3301_EdgecombeMSWLF_20160525_CAERapproval_DIN26122

PAT MCCRORY
Governor
DONALD R. VAN DER VAART
Secretary

MICHAEL SCOTT
Director
State of North Carolina | Environmental Quality | Waste Management
1646 Mail Service Center | 217 West Jones Street | Raleigh, NC 27699-1646
919 707 8200 T

May 24, 2016

Sent via email: mailto:[e-mail]

Mr. Eric Evans, Manager
Edgecombe County
P.O. Box 10
Tarboro, NC 27886

Re: Interim Corrective Action Evaluation Report
Edgecombe County Landfill, Permit #33-01

Dear Mr. Evans:

The Solid Waste Section (Section) has reviewed the Interim Corrective Action Evaluation Report,
Edgecombe County Landfill (DIN 26085) submitted on behalf of Edgecombe County by S&ME, Inc. The
Section approved a corrective action plan (CAP) (DIN 9206) for the Edgecombe County Landfill on January
16, 2009 and a subsequent CAP amendment (DIN 11254) was approved on August 9, 2010. The remedial
strategies chosen for implementation on-site include in situ isolation of surface water, in situ isolation of
groundwater, and monitored natural attenuation (MNA). In situ isolation of surface water was proposed
to be completed by maintaining a consistent contour with the pre-1998 waste area and increasing the
slope of the closed MSW area. In situ isolation of groundwater was proposed to be completed by installing
an upgradient groundwater hydraulic barrier wall along the southern waste boundary.

To date, maintaining a consistent contour with the pre-1998 waste area and increasing the slope of the
closed MSW area have been completed. MNA monitoring was conducted to assess baseline conditions
from 2010 until 2012 at which time, the Section approved Edgecombe County’s request to suspend MNA
monitoring until the upgradient barrier wall was constructed. S&ME has proposed to resume MNA
monitoring in accordance with the previously approved revised sampling and analysis plan beginning in
June 2016.

In situ isolation of groundwater using an upgradient barrier wall is the only remedial strategy that has not
been implemented. The barrier wall was proposed to be installed along the upgradient boundary of the
landfill for the purpose of diverting the flow of groundwater prior to contact with waste. The diversion of
upgradient groundwater flow is intended to reduce the volume of water contributing to leachate
generation and lower groundwater levels thereby increasing the vertical separation between the
groundwater table and bottom of waste. S&ME included a revised construction schedule for the
upgradient barrier wall in the Corrective Action Evaluation Report (CAER) with a projected start date of
May 2017 and completion in December 2017. The Section approves the resumption of MNA monitoring
and the proposed upgradient barrier wall construction schedule detailed in the CAER.

Edgecombe County LF
Interim CAER letter
May 24, 2016
Page 2 of 2

Edgecombe County should proceed with MNA monitoring and construction of the upgradient barrier wall
as outlined in the CAER. Edgecombe County shall notify the Section of any circumstances that would delay
the upgradient barrier wall construction. Failure to notify the Section and/or adhere to the construction
schedule outlined in the CAER would put Edgecombe County in violation of Rule 15A NCAC 13B .1637 (2)
and may subject the County to enforcement actions.

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 in this matter.

Sincerely,

Ervin Lane
Compliance Hydrogeologist
Solid Waste Section

cc: Sam Watts, P.G., S&ME, Inc.
Jason Watkins, Field Operations Branch Head – SWS
Ed Mussler, P.E., Permitting Branch Head – SWS
Ming-Tai Chao, P.E., Permitting Engineer – SWS
Sarah Rice, Compliance Officer – SWS
Christine Ritter, Hydrogeologist – SWS