EPA-600/2-75-058
December 1975
Environmental Protection Technology Series
                               State  of the Technology
                        SEMI-AUTOMATIC  CONTROL OF
            ACTIVATED  SLUDGE TREATMENT PLANTS


                                  Municipal Environmental Research Laboratory
                                        Office of Research and Development
                                       U.S. Environmental Protection Agency
                                               Cincinnati, Ohio 45268

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                    RESEARCH REPORTING SERIES


Research reports of the Office of Research and Development,
U.S. Environmental Protection Agency, have been grouped into
five series.  These five broad categories were established to
facilitate further development and application of environmental
technology.  Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in
related fields.  The five series are:

           1.  Environmental Health Effects Research
           2.  Environmental Protection Technology
           3.  Ecological Research
           4.  Environmental Monitoring
           5.  Socioeconomic Environmental Studies

This report  has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series.  This series describes research performed to
develop and  demonstrate instrumentation, equipment and methodol-
ogy to repair or prevent environmental degradation from point
and non-point sources of pollution.  This work provides the new
or improved  technology required for  the  control  and treatment of
pollution sources to meet environmental  quality  standards.
This document is available to the public through the National
Technical Information Service, Springfield, Virginia  22161.

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                                   EPA-600/2-75-058
                                   December 1975
          State of the Technology

         SEMI-AUTOMATIC CONTROL OF
     ACTIVATED SLUDGE TREATMENT PLANTS
                    by

               Carl A. Nagel
      County Sanitation Districts of
            Los Angeles County
        Whittier, California  90607
         Contract No. R803 055-01-0
              Project Officer

               Robert Smith
       Wastewater Research Division
Municipal Environmental Research Laboratory
          Cincinnati, Ohio  45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
    OFFICE OF RESEARCH AND DEVELOPMENT
   U.S. ENVIRONMENTAL PROTECTION AGENCY
          CINCINNATI  OHIO  45268

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                         DISCLAIMER
This report has been reviewed by the Municipal Environmental
Research Laboratory, U.S. Environmental Protection Agency,
and approved for publication.  Approval does not signify that
the contents necessarily reflect the views and policies of
the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
                             IX

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  Fred,




       I  recommend  the  following  components  for  the  A£I  program:
  I.   Evaluate and demonstrate current  technology




      A.   Programmable calculators




      B.   Desk top computers




      C.   Programmable logic  controllers




      D.   Process controllers




 II.   Evaluate the need for automated analysis




      A.   Sludge settling velocity




      B.   Sludge blanket monitor




      C.   Wastewater treatability/toxic monitor




      D.   Sludge dewaterability




      E.   Sludge cake moisture analyzer




      F.   D.O. uptake rate




III.   Evaluate proposed control strategies




 IV.   Training operators on instrumentation maintenance




  V-   A§I program self monitoring

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I.   Evaluate and Demonstrate Current Technology




         This component of the A§I program would evaluate and/or demon-




    strate the use of devices that have had substantial technology




    advancement in the past 5 years.  These devices would include




    programmable calculators, desk top computers, programmable logic




    controllers, and process controllers.   The potential use of these




    devices is outlined as follows:




    A.  Programmable Calculators




             These devices are capable of receiving a number of input




        valves such as MLVSS, RAD-VS, and sludge blanket level, and




        computing a given equation such as solids inventory.   The device




        is capable of retaining the program when shut off.   Thus,




        repetitive daily calculations can be performed more timely.




        Current cost of these devices range from $100 to $500.




    B.  Desk Top Computer (Home Computers)




             The desk top computer would analyze operational  data similar




        to the programmable calculator but have the additional advantage




        of data storage.  This allows the desk top computer to analyze




        historical data (about one year data volume) for effluent




        quality vs. operating parameter over a long time period.   This




        would be used by an engineer or class III operator to evaluate the




        operating parameters of his plant.  Current cost of these devices




        are changing rapidly with the introduction of home computers.




        Current price ranges from $2,000 to $10,000.




    C.  Programmable Logic Controllers




             These devices are capable of performing relay logic (off/on),




        timing and counting functions for process control.   These functions

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         cover 70 to 90% of all process control functions required at a




         wastewater treatment plant.   Some of these devices can interfere




         with a common telephone and  communicate with a central office.




         Thus, they can be used for remote monitoring and process control.




         Current cost of these devices are $5,000 to $10,000.




     D.   Process Controllers




              These devices are capable of performing all the  functions




         of the programmable logic controller plus analog control (flow




         control and D.O. control).  These functions cover all but the




         most exotic control functions required to operate a conventional




         wastewater treatment plant.   Current cost of these devices range




         from $5,000 to $20,000.






II.   Evaluate the Need for Automated  Analysis




          This component of the A£I program would evaluate the economic




     and process reliability benefit  of automating analysis that currently




     can only be performed manually.   This evaluation would be published




     to  inspire manufacturers to develop these instruments. Potential




     areas of investigation include the following:




     A.   Sludge settling velocity (5  min.  settling volume)




     B.   Sludge blanket




     C.   Wastewater Treatability/Toxic Monitor




     D.   Sludge dewaterability




     E.   Sludge cake moisture monitor




     F.   D.O. Uptake Rate




          The method of implementation would be to manually perform the




     analysis at a high frequency (1  hr.)  and evaluate the economic and




     process reliability benefit.

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III.  Evaluate Proposed Control Strategies




           This component of the A£I program would evaluate control strategies




      that are proposed in the literature.  This can be accomplished at




      the Test and Evaluation Facility using existing pilot plant equip-




      ment.  Possible control stratagies that may be evaluated are as




      follows :




      A.  Specific oxygen uptake rate.




      B.  Shifting from conventional activated sludge to contact




          stabilization as organic load varies.




      C.  Use of conventional math models in process control.




      D.  Use of artificial intelligence for process control.






 IV.  Training Operators on Instrumentation Maintenance




           A problem with operation of a wastewater treatment  plant through




      automation is maintaining sensor.  In most cases the maintenance




      requirement of a sensor is simply cleaning the probe.   This




      component of the A£I program would stimulate instrument  manufacturers




      to provide training on installation, operation, maintenance, and




      application of their devices.
          Program Self Monitoring




           Self monitoring is a vital component of this program.   The




          program will conduct services of wastewater treatment plants to




      determine the problem areas of automation.   This will be accomplished




      through both inhouse telephone surveys and contract surveys.

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                          FOREWORD
Man and his environment must be protected from the adverse
effects of pesticides, radiation, noise, and other forms of
pollution, and the unwise management of solid waste.  Efforts
to protect the environment require a focus that recognizes
the interplay between the components of our physical environ-
ment—air, water, and land.  The Municipal Environmental
Research Laboratory contributes to this multidisciplinary
focus through programs engaged in

  •  studies on the effects of environmental contaminants
     on the biosphere, and

  •  a search for ways to prevent contamination and to
     recycle valuable resources.

