NC0040070_Renewal (Application)_20140718

NCDENR
North Carolina Department of Environment and Natural Resources
Crory
Governor
Attn: C Edward Cross, Division Manager
Two River Utilities
PO Box 1748
Gastonia, NC 28053
Dear Mr. Cross:
July 18, 2014
John E. Skvarla, III
Secretary
JUL 2 1 2014
Subject: Acknowledgement of Permit Renewal
Permit NCO040070
Gaston County
The NPDES Unit received your permit renewal application on July 10, 2014. A member of the
NPDES Unit will review your application. They will contact you if additional information is required to
complete your permit renewal. You should expect to receive a draft permit approximately 30-45 days
before your existing permit expires.
If you have any additional questions concerning renewal of the subject permit, please contact Derek
Denard [phone].
Sincerely,
W fle*v, TkZOLf 0110L
Wren Thedford
Wastewater Branch
cc: Central Files
L\400resville Regional Office
NPDES Unit
1617 Mail Service Center, Raleigh, North Carolina 27699-1617
Location: 512 N. Salisbury St. Raleigh, North Carolina 27604
Phone: [phone] Fax: [phone]/Customer Service: 1-877-623-6748
Internet:: www.ncwater.org
An Equal OpportunityMmnative Action Employer

We are TRU to our customers!
Mr. Wren Thedford
NC DENR / DWR/ NPDES Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
Mr. Thedford,
RECEIVED/DENR/DWR
JUL 1 0 2014
Water Qual'
Permitting Se n
The City of Gastonia -Two Rivers Utilities is requesting renewal of its NPDES permit #NC0040070 for
the Two Rivers Utilities Water Treatment Plant's Alum Sludge De -watering Facility. Please find
attached the permit request, the permit application form, our process description narrative, and
copies as requested. The current permit will expire January 31, 2015. There have been no changes
to this facility or equipment since the last renewal.
If additional information is required, please contact me at [phone].
Your assistance in this matter is greatly appreciated.
C Edward Cross, Division Manager
Water Supply & Treatment Division
City of Gastonia —Two Rivers Utilities
pc: File

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Mail the complete application to:
N. C. DENR / Division of Water Resources / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617 JUL 21 2014
NPDES Permit Number INCO040070
If you are completing this form in computer use the TAB key or the up - down arrows to move from one
field to the next. To check the boxes, click your mouse on top of the box. Otherwise, please print or type.
1. Contact Information:
Owner Name
Facility Name
Mailing Address
City
State / Zip Code
Telephone Number
Fax Number
e-mail Address
City of Gastonia - Two Rivers Utilities
City of Gastonia - Alum De -watering Facility
P.O. Box 1748
Gastonia
28053
704-866-6827
704-854-6685
edc(@cilyofgastonia.com
2. Location of facility producing discharge:
Check here if same as above
Street Address or State Road
City
State / Zip Code
County
298 West Page Ave.
Gastonia
NC 28052
Gaston
3. Operator Information:
Name of the firm, consultant or other entity that operates the facility. (Note that this is not referring to the
Operator in Responsible Charge or ORC)
Name City of Gastonia
Mailing Address P.O. Box 1748
City Gastonia
State / Zip Code NC 28053
Telephone Number 704-866-6827
Fax Number 704-854-6685
4. Ownership Status:
Federal ❑ State ❑ Private ❑ Public
Page 1 of 3 Version 3/2014

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
5. Type of treatment plant:
® Conventional (Includes coagulation, flocculation, and sedimentation, usually follow
filtration and disinfection)
❑ Ion Exchange (Sodium Cycle Cationic ion exchange)
❑ Green Sand Filter (No sodium recharge)
❑ Membrane Technology (RO, nanofiltration)
Check here if the treatment process also uses a water softener ❑
6. Description of source water(s) (i.e. groundwater, surface water)
Surface Water (Mt. Island Lake)
7. Describe the treatment process(es) for the raw water:
Raw Water is pumped to the WTP from Mt. Island Lake. Aluminum Sulfate (Alum) and Sodium
Hypochlorite are added for coagulation and disinfection respectively. After coagulation,
sedimentation and filtration Sodium Hydroxide is added for pH adjustment, sodium
bicarbonate, hexameta-phosphate and ortho-phosphate are added for corrosion control, fluoride
is added as a dental health aid and sodium hypochlorite is added to maintain a chlorine
residual in the distribution system.
S. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
Sedimentation basin washwater and filter backwash water are sent to the Alum Sludge De -
watering Facility via a gravity discharge line from the WTP. When the sedimentation basins are
cleaned, the effluent is discharged to the Alum Sludge De -watering Facility and a polymer is
added to assist in sludge settling. After the sludge has settled (usually 3-5 days) the clear water
is decanted to the creek. When the sludge tank (tank #2) is full, the sludge is addressed as in
the attached Sludge Management Plan.
When a filter wash occurs, the effluent is discharged to the Alum Sludge De -watering Facility
(tank #1). There is no coagulant aid needed as the filter backwash contains very little sludge.
After the sludge has settled (usually 2-4 hours) the clear water is dechlorinated with sodium
thiosulfate and decanted to the creek. Any sludge is transferred to the sludge tank (tank #2)
and addressed as in the attached Sludge Management Plan.
9. Number of separate discharge points: 1 Outfall Identification number(s) 001
10. Frequency of discharge: Continuous ❑ Intermittent
If intermittent:
Days per week discharge occurs: 7 Duration: 4-6 hrs/day
11. Plant design potable flowrate 23.3 MGD
Backwash or reject flow 0.75 (MAX) MGD
12. Name of receiving stream(s) (Provide a map showing the exact location of each outfall, including
latitude and longitude):
Unnamed tributary to Long Creek (Please see attached map)
Page 2 of 3 Version 3/2014

