NC0024911_authorization to construct_20160712 (2)

�c v o z-4 4' It
PAT MCGRORY
Gurc rnor
C.
DONALD R. VAN DER VAART
Secretary
%� S. JAY ZIMMERMAN
Water Resources
ENVIRONMENTAL QUALITY Director
July 12, 2016
Mr. Tom Hartye
General Manager
Metropolitan Sewerage District of Buncombe County
2028 Riverside Drive
Asheville,North Carolina 28804
SUBJECT: Authorization to Construct
A to C No. 024911A03
Metropolitan Sewerage District of Buncombe County
French Broad River WRF
Dear Mr. Hartye:
A letter of request for an Authorization to Construct was received May 23, 2016, 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 40 MGD French Broad River WRF, with discharge
of treated wastewater into the French Broad`River in the French Broad River Basin.-
This authorization results in no increase in design or permitted capacity and is awarded for
the construction of the following specific modifications:
Installation of new fine screen system consisting of three (3) 40 MGD automated
mechanical screens with VFD, sluicing trough, screens washer/compactors, piping,
and controls; installation of new grit system consisting of two (2) 50 MGD..vartex
grit chambers with vacuum pumps, concentrators, water classifiers, piping, and
controls; replacement of existing influent pumps screens with two (2) 40 MGD
automated mechanical traveling rake screens with conveyor/compactors,piping, and
controls; installation of new flow splitter box,piping, and controls;refurbishment of
existing structure to new surge pump station including three (3) new 3,472 GPM at
60 ft TDH surge pumps with variable drive,piping, and controls; conversion of two
surplus digesters to two (2) 2.1 MG surge tanks, piping, and controls; in conformity
with the project plans, specifications, and other supporting data subsequently filed
and approved by the Department of Environmental Quality.
This Authorization to Construct is issued in accordance with Part III, Paragraph A of
NPDES Permit No.NCO024911 issued effective April 1,2011, and shall be subject to revocation
unless the wastewater treatment facilities are constructed in accordance with the conditions and
limitations specified in Permit No.NCO024911.
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State of North Carolina I Environmental Quality I Water Resources
1617 Mail service Center I Raleigh,North Carolina 27699-1617
Location:512 N.Salisbury St.Raleigh,North Carolina 27604,Archdale Building 9th Floor
Phone:[phone]/Fax:[phone]
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Mr.Tom Hartye, General Manager
July 12,2016
Page 2 of 3
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 Asheville Regional Office, telephone number (828) 296 - 4500, 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 I
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: Division of Water Resources, WQ
Permitting Section—NPDES, 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 j
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.
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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.
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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.
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Prior to entering into any contract(s) for construction, the recipient must have obtained all
applicable permits from the State. C
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Mr. Tom Hartye,General Manager ,
July 12,2016
Page 3 of 3
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,
S. Jay Zimmerman I
Director, Division of Water Resources
cc: Brian Thorsvold, P.E.
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HDR Engineering, Inc. of the Carolinas
440 South Church Street
Suite 1000
Charlotte,NC 28202
DWR/Asheville Regional Office, Water Quality Programs
Central Files
NPDES File
Without Engineer's Certificate attached:
Buncombe County Health Department

PAT MCCRORY
C' .
Governor
DONALD R. VAN DER VAART
Secretary
Environmental
Quality
June 10, 2016
Mr. Thomas E. Hartye, PE
General Manager
Metropolitan Sewerage District of Buncombe County
2028 Riverside Drive
Ashville MC 28804
Subject: Hourly Peak Flow Determination and Application
Authorization to Construct# 024911 A03
French Broad River WRF
Buncombe County
Dear Mr. Hartye:
As requested,the following is a formal summary in regards to our May 9, 2016 phone discussion.
(1) The grit removal system is considered a non-critical component and there is no bypass
proposed,therefore,
- with both proposed units in service they must be able to pass through the hourly peak
flow sustaining in the new upstream structures a free board no less than 12 inches.
(2) The new fine screen system is considered a critical headworks component,therefore,
- with two of the proposed three fine screens in service they must be able to pass through
the hourly peak flow sustaining in the new upstream structures a free board no less than
12 inches.
(3) With the assistance of Ken Pohlig, PhD, PE from our Division of Water Infrastructure a re-
evaluation to determine your facility hourly peak flow was conducted. The last 10 years of
reported effluent flow data was evaluated to determine the daily/monthly average peaking
factor (DPF) history for this facility. It was determined 2.2 was the appropriate DPF. Your
consultant as requested by the Division had previously provided a hourly/daily average
peaking factor(HDF)of 1.2 for non-rain event conditions. To calculate the hourly peak flow:
DPF x HDF x Permitted Flow(Design Flow) =Hourly Peak Flow
2.2x 1.2x40 MGD= 105.6 MGD
In this case, 105.6 MGD is the hourly peak flow that is to be applied. There is a possibility the current
design may meet the free board requirements. To confirm the current design will meet free board
requirements at 105.6 MGD,the hydraulic profile will need to be updated and submitted to the Division.
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 OpportunityWfiirmative Action Employer

Mr. Thomas E. Hartye,PE
General Manager
Metropolitan Sewerage District of Buncombe County
June 10, 2016
Page 2 of 2
There is no issue with the proposed design to meet reliability requirements at the NPDES permitted flow,
40 MGD.
We discussed the default design peaking factor of 2.5. The default factor only applies when no data is
available for assessment of a treatment facility anticipated flow history.
I hope this information is helpful and if you have any further questions let me know. Please advise if as
stated in your May 31, 2016 letter you still desire a meeting.
Sincerely,
on Berry, Engineer
Division of Water Resources, Complex Permitting
Cc: Asheville Regional Office/Tim Heim
DWI/Ken Pohlig, PE
Central Files
NPDES File