NC0083712_Permit Issuance_20170626

Water Resources w
Environmental Quality
June 26, 2017
Mr. Darhyl Boone, Town Manager
Town of Mars Hill
P.O. Box 368
Mars Hill, NC 28754
ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. JAY ZIMMERMAN
Director
Subject: Issuance of NPDES Permit NCO083712
Mars Hill WTP, PC-1
2085 Water Shed Road, Mars Hill 28754
Madison County
Dear Mr. Boone:
The Division of Water Resources (the Division) hereby issues the attached NPDES permit for the subject
facility. This permit is issued pursuant to the requirements of North Carolina General Statute 143-215.1
and the Memorandum of Agreement between North Carolina and the U.S. Environmental Protection
Agency dated October 15, 2007, or as subsequently amended.
The Division understands that you have made no significant changes to your facility since the last permit
renewal. We have made the following updates to your previous permit:
1. Turbidity monitoring is twice per month (2/month) with a monthly average limit of 50 NTU and a
daily maximum limit of 50 NTU.
2. Total Iron and Total Manganese monitoring has been removed.
3. Total Copper monitoring has been removed because it did not show reasonable potential to
exceed applicable water quality standards/criteria and the maximum predicted concentration was
<50% of the allowable concentration.
4. Effluent and upstream quarterly monitoring for Total Hardness (see below for information) has
been added.
5. Electronic reporting of discharge monitoring reports (eDMR) in Section A. (4.) has been added.
The NC 2007-2014 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Committee (EMC) on November 13, 2014. The US EPA subsequently approved
the WQS revisions on April 6, 2016 with some exceptions. The NC Division of Water Resources NPDES
Permitting Unit is required to implement the new dissolved metal standards in all permits public noticed after
April 6, 2016.
The new standards for most metals include acute standards. Furthermore, the freshwater standards for several
metals are expressed as the dissolved form of the metals, and seven metals have hardness -dependent
equations. As a result, the NPDES Permitting Unit will need site -specific effluent hardness data and instream
hardness data, upstream of the discharge, for each facility monitoring these metals in order to calculate permit
limitations. Effluent hardness and instream hardness sampling, upstream of the discharge, has been added to
this permit at a monitoring frequency of quarterly. See Section A. (L) Effluent Limitations and Monitoring
Requirements.
!''Nothing Compares -
State of North Carolina I Environmental Quality
1617 Mail Service Center I Raleigh, North Carolina 27699-1617
919-707-9000

Mr. Boone
June 26, 2017
Page 2 of 2
Effective December 21, 2016, federal regulations require electronic submittal of all discharge monitoring
reports (DMRs) and specify that, if a state does not establish a system to receive such submittals, then
permittees must submit DMRs electronically to the Environmental Protection Agency (EPA). The final
NPDES Electronic Reporting Rule was adopted and became effective on December 21, 2015.
The requirement to begin reporting discharge monitoring data electronically using the NC DWR's Electronic
Discharge Monitoring Report (eDMR) internet application has been added to your final NPDES permit. [See
Special Condition A. (4.)] For information on eDMR, registering for eDMR and obtaining an eDMR user
account, please visit the following web page:
ho://deg.nc.eov/about/divisions/water-resources/edmr.
For more information on EPA's final NPDES Electronic Reporting Rule, please visit the following web site:
)://www2.epa. gov/compliance/final-national-pollutant-discharge-elimination-system-npdes-electronic-
Mporhng-rule.
If any parts, measurement frequencies, or sampling requirements contained in this permit are
unacceptable, you have the right to an adjudicatory hearing, upon written request submitted within thirty
(30) days after receiving this letter. Your request must take the form of a written petition conforming to
Chapter 150B of North Carolina General Statutes, and you must file it with the Office of Administrative
Hearings, 6714 Mail Service Center, Raleigh, North Carolina 27699-6714. Unless such a demand is
made, this permit shall remain final and binding.
Please note that this permit is not transferable except after notice to the Division. The Division may
require modification or revocation and reissuance of the permit. This permit does not affect the legal
requirements to obtain other permits which may be required by the Division of Water Resources or any
other Federal, State, or Local governmental permits that may be required.
If you have questions, or if we can be of further service, please contact Derek Denard at
[[e-mail]] or call [phone].
Res ectfully,
Jay Zimmerman, Dir r
Division of Water Resources, NCDEQ
Enclosure: NPDES Permit NCO083712 (Issuance Final)
he: Central Files
NPDES Program Files
ARO Files/ Attn: Landon Davidson
ea: WSS/Aquatic Toxicology Branch / Susan Meadows [[e-mail]]
WSS/Aquatic Toxicology Branch / Cindy Moore [[e-mail]]
Darhyl Boone, Town Manager [[e-mail]]

NPDES Permit NCO083712
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF WATER RESOURCES
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
PDES
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful standards
and regulations promulgated and adopted by the North Carolina Environmental Management
Commission, and the Federal Water Pollution Control Act, as amended, the
Town of Mars Hill
is hereby authorized to discharge wastewater from a facility located at the
Town of Mars Hill Water Treatment Plant (WTP)
2085 Water Shed Road, Mars Hill, NC 28754
Madison County
to receiving waters designated as North Fork Big Laurel Creek in the French Broad River Basin, in
accordance with effluent limitations, monitoring requirements, and other conditions set forth in Parts I,
II, III and IV hereof
This permit shall become effective August 1, 2017.
This permit and authorization to discharge shall expire at midnight on July 31, 2022.
Signed this day June 26, 2017.
ay Zimmerman, P.G., Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page 1 of 8

NPDES Permit NCO083712
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby
revoked. As of this permit issuance, any previously issued permit bearing this number is no
longer effective. Therefore, the exclusive authority to operate and discharge from this facility
arises under the permit conditions, requirements, terms, and provisions included herein.
Town of Mars Hill
is hereby authorized to:
1. continue to operate a wastewater treatment system utilizing conventional water treatment
plant technology [coagulation, flocculation, sedimentation, and filtration] with a maximum,
monthly average wastewater discharge of 0.026 MGD from media filter backwash and
sedimentation basins with a design potable flowrate of 0.80 MGD and with wastewater
treatment consisting of;
• dechlorination
• wastewater treatment settling lagoon
located at the Town of Mars Hill WTP, 2085 Water Shed Road, Mars Hill, Madison County,
and
2. discharge from said treatment works via Outfall 001, at the location specified on the attached
map into North Fork Big Laurel Creek [6-112-1-(2)], a waterbody currently classified
C;ORW located within Subbasin 04-03-04 [HUC: 060101051001 ] of the French Broad River
Basin.
Page 2 of 8

