HC Ash Monofill Annual Report 2017-03-07

Annual CCR Landfill Inspection Report
Inspection Date: March 7, 2017

Halifax County Ash Monofill
Halifax County, North Carolina

Prepared for:

Halifax County Department of Public Utilities
Halifax, North Carolina

March 2017

Prepared by:

© 2017 Smith Gardner, Inc.
This document is intended for the sole use of the client for which it was prepared and
for the purpose agreed upon by the client and Smith Gardner, Inc..

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Annual CCR Landfill Inspection Report
Inspection Date: March 7, 2017

Halifax County Ash Monofill
Halifax County, North Carolina

Prepared For:
Halifax County Department of Public Utilities
Halifax, North Carolina

S+G Project No. HALIFAX-17-1

Joan A. Smyth, P.G.
Vice President, Senior Hydrogeologist

Pieter K. Scheer, P.E.
Vice President, Senior Engineer

March 2017

F-1370 F-1370
3/21/2017

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Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Table of Contents Page i
Halifax County Ash Monofill
Halifax County, North Carolina

Annual CCR Landfill Inspection Report
Inspection Date: March 7, 2017

Table of Contents
Page

1.0 INTRODUCTION ................................................................................................................... 1 
2.0 REVIEW OF AVAILABLE INFORMATION .............................................................................. 1 
3.0 INSPECTION SUMMARY ...................................................................................................... 2 
3.1 Participants ............................................................................................................... 2 
3.1 Observed Conditions ................................................................................................. 2 
3.1.1 Existing Cover ................................................................................................ 2 
3.1.2 Run-On and Run-Off Control System ........................................................... 3 
3.2 Changes in Geometry ................................................................................................ 3 
3.3 Approximate Volume of CCR ..................................................................................... 4 
3.4 Structural Weakness or Disrupting Conditions ....................................................... 4 
3.5 Other Changes Affecting Stability or Operations ..................................................... 4 
4.0 RECORDKEEPING, NOTIFICATION, AND INTERNET POSTING REQUIREMENTS .............. 4 
4.1 Recordkeeping Requirements .................................................................................. 4 
4.2 Notification Requirements ........................................................................................ 4 
4.3 Internet Posting Requirements ................................................................................ 5 
5.0 PROFESSIONAL ENGINEER’S CERTIFICATION .................................................................. 5 

FIGURE
Figure 1 Site Photo

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Table of Contents Page ii

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Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 1
1.0 INTRODUCTION
Halifax County (County) owns and operates a geomembrane lined monofill (ash monofill) for
disposal of coal combustion residuals (CCR) at the County’s landfill facility located at 921 Liles
Road Littleton, North Carolina. The ash monofill, which currently consists of 2 cells covering
approximately 20.8 acres, is used for disposal of CCR generated solely from the Westmoreland
Partners Roanoke Valley Energy Facility (ROVA) located in Weldon, North Carolina. A site photo
showing the ash monofill as well as the northern portion of the landfill facility is provided as
Figure 1.

This report documents an inspection of the ash monofill conducted on March 7, 2017 by Mr.
Pieter K. Scheer, P.E. of Smith Gardner, Inc. (S+G) and is intended to satisfy the annual
inspection requirements of 40 CFR Part 257.84(b)(1) and (b)(2), which require periodic
inspections by a qualified professional engineer and preparation of an inspection report. This
report includes S+G’s review of available information (Section 2.0) and a summary of the March
7th inspection (Section 3.0) including findings related to changes in geometry, volume of CCR in
place, and appearances or changes which may affect stability, operation, and/or safety of the
ash monofill. Recordkeeping, notification, and internet posting requirements are addressed in
Section 4.0.

2.0 REVIEW OF AVAILABLE INFORMATION
Related to the inspection, the following documents were reviewed by S+G:

 NC Solid Waste Permit No. 42-04 INDUS, issued by the NC Department of Environmental
Quality Division of Waste Management, dated June 3, 2016.
 Operations Manual, Halifax County Landfill Facility, prepared by Smith Gardner, Inc.,
dated February 2016.
 Design Report, Halifax County Ash Monofill, prepared by Hazen and Sawyer, P.C., dated
March 1992.

S+G also reviewed and discussed the County’s record keeping practices with County personnel.
This record keeping includes weekly inspections conducted by County personnel in accordance
with 40 CFR Part 257.84(a).

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 2
3.0 INSPECTION SUMMARY
This section summarizes the March 7, 2017 inspection and notes S+G’s findings related to:

 Changes in Geometry (Section 3.2);
 Approximate Volume of CCR (Section 3.3);
 Structural Weakess or Disrupting Conditions (Section 3.4); and
 Other Changes Affecting Stability or Operations (Section 3.5).

Areas observed by S+G during the inspection included both top slopes (top deck) and side slopes
of the monofill, the sump area (south end of the monofill) including the sump riser structure,
the perimeter of monofill including surface drainage, and the internal stormwater basin
including the inflow pipe (from the monofill sump) and the discharge riser/barrel structure.

3.1 Participants
The following individuals participated in the inspection:

 Pieter Scheer, P.E., Smith Gardner, Inc.
 Greg Griffin, Halifax County Public Utilities, Director
 Ed Stanfield, Halifax County Public Utilities, Solid Waste Supervisor.

3.1 Observed Conditions
Areas and structures observed by S+G during the inspection included both top slopes
(top deck) and side slopes of the monofill, the sump area (south end of the monofill)
including the sump riser structure, the perimeter of monofill including surface drainage,
and the internal stormwater basin including the inflow pipe (from the monofill sump)
and the discharge riser/barrel structure. In general, the ash monofill appeared to be in
a well-maintained condition at the time of inspection.

