NC0089630_Renewal Modification to Increase Phase I_20171120

CHARLOTTE
Wt)TER
November 20, 2017
Mr Michael Templeton, P E
Wastewater Permitting Section
Division of Water Resources
Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
RECEIVED/DENR/DWR
DEC R 5 2017
Water Resourceb
Permitting Section
Re Long Creek NPDES Permit Application — Modification to Increase Phase I Flow Capacity to 15 MGD
NPDES Permit #NC0089630
Mecklenburg County, NC
Mr Templeton,
Please let this letter serve as Charlotte Water's (CLTWater) request to modify the Long Creek NPDES permit
application previously submitted by CLTWater. In consideration of the updated preliminary engineering report
CLTWater Is increasing phase I capacity from 12 MGD to 15 MGD Please see the attached Technical Memorandum
for additional information If you have any questions concerning this change or if you need any other information
please feel free to contact our Water Quality Program Administrator, Shannon Sypolt, at 704-336-4581, or me at 704-
336-5433
Respectfully,
Ccqueline A Jarrell, P E
Operations Chief, Environmental Management Division
Charlotte Water
Cc- J Lockler (CLTWater)
S Sypolt (CLTWater)
R Hargrove (CLTWater)
Charlotte Water 5100 Brookshire Blvd, Charlotte, NC 28216 charlottewater org
v orn Operated by the City of Charlotte

FACILITY NAME AND PERMIT NUMBER PERMIT ACTION REQUESTED RIVER BASIN
Long Creek Regional WWTP, Initial Permit Catawba
A 5 Indian Country.
a Is the treatment works located in Indian Country?
❑ Yes X No
b Does the treatment works discharge to a receiving water that is either in Indian Country or that is upstream from (and eventually flows
through) Indian Country?
❑ Yes X No
A 6. Flow Indicate the design flow rate of the treatment plant (i e , the wastewater flow rate that the plant was built to handle) Also provide the
average daily flow rate and maximum daily flow rate for each of the last three years Each year's data must be based on a 12 -month time period
with the 12`h month of "this year" occurring no more than three months prior to this application submittal
�ya jC
1'1
a Design flow rate 92-8/ 25 0 U mgd
Two Years Ago Last Year This Year
b Annual average daily flow rate N/A N/A N/A
c Maximum daily flow rate N/A N/A N/A
A 7 Collection System Indicate the type(s) of collection system(s) used by the treatment plant Check all that apply Also estimate the percent
contribution (by miles) of each
X Separate sanitary sewer 100 %
❑ Combined storm and sanitary sewer %
A 8 Discharges and Other Disposal Methods
a Does the treatment works discharge effluent to waters of the U S ? X Yes ❑ No
If yes, list how many of each of the following types of discharge points the treatment works uses
I Discharges of treated effluent
u Discharges of untreated or partially treated effluent
ui Combined sewer overflow points
ro Constructed emergency overflows (prior to the headworks)
V Other
b Does the treatment works discharge effluent to basins, ponds, or other surface impoundments
that do not have outlets for discharge to waters of the U S ? ❑ Yes
If yes, provide the following for each surface impoundment
Location
Annual average daily volume discharge to surface impoundment(s)
Is discharge ❑ continuous or ❑ intermittent?
c Does the treatment works land -apply treated wastewater?
If yes, provide the following for each land application site
d
Location
Number of acres
Annual average daily volume applied to site
Is land application ❑ continuous or ❑ intermittent?
Does the treatment works discharge or transport treated or untreated wastewater to another
treatment works?
X No
❑ Yes
mgd
mgd
X No
❑ Yes X No
EPA Form 3510-2A (Rev 1-99) Replaces EPA forms 7550-6 & 7550-22 Page 3 of 22

