NC0082759_Permit Issuance_20080205

Mr. Roger D. Hellard
Orange-Alamance Water System, Inc.
P.O. Box 187
Mebane, North Carolina 27302
Dear Mr. Hellard:
Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins Director
Division of Water Quality
February 5, 2008
Subject: Issuance of NPDES
Permit NCO082759
Orange-Alamance Water System WTP
Orange County
Division personnel have reviewed and approved your application for renewal of the subject permit.
Accordingly, we are forwarding the attached NPDES discharge permit. 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).
This permit includes no major changes from the draft permit sent to you on December 19,-2007.
If any parts, measurement frequencies or sampling requirements contained in this permit are unacceptable to
you, you have the right to an adjudicatory hearing upon written request within thirty (30) days following receipt of
this letter. This request must be in the form of a written petition, conforming to Chapter 150E of the North
Carolina General Statutes, and filed with the Office of Administrative Hearings (6714 Mail Service Center,
Raleigh, North Carolina 27699-6714). Unless such demand is made, this decision shall be 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 Quality or permits required by the Division of
Land Resources, the Coastal Area Management Act or any other Federal or Local governmental permit that may
be required. If you have any questions concerning this permit, please contact Bob Guerra at telephone number
[phone], extension 539.
Sincerely,,
�47r i oleen H. Sullins
Enclosure: NPDES Permit NCO082759
Potable Water Treatment Strategies Policy Document
cc: Central Files
Raleigh Regional Office / Surface Water Protection
NPDES Unit
N""o��nnCarolina
Wulldbr
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone] Customer Service
Internet: www.ncwaterqualitv.org Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
An Equal Opportunity/Affirmative Action Employer— 509% Recycled/10% Post Consumer Paper

Permit NCO082759
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
PERMIT
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provision 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
Orange-Alamance Water System, Inc.
is hereby authorized to discharge wastewater from a facility located at the
Orange-Alamance Water System WTP
2101 US Hwy 70 East
Efland
Orange County
to receiving waters designated as the Eno River in the Neuse 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 March 1, 2008.
This permit and authorization to discharge shall expire, at midnight on January 31,
2008.
Signed this day February 5, 2008.
C, C
Col n H. Sullins, Director
Dsion of Water Quality
y Authority of the Environmental Management Commission

Permit NCO082759
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.
The Orange-Alamance Water System WTP is hereby authorized to:
1. Continue to operate a Conventional treatment drinking water plant with a
discharge of filter -backwash wastewater to the Eno. River.
2. This facility is located at 2102 US Hwy 70 East in Efland in Orange County.
3. The conventional water treatment plant process consists of:
Raw Water treatment process:
• The water is treated with Alum, Polymer, Potassium Permanganate, and
Caustic as needed for pH adjustment for proper coagulation.
• The water is then settled in a conventional sedimentation basin.
• Filtered -Chlorine is added before and after filtration.
Waterwater treatment process:
• All wastewater is generated by filter backwash and filter rewash.
• All wastewater is treated with 2.5 to 3.0 mg/l Calcium Thiosulfate for de -
chlorination
• All wastewater is settled in primary and secondary lagoons prior to
discharge.
4. Discharge from said treatment works at the location specified on the attached map
into the Eno River, classified C-NSW waters in the Neuse River Basin.

Orange-Alamance Water
System, I
Orange-Alamance Water System WTP
Latitude: 36° 05' 01" N State Grid:
Efland
Longitude: 79' 08' 25" W Permitted Flow:
Unlimited
Receiving Stream: Eno River Drainage Basin:
Neuse River Basin
Stream Class: C-NSW Sub -Basin:
03-04-01
I Facility
Location
not to scale
r
North I E

