WQ0042995_Application (FTSE)_20211202

Double D Engineering, PLLC
Transmittal
November 15, 2021
NCDEQ
Division of Water Resources
225 Green Street
Fayetteville, N.C. 28301
Attn: Trent Allen
Ref: Legacy Lakes Phase 4, Sections 1-3
Sewer Permit Application
Please find attached:
Cover letter, sewer permit application,
form, USGS map, street view map and
If you have any questions or need any
contact this office.
DOUBLE D ENGINEERING, PLLC
Lee Humphrey, Project Manager
NOV 1 8 2021
VVOROS
FAYETFEVILLE NFG!ONILO.FFICE
downstream sewer evaluation, flow tracking
the fee check.
additional information, please feel free to
150 S. Page Street
Southern Pines, NC 28387
Firm No. P-1275
PH: [phone]

Project Cover Letter
Sewer Improvements to serve Legacy Lakes Phase 4, Sections 1-3
The new 8" gravity sewer mains to serve the Legacy Lakes Phase 4, Sections 1-3 Project will connect to a
new Sewer Pump Station which will then pump to an existing 15" gravity sewer outfall belonging to the
Town of Aberdeen located on the west side of U.S. Why 15-501. The new 8" gravity sewer main will
extend 5373 If with 35 new 4' dia. manholes to serve the lots. The new Sewer Pump Station will be
equipped with new 25 HP, 190 GPM @ 105.78 TDH pumps. The new 6" PVC Sewer Force Main shall
extend 2,284 If. The Sewer Improvements to serve Legacy Lakes Phase 4, Sections 1-3 will serve 83
single family homes and townhomes @ 360 gpd/home for a total proposed flow of 29,880 gpd. The
project will also consist of 28 duplexes @ 480 gpd/duplex for a total proposed flow of 13,440. The total
proposed flow for the project is 43,320 gpd.
Downstream Sewer Evaluation
Moore County has built a hydraulic model of the entire existing Moore County Sewer System all the way
back to the Moore County WWTP. Prior to issuing the Flow Acceptance Letter, Moore County did their
own evaluation of the capacity of their downstream sewer and found they had adequate capacity in the
existing sewer mains and at the WWTP to handle the additional flow.
RECEIVED
DEWAR
WR.B!:> R
NOV 1 8 2021
kYOROS
FAYETTEVILI F-r;P,If)NA[ OFFICE

Downstream Sewer Evaluation
Sewer Improvements to serve Legacy Lakes Phas 4, Sections 1-3
8" Diameter PVC Pipe at 0.40% grade
83 Single Family Homes and Townhomes at 360/GPD = 39,960 GPD
28 Duplex's at 480 gpd = 13,440 GPD
Total flow of 43,320 GPD
43,320 gpd times 2.5 Peak Factor = 108,300 GPD
Current Average Daily Flow 162 Homes at 180 gpd x 2.5 peak factor =72,900 gpd.
MODEL:
Input Parameters
Manning n for material
Slope (ft/ft)
Pipe diameter (in)
Slope min. (8"-18" pipe)
Slope min. (21"-36" pipe)
Data
0.012
0.01
15
0.0015
FALSE
Output
Pipe Diameter (ft) 1.250
X-sex area (1/2-full) 0.613
Hydraulic Radius 0.313
Hydraulic Radius A 2/3 0.461
Slope A 1/2 0.100
Velocity (ft/s) 5.718
Flow (cfs) 3.507
Flow (gps) 26.234
Flow (gpd) 11/2 Pipe 2,266,582
Flow (gpd) 3/4 Pipe 3,399,873
Flow (gpd) Full Pipe 4,533,164
Existing Gravity Sewer has sufficent capacity to handle current and future flow.
For the Downstream Sewer Pump Stations and Outfalls, Moore County Public Utilities
has built a hydrualic model of their sewer system and inserts all proposed flow into their
Hydraulic Model prior to issueing the flow acceptance letter.
0/01NR
Nov 1 6 2021
fAYI_I EVIti pcoKi Ndi,l_OFFIGki

