7901_RockinghamMSWLF_ March2024LFGRemediationPlanAppr_FID1832177_20240320

March 20th, 2024

Sent via email – [e-mail]

Mr. Ronnie Tate
Engineering and Public Utilities Director
P.O. Box 132
Wentworth, NC 27375

RE: Landfill Gas Remediation Plan
Rockingham County Solid Waste Management Facility
Permit# 7901-MSWLF-1979
Rockingham County
FID 1832177

Dear Mr. Tate:

The Division of Waste Management, Solid Waste Section (Section) has reviewed the Landfill Gas
Remediation Plan (FID 1832128) submitted by Labella Associates (LaBella) on behalf of
Rockingham County. The remediation plan was submitted in response to concentrations of
methane above the lower explosive limit (LEL) in monitoring probes 7901-M-5 and 7901-M-12
during recent landfill gas monitoring events. Remedial action is required since both probes are
located near the property boundary.

Joyce has proposed to address LEL exceedances near the property boundary by installing six soil
gas vents near 7901-M-5 and three near 7901-M-12. The vents will be installed in sets of three
located approximately 50 feet from each other. The vents are proposed to be completed to
depths equal to auger refusal, depth to groundwater, or depth of the nearest probe dependent
upon what is encountered first. The proposed vents will be constructed using four-to-six-inch
diameter PVC pipe and each vent will be connected to the header pipe for the existing utility
flare. LaBella proposes to evaluate landfill gas measurements after four consecutive quarterly
monitoring events before providing an update to the Section which may consist of a revised

remediation plan if necessary. The Section approves the landfill gas remediation plan and
Rockingham County should proceed with implementation.

If you have any questions or need further assistance on this review, please contact me via email
at [e-mail] or by phone at [phone].

Sincerely,

Ervin Lane
Hydrogeologist
Solid Waste Section

Cc: Perry Sugg, P.G. – SWS Environmental Compliance Branch Head
Robert Pike – SWS Environmental Senior Specialist
Van Burbach – PhD, P.G. – LaBella Associates
Kandice Estes – LaBella Associates