NC0079057_Fact Sheet_20231220

NCO079057
Fact Sheet
NPDES Permit No. NC00 79057
Permit Writer/Email Contact: Gary Perlmutter, [e-mail]
Date: December 20, 2023
Division/Branch: NC Division of Water Resources/NPDES Municipal Permitting
Fact Sheet Template: Version 09Jan2017
Permitting Action:
❑x Renewal
❑ Renewal with Expansion
❑ New Discharge
❑ Modification (Fact Sheet should be tailored to mod request)
Note: A complete application should include the following:
• For New Dischargers, EPA Form 2A or 2D requirements, Engineering Alternatives Analysis, Fee
• For Existing Dischargers (POTW), EPA Form 2A, 3 effluent pollutant scans, 4 2nd species WET
tests.
• For Existing Dischargers (Non-POTW), EPA Form 2C with correct analytical requirements based
on industry category.
Complete applicable sections below. If not applicable, enter NA.
1. Basic Facility Information
Facility Information
Applicant/Facility Name:
Town of Manteo / Manteo WWTP
Applicant Address:
PO Box 246, Manteo, NC 27954
Facility Address:
710 Bowsertown Rd, Manteo, NC 27954
Permitted Flow:
0.6 MGD / 1.0 MGD
Facility Type/Waste:
MINOR Municipal: 100% domestic / MAJOR upon expansion
Facility Class:
Grade III
Treatment Units:
Micro -strainer, grit chamber, oxidation ditch, two clarifiers, two tertiary filters,
chlorine disinfection, dechlorination, post aeration, sludge digester, sludge
holding lagoon, standby power
Pretreatment Program (Y/N)
No
County:
Dare
Region
Washington
Briefly describe the proposed permitting action and facility background: The Town of Manteo has applied
for an NPDES permit renewal for its WWTP in May 2023. Review of the application found it incomplete
with the following attachments lacking:
• Process narrative
• Chemical Addendum
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NC0079057
These elements were requested on 10/18/2023 and received on 10/25/2023.
In the application cover letter the Town has requested the following:
• Maintain reduced effluent monitoring for BOD, TSS, Ammonia and Enterococci.
• Maintain reduced instream monitoring for listed parameters
The town also reported actions taken per the permit's compliance schedule for copper and
dibromochloromethane. These items will be addressed in their relevant sections below.
This facility serves a population of —1600 residents in the Town of Manteo. The facility treats 100%
domestic wastewater with no industrial users and no pretreatment program. Originally permitted as a 1.0
MGD facility, the current 0.6 MGD permitted flow was added to the permit in 1999 upon the discovery
that 0.6 MGD was the design flow. The 1.0 MGD then became an expansion flow.
Inflow and Infiltration (I&I): The Town did not report an average daily flow of I&I in the application, but
did provide the value upon request: 0.0059 MGD over the past 12 mor . The Town did describe steps
taken to minimize I&I in the application, including:
• Monitoring rainfall and collection system flow at pump stations;
• Smoke testing, pipe cameras and CCTV inspection to determine I&I locations and point repair; and
• Replacing the oldest pump station that is nearest to Shallowbag Bay and sound -rise events.
Sludge Management: From the submitted Sludge Management Plan: "The WAS [waste activated sludge]
is moved from our Clarifiers manually to an aerobic digester where it is aerated for the appropriate amount
of time based on the season for proper digestion of solids. When there is no supernatant volume left in the
Digester, we turn the aerator off to allow the sludge to settle and are able to return a clear supernatant
back to the Headworks of the Treatment Plant. Once done with decanting, the aerator is returned to working
order. At the point that the sludge blanket in the Digester is too high that it effects the quality of supernatant,
we then move the thickened blanket to our Sludge Holding Lagoon for storage and further aeration and
mixing.
We operate the Sludge Holding Lagoon in the same manner as the Digestor for further digestion and
thickening of solids. When the Sludge Holding Lagoon has reached the appropriate percentage of solids,
we stabilize the sludge by raising the pH to 12 standard units for 24 hours. Once the stabilization has been
achieved, the sludge is hauled off by truck and land applied. The hauling is conducted by a contracted
company as well as the land application of sludge. "
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NCO079057
2. Receiving Waterbody Information
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001 — Shallowbag Bay
Stream Segment:
30-21-(3)
Stream Classification:
SC
Drainage Area (miz):
--
Summer 7Q10 (cfs)
Tidal
Winter 7Q 10 (cfs):
jAL Tidal
30Q2 (cfs):
Tidal
Average Flow (cfs):
Tidal
IWC (% effluent):
100%
2022 303(d) listed/parameter:
None
Subject to TMDL/parameter:
Statewide Mercury TMDL
River Basin/HUC:
Pas uotank / 03010205
USGS Topo Quad:
4Wanteo, NC
Effluent is pumped through —6,000 linear feet (-1.1 miles) force main with a diffuser into the center of
Shallowbag Bay. The 2022 Integrated Report does not list Shallowbag Bay as no data are available for
rating. However, according to the 2021 Pasquotank River Basin Plan, the NC Division of Marine Fisheries
has classified Shallowbag Bay as a prohibited shellfish growing area within Shellfish Growing Area H-1 of
Roanoke Sound and associated creeks. The prohibited classification is due to potential fecal coliform
bacterial levels. Downstream waters in the Sound are classified as SA; HQW.
3. Effluent Data Summary
Effluent data for Outfall 001 are summarized from March 2019 through August 2023 (Table 1).
Table 1. Effluent Data Summary Outfall 001.
Parameter
Units
Average
Max
Min
Permit Limit 1
Flow
MGD
0.272
0.700
0.164700
MA = 0.6
BOD5 summer
mg/L
2
g
< 2
WA = 7.5
MA = 5.0
BOD5 winter
mg/L
2
g
< 2
WA = 15.0
MA = 10.0
BOD Removal
%
98.4
99.7
88.2
> 85
Total Suspended Solids
WA = 45.0
mg/L
2.5
3.8
< 2.5
(TSS)
MA = 30.0
TSS Removal
%
97.5
99.5
87.5
> 85
mg/L
Ammonia (NH3-N) summer
0.11
1.0
< 0.1
MA = 2.0
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NCO079057
Parameter
Units
Average
Max
Min
Permit Limit 1
Ammonia (NH3-N) winter
mg/L,
0.12
0.84
< 0.1
MA = 4.0
Dissolved Oxygen (DO)
mg/L
8.4
10.5
6.6
DA > 6.0
Enterococci
#/100 mL
1.3
120
< 1
WA = 276
(geometric mean)
MA = 35
pH
SU
7.3
7.8
6.8
6.8 - 8.5
Temperature
° C
21.2
30.7
10.0
Monitor &
Report
Total Nitrogen
mg/L
7.9
15.3
3.2
Monitor &
Report
Total Kjeldahl Nitrogen
Mg/L
1.1
2.2
< 0.5
Monitor &
(TKN)
-
Report
Total Phosphorus
mg/L,
2.62
4.72
Monitor&
Report
Total Copper
µg/L
3.9
1
MA = 3.7
DM = 5.8
Total Nickel
µg/L
8.0
i u
< 0.1
Monitor &
Report
Total Zinc
µg/L
73.5
110
35
Monitor &
Report
TRC
µg/L
10.0
14.0
< 10.0
DM = 13.0
Dibromochloromethane
µg/L
11.2
45.9
2.5
MA = 21.0
DM = 21.0
Bromodichloromethane
µg/L
13.35
24.3
7.39
Monitor &
Report
Bis(2-ethylhxyl) phthalate
mg/L
5.4 -
14.4
< 0.5
Monitor &
Report
Footnotes.
1. MA = Monthly Average; WA = Weekly Average; DM = Daily Maximum; DA = Daily Average.
2. Results < 50 µg/L considered compliant.
The highest annual average flow was 0.282 MGD, 47% of the permitted 0.6 MGD flow, in 2020.
4. Instream Data Summary
Instream monitoring may be required in certain situations, for example: 1) to verify model predictions when
model results for instream DO are within 1 mg/l of instream standard at full permitted flow; 2) to verify
model predictions for outfall diffuser; 3) to provide data for future TMDL; 4) based on other instream
concerns. Instream monitoring may be conducted by the Permittee, and there are also Monitoring
Coalitions established in several basins that conduct instream sampling for the Permittee (in which case
instream monitoring is waived in the permit as long as coalition membership is maintained).
If applicable, summarize any instream data and what instream monitoring will be proposed for this permit
action: The current permit requires instream monitoring for Temperature, DO, Salinity and pH at 1 ft
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NCO079057
intervals vertically throughout the water column at five locations, each of which was assigned an Outfall
and relative location as upstream or downstream for DMR reporting purposes (Table 2):
Table 2. Instream Monitoring Locations.
Outfall
Location
Description
001A
Upstream
Mouth of Douglas Creek
00113
Upstream
Near the mouth of Scarboro Creek
001 C
Downstream
In Shallowbag Bay approximately 800 feet northeast of Sandy Point
0011)
Downstream
In Shallowbag Bay approximately 0.4 miles southeast of Ballast Point
001E
Downstream
In Roanoke sound approximately 200 feet outside of Shallowbag Bay
These sampling locations were in the permit as early as 1992, initially with monitoring frequencies of
3/week in summer (June — September) and weekly during the rest of the year and also included fecal
coliform monitoring. Sampling at 1 ft vertical intervals was introduced in the 1998 permit. Fecal Coliform
was removed in the 2003 permit as the facility discharges treated 100% domestic wastewater. In the 2019
permit renewal, summer monitoring frequency was reduced to weekly so that all instream monitoring is
consistent.
A visual check of the instream locations found 001 D to be incorrectly described as it would lie in Roanoke
Sound if southeast of Ballast Point. It was corrected to read "in Shallowbag Bay 0.4 mi. southwest of
Ballast Point."
Instream data were acquired from submitted DMRs spanning March 2019 through August 2023 for review.
The data were checked against applicable stream standards as well as for effluent impacts, the latter via
statistical testing of outfall averages by ANOVA followed by t-test if significant differences were found.
The level of significance (p-value) for all tests were set at 0.05. In addition, the data were charted and
visually checked for seasonal trends to evaluate whether increased monitoring in summer months is
warranted or if year-round weekly monitoring is to be maintained as requested by the Town. The data are
summarized in Table 3 and discussed below.
Table 3. Instream Data Summary: averages with ranges in parentheses in the five locations (outfalls).
Parameter, units
001A
001B
001C
001D
001E
DO, mg/L
Avg = 9.3
Avg = 9.3
Avg = 9.5
Avg = 9.5
Avg = 9.6
(6.0-13.0)
(6.0-12.2)
(6.6-13.2)
(6.8-12.9)
(6.1-13.0)
Temperature, °C
Avg = 19.3
Avg = 19.5
Avg = 19.3
Avg = 19.2
Avg = 19.2
(4.4-31.4)
(5.6-31.0)
(4.3-31.0)
(4.4-31.3)
(4.3-31.4)
Salinity, %o
Avg = 10.2
Avg = 10.2
Avg = 9.9
Avg = 9.7
Avg = 9.5
(0.3-25.9)
(0.3-24.8)
(0.4-22.1)
(0.3-20.7)
(0.4-20.4)
pH, SU
Avg = 7.9
Avg = 7.6
Avg = 8.0
Avg = 7.9
Avg = 8.0
(7.1-8.3)
(6.88.8)
(7.4-8.4)
(7.18.4)
(7.4-8.4)
Dissolved Oxygen (DO) — DO is in the permit as a parameter of concern for aquatic life. Summer minima
at all stations were all above the stream standard of 5.0 mg/L (15A NCAC 02B .0211). No statistically
significant differences were found among any of the locations. Concurrent effluent average DO appears
lower but with similar summer minima.
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NC0079057
Temperature — Temperature is in the permit as a parameter of concern for aquatic life. The summer maxima
at all stations were all below the 32°C standard for lower piedmont and coastal plain waters (15A NCAC
02B .0211). No statistically significant differences were found among any of the locations. Due to the
multiple monitoring locations designated as upstream and downstream, evaluations of temperature
increases were not made. Corresponding effluent temperatures appear higher on average than those
instream.
Salinity — Salinity is in the permit due to the facility discharging freshwater effluent into saltwater and is
therefore a concern for aquatic life. No statistically significant differences were found among any of the
locations.
pH — pH is in the permit as a parameter of concern for aquatic life. Ranges among stations largely were
within the standards of 6.8 — 8.5 SU for salt water (15A NCAC 02B .0200), with only one upstream location,
Outfall OO1B having a maximum above the maximum standard. Significant differences were found with
Outfall 002 having the lowest pH on average. Concurrent effluent pH were also within the permit limits,
which are also the saltwater stream standard.
Conductivity — Conductivity is not in the current permit as it is an indicator of industrial waste. Since the
WWTP is treating 100% domestic waste with no industrial users, this parameter is not required and will not
be added to the permit.
Fecal Coliform/Enterococci — Fecal Coliform was removed from the permit in 2003 as the facility
discharges treated 100% domestic wastewater. Division guidance on instream monitoring allows for fecal
coliform to be removed unless the receiving water is either a Class B or is impaired for this parameter.
Shallowbag Bay is neither a Class B nor is impaired for the parameter, but it is excluded from shellfish
growing due to potential fecal coliform issues. Based on the relevant information and that no instream data
exist (i.e., no ambient monitoring stations are in the Shallowbag Bay area), Fecal Coliform effluent and
instream monitoring will be added to the permit at a monthly frequency at all locations to track bacterial
levels in the bay.
With the current renewal application, the Town requested that the reduced monitoring frequency of 1/week
year-round be maintained citing scheduling and use of a boat to access all instream locations of Shallowbag
Bay. Considering this request and review of the data finding no statistically significant differences among
the five monitoring locations for all parameters, current monitoring frequency is maintained.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (YIN): NO
Name of Monitoring Coalition: NA
