NC0021491_Authorization to Construct_20180627

in I
June 27, 2018
North Carolina Department of Environmental Quality
Division of Water Resources
NPDES Complex Permitting Unit
512 N. Salisbury Street, 9th Floor
Raleigh, North Carolina 27604
Subject: Town of Mocksville
Contract 11.0 — Dutchman's Creek WWTP Renovation
NPDES Permit No. NCO021491
Request for Authorization to Construct
Gentlemen:
1984.015 (34)
The Town of Mocksville is planning to modify its existing Dutchman's Creek Wastewater
Treatment Plant. In general, the project consists of constructing a headworks structure with
screening, two clarifiers, a sludge pumping station, and an aerobic digester. Ancillary equipment
will also be added as part as this project, including blowers, process pumps, and a sludge
thickener. The existing headworks, clarifiers, and RAS/WAS pump stations will be demolished.
Construction is anticipated to begin in mid 2019 and is expected to be completed within 1 -year.
On behalf of the Town, we respectfully request an Authorization to Construct. Enclosed please
find one set, along with a CD containing the following documents, for your review:
• Original executed Application for Authorization to Construct (Form ATC -12-14)
• NPDES Permit No. NCO021491
• Engineering Plans
• Engineering Specifications
• Engineering Calculations
• Residuals Management Plan
Should you have any questions or need additional information, please feel free to call me at
704.338.4668 or email me at [e-mail].
Yours very truly,
WILLIS INE RS
Charles A. illis Jr., P.E., BCEE
Enclosures
cc: Town of Mocksville
10700 Sikes Place, Suite 115
Charlotte, North Carolina 28277
704.377.9844 / NC License F-0114

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
SECTION 1: INSTRUCTIONS AND INFORMATION
A. The Division of Water Resources will accept this application package for review only if all of the items are provided and the
application is complete. Failure to submit all of the required items will result in the application package being returned as incomplete
per 15A NCAC 02T .0105(b).
B. Plans and specifications must be prepared in accordance with 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina General Statute
133-3, North Carolina General Statute 143-215.1, and Division of Water Resources Minimum Design Criteria for NPDES
Wastewater Treatment Facilities.
C. The plans and specifications submitted must represent a completed final design that is ready to advertise for bid.
D. Any content changes made to this Form ATC -12-14 shall result in the application package being returned.
E. The Applicant shall submit ONE ORIGINAL and ONE DIGITAL COPY (CD) of the application, all supporting documentation and
attachments. All information must be submitted bound or in a 3 -ring binder, with a Section tab for each Section, except the
Engineering Plans.
F. Check the boxes below to indicate that the information is provided and the requirements are met.
G. If attachments are necessary for clarity or due to space limitations, such attachments are considered part of the application
package and must be numbered to correspond to the item referenced.
H. For any project that requires review under the State Environmental Policy Act (SEPA), an Authorization to Construct cannot be
issued prior to the completion of a State Clearinghouse advertisement period for a FONSI, EIS, etc. unless the project qualifies for
a Determination of Minor Construction Activity.
I. For more information, visit the Division of Water Resources web site at: https://deg.nc.gov/about/divisions/water-resources/water-
resources-permits/wastewater-bra nch/n Ades-wastewater/authorization-to-construct.
J. In addition to this Authorization to Construct, the Applicant should be aware that other permits may be required from other Sections
of the Division of Water Resources (for example: reclaimed water facilities permits; Class A or B biosolids residuals permit).
SECTION 2: APPLICANT INFORMATION AND PROJECT DESCRIPTION
A. APPLICANT
Applicant's name
Town of Mocksville
Signature authority's name per 15A NCAC 02T .0106(b)
Leonard Barefoot
Signature authority's title
Interim Town Manager
Complete mailing address
171 South Clement Street, Mocksville, NC 27028
Telephone number
336-753-6700
Email address
[e-mail]
B. PROFESSIONAL ENGINEER
Professional Engineer's name
Charles A. Willis Jr., P.E., BCEE
Professional Engineer's title
President
North Carolina Professional Engineer's License No.
17710
Firm name
Willis Engineers
Firm License number
F-0114
Complete mailing address
10700 Sikes Place, Suite 115, Charlotte, NC 28277
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 1

Water Resources
ENVIRONMENTAL DUALITY
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
Telephone number 704-377-9844
Email address [e-mail]
C. NPDES PERMIT
NPDES Permit number
NCO021491
Current Permitted flow (MGD) — include permit
flow phases if applicable
0'98
D. PROJECT DESCRIPTION
Provide a brief description of the project: The Proiect consists of constructing a headworks structure with screening, two
clarifiers, a sludge pumping station, and an aerobic digester. Ancillary equipment will also be added as part as this project,
including blowers, process pumps, and a sludge thickener.
SECTION 3: APPLICATION ITEMS REQUIRED FOR SUBMITTAL FOR ALL PROJECTS
A. Cover Letter
® The letter must include a request for the Authorization to Construct; the facility NPDES Number; a brief project description
that indicates whether the project is a new facility, facility modification, treatment process modification, or facility expansion;
the construction timeline; and a list of all items and attachments included in the application package.
❑ If any of the requirements of 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina General Statute 133-3, North Carolina
General Statute 143-215.11 and Division of Water Resources Minimum Design Criteria for NPDES Wastewater Treatment
Facilities are not met by the proposed design, the letter must include an itemized list of the requirements that are not met.
B. NPDES Permit
® Submit Part I of the Final NPDES permit for this facility that includes Part A (Effluent Limitations and Monitoring Requirements)
for the monthly average flow limit that corresponds to the work that is requested for this project.
C. Special Order by Consent
❑ If the facility is subject to any Special Orders by Consent (SOC), submit the applicable SOC.
® Not Applicable.
D. Finding of No Significant Impact or Record of Decision
❑ Submit a copy of the Finding of No Significant Impact or Record of Decision for this project.
❑ Provide a brief description of any of the mitigating factors or activities included in the approved Environmental Document
that impact any aspect of design of this project, if not specified in the Finding of No Significant Impact or Record of Decision.
® Not Applicable.
E. Engineering Plans
® Per 15A NCAC 02T .0504(c)(1), submit one set of detailed plans that have been signed, sealed and dated by a North Carolina
Licensed Professional Engineer.
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 2

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Water Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
® Per 21 NCAC 56 .1103(a)(6), the name, address and License number of the Licensee's firm shall be included on each sheet of
the engineering drawings.
® Plans must be labeled as follows: FINAL DRAWING — FOR REVIEW PURPOSES ONLY — NOT RELEASED FOR CONSTRUCTION.
® 15A NCAC 02H .0124 requires multiple (dual at a minimum) components such as pumps, chemical feed systems, aeration
equipment and disinfection equipment. Is this requirement met by the design? ® Yes or ❑ No. If no, provide an
explanation:
Plans shall include:
® Plans for all applicable disciplines needed for bidding and construction of the proposed project (check as appropriate):
® Civil ❑ Not Applicable
® Process Mechanical ❑ Not Applicable
® Structural ❑ Not Applicable
® Electrical ❑ Not Applicable
❑ Instrumentation/Controls ® Not Applicable
❑ Architectural ® Not Applicable
❑ Building Mechanical ® Not Applicable
❑ Building Plumbing ® Not Applicable
® Plan and profile views and associated details of all modified treatment units including piping, valves, and equipment (pumps,
blowers, mixers, diffusers, etc.)
® Are any modifications proposed that impact the hydraulic profile of the treatment facility? ® Yes or ❑ No. If yes, provide
a hydraulic profile drawing on one sheet that includes all impacted upstream and downstream units. The profile shall include
the top of wall elevations of each impacted treatment unit and the water surface elevations within each impacted treatment
unit for two flow conditions: (1) the NPDES permitted flow with all trains in service and (2) the peak hourly flow with one
treatment train removed from service.
® Are any modifications proposed that impact the process flow diagram or process flow schematic of the treatment facility?
® Yes or ❑ No. If yes, provide the process flow diagram or process flow schematic showing all modified flow paths including
aeration, recycle/return, wasting, and chemical feed, with the location of all monitoring and control instruments noted.
F. ® Engineering Specifications
® Per 15A NCAC 02T .0504(c)(2), submit one set of specifications that have been signed, sealed and dated by a North Carolina
Licensed Professional Engineer.
® Specifications must be labeled as follows: FINAL SPECIFICATIONS — FOR REVIEW PURPOSES ONLY — NOT RELEASED FOR
CONSTRUCTION.
Specifications shall include:
® Specifications for all applicable disciplines needed for bidding and construction of the proposed project (check as
appropriate):
® Civil ❑ Not Applicable
® Process Mechanical ❑ Not Applicable
® Structural ❑ Not Applicable
® Electrical ❑ Not Applicable
® Instrumentation/Controls ❑ Not Applicable
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 3

Nater Resources
ENVIRONMENTAL. QUALITY
❑ Architectural
❑ Building Mechanical
❑ Building Plumbing
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
® Not Applicable
® Not Applicable
® Detailed specifications for all treatment units and processes including piping, valves, equipment (pumps, blowers, mixers,
diffusers, etc.), and instrumentation.
® Means of ensuring quality and integrity of the finished product including leakage testing requirements for structures and
pipelines, and performance testing requirements for equipment.
® Bid Form for publicly bid projects.
G. Construction Sequence Plan
® Construction Sequence Plan such that construction activities will not result in overflows or bypasses to waters of the State.
The Plan must not imply that the Contractor is responsible for operation of treatment facilities. List the location of the
Construction Sequence Plan as in the Engineering Plans or in the Engineering Specifications or in both: Sheet G-1 of
Engineering Plans.
H. Engineering Calculations
® Per 15A NCAC 02T .0504(c)(3), submit one set of engineering calculations that have been signed, sealed and dated by a North
Carolina Licensed Professional Engineer; the seal, signature and date shall be placed on the cover sheet of the calculations.
For new or expanding facilities and for treatment process modifications that are included in Section 4.C, the calculations shall
include at a minimum:
® Demonstration of how peak hour design flow was determined with a justification of the selected peaking factor.
® Influent pollutant loading demonstrating how the design influent characteristics in Section 4.13.2 of this form were
determined.
® Pollutant loading for each treatment unit demonstrating how the design effluent concentrations in Section 4.13.2 of this form
were determined.
® Hydraulic loading for each treatment unit.
® Sizing criteria for each treatment unit and associated equipment (blowers, mixers, pumps, etc.)
® Total dynamic head (TDH) calculations and system curve analysis for each pump specified that is included in Section 4.C.6.
® Buoyancy calculations for all below grade structures.
® Supporting documentation that the specified auxiliary power source is capable of powering all essential treatment units.
I. Permits
® Provide the following information for each permit and/or certification required for this project:
Permit/Certification
Not Date
Applicable Submitted
Date
Approved
Permit/
Certification
Number
If Not Issued Provide
Status and Expected
Issuance Date
Dam Safetv
x
Soil Erosion and Sediment Control
July 2018
USCOE / Section 404 Permit
x
Water Quality Certification (401)
x
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 4