The County Sanitation Districts of Los Angeles County has been
a leader in development of efficient operating and maintenance
practices in the field of wastewater treatment.  As part of
this effort, a number of semi-automatic control schemes have
been successfully developed.  The purpose of this report is to
document the theory and engineering technology needed to apply
these new techniques.  It is hoped that this report will provide
an incentive to encourage application of semi-automatic control
schemes in other wastewater treatment plants.
                              111

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                           ABSTRACT
This report documents the theory,  design and operation of
continuous on-line instrumentation currently in use by the
County Sanitation Districts of Los Angeles County, California
and further describes computer applications which provide
daily operational calculations.
Instrumentation sections include Water Level Control of
Influent Pumping, Density Control of Primary Sludge Pumping,
and Process Air, Return Sludge and Waste Sludge Control in
Activated Sludge Plants.  Theory,  design, operation and main-
tenance requirements, and results are presented for each system.
A computer application system is described which provides
daily operational parameters to the operators and prepares
monthly summary of operations reports.  A review of other
computer applications and a subroutine to compare effluent
characteristics with discharge limits is included.
This report was submitted in fulfillment of Contract Number
R 803 055-01-0, by the County Sanitation Districts of Los
Angeles County, under the sponsorship of the Environmental
Protection Agency.  Work was completed as of June 1975.
                               IV

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                           CONTENTS

                                                        Page

Abstract                                                 iv

List Figures                                             vi

List of Tables                                           ix

Acknowledgments                                          x

Sections

I      Conclusions                                       1

II     Recommendations                                   2

III    Introduction                                      3

IV     Influent Pumping - Water Level Control            7

V      Primary Sludge Pumping - Density Control          20

VI     Activated Sludge - Process Air Control            51

VII    Return Activated Sludge - Flow Control            75

VIII   Waste Activated Sludge - Flow Control             102

IX     Computer Control Applications                     117

X      Appendix - Example of Monthly Report Summarizing
        All Data and Calculations                        182
                              v

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                            FIGURES


No.                                                     Page


1   Schematic of Liquid Level Control System             10

2   Pump Sequencing and Control Point Levels             12

3   Wet Well Level VS. Plant Flow Rate                   17

4   Wet Well Level VS. Plant Flow Rate                   18

5   Diurnal Flow Pattern                                 23

6   Diurnal and Seasonal Influent Suspended
     Solids Pattern                                      24

7   Components of Typical Nuclear Density Gauge          29

8   Control Panel with Amplifier and Controller -
     Recorder                                            30

9   Amplifier and Indicating Meter                       31

10  Joint Water Pollution Control Plant
     Sedimentation Tank Layout                           33

11  Unit of Sedimentation Tanks with Pump, Meter,
     and Wet Well                                        34

12  Horizontal and Vertical Orientation of Density
     Gauge                                               35

13  Schematic of Density Control System                  37

14  Density Gauge Recording - Gassing Sludge             40

15  Density Gauge Recording - Water Leak                 40

16  Density Gauge Recording - Vacuum                     42

17  Density Gauge Recording - Erratic Reading            42

18  Density Gauge Recording - Density Control            43
                              VI

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                      FIGURES - Continued

No.                                                     Page

19  Sample Encapsulator                                  45

20  Density Gauge Recording - Noise Band                 43

21  Plant Flow, Process Air Flow, COD Loading            56

22  Oxygen Supplied Vs. Dissolved Oxygen Level           57

23  Schematic of Cam Programmer Control                  59

24  Schematic of Air/Flow Control                        62

25  Schematic of Dissolved Oxygen Control                63

26  Dissolved Oxygen Profile                             65

27  Plant Flow, Process Air Flow, Dissolved Oxygen       68
     Level

28  Instrument Flow Diagram                              72

29  Schematic of Return Sludge Flow Control              77

30  Schematic of Secondary Treatment Flow Distribution   80

31  Sludge Volume Index Plot                             83

32  Suspended Solids and Light Transmission Vs. Depth    86

33  Suspended Solids and Light Transmission Vs. Depth    87

34  Percent Light Transmission Vs. Return Sludge
     Suspended Solids                                    88

35  Light Transmission at Various Depths                 91

36  Light Transmission at Various Depths                 92

37  Light Transmission at Various Depths                 93

38  Light Transmission at Various Depths                 94

39  Light Transmisstion and Probe Actuation              97

40  Light Transmission and Probe Actuation               98

41  Schematic of Mixed Liquor Wasting                   105

42  Schematic of Return Sludge Wasting                  108

                             vii

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                      FIGURES - Continued

No.                                                     Page

43  Diurnal Variation in Return Sludge Concentration    111

44  Schematic of Waste Activated Sludge Control System  113

45  Water Renovation Plant Data Management System       122

46  WRQDMS - Schematic Diagram of On-line Programs      123

47  Example of Raw Data Collection Sheets               124-128

48  Collection Sheets for Solids Handling Unit
     Processes                                          130

49  Printout of a Status Transaction                    131

50  Printout of Update Transaction                      133

51  Typical Store Printout                              134

52  Schematic Flow Diagram of Thickening and Anaerobic
     Digestion Process at the District 26 & 32 WRP's    148

53  Printout of Typical EFFCMP Transaction              160

54  Example of Stored Effluent Compliance Limits        173

55  EFFCMP Printout When Effluent Compliance
     Violations Occur                                   174-175

56  Printout of Daily Operational Data and
     Calculations                                       176

57  Printout of Solids Handling Data and Calculations   177

58  Date Record Management Program - Typical Printout   179

59  Operational Data Management Program - Typical
     Printout                                           180
                              Vlll

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                            TABLES

No.                                                     Page

1   Summary of Influent Pump Station Data                14

2   Raw Sludge Composite Samples                         26

3   Air Control Methods Used                             55

4   Response of Process Air to Operating Variables       71

5   Long Beach Plant Operation Parameters                90

6   Percentage of Probe Actuation at Various SVI's       99

7   Loading Calculation Formulas                        136

8   Solids Calculation Formulas                         137-139

9   Aeration Time Calculation Formulas                  142-143

10  Cell Residence Time Calculation Formulas            145-146

11  Solids Handling Calculations                        151-157

12  Effluent Compliance Daily Calculation Formulas      161-162

13  Effluent Compliance 7-Day Average Calculation
     Formulas                                           164-166

14  Effluent Compliance 30-Day Average Calculation
     Formulas                                           167-172
                               IX

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                     ACKNOWLEDGMENTS
This report was prepared for the Advanced Waste Treatment
Research Laboratory (now the Wastewater Research Division,
Municipal Environmental Research Laboratory) of the U.S.
Environmental Protection Agency.  The contributions of the
following individuals in gathering the information and
preparing the text are gratefully acknowledged.
                    R.T. Haug
                    R.S. Easley
                    R.C. Caballero
                    E. Motokane
                    S. Brun
                    L.F. Bednorz
                    W.G. Schmitz
                    D.E. Schulenburg
                            x

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                           SECTION I
                          CONCLUSIONS
The greater emphasis being placed on protection of the environ-
ment has substantially increased the number and complexity of
treatment plants.  More care in control of various plant
processes is necessary to meet present and future discharge
standards.
A variety of automatic and semi-automatic instrument control
systems have been used successfully for a number of years.  These
systems aid in stabilizing processes, reduce personnel require-
ments, and improve the efficiency of treatment plants.
These instrument systems have proven to be reliable and prac-
tical.  They are suitable for use in plants of any size and
require only a reasonable amount of maintenance.
To reduce operator time and improve efficiencies, a computer
system, leased or owned, can be used to great advantage.  Human
errors are largely eliminated and up-to-date information is
readily available for review by anyone concerned with the
operation.