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years): From September 2018 through
August 2023 the facility had reported no exceedences that resulted in violation actions.
Summarize the compliance record with aquatic toxicity test limits and any second species test results (past
5 years): The facility passed 19 of 19 quarterly chronic toxicity tests. A bioassay inspection was conducted
in May 2022 in which an acute 24-hr Pimephales promelas (Fathead Minnow) test was sampled for and
which resulted in a pass, indicating compliance.
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NC0079057
Summarize the results from the most recent compliance inspection: The most recent facility inspection
conducted in November 2022 reported that the facility was in compliance with its permit. A bioassay
inspection was conducted in May 2022 in which an acute 24-hr Pimephales promelas (Fathead Minnow)
test was sampled for and which resulted in a pass, indicating compliance.
6. Water Quality -Based Effluent Limitations (WQBELs)
6.1 Dilution and Mixing Zones
In accordance with 15ANCAC 213.0206, the following streamflows are used for dilution considerations for
development of WQBELs: 1 Q 10 streamflow (acute Aquatic Life); 7Q 10 streamflow (chronic Aquatic Life;
non -carcinogen HH); 30Q2 streamflow (aesthetics); annual average flow (carcinogen, HH).
If applicable, describe any other dilution factors considered (e.g., based on CORMIX model results): NA
If applicable, describe any mixing zones established in accordance with 15A NCAC 2B.0204(b): NA
6.2 Oxygen -Consuming Waste Limitations
Limitations for oxygen -consuming waste (e.g., BOD) are generally based on water quality modeling to
ensure protection of the instream dissolved oxygen (DO) water quality standard. Secondary TBEL limits
(e.g., BOD = 30 mg/L for Municipals) may be appropriate if deemed more stringent based on dilution and
model results.
If permit limits are more stringent than TBELs, describe how limits were developed: Winter and
summer BOD5 limits in the current permit are set based on the results of a Georgia Estuary Model (GAEST
— version 2) in the 1990 wasteload allocation (WLA) for the then 1.0 MGD flow tier and maintained upon
adding the 0.6 MGD flow tier in the 1999 permit when discovered that the latter is the design flow in 1997.
No changes are proposed from the previous permit limits.
6.3 Ammonia and Total Residual Chlorine Limitations
Limitations for Ammonia are based on protection of aquatic life utilizing an ammonia chronic criterion of
1.0 mg/L (summer) and 1.8 mg/L (winter). Acute ammonia limits are derived from chronic criteria, utilizing
a multiplication factor of 3 for Municipals and a multiplication factor of 5 for Non -Municipals.
Limitations for Total Residual Chlorine (TRC) are based on the NC water quality standard for protection
of aquatic life (17 µg/L) and capped at 28 µg/L (acute impacts). Due to analytical issues, all TRC values
reported below 50 µg/L are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: The current permit
sets a daily maximum limit for TRC of 13 µg/L based on federal criteria for saltwater facilities. TRC limits
were reviewed in the attached wasteload allocation (WLA) and were found to be protective of the receiving
stream. No changes are proposed for TRC.
The current Ammonia winter monthly average and summer monthly average limits of 4 mg/L and 2 mg/L
at 0.6 MGD are set based on the results of a Georgia Estuary Model (GAEST — version 2) in the 1990
wasteload allocation (WLA) for protection against oxygen -consuming waste at 1.0 MGD. In 2003, the
Division implemented a statewide policy resulting from EPA requirements that set weekly average
Ammonia limits based on a 3:1 ratio with the monthly average. As a result, the permit adopted weekly
winter and summer ammonia limits of 12 mg/L and 6 mg/L, respectively. With the addition of the design
flow of 0.6 MGD in the 1999 permit, these limits were applied to the lower flow, while maintaining them
at 1.0 MGD redesignated as an expansion tier. Based on a WLA designed to protect aquatic life from
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NC0079057
ammonia nitrogen toxicity, run for the 2017 permit, the limits for ammonia nitrogen at 1.0 MGD were
reduced to 1.0 mg/L in the summer and 2.0 mg/L in the winter.
The WLA used in 2017 was designed for freshwater, not saltwater. To address saltwater ammonia toxicity,
a site -specific WLA was run for the current renewal, using effluent and instream temperature and pH data
as well as instream salinity data for site -specific limits applicable to saltwater. Since the receiving water is
tidal and is effectively 0.0 cfs, the results are the same at both flow tiers. The resulting site -specific saltwater
ammonia allowable concentrations are 1.4/3.4 mg/L monthly/weekly average in summer and 2.5/6.2 mg/L
monthly/weekly in winter at both flow tiers. These concentrations will be applied as limits in the permit.
Review of submitted effluent data in as summarized in Table 1, yielding nearly all to be nondetects at < 0.1
mg/L, found that the revised limits can be met with little difficulty.
6.4 Reasonable Potential Analysis (RPA) for Toxicants
If applicable, conduct RPA analysis and complete information below.
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 '/2 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 saltwater RPA was conducted on effluent toxicant data collected between March 2019 — August 2023. It
should be noted that the submitted metals data have the wrong parameter code despite the permit listing the
correct code (e.g., Total Copper is entered as CO042 when it should be 01042). Based on the proximity of
the Roanoke Sound, a class SA; HQW water, and Scarboro Creek and Douglas Creek, both class SC; HQW
waters, the High Quality Water limitations of 50% stream standards for toxicants apply. 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:
• Effluent Limit with Monitoring. The following parameters will receive a water quality -based
effluent limit (WQBEL) since they demonstrated a reasonable potential to exceed applicable water
quality standards/criteria:
o Total Copper
■ MA = 1.8 µg/L; DM = 2.9 µg/L at both flow tiers
o Total Zinc
■ MA = 42.8 µg/L; DM = 47.6 µg/L at both flow tiers
o Dibromochloromethane
■ MA, DM = 10.5 µg/L at both flow tiers
o Bis(2-ethylhexyl) phthalate
■ MA, DM = 0.2 µg/L at both flow tiers
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
the maximum predicted concentration was > 50% of the allowable concentration: Total Nickel at
both flow tiers.
o Bromodichloromethane will require monthly monitoring to gather more data for
evaluation.
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: Bromoform
at both flow tiers.
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NC0079057
• POTW Effluent Pollutant Scan Review: NA; effluent pollutant scans are not required in the current
permit at the current permitted flow of 0.6 MGD.
If applicable, attach a spreadsheet of the RPA results as well as a copy of the Dissolved Metals
Implementation Fact Sheet for freshwater/saltwater to this Fact Sheet. Include a printout of the RPA
Dissolved to Total Metal Calculator sheet if this is a Municipality with a Pretreatment Program.
6.5 Toxici , Testing Limitations
Permit limits and monitoring requirements for Whole Effluent Toxicity (WET) have been established in
accordance with Division guidance (per WET Memo, 8/2/1999). Per WET guidance, all NPDES permits
issued to Major facilities or any facility discharging "complex" wastewater (contains anything other than
domestic waste) will contain appropriate WET limits and monitoring requirements, with several exceptions.
The State has received prior EPA approval to use an Alternative WET Test Procedure in NPDES permits,
using single concentration screening tests, with multiple dilution follow-up upon a test failure.
Describe proposed toxicity test requirement: Manteo WWTP is a Minor POTW, and an acute WET limit at
90% effluent using Fathead Minnow (Pimaphales promelas) at 0.6 and 1.0 MGD flow tiers will continue
on a quarterly frequency.
6.6 Mercury Statewide TMDL Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply with
EPXs mercury fish tissue criteria (0.3 mg/kg) for human health protection. The TMDL established a
wasteload allocation for point sources of 37 kg/year (81 lb/year), and is applicable to municipals and
industrial facilities with known mercury discharges. Given the small contribution of mercury from point
sources (-2% of total load), the TMDL emphasizes mercury minimization plans (MMPs) for point source
control. Municipal facilities > 2 MGD and discharging quantifiable levels of mercury (> 1 ng/L) will receive
an MMP requirement. Industrials are evaluated on a case -by -case basis, depending if mercury is a pollutant
of concern. Effluent limits may also be added if annual average effluent concentrations exceed the WQBEL
value (based on the NC WQS of 12 ng/L) and/or if any individual value exceeds a TBEL value of 47 ng/L.
Describe proposed permit actions based on mercury evaluation: The current permit requires low level
mercury monitoring at once per 5 years, to be analyzed by EPA Method 1631E. No mercury data were
available for review, and sampling was requested on 10/27/2023. The required sample was collected on
11/13/2023, yielding a result of 1.05 ng/L, below the TBEL of 47 ng/L and the WQBEL of 12.5 ng/L at
both flow tiers. The facility is < 2 MGD and does not meet the criteria requiring an MMP. No changes are
proposed.
6.7 Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation within
this permit: Currently the receiving waterbody has no TMDL or Nutrient Management Strategy. The current
permit has monthly monitoring for Total Nitrogen and Total Phosphorus. To better understand the effluent
nitrogen, Nitrite+Nitrate (NO2+NO3) and Total Kjeldahl Nitrogen (TKN) monitoring will be added to the
permit at the same frequency as Total Nitrogen monitoring.
6.8 Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: Emerging contaminants
PFAS and 1,4-Dioxane were considered when the facility submitted its Chemical Addendum on
10/25/2023. On the Chemical Addendum the Town noted: `No anticipated additional pollutants since
issuance of last permit." The receiving water is a saltwater bay within the Roanoke Sound and not a
designated water supply. The facility discharges 100% domestic waste; thus 1,4-Dioxane is not anticipated
and no requirements for this parameter were added to the permit. However, based on the pervasive nature
of PFAS chemicals and following EPA guidance on PFAS monitoring (memo, 12/5/2022), 2/year
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NC0079057
monitoring for PFAS will be added to the permit to generate data for future evaluation. Implementation of
HAS monitoring will be delayed until six months after the final EPA Method 1633 is published in the
Federal Register to allow laboratories to become certified in the new method.
If applicable, describe any special actions (HQW or ORW) this receiving stream and classification shall
comply with in order to protect the designated waterbody: NA.
If applicable, describe any compliance schedules proposed for this permit renewal in accordance with 15A
NCAC 2H. 01 07(c) (2)(B), 40CFR 122.47, and EPA May 2007 Memo: The current permit has a compliance
schedule for Total Copper and Dibromochloromethane limits [A. (4.)] with a compliance date of July 1,
2022 for both parameters. Since the compliance date has passed, the compliance schedule will be removed
from the permit. With the new HQW-applied toxicant limitations, a five-year compliance schedule with a
dilution study option has been added to the permit for Total Copper, Total Zinc, Bromodichloromethane,
Dibromochloromethane and Bis(2-ethylhexyl) phthalate.
If applicable, describe any water quality standards variances proposed in accordance with NCGS 143-
215.3(e) and 15A NCAC 2B.0226 for this permit renewal: NA
7. Technology -Based Effluent Limitations (TBELs)
Municipals.
Are concentration limits in the permit at least as stringent as secondary treatment requirements (30 mg/L
BOD51TSS for Monthly Average, and 45 mg/L for BODs/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85% removal requirements for BOD51TSS included in the permit? YES. Review of the data for both
parameters found removal rates to be > 85%.
If NO, provide a justification (e.g., waste stabilization pond). NA
8. Antidegradation Review (New/Expanding Discharge):
The objective of an antidegradation review is to ensure that a new or increased pollutant loading will not
degrade water quality. Permitting actions for new or expanding discharges require an antidegradation
review in accordance with 15A NCAC 2B.0201. Each applicant for a new/expanding NPDES permit must
document an effort to consider non -discharge alternatives per 15A NCAC 2H.0105(c)(2). In all cases,
existing instream water uses and the level of water quality necessary to protect the existing use is maintained
and protected.
If applicable, describe the results of the antidegradation review, including the Engineering Alternatives
Analysis (EA-4) and any water quality modeling results: NA
9. Antibacksliding Review:
Sections 402(o)(2) and 303(d)(4) of the CWA and federal regulations at 40 CFR 122.44(l) prohibit
backsliding of effluent limitations in NPDES permits. These provisions require effluent limitations in a
reissued permit to be as stringent as those in the previous permit, with some exceptions where limitations
may be relaxed (e.g., based on new information, increases in production may warrant less stringent TBEL
limits, or WQBELs may be less stringent based on updated RPA or dilution).
Page 10 of 16

