4101_HighPointRiverdell_CAProgressReport_DIN28136_20160211

Remedial Action Construction Progress Report
Page 1 of 5
February 11, 16
Ms. Mary Siedlecki
North Carolina Department of Environmental Quality
Division of Waste Management
1646 Mail Service Center
Raleigh, North Carolina 27699-1646
Re: Quarterly Remedial Action Construction Progress Report, 4th Quarter 2015,
Seaboard Chemical Corp. and Riverdale Drive Landfill Site, Jamestown, North
Carolina
Dear Ms Siedlecki:
Seaboard Group II and the City of High Point, NC (hereinafter the “Parties”) provide this
Remedial Action Construction Progress Report for the former Seaboard Chemical
Corporation facility and closed Riverdale Drive Landfill located in Jamestown, NC
(collectively hereinafter referred to as the “Site”). The Remedial Action Pre-Construction
Report for the physical treatment systems was submitted to North Carolina Department of
Environment Quality (NCDEQ)1 on December 28, 2009. The report was subsequently
approved by NCDEQ on March 22, 2010. Although the Natural Treatment Systems Remedial
Action Pre-Construction Report has not been formally approved by NCDQ, it was submitted
on October 25, 2010, and the Parties have included comments on activities associated with
that process as well. Collectively these reports are referred to herein as the “Pre-
construction Report.”
Remedial Construction Work Performed since the Last Progress Report
As reported earlier, during the 3rd quarter of 2015 the Parties retained the services of Hazen
and Sawyer (H&S) of Raleigh NC to conduct on-site testing to evaluate chemical and
mechanical options to address the handling of the sludge generated when treating the
combined groundwater and leachate. After they completed their work, H&S issued a report
in late September that described their recommendations as to changes that could be made
to the system (chemical and mechanical) to address the sludge handling problem. A copy of
that report was provided in the 3rd quarter progress report.
Explanation of Flow Modifications
The Parties met on October 1, 2015 and approved the cost of the design and engineering of
a clarifier and sludge processing equipment recommended by H&S to manage the
precipitated sludge generated by all flow components, including leachate, before it enters

1 NCDEQ is used in this report to refer to the North Carolina Department of Environmental Quality (formally North Carolina Department of
Environment and Natural Resources), and collectively the associated Division of Waste Management, Solid Waste Section, Hazardous
Waste Section, and the Inactive Hazardous Sites Branch, all of which are involved in the regulatory oversight of this remedial action.
Remedial Action Construction Progress Report
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the remaining treatment processes. After these modifications are complete, flow from all
sources will be sent first to a clarifier before any other processing. At the clarifier hydrated
lime (400 mg/l) and ferric chloride (140 mg/l) will be used to precipitate and stabilize the
sludge forming components. The sludge generated will be concentrated in sludge thickening
equipment and the resulting water will be returned to the clarifier inlet. The sludge will be
handled as it is presently handled at the landfill. The stabilized system flow will be returned
to the existing treatment process from the clarifier outlet at the aeration tank (T-600) inlet
in the filter building.
The engineering design was completed and the full modification project costs were
approved and the Parties issued a Request for Proposal in late November 2015. The bids
were received and evaluated during early December and an award was made in mid-
December with a January 4, 2016 construction start date. The scheduled completion of
construction is presently estimated to be April 30, 2016 with system restart immediately
thereafter. Unfortunately, due to the system shutdown, the pilot study of the fate of the
contaminants of concern, including 1,4-dioxane, in the phytoremediation system over the
varying seasons had to be suspended after two quarters (2nd and 3rd quarters of 2015).
Therefore, that pilot study will resume during the 4th quarter of 2016 and be completed at
the end of the 1st quarter 2017.
The results of the pilot study have been encouraging. The following is a summary of the
pilot test data collected to date. Analytes were added to the pilot plot via the irrigation
water from 5/4/15 to 9/7/15. In addition, a tracer compound (Br) was metered into the
irrigation flow at a measured rate. The fates of the analytes are summarized in the following
bullets:
• Dioxane.
o 57.6 g added; 0.14 g recovered from lysimeter water and soil;
o 0.24% recovered, mostly in the drainage water. Greater than 99% removal.
• Br tracer:
o 238.4 g added; 249.2 g recovered recovered from lysimeter water and soil;
o 104% recovered (20.2% in the drainage water).
• Other contaminants of concern (CoCs) added via irrigation water were 100%
removed.
• There was no excessive phytotoxic salts accumulation in the soils.
As can be seen, when the phytoremediation system is transpiring sufficiently to uptake
100% of the irrigation flow (approximately 9-months per year) the removal efficiency for
1,4-dioxane is greater than 99%, and the removal efficiency for the other CoCs is 100%.
During the remaining 3-months the irrigation uptake by the trees declines to a point that
irrigation plus precipitation exceeds the amount taken up by the trees causing more of the
CoCs to travel with the drainage water collected in the lysimeters. Since the site is planted
with conifer trees the uptake will never decline to zero. So completing the pilot study will
provide additional insight into the fate of the CoCs during the period that the trees do not
transpire 100% of the irrigation flow.
Remedial Action Construction Progress Report
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Please contact Mr. Gary D. Babb, P.G. (919-325-0696) or James C. LaRue (210-263-7580) if
there are any questions or comments. Please direct correspondence related to this matter
to:
Gary D. Babb, P.G.
Seaboard Group II and City of High Point
c/o Babb & Associates, P.A.
P.O. Box 37697
Raleigh, NC 27627.
Communications via electronic mail should be directed to [e-mail] and
[e-mail].
Respectfully,
Seaboard Group II and City of High Point

James C. LaRue
Seaboard Group II
Gary D. Babb, P.G.
City of High Point
Attachment - Project Schedule
cc Dave Nutt, Esq. - Seaboard Trustee
Steve Anastos - Seaboard Trustee
Jeffrey Moore - City of High Point Trustee
Randy Smith - Financial Trustee
Terry Hauk - City of High Point
Jackie Drummond – NCDEQ Solid Waste

Remedial Action Construction Progress Report
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PROJECT SCHEDULE
2016
January-April Install system modifications, modify draft Construction
Completion Report to include clarifier system
May-June Test system operations and finalize the process chemistry.
July-September Operate system
October-December Operate System and resume pilot study.

Remedial Action Construction Progress Report
Page 5 of 5
CONSTRUCTION SCHEDULE

DATE ITEM
1/4-1/15 CLEAR SITE, GRUB, & GRADE
1/4-1/15 RE-PIPE LS-1
1/18-1/29 POUR CONCRETE SLABS AND TANK
2/1-2/19 INSTALL YARD PIPING & PUMPS
2/22-3/4 INSTALL ELECTRICAL WIRING
3/7-3/11 LIME & FERRIC DELIVERY AND SETUP
3/21-3/25 SLUDGE HANDLING DELIVERY AND SETUP
3/28-4/8 PROGRAMMING INTEGRATION
4/18-4/22 CLARIFIER DELIVERY AND SETUP
4/25-4/29 SYSTEM TESTING & PERMIT CLOSEOUT