)IDWR
NOV 1 8 2021
WORDS
' Division of Water Resorith & U'EVILLF REGIONAL IR,' Tracking for Sewer Extension Applications
(FTSE 10-18)
State of North Carolina
Department of Environmental Quality
Division of Water Resources
Entity Requesting Allocation: Town of Aberdeen
Project Name for which flow is being requested: Legacy Lakes Phase 4, Sections 1-3
More than one FTSE may be required for a single project if the owner of the lf'fl'TP is not responsible for all pump
stations along the route of the proposed wastewater flow.
I. Complete this section only if you are the owner of the wastewater treatment plant.
a. WWTP Facility Name: Moore County Water Pollution Control Plant
b. WWTP Facility Permit #: NC 0037508
All flows are in MGD
c. WWTP facility's permitted flow 10.0000
d. Estimated obligated flow not yet tributary to the WWTP 0.65561
e. WWTP facility's actual avg. flow
f. Total flow for this specific request
g. Total actual and obligated flows to the facility
h. Percent of permitted flow used
4.92000
0.04332
5.61893
56.1893
II. Complete this section for each pump station you are responsible for along the route of this proposed
wastewater flow.
List pump stations located between the project connection point and the WWTP:
(A) (B) (C) (D)=(B+C) (E)=(A-D)
Design Obligated,
Pump Pump Average Approx. Not Yet Total Current
Station Station Firm Daily Flow** Current Tributary Flow Plus
(Name or Permit Capacity, * (Firm / pf), Avg. Daily Daily Flow, Obligated Available
Number) No. MGD MGD Flow, MGD MGD Flow Capacity***
The Firm Capacity (design flow) of any pump station is defined as the maximum pumped flow
that can be achieved with the largest pump taken out of service.
** Design Average Daily Flow is the firm capacity of the pump station divided by a peaking factor
(pf) not less than 2.5, per Section 2.02(A)(4)(c) of the Minimum Design Criteria.
*** A Planning Assessment Addendum shall be attached for each pump station located
between the project connection point and the WWTP where the Available Capacity is < 0.
Downstream Facility Name (Sewer): Moore County Public Utilities
Downstream Permit Number: WQCS00034
Page 1 of 6
FTSE 10-18

III. Certification Statement:
I Randy G. Gould, PE certify to the best of my knowledge that the addition of
the volume of wastewater to be permitted in this project has been evaluated along the route to the receiving
wastewater treatment facility and that the flow from this project is not anticipated to cause any capacity
related sanitary sewer overflows or overburden any downstream pump station en route to the receiving
treatment plant under normal circumstances, given the implementation of the planned improvements
identified in the planning assessment where applicable. This analysis has been performed in accordance
with local established policies and procedures using the best available data. This certification applies to
those items listed above in Sections I and II plus all attached planning assessment addendums for which I
am the responsible party. Signature of this form certifies that the receiving collection system or treatment
works has adequate capacand treat tjji proposed new wastewater.
igning Officia
1tle of Signing Official
Date
Page 2 of' 6
FTSE 10-18