Permit NCO082759
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
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
and mnr»tnroel by vhq- permittee AR snecified below:
rt EFFLUENT �. > '
CHARACTERISTICS
°'' ° '• - , : LIMITS
MONITORING REQUIREMENTS
Avers a
Weekly
'"Averse
Daly Maximum
Y
L. Measurement
Fre ue e
Sample Type
" 1
Sample`
'Locationn
Flow
0.30 MGD
Continuous
Effluent
TSS
30 m
45 mgAL
2/Month
Grab
Effluent
H
6.0 - 9.0 s.u.
2/Month
Grab
Effluent
Total Residual Chlorine'
28 µg/L
2/Month
Grab
Effluent
Aluminum
Monitor & Report
Quarterly3
Grab
Effluent
Calcium
Monitor & Report
Quarterly3
Grab
Effluent
Magnesium
Monitor & Report
Quarterly3
Grab
Effluent
Manganese
Monitor & Report
Quarterly3
Grab
Effluent
Fluoride
Monitor & Report
Monthly
Grab
Effluent
Ammonia Nitrogen,
Monitor & Report
Monthly
Grab
Effluent
Total Copper
Monitor & Report
Monthly
Grab
Effluent
Total Iron
Monitor & Report
Monthly
Grab
Effluent
Total Phosphorus (TP)
Monitor & Report
Quarterly
Grab
Effluent
Total Nitrogen -
Monitor & Report
Quarterly
Grab
Effluent
Whole Effluent Toxicity
Monitoring-2
Monitor & Report
Quarterly
Grab
Effluent
Footnotes:
1. Limit and monitor only if facility adds chlorine to water that is eventually discharged
2. See Attachment A. (3)
3. Parameter should be monitored in conjunction with toxicity test
All samples collected should be from a representative discharge event.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NCO082759
A. (2) CALCULATION OF TOTAL NITROGEN LOADS
a. The Permittee shall calculate monthly and annual TN Loads as follows:
L Monthly TN Load (pounds/month) = TN x TMF x 8.34
where:
TN = the average TN concentration (mg/ L) of the samples collected
during the month
TMF = the Total Monthly Flow of wastewater discharged during the
month (MG/month). If all discharges are not recorded at the
facility, document the calculation(s) used to determine total
monthly flow
8.34 = conversion factor, from (mg/ L x MG) to pounds
H. Annual. TN Load (pounds/year) = Sum of the 12 Monthly TN Loads for the
calendar year
b. The Permittee shall report monthly Total Nitrogen results (mg/ L and
pounds/ month) in the discharge monitoring report for that month. The Permittee
shall report each year's annual results (pounds per year) in the December report for
that year.

Permit NCO082759
A. (3.) CHRONIC TOXICITY MONITORING (QRTRLY)
The permittee shall conduct quarterly chronic toxicity tests using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure", Revised February 1998, or
subsequent versions.
The effluent concentration defined as treatment two in the procedure document is 60%. The testing
shall be performed as a Ceriodaphnia dubia 7day pass/fail test. The tests will be performed during the
months of January, April, July, and October. Effluent sampling for this testing 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, DWQ Form AT-1 (original) is, to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Section
1621 Mail Service Center
Raleigh, N.C. 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Environmental 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 Environmental 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 Quality indicate potential impacts to the receiving stream, this permit may be re-
opened and modified to include alternate monitoring requirements or limits.
If the Permittee monitors any pollutant more frequently then required by this permit, the results of
such monitoring shall be included in the calculation & reporting of the data submitted on the DMR &
all AT Forms submitted.
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.

Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
Coleen H. Sullins, Director
Division of Water Quality
February 5, 2008
North Carolina Wildlife Resources Commission
Division of Inland Fisheries
Ms. Shari L. Bryant
1721 Mail Service Center
Raleigh, NC 27699-1721
Re: Public Notice Response letter
Orange-Alamance Water System WTP
NPDES Permit Renewal NCO082759
January 15, 2008
Ms Bryant:
Thank you for your comment letter of January 15, 2008 in response to the Division of Water Quality (DWQ)
Public Notice for the reissuance of the Orange-Alamance Water System WTP NPDES Permit Renewal NC0082759.
I trust you received the draft permit that you requested in your January 10, 2008 email. The Orange-Alamance
Water System WTP does not propose to utilize Calcium Thiosulphate to de -chlorinate the backwash effluent, the
facility is currently de -chlorinating its effluent prior, to settling in primary and secondary lagoons and subsequent
discharge to the Eno River.
Your understanding that Total Residual Chlorine (TRC) limits are never less than 17ug/L or greater than 28ug/L
and that the 7Q10 flow is used to calculate the allowable effluent concentration of TRC is correct. The 28ug/L
TRC limit for this facility has been in effect since April 1, 2006 and was formulated by same process as all NPDES
facilities in North Carolina who are required to have TRC limits in their NPDES permits.
A mass balance equation (using the Instream Waste Concentration (lWC) Excel spreadsheet (Attached) is used to
calculate the allowable effluent concentration of total residual chlorine (TRC). Summer 7QlO flow is used in the
calculation and the background concentration is assumed to be zero. As is the case for all toxicants except
ammonia, one limit is given for the entire year as opposed to seasonal limits. When a limit is imposed, a cap of 28
ug/L is given. This represents the concentration at which acute impacts can occur in the receiving stream.
This facility has been discharging Water Treatment backwash effluent into the Eno River under NPDES Permit
NCO082759 since 1993. The DWQ can't force an existing facility to utilize a non -discharge option. The Raleigh
Regional Office has been conducting regular Compliance Inspections and has always recommended the NPDES
permit be renewed as a point discharge.
If I can be of further service please do not hesitate to contact me at [phone] extension 536.
Sincerely,
Robert Guerra, DWQ, Point Source Branch, NPDES West
I�° hCaro ina
OvW rally
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone] Customer Service
Internet: www.ncwaterquality.org Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax [phone]
An Equal Opportunity/Affirmative Action Employer — 500/6 Recycled/10% Post Consumer Paper

