NC0089737_NPDES Application_20171103

McGill
A S S O C I A T E S
November 3, 2017
Julie Grzyb, supervisor
North Carolina Department of Environmental Quality
Division of Water Resources
WQ Permitting Section - NPDES
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Dear Ms. Grzyb:
Division dVator Rasource9
NOV - 8 2017
Water Ouality Re
glonaf Operations
—���ilie Reri
nnal Q?fire
RE: NPDES Permit Application
Short Form C- WTP
Town of Franklin Water Treatment Plant
Macon County
On behalf of the Town of Franklin we are submitting the enclosed NPDES permit application for
the discharge of treated wastewater from the town's water treatment plant. The permit would allow
discharge of wastewater from the town's water treatment plant residuals storage lagoons into
Cartoogechaye Creek. The following items are enclosed for your review and approval:
1. NPDES Permit Application — Short Form C — WTP
2. Application fee in the amount of $860.00
3. Location map with latitude and longitude
4. Water Plant Flow Diagram
5. Engineering Alternatives Analysis Report
Should you have any questions or need additional information please give me a call at'828-252-
0575 or contact me via email at [e-mail].
Sincerely,
MccGILL AINOCIATES, A.
M. KEfTH WEBB, P.E.
Vice President - Principal
Enclosures
CC: Nathanael Moore, P.E. — Town of Franklin
Summer Woodard— Town of Franklin
Rob Hartsell — Town of Franklin — w/enclosures
Jay Gibson— Town of Franklin
Tim Heim — Asheville Regional office DWQ — w/enclosures Q/
I/2015/15.00359/NPDES petnut/jg3nov17
55 Broad Street RO. Box 2259. ph: 828.252.0575
Asheville. North Carolina 28801 Asheville, North Carolina 28802 f: 828.252.2518 ..mcgiliengineers. i om

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
I "
Mail the complete application to:
{ N. C. DEQ / DWR / NPDES
1617 Mail Service Center, Raleigh, NC 27699-1617
NPDES Permit Number INCOO
jt
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 Town of Franklin
Facility Name Water Treatment Plant
Mailing Address Post Office Box 1479
City Franklin
State / Zip Code North Carolina, 28744
Telephone Number .[phone]
Fax Number [phone]
e-mail Address [e-mail]
2. Location of facility producing discharge:
Check here if same as above ❑
Street Address or State Road 437 Industrial Park Drive
City Franklin
State / Zip Code North Carolina, 28734
County Macon
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 ORQ
Name Robert Hartsell - Supervisor
Mailing Address 437 Industrial Park Drive
City Franklin
State / Zip Code North Carolina, 28734
Telephone Number [phone]
Fax Number [phone]
4. Ownership Status:
Federal ❑ State ❑ Private ❑ Public Ni,'
Pagel of4 Version 6/20177

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
S. Type of treatment plant:
® Conventional ¢ncludes 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)
Cartoogechaye Creek (surface water)
7. Describe the treatment processes) for the raw water:
Raw water pumped to pre-treatment (Actiflo) ballasted settling unit. Polyaluminum chlorosulfate
(PAC — (cedarclear-757) added as a coagulant. Flow from Actiflo to fluctuation and
sedimentation basins. Final filtration using mixed media filter. Chlorination for final disinfection
prior to storage in clearwell and pump to distribution system.
S. Describe the wastewater and the treatment process(es) for wastewater generated by the
facility:
Wastewater is generated from the pre-treatment unit (Actiflo), filter backwash, periodic cleaning
of the sedimentation basins and process instrument wastewater. Wastewater flows to a 136,700
gallon flow equalization tank, then to two alum sludge lagoons., Discharge will be from the
second alum sludge lagoon.
9. Number of separate discharge points: 1 Outfall Identification number(s)
10. Frequency of discharge: Continuous ❑ Intermittent 19
If intermittent:
Days per week discharge occurs: 7 Duration: intermittent (WTP
typically operated 14 to 16 hours per day) .
11. Plant design potable flowrate 2.0 MGD
Backwash or reject flow 0.085 MGD
12. Name of receiving stream(s) (Provide a map showing the exact location of each outfall, including
latitude and longitude):
Cartoogechaye Creek
13. Please list all water treatment additives, including cleaning chemicals or disinfection
treatments that have the potential to be discharged.
Page 2 of 4 Version 6/2017