Division of Water Resources
State of North Carolina
Department of Environmental Quality
Division of Water Resources
15A NCAC 02T .0300 — FAST TRACK SEWER SYSTEM EXTENSION APPLICATION
FTA 04-16 & SUPPORTING DOCUMENTATION
Application Number: & yF �V o be completed by DWR)
All items must be completed or the application will be returned
I. APPLICANT INFORMATION:
I. Applicant's name: Town of Aberdeen (company, municipality, HOA, utility, etc.)
2. Applicant type: ❑ Individual ❑ Corporation ❑ General Partnership
❑ Federal ❑ State/County ® Municipal
3. Signature authority's name: Harold Watts per 15A NCAC 02T .0106(b)
Title: Public Works Director
4. Applicant's mailing address: PO Box 785.
City: Aberdeen State: NC Zip: 27315-
5. Applicant's contact information:
Phone number: [phone] Email Address: [e-mail]
H. PROJECT INFORMATION:
1. Project name: Utility Improvements to serve Legacy Lakes Phase 4, Sections 1-3
2. Application/Project status:
❑ Privately -Owned Public Utility
❑ Other
DEQ I[JWR
NOV 1 8 2021
U VOROS
FAYETTEVILLERFGIONILOFFRCE
Proposed (New Permit) ❑ Existing Permit/Project
If a modification, provide the existing permit number: WQ00 and issued date:
If new construction but part of a master plan, provide the existing permit number: W000
3. County where project is located: Moore
4. Approximate Coordinates (Decimal Degrees): Latitude: 35.2502°
5. Parcel ID (if applicable): 847800593313
(or Parcel ID to closest downstream sewer)
III. CONSULTANT INFORMATION:
1. Professional Engineer: David T. Upchurch, PE
Firm: Double D Engineering, PLLC
Mailing address: 150 S. Page Street
City: Southern Pines State: NC Zip: 28387-
Phone number: [phone] Email Address: [e-mail]
Longitude: -79.2506°
License Number: 9570
IV. WASTEWATER TREATMENT FACILITY (WWTF) INFORMATION:
1. Facility Name: Moore County Water Pollution Control Plant Permit Number: NC0037508
Owner Name: Moore County
V. RECEIVING DOWNSTREAM SEWER INFORMATION (if different than WWTF):
1. Permit Number(s): WQ Downstream (Receiving) Sewer Size: 8 inch
System Wide Collection System Permit Number(s) (if applicable): WQCS
Owner Name(s): Town of Aberdeen
FORM: FTA 04-16
Page 1 of 5

VI. GENERAL REQUIREMENTS
1. If the Applicant is a Privately -Owned Public Utility, has a Certificate of Public Convenience and Necessity been attached?
❑ Yes DNo ®N/A
2. If the Applicant is a Developer of lots to be sold, has a Developer's Operational Agreement (FORM: DEV) been attached?
❑ Yes ❑No ZN/A
3. If the Applicant is a Home/Property Owners' Association, has an Operational Agreement (FORM: HOA) been attached?
❑ Yes DNo ®N/A
4. Origin of wastewater: (check all that apply):
® Residential Owned 0 Retail (stores, centers, malls)
❑ Residential Leased 0 Retail with food preparation/service
❑ School / preschool / day care 0 Medical / dental / veterinary facilities
❑ Food and drink facilities 0 Church
0 Businesses / offices / factories ❑ Nursing Home
❑ Car Wash
❑ Hotel and/or Motels
❑ Swimming Pool /Clubhouse
❑ Swimming Pool/Filter Backwash
❑ Other (Explain in Attachment)
5. Nature of wastewater : 100 % Domestic/Commercial % Commercial
% Industrial (See 15A NCAC 02T .0103(20))
�Is there a Pretreatment Program in effect? ❑ Yes ® No
6. Has a flow reduction been approved under 15A NCAC 02T .0114(fl? 0 Yes ® No
➢ If yes, provide a copy of flow reduction approval letter
7. Summarize wastewater generated by project:
Establishment Type (see 02T.0114(f))
Daily Design Flow'•"
No. of Units
Flow
Single Family Residence
360 gal/day
45
16200 GPD
Townhomes
360 gal/day
38
13680 GPD
Duplex's
480 gal/day
28
13440 GPD
gal/
GPD
gal/
GPD
gal/
GPD
Total
43,320 GPD
a See 15A NCAC 02T .0114(b), (d), (e)(1) and (e)(2) for caveats to wastewater design flow rates (i.e., minimum flow per
dwelling; proposed unknown non-residential development uses; public access facilities located near high public use
areas; and residential property located south or east of the Atlantic Intracoastal Waterway to be used as vacation rentals
as defined in G.S. 42A-4).
b Per 15A NCAC 02T .0114(c), design flow rates for establishments not identified [in table 15A NCAC 02T.01141 shall
be determined using available flow data, water using fixtures, occupancy or operation patterns, and other measured data.
8. Wastewater generated by project: 43320 GPD (per 15A NCAC 02T .0114)
➢ Do not include future flows or previously permitted allocations
If permitted flow is zero, indicate why:
❑ Pump Station or Gravity Sewer where flow will be permitted in subsequent permits that connect to this line
❑ Flow has already been allocated in Permit Number:
0 Rehabilitation or replacement of existing sewer with no new flow expected
❑ Other (Explain):
FORM: FTA 04-16
Page 2 of 5

