NC0025071_Compliance Evaluation Inspection_20230601

ROY COOPER
Governor
ELIZABETH S. BISER
Secretary
RICHARD E. ROGERS, JR.
Director
Melinda S. Ward
City of Eden
PO Box 70
Eden, NC 27289-0070
NORTH CAROLINA
Environmental Quality
June 1, 2023
Subject: Compliance Evaluation Inspection
Mebane Bridge WWTP
NPDES WW Permit No. NCO025071
Rockingham County
Dear Ms. Ward:
On May 22, 2023, Division of Water Resources (DWR) Winston-Salem Regional Office (WSRO)
staff Jesse Barnes conducted a routine compliance evaluation inspection (CEI) at the City of
Eden's Mebane Bridge WWTP in reference to NPDES permit NC0025071. Operator in Responsible
Charge (ORC) Christopher Powell and Backup ORC Matthew Tuttle were present during the
inspection. A review of the subject permit, self -monitoring program, laboratory, flow
measurement, sampling methods, operations, maintenance, records, reports, treatment plant
components, and effluent receiving waters was completed. This review reflected compliance with
the subject permit. Items of concern observed during the inspection are listed below.
Items of Concern
1. All field parameters have been performed by NC certified laboratories, either in house by
lab #168 or by contracted lab #633 Pace Analytical Services LLC — Eden NC. During the
records review, it was noted that only lab #168 has been listed on DMR reports. Please
also list lab #633, as all laboratories (including contracted labs) must be listed on DMRs if
used to report permit -required parameters.
2. The influent composite sampler collects constant volume aliquots of approximately 120 mL
at a constant time interval and is therefore not flow proportional. It was discussed after
the inspection that the permittee agrees to report effluent flow instead of influent flow
since the effluent composite sampler is flow proportional.
3. The walkways to access the center well of the secondary clarifiers were severely corroded
with many holes and may be structural) unsafe.
a]
The right of way to the outfall was overgrown with tall grass and only accessible carefully
on foot due to rocks and limbs hidden by the grass. A right of way to the outfall should be
properly maintained so that the outfall pipe can be accessed for maintenance and the
effluent and receiving waters can be easily observed.
Please be aware that the Division may take enforcement action against any permittee who fails
to comply with any requirement of their permit. Pursuant to NC General Statute (NCGS) 143-
D North Carolina Department of Environmental Quality I Division of Water Resources
Winston-Salem Regional Office 1 450 W. Hanes Mill Rd, Suite 300 I Winston-Salem, North Carolina 27105
Moan caaouNn 336.776.9800
oep.m.m or em�nmen� Qualm

215.6A, a civil penalty of not more than twenty-five thousand dollars ($25,000.00) may be
assessed against any person who violates or fails to act in accordance with the terms, conditions,
or requirements of any permit issued pursuant to G.S. 143-215.1.
If you have any questions or concerns, please do not hesitate to contact Jesse Barnes by phone
at 336-816-7351, or by email at [e-mail].
Sincerely,
DocuSigned by:
OD2D3CE3F167456...
Jennifer F. Graznak, Assistant Regional Supervisor
Water Quality Regional Operations Section
Winston-Salem Regional Office
Division of Water Resources, NCDEQ
Attachments:
1. Water Compliance Inspection Report, NCO025071
REQ� North Carolina Department ofEnvironmental Quality I Division ofWater Resources
Winston-Salem Regional Office 1 450 W. Hanes Mill Rd, Suite 300 1 Raleigh, North Carolina 27105
NORTH CAROLINA 336.776.9800
naparMeM of EmironmanW 9uallly

