NCG140000_Factsheet to Notice_20170530

DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF ENERGY, MINERAL, AND LAND RESOURCES
FACT SHEET
GENERAL PERMIT NCG140000
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
PERMIT TO DISCHARGE STORMWATER AND WASTEWATER
Permit No. NCG140000 Date: April 19, 2017
(Revised May 16, 2017)
(Corrected May 30, 2017)
1. TYPES OF DISCHARGES COVERED
a. Industrial Activities Covered by this General Permit
NCG140000 General Permit Coverage is applicable to owners or operators of industrial
stormwater discharges and on -site vehicle maintenance area stormwater discharges associated
with ready -mixed concrete manufacturing activities [standard industrial classification (SIC)
32731, and authorized process wastewater discharges. Coverage is also applicable to
stormwater point source discharges from like industrial activities deemed by the Division of
Energy, Mineral, and Land Resources (DEMLR) to be similar to these operations in the process,
or the discharges, or the exposure of raw materials, intermediate products, by-products,
products, or waste products.
b. Types of Operations Covered
Ready -mixed concrete is a covered activity as per 40 CFR 122.26(b)(14). This General Permit
covers all on -site activities and features associated with the ready -mixed concrete
manufacturing activity. Covered industrial activities and site features may include, but are not
limited to: all industrial areas where stormwater contacts scales, receiving, staging, crushing,
mixing, screening, rejects piles, loading, and stockpiles of raw, intermediate, or finished
product, by-products and waste products. Also permitted are stormwater flows from on -site
vehicle and equipment maintenance areas. Additionally, the construction and operation of
process wastewater treatment facilities, and authorized process wastewater discharges (those
associated with vehicle and equipment cleaning, raw material stockpiles, and mixing drum
cleanout) are also permitted under this permit.
The following activities are specifically excluded from coverage under this General Permit:
Disposal of process wastewater not specifically designated in this permit, and disposal of any
concrete directly into stormwater conveyances, storm sewer outfalls, or into waters of the
state.
c. Characteristics of Discharged Stormwater and Wastewater
Page 1 of 17

The ready -mixed concrete industrial process includes the delivery and storage of raw materials
(aggregates including sand, gravel and/or crushed stone, Portland cement, ash, and water)
mixed at a centralized batch plant. Flows resulting from onsite activities include stormwater
that has contacted recycled crushed concrete, vehicle maintenance areas (VMA), and raw and
waste materials. Additionally ready -mixed concrete sites discharge process wastewater flows
associated with vehicle and equipment cleaning, raw material stockpile irrigation, and mixing
drum cleanout. Flows resulting from the manufacturing process activities and from contact with
on -site materials can be highly variable in pollutant strength.
Total suspended solids (TSS) and pH continue to be the primary pollutants of concern in
stormwater discharges associated with mining activities and related land disturbances at these
sites. Process wastewater discharges from these operations have similar pollutant
characteristics, and introduce a possibility for settleable solids (SS) impacts. TSS levels are of
special concern in HQW, ORW, Trout, and PNA-classified waters, and 15A NCAC 02B .0224 sets
special limits for wastewater discharges to these waters. Because of these two factors,
stormwater benchmarks and wastewater limits have been set at lower levels for discharges to
those receiving water classifications.
Stormwater— Ready -Mix Concrete Activities: TSS and pH remain primary indicators for
stormwater pollution introduced by ready -mix concrete activities. Both parameters assist in
establishing when elevated TSS and/or pH levels in -stream are the result of the facility's
discharges.
Stormwater— Vehicle Maintenance Activities (VMAs): Although the analysis is the same, the
parameter name "Total Petroleum Hydrocarbons (TPH)" for stormwater discharges associated
with vehicle maintenance has been replaced by "Non -polar Oil & Grease by EPA Method 1664
(SGT-HEM)." This description causes less confusion for permittees and their laboratories
because the request for "TPH" can be confused with more expensive gas chromatography tests
for this group of compounds. Non -polar O&G continues to be a useful indicator for targeting
petroleum -based oils and greases. DEMLR has retained the benchmark from the previous
permit. We would only expect levels to exceed that 15 mg/I in discharges with significant oil
contamination. Based on the relatively small number of mines that trigger the need to monitor
discharges from VMAs, and the few hits outside of the pH range of 6-9, the proposed
monitoring suite removes the requirement to monitor pH.
Wastewater —Process Wastewater:
Wastewater discharge parameters are the same as in the previous permit cycle. Federal
effluent guidelines, 40 CFR 411 establish total suspended solids (TSS) and pH effluent limits for
this industry. The federal limits for TSS and pH are 50 mg/I and 6.0-9.0, respectively. However,
as in the previous permit terms, this general permit sets the limit for TSS at 30 mg/I.
Contributions of settleable solids from wastewater discharges to sensitive waters remain a
concern in North Carolina, and therefore its wastewater limit remains in this permit. 15A NCAC
02B .0224 sets limits for the total volume of wastewater in HWQ-classified water bodies. As
Page 2 of 17

