NC0083909_Permit Modification_20100914

Ala..
NCDENR
North Carolina Department of Environment and Natural Resources
Beverly Eaves Perdue
Governor
Mr. Ken Flatt
Utilities Director
Dare County Water Department
600 Mustian Street
Kill Devil Hills, NC 27948
Dear Mr. Flatt:
Division of Water Quality
Coleen H. Sullins Dee Freeman
Director Secretary
September 14, 2010
Subject: Issuance of Modified NPDES Permit
NPDES Permit NC0083909
Rodanthe/Waves/Salvo Reverse Osmosis WTP
Dare County
Class
Division personnel have completed review of the subject permit based on your June 2009 petition.
The Division concurs that the addition twelve months of data meets the current permit condition for
evaluating/amending this permit. However, the dye study is specific to the Cape Hatteras Reverse Osmosis
WTP discharge and cannot be applied to this discharge. As a saltwater discharge into a SA, HQW class
stream the applicable limits must be calculated. Based on this facility original 1994 NPDES permit. and no
expansion having occurred, only the SA water quality standard (WQS) is applicable. Technical corrections
were made where warranted.
Accordingly, we are forwarding the attached modified 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).
Summary of Changes Made to Existing Permit and Incorporated into Modified Permit
1) Permitted flow limit removed. The current Division Water Treatment Plant (WTP) Strategy does not
require a defined flow limit. However, monitoring and reporting requirements did not change.
2) Total Arsenic limits corrected and assigned as monthly average maximum limits and daily
maximum limits, monitoring reduced to monthly. The data reviewed at the required SA limits
yielded potential to exceed the monthly average limit for the Human Health standard. As a result,
the Division policy requires assignment of the applicable monthly average limit and a matching
daily maximum limit. The current Division policy requires monthly monitoring.
3) Total Cadmium, Total Chromium. Total Cyanide, Total Lead, Total Mercury, Total Nickel limits
removed and monitoring reduced to quarterly. The data reviewed at the required SA limits yielded
no potential to exceed limits. As a result, the current Division policy allows removal of the limits and
requires quarterly monitoring.
Page 1 of 2
1617 Mail Service Center. Raleigh, North Carolina 2769-0-1617
Location: 512 N. Salisbury St. Raleigh. North Carolina 27m-14
Phone. [phone] FAX: 919-8t".7-6495 t Customer Se, vice- 1-871-623-6746
• internet. Op./ i h2o slaie.rr tr,;1
One
No hCal-otina
An Equal OppertLnsty t Atir.tng-wf-, k.&4' E'esfpbp

4) Total Selenium limits corrected and assigned as monthly average maximum limits and daily
maximum limits, monitoring reduced to monthly. The data reviewed at the required SA limit yielded
potential to exceed the WQS limit. As a result, the Division policy requires assignment of the.
applicable monthly average limit and a matching daily maximum limit. The current Division policy
requires monthly monitoring.
5) Total Copper, Total Silver, Total Zinc, Total Nitrogen, and Total Phosphorus monitoring reduced to
quarterly. The current Division WTP Strategy requires quarterly monitoring.
6) Added footnote for Dissolved Oxygen (DO) and Temperature petition condition. The current Division
WTP Strategy allows this condition, Facility must demonstrate that the discharge has no significant
impact on the DO and temperature levels in the receiving stream.
7) Amended narrative on supplement page. Based on current process description added component
list.
B) Amended footnote narrative on A. (1.) page. Amended footnotes where required.
Except for cyanide, mercury, and silver, the permittee must provide data measurements for metal
parameters with at least a minimum detection limit of 2 µg/I. For silver the minimum detection limit
requirement is 1 µg/I. Mercury and cyanide detection limits are defined as part of the measurement
method.
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 Carplina General Statutes, and filed with the Office of Aoministrative 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 permits that may be required.
If you have any questions concerning this permit, please contact Ron Berry at telephone number
[phone] or at email ron.berrv(a ricdenr.00v.
Sincerely,
/,
oleen H. Stillins
Attachments
Cc: Washington Regional Office/Surface Water Protection Section (email permit and fact sheet)
Washington Regional Office/DEH/PWS/Harry Bailey (email)
Environmental Sciences Section/Aquatic Toxicology Unit/Susan Meadows (email)
TACU/James L. Pugh (email)
Central Files
NPDES Unit
Page 2 of 2

Permit NCO083909
STATE OF NORTH CAROLI NA
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,
Dare County
is hereby authorized to discharge wastewater from a facility located at the
Rodanthe/Waves/Salvo Reverse Osmosis Water Treatment Plant
Off NCSR 12
Rodanthe, NC
Dare County
to receiving waters designated as Blackmar Gut in the Pasquotank River Basin in accordance with
effluent limitations, monitoring requirements, and other conditions set forth in Parts 1, II, III and IV
hereof.
This permit shall become effective October 1, 2010.
This permit and authorization to discharge shall expire at midnight on December 31, 2012.
Signed this day September 14, 2010.
- t�-7't4
/,&P eleen . Sull n , irector
f Water Quality
By Authority of the Environmental Management Commission

Permit NCO083909
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge, are hereby
revoked. The exclusive authority to operate this facility arises under this pennit. The authority to
operate the facility under previously issued permits bearing this number is no longer effective.
The conditions, requirements, terms and provisions of this permit authorizing discharge under the
NPDES govem discharges from this facility.
Dare County is hereby authorized to:
1. Continue to discharge reverse osmosis concentrate reject water from a drinking water
treatment facility, and consisting of the following components:
o Replaceable cartridge filters
o Inhibitor addition system
o Reverse osmosis unit
o Submerged discharge
Located at the Rodanthe, Waves, Salvo Reverse Osmosis Water Treatment Plant, off NCSR
12, Rodanthe, NC in Dare County.
2. Discharge from said drinking water treatment facility at the location specified on the
attached map into Blackmar Gut, which is classified SA HQW waters in the Pasquotank
River Basin.

