NC0006548_Engineering Alternatives Analysis_20011002

NPDES DOCUMENT SCANNING COVER SHEET
NPDES Permit:
NC0006548
Wayne Farms / Dobson facility
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Plan of Action
Instream Assessment (67b)
Speculative Limits
Environmental
Assessment (EA)
Permit
History
Document Date:
October 2, 2001
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content on the reirerse side

ENGINEERING ALTERNATIVES
ANALYSIS (EAA)
for
WAYNE FARMS, LLC
Dobson, North Carolina
October 2, 2001
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Protecting the Environment and Your Investment in Pollution Control

ENGINEERING ALTERNATIVES ANALYSIS (EAA)
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WAYNE FARMS, LLC
DOBSON, NC
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ram I. GENERAL INFORMATION
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A. Wayne Farms, LLC
Surry County
P. O. Box 383, Dobson, NC 27107
Telephone:
EAA preparer: Reid Engineering Company, Inc.
1210 Princess Anne St., Fredericksburg, VA 22401
1.1
B. Wayne Farms operates a poultry processing plant in Dobson, NC
which includes a wastewater treatment plant that discharges treated
wastewater into Fisher Creek, a nearby receiving stream. The
Wayne Farms processing plant has a production capacity of
approximately 110,000 bpd. The present wastewater generation rate
is approximately 8.0 gallons per bird slaughtered. This present
pmwastewater generation rate results from a potable water use rate of
9.32 gallons/bird that is required to satisfy USDA requirements for
HAACP fecal coliform elimination on processed poultry. Wayne
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Farms has implemented numerous water use reductions and flow
restricting devices in the processing plant such as water saving
pm spray nozzles and restrictor orifice. Wayne Farms has an internal
water conservation task force to continually evaluate water use to
insure conservation methods are practical.
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Wayne Farms has also implemented wastewater recycle precedures
1.4 to reduce potable water use and the net volume of wastewater that is
discharged from the processing plant. Wastewater is recycled from
the primary screen effluent back to the processing plant to provide a
''' water source for feather flow away from the scalder room.
Wastewater is also recycled from the wastewater treatment plant
effluent back to the processing plant for seal cooling water and as a
source of wash down water in the offal room, the driveway area, and

live receiving and live shed areas; and, as a source of truck wash
water.
C. To provide capacity for a wastewater flow volume = 700,000 gpd, no
modifications are required in the existing wastewater treatment
facilities. The existing wastewater treatment system components
include one dissolved air flotation (DAF) cell pretreatment unit; one
7-day aerated flow equalization basin (FEB); one activated sludge
reactor; two final clarifiers; two sludge return pumps; one chlorine
contact basin for effluent disinfection; and, two waste activated
sludge storage lagoons. The capacities of each of these treatment
units is provided in the attached Design Summary. A schematic
process flow diagram is attached which provides sizes of treatment
system components. These existing wastewater treatment system
components have provided excellent wastewater treatment efficiency
and consistent compliance with NPDES permit limitations. A
summary of DMR report results for the wastewater treatment system
for the past year of operations is attached verifying the excellent
efficiency obtained by the Wayne Farms wastewater treatment
system.
The wastewater treatment system process Design Summary
contained in Appendix #1 that was submitted to the NC-DENR in
December 1996, provides the unit capacity of each existing
wastewater treatment system component. This Design Summary
notes that all wastewater treatment system components were sized
for a maximum design flow capacity of 1.04 MGD; therefore, none of
the existing components are inadequate for the wastewater
discharge flow volume projected maximum daily discharge flow
volume of 0.70 MGD.
A wastewater treatment system process flow schematic Drawing F1
with component sizes is attached in Appendix #2.
D. No construction project is required.
2

.
II. EVALUATION OF DISPOSAL ALTERNATIVES
A. Connection to a Sewer Collection System
P"`' The Wayne Farms plant is located on the east side of the Town of
Dobson, North Carolina. The Town of Dobson has an existing 0.35
MGD capacity wastewater treatment system vs. the required
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maximum design wastewater flow for the Wayne Farms plant of 0.70
MGD. The Town wastewater treatment system must therefore be
significantly expanded to accommodate the Wayne Farms
wastewater discharge flow volume. Such a significant expansion of
the Town Sewage Treatment Plant would require 3 to 5 years to
pm complete which would result in an unacceptable delay in the
proposed expansion of the production capacity of the Wayne Farms
ran processing plant. In addition if connection to the Town Sewage
collection system were possible, Wayne Farms would still have to
operate an on -site wastewater pretreatment system and 7-day flow
'°"'' equalization basin prior to discharge to the Town Sewage Collection
System. Connection of Wayne Farms to the Town Sewage
PRCollection System would result in the discharge of the treated
wastewater into the same receiving stream that Wayne Farms
presently discharges into resulting in no change in the total pollutant
loading discharged by Wayne Farms and the Town to the receiving
streams. The attached letter in Appendix #3 from the Town of
ir
Dobson in Appendix #2 confirms that the Town is unable to provide
the required sewer capacity for Wayne Farms.
rm 1. Existing Sewerage System
The distance to the nearest existing sewer line is
PM approximately 900 ft. If the Town is ever able to provide sewer
capacity by Wayne Farms in the future, installation of a force
ra,, main would be required to connect to the Town sewage
collection system because the poultry processing plant
wastewater treatment system is located at a lower elevation
pm than the nearest potential Town Sewer connection point.
2. No area wide sewerage system is planned within a 5 mile
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radius of the Wayne Farms plant.
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B. Land Based Disposal
1. Wayne Farms does not own land that is available and suitable
for a subsurface disposal system or for a surface spray
irrigation disposal system.
2. The attached letter (Appendix #3) from Wayne Farms confirms
sufficient land is not available to the owner for wastewater
disposal by spray irrigation.
C. Wastewater Reuse
1. Wayne Farms presently reuse treated wastewater for flushing
feathers out of the picking room of the processing plant; for
wash down water in the offal room, driveway area, receiving
area; for seal cooling water and for other non -potable uses.
USDA will only allow treated wastewater to be reused as a
potable water source inside the chicken processing plant if the
treated wastewater meets Primary Drinking Water Standards.
Consequently Wayne Farms can reuse a portion of the treated
wastewater but cannot increase the reuse of wastewater in the
processing plant unless an expensive water treatment system
is installed.
D. Surface Water Discharge
1. Wayne Farms presently provides complete wastewater
treatment prior to discharge to a surface water receiving
stream in compliance with NPDES permit limitations.
2. The existing NPDES permit limits for BOD = 345#/day = 59.0
mg/L (MA) and TSS = 465#/day = 79.7 mg/L (MA) @ 0.70
MGD do not require the use of tertiary filtration. Tertiary
filtration would reduce final effluent BOD to between 4 mg/L to
8 mg/L and TSS to between 3 mg/L to 6 mg/L.
3. The existing wastewater treatment system includes the
following components and treatment processes:
4