IWC Calculations
Orange-Alamance Water System WTP
NCO082759
Prepared By: Bob Guerra, NPDES Unit
Enter Design Flow (MGD):
Enter s7Q10(cfs):
Enter w7Q10 (cfs):
Residual Chlorine
0.3
0.3
2.2
Ammonia (NH3 as N)
(summer)
7Q10 (CFS)
0.3
7Q10 (CFS)
0.3
DESIGN FLOW (MGD)
0.3
DESIGN FLOW (MGD)
0.3
DESIGN FLOW (CFS)
0.465
DESIGN FLOW (CFS)
0.465
STREAM STD (UG/L)
17.0
STREAM STD (MG/L)
1.0
UPS BACKGROUND LEVEL (l
0
UPS BACKGROUND LEVEL
0.22
IWC (%)
60.78
IWC (%)
60.78
Allowable Conc. (ug/1)
28
Allowable Conc. (mg/1)
1.5
Ammonia (NH3 as N)
(winter)
7Q10 (CFS)
2.2
Fecal Limit
200/100ml
DESIGN FLOW (MGD)
0.3
(If DF >331; Monitor)
DESIGN FLOW (CFS)
0.465
(If DF <331; Limit)
STREAM STD (MG/L)
1.8
Dilution Factor (DF)
1.65
UPS BACKGROUND LEVEL
0.22
IWC (%)
17.45
Allowable Conc. (mg/1)
9.3
INPDES Servor/Current Versions/IWC
12/18/2007

® North Carolina Wildlife Resources Commission
Fred A. Harris, Interim Executive Director
MEMORANDUM
TO: Bob Guerra, NPDES Unit
Division of Water Quality
FROM: Shari L. Bryant, Piedmont Region Coordinator
Habitat Conservation Program
DATE: 15 January 2008
SUBJECT: Proposed Permit Renewal for Orange-Alamance Water System Inc, Orange-Alamance
WTP, Orange County, NPDES Permit No. NC0082759
Biologists with the North Carolina Wildlife Resources Commission have reviewed the subject
document. Our comments are provided in accordance with provisions of the Clean Water Act of 1977 (as
amended), Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d), North
Carolina General Statutes (G.S. 113-131 et seq.), and North Carolina Administrative Code 15A NCAC
10I.0102.
Orange-Alamance Water System, Inc. has applied for renewal of its NPDES permit to discharge
filter backwash wastewater into Eno River in the Neuse River Basin. According to the draft permit, the
wastewater, generated by filter backwash and filter rewash, would be treated with calcium thiosulfate for
de -chlorination then settled in primary and secondary lagoons prior to discharge. The daily maximum
limit for total residual chlorine is 28 lug/L.
The Eno River supports a diverse aquatic community and there are records for the federal and
state endangered dwarf wedgemussel (Alasmidonta heterodon); the federal species of concern and state
endangered green floater (Lasmigona subvirdis), yellow lampmussel (Lampsilis cariosa), and Atlantic
pigtoe (Fusconaia masoni); the federal species of concern and state significantly rare pinewoods shiner
(Lythrurus matutinus); the state threatened creeper (Strophitus undulatus) and Carolina fatmucket
(Lampsilis radiata conspicua); and the state special concern notched rainbow (Villosa constricta) in Eno
River.
Chlorine is acutely toxic to aquatic organisms and can form secondary compounds that are
detrimental to aquatic life. We are particularly concerned about impacts to the numerous listed species in
Eno River. Valenti (2006) concluded the impact of long term exposure to low doses of chlorine may
impact juvenile mussels and reduce the chance of them being recruited to the reproducing population.
It appears the applicant proposes to de -chlorinate the filter backwash water and allow water to
settle in primary and secondary lagoons prior to discharge. Although this may significantly reduce the
Mailing Address: Division of Inland Fisheries • 1721 Mail Service Center • Raleigh, NC 27699-1721
TPlrnhnnr: [phone] • Far: (919)707-O0')R