NPDES Permit NCO083712
PART I
A. (1.) EFFLUENT LIIVIITATIONS AND MONITORING REQUIREMENTS
[I 5A NCAC 02B .0400 et seq., 02B .0500 et seq.]
During the period beginning on the effective date of this permit and lasting until expiration, the
Permittee is authorized to discharge filter backwash from outfall 001. Such discharges shall be limited,
monitored and reported' by the Permittee as specified below:
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rapt-
Flow (MGD) 2
50050
2/Month
Instantaneous
Effluent
or Estimate
Total Suspended Solids (TSS) (mg/1)
C0530
30 mg/1
45 mg/1
2/Month
Grab
Effluent
Turbidity (NM 3
00070
50 NTU
50 NTU
2/Month
Grab
Effluent
pH (su)
00400
Not < 6.0 or > 9.0
2/Month
Grab
Effluent
standard units
Total Residual Chlorine (µg/1) 4
50060
28 µg/1
2/Month
Grab
Effluent
Total Zinc (µg/1) 5
01092
Quarterly
Grab
Effluent
Total Aluminum (µg/1)
01105
Quarterly
Grab
Effluent
Hardness - Total as
[CaCO3 or (Ca + Mg)] (mg/L) 5
00900
Quarterly
Grab
Effluent
Hardness -Total as
[CaCO3 or (Ca + Mg)] (mg/L) 6
00900
_
Quarterly
Grab
Upstream
Ammonia Nitrogen (mg/1)
C0610
Quarterly
Grab
Effluent
Chronic WET Testing
TGP3B
Quarterly
Grab
Effluent
Footnotes:
1. Starting December 21, 2016, begin submitting Discharge Monitoring Reports electronically using NC DWR's
eDMR application system. See Condition A. (3.).
2. For instantaneous flow monitoring, the duration of the discharge must be reported in addition to the
total flow.
3. Turbidity — Effluent turbidity shall not cause receiving -stream turbidity to exceed 50 NTU. If background
turbidity naturally exceeds 50 NTU, the effluent shall not cause background turbidity to increase. Any
discharge exceeding this permit limit will require sufficient instream sampling (upstream and/or downstream)
to verify compliance (effluent vs. background)." [NCAC 02B. 0211(21)]
4. The Division shall consider all effluent TRC values reported below 50 µg/L to be in compliance with the
permit. However, the Permittee shall continue to record and submit all values reported by a North Carolina
certified laboratory (including field certified), even if these values fall below 50 µg/L.
5. Effluent hardness sampling should be performed in conjunction with sampling for hardness dependent metals
(zinc).
6. The Permittee shall sample instream hardness, upstream of the facility's discharge. The sample shall be
representative of the hardness in the receiving stream. If the Permittee is a member of the Monitoring Coalition
Program, sampling for instream hardness may be waived as long as the Monitoring Coalition agrees to sample
Page 3 of 8

NPDES Permit NC0083712
hardness at the nearest upstream location, at a minimum frequency of quarterly, and the Permttee has obtained
approval from DWR NPDES Permitting Unit that the upstream station being monitored by the Coalition is
representative of the receiving stream for this discharge. The Permttee is responsible for submitting instream
hardness test results with its permit renewal application package. If Coalition membership is cancelled or the
Coalition terminates instream hardness sampling at the approved station, the Permttee will immediately notify
the Division and resume sampling for instream hardness, upstream of its discharge.
7. Chronic WET testing (Ceriodaphnia dubia) 7-day pass/fail test at 3.3% in January, April, July and October.
See Condition A. (2.).
Conditions:
• Samples shall be taken at the outfall but prior to mixing with the receiving waters.
• There shall be no discharge of floating solids or visible foam in other than trace amounts.
Page 4 of 8

NPDES Permit NCO083712
A. (2.) CHRONIC TOXICITY PASS/FAIL MONITORING ONLY (QUARTERLY)
[I 5A NCAC 02B .0500 et seq.]
The permittee shall conduct guarterly chronic toxicity tests using test procedures outlined in the "North
Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or subsequent
versions.
The effluent concentration defined as treatment two in the procedure document is 3_3%. The testing shall be
performed as a Ceriodaphnia dubia 7-day pass/fail test. The tests will be performed during the months of
January, April, July and October. These months signify the first month of each three month toxicity testing
quarter assigned to the facility. Effluent sampling for this testing must be obtained during representative
effluent discharge and shall be performed at the NPDES permitted final effluent discharge below all treatment
processes.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR-1) for the month in which it was performed, using the parameter code TGP3B.
Additionally, DWR Form AT-1 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days
after the end of the reporting period for which the report is made.
Test data shall be complete and accurate and include all supporting chemical/physical measurements performed
in association with the toxicity tests, as well as all dose/response data. Total residual chlorine of the effluent
toxicity sample must be measured and reported if chlorine is employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is required,
the permittee will complete the information located at the top of the aquatic toxicity (AT) test form indicating
the facility name, permit number, pipe number, county, and the month/year of the report with the notation of
"No Flow" in the comment area of the form. The report shall be submitted to the Water Sciences Section at the
address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, then monthly
monitoring will begin immediately. Upon submission of a valid test, this monthly test requirement will revert to
quarterly in the months specified above.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of
Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and modified
to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival, minimum control organism reproduction, and appropriate environmental controls, shall
constitute an invalid test and will require immediate follow-up testing to be completed no later than the last day
of the month following the month of the initial monitoring.
Page 5 of 8

NPDES Permit NCO083712
A. (3.) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
[G.S. 143-215.1(b)]
Federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and
program reports. The final NPDES Electronic Reporting Rule was adopted and became effective on
December 21, 2015.
NOTE: This special condition supplements or supersedes the following sections within Part H of this
permit (Standard Conditions for NPDES Permits):
• Section B. (11.)
• Section D. (2.)
• Section D. (6.)
• Section E. (5.)
Signatory Requirements
Reporting
Records Retention
Monitoring Reports
1. Reporting Requirements (Supersedes Section D. (2.) and Section E. (5.) (a)]
The permittee shall report discharge monitoring data electronically using the NC DWR's Electronic
Discharge Monitoring Report (eDMR) intMet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter
monitoring data and submit DMRs electronically using the internet. Until such time that the state" s
eDMR application is compliant with EPA's Cross -Media Electronic Reporting Regulation
(CROMERR), permittees will be required to submit all discharge monitoring data to the state
electronically using eDMR and will be required to complete the eDMR submission by printing,
signing, and submitting one signed original and a copy of the computer printed eDMR to the
following address:
NC DEQ / Division of Water Resources / Water Quality Permitting Section
ATTENTION: Central Files
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the
facility being physically located in an area where less than 10 percent of the households have
broadband access, then a temporary waiver from the NPDES electronic reporting requirements may
be granted and discharge monitoring data may be submitted on paper DMR forms (MR 1, 1. 1, 2, 3)
or alternative forms approved by the Director. Duplicate signed copies shall be submitted to the
mailing address above. See "How to Request a Waiver from Electronic Reporting" section below.
Regardless of the submission method, the first DMR is due on the last day of the month following
the issuance of the permit or in the case of a new facility, on the last day of the month following the
commencement of discharge.
Starting on December 21, 2020, the permittee must electronically report the following compliance
monitoring data and reports, when applicable:
Sewer Overflow/Bypass Event Reports;
Pretreatment Program Annual Reports; and
Page 6 of 8

