NCG020256_COMPLETE FILE - HISTORICAL_20161020

CIO
STORMWATER DIVISION CODING SHEET
NCG PERMITS
PERMIT NO.
IV0,��5�
DOC TYPE
O-HISTORICALFILE
❑ MONITORING REPORTS
DOC DATE
❑ D b I � I b
YYYYMMDD

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
Gregory Taveras
The Quartz Corp USA
P.O. Box 309
Spruce Pine, NC 28777
Dear Mr. Taveras:
PAT MCCRORY
Gorerno+
DONALD R. VAN DER VAART
TRACY DAVIS
RECEIVED Dberror
October 18, 2016 oC r 2 0 2016
CENTRAL FILES
DWR SECTION
Subject: General Permit No. NCG020000
The Quartz Corp USA —Sullins -Wiseman
Mine
COC NCGO20256
Mitchell County
We received a request to modify the continuous flow measurement requirement (Footnote 7 to
Table 7 in the General Permit) from Mr. Benne Hutson of McGuire Woods on behalf of The Quartz Corp
on July 26, 2016. The request asserted that wastewater discharge points SW-002 and SW-003 at this
operation do not have continuous flow. Consequently, The Quartz Corp is asking NC DEMLR to remove
the continuous flow monitoring requirements at these discharge points.
The DEMLR Stormwater Program hereby approves the modification request to allow an
instantaneous grab sample of flow or alternative estimate of a daily flow rate (for example, using rainfall
amount, percent impervious area, and/or runoff coefficient to caiculate a daily flow rate in cfs from a
precipitation event) in lieu of a continuous flow measurement reading to fulfill the flow monitoring
requirement for the specified outfalls. Please maintain this letter for your records for the duration of
coverage under this General Permit. If circumstances of the outfalls at this site change in the future, you
must notify the Division.
In addition, Mr. Hutson's letter asked for clarification about why mining wastes are classified as
wastewater discharges. Any wastes (e.g., mine tailings) from the mining process that contacts stormwater
is considered wastewater. This determination is not U.S. EPA policy but rather is based on the definition
of "process wastewater" in federal regulations in 40 CFR 122.2: "any water which, during manufacturing
or processing, comes into direct contact with or results from the production or use of any raw material,
intermediate product, finished product, byproduct, or waste product."
Mr. Hutson's letter expresses concern about EPA's interpretation being based on data from
western U.S. mines "where mine face is more likely to be reactive and leach metals." Perhaps the
company's concern centers around mine face or mine excavation stormwater drainage instead of "mining
wastes." We know there has been confusion about what stormwater run-off at a mine is considered
wastewater, especially after renewal of the NCG020000 General Permit and EPA's intensified focus on
State of North Carolina I Environmental Quality I Energy, Mineral and I and Resources
1612 Mail Service Center 1512 N. Salisbury St. I Raleigh, NC 27699
919 707 9200 T

NCG0202S6 Modification Request
October 18, 2016
Page 2
industrial mineral mines. In particular, the question about whether mine excavation area rainfall drainage
should always be considered "mine dewatering" (and therefore wastewater) has come up.
In response, DEMLR's Stormwater Program developed a guidance document to assist regional
tt
staff and NCG02 permittees in determining which discharges at a mine operation are Stormwater and
which are wastewater (enclosed). This guidance is also available on our website. Note the Division
recognizes there is some ambiguity and debate about what qualifies as "mine dewatering" in the federal
regulations, and that there may be situations where mine excavation run-off does not clearly fit the
definition of mine dewatering in 40 CFR 436, which is specific to the type of mine.
The task is not always straightforward because there are different implementation possibilities
when considering the definition of "process wastewater" in 40 CFR 122.2, the definition of "stormwater
discharge associated with industrial activity" in 40 CFR 122.26 (b)(14), and "mine dewatering" definitions
in various sub -parts of 40 CFR 436. DEMLR,must apply a determination that is consistent with federal
requirements and expects the permittee to sample discharges accordingly. We hope this guidance helps
clear up the questions you have and better understand NC's Stormwater Program's rationale. if you have
questions about specific discharge outfalls at your site, please contact the Asheville Regional Office
Stormwater Program staff to arrange a site visit.
