NC0004308_Fact Sheet_20170331

DEQ/DWR
AMENDED FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NC0004308
S'T TMMARY
Alcoa Inc. submitted a permit renewal application on August 30, 2012 for the Badin Works facility. The
current permit expired on February 28, 2013. Additional information on the permit application was
received on June 14 and August 26, 2013. This is a wastewater and stormwater permit developed jointly
with the Stormwater Permitting Program, Division of Energy, Mineral and Land Resources (DEMLR).
The Badin Works facility was operated as an aluminum smelter facility (SIC codes 3334 and 3365) until
July 2007 when it ceased operations. The facility no longer has discharges of process wastewater or
ancillary wastewaters. Domestic wastewaters are discharged to the Town of Badin WWTP. Some of the
buildings at the site have been demolished. Alcoa plans to redevelop the property for future industrial
uses. At present there is an electronic recycling facility operating at the site that doesn't contribute any
wastewater or stormwater discharges. Although the industrial operations ceased at the site, previous
activities contribute to pollutants of concern in the stormwater and/or groundwater runoff. Stormwater
runoff and infiltrated groundwater drains from the site through 10 outfalls. In addition, occasional fire
protection water is discharged through some of the. outfalls. Table 1 presents a description of all the
outfalls.
The site includes two offsite closed landfills, the Alcoa Badin Landfill (SWMU # 2) and the Old Brick
Landfill, SWMU #3 (Outfall 019). Seepage from SWMU #2 used to be discharged through outfall 021.
The seeps were connected to a pump station and rerouted to the Badin WWTP. Outfall 021 was
eliminated and closed. Seepage from SWMU #3 was previously discharged through Outfall 019. In 2007
SWMU #3 was covered with a compacted low permeable clay layer, a synthetic membrane liner and a
grass cover. A drainage system with toe -drains was installed over the liner to collect stormwater that
infiltrates through the grass cover. The stormwater that drains from the drainage system is collected in a
retention pond designed to infiltrate the collected water to the subsurface. Outfall 019 was retained for the
discharge of overflow from the retention pond.
Alcoa is currently conducting a Corrective Measures Study to address contaminated groundwater at the
site as required by the facility's RCRA permit. The Division of Waste Management is overseeing the
NC0004308 Fact Sheet
Page 1 of 21
Facility Information
A . licant/Facilit Name:
Badin Business Park LLC, (formerly Alcoa Inc.)/Alcoa Badin Works
A licant Address:
PO Box 576, Badin, NC 28009
Facility Address:
NC Hwy 740 & NCSR 1719, Badin NC
Permitted Flow:
N/A
Type of Waste:
Stormwater, Egundwater and fire protection water
Facility/Permit Status:
Renewal/Inactive Industrial Site
County:
Stant
Miscellaneous
Receiving Streams:
Badin Lake
UT Little Mountain
Creek
Stream
Classification:
WS -IV B CA (Badin Lake)
WS -IV (UT Little
Mountain Creek
303(d) Listed?
Yes
Regional Office:
Mooresville
HUC:
03040103/03040104
Permit Writer:
Teresa Rodriguez
State Grid / USGS Quad:
F18NE, F18NW Badin
& New London, NC
Date:
3/31/2017
S'T TMMARY
Alcoa Inc. submitted a permit renewal application on August 30, 2012 for the Badin Works facility. The
current permit expired on February 28, 2013. Additional information on the permit application was
received on June 14 and August 26, 2013. This is a wastewater and stormwater permit developed jointly
with the Stormwater Permitting Program, Division of Energy, Mineral and Land Resources (DEMLR).
The Badin Works facility was operated as an aluminum smelter facility (SIC codes 3334 and 3365) until
July 2007 when it ceased operations. The facility no longer has discharges of process wastewater or
ancillary wastewaters. Domestic wastewaters are discharged to the Town of Badin WWTP. Some of the
buildings at the site have been demolished. Alcoa plans to redevelop the property for future industrial
uses. At present there is an electronic recycling facility operating at the site that doesn't contribute any
wastewater or stormwater discharges. Although the industrial operations ceased at the site, previous
activities contribute to pollutants of concern in the stormwater and/or groundwater runoff. Stormwater
runoff and infiltrated groundwater drains from the site through 10 outfalls. In addition, occasional fire
protection water is discharged through some of the. outfalls. Table 1 presents a description of all the
outfalls.
The site includes two offsite closed landfills, the Alcoa Badin Landfill (SWMU # 2) and the Old Brick
Landfill, SWMU #3 (Outfall 019). Seepage from SWMU #2 used to be discharged through outfall 021.
The seeps were connected to a pump station and rerouted to the Badin WWTP. Outfall 021 was
eliminated and closed. Seepage from SWMU #3 was previously discharged through Outfall 019. In 2007
SWMU #3 was covered with a compacted low permeable clay layer, a synthetic membrane liner and a
grass cover. A drainage system with toe -drains was installed over the liner to collect stormwater that
infiltrates through the grass cover. The stormwater that drains from the drainage system is collected in a
retention pond designed to infiltrate the collected water to the subsurface. Outfall 019 was retained for the
discharge of overflow from the retention pond.
Alcoa is currently conducting a Corrective Measures Study to address contaminated groundwater at the
site as required by the facility's RCRA permit. The Division of Waste Management is overseeing the
NC0004308 Fact Sheet
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development of this study. At this time Alcoa has not yet identified measures to treat the contaminated
groundwater. Phase III of the study identified cyanide and fluoride as constituents of concern, in addition
trichloroethene (trichloroethylene; TCE) was detected in the groundwater at concentrations in excess of
the water quality standard along the northeast side of the plant site. The water quality standard for
trichloroethene is 2.5 gg/l, concentrations detected in the groundwater range from 19 to 86 µg/1. The area
where the trichloroethene was identified drains through outfalls 011 and 012. To evaluate if the
groundwater discharged from these outfalls is contaminated monitoring and limits for trichloroethene will
be included for outfalls 011 and 012.
RECEIVING STREAMS
Outfalls 002, 011, 012, 013, 020, and 019 discharge to Badin Lake, classified WS -IV, B, CA waters in the
Yadkin -Pee Dee River Basin, HUC 03040103. Badin Lake is listed in the 2012 303(d) list as impared for
fish consumption for PCB. Alcoa completed a PCB remediation project in Badin Lake in January 2013.
The project consisted of the installation of a cap over the contaminated sediment.
The Lake and Reservoirs Assessment for the Yadkin Pee Dee River Basin, March 2012, describes
conditions in Badin Lake. Badin Lake was sampled in 2011 for water quality parameters: DO, temp, pH,
total nitrogen, ammonia, total phosphorus and chlorophyll -a. DO was below the water quality standard in
September and pH was above the water quality standard in June.
Outfalls 004, 005, 017, and 018 discharge to a UT of Little Mountain Creek classified as WS -IV waters in
the Lake Tillery — Pee Dee River watershed, HUC 03040104. Little Mountain Creek is listed as impaired
for poor bioclassification.
NC0004308 Fact Sheet
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OUTFALLS DESCRIPTION
Table 1. Outfalls Description
Outfall
Receiving
ID Outfall Description
Stream
IWC
002 Prior to 2007
Non -contact cooling waters, groundwater, stormwater
Badin Lake
100%
and fire protection water.
(Yadkin River)
Latitude:
2007 After production
Stormwater, groundwater, fire protection water, and
350 24' 30"
shutdown
non -contact cooling and make-up water.
If the discharge consisted of only stormwater the outfall
Longitude:
was designated as S02.
80° 6' 57"
2013 Application
Stormwater onl
004 Prior to 2007
Non -contact waters, stormwater, groundwater, fire
UT to Little
100%
protection water
Mountain Creek
2007 After production
Fire protection water, groundwater and stormwater
shutdown
runoff.
Latitude:
If the discharge consisted of only stormwater the outfall
35° 24' 13"
was designated as SO4.
Longitude:
80° 7' 12"
2013 Application
Stormwater only
005 Prior to 2007
Non -contact cooling waters, compressor condensate,
UT to Little
100%
groundwater, stormwater and fire protection water.
Mountain Creek
After production shutdown
Fire protection water, groundwater, stormwater runoff
Latitude:
(2007)
and non -contact cooling water. If the discharge
35° 24' 8"
consisted of only stormwater the outfall was designated
Longitude:
_
2013 Application
as S05.
Groundwater,'stormwater and fire protection water
; 800 7' 17"
Prior to 2007
__[011
Overflow when outfall 012 exceeds diffuser capacity
Badin Lake
100
(see 012 description)
(Yadkin River)
After production shutdown
(2007)
2013 Application
012 Prior to 2007
(diffuser)
After production shutdown
(2007)
2013 Application
Overflow when outfall 012 exceeds diffuser capacity
(see 012 description). If the discharge consisted of onl
stormwater the outfall was designated as S 11.
012 overflow - Stormwater, groundwater and fire
protection water.
Non -contact cooling waters, compressor condensate
steam condensate. Area included the Alcoa landfill.
Latitude:
350 24' 42"
y Longitude:
80° 6' S5"
Badin Lake
(Yadkin River)
Latitude:
Fire protection water, groundwater and stormwater 350 24' 42"
runoff, non -contact cooling water condensate.
Stromwater from the former SWMU #22 area was
rerouted to this outfall in 2010. If the discharge
consisted of only stormwater the outfall was designated
as S 12.
Stormwater, groundwater and fire protection water.
NC0004308 Fact Sheet
Page 3 of 21
Longitude:
80° 6' 55"
4%
(chronic)
7%
(acute)