NPDES Permit NC0083712
Clean Water Act (CWA) Section 316(b) Annual Reports.
The permittee may seek an electronic reporting waiver from the Division (see "How to Request a
Waiver from Electronic Reporting" section below).
2. Electronic Submissions
In accordance with 40 CFR 122.410)(9), the permittee must identify the initial recipient at the time
of each electronic submission. The permittee should use the EPA's website resources to identify
the initial recipient for the electronic submission.
Initial recipient of electronic NPDES information from NPDES-regulated facilities means the entity
(EPA or the state authorized by EPA to implement the NPDES program) that is the designated
entity for receiving electronic NPDES data [see 40 CFR 127.2(b)].
EPA plans to establish a website that will also link to the appropriate electronic reporting tool for
each type of electronic submission and for each state. Instructions on how to access and use the
appropriate electronic reporting tool will be available as well. Information on EPA's NPDES
Electronic Reporting Rule is found at: hgp://www2.gpa. ov/compliance/final-national-pollutant-
discharae-elimination-system-npdes-electronic-reporting-rule.
Electronic submissions must start by the dates listed in the "Reporting Requirements" section
above.
3. How to Request a Waiver from Electronic Reportine
The permittee may seek a temporary electronic reporting waiver from the Division. To obtain an
electronic reporting waiver, a permittee must first submit an electronic reporting waiver request to
the Division. Requests for temporary electronic reporting waivers must be submitted in writing to
the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin submitting monitoring data and reports. The duration of a
temporary waiver shall not exceed 5 years and shall thereupon expire. At such time, monitoring
data and reports shall be submitted electronically to the Division unless the permittee re -applies for
and is granted a new temporary electronic reporting waiver by the Division. Approved electronic
reporting waivers are not transferrable. Only permittees with an approved reporting waiver request
may submit monitoring data and reports on paper to the Division for the period that the approved
reporting waiver request is effective.
Information on eDMR and the application for a temporary electronic reporting waiver are found on
the following web page:
hqp://dgg.nc.gov/about/divisions/water-resources/edmr
Page 7 of 8

NPDES Permit NC0083712
4. Sri natorV Requirements [Supplements Section B. (11.) (b) and Supersedes Section B. (11.) (d)]
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part
H, Section B. (I 1.)(a) or by a duly authorized representative of that person as described in Part H,
Section B. (11.)(b). A person, and not a position, must be delegated signatory authority for eDMR
reporting purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user
account and login credentials to access the eDMR system. For more information on North
Carolina's eDMR system, registering for eDMR and obtaining an eDMR user account, please visit
the following web page:
hM://dgg.nc.gov/about/divisions/Water-resources/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall
make the following certification [40 CFR 122.22). NO OTHER STATEMENTS OF
CERTIFICATION WILL BE ACCEPTED:
"I certify, under penalty of law, that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief, true, accurate,
and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment for knowing violations. "
5. Records Retention [Supplements Section D. (6.)1
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions.
These records or copies shall be maintained for a period of at least 3 years from the date of the report. This
period may be extended by request of the Director at any time [40 CFR 122.41].
Page 8 of 8

Ik Wallow Knp
North Fork Big Laurel Creek I� _ Outfall 001
� [flows south] `—�
(Y r •`
/(7�1_�
f H
Approximate
Facility Boundary f`' J. !
Water Shed Rd +� J -V !
r
� t l��i� J!�`r ��,��1 '\� •^its( y,��� +�'`' ., _ J
Ar �1
/ I
Gap''
Big Laurel Creek
23":� `ti! — Copyrigh6©20•iS3 Natgial G, ;�eog�uap ber7
Town of Mars Hill - Mar Hill WTP
NPDES Permit NCO083712
2085 Water Shed Road, Mars Hill 28754
Receiving Stream: North Fork Big Laurel Creek Stream Class: C;ORW
Stream Segment: 6-112-1-(2) Sub -Basin #: 04-03-04
River Basin: French Broad I-IUC: 060101051001
County: Madison
N
SCALE
1:24,000
g*:,1�l,T'�`� '�r
r
1:
NC Grid: •
USGS Quad: Bald Creek, NC

ASHE`/iL.l_.F.
CITIZEN TaffiS
VOICE OFTHEMOUNTAINS • CITIZEN-TRvIES.com
Public Notice
North Carolina Environmental Management
Commission/NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES Wastewater Permit
The North Carolina Environmental Management
Commission proposes to issue a NPDES wastewater
discharge permit to the person(s) listed below.
Written comments regarding the proposed permit will
be accepted until 30 days after the publish date of
this notice. The Director of the NC Division of Water
Resources (DWR) may hold a public hearing should
there be a significant degree of public interest. Please
mail comments and/or information requests to DWR
at the above address. Interested persons may visit
the DWR at 512 N. Salisbury Street, Raleigh, NC to
review information on file. Additional information on
NPDES permits and this notice may be found on our
website: http://dee .nc.gov/about/divisions/water-
reso u rces/water-resources-permits/wastewater-
branch/npdes-wastewater/public-notices, or by
calling [phone].
Town of Mars Hill applied to renew NPDES
permit for the Mars Hill WTP [NC0083712], 2085
Water Shed Road, Mars Hill, Madison County,
discharging filter -backwash wastewater to North
Fork Big Laurel Creek, French Broad River Basin.
RECEIVEDINCDEOIDWR
MAY 12 2017
Water Quality
Permitting Section
AFFIDAVIT OF PUBLICATION
BUNCOMBE COUNTY
SS.
NORTH CAROLINA
Before the undersigned, a Notary Public of said County and
State, duly commissioned, qualified and authorized by law
to administer oaths, personally appeared Kelly Loveland,
who, being first duly sworn, deposes and says: that she is
the Staff Accountant of The Asheville Citizen -Times,
engaged in publication of a newspaper known as The
News -Record & Sentinel, published and issued in the
Town of Marshall and entered as periodical class mail in
the Town of Mars Hill, in Madison County, North
Carolina; that she is authorized to make this affidavit and
sworn statement; that the notice or other legal
advertisement, a true copy of which is attached hereto, was
published in The News -Record & Sentinel on the
following dates: May 10'" 2017. And that the said
newspaper in which said notice, paper, document or legal
advertisement was published at the time of each and every
publication, a newspaper meeting all of the requirements
and qualifications of Section 1-597 of the General Statues
of North Carolina.
Signed this ], day of May, 2017
Sworn to and subscribed before me the 10' day of May,
2017
expires the 5" day of October, 2018.
Notary Publlc pF<
Q Buncombe <
[phone] 1 [phone] FAX E Y County
14 O. HENRY AVE. I P.O. BOX 2090 1 ASHEVILLE, NC 28802 1 (800) 8004204 My Comm. Exp.
C)GpME7i •,,� CA I11gTyII101
PO\ \��•