before, wastewater discharging to HWQ waters has been set at 50% of the summer 7Q10 flow.
This renewal changes the monitoring parameter from volume to a flow rate.
d. Geographic Area Covered by this General Permit
Discharges covered by this General Permit are located at any place within the political
boundary of the State of North Carolina. However, discharges located on the Cherokee Indian
Tribal Reservation are subject to permitting by the U.S. Environmental Protection Agency,
rather than DWQ, and are not eligible for coverage under this General Permit.
e. Receiving Waters
Receiving waters include all surface waters of North Carolina or municipal separate storm
sewer systems conveying stormwater to surface waters, with some notable exceptions. New or
expanding wastewater discharges to freshwater ORW-classified water bodies are prohibited in
North Carolina by 15A NCAC 2B .0225. Special limits may apply in areas draining to ORWs.
Other areas with water quality management plans may limit or prohibit new or expanding
wastewater discharges. NCG140000 will not cover wastewater discharges to these above -
mentioned water bodies. Some permittees may be able to receive individual permits for
wastewater discharges in areas draining to ORWs. Stormwater-only discharges to ORW-
classified waters may be allowed under NCG140000 with some provisions for new stormwater
discharges.
2. CONSTRUCTING AND OPERATION OF A TREATMENT FACILITY
An "Authorization to Construct" (ATC) permit for new or expanding wastewater treatment
facilities was once required by 15A NCAC 02H .0100 for the construction and operation of water
pollution control facilities necessary to comply with NPDES permit conditions. That
authorization had been incorporated into the NCG140000 General Permit to streamline the
permitting process. In 2011, Section 9 of Session Law 2011-394 eliminated the ATC
requirement for industrial wastewater treatment facilities (See Appendix A). The revised
permit contains significant revisions in Part II, Sections A and B that reflect the change.
Also now absent from the revised General Permit is the authorization to construct and operate
a Closed -Loop Recycle System (CLRS) that meets the requirements of the 15A NCAC 02T .1000
Rules. (Requirements for these recycle systems are driven by a State program and were not
impacted by SL 2011-394's changes to the State Statute.) Facilities that construct and operate
CLRS facilities must apply and obtain the necessary permits or approvals through the Non -
Discharge Permitting Program in the Division of Water Resources (DWR). This change was
prompted by the Stormwater Permitting Program's move out of DWR into DEMLR and helps
ensure appropriate Division oversight of these systems. Systems that are not designed as
closed -loop and have the potential to discharge to surface waters are still covered by
NCG140000.
Page 3 of 17

The Session Law did not remove authority for the Division to require that permittees notify the
DEMLR Regional Office in advance of operation of newly installed or expanded wastewater
treatment facilities. This directive remains a condition of this proposed permit (Part II, Section
A). The rationale is that this notification alerts NC DENR of potentially significant changes to
wastewater discharges and allows the opportunity for an inspection to verify compliance with
the NPDES permit.
3. PROPOSED DISCHARGE CONTROLS AND LIMITATIONS
a. Stormwater Pollution Prevention Plan
As in the previous version of this General Permit, stormwater pollution must be controlled
by the development and implementation of a Stormwater Pollution Prevention Plan (SPPP).
DEMLR continues to believe that effective control of the pollutant content in industrial
stormwater discharges can only be achieved when site management implements a written,
site -specific management plan serving that objective. The revised draft permit contains
several minor improvements in the SPPP largely related to improved clarity of language in
the permit text. See the draft permit for the proposed new version of the SPPP
requirements. All facilities covered under this General Permit must develop and implement
an SPPP.
b. Stormwater discharge analytical monitoring
As in the previous version of this General Permit, all permittees must perform twice -per -
year analytical monitoring of the stormwater discharges, must respond to any exceedances
of the numerical benchmark values for the monitored parameters, must keep records of the
monitoring results and the permittee's response actions, and must report the monitoring
results to DEMLR. As before, the permittee has the option of applying and obtaining
Representative Outfall Status (ROS) for one or more outfalls to reduce the obligation to
monitor all stormwater discharge outfalls (SDOs) on site. ROS designation is handled
outside of the permit and is not available for wastewater outfalls.
c. Stormwater discharges from vehicle maintenance areas (VMA)
As in the previous version of this General Permit and like most other industrial general
permits, permittees are required to separately monitor stormwater discharges originating
from site areas where vehicle maintenance activities are conducted. DEMLR's view
continues to be that monitoring discharges from qualifying vehicle maintenance areas
contributes to the prevention of stormwater pollution from those activities.
d. Qualitative (Visual) monitoring of stormwater discharges
As in previous versions of this General Permit, the permittee must perform twice -per -year
qualitative monitoring (visual monitoring) at all stormwater discharge outfalls. The
proposed revised permit no longer requires visual monitoring to coincide with the analytical
sample.
e. Numerical benchmarks and tiered response structure
Page 4 of 17