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                          SECTION II
                        RECOMMENDATIONS
This program was limited to the description and documentation
of five existing instrument control systems.  It was not within
the scope of this project to present a literature review of all
instrument systems commonly used nor to develop or test new
systems.  It is recommended, however,  that development of new
systems be supported to further enhance the reliability of
treatment processes.
It should be noted that the systems described in this report have
been in use for a substantial period of time, their reliability
has been proven, and they can be used now in most plants with a
minimum of modification being necessary.

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                          SECTION III
                          INTRODUCTION
GENERAL
Increasing emphasis on efficient treatment and disposal of
municipal wastewater has greatly increased the number and
complexity of activated sludge treatment plants.
While in most cases the planning and design leading to the
construction of new treatment plants have involved extensive
engineering work, it is not uncommon that after completion
of construction and start-up of the plant the daily operation
of the plant is left almost entirely in the hands of the
operator.  Thus, the responsibility of the plant achieving
the design objective rests with the operator.
Most operators, however, have only a limited amount of time
they can devote to actually operating the plant.  For many,
their time is also spent performing maintenance, gardening,
laboratory tests, and other miscellaneous functions.  Also,
the educational backgrounds among operators are quite diverse.
Some easily grasp the concepts necessary to operate the plant,
others, do not.
For the above reasons it is desirable to have methods to
help the operator properly run the plant.  Devices that
will allow the operator to monitor variable constituents,
calculate important operating parameters, set and maintain
proper process controls, and activate alarms will help
insure proper operation.  However, the installation of
such equipment does present certain problems.  Sophisticated
equipment is subject to frequent breakdowns, and mainte-
nance requires highly trained individuals.  Also, instal-
lation of such equipment can lead the operator to over-rely

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on the instrument and avoid thinking about the total operation
of the plant and the interrelationships existing among the
various processes.
LOCATION
This project was conducted by the County Sanitation Districts
of Los Angeles County, California.  The Districts serve the
sewage and refuse disposal needs of nearly 4 million of the
over 7 million people in Los Angeles County.  There are now
a total of twenty-seven Districts, the first established in
1923.  They are governed by a Board of Directors made up of the
mayors and county supervisors whose jurisdictional areas are
involved.  The Districts stretch from the eastern border of the
City of Los Angeles to Pomona and from Long Beach to Lancaster
and include a total of 71 cities.  Combining their efforts
under a single administration has permitted the development
of an expert technical staff capable of attacking wide ranging
problems on a regional basis.
At present, the major Districts' facility for treatment of
municipal wastewaters is the Joint Water Pollution Control
Plant  (JWPCP) located in Carson.  The plant is currently
treating over 1.25 x 10  cu m/day (330 mgd) of wastewater by
primary sedimentation and should have secondary treatment
facilities added by 1977.  The treated wastewaters are dis-
charged through a sophisticated outfall system two miles off
Palos Verdes Peninsula.  Most of the organic solids removed
during treatment are sold as fertilizer base.
In addition to the Joint Water Pollution Control Plant, the
Districts also operate and maintain ten smaller secondary
plants.  Two of these are in the Antelope Valley north of
Los Angeles.   One plant, operating at about 13,626 cu m/day
(3.6 mgd)  and serving the community of Lancaster, utilizes
oxidation ponds for secondary treatment.  There is no percolation
to the underground in this area because of the extreme tightness
of the alkali soil.   A tertiary treatment facility of 1893 cu m/day

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 (0.5 mgd) capacity was constructed in 1970 to remove nutrients
and algae from the oxidation pond water to permit its use in
recreational lakes to be operated near Lancaster by the
County Department of Recreation and Parks.  The other plant,
serving the community of Palmdale, treats about 4542 cu m/day
 (1.2 mgd); the water from the oxidation ponds is sold for
irrigation of alfalfa.
An activated sludge plant with a capacity of 18,925 cu m/day
 (5 mgd) treats the sewage from District No. 26 in the Saugus
area.  The present flow of about 12,112 cu m/day (3.2 mgd)
from this plant is discharged into the Santa Clara River Channel
and percolated into the underground to recharge the aquifers.
In nearby Valencia, Sanitation District No. 32 operates a
smaller but similar plant to that of District No. 26.  The
flow of about 4542 cu m/day  (1.2 mgd) is also discharged to
the Santa Clara River.
District No. 28 operates and maintains a small activated sludge
plant in the vicinity of La Canada to treat the sewage from
the Angeles Crest Country Club and surrounding residential area.
The effluent from this plant makes a substantial portion of the
irrigation water for the golf course.
The remaining five Districts' plants are located in the Los
Angeles Basin and employ the activated sludge process for
secondary treatment.  All of the Districts in this geographical
area are members of a Joint Outfall Agreement which provides
for joint construction, operation, and maintenance of trunk
sewers, pumping plants, and treatment works.  The maintenance
and operation of the joint outfall system, including upkeep
and repair costs,  are shared jointly by the various districts
having ownership.   These costs are proportioned according to
the amount of flow contributed by each individual District.
Each of the plants in this Los Angeles Basin grouping are
situated adjacent to a major trunk of the jointly owned trunk
sewer system.   None of these plants has solids processing

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facilities; all waste products, skimmingsf primary and waste
activated sludges are returned to the trunk sewer for transport
and later recovery and processing at the Joint Water Pollution
Control Plant.
The Districts' plants involved in this system, with their
respective designed capacities are as follows;
  1.  Pomona Water Renovation Plant,
       36,336 cu m/day (9.6 mgd)
  2.  San Jose Creek Water Renovation Plant,
       1.4 x 105 cu m/day  (37.5 mgd)
  3.  Whittier Narrows Water Reclamation Plant,
       47,312 cu m/day (12.5 mgd)
  4.  Los Coyotes Water Renovation Plant,
       1.4 x 105 cu m/day  (37.5 mgd)
  5.  Long Beach Water Renovation Plant,
       47,312 cu m/day (12.5 mgd)
OBJECTIVES
The plants operated by the County Sanitation Districts of Los
Angeles County (LACSD) have a variety of control devices which
have proven to be useful in properly operating the plants.  It
is believed that others can benefit from the knowledge gained
in this operations experience.
Accordingly, two major objectives have been pursued:
  1.  Documentation of the theory, design, and operation of
      continuous on-line instrumentation currently in use by
      LACSD.
  2.  Documentation of the computer applications the LACSD has
      developed to provide daily  operational parameters,
      calculations, and monthly summary of operations reports.

