NC0020834_Compliance Evaluation Inspection_20200729

Mal
ROY COOPER
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MICHAEL S. REGAN
sr� r� tart'
S. DANIEL SMITH
P7c•e'lur
Bill Perkinson, Public Works Director
Town of Warrenton
P.O. Box 281
Warrenton, NC 27589-281
Dear Mr. Perkinson:
^.OtRTH CAROLI`lA
Environmental Quality
July 29, 2020
Subject: Compliance Evaluation Inspection
Warren County Wastewater Treatment Plant
NPDES Permit No. NCO020834
Warren County
Mitch Hayes of the Division of Water Resources conducted the subject inspection on July 22,
2020. Your assistance and the assistance of Kenny Champion, back-up Operator in Responsible
Charge, and Teresa Harris, laboratory Supervisor, were greatly appreciated. Below is a list of
findings developed from the inspection and review of the permit:
1. The current permit expired October 31, 2019 and is under review. Please continue to
operate under the last issued permit until the permit is renewed.
2. The 2.0 MGD plant consists of the following units: influent pump station with three pumps;
manual and mechanical bar screens; vortex grit removal chamber; two (2) 1,500,000
gallon dual oxidation ditches; two (2) secondary clarifiers; four (4) tertiary sand filters;
two (2) 135,000 gallon aerobic digesters; gas chlorination and contact chambers; cascade
aeration; and gas dechlorination (sulfur dioxide) and contact chambers; two (2) on -site
generators.
3. An A to C was issued February 15, 2019 for the following: one new multi -rake mechanical
bar screen; one new 100 GPM grit classifier and auger system; conversion of existing
oxidation ditch number 1 to a flow equalization basin; installation of 4 new 30 HP propeller
mixers in oxidation ditch number 2; replacement of existing lime system with a new liquid
lime feed and storage system.
4. At the time of inspection: All three pumps were operational at the influent pump station.
The mechanical bar screen was in operation. The vortex grit chamber was out of service
due to an impeller issue. One oxidation was in use with all three rotors in operation. The
second oxidation had excessive trees and other vegetation growing in it preventing it from
being used as designed. This vegetation must be removed from the oxidation ditch and
restore it to its designated use. Influent in the oxidation ditch appeared black due to waste
from International Paper. Sludge blankets in the 12-foot sidewall depth secondary

clarifiers were one foot. Effluent appeared clear Flowing off the weirs. All four sand filters
were in use. One aerated digester was full and the other was being filled and was one -
quarter full. Effluent at the discharge point appeared clear with little foam and no solids.
5. Discharge Monitoring Reports for the review period October 2018 through May 2020 were
checked for compliance with permit limits and monitoring requirements. There were no
violations.
6. Commercial lab results, chain of custody records, and bench sheets were compared with
data submitted on the Discharge Monitoring Report (DMR) for May 2020. No
discrepancies were noted.
7. Laboratory number 349 is certified for the following parameters: DO, pH, temperature,
and total residual chlorine. Meritech Laboratory performs all other parameters.
8. The laboratory was checked in a cursory manner. All pH buffers were within expiration
date. All calibrations of instruments and temperatures of refrigerators and other
equipment are recorded daily in a log book.
9. The ORC logbook was available and being maintained. Other logbooks maintained include
the following: weekly, monthly, semi-annual, and annual equipment PM; and generator
maintenance log. The mercury minimization plan was last updated October 17, 2017.
Please respond to item number 4 about the excess vegetation in the oxidation ditch within 30
days receipt of this letter. I would like to thank you, and everyone involved with this inspection
for their time and assistance. If you have any questions concerning this letter or the inspection,
please contact Mitch Hayes at 919.791.4261 or at mitch. ha es ncdenr, ov
Sincerely,
loe
Scott Vinson, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources, NC DEQ
cc: permit file
Laserfiche

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 yrlmolday Inspection Type Inspector Fac Type
1 u 2 15 1 3 I NCO020834 111 12 20/07/22 17 18 I r I 19 I Lc J I 201 I
1=J u
21 I 8
Inspection
Work Days Facility Self -Monitoring Evaluation Rating B1 OA Reserved
67
701, I 71I LI 72 I N I 731 I 174 7 80
LJ I t l
Section B: Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW. also include
Entry Time/Date
Permit Effective Date
POTW name and NPDES permit Number)
10 30AM 20/07/22
16/06/01
Warrenton WWTP
Exit TimelDate
Permit Expiration Date
615 U5 Hwy 401 S
Warrenton NC 27589
12 45PM 20/07/22
19/10/31
Name(s) of Onsite Representative(s)1Ttles(s)1Phone and Fax Number(s)
Other Facility Data
111
Kenneth Wayne Champion11252-257-1776 1
Kenneth Wayne Champion10RC1252-257-17761
William R Perkinson1/252-257-17761
William Robert Perkinson/ORC/252-257-17761
Name, Address of Responsible Official/Title/Phone and Fax Number
Contacted
C. Wayne Mitchell,PO Box 281 Warrenton NC 275890281/1252-257-17761
Yes
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit N Flow Measurement E Operations & Maintenar 0 Records/Reports
Self -Monitoring Progran 0 Sludge Handling DispoE 0 Facility Site Review 0 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
Mitchell S Hayes DWRIRRO W01919-791-42001
Signature of Management 0 A Reviewer Agency/Office/Phone and Fax Numbers Date
cc�2c- `�r9- �9►- �fZ3�� 29, T� r�
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.