a. Two existing first stage coarse screens for removal of
,.., large solids.
b. One existing second stage rotating mechanical fine
w+ screen for removal of small solids.
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c. Wastewater pretreatment by chemical coagulation,
flocculation and flotation in one existing DAF Cell for
removal of approximately 65% to 70% BOD, 75% to
85% TSS, and 80% to 90% Oil & Grease.
d. 7-Day Hydraulic Flow Equalization in one existing
1.1 completely mixed aerated lagoon and surface aerators.
1.1 e. One 7-Day Flow Equalization Basin Effluent Pump
Station to pump pretreated wastewater 7 days/week, 24
hours/day to the biological final treatment system.
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f. One existing completely mixed activated sludge aeration
basin for final removal of BOD and Ammonia Nitrogen.
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g. Two Final Clarifiers including one existing 35' dia., and
one 60' dia. with one existing and one new Return
Activated Sludge Pump Station.
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h. One existing chlorine contact basin for final effluent
disinfection by chlorination dechlorination prior to
WI disposal by discharge to a receiving stream.
i. Two existing Waste Activated Sludge Storage Lagoons
m for storage and accumulation of excess biomass sludge
prior to ultimate disposal by truck hauling to a land
m, application site.
A schematic diagram of the Wayne Farms wastewater
treatment system is provided on attached drawings F1 and a
site plan of the treatment facility is provided on attached
drawing M1. (See Appendix #2)

4. No wastewater treatment system improvements will be
installed.
5. No capital cost is required to install wastewater treatment
Mal system improvements.
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FINAL DESIGN SUMMARY
WASTEWATER TREATMENT SYSTEM
UPGRADE/EXPANSION
FOR
WAYNE FARMS
Dobson, North Carolina
December 1996
Prepared By:
AN
Reid Engineering Company, Inc.
Illimmow
PROTECTING THE ENVIRONMENT AND YOUR INVESTMENT IN POLLUTION CONTROL

FINAL DESIGN SUMMARY
WASTEWATER TREATMENT SYSTEM UPGRADE/EXPANSION
FOR
WAYNE FARMS
Dobson, North Carolina
TABLE OF CONTENTS
A GENERAL DESIGN REQUIREMENT 1
B PRIMARY AND SECONDARY OFFAL ROOM SCREENING
OF PROCESSING PLANT WASTEWATER (EXISTING) 3
C FLOTATION CELL PRETREATMENT SYSTEM (EXISTING) 4
D FLOTATION CELL CHEMICAL FEED EQUIPMENT DESIGN (EXISTING) 7
E 7 DAY AERATED FEB BY-PASS PUMP STATION 8
F 7 DAY AERATED FLOW EQUALIZATION BASIN (MODIFICATION) 9
G 7 DAY AERATED FEB EFFLUENT PUMP STATION 12
H ACTIVATED SLUDGE AERATION BASIN (NEW) 13
I CLARIFIER FLOW DIVISION TANK (NEW) 24
J ACTIVATED SLUDGE FINAL CLARIFIERS (MODIFICATION) 27
K ACTIVATED SLUDGE RETURN PUMP STATION (MODIFICATION) 30
L WASTE SLUDGE DISCHARGE LINE 31
M WASTE ACTIVATED SLUDGE STORAGE LAGOON (SSL) 31
N EFFLUENT DISINFECTION BY CHLORINATION/DECHLORINATION (EXISTING) 33
O EFFLUENT FLOW METER (EXISTING) 36
P CHEMICAL STORAGE -FEED EQUIPMENT FOR ACTIVATED SLUDGE PROCESS 36
Q EXPECTED FINAL EFFLUENT QUALITY 37

FINAL DESIGN SUMMARY OF WASTEWATER
TREATMENT SYSTEM IMPROVEMENTS
WAYNE FARMS, INC.
Dobson, North Carolina
A. GENERAL DESIGN REQUIREMENTS
1. Description of Project
a) This wastewater treatment system upgrade and expansion is
proposed to provide improved treatment efficiency and
reliability and the additional treatment capacity required to
accommodate the increased wastewater flow volume and
pollutant loadings to be generated by a potential future
expansion of the processing facility at the Wayne Farms,
Dobson, NC processing plant site.
b) This project will upgrade and expand the existing Wayne
Farms wastewater treatment system by converting the
existing activated sludge aeration basin into a new aerated 7
day hydraulic flow equalization basin; by installing a new
activated sludge aeration basin; and, by refurbishing and
placing the existing 35' dia. gravity clarifier back into service
to operate in parallel with the existing 60' dia. gravity
clarifier.
2. Wastewater Sources
a) Processing Facility
(1) Wastewaters discharged from the processing will be
treated through a physical chemical pretreatment
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
1

system and a biological final treatment system to
reduce high concentrations of BOD, Suspended Solids,
Oil & Grease and Ammonia pollutants to comply with
NPDES permit limitations before being discharged
into Fisher River.
m, b) Sanitary Wastewater
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(1) Sanitary wastewater generated from the bathroom
facilities at the processing plant is discharged to the
Town of Dobson municipal sewer system.
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3. Design Assumptions:
1-1 a) Wastewater Flows
(1) Processing Facility
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(b) Maximum wastewater volume = 1.04 MGD, 5
1.1 days/week discharged from the processing
facility. The wastewater volume generated by
the processing plant during the two 8 hour
'w processing shifts = .79 MG and during the one
8 hour cleanup shift = .25 MG. Wastewater will
be generated by the processing plant at a flow
rate of up to approximately 900 gpm = 1.35
MGD during the two 8 hour processing shifts
w' and approximately 520 gpm = .75 MGD during
the one 8 hour cleanup shift.
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mg Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
mi
©Reid Engineering Company, Inc.
(a) Two -shift poultry processing plant operation @
90,000 to 130,000 birds/day @ 8.0 gallons per
bird or less discharged to the wastewater
treatment plant including cleanup shift flow.
2

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b) Pollutant Concentrations and Loads
(1) Processing Facility
(a) Processing Wastewater @ 1.04 MGD, 5
days/week after screening in the existing offal
room:
Pollutant Pollutant
Pollutant Concentration Loads
COD 3,750 mg/L 32,526#/day
BOD 2,500 mg/L , 21,684#/day
TSS 1,500 mg/L 13,010#/day
O&G 600 mg/L 5,204#/day
TKN 150 mg/L 1,301#/day
NH3-N 60 mg/L 520#/day
B. PRIMARY AND SECONDARY OFFAL ROOM SCREENING
OF PROCESSING PLANT WASTEWATER (EXISTING)
1. Wastewater generated at the processing facility will flow by gravity
into the existing offal room for primary screening and secondary
screening.
2. Separate meat and feather flows will receive primary screening
through two existing internally fed rotating mechanical screens with
1/8 inch diameter opening size. After primary screening, the meat
and feather flows will be combined prior to secondary screening
through one internally feed rotating mechanical screen with .02
inch dia. opening size.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
®Reid Engineering Company, Inc.
3

