NC0044121_Renewal (Application)_20190826

STtIA ,
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ROY COOPER (S- ' 1
Governor a r
MICHAEL S.REGAN - .1•.�
Secretary
V.
R.... `�"� Y
LINDA CULPEPPER NORTH CAROLINA
Director Environmental Quality
August 26, 2019
Warren Wood, City Manager
City of Hickory
1441 9th Ave Ne
Hickory, NC 28601-0398
Subject: Permit Renewal
Application No. NC0044121
Hickory WTP
Catawba County
Dear Applicant:
The Water Quality Permitting Section acknowledges the August 26, 2019 receipt of your permit renewal application and
supporting documentation. Your application will be assigned to a permit writer within the Section's NPDES WW permitting
branch. Per G.S. 150B-3 your current permit does not expire until permit decision on the application is made.
Continuation of.the current permit is contingent on timely and sufficient application for renewal of the current permit. The
permit writer will contact you if additional information is required to complete your permit renewal. Please respond in a
timely manner to requests for additional information necessary to allow a complete review of the application and renewal
of the permit.
Information regarding the status of your renewal application can be found online using the Department of Environmental
Quality's Environmental Application Tracker at:
https://deq.nc.gov/permits-regulations/permit-guidance/environmental-appl ication-tracker
If you have any additional questions about the permit, please contact the primary reviewer of the application using the
links available within the Application Tracker.
Sincerely,
tiJ‘tOiu
Wren Thedford
Administrative Assistant
Water Quality Permitting Section
ec: WQPS Laserfiche File w/application
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North.CaroLns Department of Enro ronmentai Qualdu I Divson of 1ti'ater kesouroes
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J-IICKORY City of Hickory
PO Box 398
� Hickory, NC 28603
�� ' Phone: [phone]
�� North Carolina - Fax: [phone]
Life. Well Crafted. Email: cbynum(hickorvnc.ctov
Public Utilities
August 07, 2019
North Carolina Department of Environmental Quality
Division of Water Quality, NPDES Unit
512 North Salisbury Street
Raleigh, NC 27604
RECEIVED/NGDEA/DW[t
RE: Permit Renewal Application for NPDES Permit Number NC0044121
City of Hickory Water Filtration Plant-WWTP AUG 2 0 2019
Hickory, North Carolina
Water Quality
Permitting Section
Dear Sir or Madam,
The purpose of this correspondence is to submit the Permit Renewal for the City of Hickory's
Water Treatment Facility NPDES permit. Enclosed you will find for your review the completed
Short Form C—WTP NPDES permit application. The application package includes the following:
• NPDES Permit Application —Short Form C—WTP
• Attachment A for 7.
• Attachment B for 8.
• Attachment C for 12.
• Attachment D for 15. •
• Attachment E for 15.
Thank you in advance for your review. Should you have any questions regarding this submittal,
please do not hesitate to contact me at(828) 323-7427 or via email at [e-mail].
Sincerely,
el
-#ba'"'''`-----
Caleb M. Bynum, El
Utilities Eng`neer

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Mail the complete application to:
N. C. Department of Environment and Natural Resources
Division of Water Quality / NPDES Unit
1617 Mail Service Center, Raleigh, NC 27699-1617
NPDES Permit Number NC0044121
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 City of Hickory Public Utilities
Facility Name City of Hickory Water Filtration Plant- WWTP
Mailing Address PO Box 398
City Hickory
State / Zip Code NC, 28603
Telephone Number [phone]
Fax Number ( )
e-mail Address [e-mail]
2. Location of facility producing discharge:
Check here if same as above ❑
Street Address or State Road 1560 Old Lenoir Rd.
City Hickory
State / Zip Code NC, 28601
County Catawba
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 Hickory
Mailing Address PO Box 398
City Hickory
State / Zip Code NC, 28603
Telephone Number [phone]
Fax Number [phone]
4. Ownership Status:
Federal ❑ State ❑ Private ❑ Public
Page 1 of 3 Version 5/2012

