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OPERATION AND MAINTENANCE MANUAL WASTEWATER
TREATMENT SYSTEM UPGRADE
PREPARED FOR:
MOUNTAIRE FARMS OF NORTH CAROLINA, INC
17269 NC 71 HIGHWAY N
LUMBER BRIDGE, NC 28357
Prepared By:
CIVIL & ENVIRONMENTAL CONSULTANTS, INC.
CHARLOTTE, NORTH CAROLINA
KEYSTONE ENGINEERING GROUP, INC.
FRAZER, PENNSYLVANIA
MARCH 2O20
KeYStD f1 ['. -�� M
ENGINEERING GROUP Civil & Environmental Consultants, Inc.
590 LANCASTER AVENUE, STE 200 FRAZER PA 19355 3701 ARCO CORPORATE DR, STE 400, CHARLOTTE, NC 28273
(610) 407 - 4100 / [phone] FAX [phone] FAX

Section No.
1.0
2.0
2.1
2.2
2.3
2.4
2.4.1
2.4.2
2.4.3
2.4.3.1
2.4.3.2
2.4.3.3
2.4.4
2.4.5
3.0
TABLE OF CONTENTS
Description
Page No.
INTRODUCTION.................................................................................... 1
TREATMENT SYSTEM OVERVIEW ................................................... 3
GENERAL PROJECT DESCRIPTION ............................................. 3
PROCESS WASTEWATER CHARACTERIZATION &
DESIGNBASIS.................................................................................. 4
TREATMENT PLANT EFFLUENT QUALITY ............................... 5
TREATMENT PLANT DESCRIPTION ........................................... 6
Influent Pumping Station Modification ........................................ 7
Addition of Primary Dissolved Air Flotation Unit ........................ 8
Moving Bed Biofilm Design......................................................... 8
MBBR System Sizing.................................................................. 9
MBBR Pumping Station.............................................................. 9
MBBR Aeration System.............................................................. 9
Secondary Clarification..............................................................
10
Residual Solids Handling............................................................
10
PERMITS AND STANDARDS.............................................................
11
4.0 WWTP PROCESS DESCRIPTION ...................
4.1 ACTIVATED SLUDGE SYSTEM ....................
4.2.1 Temperature ..................................................
4.2.2 Mixed Liquor Suspended Solids ...................
4.2.3 Dissolved Oxygen Control ............................
4.2.4 pH..................................................................
4.2.5 Nitrogen and Phosphorus Addition ...............
4.3 SLUDGE HANDLING .......................................
4.3.1 Clarifier Operation ........................................
5.0 OPERATIONAL AND PROCESS MONITORING
5.1 INTRODUCTION....................................................
........................... 12
........................... 12
........................... 12
........................... 13
........................... 13
........................... 14
........................... 14
........................... 15
........................... 15
.......................... 16
.......................... 16
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Table of Contents (continued)
Page ii
5.2
OPERATIONAL MONITORING....................................................
16
5.3
SYSTEM CONTROL.......................................................................
17
5.3.1
Equalization and Wastewater Feed .............................................
20
5.3.2
Operations...................................................................................
20
5.3.2.2
Alarms and Troubleshooting......................................................
20
5.3.3
Primary DAF System..................................................................
22
5.3.2.1
Operations..................................................................................
22
5.3.3.2
Alarms and Troubleshooting......................................................
23
5.3.4
Post Primary Treatment Pumping Station ...................................
25
5.3.4.1
Operations..................................................................................
25
5.3.5
MBBR.........................................................................................
27
5.3.5.1
MBBR Operations.....................................................................
27
5.3.5.2
MBBR Alarms and Troubleshooting .........................................
28
5.3.6.
Secondary DAF and Sludge Transfer .........................................
32
5.3.6.1
Secondary DAF Operations.......................................................
32
5.3.6.2
Seconary DAF Alarms and Troubleshooting .............................
32
5.3.7
Effluent Lagoon..........................................................................
35
6.0
PROCESS CONTROL AND OPERATING STRATEGY ....................
37
6.1
ACTIVATED SLUDGE PROCESS CONTROL .............................
37
6.1.1
Organic Load (SALR, SARR)....................................................
38
6.1.2
Mixed Liquor Suspended Solids, Mixed Liquor Volatile
Suspended Solids........................................................................
40
6.1.3
Dissolved Oxygen (DO).............................................................
40
6.1.4
Temperature................................................................................
41
6.1.5
pH................................................................................................
41
6.1.6
Nutrients......................................................................................
41
6.1.7
Clarification................................................................................
42
6.1.8
Sludge Settleability.....................................................................
43
6.2
POTENTIAL OPERATING PROBLEMS AND CORRECTIVE
ACTIONS.........................................................................................
44
6.2.1
Filamentous Bulking...................................................................
45
6.2.2
Shock Conditions........................................................................
46
6.2.3
Clarifier Solids Carryover...........................................................
48
7.0
SYSTEM TROUBLESHOOTING GUIDE ...........................................
49
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Table of Contents (continued)
Page iii
LIST OF TABLES
Table No. Description Page No.
2-1 Process Wastewater Characteristics 4
2-2 Summary of Wastewater Effluent Quality 6
6-1 Summary of Process Control Parameters 38
6-2 Recommended WWTS for Trending 45
7-1 System Troubleshooting Guide 50
LIST OF FIGURES
Figure No.
Description
Page No.
2-1
Current Wastewater Treatment System Flow Diagram
6
2-2
Modified Wastewater Treatment System Flow Diagram
7
5-1
Main SCADA Screen
19
5-2
Drop Down Menu From HMI
19
5-3
EQ Basin Level Configuration
21
5-4
DAF Flow Setpoints
21
5-5
EQ Basin Aerator
22
5-6
Primary DAF Flow Configuration Screen (typical of A-D)
23
5-7
Primary DAF Feed Pump Screen (typical of A through E)
24
5-8
DAF Pump Interlocks
24
5-9
Aboveground Sump Level Configuration
25
5-10
MBBR Pump 1 (typical of MBBR P2)
26
5-11
MBBR Alternation
26
5-12
MBBR Interlocks
27
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Table of Contents (continued)
Page iv
5-13
MBBR Flow Configuration
29
5-14
MBBR Pinch Valve (typical of Pinch Valve 1 and Pinch Valve 2
29
5-15
MBBR Blower 1 (typical) and Blower Valve
30
5-16
MBBR Air Scour Valves (typical)
31
5-17
MBBR Process Parameters and Alarms
31
5-18
Secondary DAF Flow Monitoring and Alarms
33
5-19
Frac Tank Screen (typical)
33
5-20
Sludge Transfer Pumps (typical)
34
5-21
Sludge Hopper Level
34
5-22
Sludge Transfer Pump Interlocks
35
5-23
Lagoon Flow
35
5-24
Lagoon Level
36
LIST OF APPENDICES
Appendix A
Glossary of Terms
Appendix B
Equipment Data Sheets
Appendix C
Non -Discharge Permit
Appendix D
Flow Schematics
Appendix E
Activated Sludge Treatment Fundamentals
Appendix F
Laboratory Test Descriptions
Appendix G
Sample Collection and Handling
Appendix H
Detailed Process Control Operating Strategy
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1.0 INTRODUCTION
Mountaire Farms of North Carolina, Inc. (Mountaire Farms), located at located at 17269 NC 71
Highway N, Lumber Bridge, NC, 28357, owns and operates a permitted (WQ0000484) wastewater
treatment plant (WWTP) that land applies its treated wastewater. Current WWTP processes
include primary treatment only and consist of solids and insoluble BOD removal using a two stage
dissolved air flotation (DAF) system. Primary treated wastewater is then discharged to an
estimated 19 million gallon aerated storage lagoon prior to being land applied. Due to concerns
of odor emitting from the storage lagoon, Mountaire Farms has elected to modify the existing
WWTP to add secondary treatment to further reduce soluble BOD prior to discharge to the storage
lagoon.
The objective of the WWTP modification is to further reduce soluble BOD to a concentration
amenable for odor control, which will likely vary based on seasonal atmospheric conditions. Since
the facility's sanitary wastewater is collected and treated separately from the process WWTP, this
proposed modification request is only for process wastewater treatment.
The facility utilizes the activated sludge process (ASP) for wastewater treatment and recently
upgraded its WWTP. This manual is a guideline for the treatment plant operating personnel. The
primary purpose of this document is to provide the operators and supervisory personnel with:
1. A summary of the basic operation and control of the wastewater treatment
unit processes;
2. A description of the means of performance monitoring for this specific plant; and
3. A guide to troubleshooting the various components of the treatment system.
This manual has been prepared on the basis of the historical operations of the WWTP and system
design. However, as operational experience is gathered and with changing conditions,
modifications to some of the procedures may become necessary. The guidelines are intended as
a supplement to, not a substitute for, long-term experience and judgment by the operating staff.
In order to maintain its value, this document must be dynamic in nature and be continually
updated by experience. These guidelines are limited in scope to the description and presentation
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of the normal operation of the treatment system and predictable departures from that mode.
Major departures from the normal mode of operation will require careful consideration by the
supervisory staff.
The users of this manual should have a basic knowledge of wastewater treatment processes. The
theoretical portions of this manual have been presented in a concise, yet complete form, foregoing
complicated mathematical expressions and highly specialized concepts. There are a number of
technical terms and abbreviations commonly used in wastewater treatment operations which are
used throughout this text. A glossary of terms is included in Appendix A as a reference.
The troubleshooting guide is primarily concerned with providing guidance to the operator when
difficulty arises. It was prepared from the viewpoint of how the problem would demonstrate
itself to the operator. For example, a high effluent BOD5 concentration is not the problem itself,
but rather a symptom of the problem. Many of the problems addressed in the guide can be
anticipated through the preparation and continuing review of plant records. A record should be
maintained indicating operating problems, their cause, effects, and corrective actions taken.
Analytical records should be maintained so that the trends in performance can be used to project
potential operating difficulties.
This manual provides a general explanation of the operation of the mechanical components of
the treatment system. For more specific instructions on the mechanical operation and
maintenance of the equipment refer to the manufacturers' operating manuals for the individual
components.
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2.0 TREATMENT SYSTEM OVERVIEW
2.1 GENERAL PROJECT DESCRIPTION
Existing major primary WWTP processes include a 330,000 gallon equalization basin, a dedicated
influent pumping station, three (3) Sorin DAF systems with a stated hydraulic rating of 800 gpm
each, an estimated 10,000 gallon above ground clarifier, one (1) World Water Works DAF system
with a stated hydraulic rating of 2,400 gpm, a 19.79 million gallon aerated storage lagoon, and a
treated wastewater irrigation system serving 24 irrigation fields. Currently process wastewater
gravity flows from the production plant and collects in the equalization basin. Wastewater is then
pumped, at varying flow rates, to the Sorin DAF system. The Sorin DAF system effluent gravity
flows to the above ground clarifier where it is pumped to the World Water Works DAF system.
Effluent from the World Water Works DAF system gravity flows to the aerated storage lagoon
prior to being chlorinated and land applied to the irrigation fields which consist of 537.8 acres of
wetting area.
The biological treatment upgrade includes the addition of a secondary treatment system for soluble
BOD reduction, as well as an additional fourth World Water Works DAF system for primary solids
removal. In summary, the biological system components will consist of two (2) moving bed
biofilm reactors (MBBR) with aeration and other appurtenances. A required chemical feed system
includes anti -foam, to both MBBR Basins. The existing World Water Works DAF will be
repurposed to remove biological solids, which will be handled separately from primary solids.
This is done because the primary solids can be sold to a renderer, while the biological solids must
be disposed of. Biological solids will be temporarily stored in one of three 21,000-gallon Frac
tanks prior to being land applied off -site by a third party contractor.
Treated effluent from the post-MBBR DAF will be discharged to the aerated storage lagoon. No
changes or modifications are proposed for the irrigation system; therefore, items related to spray
irrigation have not been addressed as part of this O&M Manual. Additionally, no changes in final
effluent quality are anticipated so changes to groundwater monitoring well data have not been
included as part of this modification request.
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2.2 PROCESS WASTEWATER CHARACTERIZATION & DESIGN BASIS
Influent process wastewater characterization is summarized in the following table (Table 1).
Wastewater samples were collected from November 30, 2017 through December 13, 2017 and
analyzed by Cameron Testing Services, Inc. Twenty (20)-four hour composite samples were
collected from both the equalization basin and from the above ground clarifier (Sorin DAF system
effluent), which will become the secondary treatment system influent.
Table 2-1: Process Wastewater Characterization
Parameter
(')Influent
Average
(a)Sorin DAF
Effluent
Average
Secondary
Treatment
Influent Design
Basis
7-day Flow, Ave
(MGD)
2.34
2.34
2.55
Flow, Max (MGD)
3.07
3.07
3.2
TS, (mg/L)
7,929
1,576
-
TSS, (mg/L)
8,549
203
200
COD, (mg/L)
6,665
1,683
I 2,000
BODs, (mg/L)
4,978
1,177
1,300
sBODs, (mg/L)
1,278
933
1,100
TN, (mg/L)
230
120
-
TKN, (mg/L)
230
119
150
N13-N, (mg/L)
25
22
30
NO2 + NO3, (mg/L)
0.49
0.33
-
Total Phos, Ave
(mg/L)
64
55
-
Ortho P, (mg/L)
59
52
75
Alk, (mg/L)
169
153
-
Source: Mountaire Farms; December 2017
Note(s): (a) Values based on 13 24-hr composite samples collected 12/1/17 through 12/13/17
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The effluent of the existing Sorin DAF system will become the secondary treatment influent.
Additional information regarding process wastewater flows are discussed in the following section.
The WWTP is currently permitted to treat 2.55 MGD of process wastewater. No changes are being
requested to increase the current permitted limit. However, Mountaire Farms currently reuses
approximately 0.75 to 1.0 MGD of primary treated wastewater. Because of the reuse water
volume, total influent flow to the process WWTP is increased and typically ranges between 3.0
and 3.2 MGD. There are no plans to modify the location that plant reuse water is taken from the
WWTP, currently located at the clarifier (post Sorin DAF treatment system). However, if
Mountaire Farms elects to begin capturing plant reuse water after the proposed secondary
treatment system, then flows through the MBBRs and post DAF would increase. Again, this
change would not affect the total volume of treated wastewater discharged to the storage lagoon
or subsequent volume required for land application. For this reason, the proposed secondary
treatment system hydraulic design basis is 3.2 MGD.
The Lumber Bridge Plant has two distinct flow volumes — weekday and weekend. Weekday flows
were estimated to average 3.03 MGD with a maximum flow rate of 3.24 MGD, and weekend flows
averaged 0.31 MGD with a maximum flow rate of 0.61 MGD.
2.3 TREATMENT PLANT EFFLUENT QUALITY
As stated previously, this modification is solely for the purpose to reduce soluble BOD entering
the storage lagoon to control odor. Because the amount of required BOD reduction will likely
fluctuate based on seasonal atmospheric conditions, the secondary treatment system will operate
to reduce BOD concentrations between 65% and 90%. No changes in the storage lagoon effluent,
or the PAN calculation, are anticipated. Table 2 summarizes estimated storage lagoon influent
concentrations of select parameters.
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Table 2-2: Summary of Wastewater Effluent Quality
Parameter
Secondary Treatment
Influent Design Basis
Storage Lagoon
Influent
Flow, Max (MGD)
(a)3.2
2.55
TSS, (mg/L)
200
100
BOD5, (mg/L)
1,300
130 to 450
TKN, (mg/L)
150
80
NH3-N, (mg/L)
30
5
NO2 + NO3, (mg/L)
-
>2
Note(s): (a) Design based on future relocation of Plant reuse water after secondary treatment
2.4 TREATMENT PLANT DESCRIPTION
Design of treatment system modifications is discussed in additional detail in the following
subsections. Modifications include piping changes to the influent pumping station, the addition of
a fifth backup pump, the addition of a fourth primary DAF, repurposing the post primary DAF
transfer pumps, the addition of a two stage MBBR system, repurposing the existing World Water
Works DAF system for secondary solids removal, and the installation of a temporary sludge
handling system. Figures 2-1 and Figure 2-2, below, illustrate a basic flow diagram of both the
existing wastewater treatment system and the proposed modifications. Major equipment data sheets
for the installed equipment are included as Appendix B.
Influent
Wastewater
Figure 2-1: Current Wastewater Treatment System Flow Diagram
To Storage
Lagoon
EQBasin Infpamp Sorin DAF Clarifier WWW
Station Systems DAF Feed WWWDaF
Pumps System
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Influent
Wastewater
Figure 2-2: Modified Wastewater Treatment System Flow Diagram
To Storage
Lagoon
Inf pum Prim Separation Aboveground
EQ Basin P �' p NfBBK Feed MBBR Secondary Separation
Station (Sorin DAF sump Pumps System (WWW DAF System)
Systems) (former clarifier)
- Existing
Proposed
2.4.1 Influent Pumping Station Modification
Currently the influent pumping station has four (4) suction lift Gorman -Rupp T-Series self -priming
pumps, model T6A-B-4 with 30 Hp motors. Each pump has dedicated flow to a Sorin DAF system
(i.e. pump `A' feeds Sorin DAF `A', pump `B' feeds Sorin DAF `B', and pump `C' feeds Sorin
DAF `C'), with one pump isolated and used as a backup. Each pump is operated using a VFD and
has a design flow rate of 750 gpm for a total system flow of 2,250 gpm (3.24 MGD).
Piping modifications of the existing pumping station will use the existing backup pump to feed the
new WWW fourth primary DAF unit. A fifth pump has been added and tied into pumps C & D
feed as a backup. The primary DAF system will operate using four (4) DAFs under normal
operations and, therefore, will reduce the overall loading to each DAF. The average flow to each
DAF will be reduced from the current level of 750 gpm to an average hydraulic loading rate of
560 gpm. No change to the existing pumps is being proposed.
Because the flow to each DAF system is being reduced overall, by extension solids loading to the
individual DAF systems will also be reduced. Based on the wastewater characterization data
provided in Section 1.2 of the application, current suspended solids removal achieved is
approximately 97% on average. Even though hydraulic loading to the DAF systems will be
reduced, only a minimal increase in suspended solids removal capacity is anticipated.
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2.4.2 Addition of Primary Dissolved Air Flotation Unit
A fourth dissolved air flotation (DAF) unit has been added within the existing wastewater
treatment building. The design hydraulic and solids loading of the fourth DAF is identical to the
existing three Sorin DAF systems. The actual hydraulic capacity of the fourth DAF is higher, at
1100 GPM, than the Sorin units (800 GPM).
2.4.3 Moving Bed Biofilm Design
The biological treatment process for secondary treatment is a moving bed biofilm reactor (MBBR).
The MBBR system was invented in the 1980's and has since become a widely used treatment
system for both domestic and industrial process wastewaters. In general, the MBBR process is an
attached growth biological treatment process. As micro-organisms begin to populate within the
reactor, they attach to the available media which is continuously mixed. Unlike a conventional
attached growth treatment process (e.g. trickling filter) where micro-organisms are attached in a
fixed place as wastewater flows pass the media, an MBBR attached growth media continuously
moves throughout the reactor with the wastewater. This action increases the micro-organisms and
influent wastewater interaction. Typical MBBR systems, such as the proposed system for
Mountaire Farms, uses a diffused aeration system to facilitate both mixing and introduction of
oxygen for biological treatment.
A key attribute of an MBBR system is that activated sludge is not recycled. Waste activated sludge
is produced as the micro-organisms `slough off of the media as their growth begins to breach the
internally protected area of the media. Waste activated sludge is then separated from the treated
wastewater using secondary clarification. Key design parameters used to size an MBBR is the
surface area loading rate (SALR) and the media fill percentage of the reactor. The SALR refers
to the mass of BOD removed per day entering the reactor per square meter of media surface area
available. Typical SALR values range from 7.5 (low rate) to 25 (high rate) grams of BOD per
square meter of media per day (g/m2/d).
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2.4.3.1 MBBR System Sizing
In order to balance the required aeration load, i.e., CFM of air needed in each MBBR tank, a step
feed system will be utilized. Based on a design loading rate of 26,650 pounds of BOD per day
(1,300 mg/L of BOD @ 2.55 MGD), an average design SALR of 20 g/m2/d, and an average media
fill of 32%, results in approximately 8,100 scfm of air required during summer months to achieve
a design BOD removal rate of 90%. Based on a step feed flow split of 50% (1.28 MGD of influent
loading to MBBR #1 and MBBR #2) and a side water depth of 29 feet, tank diameters of 52 feet
were calculated using a media surface area of 589 square meters per cubic meter and a tank fill of
32%.
Step feed flow is managed using two (2) 10-inch diameter magnetic flow meters followed by 10"
pinch valves with 6" ports. Based on raw water influent characteristics, adequate phosphorus and
nitrogen are available in the raw wastewater. An anti -foam agent will be added to control foam as
required.
2.4.3.2 MBBR Pumping Station
The existing Gorman Rupp pumps that currently pump to the World Water Works DAF from the
aboveground clarifier will be repurposed to feed the proposed MBBR reactors. Since the
equipment is no longer being utilized as a clarifier, its designation has been changed to an
aboveground sump. No changes to the existing pumps are necessary as the current system meets
system flow and head requirements.
2.4.3.3 MBBR Aeration System
Oxygen supply to the biomass will be provided using three (3) 350 HP positive displacement screw
blowers, each will the capability of providing 4,100 scfm, for a total of 12,300 scfm of air, at 15
psi, which is the maximum pressure required to overcome the 29 foot side water depth of the tank.
The aeration system will be a stainless steel course bubble diffuser supplied by an 18 inch diameter
header. Equipment Data Sheets for the selected blower is provided in Appendix B.
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2.4.4 Secondary Clarification
Design solids loading rate for secondary clarification is 1,000 mg/L of suspended solids at a
maximum flow rate of 2,250 gpm, or an estimated maximum solids loading rate of 4.03 lbs/ft2-hr.
The existing World Water Works DAF system has a flow rating of 2,400 gpm at a suspended solids
concentration ranging from 1,500 to 3,000 mg/L, or a solids loading rate range of 8.19 lbs/ft2-hr
to 16.4 lbs/ft2-hr. Biological solids collected will be pumped using an air diaphragm pump to a
temporary sludge storage system discussed in the following section. Following clarification,
treated wastewater will flow by gravity and discharge to the aerated storage lagoon.
2.4.5 Residual Solids Handling
Biological solids removed by the World Water Works DAF will be transferred and staged in one
of three 21,000-gallon Frac tanks. Sludge generation of approximately 21,000 gallons per day has
been calculated based on an average concentration of 3% solids. Sludge will be loaded into 6,000-
gallon tankers for transportation and off -site disposal. Sludge hauling will be continuous during
operations with a minimum of three (3) hauls per day. Off -site disposal will be via land application
by a third party contractor. Terra Renewal, Dardanelle, AR, has approved land application to farm
sites in Chesterfield, Darlington and Marlboro counties, South Carolina.
Once the MBBR system has been commissioned, pilot testing for sludge digestion and solids
dewatering will commence to facilitate the design of a permanent solids handling system. The
solids handling system is being addressed at a later date so that a system optimized for biological
solids can be carefully reviewed.
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3.0 PERMITS AND STANDARDS
The discharges from the Mountaire Farms treatment facility is regulated by an NCDEQ
wastewater irrigation system permit. The discharge is to sprayfields owned by Mountaire Farms
under Permit No. WQ0000484.
The Mountaire Farms discharge permit is effective March 8, 2018 through February 28, 2023
and allows the discharge of industrial wastewaters as well as a 40,000 GPD domestic
wastewater treatment plant that also discharges to the storage lagoon.
The storage lagoon effluent as well groundwater monitoring is required to be done every April,
August and December, with annual monitoring conducted in December.
Refer to Appendix C for complete permit requirements.
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4.0 WWTP PROCESS DESCRIPTION
This section provides a process description of the on -site wastewater treatment units located at the
facility. Appendix D contains a simplified process flow schematic for the wastewater treatment
system. Appendix B contains Equipment Data Sheets for the major process equipment.
4.1 ACTIVATED SLUDGE SYSTEM
After the primary DAF units, the wastewater is pumped to the two MBBR tanks, which operates as
an aeration basin. In the aeration basin, the influent wastewater is continuously mixed with floc -
forming microorganisms in the presence of dissolved oxygen. The organisms absorb and biodegrade
the organic material as food for energy and for cell synthesis, via the following basic reaction:
Microorganisms
Organics + 02 + N + P 0 CO2 + H2O + New Cells
Organic removal (i.e., CBOD removal) occurs primarily in the aeration basin. The process is
primarily controlled in several ways:
1. Temperature
2. MLSS
3. DO
4. pH
5. Nutrients
The fundamental theory of activated sludge treatment is discussed further in Appendices E through
G, with specific applicability to Mountaire Farms discussed in Section 6.0.
4.2.1 Temperature
Aeration basin temperatures between 20°C - 38°C (68-102°F) is recommended. The MBBR basins
each provide a hydraulic retention time of approximately 4.25 hours at 2.55 MGD. The aeration
basin has a total volume of 903,000 gal (total both tanks), which provides approximately 6.77 hours
detention time at an average flow of 3.2 MGD, or gpd.
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4.2.2 Mixed Liquor Suspended Solids
Biological treatment occurs because of the microorganisms that biodegrade organic material into
carbon dioxide. A typical measurement for microorganism concentration is mixed liquor suspended
solids, or MLSS. This is defined as the suspended solids concentrations of the activated sludge in
the aeration basin, and consists of wastewater suspended solids and microorganism solids. A related
term called mixed liquor volatile suspended solids (MLVSS) is used for only the microorganism
concentration. A low MLSS concentration results in incomplete CBOD removal (i.e., high effluent
BOD). High MLSS concentrations can result in operational problems due to floating sludge,
foaming, etc. (i.e., permit violations).
For MBBR systems such as the one at Mountaire, parameters to monitor are Surface Area
Loading Rate (SALR in gBOD/D/M2surface area) and Surface Area Removal Rate
(SARR)(same units). For these calculations, the Entex design surface area is used (664,550 M2)
in both tanks.
For an MBBR type system, there is no solids control other than removal of "sloughed" off solids
from the media in both MBBR tanks. MLSS levels at the facility are monitored daily by sample
analysis of aeration basin TSS.
4.2.3 Dissolved Oxygen Control
The other critical parameter for aerobic treatment is oxygen supply to allow the microorganisms
to biodegrade the wastewater. Oxygen is supplied to the aeration basin by three blowers, which
discharge into a diffuser system in the bottom of both MBBR tanks.
As shown in Figure 1 (Appendix D), each tank has one aeration grid fed by one 18" air drop legs.
This allows multiple blowers to be used to supply air to the aeration basin. Air control is provided
by varying the number of blowers in operation, throttling the air supply, and by venting excess air
supply using the vent and manual valve. This is a coarse bubble diffused air system to minimize
diffuser fouling or rupturing causing uneven air flow. Aeration control is important from an energy
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cost standpoint (since excessive aeration wastes energy), and from a process control standpoint.
Inadequate DO (i.e. DO <1.0 mg/1) can encourage the growth of filamentous organisms (causing
sludge settleability problems), odor and limit nitrification. Over -aeration can result in high DO
concentrations, foaming, also floating sludge and excessive energy costs.
The aeration system in each basin should be operated to maintain 2-3 mg/1 DO in the aeration
basin, based on spot measure using field instruments and the automatic DO probe in each basin.
A DO concentration >3 mg/1 can result in foaming as well as excessive energy costs.
4.2.4 pH