C. FLOTATION CELL PRETREATMENT SYSTEM (EXISTING)
1. Description of Chemical Treatment - Flotation Process:
a) Screened and chemically coagulated/flocculated wastewater
will flow by gravity into the existing Flotation Cell for
removal of BOD, TSS, Oil and Grease and TKN by chemical
coagulation, flocculation and flotation.
)
The wastewater pretreatment process is a chemical treatment
system that introduces polymer to initiate the solids
separation process. The proper application of the polymer
causes the solids to float to the surface with the assistance of
micron size dissolved air bubbles.
c) As soon as the polymer is added to the wastewater, the non -
soluble solid particles entering the tank will flocculate
together and, with the assistance of dissolved air bubbles
contained in the recycle pressure flow pumped into the DAF
Cell, float to the surface forming a sludge cap. A skimmer
mechanism on top of the tank is used to scrape solids off the
surface of the tank. DAF skimmings solids concentrations
of over 25% are commonly obtained when the skimmings are
allowed to decant by gravity in the sludge collection tank.
2. Design Assumptions:
a) Wastewater Flow
(1) Maximum Design Influent Flow Volume = 1.04 MGD
over 24 hours, 5 days/week
(2) Maximum Design Influent flow rate < 900 gpm =
1.30 MGD during processing shifts.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
4

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b) Pollutant Concentrations and Loads
(1) Average Influent Pollutant Concentrations and Loads
in screened processing plant wastewater @ 1.04 MGD,
5 days/week:
Pollutant Pollutant
Pollutant Concentration Loads
COD 3,750 mg/L 32,526#/day
BOD 2,500 mg/L 21,684#/day
TSS 1,500 mg/L 13,010#/day
O&G 600 mg/L 5,204#/day
TKN 150 mg/L 1,301#/day
NH3-N 60 mg/L 520#/day
3. Design Calculations:
a) The existing circular Flotation Cell constructed of concrete
will be operated with chemical coagulation, flocculation and
flotation to provide wastewater pretreatment upstream from
the proposed new 7 day Aerated Flow Equalization Basin.
The inside dimensions of the flotation cell are 34' dia. x 10'
SWD. The total effective flotation area of the Flotation Cell
= 900 ft2.
(1) Calculated maximum solids loading rate with upstream
chemical coagulation -flocculation @ 900 gpm = 1.3
MGD is approximately 820#/HR, assuming a BOD
removal efficiency of 70%, a TSS removal efficiency of
80% and an O&G removal efficiency of 90%.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
5
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b
[(2,500 mg /L)(.70)18.34(1.30 MGL < 800 Ibs /hi
24
(2) Throughput Hydraulic Surface Loading Rate =
900 gPm< 1.0 gprr,/ft2
900 ft2
(3) Solids Loading Rate =
800 lbs /hr< 1.0 lbs /ft2/h1
900 ft2
The calculated skimmings volume produced per day in the
Flotation Cell when operated using chemical coagulation
flocculation process = 12,000# to 16,000# solids/day, 5,000
to 8,000 gpd, after gravity decanting to approximately 25%
solids concentration, assuming approximately 70% BOD
removal, 80% TSS removal and 90% Oil & Grease removal
in the Flotation Cell.
c) Solids skimming from Flotation Cell will flow into two 2,000
gallon Sludge Holding Tanks adjacent to the Flotation Cell
from where solids will be pumped to a tanker truck parked
adjacent to the equipment building for further storage prior
to hauling to an off -site rendering plant for ultimate
disposal.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
6

4. Expected DAF pretreatment system effluent quality at the 1.30
MGD design daily throughput flow volume:
Pollutant
Pollutant
Concentration
BOD < 2,500 mg/L (.30) < 750 mg/L;
TSS < 1,500 mg/L (.20) < 300 mg/L;
O&G < 600 mg/L (.10) < 60 mg/L;
TKN < 150 mg/L (.67) < 100 mg/L;
NH3-N< 60 mg/L (1.0) < 60 mg/L;
Pollutant
Loads
6,505#/day
2,602#/day
520#/day
867#/day
520#/day
D. FLOTATION CELL CHEMICAL FEED EQUIPMENT
DESIGN (EXISTING)
1. The following equipment is provided for mixing, storage and
pumping chemical solutions that are necessary for operation of the
chemical coagulation -flocculation -flotation process in the DAF
pretreatment process.
a) For coagulation -flocculation of screened raw wastewater
prior to flowing into the existing DAF Cell:
(1) One 7' diameter x 7' tall, 2,000 gallon polymer
flocculant solution mix -storage tank with a 1 HP mixer
(2) Two progressive cavity polymer flocculant solution
pumps each rated @ 72 to 720 gphr @ 60 psi; One
pump @ 72 to 720 gphr will inject polymer solution at
a rate of up to 60 mg/L (dry basis) into the 900 gpm
= 1.3 MGD design influent flow rate assuming a .5 %
by weight flocculant solution strength is made up in
each 1,900 gallon mix tank 2 to 3 times/day; the
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
7

am
normal polymer flocculant dosage requirement is
expected to be between 15 to 20 mg/L (dry basis).
1.0 E. 7 DAY AERATED FEB BY-PASS PUMP STATION
1. Design Assumptions
for
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a) Average Design Pumping Rate Required = 1.04 MGD (5)
7
b
< .75 MGD
= 520 gpm, 24 hours/day
5 days/week
Maximum Design Pumping Rate Required = 1.30 MGD =
900 gpm, 14 to 16 hours/day, 5 days/week during processing
shifts.
2. Pump Selection
a) Two new submersible sewage pumps will be provided to
pump between 400 to 600 gpm at 30 feet total head from the
existing DAF Cell effluent weir box directly to the new
Activated Sludge Aeration Basin. This 7 Day FEB by-pass
pumping alternative is required to provide capability to
pump all or part of the pretreated DAF cell effluent flow
directly to the new Activated Sludge Aeration Basin.
b) Operation of one by-pass pump is required to pump the 7
day equivalent flow rate = 520 gpm directly to the new
Activated Sludge Aeration Basin. Operation of two by-pass
pumps is required to completely by-pass the 7 Day FEB and
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
8

transfer all DAF Cell effluent wastewater flow during the
two processing shifts directly to the Activated Sludge
Aeration Basin.
c) A magnetic flowmeter is provided in the By -Pass Pump
Station effluent force main with a manual flow control valve
located in a control cabinet adjacent to the new Activated
Sludge Aeration Basin to accurately measure, indicate,
totalize, and control the flow rate pumped from the DAF
rim Cell effluent weir box to the new Aeration Basin.
F. 7 DAY AERATED FLOW EQUALIZATION BASIN
(MODIFICATION)
1. Design Assumptions
a) Wastewater Flows
(1) Maximum influent flow volume from processing
operations < 1.04 MGD; 5 days/week
(2) Average design effluent pumping rate 7 days/week, 24
hours/day
= 1.04 MGD (5 days)
7 days
= .743 MGD < .75 MGD, 7 days/week
b) Pollutant Concentrations and Loads
(1) The following influent wastewater pollutant
concentrations and loads are assumed in the 7 Day
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
°Reid Engineering Company, Inc.
9

