. 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

2
As part of this evaluation process, WSP will shutdown the current remediation system to evaluate the presence 
and apparent thickness of LNAPL and dissolved phase petroleum constituents at monitoring locations under non‐
pumping conditions. During shutdown, WSP will perform six groundwater gauging events over the course of three 
(3) months. Groundwater elevations and LNAPL thickness will be obtained at all available monitoring well and 
piezometer locations. Additionally, at the completion of the shutdown evaluation, one groundwater sampling 
event will be performed to determine the extent and dispersion of concentrations of dissolved phase petroleum 
constituents and to evaluate biogeochemical parameters.  
Following the shutdown period, one new recovery well (installed in a recovery trench) will be installed in an area 
of the plume that most represents the greatest LNAPL thickness. Then, WSP will install a Geotech AC Sipper 
system or other low energy well‐specific method to remove LNAPL from the test location and evaluate the 
effectiveness over a three‐month period. The objective of the Sipper installation is to passively remove LNAPL that 
accumulates within the recovery well.  
WSP will also perform a bench study to determine the best Site‐specific Surfactant Enhanced Aquifer Remediation 
(SEAR) solutions (e.g., TASK by Tersus) needed to further reduce LNAPL levels and understand biological 
restrictions, if any. The Site‐specific formulation of the SEAR solution will be developed based on groundwater 
chemistry. 
Using results of the bench study, WSP will then evaluate the use of In‐situ SEAR in a pilot study for the purpose of 
increasing fluid mobilization and reducing recalcitrant LNAPL and dissolved phase concentrations of volatile 
organic compounds (VOCs)/ semi‐volatile organic compounds (SVOCs). The SEAR remedial approach involves the 
injection of a surfactant tailored to Site conditions to create ultra‐low interfacial tensions between LNAPL and the 
aquifer media. The surfactant solution is formulated to reduce the capillary forces trapping the LNAPL through 
contact so that it can be extracted using pumping methods or broken down geochemically to reduce LNAPL to 
more dissolved fractions so that MNA can be promoted later. 
The pilot study will focus on mobilizing for recovery the LNAPL from areas where LNAPL accumulates. WSP will 
base the placement of pilot study SEAR injection wells and LNAPL extraction wells on the results of the evaluation 
following system shutdown. Following completion of the SEAR injection pilot study, WSP will perform one year of 
groundwater monitoring to evaluate the effect of the pilot study on LNAPL thicknesses and dissolved phase 
petroleum constituents. 
Long‐term removal of residual LNAPL will be performed via the Sipper system. Full scale implementation of SEAR 
will be based upon the results of the pilot study. 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

3
1 INTRODUCTION 
This New Technology Cleanup Plan (NTCP) has been prepared for the Duke Energy Progress, LLC (Duke Energy) 
Weatherspoon Plant . If successful, this NTCP will be used to supplement the current Corrective Action Plan 
(CAP). The Duke Energy Weatherspoon Plant Site (Site) consists of a 500,000‐gallon Aboveground Storage Tank 
(AST) and an area downgradient and to the southeast, between the AST and a railroad spur. Duke Energy has 
owned the Site since 1949. The AST was installed in 1969. The AST is currently in operation at the Site. The AST 
contains #2 fuel oil. In addition to the 500,000‐gallon AST, a second, 250,000‐gallon #2 fuel oil, operational AST 
is located upgradient and to the northwest of the Site. This NTCP provides a summary of current Site 
conditions, cleanup objectives and risk‐ranking criteria, Corrective Action (CA) activities performed to date, and 
a recommendation of the most appropriate remedial approach for progressing the Site towards closure. 
The Site location relative to the surrounding area is depicted on the topographic map provided in Figure 1. A 
Site map with well locations is included as Figure 2. 
1.1 RELEASE INFORMATION 
Duke Energy has owned the Site since 1949 and operated the ASTs since their installation in 1969. Two ASTs 
(one 250,000‐gallon and one 500,000‐gallon) currently are in operation at the Site. These ASTs contain #2 fuel 
oil originally used as a backup fuel source for power generation at this facility. The contents of these ASTs are 
now used as a primary fuel source for power generation. 
Petroleum impacts exist at the Weatherspoon Plant because of a leak, discovered on March 16, 1995, due to 
corrosion of the steel bottom of the 500,000‐gallon AST. According to a pore space volume estimate by Edwin 
Andrews and Associates, P.C. (Andrews & Associates), approximately 153,600 gallons of No. 2 fuel oil was 
released. The incident number assigned by the North Carolina Department of Environmental Quality (NCDEQ), 
Division of Waste Management (DWM), Underground Storage Tank (UST) Section to the leak from the 500,000‐
gallon AST is 13884.  
In accordance with Title 15A North Carolina Administrative Code (NCAC) 02L .0506, each known incident shall 
be classified as high, intermediate, or low risk. The subject incident is currently classified as intermediate risk. 
Receptor Information and a comparison of the conditions and characteristics associated with this incident to 
the risk criteria is included in Section 3.0. 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

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1.2 SITE INFORMATION 
The subject Site is an active Duke Energy Power Plant and consists of several structures, equipment, cooling 
ponds and former coal ash ponds. The surface is a combination of paved, gravel‐covered, and grassy areas.  
1.3 OTHER RELEASES  
In addition to the subject release, another incident is associated with the Weatherspoon Plant. Incident 
number 92156 is an impacted soil area, which was discovered during plant decommissioning activities. In 2019, 
incident 92156 was surveyed and sub‐divided and a Notice of Residual Petroleum (NRP) was recorded with the 
Robeson County Register of Deeds for the sub‐divided parcel of land. 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

5
2 SITE BACKGROUND 
As noted in Section 1.1, approximately 153,600 gallons of No. 2 fuel oil was released at the Site, which 
impacted groundwater. A summary of assessment and remediation performed to date is described in Section 
2.1. 
2.1 SUMMARY OF ASSESSMENT AND REMEDIATION  
The following is provided to briefly summarize historical assessment and remedial action performed on Site, 
from release discovery to the present.  
 July 31, 1995, Site Assessment Report‐ This report was prepared for Carolina Power and Light Company 
(CP&L) by Andrews & Associates detailing repairs to the bottom of the tank and noting that leakage 
from the tank had ceased. The Site Assessment Report also provided information on the installation of 
twenty‐seven shallow piezometers and five monitoring wells. The twenty‐seven piezometers, installed 
in March 1995, were utilized to determine Site groundwater flow direction, horizontal and vertical 
extent of light non‐aqueous phase liquid (LNAPL), and the future location of Site monitoring wells. The 
resultant five monitoring wells, installed from May 15 to June 2, 1995, were installed for the purpose 
of monitoring groundwater impact, as well as the migration of released LNAPL. The author of the 
report noted that one of the five monitoring wells, MW‐3, was originally installed outside of the LNAPL 
plume, and became impacted by LNAPL.  
 January 31, 1996, CAP‐ As reported in the CAP, prepared for CP&L by Edwin Andrews & Associates, an 
estimated 40,000 gallons of No. 2 fuel oil were recovered as part of initial recovery efforts. These recovery 
activities used temporary recovery sumps that were later replaced by permanent recovery and drawdown 
wells. In their CAP, Andrews & Associates also detailed the proposed installation of an underground drip 
line to provide lateral and downgradient hydraulic control and enhance recovery efforts. The CAP also 
included a groundwater receptor evaluation. The updated receptor evaluation was included on Figure 2 of 
the November 2022 Catlin report. The information related to the Public and Private Water well 
information was included on Table 2 of the November 2022 Catlin report. 
 2004 and 2006 Additional Groundwater Control Actions‐ Catlin Engineers and Scientists (Catlin) 
performed subsequent Site remedial activities, following the approval of the initial CAP, including the 
construction of the underground drip line in 1996. As such, the drip line system was expanded to the 
revised known extent of LNAPL and dissolved‐phase impact. Three additional recovery/drawdown 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

6
wells were installed in 2008 within the known LNAPL plume, bringing the Site total to six 
recovery/drawdown wells. 
 February and March 2013 Phase Separated Product (PSP) Evaluation‐ Catlin conducted an evaluation of 
LNAPL occurrence utilizing existing groundwater monitoring points. Prior to performing the LNAPL 
evaluation, Caitlin surveyed and developed each of the existing monitoring points. The results of the 
evaluation were reported to the North Carolina Department of Environment and Natural Resources 
(NCDENR), which is now NCDEQ on June 29, 2013.  
 July 7, 2014 Direct Sensing Characterization and Reporting‐ Catlin submitted investigation results of the 
direct sensing investigation conducted by Columbia Technologies. Columbia Technologies utilized Laser 
Induced Fluorescence/Ultraviolet Optical Screening Tool (LIF/UVOST) for direct sensing in conjunction 
with direct push technology (DPT) to further define the LNAPL plume. The subsurface soil structure was 
characterized by Catlin as a silty sand to silty gravel at shallow depths to 6.5 feet below grade (fbg), 
that is underlain by a fine to very fine sand which dominates the survey area to depths ranging from 
one foot in some areas to 13 feet to 16 fbg. Beneath the sand zone the subsurface transitions to a 
clayey sand to sandy clay. LIF/UVOST data indicated that the bulk of the LNAPL was located at and near 
the water table, and within the zone of transport or groundwater smear zone. The historical high‐
water table has generally been encountered at the ground surface in the silty sand geologic unit.  Data 
also indicated subsurface conditions are conducive for mobile LNAPL. Furthermore, results of the 2014 
investigation indicated the greatest thickness of LNAPL remained beneath the concrete containment 
providing secondary containment for the 500,000‐gallon AST. Based on the results of the LIF/UVOST 
evaluation, Catlin installed and gauged four piezometers (P67‐P70) and four temporary boring points 
(T71‐T74) to correlate the direct sensing LIF/UVOST data with direct measurement of LNAPL. 
Piezometers were installed in areas of probable LNAPL accumulation and/or in areas of varying LIF 
results to correlate potentially recoverable (i.e., recoverable through pumping) versus interstitially 
trapped LNAPL. Piezometers were gauged in October 2014 and again in January 2015. Results from 
these gauging events as well as overall Site evaluations are detailed in the Treatment System 
Evaluation Report dated July 21, 2015 (Catlin 2015). The Treatment System Evaluation Report 
recommended installing five temporary 2‐inch diameter, polyvinyl chloride (PVC) piezometers within 
the 500,000‐gallon AST containment area to evaluate the volume of residual LNAPL below the 
containment area. These temporary piezometers were installed, gauged, and abandoned prior to re‐
lining the AST containment area. Subsequently, seven piezometers were installed around recovery 
wells RW‐00, RW‐01, RW‐03 and RW‐05 to be utilized during drawdown evaluations and future 
monitoring events. Piezometer measurements were used to measure drawdown and radius of 
influence as well as to observe the occurrence of mobile LNAPL and the efficiency of the recovery wells 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