This permit modification does not affect the legal requirements to obtain other permits which
may be required by the Division of Energy, Mineral, and Land Resources, or permits required by the
Division of Water Resources (DWR), Coastal Area Management Act, or any other federal or local
governmental permit that may be required. If these monitoring modifications are unacceptable to you, you may apply sooner for an individual NPDES discharge permit.
If you have any questions concerning this modification, please contact Bradley Bennett at
telephone number [phone], or Bethany Georgoulias at telephone number [phone].
Sincerely,/�04 -
.I_,
f+�'o"
for Tracy E. Davis, P.E., CPM
cc: Benne C. Hutson, McGuire Woods
Todd Mickleborough, The Quartz Corp
Toby Vinson, DEMLR Land Quality Section
Shawna Riddle, DEMLR Asheville Regional Office
Linda Wiggs, DWR Asheville Regional Office
Kip Tyler, EPA Region IV NPDES Permitting and Enforcement Branch
Stormwater Program Files
DWR Central Files
State of North Carolina I Environmental Quality i Energy, Mineral and Land Resources
1612 Mail Service Center i 512 N. Salisbury St. I Raleigh, NC 27699
919 707 9200 , T

Guidance for determination of NPDES regulatory status of various discharges on a mine site (Active and Inactive Mines
Jun 3, 2016; NC DEQ Stormwater Program
Feature contributing
} :
.not -: }
Rule or permit citations;
to a discharge
Conditions and comments
-sw '' _
ww
:Feguiatecl
other guidance
1
Undeveloped areas at the site, w/o permitted
Other areas closed out and fully reclaimed, too.
-X;-,,
Excluded from stormwater def. in
mining activity
_
X.,
J=
40CFR122.26(b)(14)
2
Overburden stockpile
Not mixed with any mined materials or other wastewater
X
_ -
'overburden' at
drainage. Better when fully stabilized.
y
40CFR122.26(b)(14)(iii)
3
Soil borrow area drainage
Like a borrow area at a construction site.
nX
'
DEQ BPJ interp. of citation above.
4
Vehicle maintenance areas
Additional monitoring, if qualified by motor oil usage. If
X, E
r
Consistent w/other regulated activity
commingled with WW, discharge instead subject to
_
';<<,'
1'°
identified at 40CFR122.26(b)(14)(viii);
wastewater sampling; additional O&G sampling could be
`T 4 -
_
- ~'"
DEQ BPJ
recommended but not required•{ er current permit).
5
Equipment boneyards
,Xc„s?
' •
'refusesites'in 122.26(b)(14)
6
AST Secondary containment release
If uncontaminated.
; X_=. -
'tank farms' in 122.26(b)(14)
7
Access and haul roads, without dust control
Except: roads off -site are not regulated
•X,f : -_``:
" .'
X,"oFl=a,t8w �:
'access roads' in sw definition in
r•
�r'3
40CFRI22.26(b)(14)
8
Access and haul roads, with dust control, when
If just stormwater runoff from sprayed roads. OK to spray
X;" ' :- .;
'�" ,'
' = '.
Above citation plus DEQ BPJ for spraying
it's stormwater
with mine pit water as lonjas no significant or sustained
�3 ..: ..
-
_ ' ' M
a-
mine dewatering water for dust control.
flow, or discharge to surface waters results. Any
F_ ,'"
Inspector BPJ to determine if excessive
chemicals used should be approved and used in proper
1v;
w _
:; =
flow or potential WQ problem is basis
doses to prevent aquatic toxicity - refer to approved
for wastewater determination.
PAMS list or consult DWR Aquatic Toxicology Branch.
? "
9
Access and haul roads, with dust control, when
If recycled or process wastewater sprayed, or if spraying
_ ~,,
X1,
>: s•'
NPDES process ww definition at
it's wastewater
excessive enough to cause sustained flow or discharge to
�'
;
_% •'
40CFR122.2 plus DEQ BPJ on prudent
surface waters. Also wastewater if any chemicals applied
�'_-
;
protection for NC surface waters.
are not approved by DWR Aquatic Toxicology or are used
- .
Inspector BPJ to determine if spray
in amounts that may cause aquatic toxicity.
excessive.
