NC0026051_Authorization to Construct_20050520

v
MCIQM&CREED
May 17, 2005
Mr. Tom Belnick
NCDENR NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
h 0s
ma - (YT
RE: Triangle Wastewater Treatment Plant Phase H Expansion
ATC No. 026051A01
NPDES Permit No. NCO026051
Dear Mr. Behlick:
M&C
hqvir K,c rel d ovft #*h
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07"
Please find attached another Partial Certification for the referenced project as we discussed.
This Partial Certification is for substantial completion of the third and final five stage biological
nutrient removal train, Train No. 3. This provides for an additional 4.0 MGD ADF capacity in
the new plant for a total of 12.0 MGD.
It is anticipated that BNR Train No. 3 will not be placed into service until such time as the
additional capacity is needed.
Please note that McKim & Creed has issued three partial certificates to date which cover all the
process units and equipment per the Authorization to Construct except for the inplant SCADA
system. A fourth and final partial certificate will be issued for this component.
If you need additional information, please let me know.
Sincerely,
�MccKIM &' CREED, P.A.
Bry. Blake, PE
Senior Project Manager
/der
Enclosures
cc: Bob Carter, Durham County
Chuck Hill, PE, Durham County
Ken Schuster, NCDENR Regional Office
Kevin Eberle, McKim & Creed, P.A.
Ty Edmondson, III, PE, T. A. Loving Co.
Milli-PWONFIEVI llUiyigilTtia®
MAY 2' 0 ' 2005
DENR • WATER QUAL0
s\1471v0003V40v05195Ma ick.DOC 200 MACKENAN COURT, CARY, NORTH CAROLINA 27511
TEL [phone] FAX [phone] www.mckimereed.com
AAM02"7

State of North Carolina
Department of Environment
and Natural Resources 2&j
.
Division of Water Quality L
Michael F.G.
Easley, Governor C D E R
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E.,, Director
PROFESSIONAL ENGINEER'S CERTIFICATION
FOR
CONSTRUCTION OF WASTEWATER TREATMENT FACILUIFS
ATC PROJECT NUMBER: 026051AOI
ur rum e
NPDES Permit No. NCO026051
I, Bryan F, Blake am a duly registered Professional Engineer
(pleaseprim)
in the State of North Carolina and have been authorized to observe (circle oneapes ica:HA mtaeltlp', full time) the
construction of the subject project for the Permittee:
Project: Durham/Triangle WWI?
Phase II Expansion
Location: Intersection of Hwy 55 and Alexander Drive
Durham County
The project consists of: BNR Train No. 3
➢ Installation of a new five stage biological nutrient removal system (one treatment
train) including the following:
• One Anaerobic Selector with three cells each 15'-9"x36'x18' (total volume 999,000
gallons)
• One Primary Anoxic Reactor with two cells each 67'x36'x18' (total volume 649,500
gallons)
• One Oxidation Ditch Aerobic Reactor 72'x339'x18' (total volume 3,200,000 gallons)
• One Second Stage Anoxic Reactor with two cells each 36'x45'x17' (total volume
412,000 gallons)
• One -Re -Aeration Stage 15'x36'x16.9' (total volume 68,000 gallons)
I hereby certify that I did
completed in substantial e
specifications.
Sigaatur�1�
rt1n>.]
and diligence and that the construction was
trust and with the approved plans and
No. 11570
Upon completion of construction and prior to operation of the modified facility, the Permittee shall provide the
Division with a certification from a professional engineer certifying that the permitted facility has been installed in
accordance with the NPDES Permit, this Authorization to Construct, and the approved plans and specifications.
The Certification should be submitted to:
NCDENRIDWQ, NPDES Unit, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E.,, Director
e�A
NCDENR
PROFESSIONAL ENGINEER'S CERTIFICATION
ATC PROJECT NUMBER: 026051AOI
nange WWTP
NPDES Permit No. NCO026051
I, Btt an F. Blake am a duly registered Professional Engineer
(please print)
in the State of North Carolina and have been authorized to observe (circle one: periodically, weekly, full time) the
construction of the subject project for the Permittee:
Project:Durham/Triangle WWTP
Phase 11 Expansion
Location: Intersection of Hwy 55 and Alexander Drive
Durham County
This certification is for substantial completion of the in -plant SCADA system.
I hereby certify that I did
completed in substantial i
Signature
and diligence and that the construction was
truct and with the approved plans and
No. 11570
Date July W 2005
Upon completion of construction and prior to operation of the modified facility, the Permittee shall provide the
Division with a certification from a professional engineer certifying that the permitted facility has been installed in
accordance with the NPDES Permit, this Authorization to Construct, and the approved plans and specifications.
The Certification should be submitted to:
NCDENBJDWQ, NPDES Unit, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617

v McIQM&CREED h
_ � -o
II ��
April 12, 2005 rnA I �'' /1'�C M&C 01471-0003 (40/60)
lVf 11
Mr. Tom Belnick l V
NCDENR NPDES Unit
1617 Mail Service Center 10
Raleigh, NC 27699-1617
RE: Triangle Wastewater Treatment Plant Phase II Expansion
ATC No. 026051AOI
NPDES Permit No. NCO026051
Dear Mr. Belnick:
Please find attached the Partial Certification for the referenced project as we discussed. The
Partial Certification is basically for placing into service one of the five stage biological nutrient
removal trains, Train No. 2, with the other process structures as noted. This provides for 4.0
MGD ADF capacity in the new plant.
McKim & Creed will process partial certifications for each of the two remaining BNR trains as
the contractor achieves substantial completion.
Also attached is the current start-up plan dated April 12, 2005 for your files. It is now
anticipated that the new process trains will be placed into service some time this week.
If you need additional information, please let me know.
Sincerely,
�McKKIM & CREED, P.A.
/J
Brya F. Blake, PE
Senior Project Manager
/der
Enclosures
cc: Bob Carter, Durham County
Chuck Hill, PE, Durham County
Ken Schuster, NCDENR Regional Office
Kevin Eberle, McKim & Creed, P.A.
Ni � � N U d N [I
APR 1 8 2005
DPR - WATER QUALITY
POINT SOURCE BRANCH
200 MACKENAN COURT, CARY, NORTH CAROLINA 27511
5:U471\M3\w\04125I36.6.doc TEL [phone] FAX [phone] www.mckimcreed.com
AA0002667

v
v McIQM&CREED
April 27, 2005 M&C 01471-0003 (40/60/70
ro
Mr. Tom Belnick
NCDENR NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
r,
RE: Triangle Wastewater Treatment Plant Phase II Expansion
ATC No. 026051A01
NPDES Permit No. NCO026051
u. .
Dear Mr. Belnick:
oil APR 2 9 2005
1
L__
I)P<R - WATf.R QUALITY
PUNT SOJiiCE BRANCH
Please find attached another Partial Certification for the referenced project as we discussed.
This Partial Certification is for placing into service the second five stage biological nutrient
removal train, Train No. 1. This provides for an additional 4.0 MGD ADF capacity in the new
plant for a total of 8.0 MGD.
McKim & Creed will process a partial certification for the one remaining BNR train as the
contractor achieves substantial completion.
It is anticipated that BNR Train No. 1 will be placed into service some time next week.
If you need additional information, please let me know.
Sincerely,
McKIM & CREED, P.A.
Bryan F. Blake, PE
Senior Project Manager
/der
Enclosures
cc: Bob Carter, Durham County
Chuck Hill, PE, Durham County
Ken Schuster, NCDENR Regional Office
Kevin Eberle, McKim & Creed, P.A.
Ty Edmondson, III, PE, T. A. Loving Co.
s: \1471\o003 WW42]sBelnick, DCC 200 MACKENAN COURT, CARY, NORTH CAROLINA 27511
TEL [phone] FAX [phone] www.mckimereed.com
.0002667

