NC0085359_Authorization to Construct_20060531

Michael F. Easley. Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
May 31, 2006
Ms. Christie Putnam, P.E.
Interim Director of Public Works
Union County Public Works Department
400 North Church Street
Monroe, North Carolina 28112-404
Subject: A to C No. 085359A02
Authorization to Construct
Twelve Mile WWTP Expansion
Union County
SRF Project No. CS370370-09
Dear Ms. Putnam:
Alan W. Klimek, P.E. Director
Division of Water Quality
A letter of request to modify Authorization to Construct No. 085359A01 was received on
May 4, 2006, by the Division. 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 2.5 MGD Twelve Mile Wastewater Treatment Plant, with discharge
of treated wastewater into Twelve Mile Creek in the Catawba River Basin.
This authorization voids Authorization to Construct No. 085359A01 previously issued on
December 21, 2005, and results in the addition of four 30 hp floating aerators (two each for the
existing two oxidation ditches) and an increase in size of the two proposed 100 hp aerators to
150 hp aerators for the two oxidation ditches currently under construction.
This authorization also includes the previous authorization, which resulted in an increase
in design and permitted capacity to 6.0 MGD, and was awarded for the construction of the
following specific modifications:
New headworks including one new mechanical screen, one new manual screen, four new
influent pumps with a firm capacity of 15 MGD, approximately 2500 lineal feet of new
24-inch force main, and an odor control system; two new 0.104 MG fermentation tanks,
two new 0.23 MG anoxic tanks, two new 0.91 MG oxidation ditches, two new 85-foot
diameter secondary clarifiers, two new 437.5 SF traveling bridge filters, a new UV
disinfection reactor, and a 1.069 MG aerobic digester.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of
NPDES Permit No. NC0085359 issued October 5, 2005, and shall be subject to revocation
unless the wastewater treatment facilities are constructed in accordance with the conditions and
limitations specified in Permit No. NC0085359.
N°?` hCaro ina
,Naturally
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh. NC 27699-1617 Phone [phone] Customer Service
Internet: h2o.enr.state.nc.us 512 N. Salisbury St. Raleigh. NC 27604 FAX [phone]
An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper

Ms. Christie Putnam, P.E., Interim Director of Public Works
May 31, 2006
Page 2
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 North Carolina Division of Water Quality.
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 this 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 Cecil G. Madden, Jr., P.E.,
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 II, 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 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 with these Acts.

Ms. Christie Putnam, P.E., Interim Director of Public Works
May 31, 2006
Page 3
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.
One (1) set of approved plans and specifications is being forwarded to you. If you have
any questions or need additional information, please contact Cecil G. Madden, Jr., P.E. at
telephone number [phone].
Sincerely,
an W. Klimek, P.1(
MM/dr
cc: James N. Struve, P.E., Hazen & Sawyer, Charlotte Office
Union County Health Department
Mooresville Regional Office, Surface Water Protection
Technical Assistance and Certification Unit
David Goodrich, Point Source Branch
Daniel Blaisdell, P.E.
Cecil G. Madden, Jr., P.E.
Valerie Lancaster
OSHA Training Officer, Les Kafel
Michelle McKay, E.I.
Mark Hubbard, P.E.
SRF