NC0026051_Compliance Evaluation Inspection_20200318

POY COOPER
Cov enwr
MICHAEL S. REGAN
secrerary
S. DANIEL SMITH
Pirccror
NORTH CAROLINA
Environmental Quality
March 18, 2020
Ms. Stephanie Brixey, Deputy Director
Department of Engineering and Environmental Services
Durham County
5926 NC Hwy 55 E
Durham, NC 27713
Subject: Compliance Evaluation Inspection
Triangle WWTP
Permit No. NCO026051
Durham County
Dear Ms. Brixey:
6"n- - =__
On March 4, 2020, Cheng Zhang of the Raleigh Regional Office (RRO) conducted a
compliance evaluation inspection of the subject facility. The assistance provided by Mr.
Shawn Davis, the operator in responsible charge (ORC), and Ms. Amy Moore, the Lab and
Compliance Manager of the facility, was appreciated as it facilitated the inspection process.
The inspection report is attached. The following observations were made:
Triangle WWTP is permitted to discharge at a rate of 12.0 MGD and consist of: influent
pump station, mechanical fine screens, mechanical grit removal, Parshall flume, three 5-
stage biological nutrient removal (BNR) trains, four secondary clarifiers, five tertiary
sand filters, post aeration, ultraviolet disinfection, sludge lagoons, waste and return
activated sludge pumping system, methanol, potassium hydroxide, and sodium
hypochlorite storage and feed systems, liquid waste activated sludge storage,
dewatering facility, and truck loading for contract composting operation. The plant
discharges to Northeast Creek, a Class WS-IV NSW water in the Cape Fear River basin.
1. Current permit expired on April 30, 2016, renewal application was received by the
Division on September 10, 2015.
2. All primary, secondary, and tertiary treatment and post -treatment processes,
especially the BNR system, were in good operational condition, with the following
exceptions:
BNR train No. 2 was offline for construction (installation of diffusors and
blowers);
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90791,4200

One of the two mechanical fine screen was taken offline for scheduled
maintenance;
One of five tertiary filters was offline with broken parts, repair is scheduled.
3. Two of the four clarifiers were not in use because of low flow. An old clarifier has
been converted to a flow equalization basin, which receives filter backwash water,
and decant from sludge storage tanks and centrifuges. The chemical feed systems
for methanol, sodium aluminate, and polymer were all functioning well.
4. Waste activated sludge is pumped to two aerated sludge storage tanks, before being
dewatered with three sludge centrifuges. Dewatered sludge cakes are loaded onto
truck trailers and hauled away by McGill twice per week for composting.
5. Four standby power generators are tested under load monthly. The generators will
be activated automatically when primary power is out. The generators have capacity
to operate the entire facility during power outrage.
6. The ORC maintains a daily logbook. Lab results, chain -of -custody forms, and DMRs
were complete and current, kept in good order and ready for review. January and
August 2019 DMR data were compared to lab bench sheets; no data transcription
errors were noted during the inspection.
7. The right of way to the outfall was well maintained. The effluent was observed to be
clear and free of solids. No visible impacts were noted immediately downstream the
effluent pipe.
8. Field lab parameter (Certificate No. 671) calibration and analysis records were reviewed
during the inspection.
The overall condition of Triangle WWTP is compliant with Division standards. If you have
any questions regarding the attached reports or any of the findings, please contact Cheng
Mang at: [phone] (or email: [e-mail]).
Sincerely,
Scott Vinson, Regional Supervisor
Water Quality Regional Operations Section
Raleigh Regional Office
Division of Water Resources
ATTACHMENTS
Compliance Inspection Reports
Cc: Central Files w/attachment
Raleigh Regional Office w/attachment

Uniled Slates Environmental Protection Agency
Form Approved,
EPA Washington D C. 20460
OMB No. 2040-0057
Water Compliance Inspection Report
Approval expires B-31-98
Section A: National Data System Coding (i.e„ PCS)
Transaction Code NPDES yrlmolday Inspection Type Inspector Fac Type
1 IN 1 2 15 I 3 NCO026051 Ill 12 20/03/04 17 181 r I 19 ) s I 201 1
LJ U IJ LJ LJ
21 6
Inspection Work Days Facility Self-Moniloring Evaluation Rating B1 OA Reserved
72 L-73LJ74 7 80
67 70I _71 Lj
Section B Facility Data
Name and Location of Facility Inspected (For Industrial Users discharging to POTW also include
Entry TimelDate
Permit Effective Date
POTW name and NPDES permit Number)
09 00AM 20/03/04
13102I01
Triangle WWfP
Exit Time/Date
Permit Expiration Date
5926 NC Hwy 55 E
Durham NC 27713
11 OOAM 20/03/04
16/04/30
Name(s) of Onsite Representative(s)Mtles(s)1Phone and Fax Number(s) Other Facility Data
111
Shawn Demetris Davis/ORC1919-560-90361
Name, Address of Responsible OffcialMile/Phone and Fax Number
Greg Sanchez,4309 Emperor Blvd Ste 110 Durham NC 277031Managing Contacted
Member1919-941-57451 N-3
Section C: Areas Evaluated During Inspection (Check only those areas evaluated)
Permit 0 Flow Measurement N Operations & Maintenar 0 Records/Reports
Self -Monitoring Progran E Sludge Handling Dispo: M Facility Site Review N Effluent/Receiving Wate
Laboratory
Section D: Summary of FindinglComments (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 Dale
Cheng Zhang DWRIRRO WO1919-791-4200r
CL1 11 lti G ,
Signalur of Management 0 A Reviewer AgencylOfficelPhone and Fax Numbers Date
L2"!,T— r f�17oZJ
_5
EPA Form 3560-3 (Rev 9-94) Previous editions are obsolete.
Page#