NC0079057
Are any effluent limitations less stringent than previous permit (YES/NO): No, but quarterly monitoring for
Bromoform was removed from the permit.
If YES, confirm that antibacksliding provisions are not violated: Based on RPA results of recent effluent
data showing no reasonable potential to exceed stream water quality standards (hereafter "RP"), monitoring
requirements for Bromoform have been removed from the permit.
10. Monitoring Requirements
Monitoring frequencies for NPDES permitting are established in accordance with the following regulations
and guidance: 1) State Regulation for Surface Water Monitoring, 15A NCAC 213.0500; 2) NPDES
Guidance, Monitoring Frequency for Toxic Substances (7/15/2010 Memo); 3) NPDES Guidance, Reduced
Monitoring Frequencies for Facilities with Superior Compliance (10/22/2012 Memo); 4) Best Professional
Judgement (BPJ). Per US EPA (Interim Guidance, 1996), monitoring requirements are not considered
effluent limitations under Section 402(o) of the Clean Water Act, and therefore anti -backsliding prohibitions
would not be triggered by reductions in monitoring frequencies.
The current permit requires reduced effluent monitoring of 2/week for BOD5, NH3, TSS and Enterococci
at both flow tiers. However, per 15A NCAC .0508, monitoring requirements for NH3 is weekly for Class
III facilities (i.e., 0.5 — 2.5 MGD permitted design flows), which Manteo WWTP is. Therefore, Ammonia
monitoring will be reset to weekly at both flow tiers.
With the permit renewal application, the Town requested the reduced monitoring frequencies be maintained,
citing that the Town meets criteria for exceptionally performing facilities as outlined in 2012 Division
guidance. Review of the past three years of data (Sep 2020 Aug 2023) found all above parameters to meet
numerical criteria. Reduced monitoring for BOD5, TSS and Enterococci is maintained at 0.6 MGD, but
reset to the rule frequency of 3/week at 1.0 MGD. A footnote will be added allowing the Permittee to request
reduced monitoring after six months at the expanded flow tier if no exceedance violations have occurred.
For instream monitoring, refer to Section 4.
11. Electronic Reporting Requirements
The US EPA NPDES Electronic Reporting Rule was finalized on December 21, 2015. Effective December
21, 2016, NPDES regulated facilities are required to submit Discharge Monitoring Reports (DMRs)
electronically. While NPDES regulated facilities would initially be required to submit additional NPDES
reports electronically effective December 21, 2020, EPA extended this deadline from December 21, 2020,
to December 21, 2025. The current compliance date, effective January 4, 2021, was extended as a final
regulation change published in the November 2, 2020 Federal Register. This permit contains the
requirements for electronic reporting, consistent with Federal requirements.
12. Summary of Proposed Permitting Actions:
Tables 4 and 5 summarize the permit conditions and proposed changes at the 0.6 and 1.0 MGD flow tiers,
respectively.
Page 11 of 16

NC0079057
Table 4. Current Permit Conditions and Proposed Changes at 0.6 MGD.
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flow
MA = 0.6 MGD
No change
15A NCAC 02B .0505
Monitor continuously
Summer:
MA = 5.0 mg/L
WQBEL. Based on protection of
WA = 7.5 mg/L
DO standard. 15A NCAC 02B
BOD5
Winter:
No change
.0200, .0508.
MA = 10.0 mg/L
Meet criteria for reduced
WA = 15.0 mg/L
monitoring frequency.
Monitor 2/week
TBEL. Secondary treatment
MA = 30 mg/L
standards, 40 CFR 133, 15A
TSS
WA = 45 mg/L
No change
NCAC 02B .0406, .0508.
Monitor 2/week
Meet criteria for reduced
monitoring frequency.
Summer:
Summer:
WQBEL. Calculated site -specific
MA = 2.0 mg/L
MA = 1.4 mg/L
limits for saltwater using
WA = 6.0 mg/L
WA = 3.4 mg/L
effluent temperature and pH and
NH3-N
Winter:
Winter:
receiving water temperature, pH
MA = 4.0 mg/L
MA = 2.5 mg/L
and salinity data following EPA
WA = 12.0 mg/L
WA = 6.2 mg/L
criteria guidelines (1989).
Monitor 2/week
Monitor weekly
State monitoring requirements,
15A NCAC 02B .0508.
MA = 35 /100 mL
WQBEL. State WQ standard, 15A
Enterococci
WA = 276 /100 mL
No change
NCAC 02B .0200
Monitor 2/week
Meet criteria for reduced
monitoring frequency.
Monitor effluent and
Shallowbag Bay prohibited from
Fecal Coliform
No requirement
all instream
shellfish harvesting due to
ITk
locations weekly
potential fecal coliform; no
instream data currently exist.
TRC
DM = 13 µg/L
No change
WQBEL. State WQ standard, 15A
Monitor 3/week
NCAC 02B .0200, 0.508
pH
6.8 — 8.5 SU
No change
WQBEL. State WQ standard, 15A
Monitor 3/week
NCAC 02B .0200
DO
DA > 6 mg/L
No change
WQBEL. State WQ standard, 15A
Monitor 3/week
NCAC 02B .0200, .0500.
Temperature
Monitor daily
No change
State monitoring requirements,
15A NCAC 02B .0508.
Total Nitrogen
Monitor quarterly
No change
State monitoring requirements,
15A NCAC 2B .0500.
TKN
No requirement
Add quarterly
To better understand effluent TN
monitoring.
concentrations.
Page 12 of 16

NC0079057
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
NO2+NO3
No requirement
Add quarterly
To better understand effluent TN
monitoring.
concentrations.
Total Phosphorus
Monitor quarterly
No change
State monitoring requirements,
15A NCAC 2B .0500.
MA = 1.8 µg/L
MA = 3.7 µg/L
DM = 2.9 µg/L
DM = 5.8 µg/L
Monitor monthly
WQBEL. RP found under HQW-
Total Copper
Monitor monthly with
Revise compliance
applied toxics standards.
a 3-yr compliance
schedule to 5 yr &
schedule
add dilution study
option
No RP found; maximum
Total Nickel
Monitor quarterly
No change
predicted value > 50% allowable
concentration.
MA = 42.8 µg/L
DM = 47.6 µg/L
Monitor monthly
WQBEL. RP found under HQW-
Total Zinc
Monitor quarterly
Add 5-yr compliance
applied toxics standards.
schedule with
dilution study
option
MA, DM = 10.5 µg/L
MA, DM = 21.0 µg/L
Monitor monthly
Dibromochloromethane
Monitor monthly with
Add 5-yr compliance
WQBEL. RP found under HQW-
a 3-yr compliance
schedule with
applied toxics standards.
schedule
dilution study
option
Bromodichloromethane
(=Dichlorobromomethane)
Monitor quarterly
Monitor monthly
More data needed for evaluation
Bromoform
Monitor quarterly
Remove from permit
No RP; maximum predicted value<
50% allowable concentration
MA, DM = 0.2 µg/L
Monitor monthly
Bis(2-ethylhexyl)
Monitor quarterly
Add 5-yr compliance
WQBEL. RP found under HQW-
phthalate
schedule with
applied toxics standards.
dilution study
option
Mercury
Monitor 115 yrs
No change
State-wide Mercury TMDL
Add 2/yr monitoring
EPA recommendations (guidance
PFAS
No requirement
with delayed
memo, 12/5/2022). Delay for labs
implementation
to become certified in method.
Fathead Minnow acute
WQBEL. No toxics in toxic
Toxicity Test
limit at 90% effluent
No change
amounts. 15A NCAC 2B.0200
and 15A NCAC 02B.0500
Page 13 of 16

NC0079057
Parameter
Current Permit 1
Proposed Change
Basis for Condition/Change
Temperature, DO, pH,
Add monthly Fecal
Shallowbag Bay excluded from
Instream monitoring
Salinity weekly at 5
of at all
shellfish growing due to potential
locations (2 upstream,
l bonsorm
locations
fecal coliform concerns
3 downstream)
(Pasquotank Basin Plan, 2021)
Electronic Reporting
Special Condition
Update Special
In accordance with EPA
Condition
Electronic Reporting Rule 2015.
Footnote.
1. MGD = Million Gallons per Day; MA = Monthly Average; WA = Weekly Average; DA = Daily Average;
DM = Daily Maximum; QA = Quarterly Average.
Table 5. Current Permit Conditions and Proposed Changes 1.0 MGD.
Parameter
Current Permit 1
Proposed Change
Basis for Condition/Change
Flow
MA 1.0 MGD
Monitor continuously
No change
15A NCAC 02B .0505
Summer:
No change in limits
MA = 5.0 mg/L
Monitor 3/week with
WA = 7.5 mg/L
option to request
WQBEL. Based on protection of
BOD5
Winter:
reduced monitoring
DO standard. 15A NCAC 02B
MA = 10.0 mg/L
if no violations after
.0200, .0508.
WA = 15.0 mg/L
6 months operating
Monitor 2/week
at 1.0 MGD.
No change in limits
Monitor 3/week with
MA = 30 mg/L
option to request
TBEL. Secondary treatment
TSS
WA = 45 mg/L
reduced monitoring
standards, 40 CFR 133, 15A
Monitor 2/week
if no violations after
NCAC 02B .0406, .0508.
6 months operating
at 1.0 MGD.
WQBEL. Calculated site -specific
Summer:
Summer:
limits for saltwater using
MA = 2.0 mg/L
MA = 1.4 mg/L
effluent temperature and pH
WA = 6.0 mg/L
WA = 3.4 mg/L
and receiving water
NH3-N
Winter:
Winter:
temperature, pH and salinity
MA = 4.0 mg/L
MA = 2.5 mg/L
data following EPA criteria
WA = 12.0 mg/L
WA = 6.2 mg/L
guidelines (1989).
Monitor 2/week
Monitor weekly
State monitoring requirements,
15A NCAC 02B .0508.
No change in limits
Monitor 3/week with
MA = 35 /100 mL
option to request
WQBEL. State WQ standard, 15A
Enterococci
WA = 276 /100 mL
reduced monitoring
NCAC 02B
Monitor 2/week
if no violations after
.0200
6 months operating
at 1.0 MGD.
Page 14 of 16

NC0079057
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Monitor effluent and
Shallowbag Bay prohibited from
Fecal Coliform
No requirement
all instream locations
shellfish harvesting due to
potential fecal coliform; no
weekly
instream data currently exist.
TRC
DM = 13 µg/L
No change
WQBEL. State WQ standard, 15A
Monitor 3/week
NCAC 02B .0200, 0.508
DO
DA > 6 mg/L
No change
WQBEL. State WQ standard, 15A
Monitor 3/week
NCAC 02B .0200, .0500.
Temperature
Monitor daily
No change
State monitoring requirements,
15A NCAC 02B .0508.
Total Nitrogen
Monitor quarterly
No change
State monitoring requirements,
15A NCAC 2B .0500.
TKN
No requirement
Add quarterly
To better understand effluent TN
monitoring.
concentrations.
NO2+NO3
No requirement
Add quarterly
To better understand effluent TN
monitoring.
concentrations.
Total Phosphorus
Monitor quarterly
No change
State monitoring requirements,
15A NCAC 2B .0500.
MA = 3.7 µg/L
MA = 1.8 µg/L
WQBEL. RP found under HQW-
Total Copper
DM = 5.8 µg/L
DM = 2.9 µg/L
applied toxics standards.
Monitor monthly
Monitor monthly
No RP found; maximum
Total Nickel
Monitor quarterly
No change
predicted value > 50% allowable
concentration.
MA = 42.8 µg/L
WQBEL. RP found under HQW-
Total Zinc
Monitor quarterly
DM = 47.6 µg/L
applied toxics standards.
Monitor monthly
Dibromochloromethane
MA, DM = 21.0 µg/L
MA, DM = 10.5 µg/L
WQBEL. RP found under HQW-
Monitor monthly
Monitor monthly
applied toxics standards.
Bromodichloromethane
Monitor quarterly
Monitor monthly
More data needed for evaluation.
(=Dichlorobromomethane)
Bromoform
Monitor quarterly
Remove from permit
No RP; maximum predicted value<
50% allowable concentration
Bis(2-ethylhexyl)
Monitor quarterly
MA, DM = 0.2 µg/L
WQBEL. RP found.
phthalate
Monitor monthly
Mercury
Monitor 115 yrs
No change
State-wide Mercury TMDL
PFAS
No requirement
Add 2/yr monitoring
EPA recommendations (guidance
memo, 12/5/2022).
Fathead Minnow acute
WQBEL. No toxics in toxic
Toxicity Test
limit at 90% effluent
No change
amounts. 15A NCAC 2B.0200
and 15A NCAC 02B.0500
Page 15 of 16