013
Prior to 2007
Stormwater, spring water, and groundwater drainage
from an area that includes a former Alcoa landfill site
(SWMUs #1 & 22).
After production shutdown Stormwater, spring water and groundwater In order to
(2007) I eliminate the potential for discharge of contaminants
from the SWMU #22 (Scrap Yard), Alcoa capped the
area and provided diversion structures to isolate the site
from any run-on flows. In 2010 the drainage channels
were lined, a barrier was installed in the roadway and
parking area, seal joints, and the stormwater flow from
the former SWMU #22 was rerouted to outfall 012. In
2011 Alcoa permanently removed and orphan line to
outfall 013 that was suspected of contributing fluoride to
the discharge.
2013 Application
019 Prior to 2007
After production shutdown
(2007)
2013 Application
017 Past and current
018 Past and current
020 ! Past and current
Badin Lake
(Yadkin River)
Latitude:
350 24' 52"
Longitude:
80° 7' 4"
Stormwater, spring water and groundwater
Groundwater seepage from Old Brick Landfill and
Badin Lake
stormwater
(Yadkin River)
In 2007 a new lining cover was installed over the
Latitude:
landfill, a drainage system was installed over the landfill
35° 24' 51"
cover. Stormwater draining from the grass surface and
the cover drainage system are collected in a retention
Longitude:
pond. The overflow from the pond is discharged through
800 6' 19"
outfall 019.
If the discharge consisted of only stormwater the outfall
was designated as S 19.
Pond overflow from the landfill cover drainage system
collection pond. (No contact with the landfill material)
Stormwater runoff
Stormwater runoff
Stormwater runoff
NC0004308 Fact Sheet
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1 100%
100%
UT to Little 100%
Mountain Creek i
Little Mountain 100%
Creek
Badin Lake 100%

PERMIT LIMITS DEVELOPMENT:
Cyanide and fluoride are parameters of concem (POC) due to historical operations at the site. Applicable
freshwater chronic water quality standards are 5 gg/l for cyanide and 1.8 mg/1 for fluoride. The Division
has not adopted acute water quality standards for either of these POC. By federal regulations the Division
has to implement limits to protect for both acute and chronic impacts. Acute limits are determined using
the %2 Final Acute Value (FAV). In 2000 the Division calculated'/2 FAV for cyanide as 22 µg/1 for trout
waters and 46.6 µg/1 for non -trout waters. The Division proposes to use the non -trout value of 46.6 µg/1
as the acute value for cyanide. At the time the current fluoride water quality standard of 1.8 mg/l was
calculated, the Division also calculated a %2 FAV of 7.8 mg/l for trout waters and 23.9 mg/l for non -trout
waters. The Division proposes to use 24 mg/1 as the acute value for fluoride.
Table 2. Water Quality Criteria
POC % Final Acute
Values on -Trout)
Chronic
Criteria
Cyanide
46.6 a/1
5 t /l
Fluoride
24 mg/1
1.8 mg/1
The existing limit for cyanide of 434 µg/1 daily maximum at outfall 012 was derived using a lh FAV of 31
gg/l which was the number calculated at that time using the most current data. Since the diffuser was
designed to achieve an initial dilution of 14:1 the dilution factor of 14 was applied to the % FAV to arrive
at the daily maximum limit.
The diffuser at outfall 012 extends 300 feet from shore at a depth of approximately 20 feet with one port
1.5 inch in diameter. The Division ran a CORMIX model in 1994 using these design parameters. The
diffuser provides rapid mixing within a short distance of the outfall. The initial dilution is 14:1 which was
used to determine acute limits. No chronic limits were established in the previous permit. As per 40 CFR
122.35 NPDES permits must have both monthly average limits and daily maximum limits. The Division
proposes to implement both daily max and monthly average limits using initial dilution of 14:1 to
determine acute limits and 26:1 to determine chronic limits.
Table 3. CORMIX Results
Distance from
I
outfall Dilution WC
0.7 ft 14:1 7%
2.6 ft 26:1 3.8%
Using the applicable dilution factors and %2 FAVs the proposed limits for outfall 012 are as follows:
Cyanide:
Daily maximum limit: use current limit of 434 gg/l
Monthly average limit = 5 x 26 = 130 gg/l
Fluoride:
Allowable daily maximum limit = 24 x 14 = 336 mg/l
Allowable monthly average limit = 1.8 x 26 = 46.8 mg/1
Reasonable potential analysis evaluation for outfall 012 resulted in no reasonable potential to exceed
these limits therefore only monitoring will be required.
For remaining outfalls the proposed limits are based on the water quality standard and the %2 FAV without
the benefit of dilution.
Cyanide:
Daily maximum limit = 46.6 gg/l
NC0004308 Fact Sheet
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Monthly average limit = 5 gg/l
Fluoride:
Daily maximum limit = 24 mg/l
Monthly average limit = 1.8 mg/1
Total Residual Chlorine:
State water quality standard 17 µg/1
117:r� t1 . ►I\� 1171 CO7►10 0WhC
DMR data from January 2009 to March 2014 were reviewed. The current permit identifies each outfall with
two outfall numbers depending on the type of discharge: 1) stormwater and groundwater combined with
non -contact water and fire protection water or 2) stormwater. Requirements were different if the discharge
was stormwater or groundwater/non-contact/stormwater. Outfalls denoted with S and the outfall number,
i.e. Outfall SO4, means that the discharge monitored was stormwater related.
Outfall 002 and Outfall 004:
Table 4. Outfall 002 DMR Data Summa ry
Parameter
Flow
Temperature
pH
TSS
Total Fluoride
TRC
Units
MGD
°C
SU
mg/l
mg/1
gg/l
Limit/Monitor
Monitor
Monitor
6-9
30/60
Monitor
Monitor
Fre uency
Weeklv
2 x month
2 x month
2 x month
Monthly
Monthly
W S
semi-annual
—RVS
1.8 mg/7
17 /l
Average
0.029668
17.9
7.3
6.7
2.7
62.5
Max
0.252
29.1
8.9
45
9.6
261
Min
0.000014
5.9
6.1
< 5
< 1
<10
# samples
334
110
119
103
62
51
Table 5. Outfall SO4 DMR Data Summary
Proposed changes Outfalls 002 and 004:
These outfalls no longer discharge groundwater, only stormwater is discharged. To maintain consistency with
NPDES stormwater permitting practices these two outfalls will be moved to the stormwater section with outfalls
017, 018 and 020.
Outfall 005:
Compliance: A Notice of Violation (NOV) was issued for an exceedance of the daily maximum limit for
pH in December 2012. The permit requires chronic toxicity at 90%. Three toxicity failures were reported
NC0004308 Fact Sheet
Page 6 of 21
Total
Total
Parameter
Flow
TSS
Aluminum
Cyanide
Total Fluoride
Units
MGD
mg/1
mg/l
gg/1
mg/1
Limit/Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Frequency
semi-annual
semi-annual
semi-annual
semi-annual
semi-annual
—RVS
S ,ug/Z
1.8 mg/l
Average
0.053211
5.6
2.6
6
11.2
Max
0.448
8.5
5.5
10
17
Min
0.0008
< 5
0.68
< 5
6.2
# samples
44
7
10
9
8
Proposed changes Outfalls 002 and 004:
These outfalls no longer discharge groundwater, only stormwater is discharged. To maintain consistency with
NPDES stormwater permitting practices these two outfalls will be moved to the stormwater section with outfalls
017, 018 and 020.
Outfall 005:
Compliance: A Notice of Violation (NOV) was issued for an exceedance of the daily maximum limit for
pH in December 2012. The permit requires chronic toxicity at 90%. Three toxicity failures were reported
NC0004308 Fact Sheet
Page 6 of 21