0
Yater Resources
ENVIRONMENTAL QUALITY
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
USCOE /Section 10
x
Stormwater Management Plan
x
CAMA
x
NCDOT Encroachment Agreement
x
Railroad Encroachment Agreement
x
Other:
Residuals Management Plan
® For all new facilities, expanding facilities, or modifications that result in a change to sludge production and/or sludge
processes, provide a Residuals Management Plan meeting the requirements of 15A NCAC 02T .0504(j) and 15A NCAC 02T
.0508; the Plan must include:
® A detailed explanation as to how the generated residuals (including trash, sediment and grit) will be collected, handled,
processed, stored, treated, and disposed.
® An evaluation of the treatment facility's residuals storage requirements based upon the maximum anticipated residuals
production rate and ability to remove residuals.
® A permit for residuals utilization or a written commitment to the Applicant from a Permittee of a Department approved
residuals disposal/utilization program that has adequate permitted capacity to accept the residuals or has submitted a
residuals/utilization program application.
❑ If oil, grease, grit or screenings removal and collection is a designated unit process, a detailed explanation as to how the
oil/grease will be collected, handled, processed, stored and disposed.
❑ Not Applicable.
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 5

State of North Carolina
Department of Environmental Quality
Division of Water Resources
Wates- Resources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
SECTION 4: PROJECT INFORMATION
A. WASTEWATER TREATMENT PLANT FLOW INFORMATION —COMPLETE FOR NEW OR EXPANDING FACILITIES
1. Provide the following flow information:
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 6
Plant Flows
Existing Plant Design
MGD
Current NPDES Permit Limit
MGD
Current Annual Average
(past 12 months)
MGD
For Past 12 Months:
Start Date: month/yr
End Date: month/yr
For Past 24 Months:
Start Date: month/yr
End Date: month/yr
Maximum Month
MGD
MGD
Maximum Day
MGD
MGD
Peak Hour
MGD
MGD
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 6

B. WASTEWATER TREATMENT FACILITY DESIGN INFORMATION —COMPLETE FOR NEW OR EXPANDING FACILITIES AND
FOR TREATMENT PROCESS MODIFICATIONS
1. Have all of the requirements of 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina General Statute 133-3 North Carolina
General Statute 143-215.1, and Division of Water Resources Minimum Design Criteria for NPDES Wastewater Treatment
Facilities been met by the proposed design and specifications? ® Yes or ❑ No. If no, provide justification as to why the
requirements are not met, consistent with 15A NCAC 02T .0105(n):
2. Provide the design influent and effluent characteristics that are used as the basis for the project design, and the NPDES
permit limits for the following parameters:
3. Based on the "Project Basis of Design" parameters listed above, will the proposed design allow the treatment facility to
meet the NPDES Permit Limits listed above? ® Yes or ❑ No. If no, describe how and why the Permit Limits will not be
met:
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 7
Project Basis of Design
Design Influent
Design Influent
Influent
Concentration
Load
Concentration -
(Must be
(Must be
Current Annual
supported by
supported by
Design Effluent
Average (past
Engineering
Engineering
Concentration and/or
NPDES Permit Limits
12 months) if
Calculations
Calculations
Parameter
Available
[Section 3.H])
[Section 3.H])
Load
(monthly average)
Ammonia Nitrogen
2.0 mg/L Summer
2.0 mg/L Summer
(NH3-N)
N/A mg/L
30 mg/L
245 Ib/day
2.0 mg/L Winter
4.0 mg/L Winter
Biochemical
5.0 mg/L Summer
5.0 mg/L Summer
Oxygen Demand
260 mg/L
250 mg/L
2043 Ib/day
(BODS)
5.0 mg/L Winter
10.0 mg/L Winter
Fecal Coliform
200 per 100 mL
200 per 100 mL
Nitrate + Nitrite
Nitrogen (NO3-N +
N/A
N/A
NO2-N)
Total Kjeldahl
N/A mg/L
Nitrogen
N/A
N/A
Total Nitrogen
N/A
N/A
N/A
N/A
Total Phosphorus
N/A
N/A
N/A
N/A
N/A
Total Suspended
136 mg/L
250 mg/L
2043 Ib/day
30.0 mg/L
30.0 mg/L
Solids (TSS)
3. Based on the "Project Basis of Design" parameters listed above, will the proposed design allow the treatment facility to
meet the NPDES Permit Limits listed above? ® Yes or ❑ No. If no, describe how and why the Permit Limits will not be
met:
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 7

Water Resources
ENVIRONMENTAL QUALITY
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
4. Per 15A NCAC 02T .0505(i), by-pass and overflow lines are prohibited. Is this condition met by the design? ® Yes or ❑ No
If no, describe the treatment units bypassed, why this is necessary, and where the bypass discharges:
5. Per 15A NCAC 02T .0505(k), multiple pumps shall be provided wherever pumps are used. Is this condition met by the
design? ® Yes or ❑ No. If no, provide an explanation:
6. Per 15A NCAC 02T .0505(1), power reliability shall be provided consisting of automatically activated standby power supply
onsite capable of powering all essential treatment units under design conditions, or dual power supply shall be provided
per 15A NCAC 02H. 0124(2)(a). Is this condition met by the design? ® Yes or ❑ No. If no, provide (as an attachment
to this Application) written approval from the Director that the facility:
➢ Has a private water supply that automatically shuts off during power failures and does not contain elevated water
storage tanks, and
➢ Has sufficient storage capacity that no potential for overflow exists, and
➢ Can tolerate septic wastewater due to prolonged detention.
7. Per 15A NCAC 02T .0505(0), a minimum of 30 days of residual storage shall be provided. Is this condition met by the
design? ® Yes or ❑ No. If no, explain the alternative design criteria proposed for this project in accordance 15A NCAC
02T .105(n):
8. Per 15A NCAC 02T .0505(8), the public shall be prohibited from access to the wastewater treatment facilities. Explain how
the design complies with this requirement: The property is enclosed within a locked fence.
9. Is the treatment facility located within the 100 -year flood plain? ® Yes or ❑ No. If yes, describe how the facility is
protected from the 100 -year flood: The existing facility was built in a flood plain. All new structures are built outside of the
flood plain where possible.
C. WASTEWATER TREATMENT UNIT AND MECHANICAL EQUIPMENT INFORMATION —COMPLETE FOR NEW OR
EXPANDING FACILITIES AND FOR MODIFIED TREATMENT UNITS
1. PRELIMINARY AND PRIMARY TREATMENT (i.e., physical removal operations and flow equalization):
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 8
No. of
Plan Sheet
Specification
Calculations
Treatment Unit
Units
Type
Size per Unit
Reference
Reference
Provided?
(Yes or No)
Manual Bar Screen
1
Manual
3.43 MGD at peak hourly flow
M-1— M-2
462100
N/A
Mechanical Bar
1
Rake
3.43 MGD at peak hourly flow
M-1— M-2
462100
No
Screen
Grit Removal
N/A
MGD at peak hourly flow
Flow Equalization
N/A
--
gallons
Primary Clarifier
N/A
Circular
ft diameter; ft side
water depth
Primary Clarifier
N/A
Rectangular
square feet; ft side
water depth
Other
N/A
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 8

Water Resources
ENVIRONMENTAL QUALITY
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
2. SECONDARY TREATMENT (BIOLOGICAL REACTORS AND CLARIFIERS) (i.e., biological and chemical processes to remove
organics and nutrients)
3. TERTIARY TREATMENT
No. of
Plan Sheet
Specification
Calculations
Treatment Unit
Units
Type
Size per Unit
Reference
Reference
Provided?
(Yes or No)
Aerobic Zones/
N/A
Circular
gallons
Tanks
(Parallel; in
side water depth
Anoxic Zones/
N/A
Rectangular
gallons
Tanks
side water depth
Anaerobic
N/A
(Gas;
gallons
Zones Tanks
N/A
tablet; liquid)
square feet
Sequencing Batch
N/A
--
gallons
Reactor (SBR)
N/A
--
gallons
Membrane
N/A
--
gallons
Bioreactor (MBR)
N/A
gallons
Secondary Clarifier
2
Circular
60 ft diameter; 14 ft side
M-3 — M-4
46 43 00
Yes
water depth
Secondary Clarifier
N/A
Rectangular
square feet; ft
side water depth
Other
3. TERTIARY TREATMENT
4. DISINFECTION
No. of
Plan Sheet
Specification
Calculations
Treatment Unit
Units
Type
Size per Unit
Reference
Reference
Provided?
(Yes or No)
Tertiary Clarifier
N/A
Circular
ft diameter; ft
Ultraviolet Light
(Parallel; in
side water depth
Tertiary Clarifier
N/A
Rectangular
square feet; ft
side water depth
Tertiary Filter
N/A
(Gas;
square feet
Tertiary Membrane
N/A
tablet; liquid)
square feet
Filtration
Post -Treatment
N/A
--
gallons
Flow Equalization
Post -Aeration
N/A
gallons
Other
4. DISINFECTION
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 9
No. of
Plan Sheet
Specification
Calculations
Treatment Unit
Units
Type
Size per Unit
Reference
Reference
Provided?
(Yes or No)
gal/day per bank at
Ultraviolet Light
(Parallel; in
peak hourly flow;number
series)
of banks;
number of lamps/bank
Chlorination
(Gas;
gallons of contact
tablet; liquid)
tank/unit
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 9