NPDES yrlmolday Inspection Type (Cont.)
3 NC0020! 4 11 12 20/07/22: 17 18 I (. I
Section �Summary of Finding/Comments (Attach additionalsheetsof narrative and checklists as necessary)
The current permit expired October 31, 2019 and is under review. Please continue to operate under the
last issued permit until the permit is renewed.
The 2.0 MGD plant consists of the following units: influent pump station with three pumps; manual and
mechanical bar screens; vortex grit removal chamber; two (2) 1,500,000 gallon dual oxidation ditches;
two (2) secondary clarifiers; four (4) tertiary sand filters; two (2) 135,000 gallon aerobic digesters; gas
chlorination and contact chambers; cascade aeration; and gas dechlorination (sulfur dioxide) and
contact chambers; two (2) on -site generators.
An A to C was issued February 15, 2019 for the following: one new multi -rake mechanical bar screen;
one new 100 GPM grit classifier and auger system; conversion of existing oxidation ditch number 1 to
flow equalization basin; installation of 4 new 30 HP propeller mixers in oxidation ditch number 2;
replacement of existing lime system with a new liquid lime feed and storage system.
At the time of inspection: All three pumps were operational at the influent pump station. The mechanics
bar screen was in operation. The vortex grit chamber was out of service due to an impeller issue. One
oxidation was in use with all three rotors in operation. The second oxidation had excessive trees and
other vegetation growing in it preventing it from being used as designed. This vegetation must be
removed from the oxidation ditch and restore it to its designated use. Influent in the oxidation ditch
appeared black due to waste from International Paper. Sludge blankets in the 12-foot sidewall depth
secondary clarifiers were one foot. Effluent appeared clear flowing off the weirs. All four sand filters
were in use. One aerated digester was full and the other was being filled and was one -quarter full.
Effluent at the discharge point appeared clear with little foam and no solids.
Discharge Monitoring Reports for the review period October 2018 through May 2020 were checked for
compliance with permit limits and monitoring requirements. There were no violations.
Commercial lab results, chain of custody records, and bench sheets were compared with data
submitted on the Discharge Monitoring Report (DMR) for May 2020. No discrepancies were noted.
Laboratory number 349 is certified for the following parameters: DO, pH, temperature, and total
residual chlorine. Meritech laboratory performs all other parameters.
The laboratory was checked in a cursory manner. All pH buffers were within expiration date. All
calibrations of instruments and temperatures of refrigerators and other equipment are recorded daily in
a log book.
The ORC logbook was available and being maintained. Other logbooks maintained Include the
following: weekly, monthly, semi-annual, and annual equipment PM; and generator maintenance log.
The mercury minimization plan was last updated October 17, 2017.

Permit: NCO020834 Owner - Facility: Warrenton VWVrP
Inspection Date: 07/22/2020 Inspection Type: Compliance Evaluation
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? M ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable ■ ❑ ❑ ❑
Sotitfs, pH, DO, Sludge Judge, and other that are applicable?
Comment:
Permit
Yes
No
NA
NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
❑
❑
❑
application?
Is the facility as described in the permit?
❑
❑
❑
# Are there any special conditions for the permit?
❑
M
❑
❑
Is access to the plant site restricted to the general public?
M
❑
❑
❑
Is the inspector granted access to all areas for inspection?
M
❑
❑
❑
Comment: Permit expired October 31. 2019, Permit is under review.
Record KeeDing
Yes
No
NA
NE
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)?
M
❑
❑
❑
Are analytical results consistent with data reported on DMRs?
■
❑
❑
❑
Is the chain -of -custody complete?
M
❑
❑
❑
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 operate ❑ ❑ ■ ❑
on each shift?
Is the ORC visitation log available and current?
M
❑
❑
❑
Is the ORC certified at grade equal to or higher than the facility classification?
0
❑
❑
❑
Is the backup operator certified at one glade less or greater than the facility classification'
M
❑
❑
❑
Is a copy of the current NPDES permit available on site?
0
❑
❑
❑