FACILITY NAME AND PERMIT NUMBER
PERMIT ACTION REQUESTED
RIVER BASIN
Long Creek Regional WWTP
Initial Permit
Catawba
If yes, describe the mean(s) by which the wastewater from the treatment works is discharged or transported to the other treatment works
(e g , tank truck, pipe)
If transport is by a party other than the applicant, provide
Transporter Name
Mailing Address
Contact Person
Title
Telephone Number ( )
For each treatment works that receives this discharge, provide the following
Name
Mailing Address
Contact Person
Title
Telephone Number ( )
If known, provide the NPDES permit number of the treatment works that receives this discharge
Provide the average daily flow rate from the treatment works into the receiving facility
mgd
e Does the treatment works discharge or dispose of its wastewater in a manner not included
in A 8 through A 8 d above (e g , underground percolation, well injection) ❑ Yes
X No
If yes, provide the following for each disposal method
Description of method (including location and size of site(s) if applicable)
Annual daily volume disposed by this method
Is disposal through this method ❑ continuous or ❑ intermittent?
EPA Form 3510-2A (Rev 1-99) Replaces EPA forms 7550-6 & 755D-22 Page 4 of 22

CHARLOTTE
W4)TER
November 20, 2017
Mr Michael Templeton, P E
Wastewater Permitting Section
Division of Water Resources
Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
Re: Long Creek NPDES Permit Application — Modification to Increase Phase I Flow Capacity to 15 MGD
NPDES Permit #NC0089630
Mecklenburg County, NC
Mr Templeton,
Please let this letter serve as Charlotte Water's (CLTWater) request to modify the Long Creek NPDES permit
application previously submitted by CLTWater In consideration of the updated preliminary engineering report
CLTWater is Increasing phase I capacity from 12 MGD to 15 MGD. Please see the attached Technical Memorandum
for additional information If you have any questions concerning this change or If you need any other Information
please feel free to contact our Water Quality Program Administrator, Shannon Sypolt, at 704-336-4581, or me at 704-
336-5433
Respectfully,
cqerauefine A Jarrell, P.E.
ptlons Chief, Environmental Management Division
Charlotte Water
Cc J Lockler (CLTWater)
S Sypolt (CLTWater)
R Hargrove (CLTWater)
Charlotte Water 5100 Brookshire Blvd, Charlotte, NC 28216 char lottewater.org
.,67) Operated by the City of Charlotte

k
DRAFT
LONG CREEK REGIONAL WWTP
PRELIMINARY ENGINEERING REPORT
Technical Memorandum No. 2: Flow Transfer
to McDowell WWTP Versus Increased Phase I
. • •ME up, I V ;. •
B&V PROJECT NO. 194851
PREPARED FOR
CHARLOTTE
W6TER
Charlotte Water
28 JUNE 2017
BLACK&VEATCH
Building a world of difference®

t Charlotte Water I LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
Table of Contents
1 Introduction.......................................................................................................................1
2 Purpose................................................................................................................................1
3 Methodology.......................................................................................................................1
3.1 Capital Costs............................................................................................................................1
3.2 Operating Costs................................................................................................................2
3.3 Net Present Cost................................................................................................... ... 3
4 Results..................................................................................................................................3
5 Conclusions & Recommendations..............................................................................4
BLACK & VEATCH I Plant Capacity Cost Evaluation