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E.,, Director
e�A
NCDENR
PROFESSIONAL ENGINEER'S CERTIFICATION
F.
ATC PROJEC'r NUMBER: 026051AOI
ur am- nang e WWTP
NPDES Permit No. NCO026051
I, Bryan F. Blake am a duly registered Professional Engineer
p ease print)
in the State of North Carolina and have been authorized to observe (circle one: pUMM{3[ity, �1t , full time) the
construction of the subject project for the Permittee:
Project:Durham/Triangle WWTP
Phase H Expansion
Location: Intersection of Hwy 55 and Alexander Drive
Durham County
The project consists of: BNR Train No.1
➢ Installation of a new five stage biological nutrient removal system (one treatment
train) including the following:
• One Anaerobic Selector with three cells each 15'-9"x36'x18' (total volume 229,000
gallons)
• One Primary Anoxic Reactor with two cells each 67'x36'x18' (total volume 649,500
gallons)
• One Oxidation Ditch Aerobic Reactor 72'x339'x18' (total volume 3,200,000 gallons)
• One Second Stage Anoxic Reactor with two cells each 36'x45'x17' (total volume
412,000 gallons)
One -Re -Aeration Stage 15'x36'x16.9' (total volume 68,000 gallons)
I hereby certify that I did regularly observe thi:
completed in substantial conformance with the
specification�7
Signature
ence and that the construction was
with the approved plans and
11570
Date April 2/-, ZUUS
Upon completion of construction and prior to operation of the modified facility, the Permittee shall provide the
Division with a cert (cation from a professional engineer certifying that the permitted facility has been installed in
accordance with the NPDES Permit, this Authorization to Construct, and the approved plans and specifications.
The Certification should be submitted to:
NCDENNDWQ NPDES Unit, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617

TRIANGLE WWTP PHASE II
START-UP PLAN
APRIL 12, 2005
The start-up plan is based on all process facilities being completed, leak tested, electrical
checked out, and ready to be placed into service. The plan is also based on transferring RAS
and/or WAS from the existing clarifiers to seed the one new BNR Train.
1. The chemical bulk storage tanks shall be checked to confirm that a sufficient supply of
the following chemicals are present:
• potassium hydroxide (supplied by Woodward & Curran)
• sodium aluminate (supplied by Woodward & Curran)
• polymer (supplied by Woodward & Curran, see Item 16)
• methanol (supplied by Loving , see Item 1.6, Page 11501-2)
• sodium hypochlorite (supplied by Woodward & Curran)
Woodward & Curran to check and confirm that all chemical bulk storage tanks
have sufficient supply of chemicals.
2. The State (Regional Office) shall be notified when Loving starts to fill the BNR trains for
leak testing as just about all plant effluent flow will be diverted to fill the BNR trains.
Woodward & Curran to notify the State.
3. RAS and/or WAS will be pumped via the existing RAS or WAS pumps and an
interconnection between the existing WAS waste line and the new WAS waste line. See
Sheet C-8. Operation of existing RAS/WAS pumps by Woodward & Curran.
4. The new WAS meter vault shall be valved so as to pass flow through the by-pass line
around the meter vault. The WAS shall enter the new RASMAS wetwell by isolating
and removing one of the new RASNVAS pumps on the south side of the station. The
corresponding check valve shall be blocked open to allow flow to enter the wetwell
through the pump discharge piping. See Sheets C-8, C-24, and D-3A. Loving to
remove RAS Pump No. 1 and block the check valve open. Loving to close the
plug valve in the discharge header between RAS Pump No. 1 and No. 2 and close
the 8" WAS valve in the discharge header at WAS Pump No. 2.
5. The appropriate RAS/WAS pump on the north side of the new RAS/WAS pump station
shall transfer flow into the new Influent Flow and RAS Distribution Box. RAS flow shall
be measured by the new RAS flow meter. See Sheets C-10 and C-12. Kruger to lock
out WAS Pump No. 1 and RAS Pump No. 1 in their control logic to prevent them
from starting during the sludge seeding operation. (Note: In manual operation,
6. The appropriate weir shall be set to allow RAS/WAS flow to enter the desired BNR Train
(Train No. 2). The other two weirs shall be raised to isolate the remaining two BNR
Trains. Weirs to be set by Loving.
7. Forward flow shall enter the desired BNR Train (Train No. 2) by pumping. Two suction
lift pumps each capable of pumping 500 GPM to 2700 GPM shall be set on top of the
S1147110W31SMW075PIan.dm 1

State of North Carolina
Department of Environment
and Natural Resources •
Division of Water Quality _ _ a
Michael G.
Easley, Governor NCDENR
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E.,, Director
PARTIAL CERTIFICATION
PROFESSIONAL ENGINEER'S CERTIFICATION
FOR
CONSTRUCTION OF WASTEWATER TREATMENT FACILITIES
ATC PROJECT NUMBER: 026051A01
Durham -Triangle WWTP
NPDES Permit No. NCO026051
1, BRYAN F. BLARE am a duly registered Professional Engineer
(pleaseprint)
in the State of North Carolina and have been authorized to observe (circle one: jSXaiQiY*, W, full time) the
construction of the subject project for the Permittee:
Project: Durham/Triangle WWTP
Phase II Expansion
Location: Intersection of Hwy 55 and Alexander Drive
Durham County
The project consists of: ONE
➢ Installation of a new five stage biological nutrient removal system (*me treatment trains) including the following:
BNR system flow distribution box
ONE • Three 16' x 36' x 18.5' (79706 gallons) anaerobic selectors
ONE • Three 36' x 67.5' x 18.25' (331709 gallons) primary anoxic reactors
ONE • Thme.339' x 36' x 18' (1,643,366 gallons) oxidation ditch aerobic reactors
ONE • Three36' x 45.5' x 17' (208,315 gallons) second stage anoxic reactors
ONE • Three 15' x 36' x 16.5' (66,656 gallons) reaeration tanks
➢ Secondary clarifier flow distribution
➢ Four 110' diameter x 16' high secondary clarifiers
➢ Two return activated sludge wetwells with two high volume (3,475 gpm) and one low volume (350 gpm) pumps per
wetwell
➢ Retuut activatedsludget?LCJwcetLtlwu pcepoxFaena4cenirolPxa cett�e4ayetetn
➢ Tertiary filter weir type flow distribution
➢ Five train traveling bridge tertiary sand filter with effective sand particle size of 0.55 to 0.65 mm and a uniformity
coefficient (D60/D10) less than or equal to 1.5
➢ Filter backwash system consisting of one 7.5 hp centrifugal pump per filter train (five pumps total)
➢ Sodium Aluminate Chemical feed system with application points located secondary clarifier influent distribution
chamber and the tertiary sand filter distribution channel
➢ Polymer feed system with application points located secondary clarifier influent distribution chamber
➢ Sodium hypochlorite feed system with application points located at the tertiary sand filter distribution channel and
the reuse water trough at the ultraviolet disinfection unit effluent
➢ Effluent flow metering system consisting of a compound rectangular sharp crested weir and a ultrasonic level sensor
➢ Installation of any appurtenances associated with the referenced modifications
certify that 1 did regularly observe this project with due care and diligence and that the construction was
:d in substantial conformance with the Authorization to Construct and with the approvsd Bans and
Signature
Registration No. 1157
Date W, `
Upon completion of construction and prior to operation of the modified facility, rmrMhausb
"ta
the
Division with a certification from a professional engineer certifying that the permit 7i d in
accordance with the NPDES Permit, this Authorization to Construct, and the approv
The Certification should be submitted to:
NCDENRIDWQ, NPDES Unit, 1617 Mail Service Center, Raleigh, North