Permit NCO083909
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on the effective date of the permit and lasting until expiration, the Permittee
is authorized to discharge through a diffuser from Outfali 001. Such discharges shall be limited and
monitored by the Permittee as specified below:
EFFLUENT
LIMITS
MONITORING
REQUIREMENTS
Monthly
Weekly
Daily
Measurement
Sample
Sample
CHARACTERISTICS
Average
Average
Maximum
Frequency
Type
Location 1
Flow, MGD
(50050)
Continuous
Recording
Effluent
pH
Not less than
6.8 S.U. nor more
2/Month
Grab
Effluent
(00400)
than
8.5 S.U.
pH
(00400)
Monthly
Grab
Upstream,
Downstream
Total Arsenic
(01002)
10 µg/I
10 µg/I
Monthly
Grab
Effluent
Total Selenium
(01147)
71 µg/I
71 µg/I
Monthly
Grab
Effluent
Total Dissolved Solids, mg/I
Monthly
Grab
Effluent
(70295)
Temperature 2, °C
Monthly
Grab
Effluent,
Upstream,
(00010)
Downstream
Dissolved Oxygen (DO) 2, mg/I
Monthly
Grab
Effluent,
Upstream,
(00300)
Downstream
Conductivity, µmhos/cm
Monthly
Grab
Effluent,
Upstream,
(00094)
Downstream
Salinity, ppt
Effluent,
(00480)
Monthly
Grab
Upstream,
Downstream
Ammonia as Nitrogen, mg/I
Monthly
Grab
Effluent
(00610)
Total Cadmium, µg/I
(01027)
Quarterly
Grab
Effluent
Total Chromium
(01034)
Quarterly
Grab
Effluent
Total Copper, µg/I
(01042)
Quarterly
Grab
Effluent
Total Cyanide 3, µg/I
Quarterly
Grab
Effluent
(00720)
Total Lead
(01051)
Quarterly
Grab
Effluent
Total Mercury, ng/I
(Method 1631E) (71900)
Quarterly
Grab
Effluent
Total Nickel, _Ng/I
(01067)
Quarterly
Grab
Effluent
Total Silver, µg/I
(01077)
Quarterly
Grab
Effluent
Total Zinc, µg/I
(01092)
Quarterly
Grab
Effluent
Total Nitrogen (TN), mg/I
TN = (NO2-N + NO3-N) + TKN
Quarterly
Grab
Effluent
(00600)

f NCSR 12
* :;:
Uncle Jimmy
Pamlico Sound Landing..�',` '- •` t t
RodantheA IJaves/Salvo
Upstream W*TP NCO083909
of
Sample '
�. ••.1'I
NC0083909 Greens Pt ,. ,�`-'.,1.. ', ��►�. :r�
Discharge :.. , r _ _ - ~ ' OAC- ,..
Blackman
i
Rodanthes
Downstream t..
Sample .'• .
, •• � ' � `� `ter
• - •l 1 • w.
Ord• IAIdo
; �� .W a�, •':
• �'.'.•
r . : n . IA
ir
.►.. r r
Gopyt{ght(C)2001, l4haptett; lIn?�-
USGS Quad: E36SE Rodanthe, NC yr .,,,
Outfall Facility
Latitude: 35° 35' 44.5" N 350 35' 42" N .
Longitude: 750 28' 12.7" W 750 28' 2" W
Stream Class: SA, HQW TFacility Location
North
Subbasin: 14UC: 03-01-55 HUC: 03020105 RodantheiWaves/Salvo Reverse. Osmosis WTP
Receiving Stream: Blackmar Gut NC0083909 Dare County

Permit NCO083909
Total Phosphorus UP), mg/l
Quarterly
Grab
Effluent
(00665)
Acute Toxicity a
Quarterly
Grab
Effluent
(TGE3E)
Footnotes:
1. Effluent samples shall be collected at point after mixing of effluent wastewater from all
treatment units and prior to discharge, unless otherwise noted. Upstream = 27 feet north of
the discharge outfall, Downstream = 50 feet south of the discharge outfall.
2. The permittee may petition the Division to have Dissolved Oxygen (DO) `and Temperature
monitoring removed as part of the next permit renewal application. The facility must
demonstrate that the discharge has no significant impact on the DO and temperature levels in
the receiving stream.
3. The Permittee shall record and submit all Total Cyanide values reported by a North Carolina
certified laboratory, even if they fall below the required minimum detection limit of 10 µg/I.
4. Acute Toxicity Monitoring (Mysidopsis bahia) @ 90.0% P/F, during the months of /anuary,
April, July, and October. See Part I, Condition A. (2.). The collection of samples shall coincide
with the sampling of other parameters.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

Permit NCO083909 •
A. (2.) ACUTE TOXICITY MONITORING (QUARTERLY)
The permittee shall conduct acute toxicity tests on a quarterly basis using protocols defined in the
North Carolina Procedure Document entitled "Pass/Fail Methodology For Determining Acute
Toxicity In A Single Effluent Concentration" (Revised July, 1992 or subsequent versions). The
monitoring shall be performed as a Mysid Shrimp (Mysidopsis bahia) 24 hour static test. The
effluent concentration at which there may be at no time significant acute mortality is 9096
(defined as treatment two in the procedure document). Effluent samples for self -monitoring
purposes must be obtained during representative effluent discharge below all waste treatment.
•The tests will be performed during the months of January, Aprili July, and October. ­ I 1 1
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 TGOE. Additionally, DWQ Form AT-2 (original) is to be sent to the following address:
Attention: North Carolina Division of Water Quality
Environmental Sciences Section
1621 Mail Service Center
Raleigh, North Carolina 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 either these monitoring requirements 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 and reported data submitted on the DMR and
AT Forms.
NOTE: Failure to achieve test conditions as specified in the cited
control organism survival and appropriate environmental controls,
and. will require immediate follow-up testing to be completed no
month following the month of the initial monitoring.
document, such as minimum
shall constitute an invalid test
later than the last day of the