7
(Figure 2). Individual flow meters were also installed in each of the four recovery wells listed above to 
determine individual flow and LNAPL recovery totals from each recovery well, respectively. 
 November 30, 2015 and January 19, 2016 Pumping Tests‐ Catlin conducted a series of 72‐ hour 
pumping tests on each recovery well (RW‐00, RW‐01, RW‐03 and RW‐05). During pumping activities, 
transducers were installed in the recovery well and three nearby wells to record groundwater 
drawdown throughout the duration of the pumping test and evaluate the radius of influence (ROI) at 
each recovery well (Catlin 2016). Groundwater was allowed to equilibrate between 72‐hour pumping 
tests. The comprehensive drawdown results from each of the pumping tests were included in a 
Drawdown Analysis and System Evaluation Report dated July 12, 2016. The overall results indicated 
that the LNAPL recovery and radial influence was likely obstructed by a combination of precipitated 
metals and biofouling within the recovery wells. The report recommended chemically cleaning each 
recovery well. 
 December 2016 Well Chemical Cleaning‐ Based on the results of the pumping tests, work was 
performed on each of the four recovery wells to remove suspected biofouling. As a result of the 
cleaning, groundwater pH at the treated wells decreased substantially. As such, three of the pumping 
wells remained off until pH values in the well exhibited a pH of at least 5.5. RW‐03 was reactivated in 
February of 2017 and RW‐01 was reactivated in June 2017. To evaluate the success of the cleaning, 
post cleaning pumping tests were performed in July 2017 on recovery wells RW‐01 and RW‐03, 
followed by long‐term LNAPL recovery monitoring. Results of the cleaning indicated an increase in ROI 
and improvement in LNAPL recovery. Specifically, RW‐01 and RW‐03 operated consistently from June 
2017 through May 2018 and recovered approximately 334 gallons of LNAPL. 
 June 15, 2018 Comprehensive Site Assessment (CSA) Report‐ Site assessment and remedial activities 
conducted at the Site between November 2015 and May 2018 were submitted to the NCDEQ on June 
15, 2018. These activities included the preliminary recovery well testing, the recovery well cleaning 
event, the post cleaning recovery well testing, and the long term LNAPL recovery evaluation. Catlin 
indicated that with aggressive well maintenance practices, LNAPL recovery could be enhanced. 
However, the long‐term success of these efforts would be limited because of excessive biofouling and 
mineralization in the vicinity of the recovery wells and aquifer matrix. In addition, a dynamic pulse 
biosparge pilot test was recommended to address LNAPL surrounding the recovery system and tank 
containment area. However, upon initial planning and evaluation, the pilot test was not scheduled due 
to AST foundation and structural integrity concerns. 
Data from the most recent sampling event, performed by Catlin and summarized in their Annual Groundwater 
Monitoring and Remediation System Report dated November 16, 2022, are summarized in Section 2.1.1. 
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2.1.1 2022 ANNUAL GROUNDWATER MONITORING AND REMEDIATION SYSTEM REPORT SUMMARY 
Between June 28 and 29, 2022, Catlin personnel performed groundwater gauging and sampling activities on‐Site. 
Catlin collected representative groundwater samples from shallow, Type II monitoring wells MW‐1 through MW‐5, 
deep well TMW‐1, WSW #1 (WS‐1) and select piezometers. Results from the June 2022 monitoring event are 
summarized below: 
Groundwater Gauging Data Summary 
Based on the June 2022 gauging data, the shallow surficial groundwater flow is generally towards the southeast, 
which is consistent with previous monitoring events. LNAPL was detected in recovery well RW‐03 (apparent 
thickness is 0.76 feet), piezometer P‐47 (0.03 feet apparent thickness), and P‐81 (0.31 feet apparent thickness). 
Groundwater contours and LNAPL thicknesses recorded during the June 2022 sampling event are presented in 
figures in the November 2022 Catlin report, respectively. 
Groundwater Sampling Data Summary 
Catlin collected a total of 19 groundwater samples for laboratory analysis from six monitoring wells (five 
shallow and one deep), 12 piezometers, and one WSW (WS‐1) during the June 2022 sampling event. Results of 
the sampling indicated the following: 
 Benzene concentrations were above the 2L Groundwater Quality Standard (GWQS) (1 microgram per 
liter [μg/L]) in the groundwater samples collected from P‐68 (15.5 μg/L), P‐70 (2.7 μg/L), T‐71 (16.0 
μg/L), P‐75 (2.7 μg/L), P‐77 (2.2 μg/L), and P‐79 (8.6 μg/L); and, 
 Naphthalene concentrations were above the 2L GWQS (6 μg/L) in the groundwater samples collected 
from MW‐3 (11.5 μg/L), P‐53 (13.5 μg/L), P‐68 (84.6 μg/L), P‐70 (17.1 μg/L), T‐71 (42.0 μg/L), P‐75 (26.6 
μg/L), P‐77 (51.4 μg/L), and P‐79 (28.0 μg/L).  
No other analyzed petroleum constituent concentrations were detected above their corresponding 2L GWQS. 
The concentrations of constituents in sample WS‐1, which was analyzed according to EPA Method 602, were 
below laboratory reporting limits. Groundwater analytical data from the June 2022 sampling event are 
presented in tables and figures in the November 2022 Catlin report.  
Catlin used the Mann‐Kendall (MK) statistical method to evaluate the dissolved benzene and/or naphthalene 
concentration trends at MW‐3 and piezometers P‐53, P‐70, T‐71, P‐75, P‐77, and P‐79 over time. Based on the 
results from the MK evaluation, dissolved benzene concentrations in MW‐3, P‐75, P‐77, and P‐79 are 
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“decreasing”, “stable” in P‐70 and there is “no trend” in T‐71. Dissolved naphthalene concentrations are 
“decreasing” at MW‐3 and P‐75 and are “stable” in P‐53, P‐70, T‐71, P‐77, and P‐79 (Catlin 2022).  
LNAPL Recovery 
As of the June 2022 sampling event, the recovery system collected approximately 125,059 gallons of LNAPL. 
Between February 2017, when pumps were replaced in the recovery wells following the chemical well cleaning, 
and June 2022, approximately 1,277 gallons of LNAPL was recovered from RW‐01 and RW‐03. Only 47 gallons 
of that was recovered in 2022. Ninety‐six percent (%) of the total LNAPL recovered at the Site occurred 
between 1995 and 2005. Overall, the LNAPL recovery system has captured a limited amount of product since 
2005. 
2.2 GEOLOGY AND HYDROGEOLOGY 
2.2.1 REGIONAL GEOLOGY/HYDROGEOLOGY 
The Site is in the Atlantic Coastal Plain Physiographic Province of North Carolina. The surficial sediments 
comprise the Columbia group, which are believed to unconformably overlie the Pee Dee and Black Creek 
formations. The Pee Dee aquifer in the vicinity of the Site is approximately 5 feet thick and is composed of fine 
to medium sand. In the vicinity of the Site the upper confining unit of the Pee Dee aquifer is thin and 
potentially absent. Below the Pee Dee aquifer lies the Black Creek confining unit which is reported to be 
approximately 5 feet thick in the area. The Black Creek formation is approximately 250 ft thick in the vicinity of 
the Site and is composed of interlayered sand and clay layers. The Black Creek Formation is the source aquifer 
for WS‐1, which is screened from 195 to 215 fbg. 
2.2.2 SITE GEOLOGY/HYDROGEOLOGY 
During the initial Site investigations, soil borings were completed to a depth of approximately 60 fbg. The 
shallow soils encountered at the Site consist of reddish‐brown to yellowish‐brown fine‐grained sand with layers 
of sand and coal fill near the surface to a depth of approximately 7 feet. Overall, the Site is underlain by 
approximately 12 to 30 feet of fine, silty sand. Various discontinuous clay lenses with varying amounts of sand 
are also present between approximately 15 to 40 fbg. Dense, fine, silty‐sand underlays the Site from 
approximately 40 to 60 fbg. Boring logs and cross sections, labeled A‐A' and B‐B', were generated during the 
initial Site Assessment work by Andrews & Associates in 1995. 
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Based on historical information at the Site, shallow groundwater is generally encountered ranging from 
approximately two to six fbg. Groundwater flow at the Site is generally to the southeast toward the cooling 
ponds, which are about 1,000 ft downgradient under a hydraulic gradient of approximately 0.0175 ft/ft. Depth 
to water at the Site fluctuates seasonally due to rainfall and changes in evapotranspiration during the spring 
and summer. It is likely that the capillary fringe in the shallow sand/silty sands at the Site is approximately 0.5 
to 1.5 feet thick, which would result in interstitial water being close to or at ground surface in some locations at 
certain times of the year. A consistent unsaturated zone (vadose zone) does not exist at the Site. 
2.3 NAPL AND DISSOLVED PHASE IMPACTS  
Impacts associated with the fuel oil release are concentrated in the shallow groundwater unit. Due to the 
lower relative density of #2 fuel oil, the dissolved phase impacts have not been detected at concentrations 
above the 2L Standards at depths below approximately 15 fbg. In areas where recovery wells have operated 
historically, the impacts may extend to approximately 25 fbg, However LNAPL and dissolved phase impacts 
have not been detected in the Type III Monitoring Well (TMW‐1) that is screened from 34‐39 fbg. There is over 
170 feet of vertical separation between impacted shallow groundwater and the Site water supply well, which 
remains unimpacted by the fuel oil release as of June 2022. 