Permit: NCO020834 Owner - Facility: Warrenton V VfP
Inspection Date: 07/22/2020 Inspection Type: compliance Evaivation
Record Keeping Yes No NA NE
Facility has copy of previous year's Annual Report on file for review? ■ ❑ ❑ ❑
Comment: This is a 2.0 MGD plant
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?
Comment: Effluent appeared clear.
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?
Comment: Meter calibrated 07.14.2020.
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?
Yes
No
NA
NE
■
❑
❑
❑
•
❑
❑
❑
❑
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■
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Yes No NA NE
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
Yes No NA NE
■ ❑ ❑ ❑
• ❑ ❑ ❑
• ❑ ❑ ❑
M ❑ ❑ ❑
❑ ❑ ❑
Comment: Two aerobic digesters, one was one quarter full being filled and the other was full.
DrVing Beds
Yes
No
NA
NE
Is there adequate drying bed space?
S
❑
❑
❑
Is the sludge distribution on drying beds appropriate?
❑
❑
r
❑
Are the drying beds free of vegetation?
0
❑
❑
❑
# Is the site free of dry sludge remaining in beds?
0
❑
❑
❑
Is the site free of stockpiled sludge?
0
❑
❑
❑
Is the filtrate from sludge drying beds returned to the front of the plant?
■
❑
❑
❑
# Is the sludge disposed of through county landfill?
❑
❑
M
❑
# Is the sludge land applied?
❑
❑
0
❑

Permit: NC0020834 Owner -Facility. Warrenton WWrP
Inspection Date: 07/22/2020 Inspection Type: Compliance Evaluation
Drying Beds Yes No NA NE
(Vacuum filters) Is polymer mixing adequate? ❑ ❑ M ❑
Comment: Drying beds are not being used.
Chemical Feed
Yes
No
NA
NE
Is containment adequate?
0
❑
❑
❑
Is storage adequate?
0
❑
❑
❑
Are backup pumps available?
0
❑
❑
❑
Is the site free of excessive leaking?
0
❑
❑
❑
Comment: Hydrated lime is feed into the oxidation ditch.
Pump Station - Influent
Yes
No
NA
NE
Is the pump wet well free of bypass lines or structures?
M
❑
❑
❑
Is the wet well free of excessive grease?
❑
❑
❑
Are all pumps present?
N
❑
❑
❑
Are all pumps operable?
■
❑
❑
❑
Are float controls operable?
❑
❑
❑
Is SCADA telemetry available and operational?
0
❑
❑
❑
Is audible and visual alarm available and operational?
❑
❑
❑
Comment: Three pumps in the pump station. All are in use
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?
N
❑
❑
❑
Is disposal of screening in compliance?
0
❑
❑
❑
Is the unit in good condition?
N
❑
❑
❑
Comment:
Grit Removal Yes No NA NE
Type of grit removal
a.Manual ❑

Permit: NCO020834
Owner -Facility: WarrentonWWTP
Inspection Date: 07/22/2020
inspection Type: Compliance Evaluation
Grit Removal
Yes
No
NA
NE
b.Mechanical
Is the grit free of excessive organic matter?
❑
❑
❑
Is the grit free of excessive odor?
❑
❑
# Is disposal of grit in compliance?
0
❑
❑
❑
Comment: vortex grit chamber was not in service due to an impeller issue.
Secondary Clarifier
Is the clarifier free of black and odorous wastewater?
Is the site free of excessive buildup of solids 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 '/4 of the sidewall depth)
Yes No NA NE
■
❑
❑
❑
M
❑
❑
❑
❑
❑
❑
■
❑
❑
❑
■
❑
❑
❑
M
❑
❑
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■
❑
❑
❑
■
❑
❑
❑
■
❑
❑
❑
❑
❑
❑
M
❑
❑
❑
Comment: Sludge blankets were one foot in both clarifiers with a sidewall depth of 12 feet.
Oxidation Ditches
Are the aerators operational?
Are the aerators free of excessive solids build up?
# Is the foam the proper color for the treatment process?
Does the foam cover less than 25% of the basin's surface?
Is the DO level acceptable?
Are settleometer results acceptable (> 30 minutes)?
Is the DO level acceptable?(1.0 to 3.0 mg11)
Are settelometer results acceptable?(400 to 800 mlll in 30 minutes)
Yes No NA NE
■
❑
❑
❑
•
❑
❑
❑
•
❑
❑
❑
■
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❑
■
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110
0
❑
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❑
Comment: One oxidation was in use with all three rotors in operation. The second oxidation had
excessive trees and other ve etation growinq in it preventing it from being used as desi ned
Nutrient Removal
# Is total nitrogen removal required?
Yes No NA NE
M ❑ ❑ ❑