Charlotte Water I LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
1 Introduction
Charlotte Water is currently considering options for phasing of a new Regional Wastewater
Treatment Plant (WWTP) at Long Creek. Provisional planning indicated a phased installation
with two phases of expansion as follows•
• Phase I - Designed for a maximum month average flow of 12 MGD1
• Phase II -Designed for a maximum month average flow of 25 MGD
A meeting was held on 16 June 2017 during which flow and load projections for the new facility
from Draft Technical Memorandum No.1 were presented to Charlotte Water. The projections
indicated that with the above sizing, planning for Phase II would need to begin very soon after
the completion of Phase I Two options for delaying the installation of Phase II were discussed
as follows -
Option 1- install a temporary pumping station and forced main to transfer an average
of 2 MGD of flow (2.4 MGD maximum month) from the Long Creek basin to the basin
feeding McDowell WWTP (which has permitted capacity to accommodate the additional
flows). The forced main would be operated up to the date the Phase II installation is put
into operation
• Option 2 - increase the size of the Phase I installation to 15 MGD2
As requested by Charlotte Water during the meeting, B&V has prepared a high level comparison
of these two approaches for sizing of the Phase I infrastructure.
2 Purpose
The purpose of the comparison is to provide Charlotte Water with a high level indication of life
cycle costs associated with each option in order to assist Charlotte Water in deciding if it would
be better build the temporary transfer main to McDowell, or to instead invest additional capital
in a larger Phase I installation at Long Creek
3 Methodology
The following section provides an overview of the methodology used in the evaluation -
3.1 CAPITAL COSTS
Capital costs were estimated as follows
A wastewater treatment plant price estimating tool (CapdetWorks from Hydromantis)
was used to estimate high level costs for a 10 MGD, 12 5 MGD and 15 MGD treatment
plant at Long Creek, assuming primary clarification, 5 stage BNR, tertiary filtration, UV
disinfection + reaeration and anaerobic digestion.
1 For the purposes of evaluation in this Technical Memorandum, it has been assumed that the initial
installation for Phase I would be 12 SMGD to make the Phase I installation exactly half the size of the
ultimate Phase II facility.
2 15 MGD was selected for compatibility with expansion to 25MGD for phase II and is only slightly larger
than the Option 1 Phase I installation assumed (12 5MGD + 2.4MGD transfer flow)
BLACK & VEATCH j Plant Capacity Cost Evaluation

Charlotte Water ( LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
• Note that costs identified in this Technical Memorandum should not be taken as an
indication of total plant cost. The costs exclude infrastructure deemed to be similar for
both options. (For example items such as preliminary treatment and effluent discharge
infrastructure which would be sized for the ultimate capacity of 25 MGD in Phase I for
both options, were not included in the costs.) The costs are high level only and have
been prepared solely for the purpose of comparison of the options being considered in
this Technical Memorandum.
For Option 1, capital costs were estimated as follows
• $7m for a temporary transfer and pumping system to McDowell in 2022 (this was an
order of magnitude cost provided in Technical Memorandum No.1)
• $76m for a 12 5 MGD treatment plant at Long Creek in 2022
• $113m for an additional 12.5 MGD treatment plant at Long Creek in 2037 (equivalent to
$76m inflated at 2 percent per year)
For Option 2, capital costs were estimated as follows.
• $89m for a 15MGD treatment plant at Long Creek in 2022
• $100m for a 10MGD treatment plant expansion at Long Creek in 2037 (equivalent to
$67m inflated at 2 percent per year)
3.2 OPERATING COSTS
The following assumptions were made with respect to operating costs.
Option 1
• Pumping energy for 2 MGD of transfer to McDowell at 190ft of head was calculated at an
average of 71kW based on 70 percent efficiency.
•
Pumping costs were calculated for each year of operation (up until installation of Phase
II in 2037) based on power cost of $0 07 in 2017, escalated at 2 percent per year
Pump station and sewer operating and maintenance costs for the transfer system were
estimated based on costs presented in Collection Systems, 0&M Fact Sheet, Sewer
Cleaning and Inspection (EPA, 1999). Costs were escalated at 2 percent per year based
on the reference date.
Option 2
Additional maintenance costs for a 15 MGD facility compared to a 12.5 MGD facility were
estimated, assuming equipment cost is equal to 30 percent of project cost, with 2
percent of equipment cost per year for maintenance. Additional maintenance is based on
2.5/15 x maintenance cost for 15 MGD. (Note the logic here is that maintenance is a
function of installed plant capacity rather than throughput Since McDowell is already
constructed, maintenance costs for McDowell will be the same for both options.)
BLACK & VEATCH I Plant Capacity Cost Evaluation