Page 2
15 January 2008
Orange-Alamance WTP
NPDES Permit No. NC0082759
amount of chlorine in the water discharged to Eno River, we are concerned about the daily maximum
limit for total residual chlorine listed in the permit renewal. It is our understanding total residual chlorine
limits are never less than 17 µg/L or greater than 28 µg/L, and the summer 7Q 10 flow is used to calculate
the allowable effluent concentration of total residual chlorine. We are concerned that in drought years,
the stream flow in the Eno River may be less than the 7Q 10 flow; therefore the wastewater discharged
may make up a greater portion of the stream flow.
Due to the presence of several rare and sensitive species in the Eno River, we offer the following
recommendations to reduce impacts to aquatic resources.
1. Use a non -discharge option for filter backwash wastewater.
2. If non -discharge is not an option, then the daily maximum limit for total residual chlorine should
be no more than 17 µg/L.
Thank you for the opportunity to comment on this permit renewal. If we can be of further
assistance, please contact our office at [phone].
Literature cited
Valenti, T.W., D.S. Cherry, R.J. Currie, R.J. Neves, J.W. Jones, R. Mair, and C.M. Kane. 2006. Chlorine
toxicity to early life stages of freshwater mussels (Bivalvia: Unionidae). Environmental
Toxicology and Chemistry, 25(9):2512-2518.
ec: Rob Nichols, WRC

