NC0020389_Fact Sheet_20210412

Fact Sheet
NPDES Permit No. NC0020389
Permit Writer/Email Contact: Cassidy Kurtz, [e-mail]
Date: April 12, 2021
Division/Branch: NC Division of Water Resources/NPDES 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 Benson / Benson WWTP
Applicant Address:
P.O. Box 69, Benson, NC 27504
(303 East Church St., Benson, NC 27504)
Facility Address:
770 Hannah Creek Rd., Four Oaks, NC 27524
Permitted Flow:
1.9 MGD
Facility Type/Waste:
MAJOR Municipal; 74% domestic, 26% industrial (based on permitted
flows)
Facility Class:
Class IV
Treatment Units:
Bar screen, Grit removal, Parshall flume, influent composite sampler,
influent screw pumps, extended aeration/oxidation basins/nutrient
reduction, secondary clarifiers, tertiary filters, chlorination,
dechlorination, post aeration, effluent flow measurements, effluent
composite sampler, alum and lime storage/handling units, aerated
sludge lagoon, stabilization lagoons, lagoon effluent return pump
station, backup generator
Pretreatment Program (Y/N)
Yes / STMP
County:
Johnston
Region
Raleigh
Page 1 of 14

Briefly describe the proposed permitting action and facility background:
The Town of Benson applied for an NPDES permit renewal at 1.9 MGD for the Benson WWTP in
September 2017. This facility serves approximately 3,320 residents within Benson. This facility has
primary Outfall 001. Benson WWTP is permitted to operate the facilities for reuse water up to 0.02672
MGD in accordance with non -discharge permit WQ0022501.
The facility maintains a pretreatment program with 1 significant industrial user (SIU). This non -
categorical SIU is Chicopee Inc. d b a Berry Plastics, which manufactures non -woven textile products for
medical end use and industrial end use.
2. Receiving Waterbodv Information:
Receiving Waterbody Information
Outfalls/Receiving Stream(s):
Outfall 001 — Hannah Creek
Stream Segment:
27-52-6
Stream Classification:
C - NSW
Drainage Area (mi2):
10.5
Summer 7Q10 (cfs)
0
Winter 7Q10 (cfs):
0.12
30Q2 (cfs):
0.25
Average Flow (cfs):
12.0
IWC (% effluent):
100% at 1.9 MGD
303(d) listed/parameter:
Yes, the segment is listed in the 2018 303(d) for Dissolved
Oxygen
Subject to TMDL/parameter:
Yes- State-wide Mercury TMDL implementation.
Sub-basin/HUC:
03-04-04 / HUC: 03020201
USGS Topo Quad:
F24NE Benson, NC
Page 2 of 14

3. Effluent Data Summary
Effluent data for Outfall 001 is summarized below for the period of April 2016 through September 2020.
Table 1. Effluent Data Summary Outfall 001
Parameter
Units
Average
Max
Min
Permit
Limit
Flow
MGD
1.14
7.48
0.138
MA 1.9
Total Monthly Flow
MG
34.69
58.54
19.128
BOD summer
mg/1
3.2
21
< 2
WA 7.5
MA 5.0
BOD winter
mg/1
3.3
43
< 2
WA 15.0
MA 10.0
TSS
mg/1
3.56
305
1.65
WA 45.0
MA 30.0
NH3N summer
mg/1
0.43
7.9
0.024
WA 3.0
MA 1.0
NH3N winter
mg/1
0.64
12.9
< 0.04
WA 6.0
MA 2.0
pH
SU
6.85
7.72
5.89
6.0<pH<
9.0
DO
mg/1
8.4
26.1
6
DA > 6.0
Fecal coliform
#/100 ml
(geomean)
2.39
> 200
< 1
(geometric)
WA 400
MA 200
Temperature
° C
20.99
31
6.3
Conductivity
umhos/cm
363.6
802
98.3
TRC
µg/1
10.6
84
2.3
DM 17.0
(< 50
compliance)
TKN
mg/1
1.54
13.68
< 0.2
NO3-N + NO2-N
mg/1
1.63
7.63
< 0.04
TN
mg/1
3.16
14.74
0.74
TN Load
lb/month
590.1
1898
9.56
lb/year
See "Other TMDLs/Nutrient Management
Strategy Considerations" (pg.8)
33,0701b/yr
TP
mg/1
1.27
4.3
0.07
QA 2.0
Total Copper
µg/1
(no detects)
< 10
< 2
Total Zinc
µg/1
14.05
45
1.2
Total Nickel
1.1.g/1
35.5
62
< 10
MA -Monthly Average, WA -Weekly Average DM -Daily Maximum, DA-Daily Average,
QA-Quarterly Average
Page 3 of 14

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/1 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 existing permit requires instream monitoring for dissolved oxygen, fecal coliform, temperature, and
conductivity. However, the permittee is a member of the Lower Neuse Basin Association, so this instream
monitoring has been waived, provided the permittee maintains its membership in the association. Data
from April 2016 through September 2020 was analyzed from LNBA Stations J5390000 (upstream of the
facility) and J5390800 (downstream of the facility). The data is summarized in Table 2 below.
Table 2. Summary of LNBA station data
Parameter
Upstream (J5390000)
Downstream (J5390800)
AVG
MAX
MIN
AVG
MAX
MIN
DO (mg/1)
6.5
12.3
0.5
5.5
11.9
1
Fecal Coliform
(cfu/100m1)
136
(geomean)
3400
23
72
(geomean)
1900
5
Temperature
(°C)
18.9
26.6
2.3
19.2
27.9
2.1
Specific
Conductance
(uS/cm)
103.7
167
68
136.6
326
80
Review of this data included analysis using Students T-test at a 95% confidence interval, where a p value
<0.05 signifies a statistically significant difference between the upstream and downstream locations.
Review indicates the following:
DO — Downstream DO dropped below the standard of 5.0 mg/1 on 28 occasions, and on 15 occasions, the
upstream DO was recorded less than 5.0 mg/1 [15A NCAC 02B .0211 (6)]. There was a statistically
significant decrease between the upstream and downstream stations (p-value = 0.014). Throughout the
period reviewed, the minimum effluent DO was 6 mg/l. On 16 occasions, downstream DO was < 5.0
mg/1, while upstream DO was not. Four of these 16 occasions correlate to elevated levels of BOD and/or
ammonia nitrogen in the facility's effluent (elevated BOD ranged from 3.6 to 6.6 mg/1; elevated ammonia
nitrogen ranged from 1.12 to 6.04 mg/1). This segment of Hannah Creek is impaired for DO.
Fecal Coliform — Throughout the period reviewed, the upstream and downstream sampling locations did
not exceed a fecal coliform geometric mean of 200/100mL. Additionally, less than 20% of the samples
collected at both the upstream and downstream sites exceeded 400/100mL, which meets the instream
standard [15A NCAC 02B .0211(7)]. There was not a statistically significant difference between the
upstream and downstream stations (p-value = 0.2).
Temperature — The state water quality standard of 32°C was maintained in this segment of Hannah
Creek throughout the period of review. Additionally, the temperature differential did not exceed 2.8°C
during the period reviewed [15A NCAC 02B .0211 (18)]. There was not a statistically significant
difference in the upstream and downstream sampling stations (p-value = 0.78).
Page 4 of 14

Specific Conductance — There was a statistically significant increase between the upstream and
downstream stations (p-value = 5.88x10-7).
The permit maintains the same instream monitoring requirements, with the addition of quarterly upstream
hardness sampling.
Is this facility a member of a Monitoring Coalition with waived instream monitoring (Y/N): YES
Name of Monitoring Coalition: Lower Neuse Basin Association
5. Compliance Summary
Summarize the compliance record with permit effluent limits (past 5 years):
From April 2016 through September 2020, the facility report limit violations as follows:
• BOD — 1 WA exceedance in 2016 (1 Proceed to NOV); 2 WA exceedances in 2017 (Proceed to
Enforcement Case); 4 WA exceedances in 2018 (2 Penalty Retracted, 1 Proceed to Enforcement
Case, 1 Proceed to NOV)
• TRC — 2 DM exceedances in 2018 (Proceed to Enforcement Case; all others <50 ug/1 =
compliant, so No Action)
• Flow — 1 MA exceedance (Proceed to NOD)
• Ammonia -Nitrogen — 3 MA exceedances in 2018 (2 Proceed to NOV, 1 Proceed to NOD); 1 WA
exceedance in 2018 (Proceed to NOV)
• pH — 1 Daily Minimum Not Reached in 2019 (No Action)
• TSS — 1 WA exceedance in 2018 (Proceed to Enforcement Case)
Summarize the compliance record with aquatic toxicity test limits and any second species test results
(past 5 years): From January 2016 through July 2020, the facility passed 20 of 21 quarterly chronic
toxicity tests (1 fail in July 2019, followed by 2 passing tests in August and September 2019), as well as 5
second species chronic toxicity tests.
Summarize the results from the most recent compliance inspection: The last facility inspection conducted
in February 2020 reported that the facility was compliant with this NPDES permit. The inspection report
noted that alum and lime were no longer used at the facility. Additionally, DWR staff discussed the need
for routine testing of the standby power units to ensure proper functioning when necessary. See attached
inspection report for full details.
6. Water Quality -Based Effluent Limitations (WQBELs)
Dilution and Mixing Zones
In accordance with 15A NCAC 2B.0206, the following streamflows are used for dilution considerations
for development of WQBELs: 1 Q 10 streamflow (acute Aquatic Life); 7Q10 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 15,4 NCAC 2B. 0204(b): NA
Page 5 of 14

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/1 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: Limitations for
BOD are based on 2003 Speculative Limits for expansion to 1.9 MGD. BOD limits are as follows:
Summer — MA 5.0 mg/1, WA 7.5 mg/1; Winter — MA 10.0 mg/1, WA 15.0 mg/1. The daily average limit
for DO is 6.0 mg/1. No changes are proposed from the previous permit limits.
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/1 (summer) and 1.8 mg/1 (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 ug/1) and capped at 28 ug/1 (acute impacts). Due to analytical issues, all TRC values
reported below 50 ug/1 are considered compliant with their permit limit.
Describe any proposed changes to ammonia and/or TRC limits for this permit renewal: Limits for
ammonia and TRC are based on 2003 Speculative Limits for expansion to 1.9 MGD. These limits were
reviewed in the attached wasteload allocation and found to be consistent with existing permit limits. The
limits for ammonia are as follows: summer — monthly average 1.0 mg/L, weekly average 3.0 mg/L;
winter — monthly average 2.0 mg/L, weekly average 6.0 mg/L. TRC limit is 17 µg/L. There are no
proposed changes.
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 reasonable potential analysis was conducted on effluent toxicant data collected between April 2016 and
September 2020. 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:
Page 6 of 14

• 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: Nickel
• 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: NA
• 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: Arsenic, Cadmium, Total Chromium, Copper, Cyanide, Lead, Molybdenum,
Selenium, Silver, Zinc
• POTW Effluent Pollutant Scan Review: Three effluent pollutant scans were evaluated for
additional pollutants of concern.
o The following parameter(s) will receive a water quality -based effluent limit (WQBEL)
with monitoring, since as part of a limited data set, two samples exceeded the allowable
discharge concentration: NA
o The following parameter(s) will receive a monitor -only requirement, since as part of a
limited data set, one sample exceeded the allowable discharge concentration: NA
o 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:
Antimony
• Permittee shall continue to report to the lowest practical quantitation level (PQL) for the
following parameters: Cadmium (<0.5 ug/1), Lead (<2.0 ug/1), Selenium (<1.0 ug/1), Silver (<1.0
ug/1)
Attached are the RPA results as well as a copy of the guidance entitled "NPDES Implementation of
Instream Dissolved Metals Standards — Freshwater Standards."
Toxicity 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: This is a Major POTW, and a chronic WET limit at 90%
effluent will continue on a quarterly frequency during the months of January, April, July, and October.
Mercury Statewide TMDL Evaluation
There is a statewide TMDL for mercury approved by EPA in 2012. The TMDL target was to comply
with EPA's 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
Page 7 of 14

control. Municipal facilities > 2 MGD and discharging quantifiable levels of mercury (>1 ng/1) 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/1) and/or if any individual value exceeds a TBEL
value of 47 ng/1.
Table 3. Mercury Effluent Data Summary
2017
2018
2019
2020
# of Samples
1
1
2
2
Annual Average Conc. ng/L
0.5
1.8
0.8
0.5
Maximum Conc., ng/L
0.5
1.8
1.00
0.5
TBEL, ng/L
47
WQBEL, ng/L
12.0
Describe proposed permit actions based on mercury evaluation: Since no annual average mercury
concentration exceeded the WQBEL, and no individual mercury sample exceeded the TBEL, no mercury
limit is required. Furthermore, the facility is < 2.0 MGD and did not report multiple quantifiable levels of
mercury (> 1 ng/1), so a mercury minimization plan (MMP) has not been added to the permit.
Other TMDL/Nutrient Management Strategy Considerations
If applicable, describe any other TMDLs/Nutrient Management Strategies and their implementation
within this permit:
The Environmental Management Commission adopted Nutrient Management Strategy rules in December
1997, classifying the entire Neuse River Basin as Nutrient Sensitive Waters. The point source rule (T15A
NCAC 2B .0713) sets Total Nitrogen (TN) discharge limits for all point source dischargers larger than 0.5
MGD. The nitrogen allocation for this permit is based on the Neuse River Nutrient TMDL. The
individual nitrogen allocations for the facilities in the Neuse River Watershed are defined in NCC000001.
The rule also allows dischargers to form a group compliance association and work together to reduce
nitrogen; this option allows the association members added flexibility in controlling nitrogen discharges.
At the same time, the association is subject to a group NPDES permit ensuring that the association and its
individual members are accountable if they exceed the applicable nitrogen limits.
Under the rule, there are three types of TN limit in the Neuse:
1. the individual limits in the dischargers' individual permits,
2. the aggregate limit in an association's group NPDES permit, and
3. the individual allocations/limits for each Association member, also in that association permit.
A discharger may be subject to the first type of limit, or to the second and third, but never to all three at
the same time. The discharger is first subject to the TN limit (if any) in its individual NPDES permit. If
becomes a co-permittee to a compliance association's group NPDES permit, it is then governed by the TN
limits in that permit. If the association complies with its group TN limit in a given year, all members are
deemed to be in compliance with their individual allocations/ limits in the group permit. If the association
exceeds its limit, the members then become subject to their individual allocations/ limits as well.
Page 8 of 14

Regardless of which permit governs a TN discharge, allocations/ limits will likely change over time as the
dischargers purchase, sell, trade, lease, or otherwise transfer nitrogen allocations. The Division will
modify the affected permits as necessary to ensure that the limits are kept up to date and reflect any such
transactions.
Under the rule, the Town was originally assigned a total nitrogen allocation of 33,790 lb/yr at end -of -
pipe. In 2008, the Town sold the equivalent of 720 lb/yr end -of -pipe to Johnston County (NC0030716). as
A result, its allocation and, its TN Load limit is reduced to 33,070 lb./yr, measured on a calendar year
basis. In addition to this limit, the Permittee will be required to report total monthly flow, total Kjeldahl
nitrogen and the sum of nitrate and nitrite in addition to the existing requirement to report monthly total
nitrogen concentrations and loads.
The Town is a member of the Neuse River Compliance Association at this time. So long as it remains a
Co-Permittee member, it is deemed to be in compliance with the TN limit in this permit, and its TN
discharge is governed instead by the Association's group NPDES permit, effective January 1, 2019.
Table 4. Total Nitrogen Annual Loads:
2016
2017
2018
2019
TN (lbs/year)
10,725
249
11,576
11,396
Other WQBEL Considerations
If applicable, describe any other parameters of concern evaluated for WQBELs: NA
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.0107(c)(2)(B), 40CFR 122.47, and EPA May 2007Memo: NA - Based on review of the
nickel data, limits have been added to the permit, and a compliance schedule was not requested at this
time.
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/1
BOD5/TSS for Monthly Average, and 45 mg/l for BOD5/TSS for Weekly Average). YES
If NO, provide a justification for alternative limitations (e.g., waste stabilization pond). NA
Are 85% removal requirements for BOD5/TSS included in the permit? YES - See attached BOD & TSS
Removal Rate Calculation spreadsheet.
If NO, provide a justification (e.g., waste stabilization pond). NA
Page 9 of 14

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 (EAA) 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(1) 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).
Are any effluent limitations less stringent than previous permit (YES/NO): NO
If YES, confirm that antibacksliding provisions are not violated: NA
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 2B.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.
For instream monitoring, refer to Section 4.
During the first draft comment period, the Town requested a monitoring frequency reduction for BOD,
TSS, Fecal coliform, and ammonia -nitrogen per the DWR Guidance Regarding the Reduction of
Monitoring Frequencies in NPDES Permits for Exceptionally Performing Facilities. Review of effluent
data from September 1, 2017 through September 30, 2020 showed that the facility meets the criteria for
reduced monitoring for BOD (winter), TSS, ammonia -nitrogen (winter), and fecal coliform, so
monitoring frequencies for these parameters will be reduced to 2/week. Monitoring is not able to be
reduced at this time for BOD (summer) due to the 3-year mean being greater than 50% of the monthly
average limit and for NH3 due to more than 15 daily samples being greater than 200% of the weekly
average limit. See the attached data summary.
Page 10 of 14

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:
Table 5. Current Permit Conditions and Proposed Changes 1.9 MGD
Parameter
Current Permit
Proposed Change
Basis for Condition/Change
Flow
MA 1.9 MGD
No change
15A NCAC 2B .0505
Total Monthly
Flow
Monitor & Report
(MG)
No change
For calculation of TN Load
BOD5
Summer:
MA 5.0 mg/1
WA 7.5 mg/1
Winter:
MA 10.0 mg/1
WA 15.0 mg/1
Monitor Daily
No change Summer
only - Daily
Winter: Monitoring
frequency 2/week
WQBEL. Based on protection of DO
standard. 15A NCAC 2B.0200.
DWR Guidance Regarding the
Reduction of Monitoring Frequencies
in NPDES Permits for Exceptionally
Performing Facilities
TSS
MA 30.0 mg/1
WA 45.0 mg/1
Monitor Daily
No change to limits
Monitoring frequency
2/week
TBEL. Secondary treatment standards
/ 40 CFR 133 / 15A NCAC 2B .0406
DWR Guidance Regarding the
Reduction of Monitoring Frequencies
in NPDES Permits for Exceptionally
Performing Facilities
NH3-N
Summer:
MA 1.0 mg/1
WA 3.0 mg/1
Winter:
MA 2.0 mg/1
WA 6.0 mg/1
Monitor Daily
No change summer
only - Daily
Winter: Monitoring
frequency 2/week
WQBEL. Based on protection of State
WQ criteria. 15A NCAC 2B.0200
DWR Guidance Regarding the
Reduction of Monitoring Frequencies
in NPDES Permits for Exceptionally
Performing Facilities
pH
6.0 — 9.0 SU
Monitor Daily
No change
WQBEL. State WQ standard, 15A
NCAC 2B .0200
DO
> 6.0 mg/1 (Daily Avg.)
Monitor Daily
No change
WQBEL. State WQ standard, 15A
NCAC 2B .0200
Page 11 of 14

Fecal coliform
MA 200 /100m1
WA 400 /100m1
No change to limits
Monitoring frequency
2/week
WQBEL. State WQ standard, 15A
NCAC 2B .0200
DWR Guidance Regarding the
Reduction of Monitoring Frequencies
in NPDES Permits for Exceptionally
Performing Facilities
Temperature
Monitor & Report Daily
(°C)
No change
15A NCAC 2B .0500
Conductivity
Monitor & Report Daily
(umhos/cm)
No change
15A NCAC 2B .0500
TRC
DM 17 µg/L
Monitor Daily
No change
WQBEL. State WQ standard, 15A
NCAC 2B .0200
TKN
Monitor & Report
(mg/L)
No change
15A NCAC 2B .0713, Nutrient Mgmt.
Strategy, Neuse River Basin
NO3-N + NO2-N
Monitor & Report
(mg/L)
No change
15A NCAC 2B .0713, Nutrient Mgmt.
Strategy, Neuse River Basin
Total Nitrogen
Monitor & Report
(mg/L)
No change
15A NCAC 2B .0713, Nutrient Mgmt.
Strategy, Neuse River Basin
TN Load
Monitor & Report
(lb/month)
33,070 lb/year
No change
WQBEL. 15A NCAC 2B .0713,
Nutrient Mgmt. Strategy, Neuse River
Basin
Total Phosphorus
Quarterly Average 2.0
mg/L
Monitor Weekly
No change
WQBEL. 15A NCAC 2B .0713,
Nutrient Mgmt. Strategy, Neuse River
Basin
Total Copper
Monitor Quarterly
Remove Monitoring
Based on Reasonable Potential
Analysis (RPA); No RP, Predicted
Max < 50% of Allowable Cw - No
Monitoring required
Total Zinc
Monitor Quarterly
Remove Monitoring
Based on RPA; No RP, Predicted
Max < 50% of Allowable Cw - No
Monitoring required
Total Nickel
Monitor Quarterly
Apply Monthly
Monitoring + Limit
MA 62.1 ug/L
DM 558.9 ug/L
WQBEL. Based on RPA; RP Shown —
Apply Monthly Monitoring with Limit
Page 12 of 14