VII. GRAVITY SEWER DESIGN CRITERIA (If Applicable) - 02T .0305 & MDC (Gravity Sewers):
1. Summarize gravity sewer to be permitted:
Size (inches)
Length (feet)
Material
8
5333
PVC
8
40
DIP
➢ Section II & III of the MDC for Permitting of Gravity Sewers contains information related to design criteria
➢ Section III contains information related to minimum slopes for gravity sewer(s)
➢ Oversizing lines to meet minimum slope requirement is not allowed and a violation of the MDC
VIII. PUMP STATION DESIGN CRITERIA (If Applicable) — 02T .0305 & MDC (Pump Stations/Force Mains):
COMPLETE FOR EACH PUMP STATION INCLUDED IN THIS PROJECT
1. Pump station number or name: 1
2. Approximate Coordinates (Decimal Degrees): Latitude: 35.0526° Longitude: -79.2504°
3. Design flow of the pump station: .04332 millions gallons per day (firm capacity)
4. Operational point(s) of the pump(s): 190 gallons per minute at 105.78 feet total dynamic head (TDH)
5. Summarize the force main to be permitted (for this Pump Station):
Size (inches)
Length (feet)
Material
6
2124
PVC
6
160
DIP
6. Power reliability in accordance with 15A NCAC 02T .0305(h)(1):
Z Standby power source or pump with automatic activation and telemetry - 15A NCAC 02T .0305(h)(1)(B):
➢ Required for all pump stations with an average daily flow greater than or equal to 15,000 gallons per day
> Must be permanent to facility
Or if the pump station has an average daily flow less than 15,000 gallons per day:
❑ Portable power source with manual activation, quick -connection receptacle and telemetry - 15A NCAC 02T
.0305(h)(1)(C)
or
❑ Portable pumping unit with plugged emergency pump connection and telemetry - 15A NCAC 02T .0305(h)(1)(C):
➢ It shall be demonstrated to the Division that the portable source is owned or contracted by the applicant (draft agreement)
and is compatible with the station.
> If the portable power source or pump is dedicated to multiple pump stations, an evaluation of all the pump stations'
storage capacities and the rotation schedule of the portable power source or pump, including travel timeframes, shall be
provided in the case of a multiple station power outage.
FORM: FTA 04-16 Page 3 of 5