i
s
NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Alum / aluminum sulfate Yes No X
Iron sulfate / ferrous sulfate Yes No X
Fluoride Yes No X
Ammonia nitrogen / Chloramines Yes No X
Zinc -orthophosphate or Sweetwater CP1236 Yes X No
List any other additives below:
Polyaluminum chlorosulfate (PAC — (cedardear-757)
Sodium hydroxide (caustic soda)
14. Is this facility located on Indian country? (check one)
Yes ❑
OF
15. Additional Information:
➢ Provide a schematic of now through the facility, include flow volumes at all points in
the water treatment process. The plan should show the points] of addition for
chemicals and all discharges routed to an outfall [including stormwater].
➢ Solids Handling Plan
16, NEW Applicants
Infom action 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.
name of
Title
1 — Vt V
Signa ure of Applicant Date
North Carolina General Statute 143-215.6 (b)(2) provides that Any person who knowingly mattes any false statement representation, or cartlHcation In any application,
record, recod, plan, or other document (Iles 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 WArticle, shall be guilty of a misdemeanor punishable by a fine not to exceed $25,000, or by
Page 3 of 4 Version 6/2017

NPDES PERMIT APPLICATION - SHORT FORM C - WTP
For discharges associated with water treatment plants
Imprisonment not to exceed six months, or by both. (18 U.S.C. Section 1001 provides a punishment by a fine of not more then $25,000 or Imprisonment not more than 5
year;, or both, for a slmilaroffense.)
Page 4 of 4 Version 6/2017

HYPOCHLORITE / CHLORINE GAS)
(CAUSTIC SODA, ZINC -ORTHOPHOSPHATE)
SLUDGE
SLUDGE
C1400
GPM (2.0 MGD)
136;700
LAGOON
LAGOON
GALLON
No.1
No.2
LINE
EQTANK
HIGH24"WASTEWATER
ISHED(SODIUM
SERVIC2940
GPM (32,200 GPD)
PUMP
STATION
o
0
U
F=
U
c~»
FILTER,
SEDIMENT
z
a
U
c
_ No. 2 .
BASIN''
0
oQ
p
a
W
¢
o
m
U
zLu
7
w
CD
Q
a
FILTER `.
SEDIMENT
CD
No.1
BASINt
o
«'
0
O
�
w
U
1400 GPM
PRETREATMENT
UNIT
"ACTIFLO"
WATER TREATMENT PLANT
FLOW DIAGRAM
FRANKLIN WATER
TREATMENT PLANT

lbllk
a
PLAN I �/
2000 0 1000 2000 4000 C o
} ?}ro GRAPHIC SCALE I INCH = 2000 FEET
un
f
�Zion Cem,�,
// L4 12_�
—��NPDES DISCHARGE PO7INT
-T
LATITUDE: 35° 09' 44" N
PLONGITUDE: 83' 26' 13" W
FRANKLIN WATER
TREATMENT PLANT,
0
' /��
WATER TREATMENT PLANT
DATE: OCTOBER, 2017
BY:
BACKWASH /WASTEWATER NPDES PERMIT
DESIGNED BY: MKW
DESIGNED MK
1II\v/� ��
CDD Bw
DESIGN REVIEW:
A S S O C I A T E S
TOWN OF FRANKLIN
ONST.R VI
CONST. REVIEW.
ENGINEERING•PLANNING•FIN ANCE
55—.ID t 7 esuevws Nc xswi w5.5ns)vwro wRMLICFHSF..eu+w
FILENAME:
15.00359 NPDES Lowoon. awg
MACON COUNTY, NORTH CAROLINA
o
�Goz23
ads
�l lU
loss
NPDES PERMIT
DISCHARGE POINT
LOCATION MAP
FIGURE
1

ENGINEERING ALTERNATIVES ANALYSIS
WATER TREATMENT PLANT UPGRADE
and
TREATMENT PLANT RESIDUALS
TOWN OF FRANKLIN
MACON COUNTY, NORTH CAROLINA
M. KEITH WEBB, P.E.
McGill
ASSOCIATES
Engineering • Planning • Finance
Asheville, North Carolina
OCTOBER, 2017
PROJECT #15.00359

TABLE OF CONTENTS
A. SUMMARY, CONCLUSION & RECOMMENDATION ...1
B. CURRENT SITUATION......................................................... 2
C. ALTERNATIVES ANALYSIS.............................................11