one in 2012 and two in 2013. 48 out of 51 samples for cyanide were above the water quality standard. 45
out of 50 samples were above the water quality standard for fluoride.
RPA was performed for fluoride and cyanide. Both parameters have reasonable potential to exceed the
water quality standards.
fable 6. Outfall 005 DMR Data Summ urs
Proposed changes:
1. Since this outfall no longer discharges non -contact cooling water, temperature monitoring and Total
Suspended Solids (TSS) limits were removed from the monitoring requirements.
2. As a result of a reasonable potential analysis the permit includes fluoride limits of 1.8 mg/1 monthly
average and 24 mg/l daily maximum and cyanide limits of 5 µg/1 monthly average and 46.6 µg/1 daily
maximum. The limits will be effective three years from the issuance date of the permit.
Outfall 011:
Compliance: NOVs were issued for one exceedance of the daily maximum pH limit in December 2012
and one exceedance of the daily maximum cyanide limit in February 2010. The permit requires annual
acute toxicity testing. The facility passed all the toxicity tests for this outfall. RPA was performed for
fluoride and cyanide. Both parameters have reasonable potential to exceed the water quality standards.
Table 7. Outfall 011 DMR Data Summary
Oil &
Total
Total
Total
Total
Parameter
Flow
TSS
Temp
pH
TRC
Aluminum
Cyanide
Fluoride
Units
MGD
mg/l
°C
SU
µg/1
mg/1
µg/1
mg/1
Limit/Monitor
Monitor
30/60
32°C
6-9
Monitor
Monitor
Monitor
Monitor
Frequency
Weeklv
2/Month
2/Month
2/Month
Monthly
Monthly
Monthly
Monthly
WS
5
18
2.1
Max
17c/l
180
5,ugfi
1.8m/l
Average
0.074004
6.1
17.2
7.3
21
0.3
18
3.7
Max
0.774
40
25.5
10.1
87
2.9
140
26
Min
0.0005
< 5
9
6.4
< 10
< 0.2
< 5
1.4
# samples
451
114
138
154
56
67
76
67
Proposed changes:
1. Since this outfall no longer discharges non -contact cooling water, temperature monitoring and Total
Suspended Solids (TSS) limits were removed from the monitoring requirements.
2. As a result of a reasonable potential analysis the permit includes fluoride limits of 1.8 mg/1 monthly
average and 24 mg/l daily maximum and cyanide limits of 5 µg/1 monthly average and 46.6 µg/1 daily
maximum. The limits will be effective three years from the issuance date of the permit.
Outfall 011:
Compliance: NOVs were issued for one exceedance of the daily maximum pH limit in December 2012
and one exceedance of the daily maximum cyanide limit in February 2010. The permit requires annual
acute toxicity testing. The facility passed all the toxicity tests for this outfall. RPA was performed for
fluoride and cyanide. Both parameters have reasonable potential to exceed the water quality standards.
Table 7. Outfall 011 DMR Data Summary
DM - Daily Maximum
Proposed Changes:
1. As a result of a reasonable potential analysis the permit includes fluoride limits of 1.8 mg/1 monthly
average and 24 mg/l daily maximum. The 46.6 µg/l daily maximum cyanide limits will be maintained
in the permit. A new monthly average limit of 5 µg/l will be implemented for cyanide. The limits
will be effective three years from the effective date of the permit.
2. The draft permit includes quarterly monitoring for trichloroethene.
NC0004308 Fact Sheet
Page 7 of 21
Oil &
Total
Total
Parameter
Flow
TSS
pH
Grease
Cyanide
Fluoride
Units
MGD
mg/l
SU
mg/l
µg/1
mg/1
Limit/Monitor
Monitor
Monitor
6-9
Monitor
46.6 (DM)
Monitor
Frequency
Quarterly
Quarterly
Quarterly
Quarterly
Quarterly
Quarterly
WQS
5 ,ug/l
1.8 m /l
Average
0.070426
47.9
7.2
5
18
2.1
Max
0.278
180
9.8
6
170
10
Min
0.000144
< 5
6.2
< 5
< 5
< 1
# sam les
29
19
25
18
24
23
DM - Daily Maximum
Proposed Changes:
1. As a result of a reasonable potential analysis the permit includes fluoride limits of 1.8 mg/1 monthly
average and 24 mg/l daily maximum. The 46.6 µg/l daily maximum cyanide limits will be maintained
in the permit. A new monthly average limit of 5 µg/l will be implemented for cyanide. The limits
will be effective three years from the effective date of the permit.
2. The draft permit includes quarterly monitoring for trichloroethene.
NC0004308 Fact Sheet
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Outfall 012:
Compliance: The permit requires chronic toxicity testing P/F at 16%. The facility passed all the tests for
this outfall. RPA was performed for fluoride and cyanide. RPA results indicate the need for a cyanide limit
but not for fluoride.
Table 8. Outfall 012 DMR Data Summary
DM - Daily Maximum
Proposed changes:
1. TSS and Oil and Grease limits in old permit due to cooling water condensate, since no longer present,
monitoring requirements for Oil and Grease were removed, TSS monitoring remains.
2. Limit for cyanide was recalculated based on dilution provided by the diffuser and current %2 FAV. (See
Permit Limit Development Section above.) The Daily Maximum limit for cyanide of 434 µg/1 will be
retained from the previous permit. A cyanide monthly average limit of 130 µg/1 will be implemented
with a schedule of compliance of 3 years.
3. The draft permit includes quarterly monitoring for trichloroethene.
Outfall 013:
Compliance: The weekly average limit for fluoride was exceeded five times resulting in three enforcement
cases and two NOVs during 2010-2011. In February 2011 Alcoa removed a line tributary to this outfall
suspected to contribute to elevated levels of fluoride. Since January 2011 values for fluoride have
significantly reduced with most values under the detection limit. The current permit requires acute toxicity
24 hr P/F at 90%. The facility passed all the toxicity tests for this outfall. RPA was performed for fluoride
and cyanide. Cyanide has reasonable potential to exceed the water quality standards.
Table 9. Outfall 013 DMR Data Summary
Oil &
Total
Total
Total
Total
Total
Parameter
Flow
TSS
Grease
pH
TRC
Aluminum
Cyanide
Fluoride
Units
MGD
mg/l
mg/1
SU
µg/l
mg/l
µg/1
mg/l
1.8 mg/l
434 µg/1
Fre uenc�
Limit/Monitor
Monitor
30/60
30/60
6-9
Monitor
Monitor
(DM)
Monitor
Frequency
Weekly
2/Month
2/Month
2/1V4onth
Monthlv
Monthly
Monthly
Monthly
W S
1.4
Max
0.753
13
17 R /1
1
5 li.igll
1.8 m /Z
Average
0.005624
6.1
< 5
7.3
24
0.5
67
6.5
Max
0.0563
26
9.5
8.2
71
3.1
290
29
Min
0.000001
< 5
< 4.6
6.4
<10
< 0.2
< 5
< 1
# samples
438
116
114
146
46
64
114
68
DM - Daily Maximum
Proposed changes:
1. TSS and Oil and Grease limits in old permit due to cooling water condensate, since no longer present,
monitoring requirements for Oil and Grease were removed, TSS monitoring remains.
2. Limit for cyanide was recalculated based on dilution provided by the diffuser and current %2 FAV. (See
Permit Limit Development Section above.) The Daily Maximum limit for cyanide of 434 µg/1 will be
retained from the previous permit. A cyanide monthly average limit of 130 µg/1 will be implemented
with a schedule of compliance of 3 years.
3. The draft permit includes quarterly monitoring for trichloroethene.
Outfall 013:
Compliance: The weekly average limit for fluoride was exceeded five times resulting in three enforcement
cases and two NOVs during 2010-2011. In February 2011 Alcoa removed a line tributary to this outfall
suspected to contribute to elevated levels of fluoride. Since January 2011 values for fluoride have
significantly reduced with most values under the detection limit. The current permit requires acute toxicity
24 hr P/F at 90%. The facility passed all the toxicity tests for this outfall. RPA was performed for fluoride
and cyanide. Cyanide has reasonable potential to exceed the water quality standards.
Table 9. Outfall 013 DMR Data Summary
WA - Weekly Average
NC0004308 Fact Sheet
Page 8 of 21
Total
Total
Paraineter
Flow
TSS
pH
Aluminum
Cyanide
Total Fluoride
Units
MGD
mg/l
SU
mg/1
µg/l
mg/l
Limit/Monitor
Monitor
30/60
6-9
Monitor
Monitor
1.8 mg/l
(WA)
Fre uenc�
Weekh
2/Month
2/Month
Monthly
Monthly
Monthlti'
W S
5 ygll
1.8 mg/l
Average
0.0243
5.3
7.6
0.3
9
1.4
Max
0.753
13
8.5
1
170
7.2
Min
0.000360
< 5
6.2
< 0.2
< 5
0.16
# samples
504
120
150
66
119
137
WA - Weekly Average
NC0004308 Fact Sheet
Page 8 of 21