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3 RISK CLASSIFICATION 
3.1 EXTENT OF PETROLEUM CONSTITUENTS 
3.1.1 SOIL  
Based on Site assessment data collected to date, the shallow water table (e.g., the seasonal high‐water table) 
and the associated capillary fringe is located approximately at or just below the land surface. As such, no 
unsaturated soil is present in the release area that has not been in contact with impacted groundwater 
because of seasonal groundwater cycles or storm events. The risks associated with shallow groundwater are 
discussed in Section 3.1.2. 
3.1.2 GROUNDWATER 
Based on Site assessment data collected to date, both LNAPL and dissolved phase groundwater impacts exist at 
the Site. The extent of groundwater impacts is described below: 
LNAPL Distribution 
The historic LNAPL extent at the Site is detailed in the 2014 Site Characterization Report (Catlin 2014). The current 
aerial extent of LNAPL is defined using the results of the LIF investigation and the ongoing fluid gauging results. 
The data indicate that LNAPL is limited to the area immediately downgradient of the AST and is generally 
contained within the berm.  
The vertical distribution of LNAPL was defined utilizing the results of the LIF investigation (Catlin 2014). Most LIF 
profiles returned responses near depths corresponding to the 3.0 to 8.0 fbg. However, in some locations, LIF 
results indicated that LNAPL was present in some areas within the recovery system radius of influence at depths 
between 3.0 and 16 fbg. The data indicate the vertical extent has been defined. 
LNAPL Mobility and Effect on Groundwater 
Mobile LNAPL is presumed to be present if it is observed to accumulate in a well. Therefore, the extent of mobile 
LNAPL at the Site can be illustrated using gauging data. Measurable LNAPL has been decreasing at the Site since 
recovery began in 1995. During the most recent gauging event in June 2022, LNAPL was detected in recovery well 
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RW‐03, and piezometers P‐47 and P‐81. The LNAPL thicknesses observed ranged from 0.03 feet to 0.76 feet 
(Catlin 2022). 
While mobile LNAPL is present, it is likely not migrating (moving into surrounding, unimpacted porous media). 
The potential for LNAPL migration can be evaluated by the analysis of historical fluid gauging over time. Also note 
that mobile LNAPL has not historically been observed in downgradient monitoring wells MW‐3, MW‐4, or TMW‐1 
since their installation in 1995 and LIF data demonstrated no presence of LNAPL in these areas. These data 
therefore indicate that the LNAPL body contains mobile LNAPL but is not migrating. 
Dissolved Phase 
Groundwater data from the June 2022 sampling event indicate that Benzene and Naphthalene exceed the 2L 
GWQS at the Site. Benzene concentrations were above the 2L GWQS (1 μg/L) in the groundwater samples 
collected from P‐68, P‐70, T‐71, P‐75, P‐77, and P‐79 and naphthalene concentrations were above the 2L GWQS 
(6 μg/L) in the groundwater samples collected from MW‐3, P‐53, P‐68, P‐70, T‐71, P‐75, P‐77, and P‐79. Based on 
the results of the June 2022 sampling, the shallow groundwater plume downgradient of the source area has 
generally been defined; however, the most recent plume boundaries upgradient and cross‐gradient to the east 
are undefined. Benzene and naphthalene groundwater concentration plume maps are included November 2022 
Catlin report.  
In general, concentrations of dissolved phase petroleum constituents in downgradient wells have decreased over 
time, which is further evidence that the LNAPL plume is not migrating. 
3.2 RECEPTOR INFORMATION  
A summary of the potential receptors located within 1,500 feet of the source area are summarized in this 
section. Potential receptors are depicted in November 2022 Catlin report.  
3.2.1 WATER SUPPLY WELLS 
The Weatherspoon plant encompasses greater than a 1,500‐foot radius around the source area. Currently, one 
active WSW (WS‐1) is located on the property approximately 350 feet West of the source area (in an 
upgradient direction). Reportedly this is a potable well, based on conversations with Duke Energy employees. It 
is the only source of potable water for the Site. Additionally, the drip system is fed by a non‐potable six‐inch 
diameter well screened from 200 to 210 fbg located approximately 195 feet to the north northwest of the 
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source area. Information regarding WSWs within 1,500 feet of the Site are detailed in the November 2022 
Catlin report.  
3.2.2 PUBLIC WATER SUPPLY WELLS  
No public WSWs were identified within 1,500 feet of the source area. Public water is not currently provided to 
the Site.  
3.2.3 SURFACE WATER  
The only surface water body considered to be “waters of the United States” nearest to the Site is the Lumber 
River, which is located approximately 1,300 feet west (hydraulically side‐gradient) of the release. 
3.2.4 WELLHEAD PROTECTION AREAS 
According to the NCDEQ, Division of Water Resources (DWR), Public Water Supply Well (PWS) Section web 
page, there are no known wellhead protection areas within 1,500 feet of the subject Site. 
3.3 COMPARISON TO RISK CRITERIA  
Risk Classification criteria are defined in Title 15A Subchapter 02L .0506 of the North Carolina Administrative 
Code (15A NCAC 02L .0506). This Site has been assigned a risk classification of intermediate. An intermediate‐
risk classification is assigned to this Site based upon the following: 
 LNAPL thicknesses greater than 0.01 feet are present at the Site. 
Although a potable water supply well is located within 1,000 feet of the source area and a non‐potable water 
supply well is located within 250 feet of the source area, neither well has been or is likely to be impacted by 
the release given the location of the wells, the depth and construction of the wells, and the formation from 
which the wells extract groundwater. Furthermore, although the groundwater within 500 feet of the source 
area of the release has the potential for future use, the use is controlled by Duke Energy and the future use can 
be restricted with a Notice of Residual Petroleum once LNAPL is removed from the Site. 
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3.4 FUTURE SITE USE CONSIDERATIONS  
Consideration must be given to managing or eliminating future Site worker exposure to petroleum affected 
soil, liquid, and vapor. Future Site workers may include construction workers and occupants of potential future 
buildings. The exposure pathways applicable to the Site are dermal contact, ingestion, and/or inhalation of 
vapors associated with impacted soil or groundwater.  
3.4.1 EXPOSURE TO IMPACTED SOIL  
Currently, the primary risk of exposure to petroleum constituents at the Site is associated with earthwork. Risk 
of inhalation, ingestion, and/or dermal contact may occur during earthwork activities within the area affected 
by LNAPL and dissolved phase petroleum constituents.  
Therefore, earthwork within impacted areas should be avoided by Site workers, if possible. If earthwork must 
occur in these areas, then proper precautions (e.g., personal protective equipment and proper health and 
safety procedures) and engineering controls (e.g., barricaded work zones, fans, etc.) should be implemented to 
reduce dermal and inhalation exposure to petroleum constituents. Furthermore, any impacted soil and 
groundwater generated because of such earthwork, should be properly managed and disposed of at an 
approved, off‐Site facility. 
3.4.2 EXPOSURE TO IMPACTED GROUNDWATER  
Due to the shallow water table, exposure to impacted groundwater, like exposure to impacted soil, may occur 
during earthwork activities within the area affected by LNAPL and dissolved phase petroleum constituents. The 
risk associated with, and approaches to mitigate exposure to, impacted groundwater during earthwork 
activities are the same as those associated with exposure to impacted soil. Additionally, although a source, 
pathway, and exposure point exist for groundwater extracted through a potable well within a 1,500‐foot radius 
of the area, the potable well is reportedly located hydraulically upgradient, extracts groundwater from a deep 
aquifer, and ongoing routine groundwater monitoring demonstrates that petroleum constituents are not 
detectable at concentrations above laboratory reporting limits in the extracted potable water. 
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3.4.3 EXPOSURE TO PETROLEUM VAPOR  
Vapor intrusion occurs when vapors from volatile constituents, like those found in petroleum, migrate upward 
into overlying buildings through cracks and gaps in the building floors, foundations, and utility conduits which 
could result in impacts to indoor air.  
The NCDEQ refers to the Interstate Technology and Regulatory Council (ITRC) for guidance on screening and 
testing of petroleum vapor intrusion (PVI). According to the ITRC guidance, the vapor intrusion pathway should 
initially be considered for all current or future buildings located within 30 feet horizontally and 5 feet vertically 
(dissolved phase sources) or 18 feet vertically (LNAPL sources – industrial Sites) of the vapor source.  
Currently, no buildings exist within 100 feet of impacted groundwater. At this time, no buildings are proposed 
for construction near impacted groundwater. If new buildings are proposed in the future, Duke Energy will 
implement engineering controls to address PVI, if appropriate. 
3.5 CLEANUP AND CLOSURE WITH LAND USE RESTRICTIONS  
Cleanup goals applicable to the Site and as presented in UST Section Corrective Action Guidelines (NCDEQ 
2021) are as follows: 
Soil—The current remediation goals for petroleum constituents in soil are levels equal to or less than the 
lowest maximum soil contaminant concentrations (MSCCs). However, because of the shallow groundwater 
table (e.g., the historical high groundwater table is located approximately at the ground surface), no 
unsaturated zone petroleum‐affected soils exist at the Site outside the capillary fringe. 
Groundwater—The remediation goals for groundwater are to restore shallow groundwater quality to levels 
that will prevent a violation of the 2L groundwater quality standards (2L GWQS) in the deep aquifer into which 
the nearby potable water supply well is installed. 
Surface Water—Surface water has not been affected by this release. Groundwater must be cleaned up to 
levels that are sufficient to prevent this Site from causing a violation of the surface water rules contained in 
15A NCAC 02B.  
LNAPL—The remediation goal for LNAPL is that no measurable amount of LNAPL greater than or equal to 0.01 
feet will exist in a groundwater monitoring well or piezometer. 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

16
Potential steps to reclassify the Site as low risk are as follows: 
 Remove LNAPL and confirm that dissolved petroleum constituent concentrations in groundwater are 
below gross contamination levels as defined in 15A NCAC 02L .0406, 
 Abandon the nearby drip line supply well, which is not used for drinking water, 
 Restrict the use of groundwater as a water supply in and around the source area. 
Once the risk classification associated with the Site is changed to low, a request for no further action can be 
initiated. 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

17
4 CURRENT REMEDIATION SYSTEM EFFECTIVENESS 
The current LNAPL recovery system has recovered a significant amount of LNAPL at the Site since installation; 
however, recent recovery has been limited and LNAPL recovery trends have become asymptotic due to thin 
aquifer conditions and poor recovery well performance. Thin layers of residual LNAPL remain within the 
subsurface and pump and treat technology may be ineffective, in the long term. Since installation, newer 
technologies have emerged that make the current system outdated.  
The current system is costly (labor and materials) to maintain relative to other remedial approaches. The 
system components, including recovery wells, system piping and pumps have reached the end of their useful 
life. Furthermore, the construction of the existing recovery wells is not suitable for the contaminant type (i.e., 
constructed of HDPE outer screen with PVC inner screen – HDPE has poor compatibility with petroleum) and 
may be restrictive to LNAPL recovery. With the retirement of the coal‐fired power units on Site, it is also 
currently unclear how the permit through which system effluent is discharged may change. 
The remaining volume of LNAPL as well as the concentration of dissolved phase constituents in groundwater 
has decreased significantly since remediation began and hydraulic control may no longer be necessary. WSP 
recommends evaluating a better approach to achieve remedial objectives and reduce the risk classification 
(i.e., cleaning up groundwater to attain risk‐based closure objectives). Future site assessment and remediation 
efforts for data collection and management will follow WSP USA Environment & Infrastructure Inc. (WSP) 
standard operating procedures outlined in Appendix A. 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

