NCS000348_Closure Plan_20220405

Stormwater Permit Closure Plan
Capital Power Southport, NC Facility
NPDES Permit No. NCS000348
Introduction:
Capital Power (CPI) is authorized under the NPDES Permit No. NCS000348 to discharge Stormwater
associated with industrial activity via Outfall 01C. Outfall 01C is a combined outfall that is comprised of
stormwater drainage areas associated with internal Outfalls 001 through 007. Effective at midnight on
March 31, 2021, the facility ceased operations and CPI began the process of closing the facility. The
facility closure is scheduled to be completed during the second quarter of 2022.
CPI is also in the process of closure of the wastewater treatment system based on the requirements of
the NPDES Permit No. NC0065099. CPI notified NCDEQ on November 9, 2021 of the planned
wastewater closure activities, and a copy of this closure plan is included as an attachment.
CPI's demolition contractor, DH Griffin, has submitted an Erosion and Sedimentation Control (ESC) Plan
to NCDEQ and is awaiting receipt of a permit to perform land disturbance work at the facility. A copy of
the Certificate of Coverage (COC) can be provided upon receipt. CPI has assumed that stormwater
runoff that occurs as a result of the land disturbance work and discharges in accordance with the ESC
Plan is allowable in accordance with Part I, Section B (Permitted Activities) of NPDES Permit No.
NCS000348. Furthermore, CPI has assumed that NPDES Permit No. NCS000348 can be rescinded
independent of the land disturbance work.
CPI continues to maintain compliance under NPDES Permit No. NCS000348 and the Stormwater
Pollution Prevention Plan (SWPPP), and the following sections provide a closure plan that will be
implemented in order to rescind the subject permit.
Closure Methodology:
The following closure steps will be completed for closure of CPI's stormwater permit.
1. Submit a Stormwater Closure Plan to NCDEQ for review and approval.
2. Officially notify NCDEQ at least 90 days prior to closure.
3. CPI and its contractors will remove potential pollutant sources associated with areas that drain
to the stormwater conveyances and ultimately to Outfall 01C. The areas of potential pollutant
sources are delineated on the attached SWPPP map and a summary of these areas is presented
below:
o Drainage Area #1:
■ Condensate Tank
■ Ash Handling and Storage Silos
■ Limestone Silo
■ Fuel Conveyors
■ Bucket Elevator Towers
o Drainage Area #2:
■ Equipment and facilities that currently drain to the wastewater basins and
discharge under NPDES Permit No. NC0065099. See attached Wastewater
Closure Plan for further details.
Page 1 of 3

o Drainage Area #3:
■ Cooling Towers
■ Cooling Tower Chemical Storage Areas
■ Rail Car Unloading Area
■ Coal Conveyors
■ Truck Dumper and Wood Conveyors
■ Railroad Spur
■ Railroad Tie Chippers and Storage Piles
o Drainage Area #4:
■ Cooling Towers
o Drainage Area #5:
■ Demineralizer Building
■ Neutralization Tank
■ Reverse Osmosis Building
■ Drum Storage Area
■ Water Tanks
■ Pump House
o Drainage Area #6:
■ Laydown Yard Area
o Drainage Area #7:
■ Ash Handling and Storage Silo
■ Limestone Silo
■ Electric Fire Pump (EFP) Transformer
■ Unloading Bay
■ Gasoline and Drum Storage Area
4. A sand filter was constructed in Drainage Area #3 and permitted under State Stormwater
Management Permit No. SW8 090511 (effective until July 2029). This stormwater control
measure was installed to address runoff from impervious areas in the vicinity of the truck
dumper and wood conveyor area. CPI also plans to rescind this permit as part of the closure
work and the land disturbing activities mentioned above which includes removal of the
associated impervious surfaces.
5. Complete closure work required under the Wastewater Closure Plan and rescind NPDES Permit
No. NC0065099. Once NPDES Permit No. NC0065099 has been rescinded, runoff from Drainage
Area #2 will discharge from the site as "stormwater". These discharges will be managed in
accordance with NPDES Permit NO. NCS000348 or the permit issued for land disturbance
activities.
6. Notify NCDEQ of completion of the subject closure work, offer opportunity for site visit, and
request that the NPDES Permit NO. NCS000348 is rescinded.
7. Prepare a written report documenting the closure work for record keeping purposes to include
photographs and a log of closure work. Receive NPDES permit recission letter from NCDEQ.
Attachments:
1. SWPPP Map
2. Wastewater Treatment System Closure Plan
Page 2of3