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                          SECTION  IV
             INFLUENT PUMPING - WATER LEVEL CONTROL
INTRODUCTION
Elevations of all but two of the secondary treatment plants
on the LACSD Joint Outfall System  are above trunk sewer
elevations serving them.  This necessitates use of influent
pump  stations to lift wastewater out of the trunk lines and
into  the plants.  These pump stations are important elements
in the treatment process.  If they fail, other processes are
useless with no flow to treat.
Most  of the  pumping plants in the  LACSD system are designed
with  variable speed pumps and liquid level control  These
include 10 treatment plants and 19 sewer lift stations.  In
general, water surface elevations  in the incoming sewers are
maintained near normal depth by varying pump speed with depth
of flow.  Although this proportional relationship between depth
and pump speed does not exactly produce normal depth for all
flows, it approximates it closely  enough to avoid adverse
effects caused by excessively high or low velocities in the
sewer.
FACILITIES AT THE LONG BEACH WATER RENOVATION PLANT
The Long Beach Water Renovation Plant was the site of data
collection to document response of the variable speed pumps
to changes in the wet well water level.  This station contains
four pumping units.   Two smaller units each consist of a
Fairbanks Morse 25.4 c m (10 inch)  centrifugal sewage pump,
Watson Flexible shafting, an Ideal Electric motor and magnetic
drive, and a liquid level control panel.  The two larger units
each consist of a Fairbanks Morse  76.2 c m (30 inch)  centrifugal

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sewage pump, Watson flexible shafting, an Ideal Electric motor
and magnetic drive, Western Gear right angle gear box, and a
Liquid Level Control panel.  Currently only the two smaller
units are operated since plant flow is not yet sufficient for
efficient operation of the larger units.
The Plant is serviced by three influent trunk sewers which
discharge into a junction box at the head of the plant.  Sewage
then flows  from the junction box through a 175.26 c m  (69 inch)
outfall to  a wet well where it is pumped into the plant.  The
influent trunk sewers are of different sizes and slopes and,
as such, it is impossible to maintain normal depth in all three
under all flow conditions.  Thus, the previous statement that
pump speed  is varied to maintain normal depth in the incoming
sewer can only be true when there is a single influent sewer.
However, the main purpose of sensing a varying wet well water
level is to avoid excessively low or high flow velocities in
the sewers.  It is not essential to maintain exact normal depth
but only to maintain water elevations within reasonable limits.
Pump speed  is varied by controlling the output speed of the
magnetic drives.  This can be accomplished either manually or
automatically by use of the liquid level control system.  Under
manual operation, start and stop of each pump is controlled by
the plant operator through use of a sequence selector switch.
A pump will start when its corresponding sequence selector
switch is set to the "Hand" position.  Pump speed is regulated
by a manual potentiometer and indicated by a tachometer.  Each
pump motor  has an adjustable (1 to 600 seconds) time delay relay
to prevent  a successive motor start until the desired time delay
on energization of the motor has elapsed.  Each variable speed
drive also  has a time delay relay to allow a sufficient time
interval to elapse after the energization of each corresponding
motor so that each motor shall start under no load and shall
attain full speed before the start of each variable speed drive.
LEVEL CONTROL SYSTEM
The level control system is used to control the influent pumps

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so that the rate of discharge from the pumping station is
approximately equal to the varying rate of sewage inflow.
Liquid level in the influent pump wet well is automatically
sensed and controlled as described below.  Level control in
the wet well is initiated by means of proper pump sequencing
and by varying the influent pump speed.  The system is capable
of sequencing pump operation and varying the speed of all
pumps as necessary to pump a variable station flow without
storage in the wet well.
A schematic diagram of the liquid level control system is shown
in Figure 1.  Major components of the system are the level
sensor and transmitter, liquid level contrpl unit, and the
motor/variable speed drive units used to power the pumps.
Primary intelligence for the level control system is obtained
from an electronic differential pressure transmitter or trans-
ducer.  This unit is used to sense the rising and falling
liquid level in a stilling well which is directly connected
to the influent wet well.  Pressure sensed in the stilling
well is converted to a 4-20 milliampere direct current control
signal, proportional to the stilling well water level.
The liquid level control unit receives the control signal
generated by the differential pressure transmitter.  This
signal is used as a pilot signal for operation of the control
equipment.  These operations include indication of the liquid
level in the wet well, initiation of start and stop functions
for all pumps, modulation of pump speed, and actuation of alarms
for high and low water levels in the wet well.
Starting and stopping of each pump is initiated by individual
current alarms which use the 4-20 ma signal produced by the
level transmitter.  Current alarms have calibrated hand dials
for adjusting the trip setting and deadband setting.
Two time delay relays (adjustable from 1 to 600 seconds)  are
provided for each pump unit.   The first relay is actuated by
a motor stop and prevents a successive motor start until the
                                9

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   LIQUID
   LEVEL
  INDICATOR
    PUMP
 SEQUENCING
 AND SPEED
 MODULATION
  HIGH AND LOW
  WATER LEVEL
    ALARMS
                                                      STILLING
                                                        WELL
LIQUID LEVEL
CONTROL UNIT
  4 20 ma SIGNAL
  PROPORTIONAL TO
  STILLING WELL
  WATER  LEVEL
                   DIFFERENTIAL
                    PRESSURE
                   TRANSMITTER
                                                 Ar
                                             WET WELL

                                                  V
                                                             n
FIGURE I    SCHEMATIC DIAGRAM OF  THE LIQUID LEVEL CONTROL SYSTEM

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desired time delay has elapsed.  This is designed to prevent
rapid starting and stopping of the pump.  The second relay is
actuated by a motor start and delays energization of the
variable speed drive.  This allows the motor to attain full
speed and start under a no load condition.
AUTOMATIC OPERATION
Pump sequencing and control points levels (based on submergence
over pump suction as well as elevations based on plant datum)
are shown in Figure 2.
These points are approximate liquid levels at which control
functions are initiated together with the level excursions
available for control of speed modulation for the various
pump combinations throughout the operating ranges.  Step numbers
in Figure 2 are pump sequencing steps applicable to any of the
four pumps which are to be selected by manually positioning
the sequence selector switches.
Assume plant flow at zero and the liquid level in the influent
pump wet well below the start setting of Step 1.  As flow begins
and the level rises, the start setting of Step 1 starts the
first pump at minimum speed and a rising level causes the pump
speed to increase in linear proportion to the rise in level.
Operation continues in this manner until the pump is operating
at maximum speed.
If the wet well level continues to rise, the start setting of
Step 2 starts the second pump and both pumps are adjusted to
equal speed so that each will discharge one-half of the station
flow.   If the level continues to rise, both pumps increase in
speed equally in linear proportion to the rise in level until
both pumps are operating at maximum speed.  Manual selection
of the same size pumping units for Steps 1 and 2 is considered
normal operation.
Continued increases in wet well water level signal sequential
starting of a third and fourth influent pump in the same manner
as that described above.   At present,  however,  only two influent
                               11

-------
  PLANT DATUM
ELEVATION  FEET
SUBMERGENCE  ON  PUMP
  SUCTION  FEET
6.0

5 .0

4.0

3.0

2.0
1 .0


0.0
1 .0
2.0

3.0
4.0


HIGH LEVEL
- ALARM _
.STEP 4 STOP!


