DEQ-CFW_00045380

Hazardous Waste Section
File Room Document Transmittal Sheet
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Your Name:
EPA ID:
Facility Name:
Document Group
Document Type:
Description:
Date of Doc:
Author of Doc:
Larry Stanley
NCD047368642
DuPont Fayetteville Works
Corrective Action (CA)
RCRA Facility Investigation (R-FI)
Phase III RF1 Progress Report: Third Quarter 2012
8/23/2012
DuPont-CRG
File Room Use Only NCD047368642
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DEQ-CFW-00045380

Hazardous Waste Section
File Room Document Transmittal Sheet
M
Your Name: Larry Stanley
3 6 8 6 4 Facility Name: DuPont Fayetteville Works
Document Group: Corrective Action (CA)
Document Type: RCRA Facility Investigation (RFI.)
Description: Phase III RFI Progress Report: Third Quarter 2-0 12
Date of Doc: 8/23/2012
Author of Doc: DuPont-CRG
File Room Lase ..Qnlv
Date Recieved by File Room:
Date Scarined:
Month Day ycar
NCD047368642
Scanner's Initiak
DEQ-CFW-00045381

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D.Yont engineering
32 jai: v ew Road
0
EP:0N�� TO, 704362t63i't
Fax; 7u.. _ 362-6V6
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August 23, 201
Ills. Elizabeth W, Cannon, Chief
Hazardous Waste Section, Division of Waste Management
North Carolina Department of Environment and Natural Resources
1646 Dail Service Center
Raleigh, NC 99-14
RE; THIRD QUARTER 2012 PHASE III RFI PROGRESS REPORT UPDATE
LETTER
DUPONT FAYETTEVILLE WORKS
FAYETTEVILLE, NORTH CAROLINA
EPA ID NO. N D 047 363 642
Dear Ms. Cannon:
This letter provides an update on the status of implementing the Phase III Resource
Conservation and Recovery Act (RCRA) Facility Investigation (RFI) Work Plan at the
E.I. du Pant de Nemours and Company (DuPont) Fayetteville Works facility (Site)
located in Fayetteville, north Carolina. The Phase III RFI Work Plan (revision 1,
dated April 3, 911) was approved by the North Carolina Department of Environment
and Natural Resources (NCDENR) in a letter dated December 2, 2011,
Due to the specific data gaps left in the investigation, certain objectives of the
Phase III RF1 must be completed and the data analyzed prior to implementing the field
investigation for other objectives. The Phase III RFI, therefore, is being implemented
in a "staged" approach. Stage 1 of the investigation consists of further delineation of
the perimeter of the clay lens in the northern and western portions of the Site. This
stage of the RFI Will Delp to meet Objective 1 in the work plan (to further characterize
site hydrogeologic conditions). The main focus of this objective is to refine the site
Conceptual model (SCM) by collecting data to fill data gaps pertaining to Where
groundwater occurs (both perched and aquifer) and Where it flows. To meet this
objective, the lateral extent and internal Continuity of the Clay lens present in the
vadoso zone above the groundwater aquifer must be determined.
As reported in the Second Quarter 2012 Phase III RFI Update letter (dated May 29,
2012), the initial step of the Stage 1 investigation was to determine which geophysical
techniques, if any, would be useful in determining the extent of the clay lens (both
laterally and vertically), the density of subsurface layers (Clay versus silt), and Whether
saturated conditions are present. used on a review of the results of the initial
geophysical survey tests conducted at the Site in January 2012 by Geophysical
Survey Investigations, PLLC (GSI), the project team determined that ground
DEQ-CFW 00045382

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Au0ust 23, 2012
Ms, Elizabeth W, Cannon
penetrating radar (CPR) and electromagnetic induction (EM) surveys could provide
useful information to help meet the objective of Stage 1 of the Phase III RFI and
decided to perform these two surveys along the remaining geophysical lines identified
in the approved wore plan. This path forward was discussed with the Site's NCDENR
representative on March 30, 2012.
During the Week of April 30, 2012,`GS1 performed EM surveys (using a CeoniCs EM34
Conductivity meter) and GPR surveys (using a Geophysical Survey Systems
SIR-2000 unit With a 200 mega -hertz antenna) along several additional geophysical
lines at the Site. DuPont received the final GSI report summarizing these additional
field activities in May 2012 and based the next step of the investigation (as described
below) on the results of the Completed geophysical surveys,
As described in Section 4.1 of the work plan and in the previous Phase III RFI Update
letters, the clay lens delineation activities at the Site Were not limited only to
geophysical interpretation, Lithologic logging using a Geoprobe`� direct -push rig was
performed during the Week of August 13, 2012 to confirm the survey results at several
locations where the EM and GPR surveys suggested that there was a possible edge
to the clay lens. The locations were selected based on an evaluation of the results of
the surveys as presented in the GSI summary report, The Geoprobeo� rig was also
used to determine the clay lens thickness and whether perched water was present at
selected locations and to investigate areas where the survey results Were
inconclusive. The Geoprobe®R rig was not used at every location along the entire
survey lines.
Path Forward
Once the results of these Geopro be`�' activities have been evaluated, a technical
memorandum With recommendations for the next stage of the Phase Ill RFI will be
prepared and submitted to NCDENR for review and discussion. It is anticipated that
the technical memorandum will be submitted in November 2012.
If you have any questions or if I can assist you further in any way, please do not
hesitate to Contact me via email at Jam ie.A.Vanbuskirkusa,dupont.com or at (704)
362-6626. The Fourth Quarter 2012 Phase III RFI Progress Report Update letter Will
be submitted by November 30, 2012.
Sincerely,
J t pjj�lx
Jamie VanBuskirk
Project Director, DuPont Corporate Remediation Group
cc: Mr. Larry Stanley — NCDENR, Hazardous Waste Section
Ms. Tracy Ovbey — Parsons Environment & Infrastructure Group
Mir, Mike Johnson — DuPont Fayetteville '+} arks
File
DEQ-CFW 00045383