9201_Wake_CItyofRaleigh_WildersGrove_MSWLF_ASDMetalsPlan_FID1319826_20190422

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April 22, 2019
Ms. Jaclynne Drummond
North Carolina Department of Environmental Quality
Asheville Regional Office
2090 U.S. Highway 70
Swannanoa, NC 28778
RE: Alternative Source Demonstration Plan
City of Raleigh
Wilders Grove Landfill
Permit No. 92-01
Dear Ms. Drummond:
On behalf of the City of Raleigh, URS Corporation — North Carolina is pleased to submit one copy of the
Alternative Source Demonstration Plan for the Wilders Grove Landfill (Site). This report provides
details of the proposed monitoring plan in order to prepare an Alternative Source Demonstration Report.
This plan is being submitted at the request of North Carolina Department of Environmental Quality
(NCDEQ).
The intent of the monitoring plan is to evaluate if lines of evidence exist to demonstrate that select metal
concentrations detected at the Site are because of the solid waste management facility or from
upgradient/background conditions.
MONITORING WELL INSTALLATION
There is currently one background monitoring well (MW-4) for the Site and it is located side -gradient (to
the east). It is proposed to install three more monitoring wells to serve as background wells in order to
better define the groundwater conditions in the area. The proposed monitoring wells will be spread out
across the upgradient area of the site. One will be installed to the northeast, to the north, and to the west
under the assumption each area can be accessed by a drill rig. The locations may be revised in the event
an area is not accessible. The proposed monitoring well locations are depicted in Attachment 1.
Each well will be installed to a depth so that the screen interval straddles the average depth to water. The
wells will be constructed with 2-inch schedule 40 PVC with 0.010-inch slotted screen and completed with
a metal protective casing and a concrete pad. The top of casing elevations will be collected following
installation of each in order to assist in evaluating groundwater flow in the vicinity. The proposed
construction details for each proposed monitoring well are included in Attachment 2.
GROUNDWATER SAMPLING SCHEDULE
In accordance with NCDEQ Solid Waste Section guidelines, it is expected that at least eight sampling
events will be required in order to calculate background standards for constituents of concern. It is
proposed to collect groundwater samples from MW-4 and the three proposed monitoring wells quarterly
for the next two years. Groundwater samples will be collected from each well utilizing low -flow
sampling techniques and shipped to a North Carolina certified laboratory to analyze each sample for
Appendix I metals. Both dissolved and total metals will be sampled for in order to evaluate the

relationship between dissolved metals and total metals concentrations. Prior to sample collection, each
well will be purged in an attempt to obtain turbidity readings of 10 NTUs or less. If turbidity readings do
not stabilize below 10 NTU, the monitoring well may be redeveloped and sampled following time to
recharge. The collected groundwater data will be utilized to develop background levels of metals for the
Site which will be submitted to NCDEQ for approval.
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Monitoring well installation is expected to occur over the summer of 2019 following approval by the
NCDEQ. It is estimated that the first groundwater sampling event for the four background wells will
occur in September 2019 and will continue quarterly through at least June 2021. Results of each
quarterly event will be included in the March and September semi-annual reports that are currently being
submitted in accordance with the revised Corrective Action Plan and Corrective Action Evaluation Report
dated March 1, 2011, and February 15, 2019, respectively. Once new background levels are accepted by
NCDEQ, quarterly monitoring of the four background monitoring wells will be transitioned to semi-
annual sampling (March/September) and an Alternative Source Demonstration Report will be prepared
and submitted to NCDEQ for review.
If you have any questions regarding this submittal, please contact the undersigned at [phone].
Sincerely,
URS Corporation — North Carolina
Mike Ranck, P.G. Jasen Zinna, P.E.
Project Manager Senior Engineer
cc: Stan Joseph, City of Raleigh