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FEB influent wastewater flow volume < 1.04 MGD, 5
days/week:
Pollutant
Pollutant Pollutant
Concentration Loads
BOD < 600 mg/L 5,204#/day
TSS < 300 mg/L 2,602#/day
O&G < 60 mg/L 520#/day
TKN < 90 mg/L 780#/day
NH3-N < 60 mg/L 520#/day
c) Emergency Wastewater Storage
(1) In the event of power failure, wastewater can be stored
in the 7 Day Flow Equalization Basin until normal
power is resumed.
d) No pollutant removals in the aerated FEB are assumed in the
design of downstream activated sludge treatment process to
provide a conservative design approach.
2. Aerated Flow Equalization Basin Design
a) FEB Dimensions and Volume:
(1) The existing below grade 2.5 MG activated sludge
aeration basin will be converted into a new 7-Day, 24
Hour Aerated Flow Equalization Basin to be operated
upstream of the proposed new above grade Activated
Sludge Aeration Basin.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
°Reid Engineering Company, Inc.
10

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(2) Minimum total volume required for 7 day hydraulic
flow equalization =
1.04 MGD (5 days) (2) = 1.50 MG vs. 2.5 MG
7 provided
b) Evaluate Mixing and Aeration requirements in the aerated
Flow Equalization Basin:
(1) bhp required for mixing 150 mg/L to 300 mg/L TSS
concentration = 25 HP/MG in FEB
bhp required = 25 HP (2.5) < 65 HP @ HWL
Mixing to be provided by 4-20 HP floating down
pumping mixers
(2) Calculate the maximum oxygen transfer requirement
in the Aerated Flow Equalization Basin:
(3)
AOTR = .60#02/#BOD (5,200# BOD/day)
24
< 130# 02/hr
Assuming an oxygen transfer capacity of 1.8# 02f HP/hr
for the existing high speed floating surface aerators,
the maximum oxygen transfer capacity provided by the
8-20 HP surface aerators to be used in the FEB is over
320#02/hr vs. only 130#02f hr required. The existing
surface aerators will be operated in staggered,
adjustable on/off cycle times to provide adequate
oxygen transfer and complete mixing of the wastewater
stored in the FEB. To provide the required minimum
oxygen transfer rate into the equalized wastewater
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
11

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pairs of the 8-20 HP surface aerators will be operated
approximately 20 minutes to 40 minutes/hour
according to the cycle time controller. Longer time
and more frequent aerator on cycles can be used if a
greater oxygen transfer rate or greater mixing energy
is required.
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G. 7 DAY AERATED FEB EFFLUENT PUMP STATION
1. Design Assumptions
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a) Average Design Pumping Rate Required = 1.04 MGD (5)
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< .75 MGD
= 520 gpm, 24 hours/day
7 days/week
�, b) Maximum Design Pumping Rate Required = 1.04 MGD =
722 gpm, 24 hours/day, 5 days/week
'i' 2. Pump Selection
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a) Two new submersible sewage pumps will be provided to
pump between 450 to 750 gpm at 40 feet total head from the
7-Day Aerated FEB to the new Activated Sludge Aeration
Basin.
b) Operation of one pump is required to pump the maximum
design 7 day flow of up to 520 gpm with the second pump
provided as an installed standby pump.
Final Design Summary
WAYNE FARMS, INC
Dobson, North Carolina
©Reid Engineering Company, Inc.
12

c) A magnetic flowmeter is provided in the FEB effluent force
main with a manual flow control valve located in a control
cabinet adjacent to the new Activated Sludge Aeration Basin
to accurately measure, indicate totalize, record and control
the flow rate pumped from 7-Day FEB to the new Aeration
Basin.
H. ACTIVATED SLUDGE AERATION BASIN (NEW)
1. Design Assumptions
a) Wastewater Flow
(1) Maximum design average daily influent flow rate =
1.04 MGD, 5 days/week, if the 7 Day Aerated FEB is
by-passed and pretreated wastewater discharged from
the upstream Flotation Cell is pumped directly into
Activated Sludge Aeration Basin.
(2) Average design daily influent flow rate = .75 MGD, 7
days/week when pretreated wastewater is pumped from
the 7 Day Aerated FEB into the new Activated Sludge
Aeration Basin.
b) Pollutant Concentrations and Loads
(1) Assume the upstream DAF Cell is operated with
chemical coagulation -flocculation.
(2) Influent pollutant loadings when influent wastewater
flow volume = 1.04 MGD, 5 days/week from the
Flotation Cell operated with chemical coagulation -
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
13

flocculation if the 7 Day Aerated FEB is by-passed
and pretreated wastewater discharged from the
upstream Flotation Cell is pumped directly into
Activated Sludge Aeration Basin:
BOD < 750 mg/L; < 6,505#/day
TSS < 300 mg/L; < 2,602#/day
O&G < 60 mg/L; < 520#/day
TKN < 100 mg/L; < 867#/day
NH3-N < 60 mg/L; < 520#/day
(2) Influent pollutant loadings when influent wastewater
flow volume = .75 MGD, 7 days/week from the 7 day
FEB:
(3)
BOD < 750 mg/L; < 4,691#/day
TSS < 300 mg/L; < 1,877#/day
O&G < 60 mg/L; < 375#/day
TKN < 100 mg/L; < 625.5#/day
NH3-N < 60 mg/L; < 375#/day
Influent pollutant loadings when the discharge flow
from the Flotation Cell is pumped at a rate of .75
MGD, 5 days/week directly to the Activated Sludge
Aeration Basin and excess flow over .75 MGD
(approximately 1.04 MGD - .75 MGD = .29 MGD) is
discharged to the 7 Day FEB with accumulated flow in
the FEB pumped to Aeration Basin over the weekend:
BOD < 750 mg/L; < 4,691#/day
TSS < 300 mg/L; < 1,877#/day
O&G < 60 mg/L; < 375#/day
TKN < 100 mg/L; < 625.5#/day
NH3-N < 60 mg/L; < 375#/day
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
14

Pal
MIR
u
Pat
Pal
Final effluent NPDES Permit monthly average limitations @
Pollutant
Permit Limit
Permit Limit in mg/L
@.75MGD 7Day
Discharge Flow
BOD
345#/day
mg/L
g/L
TSS
465#/day
75 mg/L
NH3
100#/day
16 mg/L
O&G
150#/day
24 mg/L
2. Activated Sludge BOD and TKN Removal Process Design
a) One new 95 ft. dia. x 28 ft. liquid depth, 1.50 MG Activated
Sludge Aeration Basin (ASAB) will be installed to
accomplish simultaneous carbonaceous BOD removal and
nitrification.
b) Calculate MLVSS and MLSS concentrations required in the
1.50 MG aeration basin for BOD and ammonia removal at
the minimum expected winter season design mixed liquor
temperature = 10°C at the 7 day design inflow rate = .75
MGD when pretreated wastewater is pumped from the 7
Day FEB to the Aeration Basin.
(1) For BOD removal assuming a carbonaceous BOD
removal rate = .125#BOD/#MLVSS @ 10°C:
4,691# BOD/day
.125 < 37,528# MLVSS @ 10°C
(2) For TKN removal assuming a nitrification rate = .015
TKN/#MLVSS @ 10°C, and assuming a nitrogen
Pei Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
MOP
15