Toxicity Test
Chronic limit, 90%
effluent
Monitor Quarterly
No change
WQBEL. No toxics in toxic amounts.
15A NCAC 2B.0200 and 15A NCAC
2B.0500
Effluent Pollutant
Scan
3 per permit cycle
No change
40 CFR 122. Permittee shall monitor
in 2023, 2024, 2025.
Electronic
Reporting
No requirement
Add Electronic
Reporting Special
Condition
In accordance with EPA Electronic
Reporting Rule 2015.
MGD — Million gallons per day, MA - Monthly Average, WA — Weekly Average, DM — Daily Max
13. Public Notice Schedule:
Permit to Public Notice: 11/10/2020 and 1/26/2021
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 days comment period indicating the interest of the party filing such request and the
reasons why a hearing is warranted.
14. Fact Sheet Addendum (if applicable):
Were there any changes made since the November 10, 2020 Draft Permit was public noticed (Yes/No):
Yes
If Yes, list changes and their basis below:
The Nov. 10, 2020 draft was sent to the permittee, EPA Region 4, DWR Raleigh Regional Office, DWR
Operator Certification Branch, DWR Ecosystems Branch, and DWR Aquatic Toxicology Branch. During
this comment period, the facility requested a monitoring frequency reduction for BOD, TSS, NH3, and
fecal coliform. As this change is not considered a minor modification, the draft permit will go through the
public notice period again. No additional comments were received.
• A notation was made concerning the Electronic Reporting Rule — Phase 2 Extension. extended the
Phase 2 deadline from December 21, 2020, to December 21, 2025, effective January 4, 2021. The
current compliance date has been extended to reflect this change [See A. (8.)].
• Based on NPDES guidance regarding the reduction of monitoring frequencies in NPDES permits
for exceptionally performing facilities, monitoring requirements for BOD5 (winter), NH3-N
(winter), Total Suspended Solids and Fecal Coliform have been reduced to twice per week [See
A.(1)].
The draft permit was public noticed again on January 28, 2021 and re -sent to the permittee, EPA Region 4,
DWR Raleigh Regional Office, DWR Operator Certification Branch, DWR Ecosystems Branch, and DWR
Aquatic Toxicology Branch. No comments were received during the 2nd comment period, and no further
changes were made to the permit following this public notice period.
Page 13 of 14

15. Fact Sheet Attachments:
• NH3/TRC WLA Calculations
• BOD & TSS Removal Rate Calculations
• Mercury TMDL Calculations
• PERCS Pretreatment Information Request Form
• RPA Sheets
o Input Information
o Data Analyzed
o Results Summary
o Dissolved to Total Metal Calculation
• WET Testing and Self -Monitoring Summary
• Instream Summary
• Limit Violations Summary
• NPDES Implementation of Instream Dissolved Metals Standards — Freshwater Standards
• Water Compliance Inspection Report (Feb. 24, 2020)
• Priority Pollutant Analysis Data (2017, 2018)
• Application Addendum
• Benson Request for Monitoring Frequency Reduction
• Monitoring Frequency Reduction Data Summary
Page 14 of 14

NAN
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Powered by McClatchy
Ti'.e News & Observer
421 Fayettevilre Street. Suite 10.1
Raleigh. NC 2 7601
AFFIDAVIT OF PUBLICATION
Account #
Ad Number
Identification
PO
Cols
Lines
104811
0004862308
Public Notice NC0020389
1
45
Attention:
DEPARTMENT OF WATER RESOURCES
1617 MAIL SERVICE CENTER
RALEIGH, NC 276991617
Public Notice
North Carolina Environmental Manage.
ment Commission/NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES
wastewater Permit NC0020389 Benson
The North Carolina Environmental
Management Commission proposes to
issue a NPDES wostewoter discharge
permit to the person(s) listed below.
Written comments regarding the pro-
posed permit will be accepted until 30
days after the publish date of this notice.
The Director of the NC Division of Water
Resources (DWR) may hold a public
hearing should there be a significant de-
gree of public interest. Please moil com-
ments and/or information requests to
DWR at the above address. Interested
persons may visit the DWR at 512 N. Sal-
isbury Street, Raleigh, NC 27604 to re-
view information on file. Additional in-
formation on NPDES permits and this
notice may be found on our website: http
://deq.nc.gov/about/divisions/wafer•
resources/wolar-resdurCes-
permits/wostewoter branch/npdes-
wastewater/public-notices, or by calling
[phone]. The Town of Benson
(P.O. Box 69, Benson, NC 27504) has re-
quested renewal of permit NC0020389 for
the Benson Wastewater Treatment
Plant in Johnston County. This permit-
ted facility discharges treated munici-
pal and industrial wastewater to Hannah
Creek, a Class C-NSW water in the
Neuse River Basin. Currently, 80D,
ammonia nitrogen. dissolved Oxygen, to-
tal residual chlorine. fecal coliform, to-
tal nitrogen, and total phosphorus ore
water quality limited. This discharge
may affect future allocations in the re-
ceiving stream.
N&O: January 28. 2021
STATE OF NORTH CAROLINA
COUNTY OF WAKE
Before the undersigned, a Notary Public of
Johnston County, North Carolina, duly
commissioned and authorized to administer
oaths, affirmations, etc., personally appeared
BETSY WOMBLE, who being duly swom or
affirmed, according to law, doth depose and
say that he or she is Accounts Receivable
Specialist of the News & Observer Publishing
Company, a corporation organized and doing
business under the Laws of the State of
North Carolina, and publishing a newspaper
known as The News & Observer, Wake
County and State aforesaid, the said
newspaper in which such notice, paper,
document, or legal advertisement was
published was, at the time of each and every
such publication, a newspaper meeting all of
the requirements and qualifications of Section
1-597 of the General Statutes of North
Carolina and was a qualified newspaper
within the meaning of Section 1-597 of the
General Statutes of North Carolina, and that
as such he or she makes this affidavit; and is
familiar with the books, files and business of
said corporation and by reference to the files
of said publication the attached advertisement
1
Insertion(s)
Published On:
January 28, 2021
()alit buG)/1,t,
BETSY WOMBLE, Accounts Receivable
Specialist
Electronic Notary Rtublic
State of North Carolina
Sworn to and subscribed before me this
28th day of January, 2021
My Commission Expires: 7/10/2023
L
WENDY DAWSON
Notary Public
North Carolina
Johnston County

NAN
MEDIA COMPANY
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Powered by McClatchy
The News & Observer
421 Fayetteville Street, Suite 104
Raleigh. NC 27601
AFFIDAVIT OF PUBLICATION
Account #
Ad Number
Identification
PO
Cols
Lines
104811
0004808098
NC0020389 Benson WWTP and Little Creek
1
55
Attention:
DEPARTMENT OF WATER RESOURCES
1617 MAIL SERVICE CENTER
RALEIGH, NC 276991617
Public Notice
North Carolina Environmental
Management CommissioNNPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Notice of Intent to Issue a NPDES
Wastewater Permit NC0020389 Benson
WWT P and NC0025453 Little Creek W R F
The North Carolina Environmental
Management Commission proposes to
issue a NPDES wastewater discharge
permit to the person(s) listed below.
Written comments regarding the pro-
posed permit will be aCcepted until 30
days after the publish dote of this notice.
The Director of the NC Division of Water
Resources (DWR) may hold o public
hearing should (here be a significant de-
gree at public Interest. Please mall cam-
ments and/or information requests to
DWR al the above address. Interested
persons may visit the DWR a1 512 N. Sal-
isbury Street, Raleigh, NC 27604 to re-
view information on file. Additional in-
formation on NPOES permits and this
notice may be found on our website:
http:lldeq.nc.gov/about/d ivis ions/water-
resources/water-resources perrnit7/
wastewaterbranch/npdes wastewater/
Public -notices. or by calling (919) 707-
3601. The Town of Benson (P.O. Box 69,
Benson, NC 27504) has requested renew-
al of permit NC0020389 for the Benson
Wastewater Treatment Plant in John-
ston County. This permitted facility dis-
charges treated municipal and industri-
al wastewater to Hannah Creek, a Class
C-NSW water in the Neuse River Basin.
Currently, BOD, ammonia nitrogen, dis-
solved oxygen, total residual chlorine,
fecal coliform, total nitrogen, and total
phosphorus are water quality limited.
This discharge may affect future alloca-
tions In the receiving stream. The Town
of Clayton has requested modification of
permit NC0025453 for its Little Creek
Water Reclamation Facility in Johnston
County; this permitted discharge is
treated municipal and industrial waste-
water to the Neuse River, in the Neuse
River Basin. The modification will odd
additional flow tiers and record the pur-
chase of nutrient credits for future ex-
pansions.
N&0: November 13, 2020
STATE OF NORTH CAROLINA
COUNTY OF WAKE
Before the undersigned, a Notary Public of
Johnston County, North Carolina, duly
commissioned and authorized to administer
oaths, affirmations, etc., personally appeared
BETSY WOMBLE, who being duly sworn or
affirmed, according to law, doth depose and
say that he or she is Accounts Receivable
Specialist of the News & Observer Publishing
Company, a corporation organized and doing
business under the Laws of the State of
North Carolina, and publishing a newspaper
known as The News & Observer, Wake
County and State aforesaid, the said
newspaper in which such notice, paper,
document, or legal advertisement was
published was, at the time of each and every
such publication, a newspaper meeting all of
the requirements and qualifications of Section
1-597 of the General Statutes of North
Carolina and was a qualified newspaper
within the meaning of Section 1-597 of the
General Statutes of North Carolina, and that
as such he or she makes this affidavit; and is
familiar with the books, files and business of
said corporation and by reference to the files
of said publication the attached advertisement
1
Insertion(s)
Published On:
November 13, 2020
BETSY WOMBLE, Accounts Receivable
Specialist
L-UktfY CaLkLia Carl -
Electronic Notary Pudic
State of North Carolina
Sworn to and subscribed before me this
13th day of November, 2020
My Commission Expires: 7/10/2023
WENDY DAWSON
Notary Public
North Carolina
Johnston County

NH3/TRC WLA Calculations
Facility: Benson WWTP
PermitNo. NC0020389
Prepared By: Cassidy Kurtz
Enter Design Flow (MGD): 1.9
Enter s7Q10 (cfs): 0
Enter w7Q10 (cfs): 0.12
Total Residual Chlorine (TRC)
Daily Maximum Limit (ug/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (UG/L)
Upstream Bkgd (ug/I)
IWC (%)
Allowable Conc. (ug/I)
Fecal Coliform
Monthly Average Limit:
(If DF >331; Monitor)
(If DF<331; Limit)
Dilution Factor (DF)
0
1.9
2.945
17.0
0
100.00
17
Ammonia (Summer)
Monthly Average Limit (mg NH3-N/I)
s7Q10 (CFS)
DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Ammonia (Winter)
Monthly Average Limit (mg NH3-N/I)
w7Q10 (CFS)
200/100m1 DESIGN FLOW (MGD)
DESIGN FLOW (CFS)
STREAM STD (MG/L)
1.00 Upstream Bkgd (mg/I)
IWC (%)
Allowable Conc. (mg/I)
Total Residual Chlnrinp
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. Monthly Avg limit x 3 = Weekly Avg limit (Municipals)
3. Monthly Avg limit x 5 = Daily Max limit (Non-Munis)
If the allowable ammonia concentration is > 35 mg/L, no limit shall be imposed
0
1.9
2.945
1.0
0.22
100.00
1.0
0.12
1.9
2.945
1.8
0.22
96.08
1.9
Fpcal Coliform.
1. Monthly Avg limit x 2 = 400/100 ml = Weekly Avg limit (Municipals) = Daily Max limit (Non -Muni)

NC0020389 Benson WWTP 11/9/2020
BOD monthly removal rate
Month RR (%) Month RR (%)
April-16
May-16
June-16
July-16
August-16
September-16
October-16
November-16
December-16
January-17
February-17
March-17
April-17
May-17
June-17
July-17
August-17
September-17
October-17
November-17
December-17
January-18
February-18
March-18
April-18
May-18
June-18
July-18
August-18
September-18
98.02
96.21
98.21
98.21
98.63
95.65
96.06
98.37
98.90
98.58
99.05
99.35
97.77
97.95
96.08
95.24
97.17
96.75
97.24
99.20
99.17
96.77
96.23
95.30
96.60
95.44
97.17
97.55
97.57
94.99
October-18
November-18
December-18
January-19
February-19
March-19
April-19
May-19
June-19
July-19
August-19
September-19
October-19
November-19
December-19
January-20
February-20
March-20
April-20
May-20
June-20
July-20
August-20
September-20
October-20
November-20
December-20
January-21
February-21
March-21
Overall BOD removal rate
98.30
97.54
92.44
98.42
98.41
98.45
98.25
98.71
99.42
99.20
98.92
98.52
98.56
99.08
98.00
98.02
97.29
97.66
98.33
98.77
98.11
98.69
97.90
98.24
#N/A
#N/A
#N/A
97.68
TSS monthly removal rate
Month RR (%) Month RR (%)
April-16
May-16
June-16
July-16
August-16
September-16
October-16
November-16
December-16
January-17
February-17
March-17
April-17
May-17
June-17
July-17
August-17
September-17
October-17
November-17
December-17
January-18
February-18
March-18
April-18
May-18
June-18
July-18
August-18
September-18
98.65
97.89
98.79
98.49
98.94
98.21
90.79
99.25
99.35
99.20
99.33
99.34
99.22
98.78
98.47
98.86
98.69
98.56
98.97
99.40
99.29
95.52
96.69
97.14
99.08
91.44
98.84
98.74
98.62
95.47
October-18
November-18
December-18
January-19
February-19
March-19
April-19
May-19
June-19
July-19
August-19
September-19
October-19
November-19
December-19
January-20
February-20
March-20
April-20
May-20
June-20
July-20
August-20
September-20
October-20
November-20
December-20
January-21
February-21
March-21
Overall TSSD removal rate
98.80
98.13
97.23
98.97
99.08
98.79
98.97
98.75
99.11
99.02
98.91
98.83
99.23
99.27
99.20
99.23
99.21
99.23
98.72
99.14
99.17
99.12
99.03
99.15
#N/A
#N/A
#N/A
98.41

11/9/20 WQS = 12 ng/L
Facility Name Benson WWTP / NC0020389
/Permit No. :
MERCURY WQBEL/TBEL EVALUATION V:2013-6
Total Mercury 1631E PQL = 0.5 ng/L 7Q10s =
Date Modifier Data Entry Value Permitted Flow =
4/12/17 < 1
9/12/18 1.8
8/13/19 1
10/16/19 < 1
3/23/20 < 1
6/10/20 < 1
No Limit Required
No MMP Required
0.5
1.8
1
0.5
0.5
0.5
0.000
1.900
cfs
WQBEL =
12.00 ng/L
47 ng/L
0.5 ng/L - Annual Average for 2017
1.8 ng/L - Annual Average for 2018
0.8 ng/L - Annual Average for 2019
0.5 ng/L - Annual Average for 2020

Benson WWTP / NC0020389
Mercury Data Statistics (Method 163 1E)
2017
2018
2019
2020
# of Samples
1
1
2
2
Annual Average, ng/L
0.5
1.8
0.8
0.5
Maximum Value, ng/L
0.50
1.80
1.00
0.50
TBEL, ng/L
47
WQBEL, ng/L
12.0

NPDES/Aquifer Protection Permitting Unit Pretreatment Information Request Form
PERMIT WRITER COMPLETES THIS PART: PERMIT WRITERS - AFTER you uet this form back
Check all that apply
f
from PERCS:
Notify PERCS if LTMP/STMP data we said should
Date of Request
10/30/2020
municipal renewal
X
be on DMRs is not really there, so we can get it for
Requestor
Cassidy Kurtz
new industries
you (or NOV POTW).
Facility Name
Benson WWTP
WWTP expansion
- Notify PERCS if you want us to keep a specific POC
Permit Number
NC0020389
Speculative limits
in LTMP/STMP so you will have data for next permit
Region
Raleigh
stream reclass.
renewal.
- Email PERCS draft permit, fact sheet, RPA.
Basin
Neuse
outfall relocation
- Send PERCS paper copy of permit (w/o NPDES
7Q10 change
boilerplate), cover letter, final fact sheet. Email RPA if
other
changes.
other
check
applicable PERCS staff:
Other Comments to PERCS:
BRD, CPF, CTB, FRB, TAR
Facility is rated 1.9 MGD wtih 1 SIU listed in its application (Chicopee Inc, d
X
CHO, HIW, LTN, LUM, NES, NEW, ROA, YAD
b a Berry Plastics)
PERCS
PRETREATMENT STAFF COMPLETES THIS PART:
Status
of Pretreatment Program (check all that apply)
1) facility has no SIU's, does have Division approved Pretreatment Program that is INACTIVE
2) facility has no SIU's, does not have Division approved Pretreatment Program
X
3) facility has Sills and DWQ approved Pretreatment Program (list "DEV" if program still under development)
3a) Full Program with LTMP
X
3b) Modified Program with STMP
4) additional conditions regarding Pretreatment attached or listed below
Flow, MGD
Permitted
Actual
Time period for Actual
STMP time frame:
Industrial
0.4
0.261
2015-2020
Most recent:
2019-2020
Uncontrollable
n/a
0.8327
2019-2020
Next Cycle:
2025
POC in LTMPI
STMP
Parameter of
Concern (POC)
Check List
POC due to
NPDES/ Non-
Disch Permit
Limit
Required by
EPA
Required
by 503
Sludge**
POC due
to SIU***below)****
POTW POC
(Explain
STMP
Effluent
Freq
LTMP
Effluent
Freq
BOD
4
4
Q
TSS
4
4
Q
Q = Quarterly
NH3
4
4
Q
M = Monthly
A
Arsenic
J
Q
J
Cadmium
J
J
Q
J
Chromium
J
J
Q
Al
Copper
Al
4
4
Q
Cyanide
Q
Is all data on DMRs?
4
Lead
4
4
Q
YES
X
Mercury
4
Q
NO (attach data)
Molybdenum
4
Q
'I
Nickel
'l
4
4
Q
Silver
Q
Selenium
AI
Q
Al
Zinc
N/
4
4
Q
Is data in spreadsheet?
Total Nitrogen
4
4
Q
YES (email to writer)
Phosphorus
'I
AI
Q
NO
X
Q
Q
Q
Q
*Always in the LTMP/STMP ** Only in LTMP/STMP if sludge land app or composte (dif POCs for incinerators)
*** Only in LTMP/STMP while SIU still discharges to POTW **** Only in LTMP/STMP when pollutant is still of concern to POTW
Comments to Permit Writer (ex., explanation of any POCs; info you have on IU related investigations into NPDES problems):
PERC NPDES_Pretreatment.request.form.may2016
Revised: July 24, 2007