United States Environmental Protection Agency
Form Approved.
EPA Washington, D.C. 20460
OMB No. 2040-0057
Water Compliance Inspection Report
Approval expires 8-31-98
Section A: National Data System Coding (i.e., PCS)
Transaction Code NPDES yr/mo/day Inspection Type Inspector Fac Type
1 IN 1 2 u 3 I NC0025071 111 121 23/05/22 I17 18 LC] I 19 I s I 201
21111I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I II I I I I I r6
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 QA ---------------------- Reserved -------------------
67
I 72 I ni I 71 I 74 79 I I I I I I I80
701 I 71 I LL -1 I I
LJ
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW, also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES Dermit Number)
10:OOAM 23/05/22
21/05/01
Mebane Bridge WWTP
204 Mebane Bridge Rd
Exit Time/Date
Permit Expiration Date
Eden NC 27288
01:OOPM 23/05/22
26/04/30
Name(s) of Onsite Representative(s)/Titles(s)/Phone and Fax Number(s)
Other Facility Data
Christopher Ray Powell/0RC/336-627-1009/
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
Melinda S Ward,PO Box 70 Eden NC 272890070//336-627-1009/
No
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement Operations & Maintenar Records/Reports
Self -Monitoring Progran 0 Sludge Handling Dispo: Facility Site Review Effluent/Receiving Wate
Laboratory
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
(See attachment summary)
Name(s) and Signature(s) of Inspector(s) Agency/Office/Phone and Fax Numbers Date
DocuSigned by:
Jesse Barnes DWR/WSRO WQ/336-776-9701/
5. 6/1/2023
41797473D3194ED...
Signature of Management Q A Reviewer Agency/Office/Phone and Fax Numbers Date
jDocuSigned by:
if, '-4 -'U� DWR/WSRo 336-776-9695 6/1/2023
`0=3CE3H B7456.-
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page#

NPDES yr/mo/day Inspection Type
NCO025071 I11 12I 23/05/22 117 18 i c i
(Cont.)
Section D: Summary of Finding/Comments (Attach additional sheets of narrative and checklists as necessary)
On May 22, 2023, Division of Water Resources staff Jesse Barnes conducted a routine compliance
evaluation inspection at the City of Eden's Mebane Bridge WWTP in reference to NPDES permit
NC0025071. Operator in Responsible Charge (ORC) Christopher Powell and Backup ORC Matthew
Tuttle were present during the inspection. A review of the subject permit, self -monitoring program,
laboratory, flow measurement, operations, maintenance, records, reports, treatment plant
components, and effluent receiving waters was completed. This review reflected compliance with the
subject permit.
NPDES permit NC0025071 became effective May 1, 2021 and will expire at midnight on April 30,
2026. The facility was as described in the subject permit during the inspection. The sludge lagoon
listed in the facility components was present but not in use during the inspection. The sludge lagoon
typically is not needed due to low volume, it is available for use if needed. There are no special
conditions for the subject permit. The inspector was granted access to all requested areas for
inspection.
A review of permit -required records and reports was conducted and no violations were noted. The
December 2022 DMR was reviewed and appeared to be consistent with recorded analytical results.
All permit -required parameters were reported and in the correct units. Chains of custody were
available and appeared complete. The most recent annual compliance report was available for review
and appeared to meet permit requirements. ORCs were found to hold the proper certifications and a
visitation log was available and appeared to be complete during the inspection. Additionally, a daily
maintenance log was available for review. A copy of the subject permit was available during the
inspection.
All field parameters have been performed by NC certified laboratories, either in house by lab #168 or
by contracted lab #633 Pace Analytical Services LLC — Eden NC. During the records review, it was
noted that only lab #168 has been listed on DMR reports. Please also list lab #633, as all laboratories
(including contracted labs) used to report permit -required parameters on DMRs must be reported. A
cursory review of field laboratory #168 was conducted and no issues were noted. The sample
storage refrigerator and fecal coliform incubator were observed to be the proper temperature and
monitored with appropriately calibrated thermometers. The pH calibration data sheet was reviewed
and appeared to be compliant, having utilized three-point calibration and then verification using pH 4,
7, 10, and 7.38 buffers, respectively.
The facility utilizes a sludge judge and in -situ pH and DO analyzers for process control to monitor the
treatment process at various stages. The plant appeared to be generally clean with acceptable
housekeeping during the inspection.
A Siemens flow meter was being used for reporting influent flow during the inspection. The influent
flow meter had been calibrated quarterly and was most recently calibrated in May 2023 by
Instrumentation Services Inc (ISI). The influent flow meter appeared to be operating properly during
the inspection. Mr. Powell explained that the facility has accepted pump and haul loads via a
dedicated receptacle structure that is located ahead of all components of the treatment plant.
Records and permits related to these pump and haul loads have been maintained on site and at City
Hall for review. Additionally, the facility has routinely accepted wastewater flows from a nearby Duke
Energy facility and the adjacent drinking water treatment plant. These flows have been totalized and
reported appropriately.
Two mechanical bar screens precede a mechanical grit separator and are followed by an additional
mechanical fine bar screen. All three bar screens and the grit separator appeared to be operating
properly during the inspection. Trash and solid wastes removed with these components have been
placed in drying beds to remove excess moisture and then disposed of in a landfill.
Page#