A. SUMMARY, CONCLUSION AND RECOMMENDATION
The Town of Franklin owns and operates a water treatment plant (WTP) which has a
design capacity of 2.0 MGD and is located west of downtown in the Franklin Industrial
Park off of US 64. The WTP was constructed in 1975 and last upgraded in 1997. Recent
studies identify the need to expand the WTP to a capacity of 3.0 MGD to 4.0 MGD to
meet the long term projected future demands. Average daily water demands have been
projected to increase of 1.90 MGD by year 2060 with peak day demands of 3.0 MGD.
As a part of the WTP expansion phase I improvements have been designed and permitted
and construction is beginning on these first phase improvements which consist of the
construction of an Actiflo® treatment process to address the need for either mechanical
pretreatment of the raw water or off -stream storage associated with the future expansion
of the WTP as required by the North Carolina Administrative Codes Title 15A,
Subchapter 18C entitled "Rules Governing Public Water Systems". The Actiflo® system
utilizes a micro -sand particle which is blended into the raw water stream along with
coagulant chemicals to provide a ballasted settling environment. The proposed new
pretreatment unit is situated so as flow is pumped to the unit from the raw water pump
station and then flows by gravity to the existing sedimentation basins and filters.
The proposed Actiflo® system will result in a continuous flow of wastewater from the
pretreatment unit when the WTP is in operation. This flow is estimated to be in the range
of 40 gallons per minute (gpm) to 55 gpm. The WTP currently operates on average
approximately 14 to 16 hours per day to meet current system demands. Therefore once
the pretreatment unit is in place and operational the facility will generate approximately
52,800 gpd of wastewater that must be properly handled.
In addition to the wastewater generated as a part of the new pretreatment process there
will continue to be wastewater generated as a part of the. normal plant operation
associated with the required routine filter backwash which occurs approximately every 72
Engineering Alternatives Analysis,
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017 Page 1 of 14

B.
hours of filter run. On average the filter backwash is 30,000 gpd. In addition the
sedimentation basins will require at least semi-annual cleaning, if not quarterly. This
activity typically generates an additional 150,000 gpd of wastewater.
Modifications to the WTP wastewater collection system are being made and the
backwash flow will be handled and treated utilizing the existing 136,700 gallon capacity
backwash water flow equalization tank and then the two alum sludge lagoons.
In order to provide maximum flexibility in the operation of the current WTP residuals
handling system it is proposed to secure an NPDES permit for the residuals (alum)
lagoons to allow for the discharge of clear water from the top of the lagoons back into
Cartoogechaye Creek. The town will continue to maintain the WTP wastewater system
and will schedule the removal of water treatment plant residuals from the lagoons on a
routine basis.
CURRENT SITUATION
1) Existing Water Treatment Plant
The Town of Franklin owns and operates a water treatment plant (WTP) which has a
design capacity of 2.0 MGD and is located in the Franklin Industrial Park west of
downtown and off of US 64. The WTP was constructed in 1975 and last upgraded in
1997. Therefore most of the facility is greater than 40 years old. However, despite its age
for the most part the WTP is in good condition. The WTP provides treated finished water
for the Franklin distribution system and the approximately 3,350 customers within the
town and a small portion of Macon County with water service outside the corporate
limits.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October2017
l r , " "t
Page 2 of 14

The WTP utilizes a conventional treatment process with raw water withdrawn from
Cartoogechaye Creek, a tributary of the Little Tennessee River. Raw water is pumped to
a flashmix basin where polyaluminum chlorosulfate (PAC — (cedarclear-757)) is added
to enhance coagulation and sodium hydroxide (caustic soda) is added for pH adjustment.
Raw water flow then enters two flocculation basins, each equipped with two vertical
flocculators which slowly mix the water to build a floc of the sediment in the raw water.
Coagulated water flows to two sediment basins where heavier sediments are removed by
gravity settling. These heavier sediments are removed on a routine basis, typically every
three (3) months to the alum sludge lagoons. Clarified water is then filtered by two mixed
media gravity filters prior to the addition of chlorine gas for disinfection. Finished water
is stored in a clearwell at the plant prior to being pumped into the distribution system.
Cartoogechaye Creek has an estimated "safe yield" of 4.0 MGD and based upon previous
approved studies the Town of Franklin may expand the WTP up to a capacity of 4.0
MGD to meet future demands for the water system. The current average daily demands
average 1.10 million gallons per day (MGD) with peak day demands of 1.70 MGD.
Projected future demands have been estimated to be 1.90 MGD by year 2060 with peak
day demands of 3.0 MGD.
2) Population and Demographics
The foundation of any water plant evaluation is the projection of future demands for the
water system. Future demand projections establish the framework of the WTP
upgrade/expansion by establishing an agreed upon planning horizon and corresponding
system demand. As part of a previous evaluation of the Town of Franklin water system
conducted by WK Dickson (WKD), a detailed evaluation of the Town's water system
demands was conducted. The results of this evaluation are summarized in Figure B.1
below. Town staff reviewed these projections and have concluded that they are
reasonable and acceptable for use in future planning of the water system.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residualsb
Town of Franklin, Macon County, North Carolina
October 2017 Page 3 of 14