Permit: NCO026051 Owner - Facility: Triangle VAAITP
Inspection bate: 031042020 Inspection Type: Compliance Evaluation
Operations & Maintenance Yes No NA NE
Is the plant generally clean with acceptable housekeeping? ■ ❑ ❑ ❑
Does the facility analyze process control parameters, for ex: MLSS, MCRT, Settleable M ❑ ❑ ❑
Solids, pH, DO, Sludge .fudge, and other that are applicable?
Comment: The facility analyzes MLSS. NH3. NO3. pH. DO, PO4, settleable solids, sludge iudge, and
turbidity for process control.
Permit
Yes
No NA NE
(If the present permit expires in 6 months or less). Has the permittee submitted a new
0
❑
❑
❑
application?
1s the facility as described in the permit?
❑
❑
❑
# Are there any special conditions for the permit?
❑
❑
0
❑
Is access to the plant site restricted to the general public?
M
❑
❑
❑
Is the inspector granted access to all areas for inspection?
M
❑
❑
❑
Comment: Current permit expired on 4/30/2016. Renewal application was received on 9110/2015.
Equalization basin is not listed as one of the treatment components.
Record Keeping
Yes
No
NA NE
Are records kept and maintained as required by the permit?
0
❑
❑
❑
Is all required information readily available, complete and current?
M
❑
❑
❑
Are all records maintained for 3 years (lab. reg. required 5 years)?
M
❑
❑
Cl
Are analytical results consistent with data reported on DMRs?
0
❑
❑
❑
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?
M
❑
❑
❑
(If the facility is = or > 5 MGD permitted flow) Do they operate 247 with a certified operato
0
❑
❑
❑
on each shift?
Is the ORC visitation log available and current?
0
❑
❑
❑
Is the ORC certified at grade equal to or higher than the facility classification?
0
❑
❑
❑
Is the backup operator certified at one grade less or greater than the facility classification'
M
❑
❑
❑
Page# 3

Permit: NCO026051 Owner - Facility: Triangle VWvTP
Inspection Date: 03104/2020 Inspection Type: Compliance Evaluation
Record Keeping Yes No NA NE
Is a copy of the current NPDES permit available on site? 0❑ ❑ ❑
Facility has copy of previous year's Annual Report on file for review? ■ ❑ ❑ ❑
Comment:
Pump Station - Influent
Yes
No NA NE
Is the pump wet well free of bypass lines or structures?
0
❑
❑
❑
Is the wet well free of excessive grease?
0
Cl
❑
Are all pumps present?
❑
Are all pumps operable?
Are float controls operable?
Is SCADA telemetry available and operational?
Is audible and visual alarm available and operational?
Comment:
Bar Screens
Yes
No NA NE
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?
Comment: One of the two mechanical bar screen was taken offline for repair.
Grit Removal
Yes
No
NA
NE
Type of grit removal
a.Manual
b.Mechanical
Is the grit free of excessive organic matter?
Is the grit free of excessive odor?
❑
El
# Is disposal of grit in compliance?
Comment:
Page# 4