DEQ / DWR / NPDES
EXPEDITED FACT SHEET - NPDES PERMIT DEVELOPMENT
NPDES General Permit COC NCO083712
Derek Denard, Compliance & Expedited Permitting Unit / 919-807-6307 19Jun2017
Facility Information
Applicant/Facility Name
Town of Mars Hill
Mars Hill Water Treatment Plant (WTP)
Applicant Address
P.O. Box 368, Mars Hill, NC 28754
Facility Address
2085 Water Shed Road, Mars Hill, NC 28754
Permitted Flow (MGD)
Not limited
Type of Waste
Water Plants and Water Conditioning Discharge — filter -backwash
— Conventional WTP System
Facility Class
PC-1
County
Madison
Permit Status
Renewal
Regional
Office
ARO
Stream Characteristics
Receiving Stream
North Fork Big
Laurel Creek
Stream Classification
C; ORW
Stream Segment
[6-112-1-(2)]
Drainage basin
French Broad
Summer 7Q10 (cfs)
1.2
Subbasin
[HUC]
04-03-04
[060101051001 ]
Wintery 7Q 10 (cfs)
1.7
Use Support
No Data
Category 4 Hg Only
30Q2 (cfs).
2.6
303(d) Listed
Average Flow (cfs)
5.08
State Grid
D9NW
IWC.(%)
3.3%
USGS Topo Quad
Bald Creek, NC
FACILITY SUMMARY: This facility is a conventional technology water treatment plant [coagulation,
flocculation, sedimentation, and filtration] with discharge of wastewaters from media filter backwash and
sedimentation basins with a design potable flowrate of 0.80 MGD, a backwash or reject flow of 0.0183
MGD and a maximum monthly average wastewater discharge of 0.026 MGD. The facility consists of the
following water and wastewater treatment units:
• coagulation
• flocculation
• sedimentation
• filtration
• chlorination
• dechlorination
• wastewater treatment settling lagoon
• chemicals - Potable Water Treatment
■ alum / aluminum sulfate [primary coagulant]
■ zinc -orthophosphate [corrosion inhibiter]
■ hypochlorite solution [disinfection]
■ chloramines [secondary disinfection]
■ caustic [pH adjustment]
■ super flock polymer [coagulation, flocculation]
■ calcium thiosulfate [dechlorination].
Fact Shcct
Renewal 2017 — NPDES Permit NCO083712
Page 1

RENEWAL SUMMARY: This permit reflects discharge at Outfall 001. DWR updated the following:
1. Turbidity monitoring is twice per month (2/month) with a monthly average limit of 50 NTU and a
daily maximum limit of 50 NTU.
2. Total Iron and Total Manganese monitoring has been removed.
3. Total Copper monitoring has been removed because it did not show reasonable potential to exceed
applicable water quality standards/criteria and the maximum predicted concentration was <50% of
the allowable concentration.
4. Effluent and upstream quarterly monitoring for Total Hardness (see below for information) has
been added.
5. Electronic reporting of discharge monitoring reports (eDMR) in Section A. (4.) has been added.
DISCUSSION OF CHANGES FOR RENEWAL:
Turbidity — In accordance with current WTP permitting strategy and US EPA Region IV memo dated
02/25/09, turbidity monitoring and limitation is required for this renewal. North Carolina has established
standards for Turbidity in accord with receiving -stream classification, monitoring and permit limits are
deemed appropriate to evaluate effluent compliance for freshwater [NCAC 02B. 0211(21)]. Accordingly,
the following footnote is inserted:
Turbidity Effluent turbidity shall not cause receiving -stream turbidity to exceed 50 NTU. If
background turbidity naturally exceeds 50 NTU, the effluent shall not cause background turbidity
to increase. Any discharge exceeding this permit limit will require sufficient instream sampling
(upstream and/or downstream) to verify compliance (effluent vs. background). [NCAC 02B.
0211(21)]
The 50 NTU standard applies as both a Monthly Average and Daily Maximum for this renewal. US EPA
requires both a Monthly Average and a Daily Maximum for all parameters limited [40 CFR 122.45 (d.)]. In
accordance with current WTP permitting strategy, facilities with flows <0.5 MGD are required to monitor
limited parameters at a frequency of 2/month.
Total Iron & Total Manganese — Iron and manganese no longer have water quality standards. Therefore,
there are no limits to compare monitoring data for these parameters. The NC 2007-2015 Water Quality
Standard (WQS) Triennial Review was approved by the NC Environmental Management Commission
(EMC) on November 13, 2014. The US EPA subsequently approved the WQS revisions on April 6, 2016,
with some exceptions. Iron and Manganese standards were removed. Additionally, Iron sulfate/ferrous
sulfate is not in use at this facility. Therefore, monitoring for Iron and Manganese are removed for the
permit renewal.
Total Hardiness — Effluent hardness sampling and instream hardness sampling, upstream of the discharge,
are inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the accuracy
of the permit limits and to build a more robust hardness dataset.
ELIGIBILITY FOR COVERAGE UNDER THE GENERAL PERMIT NCG590000: The Town of
Mars Hill is not eligible for the general permit because North Fork Big Laurel Creek [stream segment 6-
112-1-(2)] currently discharges to waters classified C; ORW. Discharges from WTPs to Outstanding
Resource Waters (ORW) and high quality water (HQW) are excluded from general permit NCG590000.
TOXICITY: With an IWC > 0.25%, this permit requires Chronic Whole Effluent Toxicity (WET) testing
using Ceriodaphnia dubia to be performed as a 7-day pass/fail test at 3.3% effluent concentration, once per
calendar year [TGP3B] [See Condition A. (2.).]. Review of Whole Effluent Toxicity (WET) testing data
from December 2013 to July 2016 found at overall pass rate of 100% (12 tests) [see attached Whole
Effluent Toxicity Testing and Self -Monitoring Summary].
COMPLIANCE HISTORY: No violations indicated form Ju12012 to Dec2016.
Fact Shcct
Renewal 2017 — NPDES Permit NCO083712
Pa,,c 2

STREAM: The stream at the point of discharge is identified as North Fork Big Laurel Creek with stream
index 6-112-1-(2) and currently classified C; ORW (see Figures 1 & 2). The stream was incorrectly
identified based on the USGS Quad map as Big Laurel Creek with stream index 6-112 and classified as C,
Tr; ORW (see Figure 3).
Figure 1. North Fork Big Laurel Creek [stream index 6-112-1-(2)]
Fact Shect
Renewal 2017 — NPDES Permit NC0083712
Pal-e 3

Figure 2. North Fork Big Laurel Creek [stream index 6-112-1-(2)] topographic map
i,
l 5 oen, lnwvc,ld. J �\
o-112.1aa
\ �
Fo �I W I Wmr IiiaK�BO
�:
� 1 High
4up.m 31 xWV _
1
r
Fact Sheet
Renewal 2017 — NPDES Permit NCO083712
Page 4