Attachments:
Page 3 of 3

No
Industrial
Activity
it �. � -� • � � o
No Water
Industrinl Tnnk
Activity
Utal@SK
' Punp Water
House Tank
OUTFALL
}}} ooc
�z • /
No 'Industrinl
Activity
/
V U Haller
DRA1IMff Building
AREA 7
19 Turbine
Building
Switch
Yard
Area
11
No
Industrinl
Activity
] TF LL
001 'V'
6
7StA
Truck
Dunper 1
atAnwf
..I
AA'E114 .O i
FALL OO I Cooling
00
No
Industrial O °
Activity I Snnd�
OFll0000
0
No
Industrial
Activity
(FIGURE 2: BULK "OIL" FACILITIES &SITE DRAINAGE MAP
CPI - USA North Carolina
1281 Powerhouse Drive
Southport, Brunswick County, NC
coal
Starnge
Area
No
Industrinl
Activity
0 125 250 FT
No
Sndusirinl
Activity
Wastewnter
Hnsln
Coot ��
I �
I �
rsl
R Car
L(q 1 Unloading Are
14
Tru k
nun 2
No
Industrial.
Activity
LEAF ENVIRONMENTAL
& ENGINEERING, P.C.
1426 E. NC HWY 54, STE C
DURHAM, NC 27713
480 RCP
[HITFALL UNDER RR
�005 TRACK
/ TO DUKE
ENERGY
OUTF — DISCHARGE
r13 DIC CANAL
auTFAL , LEGEND:
002 ,
Tx1
PROJECT NO.: 257019
DATE: December, 2019
DRAWN BY: KJK
APPROVED BY: TWM
FILE: CPI/Southport/SPPP
0
1) It Trap Pit (12,160-gal capacity)
2) Dlesel Fuel AST (265-gal)
3) Unloading Bay; Gasoline (30-gal) & Drum
Storage area
4) Neutrallzation Tank
5) Condensate Tank
6) Ash Silo
7) Limestone Silo
8) Trash Dumpsters
9) Miscellaneous Materlals
10) E.F.P Transformer (125-gal)
11) Two Diesel Fuel AST (1000-gal & 265-gal)
12) Wood, Ash, & Soil Piles
13) Indoor Chemical Storage
(Caustics & Flocculants)
14) Railroad Tie Crane/Chippers (200-gal) - By Others
15) Truck Dumper Hydraulic Oil Reservoirs (700-gal
& 320-gal)
16) Chipper Transformer (662-gal) - By others
17) Turbine Bldg,
- Lubrication system & Reservoirs (2 x 2000
gal)
EHC Controllers (2 x 80-gal)
18) Step-up Transformers (2 x 9750-gal)
Auxiliary Transformers (2 x 1090-gal)
19) Power transformers (2 x 77-gal)
20) it Storage Room (55-gal drums) (12 x GO -gat)
(1 x 150-gal)
21) Chipper Diesel Fuel AST (1750-gal) - By Others
-----------
Underground Pipe/Structure
Gravel Surface
— — —
Dralnage Area Boundary
H+HH+Hi+R+R+R+
Railroad Tracks
Belt Conveyor
Fenceline
8
Storm Drain
♦
Outfall Pipe
v
Overland Flow
SK
Spill Response Supplies
SCALE: AS SHOWN

Wastewater Treatment System Closure Plan
Capital Power Southport, NC Facility
NPDES Permit No. NC0065099
Introduction:
CPI USA North Carolina, LLC - Southport (CPI) is authorized under the NPDES Permit No. NC0065099 to
discharge treated coal pile runoff, fuel pile runoff from wood and tire derived fuel (TDF), low volume
wastewater, cooling tower blowdown, and reverse osmosis filter reject water via Outfall 003 (combined
flows from internal Outfalls 001, 002 and 004). Effective at midnight on March 31, 2021, the facility
ceased operations and CPI began the process of closing the facility. The facility closure is scheduled to
be completed during the third quarter of 2022.
The wastewater treatment system closure methodology outlined herein was developed based on the
requirements of NPDES Permit No. NC0065099. A summary of the permit requirements is provided
below.
NPDES Permit No. NC0065099, Part III Section D Facility Closure Requirements:
"The Permittee must notify the Division at least 90 days prior to the closure of any wastewater treatment
system covered by this permit. The Division may require specific measures during deactivation of the
system to prevent adverse impacts to water of the State. This permit cannot be seconded while any
activities requiring this permit continue at the permitted facility."
Closure Methodology:
The following closure steps will be completed for closure of CPI's wastewater treatment system.
1. Submit a Wastewater Treatment System (WWTS) Closure Plan to NCDEQ for review and
approval.
2. Officially notify NCDEQ at least 90 days prior to closure.
3. CPI and its contractors will eliminate all potential sources of wastewater from the areas that
drain to the wastewater basins that are delineated on the attached map. A summary of these
areas is presented below:
o Switch Yard
■ Owned/operated by Duke Energy -Progress and connected to the Oil Trap Pit.
■ Cut and cap the drain line from the Duke Power Switch Yard to the Oil Trap Pit.
o Rail Car Unloading
■ Confirm that no additional unloading events are scheduled.
o Wood Storage Area
■ Remove any residual wood.
o Coal Storage Pile
■ Remove any residual coal.
■ Backfill, rough -grade and seed, to minimize erosion caused by stormwater run-
off.
o Coal Stockout and Reclaim Conveyors
■ Remove any residual coal from the conveyor equipment.
o Active Coal Storage
Page 1 of 2

■ Remove any residual coal.
o Laydown Area
■ Confirm no potential pollutant sources exposed.
o Woodchip Pile
■ Remove any residual wood chips.
o Tire -Derived Fuel (TDF) Storage Area
■ Remove any residual TDF
o Oil Trap Pit
■ Remove oil from equipment in containment areas that discharge to the Oil Trap
Pit.
■ Remove any residual solids and oily wastewater from the Oil Trap Pit.
4. Clean the v-ditches leading to the WWTS.
5. Remove or cap pipelines leading to the WWTS.
6. Clean the WWTS basins.
o Remove residual solids and clean the basins.
7. Perform a visual inspection of the cleaned basins for significant cracks. If significant cracks are
found, investigate potential impact to soil in the area of the crack(s).
8. Disconnect the discharge pipe between the WWTS and Outfall 003 discharge point.
9. Notify NCDEQ of closure status and offer opportunity for site visit and confirmation inspection.
10. Break up the basins, backfill, and grade the site.
11. Notify NCDEQ of completion of the closure work, and request that the NPDES permit be
rescinded.
12. Prepare a written report documenting the closure work for record keeping purposes to include
photographs and a log of closure work.
13. Receive NPDES permit recission letter from NCDEQ.
Page 2 of 2