Water Resources
ENVIRONMENTAL QUALITY
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
Dechlorination
No. of
(Gas;
gallons of contact
Plan Sheet
Specification
Calculations
Treatment Unit
Units
tablet; liquid)
tank/unit
Reference
Reference
Provided?
S. RESIDUALS TREATMENT
6. PUMP SYSTEMS (include influent, intermediate, effluent, major recycles, waste sludge, thickened waste sludge and plant
drain pumps)
Location
No. of
purpose
Type
Plan Sheet
Specification
Calculations
Treatment Unit
Units
Type
Size per Unit
Reference
Reference
Provided?
16.3
M-5 — M-7
43 25 13
Sludge Pump Station
2
Waste Sludge
(Yes or No)
Gravity Thickening
N/A
M-5 — M-7
square feet; ft side
Sludge Pump Station
2
Scum
Tank
122
24.2
water depth
43 24 16
Sludge Thickening
Bldg.
1
Mechanical
Dry
100
11.2
M-10
467133
Yes
Thickening/
1
Rotary Drum
59 dry Ib/hour
M-8 — M-10
467133
Dewatering
Aerobic Digestion
1
253,662 gallons
M -11-M-13
N/A
Yes
Anaerobic
N/A
gallons
Digestion
Composting
N/A
dry Ib/hour
Drying
N/A
dry Ib/hour
Other
6. PUMP SYSTEMS (include influent, intermediate, effluent, major recycles, waste sludge, thickened waste sludge and plant
drain pumps)
Location
No. of
Pumps
purpose
Type
Capacity of
each pump
Plan Sheet
Reference
Specification
Reference
GPM
TDH
Sludge Pump Station
4
Return Sludge
Submersible
230
16.3
M-5 — M-7
43 25 13
Sludge Pump Station
2
Waste Sludge
Submersible
125
24.8
M-5 — M-7
43 25 13
Sludge Pump Station
2
Scum
Recirculating
122
24.2
M-5 — M-7
43 24 16
Sludge Thickening
Bldg.
1
Thickened Waste
Sludge
Dry
100
11.2
M-10
467133
7. MIXERS
Location
No. of
Mixers
Purpose
Type
Power of
each MP ixer
plan Sheet
Reference
Specification
Reference
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 10

Water Resources
ENVIRONMENTAL QUALITY
8. BLOWERS
State of North Carolina
Department of Environmental Quality
Division of Water Resources
APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
Location
No. of
Blowers
purpose
Type
Capacity of
each Blower
(CFM)
plan Sheet
Reference
Specification
Reference
Blower Pad
3
Aerobic Digestion
Positive
Displacement
516
M-14
43 10 00
Below
Any habitable residence or place of assembly under separate
100 ft
® Yes
❑ No
ownership or not to be maintained as part of the project site
Any private or public water supply source
100 ft
® Yes
❑ No
Surface waters (streams — intermittent and perennial, perennial
50 ft
®Yes
❑ No
waterbodies, and wetlands)
Any well with exception of monitoring wells
100 ft
® Yes
❑ No
Any property line
50 ft
® Yes
9. ODOR CONTROL
Location
No. of
Units
Purpose
Type
Plan Sheet
Reference
Specification
Reference
Setback Parameter
Treatment/Storage
Design? If "No", identify
Unit
Setback Waivers in Item D.2
Below
Any habitable residence or place of assembly under separate
100 ft
® Yes
❑ No
ownership or not to be maintained as part of the project site
Any private or public water supply source
D. SETBACKS— COMPLETE FOR NEW WASTEWATER TREATMENT STRUCTURES
1. The minimum distance for each setback parameter to the wastewater treatment/storage units per 15A NCAC 02T .0506(b)
are as follows:
Have any setback waivers been obtained per 15A NCAC 02T .0506(d)? ❑ Yes or ® No. If yes, have these waivers been
written, notarized and signed by all parties involved and recorded with the County Register of Deeds? ❑ Yes or ❑ No. If
no, provide an explanation:
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 11
Minimum Distance
Is Minimum Distance
Required from Nearest
Requirement met by the
Setback Parameter
Treatment/Storage
Design? If "No", identify
Unit
Setback Waivers in Item D.2
Below
Any habitable residence or place of assembly under separate
100 ft
® Yes
❑ No
ownership or not to be maintained as part of the project site
Any private or public water supply source
100 ft
® Yes
❑ No
Surface waters (streams — intermittent and perennial, perennial
50 ft
®Yes
❑ No
waterbodies, and wetlands)
Any well with exception of monitoring wells
100 ft
® Yes
❑ No
Any property line
50 ft
® Yes
❑ No
Have any setback waivers been obtained per 15A NCAC 02T .0506(d)? ❑ Yes or ® No. If yes, have these waivers been
written, notarized and signed by all parties involved and recorded with the County Register of Deeds? ❑ Yes or ❑ No. If
no, provide an explanation:
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 11

State of North Carolina
Nl-'
,, Department of Environmental Quality
Division of Water Resources
a-
WaterResources
ENVIRONMENTAL QUALITY APPLICATION FOR AUTHORIZATION TO CONSTRUCT PERMIT (FORM ATC -12-14)
SECTION 5: APPLICATION CERTIFICATION BY PROFESSIONAL ENGINEER
Professional Engineer's Certification per 15A NCAC 02T.0105:
I, Charles A. Willis Jr., P.E., BCEE, attest that this application package for an Authorization to Construct
(Typed Name of Professional Engineer)
for the Dutchman's Creek WWTP Renovation
(Facility and Project Name)
was prepared under my direct supervisory control and to the best of my knowledge is accurate, complete and consistent
with the information supplied in the engineering plans, specifications, calculations, and all other supporting
documentation for this project. I further attest that to the best of my knowledge the proposed design has been
prepared in accordance with all applicable regulations and statutes, 15 NCAC 02H. 0100, 15A NCAC 02T, North Carolina
General Statute 133-3, North Carolina General Statute 143-215.1, and Division of Water Resources Minimum Design
Criteria for NPDES Wastewater Treatment Facilities, and this Authorization to Construct Permit Application, except as
provided for and explained in Section 4.13.1 of this Application. I understand that the Division of Water Resources'
issuance of the Authorization to Construct Permit may be based solely upon this Certification and that the Division may
waive the technical review of the plans, specifications, calculations and other supporting documentation provided in this
application package. I further understand that the application package may be subject to a future audit by the Division.
Although certain portions of this submittal package may have been prepared, signed and sealed by other professionals
licensed in North Carolina, inclusion of these materials under my signature and seal signifies that I have reviewed the
materials and have determined that the materials are consistent with the project design.
I understand that in accordance with General Statutes 143-215.6A and 143-215.66, 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 with written signature placed over or adjacent to the seal and dated:
`q%%0111111119deA
. N CAR
.Z.
p . ��SS�O
°
a �
v
z �EAt-
17710
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 12

SECTION 6: APPLICATION CERTIFICATION BY APPLICANT
Applicant's Certification per 15A NCAC 02T .0106(b):
I, Leonard Barefoot, Interim Town Manager, attest that this application package for an Authorization to Construct
(Typed Name of Signature Authority and Title)
for the Dutchman's Creek WWTP Renovation Proiect
(Facility and Project Name)
has been reviewed by me and is accurate and complete to the best of my knowledge. 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. I further certify that in
accordance with 15A NCAC 02T .0120(b), the Applicant or any affiliate has not been convicted of environmental crimes,
has not abandoned a wastewater facility without proper closure, does not have an outstanding civil penalty where all
appeals have been abandoned or exhausted, are compliant with any active compliance schedule, and does not have any
overdue annual fees.
I understand that the Division of Water Resources' issuance of the Authorization to Construct Permit may be based
solely upon acceptance of the Licensed Professional Engineer's Certification contained in Section 5, and that the Division
may waive the technical review of the plans, specifications, calculations and other supporting documentation provided
in this application package. I further understand that the application package may be subject to a future audit.
I understand that in accordance with General Statutes 143-215.6A and 143-215.613 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 tso�exceed $10,000, as well as civil penalties up to $25,000 per violation.
Signature: v 5 lir Date: 64
THE COMPLETED APPLICATION AND SUPPORTING INFORMATION SHALL BE SUBMITTED TO:
NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER RESOURCES/NPDES
By U.S. Postal ServiceBy Courier/Special Delivery:
1617 MAIL SERVICE CENTER 512 N. SALISBURY STREET, 9TH FLOOR
RALEIGH, NORTH CAROLINA 27699-1617 RALEIGH, NORTH CAROLINA 27604
TELEPHONE NUMBER: [phone]
Application for Authorization to Construct Permit (FORM ATC -12-14) Page 13

t
HCDE NR
North Carolina Department of Environment and Natural Resources
Division of Water Resources
Pat McCrory
Governor
October 6, 2014
Ms. Christine Bralley, Town Manager
Town of Mocksville
171 Clement St.
Mocksville, NC 27028
Subject: Final NPDES Permit
Permit NCO021491
Dutchman Creek WWTP
Davie County
Class III Facility
Dear Ms. Bralley:
John E. Skvarla, III
Secretary
Division personnel have reviewed and approved your application for renewal of the subject
permit. Accordingly, we are forwarding the attached NPDES permit. This permit is issued
pursuant to the requireinents of North Carolina General Statute 143-215.1 and the Memorandum of
Agreement between North Carolina and the U.S. Environmental Protection Agency dated October
15, 2007 (or as subsequently amended).
The final permit contains the following changes from the draft permit:
A Nutrient Reopener Special Condition was added to the peri -nit to address a future TMDL
or management strategy for High Rock Lake. See Special Condition A.(5).
The final permit contains the following changes from your previous permit:
As a result of a Reasonable Potential Analysis (RPA) monitoring for cyanide was eliminated
from your permit monitoring requirements.
The acute cadmium limit was incorrectly expressed in the draft permit as a weekly average
limit, the limit should be a daily maximum limit as in your previous permit. This correction is
reflected in your final permit.
1601 Mail Service Center, Raleigh, North Carolina 27699-1601
Phone: [phone] Internet: www.ncdenr.gov
An Equal Opportunity I Affirmative Action Employer— Made in part by recycled paper