^STEP 3 STOP.
,STEP 2 STOP.

fSTEP
LOW

STOPI,
LEVEL
„ ALARM
-j


1



p
FALLING WET
WELL

LEVEL

IO.O

9 0

8.0

7.0

6.0
5.0


4.0
3.0
2.0

I.O
0.0


, STEP 4 START

STEP 3 START

^STEP 2 START

STEP I START
ri



RISING WET
WELL LEVEL
"




                                                      4 PUMPS ATMAX. SPEED
                                                      4 PUMPS AT MIN. SPEED
                                                      3 PUMPS AT MAX. SPEED
                                                      3 PUMPS AT MIN. SPEED
                                                      2 PUMPS AT MAX. SPEED
                                                      2 PUMPS AT MIN. SPEED
                                                      I  PUMP AT MAX. SPEED
                                                      I  PUMP AT MIN. SPEED
FIGURE 2
       PUMP SEQUENCING  ELEVATIONS

-------
pumps are required to meet the peak flow rate.
The pumps operate in reverse order when wet well level decreases.
The stop settings of Steps 1 through 4 are set so that the level
at individual pump stops will be lower than the levels at starts.
This is to prevent accidental pump shutdown in response to
momentarily lowered water levels experienced following pump
starts.  The last pump stops and does not operate (except by
manual control) when the level falls below the stop setting
of Step 1.
EXPERIMENTAL RESULTS
A recorder was placed in the control panel of the influent
pump station to continuously record wet well water level.  The
control signal provided by the differential pressure transducer
was used as input to the recorder.  This enabled wet well water
levels to be correlated with pump sequencing and plant flow rate.
Four weeks of data were obtained to document the influent pump
control system.
A summary of the experimental findings is presented in Table 1.
Incoming sewage flows were sufficient to maintain at least one
operating pump at all times, whereas two pumps were required to
carry the peak flow.  Wet well water levels initiating sequencing
of the second influent pump averaged 2.19 meters (7.2 feet)
(above pump suction) compared with the desired set point of
2.13 meters (7.0 feet).  The actual set points are adjustable
and the difference only reflects a slight error in adjustment.
Variations in wet well levels initiating pump sequencing were
extremely small.  The difference between the smallest and
largest values observed during the 30-day study period was only
1.52 c m (0.6 inch).  Thus,  while the set point adjustment was
slightly in error the water elevation which initiated the start
of the second pump was reproducible, varying insignificantly
during the study period.
The same comments apply to the wet well water level used to
signal the stop of the second influent pump.  While water level
                                13

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                           Table  1
       SUMMARY OF DATA COLLECTED  AT  LONG BEACH WATER
           RENOVATION PLANT INFLUENT PUMP STATION

Average
Variable Value a
Wet well level at start 7.20
of second influent pump
Plant flowrate at start 6.10
of second influent pump
Wet well level at stop 6.95
of second influent pump
Plant flowrate at stop 7.40
of second influent pump
Standard
Deviation Range b
0.022 0.05

0.78 2.60

0.026 0.10

0.50 2.00

a All elevations in feet above pump suction  and  flowrates
    in mgd.
b Range is defined as the difference between the smallest
    and largest value.
                              14

-------
initiating pump stop was slightly above the desired set point
value  (2.21 meters compared with 2.01 meters)  (6.95 feet
compared with 6.60 feet) the range of values varied by only
3.05 cm  (1.2 inch).
While water levels initiating pump sequencing were constant
during the study period, corresponding pumped flow rates were
not constant.  For example, plant flow rate at the start of the
second influent pump averaged 23,088 cu in/day  (6.1 mgd) but
varied from a low of 17,789 cu m/day  (4.7 mgd) to a high of
27,630 cu m/day  (7.3 mgd).  Plant flow rate at the stop of the
second influent pump varied in a similar manner.
Variation in pumped flow rate at the time of pump sequencing
was due to two causes.  First, the proportional controlling
system regulates only pump speed and not pump output.  Thus,
at any particular wet well water level, one value of pump
speed  is called for.  Should wet well water change, pump speed
will change in proportion to changing water level.  But at any
given water level pump  speed is constant.  There is no reset
function in the influent pump control system.  Second, at a
given rpm, flow rate is determined by the total dynamic head
against which the pump  works.  Dynamic head would normally be
a constant value at a given flow rate except for the fact that
rags and other debris tend to collect in the volute at the
suction side of the impeller.  This increases headloss which
decreases pump output at a given rpm.  Thus, variation in
observed flow rates at  the time of pump sequencing reflects
the degree of ragging at the pump suction.
Routine plant operation calls for deragging of influent pumps
whenever the capacity appears to be lower than normal.  During
the test period,  this required deragging on an almost daily
basis  (21 times during the 30-day study period with a labor
expenditure of approximately one-half hour per incident).   Not
only is this a nuisance as far as a plant operator is concerned,
it can affect proper pump sequencing.  Following termination of
the test period,  the practice of routine wet well cleaning was
                                15

-------
initiated.  This is accomplished during the low flow period by
manually pumping the wet well to a point below the normal low
level point.  In this manner, floatables are removed preventing
large accumulations of materials which might be drawn into a
pump at a later time causing partial stoppages.  Since initia-
tion of this procedure on a daily basis, no deragging of the
pumps has been necessary during a continuous 90-day period.
Ideally, startup of a second influent pump should not pull down
the wet well water level to such an extent that the stopping
set point is exceeded.  This would result in repeated starting
and stopping of the second pump.  The time delays, of course,
would protect the equipment from too rapid a start and stop.
Likewise, stopping of the second influent pump should not cause
the wet well level to rise to the point where it again signals
for start of the second pump.  In other words, one pump at
maximum speed should have nearly the same capacity as two pumps
at minimum speed.
Plant flow rate and wet well water levels during pump sequencing
are shown in Figures 3 and 4.  Referring to Figure 3, as flow
increased in the morning hours, the wet well level increased to
2.19 meters (7.2 feet) at which time the second pump started.
This resulted in a sudden increase in flow rate with corresponding
drawdown of the wet well.  Lowered wet well levels signalled for
reduced pump speed and eventually inflow and outflow from the
wet well were matched.  During the course of the study the wet
well was never drawn down to the point where shutoff of the
second pump occurred.
Again referring to Figure 3, as flow decreased in the early
morning hours the wet well was eventually drawn down to the
point where the second pump stopped.  This resulted in a
momentary decrease in flow rate and corresponding increase
in wet well level.  If the remaining pump was free of rags and
other debris,  it could carry the entire flow and prevent restarting
of the second pump.  However, if the intake was clogged the single
pump would be unable to carry the incoming flow-  Wet well level

                                 16

-------
UJ 0)
     80
     70
   m so
 $*
     50
        2nd PUMP
           STOP
                                                        2nd PUMP
                                                          START^
     12
   Q
   O

    I

   O
i
                        \
             AM
                              AM
                                    AM
                                                     AM
                                                                            10
AM
                                    JULY 31, 1974
FIGURE 3
   WET WELL WATER LEVEL AND  PLANT FLOWRATE  LONG  BEACH
   WATER RENOVATION  PLANT INFLUENT PUMP STATION

-------
     — o
       UJ
80
70
60
•sn
2nd PUMP
/"STOP
ck


^^


2nd PUMP
^ RESTARTS

^^


^













2nd PUMP
START"^

^x*

>


oo
         12
         10
       O
       2  8

       Q  6
                  -PUMP RESTARTS
                 AM
AM
AM
                                        JULY  28,1974
AM
10
AM
                WET  WELL WATER LEVEL AND PLANT  FLOWRATE LONG BEACH
    FIGURE 4    WATER  RENOVATION PLANT  INFLUENT  PUMP STATION

-------
would rise to set point level signalling restart of the second
pump.  The flow rate and wet well levels corresponding to this
situation are shown in Figure 4.  Restarts occurred approxi-
mately 50 percent of the time during the study period.  About
10 percent of the time two restarts were required before flow
rate was reduced to the point where a single pump was sufficient.
It should be emphasized that pump restarts are not a serious
problem in the sense of affecting pump station operation or
damaging equipment.  Too rapid starting and stopping is prevented
by the time delay relays.  However, it is probably wise to avoid
restarts as much as possible since they waste electrical power
and cause a certain amount of equipment wear.  Routine cleaning
of the wet well or increasing the elevation difference between
start and stop set points would avoid the problem.
                                19

