8803_TransylvaniaCoMSWLF_LFGRemAppr_DIN27451_20170306

March 6, 2017

Sent Via Email - [e-mail]

Jeff Brookshire
Transylvania County Solid Waste Services Director
500 Howell Road
Brevard, NC 28712

Re: Landfill Gas Remediation Plan
Transylvania County, Calvert Landfill, Permit #88-03
DIN 27451

Dear Mr. Brookshire,

The Solid Waste Section (Section) has completed a review of the Landfill Gas Remediation Plan (DIN
27440) submitted on behalf of Transylvania County by Joyce Engineering (Joyce). A landfill gas
remediation plan was submitted in response to a December 19, 2016 notice of violation (NOV) from the
Section. The NOV stemmed from the detection of landfill gas at concentrations exceeding the lower
explosive limit (LEL) since the April 2013 monitoring event. Landfill gas concentrations have been
reported above the LEL in monitoring probes GP-6, GP-8, and GP-9. Joyce conducted a site visit on
January 10, 2017 to observe site conditions and survey the landfill gas probes, groundwater monitoring
wells, and gas vents. As a result, Joyce discovered that gas probes GP-8 and GP-9 were incorrectly recorded
and GP-6 and GP-8 are now correctly identified as boundary gas probes while GP-9 was observed in an
area of decaying organic matter.

Joyce plans to install two additional landfill gas monitoring probes to replace GP-6 and GP-8. These new
probes are proposed to be installed closer to the property boundary and will be monitored on a quarterly
basis. Joyce proposed to evaluate the quarterly monitoring reports for a year prior to determining the
potential for off-site landfill gas migration and the need for a new landfill gas remediation plan. The Section
approves this interim remedial measure under the condition that Transylvania County submits a new landfill
gas remediation plan if concentrations exceed the LEL for two consecutive quarterly monitoring events in
either of the new landfill gas probes. Please contact me at [phone] or by e-mail at
[e-mail] if you have any questions or concerns regarding this letter. Thank you in advance
for your anticipated cooperation with this matter.

Sincerely,

Ervin Lane
Compliance Hydrogeologist
Solid Waste Section

cc sent via email: Hannu Kemppinen, P.G., Joyce Engineering
Jason Watkins, Field Operations Branch Head
Deb Aja, Western District Supervisor
Lee Hill, Environmental Senior Specialist
Christine Ritter, Permitting Hydrogeologist