10
Stormwater-only sediment basins
If no wastewater contribution (mine dewatering, process
X
`?;
Stormwater in: stormwater out DEQ BPJ
ww, flow from active mining area.)
w
11
Stormwater-only sediment basin cleaning spoil
Spoil may not impact wetlands.
X =
15A NCAC 2B .0231, NC wetlands
drainage
' -- `Z,'iF,_;
standards
12
Wastewater treatment or recycle basin cleaning
Includes basins that treat wastewater or mine
X
`-
Wastewater in: wastewater out, DEQ
spoil drainage
dewatering water.
BPJ
13
Processing plant: recycle water overflow or
Even if caused by rainfall or mixed with stormwater
_X
40CFR122.2 def. process ww;
process wastewater
runoff. Except: segregated areas that do not drain
- "- • =
r = - ._ _ -
plant yards' in stormwater definition at
wastewater would be stormwater, but these are rare.
:M seg.a ea
122.26(b)(14)
14
Final product stockpile drainage, when it's
For most construction materials including sand, gravel,
;X:
-
`?
final products' in stormwater def. at
stormwater
and stone; industrial sand.
'-5:"
.' °.'
40CFR122.26(b)(14)
15
Final product stockpile drainage, when it's
For some mineral mines where 'final' product is subject
r :'"`_ "
X
'.
'comes into direct contact
wastewater
to further processing; and if final product exposes
with --- intermediate product final
minerals, metals, or chemicals with aquatic toxicity or
product...' 40CFR122.2 Def. of process
other pollutant risk: DEQ may regulate as WW.
_
...t
wastewater,• DEQ BPJ
16
Mine 2�it dewatering, pumped or drained by
Including contributions from rainfall and groundwater.
X' "t `
4 : ' ` "
40CFR436.21, .31, and .41;
efforts of the operator
' =
"`
DEQ BPJ default for all mines
17
Mine 2Lit dewatering, via overflow due only to
DEQ considers these types of discharges, including those
TM_ '
-X' - ' -
'�= `
40CFR436.31 Construction sand & gravel
rain or groundwater seepage
from clay pits (not specified in regs), as regulated
sty. ,`
have effluent limits and "mine
wastewater. Except: such wet pit overflows from 436.21
X `" s
i stone wet
dewatering" includes wet pit overflows;
_
,to eW_'
. J1
436.41Industrial sand, same;

Guidance for determination of NPDES regulatory status of various discharges on a mine site (Active and4nactive Mines)
Jun 3, 2016; NC DEQ Stormwater Program
Feature contributing
- r _'
not
Rule or permit citations;
to a discharge
Conditions and comments
swt'
vvuv_" : ;
regulated
other guidance
Crushed Stone treated as stormwater, as long as not
DEQ BPJ for 436.21 Crushed stone
commingled with process generated wastewater.
_
narrower mine dewatering definition,
'
DEQ BPJ for clay.
18
Mine face / Mine excavation area drainage (not a
e.g., mining an area on a mountain side or sand mine
X
.'
DEQ BPJ; Def. of mine dewatering in
pit), when it's stormwater
excavation area(s). When water from the mine area is
."
40CFR436.21, .31, and .41. Situations
not "pumped, drained, or otherwise removed
where stormwater inside a mine is not
from the mine through the efforts of the mine
` '
intentionally routed out of the mine by
operator." But, often mine excavation area drainage
operator efforts.
will be wastewater per 19.
19
Mine face / Mine excavation area drainage (not a
e.g., active mining area on a mountain side or sand mine
_"
X ' ' "' '
" -
Consistent with mine dewatering ,
pit), when it's wastewater
excavation area(s). Any "water that is impounded
definition in citations above and 'direct
or that collects in the mine and is pumped,
;` tti ' .4=•
contact with'40CFR122.2 def. of process
drained, or otherwise removed from the mine
F
wastewater. Includes grading,
=
channeling, ditching, or outlet
through the efforts of the mine operator" is
construction intended to remove/drain
subject to effluent limitation guidelines. Also, mines
water from the active mining area. If
where mine face exposure results in significant risk to
_
f
exposure includes parameters not in
water quality standards (note, an individual permit may
�f.
NCG02 (metals, for example), a general
be required to monitor parameters not in NCG02).
F permit may not be appropriate.