-------
                           SECTION V
           PRIMARY SLUDGE PUMPING - DENSITY CONTROL
INTRODUCTION
Benefits of Thickening
Sludge thickening occurs naturally in the sludge blanket of a
primary sedimentation tank.  It is desirable to control this
thickening because of the benefits to many sewage treatment
plant processes:
  1.  Fewer gallons are pumped to transfer the same mass of
      suspended solids.
  2.  The denser the raw sludge added to the digester, the
      smaller the digester volume required.
  3.  The denser the raw sludge, the smaller is the amount of
      energy required for maintaining digester temperatures.
  4.  Dewatering filters operate more efficiently when fed by
      a sludge of high consistency.
  5.  Material transferred to storage is more concentrated,
      reducing the storage volume required.
Basis for Intermittent Pumping
Suspended solids settle continuously in a primary clarifier and
accumulate in the sludge blanket.  The sludge blanket must be
maintained at an adequate level to promote proper thickening.
This is accomplished by withdrawing the sludge out of the tank's
hopper at the same rate that it accumulates, allowing only the
thickest sludge from the bottom of the blanket to be pumped.
The following restrictive parameters have evolved from standard
practice and from the basic considerations in primary sludge
                               20

-------
pumping design:
  1.  "Sludge withdrawal piping generally has a minimum diameter
      of 15.24 to 20.32 cm  (6 to 8 in.)." *  Small pipe will
      become clogged.
  2.  "Sludge velocities between 1.52 and 2.44 mps  (5 and 8 fps)
      are, in general, found to be satisfactory."  The minimum
      acceptable to prevent settling in the lines is 0.9 mps
      (3 fps).
  3.  The rate of flow, tank design, and wastewater character-
      istics influence the tank efficiency and thus, the rate
      of accumulation of sludge within the tank.  At the JWPCP,
      the average accumulation rate for a rectangular primary
      clarifier with a surface area of 502 sq m  (5400 sq ft)
      varies from 1.26 to 2.02 £/s  (20 to 32 gpm) (average sludge
      consistency of 5.5% total solids).
The above restrictive diameter, velocity, and suspended solids
removal rate parameters have made intermittent pumping the most
practical solution over the years.  In this manner,  the parameters
are fulfilled by pumping the sludge every 20-40 minutes (based on
average accumulation rate).
Intermittent pumping may be performed manually but this practice
is extremely wasteful of the operator's time and the pumping
period may occur at a time when the operator is not at the plant
site or is occupied elsewhere.  In addition, the results
obtained by manual pumping usually are inconsistent and extremely
variable depending upon which operator is on duty.
In small treatment facilities where the number of sedimentation
basins is limited, reasonable control of sludge pumping can be
effected with simple timer controls.  In this situation, it is
important that timer settings be calculated carefully and that
positive displacement collector pumps be employed so that the
volume of sludge pumped per unit time remains fairly uniform
*
  p 200 - WPCF Manual of Practice No 8 - Sewage Treatment Plant
  Design, 1959
                                21

-------
regardless of  sludge density.  The timers can control the
pumping  from one or a series of settling basins.
For  larger treatment works, it is more efficient to use  larger
capacity centrifugal pumps and to use a single pump to serve
a  series of sedimentation basins.  In this application,  nuclear
density  gauges, in conjunction with timer controls, provide an
effective method of controlling intermittent sludge pumping.
As described later, the timer controls initiate the pumping
process  and regulate certain segments of the pumping cycle while
the  density gauge terminates the pumping process and provides
a  continuous monitoring of the solids concentration allowing
the  operator to observe density changes as they occur and to
adjust the timer settings as required.
Regardless of  which of the above two automatic methods of
controlling intermittent sludge pumping is used, the basic timer
settings depend on the accumulation rate, which is a function
of the following variables:
   1.  Diurnal  and seasonal flow.  Figure 5 shows the diurnal
      flow pattern for the Joint Water Pollution Control Plant,
      a  541 cfs (350 MGD) primary facility operated by the Los
      Angeles  County Sanitation Districts.
   2.  Diurnal  and seasonal influent suspended solids.  Figure 6
      shows the seasonal variation of influent total solids for
      the JWPCP in 1973.
  3.  Diurnal  and seasonal sludge settling and thickening
      characteristics.
The  success of timer control alone has been in treatment plants
where the timer settings have been carefully calculated and
adequate monitoring is provided.  Its success also has been in
treatment plants where the raw sludge density is unimportant,
separate sludge thickening is provided, or where large variations
in sludge density can be tolerated.
Density monitoring and control provides a short response time to
fluctuations in the diurnal accumulation rate.   As a result,  the
                                22

-------
to
               150
                 0000
0400
0800     NOON      1600



    TIME OF DAY , hrs
2000
2400
                   FIGURE 5
       TYPICAL   DAILY   FLOW   AT   THE   JWPCP

-------
to
         IJB
         1.6 H
     •S   1.4
     o
     Q.
    12


    1.0
c

£   .8
     in
    .6 -




    .4 -




    .2H
               JAN
                FEB
MAR
APR
MAY
JUN
JUL

AUG
SEP
OCT
NOV
DEC
                                                1973
          FIGURE 6
                    SEASONAL VARIATION OF INFLUENT SOLIDS  AT THE JW.PCP

-------
total volume of sludge pumped is reduced.  Its application has
been at the JWPCP where large variations in sludge density can
not be tolerated in achieving efficient digester capacity
utilization.  A brief discussion of the digestion system and
controls is included at the end of this section.
At the JWPCP, the sludge is pumped from three sedimentation
tank batteries to two raw sludge transfer stations.  Table 2
summarizes 24-hour composite samples from these two stations
during part of 1974.  The differences in sludge densities
between stations reflect the differences in accumulation rates
and thickening characteristics of the sludge.
OPERATION PROCEDURES
Adjusting Timer Settings - Timer Control Only
The timer settings are adjusted to pump a high percent total
solids and at the same time to prevent gassing (rising sludge)
in a tank.
Indirectly, the operator controls the sludge blanket level by
his timer changes.  The sludge blanket level that promotes
optimum thickening is a variable which depends upon the sludge
holding time in the blanket.  This holding time must not exceed
the minimum time required to produce gassing (rising sludge)  in
the tank.
Calculations based on suspended solids removals which have been
determined on a diurnal pattern can be made to determine the
rate at which sludge accumulates in the tank.  The timer settings
are then adjusted to pump from each tank hopper a volume of sludge
of the desired density equal to the volume of sludge that has
accumulated in the tank during the same period.  With occasional
monitoring of the sludge blanket level and visual observation of
the tank surface, minor adjustments of the timer settings can be
made to correct for lack of sufficient sludge blanket, excessive
sludge blanket or sludge bulking which has resulted from gasifi-
cation.