Freshwater RPA - 95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
REQUIRED DATA ENTRY
Table 1. Project Information
Facility Name
WWTP/WTP Class
NPDES Permit
Outfall
Flow, Qw (MGD)
Receiving Stream
HUC Number
Stream Class
L CHECK IF HQW OR ORW WQS
Benson WWTP
IV
NC0020389
001
1.900
Hannah Creek
C - NSW
LJ Apply WS Hardness WQC
7Q10s (cfs)
7Q1Ow (cfs)
30Q2 (cfs)
QA (cfs)
1Q10s (cfs)
0.00
C
0.12
C
0.25
C
12.00
C
0.00
Effluent Hardness
Upstream Hardness
Combined Hardness Chronic
Combined Hardness Acute
45.75 mg/L (Avg)
25 mg/L (Avg)
45.75 mg/L
45.75 mg/L
Data Source(s)
L CHECK TO APPLY MODEL
Table 2. Parameters of Concern
Par01
Par02
Par03
Par04
Par05
Par06
Par07
Par08
Par09
Par10
Par11
Par12
Par13
Par14
Par15
Par16
Par17
Par18
Par19
Par20
Par21
Par22
Par23
Par24
Name
1AQS Type Chronic Modifier
Acute
PQL Units
Arsenic
Aquactic Life
C
150
FW
340
ug/L
Arsenic
Human Health
Water Supply
C
10
HH/WS
N/A
ug/L
Beryllium
Aquatic Life
NC
6.5
FW
65
ug/L
Cadmium
Aquatic Life
NC
0.9315
FW
5.4899
ug/L
Chlorides
Aquatic Life
NC
230
FW
mg/L
Chlorinated Phenolic Compounds
Water Supply
NC
1
A
ug/L
* Total Phenolic Compounds
Aquatic Life
NC
300
A
ug/L
Chromium HI
Aquatic Life
NC
193.1274
FW
1484.6882
ug/L
Chromium VI
Aquatic Life
NC
11
FW
16
pg/L
Chromium, Total
Aquatic Life
NC
N/A
FW
N/A
pg/L
Copper
Aquatic Life
NC
13.2077
FW
18.5059
ug/L
Cyanide
Aquatic Life
NC
5
FW
22
10
ug/L
Fluoride
Aquatic Life
NC
1,800
FW
ug/L
Lead
Aquatic Life
NC
5.7858
FW
148.4723
ug/L
Mercury
Aquatic Life
NC
12
FW
0.5
ng/L
Molybdenum
Human Health
NC
2000
HH
ug/L
Nickel
Aquatic Life
NC
62.0786
FW
558.9190
pg/L
Nickel
Water Supply
NC
25.0000
WS
N/A
pg/L
Selenium
Aquatic Life
NC
5
FW
56
ug/L
Silver
Aquatic Life
NC
0.06
FW
0.8381
ug/L
Zinc
Aquatic Life
NC
211.4785
FW
209.7626
ug/L
Antimony
Human Health
NC
640
HH
pg/L
20389 FW RPA, input
11/9/2020

Benson WWTP
NC0020389
Freshwater RPA -
Qw (MGD) = 1.9000
1Q1OS (cfs) = 0.00
7Q1OS (cfs) = 0.00
7Q1OW(cfs)= 0.12
30Q2 (cfs) = 0.25
Avg. Stream Flow, QA (cfs) = 12.00
Receiving Stream: Hannah Creek
95% Probability/95% Confidence Using Metal Translators
MAXIMUM DATA POINTS = 58
WWTP/WTP Class: IV
IWC% @ 1Q1OS = 100
IWC% @ 7Q1OS = 100
IWC% @ 7Q10W = 96.0848287
IWC% @ 30Q2 = 92.1752739
IW%C @ QA = 19.7055872
Stream Class: C - NSW
Outfall 001
Qw = 1.9 MGD
COMBINED HARDNESS (mg/L)
Acute = 45.75 mg/L
Chronic = 45.75 mg/L
PARAMETER
TYPE
NC STANDARDS OR EPA CRITERIA
_1F
CY
a
zApplied
=
REASONABLE POTENTIAL RESULTS
RECOMMENDED ACTION
Chronic Standard Acute
n # Det. Max Pred Cw Allowable Cw
Arsenic
Arsenic
C
C
150 FW 340
10 HH/WS
ue/I.
ug/L
8 0
Note: n <_ 9
Limited data set
4.8
C.V. (default)
NO DETECTS
Acute (FW): 340.0
Chronic (FW): 150.0
Max MDL = 5
Chronic (HH): 50.7
Max MDL = 5
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
NA
Cadmium
NC
0.9315 FW 5.4899
ug/L
8 0
Note: n <- 9
Limited data set
0.950
C.V. (default)
NO DETECTS
Acute: 5.490
Chronic: 0.931
Max MDL = 1
No detects, all samples < 1 and < 0.5 ug/I; permittee
shall continue to report to lowest reporting level (<0.5
ug/I) - No monitoring required
Chromium III
NC
193.1274 FW 1484.6882
µg/L
0 0
N/A
Acute: 1,484.7
___ _ _______ _ __
Chronic: 193.1
_ _ _ _ _________________
See Total Chromium
Chromium VI
NC
11 FW 16
µg/L
0 0
N/A
Acute: 16.0
Chronic: 11.0 - -
- -------------------------
See Total Chromium
Chromium, Total
NC
µg/L
8 0
Note:n <_ 9
Limited data set
4.8
C.V. (default)
NO DETECTS
Max reported value = 2.5
Max MDL = 5
a: No monitoring required if all Total Chromium
samples are < 5 pg/L or Pred. max for Total Cr is <
allowable Cw for Cr VI.
Copper
NC
13.2077 FW 18.5059
ug/L
25 0
5.80
NO DETECTS
Acute: 18.51
___________________
Chronic: 13.21
Max MDL = 10
__________
No RP, Predicted Max < 50% of Allowable Cw - No
Monitoring required
Cyanide
NC
5 FW 22
10
ug/L
4 0
Note: n <_ 9
Limited data set
13.0
C.V. (default)
NO DETECTS
Acute: 22.0
___ _ _______ _____
Chronic: 5.0
Max MDL = 10
_ _ _ _ _ _ ___ _ _ _ ___
No detects, all samples <5 ug/I - No monitoring
required
Lead
NC
5.7858 FW 148.4723
ug/L
8 0
Note: n <- 9
Limited data set
4.750
C.V. (default)
NO DETECTS
Acute: 148.472
Chronic: 5.786
Max MDL = 5
No detects, all samples < 5 and < 2 ug/I; permittee
shall report to the lowest reporting level (<2 ug/I) - No
Monitoring required
Page 1 of 2
20389 FW RPA, rpa
11/9/2020

REASONABLE POTENTIAL ANALYSIS
H1
Use "PASTE SPECIAL-
H2
Use "PASTE SPECIAL-
Par01 & Par02
Use "PASTE
Effluent Hardness
Values" then copy '
Maximum data points =
Upstream Hardness
Values" then "COPY".
Maximum data points =
Arsenic
SPECIAL -Values"
then "COPY" .
58
58
Maximum data points
Date
Data
BDL=1/2DL Results
Date
Data BDL=1/2DL Results
Date
Data
BDL=1/2DL
Results
= 58
1
4/12/2017
40 40 Std Dev.
12.5000
1
25 25 Std Dev.
N/A
1 4/12/2017
<
5
2.5
Std Dev.
0.6944
2
9/12/2018
64 64 Mean 45.7500
2
Mean 25.0000
2 9/12/2018
<
5
2.5
Mean 2.1250
3
10/16/2019
43 43 C.V. (default) 0.6000
3
C.V. 0.0000
3 8/13/2019
<
5
2.5
C.V. (default) 0.6000
4
5/27/2020
36 36 n 4
4
n 1
4 10/15/2019
<
5
2.5
n 8
5
10th Per value 37.20 mg/L
5
10th Per value 25.00 mg/L
5 10/16/2019
<
5
2.5
6
Average Value 45.75 mg/L
6
Average Value 25.00 mg/L
6 2/11/2020
<
5
2.5
Mult Factor = 1.90
7
Max. Value 64.00 mg/L
7
Max. Value 25.00 mg/L
7 5/20/2020
<
2
1
Max. Value 2.5 ug/L
8
8
8 5/27/2020
<
2
1
Max. Pred Cw 4.8 ug/L
9
9
9
10
10
10
11
11
11
12
12
12
13
13
13
14
14
14
15
15
15
16
16
16
17
17
17
18
18
18
19
19
19
20
20
20
21
21
21
22
22
22
23
23
23
24
24
24
25
25
25
26
26
26
27
27
27
20389 FW RPA, data
11/9/2020

REASONABLE POTENTIAL ANALYSIS
Par03
Beryllium
Date Data BDL=1/2DL Results
1 4/12/2017 < 1 0.5 Std Dev.
2 9/12/2018 < 1 0.5 Mean
3 10/16/2019 < 1 0.5 C.V. (default)
4 5/27/2020 < 1 0.5 n
5
6 Mult Factor =
7 Max. Value
8 Max. Pred Cw
9 II
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Use"PASTE
SPECIAL -Values
then "COPY" .
Maximum data
points = 58
Par04
Cadmium
0.0000
0.5000
0.6000
4
2.59
0.50 ug/L
1.30 ug/L
Date Data BDL=1/2DL Results
1 4/12/2017 < 1 0.5 Std Dev.
2 9/12/2018 < 1 0.5 Mean
3 8/13/2019 < 1 0.5 C.V. (default)
4 10/15/2019 < 1 0.5 n
5 10/16/2019 < 1 0.5
6 2/11/2020 < 1 0.5 MultFactor=
7 5/20/2020 < 0.5 0.25 Max. Value
81 5/27/2020 < 0.5 0.25 Max. Pred Cw
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Use"PASTE
SPECIAL -Values
then "COPY" .
Maximum data
points = 58
Par10
Chromium, Total
0.1157 1
0.4375 2
0.6000 3
8 4
5
1.90 6
0.500 ug/I 7
0.950 ug/I 8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Date Data
4/12/2017 5
9/12/2018 5
8/13/2019 5
10/15/2019 5
10/16/2019 5
2/11/2020 5
5/20/2020 2
5/27/2020 2
Use"PASTE SPECIAL -
Values" then "COPY" .
Maximum data points =
58
BDL=1/2DL Results
2.5 Std Dev. 0.6944
2.5 Mean 2.1250
2.5 C.V. (default) 0.6000
2.5 n 8
2.5
2.5 Mult Factor = 1.90
1 Max. Value 2.5 pg/L
1 Max. Pred Cw 4.8 pg/L
20389 FW RPA, data
11/9/2020

REASONABLE POTENTIAL ANALYSIS
Pal
Use"PASTE SPECIAL-
Values"
" "COPY"
Maximum data points =
58
Par12
Use"PASTE SPECIAL-
Values" then
" "COPY"
Maximum data points =
58
Par14
SPECIAL -
Use"PASTE SPECIAL -
Values"then"COPY".
Maximum data points =
58
Copper
Cyanide
Lead
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
Date
BDL=1/2DL
Results
1
4/6/2016
<
10
5
Std Dev.
1.4967
1
4/12/2017
<
5
5
Std Dev.
0.0000
1
4/12/2017
<
5
2.5
Std Dev.
0.6944
2
7/6/2016
<
10
5
Mean 4.3600
2
9/12/2018
<
5
5
Mean 5.00
2
9/12/2018
<
5
2.5
Mean 2.1250
3
10/5/2016
<
10
5
C.V. 0.3433
3
10/16/2019
<
5
5
C.V. (default) 0.6000
3
8/13/2019
<
5
2.5
C.V. (default) 0.6000
4
1/4/2017
<
10
5
n 25
4
5/27/2020
<
5
5
n 4
4
10/15/2019
<
5
2.5
n 8
5
4/5/2017
<
10
5
5
5
10/16/2019
<
5
2.5
6
4/12/2017
<
10
5
MultFactor= 1.16
6
MultFactor= 2.59
6
2/11/2020
<
5
2.5
MultFactor= 1.90
7
7/5/2017
<
10
5
Max. Value 5.00 ug/L
7
Max. Value 5.0 ug/L
7
5/20/2020
<
2
1
Max. Value 2.500 ug/L
8
10/4/2017
<
10
5
Max. Pred Cw 5.80 ug/L
8
Max. Pred Cw 13.0 ug/L
8
5/27/2020
<
2
1
Max. Pred Cw 4.750 ug/L
9
1/2/2018
<
10
5
9
9
10
4/4/2018
<
10
5
10
10
11
7/6/2018
<
10
5
11
11
12
9/12/2018
<
10
5
12
12
13
10/3/2018
<
10
5
13
13
14
1/2/2019
<
10
5
14
14
15
4/3/2019
<
10
5
15
15
16
7/3/2019
<
10
5
16
16
17
8/13/2019
<
10
5
17
17
18
10/15/2019
<
2
1
18
18
19
10/16/2019
<
10
5
19
19
20
1/8/2020
<
10
5
20
20
21
2/11/2020
<
2
1
21
21
22
4/6/2020
<
10
5
22
22
23
5/20/2020
<
2
1
23
23
24
5/27/2020
<
2
1
24
24
25
7/8/2020
<
10
5
25
25
26
26
26
27
27
27
20389 FW RPA, data
11/9/2020

REASONABLE POTENTIAL ANALYSIS
Par16
Molybdenum
Use"PASTE SPECIAL -
Values" then "COPY" .
Maximum data points =
58
Date Data BDL=1/2DL Results •
1 8/13/2019 < 10 5 Std Dev. 1.2500
2 10/15/2019 < 10 5 Mean 4.3750
3 2/11/2020 < 10 5 C.V. (default) 0.6000
4 5/20/2020 < 5 2.5 n 4
5
6 Mult Factor = 2.59
7 Max. Value 5.0 ug/L
8 1 Max. Pred Cw 13.0 ug/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Par17 & Par18
Nickel
Date Data BDL=1/2DL Results
1 4/6/2016 34 34 Std Dev.
2 7/6/2016 < 10 5 Mean
3 10/5/2016 < 10 5 C.V.
4 1/4/2017 44 44 n
5 4/5/2017 < 10 5
6 4/12/2017 < 10 5 MultFactor=
7 7/5/2017 < 10 5 Max. Value
8 10/4/2017 < 10 5 Max. Pred Cw
9 1/2/2018 < 10 5
10 4/4/2018 < 10 5
11 5/30/2018 1.2 1.2
12 7/6/2018 45 45
13 9/12/2018 < 10 5
14 10/3/2018 39 39
15 1/2/2019 < 10 5
16 4/3/2019 < 10 5
17 7/3/2019 < 10 5
18 8/13/2019 < 10 5
19 10/15/2019 < 10 5
20 10/16/2019 < 10 5
21 1/8/2020 < 10 5
22 2/11/2020 < 10 5
23 4/6/2020 < 10 5
24 5/20/2020 < 2 1
25 5/27/2020 < 2 1
26 7/8/2020 < 10 5
27
Use"PASTE SPECIAL -
Values" then "COPY" .
Maximum data points =
58
Par19
Selenium
Use"PASTE SPECIAL -
Values" then "COPY" .
Maximum data points =
58
Date Data BDL=1/2DL Results
13.4349 1 4/12/2017 < 10 5 Std Dev. 2.0831
10.0077 2 9/12/2018 < 10 5 Mean 3.8750
1.3425 3 8/13/2019 < 10 5 C.V. (default) 0.6000
26 4 10/15/2019 < 10 5 n 8
5 10/16/2019 < 10 5
1.52 6 2/11/2020 < 10 5 MultFactor= 1.90
45.0 pg/L 7 5/20/2020 < 1 0.5 Max. Value 5.0 ug/L
68.4 pg/L 81 5/27/2020 < 1 0.5 Max. Pred Cw 9.5 ug/L
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
20389 FW RPA, data
- 4 - 11/9/2020

REASONABLE POTENTIAL ANALYSIS
Par20
Use"PASTE SPECIAL-
Values" then "COPY".
Maximum data points =
58
Par21
Use"PASTE SPECIAL-
Values" then "COPY".
Maximum data points =
58
Par22
Use"PASTE SPECIAL -
Values" then "COPY".
Maximum data points =
58
Silver
Zinc
Antimony
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
Date
Data
BDL=1/2DL
Results
1
4/12/2017
<
5
2.5
Std Dev.
1.0000
1
4/6/2016
<
10
5
Std Dev.
16.4471
1
4/12/2017
<
3
1.5
Std Dev.
1.4930
2
9/12/2018
<
5
2.5
Mean 2.0000
2
7/6/2016
51
51
Mean 35.4400
2
9/12/2018
4
4
Mean 3.3750
3
10/16/2019
<
5
2.5
C.V. (default) 0.6000
3
10/5/2016
33
33
C.V. 0.4641
3
10/16/2019
3
3
C.V. (default) 0.6000
4
5/27/2020
<
1
0.5
n 4
4
1/4/2017
<
10
5
n 25
4
5/27/2020
5
5
n 4
5
5
4/5/2017
44
44
5
6
MultFactor= 2.59
6
4/12/2017
42
42
MultFactor= 1.21
6
MultFactor= 2.59
7
Max. Value 2.500 ug/L
7
7/5/2017
23
23
Max. Value 62.0 ug/L
7
Max. Value 5.000000 pg/L
8
Max. Pred Cw 6.475 ug/L
8
10/4/2017
47
47
Max. Pred Cw 75.0 ug/L
8
Max. Pred Cw 12.950000 pg/L
9
9
1/2/2018
62
62
9
10
10
4/4/2018
32
32
10
11
11
7/6/2018
<
10
5
11
12
12
9/12/2018
47
47
12
13
13
10/3/2018
<
10
5
13
14
14
1/2/2019
32
32
14
15
15
4/3/2019
42
42
15
16
16
7/3/2019
40
40
16
17
17
8/13/2019
50
50
17
18
18
10/15/2019
57
57
18
19
19
10/16/2019
57
57
19
20
20
1/8/2020
35
35
20
21
21
2/11/2020
29
29
21
22
22
4/6/2020
39
39
22
23
23
5/20/2020
34
34
23
24
24
5/27/2020
33
33
24
25
25
7/8/2020
37
37
25
26
26
26
27
27
27
20389 FW RPA, data
11/9/2020

Date: 11/9/2020
Dissolved to Total Metal Calculator
Do NOT enter any data directly into this spreadsheet.
Enter data onto 'Table 1" under the Input Sheet and enter
"Effluent Hardness" under the Data Sheet.
In accordance with 40 CFR 122.45 (c ), permits are, have and
must be written as total metals.
This calculator has been inserted into the RPA to calculate
Total Metal allowable allocations once Table 1 has been
completed (Input Sheet) and Effluent hardness has been
entered (Data Sheet).
1) Following the spreadsheet from left to right. First
the allowable allocations for the dissolved metals will
appear for all the metals listed once Table 1 is complete
and effluent hardness entered. Use a default value of 25
mg/L if no hardness data is available. Second,
the Dissolved Metal allocations are divided by the
Translators to determine the Total Metals that can be
allocated to the Permittee. These Total Metals values are
automatically inserted into Table 2 and are the allowable
Total Metal allocations determined for the Permittee prior
to allowing for dilution. See Input sheet Table 2. The final
acute and chronic values shown under the RPA sheet are
the Total Metal values listed in Table 2 divided by the acute
and chronic IWC, respectively.
2) The Translators used in the freshwater RPA are the
Partition Coefficients published by US EPA in 1984. They
are TSS dependent equations and can be found listed with
the WQS hardness dependent equations under the sheet
labeled Equations. A fixed TSS value of 10 mg/L is used to
calculate the Translator values.
3) Pretreatment Facilities - PERCS will need a copy of the
Dissolved to Total Metal Calculator spreadsheet and the
RPA sheet along with the Final Permit. Pretreatment
Facilities are required to renew their Headwords Analysis
after renewal of their permits. Since all their metal
allocations are likely to change PERCS needs to see any new
metal permit limits and the allowable allocations for the
dissolved metals to assess Maximum Allowable Headworks
Loading (MAHL) numbers for each metal based on the
Combined Hardness values used in the permit writers RPA
calculations.
4) For Cadmium, Lead, Nickel, Chromium and Beryllium, if all
the effluent sampling data for the last three to five years
shows the pollutant at concentrations less than the
Practical Quantitative Level (PQL), it is not likely a limit or
monitoring will be put in the permit. However, if the
estimated NPDES permit limit is less than the Practical
Quantitative Limit (particularly, Cadmium and Lead) and
the pollutant is believed to be present, to assess
compliance with the new standards and for future permit
limit development, monitoring for the pollutant will be
required. If the facility is monitoring for the pollutant in its
Pretreatment LTMP, no monitoring is needed in the permit.
5) For monitoring and compliance purposes if Total
Chromium < the Chromium VI chronic Total Metal
FACILITY: Benson WWTP Outfall 001
NPDES PERMIT: NC0020389
Dissolved to Total Metal Calculator
In accordance with Federal Regulations, permit limitations must be written as Total Metals per 40 CFR 122.45(c)
Receiving
Stream
SUMMOr
7010 (CFS)
Receiving
Stream
sum
mer 7010
(MGD)
0.0000
0.0000
Rec. Stream
1010
[MGD]
0.0000
NPDES
Flow Limit
[MGD]
Total Suspended
Solids
-Fixed Value-
(mg/L)
Combined
Hardness
chronic
(mg/L)
Combined
Hardness
Acute
(mg/L)
Intam
Wastewater
Concentration
(Chronic)
Instream
Wastewater
Concentration
(Acute)
Upstream
Hardness
Average (mg/L)
Effluent
Hardness
Average
(mg/L)
9000
10 45.750 45.750
100.0000
00.0000
25
45.75
Upstream Hard Avg (mg/L) = 25
EFF Hard Avg (mg/L) = 45.75
PARAMETER
Dissolved Metals Criteria
after applying hardness
equation
Chronic Acute
[ug/I]
Cadmium (d) 0.24 1.39
0.24 0.86
Chromium III (d)(h) 39 300
Chromium VI (d)
Chromium, Total (t)
Copper (d)(h)
Lead (d)(h)
Nickel (d)(h)
Ni -WS�
Silver (d)(h,acute)
Zinc (d)(h)
11
4.6
1.06
27
0.06
61
16
6.4
27
242
0.64
60
US EPA Mt
a'
Default Partition
Coefficients Chronic Acute
(streams) lug/II [ug/I]
0.252
0.252
0.202
1.000
0.348
0.93
5.49
0.93
193.13
11.00
N/A
13.21
5.79
3.41
1484.69
16.00
N/A
18.51
0.2881 211.48 209.76
Beryllium 5
Arsenic (d) 150
1.000
1.000
6.5
150
65
340
COMMENTS (Identify parameters to PERCS Branch to maintain in facility's LTMP/STMPf
(d) = dissolved metal standard. See 15A NCAC 02B .0211 for more information.
(h) = hardness -dependent dissolved metal standard. See 15A NCAC 026.0211 for more information.
(t) = based upon measurement of total recoveable metal. See 15A NCAC 026.0211 for more information.
The Human Health standard for Nickel in Water Supply Streams is 25 mg/L which is Total Recoverable metal standard.
The Human Health standard for Arsenic is 10 pg/L which is Total Recoverable metal standard.
ACAH 45.75
ACCH 45.75
0.184 148.47
0.432 62.08 558.92
N/A
1.000 0.06 0.84