Influent Flow and RAS Distribution Box. The discharge of the pumps shall be metered
with local read out of GPM and total flow. Pumps to be furnished and setup by
Loving. Woodward & Curran to maintain operation of the pumps. (Note: The
temporary pumps are manually controlled without floats and must not be allowed
to run dry.)
8. The existing plant process train shall remain on line at all times. The existing 30" sluice
gate at the grit structure effluent box shall remain open such that forward flow not
pumped into the BNR basin shall continue to feed the existing aeration basins.
9. The Contractor shall leak test each BNR Train one at a time with plant effluent. The
testing water can be pumped from one train to the next such that the desired BNR Train
to be placed into service first receives the test water last. Leak testing is to be
completed prior to transferring RASNVAS flow into BNR. Leak testing by Loving.
10. After leak testing has been successfully completed, the desired BNR Train (Train No. 2)
to be placed into service shall have a plant effluent water level in the anaerobic, anoxic
zones and oxidation ditch that reaches the edges of rotors blades (0" rotor
submergence). Rotor blade submergence can be checked physically or read from the
PLC. Loving to provide the effluent water and confirm level.
11. The BNR train will be started and run manually without the Kruger PLC Control
Panel. See the attachment "Manual Operation Train No. 2".
12. The mixers and weirs should be placed into local or manual control. Raise the ditch
effluent weirs approximately 3 inches above lowest position and set secondary anoxic
effluent weirs at lowest position. Turn on all mixers. Kruger/Loving to set weirs and
place mixers into operation.
13. Begin seeding system with sludge approximately 24 to 48 hours prior to starting influent
flow: Woodward & Curran to operate existing RAS/WAS pumps to provide seed
sludge.
It is desirable to have seeded the new oxidation ditch with at least 300 to 500 mg/I of
MLSS from the existing system before starting influent flow. If it is possible to have
more than this, so much the better, however, Kruger does not recommend adding
seed sludge more than 48 hours in advance of adding influent. If possible, allow the
MLSS in the existing system to increase several days prior to anticipated startup to
20 or 30 % above your normal target level. Then waste the excess sludge to the
new ditch over first two to four days of seeding.
The amount of sludge needed for a desirable start-up MLSS level of 300-500 mg/I
may be estimated as following:
Volume of Seed Sludge, MG = (X mg/p x Total Basin Volume(MG)
MLSS in RASor WAS
Where X is the target MLSS level in the new ditch and the total basin
volume for the new ditch inclusive of ditch, anaerobic and anoxic
zones is about 4.5 MG
S\15)1i0 3WW75R.n d.

For example, assuming the concentration of the RASMAS flow is about 8,000 mg/I
approximately 170,000 gallons would be required to raise the MLSS level in the new
ditch to 300 mg/I.
Seeding the new ditch with RASMAS from the existing system should continue for
several days following introduction of influent until the MLSS reaches between 1000
and 1500 mg/I. At that point, it will be best to let solids accumulate through new
biological growth in the system. Woodward & Curran to provide for testing of
sludge to ensure the desired MLSS levels.
14. Once RASANAS flow from the existing clarifiers is not required, then the pumps in the
new RASNVWAS Pump Station shall be reset and valves adjusted to allow wasting of
sludge from the new process. Loving to reset RAS Pump No. 1, reset check valve
and discharge header valves for normal operation. Kruger to "unlock" RAS Pump
No. 1 and WAS Pump No. 1 in control logic to allow normal operation. (Note: RAS
Pump No. 1 to remain locked out until pump has been replaced.)
15. Verify that chemical feed systems are functional and ready for operation (sodium
aluminate, potassium hydroxide, and cationic polymer initially and methanol). Methanol
will likely be required one or two weeks later, after biological nitrification has been
established. Adjust initial feed rates per Table 1 based on actual influent flow rate.
Start the appropriate chemical feeds simultaneously with starting influent flow to the
BNR.
Table 1. Initial Chemical Dosage Recommendations
(Durham Only — Not Including Cary Flow)
Forward Flow
1 MGD
2 MGD
3 MGD
4 MGD
Chemical
m /I
al/hr
m /I
al/hr
m /I
al/hr
m /I
al/hr
Sodium Aluminate
17.2
2.5
17.2
5
17.2
7.5
17.2
10
Potassium Hydroxide
115.7
7
115.7
14
115.7
21
115.7
28
Emulsion Cationic Polymer
1
0.04
1
0.08
1
0.12
1
0.16
Methanol
3
0.47
3
0.94
3
1.41
3
1.88
16. Once the influent flow has raised the water level in the ditch so that the rotor
submergence > 4", turn on the rotors. If automatic D.O. control is functioning, the D.O.
set point should be 2.5 mg/I. It will be decreased to 1.3 mg/I when the MLSS reaches
target levels, the major criteria for achieving a stabilized system, before reducing the
D.O. set point. Loving/Kruger to place rotors into operation. (Note: Automatic D.O.
control will not be functioning at start up.)
17. Do not turn on the internal recycle pumps until it is verified that the new ditch is fully
nitrifying as evidenced by low ammonia (< 1 mg/1) and a corresponding increase in
nitrate (> 5 to 10 mg/1) in the BNR effluent (see Item 22). Woodward & Curran to
provide regular testing to track ammonia and nitrate levels. Once nitrification has
been established, start methanol feed at the rate indicated in Table 1 to the second
anoxic zone.
S'.1147110003WO4075PIan dm 3