Proposed changes:
1. As a result of a reasonable potential analysis the permit includes cyanide limits of 5 µg/1 monthly
average and 46.6 µg/1 daily maximum.
2. Modified WET test from pass/fail limit to acute monitoring quarterly test.
Outfall 019•
Compliance: There was one sampling event reported for each Outfall 019 and 19S. One sample for cyanide
was above the water quality standard, but less than the accepted lab detection level.
Tahle 10 Outfall 019 DMR Data Summary
Outfall 019
Total
Total
Total
Parameter
Flow
TSS
pH
Aluminum
Cyanide
Fluoride
Units
MGD
mg/l
SU
mg/l
n/l
mg/l
Limit/Monitor
Monitor
Monitor
6 - 9 SU
Monitor
Monitor
Monitor
Frequency
Quarterly
Quarterly
Quarterly
Quarterly
Quarterly
Quarterly
W S
S ugq
5 ,ug/l
1.8 mg/l
1/22/2010
0.001440
9.0
6.1
3.0
5.9
< 1
# samples
1
1
1
1
1
1
Outfall S19
0.008
28
8
< 5
< 1
0.39
Limit/Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Frequency
Semi-
Semi-
Semi-
Semi-
Semi-
Semi-
annually
annually
annually
annually
annually
annually
12/25/2009
0.034600
14.0
7.5
3.8
< 5
< 1
# samples
1
1
1
1
1
1
Proposed changes:
1. Permit this outfall as stormwater overflow from pond with semi-annual monitoring.
Stormwater Outfalls 017, 018 and 020:
Outfall 017:
Table 11. Outfall 017 DMR Data Summary
NC0004308 Fact Sheet
Page 9 of 21
Total
Total
Total
Parameter
Flow
COD
TSS
Cyanide
Fluoride
Aluminum
Units
MGD
mg/1
mg/1
µg/1
mg/1
mg/1
Limit/Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Frequency
Annual
Annual
Annual
Annual
Annual
Annual
F S
S ugq
1.8 t71f;/l
Average
0.0247
88
9.6
5.2
< 1
0.6
Max
0.038
210
14
5.8
< 1
0.99
Min
0.008
28
8
< 5
< 1
0.39
# samples
4
4
4
4..--4
4
NC0004308 Fact Sheet
Page 9 of 21

