NC0084387_Permit modification_19981125

State of North Carolina
Department of Environment
and Natural Resources
Division of Water Quality
James B. Hunt, Jr., Governor
Wayne McDevitt, Secretary
A. Preston Howard, Jr., P.E., Director
November 25, 1998
Mr. Randy M. Hawkins
Water Treatment Plant Supervisor
Charlotte -Mecklenburg Utilities.
7980 Babe Stillwell Farm Road
Huntersville, North Carolina 28078
AT�: •
D E N R
Subject: Permit Modification
Permit No. NCO084387
North Mecklenburg WTP
Mecklenburg County
Dear Mr. Hawkins:
On May 26, 1998, the Division of Water Quality received a request to modify NPDES Permit Number
NC0084387. Authorization is hereby granted for the installation of a discharge line from the alum sludge
storage lagoon. The modification request is granted with the understanding that the discharge from the alum
sludge storage lagoon will consist of rainwater from overland flow and supernatant from the lagoon. In
addition, it is the Division's understanding that the proposed line leading from the alum sludge storage lagoon
will tie into outfall line 001 prior to discharging into McDowell Creek.
Please find enclosed the amended Supplement to Permit Cover Sheet, which should be inserted into your
current permit. The old page should be discarded. All other terms and conditions contained in the original permit
remain unchanged and in full effect. This permit modification is issued pursuant to the requirements of North
Carolina General Statutes 143-215.1 and the Memorandum of Agreement between North Carolina and the U. S.
Environmental Protection Agency.
If any parts, measurement frequencies or sampling requirements contained in this permit 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, Post
Office Drawer 27447, Raleigh, North Carolina 27611-7447. Unless such demand is made, this decision shall be
final and binding.
If you have any questions concerning this permit modification, please contact Jeff Myhra at telephone
number [phone], extension 597.
Since y, -
eston Howard, J P.E.
cc: Mooresville Regional Office, Mike Parker
Central Files
NNPDES Unit
EPA / Roosevelt Childress
Point Source Compliance Enforcement Unit
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone]/FAX [phone]

SUPPLEMENT TO PERMIT COVER SHEET
Charlotte -Mecklenburg Utility Department
is hereby authorized to:
Permit No. NC084387
1. Continue to operate an existing treatment facility consisting of a surge/equalization basin,
polymer and bisulfite addition, clarifier, dual gravity thickeners and an alum sludge storage
lagoon located at the North Mecklenburg WTP, 7980 Babe Stillwell Farm Road, Huntersville,
Mecklenburg County (See Part III of this permit), and
2. Discharge from said treatment works at the location specified on the attached map into
McDowell Creek, which is classified as WS-IV waters in the Catawba River Basin.
3. Discharge excess rainwater from overland flow and supernatant from the alum sludge storage
lagoon through a direct line leading from the alum sludge storage lagoon to outfall line 001
prior to its discharge into McDowell Creek,

Facility Notes for North Mecklenburg WTP (NC0084387)
MEMORANDUM
TO: File
FROM: Jeff Myhra
DATE: November 19, 1998
SUBJECT: Permit file review for North Mecklenburg WTP (NC0084387)
Facility requested permission to install a direct discharge line from the on -site alum sludge
storage lagoon. The modification request was granted with the understanding that the discharge
from the alum sludge storage lagoon will consist of rainwater from overland flow and
supernatant from the lagoon. In addition, the Division required that the proposed line leading
from the alum sludge storage lagoon must tie into outfall line 001 prior to discharging into
McDowell Creek. Currently the discharge from this lagoon goes directly to the sanitary waste
sewer.
I contacted Mike Parker in the Region and he went out to take a look at the proposed location of
the discharge line. His comments are as follows:
➢ They are not adding a completely new discharge line. They will tie into the
existing outfall line 001 prior to discharging into McDowell Creek. They will
still sample at the end of the pipe.
➢ They will only be discharging supernatant (really same water as coming out of
the clarifier) from the alum sludge storage lagoon. Mike stated that most
WTPs are set up this way.
➢ The facility does not have a history of compliance problems.
➢ The site is in a rural setting with not potential treat of stormwater
contamination.
➢ The existing permit should cover all the constituents needed to protect the
water quality in McDowell Creek.
➢ They will have the capacity to direct the discharge to the town's WWTP if a
problem (contamination) is detected in the alum sludge storage lagoon.
Based on Mike Parker's comments, the Division agreed to issue the modification request.

Charlotte Mecklenburg Utilities Department
/` w'4
Mr. Dave Goodrich
Div of Water Quality
P.O. Box 29535
Raleigh, NC 27626
Dear Mr. Goodrich
We are requesting a minor permit modification for NPDES permit # NC0084387.
We want to add a discharge location from our lagoon. This discharge will be
mostly clear rainwater from off the top of the alum sludge. Currently this
discharge goes to our sanitary sewer line. The water will be gravity flow through
the same line as our clarifier discharge. It will go to the same outfall location.
Enclosed is the processing fee for the modification, my business card and a
drawing of the proposed discharge. If there is a need to come review or if more
details are needed please call me.
Sincerely,
/ XAOZ, z--
Randy Mark Hawkins
Operator Responsible Charge
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RANDY M. HAWKINS-;-'
WATER TREATMENT PLANT SUPERVISOR
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CHARLOTTE MECKLENBURG UTILITIES
7980 BABE STILLWELL FARM ROAD
HUNTERSVILLE, NC 28078
704-948 6954 EXT. 224 FAR; 704-948-7581