Figure 3. Big Laurel Creek [stream index 6-1121
2014 Integrated Report
O, U.IC k
C'7' P
Flz & i o9D
b �� • 1 V 1 �/ FrtrcF& E
pi, Uap'l
DATA SUMMARY
lonthly Average Flow for Jau2014-Dec2016 3 yearsl
parameter Max Min Count UoM
50050 - Flow, in conduit or thru treatment plant 0.02615: 0.007175 361 mgd
DMR Dailv Parameter Values for JUly2U12-Vee2U16 (4 1/2 years
Parameter
T
Max
Min
Average Count
POL
UoM
00010 - Temperature, Water Deg. Centigrade
11.3
6
8.3
4
deg c
00070 - Turbidity
28.3
1
4.6
108
ntu
00400 - pH
9
6
231
su
01042 - Copper, Total (as Cu)
10
1
3.944
18
1,5,10
ug/I
01045 - Iron, Total (as Fe)
190
50
94.11
18
50
ug/I
01055 - Manganese, Total (as Mn)
170
8
63.59
17
ug/I
01092 - Zinc, Total (as Zn)
80
11
31.88
17
ug/I
01105 -Aluminum, Total (as Al)
3400
50
1297.2
18
50
ug/I
50050 - Flow, in conduit or thru treatment plant
0.0961
0.00175
0.0175
233
mgd
50060 - Chlorine, Total Residual
28
28
28
109
28
ug/I
CO530 - Solids, Total Suspended - Concentration
29.7
2
9.4
108
mg/I
Fact Sheet
Renewal 2017 — NPDES Permit NC0083712
Page 5

RPA: The need for toxicant limits is based upon a demonstration of reasonable potential to exceed water
quality standards, a statistical evaluation that is conducted during every permit renewal utilizing the most
recent effluent data for each outfall. The RPA is conducted in accordance with 40 CFR 122.44 (d) (i). The
NC RPA procedure utilizes the following: 1) 95% Confidence Level/95% Probability; 2) assumption of
zero background; 3) use of V2 detection limit for "less than" values; and 4) streamflows used for dilution
consideration based on 15A NCAC 2B.0206. Effective April 6, 2016, NC began implementation of
dissolved metals criteria in the RPA process in accordance with guidance titled NPDES Implementation of
Instream Dissolved Metals Standards, dated June 10, 2016.
A reasonable potential analysis was conducted on effluent toxicant data collected between Ju12012-
Dec2016. Pollutants of concern included toxicants with positive detections and associated water quality
standards/criteria. Based on this analysis, the following permitting actions are proposed for this permit:
• No Limit or Monitoring: The following parameters will not receive a limit or monitoring, since they
did not demonstrate reasonable potential to exceed applicable water quality standards/criteria and
the maximum predicted concentration was <50% of the allowable concentration: Copper
• Monitoring_ Only. The following parameters will receive a monitor -only requirement since they did
not demonstrate reasonable potential to exceed applicable water quality standards/criteria, but a
chemical with this metal is in use at the water treatment plant: Zinc and Aluminum.
NPDES Implementation of Instream Dissolved Metals Standards — Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water Oualitv Standards/Aauatic Life Protection
Parameter
Acute FW, µjI
(Dissolved)
Chronic FW, µjI
(Dissolved)
Acute SW, µjI
(Dissolved)
Chronic SW, µjI
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90
81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
Fact Sheet
Renewal 2017 — NPDES Permit NCO083712
Page 6

2. gala � = Hardness dependent standard
I Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life standards
for Mercury and selenium are still expressed as Total Recoverable Metals due to bioaccumulative
concerns (as are all human health standards for all metals). It is still necessary to evaluate total
recoverable aquatic life and human health standards listed in 15A NCAC 2B.0200 (e.g., arsenic at
10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at 1.8 mg/L for aquatic life
protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/I
Cadmium, Acute
WER*{1.136672-[In hardness](0.041838)) • e^10.9151 [in hardness]-3.1485)
Cadmium, Acute Trout waters
WER*{1.136672-[In hardness](0.041838)) • e^(0.9151[ln hardness]-3.6236)
Cadmium, Chronic
WER*{1.101672-[In hardness](0.041838)) • e^(0.7998[ln hardness]-4.4451)
Chromium III, Acute
WER*0.316 . e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 • e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 • e^{0.9422[In hardness]-1.700}
Copper, Chronic
WER*0.960 • e^(0.8545[In hardness]-1.702)
Lead, Acute
WER*{1.46203-[In hardiiess](0.145712)) • e^{1.273[In hardness]-1.460)
Lead, Chronic
WER*{1.46203-[In hardness](0.145712)} • e^{1.273[In hardness]-4.705)
Nickel, Acute
WER*0.998 • e^{0.8460[In hardness]+2.255}
Nickel, Chronic
WER*0.997 • e^{0.8460[In hardness]+0.0584)
Silver, Acute
WER*0.85 • e^(1.72[ln hardness]-6.59)
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 • e^{0.8473[ln hardness]+0.884)
Zinc, Chronic
WER*0.986 • e^{0.8473[ln hardness]+0.884}
General Information on the Reasonable Potential Analysis WA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness -dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness and
so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge -specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on that
below), but it is also possible to consider case -specific translators developed in accordance with established
methodology.
Fact Sheet
Renewal 2017 - NPDES Permit NC0083712
Page 7

RPA Permitting Guidance/WOBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable
standards and the critical low -flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the
discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below
detection level), then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q 10 (the spreadsheet automatically calculates
the 1 Q 10 using the formula 1 Q 10 = 0.843 (s7Q 10, cfs) 0.113
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness -dependent metal of concern and for
each individual discharge, the Permit Writer must first determine what effluent and instream
(upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values, upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L, respectively.
If the use of a default hardness value results in a hardness -dependent metal showing reasonable
potential, the permit writer contacts the Permittee and requests 5 site -specific effluent and upstream
hardness samples over a period of one week. The RPA is rerun using the new data.
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
_ (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) + (s7010 cfs *Avg Upstream Hardness mgjQ
(Permitted Flow, cfs + s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1 Q 10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any have
been developed using federally approved methodology.
Fart Shcct
Renewal 2017 — NPDES Permit NCO083712
Page 8