For optimum biological growth, it is necessary to maintain a consistent pH in the aeration basin
mixed liquor between 6.5 and 8.5 standard units. If the pH deviates significantly from this range,
the biological organism growth can be inhibited, resulting in an upset of the system. The DCS
system continuously monitors and records each basin pH. The pH in the aeration basin must be
manually checked with a portable probe to ensure that the pH control is working properly. It is also
necessary to periodically clean and check the calibration of the pH monitoring probes.
4.2.5 Nitrogen and Phosphorus Addition
The Mountaire Farms wastewaters typically contain some nitrogen and phosphorus. Based on the
CBOD5 content of the wastes it is anticipated that an average of roughly 50 to 75 lb/day of nitrogen
and 13 to 26 lb/d of phosphorus will be required to satisfy the nutrient requirements in the aeration
basins (This is based on a CBOD5 load of 2,600 lb/d, a nitrogen requirement of 2 to 3 lb/100 lb of
BOD5, and a phosphorus requirement of roughly 0.5 to I lb/100 lb BOD5). It appears that the
nitrogen and phosphorus content in the wastewater is typically sufficient to support the required
biological nutrient requirement. When needed, nitrogen or phosphorous is added manually.
Phosphorus addition is not typically performed.
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4.3 SLUDGE HANDLING
4.3.1 Clarifier Operation
After biological treatment, the aeration basin mixed liquor (wastewater and microorganisms) is
sent to the WWW DAF. A DAF uses recycled effluent with entrained air to "float" solids for solid
removal. The effluent from the clarifier is discharged to the lagoon. Sludge is currently drained
to three 20,000 gallon Frac tanks for land application.
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5.0 OPERATIONAL AND PROCESS MONITORING
5.1 INTRODUCTION
Effective operation of the Mountaire WWTP requires the performance of the WWTP to be monitored
and this information is used for plant operation. To best utilize this information, the plant operating
staff should have knowledge of the treatment plant process status.
The essential elements include operational monitoring, analytical monitoring, and process control.
An operations logbook should be maintained at the WWTP to record and keep track of operational
and analytical monitoring data. This information is used as the basis for process control and will
help to identify problems, or potential problems, so that corrective actions can be taken. Appendix
F contains descriptions of laboratory tests that can be used by operations to diagnose problems.
Appendix G discusses sample collection and handling. Appendix H discusses detailed process
control strategies for organic loading and sludge settleability.
5.2 OPERATIONAL MONITORING
At the start of each day, the operator should review the WWTP overall control screen, most recent
analytical results, and logbook to identify any potential problems. An operations logbook should be
used to document visual inspections and data, and to record problems, or potential problems, that are
observed. An inspection of the physical WWTP components should be conducted at least twice per
shift. Equipment exhibiting excessive wear, unusual noise, or other conditions that could ultimately
impact process performance. In addition to the logbook, the supervisory control and data acquisition
(SCADA) system can trend continuously monitored data. This information can help to diagnose
current issues as well as forecasting potential future malfunctions in the system.
To summarize, operational monitoring includes:
• Visual inspections of the WWTP components;
• Routine equipment checks;
• Review of the SCADA system; and
• Review of performance monitoring data.
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Biological response to a variation in system control is not instantaneous, so the operator must
monitor operational trends of the system to anticipate problems. Appendix F contains descriptions
of analytical tests that can be used by operators to diagnose problems. Appendix G discusses
sample types.
5.3 SYSTEM CONTROL
The WWTP is controlled using two (2) programmable logic controllers (PLC). Each PLC
communicates directly with a panel mounted computer that operates both a human machine
interface (HMI) for operator control and the SCADA system for data trending. Data that is
monitored by the PLC is continuously recorded by the SCADA system. This data can be reviewed
by the operator at any time. System motors and instrumentation, with exception of the primary
and secondary DAF chemical feed systems, communicates directly with a PLC. In general, the
PLC communicates run commands, motor speed adjustment, stop commands, and alert/alarm
conditions which is then displayed on the HMI. The control system also allows for manual
operation both at the device and through the PLC.
Each device continuously displays current operating conditions on the HMI. HMI screens are
described in additional detail in the following sections. Figure 5-1 illustrates the overall system,
as shown on the HMI. The control system is comprised of the following major process screens:
• Equalization
o Flow Equalization Basin (FEB) aerator
o FEB level
• Dissolved Air Flotation (DAF) Primary Treatment Settling
o DAF A (pump operation, flow)
o DAF B (pump operation, flow)
o DAF C (pump operation, flow)
o DAF D (pump operation, flow)
o DAF E (pump operation, flow) — spare pump
• Post Primary Settling Pumping Station/Above Ground (AG) Sump/Former Clarifier
o Liquid Level
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o MBBR Feed Pump No. 1 (pump operation)
o MBBR Feed Pump No. 2 (pump operation)
• Biological Treatment
o MBBR1 o MBBR2
■ DO ■ DO
■ Level ■ Level
■ pH ■ pH
■ Temperature ■ Temperature
■ Air Scour ■ Air Scour
■ Blower ■ Blower
■ Pinch Valve 1 & Flow ■ Pinch Valve 2 & Flow
o MBBR Spare Blower with actuating valves
• Secondary Treatment Settling
o Secondary DAF Flow
o Sludge Hopper Level
o Sludge Transfer Pump 1
o Sludge Transfer Pump 2
• Frac Tank Levels (Sludge Storage)
o Frac Tank 1
o Frac Tank 2
o Frac Tank 3
• Lagoon
o Level
o Lagoon Influent Flow
From the main HMI screen, the operator can access each equipment control screen by touching the
icon, or can access alarms, interlocks, trending data, and other screens using the drop down menu
(see Figure 5-2).
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Figure 5-1: Main SCADA Screen
ijq+ K4—r*— r.,,,,. - L. — Ccd Q+
r.l .Y kNsr: li�rt _
KeYShane i
7.77 7,
now EQ Errin ��] Y 1-IY . {F 4Y.� i . l
Figure 5-2: Drop -down Menu from HMI Overview screen
Aw
r r Lvm
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.:•nlrx ---
A!J•rlll L'•.ei&_
''A ::t�s - L'RF Pumps.
.al r .�q 91"ers
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Flay. ToUls2
ETIpsrr ad Tlnra klalors I
Elatsed T]rl a N%tafs 2
EIn;X+edTrrrkr MWei!� 9
Trend - Dhf Flow
Tmnd - Flan
Trend DO
Trend WBBR i
Trend - MOOR 2
Trend -MF1HR rhyw
'rand T$ryk
.-i�ird t �f ,%Ak'S
Mend yuslom
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ai-Id. uJ.�
hto.m GFOUFrd 9lrr!p �
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hw wsr
6 AF A FLU W Totem
nAFaFLn-l txd
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Ln%.r HU W I"
FFa: T .Ik 1 F7a:
rat 7
[w rk... NvLp l
ftwh
Fra Ta.k 7
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5.3.1 Equalization and Wastewater Feed
Process wastewater flows to the FEB (T-1201) via a gravity sewer. The tank is equipped with an
ultra -sonic continuous level sensor (LE/LIT 1301). The FEB is also equipped with a surface
aerator/mixer (E-1401).
5.3.2 Operations
The Equalization Basin level is continuously monitored which is used to control the flow to the
primary DAFs using the DAF feed pumps. The PLC adjusts the speed of the pumps - as the level in
the EQ basin increases, the flow rate to the DAF increases.
5.3.2.2 Alarms and Troubleshooting
Figure 5-3 shows the EQ Basin (FEB) level configuration screen. There are warnings and alarms
for low and high level, which are adjustable by the operator. These alarms are interlocked with the
DAF Feed Pumps (following section), and flow rates to the DAF are linked to the level in the EQ
basin, increasing the desired flow rate as the level increases. These rates can also adjustable by the
operator (see Figure 5-4). Figure 5-5 shows the EQ Aerator screen which includes a motor fault
alarm. The aerator operation (on/off) can be controlled remotely by the PLC.
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Figure 5-3. EQ Basin Level Configuration
EQ Basin Level Configuration
cLayunit VdlhPL. EU Mln UP Mdde ❑MF.LA
Level
Level Ad Fault 01sable
Figure 5-4. DAF Flow Setpoints
DAF Fiow Setpoinis
F71aw 5t*LLiu rl fdamdl F3ow S(Apuint AL(udl Ruw SLtpuird Current Fluw
Funluut�
. 1 1
DAFA
Pump U
Auke ,�
UfiF tf
f'lilllp0
Atito I
DAFC
rli Imp n
Auto
liFlF U
F't 111ll l
Auto_]
Au#anatic
I lUff bLAPolflt ` R11 S.U-?JJ4' 1 P
Automatic
Ekxw suipail It - FEB 5.13-7V
Purtarnatic Plow !�etpaint - FkH Over MY . 1
LUl FLO Low 1 arxunq DAI F'S#M5 UA,DIL will sh m down. UN PUMP A caidnues to run an Dow setuolnt.
Unce FE13 Law Wa"rx] is cleared ail purrps will restart art normal flaw setpdmt.
FEB Low 1061,arn419 dims autorl1ii3U(.aIN bj- cerl 4N1 FEB tow i-inilPig dexitaiA.
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E4 Dmin Aermox
R44 ropp S 5 AdAa
i
rain
5.3.3 Primary DAF System
Figure 5-5. EQ Basin Aerator
EQ Basin Aerator
Motor Fault J: n1sahlr3
AUrnY 11f a.
The primary solids removal system consists of four (4) primary DAFs (DAF A; T-2201, DAF B; T-
2202, DAF C; T-2203, and DAF D; T-2204) for solids separation, and their associated feed pumps
(Pump A/P-1402, Pump B/P1403, Pump C/P-1404, Pump D/P-1405, and Pump E/P-1406 which is a
standby swing pump).
5.3.2.1 Operations
Primary control of the feed pumps are controlled via the PLC, however each DAF tank has its own
remote VFD which can also control the feed flow. Figure 5-4 shows the DAF flow setpoint
configuration screen. Flow setpoints to each DAF can be set to Auto or Manual mode. In auto mode
the PLC adjusts the speed of the pumps based on level ranges in the FED set by the operator. In
manual mode, the operator sets the speed the PLC should run the pump. However, in manual mode
the PLC will not monitor level to adjust the pump speed unless the FED low level alarm is triggered.
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5.3.3.2 Alarms and Troubleshooting
Each DAF has its own flow configuration screen. Figure 5-6 shows a DAF flow configuration screen
A, typical of the screens A-D. This screen shows the setpoint for each DAF, as well as the flow rate
alarms. Figure 5-7 shows a DAF feed pump control and alarm screen, typical of Pumps A-E. Figure
5-8 shows the DAF pump interlocks, which can be triggered by high or low flow, VFD fault, FEB
level, or Treatment PLC Control Power Loss.
i - DAF RA Q
Figure 5-6. Primary DAF Flow configuration screen (typical of A-D)
Primary DAF At Flow Configuration
Curren[ Value EU Min EU r
Flow � M
10 Flog AI Fault _ Disable
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Figure 5-7. Primary DAF Feed Pump screen (typical of A through E)
Primary DAF Pump A
I P fnreFy DAr Primp 1 I MQt0F F9u11 Qlgr�hl
routocoFvtrol nlgahl -
Run Slap
r 01
Faut F20loContiol
AfdnFrDiday�
Alrtnmatlr rnM nk
EQ Bdsiry LeMel DAF A Ruw
Nurllla SPA• l
I and Rift
hILLw sirtpaiFi[
F$eFnli inq
Figure 5-8. DAF Pump Interlocks
,}$ r.—,.lum=rrPrncr
-or Ww
--
� N.
IlrneLC l
Alain ComFrent
f:4k3-,J1 -09:1t525
MmegruwSump Law A.3rm AG LA
R LI�I f AJ rIII
F'h F7B Jae',] -fa I'1a5
'
itY fNl31 r.".11 LC SIII 7j IfJ1 VS'rnlnj f4C_iL
9lkrro- ALba'ulud c
.. •,•• { .: Oisprvirq l In 2 ad 2 zkr ][huL 14; 7, {o-�pkre Fielcm T:rt NS {rNdX7
DAF Pump- rnterloclis
DAF PLnila A
DA: PLlrrp D
OAR- Purrp C
I wlll Irll rrL rick
I Ixl.l IIlr.wil.lr
Fb.l Inl..i. 6.
None
NDnv
FIOFrc
Auio Jniwiattx
Puts lntwk[ki
Auto Jntorlacica
11 III nw lrwi W—rin.q16
rlrlr—l—.4w..ir j
MVA Ho Flow Marm DAFBFegLF1uw ALrm � Eu FC Hgh Fbw ALam
I AI rRy thne AlArm Ivu tl: iw. I ih,V Akvgl IMI IMIN INW AUM
DAF Punp, A VFD FSult DAF rVrQ a VW Fait DAF Pump C 4FL Fault
r—L—L PLC D.r I t r ui FLu, L,-- T.r.LIIr IIL PLi{Ne'rti PLH.r Lucy T—ulrli PLC ClydnA PLI.riff- LIm
DAF PLFrwi D
raL.w
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M LL Lmvi SVnwlird
DM D 1-10I Flory !dorm
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OnF D NqbFkrw Aldo
MUD Law %w ALnII 40
OAF PWW E VM Fa{it
Tr tmmnt rms F.Irrrd P�xor uL
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5.3.4 Post Primary Treatment Pumping Station
Primary treated effluent flows to the Above Ground Sump, T-3201, by gravity.
5.3.4.1 Operations
The level in the Above Ground Sump can be used to determine the operation of the MBBR feed
pumps, MBBR PI and MBBR P2. Figure 5-9 show the Above Ground Sump level configuration,
where the operator can set the levels for alarms. Figure 5-10 shows the MBBR P1 pump control
screen, which is typical for MBBR P2, shows the level setpoints used to control the operation of the
MBBR Pumps. Figure 5-11 shows the MBBR pump alemation screen, which allows the operator to
select which pump to be lead/lag, or let the PLC control lead/lag alternation automatically. Figure 5-
12 shows the MBBR interlocks, which includes MBBR pump interlocks with the above ground sump
level, pump VFD faults, and treatment PLC control power loss. Additionally, the MBBR related
interlocks include Pinch valve interlocks with the MBBR pumps, and for the Blower PLC
communication (discussed in the following section)
Figure 5-9. Above Ground Sump Level Configuration
� " AG Sump Cwdig
Above Ground Sump Level Configuration
arrent value EU I41n EU w7ax ❑Fisel
Level
14 Level All Fault �7 Disable
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Figure 5-10. MBBR Pump 1 (typical of MBBR P2)
MBBR Pump I
wpRR Pnnip I
Motor Fault :7 disable
'
6. motor Fam to Contror Cisahr�
Run Slop
55 AnLo
Fault Fail to Contol
Marne mayRewt
MRM PlmyL I Ar7 iuNi'mmik rnntmis
CAGdump Lauel FMRR Pump L I eadPump
5FY-uLead
Pump Start Level �P`IUE k Punp 2 Lag
MPLmrM
FInp I mwl
Land Ref
Sump +inim Lrn Level
��Irr�f M,�,yj�rr�m Level
PAMO iR
YFr1'�fiL9nrniIfj�i�
VID hiaximwn Speed � Ai[murns
allon
Figure 5-11. MBBR Alternation
-I :, M,I
MBBR PumpAJterndd1un
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Figure 5-12. MBBR Interlocks
*U : 5 XJ'A" -W 10 25 •r.: SurIIN L uw iLr II • ••{j +_fiiI
. Hum
�YIIIY i.11LIY"JVi-9
FLrY�bann yr �i.. f•s-Ia_na7inirl:rlancl?Srlrll7 iir['!C
NMR IntEri&Cks
M PR I'lun1, I
H&d 3r1c1, cr4s
Y.F
Awi�n limnir«rki-ki
Jll1306-0&oLffk 0Mp LOW Lauol
Ilim—I}r—J !]idyl 1 YVYI ^rjwl F. r
VB DR Purr41 V DFau It
Ir1A.lrrrirll M I izwwr P*mm APi mr.
Pinch V-nlve 7
NCM
Allrto rntorkKRc
ran Fl+lryc.l lrr
etrwcr riG {.jwri Lass T� cacmcnl ME
h�1iPiR rnil4a't
�LCdQrbS
i1111N
AbMit GM ntl Sump Low LWM
Aliwnl fni 0niuljl ll-rwJ"ilji�d r—w
hEEC RAMP 2 VFD Fabil t
I rpxnT ff NI I:Imrah-A Pnmwt I Ilak
Pi'pull
Vakv-a 2
1 plAl Jill L\
horn
Auto lntorkXkc
VIIIIIll r I Ir
SiowQ PLL Comm Loss Im3tmvlt PLC
i If lrllPrir k AlrllP.AiVNI Arll Phwk5 VAW WFyl1 rim Yr3.
5.3.5 MBBR
,W. bPd--TimrMC—!,,%
The moving bed biofilm reactors (MBBRs) receive flow from the MBBR feed pumps MBBR P 1 and
P2. The flow to the MBBRs is balanced using Pinch Valve 1 and Pinch Valve 2. Two blowers, Blower
1 and Blower 2, provide aeration to the MBBR reactors, with a 3rd blower, "Blower Spare", providing
redundancy. Treated effluent from the MBBRs flows by gravity to the secondary DAF.
5.3.5.1 MBBR Operations
The flow to the MBBRs flow configuration can be balanced using the pinch valves. Figure 5-13
shows the MBBR flow configuration screen which provides flow settings to be sent to the Pinch
Valves, as shown in Figure 5-14. Aeration for the MBBRs are provided by the blowers, and scour
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air is controlled by Air Scour Valves 1 and 2. Scour air is used to clean the effluent screens and
prevent fouling. The PLC controls the scour air by activing a solonoid valve (on/off) for a timed
period, which is adjustable by the operator. If a high level is detected in the MBBR, then the PLC
turns on the scour air until the level is within a normal operator set range. Figure 5-15 shows Blower
and Blower Valve control and alarms. Figure 5-16 shows the air scour valve screen, where the
operator can input the air scour frequency. The MBBRs have several process parameters which are
monitored and used for automatic control of the MBBR blowers. Figure 5-17 shows a compilation
of the MBBR DO, level, pH, and temperature controls and alarms
5.3.5.2 MBBR Alarms and Troubleshooting
Blower alarms are shown in Figure 5-15. Process parameters alarms are shown in Figure 5-17.
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Figure 5-13. MBBR Flow Configuration (typical of MBBR 1 and MBBR2)
7 F I
MBBR 1 Flag Configuration
Flow
Flaw AI Fault _.. Disable
Figure 5-14. MBBR Pinch Valve (Typical of Pinch Valve 1 and Pinch Valve 2)
� FA[I$R?V3
MBBEZ Pinch Valve i
is
ME43R Pinch Valve Fail to Control
ALarnt DeEay � Reset
opened Closad Fall to Con;rel
A Kit Yal VL+S I K 1 AkAoilldriu Lix i 1rol1
Valve FIn%hinn rgnnn 1 11,, M9DR ;Flow
F1 j ® pllit h Va[ue 2 Posi�lan
4 Hand Position
l PNrnary %IBBR FM
BBR 1
Fltrrr wilt F t
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Figure 5-15. MBBR Blower 1 (typical of Blower 2 and Blower Spare) and Blower Valves
MBBR Clower i
7{un 5[vP SS Au[a
0 ##
Fault Fad to {lama! winPdirxg Inmp
10 0
P5H Tamp Hk
Pump SpaLd
ry.in H
418443
MRRP, Blower 1
Llca:Zr Fault i UFsablc
Motor Fail to Control I_I Disable
PSH 11 Ulsable
High Windinig Temperature ! Ds52ble
High Temperature ❑ Utsable
lriarmpelay PItps.r
Hlower 1 A>titomatir Lnntrols
MBBR 1 D4
Do se" nt
Illnwwr Start 7PFDOri
131D weer ntart ^peed belay r r
L.p Tine
P6 iwi Y % ilinmin i rit.rwJ t1Yr Prry kFw 0 R Ewkr dstlon k M Fb
r�flr� rh x
MBBR Rh3wer VaIvas
h�FR ] e�iuwr �NI4Y
MOM 1 [tower Y151:it2Ellowa Yale
Fall to Close fl LHsel51e
0 # ! Fail {a Dpen n Eissb1e
0) 01 — ----------
rEil In rLYM ri! Ni Ip. F*3 Hi fliuw rwil III n1wu Md.{'� lI mer calve
4 4 * 0
Fail to Close I I Di3011)
( ] .i L Fail W Open U �i5MU
j L J ?—
JLirn ISWLiq R.
Blowei V.I4ailftcruMtm Akw
Ilr;eri Wla Lttider Ernmrjamy Power Chrly
Altematlon Uw
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Figure 5-16 MBBR Air Scour Valves (typical of 1 and 2)
"FUR
MBFR1 All SmIm Valve
open
Close
I
MBBR i Air Scour
MT r.R 1 14 R[our Yawie Autnmalk Cnwrnk
*1 W i It vrl Dlulwarr 1 Rura Iirq
MInR 2 T.r Ik Id 1 rwrJ Nraranal 911wrrr'2 RumIrq
Fdnwrr .4k.W Rrnpr"
AF Eln Tine
Air 011 Tine r 1
Figure 5-17. MBBR Process Parameters and Alarms
Ica1 WIE$:it. dC—IF'�
HIBR Tank 1 Dlarwlwd Oxyr m Cunllgumtkm MBBR 1 Level Ganf gwrauoln
omr K4P" r1I min ENKM Un tY'Aw IiV .Wi to" L*Nn
IakroNrd OXYGErl I I Livrl _
Fait DISW16 9 LmiuFeum Cos it
145GR Tank E;aH fAnllglnr#lion M UR Tank 1 Tim paratur* CvOlgura•tion
pkl inem.r�5.11e _
PHAIFaWI I'.I'a^'^' TemPelahiehJFauK fisehk
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5.3.6. Secondary DAF and Sludge Transfer
The secondary DAF receives treated wastewater from the MBBR and removes secondary solids.
5.3.6.1 Secondary DAF Operations
The secondary DAF is controlled by its local PLC panel, but can be monitored in the SCADA system,
as shown in Figure 5-18. Clarified effluent from the secondary DAF then flows by gravity to the
aerated storage lagoon. Sludge from the secondary DAF is pumped to temporary Frac Tanks 1, 2 and
3, as shown in Figure 5-19. Figures 5-20 and 5-21 show the Sludge Transfer Pump screen (typical
of 1 and 2) and the Sludge Hopper Level screen, respectively. The Sludge Transfer Pump screen also
includes a link to the Sludge Pump alternation screen where the lead/lag pump can be selected or
controlled automatically.
5.3.6.2 Seconary DAF Alarms and Troubleshooting
Figure 5-18 shows the DAF Flow alarms. Figure 5-20 shows the Sludge Hopper Level alarms, and
Figure 5-21 shows the Frac Tank level alarms. Figure 5-22 shows the Sludge Pump Interlocks, which
can be triggered due to sludge hopper level, sludge hopper level signal error, or Treatment PLC
Control Power Loss.
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Figure 5-18. Secondary DAF Flow Monitoring and Alarms
r ' Sec PAf Q
Secondary DAF Flow Configuration
N Fri Tank 1 Config
- P�
Current value EU Mkq EU NqM
Flow � = _
Flow Al Fault Disable
Figure 5-19. Frac Tank Screen (Typical of 1, 2, and 3)
Frac Tank 1 Level Configuration
Ctwrent VakAe ou ?4n ou MM offset
Low*l = = =:1
10 Level Al Fault 0 Disable
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Figure 5-20. Sludge Transfer Pumps (typical of 1 and 2)
* �tudgtirer5iterPl--> -- �i
Sludge 'transfer Pump !
` F&Aigr, Tramfrr R irnp € mIrrJA by 5U.-71 O-1
Opel, Ckdxa
i ' Sludge HUpPer Confiq
sidgP TraniferPurny3 Aornmatlr rairrnk
ShadW Huppier Lewd
Pump rri $:iptpnlnt�
Pump UH Setpair t
Sludge Ir-amfer
Rfrnr�r,atir�n
AiWF. Tranwr PYinnp 7 CPArl
Figure 5-21. Sludge Hopper Level
Sludge Hopper Level Configuration
Et rrent VaJue EU Iwtiri [U Max ❑ffset
Level ® _ _
Level Al Fault E Disable
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f ilk f
Figure 5-22. Sludge Transfer Pump Interlocks
.�
�-,��•
®- %I I
GkpLiryAIE0-�0afp 21ilffR PNz,rt
..UT.{or+Glne=vw•llme {LS C.iW�r
Sludge Transfer Pump In telrlatlts
Traraer Pwip 1
Tremfer PLwr1p 2
fkrnlylt4'rliilirr
IL-r.l G l,,-6,ia
None
NMI!
Auto IrrtcrkrLY
/,oto ]rN WDLL%
'SY!F l lrrprr 11— 1-1
'A Arr I pp —I —1—A
SMgc Heppx Lcr.el Slglal Enrol'
ht jr. ftwr l rurl E;lgvl Errrrr
It0wlM1wri M I I
i—riir.il NI I' I iii.ni M—r 11v
5.3.7 Effluent Lagoon
Finally, both the flow to, and the level at the Effluent Storage Lagoon can be monitored and alarmed
as shown in Figures 5-23 and 5-24, respectively.
Figure 5-23. Lagoon Flow
LiuCUrt:1 I-c
Lagoon Flovf Conflguratlan —
k urrul-I V-11 . EU NIhi EU Malt
Flow
Mw AI Fault LL Otsable
Lagoon Flow Alarms
Setpoint Deadband
� F�i0h Alarrn r EJrSBble
High Warning �� Disable
Low Warning I E GE' Disable
'iLaw Alarm !� Disable
Dewy x 3erReSel
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Figure 5-24. Lagoon Level.
-agoen Levi
Lagoon Level Configuration
Wrrmt Va1w, Ell No" Fly Max offset
Level
10 Level Al Fault .. MC;able
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6.0 PROCESS CONTROL AND OPERATING STRATEGY
Effective operation of a wastewater treatment facility requires that the performance of the
system be monitored and recorded (as discussed in Section 5), and that this information then
be utilized for process control. As discussed (in Section 5), monitoring should include
observations along with sample collection and analyses. Process control involves an on -going
assessment of the operating conditions and performance of the individual treatment units, and
control of the process through adjustments to the system.
Section 6.1 includes process control parameters and procedures which apply to moving bed
biofilm reactor activated sludge systems. This section is a short summary intended to provide
operators with background.
6.1 ACTIVATED SLUDGE PROCESS CONTROL
The primary parameters which affect the biological process performance in activated
sludge systems include:
• Organic load SALR (surface area loading rate) and SARR (surface area removal rate);
• MLSS and MLVSS concentration;
• DO;
• temperature;
• pH;
• Nutrients;
• Clarification; and
• Sludge settleability.
Table 6-1 summarizes the primary process control parameters. Inadequate control of any one
of these parameters can result in poor performance. Organic loading and settleability is also
discussed in greater detail in Appendix G.
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Table 6-1: Summary of Process Control Parameters
Parameter
Two Basins
Organic Load:
SALR g/M 2/d
19-22 design
SARR g/M 2/d
16-18 design
MLSS/MLVSS
Monitor
Dissolved Oxygen (DO):
1-2
pH
6.5-8.5(1)
Temperature (°C)
20 35
Nutrients Effluent Residuals (mg/1)
NH3-N + NO3-N
(2)
Total P
(2
Final DAF
Rake Speed
>0.5
Notes:
(1) Preferred pH range is 7.0 to 7.5.
(2) Nitrogen and phosphorus is typically present in wastewater in adequate loadings for treatment.
6.1.1 Organic Load (SALR, SARR)
For an MBBR process, organic loading and control is calculated differently than for a typical
activated sludge plant and is dependent on media -specific values obtained from the media supply
vendor.
The key empirical design parameter used to determine the required MBBR tank size is the
surface area loading rate (SALR) in g/m2/d. The g/d in the SALR units refers to the g/d of the
parameter being removed and the m2 in the SALR units refers to the surface area of the carrier.
Thus, for BOD removal the SALR would be g BOD/day entering the MBBR tank per m2 of
carrier surface area. For a nitrification reactor, the SALR would be g NH3-N/day entering the
MBBR tank per m2 of surface area. Finally, for denitrification design, the SALR would be g
NO3-N/day per m2 of carrier surface area.
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For any of these processes, a design value for SALR can be used together with design values of
wastewater flow rate and BOD, ammonia or nitrate concentration, to calculate the required
carrier surface area in the MBBR tank. The design carrier volume can then be calculated using
a known value for the carrier specific surface area (m2/M3). Finally, a design value for the
carrier fill % can be used to calculate the required tank volume.
For this media, the surface area is 589 m2/m3. Each tank has a 32% carrier fill volume, for a
total calculated carrier surface area of 664,600 m2. These calculations are as follows:
BOD loading rate (g/day)=Q*S *8.34 *453.59
Where:
Q
Wastewater flow in MGD
S
Influent BOD in mg/L
8.34
Converts mg/l to lb/MG (weight of water)
453.59
Converts lb to g
Surface Area Loading Rate (SALR):
SALR (g/m2/d) = Q*. *8.34 *453.59/SA
SA = Aeration basin surface area m2 = 664,600 m2 (both reactors)
From design, SALR to be less than 22 g/m2/d per reactor (i.e, below design values)
Surface Area Removal Rate (SARR):
Where:
SARR (g/m2/d) = Q * (So Se) * 8.34 * 453.59/SA
So = Influent BOD (mg/1)
Se = effluent BOD (mg/1) at basin outlet
SARR to be 16-18 g/m2/d or more per reactor (i.e., above design volumes)
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6.1.2 Mixed Liquor Suspended Solids, Mixed Liquor Volatile Suspended Solids
Common biological parameters such as Mixed Liquor Suspended Solids (MLSS) and Mixed
Liquor Volatile Suspended Solids (ML VSS) are not typically utilized in MBBR type plants.
Aeration basin TSS (MLSS) and MLVSS should be periodically monitored as a tool to identify
large accumulated sludge sloughing off of the media to identify process or biological changes
(i.e., stressed treatment plant or toxic shock). Volatile suspended solids are defined as the portion
of MLSS that can be burned off, i.e., organic, thus is taken to be an indication of the biological
portion of the Mixed Liquor (Aeration basin water).
6.1.3 Dissolved Oxygen (DO)
For proper biological treatment, the control of the dissolved oxygen (DO) within the aeration
basin is extremely important. For the Mountaire MBBR, the aeration grid is across the entire
tank, so typically there will be good distribution of air across the basin. Dead areas or areas with
high release of air could be indicative of clogged or broken air piping.
It is important to maintain a DO of at least 1 mg/1 throughout the aeration basin. To ensure
aerobic activity in the basin, maintaining a DO level of 2-3 mg/l in the basin is preferred. Too
high a DO level promotes foaming in the aeration basin.
Certain types of filamentous organisms compete when very low DO occurs in the presence of
available influent organic matter. This affects solids settling and effluent TSS, as well as effluent
BOD levels, since there may not be enough oxygen to degrade the incoming waste load.
Maintaining a DO concentration >1 mg/1 throughout the basin provides the maximum protection
against low DO filaments. DO data should be reviewed daily and corrective actions taken when
DO levels fall outside the desired levels.
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6.1.4 Temperature
For the activated sludge system the minimum temperature should be maintained at or above
201C and not be allowed to exceed 40°C (104°F) in order to avoid upsets due to overheating of
the organisms. Significant day-to-day variations in both pH and temperature should be
minimized as much as possible to avoid shocking and upsetting the biological process.
6.1.5 pH
As indicated in Table 6-1, the pH should be maintained between pH 6.5 and 8.5 at all times. pH
levels outside this range can cause significant process upsets. If the pH strays out of the 6.5 to
8.5 range, it should be adjusted into this range as soon as possible. In the activated sludge system,
to promote good process performance it is desired to maintain the pH between approximately
7.0 and 7.5 on a consistent basis to allow nitrification to take place (ammonia converted to
nitrate).
The pH levels in each aeration basin is monitored by the operators. pH is a particular concern
with regard to nitrification because the nitrification process depletes alkalinity and tends to lower
the pH. This is not typically an issue in this plant. Nitrification (ammonia oxidized to nitrate)
can be inhibited at basin pH levels greater than 7.5.
6.1.6 Nutrients
Adequate nutrients are needed to grow the desired types of organisms and ensure good sludge
settling. When nutrients are inadequate, BOD5 removal and solids settling may suffer and there
can be excessive foaming in the aeration basin. Nutrient deficiency problems are well -
documented causes of filamentous bulking and zoogloeal (slime) problems.
The primary nutrients of concern are nitrogen (N) and phosphorus (P). The adequacy of the
available nutrients can be assessed either by the influent NH3-N and soluble PO4-P, or the
effluent residual N and soluble PO4-P.
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The form of the phosphorus is critical to affecting the availability of it as a nutrient. Phosphorus
tied up in a solid or condensed form will not be readily available to the microorganisms.
Therefore, soluble phosphorus (ortho-phosphate or soluble PO4-P) is the parameter of concern.
Theoretically, for each 100 mg/l of BOD5, the microorganisms need 5 mg/1 nitrogen and 1 mg/1
phosphorus. In practice, this demand is typically about 2 to 3 mg/l nitrogen and 0.5 to 1 mg/1
phosphorus per 100 mg/l of BOD5. The quantity of each of these nutrients required is dependent
on the organic load. An estimate of the required influent NH3-N and soluble PO4-P can be
obtained from the primary influent BOD5 as follows:
NH3-N Required = Influent BOD5 (mg/1) x (2 to 5)/100 Soluble PO4-P Required =
Influent BOD5 (mg/1) x (0.5 tol)/100
The calculation based on the influent loads provides a rule -of -thumb estimate of nutrient
requirements. This can be confirmed by monitoring residual nitrogen and phosphorus levels in
the treated effluent. Generally, an NH3-N concentration of 1 mg/1 or more or a combined NH3-
N plus NO3-N residual of 1 to 3 mg/l is considered adequate. An effluent soluble PO4-P
concentration of 0.5 to 1 mg/1 or more is normally considered adequate.
Mountaire Farms typically does not add either phosphorus or nitrogen. Phosphorus, if needed,
will typically be added as phosphoric acid.
6.1.7 Clarification