18
5  SYSTEM SHUTDOWN TESTING 
WSP will shutdown the current remediation recovery system (Operating wells RW‐01 and RW‐03) to evaluate 
the presence and apparent thickness of LNAPL and dissolved phase petroleum constituents at monitoring 
locations under non‐pumping conditions. During shutdown, WSP will perform six groundwater gauging events 
over the course of three months. Groundwater elevations and LNAPL thickness will be obtained at all available 
monitoring well and piezometer locations. Additionally, at the completion of the three‐month shutdown 
evaluation, one groundwater sampling event will be performed to determine the extent and concentrations of 
dissolved phase petroleum constituents and to evaluate biogeochemical parameters within and surrounding 
the petroleum plume limits. 
Sampling will include the same suite of wells/piezometers as performed during the 2022 annual groundwater 
monitoring event (MW‐1 through MW‐5, TMW‐1, WS‐1, P‐46, P‐48, P‐53, P‐64, P‐67, P‐68, P‐69, P‐70, T‐71, P‐
75, P‐77, and P‐79) plus ten additional piezometers (P‐04, P‐10, P‐38, P‐39, P‐40, P‐41, P‐42, P‐45, P‐55, and P‐
59) to evaluate data gaps associated with the plume limits. During the event, one sample of the following will 
be collected for quality assurance/quality control (QA/QC) purposes: field blank, trip blank, and duplicate. 
Groundwater samples will be submitted to a state‐certified laboratory for analyses for the presence of VOCs 
according to EPA Method 602 with naphthalene; additionally, total and dissolved iron and manganese, ferrous 
iron, alkalinity, nitrate, nitrate, sulfate, sulfide, and total organic carbon (TOC) will be measured to evaluate 
degradation conditions associated with monitored natural attenuation (MNA). Groundwater will also be 
analyzed in the field using a water quality meter for geochemical parameters including dissolved oxygen (DO), 
oxidation reduction potential (ORP), pH, temperature, and conductivity. The target method/analyte list may be 
reduced or modified based on future sampling results; any recommended changes would be communicated to 
NCDEQ. Wells or piezometers containing LNAPL will not be sampled. 
Following the recovery well shutdown test, WSP may recommend the abandonment of select piezometers to 
optimize the groundwater monitoring network. 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

19
6 PROPOSED REMEDIATION TECHNOLOGY  
WSP proposes a new phased approach for recovery and treatment of residual LNAPL at the Site. The phased 
approach will allow WSP to confirm the efficacy of LNAPL remediation techniques before further implementing 
additional remediation techniques.  
6.1 PHASE 1 – PHASE SEPARATED PRODUCT RECOVERY 
 The manner in which LNAPL is currently being remediated is no longer effective. As such, following the 
recovery well shutdown test the recovery wells will be abandoned, and new wells (vertical or horizontal) may 
be installed in locations based on the shutdown test information (i.e., areas with greatest thickness of LNAPL). 
New recovery wells will be constructed of PVC and their screened intervals will be determined after evaluation 
of shutdown test data. 
In the new recovery wells, WSP will install a Geotech AC Sipper system or other low energy well specific 
method to remove LNAPL. The objective of the Sipper installation is to passively remove LNAPL that 
accumulates within the recovery wells. Since the Sipper system does not actively maintain drawdown at each 
of the recovery wells, LNAPL recovered will be a result of natural downgradient flow and accumulation to 
accommodate the thin aquifer zone where the LNAPL is located. Additionally, the passive nature of the system 
and the recovery of only LNAPL and not groundwater eliminates the discharge of water to the plant’s 
wastewater treatment system and NPDES permitted outfall. 
Up to eight recovery wells can be included in each Sipper control box. Any well/piezometer 2” or greater in 
diameter can be utilized as a recovery well. Therefore, the number and placement of Sipper control boxes and 
vertical or horizontal wells will be dependent upon the distribution of LNAPL observed during the shutdown 
test. A diagram of the Sipper system is included as Figure 3. 
6.1.1 OPERATION 
The Sipper system operates on three separately timed intervals that control the vacuum, purging and delay 
between cycles. The vacuum cycle controls how long the system is pumping LNAPL from the well and into the 
discharge line. The system then switches to the purging cycle which pumps air through the lines to flush the 
LNAPL into an on‐Site poly tank. The vacuum and purging cycles run consecutively to clear the line of LNAPL as 
soon as the vacuum interval is complete. Lastly the delay cycle controls the time between the purging cycle and 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

20
the next vacuum cycle. Cycle times for each operation are Site specific and will be field determined based on 
LNAPL recovery/recharge within each well.  
6.1.2 MAINTENANCE 
System inspections will be conducted by WSP monthly to ensure the pump is running and components of the 
system are operating as designed in the recovery wells. An inspection form will be completed during each visit 
to track the system’s current operating settings as well as the product recovered into the poly tank, staged 
next to the Sipper system. The inspection will also include checking that all air return lines are clear of liquid 
and properly attached, check values are operating correctly, and the poly tank is properly sealed and all LNAPL 
lines secured to the inlet port. Furthermore, the system will be fitted with telemetry such that the system can 
be monitored remotely. 
The poly tank fluid level will be measured during each inspection to determine how much LNAPL has been 
extracted since the prior inspection. The poly tank will contain graduated markings to ensure consistent 
measuring locations and to accurately track the LNAPL levels. Additionally, the poly tank will be fitted with a 
high‐level shutoff to prevent the tank from overflowing. Waste disposal will be performed utilizing a portable 
pump and hoses to pump the LNAPL from the poly tank into 55‐gallon drums. The drums will be labeled and 
staged in a designated area as instructed by Duke Energy. LNAPL will be transported off‐Site for recycling 
and/or disposal at an approved facility. 
6.2 PHASE 2 – IN‐SITU SEAR EVALUATION 
WSP will evaluate the use of In‐situ Surfactant Enhanced Aquifer Remediation (SEAR) to improve geochemical 
properties by increasing fluid mobilization and reduction of recalcitrant LNAPL and dissolved phase VOCs/ 
SVOCs using less invasive techniques. This remedial approach involves the injection of a surfactant tailored to 
Site conditions to create ultra‐low interfacial tensions between LNAPL and the aquifer media. The surfactant 
solution is formulated to reduce the capillary forces trapping the LNAPL through contact so that it can be 
extracted using pumping methods or broken down geochemically to reduce LNAPL to more dissolved fractions 
so that MNA is feasible. 
6.2.1 STEP 1 – SEAR BENCH STUDY  
WSP will perform a bench study to determine the best Site‐specific SEAR solution (i.e., TASK™ by Tersus) 
needed to further reduce LNAPL levels and understand biological restrictions, if any. The Site‐specific 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

21
formulation of the SEAR solution will be developed based on groundwater chemistry collected historically and 
during the shutdown evaluation. To evaluate potential injectants for full scale SEAR activities, one groundwater 
and one LNAPL sample, representative of Site conditions will be collected from Site wells for a bench scale 
Phase Behavior study by Tersus. One additional LNAPL sample will be collected for analysis of viscosity to 
evaluate any limitations or restrictions associated with the Sipper system. 
The bench study will provide a clear understanding of the microemulsions and capillary phenomena required 
to break down the LNAPL for better mobilization and in‐situ reduction of VOCs/SVOCs. The SEAR solution will 
be formulated to increase the solubilization and lower the energy of the area of contact between the water 
and oil to increase mobility. 
6.2.2 STEP 2 – SEAR FIELD PILOT STUDY  
WSP will perform a pilot study to determine if in‐situ SEAR methods are feasible to mobilize and ultimately 
capture LNAPL. The pilot study will target a specific source area (based on the shutdown test LNAPL thickness 
data) to mobilize LNAPL for recovery in downgradient wells. WSP will also consider the placement of injection 
and extraction wells based on the shutdown test results. However, it is currently anticipated that injection 
wells will be installed upgradient of the concrete secondary containment and extraction wells will be installed 
downgradient of the secondary containment, in proximity to the current recovery well network.  
Following completion of the SEAR pilot injection, WSP will perform one year of groundwater monitoring to 
evaluate reductions in LNAPL thicknesses and dissolved phase petroleum constituents. WSP will perform 
gauging monthly. Additionally, WSP will perform five groundwater post‐injection monitoring events (1‐month, 
3‐month, 6‐month, 9‐month, and 12‐month) to evaluate the success of the SEAR injection. WSP will select 
performance monitoring wells based on the results of the groundwater evaluation following system shutdown. 
6.2.3 STEP 3 – SEAR FULL‐SCALE DESIGN  
If the pilot study is successful and with regulatory approval, WSP will proceed to a full‐scale SEAR injection 
design to mobilize residual LNAPL for removal via the downgradient recovery well system. Long‐term removal 
of residual LNAPL will be performed via the Sipper system. A work plan will be prepared prior to full scale 
implementation. 
New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

22
7 REPORTING AND SCHEDULE  
Implementation of the NTCP will be dependent upon NCDEQ approval and receipt of necessary Duke Energy 
approvals. WSP estimates that the UST Section will require up to 60 days for review and approval. Remediation 
activities are estimated to begin within 4 weeks following approval of the NTCP by NCDEQ. Following 
completion of the pilot study, WSP will prepare a Pilot SEAR Report documenting the results of the pilot test 
and viability of the remedial alternative for progressing the Site towards closure in lieu of the current 
approach. If successful, SEAR will be implemented in a full‐scale approach.  
Following full scale implementation of SEAR, WSP will perform post‐implementation monitoring for the first 
year and as needed thereafter. The monitoring and compliance sampling network will consist of the same 
monitoring points described in Section 5. During the first year, routine reports will be prepared following each 
monitoring event. Annual monitoring and reporting is anticipated for subsequent years as needed. Each report 
will include an evaluation of the methods, frequency of monitoring and content of the technical data reported 
to NCDEQ. 
Once LNAPL is no longer present on‐Site and dissolved petroleum constituents in groundwater meet risk‐based 
cleanup criteria, WSP will work with Duke Energy to address any remaining criteria required to change the risk 
classification of the Site to low (e.g., abandon the drip system supply well), and WSP will request, on behalf of 
Duke Energy, that the NCDEQ require no further action for this incident. 

