4101_Guilford_CityHighPoint_Riverdale_MSWLF_Seaboard_ExtractionCommentLetter_FID1773533_20230223

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
MICHAEL SCOTT
Director
Gary Babb, P.G.
Babb & Associates, P.A.
Seaboard Group II and City of High Point
5506 Bradford Pear Ct.
Raleigh, NC 27606
NORTH CAROLINA
Environmental Quality
February 20, 2023
Re: Review of Q3 and Q4 2022 Extraction System Evaluation Monitoring Reports
Seaboard Group II and the City of High Point, dated January 17 and February 13, 2023
Former Seaboard Chemical and Riverdale Drive Landfill Site
Jamestown, Guilford County, North Carolina
EPA ID# NCD071574164
Dear Mr. Babb,
The Hazardous Waste Section (HWS) has reviewed the referenced documents submitted to the HWS on
January 17 and February 13, 2023, respectively. These are the first and second quarterly reports submitted
after the groundwater expansion system was expanded as outlined in Technical Memorandum No. E-I I
(TM E-11), dated January 25, 2022 and approved by the HWS on March 8, 2022.
Based on the reports, the additional extraction wells became fully operational by the end of June 2022.
The first quarterly report covered the period July to September 2022 (Q3 2022) and focused on presenting
baseline and first quarter monitoring data for pumping and non -pumping wells in the former Pond 3 (old
Seaboard site) and the South Intermittent Stream basin (SIS) areas of the site. Two wells were converted
to extraction wells in the Pond 3 area, while two new extraction wells were installed in the SIS basin. The
second report covered the October to December 2022 period (Q4 2022)
Comments applicable to both reports:
Table 1 — (Field Data and Groundwater Elevations)
• The response from Seaboard Group II and the City of High Point to our conditional approval,
dated March 8, 2022, indicated that water level measurements would be collected from well W-
29 in the Pond 3 area. The tables do not list W-29 for the first two quarterly reports.
D E Q�� North Carolina Department of Environmental Quality I Division of Waste Management
-
217 West Jones Street 1 1646 Mail Service Center I Raleigh, North Carolina 27699-1646
NORTH CAROLINA
oeParonemmrnrironmemaiouai� � 919.707.8200

Q3 and Q4 2022 Extraction System Monitoring Reports, TM E-I I
Former Seaboard facility and Riverdale Landfill
February 20, 2023
Page 2
Table 2 (Groundwater VOC Analytical Results) and text related to the table:
• Change the parentheses part of the title to also include 1,4-dioxane (1,4-D), i.e. "Groundwater
VOC and 1,4-Dioxane Analytical Results." Since the VOC and 1,4-D results are presented in
different figures, a reader might originally look for two tables (one each for VOCs and 1,4-D).
• We checked concentrations in the table vs. those reported in the laboratory reports for the
baseline and the first two quarters. There are several errors as listed below:
Sample
ID Well
Date
Sampled
Analyte
Error (Result in ug/L)
AW-2
3/22/2022
1, 1 -Dichloroethane
2.2 instead of <1 on table
9/27/2022
Chloroethane
300*+ instead of <1 on table
9/27/2022
Chloromethane
<1 instead of 300 on table
1/5/2023
Chlorobenzene; Other VOCs
1.5 instead of 2 on table; 1.1 for
other VOCs
AW-3
3/22/2022
Samples were diluted 20 times;
Other VOCs
Non -detects should be <20 instead
of <1 on table; 19 J is other VOCs
9/27/2022
Chloroethane
Add *+ data qualifier
AW-4
9/27/2022
Chloroethane
300 instead of <10 on table
RW-SIS1
3/22/2022
1,2-Dichloroethane
74 J instead of 74 on table
PW-313
3/22/2022
Cis-1,2-Dichloroethene
420 J instead of 420 on table
*+ The bullet below provides further information
• The samples for 1,4-D during the first quarter were collected approximately three months later
than the VOC samples. The text in the report mentions the later sampling date but Table 2 does
not. Include 11/17/2022 in the date column for collecting the 1,4-D samples and make a note that
the November data applies only to the 1,4-D testing.
• The chloroethane results for AW-2 and AW-3 in the first report were qualified by the laboratory
with asterisks, which according to the data qualifiers page means: "LCS and/or LCSD is outside
acceptance limits, high biased". Results that have either low or high bias need to be called out and
explained in future quarterly reports.
• The laboratory reports contain sample results for wells that are not listed in Table 2. These wells
appear to be the current extraction wells. The text of each report should refer to the additional
testing results and explain why they were not tabulated in the monitoring report.
Figures (report specific)
We appreciate the presentation of the baseline and first quarter results next to each other in
Figures 2, 3, 5 and 6. For Figure 6, the first quarter 1,4-D concentrations at AWB-4 and AW-3
are cut off on the right-hand side of the page.
In the second quarterly report, the inset graphs showing total VOC and 1,4-D concentrations are
helpful. Please continue to include them as insets or separate charts in future reports.
Include iso-concentration lines on the concentration figures in the future reports.
E Q North Carolina Department of Environmental Quality I Division of Waste Management
217 West Jones Street 1 1646 Mail Service Center I Raleigh, North Carolina 27699-1646
NORTH CAROLINA -
DaP.mm.mmEwimnm�lQu.� /� 919.707.8200

Q3 and Q4 2022 Extraction System Monitoring Reports, TM E-I I
Former Seaboard facility and Riverdale Landfill
February 20, 2023
Page 3
Please address the comments related to Table 2 and resubmit a revised table. The revised table should be
used for the future two quarterly reports that the HWS receives from the Seaboard Group II and the City
of High Point.
Please contact us if you have any questions or comments about this letter.
Eric B. Aufderhaar, P.G., Project Manager
Facilities Management Branch, Hazardous Waste Section
Division of Waste Management, NC DEQ
ec: Craig Coslett, de Maximis, Inc.
Jackie Drummond, Solid Waste Section
Kim T. Caulk, Facilities Management Branch Head, Hazardous Waste Section
E Q Q North Carolina Department of Environmental Quality I Division of Waste Management
217 West Jones Street 1 1646 Mail Service Center I Raleigh, North Carolina 27699-1646
NORTH CAROLINA _
OepammammEmimnmameiausifty /� 919.707.8200