Whole Effluent Toxicity Testing and Self Monitoring Summary
Belmont WWTP NC0021181/001 County: Gaston Region: MR() Basin: CT11,94 Feb May Aug Nov SOC JOC:
Ceri7dPF Begin: 2/1/2006 dtir lim: S% Noncomp: Single 7010: 95.0 PF: 5.0 IWC: 8.0 Freq: Q
I F
2016 Pass
2017 Pass
2018 Pass
2014 Pass
2020 Pass
h+} A
M 1 I A S 0 N
Pass Pass - Pass
Pass Pass - Pass
Pass Pass - Pass
Pass Pass - Pass
Pass Pass -
0
Belvedere WFP Carolina Water Service NC0032221/041 County: Render Region: WIRD Basin: CPF24 Jan AprJul Oct
Mysd24PF Begin: 7/1/2012 Ac P/F Lim: 90% Mhos NonComp: 7Q10: Tidal PF: IWC: Freq: Q
SOCJGC:
I F Iid .4 JN 1 I A S 0 J+f D
2016 H H 11 - 11
2017 H 11 11 - 11
2018 H - - H - - H - - H
2019 H 11 11 - 11
2020 H H H
Benson WWTP
Ceri7dPF
NC0020389/001 County: Johnston Region- RRO
Begin: 9/1/2013 dirlim:90% NonComp: Single 7Q10: 0.0
Basin: NEU04 Jan AprJul Oct
PF: 1.9 IWC: 100 Freq: CI
SOCJGC:
I
2016 Pass
2017 Pass:100(PI
2018 Pass
2019 Pass
2020 Pass
A JVP 1 I
Pass Pas
Pass ,100IP) Pas WWI
Pass - - Pas
Pass Fail
Pass - - Pas
A
1fl0(P)
S 0 N
- 11 Pass slCCV)
- Pass
Pass
1Q7 Pass
Biscoe WWTP
Ceri7dPF
NC0021504/041 County: Montgomery Region: FRO
Begin: 5/1/2014 dirlim:90% NonComp: Single 7Q10: 0.0
Basin: YAD15 Jan AprJul Oct
PF: 0.5 IWC: 100 Freq: Q
SOC JDC:
I F iid A M 1 I A S 0 N D
2016 Pass Fail :100 :.100 Pas - Pass
2017 Pass Pass Pas - Pass
2018 Pass Pass - Pas - Pass
2019 Pass :.100(P) s 100(P) A10011”Pads 01_1I s100(P) Pas - Pass
2020 Pass Fail 822 A00 Pas
Black Creek Terminal, LLC NC0089487/041 County: Wilson Region: RRO Basin: NEU07 Jan Apr Jul Oct
Fthd24PF Begin: 1/1/2019 Ac P/F Monit: 90% Ft NonComp: 7010: PF: IWC: Freq: A
SOC JGC:
I F n,} A fN 1 I A S 0 N 0
2016 H H H 11 - 11
2017 H - - H - - H - - H
2018 - 11
2019 H 11 - H H
2020 H H H
Legend: P= Fathead minnow IPimphales promelasl. H=No Flow (facility is active). s = Split test between Certified Labs
Page 9 of 121

Benson WWTP - NC0020389
Dissolved Oxygen (DO)
Date
2020-06-24
2020-06-13
2020-05-27
2020-05-16
2020-04-16
2020-03-30
2020-02-06
2020-01-09
2019-12-11
2019-11-07
2019-10-03
2019-09-21
2019-09-11
2019-08-29
2019-08-10
2019-07-27
2019-07-03
2019-06-23
2019-06-05
2019-05-18
2019-05-06
2019-04-04
2019-03-21
2019-02-21
2019-01-22
2018-12-31
2018-11-26
2018-10-29
2018-09-25
2018-09-09I
2018-08-31
2018-08-11
2018-07-30
2018-07-14
2018-06-26
2018-06-03
2018-05-24
2018-05-09
2018-04-27
1
2018-03-28
2018-02-07
2018-01-09
2017-12-06
2017-11-20
Upstream Downstream Unit Date
5.6 3.7 mg/I
5.7 3.6 mg/I
8.8 4.2 mg/I
7.9 5 mg/I
8.9 6.9 mg/I
7.4 4.9 mg/I
8.8 8.1 mg/I
12.3 9.8 mg/I
8.4 6.4 mg/I
7.6 6.4 mg/I
2.3 1.9 mg/I
6.9 4.7 mg/I
5.3 2.7 mg/I
5.3 6.6 mg/I
3.2 2.3 mg/I
5.2 5 mg/I
0.5 3.3 mg/I
2.4 2.9 mg/I
8.8 4.3 mg/I
7.1 3.6 mg/I
6.2 3.5 mg/I
9.1 7.6 mg/I I
10.3 9.1 mg/I
10.9 10.5 mg/I
11.8 11.9 mg/I
8.8 8 mg/I I
10.4 8.7 mg/I
8.4 8.6 mg/I
7.7 3.3 mg/I
1 1.9 mg/I
4.1 5.4 mg/I
6.1 2.5 mg/I
4.9 5.8 mg/I
9 3.8 mg/I
5.7 5.8 mg/I
4.6 2.8 mg/I
5.9 6 mg/I
5.3 4.1 mg/I
6.8 6.6 mg/I
7 7.2 mg/I
9.5 9.2 mg/I
9.2 9.3 mg/I
7.1 7 mg/I
7.2 7.4 mg/I
2017-10-05
2017-09-21
2017-09-10
2017-08-29
2017-08-13
2017-07-29
2017-07-05
2017-06-17
2017-06-05
2017-05-17
2017-05-01
2017-04-04
2017-03-01
2017-02-06
2017-01-04
2016-12-15
2016-11-03
2016-10-04
2016-09-22
2016-09-07
2016-08-19
2016-08-02
2016-07-22
2016-07-06
2016-06-22
2016-06-03
2016-05-24
2016-05-12
2016-04-28
Upstream Downstream Unit
5.3 6.3 mg/I
5.4 6.1 mg/I
4.9 3.7 mg/I
5.6 5.4 mg/I
2.4 1.2 mg/I
1.2 2.3 mg/I
5.1 5.3 mg/I
7.2 2.8 mg/I
5.7 6.1 mg/I
4.5 3.7 mg/I
6.4 6.5 mg/I
6.7 6.5 mg/I
6.7 6.4 mg/I
8.3 7.8 mg/I
9.1 7.4 mg/I
10.4 8.7 mg/I
6.6 6.4 mg/I
6.4 6.4 mg/I
5.1 3.5 mg/I
6.7 6.5 mg/I
3 2 mg/I
3.8 5.7 mg/I
4.1 1 mg/I
5.9 5.8 mg/I
6.4 6.3 mg/I
5.2 3.2 mg/I
7 6.8 mg/I
6.9 3.6 mg/I
6.4 6.3 mg/I
t-Test: Two -Sample Assuming Equal Variances
Variable 1 Variable 2
Mean 6.490411 5.50684932
Variance 5.925601 5.49509132
Observations 73 73
Pooled Variance 5.710346
Hypothesized Mean Diffe 0
df 144
t Stat 2.486662
P(T<=t) one -tail 0.007018
t Critical one -tail 1.655504
P(T<=t) two -tail 0.014037
t Critical two -tail 1.976575

Benson WWTP - NC0020389
Fecal Coliform
Date Upstream Downstream Unit Date Upstream Downstream Unit
2020-06-24 310 121 cfu/100rr 2016-10-04 320 44 cfu/100m1
2020-05-27 470 310 cfu/100rr 2016-09-07 664 560 cfu/100m1
2020-04-16 52 48 cfu/100rr 2016-08-02 627 70 cfu/100m1
2020-03-30 270 56 cfu/100rr 2016-07-06 470 27 cfu/100m1
2020-02-061 3400 1900 cfu/100rr 2016-06-22 270 7 cfu/100m1
2020-01-09 46 46 cfu/100rr 2016-05-24 172 38 cfu/100m1
2019-12-11 250 143 cfu/100rr 2016-04-28 340 30 cfu/100m1
2019-11-07 100 86 cfu/100m1
2019-10-03 48 25 cfu/100m1
2019-09-11 440 800 cfu/100rr t-Test: Two -Sample Assuming Equal Variances
2019-08-29 230 164 cfu/100m1
2019-07-03 42 44 cfu/100m1 Variable 1 Variable 2
2019-06-05 25 151 cfu/100rr Mean 258.098 156.960784
2019-05-06 106 102 cfu/100rr Variance 232692.3 84976.4784
2019-04-04 72 64 cfu/100rr Observations 51 51
2019-03-21 530 340 cfu/100rr Pooled Variance 158834.4
2019-02-21 60 40 cfu/100rr Hypothesized Mean Diffe 0
2019-01-22 48 40 cfu/100rr df 100
2018-12-31 39 40 cfu/100rr t Stat 1.281472
2018-11-26 39 76 cfu/100rr P(T<=t) one -tail 0.101496
2018-10-29 108 64 cfu/100rr t Critical one -tail 1.660234
2018-09-25 470 290 cfu/100rr P(T<=t) two -tail 0.202992
2018-08-31 280 370 cfu/100rr t Critical two -tail 1.983972
2018-07-301 300 400 cfu/100m1
2018-06-26 210 260 cfu/100m1
2018-05-24 141 170 cfu/100m1
2018-04-27 94 62 cfu/100m1
2018-03-28 44 8 cfu/100m1
2018-02-07 23 125 cfu/100m1
2018-01-09 26 11 cfu/100m1
2017-12-06 141 10 cfu/100m1
2017-11-20 80 106 cfu/100m1
2017-10-05 52 5 cfu/100m1
2017-09-21 130 58 cfu/100m1
2017-08-29 110 48 cfu/100m1
2017-07-05 74 56 cfu/100m1
2017-06-05 100 78 cfu/100m1
2017-05-01 54 60 cfu/100m1
2017-04-04 636 210 cfu/100m1
2017-03-01 206 28 cfu/100m1
2017-02-06 78 13 cfu/100m1
2017-01-04 60 43 cfu/100m1
2016-12-15 66 46 cfu/100m1
2016-11-031 240 112 cfu/100m1

Benson WWTP - NC0020389
Specific Conductance
Date
2020-06-24
2020-06-13
2020-05-27
2020-05-16
2020-04-16
2020-03-30
2020-02-06
2020-01-09
2019-12-11
2019-11-07
2019-10-03
2019-09-21
2019-09-11
2019-08-29
2019-08-10
2019-07-27
2019-07-03
2019-06-23
2019-06-05
2019-05-18
2019-05-06
2019-04-04
2019-03-21
2019-02-21
2019-01-22
2018-12-31
2018-11-26
2018-10-29
2018-09-25
2018-09-09
2018-08-31
2018-08-11
2018-07-30
2018-07-14
2018-06-26
2018-06-03
2018-05-24
2018-05-09
2018-04-27
1
2018-03-28
2018-02-07
2018-01-09
2017-12-06
2017-11-20
Upstream Downstream Unit
88 86 uS/cm
77 99 uS/cm
90 101 uS/cm
104 137 uS/cm
89 104 uS/cm
88 101 uS/cm
68 80 uS/cm
92 96 uS/cm
93 112 uS/cm
93 171 uS/cm
111 206 uS/cm
106 138 uS/cm
96 100 uS/cm
89 107 uS/cm
97 121 uS/cm
89 124 uS/cm
118 202 uS/cm
110 157 uS/cm
111 281 uS/cm
104 158 uS/cm
92 116 uS/cm
85 88 uS/cm
84 102 uS/cm
83 83 uS/cm
131 98 uS/cm
93 90 uS/cm
84 86 uS/cm
90 100 uS/cm
97 113 uS/cm
101 183 uS/cm
104 116 uS/cm
85 99 uS/cm
109 114 uS/cm
125 308 uS/cm
104 119 uS/cm
95 127 uS/cm
112 121 uS/cm
101 140 uS/cm
98 116 uS/cm
115 124 uS/cm
117 128 uS/cm
119 129 uS/cm
109 122 uS/cm
123 117 uS/cm
Date
2017-10-05
2017-09-21
2017-09-10
2017-08-29
2017-08-13
2017-07-29
2017-07-05
2017-06-17
2017-06-05
2017-05-17
2017-05-01
2017-04-04
2017-03-01
2017-02-06
2017-01-04
2016-12-15
2016-11-03
2016-10-04
2016-09-22
2016-09-07
2016-08-19
2016-08-02
2016-07-22
2016-07-06
2016-06-22
2016-06-03
2016-05-24
2016-05-12
2016-04-28
Upstream
97
98
120
109
122
100
116
109
92
86
105
84
128
118
108
71
98
91
92
109
161
167
114
108
156
113
108
92
129
Downstream
112
123
227
124
326
204
130
152
116
120
121
109
149
141
126
85
122
117
141
144
304
149
158
150
143
163
123
122
148
t-Test: Two -Sample Assuming Equal Variances
Mean
Variance
Observations
Pooled Variance
Hypothesized Mean Diffe
df
t Stat
P(T<=t) one -tail
t Critical one -tail
P(T<=t) two -tail
t Critical two -tail
Variable 1
103.6986
331.9635
73
1441.648
0
144
-5.229067
2.94E-07
1.655504
5.88E-07
1.976575
Variable 2
136.561644
2551.33295
73
Unit
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm
uS/cm

Benson WWTP - NC0020389
Date
2020-06-24
2020-06-13
2020-05-27
2020-05-16
2020-04-16
2020-03-30j
2020-02-06
2020-01-09
2019-12-11
2019-11-07
2019-10-03
2019-09-21
2019-09-11
2019-08-29
2019-08-10
2019-07-27
2019-07-03
2019-06-23
2019-06-05
2019-05-18
2019-05-06
2019-04-041
2019-03-21
2019-02-21
2019-01-22
2018-12-31
2018-11-26
2018-10-29
2018-09-25
2018-09-09
2018-08-31
2018-08-11
2018-07-30
2018-07-14
2018-06-26
2018-06-03
2018-05-24
2018-05-09
2018-04-27
2018-03-281
2018-02-07
2018-01-09
2017-12-06
2017-11-20
Temperature
Upstream Downstream Unit
24.1 24.2 deg C
23.9 23.5 deg C
20.5 21.5 deg C
19.9 20.4 deg C
12.9 13.8 deg C
19.8 20.5 deg C
14.2 14.4 deg C
7.1 6.2 deg C
12 12.7 deg C
12.6 13.5 deg C
24.3 25 deg C
24 20.7 deg C
24.9 24.6 deg C
22.8 23.9 deg C
25.2 25.7 deg C
24.2 24.7 deg C
25 26.2 deg C
23.6 24.5 deg C
22.1 23.5 deg C
21.2 22.1 deg C
20.4 21.6 deg C
11.8 12.1 deg C
10.2 10.4 deg C
7.7 7.4 deg C
2.3 2.1 deg C
12.5 12.5 deg C
11.4 11.3 deg C
13.5 13.5 deg C
23.1 23.4 deg C
25.3 26.1 deg C
25.6 25.8 deg C
26.1 25.6 deg C
25.2 25.3 deg C
23.5 24.5 deg C
24.8 24.7 deg C
24.1 24.8 deg C
22.6 22.7 deg C
17.5 18.6 deg C
15.9 16 deg C
8.8 9 deg C
8.6 8.4 deg C
2.4 2.5 deg C
12.6 12.7 deg C
8.5 8.6 deg C
Date
2017-10-05
2017-09-21
2017-09-10
2017-08-29
2017-08-13
2017-07-29
2017-07-05
2017-06-17
2017-06-05
2017-05-17
2017-05-01
2017-04-04
2017-03-01
2017-02-06
2017-01-04
2016-12-15
2016-11-03
2016-10-04
2016-09-22
2016-09-07
2016-08-19
2016-08-02
2016-07-22
2016-07-06
2016-06-22
2016-06-03
2016-05-24
2016-05-12
2016-04-28
Upstream Downstream Unit
18.5 18.6 deg C
21 21 deg C
20.2 19.2 deg C
21.9 23.1 deg C
24.7 25.7 deg C
25.5 26.4 deg C
24.8 24.7 deg C
25.2 25.9 deg C
23.4 23.6 deg C
20.4 22.9 deg C
21.8 21.6 deg C
16.8 16.9 deg C
15.8 15.5 deg C
6.6 6.4 deg C
11.4 11.3 deg C
7.5 8.2 deg C
16.1 16 deg C
21.3 21.1 deg C
22.8 23.1 deg C
21.5 21.4 deg C
26.6 27.9 deg C
25.8 25.6 deg C
25 26.1 deg C
24.8 24.5 deg C
22.8 22.6 deg C
23 24.9 deg C
15.9 15.7 deg C
20.6 21.6 deg C
19.6 19.4 deg C
t-Test: Two -Sample Assuming Equal Variances
Variable 1 Variable 2
Mean 18.90411 19.2068493
Variance 41.45707 43.7731469
Observations 73 73
Pooled Variance 42.61511
Hypothesized Mean Diffe 0
df 144
t Stat -0.280178
P(T<=t) one -tail 0.389872
t Critical one -tail 1.655504
P(T<=t) two -tail 0.779743
t Critical two -tail 1.976575