20
Legacy structures at a closed out and reclaimed
And for closed out and fully reclaimed portions of an
X
Excluded from stormwater def. in
mine: e.g. stabilized overburden stockpiles,
operating site
40CFR122.26(b)(14); not included in
stormwater basins, and pit/quarry overflows
process wastewater definition at
40CFR122.2
21
Deemed permitted discharges
Subject to NC rule, but not this permit. 2T covers
15A NCAC 2H .0106(f)
discharges to the land surface.
-
15A NCAC 2T .0113(a)(15),(16)
Notes:
+ What is covered by NCGD2? Stormwater and wastewater discharges from construction materials quarries, mineral mines, and stand-alone processing plants associated with them;
and clay mines. What is not covered by NCG02? Discharges from tourist gem mines; brick manufacturing w/o clay pits (NCG07); coal, peat, oil & gas, metal mining, • DOT borrow
areas (NCS000250), in -stream sand dredging (NCG52); mine operations already covered under an individual discharge permit.
• Wastewater commingled with stormwater is regulated as wastewater. Even if the discharge is rainfall driven.
• Whether regulated with a permit under the NPDES program or not, mining discharges may not cause or contribute to a violation of an in -stream water quality standard. Bring
DWR RO Supervisor into loop if observed site conditions suggest the potential for a WQS violation.
• Whether regulated with a permit under the NPDES program or not, mining discharges or operations may not: drain wetlands due to dewatering in the mine; blow out wetlands
due to the volume of discharges; or damage wetlands with pollutants from the mine property. Bring DWR RO Supervisor into the loop if observed site conditions suggest the
potential for wetlands damage whether intentional or incidental/occidental.
• The receiving water classification may determine the numerical value of the stormwater benchmarks or the wastewater limitations. See permit text.
• What if continuous flow measurement of wastewater is impractical or overly burdensome, and discharge isn't pumped (no pump curves)? EPA has advised (3/24/2016) that
continuous flow meter may not be necessary or practical in all situations, especially where flow discharge is infrequent; DEQ regions can make accommodations to allow permittees
to use an alternative method to estimate discharge flows when appropriate. Consider that discharges to HQWs are subject to flow limits in the permit (based on NC WQS). Permit
footnote language came from NPDES WW permit standard language and has remained in NCG02 for several permit cycles; DEQ will revisit at renewal.
+ Limitation of authority: This quidance table is intended as an on -site aid for DEMLR inspectors and for permittees. It does not replace relevant NC law, federal and state rules,
i'
NC602 permit conditions, DEMLR policy, or DEMLR implementation precedent.

Energy, Mineral
and Land Resources
ENVIRONMENTAL QUALITY
October 18, 2016
Gregory Taveras
The Quartz Corp USA
P.O. Box 309
Spruce Pine, NC 28777
PAT MCCRORY
Gnerrnnr.
DONALD R. VAN DER VAART
TRACY DAVIS
Din -rim.
Subject: General Permit No. NCG020000
The Quartz Corp USA — Chalk Mountain
COC NCG020257
Mitchell County
Dear Mr. Taveras:
We received a request to modify the continuous flow measurement requirement (Footnote 7 to
Table 7 in the,General Permit) from Mr. Benne Hutson of McGuire Woods on behalf of The Quartz Corp
on July 26, 2016. The request asserted that wastewater discharge points chalk-002, chalk-003, and chalk-
004 at this operation do not have continuous flow. Consequently, The Quartz Corp is asking NC DEMLR to
remove the continuous flow monitoring requirements at these discharge points.
The DEMLR Stormwater Program hereby approves the modification request to allow an
instantaneous grab sample of flow or alternative estimate of a daily flow rate (for example, using rainfall
amount, percent impervious area, and/or runoff coefficient to calculate a daily flow rate in cfs from a
precipitation event) in lieu of a continuous flow measurement reading to fulfill the flow monitoring
requirement for the specified outfalls. Please maintain this letter for your records for the duration of
coverage under this General Permit. If circumstances of the outfalls at this site change in the future, you
must notify the Division.
P
In addition, Mr. Hutson's Ietter,asked for clarification about why mining wastes are classified as
wastewater discharges. Any wastes (e.g., mine tailings) from the mining process that contacts stormwater
is considered wastewater. This determination is not U.S, EPA policy but rather is based on the definition
of "process wastewater" in federal regulations in 40 CFR 122.2: "any water which, during manufacturing
or processing, comes into direct contact with or results from the production or use of any raw material,
intermediate product, finished product, byproduct, or waste product."
