7906_DukeDanRiverLandfill_StormwaterEvent_06192017

Duke Energy
Dan River Landfill
Permit No. 7906-INDUS-2016
Stormwater Event
June 19, 2017
Dan River Landfill Stormwater Event #1
June 19, 2017
•During the morning of June 19, 2017, it was discovered that
heavy rains over the weekend had caused CCR material to
breach through the Southwest corner of landfill cell #1 into
the future cell #3 (remaining ash stack 1).
•Rainfall total over the weekend was 2.6”, not including 0.8” of
rain had fallen the previous Thursday night.
•The berm between cell #1 and cell #3 was covered with
approved cover material (sand).
•CCR excavation is still occurring in the cell #3 footprint.
Area of Concern
(1st Event)
Cell #1 Future Cell #2
Future Cell #3
Cell #1 Southwest Corner
CCR Material washed into Cell #3
Cell #1 Apparent Flow Channel
Repair work at Southwest Corner of
Cell #1
Nearest Chimney Drain
Berm repair &
improvements
Dan River Landfill Stormwater Event #2
June 19, 2017
•A second heavy rainfall event occurred during
the afternoon that produced 0.2” in
approximately 15 minutes.
•After the event, it was discovered that CCR
material had breached the cell #1 berm on the
east side of the landfill and resulted in CCR
material flowing into cell #2.
•Cell #2 is currently under construction with
the clay liner being installed.
Area of Concern
(2nd Event)
Future Cell #2
Future Cell #3
Cell #1
Breach of Cell #1 on East side
Breach of Cell #1 on East side
Cell #2 Inter-cell berm
Proposed Dan River Landfill Cell #1
Drainage Modifications
The following modifications were discussed on 6/19/17 with the project
team. Field observations may reveal additional modifications.

1.Remove sand from around the chimney drain at the Cell 1 inter-cell
berm (interior/central portion of Cell 1).
2.Remove the protective cover over the LCS lateral between the
chimney drain and the eastern edge of the cell. Direct water from the
northern part of the cell towards the LCS lateral and chimney drain.
3.Increase the Cell 1/2 berm at the breach area with soil, grade area to
direct potential overflow water to the southern part of cell 1.
4.Remove sand over the LCS corridor along the Cell 1/3 area east of the
access ramp. Keep the geotextile intact. Replace the sand with 12 to
18 inches of 78M stone.
5.Install a supplemental chimney drain in the sump area.