Permit No. NC0020389
NPDES Implementation of Instream Dissolved Metals Standards - Freshwater Standards
The NC 2007-2015 Water Quality Standard (WQS) Triennial Review was approved by the NC
Environmental Management Commission (EMC) on November 13, 2014. The US EPA subsequently
approved the WQS revisions on April 6, 2016, with some exceptions. Therefore, metal limits in draft
permits out to public notice after April 6, 2016 must be calculated to protect the new standards - as
approved.
Table 1. NC Dissolved Metals Water Ouality Standards/Aquatic Life Protection
Parameter
Acute FW, µg/1
(Dissolved)
Chronic FW, µg/1
(Dissolved)
Acute SW, µg/1
(Dissolved)
Chronic SW, µg/1
(Dissolved)
Arsenic
340
150
69
36
Beryllium
65
6.5
---
---
Cadmium
Calculation
Calculation
40
8.8
Chromium III
Calculation
Calculation
---
---
Chromium VI
16
11
1100
50
Copper
Calculation
Calculation
4.8
3.1
Lead
Calculation
Calculation
210
8.1
Nickel
Calculation
Calculation
74
8.2
Silver
Calculation
0.06
1.9
0.1
Zinc
Calculation
Calculation
90
81
Table 1 Notes:
1. FW= Freshwater, SW= Saltwater
2. Calculation = Hardness dependent standard
3. Only the aquatic life standards listed above are expressed in dissolved form. Aquatic life
standards for Mercury and selenium are still expressed as Total Recoverable Metals due to
bioaccumulative concerns (as are all human health standards for all metals). It is still necessary
to evaluate total recoverable aquatic life and human health standards listed in 15A NCAC
2B.0200 (e.g., arsenic at 10 µg/1 for human health protection; cyanide at 5 µg/L and fluoride at
1.8 mg/L for aquatic life protection).
Table 2. Dissolved Freshwater Standards for Hardness -Dependent Metals
The Water Effects Ratio (WER) is equal to one unless determined otherwise under 15A
NCAC 02B .0211 Subparagraph (11)(d)
Metal
NC Dissolved Standard, µg/I
Cadmium, Acute
WER*{1.136672-[ln hardness](0.041838)} • e^{0.9151 [In hardness]-3.1485}
Cadmium, Acute Trout waters
WER*{1.136672-[ln hardness](0.041838)} • e^{0.9151[ln hardness]-3.6236}
Cadmium, Chronic
WER*{1.101672-[ln hardness](0.041838)} • e^{0.7998[ln hardness]-4.4451}
Chromium III, Acute
WER*0.316 • e^{0.8190[ln hardness]+3.7256}
Chromium III, Chronic
WER*0.860 • e^{0.8190[ln hardness]+0.6848}
Copper, Acute
WER*0.960 • e^{0.9422[ln hardness]-1.700}
Copper, Chronic
WER*0.960 • e^{0.8545[ln hardness]-1.702}
Lead, Acute
WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[In hardness]-1.460}
Lead, Chronic
WER*{1.46203-[ln hardness](0.145712)} • e^{1.273[In hardness]-4.705}
Nickel, Acute
WER*0.998 • e^{0.8460[ln hardness]+2.255}
Nickel, Chronic
WER*0.997 • e^{0.8460[ln hardness]+0.0584}
Page 1 of 4

Permit No. NC0020389
Silver, Acute
WER*0.85 • e^{1.72[ln hardness]-6.59}
Silver, Chronic
Not applicable
Zinc, Acute
WER*0.978 • e^{0.8473[ln hardness]+0.884}
Zinc, Chronic
WER*0.986 • e^{0.8473[ln hardness]+0.884}
General Information on the Reasonable Potential Analysis (RPA)
The RPA process itself did not change as the result of the new metals standards. However, application of
the dissolved and hardness -dependent standards requires additional consideration in order to establish the
numeric standard for each metal of concern of each individual discharge.
The hardness -based standards require some knowledge of the effluent and instream (upstream) hardness
and so must be calculated case -by -case for each discharge.
Metals limits must be expressed as `total recoverable' metals in accordance with 40 CFR 122.45(c). The
discharge -specific standards must be converted to the equivalent total values for use in the RPA
calculations. We will generally rely on default translator values developed for each metal (more on that
below), but it is also possible to consider case -specific translators developed in accordance with
established methodology.
RPA Permitting Guidance/WQBELs for Hardness -Dependent Metals - Freshwater
The RPA is designed to predict the maximum likely effluent concentrations for each metal of concern,
based on recent effluent data, and calculate the allowable effluent concentrations, based on applicable
standards and the critical low -flow values for the receiving stream.
If the maximum predicted value is greater than the maximum allowed value (chronic or acute), the
discharge has reasonable potential to exceed the standard, which warrants a permit limit in most cases. If
monitoring for a particular pollutant indicates that the pollutant is not present (i.e. consistently below
detection level), then the Division may remove the monitoring requirement in the reissued permit.
1. To perform a RPA on the Freshwater hardness -dependent metals the Permit Writer compiles the
following information:
• Critical low flow of the receiving stream, 7Q10 (the spreadsheet automatically calculates
the 1Q10 using the formula 1Q10 = 0.843 (s7Q10, cfs) 0.993
• Effluent hardness and upstream hardness, site -specific data is preferred
• Permitted flow
• Receiving stream classification
2. In order to establish the numeric standard for each hardness -dependent metal of concern and for
each individual discharge, the Permit Writer must first determine what effluent and instream
(upstream) hardness values to use in the equations.
The permit writer reviews DMR's, Effluent Pollutant Scans, and Toxicity Test results for any
hardness data and contacts the Permittee to see if any additional data is available for instream
hardness values, upstream of the discharge.
If no hardness data is available, the permit writer may choose to do an initial evaluation using a
default hardness of 25 mg/L (CaCO3 or (Ca + Mg)). Minimum and maximum limits on the
hardness value used for water quality calculations are 25 mg/L and 400 mg/L, respectively.
If the use of a default hardness value results in a hardness -dependent metal showing reasonable
potential, the permit writer contacts the Permittee and requests 5 site -specific effluent and
upstream hardness samples over a period of one week. The RPA is rerun using the new data.
Page 2 of 4

Permit No. NC0020389
The overall hardness value used in the water quality calculations is calculated as follows:
Combined Hardness (chronic)
= (Permitted Flow, cfs *Avg. Effluent Hardness, mg/L) + (s7Q10, cfs *Avg. Upstream Hardness, mg/L)
(Permitted Flow, cfs + s7Q10, cfs)
The Combined Hardness for acute is the same but the calculation uses the 1Q10 flow.
3. The permit writer converts the numeric standard for each metal of concern to a total recoverable
metal, using the EPA Default Partition Coefficients (DPCs) or site -specific translators, if any
have been developed using federally approved methodology.
EPA default partition coefficients or the "Fraction Dissolved" converts the value for
dissolved metal at laboratory conditions to total recoverable metal at in -stream
ambient conditions. This factor is calculated using the linear partition coefficients
found in The Metals Translator: Guidance for Calculating a Total Recoverable
Permit Limit from a Dissolved Criterion (EPA 823-B-96-007, June 1996) and the
equation:
Cdiss =
Ctotal
1
1 + { [Kpo] [SSl'+a>] [10-6] }
Where:
ss = in -stream suspended solids concentration [mg/1], minimum of 10 mg/L used,
and
Kpo and a = constants that express the equilibrium relationship between dissolved
and adsorbed forms of metals. A list of constants used for each hardness -dependent
metal can also be found in the RPA program under a sheet labeled DPCs.
4. The numeric standard for each metal of concern is divided by the default partition coefficient (or
site -specific translator) to obtain a Total Recoverable Metal at ambient conditions.
In some cases, where an EPA default partition coefficient translator does not exist (ie. silver), the
dissolved numeric standard for each metal of concern is divided by the EPA conversion factor to
obtain a Total Recoverable Metal at ambient conditions. This method presumes that the metal is
dissolved to the same extent as it was during EPA's criteria development for metals. For more
information on conversion factors see the June, 1996 EPA Translator Guidance Document.
5. The RPA spreadsheet uses a mass balance equation to determine the total allowable concentration
(permit limits) for each pollutant using the following equation:
Ca = (s7Q10 + Qw) (Cwqs) — (s7Q10) (Cb)
Qw
Where: Ca = allowable effluent concentration (µg/L or mg/L)
Cwqs = NC Water Quality Standard or federal criteria (µg/L or mg/L)
Cb = background concentration: assume zero for all toxicants except NH3* (µg/L or mg/L)
Qw = permitted effluent flow (cfs, match s7Q10)
s7Q 10 = summer low flow used to protect aquatic life from chronic toxicity and human
health through the consumption of water, fish, and shellfish from noncarcinogens (cfs)
* Discussions are on -going with EPA on how best to address background concentrations
Flows other than s7Q 10 may be incorporated as applicable:
1Q10 = used in the equation to protect aquatic life from acute toxicity
Page 3 of 4

Permit No. NC0020389
QA = used in the equation to protect human health through the consumption of water,
fish, and shellfish from carcinogens
30Q2 = used in the equation to protect aesthetic quality
6. The permit writer enters the most recent 2-3 years of effluent data for each pollutant of concern.
Data entered must have been taken within four and one-half years prior to the date of the permit
application (40 CFR 122.21). The RPA spreadsheet estimates the 95th percentile upper
concentration of each pollutant. The Predicted Max concentrations are compared to the Total
allowable concentrations to determine if a permit limit is necessary. If the predicted max exceeds
the acute or chronic Total allowable concentrations, the discharge is considered to show
reasonable potential to violate the water quality standard, and a permit limit (Total allowable
concentration) is included in the permit in accordance with the U.S. EPA Technical Support
Document for Water Quality -Based Toxics Control published in 1991.
7. When appropriate, permit writers develop facility specific compliance schedules in accordance
with the EPA Headquarters Memo dated May 10, 2007 from James Hanlon to Alexis Strauss on
40 CFR 122.47 Compliance Schedule Requirements.
8. The Total Chromium NC WQS was removed and replaced with trivalent chromium and
hexavalent chromium Water Quality Standards. As a cost savings measure, total chromium data
results may be used as a conservative surrogate in cases where there are no analytical results
based on chromium III or VI. In these cases, the projected maximum concentration (95th %) for
total chromium will be compared against water quality standards for chromium III and
chromium VI.
9. Effluent hardness sampling and instream hardness sampling, upstream of the discharge, are
inserted into all permits with facilities monitoring for hardness -dependent metals to ensure the
accuracy of the permit limits and to build a more robust hardness dataset.
10. Hardness and flow values used in the Reasonable Potential Analysis for this permit included:
Parameter
Value
Comments (Data Source)
Average Effluent Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
45.75
Effluent pollutant scans/DMR data
Average Upstream Hardness (mg/L)
[Total as, CaCO3 or (Ca+Mg)]
25.0
Default value
7Q10 summer (cfs)
0.0
Previous Fact Sheet
1Q10 (cfs)
0.0
RPA calculation
Permitted Flow (MGD)
1.9
Previous permit/Fact Sheet
Date: 10/30/2020
Permit Writer: Cassidy Kurtz
Page 4 of 4

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Fredrick D. Nelson. Town Manager
Town of Benson
303 E. Church Street
Benson, NC 27504
NORTH CAROLINA
Environmental Quality
February 24.2020
Subject: Compliance Evaluation Inspection
Benson WWTP
NPDES Permit NC0020389
Johnston County
Dear Mr. Nelson,
On Monday, February 17, 2020, Zach Thomas and Jason Robinson of the Raleigh Regional
Office of the Division of Water Resources conducted a compliance evaluation inspection of the
treatment facilities located at the Benson WWTP. The purpose of this inspection was to ensure
compliance with the subject NPDES permit. During the inspection. the presence and
cooperation of Brian Leavitt, Operator in Responsible Charge (ORC). Tim Robbins (Director of
PU), Steve Procter (B1 lORC & Lab Supervisor). Brian Gay and other staff was helpful and
appreciated.
The Benson WWTP is located at 770 Hannah Creek Road. Four Oaks, North Carolina. The
WW-4 facility is permitted and authorized to discharge 1.9 MGD of treated wastewater through
Outfall 001 into Hannah Creek. classified C-NSW, as part of the Neuse River Basin.
This NPDES compliance evaluation inspection consisted of the following:
• Review of the NPDES permit;
• Review of the owner: facility information;
• Review of ORC log books and other operation documents:
• Review of August 2018 = January 2020 monitoring data;
• Review of August 2018 January 2020 compliance history;
• On -site inspection of the laboratory:
• On -site inspection of the wastewater treatment units.
Findings during the inspection were as follows:
I. The current NPDES permit was issued effective on September 1, 2013, and expired on April 30,
2018. A copy was available on -site. The Division received the permit renewal application for the
facility on September 18, 2017 and is currently under review'.
North Carolina Department of Environmental Quality I Division of Water Resources
Raleigh Regional Offie 3800 Barrett Drive ^ Raleigh, North Carolina 27809
919 7914200

As listed in the subject permit, the treatment components include: one (1) arc bar screen, grit removal
system, dual manual bar screens, parshall flume with flow measurement, influent composite sampler,
three (3) influent screw pumps, three (3) oxidation ditches (Ditches #1 & #3 are used for aeration and
ditch #2 is kept anoxic for nutrient removal), five (5) secondary clarifiers, a return and waste sludge
pump station, five (5) tertiary filters, a chlorine contact basin (changed from gas to liquid since last
inspection), a dechlorination basin with post aeration, an effluent flow meter (used for reporting),
effluent composite sampler, one (1) concrete lined sludge lagoon (not currently aerated), and two (2)
stabilization lagoons/influent flow storage, and backup generator. Chemical feed systems (alum and
lime) are no longer used in treatment process.
3. For the review period August 2018 January 2020, DMR violations and enforcement actions
(Notices of Deficiency, Notices of Violation, or Civil Penalty Assessments) were issued. These
actions were handled in separate correspondence. During this inspection, DWR staff also evaluated
whether the remediation efforts requested from last inspection were performed. Many improvements
were made to the facility and are detailed in item ' 7 below.
4. The inspector compared February 2019 and Jul} 2019 DMR data against the bench and analytical
data. No discrepancies were noted. For the review period. Benson WWIP has been compliant with
its Whole Effluent Toxicity limit and monitoring requirements (July 2019 results indicated a "fail",
samples were collected the two following months and results indicated a "pass'').
5. The laboratory at Benson WWTP operates under field certification #196 and analyzes the following
parameters: pl-1, temperature, dissolved oxygen, chlorine, TP, TSS, fecal coliform, and conductivity.
All other parameters are analyzed by Environment 1 or Merited Inc. A brief inspection of the meter
calibration logs and standards showed the Benson WWTP laboratory to be compliant with record -
keeping requirements. Disposable NISI certified thermometers, hich are good for I year, are used
by the operators 10 measure temperature.
6. The ORC logbook was complete and contained detailed information that included daily clarifier
sludge levels, freeboard levels, etc. The 2019 Annual Report was provided and is akailable as of
January 2020 for review on the Town's websitc in addition to being posted at Town Hall.
7. The following treatment units were evaluated during this inspection:
a) Arc/manual bar screens: Debris is collected in a rolling trash bin, then placed in a dumpster and
picked up by waste management. The ORC has implemented a higher frequency of observation to
mitigate issues. During the inspection, the chain inside of the unit came undone and was attended
to immediately. The unit is noticeably older, rusted, and staff expressed a want to replace the
entire arc bar unit to increase efficiency.
h) Grit removal system: The unit «as offline and actively being rehabbed on the day of inspection.
It was scheduled to be brought back online that afternoon. Repairs were made to the concrete
floor and walls, surfaces of unit and motor were painted and coated to help prevent breakdown.
Please not f' this office when the writ is fill} broughl hack online.
c) Influent flow meter & sampler: The influent flow meter was last calibrated 8-30-2019 by
Clearwater. The sampler temperature was noted as 3.1 degrees Celsius. The previous inspection
noted that samples were being collected at a rate that did not meet permit requirements. The
sampler is now set to collect 120 mL samples and is flow proportional.

d) Screw pumps: 2 of the 3 screwy pumps were in operation. The other scree pumps motor was to
be replaced and staff are waiting on the part to arrive. Please llol (►'this office when the third
screw pump is brought back online.
e) Oxidation ditches: Ditches # 1 & #3 are used for aeration and Ditch #2 is kept anoxic for nutrient
removal. The previous inspection noted that multiple rotors were inoperable. Rotor # 1 in Ditch
#1 has been rehabbed. Concrete has been repaired and the motor has been replaced. An
electrical part is on order and will be installed shortly after to bring the rotor back online. All
other rotors appeared to be in working order; Ditch #2 did not have any rotors running due to it
being the designated anoxic zone.
f) Clarifiers: The previous inspection revealed only 3 of the 5 clarifiers were operable. Repairs
have been made and now all five clarifiers are in good working order. Sludge blankets are
measured and documented once per day and more frequently under inclement weather. Blanket
levels appeared to be compliant. Of the 5 clarifiers, 2 are 10 ft. in depth, 2 are 12 ft. in depth and
the larger is I5ft. in depth. Algae is cleaned from the weirs weekly or as needed and placed in the
sludge wasting pit to be sent to the sludge holding lagoon.
g) Sludge Pump Station: New pumps and electrical equipment were added or replaced in the pump
house to better regulate flow to the different treatment units and the lagoon.
h) Tertiary Filters: The previous inspection revealed that only 3 of the 5 filters were operable.
Repairs have been made and 4 of 5 are back online. The 5"' filter contains broken plates that are
no longer manufactured. Staff are looking into best options For bringing this unit back online.
All operable filters are backwashed on M, W, F or as needed and appeared to be operating
sufficiently.
i) Disinfection: Per the ORC, the plant has changed From using gas to liquid sodium hypochlorite
after discussing the change with Central Office staff. Waterguard is scheduled to supply material
every two weeks. The facility keeps a powder mix as a back-up. Estimated contact time in the
chamber is 30 minutes.
j) De -chlorination and post aeration: Calcium thiosulfate is added and the effluent is post aerated
by units from the bottom of the chamber. Waterguard also supplies this material.
k) Effluent flow meter & sampler: The effluent flow meter is used for reporting and was last
calibrated 8-30-2019 by Clearwater. The meter display showed 1.88 MGD at approximately.
1 1:40 AM. The sampler temperature was noted as 3.0 degrees Celsius. The previous inspection
noted that samples were being collected at a rate that did not meet permit requirements. The
sampler is now set to collect 120 mL samples and is now, proportional.
I) Standby Power: The generator on site is equipped to pro\ ide power for the entire plant. The unit
is manually tested. The ORC stated that it has been several months since a test was last
performed. D1PR staff recommended lusting auto -testing the generator on a regular basis and
periodically under load (with appropriate documentation) to ensure that it will function properft
w/iell necessary.
In) Treatment lagoons: The facility contains three (3) lagoons. Lagoon 1 is the larger lagoon
located on the SW side of the plant. It is clay lined with a concrete curtain and is used as an
equalization basin (flow is diverted from the hcadworks unit). Lagoon 2 is the smaller lagoon
located on the SE side of plant. Il is clay lined with a concrete curtain and is also used as an
equalization basin. The third lagoon is completely concrete and is used as sludge waste
containment with a capacity of approximately 3MG. It contains aerators, but are currently not in
use until more sludge can be removed. A prey ious inspection revealed an overflow that occurred
from the sludge lagoon, high freeboard levels, and excessive amounts of vegetation growing
inside of the units; this resulted in PC-2018-0019. Sludge has since been extracted from the
lagoons and cleanup efforts have been perforted. Staff stated that approximately 1500 tons of
sludge and vegetation have been removed from Lagoon #2. In addition, debris and sludge has
been removed from the sludge wasting lagoon itself. Facility staff stated that they anticipate

another round of debris removal from the lagoons in the coming months. Freeboard levels in
both EQ basins are checked daily and documented. At the time of inspection, freeboard levels in
the sludge lagoon were compliant. Please describe the location and process in which facility staff
checkfr•eebocwd levels daily to ensure compliance with the 2-foot freeboard requirements Stated
in A. (6). of the issued permit.
8. The inspector observed the effluent discharge to Hannah's Creek via the outfall pipe to be clear with
no observable solids or foam. No detrimental impacts from the effluent discharge were observed.
The area around the outfall pipe was clear and accessible. It appears to have a "Y-split" and
discharges from hvo separate outlets in the same location. Please ver fi> this cord describe loccrtiorr of
split.
9. The ORC and Public Utility Director stated that in addition to the cleanup of the lagoons, repair of the
rotors inside of the oxidation ditches and maintenance/replacement of screen units are a top priority.
Prioritizing these items will help ensure efficiency, help prevent damage to downstream units, and
protect the Town's recent investments at the treatment facility.
Please address the conditions outlined in numbers 7 (b, d, e, I, m) & 8 of this letter and
notify the inspector at the contact information below within 45 days of receipt of this letter.
if you have questions or comments about the inspection, this report or the requirements to take
corrective action (if applicable), please contact:
Zach Thomas at 919-791-4247 or via email at zachar\.tliomas :t ncdcni,eo..
Sincerely,
Scott Vinson
Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NCDEQ
Attachments: EPA Water Compliance Inspection Report
Cc: Brian Leavitt, ORC is email: blear itt a to« nolbenson.coni)
Tim Robbins, Public Utilities Director (via email: trobbins a to«notbenson.com)
RRO Files
Laserfiche