n», -fall m A.
Table 12. Outfall 018 DMR Data Summary
Parameter
Flow COD
Units
MGD mg/l
Limit/Monitor
Monitor
Frequence_
Annual Annual
TSS
mg/1
Monitor
Annual
Cyanide
gg/l
Monitor
Annual
5
Fluoride
Aluminum!
mg/1
mg/l
Monitor
Monitor
Annual
Annual
1.8 m,-F/l
Average
Max
Min
# samples
0.0247
0.038
0.008
4
88
210
28
4
9.6
14
8
4
5.2
5.8
< 5
4
< 1
< 1
< 1
4
0.6
0.99
0.39
4
Outfall 020:
Table 13. Outfall 020 DMR Data Summa
1-,v
Flow
COD
TSS
Total
Total
Total
Parameter
Cyanide
Fluoride
Aluminum
Units
MGD
mg/l
mg/l
gg/l
mg/l
mg/l
Limit/Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Monitor
Frequence
Annual
Annual
--
Annual
—
Annual
Annual
Annual
WQ
5 ,ug/l
I.8 mg/l
Average
0.058
66
18.5
5.3
<1
0.88
Max
0.09
110
54
6.5
< 1
2.7
Min
0.018
33
<5
<5
< 1
<0.2
# samples
4
4
4
4
4
4
The requirements for stormwater outfalls were modified to be consistent with current stormwater permit
requirements and practices. Outfalls 002 and 004 will be reclassified as stormwater outfalls and grouped
under the same section as 017, 018 and 020.
SUMMARY OF PROPOSED CHANGES:
1. Updated stormwater permit conditions for consistency with current stormwater permitting
practices.
2. Outfalls 002 and 004 were included under the stormwater section.
3. As a result of a reasonable potential analysis monthly average and daily maximum limits for
cyanide and fluoride were added to outfall 005. A schedule of compliance of 3 years was
included for the new limits.
4. The limits for TSS and temperature and TRC monitoring were removed from the monitoring
requirements for outfall. 005 since there is no discharge from cooling waters or condensates.
NC0004308 Fact Sheet
Page 10 of 21

5. As a result of a reasonable potential analysis monthly average and daily maximum limits for
fluoride and a monthly average limit for cyanide were added to outfall 011. A schedule of
compliance of 3 years was included for the new limits.
6. Oil and grease was removed from the monitoring requirements for outfall 011 since there is no
discharge from cooling or condensate waters.
7. As a result of a reasonable potential analysis monthly average limit for cyanide was added to
outfall 012. A schedule of compliance of 3 years was included for the new limits.
8. TSS and Oil and Grease limits and Total Residual Chlorine monitoring were eliminated from
outfall 012. Monitoring for TSS will remain a requirement for this outfall.
9. Added quarterly monitoring for trichloroethene for outfalls 011 and 012. Trichloroethene was
detected in the groundwater at concentrations greater than the water quality criteria.
10. As a result of a reasonable potential analysis monthly average and daily maximum limits for
cyanide were added to outfall 013. A schedule of compliance of 3 years was included for the new
limits.
11. Limits for TSS were removed from the requirements for outfall 013. Monitoring for TSS will
remain a requirement for this outfall.
12. Special condition C.(5) Reopener Clause was added requiring the permittee to notify the Division
of any changes in wastewater characteristics or operations.
13. Special condition C.(6) was added describing requirements for electronic reporting of DMRs.
NC0004308 Fact Sheet
Page 11 of 21

FACT SHEET AMMENDEMENT #1
Following the public noticed from January 27, 2015 the Division received numerous public comments
many of them requesting a public hearing on the draft permit. A public hearing was held on July 1, 2015
at the Stanly County Commissioners Commons Meeting Room in Albemarle. As a result of comments
submitted during the public hearing comment period the Department determined that the permit will not
be finalized but a second draft will be issued for public notice and another round of public comments.
Changes to draft permit:
The following modifications to the January draft permit were implemented based on public comments
received during public hearing process and on Division's staff recommendations included in the Hearing
Officer Report, issued on September 30, 2015:
1. Schedule of compliance — the schedule of compliance for outfalls 005, 011, 012 and 013 was
removed from the permit.
2. Instream Monitoring — to determine if pollutants are migrating to Little Mountain Creek instream
monitoring was added to the permit. Parameters to be monitored include pH, total cyanide, total
fluoride, total lead and total arsenic. See Special Condition A. (6).
3. Trichloroethene (TCE) — As per hearing officer recommendations limits for TCE were added for
outfalls 011 and 012. Limits are based on EPA human health criteria published in July 2015. The
federal criteria is 0.6 gg/l. The proposed limit for Outfall 011 is 0.6 µg/1 since it discharges to
Badin Lake with no dilution. The proposed limit for outfall 012 is 15.6 µg/l which was calculated
based on the dilution factor of 26.
4. Priority pollutant analysis — to characterize the discharges and evaluate the presence of
contaminants in the groundwater/stormwater discharges a special condition was added to the
permit with requirements to submit a pollutant scan for outfalls 005, 011, 012 and 013 within a
year of permit effective date. See Special condition A. (7).
5. Added stormwater outfall 022 — during the site visit Division staff noticed there are two
stormwater outfalls draining stormwater from the cover of the landfill, one on the west of the
landfill which was previously denoted outfall 018 and one on the east of the landfill which was
not included in the permit. The permit includes an additional outfall identified as outfall 022 for
the east drainage channel. This outfall appears to discharge groundwater in addition to the
stormwater collected from the surface of the landfill. Monitoring requirements are included for
this outfall in condition A. (6).
6. Identifying non-stormwater outfalls - Condition B.(2)1(e) was modified and B.(2)1 (f) was added
to include additional investigation and reporting if non-stormwater flow is detected at stormwater
outfalls.
SCHEDULE FOR PERMIT ISSUANCE:
Draft Permit to Public Notice: October 14, 2015
Permit Scheduled to Issue: December 7, 2015
NC0004308 Fact Sheet
Page 12 of 21

FACT SHEET AMENDMENT #2
The Division of Water Resources (DWR) received comments on the revised draft permit public noticed
on October 14, 2015 form the Southern Environmental Law Center (SELL) on behalf of the Concerned
Citizens of West Badin Community and the Yadkin Riverkeeper, EPA Region 4, and Alcoa. No other
comments were submitted for this revised draft. Comments are summarized below followed by DWR's
response and proposed action in the final permit.
A. RESPONSE TO COMMENTS
I. SELC Comments
1. Waste Characterization. Broaden the scope of testing and waste characterization study to determine
extent of contamination from the Alcoa Badin landfill and the rest of the site.
Response: The Division of Waste Management (DWM) is the lead agency involved in the waste
characterization studies and remediation efforts focused on the Alcoa Badin landfill. The DWM has
completed a site investigation under the Superfund Section program focused on the Alcoa Badin landfill
to determine the extent of contamination. As a result of the recent site investigation, the DWM concluded
that the site qualifies for further evaluation as a candidate for EPA Superfund National Priorities List. It is
anticipated that the site will be addressed as a RCRA corrective action under the authority of the
Hazardous Waste Section. The DWR has participated with the DWM in collecting data for the site
investigation and will continue to collaborate and coordinate permitting efforts with the DWM.
The investigation results suggest that potentially contaminated groundwater was detected in the floodplain
adjacent to the landfill. Outfalls 018 and 022 are the two outfalls from the landfill. Outfall 018 was
classified in the permit as stormwater/groundwater outfall but outfall 022 was classified as stormwater
and grouped with the other stormwater outfalls in the permit. To further assess contribution from this
outfall the Division has implemented new monitoring requirements for both outfalls under the wastewater
outfalls section.
Monitoring on Little Mountain Creek was implemented with this permit to monitor water quality in the
stream. In addition, in the recently approved Water Quality Certification for the continued operation of
the hydroelectric dams DWR required monitoring of sediments from the Alcoa Badin Works Plant site to
the Narrows Dam for heavy metals, PCBs and PAHs.
2. Cyanide reporting. By treating the cyanide values with results of less than 10 gg/l as zero, DWR fails
to protect water quality and human health. The quantitation limit of 10 µg/l allows for the limit to be
exceeded and the monthly average to be skewed if all values are reported as zero.
Response: The footnote for cyanide was modified to require the use of sufficiently sensitive approved
methods for all the analyses. The following footnote will replace the footnote in the drat permit:
"The permittee shall use sufficiently sensitive test procedures approved under 40 CFR part 136 for the
analysis ofpollutants. A method is "sufficiently sensitive" when: (1) The method minimum level (ML) is
at or below the level of the effluent limit established in the permit for the measured pollutant or pollutant
parameter; or (2) the method has the lowest ML of the analytical methods approved under 40 CFR part
136 or required under 40 CFR chapter I, subchapter N or O for the measured pollutant or pollutant
parameter. The Permittee shall report on its Discharge Monitoring Reports the actual laboratory results
for each effluent sample tested. "
3. PCB limits. The permit contains no limits for PCB.
NC0004308 Fact Sheet
Page 13 of 21