New Technology Cleanup Plan April 12, 2023
Duke Energy Progress – Weatherspoon Plant
Lumberton, Robeson County, North Carolina
WSP Project: 7812-22-0872

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8 REFERENCES  
Caitlin Engineers and Scientists, Semi‐Annual Groundwater Monitoring and Initial Free Product Evaluation, June 
29, 2013. 
Caitlin Engineers and Scientists, Remedial Action – Treatment System Evaluation Report, July 21, 2015. 
Caitlin Engineers and Scientists, Site Characterization Using Laser Induced Fluorescence/Ultra Violet Optical 
Tool (LIF/UVOST) and Hydraulic Profiling Tool (HPT) Technologies Report, July 7, 2014. 
Caitlin Engineers and Scientists, Remedial Action‐Drawdown Analysis and System Evaluation Report, July 12, 
2016. 
Caitlin Engineers and Scientists, Annual Groundwater Monitoring and Remediation System Report, November 
16, 2022. 
Edwin Andrews & Associates, Site Assessment Report: Aboveground Storage Tank Fuel Oil Release, July 31, 
1996. 
Edwin Andrews & Associates, Phase I Corrective Action Plan: Aboveground Storage Tank Fuel Oil Release, 
January 31, 1995. 
Interstate Technology and Regulatory Council, Petroleum Vapor Intrusion: Fundamentals of Screening, 
Investigation, and Management, October 2014. 
NCDEQ, UST Section Corrective Action Guidelines: Petroleum and Hazardous Substance UST Releases, January 
19, 2021.
FIGURES

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Copyright:© 2013 National Geographic Society, i-cubed
Duke Weatherspoon Plant491 Power Plant RoadLumberton, Robeson County, NC
FIGURE
DR:CHK:
DATE:
SITE LOCATION MAP 1E. Bayeh xx
CLIENT:
PROJ.:7812220872
TITLE:
SCALE:SITE:
WSP USA Environment & Infrastructure, Inc.4021 Stirrup Creek Drive, Suite 100Durham, NC 27703(919) 381-9900
LOCATION:P:\Energy\Projects\Duke\Legacy Env Projects\Weatherspoon-Lumberton\CAP Evaluation_7812220872.01\13_GIS
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Duke Weatherspoon Plant491 Power Plant RoadLumberton, Robeson County, NC
FIGURE
DR:CHK:
DATE:
SITE MAP 2E. Bayeh M. Allen
CLIENT:
PROJ.:7812220872
TITLE:
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LOCATION:P:\Energy\Projects\Duke\Legacy Env Projects\Weatherspoon-Lumberton\CAP Evaluation_7812220872.01\13_GIS
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Duke Weatherspoon Plant491 Power Plant RoadLumberton, Robeson County, NC
FIGURE
DR:CHK:
DATE:
GEOTECH SIPPER SCHEMATIC
3A. Kellogg M. Allen
CLIENT:
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TITLE:
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LOCATION:\\DP:\Energy\Projects\Duke\Legacy Env Projects\Weatherspoon-Lumberton\CAP Evaluation_7812220872.01\13_GIS
Duke Energy Progress, LLC.
³Notes:Schematic provided by Geotech Environmental
2/22/2023 NTS
APPENDIX

A   
WSP STANDARD OPERATING PROCEDURES 

APPENDIX A
STANDARD OPERATING PROCEDURES
Assessment and Field Data Collection
The Standard Operating Procedures have utilized, where applicable, the field methods, sampling
procedures, sample custody, and field quality assurance as outlined in the Environmental Compliance
Branch Environmental Investigations Standard Operating Procedures and Quality Assurance Manual,
November 2001, (EISOPQAM), U.S. EPA Region IV Science and Environmental Services Division,
Athens, Georgia.
The Standard Operating Procedures has incorporated changes presented in The Field Branches Quality
System and Technical Procedures that now supersede the "Environmental Investigations Standard
Operating Procedures and Quality Assurance Manual" (EISOPQAM), November 2001, and the
"Ecological Assessment Standard Operating Procedures and Quality Assurance Manual"
(EASOPQAM), January 2002. These procedures contain routine field sampling and measurement
procedures, and quality control documents used by field investigators of the two Science and
Ecosystem Support Division (SESD) Field Branches: the Ecological Assessment Branch and the
Enforcement and Investigations Branch.
The specific sampling and field measurement procedures presented in SESD Quality System and
Technical Procedures are based on the experience of the field investigators within the field branches
and accepted professional practices which are referenced in each procedure. These documents are
intended to be dynamic and will be periodically reviewed and updated, as needed. It is the
responsibility of the user to ensure they are using the most recent version of the procedures.
Decontamination and Cross-contamination Prevention
Standard Operating Procedures #001

The following procedures shall be implemented to ensure sample collection and other related
equipment is properly decontaminated to prevent possible cross-contamination of samples. It is
imperative that equipment be properly decontaminated and measures be implemented to prevent cross-
contamination of field and sample collection equipment and actual samples that are collected.

1. All work should proceed from areas of suspected or know low contamination to areas of
suspected or known high contamination.
2. All heavy equipment (e.g., drill rigs, backhoes, etc.) shall be decontaminated prior to coming
on-site for work and all down-hole drilling equipment (e.g., auger flights, drilling rods, split
spoons, etc.) shall be decontaminated between each drilling/sampling location.
a. A decontamination station/pad shall be established for cleaning down-hole equipment.
Decontamination wastes shall be contained and collected for disposal.
b. Large equipment (e.g., augers, drilling rods) shall be decontaminated using a steam
cleaner while use of a soap solution may be appropriate for smaller pieces of
equipment (e.g., split spoons).
3. All equipment utilized in water level measurement, sample collection, or that otherwise
contacts material to be sampled will be decontaminated between each location and prior to
returning to its case and being stowed with other equipment.
a. Personnel involved with equipment decontamination shall wear clean gloves during
the decontamination process.
b. Cleaning shall be performed using a soap solution (e.g., Alconox, Liqui-Nox) with a
distilled water rinse. If equipment has contacted free product, the decontamination
process shall include an isopropyl alcohol rinse. All wash and rinse activities shall be
performed in buckets or other suitable containers. Used water should be contained in
55-gallon drums for disposal.
c. Reusable sampling equipment that has been cleaned for later use (e.g., steel trowels,
hand auger buckets, etc.) shall be wrapped in clean aluminum foil or sealed in plastic
bags until used.
4. Field personnel shall use clean gloves when handling any sampling equipment and shall avoid
contacting sampling equipment with other potentially contaminated surfaces and materials.
New gloves shall be used whenever a new sample is collected or when a break in sampling
occurs (e.g. between well purging and sampling).
5. Investigation derived waste (lDW) and other trash and debris shall be staged away from
sampling equipment and other materials to avoid potential cross-contamination.
6. Any samples that contain elevated concentrations of contaminants compared to other samples
shall be stored and shipped in a separate cooler/container. Trip blanks should be sent in any
cooler where volatile organic compound (VOC) samples are collected for analysis.

Disposal of Investigation Derived Waste
Standard Operating Procedures #002

The following activities shall be completed upon completion of fieldwork:

1. All field equipment, instruments, buckets, etc. shall be thoroughly cleaned/decontaminated per
Standard Operating Procedure #001 prior to leaving the site.

2. All Investigation Derived Waste (IDW) including used bailers, gloves, used sample
containers, purge water, excess soil cuttings, etc. that may be contaminated must be properly
contained, labeled and disposed. IDW is and will remain the property of the facility and will
be the responsibility of the Owner to dispose of this material in accordance with DEP
regulations.

a. Use on-site disposal (roll-off container, etc.) for IDW if approved by property owner
and appropriate for the type of waste generated.

b. Provide drums to stage IDW for disposal. Drum staging must be coordinated with the
property owner.

3. General solid waste (drink bottles, non-contaminated trash) may be disposed of on-site if site
has current solid waste collection containers if approved by property owner.

4. Unused equipment may be shipped back to the supplier, as appropriate, or stored for future
use.

5. The client and consultant shall define responsibility for IDW disposal as part of site-specific
scopes of work.

6. All IDW will be handled by and disposed in accordance with applicable federal, state and
local regulations at an appropriately permitted treatment or disposal facility. IDW will be
disposed of in accordance with DEP protocols, if required. If composite samples show levels
to be non-hazardous and expectable for land application, the cuttings will be spread on site.

Sample Handling Field Procedures
Standard Operating Procedures #003

1 Initial Planning

This Field Sampling Plan (FSP) contains a description of the rationale for the field activities and then
details the exact procedures to be followed to complete the work tasks needed to define soil conditions
and identify the nature and extent of soil impacts include:

 the identification of compounds of concern,
 finding the boundaries of any impacted media
 determining the direction of contaminant movement from source areas,
 locating source areas,
 defining the thickness and orientation of source areas, and
 geochemical and/or geotechnical test results, if necessary.

2 Sample Designation and Handling Plan

2.1 Sample Designation System

A sample designation system will be used to label each sample with unique sample identification. The
sample identification (ID) will be a code that identifies the sample matrix, the number of the sample
station and the depth of the sample station if applicable. The types of sample stations are:

ID Code Sample Matrix
Soil Boring SB Soil
Hand Auger HA Soil
Monitoring Wells W Ground Water
Surface Water SW Surface Water
Sediment Sample SED Pond/Stream Bed Sediment

The station number will be numeric starting with one and increasing by one as the next similar station
is installed; i.e., SB-1, SB-2, SB-3. Individual monitoring wells in a nest will be designated by lower
case letters as shallow (s), intermediate (i) and deep (d) and would read W-1s, W-1i. A soil boring
(SB) designates a boring installed and sampled with a drill rig, while (HA) designates a hand auger
installed boring. Depth below the ground surface will be added indicating the depth the sample was
obtained from (e.g. HA-1-8 (8-foot depth).

2.2 Sample Handling Plan

2.2.1 Sample Container Labeling

The following information will be placed on the sample container label or tag:

 Sample Designation,
 Site Name and Job number,
 Sample Date and Time,
 Sampler's Name or Initials,
 Type of Sample - Grab or Composite,
 Type of Analysis with Method Number,
 Type of Preservative, and
 Any Special Requirements.

The sampling team and team leader will review the work plan. A schedule of the number of locations
to be sampled each day will be prepared by the team leader and project manager. The site HASP has
been prepared by the corporate health and safety officer and reviewed with the team leader. The team
leader will review the site HASP with the sampling team. The team leader will finalize sampling
locations. The sampling order will proceed from lowest concentration of constituents of concern to
highest concentration of constituent of concern areas.

2.2.2 Sample Custody

Once the samples are removed from the sampling device, they will be transferred to properly labeled
containers, logged into the field notebook, and placed into a cooler with sufficient ice to maintain
sample temperature at 4°C ± 2°C. When full, or when the sampling is complete, the cooler will be
closed and taped shut.

Proper custody of the samples will be maintained at all times. Sample coolers will be locked in the
field truck during times when they will be out of direct view. Custody of the samples will remain with
the sampling team until relinquishment to a courier or the analytical laboratory. A chain-of-custody
(C-of-C) form will accompany each sample cooler from the time the cooler is closed and sealed until
receipt by the analytical laboratory.

A C-of-C record will accompany the sample from initial sample collection in the field to its receipt at
the laboratory. The completed original will be returned to Duncklee & Dunham as part of the final
analytical report, and a copy will be retained by the laboratory for its files. C-of-C records will be
maintained in a secured location in the field until they can be transferred to the Cary office.

2.2.3 Sample Analyses and Other Sample Handling Requirements

The work plan or proposal submitted to the client contains a review of analytical tests to be performed
on the soil, sediment, ground water, and surface waters at the Site. The chosen analytical laboratory
will provide the type and sizes of sample containers required, sample preservative methods, shipping
requirements, holding and extraction times, and methods to maintain the laboratory QA/QC.

2.2.4 Documentation

Documentation of field activities will be consist of daily field logs, drilling logs for all soil borings,
rock corings, and monitoring well installations, and sample logs for collected samples.
Documentation records will be kept in a secure location in the field until transferred to Duncklee &
Dunham's Cary office.