uptake by the biomass of approximately 3 mg/L N/100
mg/L BOD (750 mg/L BOD x .03) = 22.5 mg/L =
140.7#/day
625.5# - 140.7#
.015 < 32,320# MLVSS @ 10°C
(3) The required total MLVSS and MLSS concentrations
in the 1.50 MG aeration basin volume for BOD
"° removal and nitrification at the 10°C winter season
operating temperature assuming MLVSS/MLSS = .85
PR
37,528# + 32,320#
(8.34)(1.50 MG) =
oil
69,848# MLVSS
(8.34)(1.50 MG) = 5,583 mg/L MLVSS
MI
5,583 mg/L
OM .85 = 6,500 mg/L MLSS @ 10°C
Assume MLSS < 6,500 mg/L during winter season for
lgoR
conservative design approach.
c) Calculate the required total MLVSS and MLSS
concentrations required in the 1.50 MG aeration basin for
BOD removal and nitrification at the average summer
"im season operating mixed liquor temperature = 20°C at the 7
day design inflow rate = .75 MGD when pretreated
Pit wastewater is pumped from the 7 day FEB to the Aeration
Basin.
pm (1) For BOD removal assuming a carbonaceous BOD
removal rate = .45# BOD/# MLVSS @ 20°C:
int
Poi Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
Am
16

mgh .
WI
PM
PM
PM
PR
PM
Imi
PIM
PM
RR
MR
PRI
MI
rPR
4,691# BOD/day
.45 < 10,424# MLVSS @ 20°C
(2) For TKN removal assuming a nitrification rate = .06
TKN/#MLVSS @ 20°C, and assuming a nitrogen
uptake by the biomass of approximately 3 mg/L N/100
mg/L BOD (750 mg/L BOD x .03) = 18.0 mg/L =
140.7#/day
(3)
625.5# - 140.7#
.06 < 8,080 MLVSS @ 20°C
The required total MLVSS and MLSS concentrations
in the 1.50 MG aeration basin volume for BOD
removal and nitrification at the 20°C winter season
operating temperature assuming MLVSS/MLSS = .85
10,424# + 8,080#
(8.34)(1.50 MG) =
18,504# MLVSS
(8.34)(1.50 MG) =
1,479 mg/L
.85
1,479 mg/L MLVSS
= 1,740 mg/L MLSS @ 20°C
Assume MLSS < 2,000 mg/L during summer season
for conservative design approach.
d) Calculate MLVSS and MLSS concentrations required for
BOD and ammonia removal at season operating mixed
liquor temperature = 15°C at the 5 day design inflow rate =
1.04 MGD when the 7 Day FEB is by-passed and pretreated
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
17

wastewater is pumped from the Flotation Cell effluent
directly to the new Aeration Basin.
(1) For BOD removal assuming a carbonaceous BOD
removal rate = .30#BOD/#MLVSS @ 15°C:
6,505# BOD/day
.30 < 21,683# MLVSS @ 15°C
(2) For TKN removal assuming a nitrification rate = .03
TKN/#MLVSS @ 15°C, and assuming a nitrogen
uptake by the biomass of approximately 3 mg/L/100
mg/L BOD (750 mg/L BOD x .03) = 22.5 mg/L =
195#/day
(3)
867# - 195#
.03
< 22,400# MLVSS @ 15°C
The required total MLVSS and MLSS concentrations
in the 1.50 MG total aeration basin volume for BOD
removal and nitrification at the 15°C winter season
operating temperature assuming MLVSS/MLSS = .85
21,683# 22,400#
(8.34)(1.50 MG) =
44,083# MLVSS
(8.34)(1.3 MG) = 3,524 mg/L MLVSS
3,524 mg/L
.85
= 4,146 mg/L MLSS @ 15°C
Assume MLSS < 4,500 mg/L during summer season
for conservative design approach during conditions
when the 7 Day FEB must be by-passed.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
18

e)
Design F/M (food to biomass) ratio in Activated Aeration
Sludge Basin:
(1) @ .75 MGD, 7 day design inflow rate:
F/MT < 4,691#/day
(8.34)(1.50 MG)(6,500 mg/L)
< .06# BOD/#MLSS @ 6,500 mg/L MLSS
during winter season @ 10°C
< .18# BOD/#MLSS @ 2,000 mg/L MLSS
during the summer season @ 20°C
f) Calculations indicate that the proposed new 1.50 MG
Activated Sludge Aeration Basin will provide adequate
volume for accomplishing the required winter season BOD
and TKN (ammonia) removal down to an activated sludge
basin temperature of 10°C. The use of subsurface diffused
aeration equipment in the aeration basin will insure
maximum operating temperatures in the activated sludge
treatment process during the winter season. If winter season
aeration basin mixed liquor temperatures cannot be
maintained above 10°C, then to achieve adequate TKN
removal efficiency, the MLSS concentration must be
increased above 6,500 mg/L and/or upstream pretreatment
efficiency must be improved by increased chemical dosage in
DAF Cell to reduce the TKN loading on the downstream
Activated Sludge Treatment System.
3. Aeration Basin Equipment Design
a) Evaluate mixing and aeration requirements in the activated
sludge aeration basin:
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
19

(1) bhp required for mixing a 2,000 to 6,500 MLSS
concentration = 50 HP/MG
bhp required = 50 HP (1.3) < 65 HP
(2) Calculate the maximum summer season oxygen
transfer requirement in Aeration Basin
AOTRI = 1.4#02/#BOD applied + 4.57#02/1"'KN applied
AOTRI = 1.4(4,691#BOD/dav)+4.57(625.-140 TKN/dav)
24
= 6,567#/dav + 2,215#/day
24
AOTRI = 8,782#/day
24 = 366#02JHR in summer season (average)
AOTR2
AOTR2
(3)
Calculate the maximum winter season maximum daily
oxygen transfer requirement in the Aeration Basin
assuming the 7 day FEB is by-passed.
= 1.25(6,505#BOD/dav)+4.57 (867-195)
24
= 8,131#/dav + 3,071#/dav
24
= 11,202#/day
24 = 467#02/HR in winter season (maximum under 7
Day FEB by-pass conditions)
(4) Calculate the required corresponding maximum
standard oxygen transfer rates:
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
20

,., SOR = AOR f
Where DO
Css
(/3C DO )a(1.024)T 2°
2.0 mg/L (average DO in the
CMAS Aeration Basin)
A = .90
a = .80 @ 2,000 to 6,500 mg/L MLSS
with subsurface jet aeration
diffusers
1.024g-2°) = 1.268 @ maximum T = 30° C
Cw = 7.63 @ sea level, 30° C
Cs = 9.2 @ sea level, 20° C
Site Altitude <_ 1,200 feet
Pressure Correction Factor = .957
Ion
Csw = 7.63 [(.957)(14.7)+(.5)(.433)(25.5)*
14.7
= 7.63 (1.3325) = 10.17 mg /L
Porn
n•� Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
°Reid Engineering Company, Inc.
Pon
Css = 9.2 [14.7 + (.5)(.433)(25.5)
14.7
21