Mr. Hutson's letter expresses concern about EPA's interpretation being based on data from
western U.S. mines "where mine face is more likely to be reactive and leach metals." Perhaps the
company's concern centers around mine face or mine excavation stormwater drainage instead of "mining
wastes." We know there has been confusion about what stormwater run-off at a mine is considered
wastewater, especially after renewal of the NCG020000 General Permit and EPA's intensified focus on
State of North Carolina I Environmental Quality I Energy, Mineral and [and Resources
1612 Mail Service Center 1 512 N. Salisbury St, 1 Raleigh, NC 27699
919 707 9200 T

NCG020257 Modification Request
October 18, 2016
Page 2
industrial mineral mines. In particular, the question about whether mine excavation area rainfall drainage
should always be considered "mine dewatering" (and therefore wastewater) has come up.
In response, DEMLR's Stormwater Program developed a guidance document to assist regional
staff and NCG02 permittees in determining which discharges at a mine operation are stormwater and
which are wastewater (enclosed). This guidance is also available on our website. Note the Division
recognizes there is some ambiguity and debate about what qualifies as "mine dewatering" in the federal
regulations, and that there may be situations where mine excavation run-off does not clearly fit the
definition of mine dewatering in 40 CFR 436, which is specific to the type of mine.
The task is not always straightforward because there are different implementation possibilities
when considering the definition of "process wastewater" in 40 CFR 122.2, the definition of "stormwater
discharge associated with industrial activity" in 40 CFR 122.26 (b)(14), and "mine dewatering" definitions
in various sub -parts of 40 CFR 436. DEMLR must apply a determination that is consistent with federal
requirements and expects the permittee to sample discharges accordingly. We hope this guidance helps
clear up the questions'you have and better understand NC's Stormwater Program's rationale. If you have
questions about specific discharge outfalls at your site, please contact the Asheville Regional Office
Stormwater Program staff to arrange a site visit.
This permit modification does not affect the legal requirements to obtain other permits which
may be required by the Division of Energy, Mineral, and Land Resources, or permits required by the
Division of Water Resources (DWR), Coastal Area Management Act, or any other federal or local
governmental permit that may be required. If these monitoring modifications are unacceptable to you,
you may apply sooner for an individual NPDES discharge permit.
If you have any questions concerning this modification, please contact Bradley Bennett at
telephone number [phone], or Bethany Georgoulias at telephone number [phone],
Sincerely,
A4 ���
for Tracy E. Davis, P.E., CPM
cc: Benne C. Hutson, McGuire Woods
Todd Mickleborough, The Quartz Corp
Toby Vinson, DEMLR Land Quality Section
Shawna Riddle, DEMLR Asheville Regional Office
Linda Wiggs, DWR Asheville Regional Office
Kip Tyler, EPA Region IV NPDES Permitting and Enforcement Branch
Stormwater Program Files
DWR Central Files
State of North Carolina I Environmental Quality I Energy, Mineral and Land Resources
1612 Mail Service Center 1512 N. Salisbury St, I Raleigh, NC 27699
919 7079200 T

Guidance for determination of NPDES regulatory status of various discharges on a mine site Active and Inactive Mines
Jun 3, 2016; NC DEQ 5tormwater Program
Feature contributing
no_t ;'•°
Rule or permit citations;
to a discharge
Conditions and comments
`sw
w.w
3regulated •
other guidance
1
Undeveloped areas at the site, w/o permitted
Other areas closed out and fully reclaimed, too.
`X,'.'
Excluded from stormwater def. in
mining activity
k
40CFR122.26(b)(14)
2
Overburden stockpile
Not mixed with any mined materials or other wastewater
X
-
"''
'overburden' at
drainage. Better when fully stabilized.
40CFR122.26(b)(14)(iii)
3
Soil borrow area drainage
Like a borrow area at a construction site.
=X
DEQ BPJ interp. of citation above.
4
Vehicle maintenance areas
Additional monitoring, if qualified by motor oil usage. If
X
Consistent w/other regulated activity
commingled with WW, discharge instead subject to
identified at 40CFR122.26(b)(14)(viii);
wastewater sampling; additional 0&G sampling could be
DEQ BPJ
recommended but not required per current permit).