NC0079057
Parameter
Current Permit'
Proposed Change
Basis for Condition/Change
Three times per permit
First 1 st three yrs of
Effluent Pollutant Scan
cycle at 1.0 MGD.
operation at 1.0
40 CFR 122
MGD.
Temperature, DO, pH,
Shallowbag Bay excluded from
Instream monitoring
Salinity weekly at 5
Add Enterococci at
shellfish growing due to potential
locations (2 upstream,
all locations
fecal coliform concerns
3 downstream)
(Pasquotank Basin Plan, 2021)
Electronic Reporting
Special Condition
Update Special
In accordance with EPA
Condition
Electronic Reporting Rule 2015.
Footnote.
1. MGD = Million Gallons per Day; MA = Monthly Average; WA = Weekly Average; DA = Daily Average;
DM = Daily Maximum; QA = Quarterly Average.
13. Public Notice Schedule:
Permit to Public Notice: xx/xx/xxxx
Per 15A NCAC 2H .0109 & .0111, The Division will receive comments for a period of 30 days following
the publication date of the public notice. Any request for a public hearing shall be submitted to the
Director within the 30-day comment period indicating the interest of the party filing such request and the
reasons why a hearing is warranted.
14. NPDES Division Contact
If you have any questions regarding any of the above information or on the attached permit, please
contact Gary Perlmutter at [phone] or via email at gary_perlmutter(2deq.nc.gov.
15. Fact Sheet Addendum (if applicable):
Were there any changes made since the Draft Permit was public noticed (Yes/No): NO
If Yes, list changes and their basis below: NA
16. Fact Sheet Attachments (if applicable):
• Process Narrative
• Chemical Addendum
• 2022 Integrated Report webpage: Shallowbag Bay
• 2021 Pasquotank Basin Plan — Ch. 5.9.2, p. 13
• Monitoring Violations Report
• WET test summary sheet, p. 68
• Compliance Inspection report, Nov 2022
• NH3/TRC WLA Calculations, site -specific for saltwater
• Saltwater RPA Spreadsheet Summary
• Mercury sample result
• Mercury TMDL Evaluation for 4.14 and 6.0 MGD
Page 16 of 16

Town of Manteo WWTP Process Narrative:
The Town of Manteo's Wastewater Treatment Plant is a grade three activated sludge tertiary treatment
facility treating wastewater from the Town's sanitary sewer collection system. This plant treats wastewater
utilizing preliminary screening and grit removal, secondary biological treatment and nutrient removal via an
oxidation ditch and secondary clarifiers, tertiary effluent filtration and post aeration followed by chlorination
disinfection and de -chlorination prior to discharging effluent to Shallowbag Bay.
Wastewater entering the plant is directed through a micro -strainer unit and grit removal system. The micro -
strainer removes large and stringy objects from the wastewater flow that could damage downstream process
equipment while also rinsing the screenings, returning organics to the waste stream. Wastewater then flows
through a grit removal system that removes the inorganic solids (grit) which will not break down in the
biological system while allowing the organic solids to continue through the treatment process.
Effluent wastewater from the grit removal system and drainage from various treatment processes are pumped
by the influent pumps to the oxidation ditch where the concentration of organic matter and nitrogen are
reduced during the extended aeration activated sludge process by the biological action of microorganisms.
The organisms convert the organic matter into biomass and release nitrogen as gas. The oxidation ditch
provides the oxygen needed by microbes in the system for biological oxidation of organic materials and for the
conversion of ammonia to nitrate and the anoxic conditions needed for denitrification.
Effluent wastewater from the oxidation ditch flows to the final clarifiers which provide an undisturbed
environment for the separation of solids from the water. Prior to the two clarifier tanks, a dual chemical
program of Jenfitch JC 9830 and Jenfitch JC 1687 is injected in the splitter box downstream the oxidation ditch
which attaches to the dissolved copper in the wastewater and allows for it to settle as a floc particle with the
settled solids. After both settle in the clarifiers, the active solids along with the copper floc particles are
recycled to the oxidation ditch to maintain the microbe population at a level which promoted optimum
removal of nutrients and keep the copper floc particles from flowing downstream. Excess sludge is wasted
from the system to the aerobic digester to maintain healthy levels of microbes in the treatment process.
Wastewater displaced from the final clarifiers flows by gravity to the effluent filters. Wastewater percolates
down through the automatically backwashed filters to remove a major portion of the suspended solids in the
water.
After water flows through the filters, it flows into the chlorine contact tank. Sodium Hypochlorite is added at
the head of the tank. The wastewater is dechlorinated at the tail end of the tank by the addition of Sodium
Bisulfite. Effluent flows from the contact chamber to the post aeration structure where the water is subjected
to the action of a floating aerator to bring the dissolved oxygen concentration to appropriate levels before it is
pumped via a force main to Shallowbag Bay for dispersal.

EPA Identification Number NPDES Number Facility Name Outfall Number
Method Number Estimated Concentration (If
Pollutant (Required) CAS number (if Applicable) Reason Pollutant Believed Present in Discharge Known)
See note ... No anticipated additional pollutants since issuance of last permit.

' 2022 Integrated Report (IR) Explorer
Legend
Shaliowbag Bay
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Bey's Overall category in 2022
OSha11ow6ag
Details
was No Data
111
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��
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Stream Name
Shallow6ag Bay
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30-21-3
Filter
BIMS Index
30-21-3
stream
Shallow6ag Say,
Description
Entire Bay
St- Length
534.190992 S Acres
Stream
Classification
SC
Basin
Pasquotank
8-Digit HUC
3010205-Albemarle
Su66asin
M
2008 No Data
2010 No Data \ -
2012 No Data ✓✓✓///��f
2014 No Oata
2016 No Data \ '
2018 � No Data `/� r'� -
2020 !!No Data r
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5.9.2 Shellfish Growing Area H-1
The Division of Marine Fisheries defines this shellfish growing area as: "The H-1 growing area consists of
all waters north of a line running from Smith Island to South Point near Oregon Inlet, and south of a line
running from Northwest Point to Mann Point, including Roanoke Sound, Shallowbag Bay, Broad Creek,
and Mill Creek. Overall, the area includes a total of approximately 21,340 water acres" (NCDEQ, 2016).
The sampling station locations and growing areas were also mapped (Figure 5-4) in the Report of Sanitary
Survey Area H-1 Roanoke Sound Area July 2011 Through March 2016 (NCDEQ, 2016). Their report also
maps potential point and nonpoint sources of pollution including: wastewater treatment plants, marinas,
stormwater, subdivisions, onsite wastewater, golf courses, wildlife and domestic animals, and areas of
concern (Figure 5-5, NCDEQ, 2016).
Figure 5-4 Division of Marine Fisheries shellfish sanitation and recreational water quality section sampling stations (Map Source:
NCDEQ, 2016)
H-1 Inset Map iki
Growing Area:
Shellfishing Water
Sampling Stations _
Legend
L! Sampling Stations �`'
a. Shellhsh Growing Area BouManes - - w
id-digtl Hydrologic llnils � •_'Ly���
ShelRfah �mvring Area ClaavHications -
Approved
Contlltionally ApprovetlApen _ I
Contlltionally Appr_d G1—d _
Prohibited
1
1
p i
e lr. i
N
W E
B V
0 0.75 7.5
Alllea
Ini Inset Map #7
H 1 Crowing Area
rrtn -
Nvth W Mlne CePa'nnara of _
EnWtoemmml Duality
Di��„ lena;ne F�d�
shelfah 5aniGtim atd
aecrtatimrwater Doaliys Aim ' pi s, mtA
illo
5.9.2.1 Roanoke Sound [AU# 30-21b, 30-21c, 30-21d, 30-21e1a, 30-21g, 30-21h, 30-21i, 30-21j; Primary
Surface Water Classification: SA, Secondary Surface Water Classification: HQW, Area is 1,174 acres]
The Roanoke Sound is Impaired for shellfish growing area status. The Roanoke Sound remains on the
state's 303(d) list of impaired waters. Roanoke Sound is classified as a prohibited shellfish closure in
growing area H-1 due to potential fecal coliform bacterial levels (Figure 5-4).
Draft 13 8/11/2021

MONITORING REPORT(MR) VIOLATIONS for:
Permit: NCO079057 MRS Betweei 0 - 2018 and10 - 2023 Region: %
Facility Name: % Param Nam(% County: %
Major Minor: %
Report Date: 10/24/22 Page 1 of 1
Violation Category:Limit Violation Program Category: NPDES WW
Subbasin: % Violation Action:
PERMIT: NCO079057
FACILITY: Town of Manteo - Manteo WWTP
COUNTY: Dare
REGION: Washington
Limit Violation
MONITORING
VIOLATION
UNIT OF
CALCULATED
%
REPORT OUTFALL
LOCATION PARAMETER
DATE FREQUENCY
MEASURE
LIMIT VALUE
Over
VIOLATION TYPE VIOLATION ACTION
01 -2023 001
Effluent Chlorine, Total Residual
01/18/23 3 X week
ug/I
13 14
7.7
Daily Maximum No Action, BPJ
Exceeded
01 -2023 001
Effluent Copper, Total (as CU) -
01/03/23 Monthly
ug/I
5.8 6
3.4
Daily Maximum No Action, BPJ
Concentration
Exceeded

Whole Effluent Toxicity Testing and Self Monitoring Summary
Manteo WWTP
NCO079057/001 County:
Dare
Fthd24PF
Begin:
7/1/2019
24hr p/f ac lim: 90% ( +
NonComp: Single
J
F M
A
M
2019
-
Pass >100(P) -
-
Pass
2020
-
Pass -
-
Pass
2021
-
Pass -
-
Pass
2022
-
Pass -
-
Pass
2023
-
Pass -
-
Pass
Marion WTP (NCG590032/NC0055221)
NCO055221/001 County:
McDowell
Ceri7dPF
Begin:
3/1/2015
ANNUAL: Chr Cerio P
NonComp:
J
F M
A
M
2019
Pass
- -
Pass
-
2020
Pass
- -
Pass
-
2021
2022
Marion-Corpening Cr. WWTP
NCO031879/001 County:
McDowell
Ceri7dPF
Begin:
5/1/2021
chr lim: 63% @ 2.5M
NonComp: Single
J
F M
A
M
2019
-
Pass -
-
Pass
2020
-
Pass -
-
Pass
2021
-
Pass -
-
Pass
2022
-
Pass -
-
Pass
2023
-
Pass -
-
Pass
Mars Hill WTP
NCO083712/001 County:
Madison
Ceri7dPF
Begin:
7/1/2011
Chr Monit: 5.78%
NonComp:
J
F M
A
M
2019
Pass
- -
Pass
-
2020
Pass
- -
Pass
-
2021
Pass
- -
Pass
-
2022
Pass
- -
Pass
-
2023
Pass
- -
Pass
-
Marshall WWTP
NCO021733/001 County:
Madison
Fthd24PF
Begin:
7/1/2022
24hr p/f ac lim: 90% +
NonComp: Single
J
F M
A
M
2019
-
Pass -
-
Pass
2020
-
Pass -
-
Pass
2021
-
Pass -
-
Pass >100(P)
2022
-
Pass -
-
Pass
2023
-
Pass -
-
Pass
Region:
WARD
Basin: PAS51
Feb May Aug Nov
7Q10: Tidal
PF: 0.6 IWC: 90
Freq: Q
J
J
A
S
O
Pass
Pass
Pass
Pass
Pass
Region:
ARO
Basin: CTB30
Jan Apr Jul Oct
7Q10:
PF: IWC:
Freq: Q
J
J
A
S
O
-
Pass
-
-
Pass
H
-
-
-
- INVALID Pass
Pass
Region:
ARO
Basin: CTB30
Feb May Aug Nov
7Q10: 2.3
PF: 3.0 IWC: 67
Freq: Q
I
I
A
S
O
-
-
>100(P) Pass
>100 (P)
>100(P)
Pass
-
Pass
Pass
Pass
Region:
ARO
Basin: FRB04
Jan Apr Jul Oct
7Q10:
PF: IWC:
Freq: Q
J
J
A
S
O
-
Pass
-
-
Pass
-
Pass
-
-
Pass
-
Pass
-
-
Pass
-
Pass
-
-
Pass
Pass
-
Region:
ARO
Basin: FRB04
Feb May Aug Nov
70.10: 535
PF: 0.40 IWC: 0.12
Freq: Q
J
J
A
S
O
Pass
-
-
Pass
>100 (P)
>100 (P)
Pass>100 (P)
-
-
-
-
Pass
SOC JOC:
N
Pass
Pass
Pass
Pass
SOC JOC:
N
SOC JOC:
N
>100 (P) Pass
Pass
Pass
Pass
SOC JOC:
N
SOC JOC:
N
Pass
Pass
Pass
Pass
C
C
C
C
foil
Leeend: P= Fathead minnow (Pimohales Dromelas). H=No Flow (facilitv is active). s = Solit test between Certified Labs Page 68 of 115