Clarification is a critical part of the activated sludge process. Poor clarification performance can
cause poor effluent quality due to solids carryover, and in severe cases can cause a significant
loss of MLVSS from the system. For an MBBR type system, the performance of the biological
treatment process is NOT dependent upon successful separation of biological solids as an MBBR
does not return sludge for solids control.
The performance of the clarifier is primarily influenced by:
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• Influent flow;
• MLSS;
• sludge settleability; and
• sludge blanket level.
Process monitoring of the clarifier includes:
• visual observation of clarifier overflow and surface;
• measurement of sludge blanket levels;
• sludge settleability (using the sludge volume index (SVI) test);
• Sludge suspended solids;
• effluent TSS; and
• sludge wastage rates.
The DAF should be observed daily for surface scum buildup and effluent clarity. If a buildup of
scum occurs, the operator should first observe the skimming system to determine if it is operating
properly. If it is not, then appropriate adjustments and cleaning should be implemented.
6.1.8 Sludge Settleability
As discussed in the previous section, sludge settleability has a significant impact on clarifier and
overall system performance. Sludge settleability is a major concern in the activated sludge
process. Sludge settleability can be impacted dramatically by various process control parameters.
Improper process control and/or shock loading conditions often result in sludge settling
problems. However, even with vigilant process control, some systems are more prone to bulking
due to influent characteristics and various process factors. Sludge settleability can be checked
using the sludge settleability test described in Appendix F. This is applicable even with the use
of a DAF to float sludge. Even in an MBBR system that does not rely on return sludge, solids
removal at the secondary DAF can be important to prevent discharged solids impacting effluent
quality.
SVI (sludge volume index) is a good indicator of sludge settleability when used in conjunction
with observation of the solids settling in the clarifier. Microscopic examination is a very useful
tool in assessing the health of the biological system, and can be a particularly valuable tool for
diagnosing the cause of settleability and other problems. Any change in sludge quality observed
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in these tests will provide the operator with information necessary to make process adjustments.
Appendix H discusses some of the common causes and remedies for sludge settling problems.
The four major sources of sludge settleability problems are discussed in general below. These
are: (a) filamentous growth, (b) denitrification in the clarifier, (c) carbon dioxide release in the
clarifier, and (d) extracelluar polymers.
6.2 POTENTIAL OPERATING PROBLEMS AND CORRECTIVE ACTIONS
The performance monitoring data are one of the operator's primary controls in maintaining the
effluent quality within the discharge criteria. The biological response to an input variation is
not instantaneous, so the operator must monitor the operational trends of the system to
anticipate major problems.
To promote data review and trend evaluation, the monitoring data should be organized in
formats that allow easy review and evaluation. Monthly data summaries and chronological plots
are recommended to improve data handling.
A chronological plot of the operating data is a basic tool for summarizing performance
monitoring data. Typical parameters to be analyzed on the chronological plot are summarized
in Table 6-2. Not all of these are routinely monitored at Mountaire Farms.
Major changes in wastewater characteristics should be evaluated to determine if deterioration
of effluent quality is occurring. If so, the cause should be determined and corrected prior to
the catastrophic decline of WWTP performance. The troubleshooting guide is provided in
Section 7.0 to assist in corrective actions.
Trends in the oxygen uptake, SVI, TSS of the SVI test supernatant and microscopic
observations can identify problems early so that corrective actions can be taken before
significant impacts to effluent quality occur. These tests can also be used to identify process
control conditions that are most favorable to the health of the microorganisms. Specific problem
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conditions such as filamentous bulking, pin floc, etc. can be identified from SVI and
microscopic examination, which help to identify corrective actions.
Table 6-2: Recommended WWTS Data for Trending
Location
Parameter
COD
INFLUENT
BOD5
TSS
SARR
AERATION BASIN
MLSS (if needed)
02 Uptake
SVI
COD BOD5
DAF EFFLUENT
NH3-N TSS
This section provides a discussion of common operating problems, how to avoid them and
corrective actions. In addition to this section, the operator can refer to the troubleshooting guide
(Section 7) of this report.
6.2.1 Filamentous Bulking
Poor settleability due to filamentous overgrowth is a common problem in activated sludge
systems, and is most often caused by inadequate nutrients, low DO, or low F/M (see Section
6.1.8.1). However, poor settleability is not always caused by filaments.
Microscopic examination of a sludge sample should be performed in order to determine if
filamentous overgrowth is the problem. Note that some filaments are present even under good
operating conditions. Conducting routine microscopic exams of the sludge under normal
operating conditions will help the operator to recognize when excessive filamentous growth is
present.
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Recovering from filamentous overgrowth generally involves diagnosing and correcting the
cause of the filamentous growth (if possible) and monitoring the system closely to make sure
the proper operating conditions are being met (particularly DO, nutrients and F/M). Polymer
addition (or increased polymer dosage) upstream of the clarifiers may be necessary to avoid
solids carry-over from the clarifiers. As discussed in Appendix G chlorine addition to the RAS
can also help to control some types of filaments. This is difficult to do with an MBBR system.
6.2.2 Shock Conditions
The activated sludge system can become shocked for a variety of reasons. Signs of a shock
or other system upset include:
1. Loss of nitrification;
2. Poor Settleability;
3. Reduced oxygen uptake;
4. Excessive Foam formation;
5. High turbidity effluent;
6. Increased aeration basin TSS; and/or
7. Reduced organic removal.
Nitrifiers are generally more sensitive than the other organisms to upsets. Again, this is not
an issue for Mountaire Farms.
Some of the common factors that could potentially upset the activated sludge treatment
systems include:
• Slug Loads;
• Cold temperatures;
• Low DO;
• pH extremes; and/or
• Excessive TDS or abrupt TDS change.
A slug load of a toxic material can upset the system. In addition, a high strength slug of a
routinely treatable waste can shock the organisms. This is because the organisms are exposed
to much higher concentrations of the material during the slug load conditions than under normal
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operation. High oxygen demands from a slug load can also cause low DO conditions.
Cold temperatures can cause a slow -down in biodegradation, which can trigger an upset in the
activated sludge system. Slow -down in biodegradation kinetics can cause influent constituents
to build up to toxic levels in the mixed liquor. This can cause a toxicity impact on the
organisms in addition to the shock of cold temperatures. High temperatures will also cause a
slow down in biodegradation, which can trigger an upset. This will be due to the shock to the
organisms. With proper blending and control it should be possible to maintain sufficient
temperatures in the aeration basin (20 to 35 °C) to prevent significant slow -down or upsets
related to temperature.
pH extremes can also cause a process upset. The aeration basin should function reasonably
well in the pH range of 6.5 to 8.5 with the preferred range of about 7 to 8 in the aeration
basin. pH levels significantly outside the 6.5 to 8.5 range can cause a process upset. The
degree of upset is typically proportional to the magnitude of the deviation outside the 6.5 to
8.5 range and the length of time these conditions occur.
The pH of both the aeration basin are controlled by controlling the influent pH. Possible factors
that could cause the pH to go out of range include:
• Failure of acid or caustic feed equipment;
• Improper pH control settings;
• Alkalinity consumption from degradation of some organics; and/or
• Alkalinity consumption from nitrification.
The biodegradation process for some constituents consumes alkalinity. Therefore, slug loads
of certain wastes could cause a pH drop. The nitrification process also consumes alkalinity.
Note that the denitrification process restores some of the alkalinity lost in nitrification.
Therefore, a loss of denitrification can result in a pH drop. pH fluctuations due to nitrification
or denitrification are not issues for Mountaire.
In general, steps involved in recovering from an upset includes finding and correcting the cause
of the upset (if possible), and increased monitoring and careful control of process parameters.
This should include monitoring of the normal process control parameters such as DO, pH,
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temperature, SVI, etc. Frequent microscopic evaluation and oxygen uptake tests can be helpful
in assessing the health of the organisms.
Where upsets have caused settleability problems, it may be necessary to add polymer (or
increase polymer dosage at the secondary DAF). In severe cases, in which there has been
significant organism die -off, as evidenced by very low oxygen uptakes, it may be necessary
to consider reseeding of the system.
6.2.3 Clarifier Solids Carryover
Excessive carry-over of suspended solids from the DAF can result from a variety of
conditions which may include:
• High sludge blankets;
• Poor settleability;
• Hydraulic Overload (High Flow); and/or
• Solids Overload.
A high sludge blanket level may merely be the result of improper control of the DAF skimmer
speed or chemical feed issues. When degraded settleability occurs, this can result in problems
controlling the sludge flow.
High flows increase the solids load to the DAF and increase turbulence, increasing the
tendency for solids to overflow. At excessive flows it can be difficult to control sludge
blankets and prevent solids loss. Also, as the MLSS increases, this increases the solids loads
to the DAF, making it more difficult to control sludge removal. Generally, there is practical
limit as to the maximum MLSS a system can carry without causing difficulties in DAF
operation.
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7.0 SYSTEM TROUBLESHOOTING GUIDE
This section provides a general troubleshooting guide of common problems that may occur in
the treatment system. Every wastewater treatment system, particularly biological systems, have
different tolerances to similar problems and respond differently. Therefore, the troubleshooting
guide should be used carefully when examining the symptoms and implementing the
recommended corrective actions presented in the guide.
This troubleshooting guide is divided into five sections: problems, sequence of action,
cause, operator corrective action, and supervisor corrective action. The problems are listed
from the plant operator's perspective as to how they would recognize that the problem
existed.
The sequence of action column contains a sequence of action for determining the problem's
cause. The sequence is in order of increasing difficulty in identifying and/or solving the
problem. Simpler solutions should be attempted first. The intent is to follow the steps until the
problem is confirmed and the solution is successful in correcting the problem. There are some
cases in which all of the number steps under an alphabetical subsection should be performed.
These are noted on the troubleshooting table. For example, see Section I. A Steps (1) and (2).
This is to indicate that both (1) and (2) should be completed before stopping, even if the
problem is believed to have been found in one of the first steps.
The "Operator" and "Supervisor" Corrective Action columns are separated in order to
convey different actions which might be required.
Instructions to notify supervisory personnel are included where most important. However,
most problems covered in this section should be reviewed with supervisory personnel, when
they occur, to ensure that they are adequately resolved. In any event, when a problem is
identified and a solution attempted by the operator, the daily log should reflect the problem
as defined by the operator, the apparent cause, the corrective action taken by the operator and
the response of the system to the action over time.
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TABLE 7-1
DAF SYSTEM TROUBLESHOOTING GUIDE
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTION ACTION SUPERVISOR
CORRECTIVE ACTION
1. DAF Recycle Pump 1. Excessive air intake A. Check that rotameter airflow reading is within
Pressure Unstable/ recommended range.
Pump Abnormally Noisy B. Check that rotameter float is not stuck, giving
a false reading (w/ normal operation, the rotameter
float will bob up and down slightly). Tap the
rotameter with your finer and flush with soapy, hot
water if needed.
C. Check that there are no air leaks and/or loose
tubing connections
D. Check that o-rings in unions on both sides of the
educator are present.
2. Low back -pressure Check that pressure gauge at pump and DAF header
reads within recommended range. If pressure is too
low, air will not stay dissolved in stream. Pressure
is increased by throttling the air injection valves at
the DAF header.
3. Damaged/clogged impeller Check impeller for signs of damage, often caused by:
-chemical attack
-large/abrasive solids in the recycle stream
-pitting caused by pump cavitation
4. High Water Temperature Air solubility decreases steadily as water
temperature increases. A water temperature of 150
deg F will have about half the capacity for dissolved
air compared to a water temp of 65 deg F.
5. Recycle line intake If the butterfly valve or piping of the recycle line is
throttled/clogged not allowing full flow to the pump, this will cause an
excessive amount of air intake through the educator
6. No process water If the butterfly valve or piping of the recycle line is not
flowing through DAY allowing full flow to the pump, this will cause an
excessive amount of air intake through the educator
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TABLE 7-1
DAF SYSTEM TROUBLESHOOTING GUIDE
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTION ACTION SUPERVISOR
CORRECTIVE ACTION
2. Not Enough 1. Reduced air intake A. Check that rotameter airflow reading is
Dissolved Air in DAF: within recommended range.
B. Check that rotameter float is not stuck,
giving a false reading (w/ normal operation, the
rotameter float will bob up and down slightly).
Tap the rotameter with your finer and flush
with soapy, hot water if needed.
C. Check that there are no air leaks and/or
loose tubing connections
D. Check that o-rings in unions on both sides
of the educator are present
2. Air Loop piping A. Check air like for clogs
clogged/throttled B. Ball valve on the lower end of the doctor must
not be throttled or closed during normal DAF
operation.
C. Ball valve on the upper end of educator must not
be throttled beyond 25%.
3. High Water Air solubility decreases steadily as water
Temperature temperature increases. A water temperature of
150 deg F will have about half the capacity for
dissolved air compared to a water temp of 65 deg
F.
4. Low Back Check that the pressure gauge at pump and DAF
Pressure reads within recommended range. If pressure is
too low, air will not stay dissolved in stream.
Pressure is increased by throttling the air
injection valves at the DAF whitewater header
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TABLE 7-1
DAF SYSTEM TROUBLESHOOTING GUIDE
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTION ACTION SUPERVISOR
CORRECTIVE ACTION
5. Higher Than Process water flow rates or TSS values above the
recommended recommended maximum for the DAF will result
process water in excessive demand for whitewater, which
flow or TSS may appear as a lack in whitewater production
6. High Water Air solubility decreases steadily as water
Temperature temperature increases. A water temperature of
150 dg F will have about half the capacity for
dissolved air compared to a water temp of 65 deg
F.
3. Large Air bubbles in 1. Influent Water If the process water flowing into the DAF is not
DAF Contact is not full pipe flow enough to reach full pipe flow, this can cause
Chamber: very large bubbles to enter the DAF (mainly in the
center of the contact chamber).
2. Too much recycle a. check that the rotameter is reading the proper
line air Amount of airflow.
b. check that there are no leaks on the suction side
of the recycle piping where extra air can be pulled in
3. ARV valves If one or both of the ball valves on either side of
closed the air
Release valve (ARV) are closed, the ADP will not
be able to vent excess air off.
4. ARV needs If the ARV (air release valve) is dirty, the vent
cleaning opening
May become clogged and the ADP will not be able to
vent excess air off.
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TABLE 7-1
DAF SYSTEM TROUBLESHOOTING GUIDE
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTION ACTION SUPERVISOR
CORRECTIVE ACTION
5. Low back
pressure
i. DAF Recycle Pump 1. Worn/Damaged/
Does not Reach Clogged impeller
Required Operating
Pressure:
2. Clogged pressure
gauge
ii. Poor Solids Removal: 1. Increase rake speed
2. Check chemical feed systems
3. Check influent solids loading (do influent settling test)
Check that pressure gauge at pump and DAF
whitewater header reads within recommended range.
If pressure is too low, air will not stay dissolved in stream,
resulting in larger bubbles.
Check impeller for signs of damage, often caused by:
- Chemical attack
- Large/abrasive solids in the recycle stream
- Pitting caused by pump cavitation
If the pressure gauge orifice becomes clogged, it will
show a pressure that is lower than the actual pump
pressure. Clean orifice and check gauge calibration.
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WASTEWATER TREATMENT SYSTEM
TROUBLESHOOTING GUIDE
PROBLEM SEQUENCE OF ACTION CAUSE
OPERATOR CORRECTIVE ACTION SUPERVISOR
CORRECTIVE ACTION
1. Increasing Effluent A. Review past influent and Notify Supervisor
BOD5 effluent data. Perform (1) Check BOD bench sheets
(1) through (3). (1) Analytical at lab from lab
(1) Review BOD5 analyses (1) If BOD5 analyses thought to be
erroneous, confirm with other sample (2) Split BOD5 samples with
results before taking further action. outside laboratory.
(2) Determine whether the (2) Due to effluent solids
(2) If increase can be attributed to
increase is reflected in
other parameters such as suspended solids, refer to Section 7. A
TSS and COD. similar increase in COD is possible
confirmation of BOD5 value. (3) Calculate and monitor
(3) Review influent data. (3) An increase in influent BOD or SALR, SARR on
COD load (3) Check SALR, SARR. dailybasis
B. Review recent DO data
k1) 111AUUgUdLU LV
(1) Increase DO monitoring
(1) If low DO has been present since sample
for the aeration basin.
was obtained for BOD test, refer to
(2) Performance fluctuation
Section 4-Low DO in aeration basin.
(2) If DO was low on day of sample for
BOD5 test and increased thereafter, take
no further action - this is possible
(3) Reduced performance due to
confirmation of the BOD5 value.
(3) Check for unusual
upset
(3) If DO was abnormally high on day of
discharges to WWTP.
sample for BOD5 test, notify supervisor.
If DO has remained high since day of
sample, refer to Section 5 on Low
(1) Low SARR
(1) (a) If no increase is found in any of the
influent parameters, review the
C. Review past operating
past basin SARR data and
data (Flow, pH, SARR,
sampling procedures.
Temperature, MCRT)
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
ACTION
1. Increasing C. (continued)
Effluent BOD5 (continued)
(continued)
(1) Low SARR (1) (b) If SARR level was low on day
of BOD5 sample and has since
increased to normal, wait for
further indication of problem
from BOD5 data before
taking further action.
(a) If SARR level was low and has
remained low, refer to Section
(2) Excessive flow 6.0. Low SARR.
(2) If flow has increased while influent
BOD concentration has remained
normal, system retention time may be
inadequate.
(3) pH outside normal
operating range
(3)
Adjust basin pH to the range 6.5 to
(4) Low temperature
8•5•
(4)
Look at heating if possible. If this is
not possible, consider possible divert
some influent to pond (reducing
SARR) to compensate for slower
(5) High temperature
kinetics during cold operating
(6) Low nutrients
periods.
(5)
Check spray aerator in EQ tank.
(6)
Check effluent nutrient residuals.
Feed nutrients as required.
2. MBBR Basin A. Check pH with portable or different Probe out of calibration or Clean and recalibrate as needed
pH out of probe check probe calibration malfunction
Limits
(5) Turn on spray aerator
B. Check DAF system pH Influent pH out of range Manually adjust; too low may be coagulant feed issue
C. Do each of the following:
(1) Increase or decrease influent Continue to monitor pH closely and adjust
pH as needed influent pH as needed
(2) Check influent COD and
NH3-N loads
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WASTEWATER TREATMENT SYSTEM SHOOTING GUIDE (Continued)
PROBLEM
SEQUENCE OF ACTION
CAUSE
OPERATOR CORRECTIVE ACTION
SUPERVISOR CORRECTIVE
ACTION
3. Excessive
A.
Check aeration system.
Equipment malfunction
Check aeration system operation.
Schedule maintenance and repair to
Foaming
DO too high
Lower air flow.
minimize downtime. Add foam
During
suppressant to aeration basin.
Aeration
B.
Turn on spray aerator.
Spray aerator to break up foam.
CAUTION: SOME FOAM
SUPPRESSANTS CAN HAVE A
HARMFUL EFFECT ON THE
C,
Check defoamer feed
Defoamer feed problem
Repair/increase feed
BIOLOGICAL SYSTEM. LAB
TESTING IS NEEDED BEFORE
MAKING SELECTION.
D.
Review oxv2en uptake data
(1) Shocked
(1) If low, refer to Appendix D-Low
microorganisms
Oxygen Uptake.
(2) High or low pH
(2) Adjust pH of basins to the range
of 6.5 to 8.5.
E.
Perform (1) through (3)
(1) Review nutrient data (influent N:
BOD5 and P:BOD5 and effluent
residual nutrient levels)
(2) Review SALR and SARR data
(3) Microscopically examine sample of
floating material to determine
presence of filamentous organisms
(long, stringy, intertwined fibers)
(1) Inadequate nutrients (1) Feed appropriate levels of nutrients.
(2) Evaluate SARR data and
(2) Overloaded or adjust SALR as appropriate.
underloading
conditions
(3) Filamentous (3) Collect foam and mixed liquor
organisms samples for detailed filament
identification and determination of
potential causes. Based on results
implement corrective action plan.
(2) Based on results of filament
analysis, development and
implement corrective action plan.
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
ACTION
4. Low DO in A. Check function of D.O. meter Instrument failure Repair or replace probe or meter
MBBR Basin Note: Use field probe.
B. Check operation of aeration system Aeration system problems Inspect, repair and replace centrifugal If necessary, schedule service of
blowers, turbine aerators or diffusers, as malfunctioning equipment.
C. Inspect aeration basin for excessive Foaming
foaming
Refer to Section 3-Excessive Foaming
During Aeration.
D. Review past influent data,
including: (1) BOD5 and flow (1) Increased loading (1) Increased oxygen utilization can (1) Review cause of increased load.
result from either an increase in
BOD5 concentration or increase in
flow at the same BOD5
concentration. Increase aeration.
(2) Temperature (2) Excessive (2) Turn on EQ spray aerator, (2) Review problem with management
Temperature reduce temperature.
(>40°C)
F. Check influent for Immediate Immediate Oxygen If low dissolved oxygen occurred
Dissolved Oxygen Demand Demand suddenly, check for septic influent
wastewater.
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM
SEQUENCE OF ACTION
CAUSE
OPERATOR CORRECTIVE ACTION
SUPERVISOR CORRECTIVE
ACTION
5. Low Oxygen
A.
Obtain fresh sample and rerun
Bad sample
Uptake During
analysis to confirm value
Aeration
B.
Review influent BOD5loading data
Reduced influent loading
If needed, decrease aeration.
C.
Check for increased aeration basin
High Temperature
Increased basin temperature can result in
temperature
decreased oxygen utilization review.
Check EQ surface aerators and/or
increase.
D.
Check for decreased Aeration Basin
Cold temperature
Decreased basin temperature can result in
Temperature
decreased oxygen utilization. Review E
and F anyway.
E.
Review oxygen uptake analyses,
Analytical
Correct analytical procedure and
i.e., probe membrane, sample
equipment. Rerun analysis. Take no
further actions except to review Step E).
F.
Review past data on influent,
pH in aeration basin out
(1) Adjust pH.
(1) If aeration basin is not within
effluent and aeration basin pH
of range
a range of 6.5 to 8.5, take action
(2) After adjustment of aeration basin pH
to eliminate source of pH upset.
to proper level, rerun oxygen uptake.
(3) If no improvement, take fresh
sample, add I-g starch per liter of
sample and aerate for 2 hours.
G. Investigate possible toxic discharges Toxicity
(4) If uptake rate improves, sludge has
been shocked and should recover
within 24 hours.
(5) If uptake rate does not improve, take
steps to seed basin.
Microscopic evaluation of sludge.
Observe effluent for cloudiness due to
dead organisms.
Review production operations with
management and workers to identify
spills or other discharges to toxic
materials.
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
ACTION
6. Low SARR in the
Aeration Basin C. Review past data on effluent Excessive effluent solids If final effluent suspended solids have Check for toxic shock
suspended solids increased, refer to the Section 7-
Decreased Activated Sludge Settling.
D. Observe mixing pattern Inadequate mixing during Observe surface mixing pattern. Check If necessary, schedule service of
aeration due to equipment mixer operation. Replace all damaged or malfunctioning equipment.
problem missing diffusers. Check positions on all
drop leg valves. Check blower motor
amperage to estimate air flow.
E. Check sludge SVI and review past Poor settling rate If SVI has increased by more than 30
SVI data. percent, notify supervisor. Refer to
Section 7- Decreased Activated Sludge
Settlin¢ Rate.
F. Check nutrient levels.
Low Nutrients Adjust nutrient feed as required.
7. Decreased
A. Perform (1), (2) and (3)
Activated Sludge
(1) Review plant organic loading data
(1) Increased influent
(1) Decrease influent flow rate and/or
Settling Rate
SALR for sudden increases
BOD5 concentration
increase SARR level (see section 6-
(Greater than
or influent flow or
Low SARR in Aeration
30%)
Decreased SARR
Basin).
concentrations.
(2) Recheck sludge SVI and review
past SVI data
(2) Increased SVI due to (2) Perform Step 3
filaments
(2) Investigate cause of filaments.
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
ACTION
7. Decreased (3) Microscopically examine sample (3) Filamentous (3) a. Review process control data to (3) Review process control data.
Activated of sludge to determine presence organisms identify probable cause. Review
Sludge Settling of filamentous organisms (long, DO, pH, basin TSS and
Rate (Greater stringy, intertwined fibers) nutrient conditions to be sure they
than 30%) are in the proper range.
(continued)
b. Perform detailed filament analysis
to identify filaments and confirm
causative factor, and implement
appropriate corrective action
based on results.
(4) Review past effluent data for (4) Septic influent (4) Add oxidizing agent to collection system.
influent septicity.
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WASTEWATER TREATMENT SYSTEM TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
10. Increase in (1) Perform (1), (2),(3), and (4). Check (1)
effluent Suspended DAF sludge blanket depth.
Solids
(2) Check for floating/rising sludge (2)
(3) Perform SVI test on basin effluent. (3)
Solids carryover due (1) Check operation of DAF.
to excessive sludge
blanket.
Floating sludge (due (2) See Section 11-Excessive Floating (2) See Section 11-Excessive Floating
to denitrification or Sludge or Foam on Clarifier. Sludge or Foam on Clarifier.
septicity)
Poor settling (3) See Section 7-Decreased Activated
Sludge Settling Rate.
(4) Review process control parameters (4)(a) Dispersed growth (4)(a) Review process control
influent flow, COD, BOD5, SALR, (cloudy effluent) parameters (SVI, DO, pH, oxygen
SARR, SVI, DO, pH, oxygen uptake, SALR, SARR) See
uptake, DAF sludge blanket depth. Section 1.
(4)(b) Toxicity (indicated (4)(b) See Section 5-Low Oxygen Uptake During
by low oxygen Aeration.
uptake)
(4)(c) Excessive flow (4)(c) Notify supervisor and check for (4)(c) Take action to control flow if
sources of high flows in production possible.
plants.
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SECONDARY DAF TROUBLESHOOTING GUIDE (Continued)
PROBLEM SEQUENCE OF ACTION CAUSE OPERATOR CORRECTIVE ACTION SUPERVISOR CORRECTIVE
ACTION
1. Excessive A. Perform (1)-(3).
Floating Sludge (1) Low SARR, nutrient (1) If process control parameters are out
or Foam on (1) Review process control parameters deficiency, shock of the desired ranges take steps to
DAF to determine possible causes loading correct
(2) Microscopically examine sample of (2) Filamentous
floating material to determine organisms
presence of filamentous organisms
(long, stringy, intertwined fibers)
(3) Check residual N and P levels in (3) Polysaccharide
clarifier effluent (slime) foaming
(2) Collect foam and mixed liquor
samples for detailed filament
identification and determination of
potential causes. Based on results
implement corrective action plan.
(3) If soluble POa <1 mg/l, start daily (3) Increase frequency of checks on N
addition of phosphoric acid to and P levels in clarifier effluent
aeration basin. If NH3+NO3 <3 mg/l
or NH3 <1 mg/l, start daily addition of
urea or ammonia to aeration basin.
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SECONDARY DAF TROUBLESHOOTING GUIDE
OPERATING CONDITION CAUSE OPERATOR CORRECTIVE SUPERVISOR CORRECTIVE
ACTION ACTION
2. High Effluent TSS
a.
b. Sludge blanket>1 ft SVI>250
c. Sludge blanket SVI >250
(2) Check chemical feed
3. DAF Malfunction
a. High loading
b.(1) Problem with sludge collection
mechanism
C. Poor sludge settleability
See primary DAF troubleshooting guide
a. check basin TSS, flow
b.(1) Check DAF skimmer/sludge
collection mechanism, repair as
needed. Also check for
plugging.
c.(1) Diagnose and correct cause of
poor settleability
Troubleshooting. Also consider
polymer addition and increased
RAS as temporary steps.
a. reduce secondary flow (lower flow,
partial divert to pond)
c. Diagnose and correct cause of poor
settleability.
(3) Jar test to check chemical dose
-63- Operation and Maintenance Manual
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March 2020