United States Environmental Protect`:_n Agen, y
EPA Washmgtan 0 C 20460
Water Compliance Inspection Report
—
Form Approved
OMB No 2040-0057
Approval expires 8-31-98
— Section A: National Data System Coding (i e . PCS)
Transaction Code NPDES yr'molday Inspection
1 U 2 u 3 1 NC0020389 111 121 20102.17 117
Type
18 r. j
I I 11II1I11111
Inspector Fac Type
19W 20I I
211111II 1 1 I I I 1 1 I 1 I 1 1 1 1 I I 1 1 1 I 1 1 1
r6
Inspection Work Days Facility Self -Monitoring Evaluation Rating B1 OA
671 I 70 LL—I 71 Li 72 uU )
Reserved
731 1 174 75I
!
1 I 1 1 1 1 180
Section B: Facility Data
Name and Location of Facility Inspected (For industrial Users discharging to POTW also inriude
POTW name and NPDES permit Number)
Benson WWTP
770 Hannah Creek Rd
Benson NC 27504
Entry Time/Dale
10 OOAfvT 20/02/17
Perm I Effective Date
13109/01
Exit Time/Date
12 15PM 20/02/17
Permit Expiration Date
18/0430
Name(s) of Onsite Representative(s)ITilles(s)/Phone and Fax Number(s)
Ill
Brian Peter LeavittIORC1919-894-2373!
Other Facility Data
Name, Address of Responsible OlficialtTitle&Phone and Fax Number
Ccntacled
Keith Ryker Langdon,PO Box 69 Benson NC 275040069/Town
Manager/919-894-4953/9198941283 No
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 1.1 Flow Measurement • Operations & Maintenance MI Records/Reports
Self -Monitoring Program Sludge Handling Disposal Facility Site Review Compliance Schedules
Ellluent/Receiving Waters II Laboratory
Section D: Summary of FindinglComments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature of inns4 inspector s) Agency/Office/Phone and Fax Numbers
Jason T Robinson
obinson clv ! ✓ DWRIRRO WQI919-791-4200/
Zachary Thomas DWRIRRO WQ1919-791.4200/
Date
a j2.r'if zd
f6 PI -+4`f LL LO
Signature of M nagement 0 A Reviewer Agency/Office/Phone and Fax Numbers Dale
,/Z y/ZJ 20
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Pagep 1

NPDES yrlmolday Inspection Type
31 NC0020389 111 121 20/02f17 117 18 j r
1
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
Please see report for details.
l�ageP. 2

Permit: NC0020389 Owner - Facility: Benscn WWTP
Inspection Date: 02/17.2020 Inspection Type: Compliance Evaluation
Compliance Schedules Yes No NA NE
Is there a compliance schedule for this facility? 000111
Is the facility compliant with the permit and conditions for the review period"? • ❑ ❑ ❑
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? ❑•❑ ❑
Is access to the plant site restricted to the general public? • ❑ ❑ ❑
Is the inspector granted access to all areas for inspection? •❑ ❑ ❑
Comment: The Division received the permit renewal application for the facility on September 18, 2017
and is currently under review.
Record Keeping Yes No NA NE
Are records kept and maintained as required by the permit? 110 ❑ ❑
Is all required information readily available, complete and current? • ❑ ❑ ❑
Are all records maintained for 3 years (lab. reg. required 5 years)? • ❑ ❑ ❑
Are analytical results consistent with data reported on DMRs? 1110 ❑ ❑
Is the chain -of -custody complete? • 0 0 0
Dates, times and location of sampling 0
Name of individual performing the sampling ❑
Results of analysis and calibration ❑
Dates of analysis ❑
Name of person performing analyses 0
Transported COCs 0
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 0 0 • 0
on each shift?
Is the ORC visitation log available and current? 12000
Is the ORC certified at grade equal to or higher than the facility classification? •❑ ❑ ❑
Is the backup operator certified at one grade Tess or greater than the facility classification? • ❑ ❑ ❑
Is a copy of the current NPDES permit available on site? • 0 0 0
Page# 3

Permit: NC0020389
Owner - Facility: Benson WWTP
inspection Date: 02/17/2020 Inspection Type: Compliance Evaluation
Record Keeping
Facility has copy of previous year's Annual Report on file for review?
Comment:
Yes No NA NE
❑ ❑ ❑
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? • ❑ ❑ ❑
Does the facil.ty analyze process control parameters, for ex: MLSS, MCRT, Settleable 1 ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment;
Laboratory
Are field parameters performed by certified personnel or laboratory?
Are all other parameters(excluding field parameters) performed by a certified lab?
# Is the facility using a contract lab?
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
Incubator (BOD) set to 20.0 degrees Celsius +1- 1.0 degrees?
Comment: Field Cert # 196: some parameters are analyzed by Environment 1 or Meritech.
Influent Sampling
# 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 temperature was noted as 3.1 degrees Celsius.
Flow Measurement - Influent
# Is Flow meter used for reporting?
!s flow meter calibrated annually?
Is the flow meter operational?
(If units are separated) Does the chart recorder match the flow meter?
Yes No NA NE
MOOO
1 ❑ ❑ ❑
® ❑ ❑ ❑
• ❑ ❑ ❑
N ❑ ❑ ❑
❑ ❑ 1i ❑
Yes No NA NE
z 0 ❑ ❑
a ❑ OD
® ❑ DO
• ❑ OD
• ❑ DO
® ❑ DO
Yes No NA NE
❑ 1100
1 ❑ ❑ ❑
11000
DOMO
Pageff 4

Permit: NC00203139 Owner - Facility: Belson WWTP
Inspection Date: 02117 2020 Inspection Type; ` urevliance Evaluation
Flow Measurement - Influent Yes No NA NE
Comment: The influent flow meter was last calibrated 8-30-2019 by Clearwater.
Bar Screens
Type of bar screen
a.Manual
b.Mechanical
Are the bars adequately screening debris?
Is the screen free of excessive debris?
Is disposal of screening in compliance?
Is the unit in good condition?
Yes No NA NE
•
•
■ D ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
■ ❑❑❑
Comment: Debris is collected in a rolling trash bin, then placed in a dumpster and picked up by waste
management.
The ORC has implemented a higher frequency of observation to mitigate issues.
During the inspection, the chain inside of the unit came undone and was attended to
immediately.
The unit is noticeably older, rusted, and staff expressed a want to replace the entire arc bar
unit to increase efficiency.
Grit Removal
Type of grit removal
a.Manual
b.Mechanical
Is the grit free of excessive organic matter?
Is the grit free of excessive odor?
# Is disposal of grit in compliance?
Yes No NA NE
Comment: The unit was offline and actively being rehabbed on the day of inspection. It was scheduled
to be brought back online that afternoon. Repairs were made to the concrete floor and
walls, surfaces of unit and motor were painted and coated to help prevent breakdown. Staff
is to notify DWR when brought back online.
Equalization Basins Yes No NA NE
Is the basin aerated? ❑ ❑•❑
Is the basin free of bypass lines or structures to the natural environment? ❑ ❑ ❑
Is the basin free of excessive grease? • ❑ ❑ ❑
Are all pumps present? ❑ ❑
Are all pumps operable? • ❑ ❑ ❑
Are float controls operable? 000IM
Page# 5

Permit: NC0020389
Owner - Facility: Benson WWTP
Inspection Date: 02/17/2020 Inspection Type: Compliance Evaluation
Equalization Basins Yes No NA NE
Are audible and visual alarms operable?
# Is basin size/volume adequate?
❑ ❑ ❑ •
• ❑ ❑ ❑
Comment: Freeboard levels in both EQ basins are checked daily and documented. Staff are to
describe location and process in which freeboard levels are checked to ensure permit
compliance. See report for more details.
Lagoons
Type of lagoons?
# Number of lagoons in operation at time of visit?
Are lagoons operated in?
# Is a re -circulation line present?
Is lagoon free of excessive floating materials?
# Are bathes between ponds or effluent bathes adjustable?
Are dike slopes clear of woody vegetation?
Are weeds controlled around the edge of the lagoon?
Are dikes free of seepage?
Are dikes free of erosion?
Are dikes free of burrowing animals?
# Has the sludge blanket in the lagoon (s) been measured periodically in multiple
locations?
# If excessive algae is present, has barley straw been used to help control the growth?
1s the lagoon surface free of weeds?
Is the lagoon free of short circuiting?
Comment: An evaluation of the lagoon depths was performed on 4-23-2019.
Grass area along edge is well maintained.
See report for more details.
Aerobic Digester
Is the capacity adequate?
Is the mixing adequate?
Is the site free of excessive foaming in the tank?
# Is the odor acceptable?
# Is tankage available for properly waste sludge?
Comment:
Yes No NA NE
Facultative
3
Parallel
II❑❑❑
❑ ❑ ❑
❑ ❑ E1❑
• ❑ ❑ ❑
MOOD
• ❑ ❑ ❑
• ❑❑❑
• ❑ ❑ ❑
• ❑ ❑ ❑
DLJEJ
MI ❑ ❑ ❑
Yes No NA NE
• ❑ ❑ ❑
❑ ❑
MOOD
HOOD
• ❑ ❑ ❑

Permit: NC0020: 89 Owner - Facility. Br, nson WWTP
Inspection Date: 02117:2020 Inspection Type:=mPliance Evaluation
Secondary Clarifier
Is the clarifier free of black and odorous wastewater?
Is the site free of excessive buildup of sol ds in center well of circular clarifier)
Are weirs level?
Is the site free of weir blockage?
Is the site free of evidence of short-circuiting?
Is scum removal adequate?
Is the site free of excessive floating sludge?
Is the drive unit operational?
Is the return rate acceptable (low turbulence)?
Is the overflow clear of excessive solids+pin floc?
Is the sludge blanket level acceptable? (Approximately ': of the sidewail depth)
Yes No NA NE
▪ ❑ ❑ ❑
■ ❑❑❑
▪ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
11000
■ ❑❑❑
• ❑ ❑ ❑
11000
▪ ❑ ❑ ❑
Comment: All five clarifiers are in good working order. Sludge blankets are measured once per day and
more frequently under inclement weather. Blanket levels appeared to be compliant. Of the
5 clarifiers. 2 are 10 ft. in depth, 2 are 12 ft. in depth and the larger is 15ft. in depth. Algae is
cleaned from the weirs weekly or as needed and placed in the sludge wasting pit to be sent
to the sludge holding lagoon.
Oxidation Ditches Yes No NA NE
Are the aerators operational? •❑ ❑ ❑
Are the aerators free of excessive solids build up? 1.0 ❑ ❑
# Is the foam the proper color for the treatment process? C ❑ ❑ ❑
Does the foam cover less than 25% of the basin's surface? ❑ ❑
Is the DO level acceptable? • ❑ ❑ ❑
Are settleometer results acceptable (> 30 minutes)? ❑ ❑ 0111
Is the DO level acceptable?(1.0 to 3.0 mg/I) • 0 0 ❑
Are settelometer results acceptable?(400 to 800 mill in 30 minutes) 0 ❑ ❑
•
Comment: Rotor #1 in Ditch #1 has been rehabbed. Concrete has been repaired and the motor has
been replaced. An electrical part is on order and staff is to notify DWR when it is back
online. All other rotors appeared to be in working order: Ditch #2 did not have any rotors
running due to it being the designated anoxic zone.
Nutrient Removal Yes No NA NE
# Is total nitrogen removal required? • ❑ ❑ ❑
# Is total phosphorous removal required? • ❑ ❑ ❑
Type Biological
# Is chemical feed required to sustain process? •❑ ❑ ❑
Page# 7

Permit: NC0020389 Owner - Facility: Benson WWTP
Inspection Dale: 02/17/2020 Inspection Type: Compliance Evaluation
Nutrient Removal
Is nutrient removal process operating properly?
Comment: Alum and Lime are no longer used at the facility.
Yes No NA NE
■❑❑❑
Filtration (High Rate Tertiary) Yes No NA NE
Type of operation: Down flow
is the filter media present? • ❑ ❑ ❑
Is the filter surface free of clogging? M ❑ ❑ ❑
Is the filter free of growth? ROOD
Is the air scour operational? MID ❑ ❑
Is the scouring acceptable? • ❑ ❑ ❑
Is the clear well free of excessive solids and filter media? M ❑ ❑ ❑
Comment: 4 of 5 filters are online. The 5th filter contains broken plates that are no longer
manufactured. Staff are continuing to look into best options for bringing this unit back online.
All operable filters are backwashed on M, W, F or as needed and appeared to be operating
sufficiently.
Solids Handling Equipment Yes No NA NE
Is the equipment operational? ❑ ❑ 1.❑
1s the chemical feed equipment operational? ❑ ❑ E ❑
Is storage adequate? ❑ ❑ 1 ❑
Is the site free of high level of solids in filtrate from filter presses or vacuum Biters? ❑ CEO
Is the site free of sludge buildup on belts and:or rollers of filter press? 011.0
Is the site free of excessive moisture in belt filter press sludge cake? ❑ ❑ M ❑
The facility has an approved sludge management plan? ® ❑ ❑ ❑
Comment: New pumps and electrical equipment were added or replaced in the pump house to better
regulate flow to the different treatment units and the lagoon.
Disinfection -Liquid
Is there adequate reserve supply of disinfectant?
(Sodium Hypochlorite) Is pump feed system operational?
Is bulk storage lank containment area adequate? (free of leaks open drains)
Is the level of chlorine residual acceptable?
Is the contact chamber free of growth, or sludge buildup?
Is there chlorine residual prior to de-chlorinat on?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
❑ ❑ ❑ II
• ❑ ❑ ❑
• ❑ ❑■
Page# 8

Permit: NC0020389
Owner - Facility: Benacn WWTP
Inspection Date: 02/17 2020 Inspection Type. .,mpl:ance E=valeat:on
Disinfection -Liquid
Yes No NA NE
Comment: Per the ORC, the plant has changed from using gas to liquid sodium hvpochlorite after
discussing the change with Central Office staff. Waterquard is scheduled to supply material
every two weeks. The facility keeps a powder mix as a back-up. Estimated contact time in
the chamber is 30 minutes.
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?
Yes No NA NE
Liquid
• ❑ ❑ ❑
II ❑ ❑ ❑
• ❑ ❑ ❑
EJDD
Comment: Calcium thiosulfate is added and the effluent is post aerated by units from the bottom of the
chamber. Waterquard also supplies this material.
Are tablet de -chlorinators operational?
Number of tubes in use?
Comment:
Flow Measurement - Effluent
# Is flow meter used for reporting?
Is flow meter calibrated annually?
Is the flow meter operational?
(If units are separated) Does the chart recorder match the flow meter?
0 0 II El
0
Comment: The effluent flow meter is used for reporting and was last calibrated 8-30-2019 by
Clearwater. The meter display showed 1.88 MGD at approximately 11:40 AM.
Effluent Pipe
Is right of way to the outfall properly maintained?
Are the receiving water free of foam other than trace amounts and other debris?
If effluent (diffuser pipes are required) are they operating properly?
Yes No NA NE
110
▪ ❑ ❑ ❑
O EMECO
Oil
Yes No NA NE
▪ ❑ ❑ ❑
▪ ❑ ❑ ❑
❑ ❑ °i❑
Comment: Outfall appears to have a "Y-split" and discharges from two separate outlets in the same
location. Staff is requested to verify and describe location of split.
Effluent Sampling Yes No NA NE
Is composite sampling flow proportional? 1 ❑ ❑ ❑
Is sample collected below all treatment units? • ❑ ❑ ❑
Is proper volume collected? • ❑ ❑ ❑
Pagel

Penult: NC0020389
Owner - Facility: Benson WWTP
Inspection Date: 02/17/2020 Inspection Type: Compliance Evaluation
Effluent Sampling Yes No NA NE
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 MOOCI
representative)?
® ❑ ❑ ❑
11000
Comment: The sampler temperature was noted as 3.0 degrees Celsius. The previous inspection noted
that samples were being collected at a rate that did not meet permit requirements. The
sampler is now set to collect 120 mL samples and is flow proportional.
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?
Is there an emergency agreement with a fuel vendor for extended run on back-up power?
Is the generator fuel !eve! monitored?
Yes No NA NE
• ❑ ❑ ❑
1•❑ ❑ ❑
DDD
❑ i ❑ ❑
® ❑ ❑ ❑
❑•00
E ❑ ❑ ❑
Comment: The generator on site is equipped to provide power for the entire plant. The unit is manually
tested. The ORC stated that it has been several months since a test was last performed.
DWR staff recommended testing/auto-testing the generator on a regular basis and
periodically under load (with appropriate documentation) to ensure that it will function
properly when necessary.

Permit No. 9 1,21) .307
Dutfall et, a -
Annual Monitoring and Pollutant Scan
Facility Name Town of Benson WWTP
Date of sampling _4/ 12 / 17
Analytical Laboratory Enviroment One
Month
Year
ORC David Paul Allen
Phone [phone]
. ..... .
Paraxneter
Parameter
Code
Sample
Type
Analytical
Method
.
Qrxantrtation
Level
Sample
Result
Units of
Measurement
Ammonia (as N)
C0610
Composite
SM4500H113
0.26
tog/1
Chlorine (total residual, TRC)
50060
Grab
SM4500CLE
<10
ug/1
Dissolved Oxygen
00300
Grab
SM4500 ❑G
8.75
mg/ 1
Nitrite plus Nitrate Total (as N)
00630
Composite
EPA353.2
0.89
rn.g/1
Total Kjeldahl Nitrogen
00625
Composite
EPA351.2
0.84
mg/1
Oil and Grease
00556
Grab
SM5520B
<6
mg/1
Total Phosphorus
C0665
Composite
SM4500P
1.2
mg/1
Total Dissolved Solids
70295
Composite
EPA160.1
<2.5
mg/1
Hardness
00900
Composite
SM2340C
40
mg/1
Metals (total recoverable), cyanide and total phenols..
pes
Antimony
01097
Composite EPA204.2
<3.0
ug/1
Arsenic
Beryllium
Cadmium
Chromium
01002
01012
01027
01034
Composite EPA206.2
Composite EPA200.7
Composite EPA213.2
Composite EPA200.7
<5.0
<1.0
<1.0
<5.0
ug/1
ug/1
ug/1
ug/ 1
Copper
01042
Composite EPA220.1
<10
ug/1
Lead
01051
Composite EPA239.2
<5.0
ug/1
Mercury (Method 1631E)
COMER
Composite EPA 1631
<0.001
ug/ I
Nickel
01067
Composite EPA200.7
<10
ug/1
Selenium
01147
Composite EPA270.2
<10
ug/ 1
Silver
01077
Composite EPA200.7
<5.0
ug/1
Thallium
01059
Composite EPA279.2
<1.0
ug/1
Zinc
01092
Composite EPA289.1
42
Cyanide
00720
Grab SM4500CNE
<0.005
ug/1
ug/1
Total phenolic compounds
32730
Grab SM51. OA&B
5
ug/1
Volatile urganicycompounds
Aerolein
34210
Grab
EPA624
<100.00
ug/1
Acrylonitrile
34215
Grab
EPA624
<50
ug/1
Benzene
34030
Grab
EPA624
<5.0
ug/1
Bromoform
32104
Grab
EPA624
<5.0
ug/I
Carbon Tetrachloride
32102
Grab
EPA624
<5.0
ug/1
Chlorobenzene
34301
Grab
EPA624
<5.0
ug/1
Chlorodibromomethane
34306
Grab
EPA624
<5.0
ug/1
Chloroethane
85811
Grab
EPA624
<10
ug/I
2-chloroethyl vinyl ether
34576
Grab
EPA624
<5.0
ug/1
Chloroform
32106
Grab
EPA624
<5.0
ug/1
Dichlorobrornomethane
32101
Grab
EPA624
<5.0
ug/1
1,1-dichloroethane
34496
Grab
EPA624
<5.0
ug/1
1,2-dichloroethane
32103
Grab
EPA624
<5.0
ug/1
Trans-1,2-dichloroethylene
34546
Grab
EPA624
<5.0
ug/1
Form - DMR- PPA-1
Page 1