EPA default partition coefficients or the "Fraction Dissolved" converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in -stream ambient
conditions. This factor is calculated using the linear partition coefficients found in The
Metals Translator: Guidance for Calculating a Total Recoverable Permit Limit from a
Dissolved Criterion (EPA 823-B-96-007, June 1996) and the equation:
-Cdiss—= 1
Ctotal 1 + { [Kpo] [ss(t+a)] [10-6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used, and
Kpo and a = constants that express the equilibrium relationship between dissolved and
adsorbed forms of metals. A list of constants used for each hardness -dependent metal can
also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient (or
site -specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases, where an EPA default partition coefficient translator does not exist (ie. silver), the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is
dissolved to the same extent as it was during EPA's criteria development for metals. For more
information on conversion factors see the June, 1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration
(permit limits) for each pollutant using the following equation:
Ca = (s7Q 10 + Qw) Cwgs) — (s7Q 10) (Cb)
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (µg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw = permitted effluent flow (cfs, match s7Q 10)
s7Q 10 = summer low flow used to protect aquatic life from chronic toxicity and human health
through the consumption of water, fish, and shellfish from noncarcinogens (cfs)
* Discussions are on -going with EPA on how best to address background concentrations
Flows other than s7Q 10 may be incorporated as applicable:
IQ 10 = used in the equation to protect aquatic life from acute toxicity
QA = used in the equation to protect human health through the consumption of water, fish,
and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
Fact Shcet
Renewal 2017 — NPDES Permit NCO083712
Page 9

application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations, the discharge is considered to show reasonable
potential to violate the water quality standard, and a permit limit (Total allowable concentration) is
included in the permit in accordance with the U.S. EPA Technical Support Document for Water
Quality -Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in accordance with
the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on 40 CFR
122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and hexavalent
chromium Water Quality Standards. As a cost savings measure, total chromium data results may be
used as a conservative surrogate in cases where there are no analytical results based on chromium
III or VI. In these cases, the projected maximum concentration (95th %) for total chromium will be
compared against water quality standards for chromium III and chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are inserted
into all permits with facilities monitoring for hardness -dependent metals to ensure the accuracy of
the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25
default hardness
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25
default hardness
7Q 10 summer (cfs)
1.2
Permit File/ BIMS
1 Q 10 (cfs)
1.01
By Calculation in RPA
Maximum Monthly Average (MGD)
0.026
Jan2014-Dec2016 DMR Data
Date: March 31, 2017
Permit Writer: Derek Denard
Fact Snco
Renewal 2017 — NPDES Permit NC0083712
Pagc 10

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Table 1. Project Information
Facility Name
W WTPWTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
[]Apply WS Hardness WQC
7Q1 Os (cfs)
7Q1 Ow (cfs)
30Q2 (cfs)
CIA (cfs)
1Q10s (cfs)
Effluent Hardness -------------
Upstream Hardness
Cmbined Hardness Chronic
_o_
Combined Hardness Acute
Data Source(s)
❑CHECK TO APPLY MODEL
IJCHECK IF HQW OR ORIN WQS
Town of Mars Hill - Mars Hill WTP
PC-1
NCO083712
001
0.026
North Fork Big Laurel Creek
060101051001
C;ORW
1.20
1.70
2.60
5.08
1.01
25 mg/L (Avg)
---------------------
25 mg/L (Avg)
25 mg/L
25 ni
BIMS Data 0-2016 to 07-2016
Follow directions for data entry. In some cases a
comment menu list the available choices or a
dropdown menu will provide a list you may select
from. Error message occur if data entry does not
meet input criteria.
REQUIRED DATA ENTRY CHECK WO S
Table 2. Parameters of Concern
Name was Tyr, Chronic Modifier Acute PQL Units
Parer
Per02
Par03
Par04
Pates
Par06
Par07
Pares
Pares
Parrot
Peril
Capper
Aquatic Life
NC
7.8806
FW
10.4720
ug/L
Par12
Perri
Par14
Pari5
Paris
Pari7
Paris
Paris
Par20
Par2l
Zinc
Aquatic Life
NC
126.7335
FW
125.7052
ug/L
Par22
Aluminum
Human Health
NC
woo
HH
Ng/L
Pa23
Par26
Par25
NCO083712 9595 Final FW RPA w_upstream avg data column_diss to totalmetals_nodetects_limiteddefaults 2016_822, Input
3/31/2017

REASONABLE POTENTIAL ANALYSIS
H1
H2
Uae'PASTE SPECIAL
Uee'PASTE SPECIAL
Effluent Hardness
values' men'coav
Upstream Hardness
values^then^COPr
. Maximum data
. Maximum data.
points = 58
points = SB
Date Data BDL=112DL Results
Date
Data BDL-1/2DL Results
1
25 25 Std Dee.
NIA
1
25 25 Std Dev.
NIA
2
Mean
25.0000
2
Mean
25.0000
3
C.V.
0.0000
3
C.V.
0.0000
4
n
1
4
n
1
5
10th Per value
25.00 mg/L
5
10th Per value
25.00 mg/L
6
Average Value
25.00 mg/L
6
Average Value
25.00 mg/L
7
Max. Value
25.00 mg/L
7
Max. Value
25.00 mg/L
8
8
9
9
10
10
11
11
12
12
13
13
14
14
15
15
16
16
17
17
18
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
58
c
NC0083712 9595 Final FW RPA w_upstream Evil data column_diss to lotalmetals_nodetects_limiteddefaults 2016 822, data
-1- 3131/2017

REASONABLE POTENTIAL ANALYSIS
Pal
Par21
Use 'PASTE SPECIAL
Use 'PASTE SPECIAL
Copper
Values'than "COPY"
ZIDC
Values"then 'COPY"
. Maximum data
. Masmum data
Points a se
points = 56
Date
Data
BDL=112DL
Results
Date Data
BDL=1120L
Results
�18.9605
1
7/312012
<
10
5
Std Dev.
2.0428
1
713/2012 <
30
15
SW Dev.
2
10192012
<
10
5
Mean
2.5556
2
101=012
80
80
Mean
31.0000
3
1/212013
<
10
5
C.V.
0.7994
3
1/2/2013
54
54
C.V.
0.6116
4
4/2/2013
<
10
5
n
16
4
4/2/2013
38
38
n
17
5
7/16/2013
<
5
2.5
5
7/16/2013
17
17
6
10/812013
<
1
0.5
Mult Factor =
1.55
6
10/8/2013
15
15
Mull Factor =
1.45
7
1/1412014
2
2
Max. Value
6.00 ug/L
7
418/2014
42
42
Max. Value
80.0 uglL
8
4/8/2014
5
5
Max. Prod Cw
9.30 ug/L
8
7/2212014
22
22
Max. Pred Ow
116.0 ug/L
9
7/22/2014
<
1
0.5
9
1017/2014
13
13
10
10/72014
<
1
0.5
10
1/6/2015
39
39
11
1/6/2015
6
6
11
4/14/2015
22
22
12
4/1412015
<
1
0.5
12
717/2015
11
11
13
7/712015
3
3
13
10/13/2015
40
40
14
10113/2015
<
1
0.5
14
1/12/2016
53
53
15
1/122016
1
1
15
4/122016
33
33
16
4/12/2016
1
1
16
7/19/2016
15
15
17
7119/2016
2
2
17
10/11/2016
18
18
18
10/11/2016
1
1
18
19
19
20
20
21
21
22
22
23
23
24
24
25
25
26
26
27
27
28
28
29
29
30
30
31
31
32
32
33
33
34
34
35
35
36
36
37
37
38
38
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
51
52
52
53
53
54
54
55
55
56
56
57
57
58
1 58
NCO083712 9595 Final FW RPA w_upstream avg data column_diss to lotalmetals_nodetects_limileddefaults 2016 822, data
-2- 3/3l/2017