Permit: NCO025071
Inspection Date: 05/22/2023
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
The influent composite sampler collects constant volume aliquots of approximately 120 mL at a
constant time interval and is therefore not flow -proportional. The influent composite sampler
appeared to be operating properly during the inspection. It was discussed after the inspection that
the permittee agrees to report effluent flow instead of influent flow since the effluent composite
sampler is flow proportional.
Two parallel aeration basins with surface mixers were available for use, but only the north basin was
in use during the inspection due to low flow. Typically only one aeration basin is in use at any given
time. The aeration basin had adequate mixing, no excessive foam, no observed dead spots, and
appeared to be operating properly. Mr. Powell stated that the north aeration basin will be taken out of
service and rehabilitated in the next few months. During that time, the south aeration basin will be
used. He was asked to report such changes to the treatment process and permit component
utilization to the DWR WSRO. Two of the surface mixers were out of order during the inspection. The
solar bee floating mixers noted during the previous inspection were still present in the aeration basin,
but were out of order during this inspection. The facility has no immediate plans to use the solar bee
mixers. An in -situ dissolved oxygen (DO) analyzer was being used during the inspection to monitor
the aeration basin process.
Four secondary clarifiers were available for use, but just one was in use during the inspection. Only
one secondary clarifier has been needed during typical flows and facility staff regularly rotate which
one is used. A flow splitter box has been used to control which clarifier receives flow. The clarifier in
use has been cleaned weekly. The clarifier in use during the inspection appeared to be operating
properly with no excessive solids, no excessive algae, adequate scum removal, an operational drive
unit, and clear overflow with no visible pin floc. The walkways to access the center well of the
secondary clarifiers were severely corroded with many holes and may be structurally unsafe. Mr.
Powell stated that the sludge blanket has been measured four times per shift and maintained at a
target depth of one to two feet.
A CleanB automatic sludge treatment system has been in use at the facility rather than a
conventional digester and was in use during the inspection. Sulfuric acid and sodium chlorite liquid
solutions are pumped into the CleanB system to aid sludge treatment. Treated sludge has been
hauled by Synagro as needed.
Chlorine gas was being used for disinfection during the inspection. During the inspection, the facility
had eight one -ton cylinders of chlorine gas on site. A Risk Management Plan was available for review.
Four cylinders are typically in use, with two actively feeding chlorine gas and two on standby for
automatic switch -over. The chlorine gas system appeared to be operating properly during the
inspection. Chlorine gas was being injected into a flash mixer where it is mixed with wastewater and
then enters a baffled contact chamber. Two parallel chlorine contact chambers were available for
use, but only one was in use during the inspection due to low flow, which reflects typical operation.
The contact chamber was free of excessive algae and vegetation and appeared to be operating
properly with no observed short-circuiting.
De -chlorination has been achieved using a liquid sodium bisulfite pumping system. These pumps are
turned on and off by hand and the feed rate is manually set as needed. Sodium bisulfite was stored
in a dedicated building and storage methods appeared to be appropriate. The de -chlorination system
appeared to be operating properly during the inspection.
Effluent flow was being monitored with three Siemens in -situ flow meters. These effluent flow meters
deliver flow data to the facility's SCADA system. The flow meters had been calibrated quarterly and
Page#

Permit: NCO025071
Inspection Date: 05/22/2023
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
most recently in May 2023 by Instrumentation Services Inc (ISI). The effluent flow meters appeared to
be operating properly during the inspection.
The effluent composite sampler was reviewed during the inspection and appeared to be operating
properly. This composite sampler was programmed to capture 120 mL aliquots at variable timing,
dependent on flow data communicated from the effluent flow meters. Mr. Tuttle stated that he
occasionally adjusts the amount of flow required to trigger an aliquot capture, to ensure a sufficient
total composite volume is collected and the container does not overflow. The temperature of the
composite sample storage was observed to be 2 degrees Celsius during the inspection.
The effluent pipe was accessible during the inspection via a roughly maintained right of way. The
right of way was overgrown with tall grass and only accessible carefully on foot due to rocks and limbs
hidden by the grass. A right of way to the outfall should be properly maintained so that the outfall pipe
can be accessed for maintenance and the effluent and receiving waters can be easily observed.
Effluent treated wastewater was observed exiting the outfall pipe, falling onto an area of riprap, and
entering the receiving stream (Dan River). The effluent and receiving waters appeared to be free of
foam and other debris.
The facility has been performing upstream and downstream sampling as required by the subject
permit and properly reporting the data. The designated sampling locations were confirmed by Mr.
Powell but not visited during the inspection due to time constraints.
Page#