APPENDIX A
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

GLOSSARY
BYPASS - A pipe or conduit which permits wastewater to be moved around a wastewater
treatment plant or any unit of the plant.
BOD5 - (Biochemical Oxygen Demand) - Analytical measurement of the concentration of
biodegradable organic matter in a sample.
COAGULATION - The addition of chemicals to a wastewater to agglomerate suspended solids
and to absorb emulsified and free oils into solid particles for settling and removal.
COMPOSITE WASTEWATER SAMPLE - A combination of individual samples of water or
wastewater taken at selected intervals to minimize the effect of the variability of the individual
sample.
DETENTION TIME - The average period of time that a fluid element is held in a basin or
tank before discharge.
DISSOLVED OXYGEN (DO) — Concentration of oxygen dissolved in water. Typically
measured with DO probe.
EFFLUENT - The term used for wastewater leaving a process unit.
FINAL EFFLUENT - The effluent from the final unit operation of a wastewater
treatment plant.
FLOC - An agglomeration of finely -divided or colloidal particles resulting from certain
chemical -physical or biological operations.
FLOCCULATION - The process of agglomerating smaller floc particles together to form large
floc particles that settle easier. Requires gentle mixing conditions.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

GRAB SAMPLE - A single sample of wastewater.
HYDRAULIC LOADING - The flow per unit surface area of the clarification or
biological reactor units (where applicable).
INFLUENT - The term used for the wastewater coming into a process unit.
OIL AND GREASE (O&G) - Analytical measurement of the total concentration of oils and
greases in a sample. This includes both emulsified and free oils. Expressed in mg/L.
OUTFALL - The point or location where wastewater or drainage discharges from a sewer,
drain, or conduit.
OVERFLOW RATE - One of the criteria for the design of settling tanks in treatment
plants; expressed in gallons per day per sq. ft of surface area (gpd/sq ft) in the settling
tank.
OXIDATION — REDUCTION POTENTIAL (ORP) — Measure of or reducing conditions in a
water sample measured in mV or ORP probe.
pH - The negative logarithm of the hydrogen ion concentration in a solution. pH values run
from 0 to 14. The number 7 indicates neutrality, while numbers less than 7 indicate increasing
acidity and numbers greater than 7 indicate increasing alkalinity.
PARSHALL FLUME - A calibrated device for measuring the flow of liquid in an open
conduit.
PARTS PER MILLION (ppm) - Concentration units meaning parts of substance per
million parts of water. This is synonymous with mg/l.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

SALR — Surface Area Loading Rate: Media specific term for allowable BOD loading (in g/D) per
media surface area (in M2)
SAMPLER - A device used with or without flow measurement to obtain an aliquot portion of
water or waste for analytical purposes. May be designed for taking a single sample (grab),
composite sample, continuous sample, or periodic sample.
SARR - Surface Area Removal Rate: Media specific term for anticipated BOD removal (in g/D)
per media surface area (in M2)
SCREENING - The removal of relatively coarse, floating and suspended solids by
straining through racks or screen.
SCUM - Any extraneous matter or impurities which have risen to or formed on the surface
of a liquid.
SEWER - A pipe or conduit, generally closed, but normally not flowing full. It is for carrying
sewage and other waste liquids.
SKIMMER - Mechanism on a clarifier or thickener which skims the water surface to
remove floating scum.
SLUDGE - The accumulated settled solids deposited from sewage or industrial wastes, raw
or treated, in tanks or basins.
SLUDGE AUGER - A sludge collector (see below) that uses a screw auger to move the sludge
to the collection/discharge point.
SLUDGE COLLECTOR - A mechanical device for scraping the sludge from the bottom of a
settling tank to a central collection point from which it can be drawn off.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

