NC0073539_CEI Response_20191022

Aqua North Carolina, Inc.
4163 Sinclair Street
Denver, NC 28037
October 22, 2019
Mr. W. Corey Basinger
Regional Supervisor
Water Quality Regional Operations Section
Division of Water Resources, NCDEQ
Mooresville Regional Office
610 East Center Avenue, Suite 301
Mooresville, NC 28115
Re: Willowbrook WWTP, Mecklenburg County
Compliance Evaluation Inspection Report
NPDES Permit No. NC0073539
Dear Mr. Basinger:
www.aquanorthcarolina.com
M E'VI L E=L 10NAL
Aqua North Carolina, Inc. (Aqua) offers the following response to the items outlined in the above -
referenced Compliance Evaluation Inspection Report which was issued for the inspection conducted on
September 25, 2019:
Flow Measurement Effluent Section
The V-notch weir angle was measured at approximately 83 degrees during the inspection, however,
the flow meter was programmed to measure flows for a 90-degree v-notch weir. The Permittee
must contract a third party experienced in flow meter calibrations to verify the V-notch weir angle
and the calibration procedures.
Agua's Response: The flow meter was calibrated by Mr. Thurman Horne of Horizon Engineering
in 2017. Attached is the inspection report indicating the weir to be a 90-degree v-notch.
Additionally, Clearwater, Inc. installed the new flow meter and 2017 and performed a calibration
at that time. A copy of their report is attached as well. The weir in both calibrations was deemed
to be a 90-degree V-notch. No changes have been made since the third party calibrations were
completed.
Bar Screens
The old coarse bar screen had partially separated fi-om the WWTP structure and was being held in
place with a rope. The old bar screen should be removed as soon as possible to prevent this structure
from breaking off into the aeration basin and potentially damaging the aeration system.
Agua's Response: The old bar screen will be removed no later than November 15, 2019. Please
note a new bar screen had been installed prior to the inspection.
An Aqua America Company

If you have any questions, please do not hesitate to contact me at 704-489-9404.
Sincerely,
w
Laurie Ison
Area Manager
cc: Joe Pearce
Shannon Becker

NA,
Horizon Engineering & Consulting, Inc.
2510 Walker Road
Mt. Pleasant, N.C. 28124
704-788-4455
Flow Meter Calibration Data Sheet Fax: [phone]
Facility Name: Willowbrook Subdivisio
n City: Charlotte State: N.C.
Utility Name: Aqua North Carolina, Inc. Primary Device (weir, etc.): 90 deg. V- notch weir
Flow Meter Manf.., ISCO Model: 4230 Serial No. 196AO1804
Type: X Bubbler Ultrasonic Other
I. Primary Device: Comments:
A. Level tz- yes no
B. Free Flow yes no
C. Turbulence yes no
D. Blockage yes no
E. Surface
Buildup yes ✓n o
F . Properly
Mounted Zyes no
11. Meter.,
A. Programmed correct _Zyes no
B. Calibration:
1 Calibrated with flow cut off yes Zno
If yes, Level Before
Level After
Resume flow, compare measured level to meter reading.
Verify that readings agree yes no
If no, Flow Level Before -, 673
Flow Level After 0 "
C . Check if level to flow conversion for primary device is correct'. _Zyes no
D. Check is totalized correctly- CI yes no
Calibrated by:
, 7� Date: nZ
,/J. T.AurmapHorne, P.E. Time:

70-
Equipment Service / Calibration
PO Box 580 Indian Trail NC 28079 Phone [phone] Fax [phone] www.clearwaterinc.net
Job Date
11 /07/2017
Customer Site Location
Aqua North Carolina, Inc. - Denver
Indian Trail
Address City
4163 Sinclair Street
Denver
State Zip
NC
28037
Contact Name Email Address
Matt cotsner
[e-mail]
Phone Number Fax Number
9
Job Type
Installation
PO or SO Number Service Number
18940 17110713591366
Technician
Technician Phone
Technician Email
Micah Brewington
910-337-3952
[e-mail]
Salesman
Salesman Phone
Salesman Email
Jacob Reid
828-302-0011
[e-mail]

Meter/Sampler(1)
Calibration Letter
PO Box 580 Indian Trail NC 28079 Phone [phone] Fax [phone] www.clearwaterinc.net
Equipment Location
Willow Brooke WWTP
Equipment
Signature Ultrasonic Flow Meter
Primary Device
V-notch Weir
Size
90
Serial Number
217h03394
Totalizer
O
Units
Gallons
Begin Level
1.4
End Level
.2
Comments
Installed meter and calibrated meter with staff gauge
This is to certify that I was at your facility to calibrate the equipment listed in this letter. A
calibration sticker was placed on the equipment.
If you have any questions, or if we can be of assistance in any manner, please give us a call at [phone].

Meter/Sampler(2)
Calibration Letter
PO Box 580 Indian Trail NC 28079 Phone [phone] Fax [phone] www.clearwaterinc.net
Equipment
Sampler:
Sampler
5800
Serial Number
217j00083
This is to certify that 1 was at your facility to calibrate the equipment listed in this letter. A
calibration sticker was placed on the equipment.
If you have any questions, or if we can be of assistance in any manner, please give us a call at [phone].