REASONABLE POTENTIAL ANALYSIS
Par22
Use -PASTE SPEa
Aluminum
Values" then "COPY"
. Maximum data
points = 55
Date Data
BDL=1/2DL
Results
1
7/3/2012
1000
1000
Sid Dev.
803.1084
2
10/9/2012
580
580
Mean
1295.8333
3
1/2/2013
950
950
C.V.
0.6198
4
4/2/2013
1300
1300
n
18
5
7/16/2013
2200
2200
6
10/8/2013
880
880
Mult Factor =
1.43
7
1/14/2014
1000
1000
Max. Value
3400.0 yg/L
8
4/8/2014
1100
1100
Max. Pred Cw
4862.0 pg/L
9
7/22/2014
1500
1500
10
10/7/2014
440
440
11
116/2015 <
50
25
12
4/14/2015
1100
1100
13
7/7/2015
1600
1600
14
10/13/2015
1900
1900
15
1/12/2016
3400
3400
16
4/12/2016
2300
2300
17
7/1912016
1600
1600
18
10111/2016
450
450
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
NC0083712 9595 Final FW RPA w_upstream avg data wlumn_diss to totalmetals_nodetects_limiteddefaults 2016_822, data
- 3 - 3/3l/2017

Town of Mars Hill - Mars Hill WTP a
NCO083712 Freshwater RPA- 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
Qw (MGD) = 0.03
IQIOS(cfs)= 1.01
7QIOS lets)= 1.20
7Q10W(cfs)= 1.70
30Q2 (cfs) = 2.60
Avg. Stream Flow, QA (cfs) = 5.08
Receiving Stream: North Fork Big Laurel Creek HUC 060101051001
WWTP/WTP Class: PC-1
IWC% @ IQIOS = 3.85828140
IWC%@7QIOS= 3.267346885
IWC%@7QIOW= 2.328741348
IWC%@30Q2= 1.535012351
IW%C@QA= 0.791568064
Stream Class: C;ORW
Outfall 001
Qw = 0.02615 MGD
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS HOW OR ORW
COMBINED HARDNESS (ma/L)
Acute = 25 mg/L
Chronic = 25 mg/L
PARAMETER
TYPE
NC STANDARDS OR EPA CRITERIA
J
in
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
c'Iumiic Standard Acute
D H DeL Max Pred Cw Allowable Cw
(11
m
Acute: 135.71
No RP, Predicted Max <50%of Allowable Cw-No
Copper
NC
3.9403 FW(7QIOs) 5.2360
ug/L
18 8
9.30
Monitoring required
PrededMx5%ewNRcAwChronic: No <oo
No value> Allowable Cw
Monitoring required
Acute: 1,629.0
No RP, Predicted Max <50%ofAllowableCw-
Zinc
NC
63.3667 FW(7Q10s) 62.8526
ug/L
17 16
116.0
Monitoring required be Zinc -orthophosphate in use
---------------------------------------
Chronic: 1,939.4
No RP, Predicted Max <50%ofAllowable Cw-
No value> Allowable Cw
Monitoring required be Zinc-orthaphosphate in use
Acute: NO WQS
Aluminum
NC
i 4000 RH(7QIOs)
µg/L
18 17
4,862.00
_ _ _____ _ _
Chronic: 122423.49
_ _ _ _ _ _ _ _ _ _ _
No RP, Predicted Max <50%ofAllowableCw-
No value> Allowable Cw
Monitoring required be Alum/aluminum sulfate in use
NCO083712 9595 Final FW RPA w_upstream avg data column_dlss to totalmetals_nodetects_limiteddefaults 2016_822, rya
Page 1 of 1 X11/2017

Date: 3/31 /2017
FACILITY: Town of Mars Hill - Mars HIII WTP
NPDES PERMIT: NCO083712 Dissolved to Total Metal Calculator
In accordance with Federal Regulations, permit limitations roust be written as I oral Metals per 40 CFR 122.45(c)
Receivin
Receiving
Rea Stream NPDES
Total Sus ended
Combined
Combmed
InsVeam
Eff
j38583
Upstream Hard Avg (mg/L) = 25
EFF Hard Avg (mg/L) = 25
PARAMETER
Dissolved Metals
US EPA
Translators -using
Default Partition
Coefficients
streams
sumum lava a ueet ommUon
(MAEC) as a Total Metal
=Dheeroed Metal. Trmslalr
COMMENTS (Identify parameters to PERCS Branch to maintain in facillt7/s LTMP/STMP):
Chronic Acute
Chronic Acute
u l u
u 4 u
Cadmium (d)
Cd-Trout stream
Chromium III (d)(h)
Chromium VI (d)
Chromium, Total (t)
Copper d h
Lead h
Nickel(d)(h)
Ni - WS streams (t)
Silver (d)(h,acute)
ZJnc d h
0.15 0.82
0.252
0.591 3.24
0.59 2.01
117.73 905.08
11.00l 16.00
NIA N/A
7 88 10.47
2.94 75.49
37.23 335.21
25 N/A
0,06 0.30
126.73 125,71
0.15 0.51
0.252
0.202
_
24'i 183
_ 11 16
1.000
2.7
3.8
0.348
0.184
0.54
14
16,
145
0.432
1.000
0,288
0.06 0.30
36 36
8e Ilium
6.5
65
1.000
6.5
65
Arsenic d
150
340
1.000
150
340
(d) = dissolved metal standard. See 15A NCAC 02B .0211 for more Information.
(h) = hardness -dependent dissolved metal standard. See 15A NCAC 028.0211 for more Information.
(t) =based upon measurement oftowl recmveable mewl. See 15A NCAC 02B.0211 for more information.
The Human Health standard for Nickel in water Supply Streams Is 25 ri which is Total Recoverable metal standard.
The Human Health standard for Arsenic is 10 pg/L which is Total Recoverable metal standard.
g
g
p
luent
Stream
Stream
So5ds
Hartlness
Hartlness
Wastewater
Upstream
er Hardness
summer
summer 7010
1010 Flow Limit
-Fixed Value-
chronic
Acute
Concentration
concentration Hardness Avera9a
70ID(CFS)
(MGD)
MGD GD
(mglL)
(mgA)
(Chronic)
Average
� ( �)
vera m (mg/L)
1.2000
0.7742
0.6576 0.0262
10
25.000
25.000
3.2673
25 25