As in the previous version of this General Permit, the permittee must respond to benchmark
exceedances with increased monitoring, increased management actions, increased record
keeping, and/or the installation of stormwater BMPs in a tiered program. The exceedance
of a numerical benchmark is not considered a violation of the permit conditions, although
failure to respond as per the Tiered response structure would be. In that context, the
benchmark value is not a numerical 'permit limit', but rather a management action level
value. Four (4) benchmark exceedances require the permittee to notify the DEMLR
Regional Office, and may prompt additional requirements under the provisions of Tier
Three.
f. Wastewater discharge analytical monitoring and limitations
The draft permit specifies monitoring and reporting requirements for process wastewater
discharges. Effluent Guideline limitations for TSS and pH are mandated by 40 CFR §411, and
North Carolina Water Quality Standards in the 15A NCAC 213 .0200 rules limit total volume
discharge to High Quality Waters (HQWs) to 50 percent of the total in -stream flow of the
receiving water under 7Q10 conditions.
This draft permit proposes to (1) modify monitoring for only sensitive waters for settleable
solids (SS) and (2) reduce monitoring frequency from quarterly to semi-annually after year 1
if there are not limit exceedances during year 1.
4. MONITORING AND REPORTING REQUIREMENTS
This General Permit specifies monitoring and reporting requirements for both quantitative
(analytical) and qualitative (visual) assessment of the stormwater discharges, and operational
inspections of the entire facility. Sample parameters and sample frequency are based upon
pollutants potentially generated from ready -mixed concrete operations as reported in the
literature and in on -site monitoring reports from current DEMLR permittees. See section 1 c.
above.
The proposed monitoring and reporting requirements include the following changes:
The proposed permit has been restructured to remove authorization to construct (ATC)
requirements that are no longer applicable to this industry. In addition, authorization to
construct and operate a Closed -Loop Recycle System (CLRS) that meets design
requirements in the 15A NCAC 2T Rules is no longer included as part of this General
Permit. Explanation: The revised structure simplifies the permit and brings
requirements up to date with legislation passed in 2011 (See Appendix A). Because the
Stormwater Permitting Program has since moved out of the Division of Water Resources
(DWR), which administers the Non -Discharge Permitting Program, DEMLR concluded any
necessary reviews and approvals of Closed -Loop Recycle Systems should originate with
DWR.
Page 5 of 17

The proposed permit has updated language in the Stormwater Pollution Prevention Plan
(SPPP). Explanation: The revisions make the permit consistent with other more recently
updated general permits and attempt to reduce confusion.
The proposed permit also allows the permittee to forgo sampling if adverse weather
conditions prevent sample collection (see the Definitions section of the draft permit).
Inability to sample because of adverse weather conditions must be documented in the
SPPP, recorded on the data monitoring forms (DMRs), and DMRs submitted to DEMLR.
Explanation: DEMLR feels this is a reasonable accommodation and keeps the safety of
all employees in mind. The allowance mimics a similar provision in the EPA's 2015 Multi -
Sector Permit without the directive to take a "make-up" sample in the next monitoring
period. DEMLR routinely advises permittees to take a "make-up" sample if one is missed
during a period and plans to include this information in the final Technical Bulletin.
• The proposed permit also provides that the permittee is not required to sample runoff
events outside of the normal operating hours of the business (except in the case of
inactive facilities, as they are not operating but may still be bound to sampling
requirements —unless suspended by the Division's granting "dormant status.").
Explanation: DEMLR feels this is a reasonable accommodation and keeps the safety of
employees in mind. Also, since early 2012 the Division's Stormwater Permitting Program
has allowed NPDES stormwater permittees to avoid monitoring requirements under the
conditions of plant shut down or extended inactivity when no regulated industrial
activities were on -going. Dormant status is granted only upon the Division's inspection
of the facility, and concurrence that industrial activities have ceased and no remaining
threats to water quality exist from stormwater runoff. No wastewater generation or
discharges are allowed during the dormant status period.
• The proposed permit eliminates the requirement to record Event Duration and Total
Flow in stormwater discharges. Explanation: DEMLR has removed these parameters in
most NPDES stormwater permits over the last few years because run-off volume can be
estimated with total rainfall and drainage area (DA) percent imperviousness —
information contained in the SPPP for most industrial sites; there was little need for the
permittee to report event duration and flow (particularly because mass limits do not
apply). However, flow is still required though for discharges to waters classified as HQW
or ORW as per 15A NCAC 02B .0200.
• The proposed permit drops pH monitoring in stormwater discharges from vehicle
maintenance areas (VMA). Explanation: DEMLR observed that very few pH
measurements from VMA were outside of the benchmark range (See Appendix B) and
suggests that pH should not be considered a characteristic pollutant of concern for
vehicle maintenance areas in this industry. DEMLR has eliminated pH monitoring from
VMA monitoring for other industry sectors over the last couple of years based on
minimal added value to pollution prevention for runoff from these areas versus the rigor
of equipment calibration requirements and constraints of a 15-minute hold time. DEMLR
Page 6 of 17