3.1.1 Existing Cover
At the time of inspection, approximately 5.6 acres of the ash monofill (primarily
north slope) was covered by vegetated intermediate soil cover, which is graded to
allow drainage of run-off to perimeter drainage features (channels and basins).
The approximate area of intermediate cover is shown on Figure 1. The remaining
approximately 15.2 acres of the ash monofill consisted of exposed CCR which
was graded to drain internally to the sump area on the south end of the monofill.

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 3
The vegetation on the intermediate cover soil was mostly dormant at the time of
inspection but appeared to be in good condition. The County had used wood
mulch to stabilize a small portion of intermediate cover on the western slope.

Minor rill erosion was noted in the intermediate cover soil, mostly on the more
recently covered western slope; however, no CCR was exposed. The County
plans to improve this area with additional wood mulch.

The surface of the exposed CCR was in good shape with some rill erosion noted
where water concentrates. The County routinely regrades the exposed CCR after
rain events to repair the slope and is currently evaluating options for placement
of additional intermediate cover soil and/or a temporary cover (i.e. Posi-Shell, or
similar spray-applied cover) on much of the side slopes in order to reduce the
need for routine regrading.

3.1.2 Run-On and Run-Off Control System
The run-on control system for the ash monofill consists of perimeter grades and
drainage measures (channels and sediment basins) which prevent run-on from
entering the ash monofill and contacting exposed CCR. The run-off control
system consists of:

1) The direct run-off from intermediate cover soil to the perimeter of the
ash monofill (and to one of the sediment basins); and

2) The collection of run-off from exposed ash surfaces and routing through
the sump and internal stormwater basin. Both the sump and internal
stormwater basin have riser structures and gravel filters to allow CCR in
the runoff to drop out of suspension before discharge.

Both the run-on and run-off control system appeared to be in good working order
and in accordance with the design of the facility.

3.2 Changes in Geometry
Since the last inspection (July 8, 2016), the geometry of the ash monofill has changed
very little given that a limited quantity of CCR has been disposed of during this period
(5,144 tons or about 5,000 cubic yards (CY) based on recent waste density values).
Additionally, the County has added additional intermediate cover on the western slope
(approx. 0.3 acres) and has performed general grading of the exposed ash surfaces.

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 4
3.3 Approximate Volume of CCR
Based on County scale records, approximately 740,860 tons of CCR has been disposed of
in the ash monofill as of March 7th, 2017. The approximate volume of CCR (and
intermediate cover) contained in the ash monofill as of March 7th, 2017 is 942,000 cubic
yards (CY).

3.4 Structural Weakness or Disrupting Conditions
No appearances of actual or potential structural weakness or conditions which are or
have the potential to disrupt the operation and safety of the ash monofill were observed
during the March 7, 2017 inspection.

3.5 Other Changes Affecting Stability or Operations
No other changes which may have affected the stability or operation of the ash monofill
since the last inspection (July 8, 2016) were observed during the March 7, 2017
inspection.

4.0 RECORDKEEPING, NOTIFICATION, AND INTERNET POSTING REQUIREMENTS
Per 40CFR Part 257.84(c), Halifax County will comply with recordkeeping, notification, and
internet posting requirements as follows below.

4.1 Recordkeeping Requirements
The County will place a copy of periodic inspection reports in the the Operating Record
as required under 40CFR Part 257.105(g)(6).

4.2 Notification Requirements
The County will notify the State Director as required under 40CFR Part 257.106(g)(5)
when periodic inspection reports are made available in the Operating Record.

Notification will be made to the following individuals:

North Carolina Department of Environmental Quality (DEQ)
Raleigh Central Office
Division of Waste Management
217 W. Jones Street
Raleigh, NC 27603
1646 Mail Service Center

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 5
Raleigh, NC 27699-1646
Phone/Fax: [phone]

Mr. Michael Scott - Director
Mr. Ed Mussler, P.E. – Permitting Branch Head
Ms. Shawn McKee – Waste Management Specialist

4.3 Internet Posting Requirements
The County will post periodic inspection reports within 30 days of placing them in the
Operating Record.

5.0 PROFESSIONAL ENGINEER’S CERTIFICATION
Based on my inspection of the Halifax County Ash Monofill in Halifax County, North Carolina on
March 7, 2017 and review of available information, the design, construction, operation, and
maintenance of the CCR unit appears to be consistent with recognized and generally accepted
good engineering standards.

Pieter K. Scheer, P.E.
Printed Name of Registered Professional Engineer

Signature of Registered Professional Engineer

March 21, 2017 21666 NC
Date Registration No. State

Halifax County Ash Monofill Annual CCR Landfill Inspection Report
March 2017 Page 6

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G :\C A D \H a l i f a x \H a l i f a x 1 7 -1 \s h e e t s \H A L I -A 0 3 0 6 .m x d
DRAWN:APPROVED:SCALE:FIGURE NO.:PROJECT NO.:DATE:
C.T.J.P.K.S.1AS SHOWN Mar. 2017 HALIFAX 17-1
HALIFAX COUNTY ASH MONOFILL
SITE PHOTO
³
0 200 400 600 800Feet
ASH MONOFILL
CELLS 1&2
SCALE HOUSE
AND SCALES
OFFICE/MAINTENANCE
BUILDING
TRANSFER STATION
L I L E S R O A D
SUMP
GRAVITY MAIN
INTERNAL STORM
WATER BASIN
LIMIT OF LINER
INTERMEDIATE SOIL COVER
REFERENCE: IMAGERY FROM AERIAL SURVEY DATED
MAY 27, 2016 PERFORMED BY GEODATA CORPORATION,
ZEBULON, NC.

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