= 9.2 (1.3756) = 12.66
* Air diffuser centerline depth = 25.5 ft. in the 28.0 foot deep aeration
basin with the jet aerators installed 2.5 above the aeration basin floor.
12.66
SOTR = AOTR [(.90)(10.17)-2.0].80(1.268)
SOTR = 1.75 (AOTR)
SOTR < 1.75 (467) = 817#02/hr
850#/hr (maximum)
SOTR < 1.75 (366) = 640#02/hr
< 650#/hr (average)
(5) Calculate subsurface aeration equipment air sparging
requirements:
(a) The oxygen available per cfm per hour =
x = .23 (.075#/ft3)(60 min/hr)
= 1.035#02/cfm/hr @ 68° inlet air
(b) e = subsurface diffuser oxygen stripping or transfer
efficiency at 26.5 air sparge depth = 37%
(c) scfm required = SOR
(x)(e)
scfm (max) = 850#02/HR
(1.035)(.37) = 2,220 scfm
scfm (average) = 650#O2/HR
(1.035)(.37) = 1,697 cfm
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
@Reid Engineering Company, Inc.
22

AIM
OA
scfm < 2,300 scfrn (maximum)
scfm < 1,700 scfm (average)
(d) Max. design blower pressure with 25.5 ft. jet diffuser air
sparge submergence:
= (25.5 ft.)(.433) + 1.0 psi = 12.0 (pressure loss
plus pressure drop in air supply lines and in jet
diffuser air sparges)
(6) Oxygen transfer and mixing in the Aeration Basin will
be provided by two directional mix subsurface jet
aeration headers each with 28 jets. Flow recirculation
for each jet header will be provided by one 40 HP end
pm
suction sewage pump. The maximum air sparging
capacity of the new jet header system is approximately
3,450 scfm providing an oxygen transfer rate =
1,200#02/hr (SOTR) with air supplied by 3-100 HP
blowers each rated at 1,150 scfm at 12.0 psi. The air
PO
sparging rate with 1-100 HP blower in operation =
1,150 scfm providing an oxygen transfer rate =
�. 450#02/hr (SOTR). The air sparging rate with 2-100
HP blowers in operation = 2,300 scfm providing an
oxygen transfer rate = 900#02/hr (SOTR). Normally
two blowers will be operated with the third functioning
as an installed standby.
Mg
PO
MI
Poll
NU
4. Evaluation Sludge Wasting Requirements From Activated Sludge
Process
a) Calculate waste activated sludge production at the maximum
7 day design BOD loading rate.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
23

(1) F/MT = 4,691# BOD/day
(8.34)(1.50 MG)(6,500 mg/L)
< .06#BOD/#MLVSS (Maximum) @ 6,500 mg/L
.18# BOD/#MLVSS (Minimum) @ 2,000 mg/L
0.1 (2) Y = Expected activated sludge production rate @ .06
to .18 F/Mv ratio < .35#Sludge/#BOD applied
(3) #. Waste Activated Sludge = (.35)(4,691#Iday)
1,650#/day
(4) Volume to be wasted from sludge return flow @ 10,000 mg/L
solids concentration to the existing Waste Activated Sludge
Storage Lagoons:
= 1,650#/day
(.01)(8.34) < 19,784 gpd
< 20,000 gpd < 14.0 gpm over 24 hours/day
raq
I. CLARIFIER FLOW DIVISION TANK (NEW)
1. Design Assumptions
a) Final Clarification Process Influent Wastewater Flow Rates
aro
(1) Maximum throughput flow volume = 1.04 MGD, 5
days/week
APPI
1
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
Average throughput flow volume = .75 MGD, 7
days/week
24

PM
PEI
PRI
Pol
(2) Average inflow rate with 100% sludge recycle rate =
(.75 MGD)(2) < 1.50 MGD
(3) Average inflow rate with 200% sludge recycle rate =
(.75 MGD)(3) < 2.25 MGD
b) Mixed Liquor Suspended Solids Concentrations
(1) Minimum MLSS = 2,000 mg/L
(2) Maximum MLSS = 6,500 mg/L
2. Design Calculations
a) Flow Division Tank Sizing
(1) One 8 ft. x 17.5 ft. x 7.0 ft. side water depth Flow
Division Tank will be provided for mixing of polymer
flocculent solution and mixed liquor flow, and, for flow
control and flow division to the two Final Clarifiers.
(2) Tank volume = 7,300 gallons
(3) Calculated Hydraulic Detention Times:
(a) @ .75 MGD average design flow through rate
plus 100% sludge return flow rate = 1.50 MGD
= 1,041 gpm total flow rate
HDT = 7,300 gallons
1,041 gpm = 7.0 minutes
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
25

.
(b) @ .75 MGD average design flow through rate
plus 200% sludge return flow rate = 2.25 MGD
= 1,562 gpm total flow rate =
HDT = 7,300 gallons
1,562 gpm = 4.7 minutes
(4) Effluent Flow Division and Control
(a) Flow Division
(1) One 12" dia. pipe and one 8 " dia.
discharge pipe are provided from the Flow
Division Tank to the two Final Clarifiers.
The 12" dia. pipe feeds the 60' dia.
clarifier and the 8" dia. pipe feeds the 35'
dia. clarifier.
(2) Each clarifier influent pipe has a shut-
off/control valve to terminate the flow rate
from the Flow Division Tank to each Final
Clarifier.
(b) Flow Control
(1) One flat crested weir is provided for each
clarifier to divide and control the mixed
liquor influent flow rate into each Final
Clarifier.
OW Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
pm
26

J. ACTIVATED SLUDGE FINAL CLARIFIERS (MODIFICATION)
1.
Design Assumptions
a)
b)
Wastewater Flow
(1)
(2)
(3)
Maximum throughput flow rate = 1.04 MGD, 5
days/week
Average throughput flow rate = .75 MGD, 7
days/week
Average inflow rate with 100% sludge
(.75 MGD)(2) < 1.50 MGD
Average inflow rate with 200% sludge
(.75 MGD)(3) < 2.25 MGD
Pollutant Concentrations and Loads
(1)
(2)
recycle rate =
recycle rate =
Mixed Liquor Suspended Solids Concentration
(a) Mixed MLSS = 2,000 mg/L
(b) Maximum MLSS = 6,500 mg/L
Average design mixed liquor solids loadings rate at the
7 day design throughput flow rate = .75 MGD and
with 100% sludge recycle rate @ 6,500 mg/L MLSS
concentrations =
(.75 MGD)(6,500 mg/L)(8.34)(2.0)/24 = 3,388#/hr.
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
®Reid Engineering Company, Inc.
27