also notes that EPA's 2015 MSGP does not include pH monitoring for Sector P, Land
Transportation and Warehousing (which specifically includes vehicle maintenance
activities).
The proposed permit has updated language in the Tier Responses to Benchmark
Exceedances. Explanation: The revisions make the permit consistent with other more
recently updated general stormwater permits. Most notably, the proposed permit
allows the permittee to contact the Regional Office as early as Tier 2 to coordinate
response actions of Tier 3, rather than waiting to trigger Tier 3.
• The proposed permit reduces quarterly monitoring to semi-annual, after year 1 for
wastewater discharges, if there are no exceedances during year 1. Explanation:
DEMLR considered the relatively good wastewater monitoring data from our NCG14
permittees over the last permit cycle (See Appendix 8): 10% of pH measurements
exceeded the limit, 19% of TSS measurements were potentially over the limit, and SS
measurements exceeded the permit limit in less than 0.5% of samples. With the
preponderance of wastewater discharges within the permit limits, DEMLR concluded
that semi-annual monitoring offers similar performance and control feedback to our
permittees as quarterly sampling.
• The proposed permit eliminates the monitoring for settleable solids in wastewater
discharges, except for discharges to sensitive waters (HQW, ORW, SA, SB, PNA, Tr).
Explanation: DEMLR considered that settleable solids (SS) measurements exceeded the
permit limit of 5 ml/L in less than 0.5% of measurements (See Appendix B). DEMLR's
assessment is that sufficient control of solids discharges from ready -mixed concrete
activities can be achieved based on measuring and responding to TSS limitations. (See
Section 7 for more details)
The proposed permit eliminates the exemption of "closed -loop recycle systems
designed to operate with two feet of freeboard" from wastewater discharge
monitoring. Explanation: DEMLR considered this monitoring exemption redundant after
removing operation of Closed -Loop Recycle Systems (CLRSs) from the scope of this
permit. We have deleted the provision to avoid confusion and misinterpretation (e.g.,
ponds that may have 'freeboard" only because they routinely discharge at an outlet 2'
below a dike berm). The exemption of wastewater treatment systems that discharge
only in response to 10-year, 24-hour storms and greater from analytical sampling
provides relief that should also apply to systems that maintain large amounts of
freeboard and do not normally discharge. The removal of CLRSs from the scope of the
proposed permit (discussed earlier) is also consistent with revisions to the NCG020000
Mining NPDES General Permit at the last renewal.
The proposed permit revises the reporting requirements to be more consistent with
other general permits in DEMLR's program. r n,+; ns n 1 e R g e r r e q r ee a n AlpA-- i
Rep r+ by Nllareh 11 f o eh yeaF, n sepaFate r ,- ring of honhY. ark o eclanc-os eF
Page 7 of 17

I+r�t v;A_lat+en_I; te the Regme, @l OffnEe. The-peFrn.ttaemust simply SeRd 9NARs-te the
6e+m*-Fal Offirce v.fithin39 days ef FeceiViRg sample Fesults. €xp.IGIqat+e;--The €PA'3
This includes revisions in accordance with the EPA's Electronic Reporting Rule. This will
require all NPDES permittees to report data electronically in the 016 1 2017-18
timeframe. The Stormwater Permitting Program continues to coordinate with EPA and
the Division of Water Resources to use the eDMR infrastructure already in place to
implement electronic reporting capabilities. [corrected May 30, 2017]
• The proposed permit revises the qualitative monitoring requirements to (1) allow
representative outfall status (ROS) designation to reduce the number of outfalls
monitored throughout the permit term, and (2) no longer restrict monitoring to the
same event as the analytical samples. Explanation: DEMLR has allowed ROS for
qualitative monitoring for other general permits. Also, under this permit facilities are
subject to semi-annual facility inspections. With a monitoring frequency comparable to
other stormwater permits (twice per year), and with semi-annual facility inspections, the
combined site management oversight in support of stormwater pollution control is
sufficient and should not preclude ROS for qualitative monitoring.
• Part V, Standard Conditions for NPDES General Permits has updated language in
various sections. These include (1) Section A: Reducing period for an existing facility
that applies for coverage for the first time to develop its SPPP from 1 year to 6 months,
(2) Section B: new Electronic Reports paragraph in Section B, (3) Section C: Distinct
bypassing conditions for stormwater controls and wastewater treatment facilities, (4)
Section D: Allowance for permittee to provide analytical records to a DEMLR inspector
electronically upon request. Explanation: The revisions make the permit consistent with
other more recently issued permits in DEMLR-s Stormwater Program; address authorized
wastewater discharges covered under this General Permit; and respond to a request by
the industry to make an allowance for analytical monitoring records to be maintained at
a central location away from a mine site (often remote) but available electronically for
inspection. DEMLR also concluded that six months is a reasonable expectation for anew
facility to develop and implement an SPPP and sees no reason to retain the one year
allowance.
As before, the draft permit incorporates a modified definition of a storm event that is to be
sampled. Previous permits and most other stormwater General Permits define the stormwater
event to be sampled as the "representative storm event". The NCG140000 permit renewal now
requires permittees to sample the "Measurable Storm Event", a new term for North Carolina
stormwater permits. The "Measurable Storm Event" is an event that results in an actual
discharge, rather than an event with a rainfall measuring 0.1 inches or more. To qualify as a
Measurable Storm Event, the previous storm event must have been at least 72 hours prior.
As before, the proposed renewal permit specifies the exemption for what DEMLR considers a
"non -discharging system" with a further specification (underlined): analytical monitoring is not
required from a "basin or pond designed to contain the 25-year, 24-hour storm without
Page 8 of 17