United States Environmental Protection Agency
Form Approved.
EPA Washington, D.C. 20460
OMB No. 2040-0057
Water Compliance Inspection Report
Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN 1 2 u 3 I NCO079057 I11 121 22/11/16 I17 18I � I 19 I s I 20L]
21111I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I r6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved -------------------
67
I 72 I n, I 71 I 74 79 I I I I I I I80
70I I 71 I LL -1 I I
LJ
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES permit Number)
12:45PM 22/11/16
19/07/01
Manteo WWTP
710 Bowsertown Rd
Exit Time/Date
Permit Expiration Date
Manteo NC 27954
01:20PM 22/11/16
23/12/31
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
Joshua J O'Brien/ORC/252-473-3513/
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Josh O'Brien,PO Box 246 Manteo NC 279540246//252-473-3513/
No
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations & Maintenar Records/Reports
Self -Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Compliance Schedules
Effluent/Receiving Wate
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date
Paul Nyarko DWR/WARD WQ/252-948-3845/
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page#

NPDES yr/mo/day Inspection Type
NCO079057 I11 12I 22/11/16 117 18 i c i
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
On 11/16/2022, Paul Nyarko from the Division of Waater Resource in Washington Regional Office
conducted a Complaince Evaluation for Manteo WWTP. The facility was found to be compliance with
NPDES permit NC0079057. June 2022 DMR was spot checked with coressponding lab data. No
discrepancies were found. All records that were requested for the inspection were provided, avialable
and maintained by the permit.
Page#

Permit: NCO079057 Owner -Facility: Manteo WWTP
Inspection Date: 11/16/2022 Inspection Type: Compliance Evaluation
Compliance Schedules Yes
No
NA
NE
Is there a compliance schedule for this facility? 0
❑
❑
❑
Is the facility compliant with the permit and conditions for the review period? 0
❑
❑
❑
Comment:
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Permit
Yes
No
NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
❑
❑
■
❑
application?
Is the facility as described in the permit?
0
❑
❑
❑
# Are there any special conditions for the permit?
0
❑
❑
❑
Is access to the plant site restricted to the general public?
0
❑
❑
❑
Is the inspector granted access to all areas for inspection?
❑
❑
❑
Comment: The current permit is effective until December 31,2023
Bar Screens
Yes
No
NA
NE
Type of bar screen
a.Manual
b.Mechanical
Are the bars adequately screening debris?
0
❑
❑
❑
Is the screen free of excessive debris?
0
❑
❑
❑
Is disposal of screening in compliance?
■
❑
❑
❑
Is the unit in good condition?
M
❑
❑
❑
Comment:
Grit Removal Yes No NA NE
Type of grit removal
a.Manual ❑
b.Mechanical
Is the grit free of excessive organic matter? 0 ❑ ❑ ❑
Page# 3

Permit: NCO079057
Inspection Date: 11/16/2022
Grit Removal
Is the grit free of excessive odor?
# Is disposal of grit in compliance?
Comment:
Owner -Facility: Manteo WWTP
Inspection Type: Compliance Evaluation
Oxidation Ditches
Are the aerators operational?
Are the aerators free of excessive solids build up?
# Is the foam the proper color for the treatment process?
Does the foam cover less than 25% of the basin's surface?
Is the DO level acceptable?
Are settleometer results acceptable (> 30 minutes)?
Is the DO level acceptable?(1.0 to 3.0 mg/1)
Are settelometer results acceptable?(400 to 800 ml/I in 30 minutes)
Comment:
De -chlorination
Type of system ?
Is the feed ratio proportional to chlorine amount (1 to 1)?
Is storage appropriate for cylinders?
# Is de -chlorination substance stored away from chlorine containers?
Are the tablets the proper size and type?
Comment: Sodium Bisulfite for dechlorination
Are tablet de -chlorinators operational?
Number of tubes in use?
Comment:
Standby Power
Is automatically activated standby power available?
Is the generator tested by interrupting primary power source?
Is the generator tested under load?
Was generator tested & operational during the inspection?
Do the generator(s) have adequate capacity to operate the entire wastewater site?
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
❑ ❑ ❑ ■
■ ❑ ❑ ❑
❑ ❑ ❑ ■
Yes No NA NE
Liquid
■
❑
❑
❑
❑
❑
■
❑
■
❑
❑
❑
❑
❑
■
❑
❑
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■
❑
Yes No NA NE
■ ❑ ❑ ❑
■ ❑ ❑ ❑
❑ ❑ ❑ ■
❑ ❑ ❑ ■
■ ❑ ❑ ❑
Page# 4

Permit: NCO079057 Owner -Facility: Manteo WWTP
Inspection Date: 11/16/2022 Inspection Type: Compliance Evaluation
Standby Power Yes
No
NA
NE
Is there an emergency agreement with a fuel vendor for extended run on back-up ❑
❑
❑
■
power?
Is the generator fuel level monitored? ■
❑
❑
❑
Comment:
Influent Sampling
Yes
No
NA
NE
# Is composite sampling flow proportional?
❑
■
❑
❑
Is sample collected above side streams?
■
❑
❑
❑
Is proper volume collected?
■
❑
❑
❑
Is the tubing clean?
■
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0
■
❑
❑
❑
degrees Celsius)?
Is sampling performed according to the permit?
■
❑
❑
❑
Comment: The sampler is on constant time and volume
Effluent Sampling
Yes
No
NA
NE
Is composite sampling flow proportional?
❑
■
❑
❑
Is sample collected below all treatment units?
■
❑
❑
❑
Is proper volume collected?
■
❑
❑
❑
Is the tubing clean?
■
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0
■
❑
❑
❑
degrees Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
■
❑
❑
❑
representative)?
Comment: The sampler is on constant time and volume.
Pumps-RAS-WAS
Yes
No
NA
NE
Are pumps in place?
■
❑
❑
❑
Are pumps operational?
■
❑
❑
❑
Are there adequate spare parts and supplies on site?
■
❑
❑
❑
Comment:
Aerobic Digester Yes No NA NE
Is the capacity adequate? ■ ❑ ❑ ❑
Is the mixing adequate? ❑ ❑ ❑ ■
Page# 5

Permit: NCO079057 Owner -Facility: Manteo WWTP
Inspection Date: 11/16/2022 Inspection Type: Compliance Evaluation
Aerobic Digester Yes No NA NE
Is the site free of excessive foaming in the tank?
0
❑
❑
❑
# Is the odor acceptable?
■
❑
❑
❑
# Is tankage available for properly waste sludge?
0
❑
❑
❑
Comment:
Effluent Pipe
Yes
No
NA
NE
Is right of way to the outfall properly maintained?
0
❑
❑
❑
Are the receiving water free of foam other than trace amounts and other debris?
0
❑
❑
❑
If effluent (diffuser pipes are required) are they operating properly?
0
❑
❑
❑
Comment:
Record Keeping
Yes
No
NA
NE
Are records kept and maintained as required by the permit?
0
❑
❑
❑
Is all required information readily available, complete and current?
0
❑
❑
❑
Are all records maintained for 3 years (lab. reg. required 5 years)?
■
❑
❑
❑
Are analytical results consistent with data reported on DMRs?
0
❑
❑
❑
Is the chain -of -custody complete?
0
❑
❑
❑
Dates, times and location of sampling
❑
Name of individual performing the sampling
❑
Results of analysis and calibration
❑
Dates of analysis
❑
Name of person performing analyses
❑
Transported COCs
❑
Are DMRs complete: do they include all permit parameters?
❑
❑
❑
Has the facility submitted its annual compliance report to users and DWQ?
❑
❑
❑
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified
❑
❑
❑
operator on each shift?
Is the ORC visitation log available and current?
❑
❑
❑
Is the ORC certified at grade equal to or higher than the facility classification?
❑
❑
❑
Is the backup operator certified at one grade less or greater than the facility
❑
❑
❑
classification?
Is a copy of the current NPDES permit available on site?
0
❑
❑
❑
Facility has copy of previous year's Annual Report on file for review?
■
❑
❑
❑
Page# 6

Permit: NCO079057 Owner -Facility: Manteo WWTP
Inspection Date: 11/16/2022 Inspection Type: Compliance Evaluation
Record Keeping Yes No NA NE
Comment: Everything was in place
Flow Measurement - Influent
Yes
No
NA
NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
0
❑
❑
❑
Comment:
Flow Measurement - Effluent
Yes
No
NA
NE
# Is flow meter used for reporting?
■
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
❑
❑
0
❑
Comment: Calibrated on 10/8/2021
Secondary Clarifier
Yes
No
NA
NE
Is the clarifier free of black and odorous wastewater?
0
❑
❑
❑
Is the site free of excessive buildup of solids in center well of circular clarifier?
■
❑
❑
❑
Are weirs level?
0
❑
❑
❑
Is the site free of weir blockage?
0
❑
❑
❑
Is the site free of evidence of short-circuiting?
0
❑
❑
❑
Is scum removal adequate?
■
❑
❑
❑
Is the site free of excessive floating sludge?
■
❑
❑
❑
Is the drive unit operational?
0
❑
❑
❑
Is the return rate acceptable (low turbulence)?
0
❑
❑
❑
Is the overflow clear of excessive solids/pin floc?
■
❑
❑
❑
Is the sludge blanket level acceptable? (Approximately'/4 of the sidewall depth)
■
❑
❑
❑
Comment:
Filtration (High Rate Tertiary) Yes No NA NE
Type of operation: Down flow
Is the filter media present? 0 ❑ ❑ ❑
Page# 7

Permit: NC0079057
Inspection Date: 11/16/2022
Filtration (High Rate Tertiary)
Is the filter surface free of clogging?
Is the filter free of growth?
Is the air scour operational?
Owner -Facility: Manteo WWTP
Inspection Type: Compliance Evaluation
Is the scouring acceptable?
Is the clear well free of excessive solids and filter media?
Comment:
Sand Filters (Low rate)
(If pumps are used) Is an audible and visible alarm Present and operational?
Is the distribution box level and watertight?
Is sand filter free of ponding?
Is the sand filter effluent re -circulated at a valid ratio?
# Is the sand filter surface free of algae or excessive vegetation?
# Is the sand filter effluent re -circulated at a valid ratio? (Approximately 3 to 1)
Comment: Effluent looks good, cleared from any vegetation.
Yes
No
NA
NE
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
Yes
No
NA
NE
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
❑
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❑
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Page# 8

Facility:
Permit No.
Prepared By:
Use Site Specific (FW, SW)
Receiving Water Class
Supplemental Class
WS Classification (if needed)
Location (no site spec temp.)
Use Site Specific pH
Is Class PNA/HQW
Effluent Temperature (Summer)
Effluent Temperature (Winter)
Effluent pH (Summer)
Effluent pH (Winter)
NH3/TRC WLA Calculations
Manteo WWTP Receiving water pH(upstream-summer)
NC0079057 Receiving water pH (upstream -winter)
GB Perlmutter
SW
Temperature (upstream -summer)
Temperature (upstream -winter)
If SW or FW-SW,salinity (ppt-summer)
If SW or FW-SW,salinity (ppt-winter)
Use Site Specific upstream ammonia
Bkgd ammonia (upstream -summer)
Bkgd ammonia (upstream -winter)
28 pH (mixed -summer)
19.5 # pH (mixed -winter)
7.60 Temperature (mixed -summer)
7.60 Temperature (mixed -winter)
Enter Design Flow (MGD): 0.6
Enter s7Q10 (cfs): 0 Tidal
Enter w7Q10 (cfs): 0 Tidal
7.83 Avg
7.59 Avg
24.2 Avg
11.4 Avg
10.5
9.6
0.050
0.190
7.60
7.60
28.00
19.50
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
0
s7Q10 (CFS)
0
DESIGN FLOW (MGD)
0.6
DESIGN FLOW (MGD)
0.6
DESIGN FLOW (CFS)
0.93
DESIGN FLOW (CFS)
0.93
STREAM STD (UG/L)
17.0
INSTREAM STD (MG/L)
1.4
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
100.00
IWC (%)
100.00
Allowable Conc. (ug/1)
13
Allowable Monthly Conc. (mg/1)
1.4
Allowable Weekly Con. (mg/1)
3.4 2.5 X
Fecal Coliform
Ammonia (Winter)
Monthly Average Limit:
200/100ml
Monthly Average Limit (mg NH3-N/1)
(If DF >331; Monitor)
(If DF<331; Limit)
w7Q10 (CFS)
0
Dilution Factor (DF)
1.00
DESIGN FLOW (MGD)
0.6
DESIGN FLOW (CFS)
0.93
INSTREAM STD (MG/L)
2.5
Upstream Bkgd (mg/1)
0.220
IWC (%)
100.00
Allowable Monthly Conc. (mg/1)
2.5
Allowable Weekly Conc. (mg/1)
6.2 2.5 X
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, Monitor Only
2. For site specific, Monthly Avg limit x 2.5 - = Weekly Avg limit (Municipals); otherwise 3X, capped at 35 mg/I
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis); capped at 35 mg/I
4. Winter limits (if ammonia toxicity is limiting) cannot exceed twice the summer limits, 15A NCAC 02B .0404
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)