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 followed by
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)
100% Surface Water (Catawba River- Lake Hickory)
7. Describe the treatment process(es) for the raw water:
See Attachment A
8. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
See Attachment B
9. Number of g separate discharge points: 1
P _
Outfall Identification number(s) 001
10. Frequency of discharge: Continuous El Intermittent
If intermittent:
Days per week discharge occurs: 7 Duration: 12 hrs.
11. Plant design potable flowrate 32 MGD
Backwash or reject flow .330 MGD
12. Name of receiving stream(s) (Provide a map showing the exact location of each outfall, including
latitude and longitude):
Catawba River (Lake Hickory) - See Attachment C
13. Please list all water treatment additives, including cleaning chemicals or disinfection
treatments, that have the potential to be discharged.
Alum / aluminum sulfate Yes X No
Page 2 of 3 Version 5/2012

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Iron sulfate / ferrous sulfate Yes No X
Fluoride Yes X No
Ammonia nitrogen / Chloramines Yes No X
Zinc-orthophosphate or sweetwater CP1236 Yes X No
List any other additives below:
Sodium Hydroxide, Sodium Hypochlorite, Sulfur Dioxide
14. Is this facility located on Indian country? (check one)
Yes ❑ No
15. Additional Information: See Attachments D & E
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].
• Solids Handling Plan
16. NEW Applicants
Information needed in addition to items 1-15:
y New applicants are highly encouraged 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.
Warren Wood City Manager
Printed name of erson Signi g Title
7 i -)
U L I t
Signat Appli nt 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 5/2012

ATTACHMENT A

City of Hickory
Water Treatment Plant
The City of Hickory's Water Treatment Plant is a regional water supply
facility, providing potable drinking water to three counties and managing
three purchased water systems extending from Icard to Claremont and
from northern Alexander County to the Town of Catawba and Sherrills
Ford. We also supply water to the towns of Maiden & Long View.
The plant is a conventional surface water treatment facility, drawing water
from the Catawba River. The Catawba River Basin originates from springs
in the tallest mountains of the Appalachian Mountain chain and flows east
past Hickory. This provides us with an abundant water source, relatively
free from contamination. Duke Power operates two hydroelectric dams,
Rhodhiss upstream and Oxford downstream from the plant. These two
dams create a deep-water reservoir at our intake and help manage the
water flow to reduce contamination from water run-off.
We employ eleven state certified Operators, one state certified laboratory
Chemist and one Water Quality Technician. We operate 24 hours a day, 7
days a week... we never close! We have a rated capacity of 32 million gallons
of water per day.
., Our treatment facility
has earned the
distinction of the Area
11 Wide Optimization
Award for io of the past
15 years. This award
recognizes outstanding
turbidity removal, a key
s , 4 indicator of water quality
--- and clearly demonstrate 3
' �. ,__ improvement in public
i irh li► r
;u r - health protection.

The Treatment Process
1. Raw water is pumped
from the Catawba River
where large things such
as sticks, fish and plants
are screened at the
I
pump intake. The raw
'I water is treated with
16 I 4 chemicals in this first
step of the treatment
• R process. A chlorine
disinfectant is added to
"' the water to kill
pathogenic (disease-causing) organisms, aluminum sulfate is added to
help remove fine particles that are suspended in the water by
coagulation and sodium hydroxide is added to adjust the pH and
provide alkalinity to the mixed water. The raw water pumps push the
water to the flash mixer and gravity draws it through the rest of the
treatment process.
2. At the flash mixer, the water is rapidly mixed to evenly distribute the
chemicals. The flash mixer is a small basin that will contain the water
for just a matter of seconds and provide even distribution of the
treatment chemicals that were just added.
3. The water then flows to a 'd*
large basin where the Y} t _ z
chemicals cling to the _ y r
impurities in the water in a � _ ,,,,2�. � ;�
process called F
` u t
coagulation. Flocculators - - -
move the water slower in
this basin to provide the
chemicals contact with the impurities and to clump together in large
particles. This process is called flocculation. The water remains in
these flocculators for several minui;:es.