Permit: NCO026051 Owner -Facility,
Inspection Date: 0310412020 Inspection Type:
Triangle 1MNTP
Compliance Evaluation
Flow Measurement - Influent
Yes
No NA NE
# Is flow meter used for reporting?
❑
N
❑
❑
Is flow meter calibrated annually?
N
❑
❑
❑
Is the flow meter operational?
0
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
❑
❑
0
❑
Comment: Facility reports effluent flow on DMR.
Equalization Basins
Yes No
NA NE
Is the basin aerated?
E
❑
❑
❑
Is the basin free of bypass lines or structures to the natural environment?
■
❑
❑
❑
Is the basin free of excessive grease?
0
❑
❑
❑
Are all pumps present?
0
❑
❑
❑
Are all pumps operable?
0
❑
❑
❑
Are float controls operable?
❑
❑
0
❑
Are audible and visual alarms operable?
❑
❑
0
❑
# Is basin size/volume adequate?
M
❑
❑
❑
Comment: The EQ basin is converted from an old clarifier. It receives filter backwash, sludge digester
decant and water from the sludge centrifuges. It has an Pive
to overflow to the lagoon
Oxidation Ditches
Yes
No
NA NE
Are the aerators operational?
0
❑
❑
❑
Are the aerators free of excessive solids build up?
0
❑
❑
❑
# Is the foam the proper color for the treatment process?
0
❑
❑
❑
Does the foam cover less than 25% of the basin's surface?
■
❑
❑
❑
Is the DO level acceptable?
0
❑
❑
❑
Are setteeometer results acceptable (> 30 minutes)?
0
❑
❑
❑
Is the DO level acceptable?(1.0 to 3.0 mgll)
❑
❑
❑
Are settelometer results acceptable?(400 to 800 mlll in 30 minutes)
❑
❑
❑
Comment:
Nutrient Removal Yes No NA NE
# Is total nitrogen removal required? 0 ❑ ❑ ❑
# Is total phosphorous removal required? 0 ❑ ❑ ❑
Type Biological
# Is chemical feed required to sustain process? 0 ❑ ❑ ❑
Page# 5

Permit: NC0026051 Owner - Facility: Triangle WwrF
Inspection Date: 03104/2020 Inspection Type: Compliance Evaluation
Nutrient Removal Yes No NA NE
Is nutrient removal process operating properly?
■ ❑ ❑ ❑
Comment: Two of three 5-stage BNR trains were in service. Train No. 2 was offline and under
construction installation of diffusor.
Secondary Clarifier
Yes No NA NE
Is the clarifier free of black and odorous wastewater?
El❑
❑
Is the site free of excessive buildup of solids in center well of circular clarifier?
11
11
❑
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?
0❑
❑
Is the drive unit operational?
M
El
El
❑
Is the return rate acceptable (low turbulence)?
M0
❑
Is the overflow clear of excessive solids/pin floc?
■
❑
❑
❑
Is the sludge blanket level acceptable? (Approximately % of the sidewall depth)
M
❑
❑
❑
Comment: Two of four clarifiers were in service
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? ❑ ❑ ❑
Is the filter free of growth?
Is the air scour operational?
Cl
❑
❑
Is the scouring acceptable?
❑
❑
❑
Is the clear well free of excessive solids and filter media?
❑
❑
❑
Comment: One of five filters was offline for repair.
Disinfection - UV Yes No NA NE
Are extra UV bulbs available on site? ❑ ❑
El
Are UV bulbs clean? ❑ ❑
Is UV intensity adequate? 0 ❑ ❑ ❑
Is transmittance at or above designed level? M❑ ❑ ❑
Page# 6

Permit: NC0026051 Owner -Facility: Triangle VWVTP
Inspection bale: 03/04/2020 Inspection Type: Compliance Evaluation
Disinfection - UV Yes No NA NE
Is there a backup system on site? M ❑ ❑ ❑
Is effluent clear and free of solids? 0 ❑ ❑ ❑
Comment: Facility alternates one of two banks of UV lights.
Pumps-RAS-WAS
Yes
No
NA NE
Are pumps in place?
0
❑
❑ ❑
Are pumps operational?
0
❑
❑ ❑
Are there adequate spare parts and supplies on site?
M
❑
❑ ❑
Comment: Four RAS pumps and two WAS pumps.
Lagoons
Yes No NA
NE
Type of lagoons?
Facultative
# Number of lagoons in operation at time of visit?
1
Are lagoons operated in?
# Is a re -circulation line present?
❑
■
❑
❑
Is lagoon free of excessive floating materials?
0
❑
❑
❑
# Are baffles between ponds or effluent baffles adjustable?
❑
❑
❑
Are dike slopes clear of woody vegetation?
r
❑
❑
❑
Are weeds controlled around the edge of the lagoon?
❑
❑
❑
Are dikes free of seepage?
0
❑
❑
❑
Are dikes free of erosion?
0
❑
❑
❑
Are dikes free of burrowing animals?
0
❑
❑
❑
# 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?
❑
❑
❑
Is the lagoon surface free of weeds?
0
❑
❑
❑
Is the lagoon free of short circuiting?
M
❑
❑
❑
Comment: Plenty of freeboard available at the time of inspection.
Influent Sampling
Yes
No
NA NE
# Is composite sampling flow proportional?
M
❑
❑
❑
Is sample collected above side streams?
M
❑
❑
❑
Is proper volume collected?
M
❑
❑
❑
Is the tubing clean?
0
❑
❑
❑
Page# 7