DENR/DWQ
FACT SHEET FOR NPDES PERMIT DEVELOPMENT
NPDES No. NC0083909
Facility Information
Applicant/Facility
Name:
Rodanthe, Waves, Salvo Reverse Osmosis WTP
Applicant Address:
600 Mustian Street; Kill Devil Hills, NC 27948
Facility Address:
Off NCSR 12, Rodanthe, NC
Permitted Flow
NA (Design = 0.3 MGD)
Type of Waste:
RO reject water
Facility/Permit Status:
Class I/Active; MOD
County:
Dare County
Miscellaneous
Receiving Stream:
Blackmar Gut
Stream Classification:
SA, HQW
Subbasin:
03-01-55
Index No.
30-22-13
Drainage Area (mi2y
Tidal
303(d) Listed?
No
Summer 7010 (cfs)
Tidal
Regional Office:
Washington'
Winter 7Q10 (cfs):
Tidal
State Grid / USGS
Quad:
E36SE
Rodanthe, NC
30Q2 (cfs)
Tidal
HUC:
03020105
Average Flow (cfs):
Tidal
Permit Writer:
Ron Berry
IWC MY
IWC = 100%
Date:
9/8/10 7771
BACKGROUND
Dare County operates a reverse osmosis -based drinking water treatment facility that serves
the outer banks communities of Rodanthe, Waves, and Salvo. Wells provide the raw water
source. The facility discharges reverse osmosis reject water via a submerged discharge
adjacent to. a seawall into Pamlico Sound, a class SA, HQW water in the Pasquotank River
Basin.
PROCESS
Well water is pumped from wells through replaceable cartridge filters followed by the
addition of a non -zinc based inhibitor, and continues through a reverse osmosis unit. Reject
wastewater from the reverse osmosis unit is constantly discharged to remove the
concentrated solids through a submerged pipe adjacent to a seawall into Pamlico Sound.
No other chemical additives of significance are used in this part of the process.
HISTORY
This facility was original permitted in 1994 and has not been expanded nor changed its
primary operation since receiving its original NPDES permit. In 1994 the HQW class did not
exist and was not applicable until after 1995. The current discharge is into a class SA, HQW
receiving stream, by HQW definition only an expanded or new dischargers is subject to the
HQW water quality standard (WQS). In previous permits renewals HQW WQS was
sometimes applied. Also, the prevailing water treatment plant (WTP) strategy was applied.
As a non -modeled tidal discharge the instream waste concentration (IWC) is defined as
100%.
The current permit was issued in March 2009 and was based on an (IWC) of 100%, and did
not apply the HQW-based WQS limits but did apply full SA WQS limits. The reasonable
potential analyses (RPA) for the collected effluent data indicated the potential for the
discharge to exceed the Total Arsenic, Total Cadmium, Total Chromium, Total Cyanide,
Total Lead, Total Mercury, Total Nickel, and Total Selenium defined WQS limits. As a result,
the issued permit included new effluent limits and new monitoring requirements for Total
Arsenic, Total Cadmium, Total Chromium, Total Cyanide, Total Lead, Total Mercury, and
Total Nickel. The Total Selenium limit was amended.

A special condition that allows the permittee to petition for re-evaluation of the newly
added WQS limits and measurement frequency after a minimum of twelve months of new
data was included in the current permit. In May 2009 a written petition to (1) re-evaluate
the new limits and to (2) apply the IWC of 6.5% used for NCO085707 was received. The
permittee stated that the discharge flow has not changed nor has the well water quality
changed since start up. The petition also requested that the monitoring frequency be
returned to its 2003 levels.
PERMITTING STRATEGY
A run chart of all reported effluent discharge flow from 2005 to present was developed. The
flow run chart confirmed that the experienced discharge flow was about the same year to
year. However, the dye study is only applicable to NCO085707 so all WQS calculation for
this permit (NC0083909) will be based on an IWC of 100%.
Reasonable Potential Analysis (RPA)
The Division conducted EPA -recommended analyses to determine the reasonable potential
-for toxicants to be discharged by this facility into SA waters (full WQS values), based on
DMR data from June 2009 to June 2010 applying the IWC of 100%. The majority of the data
was below reported detection limits. Evaluations were conducted for Total Arsenic, Total
Cadmium, Total Chromium, Total Cyanide, Total Lead, Total Mercury, Total Nickel, and Total
Selenium. For definition purposes the RPA for Total Copper, Total Silver, and Total Zinc
were also determined.
Results suggest reasonable potential for the facility to discharge Total Arsenic and Total
Selenium in excess of the defined SA limits. The required SA limits for Total Arsenic will be
based on the potential to exceed the Human Health standard (HH) of 10 µg/l, and
expanded to include a matching daily maximum limit. The existing Total Selenium limit will
be continued but amended to be applied as a monthly average limit and a daily maximum
limit. The monitoring frequency for Total Arsenic and Total Selenium will be reduced to
monthly based on current policy. Total Cadmium, Total Chromium, Total Cyanide, Total
Lead, Total Mercury, and Total Nickel showed no reasonable potent►al to exceed defined SA
limits. Total Cadmium, Total Chromium, Total Cyanide, Total Lead, Total Mercury, and Total
Nickel limits will be removed and monitoring frequency reduced to quarterly based on
current policy.
For clarity, the cover letter will include minimum detection statements for metal
parameters (except cyanide, mercury, silver) in cover letter.
Applying current WTP Strategy
Per Division policy upon opening a permit the prevailing WTP strategy is applicable. As a
result Total Nitrogen and Total Phosphorus measurement frequencies were reduced to
quarterly. A new footnote special condition was added that gives the permittee the option
to petition the Division at the next permit renewal for consideration of removal of Dissolved
Oxygen (DO) and temperature requirements contingent on demonstrating the discharge
has no significant impact on DO and temperature levels in the receiving stream. The
current strategy does not require assignment of a permitted flow so the flow limit was
removed. However, flow monitoring requirements have not changed.
Since Total Copper, Total Silver, and Total Zinc are action level parameters per WTP policy
monitoring for these parameters were reduced to quarterly.
As part of the next permit renewal, the current WTP strategy allows removal of non -limited
quarterly monitored metals requirements, other than action level, if sufficient data is
available to conduct a RPA and it shows no reasonable potential for that metal to exceed its
SA limits. Therefore, upon re-evaluation at the next permit renewal the newly defined non -
limited quarterly monitored metals can be considered for removal from this permit.
Other Technical Corrections
Based on a conversation with the operator the current WTP process was confirmed and
includes replaceable cartridge filters, the addition of a non -zinc inhibitor to the feed water

Permit NC0001376-
(Continued from A. (4.) ANNUAL LIMITS FOR TOTAL NITROGEN)
iii. If the Permittee intends to join or leave a compliance association, the Division must
be notified of the proposed action in accordance with the procedures defined in the
association's NPDES permit.
(1) Upon receipt of timely and proper notification, the Division will modify the
permit as appropriate and in accordance with state and federal program
requirements. F F F
(2) Membership changes in a compliance association become effective on
January 1 of the year following modification of the association's permit.
e. The TN monitoring and reporting requirements in this Permit remain in effect until expiration
of this Permit and are not affected by the Permittee's membership in a compliance
association.
A. K) TOTAL NITROGEN ALLOCATIONS
a. The following table lists the Total Nitrogen (TN) allocation(s) assigned to, acquired by, or
transferred to the Permittee in accordance with the Neuse River nutrient management rule
(T15A NCAC 02B .0234) and the status of each as of permit issuance, For compliance
purposes, this table does not supercede any TN limit(s) established elsewhere in this permit or
in the NPDES permit of a compliance association of which the Permittee is a Co-Permittee
Member.
ALLOCATION
ALLOCATION AMOUNT (1)
TYPE
SOURCE
DATE
STATUS
Estuary (lb/yr)
Discharge (lb/yr)
Base
Assigned by Rule
(T15A NCAC 02B .0234)
12/7/97
28,223.5
56,447
Active
Decremental Deeded to LNRA/City of Raleigh (Z) 8/4/99
28,223.5
56,447
Deducted
TOTAL
0
0
Active
Footnote:
(1) Transport Factor = 50%
(2) Prior to ownership change to Riverplace II, LLC in November 1999.
b. Any addition, deletion, or modification of the listed allocation(s) (other than to correct
typographical errors) or any change in status of any of the listed allocations shall be
considered a major modification of this permit and shall be subject to the public review
process afforded such modifications under state and federal rules.