SUPERNATANT - The relatively clear liquid formed at the surface of a clarifier,
thickener or digester under settling conditions.
SUSPENDED SOLIDS (SS) - Solids that or are in suspension in wastewater.
TOTAL DISSOLVED SOLIDS (TDS) - Measurement of the concentration of solids
dissolved in the sample.
TS (Total Solids) - The total amount of solids in a wastewater in including both dissolved (TDS)
and suspended solids (TSS).
TSS (Total Suspended Solids) - Analytical measurement of the concentration of suspended
solids in a wastewater. Expressed as mg of suspended solids per liter of sample.
TURBIDITY - A condition of a liquid due to fine visible material in suspension which may not
be of sufficient size to be seen as individual particles by the naked eye but which prevents some
degree of passage of light through the liquid.
UNDERFLOW - The bottom discharge from a clarifier or thickener.
WEIR - A dam over which water is allowed to flow. The primary clarifier and sludge
thickener have weirs around their edges to control the flow of supernatant and to minimize
sludge from going out through the primary effluent or sludge supernatant.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

APPENDIX B
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
Activated Sludge Reactor
EQ. No..
Number: Two
Type: MBBR (mixed bed bioreactors)
Manufacturer: Entex Equivalent
Model: N/A
Design Flow: 2.5 MGD
Return Sludge Flow (MGD) 0
Design Criteria:
SALR of 20 g/m2/d
Media Req'd CM (CF):
1125 (39,730)
Media Type:
Entex Bioportz
Media Fill:
32%
Tank Dimensions:
52' Dia x 29' ft SWD
Effluent Criteria:
65% to 90% sBOD removal
Accessories (supplied):
Influent Screens
Effluent Screens
DO probe
Screen score (using air)
Basin DO control
Ancillary Equipment
Tanks
(specified elsewhere):
Aeration grid
Blowers
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
Aeration Grid
EQ. No..
Number:
Purpose:
Manufacturer:
Minimum:
Maximum:
Pressure Prop (at Dropleg)
Drop Pipe Size:
Materials of Construction:
Diffuser:
Accessories:
Tank Info:
Dia:
Height:
Max Liquid SWD;
Tank Reference Drawing:
Two (2)
To mix and provide oxygen to MBBR
Tanks 1 and 2
Entex or Engineer -Approved Equivalent
4000 scfm (per tank)
11,744 scfm
15 psig
18"
304 SS Drop Pipe
304 SS Header
Coarse Bubble
Yoke lateral supports, drop pipe supports
MBBR tanks
52'
35'
31.5'
271,272
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
MBBR Tanks
EQ. No.:
Number:
Manufacturer:
Material of Construction
Volume:
Dimensions:
Type:
Service:
Working Temperature:
Working Pressure:
Contents:
Interior Piping:
Two (2)
Tarsco or Equal
304 SS
556,000 gallons with 5 ft freeboard
52' foot diameter by 35' foot sidewall
height
Cylindrical
MBBR tanks
Ambient
Atmospheric
Wastewater
Yes. See nozzle schedule, aeration
diffuser grid (by others)
Seismic Group: II
Accessories: Steps and cat -walk, nozzles as shown on
drawings; pipe supports
Ref. Drawing: 271,272
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
Sludge Storage Tanks
EQ. No.:
Number:
Manufacturer:
Material of Construction:
Volume:
Dimensions:
Type:
Service:
Working Temperature
Working Pressure:
Contents:
Interior Piping:
Seismic Group:
Accessories:
Three (3)
Rental Equipment (Frac Tanks)
Epoxy Coated Steel
21,000 gallons
560" x 102" x 120"
Frac Tank
Waste Activated Sludge Tank
Ambient
Atmospheric
Wastewater, waste activated sludge
No
II
Level gauges, outlet manifold (by others)
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
Aeration Blowers
EQ. No.:
Number Pumps:
Purpose:
Manufacturer:
Model:
Speed:
Discharge Temp.:
Design Inlet Temp.:
Blower Elevation (ASL)
Pump Motor:
Size:
Electrical:
Type:
Capacity, each:
Discharge Pressure:
Materials of Construction:
Type:
Accessories:
Sound Level:
Three (3)
Provide air for MBBR tanks
Excelsior Equivalent
Cycloblower HE250 CDL 750 RC2
Max 2200 rpm
263
80OF
200 ft
350 HP
460 V/3pH/60 Hz
TEFC
Motor FLA 515A at 460 V
Max 4043 scfm (@ 60 Hz)
15 psig
Manufacturer Standard
Positive Displacement
Air inlet filter, air outlet silencer, NEMA
3R noise enclosure; space heater; EAP 11
drive panel, exhaust fan w/ thermostat
(1/3 HP, 115/230/l/60); relief valve,
check valve
Approx. Dimensions, 172" x 82" x 136"
(LxWxD):
Connections: 12" outlet
14" inlet
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
DAF Sludge Pump and Transfer
EQ. No.:
Number: Two (2)
Type: Bolted air -powered diaphragm, ball valve
Manufacturer: Wilden or equal
Model: PS8
Design Flow:
60 GPM at 20 psig
Air Requirements:
10 SCFM up to 100 psig
Fluid Pumped:
Wastewater sludge; DAF float flange
Inlet and Outlet Size:
2" inlet, 2" outlet
Materials of Construction:
Diaphragm:
Wil-Flex
Wetted Parts:
Polypropylene
Accessories:
Air filter, pressure regulator (by others)
Approx. Pump Dimensions,
24" x 19" x 32"
(LxWxD)
Pump Weight:
89 lb.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
MBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
New Primary DAF Unit
Number:
Manufacturer:
DAF Model Number:
Design Flow:
Mfr Design Inlet TSS
DAF Function:
Liquid Material:
Liquid Specific Gravity:
Working Pressure:
Materials of Construction:
Operating Weight:
Dimensions:
End Connections:
Driver:
Controls:
Electrical:
Accessories:
MFR Rated Flow: 1111 GPM
One
Word Water Works
600 gpm / 800 gpm hydraulic
2500 mg/L
Mfr Design Effluent TSS <250 mg/L
Primary Treatment
Wastewater
1.0
Atmospheric
Polypropylene
132,940 lbs.
27'6" x 8'xl4'9"
Float discharge — TBD
Influent — 6"
Effluent — 12"
2 Hp skimmer drive
Recycle pump
Match existing
480 V/3 phase/60 Hz
Polymer feed pumps
4-2 HP with VFD Moyno Pumps
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

EQUIPMENT DATA SHEET
NIBBR TREATMENT SYSTEM
MOUNTAIRE FARMS
LUMBER BRIDGE, NC
Pre -Engineered Building
Quantity:
One (1)
Type:
Pre -fabricated steel
Size:
20-ft by 15-ft; 10-ft interior wall clearance
Doors:
One double door, one additional man door
Color:
Mfr. Standard as Approved by Owner
Insulation:
Mfr. Standard
Options:
Lighting, heat pump, mini-split-M-01
Power:
120/208 V 3 ph
Panel Schedule:
See Drawing 502
Additional:
NC PE Stamped Drawings
Suitable for Building Permit
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

APPENDIX C
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
NORTH CAROLINA
EnNronmenral Quality
September 11, 2019
PHB.LIP PLYLAR—PRESIDENT
MouNTAIRE FARMS OF NORTH CAROLINA CORP.
POST OFFICE BOX 1320
MILLSBORO, DELAWARE 19966
Subject: Permit No. W00000484
Mountaire Farms - Lumber
Bridge W WTF
Wastewater Irrigation System
Robeson County
Dear: Mr. Plylar
In accordance with your permit minor modification request received June 14, 2019, we are
forwarding herewith Permit No. W00000484 dated September 11, 2019, to Mountaire Farms of North
Carolina Corp. for the continued operation of the subject wastewater treatment and irrigation facilities.
The following modifications to the subject permit are as follows:
• The #D DAF unit capacity has increased from 800 GPM to 1,100 GPM.
• Corrections have been made to the facility description.
• The Permittee has changed from "Mountaire Farms, Inc." to "Mountaire Farms of North
Carolina, Corp„
This permit shall be effective from the date of issuance through February 28, 2023, shall void
Permit No. W00000484 issued October 1, 2018, and shall be subject to the conditions and limitations
therein. The Permittee shall submit a renewal application no later than September 1, 2022.
Please pay attention to the monitoring requirements listed Attachments A, B, and C for they may
differ from the previous permit issuance. Failure to establish an adequate system for collecting and
maintaining the required operational information shall result in future compliance problems.
The Division has removed the following permit conditions since the last permit issuance dated
October 1, 2018:
➢ Old Conditions I.I. and 1.2. —These conditions have been met.
➢ Old Condition I.4. — This schedule has been met.
➢ Old Condition VI.2. — This condition has been removed because the permit is not voidable.
➢ Old Condition VI.10. —This condition has been.replaced.
D E Q North Carolina Department of Environmental Quality Division of Water Resources
512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
�-, � 919JOT9000

Mr. Phillip Plylar
September 11, 2019
Page 2 of 2
The following permit conditions are new since the last permit issuance dated October 1, 2018:
➢ Condition U.11. — The setbacks have been modified to reflect when the facilities were originally
permitted.
➢ Condition 1I1.16. — Metering equipment shall be tested and calibrated annually.
➢ Condition IV.9. — The maintenance log shall include date of irrigation equipment calibration.
➢ Condition VI.10. — This permit shall not be renewed if the Permittee or any affiliation has not
paid the required annual fee.
If any parts, requirements, or limitations contained in this permit are unacceptable, the Permittee
has the right to request an adjudicatory hearing upon written request within 30 days following receipt of
this permit. This request shall be in the form of a written petition, conforming to Chapter 1 SOB of the North
Carolina General Statutes, and filed with the Office of Administrative Hearings at 6714 Mail Service
Center, Raleigh, NC 27699-6714. Otherwise, this permit shall be final and binding.
One set of approved plans is being forwarded to you. Ifyou need additional information concerning
this permit, please contact Tessa Monday [phone] or tessa.mondav("a)ncdeor.Roy.
Sincerely,
'Xmda Culpepper, Director
' Division of Water Resources
cc: Robeson County Health Department (Electronic Copy)
Fayetteville Regional Office, Water Quality Regional Operations Section (Electronic Copy)
George Tyrian, PE — Keystone Engineering Group (Electronic Copy)
Beth Buffington — Protection and Enforcement Branch (Electronic Copy)
Laserfiche File (Electronic Copy)
Digital Permit Archive (Electronic Copy)
Central Files

NORTH CAROLINA
ENVIRONMENTAL MANAGEMENT COMMISSION
DEPARTMENT OF ENVIRONMENTAL QUALITY
RALEIGH
WASTEWATER IRRIGATION SYSTEM PERMIT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as
amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
Mountaire Farms of North Carolina Corp.
Robeson County
FOR THE
operation of a 2,550,000 gallon per day (GPD) wastewater treatment and irrigation facility consisting of
the:
continued operation of: a 1,100 gallon per minute (GPM) dissolved air floatation (DAF) clarifier unit (#D);
two 460,000 gallon MMBR (moving bed biofilm reactor) units with three 4,200 cubic feet per minute
(CFM) blowers; chemical feed systems; a transfer pump (located before the 2,400 GPM WWW DAF
(dissolved air floatation) unit to remove biological solids; reconfiguration of two 1,200 GPM pumps (feed
forward to MBBR units) at the above -ground sump; a 50 GPM sludge transfer pump at the treatment
building; and all associated piping, valves, controls, and appurtenances; the
continued operation of an existing industrial wastewater treatment plant consisting of rotary screens; a flow
equalization basin with a floating aerator; a feed forward pump station with five 600 GPM feed forward
pumps, and associated high-water alarms; a feed forward pump station with two 1,200 GPM feed forward
pumps, and associated high-water alarms; three 800 GPM DAF (#A through C) units with a nitrogen
removal system and clarifier (Sorin Treatment System); a 2,400 GPM DAF unit with two 280 CFM
dissolved air pumps; a 2,400 advanced pipe flocculator with a flow meter; four 2,500 gallon polymer tanks
with two 25 GPH chemical metering pumps; a 19.79 million gallon (MG) 60 millimeter (mm) synthetically
lined aerated storage lagoon with four aerators and 1.18 MG of permanent storage; chlorine disinfection;
and all associated piping, valves, controls, and appurtenances; the
continued operation of: a 409,000 GPD domestic wastewater treatment plant; and all associated piping,
valves, controls, and appurtenances; the
continued operation of a wastewater irrigation system consisting of. a spray irrigation pumping station with
three vertical turbine pumps serving 17 center pivots and solid set irrigation fields (Fields A through M)
with a wetted area of 254.97 acres; two 1,000 GPM vertical turbine spray irrigation pumps serving 15 center
pivots and solid set irrigation fields (Fields N through 2) with a wetted area of 266.47 acres for a cumulative
area of 537.8 acres; and all associated piping, valves, controls, and appurtenances; and the
continued operation of a groundwater management system consisting of 493 linear feet (LF) of 8-inch
gravity sewer; a 225 GPM pump station (Field C) with duplex pumps, high-water alarms, manual power
transfer switch, and an emergency generator hookup, five 0.52 acre infiltration basins; and all associated
piping, valves, controls, and appurtenances;
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I.
to serve the Mountaire Farms — Lumber Bridge WWTF, with no discharge of wastes to surface waters,
pursuant to the application received June 14, 2019, and in conformity with the Division -approved plans and
specifications considered a part of this permit.
This permit shall be effective from the date of issuance through February 28, 2023, shall void Permit No.
WQ0000484 issued October 1, 2018, and shall be subject to the following conditions and limitations:
1. Prior to March 8, 2020, the Permittee shall submit to the Non -Discharge Branch a Groundwater Report
summarizing the groundwater quality (up -gradient and down -gradient) within the compliance
boundary. The Groundwater Report shall include: (1) a table with depth -to -water measurements in
each well, (2) a table with current and historical laboratory data for each well; (3) a site map showing
each well and potentiometric surface data; (4) and a discussion of any non-compliance items or
notifications required in Condition IV.16. When the concentration of any substance equals or exceeds
the standard at the review boundary as determined by monitoring, the permittee shall take action in
accordance with the provisions of Rule 15A NCAC 02L .0106. [15A NCAC 02T .0108(b)(1)(B)]
2. The Permittee shall request renewal of this permit on Division -approved forms no later than September
1, 2022. [15A NCAC 02T .0105(b), 02T .0109]
II. PERFORMANCE STANDARDS
1. The Permittee shall maintain and operate the subject non -discharge facilities so there is no discharge to
surface waters, nor any contravention of groundwater or surface water standards. In the event the
facilities fail to perform satisfactorily, including the creation of nuisance conditions due to improper
operation and maintenance, or failure of the irrigation areas to assimilate the effluent, the Permittee
shall take immediate corrective actions, including Division required actions, such as the construction
of additional or replacement wastewater treatment or disposal facilities. (I5A NCAC 02T
.0108(bx 1)(A)]
2. This permit shall not relieve the Permittee of their responsibility for damages to groundwater or surface
water resulting from the operation of this facility. [15A NCAC 02T .0108(b)(1)(A)]
3. Groundwater monitoring wells shall be constructed in accordance with 15A NCAC 02C .0108
(Standards of Construction for Wells Other than Water Supply), and any other jurisdictional laws and
regulations pertaining to well construction. [15A NCAC 02C .0108]
4. Effluent quality shall not exceed the limitations specified in Attachment A. [15A NCAC 02T
.0108(b)(lXA), 02T .0505(b)]
5. Application rates, whether hydraulic, nutrient, or other pollutant, shall not exceed those specified in
Attachment B. [ 15A NCAC 02T .0108(bx 1)(A)]
6. Wastewater irrigation fields permitted on or after December 30, 1983 have a compliance boundary that
is either 250 feet from the wastewater irrigation area, or 50 feet within the property boundary,
whichever is closest to the wastewater irrigation area. Any exceedance of groundwater standards at or
beyond the compliance boundary shall require corrective action. Division -approved relocation of the
compliance boundary shall be noted in Attachment B. Multiple contiguous properties under common
ownership and permitted for use as a disposal system shall be treated as a single property with regard
to determination of a compliance boundary. [ 15A NCAC 02L .0106(d)(2), 02L .0107(b), 02T .0105(h),
G.S. 143-215.1(i), G.S. 143-215.1(k)]
7. The review boundary is midway between the compliance boundary and the wastewater irrigation area.
Any exceedance of groundwater standards at or beyond the review boundary shall require preventative
action. [ 15A NCAC 02L .0106(d)(1), 02L .0108]
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8. The Permittee shall apply for a permit modification to establish a new compliance boundary prior to
any sale or transfer of property affecting a compliance boundary (i.e., parcel subdivision). [ 15A NCAC
02L .0107(c)]
9. No wells, excluding Division -approved monitoring wells, shall be constructed within the compliance
boundary except as provided for in 15A NCAC 02L .0107(g). [ 15A NCAC 02L .0107]
10. Except as provided for in 15A NCAC 02L .0107(g), the Permittee shall ensure any landowner who is
not the Permittee and owns land within the compliance boundary shall execute and file with the
Robeson County Register of Deeds an easement running with the land containing the following items:
a. A notice of the permit and number or other description as allowed in 15A NCAC 02L .0107(f)(1);
b. Prohibits construction and operation of water supply wells within the compliance boundary; and
c. Reserves the right of the Permittee or the State to enter the property within the compliance boundary
for purposes related to the permit.
The Director may terminate the easement when its purpose has been fulfilled or is no longer needed.
[15A NCAC 02L .0107(f)]
11. The facilities herein were permitted per the following setbacks:
a. The facilities originally permitted prior to October 1, 1987 under Permit No. 465411, and
subsequently never modified after October 1, 1987, have no setbacks. The original permit (Permit
No. 4654R) pre -dates administrative code 15A NCAC 02H .0219(j), which was effective October
1, 1987. Original facilities with no modifications or expansions are is still covered under the 15A
NCAC 02H .0200 rules effective February 1, 1976, which contain no setback requirements. [I 5A
NCAC 02H .0200]
b. The setbacks for spray irrigation sites originally permitted or modified from October 1, 1987 to
January 31, 1993 are as follows (all distances in feet):
i. Each habitable residence or place of assembly under separate ownership:
4001
I Each private or public water supply source:
100
iii. Surface waters:
100
iv. Groundwater lowering ditches:
100
v. Surface water diversions (upslope):
100
vi. Surface water diversions (downslope):
100
vii. Each well with exception of monitoring wells:
100
viii. Each property line:
1502
ix. Top of slope of embankments or cuts of two feet or more in vertical height:
100
x. Each water line:
10
xi. Each swimming pool:
100
xii. Public right of way:
50
xiii. Nitrification field:
20
xiv. Each building foundation or basement:
100
1 Habitable residences or places of assembly under separate ownership constructed after the
facilities herein were originally permitted or subsequently modified are exempt from this
setback.
2 Setbacks to property lines are not applicable when the Permittee, or the entity from which the
Permittee is leasing, owns both parcels separated by the property line.
[15A NCAC 02H .02190)(5)]
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Page 3 of 11