Surface and Shallow Soil Collection
Standard Operating Procedures #004

Surface and shallow soil samples are typically collected using stainless steel trowels, spoons, or
scoops using the following procedure:

1. A decontaminated trowel, spoon, or scoop is used to remove grass, gravel, or other surface
cover in the area to be sampled.
2. The underlying soil material is then collected and placed into a decontaminated bowl or
directly into the sample container using a second decontaminated trowel, spoon, or scoop.
a. For volatile analysis, soil is collected using specially design equipment
(e.g.EnCorelTM, sampler or other approved method) to directly collect and contain the soil to
minimize the loss of volatile constituents.
b. For non-volatile analysis, soil may be placed into a bowl and mixed to assure that a
homogenous sample is delivered to the laboratory for analysis. Once the soil is mixed, it is
then placed into the appropriate sample container(s).
3. The steel trowels, spoons, or scoops are decontaminated between each sampling location.

Hand augers can be used to collect shallow soil samples to characterize shallow soil strata. The hand
auger is typically used as a screening method and can provide preliminary indication of stratigraphy
and the presence of contaminants in shallow soils. A borehole is advanced by pushing and turning the
auger rods and bucket and retrieving collected soil from the auger bucket. Samples collected from
hand auger borings are considered "disturbed" samples. The following procedure is used in collecting
soil samples using a hand auger:

1. A decontaminated hand auger assembly (handle, extensions and auger head or bucket) is
manually advanced to the desired sampling depth by turning clockwise and pushing
downward on the assembly handle.
2. After the auger head is filled with soil, the assembly is pulled from the subsurface, and the
contents are removed by either turning the assembly upside-down or by inserting a hand tool
such as a decontaminated stainless steel spoon, trowel, etc. This process continues until the
boring is terminated or the collection of a sample for laboratory analysis is desired.
3. Samples for laboratory analysis are collected using a decontaminated auger head. The soil
sample is collected directly from the auger head or by the use of decontaminated hand tools
depending on soil consistency.
a. For volatile analysis, soil is collected from the auger head directly into a sample
container to minimize the toss of volatile constituents.
b. For non-volatile analysis, soil may be placed into a bowl and mixed to assure that a
homogenous sample is delivered to the laboratory for analysis. Once the soil is mixed
it is then placed into the appropriate sample container(s).
4. Abandonment of the boring entails backfilling with bentonite or grout if the boring is
terminated below the water table. Otherwise, the boring is abandoned by backfilling with
auger cuttings.
5. The steel auger head, extension rods and handle, are decontaminated prior to the start of each
hand-auger boring. Additionally, the auger head is decontaminated during the advancement of
the boring prior to collecting each soil sample intended for laboratory analysis.
Hollow-Stem Auger Drilling and Soil Profiling/Sampling
Standard Operating Procedures #005

Hollow-stem auger borings can be used to characterize soil profiles, determine the presence of organic
vapors, and to obtain soil samples for subsequent laboratory analysis. Hollow-stem auger borings can
also be the first step in the process of installing a ground water monitoring well. (Refer to appropriate
standard procedures for well installation.)

1. Decontaminate all down-hole drilling/sampling equipment prior to the start of work and
between drilling/sampling locations (i.e. between each boring for augers and between each
sample location for splits spoons and other sampling equipment).

2. Advance augers to desired depth using continuous flight, hollow-stem augers attached to a
truck, trailer, or ATV-mounted drilling rig.

3. Soil samples are collected at regular intervals, as required by the Sampling and Analysis Plan,
by advancing the augers to a depth just above the desired sampling zone. Typically a five-foot
sample interval is used. A decontaminated split-spoon sampler is attached to the drill rod and
lowered through the center of the augers and driven into the soil with a 140-pound hammer
according to ASTM D-1586. The split-spoon is retrieved and opened to reveal the semi-
undisturbed soil sample. The following information is recorded on the Boring Log maintained
for each boring (see attached example of an appropriate boring log form in Appendix B):

a. Standard Penetration Test (SPT) results (i.e. the number of hammer blows per each
six-inch increment of the l8ꞏinch to 24-inch split-spoon penetration or fraction
thereof).

b. The soil type classified according to the Unified Soil Classification System USCS)
Visual-Manual Procedure (ASTM D-2488) or other recognized method (e.g., USDA
soil triangle).

c. Other pertinent comments, including color, odor, and moisture content.

4. Collect samples from each split spoon for organic vapor (total volatile organic compounds
(VOCs) using the following procedure:

a. Place an aliquot of the soil sample in a clean, airtight container (sealed Zip-Lock® bag,
sealed glass jar, or sealed plastic container) as quickly as possible after sample
collection.

b. Label the container with boring number and sample depth.

c. Allow the samples to sit for approximately 15 minutes to allow the VOC
concentration to equilibrate between the soil and air in the container headspace.

d. A flame ionization detector (FID) or photo-ionization detector (PID) instrument probe
is then inserted into the container to measure the headspace VOC concentration (read
directly from the read-out display in parts-perꞏ million (ppm) of total VOCs). The
container is opened enough to insert the probe but no further to prevent loss of VOC
constituents to the atmosphere.

e. VOC concentration is recorded on the boring log/field notes.

5. Collect samples for laboratory analysis, as needed based upon the project requirements, using
the following procedure:

a. Potential laboratory samples are placed into the appropriate sample container(s)
required for the specific analyses to be performed immediately after the samples are
retrieved.

b. Select samples to be submitted to the laboratory based upon organic vapor screening
visual observations, project Sampling and Analysis Plan, etc.

c. Handle samples in accordance with standard sample handling, shipping, and chain-of-
custody practices as presented in the project Quality Assurance Project Plan and
Sampling and Analysis Plan.

6. Upon boring termination at the desired depth or auger refusal (bedrock), the boring is ready
for monitor well installation or will be advanced deeper by using other drilling techniques. If
the boring is to be abandoned, it is sealed with cement grout if terminated below the water
table. Otherwise, the boring is backfilled with auger cuttings, natural material, or cement
grout.

7. Upon completion of work, any excess soil that cannot be used as backfill in the core holes
must be properly managed. Management of this material shall be as directed by the
consultants Technical Lead/Project Manager and client in accordance with Standard Operating
Procedure #002.

Direct Push Borings and Soil Profiling/Sampling
Standard Operating Procedures #006

Direct push (e.g., Geoprobe™ or similar drill rigs) equipment may be utilized as an alternative to
hollow-stem auger borings to characterize soil profiles, determine the presence of organic vapors, and
obtain soil samples for subsequent laboratory analysis. Direct push equipment can also be used to
collect ground water samples and/or to install small diameter piezometers/monitoring wells.

1. Decontaminate all down-hole coring/sampling equipment prior to start of work and between
locations (i.e., between each boring for push rods and between each use for samplers).
2. Advance direct push soil coring equipment using truck or ATV-mounted direct push
equipment. Coring equipment is advanced using a hydraulic hammer and the weight of the
direct push rig.
3. Depending on equipment used, either collect continuous soil cores or advance sampler to
specific interval to collect soil core(s) based on the Sampling and Analysis Plan. A
precleaned, disposable acetate sleeve is placed into the core sampler, which is advanced
continuously or advanced and opened at the desired interval depending on the equipment used.
The sample is retrieved and the acetate sleeve containing the soil core is removed. The sleeve
is opened to reveal the semi-undisturbed soil sample. The following information is recorded
on the Test Boring Log maintained for each boring (see attached example of an appropriate
boring log form in Appendix B):
a. The soil type classified according to the Unified Soil Classification System (USCS)
Visual-Manual Procedure (ASTM D-2488) or other recognized method (e.g., USDA
soil triangle).
b. Other pertinent comments including color, odor, moisture content, type and size of
rock fragments (if present), and presence of fill materials.
4. Collect sample from each soil core for organic vapor ([total volatile organic compounds
(VOCs) screening using the following procedure:
a. Place an aliquot of the soil sample in a clean, airtight container (either sealed Zip-
Lock® bag, sealed glass jar, or plastic container) as quickly as possible after sample
collection.
b. Label container with boring number and sample depth.
c. Allow samples to sit for approximately 15 minutes to allow for VOC concentration to
equilibrate between the soil and the air in the container heads pace.
d. A flame ionization detector (FID) or photoꞏ ionization detector (PID) instrument
probe is then inserted into the container to measure the headspace VOC concentration.
(Read the concentration directly from the read-out display in parts-per-million (ppm)
of total VOCs.) The container is opened only enough to insert the probe to prevent
loss of VOCs to the atmosphere.
e. VOC concentration is recorded on the boring log/field notes.
5. Collect samples for laboratory analysis, as needed based upon the project requirements, using
the following procedure:
a. Potential laboratory samples are placed into the appropriate sample container(s)
required for the specific analyses to be performed immediately after the sample is
retrieved.
b. Select samples to be submitted to the laboratory based upon organic vapor screening,
visual observations, etc.
c. Handle samples in accordance with standard sample handling, shipping, and chain-of-
custody practices (Standard Operating Procedure 003).
6. The core hole is abandoned upon coring termination at the desired depth or at direct push
refusal. The core hole is filled with bentonite pellets if terminated below the water table.
Otherwise, the core hole is filled with recovered core material, natural on-site material, or
bentonite pellets.
7. Ground water samples may be collected from the core hole using a specialized, sealed,
discrete interval ground water sampler such as the Geoprobe™ Screen Point 15 Groundwater
Sampler. A sampler with a stainless steel screen is preferred for decontamination purposes.
Samples are collected as follows:
a. Advance decontaminated sampler on push rods to desired depth.
b. Retract outer sleeve of sampler to expose screen and allow ground water to enter
sampler.
c. Use peristaltic pump with precleaned, disposable tubing or small diameter bailer to
extract ground water from the sampler in accordance With Standard Operating
Procedure #010. (Noteꞏ when a sample is collected immediately from such a sampler,
there is no stagnant water to be purged. However, standard purging methods should
be used when ground water recharge rates allow to ensure a representative sample is
collected. Recharge into the sampler may be slow particularly in formations with
low-permeability, and care should be taken to property purge the well while allowing
for adequate recharge for representative sample collection. If the sampler is left in the
formation for greater than 24 hours, the well must be properly purged to remove the
stagnant water.
d. Discharge ground water into the appropriate sample container(s) required for the
specific analyses to be performed immediately after the sample is retrieved.
e. Handle samples in accordance with standard sample handling, shipping, and chain-of-
custody practices as outlined in the Quality Assurance Project Plan.
8. Small diameter piezometers/monitoring welts may be installed in the core hole upon removal
of the coring equipment. Screen and casing pipe are lowered into the hole, and the
piezometer/monitoring well is constructed following standard practices as described in
Standard Operating Procedure #007.
9. Upon completion of work, any excess soil that cannot be used as backfill in the core holes
must be properly managed. Management of this material shall be as directed by the
consultant's Technical Lead/Project Manager and client In accordance with Standard
Operating Procedure #002.

