NC0085863_Permit Modification Request_20120208

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NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Charles Wakild, P.E. Dee Freeman
Governor Director Secretary
February 8, 2012
Mr. Thomas J. Roberts
Aqua North Carolina, Inc.
202 MacKenan Ct
Cary, N.C. 27511
Subject: Modification of NPDES Permit NC0085863
Waterfall Plantation WTP
Wake County
Dear Mr. Roberts:
The Division has reviewed the modification request you submitted on January 27, 2012. The
Division has no objection to your request. This modification is issued pursuant to the requirements of North
Carolina General Statute 143-215.1 and the Memorandum of Agreement between North Carolina and the
U.S. Environmental Protection Agency dated October 15, 2007 (or as subsequently amended).
This modified permit includes the following changes from your current permit:
D The Flow limit has been deleted.
D Monitoring for Total Iron has been reduced to Quarterly.
If any parts, measurement frequencies or sampling requirements contained in this modification are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty(30)
days following receipt of this letter. This request must be in the form of a written petition, conforming to
Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings
(6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless such demand is made, this
decision shall be final and binding.
This permit is not transferable except after notice to the Division. The Division may require
modification or revocation and reissuance of the permit. This permit does not affect the legal requirements
to obtain other permits which may be required by the Division or permits required by the Division of Land
Resources, the Coastal Area Management Act or any other Federal or Local governmental permit that may
be required. If you have any questions concerning this matter, please contact Charles H. Weaver at(919)
807-6391 or via e-mail [[e-mail]].
'Sincere ,
7
Charles Wakild, P.E.
cc: Central Files
Raleigh Regional Office/Surface Water Protection
NPDES Unit
1617 Mail Service Center,Raleigh,North Carolina 27699-1617 One
512 North Salisbury Street,Raleigh,North Carolina 27604 North Carolina
Phone: [phone] FAX [phone] I Internet:www.ncwaterquality.org
Xatura//y
An Equal Opportunity/Affirmative Action Employer—50%Recycled/10%Post Consumer Paper

Permit NC0085863
A. (1) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on February 1, 2012 and lasting until expiration, the
Permittee is authorized to discharge filter backwash from outfall 001. Such discharges
shall be limited and monitored by the Permittee as specified below:
PARAMETER LIMITS MoNrt RiNN�G R`EQUIREME TS
[PCS Code] Monthly Daily Measurement Sample Sample
Average Maximum Frequency. Type Location
Flow 1 Instantaneous Recorder Effluent
[50050]
Total Monthly Flow(TMF)2 Monitor&Report(MGM) Monthly Calculated Effluent
Total Suspended Solids(TSS) 30.0 mg/L 45.0 mg/L 2/Month Grab Effluent
[00310]
pH >6.0 and<9.0 standard units 2/Month Grab Effluent
[00400] - -
Total Iron Quarterly Grab Effluent
[01045]
Total Residual Chlorine(TRC)3 28 pg/L 2/Month Grab Effluent
[50060]
Nitrate/Nitrite Nitrogen Monitor&Report(mg/L) Semi-annually Grab Effluent
(NO2-N+NO3-N) [00630]
Total Kjeldahl Nitrogen(TKN) Monitor&Report(mg/L) Semi-annually Grab Effluent
[00625]
Total Nitrogen(TN)2 Monitor&Report(mg/L) Semi-annually Calculated Effluent
[00600]
Monitor&Report Monthly Calculated Effluent
TN Load=TN x TMF x 8.34 2 (pounds per month) [QM600]
Monitor&Report Annually Calculated Effluent
(pounds per year) [QY600
Total Phosphorus(TP) Monitor&Report(mg/L) Semi-annually Grab Effluent
[00665]
Footnotes:
1. Backwash flow total is measured and reported on the day that it occurs. The DMR calculated average of the
reported daily events is used for compliance determination.
2. TN Load is the mass quantity of TN discharged over a given time period. See A. (2) for Total Nitrogen
monitoring, calculating, and reporting requirements.
3. TRC limit applies for any chlorine or chlorine derivative addition. The Permittee shall report all effluent TRC
values reported by a NC-certified laboratory(including field-certified]. Effluent values below 50µg/L will be
treated as zero for compliance purposes.
All samples collected should be from a representative discharge event.
There shall be no discharge of floating solids or visible foam in other than trace amounts.

AQUA,m Aqua North Carolina, Inc. Thomas J.Roberts
202 MacKenan Court President and Chief Operating Officer
Cary, NC 27511
T:919.653.5770
F:919.460.1788
January 25 2012 [e-mail]
www.aquanorthcarolina.com
Mr. Tom Belnick
[e-mail]
NPDES Unit Supervisor
NCDENR
1601 Mail Service Center
H
Raleigh, NC 27699-1601 JAN 2 7 2012
RE: NPDES Permit NC0085863
DENPOINTR OURCE BUALg y
Waterfall Plantation WTP
Dear Mr. Belnick,
In accordance with the attached Changes to Water Treatment Plant Strategy (October 2009), Aqua North
Carolina, Inc. (Aqua) requests the following permit modifications be made to NPDES Permit
NC0085863:
• Remove flow limits as noted in Changes to Water Treatment Plant Strategy (October 2009), item
I. When this permit was initially issued, there were no flow limits. However, when the permit
was renewed in 2008 a flow limit of 0.005 MGD was instituted. Aqua respectfully requests that
this flow limit be removed.
• Change the total iron monitoring requirement from monthly to quarterly monitoring requirement
as noted in Changes to Water Treatment Plant Strategy (October 2009), item III.
Thank you very much for your consideration in this matter. If you need any further information from
me, please do not hesitate to contact me.
S., er; y/
Thomas J. •serts
President .nd COO
lms
Attachments
ec: Central Operations Supervisor
Waterfall Plantation WTP File
An Aqua America Company