Permit: NCO025071 Owner -Facility: Mebane Bridge WWTP
Inspection Date: 05/22/2023 Inspection Type: Compliance Evaluation
Permit
Yes
No
NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
❑
❑
❑
application?
Is the facility as described in the permit?
0
❑
❑
❑
# Are there any special conditions for the permit?
❑
0
❑
❑
Is access to the plant site restricted to the general public?
0
❑
❑
❑
Is the inspector granted access to all areas for inspection?
0
❑
❑
❑
Comment: NPDES permit NCO025071 became effective Mav 1, 2021 and will expire at midniqht on
April 30, 2026. The facility was as described in the subject permit during the inspection.
The sludge lagoon listed in the facility components was present but not in use during
the inspection. The sludge lagoon typically is not needed due to low volume, it is
available for use if needed. There are no special conditions for the subject permit.
The inspector was granted access to all requested areas for inspection.
Record Keeping
Are records kept and maintained as required by the permit?
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?
Is the chain -of -custody complete?
Dates, times and location of sampling
Name of individual performing the sampling
Results of analysis and calibration
Dates of analysis
Name of person performing analyses
Transported COCs
Are DMRs complete: do they include all permit parameters?
Has the facility submitted its annual compliance report to users and DWQ?
(If the facility is = or > 5 MGD permitted flow) Do they operate 24/7 with a certified
operator on each shift?
Is the ORC visitation log available and current?
Is the ORC certified at grade equal to or higher than the facility classification?
Is the backup operator certified at one grade less or greater than the facility
classification?
Is a copy of the current NPDES permit available on site?
Facility has copy of previous year's Annual Report on file for review?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Page# 5

Permit: NCO025071
Inspection Date: 05/22/2023
Record Keeping
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
Yes No NA NE
Comment: A review of permit -required records and reports was conducted and no violations were
noted. The December 2022 DMR was reviewed and appeared to be consistent with
recorded analytical results. All permit -required parameters were reported and in the
correct units. Chains of custody were available and appeared complete. The most
recent annual compliance report was available for review and appeared to meet permit
requirements. ORCs were found to hold the proper certifications and a visitation log
was available and appeared to be complete during the inspection. Additionally, a daily
maintenance log was available for review. A copy of the subject permit was available
during the inspection.
Laboratory
Yes
No
NA
NE
Are field parameters performed by certified personnel or laboratory?
0
❑
❑
❑
Are all other parameters(excluding field parameters) performed by a certified lab?
0
❑
❑
❑
# Is the facility using a contract lab?
0
❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0
0
❑
❑
❑
degrees Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
0
❑
❑
❑
Incubator (BOD) set to 20.0 degrees Celsius +/- 1.0 degrees?
❑
❑
❑
Comment: All field parameters have been performed by NC certified laboratories, either in house
by lab #168 or by contracted lab #633 Pace Analytical Services LLC — Eden NC.
During the records review, it was noted that only lab #168 has been listed on DMR
reports. Please also list lab #633, as all laboratories (including contracted labs) used to
report permit -required parameters on DMRs must be reported. A cursory review of field
laboratory #168 was conducted and no issues were noted. The sample storage
refrigerator and fecal coliform incubator were observed to be the proper temperature
and monitored with appropriately calibrated thermometers. The PH calibration data
sheet was reviewed and appeared to be compliant, having utilized three-point
calibration and then verification using PH 4, 7, 10, and 7.38 buffers, respectively.
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? 0 ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ❑ ❑ ❑
Solids, pH, DO, Sludge Judge, and other that are applicable?
Comment: The facility utilizes a sludge Judge and in -situ pH and DO analyzers for process control
to monitor the treatment process at various stapes. The plant appeared to be generally
clean with acceptable housekeeping during the inspection.
Standby Power
Yes
No
NA NE
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?
❑
❑
❑
■
Page# 6