going to the reverse osmosis unit, and a submerged discharge. The supplement page was
revised to reflect the WTP operation by the addition of a component list.
SUMMARY OF MOD CHANGES
In keeping with Division policies the following will be incorporated into the permit and does
not require public notice:
• Removed permitted flow limit.
• Amended Total Arsenic limits and reduced monitoring to monthly.
• Removed Total Cadmium limit and reduced monitoring to quarterly.
• Removed Chromium limits and reduced monitoring to quarterly.
• Reduced Total Copper monitoring to quarterly.
• Removed Total Cyanide Limit and reduced monitoring to quarterly.
• Removed Total Lead limits and reduce monitoring to quarterly.
• Removed Total Mercury limit and reduced monitoring to quarterly.
• Removed Total Nickel limit and reduced monitoring to quarterly.
• Amended Total Selenium limits and reduce monitoring to monthly.
• Reduced Total Silver monitoring to quarterly.
• Reduced Total Zinc monitoring to quarterly.
• Reduced Total Nitrogen monitoring to quarterly.
• Reduced Total Phosphorus to monitoring to quarterly.
• Added footnote condition for petition of Dissolved Oxygen and Temperature
removal at next renewal.
• Amended narrative on supplement page.
• Amended footnote narrative on A. (1.).
NPDES DIVISION CONTACT
If you have questions regarding any of the above information or on the attached permit,
please contest Ron Bep:y at [phone] or email [e-mail].
NAME:
REGIONAL OFFICE COMMENTS
NAME: DA
SUPERVISOR: DA

Table 1. Project Information
Facility Name
WWTP Grade
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
Stream Class
7Q10s (cfs)
7Q10w (cfs)
3OQ2 (cfs)
QA (cfs)
Time Period
Data Source(s)
Rodanthe WTP
1
NCO083909
001
0.3
Black mar Gut
SA, HOW
June 2009 - June 2010
DMRs Note:
Tidal iWC= IOOIA Startup/permitted 1994 before
HQW class, no changes since 2994, HQW rules not
Par0l
ParOi
ParO;
Para;
ParOf
PWO]
Par09
Par1a
Par11
Par19
Par13
Par14
Par15
Table 2. Parameters of Concern
Name Type Chromic Mocffw Acute PQL Units
Arsenic
NC
50
ug/L
Cadmium
NC
5
42
ug/L
Chromium
NC
20
ug/L
Cyanide
NC
1
N
1
10
ug/L
Lead
NC
25
N
221
ug/L
Mercury
NC
25
2
ng/L
Nickel
NC
8.3
75
ug/L
Selenium
NC
71
ug/L
Silver
NC
0.1
AL
1.9
ug/L
Zinc
NC
86
AL
95
ug/L
Copper
NC
3
AL
5.8
ug/L
ug/L
ug/L
ug/L
RPA, input
9/8/2010

REASONABLE POTENTIAL ANALYSIS
Rodanthe WTP
NCO083909
Time Period Jerre 2009 - Jane 2DID
Qw (MGD) 0.3
7010S (cfs) Tidal
701OW (Cfs) Tidal
3002 (ds) Tidal
Avg. Sneem Flow, CA (cfs) Tidal
Rec%ing Stream Blaclanar Out
WWTP Class 1
IWC (%) 0 7010S 100
e 7010W 100 NIA
0 30Q2 100 WA
e QA 100 NIA
Stream Class SA, HQW MIA
Outfall 001
Ow = 0.3 MGD
Ce tfla€lon of 1010 based on 7010
1010 - 0.843 (7Q10) Qm
STANDARDS&
PARAmmTER
TYPE
CRITERIAW
PQL
UnRs
REASONABLE POTENTIAL RESULTS
RECORD ACTION
IMCwol X FAYI
• fax Nirild O r AGO" Or
M
Cbork Aarft
Aate: NO MW
ADO DAILY MAXLMUM LIMIT = CHRONIC LIMIT
--------
Arserrc
NC
50
uGfl.
26 7
282
----- Dom•-----•— i i�
RPAshows to exceed HH 10
C
10
rgfl.
NC:
_ _
Cxronic 50
AMEND LIMIT TO HH 3 MONTHLY AVERAGE MAXtMUh
G
Chronic 10
REDUCE MONITORING TO MONTHLY PER POLICY
Acubms 42
Noecommoired
Cadrdusn
NC
5.0 42
W&
W 0
2.5
rdGs Wm detect bvcl, ltsDaia+Al rdGs bekrw detect love
_
RPA shows no potmtlsl I
REMOVE LIMIT, REDUCE MONITORING TO QUARTERL
Pate: NO WQS
_ ----------------
Chranhan
NC
20
uWL
28 3
73 7
_-- _
_
Nne rdg ebae deMCt loud
tlsorie 20
RPA shows no polrntlW
REMOVE LIMIT REDUCE MOMTCIRING TO QUARTERL
Aorta 1.0
No action required
Cya d tr
NC
1.0 N 1.0
10
uWL
26 0
5.0
_—_ _ _
trigs beloir PQL. historically rd� below PQL
Cts+arEe: 1A
RPA deemed no potattd
REMOVE LIMIT, REDUCE MONITORING TO QUARTER!
Acdo: 221
NofeOoerrequhsd-------------_-------
LOW
NC
25 N 221
uWL
26 t
17.2
-------
rd0dxm&h:c11ft1el
C7roric: 25
RPAshows no poter tel
REMOVE LIMIT. REDUCE MONITORING TO QUARTERL
Ante: NO WOsS
mane ry
NC
25
2
rg&
26 0
13
_
_ _ _ —_---_—
_
Cxrortc 25.0
One rdG above PCS.. RPA choirs no pot�ei
REMOVE LIMIT, REDUCE MONITORING TO QUARTERL
Aorta: 75
N_oadionraquired
Nldcel
NC
8.3 75
uglL
26 0
4.0
.-----••----•---_—_--_-
AN n:lp below doted level, Hsto c* rdo below dated love
CxttacriC 8S
RPAstrowsnapoterttal I
REMOVE LIMB, REDUCE MO;WOFW9G TO QUARTERL"
Mato~ NOWGS
ADDIDAILYMAMMUMUllff-CHRONICLIMIT-•--
Sdonksn
NC
71
uyrl.
26 26
138.7
_
RPAshompd&*ai
___
C7�ncia 71
AMEND LIMIT TO MONTHLY AVERAGE MAXIMUM
REDUCE MONITORING TO MONTHLY PER POLICY
A utm Is
Sam
NC
0.10 AL 12
uWL
13 0
&3
............
rdpst P'n dot dbvd
C h=L-- R1
Per poky
REDUCE MONITORING TO QUARTERLY
Acute: 95
zkW
NC
86 AL 95
ug&
13 2
25.8
_—_ _
RPA shows no potential
Chrertc d6
Par poky
SCE MOKI TORINGG TO QUARTERLY
Ache: 5.8
Copper
NC
&0 AL 5.8
uGt.
13 1
49.0
RPAshompotaft
Crrottc 3.0—
Prrpoilry
REDUCE MONITORING TO QUARTERLY
Ante: NO WOOS
UGfL
0 0
WA
_
------------------------------
Cxsoric NIA
Aate: NO WQS
UGIL
0 0
NIA
_
----•-------------------------
C7senic WA
Aorta NOWQS
ugA.
0 0
NIA
_
------------- -----------------
Cxs+onic WA
Aorta NOWQS
t
UGIL
0 0
NIA
_
----•-------------------------
Ctroric N!A
__j
•L gaw. «R rasralDRs horGe
Cs
NC a Alpt►earcbpGer*
A = Acstha6c
RPA. rpa
902010