18. One of the new clarifiers (Clarifier No. 3) shall be placed into service with the other three
off-line. The clarifier will be empty and allowed to fill with forward flow from the BNR
Train. Start sodium aluminate feed when forward flow is initiated to the clarifier.
Woodward & Curran shall have their chemical supplier jar testing the MLSS
entering the clarifier to determine the proper polymer. McKim & Creed would
anticipate the use of a cationic polymer. Once the correct polymer is identified, the
polymer shall be supplied at the recommended dosage to the forward flow entering the
clarifier. The first clarifier shall continue to fill and allowed to stabilize establishing the
sludge blanket after the BNR Train has stabilized (see Items 19 and 24). As the forward
flow is increased to the first BNR Train, a second clarifier (Clarifier No. 2) can be brought
on line if needed. The two remaining off-line clarifiers (Clarifier No. 1 and No. 4) shall
serve as storage basins if there is an upset of the BNR Train. Flow can be diverted into
the off-line clarifiers by weir adjustment at the Clarifier Distribution Box. See Sheet C-
21. Woodward & Curran is to bring on-line the second clarifier as needed.
19. Once flow is entering the secondary clarifier and RAS flow can be discharged from the
clarifier, the RAS pumps should be switched on and the RAS should be adjusted to
100% of the influent flow. It is not necessary to establish a sludge blanket during
startup, rather keep the RAS rate high to ensure most of the MLSS solids reside in the
aeration basins where there is food and oxygen available for growth rather than the
clarifier. Control of RAS pumping shall be set by Kruger in the control logic for
start-up. (Note: However at start up the RAS pumps shall be manually operated.
20. Implement automatic level control at PLC or SCADA and set rotor submergence at
8 inches. Woodward & Curran to set automatic level control. The ditch weir shall
be manually adjusted at start up in accordance with the attachment.
21. Monitor MLSS in the oxidation ditch at least once per day (maybe more often) during
seeding. The initial influent flow rate may be estimated as following using the aerobic
F:M as the basis for controlling flow volume. Woodward & Curran to provide for
monitoring of MLSS levels.
Influent flow, MGD = (F: M) x 0.7 * MLSS(mg/1) x Ditch Volume(MG)
Infuent BOD(mg / 1)
NOTE: The aerobic F:M is estimated using the ditch volume only and does not
include the volume of the anaerobic zones, the anoxic zones, or solids in the
clarifier.
An aerobic F:M ratio about 0.15 to 0.2 is initially desired in order to accelerate
sludge build-up during start-up. The following table shows the estimation of
influent flow vs. MLSS assuming an influent BOD of about 150 mg/I on average
and a ditch volume of about 3 MG. Continue seeding until MLSS reaches target
levels (about 3,000-4,000 mg/I).
S \1471\0003\00\04075PIan dm 4

Table 2. Recommended flow, MLSS and F:M ratio during Start-up
Influent Flow, MGD
MLSS, mg/I
Approximate F:M
0.5 to 0.7
300 to 400
0.17
1.0 to 1.2
600 to 700
0.14
1.5 to 1.7
900 to 1,100
0.12
2.0 to 2.2
1,400 to 1,600
0.10
2.3 to 2.5
1,900 to 2,200
0.09
3.0 to 3.2
2,400 to 2,600
0.09
3.5 to 4 MGD
3,000 to 3,300
0.09
The values in Table 2 assume the wastewater temperature is 12 to 150C and an influent
BOD of approximately 150 mg/I. The values in this table should be considered
approximate. Decrease influent flow if effluent ammonias rise above 2 mg/I or effluent
BOD rises above 15 mg/I., the influent BOD increases significantly, or the MLSS
temperature in the oxidation ditch falls below 10 to 111C.
A recommended monitoring schedule for process startup is listed in Table 3. As an
absolute minimum, the ditches should be monitored for MLSS and ammonia and the
clarifier effluent composite analyzed for ammonia. Kruger assumes that plant staff has
the capability onsite to monitor ammonia and MLSS daily. Once the ditch is stabilized,
the frequency of monitoring can be reduced.
S'\1471\0003%0\04075PIan. dM 5

Table 3. Recommended Monitoring Schedule During BNR Process Start-up
(Raw
BNR
Influent
Influent
Anaerobic
Secondary
(pre
(post
Selector
Oxidation
Clarifier
WAS/
Parameters
screening)
screening)
3rd stage)
Ditches
Effluent
RAS
Organic
CBOD5-Total
DC*
DC
---
—
DC
—
Solids
TSS
DC*
DC
---
Twice/day
DC
W
VSS
W
W
DG
-
Nitrogen
TN
DC*
W
DG
DC
DG
TKN
DC*
W
---
DG
DC
DG
NH4-N
DC*
DC
—
DG
DC
DG
NO3-N
0
0
—
DG
DC
DG
Phosphorus
TP
DC*
DC
DG
—
DC
—
PO4-P
DG
DG
DG
DG
DC
—
Operational
Indicators
pH
DG
DG
—
DG
DG
—
Alkalinity
DG
DG
---
DG
Temperature
DG
DG
-
---
--
Mixed Liquor
Settled Sludge
—
—
-
Once/day
---
---
Volume (5,30,60
Min
TP in Mixer Liquor
O
DG
---
DC: Daily composite sample
DC*: Manual daily composite sample minimum of 5 samples taken to correlate with the post
screening samples
DG: Daily grab sample
W: Weekly (twice/week)
O: Occasional
22. Once nitrification is stabilized, as evidence by effluent ammonias < 1 mg/ and a rise in
effluent nitrates, the internal recycle pumps can be started. The pumps should be set to
return about 100 to 150% of the influent flow rate. Woodward & Curran to start
internal recycle pumps.
23. It may be desirable to begin wasting some sludge from the new system once the MLSS
reaches about 1,500 mg/I to 2,000 mg/I or 15-20 days after seeding, whichever comes
first. The volume of waste sludge can be estimated based on a SRT of 15-20 days and
should be less than net growth of activated sludge in oxidation ditches to allow continued
accumulation of solids. Kruger will advise during startup on when to begin wasting
and how much to waste.
24. At MLSS of about 2000 mg/l, adjust RAS flow to maintain a 1-2 ft sludge blanket depth in
secondary clarifiers. The sludge blanket should be checked at approximately the same
time each day in the same location in the clarifier. Woodward & Curran to make
adjustment to RAS pumps and provide for checking of sludge blankets.
25. As forward flow leaves the first clarifier, one new filter (Filter No. 1) shall be placed into
service. Influent sluice gates for four filters shall be shut and one sluice gate shall be
open for the filter to be placed into service. See Sheet C-25. Woodward & Curran
S\1471\000160\04075PIandcc