Permit: NCO025071 Owner -Facility: Mebane Bridge WWTP
Inspection Date: 05/22/2023 Inspection Type: Compliance Evaluation
Standby Power Yes No NA NE
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 level monitored? ❑ ❑ ❑
Comment: Standby power was not evaluated.
Flow Measurement - Influent
Yes
No
NA
NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
E
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
❑
❑
❑
Comment: A Siemens flow meter was beinq used for reportinq influent flow durinq the inspection.
The influent flow meter had been calibrated quarterly and was most recently calibrated
in May 2023 by Instrumentation Services Inc (ISI). The influent flow meter appeared to
be operating properly during the inspection. Mr. Powell explained that the facility has
accepted pump and haul loads via a dedicated receptacle structure that is located
ahead of all components of the treatment plant. Records and permits related to these
pump and haul loads have been maintained on site and at City Hall for review.
Additionally, the facility has routinely accepted wastewater flows from a nearby Duke
Energy facility and the adjacent drinking water treatment plant. These flows have been
totalized and reported appropriately.
Bar Screens
Yes
No
NA NE
Type of bar screen
a.Manual
❑
b.Mechanical
Are the bars adequately screening debris?
0
❑
❑
❑
Is the screen free of excessive debris?
■
❑
❑
❑
Is disposal of screening in compliance?
0
❑
❑
❑
Is the unit in good condition?
0
❑
❑
❑
Comment: Two mechanical bar screens precede a mechanical grit separator
and are followed by
an additional mechanical fine bar screen. All three bar screens and the grit separator
appeared to be operating properly during the inspection. Trash and solid wastes
removed with these components have been placed in drying
beds to remove excess
moisture and then disposed of in a landfill.
Grit Removal
Yes
No
NA
NE
Type of grit removal
Page# 7

Permit: NCO025071
Inspection Date: 05/22/2023
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
Grit Removal
Yes
No
NA
NE
a.Manual
❑
b.Mechanical
Is the grit free of excessive organic matter?
■
❑
❑
❑
Is the grit free of excessive odor?
0
❑
❑
❑
# Is disposal of grit in compliance?
0
❑
❑
❑
Comment: Two mechanical bar screens precede a mechanical grit separator and are followed b
an additional mechanical fine bar screen. All three bar screens and the grit separator
appeared to be operating properly during the inspection. Trash and solid wastes
removed with these components have been placed in drying beds to remove excess
moisture and then disposed of in a landfill.
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?
Yes No NA NE
❑ ■ ❑ ❑
■ ❑ ❑ ❑
❑ ❑ ❑ ■
• ❑ ❑ ❑
• ❑ ❑ ❑
❑ ■ ❑ ❑
Comment: The influent composite sampler collects constant volume aliquots of approximately 120
mL at a constant time interval and is therefore not flow proportional. The influent
composite sampler appeared to be operating properly during the inspection. It was
discussed after the inspection that the permittee agrees to report effluent flow instead
of influent flow since the effluent composite sampler is flow proportional.
Aeration Basins
Yes
No
NA NE
Mode of operation
Type of aeration system
Surface
Is the basin free of dead spots?
0
❑
❑
❑
Are surface aerators and mixers operational?
0
❑
❑
❑
Are the diffusers operational?
❑
❑
0
❑
Is the foam the proper color for the treatment process?
0
❑
❑
❑
Does the foam cover less than 25% of the basin's surface?
0
❑
❑
❑
Is the DO level acceptable?
❑
❑
❑
Is the DO level acceptable?(1.0 to 3.0 mg/1)
❑
❑
❑
■
Page# 8