Response: The permit includes a requirement for priority pollutant analysis for all wastewater outfalls
that includes testing for PCBs, if PCBs are found to be present above water quality standards in the
monitored outfalls, DWR would implement limits accordingly. In addition, Alcoa will be monitoring lake
sediments for PCBs under the Water Quality Certification.
4. TCE limits. Limits for TCE at outfall 012 are based on an outdated water quality model, the model
should be updated.
Response: The permit will include a Special Condition to require an update of the mixing zone analysis
for outfall 012. Limits will be adjusted accordingly.
5. Cyanide and Fluoride limits for stormwater outfalls. Outfalls 002, 004, 017, 018, 020, and 022
should have limits for cyanide and fluoride.
Response: The requirements for the stormwater outfalls included in the permit are developed by DEMLR
following stormwater permitting guidance and regulations. Since these outfalls only discharge in response
to storm events, monitoring requirements and other permit conditions are different than outfalls permitted
following NPDES wastewater guidance. Stormwater monitoring requirements follow a tiered response to
address pollutants in the stormwater.
6. Priority Pollutant Scan. Require a priority pollutant scan at every outfall.
Response: Priority pollutant scans will be required for all the wastewater outfalls (005, 011, 012, 013,
018 and 022). At this time DWR is not adding priority pollutant scans to stormwater outfalls. In addition,
the permit includes a priority pollutant scan for one downstream station in Little Mountain Creek.
7. Anti -degradation. The draft permit conflicts with the Anti -degradation policy in Federal and North
Carolina law. Little Mountain Creek and Badin Lake should be protected for all designated uses.
Response: Antidegradation analysis is reserved for new and expanding discharges, while this permit
action is for a renewal. There are more limits imposed in this permit renewal compared to the previous
permit, therefore surface water quality should improve. Badin Lake and Little Mountain Creek are
classified water supply, in implementing limits the Division applies the water quality standards and
criteria for water supply and human health to protect existing uses. There is also no basis for statements
claiming that this permit is likely to increase pollutant loading to the waterbodies.
8. Civils Rights Act/Environmental Equity Initiative. The draft permit does not comply with Title VI
of the Civil Rights Act. If the state takes action such as issuing a permit that disparately impacts people of
color additional remedy is provided through federal law. The permit doesn't adequately set limits or
monitoring for toxic pollutants, it's likely to have adverse and disproportionate impact on the local
community on the basis of race. The public process does not comport with the North Carolina
Environmental Equity Initiative. There should be a demographic data analysis on the fact sheet and
additional public outreach regarding the community's knowledge of waste in the landfill adjacent to the
permitted outfalls.
Response: This facility began aluminum smelting operations in 1917, and the site location was based on
availability of nearby hydropower supplied by dams on the Yadkin River. The NPDES permit is based
on protection of surface water quality standards. The permit limits are designed to protect for human
health and water supply. The proposed new permit limits for cyanide will reduce potential human health
impacts. The removal of the compliance schedule will also expedite compliance with surface water
quality standards. The Division has provided public comment opportunities for proposed actions
pertaining to this site. A public notice of the public hearing was placed in a local newspaper, and a public
hearing was held on this draft permit to obtain input from local citizens. The hearing was well attended by
NC0004308 Fact Sheet
Page 14 of 21

community groups and the nearby community residents. The community was given opportunities to
comment on this permit meeting the provisions of the law. DWM has also held public meetings in the
past to discuss RCRA activities at this site.
H. EPA Region 4 Comments
1. Cyanide. Investigate the use of other methods to analyze cyanide that have detection levels below the
water quality standard.
Response: DWR modified the footnote to require sufficiently sensitive approved method for the analysis
of cyanide and fluoride. The following footnote will replace the footnote in the drat permit:
"The permittee shall use sufficiently sensitive test procedures approved under 40 CFR part 136 for the
analysis of pollutants. A method is "sufficiently sensitive " when: (1) The method minimum level (ML) is
at or below the level of the effluent limit established in the permit for the measured pollutant or pollutant
parameter; or (2) the method has the lowest ML of the analytical methods approved under 40 CFR part
136 or required under 40 CFR chapter 1, subchapter N or O for the measured pollutant or pollutant
parameter. The Permittee shall report on its Discharge Monitoring Reports the actual laboratory results
for each effluent sample tested. "
2. Continuous outfalls. Clarify if outfalls 005, Ol 1 and 012 are continuous. If they are, according to 40
CFR 122.45(d)(1), outfall 011 and 012 should have both a monthly average and a daily maximum limit
for TCE. In the absence of acute criteria, a factor of 1.5 or 2 is often applied.
Response: Outfalls 005 and 012 are continuous. Outfall 011 is not continuous. The limits and sampling
requirements for outfall 011 were modified to reflect the non -continuous nature of the discharge. Samples
will be grab samples and the limits will be expressed as daily maximums.
Following EPA recommendations, the daily maximum limits for TCE for outfalls 011 and 012 will be
calculated based on a multiplication factor of 1.5.
3. Priority Pollutant Scan Outfall 019. Consider adding a priority pollutant scan at outfall 019.
Response: Outfall 019 discharge consists of stormwater overflow from the pond that collects runoff from
the cover of the closed old brick landfill. DWR retained the outfall in the permit although it is not covered
under stormwater regulations. This outfall doesn't discharge frequently and is not a concern for priority
pollutants. DWR will not add a priority pollutant scan at this time.
4. Priority Pollutant Scan Little Mountain Creek. Consider running a priority pollutant scan at
proposed monitoring locations in Little Mountain Creek.
Response: The Division agrees to require a priority pollutant scan for Little Mountain Creek. The
requirement was added to the instream monitoring requirements for Little Mountain Creek.
5. Reduction in monitoring frequency. Document rationale as to why the monitoring frequencies were
reduced at outfalls 005, 012, 013 and 018.
Response: DWR's policy on sampling for metals and toxicants is to implement monthly monitoring
when the toxicant requires a limit and quarterly when the toxicant does not require a limit. Quarterly
testing for 5 years provides sufficient data to preform reasonable potential at the time of permit renewal.
6. Mixing Zone analysis. Conduct an updated mixing study using background concentrations and up to
date mixing zone model. Collect water samples at the edge of the mixing zone.
NC0004308 Fact Sheet
Page 15 of 21