4. The treated water then moves to the settling basins where the large,
heavy particles quickly settle to the bottom. Water moves very slowly
and is not disturbed during the sedimentation process. Depending on
raw water flow rate, it takes from 6 to 12 hours for the water to move
through these basins.
5. After making its journey across
the settling basin, the water
• along the top of the
"4` sedimentation basin flows
t �R
A4 # through common troughs to the
¢ 14•1 'Y filters. The filters are comprised
_t of layers of gravel, sand and
hard coal (anthracite). The
filters remove any of the
E remaining small particles of floc
that failed to settle and any
other impurities left in the
. water.
6. After filtering, the water is
chemically treated once again.
Chlorine is added to provide
enough residual to remain in a 61:
the distribution system. OF-
Fluoride is added to prevent - ;t .; o 14"-
Imo ,,
tooth decay. More Sodium
Hydroxide is added to raise the i' =4 = k1.
pH level of the water. Finally, a ,
Phosphate is added to inhibit
corrosion and prevent copper
and lead from leaching into the
water through piping in the a'
distribution system.

.1 > 7. The finished water is then
stored in ground storage
tanks, called clearwells
— E. .; , ; before being pumped to
,.v.,. elevated storage tanks. The
water is stored in these tanks
5 for hours. This gives the
. _.. just
-.)1`i
final dosing of disinfectant
some time to work before the
. . . am ',, water is delivered to the first
customers.
t M,
8. The final step is pumping the .
finished water to the elevated ,;. ; : ; N
storage tanks. The elevated ' `_ . --
storage tanks create water `
h.
pressure to deliver the water ,„, ' ' -
: -•.,,--- -.±a`ice+
to customers and provide a ° .•
ready supply for the customer.
J
F
a

Sodium Hypochlorite Generation
''' , . - For over a century, water
I
i` '1' I plants have used chlorine
1 )1 s gas. It is a very good
Oa 4 �;. ! , disinfectant, but safety is a
...A if
:', "''gig ' um!: major concern in its use
.�r
` ' and handling. Many water
' MICROCLO� / . o plants have switched to
:' �-+,74 ' I sodium hypochlorite as a
. r disinfectant. Most plants
- r r . ° 4111 have concentrated
1 !,-, i ;"' ;,, �� ° commercial grade delivered
•► •
' ° by
truck, but Hickorywas
1 I, n
I the first in North Carolina
t y ft- `+ ti ���1����,i/47 t ypurchase its own sodium
hypochlorite generator.
The sodium hypochlorite generator system was upgraded in 2018 and
consists of 2 units with a capacity of up to i600 pounds per day. Each unit
consists of 5 electrolytic cells arranged vertically to increase safety.
Saturated brine and water are pumped into the unit and electrical energy is
applied. The electro-chemical reaction breaks the hydrogen bond in the
water to create sodium hypochlorite and hydrogen gas. The sodium
hypochlorite is pumped into storage tanks while the hydrogen gas is diluted
and vented to the air.
Chlorine gas reacts with organics in the water to create chemicals in the
tri-halomethane group. These chemicals have been identified by the
Environmental Protection Agency as possible carcinogens. Sodium
hypochlorite seems to be less prone to reacting with organics in this
manner and reduces harmful by-products found in the distribution system.
Also, the sodium hypochlorite seems to keep a residual longer in the
distribution system using smaller dosages than just chlorine gas.