REASONABLE POTENTIAL ANALYSIS
1
2
AfS@RIC
Cadmium
Date
Data
BDL¢112DL
Results
Date
Data
BDLA12DL
Results
1
Jun-2009
130
13.0
Std Dev.
32728
1
Jun-2009
4
5
2.5
Std Dev.
0.0000
2
Jun-2009
'
13.0
130
Mean
6.6346
2
Juan-2009
'
5
2.5
Mean
2.5000
3
Jul-2009
:
10.0
10.0
C.V.
0.4933
3
Jul-2009
5
2.5
C.V.
0.0000
4
J42009
!!
k""
100
5.0
n
26
4
Jul-2009
5
2.5
n
26
5
Aug-2009
70
7.0
S
Au8-2009
5
25
6
Aug-2009
-- #
5.0
2.5
Mutt Factor =
1.8800
6
Aug-2009
f
S
2.5
Mk�lt Factor =
1.0000
7
Sep-2009
#
12.0
12.0
Max. Value
15.0 u91L
7
Sep-2009
;< i
5
2.5
Nkm Value
2.5 ug/L
8
Sep-2009
100
5.0
Max Pred Cw
282 ug/L
8
Sep-2009
� �� �
5
2.5
Max. Prod Cw
2.5 ug/L
9
Od-2009
10.0
5.0
9
Oci-2009
j
S
25
10
Oct•2009
! =
10.0
5.0
10
Oct-2009
5
2.5
11
Now-2009
} "*
100
5.0
11
No*2009
` E
S
2.5
12
Novi-2009
1 i`.
10.0
5.0
12
Nov-2009
ii- t
5
2.5
13
Dec.2009
100
50
13
Dec2009
E;
5
2.5
14
Deo-2009
r.1;1
100
5.0
14
Deo-2009
!'..
5
2.5
15
Jan-2010
1 1
10.0
5.0
15
Jan-2010
�' *i
5
25
16
Jan2010
1 c"
100
50
16
Jan`2010
5
2.5
17
Feb-2010
KOC
10.0
5.0
17
Feb-2010
kA'
5
2.5
18
Feb 2010
1710i
10.0
5.0
18
Feb-2010
ici
5
2.5
19
Mar•2010
4` f
10.0
5.0
19
Mar-2010
5
2.5
20
Mar 2010
I ='
10.05.020
Mer-2010.
;'S;
5
25
21
Apr-2010
i ';''
15.0
15 0
21
Apr 2010
j <!
5.5
22
2010
10.0
10.0
22
Apr 2010
;;
.5
23
Mays-2010
'- 41
10.0
5.0
23
May-2010
5
2.5
24
May-2010
f-A'
10 0
5.0
24
May2010
5
2.5
25
Jun-2010
K j
10.0
5.0
25
Jun-2010
C!
5
2.6
26
Jun-2010
;'cy
10.0
5.0
26
Jun-2010
5
25
27
L.i
27
.J
RPA, data
-1- 8/20/2010

REASONABLE POTENTIAL ANALYSIS
3
4
Chromium
Cyanide
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=112DL
Results
1
Jun-2009
1
1.0
Std Dev.
1.3767
1
Jun-2009
<
5
5.0
Std Dev.
0.0000
2
Jun-2009
1
1.0
Mean
4.8462
2
Jun-20D9
<
5
5.0
Mean
5.0000
3
Jul-2009
<
10
5.0
C.V.
02941
3
Jul-20D9
<
5
5.0
C.V.
0.0000
4
Ju42009
<
10
5.0
n
26
4
JuL2009
<
5
5.0
n
26
5
Aug-2009
9
9.0
5
Aug-2009
<
5
5.0
6
Aug-2009
<
10
5.0
Mult Factor
1.4600
6
Aug-2009
<
5
5.0
Mint Factor=
1.0000
7
Sep-2009
<
10
5.0
Max. Value
9.0 uglL
7
Sep-2009
<
5
5.0
Max. Value
5.0 ug/L
8
Sep-2009
<
10
5.0
Max. Prod Cw
13.1 ug/L
8
Sep-2009
<
5
5.0
Max. Pred Cw
5.0 ug/L
9
Oct-2009
<
10
5.00
9
Oct-2009
<
5.0
5.0
10
Oct-2009
<
10
5.00
10
Oct-2009
<
5.0
5.0
11
Nov-2009
<
10
5.00
11
Nov-2009
<
5.0
5.0
12
Nov-2009
<
10
5.00
12
Nov-2009
<
5.0
5.0
13
Dec-2009
<
10
5.00
13
Dec-2009
<
5.0
&0
14
Dec-2009
<
10
5.00
14
13 o-2009
<
5.0
5.0
15
Jan-2010
<
10
S.OD
15
Ja 2010
<
5.0
5.0
16
Jan-2010
<
10
5.013
16
Jarf2010
<
5.0
5.0
17
Fe62010
<
10
5.00
17
Feb2010
<
5.0
5.0
18
Feb-2010
<
10
5.00
18
Feb-2010
<
5.0
5.0
19
Mar-2010
<
10
5.00
19
Mar-2010
<
5.0
5.0
20
Mar-2010
<
10
SAD
20
Mar-2010
<
5.0
5.0
'.. 21
Apr-2010
<
10.0
5.00
21
Apr-2010
<
5.0
5.0
22
Apr-2010
<
10
5.00
22
Apr-2010
<
5.0
5.0
23
May-2010
<
10
5.00
23
May-2010
<
5.0
5.0
24
May-2010
<
10
5.00
24
May-2010
<
5.0
5.0
25
Jun-2010
<
10
5.00
25
Jun-2010
<
5.0
5.0
26
Jun-2010
<
10
5.00
26
1u 2010
<
5.0
5.0
27
27
RPA, data
- i - 8/20/2010