shall set the sluice gates and place the one filter into service. When the second
BNR Train is placed into service and all forward flow has been diverted from the existing
plant into the new BNR process trains, a second filter (Filter No. 2) shall be placed into
service.
26. Once the MLSS concentration is between 2,500 and 3000 mg/1 and nitrification is
stabilized, the RAS Bleed to the second anoxic stage may be started. The RAS bleed
should be incrementally increased daily until the MLSS in the Secondary Anoxic zone is
approximately 800 to 1000 mg/I higher than in the oxidation ditches. During this
adjustment period lasting a few days, collect a sample of MLSS for solids measurement
from the secondary anoxic zone in addition to the sample collected in the oxidation ditch.
Typically the RAS bleed rate will be between 20 and 30 percent of the RAS flow rate and
the target MLSS in the secondary anoxic should be about 700 to 1000 mg/I higher than
in the oxidation ditch upstream. Once the RAS bleed is set, sampling in the secondary
anoxic zone can be reduced to once per week. Lower the DO set point in the oxidation
ditch to 1.3 mg/I. Woodward & Curran to make the RAS bleed adjustment and
provide for testing MLSS levels.
27. After approximately four weeks of operation, begin monitoring the ortho-phosphate in the
selector and the total phosphate concentration in the influent about twice per week to
detect onset of biological phosphorus removal. Chemical addition (sodium aluminate)
will probably be required into the clarifiers, particularly during startup if phosphorus limits
must be met. Woodward & Curran to provide for monitoring the ortho-phosphate
level.
28. After the first BNR Train (Train No. 2) has stabilized, the second BNR Train (Train No. 1)
will be started up. The startup process shall be as outlined above except seed sludge
shall be provided from the new clarifiers and will not be required from the existing
clarifiers. The 30" sluice gate at the grit structure effluent box shall be closed allowing all
forward flow to enter the two BNR Trains. This will eliminate the need for the temporary
pumps (Item 7) as the forward flow will be gravity flow. Once the 30" sluice gate is
closed, the existing plant can be allowed to go off-line. Once the existing plant is off-line,
the effluent pump station can be shut down and the 30" sluice gate at the UV structure
influent box can be closed. See Sheet C-17 of the Phase I plans. Woodward & Curran
to place the existing plant off-line and close the appropriate sluice gates.
BOD removal should begin to occur immediately if seeding is adequate and the influent flow is
not increased too rapidly. Nitrification should also follow rapidly again if the F:M ratio does not
get too high. During the first couple of days of startup, there will be a considerable dilution
effect to offset any delay in onset of nitrification. Sufficient MLSS must be accumulated to see
good nitrogen removal and this may require several weeks. Kruger would recommend holding
off on methanol addition until solids are at target levels and effluent TN levels have stabilized.
Biological phosphorus will require significantly more time and will be very much dependant on
the presence of soluble BOD in the influent. If the soluble BOD is present, biological
phosphorus removal should begin to take place within 6 - 10 weeks after initial startup and
steadily improve thereafter if the system is suitably loaded. The onset of biological phosphorus
removal is detected by monitoring the ortho-phosphate concentration in the last stage of the
anaerobic selector. Typically, it will be 3 to 5 times the ortho-phosphate concentration in the
influent if the release/uptake cycle is established. After approximately four weeks of operation,
S.\1471\0000\00\04075P1an.dM 7

begin monitoring the ortho-phosphate in the selector and the total phosphate concentration in
the influent about twice per week.
Kruger personnel will visit the site the first few days of startup and will always be available for
consult.
The County has agreed for Woodward & Curran to provide a designated start-up coordinator.
Woodward & Curran to inform the County of the designated person.
S:1147iW0001fi0W4075P1an,Eoc 8

MANUAL OPERATION TRAIN #2
BEFORE TURN ON ROTORS, MAKE SURE ROTOR SUBMERGENCE _> 4"
Initial Manual Mode Start-up
• After leak testing, water levels in the ditch should reach the edges of rotor blades. Turn on
all mixers
• Drop secondary anoxic effluent weir down to the lowest position
• Under manual operation mode, adjust weir position according to the flow rates listed in
Table 1. The flow rates listed here are the anticipated start-up raw influent plus RAS flow.
For example, assume the start-up flow rate of 2.0 MGD and RAS flow of 1.0 MGD, the total
influent to the ditch would be 3.0 MGD, then the ditch effluent weir would be raised 2.0
inches from its lowest position. If the total flow rate to the ditch is more than 6.0 MGD, the
effluent weir would be in the lowest position.
Table 1. Rotor submergence and weir position at different flowrate
Flow rate, MGD*
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
Water head over weir, inch
1.2
1.9
2.5
3.0
3.5
4.0
4.4
4.8
Initial weir elevation, inch'
3
2.5
2
1.5
1.0
0
0
0
Approx. rotor
submergence, inch
8.2
8.4
8.5
8.5
8.5
8.0
8.4
8.8
* Including RAS flow
+ Measured from the lowest weir position
• Add seeding sludge, and turn on re -aeration blowers. Once rotor submergence > 4", turn on
all rotors.
• Pump raw influent to the BNR train when mixed liquor concentrations reach above 500
mg/l.
• If necessary, re -adjust the ditch effluent weir position to maintain an optimal rotor
submergence of 8.5 inches.
• Adjust secondary effluent weir positions so that the water levels (read from water level
sensors) in secondary anoxic zones are 3" inches lower than in the ditch.
• Once fully nitrification has been established, turn on internal recycle pumps and set flow
rate about 100 - 200%of influent flow rate or based on effluent quality.
s�1a71\0D0 0%04075P1an.d« 9

Switch from Auto Control Mode to Manual control
• Switch mixers, rotors and internal recycle pumps to manual mode.
• All mixers should be ON
• Adjust weir position according to Table 1. Please note that the weir positions are
determined by the peak flow. For example, if the daily peak flow is 4 MGD and RAS is 3.0
MGD, then the weir will be drop down to the lowest position.
• Turn on all rotors manually or use the following equations to estimate the number of rotor in
operation.
AOR, IbsO2/day=1.2BOD (Ibs/day) + 4.6 NH3 (Ibs/day)
SOR, IbsO2/day=1.4*AOR
Number of rotors required = SOR (IbsO2/hr)1176 IbsO2/hr.rotor
Adjust secondary effluent weir positions so that the water levels (read from water level
sensors) in secondary anoxic zones are 3" inches lower than in the ditch.
Set the internal recycle pumps flow as 100-200% of influent flow.
S'.\147110WMM04075PIan. tlac 10

v MCIQM & CREED
v
June 20, 2002
Mr. Tom Belnick
NCDENR
Division of Water Quality
NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
RE: Triangle Wastewater Treatment Plant
Phase I Expansion
ATC No. 026051 ACF
Dear Mr. Belnick:
M&C 01471-0001 (40/60)
The Phase I Expansion project is nearing completion. The County has placed into service the
various components as listed in the ATC for start-ups, adjustments, and training. As the County's
Engineer of Record, we are not yet ready to certify completion until the County is in a position to
accept all equipment. However, we wanted to notify you that plant flow has been diverted into
these new facilities. We will provide the required certification as soon as practical.
If you have any questions, please give me a call.
Sincerely,
Bry n . lake, PE
Senior Project Manager
/der
cc: Chuck Hill, PE
EON b Z Nnr
200 MACKENAN COURT, SUITE 200, CARY. NORTH CAROLINA 27511
S:\1471\0001\40-Permit\06203gelnck.Yft 919.233.8091 FAX [phone] www.mckimcreed.com
AA0002"7