c. The additional 162.14 acres of spray irrigation sites were originally permitted between February 1,
1993 and August 31, 2006. The setbacks for spray irrigation sites originally permitted or modified
from February 1, 1993 to August 31, 2006 are as follows (all distances in feet):
i. Each habitable residence or place of assembly under separate ownership:
4001
ii. Each private or public water supply source:
100
iii. Surface waters:
100
iv. Groundwater lowering ditches:
100
v. Surface water diversions (upslope):
100
vi. Surface water diversions (downslope):
100
vii. Each well with exception of monitoring wells:
100
viii. Each property line:
1502
ix. Top of slope of embankments or cuts of two feet or more in vertical height:
15
x. Each water line:
10
xi. Each swimming pool:
100
xii. Public right of way:
50
xiii. Nitrification field:
20
xiv. Each building foundation or basement:
15
1 Habitable residences or places of assembly under separate ownership constructed after the
facilities herein were originally permitted or subsequently modified are exempt from this
setback.
2 Setbacks to property lines are not applicable when the Permittee, or the entity
from which the
Permittee is leasing, owns both parcels separated by the property line.
[15A NCAC 02H .02190)(5)]
d. The storage and treatment units (19.79 MG storage lagoon, 40,000 GPD domestic wastewater
treatment facility, and industrial wastewater treatment facility) were originally permitted and
modified between February 1, 1993 to August 31, 2006. The setbacks for storage and treatment
units originally permitted or modified from February 1, 1993 to August 31, 2006 are as follows (all
distances in feet):
i. Each habitable residence or place of assembly under separate ownership: 1001
ii. Each private or public water supply source: 100
iii. Surface waters: 50
iv. Each well with exception of monitoring wells: 100
v. Each property line: 502
vi. Nitrification field: 20
1 Habitable residences or places of assembly under separate ownership constructed after the
facilities herein were originally permitted or subsequently modified are exempt from this
setback.
2 Setbacks to property lines are not applicable when the Permittee, or the entity from which the
Permittee is leasing, owns both parcels separated by the property line.
[15A NCAC 02H .02190)(5)]
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e. The setbacks for storage and treatment units originally permitted or modified on or after September
1, 2018 are as follows (all distances in feet):
i. Each habitable residence or place of assembly under separate ownership: 1001
ii. Each private or public water supply source: 100
iii. Surface waters: 50
iv. Each well with exception of monitoring wells: 100
v. Each property line: 501
Habitable residences or places of assembly under separate ownership constructed after the
facilities herein were originally permitted or subsequently modified are exempt from this
setback.
2 Setbacks to property lines are not applicable when the Permittee, or the entity from which the
Permittee is leasing, owns both parcels separated by the property line.
[15A NCAC 02T .0506(b), 02T .0506(e), 02T .0506(f)]
IIL OPERATION AND MAINTENANCE REOUIREMENTS
1. The Permittee shall operate and maintain the subject facilities as a non -discharge system. [15A NCAC
02T .0500]
2. The Permittee shall maintain an Operation and Maintenance Plan, which shall include operational
functions, maintenance schedules, safety measures, and a spill response plan. [15A NCAC 02T
.0507(a)]
3. Upon the Water Pollution Control System Operators Certification Commission's (WPCSOCC)
classification of the subject non -discharge facilities, the Permittee shall designate and employ a certified
operator in responsible charge (ORC), and one or more certified operators as back-up ORCs. The ORC
or their back-up shall operate and visit the facilities as required by the WPCSOCC. [15A NCAC 02T
.0117]
4. The Permittee shall maintain vegetative cover on the irrigation sites, such that crop health is optimal,
allows even effluent distribution, and allows inspection of the irrigation system. [I SA NCAC 02T
.0507(b)]
5. The Permittee shall take measures to prevent effluent ponding in or runoff from the irrigation sites
listed in Attachment B. [15A NCAC 02T .0507(c)]
6. The Permittee shall not irrigate treated effluent during inclement weather, or when the soil is in a
condition that will cause ponding or runoff. [15A NCAC 02T .0505(x)]
7. Irrigation equipment shall be tested and calibrated once per permit cycle. [15A NCAC 02T .0507(d)]
8. Only treated effluent from the Mountaire Farms — Lumber Bridge WWTF shall be irrigated on the sites
listed in Attachment B. [15A NCAC 02T .0501 ]
9. The Permittee shall not allow vehicles or heavy machinery on the irrigation area, except during
equipment installation or maintenance activities. [15A NCAC 02T .0507(e)]
10. The Permittee shall prohibit public access to the wastewater treatment, storage, and irrigation facilities.
[ I SA NCAC 02T .0505(q)]
11. The Permittee shall dispose or utilize generated residuals in a Division -approved manner. [ I SA NCAC
02T .0508, 02T .1100].
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12. The Permittee shall not divert or bypass untreated or partially treated wastewater from the subject
facilities. [15A NCAC 02T .05050)]
13. Freeboard in the 19.79 MG synthetically lined aerated storage lagoon shall not be less than two feet at
anytime. [15A NCAC 02T .0505(d)]
14. A gauge to monitor waste levels in the 19.79 MG synthetically lined aerated storage lagoon shall be
provided. This gauge shall have readily visible permanent markings, at inch or tenth of a foot
increments, indicating the following elevations: maximum liquid level at the top of the temporary liquid
storage volume; minimum liquid level at the bottom of the temporary liquid storage volume; and the
lowest point on top of the dam. [15A NCAC 02T .0507(f)]
15. A protective vegetative cover shall be established and maintained on all berms, pipe runs, erosion
control areas, surface water diversions, and earthen embankments (i.e., outside toe of embankment to
maximum allowable temporary storage elevation on the inside of the embankment). Trees, shrubs, and
other woody vegetation shall not be allowed to grow on the earthen dikes or embankments. Earthen
embankments shall be kept mowed or otherwise controlled and accessible. [ 15A NCAC 02T .0507(g)]
16. Metering equipment shall be tested and calibrated annually. [15A NCAC 02T .0507(d)]
17. The application of chemicals to Field C and F groundwater management system infiltration basins is
expressly prohibited. [15A NCAC 02T .0 1 08(b)(1)(A)]
18. Fields C and F groundwater management infiltration basins shall be operated and maintained to prevent
the bed surfaces from becoming sealed and established with vegetative growth. The infiltration basin
bed surfaces shall be kept free of vegetative growth at all times. Vegetation shall be removed manually
so that minimal disturbance will occur. The basin beds shall be raked a minimum of once per month.
[15A NCAC 02T .0108(bXl)(A)]
19. The Permittee shall remove harvested hay from within the compliance boundary. [15A NCAC 02T
.0108(bxixA)]
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IV. MONITORING AND REPORTING REQUIREMENTS
1. The Permittee shall conduct and report any Division required monitoring necessary to evaluate this
facility's impact on groundwater and surface water. [15A NCAC 02T .0108(c)]
2. A Division -certified laboratory shall conduct all analyses for the required effluent, groundwater, and
surface water parameters. [15A NCAC 02H .0800]
3. Flow through the treatment facility shall be continuously monitored, and daily flow values shall be
reported on Form NDMR. Facilities with a permitted flow less than 10,000 GPD may estimate their
flow from water usage records provided the water source is metered. [15A NCAC 02T .0105(k), 02T
.0108(c)]
4. The Permittee shall monitor the treated effluent at the frequencies and locations for the parameters
specified in Attachment A. [15A NCAC 02T .0108(c)]
S. The Permittee shall maintain records tracking the amount of effluent irrigated. These records shall
include the following information for each irrigation site listed in Attachment B:
a. Date of irrigation;
b. Volume of effluent irrigated;
c. Site irrigated;
d. Length of time site is irrigated;
e. Continuous weekly, monthly, and year-to-date hydraulic (inchestacre) loadings;
f. Continuous monthly and year-to-date loadings for any non -hydraulic parameter specifically
limited in Attachment B;
g. Weather conditions; and
h. Maintenance of cover crops (types, tonnage harvested, fertilizer amendments, etc.).
[15A NCAC 02T .0108(c)]
6. Freeboard (i.e., waste level to the lowest embankment elevation) in the 19.79 MG synthetically lined
aerated storage lagoon shall be measured to the nearest inch or tenth of a foot, and recorded weekly.
Weekly freeboard records shall be maintained for five years, and shall be made available to the Division
upon request. [15A NCAC 02T .0108(c)]
7. Three copies of all monitoring data (as specified in Conditions IV.3. and IVA) on Form NDMR for
each PPI and three copies of all operation and disposal records (as specified in Conditions IV.5. and
IV.6.) on Form NDAR 1 for every site in Attachment B shall be submitted on or before the last day of
the following month. If no activities occurred during the monitoring month, monitoring reports are still
required documenting the absence of the activity. All information shall be submitted to the following
address:
Division of Water Resources
Information Processing Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
[ 15A NCAC 02T .0105(1)]
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8. The Permittee shall maintain a record of all residuals removed from this facility. This record shall be
maintained for five years, and shall be made available to the Division upon request. This record shall
include:
a. Name of the residuals hauler;
b. Non -Discharge permit number authorizing the residuals disposal, or a letter from a municipality
agreeing to accept the residuals;
c. Date the residuals were hauled; and
d. Volume of residuals removed.
[15A NCAC 02T .0508(b)]
9. A maintenance log shall be kept at this facility. This log shall be maintained for five years, and shall
be made available to the Division upon request. This log shall include:
a. Date of flow measurement device calibration;
b. Date of irrigation equipment calibration;
c. Visual observations of the plant and plant site; and
d. Record of preventative maintenance (e.g., changing of equipment, adjustments, testing, inspections
and cleanings, etc.).
[15A NCAC 02T .0507(h)]
10. Monitoring wells MW 14, MW-15, MW-37, MW47, MW48, MW-49, MW-50, MW 51, MW-52,
MW-53, MW-54, MW 55, and MW 56 shall be sampled at the frequencies and for the parameters
specified in Attachment C. All mapping, well construction forms, well abandonment forms and
monitoring data shall refer to the permit number and the well nomenclature as provided in Attachment
C and Figure, 1. [15A NCAC 02T .0105(m)]
11. Two copies of the monitoring well sampling and analysis results shall be submitted on a Compliance
Monitoring Form (OW-59), along with attached copies of laboratory analyses, on or before the last
working day of the month following the sampling month. The Compliance Monitoring Form (GW-59)
shall include this permit number, the appropriate well identification number, and one GW-59a
certification form shall be submitted with each set of sampling results. All information shall be
submitted to the following address:
Division of Water Resources
Information Processing Unit
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
[15A NCAC 02T .0105(m)]
12. An annual representative soils analysis (i.e., Standard Soil Fertility Analysis) shall be conducted on
each irrigation site listed in Attachment B. These results shall be maintained at the facility for five
years, and shall be made available to the Division upon request. Each Standard Soil Fertility Analysis
shall include the following parameters:
Acidity
Exchangeable Sodium Percentage
pH
Base Saturation (by calculation)
Lead '
Phosphorus
Cadmium '
Magnesium
Potassium
Calcium
Manganese
Sodium
Cation Exchange Capacity
Nickel '
Zinc
Copper
Percent Humic Matter
' Cadmium, Lead, and Nickel shall be sampled once per permit cycle and a licensed soil scientist shall
submit these results accompanied by a report evaluating the soil with the renewal application.
[1 SA NCAC 02T .0108(c)]
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V.
13. A licensed agronomist shall supervise surface and deep penetrating soil aeration maintenance on an as -
needed basis for all irrigation sites listed in Attachment B. [15A NCAC 02T .0108(bX 1 XA)]
14. Scheduled maintenance of the irrigation and infiltration sites listed in Attachment B shall be performed
as needed. Maintenance shall include actions to ensure that effluent ponding and runoff does not occur
and shall include an annual report by an agronomist or agricultural expert concerning crops and
operation for the upcoming year. This report shall be submitted to the Non -Discharge Branch, 1617
Mail Service Center, Raleigh, NC 27699-1617. [15A NCAC 02T .0108(b)(1)(A)]
15. Noncompliance Notification:
The Permittee shall report to the Fayetteville Regional Office, telephone number [phone],
within 24 hours of first knowledge of the following:
a. Treatment of wastes abnormal in quantity or characteristic, including the known passage of a
hazardous substance.
b. Any process unit failure (e.g., mechanical, electrical, etc.) rendering the facility incapable of
adequate wastewater treatment.
c. Any facility failure resulting in a discharge to surface waters.
d. Any time self -monitoring indicates the facility has gone out of compliance with its permit
limitations.
e. Ponding in or runoff from the irrigation sites.
Emergencies requiring reporting outside normal business hours shall call the Division's Emergency
Response personnel at telephone number [phone], [phone], or [phone]. All
noncompliance notifications shall file a written report to the Fayetteville Regional Office within five
days of first knowledge of the occurrence, and this report shall outline the actions proposed or taken to
ensure the problem does not recur. [ 15A NCAC 02T .0108(b)(1 XA)]
1. The Permittee shall perform inspections and maintenance to ensure proper operation of the wastewater
treatment and irrigation facilities. [15A NCAC 02T .0507(i)]
2. The Permittee shall inspect the wastewater treatment and irrigation facilities to prevent malfunctions,
facility deterioration, and operator errors that may result in discharges of wastes to the environment,
threats to human health, or public nuisances. The Permittee shall maintain an inspection log that
includes the date and time of inspection, observations made, and maintenance, repairs, or corrective
actions taken. The Permittee shall maintain this inspection log for a period of five years from the date
of the inspection, and this log shall be made available to the- Division upon request. [ 15A NCAC 02T
.0507(h), 02T .0507(i)]
3. Division authorized representatives may, upon presentation of credentials, enter and inspect any
property, premises, or place related to the wastewater treatment and irrigation facilities permitted herein
at any reasonable time for determining compliance with this permit. Division authorized
representatives may inspect or copy records maintained under the terms and conditions of this permit,
and may collect groundwater, surface water, or leachate samples. [G.S. 143-215.3(a)(2)]
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VI. GENERAL CONDITIONS
1. Failure to comply with the conditions and limitations contained herein may subject the Permittee to a
Division enforcement action. [G.S. 143-215.6A,143-215.6B, 143-215.6C]
2. This permit is effective only with respect to the nature and volume of wastes described in the permit
application, and Division -approved plans and specifications. [G.S. 143-215.1(d)]
3. Unless specifically requested and approved in this permit, there are no variances to administrative codes
or general statutes governing the construction or operation of the facilities permitted herein. [I 5A
NCAC 02T .0105(n)]
4. The issuance of this permit does not exempt the Permittee from complying with all statutes, rules,
regulations, or ordinances that other jurisdictional government agencies (e.g., local, state, and federal)
may require. [15A NCAC 02T .0105(c)(6)]
5. If the permitted facilities change ownership, or the Permittee changes their name, the Permittee shall
submit a permit modification request on Division -approved forms. The Permittee shall comply with
all terms and conditions of this permit until the permit is transferred to the successor -owner. [G.S. 143-
215.1(d3)]
6. The Permittee shall retain a set of Division -approved plans and specifications for the life of the facilities
permitted herein. [15A NCAC 02T .0105(o)]
7. The Permittee shall maintain this permit until the proper closure of all facilities permitted herein, or
until the facilities permitted herein are permitted by another authority. [15A NCAC 02T .01050)]
8. This permit is subject to revocation or modification upon 60-day notice from the Division Director, in
whole or part for:
a. violation of any terms or conditions of this permit or Administrative Code Title 15A Subchapter
02T;
b. obtaining a permit by misrepresentation or failure to disclose all relevant facts;
c. the Permittee's refusal to allow authorized Department employees upon presentation of credentials:
i. to enter the Permittee's premises where a system is located or where any records are required
to be kept;
I to have access to any permit required documents and records;
iii. to inspect any monitoring equipment or method as required in this permit; or
iv. to sample any pollutants;
d. the Permittee's failure to pay the annual fee for administering and compliance monitoring; or
e. a Division determination that the conditions of this permit are in conflict with North Carolina
Administrative Code or General Statutes.
[ 15A NCAC 02T .0110]
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9. Unless the Division Director grants a variance, expansion of the facilities permitted herein shall not
occur if any of the following apply:
a. The Permittee or any parent, subsidiary, or other affiliate of the Permittee has been convicted of
environmental crimes under G.S. 143-215.6B, or under Federal law that would otherwise be
prosecuted under G.S. 143-215.6B, and all appeals of this conviction have been abandoned or
exhausted.
b. The Permittee or any parent, subsidiary, or other affiliate of the Permittee has previously abandoned
a wastewater treatment facility without properly closing the facility.
c. The Permittee or any parent, subsidiary, or other affiliate of the Permittee has not paid a civil
penalty, and all appeals of this penalty have been abandoned or exhausted.
d. The Permittee or any parent, subsidiary, or other affiliate of the Permittee is currently not compliant
with any compliance schedule in a permit, settlement agreement, or order.
e. The Permittee or any parent, subsidiary, or other affiliate of the Permittee has not paid an annual
fee.
[15A NCAC 02T .0120(b), 02T .0120(d)]
10. This permit shall not be renewed if the Permittee or any affiliation has not paid the required annual fee.
[15A NCAC 02T .0120(c)]
Permit issued this the 111 day of September 2019
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT
?Linda Culpepper, Director
Division of Water Resources
By Authority of the Environmental Management Commission
Permit Number W00000484
W00000484 Version 4.2 Shell Version 181105 Page 11 of 11

- I •

ATTACH M ENT A — LIMITATIONS AND MONITORING REQUIREMENTS
PPI 001- Storage Lagoon Effluent
Permit Number: WQ0000484 Version: 4.2
EFFLUENT CHARACTERISTICS
EFFLUENT LIMITS
MONITORING REQUIREMENTS
PCs
Code
Parameter Description
Units of
Measure
Monthly
Average
Monthly
Min c
Daily Minimum
Daily Maximum
Measurement
Frequency
Sample
Type
00310
BOD, 5-Day (20 °C)
mg/L
2 x Month
Grab
01027
Cadmium, Total (as Cd) -
mg/L
Monthly
Grab
00916
Calcium, Total (as Ca)
mg/L
Monthly
Grab
00940
Chloride (as Cl)
mg/L
3 x Year
Grab
50060
Chlorine, Total Residual
mg&
5 x Week
Grab
31616
Coliform, Fecal MF, M-FC Broth, 44.5 °C
#/100 mL
2 x Month
Grab
01042
Copper, Total (as Cu)
mg/L
Monthly
Grab
50050
Flow, in Conduit or thru Treatment Plant
GPD
2,550,000
Continuous
Recorder
01051
Lead, Total (as Pb)
mg/L
Monthly
Grab
00927
Magnesium, Total (as Mg)
mg/L
Monthly
Grab
01067
Nickel, Total (as N)
mg/L
Monthly
Grab
00610
Nitrogen, Ammonia Total (as N)
cng/L
2 x Month
Grab
00625
Nitrogen, Kieldahl, Total (as N)
mg/L
2 x Month
Grab
00620
Nitrogen, Nitrate Total (as N)
mg/L
2 x Month
Grab
00600
Nitrogen, Total (as N)
mg/L
2 x Month
Grab
00400
pH
su
5 x Week
Grab
00665
Phosphorus, Total (as P)
mg/L
2 x Month
Grab
WQ09C
Plant Available Nitrogen - Concentration
IRA
2 x Month
Grab
00931
Sodium Absorption Ratio
ratio
Monthly
Grab
00929
Sodium, Total (as Na)
mg/L
Monthly
Grab
70300
Solids, Total Dissolved —180 °C
mg/L
3 x Year
Grab
00530
Solids, Total Suspended
mg/L
2 x Month
Grab
01092
Zinc, Total (as Zn)
mg/L
Monthly
Grab
1. 3 x Year sampling shall be conducted during April, August, and December.
WQ0000494 Version 4.2 Attachment A Pagel of 2

PPI 002 — Industrial WWTF Effluent
EFFLUENT CHARACTERISTICS
EFFLUENT LIMITS
MONITORING REQUIREMENTS
PCS
Code
Parameter Description
Units of
Units
Monthly
Average
Monthly
Geometric Mean
Daily Minimum
Daily Maximum
Measurement
Frequency
Sample
Type
50050
Flow, in Conduit or thru Treatment Plant
GPD
2,550,000
Continuous
Recorder
PPI 003 — Domestic WWTP Effluent
EFFLUENT CHARACTERISTICS
EFFLUENT LIMITS
MONITORING REQUIREMENTS
PCs
Code
Parameter Description
Units of
Measure
Monthly
Average
Monthly
Geometric Mean
Daily Minimum
Daily Maximum
Measurement
Frequency
Sample
Type
50050
Flow, in Conduit or d= Treatment Plant
GPD
40,000
Continuous
Recorder
PPI 004 — Surface Water Monitoring Station SW-1(34.872584%-79.116861°)
EFFLUENT CHARACTERISTICS
EFFLUENT LIMITS
MONITORING REQUIREMENTS
PCs
Code
Parameter Description
Units of
Measure
Monthly
Average
Monthly
Geometric Mean
Daily Minimum
Daily Maximum
Measurement
Frequency
Sample
Type
00620
Nitrogen, Nitrate Total (as N)
mg/L
T—
Monthly
Grab
PPI 005 — Groundwater Lowering System Effluent (Feld C Underdrain to Infiltration Basins)
EFFLUENT CHARACTERISTICS
EFFLUENT LBUTS
MONITORING REQUIREMENTS
PCS
Code
Parameter Description
Units of
Measure
Monthly
Average
Monthly
Geometric Mean
Daily Minimum
Daily Maximum
Measurement
Frequency
Sample
,hype
50050
Flow, in Conduit or thru Treatment Plant
GPD
Continuous
Recorder
WQ0000494 Version 4.2 Attachment A Page 2 of 2

ATTACHMENT B — APPROVED LAND APPLICATION SITES AND LEWTATIONS
Mountaire Farms of North Carolina Corp. — Mountaire Farms - Lumber Bridge WWTF
Permit Number: WQ0000484 Version: 4.2
IRRIGATION AREA INFORMATION
APPLICATION LIMITATIONS
Field
Owner
County
Latitude
Longitude
Net Acreage
Dominant
Soil Series
Parameter
Hourly
Rate
Yearly
Max
Units
A
Mountaire Farms Inc.'
Robeson
34.872092°
-79.107353°
8.20
pog
01284 —Non-Discharge Application Rate
78
inches
WQ09 — Plant Available Nitrogen
350
lbstacre
B
Mountaire Farms Inc. '
Robeson
34.872877°
-79.109168°
6.75
WkB
01284 — Non -Discharge Application Rate
78
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
C
Mountaire Farms Inc. '
Robeson
34.8716240
-79.1026730
13.60
Wkg
01284 — Non -Discharge Application Rate
78
inches
WQ09 — Plant Available Nitrogen
264
lbs/acre
D
Mountaire Farms Inc. '
Robeson
34.874528°
-79.111558°
3.50
WkB
01284 — Non -Discharge Application Rate
WQ09 — Plant Available Nitrogen
78
350
inches
lbstacre
E
Mountaire Farms Inc. '
Robeson
34.876730°
-79.113280°
4.70
Wkg
01284 — Non -Discharge Application Rate
WQ09 — Plant AvaMle Nitrogen
91
350
inches
lbs/acre
F
Mountaire Farms Inc.
Robeson
34.875083°
-79.I06307°
26.53
WkB
01284 —Non-Discharge Application Rate
78
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
G
Mountaire Farms Inc. '
Robeson
34.879093°
-79.11013r
47.79
WkB
01294 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
H
Mountaire Farms Inc. '
Robeson
34.878548°
-79.104497°
14.19
WkB
01284 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
I
Mountaire Farms Inc. '
Robeson
34.877600°
-79.108411 °
13.58
WkB
01284 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
J
Mountaire Farms Inc. '
Robeson
34.885146°
-79.117971 °
58.26
WkB
01284 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
K
Mountaire Farms Inc. '
Robeson
34.888060°
-79.1156830
9.86
Lag
01284 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbstacre
L
Mountaire Farms Inc. '
Robeson
34.8882200
-79.112341 °
24.94
LaB
01284 — Non -Discharge Application Rate
91
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
M
Mountaire Farms Inc. '
Robeson
34.868600°
-79.107500°
23.07
Pog
01284 — Non -Discharge Application Rate
52
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
N
Mountaire Farms Ina '
Robeson
34.871606°
-79.1215800
78.87
Pog
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
O
Mountaire Farms Inc. '
Robeson
34.8672760
-79.123579°
19.89
NoA
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
WQW00484 Version 4.2 Attachment B Page 1 of 2

P
Mountaire Farms Inc. '
Robeson
34.8655470
-79.1207120
28.64
WkB
01294 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
Q
Mountaire Farms Inc. '
Robeson
34.863033°
-79.1166981
23.80
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
R
Mountaire Farms Inc. '
Robeson
34.8640580
-79.1145990
19.16
pog
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
S
Mountaire Farms Inc.
Robeson
34.878136°
-79.123882°
12.74
WkB
01294 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
T
Mountaire Farms Inc. '
Robeson
34.875146°
-79.1232090
6.25
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acrc
U
Mountaire Farces Inc. '
Robeson
34.8701080
-79.124251 °
3.65
WkB
01284 — Non -Discharge Application Rate
0.60
86
inchesWQ09
— Plant Available Nitrogen
350
lbs/acre
V
Mountaire Farms Inc. '
Robeson
34.8686970
-79.1188070
14.70
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
W
Mountaire Fauns Inc. '
Robeson
34.866495°
-79.117085°
11.08
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
X1
Mountaire Farms Inc.'
Robeson
34.858233°
-79.116596°
25.83
NoA
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
X2
Mountaire Fames Inc. '
Robeson
34.955085'
-79. l 16782°
11.55
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
Y
Mountaire Farms Inc. '
Robeson
34.860833°
-79.113544°
3.21
NoA
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 — Plant Available Nitrogen
350
lbs/acre
Z
Mountaire Farms Inc.'
Robeson
34.8576070
-79.1127760
7.10
WkB
01284 — Non -Discharge Application Rate
0.60
86
inches
WQ09 —Plant Available Nitrogen
350
lbs/acre
Totals
521.44
1. The corporate name is Mountaire Farms, Inc. and the name used in the State of North Carolina is Mountaire Farms of North Carolina, Corp.
WQ0000484 Version 42 Attachment B Page 2 of 2

