NC0020443_AUTHORIZATION TO CONSTRUCT_20141030

NPDES DOCUMENT SCANNiNC COVER SHEET
NPDES Permit: NCO020443
Columbia WWTP
Document Type: Permit Issuance
Wasteload Allocation
Authorization to Construct
(AtC)
Permit Modification
Speculative Limits
201 Facilities Plan
Instream Assessment (67B)
Environmental Assessment (EA)
Permit
History
Document Date: October 30, 2014
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Town of Columbia
A To C No. 020443A01
September 30, 2010
,,vv�� Engineer's Certification
17 CEc fc G._�DVE►U J9: , as a duly registered Professional Engineer in
the State of North Carolina, having been authorized to observe(periodically/weekly/full time)
the construction of the modifications and improvements to the Town orColumbia WWTP,
located on NCSR 1219 in Tyrrell County for the Town of Columbia, hereby state that, to the best
of my abilities, due care and diligence was used in the observation of the following construction:
Installation of an influent flow meter;a mechanical bar screen rated at peak flow
of 2 MGD with manual bar screen bypass; aerated grit removal system with a 3
Hp blower and grit washer;a flow.splitter box; a 325,000 gallon oxidation ditch
with dual 42"rotors; two.(2) 30-ft diameter clarifiers with 12-ft side water depth;
an effluent pump station including two (2) 1,390 GPM pumps with VFD; an
outfall pump station including two (2) 1,390 GPM, 20 Hp pumps with VFD;
sodium hypochlorite chlorination system with 650-gallon storage tank and two(2)
13 GPM chemical feed pumps; a calcium thiosulfate dechlorination system.with
650-gallon storage tank and two(2) 13 GPM chemical feed pumps; a 194,400
gallon sludge digester with a 30 Hp floating aerator; repurposing of two (2)
existing effluent pumps as 625 GPM return sludge pumps; approximately 1,700
If of 12-inch outfall force main; an effluent flow meter; a 34-ft 12-inch diameter
HIVE diffuser assembly with 15 3-inch diameter PVC diffuser nozzles; effluent
pump station and chlorination system building; outfall pump station and
dechlorination system building;demolition of previously abandoned treatment
units including an oxidation ditch, pump station, clarifier, and sludge drying beds
and an existing grit removal structure; associated pumps, motors, meters,
electrical service, and controls; site work including yard piping, valving, and other
appurtenances, in conformity with the project plans, specifications, and other
supporting data subsequently filed and approved by the Department of
Environment and Natural Resources.
1 certify that the construction of the above referenced project was observed to be built within
substantial compliance and intent of the approved plans and specifications.
We understand that the new limits associated with the modifications to expand to 0.6 MGD now
apply.
Signature Registration No.
Date 1 U D . _.
\\01 11CA
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Send to: Construction Grants &Loans
11633 Mp Service Center
_2�°� SEA g r _
t.635
Raleigh,NC 27699-1633 -
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Berry, Ron
From: Cecil G. Madden, PE <[e-mail]>
Sent: Thursday, October 30, 2014 10:05 AM
To: Bullock, Robert; Berry, Ron
Cc: [e-mail]; [e-mail]
Subject: Columbia CN 20 - Engineer's Certification ACO20443A01
Attachments: Columbia WWTP Expansion - Eng Certification.pdf
Hello Mr. Bullock and Mr. Berry,
Attached is the Town of Columbia's Engineer's Certification concerning the Expansion of the WWTP.The Town
understands that the new limits go into effect for the month of October.The modifications have been constructed, and
are being tested.The Town is experiencing fundamental problems with key pieces of equipment. The equipment issues
include the following:
1. The outfall flow meter is not functioning properly.
The display is on, and shows error No. F70.
This Error code indicates cable connection issues.
Dustin checked the cable connections. They seem to be OK.
Then, someone with Lord and Company came out and checked the terminations, and said that the meter was
fine but that there was a problem with the wire between the meter and the display.
This.flow meter provides a signal to the Calcium Thiosulfate feed and the sampler. Because it is not functioning
properly, the sampler is not properly flow paced, and neither is the chemical feed.This should also impact the
chart recorder.The contractor has been advised this needs to be fixed quickly.