discharging, and that can regain capacity to hold such an event within five (5) days' time
through means other than discharge to surface waters." Often permittees mistakenly interpret
other stormwater control measures (SCM) (such as sediment basins, wet ponds, etc.) "designed
for the 25-year storm" to qualify for the exemption from monitoring, when in reality those
systems do not qualify. Such SCM's do in fact discharge to draw down volume; they are simply
designed to safely pass the design event over the emergency spillway without compromising
the control structure. In other words, DEMLR is clarifying that discharges only in response to a
storm that is rg eater than a 25-year, 24 hour storm are not regulated by this permit.
As before, the proposed renewal permit specifies qualitative (visual) monitoring of each
stormwater outfall for the purpose of evaluating the effectiveness of stormwater control
measures and assessing new sources of stormwater pollution. Qualitative monitoring
parameters include color, odor, clarity, floating and suspended solids, foam, oil sheen, and
other obvious indicators of stormwater pollution. The revised permit proposes additional
flexibility to allow representative outfall status (ROS) specifically for qualitative monitoring
(not just for analytical monitoring) without the requirement to qualitatively monitor all outfalls
at least annually.
S. COMPLIANCE SCHEDULE
The proposed compliance schedule in Part V, Section A was modified to address facilities that
are renewing coverage under this new permit, and to reduce the time period for SPPP
development at existing facilities applying for first-time coverage (from 12 months to 6
months). The permittee is required to comply with Limitations and Controls specified for
stormwater discharges in accordance with the following schedule:
Existing Facilities already operating but applying for permit coverage for the first time: The
Stormwater Pollution Prevention Plan shall be developed and implemented within 6 months of the
effective date of the Certificate of Coverage and updated thereafter on an annual basis. Secondary
containment, as specified in Part III of this General Permit, shall be accomplished within 12 months
of the effective date of the issuance of the Certificate of Coverage.
New Facilities applying for coverage for the first time: The Stormwater Pollution Prevention Plan
shall be developed and implemented prior to the beginning of discharges from the operation of the
industrial activity and be updated thereafter on an annual basis. Secondary containment, as specified
in Part III of this General Permit shall be accomplished prior to the beginning of discharges from the
operation of the industrial activity.
Existing facilities previously permitted and applying for renewal under this General Permit:
All requirements, conditions, limitations, and controls contained in this permit (except new SPPP
elements in this permit renewal) shall become effective immediately upon issuance of the Certificate
of Coverage. New elements of the Stormwater Pollution Prevention Plan for this permit renewal
shall be developed and implemented within 6 months of the effective date of this General Permit and
updated thereafter on an annual basis. Secondary containment, as specified in Part III of this General
Permit shall be accomplished prior to the beginning of discharges from the operation of the
industrial activity.
6. SPECIAL CONDITIONS WHICH WILL HAVE A SIGNIFICANT IMPACT ON THE DISCHARGE
Page 9 of 17