Permit: NCO025071
Inspection Date: 05/22/2023
Aeration Basins
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
Yes No NA NE
Comment: Two parallel aeration basins with surface mixers were available for use, but only the
north basin was in use during the inspection due to low flow. Typically only one
aeration basin is in use at any given time. The aeration basin had adequate mixing, no
excessive foam, no observed dead spots, and appeared to be operating properly. Mr.
Powell stated that the north aeration basin will be taken out of service and rehabilitated
in the next few months. During that time, the south aeration basin will be used. He was
asked to report such changes to the treatment process and permit component
utilization to the DWR WSRO. Two of the surface mixers were out of order during the
inspection. The solar bee floating mixers noted during the previous inspection were still
present in the aeration basin, but were out of order during this inspection. The facility
has no immediate plans to use the solar bee mixers. An in -situ dissolved oxygen (DO)
analyzer was being used during the inspection to monitor the aeration basin process.
Secondary Clarifier
Yes
No
NA
NE
Is the clarifier free of black and odorous wastewater?
0
❑
❑
❑
Is the site free of excessive buildup of solids in center well of circular clarifier?
0
❑
❑
❑
Are weirs level?
❑
❑
❑
Is the site free of weir blockage?
0
❑
❑
❑
Is the site free of evidence of short-circuiting?
■
❑
❑
❑
Is scum removal adequate?
0
❑
❑
❑
Is the site free of excessive floating sludge?
0
❑
❑
❑
Is the drive unit operational?
0
❑
❑
❑
Is the return rate acceptable (low turbulence)?
■
❑
❑
❑
Is the overflow clear of excessive solids/pin floc?
0
❑
❑
❑
Is the sludge blanket level acceptable? (Approximately'/4 of the sidewall depth)
❑
❑
❑
Comment: Four secondary clarifiers were available for use, but iust one was in use durinq the
inspection. Only one secondary clarifier has been needed during typical flows and
facility staff regularly rotate which one is used. A flow splitter box has been used to
control which clarifier receives flow. The clarifier in use has been cleaned weekly. The
clarifier in use during the inspection appeared to be operating properly with no
excessive solids, no excessive algae, adequate scum removal, an operational drive
unit, and clear overflow with no visible pin floc. The walkways to access the center well
of the secondary clarifiers were severely corroded with many holes and may be
structurally unsafe. Mr. Powell stated that the sludge blanket has been measured four
times Der shift and maintained at a taraet depth of one to two feet.
Disinfection -Gas
Yes
No
NA
NE
Are cylinders secured adequately?
0
❑
❑
❑
Are cylinders protected from direct sunlight?
0
❑
❑
❑
Is there adequate reserve supply of disinfectant?
■
❑
❑
❑
Is the level of chlorine residual acceptable?
❑
❑
❑
Page# 9

Permit: NCO025071 Owner -Facility: Mebane Bridge WWTP
Inspection Date: 05/22/2023 Inspection Type: Compliance Evaluation
Disinfection -Gas
Yes
No
NA
NE
Is the contact chamber free of growth, or sludge buildup?
0
❑
❑
❑
Is there chlorine residual prior to de -chlorination?
❑
❑
❑
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No.
0
❑
❑
❑
7782-50-5)?
If yes, then is there a Risk Management Plan on site?
❑
❑
❑
If yes, then what is the EPA twelve digit ID Number? (1000- - )
If yes, then when was the RMP last updated?
Comment: Chlorine qas was beinq used for disinfection durinq the inspection. Durinq the
inspection, the facility had eight one -ton cylinders of chlorine gas on site. A Risk
Management Plan was available for review. Four cylinders are typically in use, with two
actively feeding chlorine gas and two on standby for automatic switch -over. The
chlorine gas system appeared to be operating properly during the inspection. Chlorine
gas was being infected into a flash mixer where it is mixed with wastewater and then
enters a baffled contact chamber. Two parallel chlorine contact chambers were
available for use, but only one was in use during the inspection due to low flow, which
reflects typical operation. The contact chamber was free of excessive algae and
vegetation and appeared to be operating properly with no observed short-circuiting.
De -chlorination
Yes
No
NA
NE
Type of system ?
Liquid
Is the feed ratio proportional to chlorine amount (1 to 1)?
❑
❑
❑
Is storage appropriate for cylinders?
❑
❑
0
❑
# Is de -chlorination substance stored away from chlorine containers?
0
❑
❑
❑
Are the tablets the proper size and type?
❑
❑
0
❑
Comment: De -chlorination has been achieved usinq a liquid sodium bisulfite pumpinq system.
These pumps are turned on and off by hand and the feed rate is manually set as
needed. Sodium bisulfite was stored in a dedicated building and storage methods
appeared to be appropriate. The de -chlorination system appeared to be operating
properly during the inspection.
Are tablet de -chlorinators operational? ❑ ❑ 0 ❑
Number of tubes in use?
Comment:
Pumps-RAS-WAS
Yes
No
NA NE
Are pumps in place?
❑
❑
❑
Are pumps operational?
❑
❑
❑
Are there adequate spare parts and supplies on site?
❑
❑
❑
Comment:
Page# 10