Shallow Monitoring Well and Piezometer Installation
Standard Operating Procedures #007

Shallow monitoring wells and piezometers are installed in unconsolidated material to provide secure
sampling points for the uppermost zones of water table (unconfined) aquifers. Following boring
termination (typically borings advanced using hollow-stem augers), the well is constructed. The well
is built within the hollow stem of the augers as this allows for protection of the welt screen against
collapse of the borehole before the well filter pack is properly emplaced. The auger flights may be
removed from the ground prior to well construction if there is reason to believe that the borehole will
not collapse. If a well is constructed within a borehole advanced using air rotary drilling or direct
push technology, the drilling equipment must be removed prior to well construction.

The following procedure is used for well construction:

1. Clean, flush-threaded well casing with slotted well screen (typically Schedule 40 polyvinyl
chloride (PVC)) is lowered into the borehole. Compatibility of screen material and slot size
with site conditions must be considered. Stainless steel well screen may be needed at
extremely contaminated sites.
2. Filter sand is then gravity-fed into the annulus between the well screen and the inside of the
augers as the augers are slowly pulled from the borehole (or between the well screen and the
boring walls if the drilling equipment has been removed). Filter sand is added to a height of
approximately one to two feet above the top of the screen.
3. A bentonite seal is emplaced above the sand filter pack (about one to two feet thick) to prevent
vertical movement of ground water within the borehole (i.e., to prevent cross contamination
from upper to lower zones). Bentonite pellets are placed into the annular space above the sand
filter pack and then hydrated with distilled water to create a low permeability barrier.
4. A neat cement grout is then tremmie (gravity-fed, if the bentonite seal is within a few feet of
the surface) into the remaining annulus to ground surface.
5. The uppermost portion of each well is constructed to protect the well casing from damage.
a. The protective cover may be finished above grade with a steel protective outer casing
with locking cover. A slip cap is typically placed over the well casing to prevent dirt
and debris from entering the well.
b. The protective cover may be finished at grade with a steel man way with a bolt-down
cover. A locking, watertight expanding cap is placed on the well to prevent dirt,
debris, and water from entering the well.
6. The following information is recorded to complete the Boring Log/Well Completion Record
(see attached example of an appropriate well completion record form in Appendix B):
a. Depth of borehole
b. Length of screen pipe and actual screened interval
c. Length of casing pipe
d. Screen slot size
7. The top of casing (TOC of the wells is surveyed for horizontal and vertical control for use in
evaluating hydraulic gradients.
8. Wells should be labeled when constructed (metal tags in or on well protective casing). A
description of the well location should be included in the field notes.
9. If the well is to be used as a temporary (one-time) sampling point, cement grout is not placed
above the bentonite seal. After sampling, the temporary well can be abandoned by either
pulling the casing/screen and filling the borehole with cement grout, or by leaving the casing
in place and filling the casing and annular space above the bentonite seal with cement grout.
10. Piezometers are installed when there is only a need to measure liquid levels (rather than
collecting actual ground water samples). Piezometers are typically constructed with small
diameter (l-inch) casing.
11. Prior to sampling, monitoring wells are developed to reduce the amount of sediment in well
annular space. This enhances the flow of ground water from the formation into the well and
helps to ensure that the samples collected are representative of the quality of water in the
aquifer. The well may be developed using a bailer or small pump as follows:
a. A disposable bailer or decontaminated pump is lowered into the well and allowed to
sink to the bottom of the well casing.
b. If the well is developed by manual bailing, the bailer is raised using periodic, sharp
upward tugs (surges). The surging motion of the bailer causes water to be extracted
from the formation, through the screen filter pack into the screen. This also causes
fine material that may have been mixed into the filter pack during installation to
become suspended in the well water so that it can be removed via bailing.
c. If the well is developed using a pump, the pump must be periodically raised with
sharp tugs to facilitate the removal of sediment from the filter pack and well casing.
d. Well development continues with water removal and periodic surging until the bailed
water becomes as clear as practical.
e. In some cases, the well will go dry before the "clear water" endpoint is reached. If
this happens, the well should be given time to recharge and the process repeated. If,
after several such attempts, the well water remains turbid, the development process
can cease. It is possible that, in certain low-yielding geologic units, a well cannot be
developed to the clear water condition in a practical length of time. The endpoint for
well development should be coordinated with the Technical lead/Project Manager.
12. Well Abandonment - when a decision is made to abandon a monitoring well, the borehole
should be sealed in such a manner that the well can not act as a conduit for migration of
contaminants from the ground surface to the water table or between aquifers. To properly
abandon a well, the preferred method is to completely remove the well casing and screen from
the borehole, clean out the borehole and backfill with a cement or bentonite grout, neat
cement, or concrete.
a. As stated the preferred method should be to completely remove the well casing and
screen from the borehole. For shallow wells this can be accomplished by attaching a
drilling rig cable tool to the casing and slowly pulling the casing from the well.
i. The clean borehole can then be backfilled with the appropriate grout
material. The backfill material should be placed into the borehole from the
bottom to the top by pressure grouting with the positive displacement method
(tremmie method).
ii. The top 2 feet of the borehole should be poured with concrete to insure a
secure surface seal (plug).
b. If the casing cannot be readily removed the well can be grouted with the casing left in
the borehole. The preferred method in this case is as follows:
i. Pressure grout the borehole by placing the tremmie tube to the bottom
of the well casing, which will be the well screen or the bottom sump
area below the well screen.
ii. The pressurized grout is forced out through the well screen into the
filter material and up the inside of the well casing sealing holes and
breaks that are present.
iii. The tremmie tube is retracted slowly as the grout fills the casing.
iv. The casing is cut off even with the ground and filled with concrete to
a depth of 2 feet below the surface. If the casing has been broken off
below the surface, the grout should be tremmied to within 2 feet of
the surface and then finished to the ground surface with concrete.
c. If geologic conditions warrant the complete removal of the well casing, sand pack and
other well construction materials, the well must then be over drilled and grouted.
After the casing materials have been removed from the borehole, the borehole should
be cleaned out and pressure grouted with the approved grouting materials. As
previously stated, the borehole should be finished with a concrete surface plug.
13. Temporary Monitoring Well Typesꞏ five types of monitoring wells which have been shown to
be acceptable are presented in the order of increasing difficulty to install and increasing cost:
a. No Filter Pack - this is the most common temporary well and is very effective in many
situations. After the borehole is completed, the casing and screen are simply inserted.
This is the most inexpensive and fastest well to install. This type well is extremely
sensitive to turbidity fluctuations, because there is no filter pack. Care should be
taken to not disturb the casing during purging and sampling.
b. Inner Filter Pack - this differs from the "No Pack" in that a filter pack is placed inside
the screen to a level approximately 6 inches above the well screen. This ensures that
all water within the casing has passed through the filter pack. For this type well to
function properly, the static water level must be 6ꞏto 12 inches above the filter pack.
c. Traditional Filter Pack - for this type, the screen and casing are inserted into the
borehole, and the sand is poured into the annular space surrounding the screen and
casing. Occasionally, it may be difficult to effectively place a filter pack around
shallow open boreholes, due to collapse. This method requires more sand than the
"inner filter pack" well, increasing material costs. As the filter pack is placed, it
mixes with the muddy water in the borehole, which may increase the amount of time
needed to purge the well to an acceptable level of turbidity.
d. Double Filter Packꞏ- the borehole is advanced to the desired depth. As with the "inner
filter pack" the well screen is filled with filter pack material and the well screen and
casing inserted until the top of the filter pack is at least 6 inches below the water table.
Filter pack material is poured into the annular space around the well screen. This type
temporary well construction can be very effective in aquifers where fine silts or clays
predominate. This construction technique takes longer to implement and uses more
filter pack material than others previously discussed.
e. Well-in-a-Well - the borehole is advanced to the desired depth. At this point, a l-inch
well screen and sufficient riser is inserted into a 2-inch well screen with sufficient
riser, and centered. Filter pack material is then placed into the annular space
surrounding the 1-Inch well screen, to approximately 6 inches above the screen. The
well is then inserted into the borehole. This system requires twice as much well
screen and casing, with subsequent increase in material cost. The increased amount of
well construction materials results in a corresponding increase in decontamination
time and costs. If pre-packed wells are used, a higher degree of QA/QC will result in
higher overall cost.

Liquid Level Measurement
Standard Operating Procedures #008

Liquid levels (depth to ground water and free product, as applicable) in monitoring wells and
piezometers are measured (gauged) using an electronic water level indicator or oil/water interface
probe as appropriate based on site conditions. Specific steps in the measurement process are as listed
below.

Note: liquid levels shall be measured in all wells prior to sampling so that the measurements are
collected over the shortest time period possible. If all wells can be sampled within one day, the
ground water level measurements may be obtained for each well as it is sampled.

1. Remove protective covers, locks, and well caps from all wells to be gauged, and allow the
ground water to equilibrate to atmospheric pressure. Note if any wells are under pressure,
under vacuum, or have an odor. Screen well casing for organic vapors using a photoionization
detector (PID) or flame ionization detector (FID) if required by the project. Record pertinent
observations and measurements in field notes.

2. If the well cap, lock, etc. is damaged or missing, document the condition in the field notes, and
replace the material as needed.

3. If a dedicated bailer is contained/stored in the well, remove it, and place it on clean plastic
sheeting or aluminum fait to prevent field contamination.

4. Measure liquid levels starting at the background or least impacted well(s) and moving to the
most impacted wells.

a. Measure depth to ground water and depth to free product, as appropriate, from the
surveyed control point on well top of casing.
b. Record measurements in the field notes along with any pertinent comments.

5. Decontaminate the water level indicator and/or oil/water interface probe before use, between
each well, and upon completion of measurements.

a. Rinse probe and tape with soap solution followed by a distilled water rinse.
b. Wash portions exposed to free product with isopropyl alcohol followed by a distilled
water rinse.

6. Replace well caps, locks, and bailers, if necessary, and replace protective cover.

Note: High viscosity (thick) oil tends to stick to the oil/water interface probe and can result in
exaggerated measurements of free product thickness. To minimize this effect, lower the oil/water
interface probe until the probe signals water. Then, slowly raise the probe until the presence of oil is
indicated. Record the second measurement as the depth to water in the well. If measurement with the
oil/water interface probe is not effective, a bailer may be lowered into the well and the free product
thickness in the bailer can then be measured.

Well Sampling Using a Bailer
Standard Operating Procedures #009

Bailers can be used to manually collect representative ground water samples from relatively shallow,
small-diameter wells (i.e., 6-inch diameter or smaller). A dedicated Teflon bailer, decontaminated
Teflon bailer, or disposable polyethylene bailer is used with new nylon cord/rope to purge and then
sample the well. Specific steps in the sampling process are as follows:

1. Remove the well cover, lock, and well cap.

2. Record the Photoionization Detector (PID) reading in the well casing as necessary based on
project requirements.

3. Make sure all equipment has been thoroughly decontaminated before use.

4. Gauge the depth to water from the top of casing (TOC) mark on the well casing using an
electronic water level indicator or oil water interface probe.