Charlotte Water I LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
All other 0&M costs were assumed to be the same for both options (i.e. treatment cost
for 2 MGD at McDowell was assumed to be the same as the treatment cost for 2 MGD at
Long Creek).
3.3 NET PRESENT COST
A life cycle evaluation was prepared based on the following assumptions:
• All installed plant and equipment was assumed to depreciate linearly over 40 years. A
residual value was assigned to plant in 2044 based on this assumption
• The temporary transfer infrastructure was assumed to have no residual value after
Phase II installation.
• Net present cost of each option was calculated over 22 years, based on 4 percent cost of
capital.
4 Results
Results showing the outcome of the life cycle cost evaluation for Option 1 and Option 2 are
provided in Table 4-1 and Table 4-2 respectively.
Table 4-1— Life cycle cost results showing net present costs for Option 1
Plant Capital Cost l # $76.3 m !! $63 0 m ' �— $139.3 m_ !
Temporary transfer capital cost —� — $70m $O.0 m � $7.0m
Residual value of infrastructure In 2044 yI' _
-$37.5 m �, -$51.9 m �`� x$89.4 m
O&M Cost Differences $1 2 m� $0.0 m $12m
Total NPV __ $47.0 m $110 m
1 Values are presented for comparison of Options land 2 only, and exclude capital and operating costs deemed to be similar for both
options These costs should not be used out of context
Table 4-2 - Life cycle cost results showing net present costs for Option 2
Plant Capital Cost ----11,_$89.4
m
$55 3-m
! $144.7 m
Temporary transfer capital cost
—a;
$0 0 m
$0.0 m
$0 0 ,m
-
F Residual value of infrastructure in 2044
L� w _ � .�
_ _
-$40 2 m
I _ �__
j� _$45 6 m �I
_
-- I
_ $85 8 m— y
O&M Cost Differences
$13m
$0.0 m
$1.3 m
j Total NPV
I $50 5 m ��
—i
$9.7m l!
f----- _
$601m
1 Values are presented for comparison of Options 1 and 2 only, and exclude capital and operating costs deemed to be similar for both
options These costs should not be used out of context.
Figure 4-1 provides a comparison of net present costs for each option categorized by phase and
for the total installation.
BLACK & VEATCH I Plant Capacity Cost Evaluation

Charlotte Water' LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
$200 0 m
$1500m
$1000m
'o
$50 0 m
a`
z
u
$00m
`n
6
E
0
u -$50 0 m
-$150 0 m
Figure 4-1— Summary of life cycle cost results
5 Conclusions & Recommendations
Based on the results presented in Figure 4-1, the following conclusions were reached
• 0&M cost differences (pumping for Option 1 and additional maintenance for Option 2)
were negligible compared to capital costs
• Capital costs for Phase I are likely to be similar for both options with Option 2 showing a
slightly higher capital cost. Although Option 2 involves a larger installation at Long
Creek, most of the cost difference between a 15 MGD plant and a 12.5 MGD plant is taken
up by the additional cost of the pumped transfer system.
• Capital costs for Phase II will be lower for Option 2, due to the smaller expansion
required
• Overall, on a net present cost basis, life cycle costs were similar for both options,
regardless of whether or not the residual value of assets was accounted for in the
evaluation
With the life cycle costs for both options being similar, it is recommended that Charlotte Water
should proceed with Option 2, as this will avoid the operational challenge of having another
sewer system to operate and maintain. Option 2 also delays the installation schedule of Phase 2
versus Option 1 due to the increased treatment capacity.
BLACK & VEATCH 1 Plant Capacity Cost Evaluation
I
valuevalueote
,Total NPV
-- - - —
— ——
- — - —
- -- -� ■ O&M Cost Differences
0 Residual value of infrastructure m 2044
_ _ _
N Temporary transfer capital cost
0 tl 11 0 2,
P I I
0 1, O0!,2,
P If P1
0 tto 1, Opa 2,
ous ota
Option 1, OPt�on 2, a Plant Capital Cost
Overall NPV Overall NPV
i
1
Figure 4-1— Summary of life cycle cost results
5 Conclusions & Recommendations
Based on the results presented in Figure 4-1, the following conclusions were reached
• 0&M cost differences (pumping for Option 1 and additional maintenance for Option 2)
were negligible compared to capital costs
• Capital costs for Phase I are likely to be similar for both options with Option 2 showing a
slightly higher capital cost. Although Option 2 involves a larger installation at Long
Creek, most of the cost difference between a 15 MGD plant and a 12.5 MGD plant is taken
up by the additional cost of the pumped transfer system.
• Capital costs for Phase II will be lower for Option 2, due to the smaller expansion
required
• Overall, on a net present cost basis, life cycle costs were similar for both options,
regardless of whether or not the residual value of assets was accounted for in the
evaluation
With the life cycle costs for both options being similar, it is recommended that Charlotte Water
should proceed with Option 2, as this will avoid the operational challenge of having another
sewer system to operate and maintain. Option 2 also delays the installation schedule of Phase 2
versus Option 1 due to the increased treatment capacity.
BLACK & VEATCH 1 Plant Capacity Cost Evaluation