Facility:
Permit No.
Prepared By:
Use Site Specific (FW, SW)
Receiving Water Class
Supplemental Class
WS Classification (if needed)
Location (no site spec temp.)
Use Site Specific pH
Is Class PNA/HQW
Effluent Temperature (Summer)
Effluent Temperature (Winter)
Effluent pH (Summer)
Effluent pH (Winter)
NH3/TRC WLA Calculations
Manteo WWTP Receiving water pH(upstream-summer)
NC0079057 Receiving water pH (upstream -winter)
GB Perlmutter
Yes
SW
Temperature (upstream -summer)
Temperature (upstream -winter)
If SW or FW-SW,salinity (ppt-summer)
If SW or FW-SW,salinity (ppt-winter)
Use Site Specific upstream ammonia
Bkgd ammonia (upstream -summer)
Bkgd ammonia (upstream -winter)
28 pH (mixed -summer)
19.5 # pH (mixed -winter)
7.60 Temperature (mixed -summer)
7.60 Temperature (mixed -winter)
Enter Design Flow (MGD): 1.0
Enter s7Q10 (cfs): 0 Tidal
Enter w7Q10 (cfs): 0 Tidal
7.83 Avg
7.59 Avg
24.2 Avg
11.4 Avg
10.5
9.6
0.050
0.190
7.60
7.60
28.00
19.50
Total Residual Chlorine (TRC)
Ammonia (Summer)
Daily Maximum Limit (ug/1)
Monthly Average Limit (mg NH3-N/1)
s7Q10 (CFS)
0
s7Q10 (CFS)
0
DESIGN FLOW (MGD)
0.6
DESIGN FLOW (MGD)
1
DESIGN FLOW (CFS)
0.93
DESIGN FLOW (CFS)
1.55
STREAM STD (UG/L)
17.0
INSTREAM STD (MG/L)
1.4
Upstream Bkgd (ug/1)
0
Upstream Bkgd (mg/1)
0.22
IWC (%)
100.00
IWC (%)
100.00
Allowable Conc. (ug/1)
13
Allowable Monthly Conc. (mg/1)
1.4
Allowable Weekly Con. (mg/1)
3.4 2.5 X
Fecal Coliform
Ammonia (Winter)
Monthly Average Limit:
200/100ml
Monthly Average Limit (mg NH3-N/1)
(If DF >331; Monitor)
(If DF<331; Limit)
w7Q10 (CFS)
0
Dilution Factor (DF)
1.00
DESIGN FLOW (MGD)
1
DESIGN FLOW (CFS)
1.55
INSTREAM STD (MG/L)
2.5
Upstream Bkgd (mg/1)
0.220
IWC (%)
100.00
Allowable Monthly Conc. (mg/1)
2.5
Allowable Weekly Conc. (mg/1)
6.2 2.5 X
Total Residual Chlorine
1. Cap Daily Max limit at 28 ug/I to protect for acute toxicity
Ammonia (as NH3-N)
1. If Allowable Conc > 35 mg/I, Monitor Only
2. For site specific, Monthly Avg limit x 2.5 - = Weekly Avg limit (Municipals); otherwise 3X, capped at 35 mg/l
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis); capped at 35 mg/I
4. Winter limits (if ammonia toxicity is limiting) cannot exceed twice the summer limits, 15A NCAC 02B .0404
Fecal Coliform
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)

Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
Stream Class
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
Data Source(s)
Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
aREQUIRED DATA ENTRY
Table 1. Project Information Table 2. Parameters of Concern
0 CHECK IF HQW OR ORW WQS Name WQs Type Chronic Modifier Acute PQL Units
Manteo WWTP
Grade III
NCO079057
001
0.600
Shallowbag Bay
Sc
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Submitted DMRs
Saltwater streams are tidal resulting in all IWC % = 100%. If
an approved model is conducted then a chronic dilution
factor is determined and can be applied to a discharge to
calculate its IWC % . If a stream is classified as a SA or
ORINthen its is also classified as a HQW. The appropriate
IWC % must be defined to properly calculate WQS-based
limits.
Par01
Par02
Par03
Par04
Par05
Par06
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Arsenic
Aquatic Life
C
36
SW
69
ug/L
Arsenic
Human Health
C
10
HH
ug/L
Cadmium
Aquatic Life
NC
8.9
SW
40.2
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
10
ug/L
Chromium VI
Aquatic Life
NC
50.4
SW
1107.8
ug/L
Chromium, Total
Aquatic Life
NC
N/A
SW
N/A
ug/L
Copper
Aquatic Life
NC
3.7
SW
5.8
ug/L
Cyanide
Aquatic Life
NC
1
SW
1
10
ug/L
Lead
Aquatic Life
NC
8.5
SW
220.8
ug/L
Mercury
Aquatic Life
NC
25
SW
0.5
ng/L
Molybdenum
Human Health
NC
2.0
HH
mg/L
Nickel
Aquatic Life
NC
8.3
SW
74.7
ug/L
Selenium
Aquatic Life
NC
71
SW
ug/L
Silver
Aquatic Life
NC
0.1
SW
2.2
ug/L
Zinc
Aquatic Life
NC
85.6
SW
95.1
ug/L
Dibromochloromethane
Human Health
C
21
HH
pg/L
Bromodichloromethane
Human Health
C
27
HH
fag/L
Bromoform
Human Health
C
120
HH
pg/L
Bis (2-ethylhexyl) phthalate
Human Health
C
0.37
HH
ttg/L
NOTE: The aquatic life chronic and acute WQS for several metals are calculated based on EPA conversi(
see "Diss. SW stds. As TM" for more details and summary of calculated WQS..
79057 Saltwater RPA 2023,input
12/21 /2023

REASONABLE POTENTIAL ANALYSIS - DATA
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
Date Data
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
Chromium, Total
Values" then "COPY"
Maximum data
points = 58
Copper
BDL=1/2DL Results
Date Data
BDL=1/2DL
Results
Std Dev.
NO DATA
1
7/1/2019
5
5
Std Dev.
Mean
NO DATA
2
8/5/2019
6
6
Mean
C.V.
NO DATA
3
9/3/2019
5
5
C.V.
n
0
4
10/7/2019
4
4
n
5
11 /4/2019
3.8
3.8
Mult Factor =
N/A
6
12/2/2019
3
3
Mult Factor =
Max. Value
N/A ug/L
7
1/6/2020
3
3
Max. Value
Max. Pred Cw
N/A ug/L
8
2/4/2020
4
4
Max. Pred Cw
9
3/2/2020
4
4
10
4/8/2020
5
5
11
5/4/2020
7
7
12
6/1/2020
6
6
13
7/6/2020
4
4
14
8/10/2020
4
4
15
8/25/2020
7
7
16
9/3/2020
4
4
17
9/8/2020
7
7
18
10/5/2020
5
5
19
11 /2/2020
7
7
20
11/16/2020
5.5
5.5
21
12/7/2020
4
4
22
1 /5/2021
3
3
23
2/2/2021
3
3
24
3/1/2021
4
4
25
4/5/2021
6
6
26
5/3/2021
7
7
27
6/1 /2021
4
4
28
7/6/2021
4
4
29
8/2/2021
4
4
30
9/7/2021
4
4
31
10/4/2021
5
5
32
11/1/2021
5
5
33
12/6/2021
4
4
34
1 /3/2022
3
3
35
2/7/2022
4
4
36
3/7/2022
5
5
37
4/4/2022
6
6
38
5/2/2022
7.1
7.1
39
6/6/2022
3
3
40
7/18/2022
2
2
41
8/4/2022
4
4
42
8/22/2022
2
2
43
9/6/2022
1.7
1.7
44
10/3/2022
2
2
45
11 /7/2022
1
1
46
12/5/2022
2
2
47
1 /3/2023
6
6
48
1 /31 /2023 <
2.5
1.25
49
2/6/2023
2
2
50
3/6/2023
1
1
51
4/3/2023
1
1
52
5/1/2023 <
1
0.5
53
6/5/2023
1
1
54
7/3/2023 <
1
0.5
55
8/7/2023
2.1
2.1
56
57
58
Values" then "COPY"
Maximum data
points = 58
1.8574
3.8991
0.4764
55
1.0100
7.10 ug/L
7.17 ug/L
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
Nickel
Values" then "COPY"
Selenium
Values" then "COPY"
Maximum data
. Maximum data
points = 58
points = 58
Date
Data
BDL=1/2DL
Results
Date Data
BDL=1/2DL Results
1
8/5/2019
1
1
Std Dev.
1.9177
1
Std Dev.
NO DATA
2
11/4/2019
<
10
5
Mean
3.9735
2
Mean
NO DATA
3
2/5/2020
<
10
5
C.V.
0.4826
3
C.V.
NO DATA
4
5/4/2020
<
10
5
n
17
4
n
0
5
8/10/2020
<
1
0.5
5
6
11/2/2020
<
10
5
Mult Factor =
1.3500
6
Mult Factor =
N/A
7
2/2/2021
<
10
5
Max. Value
5.00 ug/L
7
Max. Value
N/A ug/L
8
5/3/2021
1
1
Max. Pred Cw
6.75 ug/L
8
Max. Pred Cw
N/A ug/L
9
8/2/2021
<
10
5
9
10
11 /1 /2021
<
0.1
0.05
10
11
2/7/2022
<
10
5
11
12
5/2/2022
<
10
5
12
13
8/4/2022
<
10
5
13
14
11 /7/2022
<
10
5
14
15
2/6/2023
<
10
5
15
16
5/1/2023
<
10
5
16
17
8/7/2023
<
10
5
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
79057 Saltwater RPA 2023,data
Date}

REASONABLE POTENTIAL ANALYSIS - DATA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
Silver
Values" then "COPY"
Maximum data
points = 58
Date Data BDL=1/2DL Results
Std Dev.
NO DATA
Mean
NO DATA
C.V.
NO DATA
n
0
Mult Factor =
N/A
Max. Value
N/A ug/L
Max. Pred Cw
N/A ug/L
Date
1 3/5/2019
2 6/5/2019
3 8/5/2019
4 11 /4/2019
5 2/5/2020
6 5/4/2020
7 8/10/2020
8 11 /2/2020
9 2/2/2021
10 5/3/2021
11 6/1 /2021
12 8/2/2021
13 11 /1 /2021
14 2/7/2022
15 5/2/2022
16 8/4/2022
17 11 /7/2022
18 2/6/2023
19 5/1 /2023
20 8/7/2023
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
Zinc
Data
BDL=1/2DL
Results
70
70
Std Dev.
74
74
Mean
101
101
C.V.
91
91
n
91
91
70
70
Mult Factor =
81
81
Max. Value
92
92
Max. Pred Cw
74
74
79
79
93
93
68
68
87
87
72
72
110
110
61
61
35
35
46
46
35
35
41
41
Values" then "COPY"
Maximum data
points = 58
21.3775
73.5500
0.2907
20
1.1700
110.0 ug/L
128.7 ug/L
79057 Saltwater RPA 2023,data
Date}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
REASONABLE
POTENTIAL ANALYSIS
- DATA
Dibromochloromethane Values" then "COPY'
Values" then "COPY"
Bromodichloromethane
Maximum data
. Maximum data
points = 58
points = 58
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
7/1 /2019
12.2
12.2
Std Dev.
6.3740
1
9/3/2019
13.2
13.2
Std Dev.
3.7462
8/5/2019
10.1
10.1
Mean
11.2128
2
12/2/2019
11.5
11.5
Mean
13.3550
9/3/2019
8.7
8.7
C.V.
0.5685
3
3/2/2020
15.9
15.9
C.V.
0.2805
10/7/2019
11.5
11.5
n
53
4
6/1/2020
14.8
14.8
n
16
11 /4/2019
45.9
45.9
5
9/8/2020
9.79
9.79
12/2/2019
8.6
8.6
Mult Factor =
1.0200
6
12/7/2020
12.2
12.2
Mult Factor =
1.2100
1/6/2020
14.6
14.6
Max. Value
45.90000 lag/L
7
3/1/2021
10.7
10.7
Max. Value
24.30000 lag/L
2/4/2020
8.2
8.2
Max. Pred Cw
46.81800 lag/L
8
6/1/2021
14.3
14.3
Max. Pred Cw
29.40300 lag/L
2/12/2020
14.2
14.2
9
9/7/2021
15.2
15.2
3/2/2020
10
10
10
12/6/2021
12.2
12.2
4/8/2020
15.5
15.5
11
3/7/2022
11.8
11.8
5/4/2020
16.6
16.6
12
6/6/2022
11.7
11.7
6/1 /2020
10.4
10.4
13
9/6/2022
24.3
24.3
7/6/2020
8.34
8.34
14
12/5/2022
12.2
12.2
8/10/2020
22.1
22.1
15
3/6/2023
7.39
7.39
8/25/2020
2.5
2.5
16
6/5/2023
16.5
16.5
9/8/2020
4.5
4.5
17
10/5/2020
17
17
18
11 /2/2020
16.2
16.2
19
11 /16/2020
13.2
13.2
20
12/7/2020
11.3
11.3
21
1 /5/2021
5.9
5.9
22
2/1/2021
5.3
5.3
23
3/1/2021
7.2
7.2
24
4/5/2021
5.1
5.1
25
5/3/2021
8.6
8.6
26
6/1/2021
9.44
9.44
27
7/6/2021
8.4
8.4
28
8/2/2021
7.9
7.9
29
9/7/2021
8.3
8.3
30
10/4/2021
7
7
31
11 /1 /2021
12.2
12.2
32
12/6/2021
6.1
6.1
33
1 /3/2022
11.6
11.6
34
2/7/2022
8.1
8.1
35
3/7/2022
6.5
6.5
36
4/4/2022
5.8
5.8
37
5/2/2022
8.3
8.3
38
6/6/2022
7.7
7.7
39
7/7/2022
8.7
8.7
40
8/4/2022
11.5
11.5
41
9/6/2022
14.4
14.4
42
10/3/2022
17.8
17.8
43
11 /7/2022
8.7
8.7
44
12/5/2022
11.6
11.6
45
1 /3/2023
14.7
14.7
46
2/6/2023
4.3
4.3
47
3/6/2023
10.2
10.2
48
4/3/2023
15.6
15.6
49
5/1 /2023
16.4
16.4
50
6/5/2023
17.1
17.1
51
7/3/2023
13.9
13.9
52
8/7/2023
8.3
8.3
53
54
55
56
57
58
79057 Saltwater RPA 2023,data
Date}