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
lease list all water treatment additives, including cleaning chemicals or disinfection
,eatments, that have the potential to be discharged.
lum / aluminum sulfate Yes X No
..on sulfate /ferrous sulfate Yes No
Fluoride Yes X No
Ammonia nitrogen / Chloramines Yes No
Zinc -orthophosphate or sweetwater CP1236 Yes X No
List any other additives below:
X
Sodium hypochlorite, Sodium hydroxide, Fluoride, Sodium Bicarbonate,
Hexameta-phosphate, ortho-phosphate
14. Is this facility located on Indian country? (check one)
Yes ❑ No
15. Additional Information:
Provide a schematic of flow through the facility, include flow volumes at all points in
the water treatment process. The plan should show the point[s] of addition for
chemicals and all discharges routed to an outfall [including stormwater]. (Please see
attached)
Solids Handling Plan (Please see attached narrative -"Sludge Management Plan")
16. NEW Applicants
Information needed in addition to items 1-15:
New applicants are strongly recommended to contact a permit coordinator with the
NCDENR Customer Service Center.
Was the Customer Service Center contacted? ❑ Yes ❑ No
Analyses of source water collected
Engineering Alternative Analysis
Discharges from Ion Exchange and Reverse Osmosis plants shall be evaluated using a
water quality model.
17. Applicant Certification
I certify that I am familiar with the information contained in the application and that to the
best of my knowledge and belief such information is true, complete, and accurate.
C Edward Cross Division Manager
Printed name of Per n Signing Title
7, 9-,
Signature of Applicant
Date
North Carolina General Statute 143-215.6 (b)(2) provides that: Any person who knowingly makes any false statement representation, or certification in any application,
record, report, plan, or other document files or required to be maintained under Article 21 or regulations of the Environmental Management Commission implementing that
Article, or who falsifies, tampers with, or knowingly renders inaccurate any recording or monitoring device or method required to be operated or maintained under Article 21
or regulations of the Environmental Management Commission implementing that Article, shall be guilty of a misdemeanor punishable by a fine not to exceed $25,000, or by
imprisonment not to exceed six months, or by both. (18 U.S.C. Section 1001 provides a punishment by a fine of not more than $25,000 or imprisonment not more than 5
years, or both, for a similar offense.)
Page 3 of 3
Version 3/2014

JVERS
U T I L I T I E S
We are TR U to our customers!
July 8, 2014
Water Supply & Treatment Division
Sludge De -watering Facility
Sludge Management Plan
The City of Gastonia — Two Rivers Utilities' Water Supply & Treatment Division's Sludge De -
watering Facility, NPDES #NC0040070, receives its total in -flow from the Water Treatment Plant.
The majority of this flow consists of effluent from filter backwashes, sedimentation basin clean -
outs, ancillary leakage from pipes and sample points, and drainage from in —line analytical
equipment. Most of the solids received at the plant are associated with the sedimentation basin
clean -outs and are treated with polymer to enhance settling when necessary.
Flow received by this plant is directed to one of two 0.6 million -gallon basins, where the solids are
allowed ample time to settle. The water is removed by decant pumps which are operated on a
float -ball system to insure that sludge is not inadvertently pumped to the discharge. Also,
operational personnel at the Water Treatment Plant monitor the turbidity of the discharge effluent
while the decant pumps are in operation. From March 2006 to present, the effluent has been
discharged to the Long Creek Wastewater Treatment Plant under City of Gastonia — Two Rivers
Utilities Wastewater Treatment Division SIU Permit #1064. Due to this fact, a request to place our
NPDES Permit in an "inactive" status was made to the NCDENR Division of Water Quality and
approved in a letter dated May 26, 2009.
Presently, sludge is stored in basin #2 until it is filled. When ready to be moved, the sludge is
analyzed and is disposed of by an outside vendor who removes the sludge via a portable sludge
pressing operation that de -waters the sludge and transports the residuals to a permitted landfill.
This facility also has the capability to pump residuals directly to the City of Gastonia — Two Rivers
Utilities' Long Creek Wastewater Treatment Plant, if necessary.
C Edward Cross, Division Manager
Water Supply and Treatment Division
City of Gastonia —Two Rivers Utilities

* N
ROAD CLASSIFICATION
PRIMARY HIGHWAY LIGHT -DUTY ROAD. HARD OR
HARD SURFACE IMPROVED SURFACE
SECONDARY HIGHWAY
HARD SURFACE E:� UNIMPROVED ROAD
Latitude 35°16'06" Longitude 8111116"
Map # F14SW
Stream Class
Discharge Class
Sub -basin 030836
WS-II
Water Treatment Plant
Receiving Stream UT to Long Creek/Catawba River
Design Q 1.2 MGD '
SCALE 1:24 000
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1 1 KILOMETER
CONTOUR 1 FEET
QUAD LOCATION City of Gastonia
NCO040070
Gaston County
WTP

City of Gastonia — Two Rivers Utilities
Alum Sludge De -watering Facility
Line Diagram - (July 2014)
/ Basin # 1
600,000 gals.
Polymer
addition
Basin #2
600,000 gals_
Sludge /
Inventory
Alum Sludge
Facility
De -chlorination
Effluent
--------- -----♦ Collection
Box
Water Plant
To Long Creek
W WTP
A To discharge to
tributary to
Long Creek
Legend
0 Influent
------► Effluent