Charlotte Water I LONG CREEK REGIONAL WWTP PRELIMINARY ENGINEERING REPORT
$200.0 to
$150.0 m
« $100Dm
u°
d $50.0 m
z
z
Y
$ $0.0 m
E
e
u -$50.0 m
$100.0 m
-$150-0m
Figure 4-1— Summary of life cycle cost results
5 Conclusions & Recommendations
Based on the results presented in Figure 4-1, the following conclusions were reached:
• 0&M cost differences (pumping for Option 1 and additional maintenance for Option 2)
were negligible compared to capital costs
• Capital costs for Phase I are likely to be similar for both options with Option 2 showing a
slightly higher capital cost. Although Option 2 involves a larger installation at Long
Creek, most of the cost difference between a 15 MGD plant and a 12.5 MGD plant is taken
up by the additional cost of the pumped transfer system.
• Capital costs for Phase II will be lower for Option 2, due to the smaller expansion
required.
• Overall, on a net present cost basis, life cycle costs were similar for both options,
regardless of whether or not the residual value of assets was accounted for in the
evaluation.
With the life cycle costs for both options being similar, it is recommended that Charlotte Water
should proceed with Option 2, as this will avoid the operational challenge of having another
sewer system to operate and maintain. Option 2 also delays the installation schedule of Phase 2
versus Option 1 due to the increased treatment capacity.
BLACK & VEATCH ( Plant Capacity Cost Evaluation
N- inciticling-1clu.1—
value of assets
■Total NPV
0&M Cost Differences
■ Residual value of infrastructure in 2044
transfer capital cost
Option 1, Option 2, ■ Plant Capital Cast
Overall NPV Overall NPV.
.■Temporary
O
III,
.-..■
2,
I
O 1, 0 2,
II P It
1, O
2,
Figure 4-1— Summary of life cycle cost results
5 Conclusions & Recommendations
Based on the results presented in Figure 4-1, the following conclusions were reached:
• 0&M cost differences (pumping for Option 1 and additional maintenance for Option 2)
were negligible compared to capital costs
• Capital costs for Phase I are likely to be similar for both options with Option 2 showing a
slightly higher capital cost. Although Option 2 involves a larger installation at Long
Creek, most of the cost difference between a 15 MGD plant and a 12.5 MGD plant is taken
up by the additional cost of the pumped transfer system.
• Capital costs for Phase II will be lower for Option 2, due to the smaller expansion
required.
• Overall, on a net present cost basis, life cycle costs were similar for both options,
regardless of whether or not the residual value of assets was accounted for in the
evaluation.
With the life cycle costs for both options being similar, it is recommended that Charlotte Water
should proceed with Option 2, as this will avoid the operational challenge of having another
sewer system to operate and maintain. Option 2 also delays the installation schedule of Phase 2
versus Option 1 due to the increased treatment capacity.
BLACK & VEATCH ( Plant Capacity Cost Evaluation