5
Equipment boneyards
X -
'refuse sites' in 122.26(b)(14)
6
AST Secondary containment release
If uncontaminated.
X'.
'tank forms' in 122.26(b)(14)
7
Access and haul roads, without dust control
Except: roads off -site are not regulated
CX '
X, off
'access roads' in sw definition in
road:-
40CFR122.26(b)(14)
8
Access and haul roads, with dust control, when
If just stormwater runoff from sprayed roads. OK to spray
:.X, •_.' - :'
-.7,
Abave citation plus DEQ BPJ for spraying
it's stormwater
with mine pit water as long as no significant or sustained
~.
_'
mine dewatering water for dust control.
flow, or discharge to surface waters results. Any
' ' `_•;
•,, ., i
Inspector BPJ to determine if excessive
chemicals used should be approved and used in proper
flow or potential WQ problem is basis
doses to prevent aquatic toxicity — refer to approved
for wastewater determination.
PAMS list or consult DWR Aquatic Toxicology Branch.
�^
~
r _,.
9
Access and haul roads, with dust control, when
If recycled or process wastewater sprayed, or if spraying
>:�.
X. =
NPDES process ww definition at
it's wastewater
excessive enough to cause sustained flow or discharge to
40CFR122.2 plus DEQ BPJ on prudent
surface waters. Also wastewater if any chemicals applied
._
a
:
protection for NC -surface waters.
are not approved by DWR Aquatic Toxicology or are used
g _
wti
ti y
Inspector BPJ to determine if spray
in amounts that may cause aquatic toxicity.
_
f'
excessive.
10
5tormwater-only sediment basins
If no wastewater contribution (mine dewatering, process
X. `
Stormwater in: stormwater out, DEQ BPJ
ww, flow from active mining area.)
11
Stormwater-only sediment basin cleaning spoil
Spoil may not impact wetlands.
:X.
=
1SA NCAC 2B .0231, NC wetlands
drainage
standards
12
Wastewater treatment or recycle basin cleaning
Includes basins that treat wastewater or mine
° 7:..
X :
L
Wastewater in: wastewater out, DEQ
spoil drainage
dewatering water.
`r' .,'. '
.+ -,
BPJ
13
Processing plant: recycle water overflow or
Even if caused by rainfall or mixed with stormwater
-
X
40CFR122.2 def. process ww;
process wastewater
runoff. Except., segregated areas that do not drain
- -
-
plant yards' in stormwater definition at
wastewater would be stormwater, but these are rare.
Xi.!eg:ama'
I` =`
122.26(b)(14)
14
Final product stockpile drainage, when it's
For most construction materials including sand, gravel,
X'
-
final products' in stormwater def. at
stormwater
and stone; industrial sand.
_
40CFR122:26(b)(14)
15
Final product stockpile drainage, when it's
For some mineral mines where 'final' product is subject
.
-X
s A`-
'comes into direct contact
wastewater
to further processing; and if final product exposes
_
with... intermediate product, final
minerals, metals, or chemicals with aquatic toxicity or
w L ,' r .-
product...' 40CFRi22.2 Def. of process
other pollutant risk: DEQ may regulate as WW.
wastewater, DEQ BPJ
16
Mine pt dewatering, pumped or drained by
Including contributions from rainfall and groundwater.
X
40CFR436.21, .31, and .41;
efforts of the operator
DEQ BPJ default for all mines
17
Mine F. Lit dewatering, via overflow due only to
DEQ considers these types of discharges, including those
Nr` '_
X ,
40CFR436.31 Construction sand &grave!
rain or groundwater seepage
from clay pits (not specified in regs), as regulated
a.+= .-;_
..
have effluent limits and "mine
wastewater. Except: such wet pit overflows from 436.21
'X-"""Shwa-'
'•
�:_ •;
dewatering" includes wet pit overflows;
.
'
stone wet
pkoverfiow
_
-
.��, -
- -
436.41 industrial sand, same;

Guidance for determination of NPDES regulatory status of various discharges on a mine site Active and Inactive Mines)
Jun 3, 2016; NC DEQ Stormwater Proqram
Feature contributing
not -.