ATTACHMENT 1

r
x ,
4 x� xl
Ix 1. EXISTING TOPO PROVIDED BY WAKE COUNTY GIS
DATA, DATED SEPTEMBER 2013.
Uo 2. LIMITS OF WASTE SHOWN ARE APPROXIMATE.
i 3. GROUNDWATER ELEVATIONS MEASURED ON SEPTEMBER
x1 x 20-24, 2018.
!
r '
Ix xM
4 x
x° xp LEGEND
= xi
= x, MW-2
_ p z 230.6 DENOTES GROUNDWATER MONITORING
t xp WELL LOCATION AND IDENTIFYING
1 x� NUMBER AND MEASURED GROUNDWATER
SW-2 . p t x ELEVATION ON REFERENCED DATE
t MW-201 S
DENOTES ACM GROUNDWATER MONITORING
WELL LOCATION AND IDENTIFYING MEASURED GROUNDWATERE ENUMBER AND
ELEVATION ON
1 �
0 1 1 O ox x x� REFERENCED DATE
1 r 2 3.205S 1 I x x x xp xg SW-2
DENOTES SURFACE WATER
� — x � ® MONITORING LOCATIONS
Mw-202S = xM xl AND IDENTIFYING NUMBER
14W-6 ta •_ TT ex
v �1�MW— 0x MW-201S 201.09 x
I 2D x 180.27 x r x x
t1 4 1= E 203.80
1D
MW-203S x 0 4 p
MW-207S
174.2� o x
� x R x€ x!
66.05 p o
MW-207D x o !x x
160.29 x a !x x !
E � !x p i
xp
x xg Ix MW-104D 1© sx (n\ D X O d
•x188.82 x= Mw-102s A � x1 1 0
2149 O
PROPERTY LINE, TYP
■ . �
MW-2043 MW-1043 x1 �© x x
170.29 1t MW-103S
88.99
231.02
lklkO
xg
D
0
x
MW-208S-1 —M 502W MW-9 \� !' !• .: •e e.
165.38 MW-205S 171.68
—2 SW-1
170.69 ! • ! • !
MW-208D MW-106S
124.90 MW-206D 181.02 !• !"
4
MW-100D .!
MW—loos .! •! l
CRABTREE CREEK 1s1.70 .!
Mw-2 !'fv
189.86 p ! " •!
a
• 200.59 "e .! "1 �
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m ,.
a 239.69 i !
!• i
MW-8 MW-12 M —11 r • " \
n 223.95 23 60 234.31
i
I APPROXIMATE LIMIT OF WASTE, TYP
© x, o
PROPERTY LINE, _
e •! Q 0
Q a" u
xa !• "!
! . •! • ! e . • e 242.01 !
.!'
s •, 300 150 0
� 300'
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1 "=300'-0" Eli
DESIGNED JAB
DRAWN MDW CITY OF RAL E I G H DATE ISSUED: 1 /29/19
CHECKED JABA�=COM PROJ. ENGR. JAB DEPARTMENT OF SOLID WASTE SERVICES
1600 PERIMETER PARK DRIVE, SUITE 406 SITE PLAN
THE SCALE BAR BELOW MORRISVILLE, NORTH CAROLINA 27560 Fig. a 1
MEASURES ONE INCH LONG ON PHONE: [phone]
1 GROUNDWATER ELEV. ASSESS. j 9/24/131 MDW THE ORIGINAL DRAWING W I L D E RS GROVE LANDFILL
NO. ISSUED FOR I DATE I BY DRAWING NUMBER

ATTACHMENT 2

Attachment 2
Proposed Monitoring Well Construction Details
Wilders Grove Landfill
Location
Permanent ID
Well Diameter (inches)
Description
NE of MW-11
MW-13
2
20 feet bgs. HSA, 15 foot screen
N of MW-9
MW-14
2
30 feet bgs. HSA, 20 foot screen
W of MW-105S
MW-15
2
25 feet bgs, HSA, 15 foot screen