NC0024945_Authorization to Construct_20150304

NCDENR
North Carolina Department of Environment and Natural Resources
Pat McCrory Donald R. van der Vaart
Governor Secretary
March 4, 2015
Julie McLelland, P.E.
Senior Project Manager
Charlotte Water
5100 Brookshire Blvd
Charlotte,North Carolina 28216
SUBJECT: Authorization to Construct
A to C No. 024945A03
Charlotte-Mecklenburg Utilities
Irvin Greek WWTP
Dear Ms. McLelland:
A letter of request for an Authorization to Construct was received December 4, 2014, by the
Division of Water Resources (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 15 MGD Irvin Creek WWTP, with discharge of treated wastewater into
the Irvin Creek in the Catawba River Basin.
This authorization results in no increase in design or permitted capacity and is awarded for the
construction of the following specific modifications added or modified in Phase 2 that are not
previously approved in A to C No. 024945A02 and are not considered general maintenance:
Installation of new primary clarifiers effluent collection manway with one (1) 5 HP
vertical turbine mixer, chemical addition, piping, and controls; demolition of north
aeration basins; modification of aeration basin influent distribution channel to include six
(6) 1 HP vertical turbine mixers, drop air diffuser system, piping, and controls;
installation of two (2) 0.97 MG aeration basins with anoxic zone, selector zone, aerobic
zone, four (4) 1 HP vertical turbine mixers (2 per basin), fine bubble air diffuser
segments, drain system, piping, and controls; modification of existing 5 south aeration
basins to include ten (10) 1 HP vertical turbine mixers (2 per basin), fine bubble air
diffuser segments, piping, and controls; installation of new blower system consisting of
four(4) 5,700 SCFM at 7.6 psig high speed blowers with VFD motor control, piping, and
other controls; modification of two (2) 12 ft diameter carbon steel alkalinity chemical
storage tanks to include per tank a 10 HP vertical mixer and baffle system; modification
of six (6) chemical feed pumps to 70 GPH at 100 psig with VFD motor control (3 pumps
wetted components to meet alkalinity pump specifications, 3 pumps wetted components
1617 Mail Service Center,Raleigh,North Carolina 27699-1617
Location:512 N.Salisbury St.Raleigh,North Carolina 27604
Phone:[phone] Fax:[phone]
Internet www.ncdenr.gov
An Equal Opportunitoffirmative Action Employer

Julie McLelland,P.E., Senior Project Manager ,
March 4,2015
Page 2 of 3
to meet metal salt pump specifications); installation of two (2) 50 GPM at 30 ft THD
recirculation/transfer metal salt solution pumps, and piping; installation of a two (2) 25
GPM at 15 ft TDH chemical storage containment sump pumps, and piping; in conformity
with the project plans, specifications, and other supporting data subsequently filed and
approved by the Department of Environment and Natural Resources.
Note: Upon completion of approved items that are part of Phase 1 and Phase 2 in the
original A to C No. 024945A02 permit issued February 17, 2010, the Mooresville Office
shall be notified and the Engineering Certificate shall be submitted accordingly. Partial
Engineering Certificates are acceptable, each marked to indicate which items were
completed.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of NPDES
Permit No. NC0024945 issued effective January 1, 2013, and shall be subject to revocation unless the
wastewater treatment facilities are constructed in accordance with the conditions and limitations
specified in Permit No.NC0024945.
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 Mooresville Regional Office, telephone number [phone], 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: NPDES Unit, DWR/DENR, 1617 Mail Service Center,
Raleigh,NC 27699-1617.
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 II, III and IV facility at least daily, excluding weekends and

Julie McLelland,P.E., Senior Project Manager
March 4,2015
Page 3 of 3
holidays, must properly manage the facility, must document daily operation and maintenance of the
facility, and must comply with all other conditions of T15A:8G.0202.
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 Dam
Safety Act. In addition,the specifications must clearly state what the contractor's responsibilities shall
be in complying v. th these Acts.
L
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.
If you have any questions or need additional information, please contact Ron Berry at
telephone number(919) 807-6396.
Sincerely,
� ,� Au
S. Jay Zimmerman
Director, Division of Water Resources
cc: James N. Struve, P.E.
Hazen and Sawyer, PC
4944 Parkway Plaza Blvd
Suite 375
Charlotte,NC 28217
DWR/Mooresville Regional Office, Water Quality Programs
Central Files
NPDES File
Without Engineer's Certificate attached:
Mecklenburg County Health Department
i

Charlotte Water
Irwin Creek WWTP
Authorization to Construct No. 024945A03
Issued March 4, 2015
Engineer's Certification
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 Irwin Creek Wastewater
Treatment Plant, located in Mecklenburg County, hereby state that, to the best of my abilities,
due care and diligence was used in the observation of the following construction:
Installation of new primary clarifiers effluent collection manway with one (1) 5
HP vertical turbine mixer, chemical addition, piping, and controls; demolition of
north aeration basins; modification of aeration basin influent distribution channel
to include six (6) 1 HP vertical turbine mixers, drop air diffuser system, piping,
and controls; installation of two (2) 0.97 MG aeration basins with anoxic zone,
selector zone, aerobic zone, four (4) 1 HP vertical turbine mixers (2 per basin),
fine bubble air diffuser segments, drain system,piping, and controls; modification
of existing 5 south aeration basins to include ten(10) 1 HP vertical turbine mixers
(2 per basin), fine bubble air diffuser segments, piping, and controls; installation
of new blower system consisting of four (4) 5,700 SCFM at 7.6 psig high speed
blowers with VFD motor control, piping, and other controls; modification of two
(2) 12 ft diameter carbon steel alkalinity chemical storage tanks to include per
tank a 10 HP vertical mixer and baffle system; modification of six (6) chemical
feed pumps to 70 GPH at 100 psig with VFD motor control (3 pumps wetted
components to meet alkalinity pump specifications, 3 pumps wetted components
to meet metal salt pump specifications); installation of two (2) 50 GPM at 30 ft
THD recirculation/transfer metal salt solution pumps, and piping; installation of a
two (2) 25 GPM at 15 ft TDH chemical storage containment sump pumps, and
piping; in conformity with the project plans, specifications, and other supporting
data subsequently filed and approved by the Department of Environment and
Natural Resources.
I certify that the construction of the above referenced project was observed to be built within
substantial compliance, intent and in conformity with all applicable regulations and statutes and
the project plans, specifications, and other supporting documentation comprising the
Authorization to Construct Permit Application package.
I
i
Signature Registration No.
Date
Mail this Certification to: Attn: Ron Berry
Complex Permitting Unit �Q�
DENR/DWR/Water Quality Programs
1617 Mail Service Center
Raleigh,NC 27699-1617 \