• 1 •
• . REASONABLE POTENTIAL ANALYSIS
s
6
Lead
AMemury
Date
Data
BDL;1RDL
Results
Date
Data
BDL" 1/2DL
Results
1
Jun-2009
�
5
25
Std Dev.
1.7237
1
Jun-2009
<'
1
1.0
Sid Dev.
0.0490
2
Jun-2009
c
5
2.5
Mean
4.1346
2
Jun-2009
1
1.0
Mean
1.0096
3
Jul-2009
*
5
2.5
C.V.
0.4169
3
Jul-2009
i ;� i
2.5
1.3
C.V.
0.0486
4
Jul-2009
10
5.0
n
26
4
Jul-2009:
f
1
1.0
n
26
5
Aug-2009
}
5
25
5
Aug-2009
--01
1
1.0
6
Aug-2009
S
2.5
Mutt Factor =
1.7200
6
Aug-2009
1
1.0
Mtult Factor =
1.0000
7
Sep-2009
5
ZS
Max. Value
10.0 ug/L
7
Sep-2009
i`E;
1
1.0
Max Value
1.3 nglL
8
Sep-2009
'
5
2.5
Max. Peed Cw
172 uglL
8
Sep-2009
i; .
1.38
1.0
Max. Pred Cw
1.3 ng/L
9
Oct-2009
;: <:
10
5.0
9
Oct-2009
f. t •
1
1.000
10
Oct 2009
10
10.0
10
Oct-2009
c;
1
1.000
11
Nov-2009
c-;
10
5.0
11
Nbv-2009
i
1
1.000
12
Nov-2009
4
10
5.0
12
Nov-2009
1
1.000
13
Deo-2009
'°<;
10
5.0
13
Dec-2009
!;ei
1
1.000
14
Deo-20M
�. -i5j
5
25
14
Deo-2009
i.
1
1.0
15
Jan-2010
; ic
5
25
15
Jan-2010
i '�Oi
1
1.0
16
Jan-2010
i iA °
5
5
2,
16
Jan-2010
i
1
1.0
17
Feb-2010
c;A-
5
2.5
17
Feb-2010
j�
P4
1
1.0
18
Feb-2010tl
10
5.0
18
Feb-2010
f t;
1
1.0
19
Mar--2010
e i
10-
5.0
19
Mar-2010
i 4?
1
1.0
20
Mar 2010
'-
10
5.0
20
Mar-2010
1
1 A
21
Apr-2010
10
5.0
21
Apr-2010
1
1.0
22
Apr-2010
10
so
22
Apr-2010
1
1.0
23
May-2010
'
10
5.0
23
May-2010
:�t'`
1
1.0
24
May-2010
's<.i
10
5.0
24
May-2010
l ti
1
1.0
25
Jun-2010
[,Aii
10
5.0
25
Jun-2010
I
1
1.0
26
Jun-2010
1"
10
5.0
26
Jun-2010
! i
1
1.0
27
RPA, data
-1 - 8/20/2010

REASONABLE POTENTIAL ANALYSIS
7
g
Nickel
Selenium
Date Data
BDL=112DL
Results
Date
Data
BDL=112DL
Results
1
Jun-2009 eY
5
2.5
SW Dev.
0.7557
1
Jun-2009
57
57.0
Std Dev.
19.9700
2
Jun-2(09 is
5
2.5
Mean
3.3654
2
Jun-2009
56
56.0
Mean
32.1923
3
Jul-2009s e
5
2.5
C.V.
02246
3
Jul-2009
,
37
37.0
C.V.
0.6203
4
Jul-2009 _ 3
5
2.5
n
26
4
JW-2009
10
10.0
n
26
5
Aug-2009 i.j4l
5
2.5
5
A11w0
_
27
27A
6
Aug-2009y
5
2.5
Mint Fedor =
1.0000
6
Aug-2009
_
14
14.0
Mutt Fedor
2.1700
7
Sep-2009
5
2S
Max. Value
4.0 ug/L
7
S�-2009
{ ::
56
56.0
MWL Value
63.0 ug/L
8
Sep-2009 IT
5
2.5
Max. Pred Cw
4.0 ug/L
8
Sep-2009
32
32.0
Max. Prod Cw
136.7 ug/L
9
Od-2009
5
2.5
9
Od-2009
63
63.0
10
Od 2009 ; _;
5
2.5
10
Oct-=!)
13
13A
11
Nov-2009 j <=
8
4.0
11
Nov-2009
i',:
5
5.0
12
Nov-2009 E cs
5
2.5
12
Nov-2009
58
58.0
13
Dea2009
8
4.0
13
Deo-2009
22
22.0
14
Dec2009 Eire
'
8
4.0
14
Dec2009
�= ;
k
26
26.0
15
Jan-2010
8
4.0
15
Jan-2010
:
55
55A
16
Jan-2010 i c
8
4.0
16
Jan-2010`
f
21
21.0
17
Feb-2010
8
4.0
17
Feb-2010
j:' : i
13
13.0
18
Feb-2010 f'e
8
4.0
18
Feb-2010
32
32.0
19
Mar-2010 s
8
4.0
19
Mar-2010
is
5
5.0
20
Mae 2010 :;ki
8
40
20
Mar-2010
S
S0
21
Apr-2010 '.fix
8
4.0
21
Apr-2010
-;
58
58.0
22
Apr-2010 t
8
4.0
22
Apr-2010
`_'
35
35.0
23
May62010
8
4.0
23
May-2010
5
5.0
24
May-2010 „c,
8
4.0
24
May-2010
54
54.0
25
Jun-2010 c
8
4.0
25
Juw2010
i - 7'!,!
37
37.0
26
Jun-2010
8
4.0
26
Jun-2010
_`.�
41
41.0
27
<<'_:
27
RPA, data
-1- 8J20/2010