MEI
(3)
Maximum design mixed liquor solids loadings rate at
the 7 day design throughput flow rate = .75 MGD and
with 200% sludge recycle rate @ 6,500 mg/L MLSS
concentrations =
(.75 MGD)(6,500 mg/L)(8.34)(3.0)/24 = 5,082#/hr.
2. Calculate Clarifier Loading Rates
a) The 60' dia. and 35' dia. final clarifiers will be provided with
hydraulic suction sludge pickup mechanism, surface skimmer
and one scum box.
b) The 60 ft. dia. circular clarifier will have an effective surface
overflow area and floor area = 2,800 ft2.
c) Clarifier Flow Division Ratios
'-+ Clarifier Area % of Total
60' dia. clarifier area = 2,800 ft2 74.4%
0.' 35' dia. clarifier area = 960 ft2 25.5%
Total Surface Area = 3,760 ft2 100%
% of Flow to 60' dia. clarifier = 75%
% of Flow to 35' dia. clarifier = 25%
d) 60' dia. Clarifier Volume = 230,000 gallons
35' dia. Clarifier volume = 79,000 gallons
Total Clarifier Volume = 309,000 gallons
Pon Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
28

PIN
fon
e) Hydraulic Surface Loading Rate (HSLR)
HSLR(avg)
= 750,000 gpd
3,760 ft2
200 gpd/ft2 @ avg. 7 day throughput
flow rate = .75 MGD
HSLR(max) = 1,040,000 gpd
3,760 ft2
280 gpd/ft2 @ max avg. 5 day
throughput flow rate = 1.04 MGD
f) Design solids loading rate (SLR) assuming an influent flow
rate = .75 MGD and a 100% sludge recycle rate with a
maximum MLSS concentration < 6,500 mg/L
SLR = (.75 MGD)(2)(8.34)(6,500 mg/L)
3,760 ft2
22.0#/ft2/day @ 7 day inflow = 2.30 MGD
including 100% sludge recycle flow
g) Minimum hydraulic detention time (HDT) assuming a 100%
sludge recycle rate
HDT = (309,000 gallons)(24)
(750,000)(2)
= 4.9 hours @ 7 day inflow rate =
1.50 MGD including 100% sludge
recycle flow
p., Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
29

fel
FaII
K. ACTIVATED SLUDGE RETURN PUMP STATION
(MODIFICATION)
1. Three self -priming sludge return (RAS) pumps will be provided in
the existing Sludge Return Pump Station located adjacent to the
two Final Clarifiers. The pumps are provided to recycle activated
sludge from the 60 ft. dia. and 35 ft. dia. Final Clarifiers to either
the new Aeration Basin or the 7 Day FEB.
One existing RAS pump will be modified to provide a sludge
recycle capacity = 240 gpm = .35 MGD = 185% of the
throughput flow rate (.75 MGD x .25 = .1875 MGD) into the 35'
dia. final clarifier. The second existing RAS pump will be
modified to provide a sludge recycle capacity = 400 gpm = .576
MGD = 100% of the throughput flow rate (.75 MGD x .75 =
.5625 MGD) into the 60' dia. final clarifier. The new RAS pump
will provide a sludge recycle capacity = 400 gpm = .576 MGD =
100% of the throughput flow rate (.75 MGD x .75 = .5625 MGD)
into the 60' dia. final clarifier. The two modified existing RAS
pumps will be rated at 240 gpm @ 85 feet and 400 gpm @ 85 feet.
The new RAS pump will be rated at 400 gpm @ 85 feet. The
total sludge return rate provided by operation of one small and
one large sludge return pump is approximately 640 gpm = .92
MGD = 125% RAS rate. The total sludge return rate provided
by operation of three sludge return pumps is approximately 1,040
gpm = 1.50 MGD = 200% RAS rate.
2. One existing RAS pump will normally be operated to provide a
sludge recycle rate = 50% to 150% of the 7 day throughput flow
rate = .75 MGD x .25 = .1875 MGD from the 35 ft. dia. clarifier.
Two sludge return pumps can be operated in parallel to provide a
sludge recycle rate over 200% from the 35' dia. clarifier. The new
RAS pump will normally be operated to provide a sludge recycle
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
30

Pot
luil
rate = 50% to 100% of the 7 day throughput rate = .75 MGD x
.75 = .5625 MGD from the 60' dia. clarifier.
3. Two magnetic flow meters are provided in the Sludge Return
Pump Station to accurately measure, indicate and totalize the
sludge recycle flow from each Final Clarifier to the new Aeration
Basin. Each flow meter is provided with a digital flow indicator
and with a downstream flow control valve to allow the sludge
recycle flow from each clarifier to be throttled and controlled.
L. WASTE SLUDGE DISCHARGE LINE (NEW)
1. One waste sludge discharge line is provided to pump and transport
waste activated sludge from the sludge return pump station
discharge header to the Waste Activated Sludge Lagoons.
2. A magnetic flow meter is provided on this waste sludge discharge
line to indicate and totalize the waste activated sludge pumping
rate and volume transferred to Waste Sludge Storage Lagoons.
M. WASTE ACTIVATED SLUDGE STORAGE LAGOONS
(EXISTING)
1. At the expected F/M ratio of .06 to .18# BOD/#MLSS, sludge
must be wasted at a rate of approximately .30 to .40#/#BOD
applied from the activated sludge treatment system. At the design
7 day BOD load of 4,691#/day approximately 1,650#/day (dry
basis) of activated sludge must be wasted from the activated sludge
process each day to maintain the correct MISS concentration in
the aeration basin. Activated sludge will be wasted by being
pumped from the clarifier sludge return pump station discharge
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
31

Pool
1105
line to the existing Waste Activated Sludge Storage Lagoons for
storage prior to being hauled to a State approved land application
site for ultimate disposal.
The calculated maximum waste activated sludge volume to be
pumped to the Waste Activated Sludge Storage Lagoons = 20,000
gpd < 14.0 gpm over 24 hours/day.
2. The two existing sludge lagoons will continue to be used for waste
activated sludge storage prior to ultimate disposal by land
application. Each sludge lagoon has a maximum storage volume
= 500,000 gallons providing a total sludge lagoon volume =
1,000,000 gallons.
3. Assuming that the waste activated sludge will gravity thicken in the
sludge lagoons to approximately 5% solids concentration, the
annual sludge accumulation volume is calculated as follows:
1,650# activated sludge/day (365)
.05 (8.34) = 1,450,000 gallons/year
4. If the two sludge lagoons are regularly decanted with decant water
pumped to the 7 Day FEB, the two sludge lagoons will provide
approximately 6 to 9 months sludge storage capacity.
5. Sludge should be pumped from each sludge lagoon approximately
every six months by a commercial sludge disposal company and
hauled to a State approved land application site for ultimate
disposal.
PIM Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
32