The special conditions in the draft General Permit are the requirements for implementation of
the new electronic reporting of monitoring reports [G.S. 143-215.1(b)]. These are included in
Part IV. Section F.
7. BASIS FOR CONTROLS AND LIMITATIONS
Stormwater Discharges
The conditions of this draft General Permit have been designed using best professional
judgment to achieve water quality protection through compliance with the technology -based
standards of the Clean Water Act (Best Available Technology [BAT] and Best Conventional
Pollutant Control Technology [BCT]). Where the Director determines that a water quality
standard violation is occurring and water quality -based controls or effluent limitations are
required to protect the receiving waters, coverage under the General Permit shall be
terminated and an individual permit will be required. Based on a consideration of the
appropriate factors for BAT and BCT requirements, and a consideration of the factors discussed
below in this fact sheet for controlling pollutants in stormwater discharges associated with the
activities as described in Item 1 (Types of Discharge Covered), this proposed permit retains a set
of requirements for developing and implementing stormwater pollution prevention plans, and
specific requirements for monitoring and reporting on stormwater discharges.
The proposed permit conditions reflect the Environmental Protection Agency's (EPA) and North
Carolina's continued pollution prevention approach to stormwater permitting. The quality of
the stormwater discharge associated with an industrial activity will depend on the availability of
pollutant sources. The Division maintains the position that implementing Best Management
Practices (BMPs) and traditional stormwater management practices which control the source of
pollutants meets the definition of BAT and BCT. The proposed permit conditions (for
stormwater) are not numeric effluent limitations, but rather are designed to be flexible
requirements for developing and implementing site specific plans to minimize and control
pollutants in the stormwater discharges associated with the industrial activity.
Title 40 Code of Federal Regulations (CFR) Part 122.44(k)(2) authorizes the use of BMPs in lieu
of numeric effluent limitations in NPDES permits when the agency finds numeric effluent
limitations to be infeasible. The agency may also impose BMP requirements which are
"reasonably necessary" to carry out the purposes of the Act under the authority of 40 CFR
§122.44(k)(3). The conditions of the revised renewal permit are retained under the authority of
both of these regulatory provisions. The pollution prevention requirements (BMP
requirements) operate as limitations on effluent discharges that reflect the application of
BAT/BCT. The basis is that the BMPs identified require the use of source control technologies
which, in the context of this permit, are the best available of the technologies economically
achievable (or the equivalent BCT finding).
All facilities covered by this stormwater General Permit must prepare, retain, implement, and
(at a minimum of annually) update a stormwater pollution prevention plan (SPPP). The term
Page 10 of 17

"pollution prevention" distinguishes this source reduction approach from traditional pollution
control measures that rely on end -of -pipe treatment to remove pollutants in the discharges.
The pollution prevention approach adopted in the SPPPs in this renewal permit still focuses on
two major objectives: 1) to identify sources of pollution potentially affecting the quality of
stormwater discharges associated with industrial activity from the facility; and 2) to describe
and ensure that practices are implemented to minimize and control pollutants in those
discharges from the facility.
The Division believes that it is not appropriate, at this time, to require a single set of effluent
limitations (for stormwater) or a single design or operational standard for all facilities which
discharge stormwater associated with industrial activity. The permit instead establishes a
framework for the development and implementation of a site -specific SPPP. This framework
provides flexibility to address the variable risk for pollutants in stormwater discharges
associated with the industrial activities from this industry sector, while ensuring procedures to
prevent stormwater pollution at a facility are appropriate given the processes employed,
engineering aspects, functions, costs of controls, location, and age of facility (as discussed in 40
CFR §125.3). This approach also allows flexibility to establish controls to address varying
sources of pollutants at different facilities.
There has been no significant change to this rationale since the previous general permit.
Stormwater Benchmarks
The proposed pH benchmark range is based on N.C. Water Quality Standards contained in 15A
NCAC 02B .0211 and is consistent with other renewed general stormwater permits. The total
suspended solids (TSS) benchmark of 100 mg/I is based on the median concentration derived
from the National Urban Runoff Program (NURP) study in 1983 and serves as a benchmark in
industrial stormwater permits with TSS monitoring. The lower TSS benchmark for ORW, HQW,
trout, and primary nursery area (PNA) waters of 50 mg/I reflects half that base value and was
set to flag potential problems in discharges to waters with much lower Water Quality Standards
for TSS concentrations (20 mg/I for HQW and ORW; 10 mg/I for trout and PNA waters).
The non -polar oil and grease (vehicle maintenance only) benchmark of 15 mg/I has been
carried over from the previous permit cycle. The value is consistent with other states'
benchmarks and/or limits at the time it was introduced and reflects a value we would associate
only with significant oil contamination.
Wastewater Discharge Limitations
The authorized process wastewater discharge types from vehicle and equipment cleaning, raw
material stockpiles, and mixing drum cleanout are also retained in this draft permit. This draft
permit includes non -polar oil and grease action levels for wastewater when VMA-derived
stormwater drains and commingles with wastewater before discharge. The draft permit
effluent limitations are based on N.C. Water Quality Standards and Categorical Effluent
Limitations. The pH and TSS limitations are based on water quality standards in 15A NCAC 213
Page 11 of 17