2. The meter at the effluent pump station is not functioning properly. Daily totals from the influent meter and the
effluent pump station should be similar(within say 10%).They are not close.The flow signal is important
because it affects the pacing of the sodium hypochlorite and the chart recorder. Without a proper signal for
pacing the Town cannot meet effluent limits for enterococci and residual chlorine. Someone from Lord and
Company observed the flow meter at the effluent pump station, and observed an error message which states
the pipe is empty or not full.This was confirmed when the operator replaced a chemical feed nipple in the
chlorine feed room.This pipe was designed to remain full. The contractor has been advised to resolve this
concern.There are three ways that the engineer would expect the pipe might possibly drain. They are as
follows:
a. If the discharge pipe were lower than the header pipe, then when the pumps cut off the pipe could
drain. However,the Invert of the discharge pipe was designed to be elevation 11.5'. The invert of the
header was designed to be elevation 10.0'. The installed elevations may not matched the design
elevations.
b. The water could drain back through the pumps. However, there are check valves that close when the
pumps cut off,The weights may need to be extended to force them to close sooner and thus prevent
back flow. The check valves may not be seating properly.
c. The force main could have a leak.
3. As a part of Start Up the equipment supplier should have calibrated the flow meters.The State expects the
equipment to have a calibration sticker placed on the flow meter that is dated and signed by the technician that
calibrated the flow meter.The presence of the sticker implies that the technician has observed the flow meter in

operation, acknowledges that the equipment is properly installed, is functional, anfis'pi'dMing accurate flow
measurement. The contractor has been advised.
4. Clarifier No. 3 has issues with the outside skimmer and sludge rake. It is not operating; therefore,this clarifier is
out of commission. This type of issue happened with Clarifier No.4.We do not know the cause, but have
speculated it may be an electrical issue similar to the one experienced with Clarifier No. 4. The electrical
subcontractor came to the site and advised that there is no electrical problem with the wiring. He thinks it may
have to do something to do with the drive motor. When you turn the on the motor, the clarifier sludge scraper
and outside skimmer rotate. Typically, it will rotate one or two full turns. Occasionally, it will rotate several
turns. It always stops in the same place.When it stops, it trips the on—off switch. Some concern was raised that
the sludge scrapers were possibly scraping the bottom, or rubbing on the side wall, or rubbing on the skirt. In an
effort to confirm or deny this,condition, the Town drained the clarifier completely. None of the mechanism is
dragging on the wall or the skirt. Some of the sludge scrapers were barely touching the floor in places.The rakes
were adjusted to resolve this issue; however,the failure condition still exists.
The contractor has been advised this is a critical issue that needs to be resolved quickly.
5. Rotor No. 3 has had more movement than any of the other three rotors at the WWTP. Questions were raised
about the rotor movement at start up.The Manufacturer insisted that it was within the acceptable
range. Initially our concern was that this movement would result in premature bearing wear and potential rotor
failure. Now a few months into operation, we are experiencing a noise that could be indicative of premature
bearing wear. We believe the movement is excessive.The movement is so excessive that tack welds have
broken on the safety guard.The manufacture should check this out. It appears something needs to be replaced
to eliminate the excessive movement. We are taking this unit out of service until the issue is resolved. The
contractor has been advised we want this resolved prior to final payment.
6. The exhaust fan in the electrical room has failed. It appears that it needs to be replaced. (Minor but needs to be
resolved.)
We are continuing to work with the contractor to resolve the outstanding issues. Should you have questions
please do not hesitate to give me a call.
Regards,
INC-
Cecil G. Madden,Jr., P.E.
McDavid Associates, Inc.
P. O. Box 1776
Goldsboro, NC 27533
[phone]
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NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Secretary
September 30, 2010
Mr. F. Michael Griffin
Town of Columbia
P.O. Box 361
Columbia, North Carolina 27925
SUBJECT: Authorization to Construct
A to C No. 020443A01
Town of Columbia
Town of Columbia WWTP
Tyrrell County
Dear Mr. Griffin:
A letter of request for an Authorization to Construct was received February 22, 2010 by
the Division of Water Quality(Division), and final plans and specifications for the subject
project have been reviewed and found to be satisfactory. Authorization is hereby granted for the
construction of modifications to the existing 0.3 MGD Wastewater Treatment Plant, with,
discharge of treated wastewater into the Scuppernong River in the Pasquotank River Basin.