Response: A Special Condition was added to the permit to require a revision of the dilution model. The
instream monitoring requirements were modified to include Lake Badin at the edge of the mixing zone.
7. Reasonable potential analysis. RPA should include background concentrations.
Response: Under current procedures for RPA DWR doesn't use background data. The DWR ambient
monitoring program suspended monitoring for metals/toxicants several years ago to evaluate clean
sampling methods. DWR has minimal amount of data to use as background, a few data points for Little
Mountain Creek show cyanide and fluoride as less than detection in an upstream background location.
DWR has no data for Badin Lake to use in an RPA.
III. Alcoa Comments:
1. WET dilution outfall 012. Dilution for whole effluent toxicity test for Outfall 012 should match
dilution used to calculate the chronic limits (16% vs 3.8%).
Response: Until the dilution model is revised DWR agrees to use the chronic dilution of 26:1 (3.8 %
IWC). The WET test will be modified to reflect an IWC of 3.8 %.
2. Cyanide limit outfall 012. Cyanide daily maximum limit for outfall 012 was not calculated using the
dilution from the diffuser but was retained from previous permit. The previous limit was established using
trout water criteria, should be non -trout water criteria.
Response: The limit of 434 µg/1 in the current permit was calculated in 1989 using the calculated %2 FAV
of 31 µg/1. The Division subsequently revised the acute criteria for cyanide and established a %2 FAV for
non -trout waters of 46.6 µg/1. DWR agrees to modify the acute daily limit using the dilution factor of
14:1 and the non -trout criteria of 46.6 µg/1 as it was also used for other outfalls. The applicable daily
maximum limit is 652 µg/1.
3. Schedule of Compliance. Reinstate schedule of compliance for cyanide and fluoride limits.
Response: Based on public concerns, the Department withdrew the compliance schedule for outfalls 005,
011, 012, and'013. Alcoa can employ other mechanisms for attaining compliance with new limits such as
a special order by consent (SOC). This is a more appropriate mechanisms than addressing the non
compliance with a schedule of compliance in the permit as the SOC is designed to address compliance
issues and track schedules and fines. Alcoa was aware that water quality standards were exceeded at most
outfalls for several years and has indicated that studies had been started some time ago to identify the
sources and develop an action plan. These efforts can be included in the special order.
4. Instream monitoring. Reduce number of monitoring stations on Little Mountain Creek from five to
two.
Response: The instream monitoring locations were modified to coincide with stations monitored under
the CERCLA study. The three stream channels in the area below the landfill were added as monitoring
locations. Little Mountain Creek stations were reduced to three, one upstream of the landfill, one
downstream of the landfill but before the confluence with the tributary and one downstream below the
confluence with the tributary.
5. TCE. Delete TCE limits from outfalls 011 and 012, there is no data to show RP. Change permit
parameter to trichloroethylene. Use NC criteria vs federal criteria.
Response: DWR does not agree to remove the limits for TCE. The data indicated concentrations as high
as 86 µg/1 in groundwater. The Division agrees to modify the limit using the state water quality standard
of 2.5 µg/1 and to use the alternative name of trichloroethylene.
NC0004308 Fact Sheet
Page 16 of 21

6. Cyanide limit. Change total cyanide limits to free cyanide.
Response: North Carolina adopted a freshwater cyanide water quality standard of 5 µg/1 for protection of
aquatic life. The North Carolina water quality standard to protect for aquatic life is expressed as total
cyanide. EPA recently published updated human health criteria for cyanide for consumption of water and
for consumption of organisms. Human health criteria applicable for water supply waters is 4 µg/1.
Although the reference doses EPA used were for free cyanide, the criteria is expressed as total cyanide.
Since the NC water quality standard is expressed as total cyanide and the new EPA human health criteria
is also expressed as total cyanide, the limit in the permit is expressed as total cyanide.
7. WET test at outfall 011. Change whole effluent toxicity test for outfall 011 from quarterly to annual.
Response: DWR does not agree to change the test from quarterly to annual. The quarterly chronic test
for outfall 011 was implemented to be consistent with outfalls 005 and 013 since they are all classified as
discharges of groundwater and stormwater.
8. Outfall 001 Limits. Change limits and sample type for outfall 011 from chronic to acute since this
outfall is not continuous.
Response: DWR agrees to change the monitoring requirements for this outfall as it is not continuous.
Sampling type was modified to grab for all parameters. Limits were modified to acute limits as daily
maximums.
9. Outfall 019. Delete outfall 019, the discharge is not related to industrial activities.
Response: The Division does not agree to delete outfall 019. There is limited discharge data for this
outfall. In addition, EPA suggested more monitoring. Although the monitoring suggested by EPA is not
been implemented now, once more data is collected during this permit cycle the Division will reconsider
removing the outfall.
10. Representative outfalls. Representative outfall for outfalls 018 and 022
Response: DEMLR does not agree to grant representative outfall status to outfalls 018 and 022 at this
time. As a result of the CERCLA site investigation Outfalls 018 and 022 will be reclassified to
groundwater/stormwater and new monitoring requirements applied.
11. WET test frequency reduction. Reduce toxicity test frequency if performance criteria is
demonstrated.
Response: DWR does not agree to the reduction in monitoring for toxicity testing. Quarterly sampling is
the minimum required frequency for the EPA approved test procedures.
12. Compliance schedule stormwater outfalls. Include a compliance schedule for stormwater outfalls
Response: DEMLR does not agree to a schedule of compliance. The Tiered approach in the stormwater
section is comparable to a built-in compliance schedule for stormwater pollutants.
B. ADDITIONAL MODIFICATIONS TO PERMIT
I. DWM Investigation
NC0004308 Fact Sheet
Page 17 of 21

The Division of Waste Management finalized the report for the Special Investigation (SI) of the Alcoa
Badin Landfill on June 14, 2016. The main focus of the investigation was to evaluate possible migration
of contaminants from the landfill seepage collection system to groundwater, adjacent wetlands, and/or
surface water.
Monitoring results revealed the presence of cyanide and fluoride in the stream channels on the floodplain
adjacent to the landfill seep collection systems. Fluoride was detected in Little Mountain Creek samples at
levels below the water quality standards. Cyanide and fluoride were detected in the wetland and in one of
the drainage channels suggesting that groundwater could be migrating from the landfill into the wetland
area. The eastern channel where groundwater was observed is below outfall 022. Given the results of the
SI the Division will require additional monitoring for Outfalls 018 and 022 and applying effluent
monitoring requirements similar to the other non-stormwater outfalls. In addition, instream monitoring
requirements were added for the three stream channels below the landfill.
Proposed monitoring for Outfalls 018 and 022:
Parameter
I Monitoring Requirement
Flow
_Monthly Monitoring
Total Suspended
Quarterly Monitoring
Solids
Total Cvanide
Quarterly Monitorin}7
Total Fluoride
Quarterly Monitoring
pH
Monthly Monitoring
j Acute toxicity
Quarterly Monitoring
II. Little Mountain Creek Monitoring
Alcoa recently completed the installation of a slurry wall and new leachate collection system at the base
of the landfill. This project is expected to reduce or eliminate the infiltration of groundwater towards the
wetlands area. In order to evaluate the effect of the project the instream sampling in Little Mountain
Creek will be implemented as a monitoring study under a special condition in the permit. Special
condition A. (8) was modified to include the requirements for the study. After one year of data is
collected the data will be revised and evaluated to determine further actions and modifications to the
sampling plan.
III. Revised RPA
1. Outfall 005 — The RPA was revised to include TRC data. The RPA shows that a limit is necessary for
outfall 005. There is no dilution for this outfall therefore the daily maximum limit of 17 gg/l applies.
2. Outfall 012 — The RPA was revised to include TRC. The data shows no reasonable potential to exceed
the TRC standard. The dilution provided by the diffuser ensures that the water quality standard is not
exceeded.
C. SUMMARY OF PROPOSED PERMIT MODIFICATIONS
Comments from SELC
Broaden scope of
testing/waste
characterization
Permit Section Permit Action/Response
Part I ' No modifications are proposed.
Cyanide reporting value of A.1, A.2, A.3, Modified footnotes for outfalls 005, 011, 012 and 013 to
10 gg/l allows for limit A.4 require the use of the most sensitive method
exceedances and monthly
NC0004308 Fact Sheet
Page 18 of 21