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
Michael F. Easley, Governor
William G. Ross, Jr., Secretary
Alan W. Klimek, P.E., Director
June 10, 2002
Mr. Chuck Hill, P.E.
County of Durham
200 E. Main Street
Durham, North Carolina 27701
`•1
NCDENR
Subject: Authorization to Construct
ATC No. 026051A01
NPDES Permit No. NCO026051
Durham/triangle WWTP
Durham County
Dear Mr. Shaw:
The Division of Water Quality's NPDES Unit has reviewed your request for an Authorization to
Construct at the Durham/Triangle W WTP. The Division finds the proposed improvements to be
satisfactory and hereby grants authorization for the following:
➢ Installation of a new five stage biological nutrient removal system (three treatment
trains) including the following:
• Biological Nutrient Removal System flow distribution box
• Three 16' x 36' x 18.5' (79706 gallons) anaerobic selectors
• Three 36' x 67.5' x 18.25' (331709 gallons) primary anoxic reactors
• Three 339' x 36' x 18' (1,643,366 gallons) oxidation ditch aerobic reactors
• Three 36' x 45.5' x 17' (208,315 gallons) second stage anoxic reactors
• Three 15' x 36' x 16.5' (66,656 gallons) reaeration tanks
➢ Clarifier flow distribution box
➢ Four 110' diameter x 16' high secondary clarifiers
➢ Two return activated sludge wetwells with two high volume (3,475 gpm) and one low
volume (350 gpm) pumps per wetwell
➢ Return activated sludge PLC based flow proportional control pump control system
➢ Tertiary filter weir type flow distribution
➢ Five train traveling bridge tertiary sand filter with effective sand particle size of 0.55 to
0.65 mm and a uniformity coefficient (D60/D10) less than or equal to 1.5
➢ Filter backwash system consisting of one 7.5 hp centrifugal pump per filter train (five
pumps total)
1617 Mail Service Center, Raleigh, North Carolina 27699-1617 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer Internet: http:.*//h2o.enr,state.nc.us/

Durham/Triangle WWTP
NPDES Permit No. NC0026051
ATC No. 026051A01
Page 2
➢ Sodium Aluminate Chemical feed system with application points located secondary
clarifier influent distribution chamber and the tertiary sand filter distribution channel
➢ Polymer feed system with application points located secondary clarifier influent
distribution chamber
➢ Sodium hypochlorite feed system with application points located at the tertiary sand
filter distribution channel and the reuse water trough at the ultraviolet disinfection unit
effluent
➢ Effluent flow metering system consisting of a compound rectangular sharp crested weir
and a ultrasonic level sensor
➢ Installation of any appurtenances associated with the referenced modifications
This Authorization to Construct is issued in accordance with NPDES Permit No. NC0026051,
issued May 22, 2002, and shall be subject to revocation unless the wastewater treatment facilities
are constructed in accordance with the terms and conditions of the permit.
The June 2002 Interim Biosolids Management Plan is hereby incorporated as a condition for this
Authorization to Construct. According the Interim Biosolids Management Plan, annual sludge
removal from the facultative sludge storage lagoons is required. However, more frequent sludge
removal may be required to maintain two feet of free board in the sludge storage lagoons.
Therefore, an additional condition for this authorization to construct is that sludge shall be
removed from the lagoons annually or more frequently if required to maintain at least two feet of
free board in the lagoons at all times.
The Permittee shall notify the Water Quality Supervisor of the Raleigh Regional Office, telephone
number [phone], at least forty-eight (48) hours prior to operation of the installed facilities, so
that an in -place inspection can be made. Notification shall be made during the normal office hours
of 8:00 a.m. until 5:00 p.m., Monday through Friday.
En¢ineei s Certification
Upon completion of construction and prior to operation of the modified facility, the Permittee shall
provide the Division with a certification (copy enclosed) from a professional engineer registered in
North Carolina certifying that the permitted facility has been installed in accordance with the
NPDES Permit, this Authorization to Construct, and the approved plans and specifications. The
Certification should be submitted to: NCDENR / DWQ NPDES Unit,1617 Mail Service Center,
Raleigh, North Carolina 27699-1617.
Requirements for Certified Operator
The Permittee shall employ a certified wastewater treatment plant operator to be in responsible
charge (ORC) of the wastewater treatment facilities. The operator must hold a certificate of the
type and grade at least equivalent to or greater than the classification assigned to the wastewater
treatment facilities by the Certification Commission. The Permittee must also employ a certified
back-up operator of the appropriate type and grade to comply with the conditions of Title 15A,
Chapter 8G, .0200. The ORC of the facility must visit each Class I facility at least weekly and each
Class II, III, and IV facility at least daily, excluding weekends and holidays, and must properly

Durham/Triangle WWTP
NPDES Permit No. NCO026051
ATC No. 026051 AO
Page 3
manage and document daily operation and maintenance of the facility and comply with all other
conditions of Title 15A, Chapter 8G, .0200.
Additional Requirements
The Operational Agreement between the Permittee and the Environmental Management
Commission is incorporated herein by reference and is a condition of this Permit. Noncompliance
with the terms of the Operational Agreement shall subject the Pem-dttee to all sanctions provided
by G. S.143-215.6 for violation of or failure to act in accordance with the terms and conditions of
this Permit.
Failure to abide by the requirements contained in this Authorization to Construct may subject the
Permittee to an enforcement action by the Division of Water Quality in accordance with North
Carolina General Statute 143-215.6A to 143-215.6C.
The issuance of this Authorization to Construct does not preclude the Permittee from complying
with any and all statutes, rules, regulations, or ordinances which may be imposed by other
government agencies (local, state, and federal) which have jurisdiction.
The Permittee shall maintain a copy of the approved plans and specifications on file for the life of
the facility. One (1) copy of the approved plans and specifications is enclosed for your records.
If you have any questions about this Authorization to Construct, please contact Mike Myers, at
[phone], extension 508.
Sincerely,
Alan W. Klimek, P.E.
Director
Enclosures: Project Plans and Specifications (approved)
Engineer's Certification Form
cc: Raleigh Regional Office, Water Quality
Technical Assistance and Certification Unit
Central Files
111W Unit Files t
Mr. Bryan Blake, P.E. - McKim and Creed
2625 Dillard Dr., Suite 117
Cary, North Carolina 27511

STAFF REPORT AND RECOMMENDATIONS
FOR AUTHORIZATION TO CONSTRUCT AN UPGRADE 12.0 MGD
PLANT WITH BNR, CHEMICAL PHOSPHOROUS PRECIPITATION,
TERTIARY SAND FILTRATION AND UV DISINFECTION
SOC PRIORITY PROJECT: Yes _ No X
If Yes, SOC No.:
Date: May 2, 2002
To: NPDES Unit D rn-
Attention: Mike Myers ll''�%
County: Durham MAY - 7 2002 D
Permit No.: NCO026051
ATC Permit No.: 026051A01 DENR-w"'R OI1.1L17Y
POINT SOURCE E3 RAn!(_H
PART I -GENERAL INFORMATION
I. Facility and Address: Triangle WWTP
NC Highway 55 and NCSR 2028
West of RTP
Durham County
2. Report Prepared by: Ken Schuster
3. Date of most recent NPDES Staff Report (attach copy): November 29,1995 report
4. Changes since previous action on NPDES Permit: The revised draft NPDES permit
revision is presently being reviewed by EPA.
5. Discharge Point(s), list for all discharge points:
Latitude: 35° 52' 50" Longitude: 78° 53' 50"
Attach a USGS map extract and indicate treatment facility site and discharge point on map.
U.S.G.S. Quad No.: D23NW U.S.G.S. Quad Name: Southwest Durham, NC
6. Treatment plant classification (attach completed rating sheet): IV
Non -Discharge Staff Report
Page 1