Why Drink Purified Water?
Purified drinking water is tested every day for pathogenic bacteria in our
state certified laboratory. We conduct nearly 100,00o individual laboratory
tests each year. Our chemist and operators continuously monitor chlorine
content, daily physical analysis, and treatment monitoring tests to assure
quality standards that meet or exceed all state and federal regulations for
drinking water. Fluoride is added for the prevention of tooth decay (this is
particularly important in children). The City of Hickory's water has a low
iron and hardness content so that it will wash clothes better. But mainly,
it's safe and has a pleasant taste!
0 �.
Los-, u
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For Further Information
Thanks for stopping by our web site! If we can be of further assistance, please feel free to
call the City of Hickory Water Treatment Plant at (828) 323-753o.
.411L. C A T A W B A
811 . WATEREE
DrinkTøp
www.ric8 .Ur. WATER MANAGEMENT GROUP

ATTACHMENT B

Backwash Waste Water Process Summary
The Backwash Wastewater Process involves the separation of solids from
the Filter Backwash Water, pumping settled solids to the Northeast
Wastewater Treatment Facility for processing, and returning the water to
the Catawba River. Decant water that is discharged to the Catawba River
is treated with Sulfur Dioxide to remove any remaining Chlorine residual.
Backwash from the filters is drained to the Equalization Tank (EQ Tank).
When the EQ Tank reaches a level of about 12 feet, sludge from the
bottom of the EQ Tank is moved to a Sludge Transfer Pump vault. Sludge
Transfer Pumps move the sludge in the vault to the Sludge Thickening
Tank before being pumped to the Sewer Lift Station and eventually to
the Northeast Wastewater Treatment Facility.
Floc in suspension in the EQ Tank precipitates down to the bottom of the
tank, leaving Supernate on top of a sludge blanket. This Supernate is
decanted to the Dechlorination Vault. Discharge from the EQ Tank is sent
to the Sludge Thickening Tank. Floc continues to precipitate, producing
supernate and this is also decanted to the dechloronation system.
In the Dechlorination Vault, effluent Supernate is mixed with Sulfur
Dioxide to remove all residual Chlorine before discharging to the
Catawba River. All flows are by gravity with the exception of the Sludge
Transfer Pumps between the EQ Tank and the Sludge Thickening Tank
and the Sludge Pump to the Sewer Lift Station.
Solids are handled by the Northeast Wastewater Treatment Facility
through normal plant operations, gravity belt thickening and ultimate
disposal at the Regional Compost Facility.

ATTACHMENT C

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ATTACHMENT D

City of Hickory - Sludge Treatment Schematic
• Sludge T-Valve
Transfer Location
Pumps ,
J
. +,` Sludge Equilization `,
I Thickening Tank
Tank (EQ) I '
Supernate
`
Decant
--- -
- Backwash Water
0 ��� — from Filter Bldg.
ii
xi I
Dechlorinationes Supernate
co II Treatment Vaultir
Sulfur Dioxide Decant
1 J
U II (L-..----_.
Sludge Line
Sludge Line
II
MIIIIIF link I" titttttt of
I.Water enters the EQ Tank from the Filter Building.
Existing Belt-Pres 2-When the water level reachs 12 foot, sludge from the
Building bottom of the EQ is moved via the T-Valve to the Sludge
Transfer Pumps,then to the Sludge Thickening Tank.
I 3- Sludge from the Sludge Thickening Tank is pumped with
the Pump in the Belt Press Building to the Sewer Pump
Station,
4-Supernate from the EQ Tank and the Sludge Tank is
decanted to the Dechlorination Treatment Vault.
Sewer Pump 5-Sulfur Dioxide is used to dechlorinate the effluent.
Station
6-The effluent is discharged into the Catawba River.

ATTACHMENT E

Solids Handling Plan
Alum sludge generated by the treatment process is removed from the
plant and stored in thickening tanks. Solids are allowed to settle in these
tanks to achieve an optimum percent solid slurry and supernate is drawn
from the tank and discharged to the Catawba River (Lake Hickory) via
NPDES Permit #NC0044121 . The remaining solids are discharged to the
City of Hickory "Far East" sewer lift station at a rate of 4,000 gallons per
week and then pumped to the City of Hickory Northeast Wastewater
Treatment Facility, (NPDES Permit #NC0020401) via the City of Hickory
Collection System, (Permit #WQCS00020) for treatment and ultimate
disposal. Solids generated at the Northeast Wastewater Treatment
Facility are trucked to the Hickory Regional Compost Facility, (Permit
#WO0004563) and processed into Class "A" compost under 503
regulations.