ATTACHMENT C — GROUNDWATER MONITORING AND LIIVIITATIONS
Permit Number: WQ0000484 Version: 4.2
Monitoring Wells: MW-14, MW 15, MW-37, MW47, MW48, MW49, MW-50, MW-51, MW-52, AM-53, AM-54, MW-55, and AM-56 8
GROUNDWATER CHARACTERISTICS
GROUNDWATER STANDARDS
MONITORING REQUIREMENTS
PCS Code
Parameter Description
Daily Maximum
Frequency Measurement
Sample Type
Footnotes
00680
Carbon, Tot Organic (TOC)
mg/L
3 x Year
Grab
1,6
00940
Chloride (as Cl)
250
mg/L
3 x Year
Grab
1
31616
Coliform, Fecal MF, M-FC Broth, 44.5 °C
#/100 mL
3 x Year
Grab
1
00610
Nitrogen, Ammonia Total (as N)
1.5
mg/L
3 x Year
Grab
1
00620
Nitrogen, Nitrate Total (as N)
10
mg/L
3 x Year
Grab
1
00400
pH
6.5-8.5
Sul
3 x Year
Grab
1,2
00665
Phosphorus, Total (as P)
mg/L
3 x Year
Grab
1
70300
Solids, Total Dissolved -180 °C
500
mg/L
3 x Year
Grab
1
GWVOC
Volatile Compounds (GW)
Present: Yes/No
Annually
Grab
1, 4, 5
82546
Water Level, Distance from measuring point
feet
3 x Year
Calculated
1, 2, 3
1. 3 x Year monitoring shall be conducted in April, August, and December; Annual monitoring shall be conducted every December.
2. The measurement of water levels shall be made prior to purging the wells. The depth to water in each well shall be measured from the surveyed point on the top of the casing. The measurement of
pH shall be made after purging and prior to sampling for the remaining parameters.
3. The measuring points (top of well casing) of all monitoring wells shall be surveyed to provide the relative elevation of the measuring point for each monitoring well. The measuring points (top of
casing) of all monitoring wells shall be surveyed relative to a common datum.
4. Volatile Organic Compounds (VOC) - In December only, analyze by one of the following methods:
a Standard Method 6230D, PQL at 0.5 µg/L or less
b. Standard Method 6210D, PQL at 0.5 µg/L or less
c. EPA Method 8021, Low Concentration, PQL at 0.5 µg/L or less
d. EPA Method 8260, Low Concentration, PQL at 0.5 µg/L or less
e. Another method with prior approval by the Water Quality Permitting Section Chief
Any method used shall meet the following qualifications:
a A laboratory shall be DWR certified to run any method used.
b. The method used shall include all the constituents listed in Table VIII of Standard Method 6230D.
c. The method used shall provide a PQL of 0.5 µg/L or less that shall be supported by laboratory proficiency studies as required by the DWR Laboratory Certification Unit. Any constituents
detected above the MDL but below the PQL of 0.5 µg/L stall be qualified (estimated) and reported.
5. If any volatile organic compounds (VOC) are detected as a result of monitoring as provided in Attachment C, then the Fayetteville Regional Office supervisor, telephone number [phone],
shall be contacted immediately for further instructions regarding any additional follow-up analyses required.
6. If TOC concentrations greater than 10 mg/L are detected in any downgradient monitoring well, additional sampling and analysis shall be conducted to identify the individual constituents comprising
this TOC concentration. If the TOC concentration as measured in the background monitor well exceeds 10 mg/L, this concentration will be taken to represent the naturally occurring TOC
concentration. Any exceedances of this naturally occurring TOC concentration in the downgradient wells shall be subject to the additional sampling and analysis as described above.
7. Monitoring wells shall be reported consistent with the nomenclature and location information provided in Figure 1 and this attachment
WQ0000484 Version 4.1 Attachment C Pagel of 2

N
O
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atl
N
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APPENDIX D
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

BISULFITE
(BY CHEMICAL SUPPLIER)
POLYMER
REAGENT
PROCESS -
WASTEWATER
yi
(GRAVITY FLOW)
T--2201
EX/ST/NG SORIN DAF A
(800 GPM)
POLYMER
REAGENT
EX/SANG E0, 84S/N
(",000 G4L)
I I
T--2202
EX/SANG SORIN DAF B
(800 GPM)
POLYMER
R�GENT
■
T-2203
EX/SANG SORIN DAF C
(800 GPM)
POLYMER
GENT
I i I I
S
w
a
a
N
W �
W
S
U U
S wto
T 3201 IX/SANG - MBBR
EX/SANG I FEED PUMPS T '
S ABOVEGROUND SUMP
(Former Existing Clarifier) NEW MBBR
No. 1
0
ST4 II
� III
EXISnNG PLANT REUSF
REUSE PUMPS
LA J
Q Q
a
a a a
NEW BLOWERS
(4,200 SCFM ® 15 PSIG)
0 0
W W
Z Z
Nc LL
�kImw w
J zi
a.0
w j j
J N
a QJQ J
N F U U
W WW
W W Q } J }}
D U U m d m
w
o�
- �yl
TO LAGOON
NEW MBBR
No. 2 LXISA v%
EXISANG WORLD WATER
WORLD DAM
(2400 GPM)
CONTAINMENT CURB TO TRUCK
LOADING
TEMPORARY SLUDGE
STORAGE TANK
(3 FRAC TANKS)
- - — No _ TO PROCESSING
PLANT
NEW SPARE
PUMP
(lam
g BYPASS TO LAGOON
PRIMARY SOLIDS
(TO TRUCK/HAULING)
S PRIMARY SOLIDS
(TO TRUCK/HAULING)

APPENDIX E
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

ACTIVATED SLUDGE TREATMENT FUNDAMENTALS
This section provides a general description of the fundamentals of activated sludge
treatment.
Mountaire Farms utilizes an activated sludge biological process designed to
accomplish organic removal from the facility waste streams as the second step in its
wastewater treatment process. Nitrification/denitrification is not a major requirement
of the activated sludge process, although the concept behind the theory is briefly
described in this section. The type of biological process used by Mountaire Farms,
MBBR, is somewhat different in its details (as described in Section 6) but these
fundamentals still apply.
The activated sludge process includes two major process units: the aeration basin and the
clarifiers. In the aeration basin, the influent wastewater is continuously mixed with floc -
forming microorganisms in the presence of dissolved oxygen. The organisms absorb and
biodegrade the organic material as food for energy and for cell synthesis, via the following
basic reaction:
Microorganisms
Organics + 02 + N + P 0 CO2 + H2O + New Cells
Organic removal (i.e., BOD removal) occurs primarily in the aeration basin. The
wastewater/microorganism mixture (referred to as the mixed liquor (MLSS)) flows from
the aeration basin to the clarifier(s). The clarifiers provide quiescent conditions, which
allow the sludge organisms to settle out, leaving a relatively clear supernatant. The
clarifier supernatant is discharged as effluent. The settled sludge concentrates at the
bottom of the clarifier, and is continuously pumped from the clarifier back to the aeration
basin. For Mountaire Farms, the secondary DAF functions as a clarifier. Because the
microorganisms grow on media, only excess sludge is discharged to the DAF for removal,
and there is no settled sludge typically pumped back to the aeration basin.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

By returning the sludge back to the aeration basin, high concentrations of organisms are
maintained in the aeration basin. Thus, relatively low detention times in the aeration basin
are required to obtain the treatment efficiency which is required to meet effluent permit
limits. The excess sludge created by biological synthesis and the accumulation of non -
biodegradable solids must be wasted and subsequently treated. The sludge, depending on
its age, consists of varying amounts of degradable material.
The primary function of an activated sludge system is to achieve removal of organics.
Biodegradable organics are commonly measured using the 5-day biochemical oxygen
demand test (BOD5). BOD5 removals of 98 to 99 percent should be achievable under
normal operation. Nitrogen removal is not necessary in the activated sludge system since
the wastes fed to the system are low in nitrogen, and there are no permit limits for ammonia
(nitrification) or for nitrate/nitrite (denitrification). Basic descriptions of nitrification
(Section IA) and denitrification (Section 113) are included here for operator general
knowledge.
In order for the activated sludge process to function, adequate controls are required.
Section 6 of this manual provides a detailed of description of the operational controls for
the Mountaire Farms treatment plant. In general, the major process control parameters
include:
• Organic Load F/M); Dissolved Oxygen (DO); pH;
• Temperature; and Nutrients.
The performance of an activated sludge system requires adequate control of these above
parameters. The organic loading is often referred to in terms of food -to -microorganism
(F/M) ratio. The F/M ratio is defined as the ratio of the mass of influent BOD5 applied to
the system (lb/day) to the mass of organisms in the system (lbs of MLVSS). The MLVSS
(mixed liquor volatile suspended solids) refers to the concentration of volatile suspended
solids in the aeration basin. Volatile solids are assumed to be largely composed of
microorganisms, thus MLVSS provides a measure of the amount of organisms in the
system (See Appendix F for additional explanation). Typical systems are designed to
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

operate at an F/M of 0.3 to 0.6 lb BOD5/lb MLVSS day. The F/M is controlled by the
operator's control of the MLVSS. The sludge organisms continuously reproduce as a
result of the influent organic material provided. The sludge production is generally
approximately 0.3 to 0.6 lb sludge/lb BOD5. In order to maintain the desired F/M ratio,
the sludge must be wasted from the system on a regular basis. Refer to Section 6 of this
manual for a more detailed discussion of process control.
IA. Nitrification
Influent nitrogen may be present in the form of ammonia (NH3-N) and organically
bound nitrogen. Organic nitrogen is converted to NH3-N by carbon oxidizing
(heterotrophic) organisms. NH3-N is converted to NO3-N via nitrification by
nitrifying organisms. Some additional nitrogen removal is accomplished in the
activated sludge process through cell synthesis. The nitrification process is a two-
step process in which specialized nitrifying bacteria convert NH3-N to NO3-N via
the following reactions:
Nitrosomonas
2NH4+ + 302 0 2NO2- + 2 H2O + 4H+ + New Cells
Nitrobacter
2NO2- + 02 2 NO3 + New Cells
As shown in the equations above, the nitrification process produces H+ ions, i.e. it
consumes alkalinity. The nitrification process consumes 7.14 lb CaCO3 alkalinity
per lb of NH3-N nitrified. The nitrification process is carried out by a different set
of organisms than those responsible for organic removal and denitrification. The
nitrifying organisms grow in the mixed liquor along with the other
microorganisms, provided that the right conditions are provided. Nitrifying
bacteria are sensitive to process conditions including the system F/M, sludge age,
temperature, DO, pH, TDS, and NH3-N concentrations.
Operation and Maintenance Manual
Wastewater Treatment System Upgrade
March 2020