                                25

-------
               TABLE 2
  MEASURED RAW SLUDGE TOTAL  SOLIDS
FROM TRANSFER STATIONS AT THE  JWPCP
         March-August, 1974
Week
Ending
3-15
3-22
3-29
4-5
4-12
4-19
4-26
5-3
5-10
5-17
5-24
5-31
Percent Total Solids
Raw Sludge
Transfer
Station #1
6.2
5.8
5.6
5.5
5.8
5.6
5.5
5.7
5.5
5.6
6.0
5.6
Raw Sludge
Transfer
Station #2
5.3
5.6
5.5
5.7
5.3
5.4
5.3
5.0
5.0
5.2
5.0
4.9
Week
Ending
6-7
6-14
6-21
6-28
7-5
7-12
7-19
7-26
8-2
8-9
8-16
8-23
Percent Total Solids
Raw Sludge
Transfer
Station #1
5.4
5.5
5.4
-
5.6
5.3
5.4
5.4
5.4
5.5
5.5
5.7
Raw Sludge
Transfer
Station #2
5.3
5.3
5.3
-
5.2
4.9
4.9
5.2
5.2
5.1
5.1
4.7
                  26

-------
For example, if the analyses are made on 4-hour composites, the
approximate accumulation rate for each individual period can be
determined by the following formula:
Accumulation rate (gal per period)
= Dry suspended solids removed  (mg/1) x Flow  (MGD/Tank)
  Percent consistency  (decimal) x 60  (min/hr)
x 4 hrs/period
   (24 hrs/day)
The control timers are then set so that the volume pumped during
the period equals the volume accumulated during the same period.
Adjusting Timer Settings with Density Controls
With density control, a timer is used to regulate the pump "off"
time rather than the pump "on" time.  The pump "off" time is set
to permit sufficient accumulation of sludge so that density
control can be the dominant factor.
At the JWPCP, three separate trunk sewers with different flows
and suspended solids concentraions enter the plant.  As a result,
the accumulation rates in the three sedimentation tank batteries
(El, E2, E3) are different.  Shown below are the average 24-hour
per day accumulation rates  (based on 5.5% total solids) entering
JWPCP during the period February - May, 1974.
                Average Accumulation Rate (gpm)
          Time Period              El    E2    E3
          Feb - May, 1974          22    32    28.5
DESIGN
General
The sludge pumping control system described in this report
utilizes nuclear density gauges.  Ultrasonic density gauges
are also available but the LACSD have no operational experience
in their application.
Description of Nuclear Density Gauges
The principle of operation is based upon the fact that gamma
radiation is absorbed as it passes through various materials
                                27

-------
and that this absorption is a function of the density of the
material.
The components of a common gauge are shown in Figure 7.  A
source of gamma radiation (Cesium-137) is placed on one side
of the pipe and a measuring cell, or detector, on the opposite
side.  The measuring cell converts the variable radiation field
produced by changes in density directly into an electrical
current.  This current signal is then amplified and transmitted
to a recorder-controller.  Figure 8 shows that both the amplifier
and recorder-controller are mounted in the same control panel
at the JWPCP.
The output of the amplifier is also displayed on its front panel
by an indicating meter as shown in Figure 9.  In addition, the
amplifier has several operating controls located on its front or
side panels.  Among these are the following  (exact names vary
between manufacturers):
  1.  Zero Suppression- This control allows adjusting the
      beginning point of the measurement.  The "residual" current
      at the reference specific gravity is nullified by a
      compensating current of opposite polarity.
  2.  Time Constant - This control permits obtaining a balance
      between the noise band and the process rate of change.  The
      noise band (pen wipe on a recorder) indicates the random
      fluctuations of the meter reading and is caused by the
      statistical variations in the emissions of the radioactive
      source.
  3.  Calibration - This control adjusts the full scale sensi-
      tivity of the amplifier.
  4.  Recorder - This control adjusts the amplifier output to
      the recorder.
  5.  Check Zero - This control allows adjusting instrument
      electrical zero.
The recorder is of the two-pen type with set point indicator,
as shown in Figure 9.  The inner pen records sludge density

                               28

-------
   RAW SLUDGE TO
   BE  MEASURED
RADIOACTIVE
SOURCE HOLDER 1-1
: T
ED



X
0

ft
'/st






AMPLIFIER

Hi

t
*^\ 1
I MEASURING RECORDEF
^ CELL CONTROLL
FIGURE 7
COMPONENTS  OF A  TYPICAL
NUCLEAR  DENSITY  GAUGE
                        29

-------






        ©i©i®i@i©i©i©

                                     INDICATING
                                     LIGHTS
                                     RECORDER
                                     CONTROLLER
TIMERS
                                     AMPLIFIER AND
                                     INDICATING
                                     METER
FIGURE 8   TYPICAL  SEDIMENTATION UNIT CONTROL
                    AT  THE JWPCP
    PANEL
                      30

-------
FIGURE 9
CLOSE-UP VIEWS OF RECORDER-CONTROLLER
(ABOVE) AND DENSITY GAUGE  AMPLIFIER (BELOW)
                            31

-------
just as it is displayed on the amplifier indicating meter while
the outer pen records collector pump on and off time, see
Figure 20.  The set point indicator can be set for any density.
Both recorder and indicating meter are calibrated in percent
total solids  (0-10%).
Description of JWPCP Pumping System
The JWPCP has 52 sedimentation tanks arranged into ten pumping
units of four to six tanks each, see Figure 10.  Each tank is
equipped with a draw off valve which consists of a gate valve
operated by an air piston.  The sludge draw off lines from the
individual tanks in a unit are manifolded together and connected
to a single collector pump, as shown in Figure 11.  Each centri-
fugal, nonclog pump provides a 6.1-7.6 m (20-25 ft)  static lift
and has a sludge pumping rate in the range of 47.3-78.86 H/s
 (750-1250 gpm).
The density gauge for each unit is located below the wet well
discharge point and relatively close to the pump itself.  This
arrangement assures a full pipe.  Both horizontal and vertical
upflow orientation of the density gauges have provided satis-
factory operation, see Figure 12.  However, vertical upflow
orientation is preferred since sand will settle out on the
bottom of a horizontally mounted gauge and falsely indicate a
high density.  This has been a problem during wet weather periods
when huge quantities of sand often enter the plant.
The timers and controller for the sludge valves and pump are
mounted just above the density gauge amplifier for each unit
and in the same control panel, see Figure 8.  Each unit has a
master timer  (0-120 min)  which controls the off time of the
pumping sequence.   It is this timer which is adjusted to
compensate for diurnal and seasonal variations.  In addition,
each unit has four to six (depending on the number of tanks in
the unit)  tank timers or delay timers (0-5 min).   The primary
purpose of the tank timers is to insure that a new supply of raw
sludge has reached the density measuring unit and that the control

                                32

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              ii
           TANKS  61-66
              10

           TANKS 55-60
                             TRANSFER
                             STATION
FIGURE 10
LAYOUT  OF SEDIMENTATION TANK UNITS
           AT THE JWPCP
                         33

-------
OJ
    TRANSFER
    STATION
    WETWELL
                           INFLUENT ra&asftaag^S
DENSITY
GAUGE
                         SLUDGE
                         PUMP
                                                      SLUDGE BLANKET

                                               PRIMARY SEDIMENTATION  TANKS
                                        TANK DRAW
                                        OFF VALVE

                                                                               PRIMARY
                                                                               EFFLUENT

    FIGURE  I
           SCHEMATIC  DIAGRAM   OF  A  SLUDGE  PUMPING  UNIT

-------
FIGURE 12
   VERTICAL  (ABOVE)  AND HORIZONTAL
(BELOW) INSTALLATION OF DENSITY GAUGES
                         35