.0200, .0300, and .0400 (40 CFR by reference). Rules in 15A NCAC 02B .0221 and .0222 prohibit
any settleable solids attributable to industrial or other wastes, which supports a limit on the
wastewater discharges in this General Permit for SA, SB, and PNA waters. DEMLR also
concluded that applying these SS limits to high quality waters (HQW) and trout (Tr)
classifications is appropriate for protecting such waters. The effluent limit for SS is carried over
from the previous permit. DEMLR is proposing monitoring for settleable solids only for
sensitive waters. More stringent TSS average limits and total flow volume limits are based on
N.C. Water Quality Standards for HQW, Trout, and PNA waters.
The draft renewal permit specifies that written authorization is not required when flocculants
already approved by the Division are administered in accordance with approved maximum
application doses and any other current requirements.
The draft permit also incorporates a limit on total volume of wastewater discharged to HQW
classified waters (50 percent of the 7Q10 flow), as mandated in the 15A NCAC 02B .0224 Rules.
DEMLR recognizes that a 7Q10 cannot be calculated for tidally -influenced waters and will
continue to use best professional judgement to implement this provision on a case -by -case
basis.
8. REQUESTED VARIANCES OR ALTERNATIVES TO REQUIRED STANDARDS
There are no requested variances or alternatives to required standards. Facilities requesting
variances to required standards will not be covered under this General Permit but will instead
be required to seek coverage under an individual permit.
9. THE ADMINISTRATIVE RECORD
The administrative record, including application, draft permits, fact sheet, public notice,
comments received, and additional information is available by writing to:
Stormwater Permitting Program
Division of Energy, Mineral, and Land Resources
1612 Mail Service Center
Raleigh, North Carolina 27699-1612
The above documents are available for review and copying at:
Archdale Building, 91h Floor
DEMLR Stormwater Permitting Program
512 N. Salisbury Street
Raleigh, North Carolina
between the hours of 8:00 AM and 5:00 PM Monday through Friday. Copies will be provided at
a charge of 10 cents per page.
Page 12 of 17

10. STATE CONTACT
Additional information about the draft permit may be obtained at the above address between
the hours of 8:00 AM and 5:00 PM Monday through Friday by contacting:
Rick Riddle at [phone] 1 [e-mail] or,
Robert Patterson at [phone] 1 [e-mail]
11. SCHEDULE OF PERMIT ISSUANCE
Draft Permit Public Notice — Statewide notice published May 15, 2017
Draft available online May 15, 2017
Comment Period Ends June 15, 2017
Permit Issue Date — Scheduled for June 30, 2017
Effective July 1, 2017
12. PROCEDURE FOR THE FORMULATION OF FINAL DETERMINATIONS
a. Comment Period
The Division of Energy, Mineral, and Land Resources proposes to issue the NPDES General
Permit for the above described stormwater discharges subject to the outlined limitations,
management practices, and conditions. These determinations are open to comment from
the public.
Interested persons are invited to submit written comments on the permit text or on the
Division's proposed determinations to the following address:
Stormwater Permitting Program
Division of Energy, Mineral, and Land Resources
1612 Mail Service Center
Raleigh, North Carolina 27699-1612
Attn: Rick Riddle
All comments received within thirty days following the date of public notice are considered
in the formulation of final determinations.
b. Public Meeting
The Director of the Division of Energy, Mineral, and Land Resources may hold a public
meeting if there is a significant degree of public interest in a proposed permit or group of
permits. Public notice of such a meeting will be circulated in newspapers in the
geographical area of the discharge and to those on the Division's mailing list at least 30 days
prior to the meeting.
c. Appeal Hearing
Page 13 of 17

An applicant whose permit is denied, or is granted subject to conditions he deems
unacceptable, shall have the right to a hearing before the Commission upon making written
demand to the Office of Administrative Hearing within 30 days following issuance or denial
of the permit.
d. Issuance of a Permit When no Hearing is Held
If no public meeting or appeal hearing is held, after review of the comments received, and if
the Division's determinations are substantially unchanged, the permit will be issued and
become effective on the first day of the month following the issuance date. This will be the
final action of the Division of Energy, Mineral, and Land Resources.
If a public meeting or appeal hearing is not held, but there have been substantial changes,
public notice of the Division's revised determinations will be made. Following a 30-day
comment period, the permit will be issued and will become effective on the first day of the
month following the issuance date. This will be the final action of the Division unless a
public meeting or appeal hearing is granted.
Page 14 of 17

APPENDIX A
Removal of Authorization to Construct (ATC) Requirements for
Industrial Treatment Excerpted from Session Law 2011-394
SECTION 9. G.S. 143-215.1 reads as rewritten (changes in highlight):
"§ 143-215.1. Control of sources of water pollution; permits required.
(a) Activities for Which Permits Required. — No Except as provided in subsection (a5) of this
section, no person shall do any of the following things or carry out any of the following activities
unless that person has received a permit from the Commission and has complied with all conditions
set forth in the permit:
(1) Make any outlets into the waters of the State.
(2) Construct or operate any sewer system, treatment works, or disposal system within the
State.
(3) Alter, extend, or change the construction or method of operation of any sewer system,
treatment works, or disposal system within the State.
(4) Increase the quantity of waste discharged through any outlet or processed in any treatment
works or disposal system to any extent that would result in any violation of the effluent
standards or limitations established for any point source or that would adversely affect the
condition of the receiving waters to the extent of violating any applicable standard.
(5) Change the nature of the waste discharged through any disposal system in any way that
would exceed the effluent standards or limitations established for any point source or that
would adversely affect the condition of the receiving waters in relation to any applicable
standards.
(6) Cause or permit any waste, directly or indirectly, to be discharged to or in any manner
intermixed with the waters of the State in violation of the water quality standards applicable
to the assigned classifications or in violation of any effluent standards or limitations
established for any point source, unless allowed as a condition of any permit, special order or
other appropriate instrument issued or entered into by the Commission under the provisions
of this Article.
(7) Cause or permit any wastes for which pretreatment is required by pretreatment standards
to be discharged, directly or indirectly, from a pretreatment facility to any disposal system or
to alter, extend or change the construction or method of operation or increase the quantity or
change the nature of the waste discharged from or processed in that facility.
(8) Enter into a contract for the construction and installation of any outlet, sewer system,
treatment works, pretreatment facility or disposal system or for the alteration or extension of
any such facility.
(9) Dispose of sludge resulting from the operation of a treatment works, including the
removal of in -place sewage sludge from one location and its deposit at another location,
consistent with the requirement of the Resource Conservation and Recovery Act and
regulations promulgated pursuant thereto.
(10) Cause or permit any pollutant to enter into a defined managed area of the State's waters
for the maintenance or production of harvestable freshwater, estuarine, or marine plants or
animals.
(11) Cause or permit discharges regulated under G.S. 143-214.7 that result in water pollution.
Page 15 of 17