4)
3) Figure B.1— Water System Demand Projections
Water System Demand Projections
Town of Franklin
3.5
t
2.5
l7 2
m
E 1.5
w
—
_
0.5
0
2010 2015 2020 2030 2040 2050 2055
—*-Estimated Average Daily Usage (MGD) —6—Estimated Max. Daily Usage (MGD)
SOURCE: COMPREHENSIVE WATER MODEL AND MASTER PLAN, WKDICKsoN, 2013
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017
Page 4 of 14

The Town of Franklin has identified the need to expand the capacity of the water
treatment plant to 3.0 MGD or even 4.0 MGD to meet these projected future demands.
An interim first phase of this project has been designed, permitted and is scheduled to
begin construction. This interim phase consist of the addition and of construction of an
Actiflo® treatment process to address the need for either mechanical pretreatment of the
raw water or off -stream storage. The previous engineering report prepared as a part of the
WTP upgrade evaluated the alternatives for mechanical pre-treatment or off -stream
storage and recommended the construction of the Actiflo® system. The Actiflo® system
utilizes a micro- sand particle which is blended into the raw water stream along with
coagulant chemicals to provide a ballasted settling environment. The proposed new
pretreatment unit is situated so as flow is pumped to the unit from the raw water pump
station and then flows by gravity to the existing sedimentation basins and filters.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017
Page 5 of 14

PLAN
WHICSCALE u I INCH 2(Hxl FEE, I
F*ankfin
N
7
-A-
El 04
7
23
10
------ -- 44
------aNPDES DISCHARGE POINT,t
j
FRANKLIN WATER �Co"ds
m
TREATMENT PLANT %
.44
e
It
A�
:-S-
V
S
omc WATER TREATMENT PLANT
FIGURE
BACKWASH I WASTEWATER NPOES PERMIT
G LOCATION MAP
f I A 1 1-3 S TOWN OF FRANKLIN
1116111 1 klN..
NtACON COUNTY NORTH CAROLINA I
0
m
u
0
z
c 0
< CL .0 u
> C u
E
01 r-
I
E
E
W y U- r4
cu
.9 lu
to 0 -0 3:
m
ul 3: m 0

Proposed Improvements
As described above the current project scheduled to begin construction includes the
construction of an Actiflo® treatment process for the pretreatment of the raw water prior
to sedimentation and filtration. Unlike the current WTP process the new proposed
Actiflo® system will result in a continuous flow of wastewater from the pretreatment unit
when the WTP is in operation. This flow is estimated to be in the range of 40 gallons per
minute (gpm) to 55 gpm. The WTP currently operates on average approximately 14 to 16
hours per day. Therefore once the in pretreatment unit is in place and operational the
facility will generate approximately 52,800 gpd of wastewater that must be handled. In
addition to the wastewater generated as a part of the pretreatment process there is also
wastewater associated with the required routine filter backwash which occurs
approximately every 72 hours of filter run. On average the filter backwash is 30,000 gpd.
In addition the sedimentation basins will require at least semi-annual cleaning, if not
quarterly. This activity typically generates an additional 150,000 gpd of wastewater.
Modifications to the WTP wastewater collection system are being made and the
backwash flow will be handled and treated utilizing the existing 136,700 gallon capacity
backwash water flow equalization tank and then the two alum sludge lagoons.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017
Page 7of14