IX. SETBACKS & SEPARATIONS — (02B .0200 & 15A NCAC 02T .0305(f)):
1. Does the project comply with all separations found in 15A NCAC 02T .0305(f) & (g)
D. 15A NCAC 02T.0305(fj contains minimum separations that shall be provided for sewer systems:
ZYes El No
Setback Parameter*
Separation Required
24 inches
Storm sewers and other utilities not listed below (vertical)
Water mains (vertical -water over sewer including in benched trenches)
18 inches
Water mains (horizontal)
10 feet
Reclahned water lines (vertical - reclaimed over sewer)
18 inches
Reclaimed water lines (horizontal - reclaimed over sewer)
2 feet
**Any private or public water supply source, including any wells, WS-I waters of Class I or
Class II impounded reservoirs used as a source of drinking water
100 feet
**Waters classified WS (except WS-I or WS-V), B, SA, ORW, HQW, or SB from normal
high water (or tide elevation) and wetlands (see item IX.2)
50 feet
**Any other stream, lake, impoundment, or ground water lowering and surface drainage
ditches
10 feet
Any building foundation
5 feet
Any basement
10 feet
Top slope of embankment or cuts of 2 feet or more vertical height
10 feet
Drainage systems and interceptor drains
5 feet
Any swimming pools
10 feet
Final earth grade (vertical)
36 inches
➢ 15A NCAC 02T.0305(g) contains alternatives where separations in 02T.0305(fl cannot be achieved.
➢ **Stream classifications can be identified using the Division's NC Surface Water Classifications webpage
➢ If noncompliance with 02T.0305(f) or (g) see Section X of this application
2. Does the project comply with separation requirements for wetlands? (50 feet of separation) ® Yes ❑ No ❑ N/A
➢ See the Division's draft separation requirements for situations where separation cannot be meet
➢ No variance is required if the alternative design criteria specified is utilized in design and construction
➢ As built documents should reference the location of areas effected
3. Does the project comply with setbacks found in the river basin rules per 15A NCAC 02B .0200? ❑ Yes ❑ No ® N/A
➢ This would include Trout Buffered Streams per I5A NCAC 2B.0202
4. Does the project require coverage/authorization under a 404 Nationwide or
individual permits or 401 Water Quality Certifications?
➢ Information can be obtained from the 401 & Buffer Permitting Branch
❑ Yes ®No
5. Does project comply with 15A NCAC 02T.0105(c)(6) (additional permits/certifications)? ® Yes ❑ No
Per 15A NCAC 02T.0105(c)(6), directly related environmental permits or certification applications are being prepared, have
been applied for, or have been obtained. Issuance of this permit is contingent on issuance of dependent permits (erosion and
sedimentation control plans, stormwater management plans, etc.).
6. Does this project include any sewer collection lines that are deemed "high -priority?"
Per 15A NCAC 02T.0402, "high -priority sewer" means "any aerial sewer, sewer contacting surface waters, siphon, or sewer
positioned parallel to streambanks that is subject to erosion that undermines or deteriorates the sewer.
❑ Yes ®No ❑ N/A
➢ If yes, include an attachment with details for each line, including type (aerial line, size, material, and location).
High priority lines shall be inspected by the permittee or its representative at least once every six -months and
inspections documented per 15A NCAC 02T.0403(a)(5) or the permitee's individual System -Wide Collection permit.
FORM: FTA 04-16 Page 4 of 5

X. CERTIFICATIONS:
1. Does the submitted system comply with 15A NCAC 02T, the Minimum Design Criteria for the Permitting of Pump Stations
and Force Mains (latest version), and the Gravity Sewer Minimum Design Criteria (latest version) as applicable?
ZYes No
If No, complete and submit the Variance/Alternative Design Request application (VADC 10-14) and supporting documents
for review. Approval of the request is required prior to submittal of the Fast Track Application and supporting
documents.
2. Professional Engineer's Certification:
I, IAA V I O T. U Fc.Nlu Rc4 Fe
(Professional Engineer's name from Application Item III.1.)
attest that this application for
has been reviewed by me and is accurate, complete and consistent with the information supplied in the plans, specifications,
engineering calculations, and all other supporting documentation to the best of my knowledge. I further attest that to the best
of my knowledge the proposed design has been prepared in accordance with the applicable regulations, Gravity Sewer
Minimum Design Criteria for Gravity Sewers (latest version), and the Minimum Design Criteria for the Fast -Track
Permitting of Pump Stations and Force Mains (latest version). Although other professionals may have developed certain
portions of this submittal package, inclusion of these materials under my signature and seal signifies that I have reviewed this
material and have judged it to be consistent with the proposed design.
NOTE - In accordance with General Statutes 143-215.6A and 143-215.6B, any person who knowingly makes any false
statement, representation, or certification in any application package shall be guilty of a Class 2 misdemeanor, which may
include a fine not to exceed $10,000, as well as civil penalties up to $25,000 per violation.
North Carolina Professional Engineer's seal, signature, and date:
3. Applicant's Certification per 15A NCAC 02T .0106(b):
CAR ri
11.10•Ll
1, A eftgC J _ P -rtw- attest that this application for
(Signature Authority's name & title from Application Item I.3.)
has been reviewed by me and is accurate and complete to the best of my knowledge. I understand that if all required parts of
this application are not completed and that if all required supporting documentation and attachments are not included, this
application package is subject to being returned as incomplete. I understand that any discharge of wastewater from this non -
discharge system to surface waters or the land will result in an immediate enforcement action that may include civil penalties,
injunctive relief, and/or criminal prosecution. I will make no claim against the Division of Water Resources should a
condition of this permit be violated. I also understand that if all required parts of this application package are not completed
and that if all required supporting information and attachments are not included, this application package will be returned to
me as incomplete.
NOTE - In accordance with General Statutes 143-215.6A and 143-215.6B, any person who knowingly makes any false
statement, representation, or certification in any application package shall be guilty of a Class 2 misdemeanor, which may
include a fine not to exceed $10,000 as well as civil penalties up to $25,000 per violation.
Date: t<// /d/C9(0- I
FORM: FTA 04-16
Page 5 of 5