AFFIDAVIT OF PUBLICATION
NORTH CAROLINA.
Orange County. Ss.
r PIiBUQ' NOTIC
STATEU NORTH` i A
ENVIRONMENTAL MANAGEIiAENl�.� r;
GONIMISSIOWNPDWS UNIT,+:P
1617-MAILLSERVICEi* CENTER.
RALEiGH:I+NC--
699.161I��" I ti•
Nomt ICATiort: o�NTn ,:-ro- ;
RK Tart"�� �,
-NC,. IStatute143:215X h NCAC 02H.0109 and:
other, lawful standards and regulations, the North Cgroll-
na Envlronmerdal Ma��aaBSeement Commission Proposes to
Issue a Natiorwcl Poltutent,Df rge E[Im1l ton System
(NPOES)'yy6stcvvaterdi 1§epen}tittotheperson(s).
Iistedbetaweifcti45 the'pubilihdateaithis
notj
Wriften`comme.nts regardin the proposed permit'w111 be
accepted until 30 days after the publish date o f this notice.
All comments reealved PriorFto that date are considered
in tare final determinatldns resarding the posed per-
mit. The Director of the NC -Division of Water Quality
may decide to.hold A blic meeting for the proposed
public should
th is o�t{ iv�~a s! n� cant degree of
Copies bt the draft perrnit'arather supporting in4ormd=
Lion on- file user to determine Ohdlttonq present In the
draft permit are available upon: bequest and_ payment of.
the costs of reproduction. Mail camments_arMr requests.
for information to the NC Division of,Water Quality atihe
above. oddness ,or. call Dina �Spr(nkle=' [phone],
extension 363 at the Paint Source Branch: Please Include
the NPD.ES permit- numbet,(below):tn any cammuhlca-
tion.1riterested ppeersons may also -visit She Division of
Water Quality anz N. SalisburY'Street, Raleigh* NC
Z76044148 between." hours of pi00 a m and 5:00 P.m: to
revieN► trifarrnation oii .Ss r , v �; 4 � t •, . ;
NPDES' Perrrt(f',Niirsb�r.�iC0o3i864; Arbon Hills Mobile*
Home Park, 4620.RelgalWood' Road, •Durham, NC 2M7.
has apptied for a permit renewal for a facility located In i
orange-:Couniy dlschargtng­treated-wastewater- Into
Stony.Craeek in the Neuse River Basin. Currently BODS;
ammdhia, fecal, eoliform and total residual chlorine.arc
water quality limited. This discharge may affect future
allocaf qns In tt,�� reo wing
e;0�a it A amanoo r, temr C hip pplidd
`fb rer1ei 0141' PDES) emit.-008Y759f&theardns*
Alamapc _W-TPF�Ih15, itted.facilllydischa filter
bat irrastewata ;thdr 6E Rive jn-.the. Neuse
Rive o Current) .rota) ideal chorine and total.
phosphorus are wale 4uaIMI Ited;::Thls discharge
may affecfi ryda-- to-600 pns ( Rl6 portioir of Ythe Eno
�`:rCeron�ebv/ra'elPe.:dataixxfac. �ll� tR.w13unt� �Cq aas
s;..ahpplled' idr
PES tsS goIit'tan.Mobile
facility
Nei.. L
proposes todisct ct Jov- tcri) te'rtia wa erfrom ,
greensand,.flRers�d arrYurlriarried'tri ry=.to, Rhodes'
Cree �tlthe.Meuse Rive��astM,CO retttly�'tatat tesldual
chlor�neris pater gtialif ►slfinited:+ Tii[of th6w rg rs !
;affect future citoc ions ri this por�ton of ttie waters
Chapel: HIII..News: Decembe*23, •2007.,r�Y., t
Before the undersigned, a Notary Public of Chatham
County North Carolina, duly commissioned and authorized to
administer oaths, affirmations, etc., personally appeared
Donna Clayton, who, being duly sworn or affirmed, according
to law, doth depose and say that she is Billing Manager -Legal
Advertising of The Chapel Hill News a corporation organized
and doing business under the Laws of the State of North
Carolina, and publishing a newspaper known as The Chapel
Hill News , in the City of Chapel Hill, Orange County and
State aforesaid, the said newspaper in which such notice,
paper, document, or legal advertisement was published was, at
the time of each and every such publication, a newspaper
meeting all of the requirements and qualifications of Section 1-
597 of the General Statutes of North Carolina and was a
qualified newspaper within the meaning of Section 1-597 of
the General Statutes of North Carolina, and that as such she
makes this affidavit; that she is familiar with the books, files
and business of said corporation and by reference to the files
of said publication the attached advertisement for NC
DMSION OF WATER QUALITY was inserted in the
aforesaid newspaper on dates as follows: 12/23/07
Account Number: 73350833
The above is correctly copied from the books and files of the aforesaid Corporation and publication.
Est Sete �'OF�,.
i notary i
rOm Co` ; %�%�,
Donna Clayton, Billing Manager- gal Advertising
Wake County, North Carolina
Sworn or affirmed to, and subscribed before me, this
26 day of DECEMBER , 2007 AD
by Donna Clayton
In Testimony Whereof, I have hereunto set my hand
and affixed official seal, the y and year aforesaid.
Janet Scroggs, Notary b c
My comnussion expires 10 of March 2009.