Currently all non -sanitary wastewater from the WTP facility, primarily filter backwash
water and sediment basin drains flows to a pair of WTP residuals (alum sludge) lagoons
located below the WTP along the banks of Cartoogechaye Creek. Filter backwash water
flows from the WTP through a 24-inch sewer line to a 136,700 gallon capacity concrete
sludge thickening tank prior to then flowing to the two alum sludge lagoons. This tank
basically serves as a flow equalization tank with the filter backwash water flowing
though the tank to the alum sludge lagoons.
As a part of the WTP improvements the WTP wastewater piping is being modified so
that all backwash water (filter backwash, sediment basin cleaning and the Actiflo
system) will first flow to the existing 136,700 gallon circular concrete tank. This tank
will function as a flow equalization tank and modulated flows will then exit the tank and
to the lagoons.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017
Page 8 of 14

The two existing alum sludge lagoons are both unlined with an approximate combined
volume of 1.8 MG and were built in 1975 as a part of the original WTP construction.
These lagoons have been in service at this facility since it first went on-line and the
residuals in the lagoons was recently (2011) removed and land applied on local farm
land for beneficial use. These lagoons and the residuals handling system are typical for
WTP facilities with a high quality water source.
While the alum sludge lagoons have functioned adequately, there is a concern on the
part of the WTP operation staff that with the daily flow of wastewater associated with
the Actiflo® pretreatment process removal of clear water from the lagoons on a routine
basis will be required to provide adequate volume for wastewater from the WTP.
Historically the water treatment plant operators have relied on evaporation and/or
infiltration of the clear water from the lagoons to provide the hydraulic capacity
required.
The existing alum sludge lagoons along with the 136,700 gallon capacity now
equalization tank should provide adequate hydraulic capacity for the WTP and the
pretreatment unit. With the two lagoons relationship adjacent to Cartoogechaye Creek,
and no additional undeveloped space on the plant site options for the expansion and
construction of additional lagoons is limited. Increasing the depth of the lagoons is not a
feasible option as they are currently located above the water surface of the creek and
lowering of the lagoons would drop them below the water table.
In order to provide maximum flexibility in the operation of the current alum sludge
system it is proposed to secure an NPDES permit for the lagoons to allow for the
discharge of clear water from the top of the lagoons into Cartoogechaye Creek. Clarified
water will be decanted and removed from the top of the lagoons and returned to
Cartoogechaye Creek. This water should be of very good quality and is essentially the
water previously removed from the stream with trace amounts of treatment chemicals
Engineering Alternatives Analysist-
Water Treatment Plant Upgrade'`
,,r
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017 Page 9 of 14

(polyaluminum chlorosulfate (PAC — (cedarclear-757)), sodium hydroxide (caustic
soda), and Sodium hypochlorite (bleach). The town will continue to maintain the
wastewater system and will schedule the removal of water treatment plant residuals from
the lagoons on a routine basis.
C. ALTERNATIVES ANALYSIS
Four alternatives have been identified for the Franklin WTP upgrade to provide the operational
flexibility needed for the WTP residuals generated as a part of the enhanced treatment process.
These are:
1. No Action
2. Construction of additional Residual Storage Lagoons.
3. Secure an NPDES permit to allow decant and discharge from the Existing Lagoons.
4. Connection to public sewer collection system
ALTERNATIVE # I — NO ACTION
This alternative consists of taking no action to make improvements to the existing residual
system (alum sludge) at the Franklin WTP. The existing system has a combined volume of
approximately 1,936,000 gallons in the backwash tank and the two lagoons, provided the two
lagoons are cleaned of residuals. However, over time the lagoons will capture residuals (alum
sludge) and will fill -up, reducing the capacity. Currently there is no method to remove or decant
clear water from the lagoons. Water must either evaporate and/or infiltrate through the residuals
in the lagoon into the groundwater system. Depending upon this type of system for the removal
of water necessary to provide adequate volume for additional backwash water is not reliable,
especially during the winter months and periods of heavy rainfall.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017 Page 10 of 14