t:1JCi `J l'7.1„1
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NOV 1 8 Z021
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FAYETTELOMETTAVkingi_seeeptlance for Sewer Extension Applications
(FTSE 04-16)
State of North Carolina
Department of Environmental Quality
Division of Water Resources
Entity Requesting Allocation: Town of Aberdeen
Project Name for which flow is being requested: Legacy Lakes Phase 4, Sections 1-3
More than one FTSE may be required for a single project if the owner of the WWTP is not responsible for all pump
stations along the route of the proposed wastewater flow.
I. Complete this section only if you are the owner of the wastewater treatment plant. CNC dwngt
a. WWTP Facility Name: Moore County Water Pollution Control Plant
b. WWTP Facility Permit #: NC0037508
All flows are in MGD
c. WWTP facility's permitted flow 10.0000
d. Estimated obligated flow not yet tributary to the WWTP 0.54650
e. WWTP facility's actual avg. flow 4.40600
f. Total flow for this specific request 0.04332
g. Total actual and obligated flows to the facility 4.97014
h. Percent of permitted flow used 49.7447
II. Complete this section for each pump station you are responsible for along the route of this
proposed wastewater flow.
List pump stations located between the project connection point and the WWTP:
(A) (B) (C) (D)=(B+C) (E)=(A-D)
Design Obligated,
Pump Average Daily Approx. Not Yet Total Current
Station Firm Flow** Current Avg. Tributary Flow Plus
(Name or Capacity, * (Firm / pf), Daily Flow, Daily Flow, Obligated Available
Number) MGD MGD MGD MGD Flow Capacity***
* The Firm Capacity of any pump station is defined as the maximum pumped flow that
can be achieved with the largest pump taken out of service.
** Design Average Daily Flow is the firm capacity of the pump station divided by a peaking
factor (pf) not less than 2.5.
*** A Planning Assessment Addendum shall be attached for each pump station located
between the project connection point and the WWTP where the Available Capacity is < 0.
Downstream Facility Name (Sewer): Moore Co. Water Pollution Control Plant
Downstream Permit Number: unknown
Page 1 of 6
FTSE 04-16

III. Certification Statement:
I Ab?726 v t 75 certify to the best of my knowledge that the addition of
the volume of wastewater to be permitted in this project has been evaluated along the route to the
receiving wastewater treatment facility and that the flow from this project is not anticipated to
cause any capacity related sanitary sewer overflows or overburden any downstream pump station
en route to the receiving treatment plant under normal circumstances, given the implementation
of the planned improvements identified in the planning assessment where applicable. This
analysis has been performed in accordance with local established policies and procedures using
the best available data. This certification applies to those items listed above in Sections I and II
plus all attached planning assessment addendums for which I am tho rooponsib}e party.
Signature of this form indicates acceptance of this wastewater flow.
Signing Cfial Signal re
11//anal
Date
Page 2 of 6
FTSE 04-16