Low -flow characteristics for Eno River near Efland ... Re: Flow request...
Subject: Low -flow characteristics for Eno River near Efland ... Re: Flow request for NCO082759 NPDES
permit renewal for Orange-Alamance Water Treatment Plant - Efland, NC
From: John C Weaver <[e-mail]>
Date: Tue, 11 Dec 2007 11:38:13 -0500
To: Bob Guerra <[e-mail]>
CC: John C Weaver <[e-mail]>
In response to your inquiry about the low -flow characteristics for a location on the Eno River near Efland in
Orange County, the following information is provided:
A check of the low -flow files here at the USGS North Carolina Water Science Center indicates a previous
determination completed at a location immediately downstream of your point of interest. Low -flow
estimates were completed in response to a previous request at this location (station id 02084902, drainage
area 41.8 sgmi, at U.S. Hwy 70). The only record of discharge is one miscellaneous measurement made
in 1986 just downstream of the dam (station id 02084901, drainage area 41.2 sgmi). In the absence of
data sufficient for a low -flow analysis, estimates of low -flow characteristics can be determined by
assessing the range of low -flow yields (expressed as flow per square mile drainage area, or cfsm) at
nearby sites where values have been previously estimated. The annual 7Q10 low -flow yield used in the
previous estimate was 0.015 cfsm, based on the 7Q10 yield at an upstream partial -record site on the Eno
River. Similarly, the winter 7Q10 low -flow yield used in the previous estimate was 0.066 cfsm.
The "most recent' low -flow information published for this area is USGS Water -Resources Investigations
Report 98-4135, "Low -flow characteristics and discharge profiles for selected streams in the Neuse River
basin, North Carolina" (Weaver, 1998). This report provides low -flow characteristics (based on data
through 1996) for USGS continuous- and partial -record sites in the Neuse River basin where sufficient
data is available for analyses. However, the report does not provide statistical relations for estimating
low -flow characteristics at ungaged locations.
There is no online version of the report available, but ordering information for the report is available at
hftp://pubs.er.usgs.gov/usgspubs/Wri/wri984135.
In Tables 6 and 7 of this report, there are several nearby sites in the Eno River and Sevenmile Creek
basins for which low -flow discharge estimates are provided. Expressing these estimates as low -flow yields
provides some indication of the yield range that could potentially be applicable to your location. The
annual 7Q10 low -flow yields at two sites on the Eno River are 0.0075 and 0.0072 cfsm, about half the yield
used in the previous estimate. Similarly, the winter 7Q10 low -flow yields are 0.07 and 0.03 cfsm (average
at about 0.054 cfsm). Both of these more recent yields are less than those used in the 1988 estimate.
Applying the drainage area at the location just downstream of the dam Q41.2 sgmi) to the above average
yields, the resulting annual and winter 7Q10 values are about 0.3 and fs, respectively.
2.2
'-Q 1 O�,V
The USGS operates a long-term gaging station on the Eno River at Hillsborough (station id 02085000,
drainage area 66.0 sgmi). A quick update of the 7Q10 discharge based on a period of record that includes
the years of additional data indicates the published 7Q1 kdischarge (0.5 cfs) is still an appropriate
estimate.
Based on the most recent daily discharge published for this site
(http://weblOcapp.er.usgs.gov/imf/sites/adrO6/pdfs/02085000.21
Hillsborough gage is about 61 cfs, equivalent to abouC0.93 cfsn
.pdf), the average annual flow at the
A t/q
1 of 2 12/18/2007 8:02 AM

Low -flow eharacteristics for Eno River near Efland... Re: Flow request...
Hope this information is helpful.
Thank you.
Curtis Weaver
J. Curtis Weaver, Hydrologist, PE
USGS North Carolina Water Science Center
3916 Sunset Ridge Road
Raleigh, NC 27607
Telephone: [phone] // Fax: [phone]
E-mail address -- [e-mail]
Internet address -- http://nc.water.usgs.gov/
Bob Guerra <[e-mail]> To [e-mail]
11/29/2007 01:44 PM cc
Subject Flow request for NCO082759 NPDES permit renewal for
Orange-Alamance Water Treatment Plant - Efland, NC
Pursuant to our phone conversation from yesterday, please find attached
the Site map with Lat & Longs for this facility. Please provide the
7Q10 summer and winter flows as well as the average flows for this
section of the Eno river. The discharge point from the facility is
approx 150 feet downstream of the Corporation Lake Dam. If you need
more information please email or call at 919-733-5083 ext 539. Thanks
in advance for your assistance.
[attachment 1182759 (10-29-07).ppt" deleted by John C Weaver/WRD/USGS/DOI]
2 of 2 12/18/2007 8:02 AM

f
yw..
4
'Y f r
'
VO�NsY,
S Af jl�{ p
�'ST
i`,�p}4�1..
j1, �`I�xr if }
4♦� 1.. y,r f
�,`.-"

—low M
be.
N'MrAVI-1 vmQ PEW, �*6
Sam doom
`gym-E_Iwgdo"-
CA US Tir
CAUSTIC

l4m
ALUM
W riom
ftiotsmosi

■
t s rtIi NY�"IW 9Gl�4�lrY 4�i'.y i+i6�,l�y . ..
- W p

a; w
�.Q'ih..:11.4►. .Yea .. � � lH. ..
t
/
'�:,�
i

.�
��
1• t
9
b
k sr:+
�i

1
i
E
�
I
�
� f i� �
�
�
�
�i
� f
v,1
1 �I 1
1
�:
�
�
�:
{ .
�:�
�,
�. .
��
h
:'
�
t

VIP t
A
K

- . RfFm
40 Y

A...
It . .