Permit: NCO020834 Owner -Facility: WarrentonvUWTp
Inspection Date: 07/22/2020 Inspection Type: Compliance Evaluation
Nutrient Removal Yes No NA NE
# Is total phosphorous removal required? 0 ❑ ❑ ❑
Type Biological
# Is chemical feed required to sustain process? ❑ E ❑ ❑
Is nutrient removal process operating properly? E ❑ ❑ ❑
Comment: TP and TN are monitor and report.
Filtration (High Rate Tertiary)
Yes
No
NA
NE
Type of operation:
Down flow
1s the filter media present?
N
❑
❑
❑
Is the filter surface free of clogging?
N
❑
❑
❑
Is the filter free of growth?
N
❑
❑
❑
Is the air scour operational?
❑
❑
E
❑
Is the scouring acceptable?
❑
❑
■
❑
Is the clear well free of excessive solids and filter media?
0
❑
❑
❑
Comment:
Disinfection -Gas
Yes
No
NA
NE
Are cylinders secured adequately?
N
❑
❑
❑
Are cylinders protected from direct sunlight?
E
❑
❑
❑
Is there adequate reserve supply of disinfectant?
N
❑
❑
❑
Is the level of chlorine residual acceptable?
0❑
❑
❑
Is the contact chamber free of growth, or sludge buildup?
N❑
❑
❑
Is there chlorine residual prior to de -chlorination?
H
0
❑
❑
Does the Stationary Source have more than 2500 Ibs of Chlorine (CAS No. 7782-50-5)?
❑
E
❑
❑
If yes, then is there a Risk Management Plan on site?
❑
❑
E
❑
If yes, then what is the EPA twelve digit ID Number? 00007
If yes, then when was the RMP last updated?
Comment: Does not store more than 2500 Ibs of chlorine.
De -chlorination Yes No NA NE
Type of system ? Gas
Is the feed ratio proportional to chlorine amount (1 to 1)? 0 ❑ ❑ ❑
Is storage appropriate for cylinders? 0 [] 11 ❑

Permit: NCO020834 Owner - Facility: Warrenton wwTP
Inspection Date: 07/22/2020 Inspection Type: Compliance Evaluation
De -chlorination Yes No NA NE
# Is de -chlorination substance stored away from chlorine containers? M ❑ ❑ ❑
Comment:
Are the tablets the proper size and type? ❑ ❑ M ❑
Are tablet de -chlorinators operational? ❑ ❑ 0 ❑
Number of tubes in use?
Comment:
Standby Power
Yes
No
NA
NE
Is automatically activated standby power available?
0
❑
❑
❑
Is the generator tested by interrupting primary power source?
0
❑
❑
❑
Is the generator tested under load?
0
❑
❑
❑
Was generator tested & operational during the inspection?
❑
0
❑
❑
Do the generator(s) have adequate capacity to operate the entire wastewater site?
M
❑
❑
❑
Is there an emergency agreement with a fuel vendor for extended run on back-up power?
0
❑
❑
❑
Is the generator fuel level monitored?
M
❑
❑
❑
Comment: Both generators are load tested weekly.
Pumps-RAS-WAS
Yes
No
NA
NE
Are pumps in place?
❑
❑
❑
Are pumps operational?
❑
❑
❑
Are there adequate spare parts and supplies on site?
❑
❑
❑
i�g
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 degrees
■
❑
❑
❑
Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
❑
❑
0
❑
Incubator (BOD) set to 20.0 degrees Celsius +1- 1.0 degrees?
❑
❑
0
❑
Comment: Laboratory number 349 is certified for the following parameters: DO. pH. temperature, and
total residual chlorine. Meritech Laboratory performs all other parameters.

Permit: NCO020834 Owner -Facility: Warrenton WwrP
Inspection pate: 07I22?2020 Inspection Type: Compliance Evaluation
Influent Sampling
Yes
No
NA
NE
# Is composite sampling flow proportional?
N
❑
❑
❑
Is sample collected above side streams?
M
❑
❑
❑
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
M
❑
❑
❑
Celsius)?
Is sampling performed according to the permit?
0❑
❑
❑
Comment: Sampler tem erature was 5 degrees C.
Effluent Sampling
Yes
No
NA
NE
Is composite sampling flow proportional?
M
❑
❑
❑
Is sample collected below all treatment units?
0
❑
❑
❑
Is proper volume collected?
❑
❑
❑
Is the tubing clean?
N❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
N
❑
❑
❑
Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
M
❑
❑
❑
representative)?
Comment: Sampler temperature was 5 degrees C.