PROVIDE ADDITIONAL INFORMATION FOR PARTS I, II, AND III ONLY IF IT IS
NOT PROVIDED IN ATTACHED STAFF REPORT
Date of Investigation:
8. Persons Contacted and Telephone Number:
9. Directions to Site:
10. Site size and expansion area consistent with application? Yes: _ No:
If No, explain:
11. Topography (relationship to flood plain included):
12. Location of nearest dwelling:
13. Receiving stream or affected surface waters: Northeast Creek
a. Classification: WS-IV NSW
b. River Basin and Subbasin No.: Cape Fear, subasin 30605
C. Describe receiving stream features and pertinent downstream uses:
PART II - DESCRIPTION OF DISCHARGE AND TREATMENT WORKS
a. Volume of Wastewater to be permitted: Upgrade from 6.0 to 12.0 MGD
b. What is the current permitted capacity of the Waste Water Treatment facility?
6.0 MGD
C. Actual treatment capacity of the current facility (current design capacity)?
6.0 MGD
d. Date(s) and construction activities allowed by previous Authorization to Construct
issued in the previous two years: New headworks and UV disinfection (ATC no.
026051ACF dated 3/23/O1) and post-aeration(ATC no. 026051ACE dated
12/10/99)
e. Please provide a description of existing or substantially constructed wastewater
treatment facilities: The phase I construction started March 2002
f. Please provide a description of proposed wastewater treatment facilities: Phase II:
Upgrade to 12.OMGD and installation of five stage biological nutrient removal
Non -Discharge Staff Report
Page 2

system (BNR) with chemical phosphorous precipitation and tertiary sand
filtration
g. Possible toxic impacts to surface waters:
h. Pretreatment Program (POTWs only):
in development: _ approved: X
should be required: _ not needed:
2. Residuals handling and utilization/disposal scheme:
a. If residuals are being land applied, please specify DWQ permit no.: WQ0007989
reissued 11/8/99, expires 10/31/04
Residual Contractor:
Telephone No.:
b. Residuals stabilization: PSRP: _ PFRP:
Other:
C. Landfill:
d. Other disposal/utilization scheme (Specify):
3. SIC Code(s):
4. Wastewater Code(s) of actual wastewater, not particular facilities i.e.., non -contact cooling
water discharge from a metal plating company would be 14, not 56. Include more than one
code if applicable:
5. Main Treatment Unit Code:
PART IH - OTHER PERTINENT INFORMATION
1. Is this facility being constructed with Construction Grant Funds or are
any public monies involved. (municipals only)? No
2. Special monitoring or limitations (including toxicity) requests:
3. Important SOC, JOC or Compliance Schedule dates: (Please indicate)
Date
Non -Discharge Staff Report
Page 3

Submission of Plans and Specifications
Begin Construction
Complete Construction
4. Alternative Analysis Evaluation: Has the facility evaluated all of the non -discharge options
available? Please provide regional perspective for each option evaluated.
Spray Irrigation:
Connection to Regional Sewer System:
Subsurface:
Other disposal options:
5. Other Special Items:
PART IV - EVALUATION AND RECOMMENDATIONS
The Raleigh Regional Office has reviewed the current submittal package requesting
Authorization to Construct (ATC) for the Phase H expansion. This expansion will include:
1. Five stage biological treatment Kruger A2O process utilizing an anaerobic "selector",
primary anoxic tank, aerobic reactor (oxidation ditch), secondary anoxic reactor, and re -
aeration tank to remove organics and nutrients.
2. Alum (or sodium aluminate) is added to the mixed liquor prior to distribution chamber to
four 110' dia. x 16' SWD center -feed clarifiers. These clarifiers will maintain a minimum 15"
blanket at all times to create anoxic conditions and improved colloidal solids capture, prior
to recycling sludge back to the first BNR tank.
3. Replace the existing tertiary filtration with new five -celled traveling bridge type tertiary
sand filtration. A traveling backwash hood will be used for cleaning. The hood is indexed
to stop on each cell, lowered for a seal, and a backwash pump draws filter effluent from the
underlying effluent plenum. Backwash cycles will be able to be initiated either manually,
by timer, or via liquid level sensors.
Our staff has reviewed our files of the above referenced site, as well as the plans and
specifications submitted, in order to make the following comments and recommendations for the
request.
The construction of the new phase I headworks and UV disinfection has started as allowed
by ATC no. 026051ACF dated 3/23/O1. The treatment train top of wall elevations are shown above
the 100 year elevation of 251.7 (251.75 was shown on one detail), as well as the chemical
containment walls. I did not see elevations for the electrical equipment panels, etc. These need to
be well above the 100 year flood elevation also.
With three BNR treatment trains, 4 clarifiers, and 5 tertiary sand filter cells reliability as per
211.0124 is met. There are 3 each RAS/WAS pumps. The chemical feed systems have multiple
pumps for the various trains and meet reliability requirements. Three emergency generators for 100%
are included. A 500KW generator for headworks, administration building, and analytical laboratory.
A 1400KW generator for BNR process, clarifiers, and the RAS/WAS pumping system. A 500KW
Non -Discharge Staff Report
Page 4

generator for tertiary filtration, UV disinfection, post aeration, maintenance building, and chemical
feed systems.
The DWQ issued speculative limits on July 7, 2000 and they are shown on Table VI-2 in the
calculation manual. The entry in the table for the design year TN show "8371 lbs/d". The related
footnote does show it correctly: At 12 MGD 8,371 lb TN/month corresponds to an average
concentration of 2.75 mg/l.
The plant chemical feed capabilities will be; methanol introduced to the 2nd and 4th BNR
stages, potassium hydroxide feed in the oxidation ditches to maintain alkalinity, sodium aluminate
for phosphorous removal with capability to feed to the clarifier distribution box or the filters,
polymer for settling added to the clarifiers, and sodium hypochlorite to control biological growth in
the filters.
The SCADA is defined in volume 2 of the technical specifications.
An inspection of the present treatment plant was made on April 1, 2002 by Kirk Stafford of
this office. During the inspection it was noted that no staff gauge was present in either of the sludge
lagoons. Mr Cozart, the ORC stated that the staff gages were knocked down during sludge removal
in 2000 by the contractor and that the contractor was supposed to reinstall the gages. The West
lagoon had approximately 12 inches of freeboard and the East lagoon had approximately 18 inches
of freeboard. The RRO would like to ensure that those gages are replaced as soon as possible.
The RRO is concerned that phase II will not include residuals handling and that the phase
III residuals management construction is not planned to start until March of 2005. The ORC has
stated that during Phase I of the plant upgrade, the West lagoon sludge is scheduled to be land
applied. It is not clear what will be done with the sludge in the East Lagoon.
The regions previous comments from the EAA review include:
The RRO is concerned that the solids handling process is not adequately addressed in the EAA.
Although there is some mention to digesters and thickeners, there do not appear to be any shown
on the map of the f nal recommended alternative. The f nal recommended alternative shows one
sludge lagoon is to remain operational at least until start-up of new facility, however, there do not
appear to be any other sludge storage facilities identified. The RRO recommends that both sludge
storage lagoons be taken out of service once the new facility is on-line, and that appropriate new
storage tanks, digesters, and any other necessary solids handling equipment be included with Phase
II of construction. (This may already be the case, but it did not appear clear in the EAA)
The City should address whether the lagoons are storage lagoons or treatment lagoons and
how they are complying with the 503 requirements
Based on the above, the RRO recommends that the subject project be awarded an ATC as
requested, pending P&E satisfaction of all requirements. The RRO would also appreciate
correspondence back�pertaining to any request for additional information.
Signature of repo preparer Date
� oL
Water Qu ty R nal Supervisor a
Non -Discharge Staff Report
Page 5 6