1B. Denitrification
Denitrification is a biological process in which activated sludge organisms reduce
NO3-N to nitrogen gas (N2). The denitrification process occurs under anoxic
conditions and is performed by "facultative" heterotrophic bacteria. Anoxic
conditions refer to a condition of low dissolved oxygen levels (less than 0.5 mg/1).
Denitrification is generally performed by the same organisms that use oxygen to
oxidize organics when dissolved oxygen is present. They are "facultative" in that
they will use dissolved oxygen for oxidation when it is present. However, in the
absence of dissolved oxygen they will utilize NO3-N as an alternative electron
acceptor for oxidizing organic material as follows:
Microorganisms
NO3 + Organics N2 gas + CO2 + OH- + New Cells
The nitrogen gas is released to the atmosphere, thus completing nitrogen removal
from the wastewater. The primary conditions required for denitrification to occur
are:
1. Anoxic or extremely low dissolved oxygen conditions;
2. The presence of NO3-N;
3. An organic carbon source for biological respiration; and
4. Adequate anoxic detention time
The denitrification process occurs in the optimum pH range of 6.5 to 8.5. The
denitrification produces alkalinity in the amount of 3.57 lb as CaCO3 per lb of
NO3-N denitrified, thus the denitrification process restores some of the alkalinity
lost in the nitrifying process.
1C. Applicability to Mountaire Farms
The Mountaire Farms wastewater treatment plant provides biological degradation
of the organic constituents, but has not been designed for nitrification or
denitrification. The waste streams are low in nitrogen, and the nitrogen present in
the wastewater will be utilized as a nutrient for the microorganisms. Some
nitrification will take place as part of the plant operation, but denitrification will
not take place in the system as designed.
Operation and Maintenance Manual
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APPENDIX F
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LABORATORY TEST DESCRIPTIONS
Explanations of some of the analytical parameters are presented below. The procedures
for performing dissolved oxygen uptake and sludge volume index (SVI) tests are included.
Analytical methods for other parameters are not included in this manual but should be
performed in accordance with Standard Methods for the Examination of Water and
Wastewater or EPA Method for Chemical Analysis of Water and Wastes, or other
acceptable method. Care should be taken to ensure that the correct sampling containers
and preservation are used, in accordance with the procedures contained in the above
references and outlined herein.
1.0 Biochemical Oxygen Demand (BOD5)
The 5-day biochemical oxygen demand (BOD5) analysis is an attempt to simulate
the effect a waste will have on the dissolved oxygen level in the receiving stream.
The BOD5 test measures the oxygen depletion in the sample over a 5-day period.
This is the most widely used method for estimating the strength of domestic or
other biodegradable wastes. The greater the oxygen depletion, the stronger the
waste and the higher the BOD5.
The BOD5 test gives an indication of the amount of oxygen needed to stabilize or
biologically oxidize the waste and provides a very good indication of the amount
of food the activated sludge organisms are receiving. A major disadvantage of this
analysis is that there is a 5-day lag between sampling and the results. These tests
are performed by an outside laboratory for Mountaire.
2.0 Chemical Oxygen Demand (COD)
The 5-day lag period for the BOD5 test is can be a problem in terms of responding
quickly to changes in operating conditions. A more instantaneous measure of
organic waste strength can be obtained using the chemical oxygen demand (COD)
test. The COD test measures oxygen demand by analyzing the amount of organic
matter in a water sample oxidized by potassium dichromate in strong acid solution
when refluxed for two hours. This test provides the operator with information on
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the influent loading very quickly. The results of the COD tests are higher than the
results of the BOD5 test. For a given waste stream, the ratio of BOD5 to COD is
often times fairly consistent. A general relationship between the BOD5 and COD
should be developed by plotting BOD5 (y-axis) as a function of the COD
concentration (x-axis). Once this relationship has been established for influent
samples and effluent samples, the BOD5 can usually be predicted from a COD
value. The BOD5/COD ratio normally changes through the treatment process.
Therefore, separate correlations for BOD5/COD should be developed for influent
and effluent.
COD tests are conducted by lab personnel at Mountaire and at outside laboratories
for Mountaire.
3. Mixed Liquor Volatile Suspended Solids (MLVSS)
Mixed Liquor Volatile Suspended Solids (MLVSS) provides a measure of the
concentration of microorganisms in the aeration basin. The MLVSS test measures
the concentration of suspended solids that can be volatilized in a muffle furnace at
high temperature and is expressed in milligrams of volatile suspended solids per
liter of mixed liquor. Volatile suspended solids in the mixed liquor are generally
considered to be composed primarily of microorganisms. This test is important
because it provides an indication of the concentration of microorganisms and is
used in calculating the food to microorganism F/M ratio, which is the process
loading criteria used in control of the activated sludge process.
MLVSS tests are not performed at Mountaire, using suspended solids tests
(MLSS described below) instead.
4. Mixed Liquor Suspended Solids (MLSS)
Mixed Liquor Suspended Solids (MLSS) is related to the MLVSS. The MLSS test
measures the total suspended solids in the mixed liquor. This includes both the
volatile suspended solids (MLVSS) and inert solids.
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The MLSS analysis is easier to perform than the MLVSS analysis. Under stable
process conditions the MLVSS/MLSS ratio will remain relatively consistent.
Therefore, the MLSS concentration can be used to estimate the MLVSS
concentration. The MLSS test is also important for monitoring the buildup of
inorganics in the system and checking the solids loading during settling.
5. Oxygen Uptake Test
The oxygen uptake test measures the amount of oxygen utilized by a unit weight of
mixed liquor microorganisms in a unit time, and is expressed as lb 02 per lb
MLVSS per day. Oxygen uptake is an important monitoring parameter because it
reflects the activity of the microorganisms. High oxygen uptakes typically occur
under high organic loading or high F/M conditions. Low oxygen uptakes occur
during low loading conditions, or can result from inhibition of the sludge organisms.
This test can be used to verify the viability of the process organisms and identify
the occurrence of severe upset conditions such as shock loading or toxicity. The
procedure to conduct the oxygen uptake test is included at the end of this appendix.
6. Settleability Test
The sludge settleability test is used to give an overall indication of "sludge quality"
and how well the mixed liquor solids should settle in the secondary clarifier. For
the settleability test an aeration basin mixed liquor sample is placed in a 1-liter
graduated cylinder or "settleometer" to measure and observe solids settling
characteristics under ideal conditions.
An important factor in running the settleability test is to observe the settling and
compaction characteristics of the MLSS. Often operators walk off after setting up
the test and come back to read and record the settling level at the end of 30 minutes.
In doing this, they may miss important information by not observing how the sludge
settles. Use of the 30-minute test results only to calculate the SVI does not provide
the maximum benefit for process control. The operator should attempt to record the
following observations during the test so that correlations to other laboratory
control tests used for process control can be made:
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A. First Five to Ten Minutes
1. Do sludge particles agglomerate while forming blanket?
2. Does sludge compact slowly and uniformly, leaving a clear liquid, or
do sludge particles fall through a cloudy liquid?
3. How much and what type of straggler floc, if any, remains in the
liquid?
B. End of 30 Minutes
1. Has the sludge floc compacted to the appearance of looking crisp with
sharp edges and somewhat like a sponge? or,
2. Does the floc look feather -edged fluffy and somewhat homogenous?
C. End of 60 Minutes
1. Has any settled sludge floated to the surface of the cylinder?
2. Did the sludge to split or float to the surface?
These observations provide a check on the secondary clarifier sludge
blanket characteristics and removal rates in relation to sludge detention
time in the clarifier.
7. SVI
The sludge volume index (SVI) test uses the results of the MLSS test and the
settleability test in order to provide an index to quantify the settleability of the
sludge. The SVI is expressed in terms of volume in milliliters occupied by one gram
of mixed liquor suspended solids (ml/g). The SVI is an index of the solids settling
and compaction characteristics and will indicate whether or not the sludge is
developing bulking tendencies (solids settling problems). The SVI parameter
provides a good indication of the overall health of the activated sludge. Table E-1
provides a general correlation between SVI and sludge settling characteristics.
Note that these are general guidelines. The relationship between bulking tendency
and SVI varies from plant to plant. In other words, an SVI that may indicate the
onset of bulking in one plant may be in the normal operating range for another
plant. The SVI values that represent bulking conditions will have to be established
for each WWTP.
TSS analysis of the SVI test supernatant provides an indication of the TSS
concentration which can be expected in the treated effluent from the plant. It also
assists in tracking conditions such as pin floc (presence of dispersed solids which do
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not settle) which may not be evident in the numerical results of the SVI test alone.
The procedure to complete the SVI test is included at the end of this appendix.
TABLE E-1
SVI VALUES IN RELATION
TO SLUDGE BULKING TENDENCY("
Value
Description of Settling
(ml/g)
Characteristics
<150
Excellent
150-250
Good
250-350
Fair
>350
Poor
Note: (1) These are general values for reference only. The bulking tendency relative to the SVI
values will vary from WWTP to WWTP. SVI values that represent bulking conditions must be
established for each WWTP.
8. Microscopic Examination
Microscopic examination of the mixed liquor can be a significant aid in the
evaluation of the activated sludge process. The presence of various microorganisms
within the sludge floc can rapidly indicate the health of the biological system. An
upset or unhealthy sludge can lead to reduced organic and nitrogen removal, high
effluent turbidity and TSS and/or poor settling. The predominant microorganisms
are the heterotrophic and autotrophic bacteria which are responsible for most of the
treatment of the wastewater. In addition, protozoa plays an important role in
clarifying the wastewater and act as indicators of the health and stability of the
biological sludge system.
Protozoa are higher life forms that feed on the bacteria. A predominance of
protozoa (ciliates) and rotifers in the mixed liquor is a sign of a stable biological
system. The absence of these higher organisms often indicates a system that has
been overloaded, shocked or is experiencing toxicity. Toxicity, overload or shock
can cause reduced treatment performance, high effluent turbidity and poor settling.
Another concern is the development of filamentous organisms. Filaments appear as
long stringy spaghetti like organisms. Excessive growth of filamentous organisms
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can cause sludge bulking. The sludge floc is unusually light and fluffy because it
has a low density.
Observation of microorganism activity and predominance in the activated sludge
can be used to assist the operator in process control decisions, such as increasing or
decreasing the F/M and MLSS or the need to respond to an upset or shock condition.
These observations make it possible to detect a significant shift in the
microorganism population as an upset develops and before it causes a catastrophic
decline of the solids settling characteristics and treatment process performance.
These changes can be correlated with the SVI results, observations in the solids
settleability test and changes in F/M to confirm the need for process changes.
9. DO Profiles and Anoxic ORP
DO profiling, which refers to measuring DO at various locations in the basin, is
not typically necessary at Mountaire to verify a proper air distribution. This
information can be used to make adjustments to the aeration systems. Once the
aeration is set, it is not typically necessary to perform DO profiles regularly,
unless influent loads change significantly or process performance deteriorates.
DO profiles and anoxic ORP measurements are extremely useful for diagnosing
process problems (such as inadequate nitrification or denitrification).
Mountaire monitors DO concentrations in each MBBR basin to verify proper
oxygen distribution.
ORP (oxidation-reduction potential) is a measurement of the reducing or
oxidizing conditions in the liquid. In general ORP levels of <+50 mV are
conducive to denitrification, with lower values indicating a greater tendency for
denitrification. ORP is measured using a portable ORP probe (which can be
plugged into a pH meter). At DO levels less than approximately 0.5 ppm, the
accuracy of DO meters deteriorates significantly. ORP measurements provide a
better indication of anoxic conditions in the anoxic zone. This is not usually
needed for Mountaire operations.
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OXYGEN UPTAKE RATE (OUR)
INTRODUCTION
The oxygen uptake rate is a measure of the rate of consumption of oxygen by the
microorganisms. It serves as an index of the general state of health of the micro-
organisms.
EQUIPMENT
The following equipment are required to perform the test:
1. BOD bottle
2. DO Meter with self -stirring BOD bottle probe or standard BOD bottle
probe with magnetic stirrer (YSI Model 54 or equivalent).
3. Stopwatch
4. Air supply
5. Air diffuser stone
PROCEDURE
1. Collect a 400 ml or more mixed liquor sample.
2. Aerate sample to a DO of 5 to 7 mg/L or more.
3. Pour mixed liquor sample into a BOD bottle filling the bottle to the top of the neck.
4. Insert the DO probe making sure that no air bubbles are present in the bottle. Ensure
that the contents of the bottle are completely mixed. If the solids are too heavy for the
probe stirrer to completely mix the bottle's contents, the additional stirring provided
by a magnetic stirrer may be required.
5. Record the DO in the sample and initiate the stopwatch.
6. Record the DO in the bottle at 30 second intervals, recording the values in the
appropriate column on the data sheet. Based on experience, depending on the rate of
decline in DO it may be desirable to adjust the time interval between readings to 60
seconds or more.
7. Each time the DO is measured, calculate the DO drop. The DO drop is the DO drop
between the current reading and the previous one. For example if the previous DO
reading was 4.0 mg/L and the current reading is 3.5 mg/L the DO drop = 4.0-3.5=0.5
mg/L.
8. At first, the DO drops may vary from one time interval to the next. As the experiment
progresses the DO drops should become more consistent. The test may be terminated
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after a constant drop in DO has been observed over four (4) or more consecutive
time intervals.
9. Calculate the OUR using the DO drop that was observed consistently over four (4) or
more time intervals.
DO Drop ('9
OUR )
=
Time Interval (min)
Procedure for SVI (Sludge Volume Index) Test
1. Collect a sample of mixed liquors from the aeration basin (723).
2. Fill a 1-liter graduated cylinder to the 1-liter mark. Mix well, then remove stirrer.
3. Record interface level after 30 minutes.
Calculations of SVI
1. For 1-liter sample:
SVI = settled sludge volume (ml) x 1000
mg
For other 1-liter samples, multiply the number calculated above by:
1000
sample volume (ml)
SVI calculation example:
Volume sample = 1000 ml
Volume settled sludge = 100 ml
MLSS = 2500 mg/l
100 ml
SVI = x 1000 = 40 ml/g
2,500 mg/L
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APPENDIX G
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SAMPLE COLLECTION AND HANDLING
Successful control and monitoring depends on obtaining reliable analytical results, which
can be obtained only if the samples are collected and handles properly. Specifically, the
following should be ensured:
1. Samples are truly representative of the wastestream.
2. Proper sampling techniques are used.
3. Samples are properly preserved and stored until analyzed.
To meet the first requirement, it is imperative that samples be taken from points where
adequate mixing exists and no segregation of solids due to partial settling or flotation
occurs. Points where suspended solids or floating oil have accumulated should be
avoided.
Samples can be generally classified as "In Basin", "Grab", "Flow Weighted Composite"
and "Time Weighted Composite". "In basin" refers to parameters which are measured by
inserting a probe or other measuring device directly in the aeration basin (such as DO,
ORP, temperature and pH).
Grab samples are used either when a composite sample is not necessary, and/or if it is
undesirable to allow the sample to sit in a sampling container for an extended period. Mixed
liquor and sludge samples are normally collected as grabs. Due to the detention time and
mixing in the aeration basin, parameters such as MLSS and MLVSS do not normally vary
significantly over a short period, and it is undesirable to allow sludge samples to sit for
long periods.
Composite samples are desirable for parameters which may vary significantly over time.
As shown in Table F-I for parameters such as COD, BOD5, TSS, TKN, etc. it is desirable
to collect composite samples. Composite samples are usually collected over a 24-hour
period. Composite samples are intended to reflect the average level of a parameter over the
composite period. This provides the advantage of leveling out instantaneous spikes and
dips which may occur, and provides a better representation of the influent loads to a system,
or the effluent loads being discharged in the final effluent.
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Composite samples may be time weighted or flow weighted. Time weighted composite
samples are collected by collecting sample aliquots at given time intervals and mixing the
aliquots together to make the composite. For example an aliquot may be collected every
1/2 hour. These can be done by hand (provided that an operator is available to grab an
aliquot at each interval) or using an automatic sampler. Time weighted composites provide
a better representation of average conditions and average loads as compared to grab
samples. However, time weighted composites may be skewed due to variations in flow.
Since time weighted composites do not account for variations in flow, aliquots collected
during low flow periods are weighted the same as those collected during higher flows.
This introduces some error when using time composites for estimating influent and
effluent loads.
Flow weighted samples provide the best representation of average loads. For flow weighted
sampling, it is necessary to use an automatic sampler linked to a flow meter. Sample aliquots
are collected at a given flow interval. For example, the sampler may be programmed to
collect a sample aliquot for every 1,000 gallons of flow. ForMountiare, the effluent samples
are flow weighted based on the effluent flow meter.
In order to obtain a representative sample, several precautions are necessary. Some of these
precautions and general sampling rules are as follows:
1. The samples should be taken at a place where the wastewater is well mixed, such
as near a Parshall flume or a location with hydraulic turbulence. Weirs tend to
enhance the settling of solids immediately upstream and the accumulation of
floating oil or grease immediately downstream. Such locations should be avoided
as a sample source;
2. If necessary, a low level of turbulence can be induced by blowing air through the
wastestream if the wastestream is not to be analyzed for dissolved gases or volatile
matter. Mechanical stirring may be used to induce turbulence with much less
influence on the results;
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3. The sample should be taken in the center of the channel of flow where the velocity
is highest and the possibility that solids have settled is a minimum. The mouth of
the collecting container should be placed a few inches below the water surface to
avoid an excess of floating materials;
4. The sampling of wastestreams with free oil requires special attention. At places in
the wastestream where oil floats, it is simple to obtain a sample of the oil to
analyze, but difficult to determine the quantity of oil. A method commonly used
to estimate total volume is to divert the wastestream into a container. After
separating the two fluids, it is possible to measure the thickness of the oil layer
and thus ascertain the volume of oil present. Since oil adheres to the sampling
device, frequent cleaning is required;
5. The sample container and sampling device should be clean and uncontaminated;
6. The volume of the sample obtained should be sufficient to perform all the required
analyses and include an additional amount for repeating any doubtful analyses. The
required volume of sample for most analyses is shown in Table 5-3. The sample
volume required will depend on the analytical technique and the strength of the
waste stream, and can be refined based on experience. Depending on the frequency
of sampling and the individual sample volume, the total composited sample should
be between 2 and 4 liters;
7. Samples should be preserved appropriately as indicated in Table 5-3. Note that
some parameters require the same preservation and can be stored in the same
bottle; and
8. Each sample container should be labeled with an identification card containing, as
a minimum, the following information:
a. Designation or location of sample collection.
b. Date and time of collection.
c. Indication of grab or composited sample with appropriate time andvolume
information.
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d. For official compliance samples and for other samples being sent to an
outside lab, a chain of custody form should be completed and accompany
the samples.
Samples should be analyzed as soon as possible after collection. Unless a sample can be
analyzed immediately after collection, it must be preserved immediately as indicated in
Table 5-3. Preservation techniques include chilling, and H2SO4 or NaOH addition. Note
that where H2SO4 or NaOH addition is required, as for metals or nitrogen, it is common
practice for the lab to provide pre -preserved bottles, i.e., the clean bottle already has the
required amount of preservative in it. If this is the case, the sample collection must take
care to avoid spilling the preservative. The table includes parameters that are not a part of
the routine monitoring program at this plant, but may be analyzed occasionally for special
purposes.
TABLE F-1: SAMPLE VOLUME AND PRESERVATION
Parameter
Typical Volume
Required(I) (ml)
Preservative
Max
Holding
Period
BOD5
500
Cool to VC
48 hours
TSS
200
Cool to 4°C
7 days
Color
500
Cool to 4°C
24 hrs
Alkalinity
100
Cool to 4°C
14 days
Acidity
100
Cool to 4°C
14 days
Chloride
100
None Required
7 days
Fluoride
100
None Required
7 days
Total Hardness
100
5 ml HNO3 per liter
6 months
TOC
100
2 ml H2SO4/ liter (pH 2)
7 days
COD
100
2 ml H2SO4/ liter & Cool to 4°C
28 days
NH3-N
500
2 ml H2SO4/liter & Cool to VC
28 days
TKN
500
2 ml H2SO4/liter & Cool to VC
28 days
NO3/NO2-N
100
2 ml H2SO4/liter & Cool to VC
28 days
TP
100
2 ml H2SO4/liter & Cool to VC
28 days
Oil and Grease
2000
2 ml H2SO4/liter & Cool to VC
24 hours
Soluble PO4-P
100
Filter immediately & Cool to VC
48 hrs
Metals -Total
100
HNO3 pH <2
6 months
Metals -Soluble
100
Filter immediately then HNO3 pH <2
6 months
Note: (1) Sample volumes are conservative estimates. Actual minimum volume may vary depending on the
sample concentration and laboratory technique.
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APPENDIX H
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APPENDIX H
DETAILED PROCESS CONTROL OPERATING STRATEGY
ORGANIC LOAD AND SETTLEABILITY
The proper control of these parameters is discussed in this section (Section H-1).
1. Organic Load (F/M, MLVSS, and MCRT)
The characteristics and performance of the biological system are largely influenced
by the organic loading to the system and the sludge age (or mean cell residence
time (MCRT)). The organic loading is defined in terms of the food -to -
microorganism ratio (F/M). The F/M is usually defined as the lb/day of influent
BODs per lb of MLVSS in the aeration basin, and is calculated as follows:
F/M = Inf BODs Load (lb/d)
MLVSS (mg/1) x Basin Volume (MG) x 8.34
The units of F/M are lbs BODs applied/lb VSS-day or day-1 . The sludge age or mean
cell residence time (MCRT) defines the average age or residence time of the
organisms in the system. The sludge age impacts what microorganisms will
predominate in the system (some organisms take longer to grow than others). A low
sludge age (less than 5 days) can result in an unstable system that is susceptible to
upset. Typical sludge age should be in excess of 10 days. 5-15 days is typical for
an activated sludge plant with up to 30 days typical for an extended aeration plant.
The sludge age (MCRT) is equal to the mass of organisms in the system divided
by the mass of organisms leaving the system. Organisms leave the system through
sludge wasting and through solids carry-over from the clarifiers. Sludge age
(MCRT) is calculated as:
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MCRT = MLSS (mg/1) x Basin Volume (MG)
[WAS (MGD) x Waste Sludge TSS (mg/1)] + [Effluent (MGD) x Eff
TSS(mg/l)]
WAS = Waste Activated Sludge flow (MGD)
The F/M and the sludge age are related by the yield coefficient (Y), which
is the net mass of biosolids produced per lb of BODs:
MCRT = 1
F/M (d"1) x Y (lb VSS/lb BODs)
For a given system and waste composition, the yield coefficient (Y) is
relatively constant. Therefore, the average F/M and the MCRT are directly
related. As the F/M is increased, the MCRT will decrease. This is because
increased food addition will promote faster organism growth, which will
require more sludge wasting to maintain a given MLVSS. As the WAS
increases, the MCRT decreases. Since F/M and MCRT are directly related,
either of these parameters can be used as the primary control parameter,
with the other parameter being monitored on a secondary basis.
The recommended control procedure is to control the MLVSS in order to
maintain a relatively constant F/M. The operator controls the MLVSS
through sludge wasting. The target MLVSS can be calculated in order to
achieve a desired F/M level by rearranging Equation 6-1 as follows:
Target MLVSS (mg/1) = Influent BODs Load (lb/d) (eq 6-3)
F/M (d-1) x Basin Volume (MG) x 8.34
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Once a target MLVSS is calculated, the required sludge wasting to
obtain the target MLVSS can be calculated as follows:
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MI
WAS (MG) = (Actual MLVSS (mg/1) — Target MLVSS (mg/1)) x (2.77 MG) (eq
RSVSS (mg/1)
Note that RSVSS is the volatile suspended solids concentration of the return
sludge. The analytical schedule (Table 5-1) calls for measurement of RSSS
(sludge TSS). The RSVSS can be determined through direct measurement or by
multiplying the RSSS values by the ratio of MLVSS/MLSS in the aeration basin.
An effort should be made to maintain a regular wasting schedule in order to
minimize fluctuations in MLVSS levels. Note that there can be considerable
analytical variability in MLSS and MLVSS analytical results. Therefore, caution
should be used to avoid making major changes based on a single analysis. Daily
influent BOD5 loads need to be tracked. Since daily BOD5 results are not available
right away, the daily COD data can be used to provide an estimate of current BOD5
loads. As changes in influent BOD5 load occur, this will impact the target MLVSS
required to maintain a consistent F/M. However, influent BOD5 loads may vary
significantly from day to day, and it is not possible to try to vary the target MLVSS
each day to account for these variations. Instead, in general, the target MLVSS
should be calculated based on long-term average BOD5 loads, with the objective of
maintaining a relatively constant average F/M. The appropriate averaging period
will vary from system to system. A rolling 30-day average is typical for this type
of system.
The primary parameters that the operator should calculate with regard to organic
load include:
• Daily Influent BOD5 & Nitrogen Load;
• Rolling 30-day Avg BOD5 & Nitrogen Load;
• Daily F/M;
• Rolling 30-day average F/M; and
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• Sludge Age (MCRT).
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The operator should calculate rolling 30-day average BOD5 loads and F/M each
day a new data point is received. This way, the operator will be able to recognize
long-term changes in BOD5 loads, and make adjustments to the target MLVSS to
maintain the desired F/M. In addition, by reviewing the actual 30-day rolling
average F/M values, along with the overall process performance, the operator can
assess the appropriateness of the F/M and the overall plant operating strategy, and
make adjustments as needed.
The primary control objective is based on the 30-day average F/M. The daily F/M
(calculated based on the influent BOD5 load and MLVSS on an individual daily
basis) should also be calculated and reviewed. The daily F/M will vary from day
to day, and will indicate if there are major changes in the system which may need
to be addressed. The biological process is not normally adversely impacted by
short-term variations in waste load, except when extremely high loading conditions
(overload) occur. Even though the daily F/M is not normally the governing control
parameter, the operator should still calculate and review daily waste loads and F/M
on a daily basis (in addition to the long-term averages). This will help the operator
to identify when extreme conditions or conditions that may cause process problems
are occurring.
If there is a significant abrupt change in the waste characteristics and/or load, the
source of this change should be evaluated. If this change is anticipated to hold for
a period of time, it may be necessary to be proactive in adjusting the target MLVSS
based on the current conditions. For example, if an event happens in the production
facility which causes influent BOD5 loads to increase substantially and remain high
for several days or more, it may be desirable to increase the target MLVSS based
on these new load conditions to minimize the impact of the load increase (rather
than controlling solely based on the 30-day rolling average waste load, which does
not account fully for the change in waste characteristics).
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Another situation would be an anticipated increase in load that will occur due to
an anticipated change in a production process or startup of a new production
process. If the load increase will be substantial and will continue over a long
period, then it may be desirable to estimate the BOD5 load ahead of time and adjust
the target MLVSS based on this new load, so that the sludge inventory can be
increased ahead of time. In addition, if there is a significant drop in waste load,
and it is anticipated that the lower load will occur over an extended period (such
as downtime of a production process) this may require lowering the target MLVSS
once the waste load has reduced, in order to avoid an extended low F/M period.
As indicated in Table 6-1 the biological treatment plant is designed to operate in an
average F/M range of 0.3 (two basins) to 0.6 (one basin). With operating experience
the operator will gain a better understanding of how each system responds to
various F/M levels, and to determine what the optimal F/M is for each system. Note
that as waste conditions change the system operating characteristics may change
and it may be necessary to adjust the target F/M. Due to variability in the
degradability of different wastes, the addition or omission of certain waste streams
may impact the plant operation and impact the optimum F/M operating conditions.
With experience and through reviewing the operating and performance data, the
operator will gain an understanding of the impact of various waste streams. For this
reason, it is important to calculate the rolling average F/M on a daily basis, based
on the most recent available data, and to compare this with the other operating
performance data.
As discussed earlier, the MLVSS is determined based on maintaining the desired
F/M. As indicated in Table 6-1, the biological system accommodates a wide range
in MLVSS values corresponding to a wide range in average influent loads. In
general the practical upper limit for MLVSS is approximately 6,000 mg/l.
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The F/M and sludge age ranges presented in Table 6-1 are typical for this type of
system and should provide good process stability. With operating experience, it
may be desirable to modify these ranges slightly. In general too low an F/M (high
sludge age) can cause the development of filamentous organisms and settling
problems. Too high an F/M (low sludge age) can also cause poor settling, poor
organic and poor nitrogen removal.
2. Clarification
Clarification is a critical part of the activated sludge process. Poor clarification
performance can cause poor effluent quality due to solids carryover, and in severe
cases can cause a significant loss of MLVSS from the system. The performance of
the biological treatment process is dependent upon successful separation of
biological solids and return of the settled sludge to the aeration basin. The
performance of the clarifier is primarily influenced by
• Influent flow;
• MLSS;
• return sludge flow rate;
• sludge settleability; and
• sludge blanket level.
Process monitoring of the clarifier includes:
• visual observation of clarifier overflow and surface;
• measurement of sludge blanket levels;
• sludge settleability (using the sludge volume index (SVI)test);
• return sludge suspended solids (RSSS);
• effluent TSS;
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• return sludge (RAS) flow rate; and
• sludge wastage rates.
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A primary operating objective with regard to clarification is maintaining the
sludge blankets at the appropriate level. Too high a sludge blanket can cause
excessive carry-over of sludge solids to the effluent, and reduces the inventory of
solids in the aeration basin (i.e., the MLVSS) available for the treatment process.
A high sludge blanket depth (and the resulting long sludge detention time in the
clarifier) can also contribute to rising sludge due to denitrification in the clarifier
(see Section 6.1.8.2).
In most activated sludge systems it is desirable to maintain the sludge blanket level
at 1 to 3 ft. The optimum operating level can best be determined based on
operating experience.
The sludge blanket level is impacted by the return sludge flow (RAS) rate, influent
flow, MLSS, sludge settling characteristics and return sludge suspended solids
(RSSS) concentration. In general, the required RAS flow can be determined by a
mass balance based on the following equation:
QRAS — Qlnfluent X MLSS
RSSS - MLSS
Under steady state conditions the mass of solids returned to the aeration basin via
the return sludge must equal the mass of solids entering the clarifiers via the
aeration basin effluent (minus the amount of sludge wasted, or carried over in the
clarifier effluent). As indicated in the equation above, increasing influent flow
and/or increased MLSS tend to increase the required RAS flow (since these both
result in increased solids load to the clarifiers). Decreasing RSSS increases the
required RAS flow (since the solids in the return sludge are less concentrated).
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The RSSS is an important factor in determining the sludge blanket level and the
required RAS rate. The RSSS is related to the sludge settleability, and the sludge
blanket depth. To a limited extent, as the sludge blanket increases, this causes more
compaction in the sludge at the bottom of the clarifier and increases the RSSS. This
phenomenon provides some degree of self -correction in the system, and helps to
eliminate the need to constantly adjust the RAS flow in response to normal
variations in influent flow.
In practice, the RAS rate is normally adjusted incrementally on more or less a trial
and error basis, in response to the clarifier sludge blanket levels. For example, if
the operator sees that the sludge blanket depths are increasing to an unacceptable
level, he/she may decide to increase the RAS flow incrementally (in addition to
assessing the cause of the increase). An increased level of sludge in the clarifier
may indicate the need to waste sludge. It is normally not necessary to vary the RAS
flow on a daily basis in response to routine variations in flow, except when there
are high flows (such as those associated with storm flow).
Once the return sludge flow rate has been changed, the sludge blanket will normally
approach an equilibrium level within several hours. This may affect the RSSS
concentration and require further adjustment of the return sludge flow rate.
If the sludge settleability degrades, this will have a dramatic impact on sludge
blanket levels, due to the formation of a less dense, less compact sludge blanket,
and due to the fact that the RSSS often thins out when settleability is poor. As an
initial response to degraded settleability and increasing sludge blanket, it is often
necessary to increase the RAS flow. Polymer addition can also be used to aid in
settling. However, if settleability continues to degrade, it may not be possible to
control the sludge blanket through polymer and increased RAS. Therefore, it is
imperative that the operator also diagnose and address the cause of the poor
settleability (see Section 6.2.8).
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The secondary clarifiers should be observed daily for surface scum buildup and
effluent clarity. If a buildup of scum occurs, the operator should first observe the
skimming system to determine if it is operating properly. If it is not, then appropriate
adjustments and cleaning should be implemented.
3. Sludge Settleability
As discussed in the previous section, sludge settleability has a significant impact
on clarifier and overall system performance. Sludge settleability is a major
concern in the activated sludge process. Sludge settleability can be impacted
dramatically by various process control parameters. Improper process control
and/or shock loading conditions often result in sludge settling problems.
However, even with vigilant process control, some systems are more prone to
bulking due to influent characteristics and various process factors.
SVI is a good indicator of sludge settleability when used in conjunction with
observation of the solids settling in the clarifier. Microscopic examination is a
very useful tool in assessing the health of the biological system, and can be a
particularly valuable tool for diagnosing the cause of settleability and other
problems. Any change in sludge quality observed in these tests will provide the
operator with information necessary to make process adjustments.
This section discusses some of the common causes and remedies for sludge
settling problems. The four major sources of sludge settleability problems are
discussed in general below. These are: (a) filamentous growth, (b) denitrification
in the clarifier, (c) carbon dioxide release in the clarifier, and (d) extracelluar
polymers. A more detailed discussion of the activated sludge system operations
and strategies to control sludge settling is included in Section 6.3.
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3.1 Filamentous Organism Growth
All activated sludges contain some filamentous organisms, and a small amount
of filamentous organisms actually improves floc integrity and effluent turbidity.
However, overgrowth of filamentous organisms can cause serious sludge settling
problems. There are several different conditions that can lead to excessive
filamentous growth. The most common causes include low F/M, low nutrients
and low DO. As discussed in previous sections, it is important to control these
parameters correctly to avoid filaments. There are a variety of other less common
causes, which are beyond the scope of this manual and are not discussed here.
The operator should periodically view the sludge under a microscope, even when
settleability is good. If settleability begins to degrade (as evidenced by poor
performance or increased SVI) microscopic examination can indicate if the
settling problem is being caused by filaments or by other reasons. If settling
continues to degrade or if serious settling problems occur, the sludge can be
examined by a microbiologist to determine the specific types of filaments or other
causes of the settling problems. This type of analysis is also particularly useful if
the settleability problem cannot be linked to one of the common causes discussed
here.
One method the operator may use to control filaments is to add chlorine or other
oxidant to the return sludge. Approximately 5-10 pounds of chlorine per 1,000
pounds of MLSS have been shown to help to control many types of filaments.
It may be possible to substitute peroxide or another oxidant in place of chlorine.
In some cases oxidant addition can cause high turbidity. This is dependent on the
floc structure and the oxidant dose. High oxidant dosages can cause high turbidity
due to destruction of the organisms and breakup of the floc. Chlorine (or other
oxidant) addition is not known to be as effective for actinomycete control.
Polymer addition can also aid in sludge settling when settleability is poor.
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3.2 Biological Denitrification
In the biological denitrification process the organisms convert the nitrate to
nitrogen gas. If significant denitrification occurs in the clarifier sludge blanket,
this can result in the production of nitrogen gas bubbles which float to the top of
the clarifier carrying sludge floc with them. Conditions leading to this include:
• inadequate removal of NO3-N in the anoxic treatment step;
• low DO in the aeration basin effluent; and/or
• long sludge residence time (too high sludge blanket) in the clarifier.
The susceptibility to this phenomenon varies from system to system. Anoxic
conditions are encouraged in the clarifier sludge if the sludge blanket is too high
(i.e. the residence time in the clarifier is too long). Having some DO in the
clarifier influent (aeration basin effluent) helps to minimize anoxic conditions in
the clarifier and in most cases will help to minimize sludge floating. Septic
conditions associated with excessive sludge blanket depths can also lead to
floating sludge due to hydrogen sulfide and other gases besides nitrogen. The
control of floating sludge requires the operator to recognize the problem and
identify and address the specific cause.
3.3 Carbon Dioxide Gassing
The biological nitrification-denitrification process has a tendency to provide
carbon dioxide gassing at low pH levels. Under low pH conditions, when there is
not adequate mixing or stripping, carbon dioxide gas bubbles may form in the
aeration basin. As the gas containing mixed liquor flows to the clarifier, there is
a release of carbon dioxide resulting in a floating sludge. The operational control
to reduce this clarifier-gasing problem is to increase alkalinity to bring the pH
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above 6.8, which will reduce the formation of carbon dioxide.
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3.4 Extracellular Polymers
The microbial system in activated sludge forms extracelluar polymers. These
polymers, under normal conditions, bind the biological floc together and provide
a sludge which settles good and has a low effluent TSS. However, under stress
conditions (low nutrients, very low loadings, high loadings, septic wastewaters,
etc.), there can be a change in the extracelluar polymer formation. This can result
in foaming, floating solids and a turbid effluent. When these conditions occur
the changes in the system operation need to be addressed.
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