6301_MooreCDLF_ASDResponcse_DIN28497_20170928

September 28, 2017

Sent Via Email - [e-mail]
Mr. Chad Beane
Moore County Solid Waste
P.O. Box 1927
Carthage, North Carolina 28327

Re: Alternate Source Demonstration
Active Moore County C&D Landfill
Moore County
Solid Waste Permit Number 6301-CDLF-1992
DIN 28497

Dear Mr. Beane:

The Solid Waste Section (Section) has completed a review of the Alternate Source Demonstration dated
February 28, 2017 (DIN 28496) and submitted on behalf of Moore County (County) by Golder Associates for
the active and unlined Moore County C&D Landfill, Solid Waste Permit Number 6301-CDLF-1992. The Alternate
Source Demonstration was submitted in accordance with 15A NCAC 13B .0545 in response to groundwater
exceedances of volatile organic compounds and a Section letter dated March 14, 2016 (DIN 25773) instructing
the County to establish an Assessment Monitoring program for the C&D Landfill or demonstrate that a source
other than the C&D Landfill caused the contamination.

Within the Alternate Source Demonstration, the constituents of concerns for the C&D Landfill include the
following volatile organic compounds (VOCs): acetone, benzene, vinyl chloride, chlorobenzene, chloroethane,
1,2-dichlorobenzene, 1,4-dichlorobenzene, 1,1-dichloroethane, cis-1,2-dichloroethene, tetrachloroethene
(PCE), trichloroethene (TCE), and xylenes. Additional groundwater sampling was conducted that included soil
gas and headspace readings, and leachate samples. The County reviewed historical trends, utilized indicator
parameters, and reviewed both the laboratory and field data.

Based upon the information provided within Moore County’s Alternate Source Demonstration for the active
and unlined C&D Landfill for VOCs only, the Section does not approve the Alternate Source Demonstration for
VOCs at this time. The Section will not issue a determination on the Alternate Source Demonstration until 1)
the County implements the active landfill gas system as stated and approved in 2012 (DIN 17133) at the
upgradient closed and unlined MSW Landfill to reduce the landfill gas concentrations, and 2) VOC
concentrations decrease in the groundwater monitoring wells at both the MSW Landfill and the C&D Landfill.
When these actions have been achieved, the Alternate Source Demonstration will be reevaluated to determine
if the MSW Landfill may or may not be contributing to the VOCs being detected at the active and unlined C&D
Landfill.

Pursuant to 15A NCAC 13B .0545, Moore County is required to initiate Assessment Monitoring at the active
and unlined C&D Landfill. In the future, Moore County may petition the Solid Waste Section to revert back to
Detection Monitoring in accordance with 15A NCAC 13B .0545(b)(9).

The County will also be required to select an additional groundwater corrective action remedy to restore
groundwater quality at and beyond the MSW Landfill’s compliance boundary, to effectively reduce the overall
groundwater contamination at the MSW Landfill, and to control the migration of contaminated groundwater
to prevent unacceptable impacts from the MSW Landfill.

A second letter will follow detailing the required additional activities to be conducted at the closed and unlined
MSW Landfill. The County needs to address both the C&D Landfill and the MSW Landfill simultaneously.

Moore County is responsible for addressing the organic groundwater exceedances, the inorganic groundwater
exceedances, and landfill gas exceedances to ensure the protection of public health and the environment.
Please plan your County’s budget accordingly to address these critical post closure care issues at the closed
and unlined MSW Landfill as well as the ongoing groundwater issues at the active and unlined C&D Landfill.

If you have any questions or concerns regarding this letter, please feel free to contact me by email at
[e-mail] or by phone at 828.296.4706. Thank you for your anticipated cooperation
with these matters.

Sincerely,
Jaclynne Drummond
Compliance Hydrogeologist
Solid Waste Section, Division of Waste Management
NCDEQ

cc sent via email: Ellen Lorscheider, Section Chief
Jason Watkins, Field Operations Branch Head
Ed Mussler, Permitting Branch Head
Drew Hammonds, Eastern District Supervisor
Amanda Freeman, Senior Environmental Specialist
Elizabeth Werner, Permitting Branch Hydrogeologist
Donna Wilson, Permitting Branch Engineer
Ming Chao, Permitting Branch Engineer
Wayne Vest, Moore County Manager
Randy Gould, Moore County Public Works Director
Ben Draper, Golder Associates NC, Inc.
Rachel Kirkman, Golder Associates NC, Inc.