(12) Construct or operate an animal waste management system, as defined in G.S. 143-
215.1 OB, without obtaining a permit under either this Part or Part 1A of this Article.
(a I) In the event that both effluent standards or limitations and classifications and water quality
standards are applicable to any point source or sources and to the waters to which they discharge, the
more stringent among the standards established by the Commission shall be applicable and
controlling.
(a2) No permit shall be granted for the disposal of waste in waters classified as sources of public
water supply where the head of the agency that administers the public water supply program pursuant
to Article 10 of Chapter 130A of the General Statutes, after review of the plans and specifications for
the proposed disposal facility, determines and advises the Commission that any outlet for the disposal
of waste is, or would be, sufficiently close to the intake works or proposed intake works of a public
water supply as to have an adverse effect on the public health.
(0) If the Commission denies an application for a permit, the Commission shall state in writing the
reason for the denial and shall also state the Commission's estimate of the changes in the applicant's
proposed activities or plans that would be required in order that the applicant may obtain a permit.
(a4) The Department shall regulate wastewater systems under rules adopted by the Commission for
Public Health pursuant to Article 11 of Chapter 130A of the General Statutes except as otherwise
provided in this subsection. No permit shall be required under this section for a wastewater system
regulated under Article 11 of Chapter 130A of the General Statutes. The following wastewater
systems shall be regulated by the Department under rules adopted by the Commission:
(1) Wastewater systems designed to discharge effluent to the land surface or surface waters.
(2) Wastewater systems designed for groundwater remediation, groundwater injection, or
landfill leachate collection and disposal.
(3) Wastewater systems designed for the complete recycle or reuse of industrial process
wastewater.
(a5) No permit shall be required to enter into a contract for the construction, installation, or
alteration of any treatment works or disposal system or to construct, install, or alter any treatment
works or disposal system within the State when the system's or work's principle function is to
conduct, treat, equalize, neutralize, stabilize, recycle, or dispose of industrial waste or sewage from
an industrial facility and the discharge of the industrial waste or sewage is authorized under a permit
issued for the discharge of the industrial waste or sewage into the waters of the State.
Notwithstanding the above, the permit issued for the discharge may be modified if required by
federal regulation.
Page 16 of 17

APPENDIX B
NCG140000 DATA SUMMARY (2011-2016)
Stormwater, self -reporting data for the period 2011- 2016
Parameter
Count of
Percentage
Reported
Benchmark
Exceedances
Range
TSS
66 / 754
9%
0 - 840 mg/L
100 mg/L
50 mg1L (ORW, HQW, Tr,
PNA)
pH
75 / 780
10%
0.9 - 11.63 ml/L
6 - 9 std units
VMA TPH
2 60
3%
0- 40 m L
15 m L
VMA TSS
3 / 56
5%
0 - 140 mg/L
100 mg/L
50 mg1L (ORW, HQW, Tr,
PNA)
VMA pH
4 / 57
7%
6.2 - 10.4 std
6 - 9 std units
units
New Motor
60 reports
55 gal/mo (Permit
oil usage
trigger)
Permitees
11 / 293
4%
In Tier 2
Wastewater, self -reporting data for the period 2010 - 2016
Parameter
Count of
Percentage
Reported Range
Limitation
Exceedances*
TSS
125 / 663
19%
0.1 - 898 mg/L
30 mg/L max
(20 mg1L for HQW, 10
mglLfor out & PNA
Settleable
3 / 611
0.5%
0.1- 80.5 ml/L
5 ml/L
Solids
pH
69 / 692
10%
5.7 - 11.5 std units
6 - 9 std units
6.8 - 8.5 std units
(saltwaters)
VMA TPH
1 / 569
0.2%
0.98 - 16.4 mg/L
N/A (15 mg1L
benchmark only)
Page 17 of 17