Denard, Derek
From:
Denard, Derek
Sent:
Friday, March 31, 2017 12:00 PM
To:
'[e-mail]'
Subject:
Eligibility for General Permit NCG590000 - Mar Hill WTP NC0083712
Attachments:
NCG590000.pdf; Technical Bulletin NCG590000.pdf
Mr. Boone,
We received your request to convert Individual permit N00083712 to general permit NCG590000. Regretfully, one detail
was overlooked for this facility. Discharges to Outstanding Resource Waters (ORW) and high quality waters (HQW) are
excluded from the general permit. Mars Hill WTP discharges to waters currently classified as C; ORW. Please note this
limitation as outlined in Part 1 A. (2) of general permit NCG590000 and in the Technical Bulletin. Sorry for any
inconvenience this may have caused you or your staff.
A draft for the renewal of Individual permit NC0083712 will be submitted for public notice shortly.
If you have any questions, please contact me.
Sincerely,
Derek C Denard
Environmental Specialist
Compliance & Expedited Permitting Unit
N.C. Division of Water Resources
N.C. Department of Environmental Quality
919 807 6307 office
derek.denard Ca)ncdenr.cov
N. C. Division of Water Resources
Water Quality Permitting Section - NPDES
1617 Mail Service Center
Raleigh, NC 27699-1617
Nothing Compares ,.
Email correspondence to and from this address is subject to the
North Carolina Public Records Law and may be disclosed to third parties.

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Mail the complete application to:
N. C. DENR / Division of Water Resources / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617
NPDES Permit Number NCO083712
If you are completing this form in computer use the TAB key or the up - down arrows to move from one
field to the next. To check the boxes, click your mouse on top of the box Otherwise, please print or type.
1. Contact Information:
Owner Name
Facility Name
Mailing Address
City
State / Zip Code
Telephone Number
Fax Number
e-mail Address
Town of Mars Hill
Mars Hill Water Treatment Plant Lagoon
PO Box 368
Mars Hill
NC 28754 RECEIVED/DEhjgLnuL
[phone] APP
[phone]
•.alai wuamv
robmsamsQayahoo.com Permitina SPCffCV
2. Location of facility producing discharge:
Check here if same as above ❑
Street Address or State Road
2085 Water Shed Road
City
Mars Hill
State / Zip Code
28754
County
Madison
3. Operator Information:
Name of the firm, consultant or other entity that operates the facility. (Note that this is not referring to the
Operator in Responsible Charge or ORC)
Name Town of Mars Hill
Mailing Address PO Box 368
City Mars Hill
State / Zip Code NC 28754
Telephone Number [phone]
Fax Number [phone]
4. Ownership Status:
Federal ❑ State ❑ Private ❑ Public
S. Type of treatment plant:

NPI)ES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
® Conventional (Includes coagulation, flocculation, and sedimentation, usually . followed by
filtration and disinfection)
❑ Ion Emchange (Sodium Cycle Cationic ion exchange)
❑ Queen Sand Filter (No sodium recharge)
❑ Membrane Technology (RO, nanofiltration)
Check here if the treatment process also uses a water softener ❑
6. Description of source water(s) (Le. groundwater, surface water)
Surface water
7. Describe the treatment process(es) for the raw water.
sedimentation
S. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
Sand filter backwash and flush water is piped to a lagoon where the alum sludge settles to
the bottom of the lagoon and effluent is discharged from the top and goes through a tablet
dechlorination before being discharged into receiving stream.
9. Number of separate discharge points: 01 Outfall IdeatiScation number(s) 91
10. Frequency of discharge: Continuous ❑ Intermittent
If intermittent:
Days per week discharge occurs: 7 Duration: 12 hrs
11. Plant design potable flowrate NA MGD
Backwash or reject flow 0.0183 MGD average 2014
12. Name of receiving stream(s) (Provide a main showing the exact location of each outfall, including
latitude and longitudef
North Fork Big Laurel Creek
13. Please list all water treatment additives, including cleaning chemicals or disinfection
treatments, that have the potential to be discharged.
Alum /aluminum sulfate Yes X No
Iron sulfate / ferrous sulfate Yes No X
Fluoride Yes No X

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Ammonia nitrogen / Chloramines Yes No X
Zinc -orthophosphate or sweetwater CP1236 Yes X No
List any other additives below:
Hypochlorite Solution
Caustic
Super flock polymer
14. Is this facility located on Indian country? (check one)
Yes ❑ No
15. Additional Information:
Provide a schematic of flow through the facility, include flow volumes at all points in
the water treatment process. The plan should show the point[s] of addition for
chemicals and all discharges routed to an outfall [including stormwater].
Solids Handling Plan
16. NEW Applicants
Information needed in addition to items 1-15:
New applicants are strongly recommended to contact a permit coordinator with the
NCDENR Customer Service Center.
Was the Customer Service Center contacted? ❑ Yes ❑ No
Analyses of source water collected
Engineering Alternative Analysis
Discharges from Ion Exchange and Reverse Osmosis plants shall be evaluated using a
water quality model.
17. Applicant Certification
I certify that I am familiar with the information contained in the application and that to the
best of my knowledge and belief such information is true, complete, and accurate.
North Carolina General Statute 143-215.6 (bK2) provides that Any person who Imowkgfy makes any false statement representation, or certification in any application,
record, report, plan, or other document files or required to be maintained under Article 21 or regulations of the Environmental Management Commission implementing that
Article, or who falsifies, tampers with, or knowingly renders inaccurate any recordiN or mondorkg device or method required to be operated or maintained under Article 21
or regulations of the Environmental Management Commission implementing that Article, shall be guilty of a misdemeanor punishable by a free not to exceed $25,000, or by
imprisonment not to exceed sir months, or by both. (18 U.S.C. Section 1001 provides a punishment by a fine of not more than f25,000 or vnprsonment not more than 5
years, or both, for a similar offense.)

NCO083712
Town of Mars Hill Water Plant Lagoon
Solids Handling Plan
At the current time The Town of Mars Hill is utilizing a Geotube to dewater our Alum
Sludge. We have a temporary permit to place the Geotube above the Lagoon and the
effluent from the Geotube is carried back to the Lagoon before discharge. At such time
when the Geotube is full and dry the town will haul the alum sludge to an approved
landfill or disposal site. The lagoon will hold sludge for 5 to 7 years before it requires
pumping.

'b-% s 66QfT

McGill
Sewer Map Legend
® Treatment Plant
") Odor Control Station
Pump Station
8 Air Release Valve
0 Manhole
0 Unverified Manhole
—Gravity Sewer
Unverified Gravity See
—Force Alain
Go. sle earth
3r°56'19,bG
a9"'�� "�O
,McGill
Water Map Legend
Treatment Plant
Raw Water Reservoir
Storage Tank
8 Control Valve
I System Valve
IS Pump Station
Hydrant
i1 Master Meter
Water Mains
__ Raw Water Line

I
= County Boundary
• NPDES discharger
Fb_hy.Shp
Highways
Municipal boundary
N
A
Town of Mars Hill
Mars Hill WTP-Lagoon
NCO083712
Madison County
1 0 1 Miles
Facility Information
State Grid: D9NW
USGS Quad: Bald Creek
Subbasin: 0403-D6
6