v MMIQMC,REED
v
July 6, 2001
Ms. Sue Homewood
Environmental Engineer
NCDENR
Division of Water Quality
512 S. Salisbury Street
Raleigh, NC 27604
Re: Triangle Wastewater Treatment Plant
Durham County
Dear Ms. Homewood:
M&C Project # 014710003 (10)
This letter is in follow-up to our conversation regarding our May 23n0 letter addressing the
use of reuse water for the proposed Administration/Laboratory Building. As proposed,
the upgrade and expansion of the wastewater facility will be comprised of a 5-stage BNR
process, clarifier, tertiary filters and UV disinfection. Although the speculative limits
require a suspended solids limit of 30 mg/I, the process has been designed to meet
reuse quality with a suspended solids limit of 5 mg/l with a maximum day of 10 mg/I.
The County is planning to utilize "purple" coded piping with valves properly labeled and
locking. However, the County is asking for an exemption concerning continuous turbidity
monitoring and the ability to return effluent that exceeds the TSS or fecal levels. The
reason being is the reuse line serving the new Administration/Laboratory Building will
actually branch off of the internal wash down system. The wash down system will
provide plant effluent for screen washing, clarifier spray system, wash down, etc. These
items are not part of a reuse system and therefore, do not have to meet the reuse
standards. We have designed an internal wash down system utilizing pumps and a
hydro pneumatic pressurized storage tank to provide both the wash down system and
the "reuse system". The storage tank is designed to manually drain if an upset occurs.
Also, this proposed system will be on -site and will be monitored by plant personnel who
understand the issues related to reuse water systems.
We trust this answers your questions. If we can provide any additional information,
please let me know.
Sincerely,
McKim & Creed, P.A.
kBaZtlak�e, PE
Project Manager
cc: Chuck Hill, PE
David Hahn
S:/1471/0003/10/070601R0 DILLAwooAtr.doc' SUITE 117, CARP, NORTH CAROLINA 27511
TEL [phone] FAX [phone] www.mcklmcrood.com
AAM2"7

v MCIQM & CREED
v
May 23, 2001
Mr. Kim Colson, P.E.
NCDENR
Division of Water Quality
512 N. Salisbury Street, Suite 942
Raleigh, North Carolina 27604
RE: Triangle Wastewater Treatment Plant, Durham, North Carolina
Dear Mr. Colson:
M&C 01471-0003 (10)
In the follow-up to our meeting on May 151", please find the enclosed documents:
• July 7, 2000 Speculative Limits Letter
• April 10, 2001 FONSI Letter
• April 17, 2001 Request for NPDES Submittal
On behalf of Durham County, McKim & Creed has submitted the NPDES permit application for
review and approval. The State has started their formal review procedure of the application.
It is the County's intentions to serve the new Administration/Laboratory Building with reuse water
for the restrooms, HVAC system, and vehicle washdown for water conservation. The County is
also interested in this approach as a test case or model for implementation of a future reuse
system and for their LEEDS building program. However, at this time, the County is not ready to
start a full fledge reuse system to the public.
The planned upgrade of the wastewater facilities includes a 5-stage BNR process, clarifiers,
filters and UV disinfection with post aeration. The on -site reuse system will pump water out of
the discharge channel of the UV reactor. The County would like to propose in the interim that
liquid chlorine be utilized and injected in the reuse water stream prior to entering the
hydropneumatic storage tank. This would allow for additional disinfection of the reuse stream to
maintain a fecal count of 14. The plant NPDES permit requires sampling in order to monitor
discharge limits for fecal, TSS, BOD, and TN. We would suggest an additional sample on the
reuse stream for fecal only. This interim approach is proposed as the reuse water will be on -site
and basically in contact with plant personal only.
SM47110003110-COMM\05231COIwn dw
5625 DILLARD DR., SUITE 117, CARY, NORTH CAROLINA 27511
TEL [phone] FAX [phone] www.mcklmcraGd.com
AA0002667

Mr. Kim Colson, P.E.
May 23, 2001
Page 2
At the meeting, we understood that an RPZ device will be required on site to protect the potable
water supply. We are planning to install this device at the building. Also, several suggestions
were made for troubleshooting the reuse system. First, a water meter was suggested to be
installed on the reuse line to monitor usage. A port for injecting tracing dye in the reuse system
was also suggested to help with tracing cross connections. It was also suggested that pictures
be taken during construction to document the locations of the reuse lines in the walls and slabs.
The County is in agreement to provide these items in the design of the system piping.
After your review of this information, we request your directions on implementation. On behalf of
the County, we thank you for your time and input.
Very truly yours,
McKIM & CREED, P.A.
Bry . Bla e, P.E.
Pr ' ct Manager
i
/der
Enclosures
cc: Chuck Hill, P.E.
David Hahn
Wayne Munden
5 \147 I TM3110.COMWC5231Colsan Ecc
*MCIUM&CREED

North Carolina
Department of Administration
Michael F. Easley, Governor
April 10, 2001
Mr. Milt Rhodes
N.C. Dept of Env. & Nat. Resources
Div. of Water Quality
1617 Mail Service Ctr.
Raleigh, NC 27699-1617
Dear Mr. Rhodes:
Gwynn T. Swinson, Secretary
Re: SCH File # 01-E-4300-0536; Environmental Assessment/Finding of No Significant Impact
Durham County Triangle Wastewater Treatment Facility Upgrade and Expansion
The above referenced environmental impact information has been reviewed through the State
Clearinghouse under the provisions of the North Carolina Environmental Policy Act.
No comments were made by any state/local agencies in the course of this review. Therefore, no further
environmental review action on your part is required for the compliance with the Act.
Best regards.
cc: Region J
Sincerely,
6� 6sol-ex-
Ms. Chrys Baggett
Environmental Policy Act Coordinator
116 West Jones Street Raleigh, North Carolina 27603-8003 Telephone [phone]
An Equal Opportunity / Affifmative Action Employa

Michael F. Easley
Governor
r William G. Ross Jr.
—I Department of Environment and Natural Resources
Kerr T. Stevens, Director
Division of Water Quality
April 17, 2001
Kevin Eberle. P.E.
McKim & Creed
5625 Dillard Drive, Suite 117
Cary, North Carolina 27511
Re: SCH File #01-E-4300-0536, DWQ #12734, Durham County WWTP Upgrade and
Expansion EA
Dear Mr. Eberle:
On April 10, 2001, the State Clearinghouse deemed the North Carolina Environmental
Policy Act review on the above project complete (see attached letter from the Clearinghouse). It
is now acceptable to proceed with your permit applications through the Division of Water
Quality for the proposed project. No further actions on the Environmental Assessment are
required.
If there is anything I can assist you with, please do not hesitate to give me a call at (919)
733-5083, ext. 366.
Sincerely,
Milt Rhodes
Watershed Planner
enclosure (SCH letter)
cc: Dave Goodrich, NPDES Permitting Unit (w/o SCH Letter)
Ken Schuster, Raleigh Regional Office (w/o SCH Letter)
XD NR
N. C. Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 [phone] Customer Service
1 800 623-7748