Ms. Bralley
October 6, 2014
Page 2 of 2
• Monitoring for copper, silver and zinc was modified to quarterly according to the Division's
monitoring frequency guidance for metals.
• The requirement to perform effluent pollutant scans was modified from annual to three
times during your permit cycle. See Special Condition A.(3). This condition also includes
requirements for toxicity testing with alternate species.
• The permit includes a Special Condition [See Part I, A. (4.)] to address the Environmental
Protection Agency's (EPA's) pending requirement for you to provide electronically -
submitted Discharge Monitoring Reports (eDMRs).
If any parts, measurement frequencies or sampling requirements contained in this permit are
unacceptable to you, you have the right to an adjudicatory hearing upon written request within thirty
(30) days following receipt of this letter. This request must be in the form of a written petition,
conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of
Administrative Hearings (6714 Mail Service Center, Raleigh, North Carolina 27699-6714). Unless
such demand is made, this decision shall be final and binding.
Please note that this permit is not transferable except after notice to the Division. The
Division may require modification or revocation and reissuance of the permit. This permit does not
affect the legal requirements to obtain other permits which may be requited by the Division of
Water Resources or permits required by the Division of Land Resources, the Coastal Area
Management Act or any other federal or local governmental permits that may be required.
If you have` any questions concerning this permit, please contact Teresa Rodriguez at
telephone number [phone] or at email [e-mail].
SYerely,
ornas A. Reeder, Director
Division of Water Resources, NCDENR
cc: NPDES Files
Central files
Envirolink, Ms. Heather Adams, PO Box 670, Bailey, NC 27807
Winston Salem Regional Office / Surface Water Protection Section (e -copy)
Aquatic Toxicology Branch, Susan Meadows (e -copy)
Ecosystems Branch, Carrie Ruhhzran (e -copy)

Permit NCO021491
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER RESOURCES
TO DISCHARGE WASTEWATER UNDER THE
NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM
In compliance with the provisions of North Carolina General Statute 143-215.1, other lawful
standards and regulations promulgated and adopted by the North Carolina Environmental
Management Commission, and the Federal Water Pollution Control Act, as amended, the
Town of Mocksville
is hereby authorized to discharge wastewater from a facility located at the
Dutchman Creek WWTP
295 Garwood Road
Mocksville
Davie County
to receiving waters designated as Dutchman Creek in the Yadkin -Pee Dee River Basin in
accordance with effluent limitations, monitoring requirements, and other conditions set
forth in Parts I, II, III, and IV hereof.
The permit shall become effective November 1, 2014.
This permit and the authorization to discharge shall expire at midnight on June 30, 2019.
Signed this day October 6, 2014.
G t
t Thomas A. Reeder, Director
Division of Water Resources
By Authority of the Environmental Management Commission
Page I of 8

Permit NCO021491
SUPPLEMENT TO PERMIT COVER SHEET
All previous NPDES Permits issued to this facility, whether for operation or discharge are hereby revoked. As of this
permit issuance, any previously issued permit bearing this number is no longer effective. Therefore, the exclusive
authority to operate and discharge from this facility arises under the permit conditions, requirements, terms, and
provisions included herein.
The Town of Mocksville is hereby authorized to:
1. Continue to operate the existing 0.98 MGD wastewater treatment system that includes
the following components:
➢ Flow splitter box
➢ Mechanical fine screening
9 Grit removal
➢ Flow measurement
➢ Three aeration basins
➢ Three secondary clarifiers
9 Chlorination and dechlorination units
9 Sludge recirculation and wasting
➢ Aerobic digester
➢ Emergency generator
This facility is located at the Dutchman s Creek WWTP (295 Garwood Road,
Mocksville) in Davie County.
2. Discharge from said treatment works at the location specified on the attached map into
Dutchman Creek, classified C waters in the Yadkin -Pee Dee River Basin.
Page 2 of 8

Permit NCO021491
A. (1.) EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
During the period beginning on the effective date of the permit and lasting until permit expiration, the
Permittee is authorized to discharge from outfall 001. Such discharges shall be limited and monitored6 by the
Permittee asspecified below:
EFFLUENT
LIMITS
MONITORING REQUIREMENTS
„ Monthly
Weekly
..
Daily
Measurement
Sample
:
Sample
CHARACTERISTICS
.
Avera- e " :
Avera "e
Maximum',
: .Fre `ueh
Te_:.,
,Locaf ori?,:.
Flow
0.98 MGD
Continuous
Recording
I or E
BOD5 20 °C2
5.0 mg/1
7.5 mg/l
3/Week
Composite
LE
(April 1- October 30)
BOD5 20 °C2
10.0 mg/L
15.0 mg/L
3/Week
Composite
I, E
(November 1- March 31)
Total Suspended Solids2
30.0 mg/l
45.0 mg/l
3/Week
Composite
1, E
Temperature
Daily
Grab
E, U, D
Dissolved Oxygen
3/Week
Grab
E, U, D
Fecal Coliform
200 / 100 ml
400 / 100 ml
3/Week
Grab
E
(geometric mean)
NH3 as N
2.0 mg/l
6.0 mg/l
3/Week
Composite
E
(April 1- October 30
NH3 as N (winter)
4.0 mg/L
12.0 mg/L
3/Week
Composite
E
November 1 - March 31
Total Nitrogen
(NO2 + NO3 + TKN)
Quarterly
Composite
E
Total Phosphorus
Quarterly
Composite
E
H
6.0 - 9.0 standard units
3/Week
Grab
E
Total Residual Chlorine
28µg/1
2/Week
Grab
E
Chronic Toxici s
Quarterly
Composite
E
Cadmium
5.3 µ /l 36 pg/1
Monthly
Composite
E
Copper
Quarterly
Composite
E
Zinc
Quarterly
Composite
E
Silver
Quarterly
Composite
E
Effluent Pollutant Scan
Monitor and Report
Footnote 7
Footnote 7
E
Notes:
1. I= Influent. E= Effluent. U= Upstream approximately 100 feet upstream from the outfall. D= Downstream
approximately 0.5 miles downstream from the outfall. Upstream and downstream samples shall be grab
samples collected 3/week during June, July, August, and September and once per week during the rest of the
year. As a participant in the Yadkin Pee -Dee River Basin Association, the subject facility is not responsible for
conducting the instream monitoring requirements as stated above. Should your membership in the agreement
be terminated, you shall notify the Division immediately and the instream monitoring requirements specified in
your permit will be automatically reinstated.
2. The monthly average effluent BOD5 and Total Suspended Solids concentrations shall not exceed 15 percent of
the respective influent value (85 % removal).
3. The daily average dissolved oxygen effluent concentration shall not be less than 6.0 mg/1 from April 1 to
October 31, and no less than 5.0 mg/L.from November 1 to March 31.
4. The Division shall consider all effluent total residual chlorine values reported below 50 µg/l to be in compliance
with the permit. However, the Permittee shall continue to record and submit all values reported by a North
Carolina certified laboratory (including field certified), even if these values fall below 50 gg/l.
5. Chronic Toxicity (Ceriodaphnia) at 37%: January, April, July, and October (see condition A. (2.)).
6. No later than 270 days from the effective date of this permit, begin submitting discharge monitoring reports
electronically using NC DWWs eDMR application system. See Special Condition A (4).
7. The permittee shall perform three Effluent Pollutant Scans during the term of this permit [see A. (3)].
Page 3 of 8

Permit NCO021491
There shall be no discharge of floating solids or visible foam in other than trace amounts.
A. (2.) QUARTERLY CHRONIC TOXICITY PERMIT LIMIT
The effluent discharge shall at no time exhibit observable inhibition of reproduction or significant mortality to
Ceriodaphnia dubia at an effluent concentration of 37%.
The permit holder shall perform at a minimum, quarterli monitoring using test procedures outlined in the
"North Carolina Ceriodaphnia Chronic Effluent Bioassay Procedure," Revised December 2010, or subsequent
versions or "North Carolina Phase II Chronic Whole Effluent Toxicity Test Procedure" (Revised- December
2010) or subsequent versions. The tests will be performed during the months of January, April, July, and
October. These months signify the first month of each three-month toxicity testing quarter assigned to the
facility. Effluent sampling for this testing must be obtained during representative effluent discharge and
shall be performed at the NPDES permitted final effluent discharge below all treatment processes.
If the test procedure performed as the first test of any single quarter results in a failure or ChV below the
permit limit, then multiple -concentration testing shall be performed at a minimum, in each of the two
following months as described in "North Carolina Phase II Chronic Whole Effluent Toxicity Test
Procedure" (Revised -December 2010) or subsequent versions.
All toxicity testing results required as part of this permit condition will be entered on the Effluent Discharge
Monitoring Form (MR -1) for the months in which tests were performed, using the parameter code TGP3B for
the pass/fail results and THP3B for the Chronic Value. Additionally, DWR Form AT -3 (original) is to be sent
to the following address:
Attention: North Carolina Division of Water Resources
Water Sciences Section/Aquatic Toxicology Branch
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Completed Aquatic Toxicity Test Forms shall be filed with the Water Sciences Section no later than 30 days
after the end of the reporting period for which the report is made.
Test data shall be complete, accurate, include all supporting chemical/physical measurements and all
concentration/response data, and be certified by laboratory supervisor and ORC or approved designate
signature. Total residual chlorine of the effluent toxicity sample must be measured and reported if chlorine is
employed for disinfection of the waste stream.
Should there be no discharge of flow from the facility during a month in which toxicity monitoring is
required, the permittee will complete the information located at the top of the aquatic toxicity (AT) test form
indicating the facility name, permit number, pipe number, county, and the month/year of the report with the
notation of "No Flow" in the comment area of the form. The report shall be submitted to the Water Sciences
Section at the address cited above.
Should the permittee fail to monitor during a month in which toxicity monitoring is required, monitoring will
be required during the following month. Assessment of toxicity compliance is based on the toxicity testing
quarter, which is the three month time interval that begins on the first day of the month in which toxicity
testing is required by this permit and continues until the final day of the third month.
Should any test data from this monitoring requirement or tests performed by the North Carolina Division of
Water Resources indicate potential impacts to the receiving stream, this permit may be re -opened and
modified to include alternate monitoring requirements or limits.
NOTE: Failure to achieve test conditions as specified in the cited document, such as minimum control
organism survival, minimum control organism reproduction, and appropriate environmental controls, shall
Page 4 of 8