average calculation is
skewed.
3 Add limits for PCB for all
outfalls
4 j Update Cormix model
A.1, A.2, A.3,
AA, A.5
C. (7) (new)
5 Add limits for cyanide and B.1
fluoride for stormwater
outfalls
6 Add PPA sampling for all A.1, A.2, A.3,
outfalls A.4. A.5
7 1 Anti -degradation I N/A
Civil Rights Act/NC N/A
Equity Initiative
No modifications are proposed. PCB data will be collected
through the PPA.
Added Special Condition C. (7). This conditions includes
requirements to revise the model within two years of permit
effective date.
No modifications are proposed. The stormwater section of the
permit follows stormwater permitting guidance.
No modifications are proposed. The permit will maintain PPA
requirements for Outfalls 005, 011, 012, 013, 018 and 022,
PPA will not be added for stormwater outfalls.
No modifications are proposed. Antidegradation analysis is
reserved for new and expanding discharges. The permit has
more stringent limits than the previous permit.
No modifications are proposed. This facility has been located
in Badin since it began operations in 1917. Public notice was
published in area newspapers and a hearing was held on the
draft permit to collect public comments. Other public meetings
were held in the past to discuss activities at the site.
Comments from EPA
Permit Section
Permit Action/Response
1
Investigate cyanide
A.1, A.2, A.3,
Modified footnotes for outfalls 005, 011, 012 and 013 to
detection limit
AA
require the use of sufficiently sensitive methods.
Outfall 005 is continuous, no changes are necessary.
2
Clarify if outfalls 005,
A.1, A.2, A.3
011, 012 are continuous or
Outfall 011 is not continuous, limits will be modified to daily
episodic
maximums and sample type to grab. Added TCE daily limit of
3.7 gg/1.
Outfall 012 is continuous, Added TCE daily limit of 97.5 µg/1.
TCE daily maximum limits were calculated based on a
A.7
multiplication factor of 1.5 as recommended by EPA.
3
Add PPA to outfall 019
No modifications are proposed. Only outfalls that discharge
A.6
groundwater and stormwater will be required to perform PPA.
4
Consider a PPA for
PPA was added for the downstream location for Little
instream locations in LMC
Mountain Creek.
5
Document rationale for
A.1, A.2, A.3,
Monitoring frequency were reduced according to DWR policy
monitoring frequency
AA
on metals sampling frequency. When a limit is required in the
reduction
permit as a result of RPA the parameter is monitored monthly.
When no limit is required quarterly monitoring is
implemented.
6 Update mixing C.(7) (new)
study/collect samples in
Lake
7 Include background
concentrations in RPA
RPA
Added Special Condition C. (7). This conditions includes
requirements to revise the model within two years of permit
effective date. Added instream monitoring requirements for
Lake Badin at the edge of the mixing zone.
No modifications are proposed. Current RPA procedures
doesn't use background data, DWR does not have current
instream data for metals.
NC0004308 Fact Sheet
Page 19 of 21

i
Comments from Alcoa Permit Section
Permit Action/Response
1 Modify outfall 012
C.3
DWR agrees to modify the toxicity test concentration to 3.8%
dilution for toxicity test
to be consistent with the procedure used to calculate the limits
from 16 to 3.8%
for this outfall.
2
Recalculate cyanide limit
A.3
_
DWR agrees to modify the cyanide limit using a chronic
for outfall 012 using non
dilution of 26:1 and the non -trout cyanide criterion of 46.6
trout criteria and chronic
µg/1. The previous permit limit was calculated with an
dilution
outdated cyanide criterion. The daily maximum cyanide limit
was modified to 652 1.
3 Reinstate schedule of
A.1, A.2, A.3, No modifications are proposed. Due to public concerns the
compliance
A.4 Department withdrew the schedule of compliance.
4
Reduce number of
A.8
The number of stations were not reduced but were modified,
monitoring stations in
new monitoring station were implemented in the channels
Little Mountain Creek
below the landfill.
5
Delete TCE limits
A.2, A.3
No modifications are proposed. The limits will remain in the
..........
permit.
6
Change total cyanide
A.1, A.2, A.3,
No modifications are proposed. The cyanide water quality
limits to free cyanide
AA
standard is expressed as total cyanide, therefore the permit has
to be expressed as total cyanide as well.
7 Reduce Outfall 011 testing
C.2 No modifications are proposed. Quarterly monitoring is the
frequency for toxicity test
minimum approved monitoring frequency.
from uarterly to annual
8 Change outfall. 011 chronic
A.2
As this is not a continuous discharge DWR agrees to
limits to acute
implement acute limits as daily maximum limits.
9
Change outfall 011 sample
A.2
DWR modified the sampling type from composite to grab.
type to grab
10
Delete outfall 019
A.5
No modifications are proposed at this time.
11
Representative outfall
B.1 No modifications are proposed at this time.
designation for outfalls
018 and 022
A.1, A.2, A.3, No modifications are proposed. Minimum sampling frequency
12
Reduce tox testing
frequency based on
A.4 is quarterly.
performance
13
Add compliance schedule B.1 No modifications are proposed. The stormwater requirements
for stormwater are designed to provide time for the facility to investigate and
develop management actions if pollutants are found to be
present in the stormwater outfalls.
Additional Modifications
Permit Section Rationale
1 Modify outfalls 018 and A. 5, A.7
A Special Investigation by the DWM noted that groundwater
022 effluent monitoring
was entering the ditches that discharge from the landfill area.
requirements
2
_
Special Study Little
A. 8
Instream sampling study to evaluate effect of slurry wall at
Mountain Creek
A. 1
bottom of landfill.
3
Added TRC limit to outfall
Reasonable potential to exceed the water quality standard.
005
NC0004308 Fact Sheet
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NPDES DIVISION CONTACT
If you have questions regarding any of the above information or on the attached permit, please contact
Teresa Rodriguez at 919-807-6387.
NAME: DATE: 5/2/2017
NC0004308 Fact Sheet
Page 21 of 21