Date Data
1 9/3/2019
2 12/2/2019 <
3 3/2/2020
4 6/1/2020
5 9/8/2020
6 12/7/2020
7 3/1 /2021
8 6/1 /2021
9 9/7/2021
10 12/6/2021
11 3/7/2022
12 6/6/2022
13 9/6/2022
14 12/5/2022
15 3/6/2023
16 6/5/2023
17
18
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
REASONABLE POTENTIAL ANALYSIS - DATA
Bromoform Values" then "COPY' Bis (2-ethylhexyl) phthalate
Maximum data
points = 58
BDL=1/2DL Results
0.6
0.6
Std Dev.
0.5
0.25
Mean
2.6
2.6
C.V.
1.36
1.36
n
0.76
0.76
1.74
1.74
Mult Factor =
1.11
1.11
Max. Value
0.84
0.84
Max. Pred Cw
0.75
0.75
0.7
0.7
2.1
2.1
0.74
0.74
2.14
2.14
2.83
2.83
4.34
4.34
4.6
4.6
Date Data
1.3176
1
10/14/2019
<
1.7163
2
12/2/2019
<
0.7677
3
3/2/2020
<
16
4
6/1/2020
<
5
9/8/2020
1.6000
6
12/7/2020
<
4.60000 pg/L
7
3/1/2021
<
7.36000 pg/L
8
6/1/2021
<
9
9/7/2021
<
10
12/6/2021
<
11
3/7/2022
<
12
6/6/2022
<
13
9/6/2022
<
14
12/5/2022
<
15
3/6/2023
16
6/5/2023
17
18
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
BDL=1/2DL Results
5
2.5
Std Dev.
0.5
0.25
Mean
5
2.5
C.V.
5.1
2.55
n
5.52
5.52
5
2.5
Mult Factor =
5
2.5
Max. Value
5
2.5
Max. Pred Cw
5.05
2.525
5.05
2.525
5
2.5
5
2.5
5
2.5
5
2.5
14.4
14.4
5.93
5.93
Values" then "COPY"
Maximum data
points = 58
3.1745
3.5125
0.9038
16
1.7100
14.40000 lag/L
24.62400 lag/L
79057 Saltwater RPA 2023,data
Date)

Manteo WWTP
Outfall 001
NCO079057 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
Qw (MGD) = 0.60 WWTP/WTP Class: Grade III
1Q10S (cfs) = Tidal, IWC = 100% IWC% @ 1Q10S = 100
7Q10S (cfs) = Tidal, IWC = 100% IWC% @ 7Q10S = 100
7Q10W (cfs) = Tidal, IWC = 100% IWC% @ 7Q10W = 100
30Q2 (cfs) = Tidal, IWC = 100% IWC% @ 30Q2 = 100
Avg. Stream Flow, QA (cfs) = Tidal, IWC = 100% IWC% @ QA = 100
Receiving Stream: Shallowbag Bay Stream Class: SC
Qw = 0.6 MGD
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS HQW OR ORW.
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
TYPE
(1
CCY
a
Z
RECOMMENDED ACTION
Applied
Chronic Acute
D
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (SW): 34.5
Arsenic
C
18 SW(7Q1Os) 34.5
ug/L
0 0
N/A
Chronic (SW)----18.0 --
----------------------------
Arsenic
C
5 HH(Qavg)
ug/L
------------------------------------------------
Chronic (HH) 5.0
Acute: 20.10
Cadmium
NC
4.45 SW(7Q10s) 20.1
ug/L
0 0
N/A
------4.45 --
--Chronic:
----------------------------
Acute: NO WQS
Total Phenolic Compounds
NC
150 A(30Q2)
10.0
ug/L
0 0
N/A
------150.0 --
--Chronic:
----------------------------
Acute: 553.9
Chromium VI
NC
25.2 SW(7Q10s) 553.9
ug/L
0 0
N/A
------25.2 --
--Chronic:
----------------------------
Chromium, Total
NC
ug/L
0 0
N/A
Acute: 2.90
Copper
NC
1.85 SW(7Q1Os) 2.9
ug/L
55 52
7.17
Chronic:1.85
RPA found - apply Monthly Monitoring with
47 values > Allowable Cw
Limit
Acute: 0.5
Cyanide
NC
0.5 SW(7Q1Os) 0.5
10.0
ug/L
0 0
N/A
--Chronic------ --
----------------------------
0.5
Acute: 110.40
Lead
NC
4.25 SW(7Q1Os) 110.4
ug/L
0 0
N/A
------4.25 --
--Chronic:
----------------------------
Acute: NO WQS
Mercury
NC
12.5 SW(7Q10s)
0.5
ng/L
0 0
N/A
------12.5 --
--Chronic:
----------------------------
Page 11 of 12
79057 Saltwater RPA 2023,rpa
12/21 /2023

Manteo WWTP
Outfall 001
NCOO79O57
Saltwater RPA 95% Probablity/95% Confidence
Qw=O.6MGD
Acute: NO WQS
Molybdenum
NC
1 HH(7QIOs)
mg/L
0 0
N/A
--Chronic------ --
----------------------------
1.0
Acute: 37.35
Nickel
NC
4.15 SW(7Q1 Os) 37.35
ug/L
17 2
6.8
Chronic:4.15
No RPA, Predicted Max > 50% of Allowable
13 values > Allowable Cw
Cw - apply Quarterly Monitoring
Acute: NO WQS
Selenium
NC
35.5 SW(7QIOs)
ug/L
0 0
N/A
------35.5 --
--Chronic:
----------------------------
Acute: 1.10
Silver
NC
0.05 SW(7Q10s) 1.1
ug/L
0 0
N/A
------0.05 --
--Chronic:
----------------------------
Acute: 47.6
Zinc
NC
42.8 SW(7Q10s) 47.55
ug/L
20 20
128.7
Chronic:42.8
RPA found - apply Monthly Monitoring with
17 values > Allowable Cw
Limit
Acute: NO WQS
Dibromochloromethane
C
10.5 HH(Qavg)
µg/L
53 53
46.818
Chronic:10.5
RPA found - apply Monthly Monitoring with
23 values > Allowable Cw
Limit
Acute: NO WQS
Bromodichloromethane
C
13.5 HH(Qavg)
µg/L
16 16
29.403
Chronic:13.5
RPA for non -AL - apply Monthly Monitoring
6 values > Allowable Cw
with Limit
Acute: NO WQS
Bromoform
C
60 HH(Qavg)
µg/L
16 15
7.36
Chronic:60
No RPA, Predicted Max < 50% of Allowable Cw
No value > Allowable Cw
- No Monitoring required
Acute: NO WQS
Bis (2-ethylhexyl) phthalate
C
0.185 HH(Qavg)
µg/L
16 3
24.624
_
Chronic 0.185
RPA for non -AL - apply Monthly Monitoring
16 values > Allowable Cw
with Limit
Acute:
0 0
N/A
--Chronic-----------
----------------------------
Acute:
0 0
N/A
-----------------
---------------------------
Chronic:
Acute:
0 0
N/A
--Chronic-----------
----------------------------
Page 12 of 12
79057 Saltwater RPA 2023,rpa
12/21 /2023

Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
Stream Class
7Q10s (cfs)
7Q10w (cfs)
30Q2 (cfs)
QA (cfs)
1 Q10s (cfs)
Data Source(s)
Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
aREQUIRED DATA ENTRY
Table 1. Project Information Table 2. Parameters of Concern
0 CHECK IF HQW OR ORW WQS Name WQs Type Chronic Modifier Acute PQL Units
Manteo WWTP
Grade III
NCO079057
001
1.000
Shallowbag Bay
Sc
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Tidal, IWC = 100%
Submitted DMRs
Saltwater streams are tidal resulting in all IWC % = 100%. If
an approved model is conducted then a chronic dilution
factor is determined and can be applied to a discharge to
calculate its IWC % . If a stream is classified as a SA or
ORINthen its is also classified as a HQW. The appropriate
IWC % must be defined to properly calculate WQS-based
limits.
Par01
Par02
Par03
Par04
Par05
Par06
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Arsenic
Aquatic Life
C
36
SW
69
ug/L
Arsenic
Human Health
C
10
HH
ug/L
Cadmium
Aquatic Life
NC
8.9
SW
40.2
ug/L
Total Phenolic Compounds
Aquatic Life
NC
300
A
10
ug/L
Chromium VI
Aquatic Life
NC
50.4
SW
1107.8
ug/L
Chromium, Total
Aquatic Life
NC
N/A
SW
N/A
ug/L
Copper
Aquatic Life
NC
3.7
SW
5.8
ug/L
Cyanide
Aquatic Life
NC
1
SW
1
10
ug/L
Lead
Aquatic Life
NC
8.5
SW
220.8
ug/L
Mercury
Aquatic Life
NC
25
SW
0.5
ng/L
Molybdenum
Human Health
NC
2.0
HH
mg/L
Nickel
Aquatic Life
NC
8.3
SW
74.7
ug/L
Selenium
Aquatic Life
NC
71
SW
ug/L
Silver
Aquatic Life
NC
0.1
SW
2.2
ug/L
Zinc
Aquatic Life
NC
85.6
SW
95.1
ug/L
Dibromochloromethane
Human Health
C
21
HH
pg/L
Bromodichloromethane
Human Health
C
27
HH
fag/L
Bromoform
Human Health
C
120
HH
pg/L
Bis (2-ethylhexyl) phthalate
Human Health
C
0.37
HH
ttg/L
NOTE: The aquatic life chronic and acute WQS for several metals are calculated based on EPA conversi(
see "Diss. SW stds. As TM" for more details and summary of calculated WQS..
79057 Saltwater RPA 2023,input
12/21 /2023