Permit NCO021491
constitute an invalid test and will require immediate follow-up testing to be completed no later than the last
day of the month following the month of the initial monitoring.
A. (3) EFFLUENT POLLUTANT SCAN
The Permittee shall perform a total of three (3) Effluent Pollutant Scans for all parameters listed below. One scan
must be performed in each of the following years: 2015, 2016, and 2017. Analytical methods shall be in
accordance with 40 CFR Part 136 and shall be sufficiently sensitive to determine whether parameters are present
in concentrations greater than applicable standards and criteria. Samples should be collected with one quarterly
toxicity test each year, and must represent seasonal variation [i.e., do not sample in the same quarter every year].
Unless otherwise indicated, metals shall be analyzed as "total recoverable."
Ammonia (as N)
Trans-1,2-dichloroethylene
Bis (2-chloroethyl) ether
Chlorine (total residual, TRC)
1,1-dichloroethylene
Bis (2-chloroisopropyl) ether
Dissolved oxygen
1,2-dichloropropane
Bis (2-ethylhexyl) phthalate
Nitrate/Nitrite
1,3-dichloropropylene
4-bromophenyl phenyl ether
Kjeldahl nitrogen
Ethylbenzene
Butyl benzyl phthalate
Oil and grease
Methyl bromide
2-chloronaphthalene
Phosphorus
Methyl chloride
4-chlorophenyl phenyl ether
Total dissolved solids
Methylene chloride
Chrysene
Hardness
1,1,2,2 -tetrachloroethane
Di -n -butyl phthalate
Antimony
Tetrachloroethylene
Di-n-octyl phthalate
Arsenic
Toluene
Dibenzo(a,h) anthracene
Beryllium
1,1,1 -trichloroethane
1,2 -dichlorobenzene
Cadmium
1,1,2 -trichloroethane
1,3 -dichlorobenzene
Chromium
Trichloroethylene
1,4 -dichlorobenzene
Copper
Vinyl chloride
3,3-dichlorobenzidine
Lead
Acid -extractable compounds:
Diethyl phthalate
Mercury (EPA Method 1631E)
P -chloro -m -cresol
Dimethyl phthalate
Nickel
2 -chlorophenol
2,4-dinitrotoluene
Selenium
2,4-dichlorophenol
2,6-dinitrotoluene
Silver
2,4 -dimethylphenol
1,2-diphenylhydrazine
Thallium
4,6-dinitro-o-cresol
Fluoranthene
Zinc
2,4-dinitrophenol
Fluorene
Cyanide
2-nitrophenol
Hexachlorobenzene
Total phenolic compounds
4-nitrophenol
Hexachlorobutadiene
Volatile organic compounds:
Pentachlorophenol
Hexachlorocyclo-pentadiene
Acrolein
Phenol
Hexachloroethane
Acrylonitrile
2,4,6 -trichlorophenol
Indeno(1,2,3-cd)pyrene
Benzene
Base -neutral compounds:
Isophorone
Bromoform
Acenaphthene
Naphthalene
Carbon tetrachloride
Acenaphthylene
Nitrobenzene
Chlorobenzene
Anthracene
N-nitrosodi-n-propylamine
Chlorodibromomethane
Benzidine
N-nitrosodimethylamine
Chloroethane
Benzo(a)anthracene
N-nitrosodiphenylamine
2-chloroethylvinyl ether
Benzo(a)pyrene
Phenanthrene
Chloroform
3,4 benzofluoranthene
Pyrene
Dichlorobromomethane
Benzo(ghi)perylene
1,2,4-trichlorobenzene
1,1-dichloroethane
Benzo(k)fluoranthene
1,2-dichloroethane
Bis (2-chloroethoxy) methane
Page 5 of 8

Permit NCO021491
Reporting. Test results shall be reported on DWR Form -A MR-PPA1 (or in a form approved by the Director)
by December 31s' of each designated sampling year. The report shall be submitted to the following address:
NC DENR/ DWR/ Central Files, 1617 Mail Service Center, Raleigh, North Carolina 27699-1617.
A. (4) ELECTRONIC REPORTING OF DISCHARGE MONITORING REPORTS
Proposed federal regulations require electronic submittal of all discharge monitoring reports (DMRs) and
specify that, if a state does not establish a system to receive such submittals, then permittees must submit
DMRs electronically to the Environmental Protection Agency (EPA). The Division anticipates that these
regulations will be adopted and is beginning implementation in late 2013.
NOTE: This special condition supplements or supersedes the following sections within Part H of this permit
(Standard Conditions for NPDES Permits):
• Section B. (11.) Signatory Requirements
• Section D. (2.) Reporting
• Section D. (6.) Records Retention
• Section E. (5.) Monitoring Reports
1. Reporting rSupersedes Section D. (2.) and Section E. (5.) (a)1
Beginning no later than 270 days from the effective date of this permit, the permittee shall begin reporting
discharge monitoring data electronically using the NC DWR's Electronic Discharge Monitoring Report
(eDMR) internet application.
Monitoring results obtained during the previous month(s) shall be summarized for each month and
submitted electronically using eDMR. The eDMR system allows permitted facilities to enter monitoring
data and submit DMRs electronically using the internet. Until such time that the state's eDMR
application is compliant with EPA's Cross -Media Electronic Reporting Regulation (CROMERR),
permittees will be required to submit all discharge monitoring data to the state electronically using eDMR
and will be required to complete the eDMR submission by printing, signing, and submitting one signed
original and a copy of the computer printed eDMR to the following address:
NC DENR / DWR / Information Processing Unit
ATTENTION: Central Files / eDMR
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
If a permittee is unable to use the eDMR system due to a demonstrated hardship or due to the facility
being physically located in an area where less than 10 percent of the households have broadband access,
then a temporary waiver from the NPDES electronic reporting requirements maybe granted and
discharge monitoring data may be submitted on paper DMR forms (MR 1, 1.1, 2,3) or alternative forms
approved by the Director. Duplicate signed copies shall be submitted to the mailing address above.
Requests for temporary waivers from the NPDES electronic reporting requirements must be submitted in
writing to the Division for written approval at least sixty (60) days prior to the date the facility would be
required under this permit to begin using eDMR. Temporary waivers shall be valid for twelve (12)
months and shall thereupon expire. At such time, DMRs shall be submitted electronically to the Division
unless the permittee re -applies for and is granted a new temporary waiver by the Division.
Information on eDMR and application for a temporary waiver from the NPDES electronic reporting
requirements is found on the following web page:
htW://portal.iicdenr.org/web/wq/""­adii-dn/­bog/"`ipu/edmr
Page 6 of 8

Permit NC0021491
Regardless of the submission method, the first DMR is due on the last day of the month following the
issuance of the permit or in the case of a new facility, on the last day of the month following the
commencement of discharge.
2. Signatory Requirements [Supplements Section B. (11.) (b) and supersedes Section B. (11.) (d)j
All eDMRs submitted to the permit issuing authority shall be signed by a person described in Part II,
Section B. (11.)(a) or by a duly authorized representative of that person as described in Part II, Section B.
(11.)(b). A person, and not a position, must be delegated signatory authority for eDMR reporting
purposes.
For eDMR submissions, the person signing and submitting the DMR must obtain an eDMR user account
and login credentials to access the eDMR system. For more information on North Carolina's eDMR
system, registering for eDMR and obtaining an eDMR user account, please visit the following web page:
http://portal.ncdenr.org/web/wq/­admin/bog/­ipu/edmr
Certification. Any person submitting an electronic DMR using the state's eDMR system shall make the
following certification [40 CFR 122.22]. NO OTHER STATEMENTS OF CERTIFICATION WILL BE
ACCEPTED:
"I certifij, under penalty of law, that this document and all attachments were prepared under my direction or
supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the
information submitted. Based on nay inquiry of the person or persons who manage the system, or those persons
directly responsible for gathering the information, the information submitted is, to the best of my knowledge and
belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information,
including the possibility of fines and imprisonment far knowing violations. "
3. Records Retention [Supplements Section D. (6.)1
The permittee shall retain records of all Discharge Monitoring Reports, including eDMR submissions.
These records or copies shall be maintained for a period of at least 3 years from the date of the report.
This period may be extended by request of the Director at any time [40 CFR 122.41].
A. (5) Nutrient Reopener for High Rock Lake
This permit may be reopened and modified to implement nutrient requirements in accordance with any
future TMDL and/or nutrient management strategy for High Rock Lake.
Page 7 of 8

Town of Mocksville Residual Management Plan
Dutchman's Creek WWTP Renovation
The Dutchman's Creek WWTP currently operates under a Land Application of Residual Solids (503) Permit
for residual management. The proposed Dutchman's Creek WWTP Renovation project will significantly
improve upon the facility's existing residual management strategy, eliminating all problematic
components of the current design.
Excess solids at Dutchman's Creek WWTP are currently treated in a single 176,000 gallon aerobic
digester. The digester currently relies on a single mechanical aerator to keep the sludge well -mixed and
aerated, but due to frequent malfunctions of this aerator, the operators are heavily reliant on lime
stabilization to meet their Land Application requirements. The digester has fixed -elevation decanters
that only have the ability to decant to two of the three aeration basins. Additionally, the digester has a
drain that conveys sludge to truck loading station for hauling. There is no way to drain the digester
without additional pumping.
The proposed biosolids management process will add an additional aerobic digester to allow for a more
efficient digestion process. Both the existing and new digester will be fitted with a telescoping valve that
will allow the operator to decant residual water back to the influent pumping station of the WWTP. Each
digester will also have a sludge drain that combine flows prior to the existing truck loading station,
allowing a truck to haul sludge from either digester from a single location. Both digesters will be fitted
with a diffused air system, eliminating the digestion inefficiencies caused by the faulty mechanical aerator.
Upstream of the digestion process, a sludge thickener will be added to increase the solids content of the
sludge prior to digestion. This sludge thicker will be accompanied by a polymer feed system, along with
an intermediate pumping station to convey the thickened sludge to the digesters. A flow diagram for the
facility's sludge management strategy is shown on page 2 of the Residual Management Plan.
In addition to improved sludge management, the proposed Dutchman's Creek WWTP Renovation project
will replace the existing problematic screening equipment in the influent pump station with a screen
located in a new headworks structure to remove non-organic debris from the influent flow. The new
screening unit will be a mechanical rake design with 6 mm screen openings. The unit will be equipped
with a screw conveyor, spray wash system and compactor discharging the screened, washed material into
a dumpster. A manual bar screen with 1 -inch bar spacing will also be provided in the event the primary
screening unit is out of service or has failed to operate properly. The manually screened material will also
be placed in the dumpster. The dumpster will be hauled off-site for disposal, as is currently done.
Willis Engineers
1984.015 1 June 2018