Permit: NCO026051 Owner - Facility: Triangle WWfP
Inspection Date: 03/04/2020 Inspection Type: Compliance Evaluation
Influent Sampling Yes No NA NE
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees R❑ ❑ ❑
Celsius)?
Is sampling performed according to the permit? 0 ❑ ❑ ❑
Comment:
Effluent Sampling
Yes
No
NA NE
Is composite sampling flow proportional?
❑
❑
❑
Is sample collected below all treatment units?
❑
❑
❑
Is proper volume collected?
0
❑
❑
❑
Is the tubing clean?
M❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
0❑
❑
❑
Celsius)?
Is the facility sampling performed as required by the permit (frequency, sampling type
M
❑
❑
❑
representative)?
Comment:
Laboratory
Yes
No
NA NB
Are field parameters performed by certified personnel or laboratory?
x
❑
❑
in
Are all other parameters(excluding Feld parameters) performed by a certified lab?
0
❑
❑
❑
# Is the facility using a contract lab?
N❑
❑
❑
# Is proper temperature set for sample storage (kept at less than or equal to 6.0 degrees
M
❑
❑
❑
Celsius)?
Incubator (Fecal Coliform) set to 44.5 degrees Celsius+/- 0.2 degrees?
M
❑
❑
❑
Incubator (BOD) set to 20.0 degrees Celsius +1- 1.0 degrees?
0
❑
❑
❑
Comment:
Standby Power
Yes
No
NA NE
Is automatically activated standby power available?
N
❑
❑
❑
Is the generator tested by interrupting primary power source?
M
❑
❑
❑
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?
M
❑
❑
❑
Is there an emergency agreement with a fuel vendor for extended run on back-up power?
N
❑
❑
❑
Is the generator fuel level monitored?
0
❑
❑
❑
Page# 8

Permit: NCO026051 Owner- Facility: Triangle w4NfP
Inspection Date: 03/04/2020 Inspection Type: Compliance Evaluation
Standby Power Yes No NA NE
Comment: Four generators are tested monthly.
Effluent Pine Yes No NA NE
Is right of way to the outfall properly maintained? M ❑ ❑ ❑
Are the receiving water free of foam other than trace amounts and other debris? M ❑ ❑ ❑
If effluent (diffuser pipes are required) are they operating properly? ❑ ❑ 0 ❑
Comment:
Flow Measurement - Effluent
Yes
No NA
NE
# Is flow meter used for reporting?
0
❑
❑
❑
Is flow meter calibrated annually?
❑
❑
❑
Is the flow meter operational?
M
❑
❑
❑
(If units are separated) Does the chart recorder match the flow meter?
❑
❑
0
❑
Comment: Last calibrated on 9/28/2019.
Upstream / Downstream Samplina Yes No NA NE
Is the facility sampling performed as required by the permit (frequency, sampling type, an( 0 ❑ ❑ ❑
sampling location)?
Comment:
Aerobic Digester
Yes No NA NE
Is the capacity adequate?
0
❑
❑
n
Is the mixing adequate?
❑
❑
❑
Is the site free of excessive foaming in the tank?
0
❑
❑
❑
# Is the odor acceptable?
0
❑
❑
❑
# Is tankage available for properly waste sludge?
0
❑
❑
❑
Comment: One of two sludgie tank was almost em t . The other was not aerated or mixed let settle for
decanting).
Solids Handling Equipment
Yes No NA NE
Is the equipment operational?
❑
❑
❑
Is the chemical feed equipment operational?
❑
❑
❑
Is storage adequate?
❑
❑
❑
Is the site free of high level of solids in filtrate from filter presses or vacuum filters?
❑
❑
❑
Page# 9

Permit: NC0026051 Owner -Facility:
Triangle WVVTP
Inspection Date: 03/04/2020 Inspection Type:
Compliance Evaluation
Solids Handlingg Equipment
Yes
No NA NE
Is the site free of sludge buildup on belts and/or rollers of filter press?
DONE-]
Is the site free of excessive moisture in belt filter press sludge cake?
❑
❑
M
❑
The facility has an approved sludge management plan?
Comment: Three sludge centrifuges. Not in ol2earton at the time of inspection.
Chemical Feed
Yes
No NA NE
Is containment adequate?
Is storage adequate?
D El
El
Are backup pumps available?
El El
D
Is the site free of excessive leaking?
❑ ❑
Comment: Methanol is fed to the secondary
anoxic zone for nitrogen removal. Sodium aluminate
is fed
to clarifiers litter box for phosphorous
removal. Sodium hyl2ochlorite can be fed to
headworks for odor control not fed at the time of inspection).
Page# 10