This authorization results in an increase in design and permitted capacity to 0.6 MGD,
and is awarded for the construction of the following specific modifications:
Installation of an influent flow meter; a mechanical bar screen rated at peak flow
of 2 MGD with manual bar screen bypass; aerated grit removal system with a 3
Hp blower and grit washer; a flow splitter box; a 325,000 gallon oxidation ditch
with dual 42" rotors; two (2) 30-ft diameter clarifiers with 12-ft side water depth;
an effluent pump station including two (2) 1,390 GPM pumps with VFD; an
outfall pump station including two (2) 1,390 GPM, 20 Hp pumps with VFD;
sodium hypochlorite chlorination system with 650-gallon storage tank and two (2)
13 GPM chemical feed pumps; a calcium thiosulfate dechlorination system with
650-gallon storage tank and two (2) 13 GPM chemical feed pumps; a 194,400
gallon sludge digester with a 30 Hp floating aerator; repurposing of two (2)
existing effluent pumps as 625 GPM return sludge pumps; approximately 1,700
If of 12-inch outfall force main; an effluent flow meter; a 34-ft 12-inch diameter
HDPE diffuser assembly with 15 3-inch diameter PVC diffuser nozzles; effluent
pump station and chlorination system building; outfall pump station and
dechlorination system building; demolition of previously abandoned treatment
1617 Mail Service Center,Raleigh,North Carolina 27699-1617 One
Location:512 N.Salisbury St:Raleigh,North Carolina 27604 NOrthCarolina
Phone:[phone] FAX:[phone] Customer Service:1-877-23-6748 intemet:www.ncwalerquality.org ��t��t+Q`L I/J/
An Equal opportunity 1 Affirmative Action Employer rJ

4
Mr. Michael Griffin
September 30, 2010
Page 2
units including an oxidation ditch, pump station, clarifier, and sludge drying beds
and an existing grit removal structure; associated pumps, motors, meters,
electrical service, and controls; site work including yard piping, valving, and other
appurtenances, in conformity with the project plans, specifications, and other
supporting data subsequently filed and approved by the Department of
Environment and Natural Resources.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of
NPDES Permit No.,NCO020443 issued July 21, 2009 and shall be subject to revocation unless
the wastewater treatment facilities are constructed in accordance with the conditions and
limitations specified in Permit No. NC0020443.
The sludge generated from these treatment facilities must be disposed of in accordance
with G.S. 143-215.1 and in a manner approved by the Division.
In the event that the facilities fail to perform satisfactorily, including the creation of
nuisance conditions, the Permittee shall take immediate corrective action, including those as may
be required by the Division, such as the construction of additional or replacement wastewater
treatment or disposal facilities.
The Washington Regional Office, telephone number(252) 946-6481, shall be notified at
least forty-eight (48)hours in advance of operation of the installed facilities so that an on site
inspection can be made. Such notification to the regional supervisor shall be made during the
normal office hours from 8:00 a.m. until 5:00 p.m. on Monday through Friday, excluding State
Holidays.
Upon completion of construction and prior to operation of this permitted facility, a
certification must be received 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. Mail the Certification to: Construction Grants & Loans,
DWQ/DENR, 1633 Mail Service Center, Raleigh, NC 27699-1633.
Upon classification of the facility by the Certification Commission, 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 T15A:8G.0202. The ORC of the facility must visit each
Class I facility at least weekly and each Class I1, III and IV facility at least daily, excluding
weekends and holidays, must properly manage the facility, must document daily operation and
maintenance of the facility, and must comply with all other conditions of T 15A:8G.0202.

}
r
Mr. Michael Griffin
September 30, 2010
Page 3
A copy of the approved plans and specifications shall be maintained on file by the
Permittee for the life of the facility.
During the construction of the proposed additions/modifications, the permittee shall
continue to properly maintain and operate the existing wastewater treatment facilities at all times,
and in such a manner, as necessary to comply with the effluent limits specified in the NPDES
Permit.
You are reminded that it is mandatory for the project to be constructed in accordance
with the North Carolina Sedimentation Pollution Control Act, and when applicable, the North
Carolina Darn Safety Act. In addition, the specifications must clearly state what the contractor's
responsibilities shall be in complying with these Acts.
Prior to entering into any contract(s) for construction, the recipient must have obtained all
applicable permits from the State.
Failure to abide by the requirements contained in this Authorization to Construct may
subject the Permittee to an enforcement action by the Division 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.
One (1) set of approved plans and specifications is being forwarded to you. If you have
any questions or need additional information, please contact Seth Robertson, P.E. at telephone
number [phone].
Sincerel
yC.Coleen H. Sullins
st:sr
cc: F. Tyndall Lewis, P.E., McDavid Associates, Inc., 109 E. Walnut St.,
Goldsboro, NC 27530
Tyrell County Health Department
DWQ Washington Regional Office, Surface Water Protection
Technical Assistance and Certification Unit
Point Source Branch, NPDES Program
Steve Tsadwa
ATC File