NC0085359_Authorization to Construct_20080215

NPDES DOCUMENT $CANNIN1i COVER SHEET
NC0085839
Twelve Mile Creek WWTP
NPDES Permit:
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC) .,
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
February 15, 2008
Thiia document ins printed on reusse paper. - ignore any
content on the reYernse Elide

Q � C3 / erR4 y • _ (/ Michael F. Easley, Governor
A TF,Y
6r� au`/� ar� William G. Ross Jr., Secretary
orth Carolina Department of Environment and Natural Resources
—i Coleen H. Sullins, Director
Division of Water Quality
February 15, 2008
Mrs. Christie L. Putnam
Director of Public Works
Union County Public Works
500 North Main Street
Monroe, North Carolina 28112
SUBJECT: Authorization to Construct
A to C No. 085359A05
Union County Public Works
Twelve Mile Creek WWTP
Odor Control Improvements
Union County
Dear Mrs. Putnam:
A letter of request for Authorization to Construct was received October 20, 2007, by the
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 2.5 MGD Twelve Mile Creek Wastewater Treatment Plant, with discharge of treated
wastewater into Twelve Mile 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:
New Odor Control Facility including a 10,500 gallon sodium hydroxide storage tank and
feed pumps; a 4,250 gallon sulfuric acid storage tank and feed pumps; a 10,500 gallon
sodium hypochlorite storage tank and feed pumps; dual 11-foot diameter, 10-feet depth
scrubber towers; dual 725 gpm recirculation pumps and one 40,000 scrubber fan; covers
for the grit facilities and four digesters; associated yard piping; instrumentation and
electrical work, 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. NC0085359 issued June 26, 2006, 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.
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.
Noa` Carolina
,Naturally
North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone [phone] Customer Service
Internet: www.ncwaterqualitv.orq 512 N. Salisbury St. Raleigh, NC 27604 FAX [phone]
An Equal Opportunity/Affirmative Action Employer— 50% Recycled/10% Post Consumer Paper

Mrs. Christie L. Putnam
February 15, 2008
Page 2
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 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.
Prior to entering into any contract(s) for construction, the recipient must have obtained all
applicable permits from the State.

Mrs. Christie L. Putnam
February 15, 2008
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 Ken Pohlig, P.E. at telephone
number [phone].
Sincerely,
pt— Colecn H. Sullins
kp
fir. G ,e_e;_<,a__<,e,e___ee
cc: James N. Struve, P.E. — Hazen and Sawyer, PC, Charlotte
Union County Health Department
DWQ Mooresville Regional Office, Surface Water Protection
DWQ, Technical Assistance and Certification Unit
DWQ, Point Source Branch, NPDES Program
Daniel Blaisdell, P.E.
Ken Pohlig, P.E.
ATC File

Union County Public Works
A To C No. 085359A05
Twelve Mile Creek WWTP
Odor Control Improvements
Issued February 15, 2008
Engineer's Certification
I, , 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 Twelve Mile Creek WWTP,
located on 3104 Providence Road South, Waxhaw, for Union County, hereby state that, to the
best of my abilities, due care and diligence was used in the observation of the following
construction:
New Odor Control Facility including a 10,500 gallon sodium hydroxide storage tank and
feed pumps; a 4,250 gallon sulfuric acid storage tank and feed pumps; a 10,500 gallon
sodium hypochlorite storage tank and feed pumps; dual 11-foot diameter, 10-feet depth
scrubber towers; dual 725 gpm recirculation pumps and one 40,000 scrubber fan; covers
for the grit facilities and four digesters; associated yard piping; instrumentation and
electrical work, 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 and intent of the approved plans and specifications.
Signature Registration No.
Date
Send to: Construction Grants & Loans
DENR/DWQ
1633 Mail Service Center
Raleigh, NC 27699-1633