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June 17, 2020
DECii+ liVVR
NOV182021
Mr. Lee Humphrey
Double D Engineering, PLLC WILMS
150 S. Page Street F aYE) IEViLLEREGIONAL.0FF10E
Southern Pines, NC 28376
Re: Legacy Off -Site Sewer
Hydraulic Analysis
Lee,
ter;
*GINS 0:401
4RK A.
(0-11-28
Digitally signed by Mark Lacy, P.E.
Date: 2020.06.17 17:56:06 -04'00'
We have completed a hydraulic analysis of the existing off -site 8-inch sewer main used to convey all
wastewater from the Legacy development and the Academy of Moore County to the county outfall. The
existing sewer main consists of approximately 6,500 If of 8-inch pipe that mostly operates by gravity. The
line begins with a manhole at the discharge point of the existing 6-inch forcemain from Lift Station 10 on
Kerr Lake Road. This line also conveys flow from the pump station serving the Academy of Moore
County. The existing pumped flow is approximately 240 GPM. In addition to this flow, all wastewater
from the Legacy Phase 2 pump station (210 GPM) and Legacy Phase 4 pump station (190 GPM) will also
discharge at this location. As such, the potential instantaneous discharge to the line is expected to be
640 GPM.
Based on the record drawings, the sewer line was installed on grade up to the point where it crosses the
railroad. At this crossing, the line functions similar to an inverted siphon. The line includes two air vents
that consist of an inline wye and vent pipe that is open to atmosphere. The vents do not include any
provision to prevent an overflow if the line becomes blocked downstream or if capacity is exceeded.
The hydraulic analysis indicates that there is not enough capacity for the existing and proposed flow with
the current configuration since the vent pipes are open to atmosphere. The pipe profile and calculated
hydraulic grade line are shown in the attached graph. Modifications are recommended to ensure
adequate capacity is available without causing an overflow. An additional concern is the section of pipe
crossing the railroad. During normal operation, velocity through this segment is expected to be relatively
low, which will allow solids to settle. The steep slope at the exit of this section makes solids removal
more difficult even at higher flow rates.
In order to address the capacity and operational concerns, we recommend that the two existing vents be
modified to include combination air valves. These would allow the line to vent while preventing an
overflow. We also recommend the installation of a flushing connection upstream of the railroad to allow
140 Aqua -Shed Court, Aberdeen, North Carolina 28315 * PH: 910/420-1437 * FAX: [phone]
License No. P-1095

Mr. Lee Humphrey
Page 2
June 17, 2020
the line to be flushed or pigged periodically. The connection should include an in -line wye or tee, above
grade connection for a bypass pump, and isolation valves. In addition, the inside drop at the connection
to the county outfall should be inspected to confirm adequate thrust restraint is provided and improved
as needed.
In addition to the analysis of the off -site sewer, we have modeled the proposed pump stations to be
installed for Phase 2 and Phase 4. The forcemain's from these stations will combine into a common 6-
inch forcemain at the intersection of Legacy Lakes Way and Hwy 15-501 and continue to the discharge
point at the beginning of the off -site sewer main. The recommended design operating point for each
pump station is provided below. These operating points reflect simultaneous operation of both stations
and are based on design information that you provided. Note that the total dynamic head (TDH) given is
based on a Hazen Williams C-Factor of 120 for PVC piping and 100 for DI station piping.
• Phase 2 Pump Station: 210 GPM @ 153' TDH
• Phase 4 Pump Station: 190 GPM @ 138' TDH
Please do not hesitate to contact me with any questions or if you need anything else,
Sincerely,
LKC ENGINEERING, PLLC
Mark Lacy, P.E.

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