w
o
Q
°0
Q N
F-
Q
z
o
F
w
U
N
Z
F-
z
Ld
J
Lij
2i
J
Q
C)
O
J
C7
w
F-
V)
C)
LLJY �
D
FF-
w
p
=
U
N
<
(
O
N
H
U
Z
a
z
Q
J
Ld
z
� W
w �
U
� W
C�
0
U Q
z
J
J
�
U)
Q
Z�W
�0w
p
z
dow
o
z
z
Q
v~iow
XOC�
Oro
Q
0
J
woo
ago
N
Q
O
= Q
N
CD
V)U
CL
2
D W
WCL
F-
a
W
z
w
F
z
N
W
J
w
J
z
-
w
z
r
m
o
-
0
0
wZ�
CD
�
~
(fM)
0WHY
W
U
�y}
w
o
W
N=N
W
F
z
w
o
LD
U
z
W
bl
Ld
w
L,
NO1103JNISI0 01 M0I3
Of
g
z
Z
m
m
z
O
a
Ld
w
Q
M
O
K
w
3
O
J
li
VLL0--A ON 'OIC ON - LLZ8Z VNI]ONVO H121ON '31iMIVHO '30V1d S3AIS OOLOI 'ONI Sa33NION3 SI-1-11M

Engineering Calculations
Wastewater Facilities
Contract 11.0
Dutchman's Creek WWTP Renovation
CWSRF Project No. CS370606-02
WONI1SENGINEERS
10700 Sikes Place, Suite 115
Charlotte, North Carolina 28277
North Carolina License No. F-0114

TOWN OF MOCKSVILLE
WATERWATER FACILITIES
CONTRACT 11.0 — DUTCHMAN'S CREEK WWTP RENOVATION
DESIGN CALCULATIONS
TABLE OF CONTENTS
1 Influent Design Criteria
2 Peaking Factor Calculation
3-6 Basis of Design
7 Diffuser Quantity Calculation
8-9 Blower Requirements
10-13 Return Activated Sludge (RAS) System Head Development
14-16 Waste Activated Sludge (WAS) System Head Development
17-19 Scum System Head Development
20-25 Buoyancy Calculations
26-27 Sludge Thickener Requirements
28 Load Tabulation
Willis Engineers i
1984.015 June 2018

Town of Mocksville
Dutchman's Creek WWTP Renovation
Influent Design Criteria
The influent parameters in our Basis of Design was based on the median value of the 30 -day rolling
average of several years of Plant DMR data. Because there are several measurements with extreme
outliers (likely due to sampling error), using the median instead of the mean values provides a better
indication of the central tendency for the Dutchman's Creek WWTP influent design constituents.
The selected influent design parameters are similar to those for the previous plant projects, as well as
those used by the original equipment manufacturers. Below is the table summarizing the design
parameters.
The design loading was calculated as follows:
Loading = 8.34 x Flow in MGD x Concentration in mg/L
Dutchman's Creek Historical
(mg/0
Design Selection
(mg/0
BOD
216
250
TSS
210
250
The design loading was calculated as follows:
Loading = 8.34 x Flow in MGD x Concentration in mg/L
Willis Engineers
1984.015 1 June 2018
Design Selection
(lbs/day)
BOD
2043
TSS
2043
Willis Engineers
1984.015 1 June 2018

Town of Mocksville
Dutchman's Creek WWTP Renovation
Assumptions
Qcoi Avg Flow at Cooleemee WWTP
QDutch Avg Flow at Dutchman's Creek WWTP
p Avg People Per Household
S Mocksville Total Service Connections
PDUtch Dutchman's Creek Served Population, Thousands
PF Peaking Factor
Formulas
PDUtch Dutchman's Creek Served Population
PF Peaking Factor
Calculations
PDutch Dutchman's Creek Served Population
PF Peaking Factor
Peaking Factor Calculation
221,700 gpd
452,000 gpd
2.6 people/house
2419 Connections
X Thousand People
X
S x QDutch/(Qcoi + QDutch) x p/1000
(18 + PDutch1/z)/(4+PDutchl/2)
4.22 Thousand People
3.3
Say 3.5
Willis Engineers
1984.015 2 June 2018

Town of Mocksville
Dutchman's Creek WWTP Renovation
Design Parameters:
Influent
Design Daily Flow
Peak Hourly Flow
BOD (5 -day)
Total Suspended Solids
Effluent (summer limits):
BOD (5 day) Weekly
Monthly
Total Suspended Solids Weekly
Monthly
Plant and Process Facilities
Note: Plant upgrades are shown in RED
Basis of Design
980,000 gpd
3,430,000 gpd
250 mg/I
250 mg/I
7.5 mg/I
5 mg/I
45 mg/I
30 mg/I
1 Influent Pumping Station
Pump
Number
3
Type Submersible, Non -Clog
Pump Capacity, each
1,150 gpm
Drive Size, each
30 HP
Force Main
8 inch transitions to 12 inch at by-pass connection
Diameter
8 in
Length
49 ft
Diameter
12 in
Length
270 ft
2 Headworks
Replace Screening Equipment in new headworks facility
Screening
Type
Manual Bypass
Quantity
1
Width
3 feet
Spacing
1 in
Capacity
2382 gpm
Type
Mechanical Rake
Quantity
1
Width
3 feet
Spacing
6 mm
Capacity
2382 gpm
Drive
2 HP
Washer/Conveyor
5 HP
Willis Engineers
1984.015 3 June 2018

Town of Mocksville Basis of Design
Dutchman's Creek WWTP Renovation
3 Extended Aeration Basins
Number
3
Volume, each
340,000 gallons
Volume, Total for Plant
1,020,000 gallons
Detention
25 hours
Floating Aerators (total for plant)
Number
2 per basin
Motor
25 HP
4 Secondary Clarification
Construct new clarifiers sized to current industry standards
Number
2
Recycle Ratio
1
Max Allowable Avg Solid Loading Rate
20 Ibs/ft^2/day
Max Allowable Peak Solid Loading Rate
35 Ibs/ft^2/day
Max Allowable Hydraulic Loading
1000 gpd/ft^2
Average Solid Loading Rate
40866 lbs/clay/clarifier
Peak Solid Loading Rate
91,948.50 lbs/clay/clarifier
Hydraulic Loading Rate
1715000 gpd/clarifier
Avg Solid Loading Area
2043.3 ft^2
Peak Solid Loading Area
2,627.10 ft^2
Peak Hydraulic Area
1715 ft^2
Solids Loading Diameter
51 ft
Peak Solid Loading Diameter
58 ft
Hydraulic Loading Diameter
47 ft
Selected Diameter
58 ft
Depth
14 ft
Volume (each)
275,110 gallons
Willis Engineers
1984.015 4 June 2018

Town of Mocksville Basis of Design
Dutchman's Creek WWTP Renovation
5 Process Pumps
New RAS and WAS pump station; add chopper pumps for scum management
RAS
Number
4 total
Type
Submersible
Recycle Flow
230 GPM Each
Drive Size, Each
7.5 HP
WAS
Number
2 Total
Type
Submersible
Wasting Rate
125 GPM each
Drive Size, Each
3 HP
Scum
Number
2
Type
Chopper
Capactiy
122 GPM
Drive Size, Each
10 HP
Thickened Sludge
Number
1
Type
Dry
Capactiy
100 GPM
Drive Size, Each
3 HP
6 Sludge Thickening
Add sludge thicking to increase aerobic digester retention time and sludge storage
Solids Thickening Achievable 4
Type Rotary Drum
Drive Size 3 HP
Dry Capacity 59 lbs/hr
Willis Engineers
1984.015 5 June 2018

Town of Mocksville
Dutchman's Creek WWTP Renovation
Basis of Design
7 Aerobic Digester Basin
Add new digester and replace existing mechanical aerator with diffused air
Existing
Number
1 Tank
Diameter
50 ft
Depth
12 ft
Volume (New)
176,154 gallons
HRT/SRT @ Average Flow
46 days
HRT/SRT @ 80% Design Flow
27 days
Aeration
Aeration Requirement
Flow
New
Number
Diameter
Depth
HRT/SRT @ Average Flow
HRT/SRT @ 80% Design Flow
Volume (New)
Aeration
Aeration Requirement
Flow
Blowers
Number
Type
Capacity
Drive Size, Each
8 Disinfection
Type
Number of Basins
Chlorine Contact
Dechlorination Contact
25 CFM/1000 CF
589 SUM
1 Tank
60 ft
12 ft
66 days
40 days
253,662 gallons
25 CFM/1000 CF
848 SUM
3
Positive Displacement
516 SUM
20 HP
Chlorine Contact and Dechlorination
2
5,000 cf/basin
160 cf/basin
Willis Engineers
1984.015 6 June 2018