Manteo WWTP
Outfall 001
NCO079057 Saltwater RPA 95% Probablity/95% Confidence
MAXIMUM DATA POINTS = 58
Qw (MGD) = 1.00 WWTP/WTP Class: Grade III
1Q10S (cfs) = Tidal, IWC = 100% IWC% @ 1Q10S = 100
7Q10S (cfs) = Tidal, IWC = 100% IWC% @ 7Q10S = 100
7Q10W (cfs) = Tidal, IWC = 100% IWC% @ 7Q10W = 100
30Q2 (cfs) = Tidal, IWC = 100% IWC% @ 30Q2 = 100
Avg. Stream Flow, QA (cfs) = Tidal, IWC = 100% IWC% @ QA = 100
Receiving Stream: Shallowbag Bay Stream Class: SC
Qw = 1 MGD
YOU HAVE DESIGNATED THIS RECEIVING
STREAM AS HQW OR ORW.
PARAMETER
NC STANDARDS OR EPA CRITERIA
REASONABLE POTENTIAL RESULTS
TYPE
(1
CCY
a
Z
RECOMMENDED ACTION
Applied
Chronic Acute
D
n # Det. Max Pred Cw Allowable Cw
Standard
Acute (SW): 34.5
Arsenic
C
18 SW(7Q1Os) 34.5
ug/L
0 0
N/A
Chronic (SW)----18.0 --
----------------------------
Arsenic
C
5 HH(Qavg)
ug/L
------------------------------------------------
Chronic (HH) 5.0
Acute: 20.10
Cadmium
NC
4.45 SW(7Q10s) 20.1
ug/L
0 0
N/A
------4.45 --
--Chronic:
----------------------------
Acute: NO WQS
Total Phenolic Compounds
NC
150 A(30Q2)
10.0
ug/L
0 0
N/A
------150.0 --
--Chronic:
----------------------------
Acute: 553.9
Chromium VI
NC
25.2 SW(7Q10s) 553.9
ug/L
0 0
N/A
------25.2 --
--Chronic:
----------------------------
Chromium, Total
NC
ug/L
0 0
N/A
Acute: 2.90
Copper
NC
1.85 SW(7Q1Os) 2.9
ug/L
55 52
7.17
Chronic:1.85
RPA found - apply Monthly Monitoring with
47 values > Allowable Cw
Limit
Acute: 0.5
Cyanide
NC
0.5 SW(7Q1Os) 0.5
10.0
ug/L
0 0
N/A
--Chronic------ --
----------------------------
0.5
Acute: 110.40
Lead
NC
4.25 SW(7Q1Os) 110.4
ug/L
0 0
N/A
------4.25 --
--Chronic:
----------------------------
Acute: NO WQS
Mercury
NC
12.5 SW(7Q10s)
0.5
ng/L
0 0
N/A
------12.5 --
--Chronic:
----------------------------
Page 2 of 3
79057 Saltwater RPA 2023,rpa
12/21 /2023

Manteo WWTP
Outfall 001
NCOO79O57
Saltwater RPA 95% Probablity/95% Confidence
Qw = 1 MGD
Acute: NO WQS
Molybdenum
NC
1 HH(7QIOs)
mg/L
0 0
N/A
--Chronic------ --
----------------------------
1.0
Acute: 37.35
Nickel
NC
4.15 SW(7Q1 Os) 37.35
ug/L
17 2
6.8
Chronic:4.15
No RPA, Predicted Max > 50% of Allowable
13 values > Allowable Cw
Cw - apply Quarterly Monitoring
Acute: NO WQS
Selenium
NC
35.5 SW(7QIOs)
ug/L
0 0
N/A
------35.5 --
--Chronic:
----------------------------
Acute: 1.10
Silver
NC
0.05 SW(7Q10s) 1.1
ug/L
0 0
N/A
------0.05 --
--Chronic:
----------------------------
Acute: 47.6
Zinc
NC
42.8 SW(7Q10s) 47.55
ug/L
20 20
128.7
Chronic:42.8
RPA found - apply Monthly Monitoring with
17 values > Allowable Cw
Limit
Acute: NO WQS
Dibromochloromethane
C
10.5 HH(Qavg)
µg/L
53 53
46.818
Chronic:10.5
RPA found - apply Monthly Monitoring with
23 values > Allowable Cw
Limit
Acute: NO WQS
Bromodichloromethane
C
13.5 HH(Qavg)
µg/L
16 16
29.403
Chronic:13.5
RPA for non -AL - apply Monthly Monitoring
6 values > Allowable Cw
with Limit
Acute: NO WQS
Bromoform
C
60 HH(Qavg)
µg/L
16 15
7.36
Chronic:60
No RPA, Predicted Max < 50% of Allowable Cw
No value > Allowable Cw
- No Monitoring required
Acute: NO WQS
Bis (2-ethylhexyl) phthalate
C
0.185 HH(Qavg)
µg/L
16 3
24.624
_
Chronic 0.185
RPA for non -AL - apply Monthly Monitoring
16 values > Allowable Cw
with Limit
Acute:
0 0
N/A
--Chronic-----------
----------------------------
Acute:
0 0
N/A
-----------------
---------------------------
Chronic:
Acute:
0 0
N/A
--Chronic-----------
----------------------------
Page 3 of 3
79057 Saltwater RPA 2023,rpa
12/21 /2023

Environmental Chemists, Inc.
envirochem 6602 Windmill Way, Wilmington, NC 28405 • 910.392.0223 Lab • 910.392.4424 Fax
710 Bowsertown Road, Manteo, NC 27954 - 252.473.5702 Lab/Fax
255-A Wilmington Highway, Jacksonville, NC 28540 - 910.347.5843 Lab/Fax
ANALYTICAL & CONSULTING CHEMISTS
[e-mail]
Town of Manteo
Date of Report: Dec 05, 2023
Post Office Box 246
Manteo Report #: 23M-2347
Manteo NC 27954
Report #: 2023-26761
Attention:
Customer ID: 08110017
Project ID: Wastewater
Lab ID Sample ID: M-3931
Collect Date/Time
Matrix Sampled by
23-64839 Site: Influent
11/13/2023 9:55 AM
Water Josh O'Brien
Test
Method
Results Date Analyzed
Residue Suspended (TSS)
SM 2540 D-2015
116 mg/L 11/16/2023
BOD
SM 5210 6-2016
152 mg/L 11 /15/2023
Sample estimated. Did not meet quality
control requirements; GGA=82%, below acceptable limits of 85-115%.
Lab ID Sample ID: M-3932
Collect Date/Time
Matrix Sampled by
23-64840 Site: Effluent
11/13/2023 9:50 AM
Water Josh O'Brien
Test
Method
Results Date Analyzed
Residue Suspended (TSS)
SM 2540 D-2015
<2.5 mg/L 11/16/2023
Ammonia Nitrogen
SM 4500 NH3 D-2011
<0.1 mg/L 11/21/2023
BOD
SM 5210 B-2016
<2 mg/L 11115/2023
Sample estimated. Did not meet quality
control requirements; GGA=82%, below acceptable limits of 85-115%.
Lab ID Sample ID: M-3930
Collect Date/Time
Matrix Sampled by
23-64841 Site: Effluent- Grab
11/13/2023 9,50 AM
Water Josh O'Brien
Test
Method
Results Date Analyzed
Enterococci
EnterolertlDEXX
<1 MPN1900ml 11/13/2023
Lab ID Sample ID:
Collect DateITime
Matrix Sampled by
23-64842 Site: Effluent
11/13/2023 10:15 AM Water Josh O'Brien
Test
Method
Results Date Analyzed
LL Mercury
EPA 1631e
1.05 ng/L 12/02/2023
Lab ID Sample ID:
Collect Date/Time
Matrix Sampled by
23-64843 Site: Field Blank
11/13/2023 10:15 AM Water Josh O'Brien
Test
Method
Results Date Analyzed
LL Mercury
EPA 1631e
3.94 ng/L 12/03/2023
Comment:
Reviewed by:
Report # :2023-26761 Page 1 of 1

Mercury (CVAFS)
Client Environmental Chemist, Inc. Laboratory ILi YK20024-015
Description 23-64842 Matrix Aqueous
Date Sampled.1111312023 1015
Date Received.1112012023
Run Prep Method Analytical Method Dilution Analysis Date Analyst Prep Date Batch
1 1631E 1 12102.r2023 0801 KAJ 11 r28. 2023 1512 9044
CAS Analytical
Parameter Number Method Result Q LOO Units Run
Mercury (CVAFS) 7439-97-6 1631E 1.05 0.500 ng1L 1
1-00 = Limit of Quant,tat,on B = Detected n ;he method blank E = Quantitation of compound exceeded the ca.ibfauon range 0 = Surrogate fa lure
NO = Net detected a! or above the LOQ N = Recovery is out of criteria P = The RPD bet.veen .,vo GC cc umns eRceeds 10°o L = LCS LCSD fa. ure
H = Out of holding time V/ = Reported on-net'+eight basis S = MS MSD failure
Pace Analytical Services LAC (formerly Shealy Environmental Services. Inc )
106 Vantage Point Drive West Columbia. SC 29172 [phone] Fax [phone] www.pacelabs coin
23-zL 161

Mercury (CVAFS)
Client Environmental Chemist, Inc. ab:.ratnry 0 YK20024-016
Description- 23-64843 Matrix Aqueous
Date Sampled 1111312023 1015
Date Received. 1112012023
Run Prep Method Analytical Method Dilution Analysis Date Analyst Prep Date Batch
2 163'.E 1 12'03,2023 1926 KAJ 11'28;2023 1512 90944
CAS Analytical
Parameter Number Method Result Q LOQ Units Run
Mercury (CVAFS) 7439-97-6 1631E 3.94 0.500 ng!L 2
LOO = L.m,t of QuanLtatron B = Detected.n the method blank E = Ouantdaucn of compound exceeded the oa+brauoo range O = Surrogate facture
NO = Not detected at or above :he LOO N = Reco,ery rs out of cnterra P = The RPD bec:+een ;,vo GC co um�s eeteeds 40- L = LCS LCSO fa. ure
H = Out ct noldmg ame W = Reported on -net wergnt basis S = MS h1SD fa -lure
Pace Analytical Services. LLC (formerly Shealy Environmental Services. Inc.)
106 Vantage Point Drive West Columbia. SC 29172 [phone] Fax [phone] t www pacelabs cam

Environmental Chemist, Inc., Wilmington, NC Lab #94 6602 Windmill Way
Wilmington, NC 28405
910,392.0223
Sample Receipt Checklist
Client:
Date: � l �12_S Report Number: 2023- -�
Receipt of sample:
ECHEM Pickup ❑ Client Delivery ❑ UPS i I FedEx ❑ Oth-r ❑
❑
YES
10
NO
❑x N/A
11. Were custody seals present on the cooler?
❑
YES
10
NO
N/A 12.
If custody seals were present, were they intact/unbroken?
Original temperature upon receipti°C Corrected temperature upon receipt
How temperature taken:
❑ Temperature Blank 0 Against Bottles
IR Gun ID: Thomas Traceable S/N 210886869 IR Gun Correction Factor °C: 0.0
x❑
YES
❑
NO
3. If temperature of cooler exceeded 6"C, was Project Mgr./QA notified?
E9
YES
❑
NO
4. Were proper custody procedures {relinquished/received) followed?
0
YES
❑
NO
5. Were sample ID's listed on the COC?
YES
❑
NO
6. Were samples ID's listed on sample containers?
YES
❑
NO
7. Were collection date and time listed on the COC?
0
YES
❑
NO
8. Were tests to be performed listed on the COC?
YES
❑
NO
9. Did samples arrive in proper containers for each test?
0
YES
❑
NO
10. Did samples arrive in good condition for each test?
0
11. Was adequate sample volume available?'
0
12. Were samples received within proper holding time for requested tests?
❑
13. Were acid preserved samples received at a pH of <2?
❑
Y14.
U
Were cyanide samples received at a pH >12?
❑
Y15.
Were sulfide samples received at a pH >9?
❑
Y16.
Were NH3/TKN/phenol received at a chlorine residual of <0.5 m/L? **
❑
Y17.
Were Sulfide/Cyanide received at a chlorine residual of<0.5 m/L?
❑
Y18.
Were orthophosphate samples filtered in the field within 15 minutes?
* TOC/Volatiles are pH checked at time of analysis and recorded on the benchsheet.
** Bacteria samples are checked for Chlorine at time of analysis and recorded on the benchsheet.
Sample Preservation: (Must be completed for any sample(s) incorrectly preserved or with headspace)
Samples) were received incorrectly preserved and were adjusted accordingly
by adding (circle one): H2SO4 HNO3 HCl NaOH
Time of preservation: If more than one preservative is needed, notate in comments below
Note: Notify customer service immediately for incorrectly preserved samples. Obtain a new sample or
notify the state lab if directed to analyzed by the customer. Who was notified, date and time:
Volatiles Sample(s) were received with headsoace
COMMENTS:
DOC. QA.002 Rev 1
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12/21/23 WQS = 12.5 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6
Facility Name Manteo WWTP / NC0079057 No Limit Required
/Permit No.
No MMP Required
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s = 0.000 cfs WQBEL = 12.50 ng/L
Date Modifier Data Entry Value Permitted Flow = 0.600 47 ng/L
11/13/23 1.05 1.05 1.1 ng/L - Annual Average for 2023

12/21/23 WQS = 12.5 ng/L MERCURY WQBEL/TBEL EVALUATION V:2013-6
Facility Name
Manteo WWTP / NC0079057 No Limit Required
/Permit No.
No MMP Required
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s = 0.000 cfs WQBEL = 12.50 ng/L
Date Modifier Data Entry Value Permitted Flow = 1.000 47 ng/L
11/13/23 1.05 1.05 1.1 ng/L - Annual Average for 2023