Rule or permit citations;
to a discharge
Conditions and comments
sw
wW. '"
..regulated
other guidance
Crushed Stone treated as stormwater, as long as no
;,7.
DEQ BPI for 436.21 Crushed stone
commingled with process generated wastewater.
s
;. -
narrower mine dewatering definition;
DEQ BPI for clay.
18
Mine face / Mine excavation area drainage (not a
e.g., mining an area on a mountain side or sand mine
-X
DEQ BPI; Def. of mine dewatering in
pit), when it's stormwater
excavation area(s). When waterfrom the mine area is
40CFR436.21, .31, and .41. Situations
not "pumped, drained, or otherwise removed
where stormwater inside a mine is not
from the mine through the efforts of the mine
intentionally routed out of the mine by
operator." But, often mine excavation area drainage
,,�• �n
operator efforts.
will be wastewater per 19.
19
Mine face / Mine excavation area drainage (not a
e.g., active mining area on a mountain side or sand mine
X.'.
Consistent with mine dewatering
pit), when its wastewater
excavation area(s). Any "water that is impounded
definition in citations above and 'direct
or that collects in the mine and is pumped,
contact with' 40CFR122.2 def. of process
drained, or otherwise removed from the mine
wastewater. Includes grading,
channeling, ditching, or outlet
through the efforts of the mine operator" is
r
_
construction intended to remove/drain
subject to effluent limitation guidelines. Also, mines
' _ ` z
. _
water from the active mining area. If
where mine face exposure results in significant risk to
exposure includes parameters not in
water quality standards (note, an individual permit may
NCG02 {metals, for example}, a general
be required to monitor parameters not in NCG02).
-
permit may not be appropriate.
20
Legacy structures at a closed out and reclaimed
And for closed out and fully reclaimed portions of an
X -
Excluded from stormwater def. in
mine: e.g. stabilized overburden stockpiles,
operating site
40CFR122.26(b){14}; not included in
stormwater basins, and pit/quarry overflows
; ,
process wastewater definition at
40CFR122.2
21
Deemed permitted discharges
Subject to NC rule, but not this permit. 2T covers
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-
15A NCAC 2H .0106(f)
discharges to the land surface.
15A NCAC 2T .0113(a)(15),{16}
Notes.
What is covered by NCG02? Stormwater and wastewater discharges from construction materials quarries, mineral mines, and stand-alone processing plants associated with them,•
and clay mines. What is not covered by NCG02? Discharges from tourist gem mines; brick manufacturing w/o clay pits (NCG071,• coal, peat, oil & gas; metal mining,- DOT borrow
areas (NC5000250); in -stream sand dredging (NCG52); mine operations already covered under an individual discharge permit.
• Wastewater commingled with stormwater is regulated as wastewater. Even if the discharge is rainfall driven.
Whether regulated with a permit under the NPDES program or not, mining discharges may not cause or contribute to a violation of an in -stream water quality standard. Bring
DWR RO Supervisor into loop if observed site conditions suggest the potential for a WQS violation.
Whether regulated with a permit under the NPDES program or not, mining discharges or operations may not: drain wetlands due to dewatering in the mine; blow out wetlands
due to the volume of discharges; 'or damage wetlands with pollutants from the mine property. Bring DWR RO Supervisor into the loop if observed site conditions suggest the
potential for wetlands damage whether intentional or incidentallaccidento[.
• The receiving water classification may determine the numerical value of the stormwater benchmarks or the wastewater limitations. See permit text.
What if continuous flow measurement of wastewater is impractical or overly burdensome, and discharge isn't pumped (no pump curves)? EPA has advised {3/24/2016) that
continuous flow meter may not be necessary or practical in all situations, especially where flow discharge is infrequent; DEQ regions can make accommodations to allow permittees
to use an alternative method to estimate discharge flows when appropriate. Consider that discharges to HQWs are subject to flow limits in the permit (based on NC WQS). Permit
footnote language came from NPDES WW permit standard language and has remained in NCG02 for several permit cycles; DEQ will revisit at renewal.
• limitation of authority: This guidance table, is intended as an on -site aid far DEMLR inspectors and for permittees. It does not replace relevant NC law, federal and state rules,
NCG02 permit conditions, DEMLR policy, or DEMLR implementation precedent.