Town of Mocksville Diffuser Quantity Calculation
Dutchman's Creek WWTP Renovation
Blowers
Air Per Blower 516 SUM
Quantity 3
Existing Aerobic Digester
Air Required
589 SUM
Air Available
634 SUM
Max Air per Diffuser
15 SUM
Total Diffusers
39.3 Diffusers
As Drawn
52 Diffusers
Length of Air Piping per side
112.5 Feet
Diffuser Spacing
4.3 Feet
Actual Air per Diffiser
12.2 SUM
New Aerobic Digester
Air Required
848 SUM
Air Available
914 SUM
Max Air per Diffuser
15 SUM
Total Diffusers
56.5 Diffusers
As Drawn
70 Diffusers
Length of Air Piping per side
314 Feet
Diffuser Spacing
4.5 Feet
Actual Air per Diffiser
13.1 SUM
Willis Engineers
1984.015 7 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Aeration Piping Headloss
Scenario: Both Digesters Online
Blower Requirements
Willis Engineers
1984.015 8 June 2018
Design Flow
1548
SCFM
Altitude/Temp Adjustment
1.05
Submerged Depth of Discharge
11.2
ft
Static HL
4.8
psi
Static+Friction HL
5.79
psi
Air per Diffuser
13.1
SCFM
Diameter Length
Equivalent
Length
HL Total
Segment
SCFM
HL per 100 ft
(in) (ft)
of Fittings (ft)
(in)
Al
8 81
118
1548
2.8
5.57
A2
6 10
33
914
5.1
2.19
A3
6 40
63
914
5.1
5.23
a
6 8
30
835
4.5
1.71
b
6 8
30
705
3
1.14
c
6 8
30
548
2
0.76
d
6 8
30
365
0
0.00
e
6 8
30
208
0.75
0.29
f
6 8
30
78
0.05
0.02
g
3 2.25
22
39
0.01
0.00
h
3 4.5
22
26
0.005
0.00
1
3 4.5
22
13
0.005
0.00
j
Diffuser -
-
13
-
8.20
IHL (in)
25.1
FHL (psi)
0.91
Willis Engineers
1984.015 8 June 2018

D
m
®
❑
D
Z �
00
Q
Z
❑
CA W
®
D
Z
El
m
z
G
I
I I
z
II
m
f z
01
m
OD N
II WAC
���^
V,
N0
II �ZC)
�C
II zm
_0
m Z
0 CA
D
ON
D
m z
Crl `
D
=-9
D
CO C
r' -9
F—
�c
m
=
O
0
m
0 A
\�
Z7 D
z
m mCA
z
O
Fj
O
N
n Ci
o
m
m
N
m0
F-9 fTl
G
A
� �
r
Z �
m
awm
K:
0
Cf)
O
CA
:E
A
m
A
_
D
C
r_
Cf)D
C
z
m
o j
C
z
c�
m
m
cn
N
m
O
a7
W
m

Town of Mocksville
Dutchman's Creek WWTP
Narrative:
A system head curve for the
new RAS recycle pumps
System Configuration
Top of Wetwell
663.50 ft MSL
Wetwell Bottom
648.50 ft MSL
Water Level
661.50 ft MSL
Discharge
664.75 ft MSL
Static Head
3.25 ft
25
20
w
10
5
0
0
RAS System Head Development
Pump
Discharge 4"
Impeller 9.00"
Motor 7.5 HP
Pump Efficiency 67.00%
100 200 300 400
Flow (gpm)
70
60
50
40
30
io
m
Willis Engineers
1984.015 10 June 2018
i
♦
♦
♦
♦
♦
Fairbanks Nihjuis 5432
1 Pump System Head
3 Pump System Head
— — Efficiency
100 200 300 400
Flow (gpm)
70
60
50
40
30
io
m
Willis Engineers
1984.015 10 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Friction losses based on C
Diameter (in)
Length (ft)
Sum K
Q (gpm)
300
230
Q (gpm)
0
50
100
150
200
230
300
350
400
450
500
550
600
650
700
750
800
850
115
4
4
4
6
22
28
9
500
5.56
0.9
1.7
2.57
Hf
Hm
1.6
5.1
1.0
3.0
Hf
Hm
0.0
0.0
0.1
0.1
0.2
0.6
0.4
1.3
0.8
2.3
1.0
3.0
1.6
5.1
2.1
6.9
2.7
9.0
3.4
11.4
4.1
14.1
4.9
17.0
5.7
20.3
6.7
23.8
7.6
27.6
8.7
31.7
9.8
36.1
10.9
40.7
RAS System Head Development
Hm
Duty Point
0.1
14.9
Hf
Hm
Hf
Hm
Hf
2.0
0.8
0.2
0.2
1.7
1.2
0.5
0.1
0.1
1.0
Hf
Hm
Hf
Hm
Hf
0.0
0.0
0.0
0.0
0.0
0.1
0.0
0.0
0.0
0.1
0.3
0.1
0.0
0.0
0.2
0.6
0.2
0.1
0.0
0.5
1.0
0.4
0.1
0.1
0.8
1.2
0.5
0.1
0.1
1.0
2.0
0.8
0.2
0.2
1.7
2.7
1.1
0.3
0.2
2.2
3.5
1.5
0.4
0.3
2.9
4.3
1.8
0.5
0.4
3.6
5.2
2.3
0.6
0.5
4.3
6.2
2.8
0.7
0.6
5.2
7.3
3.3
0.8
0.7
6.0
8.5
3.9
0.9
0.8
7.0
9.7
4.5
1.0
0.9
8.0
11.0
5.1
1.2
1.1
9.1
12.4
5.8
1.3
1.2
10.3
13.9
6.6
1.5
1.4
11.5
RAS System Head Development
Hm
TDH
0.1
14.9
0.0
16.3
3 Pumps
Hm
TDH
TDH
0.0
3.3
3
0.0
3.6
4
0.0
4.7
6
0.0
6.3
9
0.0
8.6
13
0.0
10.2
16
0.1
14.9
25
0.1
18.9
32
0.1
23.5
41
0.1
28.7
51
0.1
34.4
61
0.2
40.7
73
0.2
47.6
86
0.2
55.0
99
0.3
63.0
114
0.3
71.5
130
0.4
80.6
147
0.4
90.2
164
Willis Engineers
1984.015 11 June 2018

LL L
TOWN OF MOCKSVILLE
WIIIISENGINEERS DUTCHMAN'S CREEK WWTP
RAS SYSTEM HEAD DEVELOPMENT
JUNE 2018
19
SCALE PAGE
1'=5' 12

SS SS
SS
FTI
a
0
e
TOWN OF MOCKSVILLE JUNE 2018
OMEN
WINISENGINEERS DUTCHMAN'S CREEK WWTP
SCALE PAGE
RAS SYSTEM HEAD DEVELOPMENT 1"=50' 13

Town of Mocksville
Dutchman's Creek WWTP
Narrative:
A system head curve for the new WAS pumps
System Configuration
Motor
Top of Wetwell
663.50 ft MSL
Wetwell Bottom
642.50 ft MSL
Water Level
661.50 ft MSL
Discharge
679.70 ft MSL
Static Head
18.20 ft
50
45
40
35
d
x
v
30
R
C
0
25
0
20
15
10
5
0
0
WAS System Head Development
Pump
Impeller
5.81"
Motor
2.00
Efficiency
46.00%
Speed
1750 RPM
50 100 150
Flow (gpm)
100
90
80
70
60
w
50 y
`m
a
40
30
20
10
0
200
Willis Engineers
1984.015 14 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Friction losses based on C =
Diameter (in)
Length (ft)
Sum K
Q (gpm)
Hf
125
4.5
Q (gpm)
Hf
0
0.0
50
0.8
100
3.0
150
6.4
200
10.8
250
16.4
300
22.9
350
30.5
400
39.1
450
48.6
500
59.0
550
70.4
600
82.7
650
95.9
700
110.0
750
125.0
800
140.8
850
157.5
900
175.1
950
193.5
1000
212.8
WAS System Head Development
115
4 6
317 268.45
7.85 8.95
Duty Point
Hm
Hf
Hm
TDH
1.2
0.5
0.3
24.8
Hm
Hf
Hm
TDH
0.0
0.0
0.0
18.2
0.2
0.1
0.0
19.4
0.8
0.4
0.2
22.5
1.8
0.7
0.4
27.5
3.2
1.3
0.7
34.2
5.0
1.9
1.1
42.6
7.2
2.7
1.6
52.6
9.7
3.6
2.2
64.2
12.7
4.6
2.9
77.5
16.1
5.7
3.6
92.2
19.9
7.0
4.5
108.5
24.1
8.3
5.4
126.4
28.6
9.7
6.4
145.7
33.6
11.3
7.6
166.6
39.0
13.0
8.8
188.9
44.7
14.7
10.1
212.7
50.9
16.6
11.5
238.0
57.5
18.6
12.9
264.7
64.4
20.6
14.5
292.9
71.8
22.8
16.2
322.5
79.5
25.1
17.9
353.5
Willis Engineers
1984.015 15 June 2018

SS SS
SS
FTI
0
TOWN OF MOCKSVILLE JUNE 2018
UUMIS ENGINEERS DUTCHMAN'S CREEK WWTP
SCALE PAGE
WAS SYSTEM HEAD DEVELOPMENT 1 "=50' 16

Town of Mocksville
Dutchman's Creek WWTP
Narrative:
A system head curve for the new scum pumps
System Configuration
Motor
Top of Wetwell
663.50 ft MSL
Wetwell Bottom
651.50 ft MSL
Low Water Level
661.50 ft MSL
Discharge
679.70 ft MSL
Static Head
18.20 ft
40
35
30
w
R 25
m
x
E
c
p 20
a
0
15
10
A
0
0
Scum System Head Development
Pump
Discharge
3"
Motor
10 HP
Speed
1750 RPM
Efficiency
0.32
50 100 150 200 250
Flow (gpm)
50
45
40
35
0
m
30 2
m
m
CL
49
20
15
10
300
Willis Engineers
1984.015 17 June 2018
i
i
i
i
/
/
/
/
/
/
/
/
System Head
6.0 Vaughan V3FR
— — — Efficiency
50 100 150 200 250
Flow (gpm)
50
45
40
35
0
m
30 2
m
m
CL
49
20
15
10
300
Willis Engineers
1984.015 17 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Friction losses based on C =
Diameter (in)
Length (ft)
Sum K
Q (gpm) H
122
Q (gpm) H
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
Scum System Head Development
115
4 6
308 268
7.67 5.14
106.9
121.5
136.9
153.1
170.2
188.1
206.8
Duty Point
f
Hm
Hf
Hm
TDH
4.2
1.2
0.5
0.2
24.2
f
Hm
Hf
Hm
TDH
0.0
0.0
0.0
0.0
18.2
0.8
0.2
0.1
0.0
19.3
2.9
0.8
0.4
0.1
22.4
6.2
1.7
0.7
0.2
27.1
10.5
3.1
1.3
0.4
33.5
15.9
4.9
1.9
0.6
41.5
22.3
7.0
2.7
0.9
51.1
29.7
9.5
3.6
1.3
62.2
38.0
12.4
4.6
1.6
74.8
47.2
15.7
5.7
2.1
89.0
57.4
19.4
6.9
2.6
104.5
68.4
23.5
8.3
3.1
121.5
80.4
28.0
9.7
3.7
140.0
93.2
32.8
11.3
4.3
159.9
38.1
12.9
5.0
181.2
43.7
14.7
5.8
203.9
49.7
16.6
6.6
228.0
56.2
18.5
7.4
253.4
63.0
20.6
8.3
280.3
70.1
22.8
9.3
308.5
77.7
25.0
10.3
338.1
Willis Engineers
1984.015 18 June 2018