REASONABLE POTENTIAL ANALYSIS
9
10
Silver
Zinc
Date
Data
BDL=112DL
Results
Date
Data
BDL=112DL
Results
1
Jun-2009
6.0
2.5
Std Dev.
1.2010
1
Jun-2009
&0
2.5
Std Dew
2.39
2
Jul-2009
5.0
2.5
Mean
4.2308
2
Jul-2009
120
12.0
Mean
5.38
3
Aug-2009
&0
2.5
C.V.
0.2839
3
Aug-2009
8.0
8.0
C.V.
0.44
4
Sep-2009
5.0
2.5
n
13
4
Sep-2009
5.0
2.6
n
13
5
Oct-2009
10.0
5.0
5
Oct-2009
10.0
5.0
6
Nov-2009
10.0
6.0
Mult Factor =
1.65
6
Nov-2009
10.0
5.0
Mull Factor =
2.1500
7
Dec-2009
10.0
5.0
Max. Value
5.0 ug/L
7
0e 2009
10.0
5.0
Max. Value
12.0 ug/L
8
Jan-2010
10.0
5.0
Max. Fred Cw
8.3 uglL
8
Jan-2010
10.0
5.0
Max. Pred Cw
25.8 ug/L
9
Feb-2010
10.0
5.0
9
Feb-2010
10.0
5.0
10
Mar-2010
10.0
5.0
10
Mar-2010
10.0
5.0
11
Apr-2010
10.0
5.0
11
Apr-2010
10.0
5.0
12
May-2010
10.0
5.0
12
May-2010
10.0
5.0
13
Jurt-2010
10.0
5.0
13
Jun-2010
10.0
5.0
14
14
15
15
RPA, data
- 1 - 8/25/2010

REASONABLE POTENTIAL ANALYSIS
Date
Data
BDL=112DL
Results
1 Jun-2009
5
2.5
Sid Dev.
3.4872
2 Jul-2009
5
2.5
Mean
5.0769
3 Aug-2009
5
2.5
C.V.
0.6869
4 Sep-2009
5
2.5
n
13
5 Oct-2009
16
16.0
6 Nov-2009
10
5.0
Mull Factor =
3.0600
7 Deo-2009
10
5.0
Max. Value
16.0
8 Jan-2010
10
5.0
Max. Fred Cw
49.0
9 Feb-2010
10
5.0
10 Mar-2010
10
5.0
11 Apr-2010
10
5.0
12 May-2010
10
5.0
13 Jun-2010
10
5.0
14
RPA, data
1 - 8/25/2010

Date: 8/20/10 DMR data fro Rodanthe WTP
pb: idb NCO083909
0 Flow Rdg Flow Monthly Avg Permitted Flow
0.35
0.25
0.20
-
o
0
0.15
- -----
0.10
A
0.05
■
-1p % w r,
?4R
0
0.00
8
w 0
0
9
9 9 1O >
tO o 9 9 00 9
n 4 >
SA, HQW class
Acute toxicity monitoring 90%

Date: 8/20/10 DMR data for Rodanthe WTP
pb: fd1b NC0083909
0 Arsenic Rdg D Monthly Avg —Monthly Avg Limit
25.0 -------- -------------
20.0 * - . - - - - - - - - - o------ *__ 0 -----0- - ---------------
15.0 -0 - -
10.0 Ej - U) *000, -.w -W- ­00 -oo
o Do
U
5.0
0.0
o
00 00
g 9 9
M Go W M a) CL go M 0 M 06
LL. 4A L.L LL
Cadmium Rdg El Monthly Avg —Monthly Avg Umit —Daily Max Umit
25.0
20.0
ALL RDS LESS THAN
15.0
10.0 0 0 -------- --
5.0
00
W LJ W U
0.0
-5 tic M c 75 tho
8 eo CO go go CL
LPLdcc LL. LL M 41t
o Chromium Rdg o Monthly Avg —Monthly Avg Umit
70.0 ---------------------
60.0 -------------
50.0 o-------- -- -----------------------
40.0
30.0 - - - - - -
ID 13 -0 1]
20.0 ------- -
10.0 .0 ee "fte,86619 .900,0 es es e 0-"'w--O
0 0 El El E3 0 El 0 El 13
0.0
00 00 00 00 CO CO CO 00 Go 00 a% Cn
9 9 9 9 9 9 9 9 9 9
CL r .0 75
C .0 & c CL r-
ap cc CL CC Qj M 0 ap M
W� zo

Oate: 8/20/10 DMR data for Rodenthe WTP
pb:,Idb NCO083909
o
Nickel Rdg
0 Monthly Avg Monthly Avg Limit ---
Daily Max Limit
60.0
i
-
-
-
i
soo
ALL RDGS LESS THAN
40.0
-
----
20.0
-
------------
----------------
----
10.0
-
-
--------
f
O
000 40 .00 O
000
00 0 j
ao
-
- -
----
-
�- --
-
- -
-
:_s r
-- -
-
T
T
T
Q
Q
00
CL >
T
Li
Q
''
Q
of v Z
p
C
►- ? C
LEQ
-' Q y V
2
O LL
a
o
Selenium Rdg
El
Monthly Avg
Monthly Avg
Limit
I
70.0
-
--
----------------
--
60.0-
o
O
50.0
-
- -
- -
--------
----
40.0
-
- ----
----------
----
- -- 0---------0
------ --
----------
0 Ci1 I
O
30.0
0
0
I.;',
I
20.0
-
---
--
O
--------0----------
----
10.0
-' -
----------------
- -
El ED
---- ----
- O O
O
bn oM
On
O- LT
Cn
on 0
0�0
ao--
-- T
-� , -
- - --
-
c
'�
LL
c��.
a
�-
c
-+
oo
Q
ai >
Cn v Z
O
a �. c
Li Q �0
ao ai
''
>
rr
Li
>.
Q M
c