Annual Monitoring and Pollutant Scan
Month
Year
Permit No.
Outfall
.:.. •,� - - •,�,:� x• �'� �'�_ �`� �,:::_::-'::':.> :::.::::.
.7,
.....,;,;;i' ,:. -',:::
...
-:Paramefier'
,:.Cole::.::.::
.:, Sa3mple .:.'.
e::.::....
- Analytical
Method
Quantrtation:.:
Level
- ::.Sample
Result
n 's n >.::=..
Measurement
1,1-dichloroethylene
34501
Grab
EPA624
<5.0
ug/1
1,2-dichlaropropane
34541
Grab
EPA624
<5.0
ug/1
1,3-dichloropropylene
77163
Grab
EPA624
<5.0
ug/1
Ethylbenzene
34371
Grab
EPA624
<5.0
ug/1
Methyl Bromide
34413
Grab
EPA624
<10
ug/1
Methyl Chloride
34418
Grab
EPA624
<5.0
ug/1
Methylene Chloride
34423
Grab
EPA624
<10
ug/1
1,1,2,2-tetrachloroetharie
81549
Grab
EPA624
<5.0
ug/1
Tetrachloroethylene
34475
Grab
EPA624
<5.0
ug/1
Toluene
34010
Grab
EPA624
<5.0
ug/1
1,1,1-trichloroethane
34506
Grab
EPA624
<5.0
ug/1
1,1,2-trichloraethane
34511
Grab
EPA624
<5.0
ug/1
Trichloroethylene
39180
Grab
EPA624
<5.0
ug/1
Vinyl Chloride
39175
Grab
EPA624
<10
ug/1
�,..,.,:-..�..- `i--.P-+3=:..-3Zs
•
-
58,
3`.TL.:.. s
Pns :s a-++•7!r;'.xI
_... I F
// ,,xx :sir"..
- 4... `?�3 �
r�-ram-- -- -
r��..
F
.�-: F
3 9CX
.q; . a•'i , 4?i
{
�tF:=a ': .sE
vv �}.¢'
.-i.�f�9:'; �%}�3•'�`e3-..§.
�':�iS'Y��'.:
� s.-. 3 3
e¢ yai
" .'S'i i >e
y��
}�;ri1;:
J `-,
��3
,.
.:.c.:
k
. - : 1:',
•-•:M.t x�
:•'��:3..��-
sY' s:'•
-:x�i-.r.x.,..-.._..•..
s. s.....r::.:^n •:,: .::.,:.
P-chloro-to-creso
34452
Grab
EPA625
<20
ug/1
2-chlorophenol
34586
Grab
EPA625
<10
ug/1
2,4-dichlorophenol
34601
Grab
EPA625
<10
ug/1
2,4-dimethylphenol
34606
Grab
EPA625
<10
ug/1
4,6-dinitro-o-cresol
34657
Grab
EPA625
<50
2,4-dinitrophenol
34616
Grab
EPA625
<50
ug/1
2-nitrophenol
34591
Grab
EPA625
<10
ug/1
4-nitrophenol
34646
Grab
EPA625
<50
ug/1
Pentachlorophenol
39032
Grab
EPA625
<50
ug/1
Phenol
34694
Grab
EPA625
<10
ug/1
2,4,6-trichloropherol
34621
Grab
EPA625
<10
ug/1
14$0" neutral compounds;,:::
Acenaphthene
34205
Grab
EPA625
<10
ug/1
Acenaphthylene
34200
Grab
EPA625
<10
ug/1
Anthracene
CO220
Grab
EPA625
< 10
ug/
Benzidine
39120
Grab
EPA625
<100
ug/1
Benzo(a)anthracene
34526
Grab
EPA625
<10
ug/1
Benzo(a)pyrene
34247
Grab
EPA625
<10
ug/1
3,4 benzofuoranthene
34230
Grab
EPA625
<10
ug/1
Benzo(ghi}perylene
34521
Grab
EPA625
<10
ug/1
Benzo(k)fluoranthene
34242
Grab
EPA625
<10
ug/1
Bis (2-chloroethoxy) methane
34278
Grab
EPA625
< 10
ug/1
Bis (2-chloroethyl) ether
34273
Grab
EPA625
<10
ug/1
Bis (2-chloroisopropyI) ether
34283
Grab
EPA625
<10
ug/1
Bis (2-ethylhexyl) phthalate
39100
Grab
EPA625
<20
ug/1
4-bramophenyl phenyl ether
34636
Grab
EPA625
<10
ug/1
Butyl benzyl phthalate
34292
Grab
EPA625
<10
ug/I
2-chloronaphthalene
34581
Grab
EPA625
<10
ug/I
4-chlorophenyl phenyl ether
34641
Grab
EPA625
<10
ug/ I
Chrysene
34320
Grab
EPA625
<10
ug/1
Form - DMR PPA-1
Page 2

Annual Monitoring and Pollutant Scan
Permit No.
Outfall
Month
Year
Parameter :>;= ` ;;:;:::::::::: :.:.;: ;
Parameter
: Code
Sample
Type,,
Analytical
Method
Quantitation
Level
Sample
Result
Units of
Measurement
Di-E.-butyl phthalate
39110
Grab
EPA625
<10
10
ug/1
Di-n-octyl phthalate
34596
Grab
EPA625
<10
ug/j
Dibenzo(a,h)anthracene
34556
Grab
EPA625
<10
ug/1
1,2-dichlorobenzene
34536
Grab
EPA625
<10
ug/1
1,3-dichlorobenzene
34566
Grab
EPA625
<10
ug/1
1,4-dichlorobenzene
34571
Grab
EPA625
<10
ug/1
3,3-dichlorobenzidine
34631
Grab
EPA625
<10
ug/1
Diethyl phthalate
34336
Grab
EPA625
<10
ug/1
Dimethyl phthalate
34341
Grab
EPA625
<10
ug/I
2,4-dinitrotoluene
34611
Grab
EPA625
<10
ug/1
2,6-dinitrotoluene
C0626
Grab
EPA625
<10
ug/I
1,2-diphenylhydrazine
34346
Grab
EPA625
<10
ug/1
Fluoranthene
C0376
Grab
EPA625
<10
ug/1
Fluorene
34381
Grab
EPA625
r 10
ug/1
Heyachlorobenzene
C0700
Grab
EPA625
<10
ug/1
Hexachlorobutadiene
39702
Grab
EPA625
<10
ug/1
Hexachiorocyclo-pentadiene
34386
Grab
EPA625
<10
ug/1
Hexachloroethane
34396
Grab
EPA625
<10
ug/1
Indeno(1,2,3-cd)pyrene
34403
Grab
EPA625
<10
ug/1
Isophorone
34408
Grab
EPA625
<10
ug/1
Naphthalene
34696
Grab
EPA625
<10
ug/1
Nitrobenzene
34447
Grab
EPA625
<10
ug/1
N-nitrosodi-n-propylamine
34428
Grab
EPA625
<10
ug/1
N-nitrosodimethylamine 34438
Grab
EPA625
<10
ug/ I
N-nitrosodiphenylamine 34433
Grab
EPA625
<10
ug/1
Phenanthrene 34461
Grab
EPA625
<10
ug/1
Pyrene 34469
Grab
EPA625
<10
ug/1
1,2,4,-trichlorobenzene 34551
Grab
EPA625
<10
ug/1
"I certify, under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance
with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my
inquiry of the person or persons who managed the system, or those persons directly responsible for gathering the information, the
information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant
penalties for submitting false information, including the possibility of fines and imprisonment for knowing violations."
Authorized Representative name
Signature
Date
Form. - DMR- PPA-1
Page 3

ERN° CM
EcompatiNd
11:4::::OA.I WON 1'::UHIVE•.:,.
•`GREEN V ILLEi. N. J 2i85$
TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OAKS ,NC 27524
PARAMETERS
Total 1jjeldahl Nitrogen as N,mg11
Nitrate -Nitrite as N, mg/1
Oil & Grease (HEM), tng/l
Phenol, ug/I
Total Cyanide, mg/1
Total Hardness, mg/1
Total Dissolved Residue, mg/1
Antimony, ug/1
Arsenic, ug/1
Beryllium, ug/1
Cadmium, ug/1
Total Chromium, ug/1
Copper, ug/1
Lead, ug/I
Nickel, ug/1
Selenium, ug/1
Silver, ug/1
Thallium, ug/I
Zinc, ug/1
Effluent Analysis Method
Date Analyst Code
1.11 09/27/18 TLH 351.2 R2-93
2.07 09/25/18 BLD 353.2 R2-93
<5 09/19/18 SEJ 1664E
<5 09/18/18 SEJ 420.1-78
<0.005 09/19/18 SEJ 4500CNE-11
64 09/17/18 HMM 2340C-11
240 09/13/18 3 B-I 2540C-11
4 10/08/18 LFJ EPA200.8
<5.0 09/25/18 MTM 3113E-10
<1.0 09/24/18 LFJ EPA200.7
<1.0 09/26/18 MTM 3113E-10
<5.0 09/24/18 LFJ EPA200.7
<10 09/24/18 LFJ EPA200.7
<5.0 09/29/18 MTM 3113E-10
<10 09/24/18 LFJ EPA200.7
<10 09/27/18 MTM 3113B-10
<5.0 09/24/18 LFJ EPA200.7
<1.0 10/08/18 LFJ EPA200.8
47 09/24/18 LEI EPA200.7
[FAX (252} 756 0633 ;
ID : 388 J
DATE COLLECTED: 09/12/18
DATE REPORTED : 10/30/18
REVIEWED BY:

wilreaugrA i
umpoQmloc
4 OAK ii N DR1VE
G EE VJLLE,-N C 2785 3
CLIENT: TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOt.R OAKS, NC 27524
REVIEWED BY:
CLIENT ID:
.PIONS-s
FAX (252) Th&0633:
388 J
ANALYST: ZAP
DATE COLLECTED: 09/12/18
DATE ANALYZED: 09/13/18
DATE REPORTED: 10/30/18
VOLATILE ORGANICS
EPA METHOD 624.1
Effluent
PARAMETERS, ug/1
1. Chloromethane
2. Vinyl Chloride
3. Bromomethane
4. Cliloroethane
5, Trichlorofluoromethane
6. 1,1-Dichloroethane
7. Methylene Chloride
8. trans-1,2-Dichioroethene
9. 1,1 -Dichloroethen e
10. Chloroform
11. 1,1,1-Trichloroethane
12. Carbon Tetrachloride
13. Benzene
14. 1,2-Dichloroethane
15. Trichloroethene
16. 1,2-Dichlo ropropane
19, Bromodichloromethane
18. 2-Chloroethylvinyl Ether
19. cis-1,3-Dichloropropene
20. Toluene
21, trans-1,3-Dichloropropene
22. 1,1,2-Trichloroethane
23. Tetrachloroethene
24. Dibramochloromethane
25. Chlorobenzene
26. Ethylbenzene
27. Bromoform
28, 1 ,1,2 ,2-Tetrachloroethane
29. 1,3-Dichlorobenzene
30. 1 ,4-Dichloroben z ene
31. 1 ,2-D ichlorobenzene
32. Acroiein
33. Acrylonitrile
< 10.00
10.00
C 10.00
C 10.00
<5.00
< 5.00
10.00
< 5.00
< 5.00
C5.00
<5.00
C 5.00
<5.00
C 5.00
C 5.00
5.00
S.00
S.00
C5.00
<5.00
<5.00
<S.00
<5.00
<5.00
5.00
<5.00
<5.00
C 5.00
<5.00
C 5.00
<5.00
<100.00
C 50.00

A-i3t fir [ moBR 1
BOITp@Vgbg
1 4:OAKMoNF DRIVE::..;.
GREENVILLE2Th5
CLIENT: TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OAKS, NC 27524
REVIEWED BY:
SEMIVOLATILE ORGANICS
EPA METHOD 625.1
CLIENT ID:
inking [hater :7; 37715
Waatewate= :0
HONE (252; : 206
FAX (252y : b6-€3633
388.7
ANALYST: OAP
DATE COLLECTED: 09/12/18
DATE EXTRACTED: 0 9 / 17 / 18
DATE ANALYZED: 09/21/18
DATE REPORTED: 10/30/18
Effluent
PARAMETERS, nil
1. N-Nitrosodimethylemine
2. Phenol
3. Bis(2-Chloroethyl) Ether
4. 2-Chlorophenyl
5. 1,3-Dichlorobenzene
6. 1,4-Dichlorobenzene
7. 1,2-Dichlorohenzene
8. Bis(2-Chloro-l-methylethyl) Ether
9. Hexachloroethane
10. N-Nitroso-Di-N-Propylamine
11. Nitrobenzene
12. Isophorone
13. 2-Nitropheuol
14. 2, 4-Dimethy l phe nol
15. Bis(2-Chloroethoxy) Methane
16. 2,4-Dichlorophenol
17. 1,2,4-Trichlorobenaene
18. Naphthalene
19. Hexachlarobutadiene
20. 4-Chloro-3-Methylphenol
21. Hexachlorocyclopentadiene
22. 2,4,6-Trichlo rophenol
23. 2-Chlorouaphthalene
24. Acenaphthylene
25. Dimethylphthalate
26. 2,6-Dinh rntoluene
27. Acenaphthene
28. 2,4-Dinitrophenol
29. 4-Nitrophenol
30. 2,4-Dinitrototuene
31. Fluorene
32. Diethylphthalate
33. 4-Chlorophenyl Phenyl Ether
34. 4, 6-Dinitro-2-Methylph enol
35. N-Nitrosodiphenylamine
36. 4-Broniophenyl Phenyl Ether
37. Hexachlorobenzene
38. Pentachlorophenol
39. Phenanthrene
40. Anthracene
41. Di-N-Butytphthalate
42. Fluoranthene
43. Benzidme
44. Pyrene
45. Butylbenzylphthlate
46. Benzo[alanthracene
47. 3,3-Dicblorobenzidine
48. Chrysene
C 10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<20.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<10.00
<50.00
<50.00
<10.00
<10.00
<10.00
<10.00
<50.00
<10.00
<10.00
<10.00
<50.00
<10.00
<10.00
<10.00
<10.00
< 100,00
<10.00
<10.00
<10.00
<10.00
<10.00
Page: 1

md
ENglirffinr-oll fIIJI .:�'�`.'i EJ j, e V
`:IOAKMONTipF l' E
REE VtLLE;`.l_C7€ q
CLIENT: TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OARS, NC 27524
REV'IEp9ED BY :
SEMIVOLATILE ORGANICS
EPA METHOD 625.1
CLIENT ID:
ON [phone]
:FAX :[phone]
389 J
ANALYST: JAP
DATE COLLECTED: 09/12/16
DATE EXTRACTED: 09/17/18
DATE ANALYZED: 09/21/18
DATE REPORTED: 10/30/18
PARAMETERS, ug/I
Effluent
49.
Bis(2-Ethylhexyl)phthalate
<20.00
50.
Di-N-Octylphthalate
<10.00
51.
Benzo[bltiuoranthene
<10.00
52.
Benzo[k]tluoranthene
C 10,00
53.
Benzo[a]pyrene
<10.00
54.
Indeno(1,2,3-C,d)pyrene
<10.00
55.
Dibenzo[a,h]anthracene
<10.00
56.
Benzo[g,h,ilperylene
<10.00
57.
.1,2-Diphenylhydrazine
<10.00
Page; 2

Environment 1, Inc.
P.O. EttlX7,8'5, 114 Oakmont Dr.
Greenville, NC 27858
environrentlinc.cosn
Phone [phone]'• Fax [phone]
CLIENT: 388 J Week: 33
TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OAKS NC 27524
[phone]
LSAMPLE LOCATION
Effluent
COLLECTION
DATE
11ME
4"5 fit)
P DISINFECTION
CHAIN OF CUSTODY RECORD
Gn
uuv akc'h42,14w12--(-1,
❑ CHLORINE
rj NONE
15
G G
Page 1 of
1
CHLORINE NEUTRALIZED AT COLLECTION
GP P PP GG
G
7271
G G
72- pH CHECK (LAB)
G CONTAINER TYPE, PIG
C C C
44 C
CDC A A A A
ra
� W
z
A
A
4
EPA 624 (APA)
624 DupliratP 1
CHEMICAL PRESERVATION
1-
0,
thj
5
A -NONE D•NAOH
8-HNO3
C - itSO4
E•HCL
F - ZINC ACETATEINAOH
G • NATHIOSULFATE
CLASSIFICATION:
WASTEWATER (NPDES)
DRINKING WATER
DWOJGW
SOLID WASTE SECTION
CHAIN OF CUSTODY (SEAL) MAINTAINED
OURINIPMENT/DELIVERY
RELINQUISHED BY (SIG.) ( AMPLER) DATE/TIME
DATET1 E
31 INOUISHED B
G.)
eFt QUISH Bile(a)
DATE(TIME
R s EKED BY
RECEIVE r BY
RECEIVED BY (SIG.)
DATE/TIME
Vaik F J 5
DATE/TIME
DATFJII flME
'4,0
COMMENTS:
SAMPLES COLLECTED BY:
(Please Print) \A �7 A i A:. c;ke-
SAMPLESRECEIVED IN LABAT ! �c
oC
FORM 05
PLEASE READ Instructions for completing this form on the reverse side.
Samp)er must pace a "C" for composite sample or a "G" for
Grab sample in the blocks above for each parameter requested.
338297

EENViLIE; N' C 27858.;:::
TOWN OP BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OAKS .NC 27524
PARAMETERS
Mercury (Method 1631E}, ngll
D Lnkinq na_e- ]..--
e'aWat?r ZF: 1D•
ID##: 388 E
DATE COLLECTED: 09/12/18
DATE REPORTED : 09/26/18
REVIEWED BY:
Effluent Field Analysis Method
Blank Date Analyst Code
1.8 <1 09/25/18 MTM EPA1631E

Environment ent I,h c.
# ..O 1T x 7085, 114 Oakmont Dr.
Green ille, NC 27858
env iro rn M.
Phone [phone] • Fax [phone]
CLIENT: 388 E Week: 30
TOWN OF BENSON WWTP
MR. PAUL ALLEN
770 HANNAH CREEK ROAD
FOUR OAKS NC 27524
[phone]
SAMPLE LOCATION
Effluent
L_Field Blank
RELINQUISHED BY (S
UISHED BY
RELINQUISH
FORM #5
COLLECTION
DATElTIME
1 rAgiNFLC'FTON
jCHLORINE
UUv
NONE
lj
RECEIbEED BY (SIG)
L AIN OF CUSTODY RECORD
PLEASE READ Instructions tor completing this form on the reverse side.
DTEmME
ri
DAT AE:
DATE/i1ME
L
Pageof��
CHLORINE NEL6ALIZED AT COLLECTION
pH CHECK (LIB)
{
CONTAINER TYPE, PIG
CHEM [CAL PRESEFNATICN
A - NONE
B-H OI
C-H2S
t} - NAOH
E-I-ICL
F - ZINC ACETATE/NAOH I
G - NATNCSUILFATE
CLP,SS1FICATION:
WASTEWATER (NPDES)
DR1NKING WATER
DWP/GW
99ID WASTE SECTION
CHAIN OF CdST0DY (SEAL) MAINTAINED
DURING SHIPMENT/DELIVERY
� N
SAMPLES C CTED BY:
(Pose Print} AA
Sven rse 4 r.
SAMPLES RECEIVED IN LAB AT Z2 . Z °C
COMMENTS:
SAMPLES WERE PRESERVED WITH
ONeit.0'p _AT g'13 RL
Sampler must place a "C" for composite sample or a "G" for
Grab sample in the blocks above for each parameter requested.
N° 352542

Attachment A —Request for Missing Information
Table 2. EPA Application Form 2A Missing information
40 CFR
1 1 :.
122.21(j)(1)
Email address of facility contact
Brian Leavitt, Superintendent 1 ORC [e-mail]
1::2:`..
Applicant email address
Tim Robbins, Public Utilities Director trobbins@townofbenson,com
:13:
Email address of the organization transporting the discharge for treatment prior to discharge
Not Applicable (Ali treatment at plant with discharge directly to Hannah Creek)
'1.4
Email address of the organization receiving the discharge for treatment prior to discharge
Not Applicable
1.5
Do you intend to request or renew one or more of the variances authorized at 40 CFR 122.21(n)? (Check all that apply. Consult
with your NPDES permitting authority to determine what information needs to be submitted and when.)
Discharges into marine waters (CWA Section ❑ Water quality related effluent limitation (CWA
301(h)) Section 302(b)(2))
® Not applicable
` .1 ,6
40 CFR
1.7
Email address of contractor responsible for operational or maintenance aspects of the treatment works
Not Ai •licable Plant Staff ierform this work
122.21(j)(6)
Indicate the number of SIUs and NSCIUs that discharge to the POTW,
NUmberofSIU5 ;:
:Number:ofClUJs'
1: Chicopee, Inc., d.b.a. Berry Plastics IUP # 0001
0
1.8
Certification Statement
1 certify under penalty of law that this document and all attachments were prepared under my direction or supervision in
accordance with a system designed to assure that qualified personnel property gather and evaluate the information submitted,
Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the
information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. 1 am aware that
there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing
violations.
Name (print or type first and last name)
Brian Leavitt
Official title
Superintendent I CRC
Date signed
10/30/2020

Process Flow Narrative
Benson Wastewater Treatment Plant
NPDES Permit No. NC0020389
Non -Discharge Permit No. WQ0012514
The Town of Benson operates a 1.9 MGD modified biological nutrient removal (BNR) plant
which discharges its effluent into Hannah Creek in the Neuse River Basin under NPDES Permit
No. NC0020389. The plant consists of a mechanically cleaned bar screen, a manually cleaned
bar screen (by-pass), a mechanically cleaned grit removal system, a comminutor, 9-inch Parshall
flume for influent flow metering, influent wastewater pumping, modified oxidation ditches for
biological nutrient removal, secondary clarifiers, sludge recirculation and waste pumping, nitrate
internal recycle pumps, lime feed system for alkalinity and pH control, alum feed system for
back-up chemical phosphorus removal and effluent polishing, tertiary filtration, chlorine
disinfection system, dechlorination system, post aeration, aerated sludge holding basin for long-
term sludge stabilization and storage, and sludge loading station for disposal of stabilized sludge
by land application.

MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 10/21/2C Page 1 01 4
Permit: nc0020389 MRs Betweei 4 - 2016 and10 - 2020
Facility Name: % Param Nam( %
Major Minor: %
Region: %
County: %
Violation Category:%
Subbasin:%
Program Category:
Violation Action: %
PERMIT: NC0020389
FACILITY: Town of Benson - Benson WWTP
COUNTY: Johnston
REGION: Raleigh
Limit Violation
MONITORING OUTFACE
REPORT
LOCATION
PARAMETER
VIOLATION
DATE FREQUENCY MEASURE
UNIT OF
LIMIT
CALCULATED
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
05-2016 001
10-2016 001
07-2017 001
09-2017 001
05-2018 001
05-2018 001
05-2018 001
09-2018 001
12-2018 001
08-2016 001
02-2018 001
02-2018 001
02-2018 001
02-2018 001
02-2018 001
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
BOD, 5-Day (20 Deg. C) -
Concentration
Chlorine, Total Residual
Chlorine, Total Residual
Chlorine, Total Residual
Chlorine, Total Residual
Chlorine, Total Residual
Chlorine, Total Residual
05/07/16
10/15/16
07/22/17
09/30/17
05/19/18
05/26/18
05/31/18
09/22/18
12/22/18
5 X week
5 X week
5 X week
5 X week
5 X week
5 X week
5 X week
5 X week
5 X week
08/11/16 5 X week
02/01/18 5 X week
02/02/18 5 X week
02/05/18 5 X week
02/06/18 5 X week
02/07/18 5 X week
mg/I
mg/I
mg/I
mg/I
mg/I
mg/I
mg/I
mg/I
mg/I
ug/I
ug/I
ug/I
ug/I
ug/I
ug/I
7.5 8.48 13.1 Weekly Average
Exceeded
7.5 13.58 81.1 Weekly Average
Exceeded
7.5 9 20 Weekly Average
Exceeded
7.5 9.04 20.5 Weekly Average
Exceeded
7.5 7.78 3.7 Weekly Average
Exceeded
7.5 8.68 15.7 Weekly Average
Exceeded
5 6.55 30.9 Monthly Average
Exceeded
7.5 11.26 50.1 Weekly Average
Exceeded
15 15.6 4 Weekly Average
Exceeded
17 20 17.6 Daily Maximum
Exceeded
17 24 41.2 Daily Maximum
Exceeded
17 18 5.9 Daily Maximum
Exceeded
17 20 17.6 Daily Maximum
Exceeded
17 23 35.3 Daily Maximum
Exceeded
17 30 76.5 Daily Maximum
Exceeded
Proceed to NOV
No Action, BPJ
Proceed to
Enforcement Case
Proceed to
Enforcement Case
Penalty Retracted
Penalty Retracted
Proceed to
Enforcement Case
Proceed to NOV
No Action, BPJ
No Action, BPJ
No Action, BPJ
No Action, BPJ
No Action, BPJ
No Action, BPJ
No Action, BPJ

MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 10/21/2C Page 2 of 4
Permit: nc0020389 MRs Betweei 4 - 2016 and10 - 2020 Region: % Violation Category:% Program Category: %
Facility Name: % Param Nam(% County: % Subbasin:% Violation Action: %
Major Minor: %
PERMIT: NC0020389
FACILITY: Town of Benson - Benson WWTP
COUNTY: Johnston REGION: Raleigh
Limit Violation
MONITORING UNIT OF
OUTFALL LOCATION PARAMETER VIOLATION FREQUENCY
REPORT DATE MEASURE
LIMIT
CALCULATED
VALUE Over
VIOLATION TYPE VIOLATION ACTION
02 - 2018 001 Effluent Chlorine, Total Residual 02/08/18 5 X week ug/I 17 29 70.6 Daily Maximum No Action, BPJ
Exceeded
02 - 2018 001 Effluent Chlorine, Total Residual 02/12/18 5 X week ug/I 17 35 105.9 Daily Maximum No Action, BPJ
Exceeded
02 - 2018 001 Effluent Chlorine, Total Residual 02/13/18 5 X week ug/I 17 34 100 Daily Maximum No Action, BPJ
Exceeded
02 - 2018 001 Effluent Chlorine, Total Residual 02/14/18 5 X week ug/I 17 45 164.7 Daily Maximum No Action, BPJ
Exceeded
02 - 2018 001 Effluent Chlorine, Total Residual 02/15/18 5 X week ug/I 17 27 58.8 Daily Maximum No Action, BPJ
Exceeded
05-2018 001 Effluent Chlorine, Total Residual 05/15/18 5 X week ug/I 17 84 394.1 Daily Maximum Proceed to
Exceeded Enforcement Case
05-2018 001 Effluent Chlorine, Total Residual 05/16/18 5 X week ug/I 17 50 194.1 Daily Maximum Proceed to
Exceeded Enforcement Case
05 - 2018 001 Effluent Chlorine, Total Residual 05/17/18 5 X week ug/I 17 40 135.3 Daily Maximum No Action, BPJ
Exceeded
05-2018 001 Effluent Chlorine, Total Residual 05/18/18 5 X week ug/I 17 49 188.2 Daily Maximum No Action, BPJ
Exceeded
05-2018 001 Effluent Chlorine, Total Residual 05/21/18 5 X week ug/I 17 32 88.2 Daily Maximum No Action, BPJ
Exceeded
05 - 2018 001 Effluent Chlorine, Total Residual 05/22/18 5 X week ug/I 17 46 170.6 Daily Maximum No Action, BPJ
Exceeded
05 - 2018 001 Effluent Chlorine, Total Residual 05/23/18 5 X week ug/I 17 47 176.5 Daily Maximum No Action, BPJ
Exceeded
02 -2020 001 Effluent Flow, in conduit or thru 02/29/20 Continuous mgd 1.9 1.94 2.1 Monthly Average Proceed to NOD
treatment plant Exceeded
10 - 2016 001 Effluent Nitrogen, Ammonia Total (as 10/15/16 5 X week mg/I 3 5.42 80.8 Weekly Average No Action, BPJ
N) - Concentration Exceeded
10 - 2016 001 Effluent Nitrogen, Ammonia Total (as 10/31/16 5 X week mg/I 1 1.6 60.0 Monthly Average No Action, BPJ
N) - Concentration Exceeded
01 -2018 001 Effluent Nitrogen, Ammonia Total (as 01/31/18 5 X week mg/I 2 2.57 28.4 Monthly Average Proceed to NOV
N) - Concentration Exceeded

MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 10/21/2C Page 3 of 4
Permit: nc0020389 MRs Betweei 4 - 2016 and10 - 2020
Facility Name: % Param Nam( %
Major Minor: %
Region:
County: %
Violation Category:%
Subbasin:%
Program Category: %
Violation Action: %
PERMIT: NC0020389
FACILITY: Town of Benson - Benson WWTP
COUNTY: Johnston
REGION: Raleigh
Limit Violation
MONITORING OUTFALL
REPORT
LOCATION
PARAMETER
VIOLATION
DATE FREQUENCY MEASURE
UNIT OF
LIMIT
CALCULATED
VALUE
Over
VIOLATION TYPE
VIOLATION ACTION
04-2018 001
09-2018 001
09-2018 001
10-2019 001
06-2018 001
Monitoring Violation
MONITORING OUTFALL
REPORT
Effluent
Effluent
Effluent
Effluent
Effluent
LOCATION
Nitrogen, Ammonia Total (as
N) - Concentration
Nitrogen, Ammonia Total (as
N) - Concentration
Nitrogen, Ammonia Total (as
N) - Concentration
pH
04/30/18
09/22/18
09/30/18
5 X week
5 X week
5 X week
10/03/19 5 X week
Solids, Total Suspended - 06/02/18 5 X week
Concentration
PARAMETER
VIOLATION
DATE FREQUENCY MEASURE
mg/I
mg/I
mg/I
su
mg/I
UNIT OF
1
3
1
1.03 3.4 Monthly Average
Exceeded
7.23
2.9
141.1
189.9
Weekly Average
Exceeded
Monthly Average
Exceeded
6 5.89 1.8 Daily Minimum Not
Reached
45 76.25 69.4 Weekly Average
Exceeded
LIMIT
CALCULATED
VALUE
Over
VIOLATION TYPE
Proceed to NOD
Proceed to NOV
Proceed to NOV
No Action, BPJ
Proceed to
Enforcement Case
VIOLATION ACTION
11-2016 001
09-2017 001
09-2017 001
06-2018 001
09-2017 001
06-2018 001
06-2018 001
Other Violation
MONITORING OUTFALL
REPORT
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
Effluent
LOCATION
Conductivity
Nitrite plus Nitrate Total (as
N)
Nitrogen, Kjeldahl, Total (as
N)
Nitrogen, Kjeldahl, Total (as
N)
Nitrogen, Total -
Concentration
Nitrogen, Total -
Concentration
Phosphorus, Total (as P) -
Concentration
PARAMETER
11/12/16 5 X week umhos/cm
09/02/17 Weekly mg/I
09/02/17 Weekly mg/I
06/02/18 Weekly mg/I
09/02/17 Weekly mg/I
06/02/18 Weekly mg/I
06/02/18 Weekly mg/I
VIOLATION
UNIT OF
DATE FREQUENCY MEASURE
LIMIT
CALCULATED
VALUE
Over
Frequency Violation
Frequency Violation
Frequency Violation
Frequency Violation
Frequency Violation
Frequency Violation
Frequency Violation
No Action, Facility
Reporting Error
Proceed to
Enforcement Case
Proceed to
Enforcement Case
Proceed to
Enforcement Case
Penalty Retracted
Proceed to
Enforcement Case
Proceed to
Enforcement Case
VIOLATION TYPE VIOLATION ACTION

MONITORING REPORT(MR) VIOLATIONS for:
Report Date: 10/21/2C
Page 4 al
Permit: nc002038 MRs Betweei 4 - 2016 and10 - 2020
Facility Name: % Param Nam( %
Major Minor: %
Region: %
County: %
Violation Category:%
Subbasin:%
ligProgram Category: %
Violation Action:
PERMIT: NC0020389
FACILITY: Town of Benson - Benson WWTP
COUNTY: Johnston
REGION: Raleigh
Other Violation
MONITORING OUTFACE
REPORT
LOCATION
PARAMETER
VIOLATION UNIT OF
FREQUENCY
DATE MEASURE
LIMIT
CALCULATED
VALUE Over
VIOLATION TYPE VIOLATION ACTION
07 - 2019 10/04/19
Aquatic toxicity permit Proceed to NOV
limit violation

MAYOR
JERRY M. MEDLIN
MAYOR PRO-TEM
CASANDRA P. STACK
COMMISSIONER
MAXINE HOLLEY
JAMES D. JOHNSON
DEAN MCLAMB
WILLIAM NEIGHBORS
DR. R. MAX RAYNOR
December 4, 2020
NC DEQ/DWR
Attn: NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Dear Permitting Unit*
TOWN OF BENSON
P.O. BOX 69
303 EAST CHURCH STREET
BENSON, NC 27504
[phone]
FAX [phone]
www.townofbenson.com
TOWN MANAGER
FREDERICK NELSON
ASSISTANT TOWN MANAGER
KIMBERLY PICKETT
TOWN CLERK
ANGELA THORNTON
TOWN ATTORNEY
R. ISAAC PARKER
Subject: NPDES Permit Renewal
Permit Renewal - Supplemental Information
Benson WWTP
NPDES Permit #NC0020389
Johnston County
The Town of Benson WWTP has received a draft permit for review for NPDES #NC0020389. We have
recently been informed that a request for reduced monitoring could be made during the renewal process.
We are submitting this additional information to be considered during the renewal process. We are
requesting that monitoring for BOD5, TSS, NH3-N and Fecal Coliform be reduced under the
"exceptionally performing facilities" criteria to two times per week.
The attached data (summarized in the following table) indicates that the WWTP effluent has greatly
exceeded the minimum criteria for reduced monitoring. The most restrictive summer limits were used
for calculating removal rates for BOD5, TSS and Fecal Coliform. For NH3-N, a weighted average was
calculated using the winter and summer limits. The data used for this 3-year analysis was for the period
of October 2020 — November 2017.
Analysis of testing results for the past three years:
- Percent of Monthly Average Limit
Parameter
Monthly
Limit
3-Year Average
% of Limit
BOD5
5.0 mg/1
2.1 mg/1
42 %
TSS
30.0 mg/L
2.0 mg/L
7 %
Fecal Coliform
200/100 ml
1.4 colonies/100 ml
2%
NH3-N
1.42 mg/1 (Average)
0.5 mg/1
35.3%

- Number of Samples Over 200% of Monthly Average Limit
Parameter
200% of Monthly Limit
Number of Samples Over
BOD5
10.0 mg/1
8
TSS
60 mg/L
11
NH3-N
2.0/4.0
10
Number of Samples Over 200% of Weekly Average Limit
Parameter
200% of Weekly Limit
Number of Samples Over
Fecal Coliform
800
0
In addition to the exceptional test results, the Benson WWTP is in compliance with all other criteria
listed in Section B Approval Criteria of the October 22, 2012 guidance document regarding reduction
of monitoring frequencies.
The Town appreciates the Division's effort to reduce the regulatory and monetary burden on systems
that strive consistently to provide exceptional wastewater treatment. We thank you for your consideration
in these matters. If you have any additional questions or comments, please contact Brian Leavitt at:
[phone] or [e-mail].
Sincerely,
T m Robbins, Public Utilities Director
Town of Benson

Three Year Data Summary - Benson NPDES #0020389
2020
BOD Ave BOD Max
TSS Ave
TSS Max
FC Ave
FC Max
NH3 Ave
NH3 Max
October
0.20
2.40
0.12
2.80
18.80
66.00
0.04
0.20
September
0.50
3.90
0.00
0.00
14.30
72.00
0.09
0.30
August
1.20
4.30
0.00
0.00
13.40
48.00
0.16
1.27
July
0.70
4.50
0.00
0.00
6.10
88.00
0.04
0.26
June
1.18
4.10
0.00
0.00
11.50
76.00
0.05
0.32
May
0.60
3.20
0.00
0.00
14.00
56.00
0.09
0.55
April
1.50
6.70
1.10
18.00
6.60
70.00
0.05
0.30
March
4.20
18.00
0.00
0.00
2.30
62.20
0.20
2.60
February
3.20
6.30
0.14
2.80
2.30
74.30
0.30
1.80
January
2.15
5.80
0.00
0.00
1.40
21.60
0.48
2.45
Dec-19
2.20
7.20
0.00
0.00
1.30
5.20
0.18
1.30
November
0.57
3.30
0.00
0.00
1.30
8.50
0.10
0.32
2019
BOD Ave BOD Max
TSS Ave
TSS Max
FC Ave
FC Max
NH3 Ave
NH3 Max
October
1.10
5.30
0.12
2.80
2.00
10.30
0.10
0.34
September
1.20
4.40
1.06
13.40
2.81
46.50
0.45
3.21
August
1.10
4.20
1.20
3.10
4.70
50.40
0.10
0.25
July
0.43
3.10
0.96
2.90
2.60
91.70
0.12
0.45
June
0.12
2.40
0.14
0.29
5.12
62.00
0.14
0.29
May
1.50
3.60
1.48
3.00
3.50
41.40
0.20
0.68
April
2.20
3.60
1.00
2.90
1.00
2.00
0.39
2.20
March
1.59
4.30
1.30
3.90
1.00
2.00
0.08
0.17
February
1.00
16.00
0.49
4.20
1.00
0.00
0.16
0.34
January
1.00
8.20
0.59
7.20
1.00
2.00
0.70
12.90
Dec-18
5.40
22.00
4.30
10.90
1.19
4.10
1.20
4.70
November
1.86
6.60
2.50
16.00
1.60
72.30
0.68
6.74
2018
BOD Ave BOD Max
TSS Ave
TSS Max
FC Ave
FC Max
NH3 Ave
NH3 Max
October
1.52
10.00
1.76
3.90
2.00
16.00
0.26
0.46
September
4.70
15.00
8.30
28.80
10.30
200.00
2.88
7.90
August
1.30
6.20
1.90
7.80
3.83
52.00
0.21
0.56
July
2.73
10.00
1.91
5.90
3.16
44.30
0.33
0.54
June
2.96
8.90
1.67
4.60
3.90
31.80
0.20
0.49
May
6.54
21.00
17.20
305.00
2.90
77.20
0.76
1.64
April
4.33
11.00
1.39
6.50
4.30
104.30
1.03
2.90
March
5.96
25.00
5.70
9.00
1.10
9.00
1.83
3.84
February
4.30
18.00
7.00
14.60
1.00
0.00
1.50
2.88
January
4.44
43.00
8.70
20.00
1.60
30.00
2.50
3.80
Dec-17
0.46
2.80
0.16
2.80
1.00
0.00
0.22
0.43
November
0.11
2.10
0.00
1.00
1.10
4.00
0.23
0.36
3-Year Arithmetic Average
2.1
2.0
0.5
Maximum Daily Result
43.00
305.00
200.00
12.90
3-Year Geometric Mean Average
4.4
Permit Limit
5.0
30.0
200
1.42 (Ave. 12 month limit)
of Limit
42%
7%
2%
35.3%

Reduction in Frequency Evalaution
Facility:
Benson WWTP
Permit No.
NC0020389
Review period (use
3 yrs)
9/1/2017 - 9/30/2020
Approval Criteria:
Y/N?
1. Not currently under SOS
Y
2. Not on EPA Quarterly noncompliance
report
Y
3. Facility or employees convicted of CWA
violations
N
Data Review
Units
Weekly
average
limit
Monthly
average
limit
50%
MA
3-yr mean
(geo mean
for FC)
< 50%?
200%
MA
# daily
samples
>200%
<15?
200%
WA
# daily
samples
>200%
< 20?
# of non -
monthly
limit
violations
> 2?
# civil penalty
asessment
> 1?
Reduce
Frequency?
(Yes/No)
BOD (summer)
mg/L
7.5
5
2.5
2.5143162
N
10
13
Y
3
Y
2
Y
N
BOD (winter)
mg/L
15
10
5
3.1050336
Y
20
4
Y
0
N
0
N
Y
TSS
mg/L
45
30
15
2.9127285
Y
60
1
Y
1
N
1
N
Y
Ammonia (summer)
mg/L
3
1
0.5
0.3935983
Y
2
20
N
1
N
0
N
N
Ammonia (winter)
mg/L
6
2
1
0.7311242
Y
4
3
Y
0
N
0
N
Y
Fecal Coliform
#/100
400
200
100
1.771642
Y
800
0
Y
0
N
0
N
Y