5 Using the depth to water measurement, total depth of the well, and well diameter, calculate the
required purge volume. (Conversion factors for water column height to volume are as
follows: 0.16 gallons per foot for a 2-inch well and 0.61 gallons per foot for a 4-inch well).
Record the absence or presence of free phase petroleum hydrocarbons (or free product). The
calculation of the required purge volume is as follows:

Volume of water in well (gallons) = (Total Depth of Well - Depth to Water) * Conversion
Factor

Total Purge Volume (gallons) = 3 * Volume of water in well

6. Water is removed (purged) from the well before sampling in order to remove stagnant water in
the well column and to allow freshꞏ or representative formation water to enter the well screen.

a. Gently lower the bailer to the bottom of well with cord/rope and remove accumulated
ground water.
b. Continue the purge process until at least three well volumes have been removed or the
well is bailed dry. To determine the volume purged, estimate approximately 0.25
gallons (or 1 liter) as the volume of a 36-inch bailer, or use a graduated bucket.
c. A representative water sample shall be collected at a minimum frequency of once after
each well volume is purged. These samples shall be checked in the field to assure that
the water quality parameters (pH, temperature, and specific conductance) have
stabilized (i.e., readings are within 10% of the previous measurement). If water
quality parameters have not stabilized, the purge process is continued. The ground
water purge measurements shall be recorded in the field notes or on a separate Ground
Water Purge Data form (see attached example of an appropriate boring log form in
Appendix B).
d. Upon completion of purging and prior to sampling, the bailer and cord/rope shall be
tied off inside the well casing or removed from the well and placed on clean plastic
sheeting or aluminum foil to prevent field contamination of the sampling equipment.
e. Purge water shall be collected and managed as directed by the Technical lead/Project
Manager. In certain circumstances, it may be permissible to discharge purge water to
the ground surface if approved by the regulatory agency coordinating the work.

7. Upon satisfactory completion of well purging, ground water samples are collected for
analysis.

a. Ground water sampling is performed within 24 hours of purging to minimize the loss
of any volatile compounds present (unless insufficient water has re-entered the well).
b. The bailer is lowered gently below the water surface (until completely submerged, if
possible). It is then retrieved, and the water is gently poured into the appropriate
sample containers.
c. The sample containers are labeled with well number, date, time, and analysis to be
conducted. Samples are collected and contained in order of volatilization sensitivity.
The preferred collection order for some common ground water parameters is as
follows:
i. Volatile organics
ii. Total organic carbon
iii. Total petroleum hydrocarbons
iv. Semivolatile organics
v. Pesticides, PCBs, herbicides
vi. Total metals
vii. Phenols
viii. Sulfate and chloride
ix. Nitrate and ammonia
d. All samples are logged on a chain-of-custody form and immediately stored in an ice-
filled cooler (maintaining a temperature of approximately 4°C ± 2°C). Samples are
transported to the laboratory under EPA approved chain-of-custody procedures.

Monitoring Well Sampling Using a Pump
Standard Operating Procedures #010

Various types of pumps can be used to collect representative ground water samples from monitoring
wells. For the purposes of most assessment work dedicated ground water pumps will not typically be
installed. However, there are times when collecting samples using decontaminated pumps may be
applicable, such as collection of samples from deep wells or when low-flow sampling is desired to
reduce sample turbidity. Other times, a non-dedicated pump will be used to collect ground water
samples. Such pumps shall be primarily of stainless steel and Teflon construction (components that
will be in contact with the water) for ease of decontamination between locations. Disposable
polyethylene or similar inert tubing is used to convey the ground water to the surface. Specific
purging and sampling methods using pumps will be outlined in the sampling and analysis plan (SAP).

The primary goal for the sampling using pumps is to collect ground water samples that are
representative of the organic and inorganic dissolved and particulate components of the ground water
by low flow methods that minimize stressing the aquifer. A secondary goal is minimizing the volume
of purged water that is removed from the well requiring disposal as investigation derived waste
(IDW). The reference for the low flow pumping is EPA Region 1, 1996, Low Stress (Low Flow)
Purging and Sampling Procedure for the Collection of Ground Water Samples from Monitoring Wells:
Revision Number 2, July 30.

The wells are sampled when the field parameters become stabilized for the last three consecutive
measurements. The field parameters and the stabilization goals are presented below:

Turbidity 10% for values greater than 10 NTU
Dissolved Oxygen (DO) 10%
Specific Conductance 10%
Temperature 10%
pH ± 0.1 unit
Oxidation-Reduction Potential (ORP) ± 10 millivolts

Low Flow Purging and Sampling with Pumps

1. Remove the well cover, lock, and well cap.
2. Record the organic vapor levels on the top of the well casing using flame ionization detector
(FID) or photo-ionization detector (PID) as necessary based on project requirements.
3. Make sure all equipment has been thoroughly decontaminated before use.
4. Gauge the depth to water from the top of casing (TOC) mark on the well casing using and
electronic water level indicator or oil water interface probe.
5. Review the construction details for the well and determine the depth from the TOC to the
midpoint of the well screen.
6. Lower the submersible pumps (bladder, turbine, displacement, etc.) or the intake line of the
peristaltic pumps or centrifugal pumps to the center of the well screen. (Note: For wells that
have known intervals within the well screen that have higher hydraulic conductivities or higher
chemical concentrations, the SAP may specify the pump intake or intake line be placed in
these intervals.)
7. Connect the pump discharge line to the flow-through cell and the discharge line from the flow
through-cell to a five gallon bucket. Unless otherwise specified in the SAP, food-grade
polyethylene line will be used.
8. Begin low flow pumping with at the lowest pump control setting and continue to adjust the
pump control setting until the water just moves from the intake of the pump to the flow cell.
The criteria for judging that low stress is being applied to the aquifer is monitoring the static
water level in the well after the pump has been set and maintaining 0.3 feet or less of
drawdown. A typical range of extraction rates for low flow is 100 mL/minute to 400
mL/minute. (Note: In some cases the minimal drawdown that can be achieved and the pump
move water through the flow-through cell may exceed 0.3 feet but remain stable. Continue
pumping and begin the monitoring the field parameters until stabilization.) The flow rate of
the pump should be measured using a graduated cylinder or graduated bucket and recorded
each time field parameters are recorded.
9. Once the field parameters have stabilized, the pump discharge tubing is disconnected from the
flow-through cell and is now ready to fill the sample containers.
10. The sample containers are labeled with well number, date, time, and analysis to be conducted.
Samples are collected and contained in order of volatilization sensitivity. The preferred
collection order for some common ground water parameters is as follows:
i. Volatile organics
ii. Total organic carbon
iii. Total petroleum hydrocarbons
iv. Semivolatile organics
v. Pesticides, PCBs, herbicides
vi. Total metals
vii. Phenols
viii. Sulfate and chloride
ix. Nitrate and ammonia
11. All samples are logged on a chain-of-custody form and immediately stored in an ice-filled
cooler (maintaining a temperature of approximately 4°C ± 2°C). Samples are transported to
the laboratory under EPA approved chain-of-custody procedures.

Top of Water Column Purging

1. Remove the well cover, lock, and well cap.
2. Record the organic vapor levels on the top of the well casing using flame ionization detector
(FID) or photo-ionization detector (PID) as necessary based on project requirements.
3. Make sure all equipment has been thoroughly decontaminated before use.
4. Gauge the depth to water from the top of casing (TOC) mark on the well casing using and
electronic water level indicator or oil water interface probe.
5. Using the depth to water measurement, total depth of the well, and well diameter, calculate the
required purge volume. (Conversion factors for water column height to volume are as
follows: 0.16 gallons per foot for a 2-inch well and 0.61 gallons per foot for a 4-inch well).
Record the absence or presence of free phase petroleum hydrocarbons (or free product). The
calculation of the required purge volume is as follows:

Volume of water in well (gallons) = (Total Depth of Well - Depth to Water)*
Conversion Factor

Total Purge Volume (gallons) = 3 * Volume of water in well

6. Purging with Pumps:
a. When peristaltic pumps or centrifugal pumps are used, only the intake line is placed
into the water column.
b. When submersible pumps (bladder, turbine, displacement, etc.) are used, the pump
itself is lowered into the water column. The pump must be decontaminated prior to
use.
c. Purging Entire Water Column - the pump/hose assembly used in purging should be
lowered into the top of the standing water column and not deep into the column. This
is done so that the purging will “pull” water from the formation into the screened area
of the well and up through the casing so that the entire static volume can be removed.
If the pump is placed deep into the water column, the water above the pump ma y not
be removed, and the subsequent samples, particularly if collected with a bailer, may
not be representative of the ground water. (For wells with a low recharge rate it may
be necessary to gradually lower the pump/intake line into the well as the water level
drops.) (Careful consideration shall be given to using pumps to purge wells which are
excessively contaminated with oily compounds, because it may be difficult to
adequately decontaminate severely contaminated pumps under field conditions.)
d. Continue the purge process until at least three well volumes have been removed or the
well is pumped dry.
e. A representative water sample shall be collected at a minimum frequency of once after
each well volume is purged. These samples shall be checked in the field to assure that
the field parameters have stabilized (see values listed above). If water quality
parameters have not stabilized, the purge process is continued. The ground water
purge measurements shall be recorded in the field notes or on a separate Cround
Water Purge Data form (see attached example of an appropriate ground water purge
data form in Appendix B).
7. Sampling Equipment Available
a. Peristaltic pump
b. Stainless steel and Teflon' bladder pump,
c. Stainless steel and Teflon', variable speed centrifugal pump (e.g., Grundfos Redi-
Flo2)
8. Sampling Techniques
a. Peristaltic pump
i. Precleaned disposable tubing is placed into the pump and from pump to well.
ii. Intake is lowered to the appropriate depth.
iii. Pump is activated with speed adjusted for appropriate flow rate based on well
recharge and types of samples to be collected.
iv. Ground water is discharged into appropriate sample containers.
b. Submersible bladder Pumps and variable speed centrifugal pumps.
i. After purging has been accomplished with a bladder pump, the sample is
obtained directly from the pump discharge.
ii. The pump rate should be reduced during sample collection to minimize
sample disturbance, particularly with respect to samples collected for volatile
organic compounds analysis.
9. The sample containers are labeled with well number, date, time, and analysis to be conducted.
Samples are collected and contained in order of volatilization sensitivity. The preferred
collection order for some common ground water parameters is as follows:
i. Volatile organics
ii. Total organic carbon
iii. Total petroleum hydrocarbons
iv. Semivolatile organics
v. Pesticides, PCBs, herbicides
vi. Total metals
vii. Phenols
viii. Sulfate and chloride
ix. Nitrate and ammonia
10. All samples are logged on a chain-of-custody form and immediately stored in an ice-filled
cooler (maintaining a temperature of approximately 4°C ± 2°C). Samples are transported to
the laboratory under EPA approved chain-of-custody procedures.