SS SS
SS
FTI
0
TOWN OF MOCKSVILLE JUNE 2018
UUMIS ENGINEERS DUTCHMAN'S CREEK WWTP
SCALE PAGE
SCUM SYSTEM HEAD DEVELOPMENT 1 "=50' 19

Town of Mocksville
Dutchman's Creek WWTP
Buoyancy
Maximum Ground Water Elevation
RAS Valve Vaults Buoyancy Calculation
665.70 ft M51-
Depth
SL
Depth to Wet Well Invert
5.83 ft
Wet Well Cross Section Area
46.7 ft 2
Bottom Slab Area
46.7 ft 2
Bottom Slab Thickness
0.5 ft
Wet Well Volume
296 ft 3
Submerged Depth
6.3 ft
Weight of Water
62.4 pcf
Buoyancy
18,444 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
10.7 ft 2
Weight of Walls
9664 lbs
Weight of Base
3619 lbs
Weight of Ballast
7238 lbs
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
20,520 Ib
Net Downforce
2,077 lb
(ok)
Willis Engineers
1984.015 20 June 2018

Town of Mocksville
Dutchman's Creek WWTP
RAS /WAS Wet Well Buoyancy Calculation
Buoyancy
Maximum Ground Water Elevation
665.70 ft M51-
SLDepth
Depthto Wet Well Invert
21.00 ft
Wet Well Cross Section Area
156.00 ft 2
Bottom Slab Area
217.00 ft 2
Bottom Slab Thickness
1.50 ft
Wet Well Volume
3602 ft 3
Submerged Depth
23 ft
Weight of Water
62.4 pcf
Buoyancy
224,734 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
41
Weight of Walls
133455
Weight of Divider Wall
21700
Weight of Base
50453 lbs
Weight of Soil
26989
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
232,597 Ib
Net Downforce
7,863 lb
(ok)
Willis Engineers
1984.015 21 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Scum Wet Well Buoyancy Calculation
Buoyancy
Maximum Ground Water Elevation
665.70 ft M51-
SLDepth
Depthto Wet Well Invert
12.00 ft
Wet Well Cross Section Area
23.4 ft 2
Bottom Slab Area
28.2 ft 2
Bottom Slab Thickness
0.5 ft
Wet Well Volume
294 ft 3
Submerged Depth
12.5 ft
Weight of Water
62.4 pcf
Buoyancy
18,372 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
7 ft 2
Weight of Walls
13692 lbs
Weight of Base
2185 lbs
Weight of Soil
2876 pcf
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
18,753 Ib
Net Downforce
MOW;
(ok)
Willis Engineers
1984.015 22 June 2018

Town of Mocksville WAS Valve Vaults Buoyancy Calculation
Dutchman's Creek WWTP
Buoyancy
Maximum Ground Water Elevation
665.70 ft MSL
Depth to Wet Well Invert
4.83 ft
Wet Well Cross Section Area
17.1 ft 2
Bottom Slab Area
17.1 ft 2
Bottom Slab Thickness
0.5 ft
Wet Well Volume
91 ft 3
Submerged Depth
5.3 ft
Weight of Water
62.4 pcf
Buoyancy
5,691 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
6.3 ft 2
Weight of Walls
4679 lbs
Weight of Base
1326 lbs
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
6,005 Ib
Net Downforce
314 Ib
(ok)
Willis Engineers
1984.015 23 June 2018

Town of Mocksville Flowmeter Vault Buoyancy Calculation
Dutchman's Creek WWTP
Buoyancy
Maximum Ground Water Elevation
665.70 ft MSL
Depth to Wet Well Invert
4.83 ft
Wet Well Cross Section Area
14.7 ft 2
Bottom Slab Area
14.7 ft 2
Bottom Slab Thickness
0.5 ft
Wet Well Volume
78 ft 3
Submerged Depth
5.3 ft
Weight of Water
62.4 pcf
Buoyancy
4,887 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
5.7 ft 2
Weight of Walls
4263 lbs
Weight of Base
1139 lbs
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
5,402 Ib
Net Downforce
515 Ib
(ok)
Willis Engineers
1984.015 24 June 2018

Town of Mocksville
Dutchman's Creek WWTP
Splitter Box Buoyancy Calculation
Buoyancy
34.7
Maximum Ground Water Elevation
665.70 ft MSL
Depth to Wet Well Invert
5.00 ft
Wet Well Cross Section Area
76.7 ft 2
Bottom Slab Area
76.7 ft 2
Bottom Slab Thickness
1.0 ft
Wet Well Volume
460 ft 3
Submerged Depth
6.0 ft
Weight of Water
62.4 pcf
Buoyancy
28,705 Ib
Structure Weight
Cross Sectional Area of Concrete Walls
34.7
Weight of Walls
26869
Weight of Base
11884 lbs
Unit Weight of Reinforced Concrete
155 pcf
Unit Weight of Saturated Soil
47.6 pcf
Approximate Weight of Structure
38,753 Ib
Net Downforce
10,048 Ib (ok)
Willis Engineers
1984.015 25 June 2018

Town of Mocksville
Dutchman's Creek WWTP Renovation
Flow/ Kinetic Parameters:
Average Plant Flow
0.45 MGD
Design Plant Flow
0.98 MGD
Yield
0.5 lbs VSS/Ibs BOD
Influent BOD
250 mg/I
Effluent BOD
5 mg/I
Influent TSS
250 mg/I
Effluent TSS
30 mg/I
Volatile Fraction of TSS
75%
Sludge Solids (without solids thickening)
0.5% to 1.0%
Proposed Sludge Solids (thickened)
2.0% to 4.0%
Specific Gravity
1.005
Puma Parameters:
Sludge Thickener Requirements
Waste Pump Flow Rate (to thickeners)
100 to 125 gpm.
Thickener Run Time at Current Flow
4 hours / day
Thickener Run Time at Design Flow
6 hours / day
After the sludge is thickened, it will need to be pumped to the aerobic digesters:
Static Elevation:
12 feet
Pipe Length:
122 feet
Diameter:
6 inches**
Fittings:
90 ° Bends
4
Plug Valves
4
Tees (side outlet)
2
** Pipe diameter can be reduced if necessary
Willis Engineers
1984.015 26 June 2018

Town of Mocksville Sludge Thickener Requirements
Dutchman's Creek WWTP Renovation
Solids Production, Average Flow:
From TSS = (1 — 0.75) * (250 mg — 30 s
I mg l) * 8.34 * 0.45 MGD = 207 lbs
Y
C mg 5mg) lbs VSS
From BOD = 250 l — l * 8.34 * 0.45 MGD * 0.5 lbs BOD = 460 lbs/day
lbs lbs lbs
Total Solids = 207 da + 460 da da = 667
Y Y Y
Solids Production, Design Flow:
mg mg lbs
From TSS = (1 — 0.75) * (250-30—) l — * 8.34 * 0.98 MGD = 408 day
mg 5mg lbs VSS
From BOD = (250 l — l ) * 8.34 * 0.78 MGD * 0.5 lbs BOD
= 1001 lbs/day
lbs lbs lbs
Total Solids = 359 da + 797 da da = 1409
Y Y Y
Daily Volume of Sludge to Thickeners, Average Flow:
667las
Volume = y lbs = 15,915 gpd
1.005 x (0.5% ) x 8.34 gal
Daily Volume of Sludge to Thickeners, Design Flow:
1409las
Volume = y lbs = 33,620gpd
1.005 x (0.5%) x 8.349x1
Willis Engineers
1984.015 27 June 2018

ELECTRICAL LOAD TABULATION
FEEDER DESCRIPTION KVA USE NET
MDP -1
TREATMENT CELL 2
93.0
2.0
100%
2.0
350A
4
@
7.5HP
36.0
100%
36.0
AERATORS
2 @ 25HP
54.0
100%
54.0
100%
PANEL SPB2
MISC
2.0
100%
2.0
22.0
PANEL CLB2
MISC
2.0
100%
2.0
2HP
BLOWERS
2 @ 5HP
12.0
100%
12.0
MDP -3
DIGESTER AREA
300A
PANEL PD
MISC
5.4
50%
2.7
DRUM
11.1
100%
11.1
HVAC
10.0
100%
10.0
HEADWORKS
9.0
67%
6.0
BLOWERS
3 ® 20HP
63.0
67%
42.0
MDP -4 CLARIFIER AREA
300A
PANEL PC
MISC
93.0
2.0
100%
2.0
RECYCLE PUMPS
4
@
7.5HP
36.0
100%
36.0
WASTE PUMPS
3
©
3HP
10.0
100%
10.0
SLUDGE PUMPS
2
@
10HP
22.0
100%
22.0
CLARIFIERS
2
©
2HP
6.0
100%
6.0
MDP -5 INFLUENT PUMP STATION
400A
INFLUENT PUMPS
3 © 30HP
93.0
100%
93.0
MDP -6 TREATMENT CELL 3
400A
AERATORS
2 @ 25HP
54.0
100%
54.0
PANEL SPB3
MISC
2.0
100%
2.0
BLOWERS
2 © 5HP
12.0
100%
12.0
MDP -13 LAB BUILDING
200A
PANEL L1
MDP -14 TREATMENT CELL 1
250A
AERATORS
MISC 5.0 100% 5.0
2 © 25HP 54.0 100% 54.0
440.5 KVA © .85PF = 374.4 KW.
THE EXISTING GENERATOR IS RATED 400 KW, OR 500 KVA © .8PF.
28