�-7�7�

1J
2 111K

LY
.-4W
4
"VARWNW
JR:

YIN
4 Rqr ..
tr. 's' `e yr
�v f� '✓ �'
1 »
� o
r
il�ti
FYI 1
r'v�
f
t
L [
q

1 !rv, " t��v
a`."li ,�- r r x ;� •! `/..:r^,S*C 7 Fr `8%1 Ail
'y��-s 1 n 1 ! i �r •� 144 s11.4 r�« 400 ik{ 4
J k 'yam �' trt ` i.: ;. >t1 A r`fl y +� ��i �j'•rt S'�)t•��
e �
5

..1 " - ;T - 1 I.l ..`1{ l 1 . • J F /r� (//�$i Rjf/T��. y.A '1 Y '#'� /. `t{\`.�4
� i 1;• xG 1\ • '•�/v J 'HF LI -/ �I�j 1.1 � - ,/�' 9
r ��I- H \Kr �JI. YS( hja.' 11l �/li�i �Y'i r 4rt</. I � i i `�, 1
I �\ I +` �11 � i 1 1 I f�,�Y / r • f '� /� �i \ � 1 � 1r V r � /
_U jib i , i
G _ -. -.� ii ' n. i.
� . / ` � 1 � yip ♦ .!t '✓
.. •S4 � .r`Fa. F
),
. I� � n
1
� � iµ( Y
a 1 r.l /. �� .1 71�
.`. � w
i= ,'
/ ;�
F
• ,. _ s
' ��• `� - /
1.
_ �
_ ^' � •! •i
• • � - ��,�
r � ._
_, — �y.,�
• � 1 t n � '
_ /'�
ti
_ � r� c �
e - � � � ~� - Ev\
L _ 5�.��j

-MMIMM--loomw
NI AT IlIII

----------
ti
y 1�. I ►P a
t }
It _ � �tt + A.� �iy+,'�+,�( !o•'
Ki'. _ .., hwhy'o41 �17� Mff44glgb/ �� 1
' .... iyr prn w.MryvJ: ..• a `: � ._... .. - E •Yr�^ >�
MrMrMo-':..: '� A'e+M'+>e/'�ll" i MN M.' t f ♦ " • .e.any .,. s w3 s . {` !.� �
.,y p

Orange-Alamance Water System, Inc.
POST OFFICE BOX 187 MEBANE, NORTH CAROLINA 27302 TELEPHONE: [phone]
July 19, 2007
Mrs. Frances Candelaria
NCDENR/DWQ/Point Source Branch
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Re: Renewal for NPDES Permit NCO082759
Dear Mrs. Candelaria:
J U L 2 3 2007
Orange-Alamance Water System, Inc. would like to request renewal of NPDES
Permit NC0082759. Please find attached one signed original and two copies of
the completed application form. Attached also is a diagram of the flow through
the facility and one signed original and two copies of our statement regarding the
sludge management plan.
If any further information is required, please feel free to contact me at [phone].
Sincerely,
ORANGE-ALAMANCE WATER SYSTEM, INC.
at — -; `
rs.) Sandra Faye Metcalf,
Manager
I"
N

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Mail the complete application to:
N. C. Department of Environment and Natural Resources
Division of Water Quality / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617
NPDES Permit Number INCO082759
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 ORANGE-ALAMANCE WATER SYSTEM, INC.
Facility Name ORANGE-ALAMANCE WATER SYSTEM, INC.
Mailing Address P O BOX 187
City MEBANE
State / Zip Code NC 27302
Telephone Number [phone] OR [phone]
Fax Number [phone]
e-mail Address [e-mail]
2. Location of facility producing discharge:
Check here if same as above ❑
Street Address or State Road 2101 US 70 E
City EFLAND
State / Zip Code NC 27243
County ORANGE
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 ORANGE-ALAMANCE WATER SYSTEM, INC.
Mailing Address P O BOX 187
City MEBANE
State / Zip Code NC 27302
Telephone Number [phone]
Fax Number [phone]
4. Ownership Status:
Federal ❑ State ❑
S. Type of treatment plant:
Private
Public ❑
Page i of 3 C-WTP 03/05