While the two lagoons and the backwash tank can provide as much as 23 days of theoretical
storage for the Actiflo and filter backwash water this volume is only available when the system is
100% cleaned of residuals. Operation of the WTP results in the generation of residuals which
must be stored in the two lagoons, therefore continuously reducing the capacity.
Continued operation of the system with no increased ability to decant and remove clear water
meeting typical parameters for discharge back to Cartoogechaye Creek is not feasible and is not
recommended as it subjects the WTP to potential violations for system overflows.
ALTERNATIVE # 2 — BUILD ADDITIONAL LAGOONS
This alternative consist of building an additional residuals storage lagoon to provide additional
wastewater storage volume. A lagoon with a capacity equal to the two current lagoons is
recommended. Land owned by the Town of Franklin at the WTP is limited and there are no
locations on the current site available to build a new lagoon. Property adjacent to the WTP is also
not available for purchase to build a third lagoon.
Of even more concern is that the construction of a third larger lagoon which would provide
additional residual storage volume, the removal of clarified water would still be through either
evaporation and/or infiltration and would be very weather dependent and not reliable.
This option is therefore not recommended.
ALTERNATIVE # 3 — NPDES PERMIT FOR THE EXISTING LAGOONS
This alternative will require the construction of no new lagoons or other residual treatment
facilities. Minor improvements to the current wastewater discharge piping will be made to allow
for the optimization of the current facilities. The existing system has a combined volume of
approximately 1,936,000 gallons in the backwash tank and the two lagoons, provided the two
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017 Page 11 of 14

lagoons are cleaned of residuals. This provides as much as 23 days of storage for the Actiflo and
filter backwash volume when the system is 100% cleaned. There is adequate volume to allow the
i
residuals to settle by gravity in the two lagoons with the clear water discharged to Cartoogechaye
Creek, under the provisions of a new NPDES permit. The ability to decant and remove clear
water from the surface of the lagoons will provide the needed flexibility the WTP operation staff
require. Typical effluent parameters for discharge of the treated wastewater from water treatment
facilities and in this case back to Cartoogechaye Creek appears to be the most feasible
alternative. Similar operations and systems are common at other WTP utilizing similar high
quality raw water sources.
The clarified water to be decanted and removed from the lagoons and returned to Cartoogechaye
Creek should be of very good quality and is essentially the water previously removed from the
stream with trace amounts of treatment chemicals (polyaluminum chlorosulfate (PAC —
(cedarclear-757)), sodium hydroxide (caustic soda), and Sodium hypochlorite (bleach). The
town will continue to maintain the wastewater system and will schedule the removal of water
treatment plant residuals from the lagoons on a routine basis.
ALTERNATIVE # 4 — CONNECTION TO A PUBLIC SEWER SYSTEM
This alternative would consist of connecting the wastewater system, at the WTP to the existing
Town of Franklin sewer collection and treatment system. The town does have an 8-inch gravity
sewer line located approximately 250 feet from the alum sludge lagoons.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October2017
Page 12 of 14

This sewer has a capacity of 255 gpm and provides service to the Franklin/Macon County
Industrial Park. There is limited capacity to accept flow from the Franklin WTP in this sewer
line.
In addition to the limited capacity of the sewer line near the WTP the gravity sewer line conveys
flow to a sewer pump station which then pumps the flow through a force main to another gravity
sewer line. This sewer line then conveys flow to a second sewer pump station which pumps
wastewater to the wastewater treatment plant (WWTP). Like most sewer collection systems
inflow and infiltration I/I is a problem for the Town of Franklin. The age of the majority of the
sewer collection system and the materials of construction present an ongoing challenge for the
town. The higher sewer flows especially during periods of excessive overflow subject the sewer
collection system to potential sewer overflows and stress the WWTP at these higher flows to
operate within limits.
Engineering Alternatives Analysis I!g { C
Water Treatment Plant Upgrade
e+
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October 2017 Page 13 of 14

The Town of Franklin has an ongoing I/I abatement program and continues to set aside funds on
an annual basis to address the UI flow situation. Water to be decanted and removed from the
WTP residual (alum) storage lagoons is expected to be of a quality that will allow the water to be
discharged back to Cartoogechaye Creek with no negative environmental issues. Discharge of
this water to the public sewer system will present continued I/I problems for the town's sewer
system and will potentially require the upgrade and expansion of a number of the wastewater
collection and pumping system components.
Due to the potential negative impacts on the town's sewer collection and treatment system the
connection to the public sewer system is not recommended.
Engineering Alternatives Analysis
Water Treatment Plant Upgrade
and Treatment Plant Residuals
Town of Franklin, Macon County, North Carolina
October2017
Page 14 of 14