' r
'•_ ' Date: 8/20/10 DMR data for Rodanthe WTP
• ; -,pb: `rdb
NC0083909
o Cyanide Rdg r Monthly Avg MonthlyAvg/Daily Limits
12.0 - -
10.0
8.0 ---- ---- -
ALL RDGS LESS THAN PQIL 10 µdl
6.0 -- - -- - - ---- J�--{* E>-------��-�- --
El 00000130 OJOE] *[DODOS*
D El
4.0 - --- - -- - ---- - -------
i
2.0
f
0.0
9 9 4 4�� 4 4��� Q Q� g? �� g? �? g? � `� �' Q o 0 0 0 0 o
� �- 7 a M Q. � 7 y r G y C 0cc
a a C
u. Q Vl Z O LL g Q Q Vf Z O ti Q
o Lead Rdg EJ Monthly Avg Monthly Avg Limit Daily Mau Limit
300.0 --- - --- --- --- -
250.0 r -
0!
3.� I
i
-- - - - - - - - - - - - - - - - -
I
150.0------ - -
100.0------- -- - -- [--------------------------- —------- --------------------------------
i
50.0
i
o Mercury Rdg ri Monthly Avg Monthly Avg Limit
250.0 y - - - -
200.0 ©
----- o - - o a
oUJ-
- - ----- -- -- - t
M
to
.c
100.0
Er-
eJ
---- - --- -- -- ------ ------i
O
50.0
- -
t
- - - - ----- -
3
ALL RIDS BELOW PQL 2 ng/I
ao
0
0o4 ao co4 00 0o 00
�? ao 00
4 4 4 4 4
co
q
�?
o+ c+ o 0 0 0 0 0
g? 4
c
►- a- c ao n
LL.a
> c
0 c
> c 0o a > c .o ►- > c
a n i o LL a -'.

Permit NCO083909
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 from outfall 001. Such discharges shall be limited and monitored by the Permittee as
specified below:
EFFLUENT
CHARACTERISTICS
(Parameter Codes)
LIMITS
MONITORING REQUIREMENTS
Monthly
Average
Weekly
Average
Daily
Maximum
Measurement
Frequency
Sample
Type
Sample Location'
Flow (50050)
0.3 MGD
Continuous
Recording
Effluent
Total Dissolved Solids 70295
Monthly
Grab
Effluent
pH2 (00400)
Monthly
Grab
Effluent, Upstream,
Downstream'
Temperature (00010)
Monthly
Grab
Effluent, Upstream,
Downstream'
Salinity (00480)
Monthly
Grab
Effluent, Upstream,
Downstream'
Dissolved Oxygen (00300)
Monthly
Grab
Effluent, Upstream,
Downstream'
Conductivity (00094)
Monthly
Grab
Effluent, Upstream,
Downstream'
Ammonia Ni en 00610
Monthly
Grab
Effluent
Total Nitrogen 00600
Monthly
Grab
Effluent
Total Phosphorus 00665
Monthly
Grab
Effluent
Total Copper 01042
1
Monthly
Grab
Effluent
Total Zinc 01092
Monthly
Grab
Effluent
Total Seleniums 01147)
C71
c ,
2/ Month
Grab
Effluent
Total C anides^ 00720
2 / Month
Grab
Effluent
Total Arsenica 01002
251
50 /LZI6-.-
2 / Month
Grab
Effluent
Total Cadmium3 0102
2 , b
5
2 / Month
Grab
Effluent
Total Chromium3 01034
2 / Month
Grab
Effluent
Total Leada 01051
2/ Month
Grab
Effluent
Total Mercu a 71900
25 n IL
2 / Month
Grab
Effluent
Total Nickela 0106
8 /L
2/ Month
Grab
Effluent
T r 01077
✓o.S
MonthlyGrab
Effluent
Acute Toxin GE3E
Quarterly
Composite
Effluent
F�+*.o s• � t
1. Upstream = 27 feet north of the outfallDo s�trte'aa 0 50 feet south of the outfall.
2. The Effluent pH shall not be less than 6.8 standard units nor greater than 8.5 standard units.
3. After collection of twelve months of data, the permittee may request the Division reevaluate the data and reasonable
potential to exceed water quality standards.
4. The Division shall consider all cyanide values reported below 10 µg/L to be "zero" for compliance purposes. However, the
Permittee shall record and submit all values reported by a North Carolina -certified laboratory, even if these values fall
below 10 pg/L.
5. Acute Toxicity (Mysibprir babia) P/F: January, April, July and October (see A. (2)).
There shall be no discharge of floating solids or visible foam in other than trace amounts.
N�
SAtVYW �= r��1
l� �

Permit NCO083909
A. (2.) ACUTE TOXICITY PERMIT MONITORING (QUARTERLY)
The Permittee shall conduct acute toxicity tests on a quarterlr� basis using protocols defined in the
North Carolina Procedure Document entitled "Pass/Fail Methodology For Determining Acute Toxicity
In A Single Effluent Concentration" (Revised -July, 1992 or subsequent versions). The monitoring
shall be performed as a Mysidopsis Bahia 24 hour static test. The effluent concentration defined as
treatment two in the procedure document will be 90%. Effluent samples for self -monitoring purposes
must be obtained during representative effluent discharge below all waste treatment. The tests will
be performed during the months of January, April, July and October.
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 TGE3E. Additionally, DWQ Form AT-2 (original) is to be sent to the following address:
Attention: Environmental Sciences Section
North Carolina Division of Water Quality
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 until such time that a valid test is submitted. 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 maybe 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 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.

COUNTY OF DARE
Water Department
600 Mustian Street. Kill Devil Hills, NC 27948
Ken Flatt
Utilities Director
May 27, 2009
Karen Rust, Environmental Specialist
NC Division of Water Quality
Eastern NPDES Program
1617 Mail Service Center
Raleigh, NC 27699-1617
Karen,
[phone]
fax [phone]
Dare County is requesting the effluent limits for the Rodanthe/Waves/Salvo Reverse
Osmosis WTP (NC0083909) and the Cape Hatteras Reverse Osmosis WTP (NC0085707)
be recalculated based on a 6.5% in stream waste concentration as shown in the dye
performance study conducted by Aquaeter in July 2001.
We request the permit limits and sampling frequency be restored to the limits in the previous
permits since there have been no changes in our water production processes, raw water
sources, or receiving waters since both facilities were brought on line.
Your consideration is appreciated.
Best Regards,
KC
Ken Flatt
Utilities Director
Dare County Water Department
600 Mustian St.
Kill Devil Hills, NC 27948
252 475-5606
RECEIVED
JUN -1 2009
DENR - WATER QUALITY
POINT SOURCE BRANCH
CcA Kristen Jarman, Environmental Specialist - DWQ Regional Office
LAND OF BEGINNINGS