NPDES 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 Exchange (Sodium Cycle Cationic ion exchange)
❑ Green 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) (i.e. groundwater, surface water)
SURFACE WATER
7. Describe the treatment process(es) for the raw water:
RAW WATER IS TREATED WITH ALUM, POLYMER, POTASSIUM PERMANGANATE, AND
CAUSTIC AS NEEDED FOR PH ADJUSTMENT FOR PROPER COAGULATION, THEN SETTLED
IN CONVENTIONAL SEDIMENTATION BASIN, THEN FILTERED -CHLORINE IS ADDED
BEFORE AND AFTER FILTRATION.
8. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
ALL WASTEWATER IS GENERATED BY FILTER BACKWASH AND FILTER REWASH. ALL
WASTEWATER IS TREATED WITH 2.5 TO 3.0 MG/L CALCIUM THIOSULFATE FOR
DE -CHLORINATION, THEN SETTLED IN PRIMARY AND SECONDARY LAGOONS BEFORE
DISCHARGE.
9. Number of separate discharge points: 1
Outfall Identification number(s) .001
10. Frequency of discharge: Continuous ❑ Intermittent
If intermittent:
Days per week discharge occurs: 3 Duration: 15 MINUTES FOR
REWASH, 30 TO 35 MINUTES FOR BACKWASH AND REWASH
70P " eI ° o
11. Plant design potable flowrate .90 MGD
Backwash or reject flow 1.44 MGD�1
12. Name of receiving streams) (Provide a map showing the exact location of each outfall, including
latitude and longitude):
ENO RIVER, LATITUDE:34?05' 00% LONGITUDE 79°08' 25"
Page 2 of 3 C-WTP 03/05

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
13. Please list all water treatment additives, including cleaning chemicals or disinfection
treatments, that have the potential to be discharged.
ALUM, POLYMER, POTASSIUM PERMANGANATE, PHOSPHATE, FLUORIDE, CHLORINE,
AQUEOUS AMMONIA 19%, AND CAUSTIC SODA 25%
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 treatment process, and point of addition of chemicals.
Solids Handling Plan
16. NEW Applicants
Information needed in addition to items 1-15.
New applicants must 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.
Ro&GP, Z), 14E-L(,Rg-6 WATtIL A -1 (Y1 A10 AG-Ga-
Prirkted name of Person Signing Title
of
bate
North Carolina General Statute 143-215.6 (b)(2) provides that: Any person who knowingly 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 recording or
monitoring 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 fine not to exceed $25,000, or by imprisonment not to exceed six months, or by both. (18 U.S.C. Section
1001 provides a punishment by a fine of not more than $25,000 or imprisonment not more than 5 years, or both,
for a similar offense.)
Page 3 of 3 C-WTP 03/05

11,4-15/2007 15:53 1919563-0882 ORANGE ALAMANCE PAGE 07
Orange-Alann.ance Water System, Inc.
POST CP'F= BOX 187 MEBANE, NORTH CAROLMA 27302TKLCMHOt4E: 019i'569.8212
SLUDGE MANAGEMENT T PLAN
Ozengc»Alammce Water System, Inc. does not have a written sludge management plan,
Sludge is settled and hold in two (2) lagoons until lagoons reach capacity. Orange -
A lamanoc will then coot nwt with a sludge romoval company to remove sludge.
Roger killard,, Plant Superintendent
Date

FACT SHEET FOR EXPEDITED PERMIT RENEWALS
Rasic information to determine potential for expedited permit renewal
Reviewer/Date
Permit Number
Facility Name
�` r- �•��C �'t
,e
Basin Name/Sub-basin number
Receiving Stream
t34 t
Stream Classification in Permit
G-- NS ul-7
Does permit need NH3 limits?
C�
Does permit need TRC limits?
O
Does permit need Enteroccoci limit?.
Does permit have toxicity testing?
Does permit have Special Conditions?
Does permit have instream monitoring?
Is the stream impaired (on 303(d) list)?
C�
Any obvious co m liance concerns?
Any permit mods since lastpermit?
Existing expiration date
New expiration date
Miscellaneous Comments
G
YES_ This is a SIMPLE EXPEDITED permit renewal (administrative
renewal with no chap es or only 'nor changes such as TRC, NH3,
name/ow p c anges).
YES_ This i a MORE COMPLEX EXPEDITED permit rene al (includes
Speci gement Plan),
Conventional WTP, 303(d) listed, toxicity testing, instream monitoring,
compliance concerns, phased limits). Basin Coordinator to make case -by -
case decision.
YES_ This permit CANNOT BE EXPEDITED for one of the following reasons:
• Major Facility (municipal/industrial)
• Minor Municipals with pretreatment program
• Minor Industrials subject to Fed Effluent Guidelines (lb/day limits for BOD, TSS, etc)
• Limits based on reasonable potential analysis (metals, GW remediation organics)
• Permitted flow > 03 MGD (requires full Fact Sheet)
• Permits determined by Basin Coordinator to be outside expedited process
TR Version 9/7/2007
3�� I Z�Jc.