Permit: NCO025071
Inspection Date: 05/22/2023
Solids Handling Equipment
Is the equipment operational?
Is the chemical feed equipment operational?
Owner -Facility: Mebane Bridge WWTP
Inspection Type: Compliance Evaluation
Is storage adequate?
Is the site free of high level of solids in filtrate from filter presses or vacuum filters?
Is the site free of sludge buildup on belts and/or rollers of filter press?
Is the site free of excessive moisture in belt filter press sludge cake?
The facility has an approved sludge management plan?
Yes No NA NE
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
❑ ❑ ❑ ■
❑ ❑ ❑ ■
❑ ❑ ❑ ■
❑ ❑ ❑ ■
Comment: A Clean automatic sludge treatment system has been in use at the facility rather than
a conventional digester and was in use during the inspection. Sulfuric acid and sodium
chlorite liquid solutions are pumped into the CleanB system to aid sludge treatment.
Treated sludge has been hauled by Synagro as needed.
Chemical Feed
Yes
No
NA NE
Is containment adequate?
0
❑
❑ ❑
Is storage adequate?
N
❑
❑ ❑
Are backup pumps available?
❑
❑
❑
Is the site free of excessive leaking?
0
❑
❑ ❑
Comment:
Flow Measurement - Effluent
Yes
No
NA
NE
# Is flow meter used for reporting?
❑
0
❑
❑
Is flow meter calibrated annually?
0
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
❑
❑
❑
Comment: Effluent flow was being monitored with three Siemens in -situ flow meters.
These
effluent flow meters deliver flow data to the facility's SCADA system. The flow meters
had been calibrated quarterly and most recently in May 2023 by Instrumentation
Services Inc (ISI). The effluent flow meters appeared to be operating properly
during
the inspection.
Effluent Sampling
Yes
No
NA
NE
Is composite sampling flow proportional?
0
❑
❑
❑
Is sample collected below all treatment units?
0
❑
❑
❑
Is proper volume collected?
❑
❑
❑
Is the tubing clean?
0
❑
❑
❑
Page# 11

Permit: NCO025071 Owner -Facility: Mebane Bridge WWTP
Inspection Date: 05/22/2023 Inspection Type: Compliance Evaluation
Effluent Sampling Yes
No
NA
NE
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 0
❑
❑
❑
degrees Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type 0
❑
❑
❑
representative)?
Comment: The effluent composite sampler was reviewed durinq the inspection and appeared to
be operating properly. This composite sampler was programmed to capture 120 mL
aliquots at variable timing, dependent on flow data communicated from the effluent flow
meters. Mr. Tuttle stated that he occasionally adjusts the amount of flow required to
tripper an aliquot capture, to ensure a sufficient total composite volume is collected
and the container does not overflow. The temperature of the composite sample
storage was observed to be 2 degrees Celsius during the inspection.
Effluent Pipe Yes No
NA NE
Is right of way to the outfall properly maintained? ❑ 0
❑ ❑
Are the receiving water free of foam other than trace amounts and other debris? 0 ❑
❑ ❑
If effluent (diffuser pipes are required) are they operating properly? ❑ ❑
0 ❑
Comment: The effluent pipe was accessible during the inspection via a roughly maintained right of
way. The right of way was overgrown with tall grass and only accessible carefully on
foot due to rocks and limbs hidden by the grass. A right of way to the outfall should be
properly maintained so that the outfall pipe can be accessed for maintenance and the
effluent and receiving waters can be easily observed. Effluent treated wastewater was
observed exiting the outfall pipe, falling onto an area of riprap, and entering the
receiving stream (Dan River). The effluent and receiving waters appeared to be free of
foam and other debris.
Upstream / Downstream Sampling Yes No
NA NE
Is the facility sampling performed as required by the permit (frequency, sampling type, 0 ❑
❑ ❑
and sampling location)?
Comment: The facility has been performing upstream and downstream sampling as required by
the subject permit and properly reporting the data. The designated sampling locations
were confirmed by Mr. Powell but not visited during the inspection due to time
constraints.
Page# 12