N. EFFLUENT DISINFECTION BY CHLORINATION/
DECHLORINATION (EXISTING)
1. To comply with fecal coliform bacteria limitations, the treated
wastewater discharged form the final clarifiers will be disinfected
by chlorination. Chlorine residual will be removed by
dechlorination prior final effluent discharge.
2. The existing chlorine contact basin with separate chlorination-
,. dechlorination zones will continue to be used for final effluent
disinfection. The chlorination-dechlorination zones have the
following dimensions and volume:
a) Total Channel Length = 96.0 feet
Channel Width = 5.0 feet
Channel Depth = 5.5 feet
Chlorination Zone Length = 83.0 ft.
Dechlorination Zone Length = 13.0 ft.
b) Total Volume = 3,775 ft3 = 28,250 gallons
Chlorination Zone Volume = 2,282.5 ft3 = 17,000 gallons
Dechlorination Zone Volume = 357.5 ft3 = 2,674 gallons
3. Hydraulic Detention Time in Chlorination Zone
a) @ Average 7 day design inflow rate = .75 MGD = 520
gpm
r Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
oiR
33

PIM
t = 17,000 gallons
520 gpm = 32.0 minutes
b) @ Maximum 5 day design inflow rate = 1.04 MGD = 722
gpm
,.� t = 17,000 gallons
722 gpm = 23.5 minutes
4. Hydraulic Detention Time in Dechlorination Zone
a) @ Maximum 7 day design inflow rate = .75 MGD = 520
gpm
t = 2,674 gallons
520 gpm = 5.0 minutes
b) @ Maximum 5 day design inflow rate = 1.04 MGD = 722
gpm
t = 2,674 gallons
722 gpm = 3.7 minutes
5. Contact Basin Cleaning
a) The contact basin in designed to be completely drained to
allow for cleaning by operating a submersible drain pump to
pump drainage wastewater into the nearby sludge lagoons.
6. Chlorination Equipment
a) Chlorine gas will continue to be used to accomplish final
effluent disinfection in the chlorination zone of the contact
basin. Chlorine gas is fed from one of two available 150#
cylinders; heated cylinder mounted chlorinators are installed
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
34

on each of the two 150# cylinders with one automatic
switch -over unit; one existing chlorine feed rate controller
and one existing chlorine ejector will be used in the chlorine
equipment room located adjacent to the contact chamber.
b) Each chlorinator has a feed capacity of 200#/day allowing
for a maximum dosage rate = 32 mg/L at the design average
7 day flow of .75 MGD.
c) Since upstream 24 hours, 7 day flow equalization is provided,
chlorine dosage can be adjusted manually to assure
compliance with fecal coliform and chlorine residual
Poi
limitations.
7. Dechlorination Equipment
a) Sulfur dioxide gas will continue to be used to accomplish
dechlorination in the dechlorination zone of the contact
basin. Sulfur dioxide gas is fed from one of two available
0.1 150# cylinders; heated cylinder mounted sulfonators are
installed on each 150# cylinders with one automatic switch -
over unit; one sulfur dioxide feed rate controller and one
sulfur dioxide ejector are installed in the existing sulfur
dioxide equipment room located adjacent to the contact
,., chamber.
b) Each sulfonator has a feed capacity of 200#/day allowing for
a maximum dosage rate = 32 mg/1 at the design average 7
day flow of .75 MGD providing a sulfur dioxide to chlorine
feed ratio of up to 1/1.
c) Since upstream 24 hour, 7 day flow equalization is provided,
sulfur dioxide dosage can be adjusted manually to assure
compliance with chlorine residual limitations.
gun
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
°Reid Engineering Company, Inc.
ram
35

Pal
O. EFFLUENT FLOW METER (EXISTING)
1. One magnetic flow meter (flow capacity > 1,400 gpm = 2.0 MGD)
is provided to measure the total discharge flow from the Final
Effluent Pump Station to the receiving stream.
P. CHEMICAL STORAGE -FEED EQUIPMENT FOR ACTIVATED
SLUDGE PROCESS
1. The following equipment is provided for mixing, storage and
pumping chemical solutions that are necessary for operation of the
Activated Sludge Treatment System and Final Clarifiers:
a) For pH adjustment of mixed liquor contained in the
Aeration Basin to maintain the activated sludge nitrification
process mixed liquor pH between 7.2 to 8.2 units; or, for
adjustment of final effluent pH above 6.0 units:
(1) One 4.33 ft. dia. x 5 ft. tall 560 gallon fiberglass tank
is provided for make-up and storage of magnesium
hydroxide solution.
(2) Magnesium hydroxide solution is dosed by gravity into
the existing DAF effluent wet well for mixing with
pretreated wastewater prior to wastewater flowing by
gravity into the 7 Day FEB or wastewater pumping
into the new Activated Sludge Aeration Basin.
b) For dosing of flocculent settling aid polymer solution into
the final clarifier influent mixed liquor:
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
36.

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Pot
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PPR
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(1) One 4.33 ft. dia. x 5 ft. tall 560 gallon fiberglass tank
is provided for make-up and storage of magnesium
hydroxide solution.
(2) Two polymer solution pumps are provided each rated
to pump from 72 to 720 GPH of solution, resulting in
dosage rates from 5 to 50 mg/L with one pump in
service in service at the design average clarifier inflow
rate = .75 MGD x 2 = 1.50 MGD assuming a 100%
sludge recycle rate and assuming a .5% polymer
solution strength is made up in the polymer solution
mix tank.
Polymer Dosage = (720 gphr)(24)(8.34)(.005)
(.75 MGD)(2)(8.34)
= 57 mg/L with one pump in service
Q. EXPECTED FINAL EFFLUENT QUALITY
1. Final effluent NPDES Permit Monthly Average Limitations:
Pollutant
PermitLimit
Permit Limit in mg/L
(#/day)
@ .75 MGD 7 Day
Discharge Flow
BOD
345#IdaY
mg/L
�
TSS
465#/day
75 mg/L
NH3
100#/day
16 mg/L
O&G
150#/day
24 mg/L
Fecal Coliform
< 200 MPN/100 m1
Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
37

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2. Expected Final Effluent Quality:
Pollutant
Permit Limit @
.75 MGD(mg/L)
Expected Concentration
BOD
TSS
NH3
O&G
Fecal Coliform
55 mg/L
75 mg/L
16 mg/L
24 mg/L
< 200 MPN/100 ml
5 - 15 mg/L
10 - 20 mg/L
1 - 4 mg/L
0 - 2 mg/L
< 100 MPN/100 ml
,..� Final Design Summary
WAYNE FARMS, INC.
Dobson, North Carolina
©Reid Engineering Company, Inc.
38

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16:41 WAYNE FARMS 4 5403718576
NO.494 1304
• E <19/99
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PHONE 107 WEST ATKINS STREET • POST OFFICE BOX 351 FAX
(336) 3864982 DOBSON, N.C. 27017
[phone]
TOWN OF DOBSON
March 17, 1999
—••••• —. ...-••a,.--,,.�;ari,- •
Mr. Rob Poindexter, Engineer
Wayne Farms
P. 0. Box 383
Dobson, N. C. 27017
Dear Mr. Poindexter:
The Town of Dobson's wastewater plant currently has a
treatment capacity of .350 MGD, which is not adequate to
handle the discharge requirements of your company.
Should you need further information, please advise.
•
Sincerely,
Town Manager