-------
of the pump is not being accomplished by residual sludge in the
suction line.  These timers are set for the minimum time required
to accomplish this purpose (normally 1 min.).  In case of mal-
function of the density unit however, they can be used to control
the pumping cycle.  Red lights located above the recorder for
each unit correspond to the collector pump and each draw off
valve, indicating when the pump is on and when each valve is open.
Sequence of Operation
The following pumping sequence is shown schematically in Figure 13.
When the master timer zeros out, the first tank timer is activated;
this opens the first draw off valve.  At the same time, the col-
lector pump is turned on and sludge is pumped out of the first
hopper.  If the density of the sludge being pumped is higher than
set point when the first tank timer zeros out, the first valve
will remain open and the hopper will continue to be pumped until
the density drops below set point.  At this time, the first valve
will close and the second tank timer will be activated, opening
the second valve.  This sequence will continue until all four
(or six)  tank hoppers have been pumped, after which the master
timer, which has since reset, will be activated again.  If the
density of the sludge being pumped from any tank is below the
set point when its timer zeros out, the valve on that tank will
close and the timer for the next tank in the unit will be acti-
vated.  Thus, both over-pumping (except that caused by excessive
tank timer settings)  and under-pumping are eliminated because
density is the controlling factor.
Timer changes usually follow a diurnal flow cycle, such as
Figure 1.   In the following discussion, only the off timer setting
is changed;  the tank timer setting remains constant.
  1.   300-900 Hours - The off timer setting is increased during
      this period since the accumulation rate is decreasing.
      Often,  however, the sludge enters the plant partially
      digested or septic.  As a result, the holding time during
      this period must be reduced to prevent gassing.   The off

                                36

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                                     TANK
                                                         TIMERS
                   PUMP
                   START 8
                   STOP
   SET
   POINT
  DENSITY
CONTROLLER
                A

                 I
                 l
TO
TRANSFER
STATION
WETWELL
              DENSITY
               GAUGE
              TANK DRAW
              OFF  VALVE
             SLUDGE
             PUMP
                                                                               _J
No. 4
FIGURE 13    SCHEMATIC DIAGRAM OF DENSITY CONTROLLED  SLUDGE PUMPING SYSTEM AT JWPCP

-------
timer setting is thus increased but not in direct proportion to
the decrease in accumulation rate.
  2.  900-1400 Hours - The off timer setting is gradually
      decreased during this period  since the accumulation rate is
      increasing.   However, fresher sludge enters the plant and a
      higher sludge blanket level can be maintained without gas-
      sing.  The off timer setting  is thus decreased but not in
      direct proportion to the increase in accumulation rate.
  3.  1400-300 Hours - The off timer setting is somewhat constant
      since the accumulation rate is unchanged.
Adjusting Timer Settings - Density  Control
In using density control,  only the  off timer setting is changed.
The tank timer functions as a delay timer that assures the line
is clear of sludge remaining from the previous cycle or from the
previous tank.
The operator routinely observes the density chart trace and com-
pares it to the set point.   Off timer settings are adjusted
according to the following procedure.
  1.  During the daily period of lowest sludge accumulation, the
      off timer is adjusted to a maximum setting which does not
      require density control (i.e., the density trace does not
      exceed the set point at the end of the one minute pumping
      from each tank).   This adjustment is necessary at the JWPCP
      due to the septic condition of the wastewater during this
      low flow period.   It is impossible to store the sludge in
      the sedimentation tanks long  enough to reach the desired
      density without gasification  occurring.   In this case there
      is the option of lowering the set point rather than adjust-
      ing the off  timer; however, this is impractical due to the
      inacessibility of the set point adjustment on some units.
  2.   During the day,  the  pumping time from each tank should in-
      crease in proportion to the increase in accumulation rate.
      For example,  if the  accumulation rate roughly doubles during
      a  day,  then  the actual pumping from each tank should roughly

                                38

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double.  If the density controlled pumping timer becomes exces-
sive, then the off timer setting should be decreased to increase
the frequency of pumping cycles.
Reading Density Charts
Probably the greatest advantage of density gauges is the contin-
uous recording of the sludge density-  The recorder trace tells
the operator the condition of the sludge and any problems or
malfunctions in the pumping system.
The following section discusses the more common recorder traces
and what they mean.  Interpreting recorder traces is difficult
since a single trace can have several causes.
  1.  Gassing Tanks - Figure 14 shows a recorder trace which
      indicates under-pumping from the unit tanks (i.e., the
      off timer setting is too high).  Between noon and 2 p.m.,
      the density being pumped is around six percent.  However,
      after the pump stops the trace immediately drops to
      around four percent and remains at this low level until
      pumping is again started.  This drop indicates separation
      of the sludge caused by gassing and settling in the gauge.
      Figure 14 shows that the condition improved after the off
      timer (OT)  setting was decreased from 20 to 10 minutes.
      An immediate improvement such as this does not always
      occur.  Visually observing the tanks and taking corrective
      action can usually prevent this problem from developing.
      An observation of gas bubbles above the collection sump
      is an indicator of trouble and immediate action should be
      taken to decrease the setting on the off timer.  If only a
      portion of the tanks in a unit show gassing, corrective
      action dictates temporarily increasing the delay timers
      on only the affected tanks.   This action causes increased
      pumping from these tanks without regard to density.  The
      delay timers should be returned to their normal setting
      after the gassing sludge condition has ceased.
                               39

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FIGURE 1.4
SECTION OF  DENSITY  CHART  SHOWING
            GASING TANKS
 FIGURE  15
                                 SLUDGE  PUMP  OFF

                                      SLUDGE  PUMP ON
SECTION  OF  DENSITY  CHART  SHOWING
       WATER  LEAK  INTO  LINE
                       40

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  2.  Water Leak into Line - The recorder trace  in Figure 15
      indicates a water leak into the sludge piping.  During
      pumping the density is observed to be around six percent.
      However, after the pump stops the line fills up with water
      and the trace drops to zero.  The leak is  usually caused
      by a faulty solenoid valve on the pump packing gland.
  3.  Vacuum in Line - Figure 16 shows a sudden  drop in the chart
      trace each time the pump starts.  This drop indicates
      either a vacuum on the line or a very small water leak.
      A vacuum such as this could be caused by a draw-off valve
      closing before the pump has shut off.
  4.  Erratic Charts - An erratic trace such as  Figure 17 usually
      requires visual inspection of the sludge to determine what
      density is being pumped.  Several possible causes exist
      which include the following:  a gross object (such as a
      block of wood) stuck in the gauge, sand settling in the
      gauge, or an instrument malfunction.  If a unit has less
      than three tanks in service, an erratic trace which
      resembles Figure 15 will occur.
  5.  Density Control - Figure 18 shows the sludge density
      exceeding the overriding set point on every pumping between
      2 p.m. and 6 p.m.  As previously described, the pumping
      continues until the density from each tank drops below
      set point.
CALIBRATION AND MAINTENANCE
General
The procedures outlined below are described thoroughly in
manufacturer equipment manuals such as Ohmart or Chicago-Nuclear.
They are presented here to familiarize the reader with the
maintenance requirements of nuclear density gauges.
Calibration Procedures
  1.  Sampling Technique - Every week one calibration sample is
      taken from each density gauge.  Two technicians are
                                41

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  FIGURE 16
  SECTION  OF  DENSITY CHART SHOWING
             VACUUM IN LINE
FIGURE 17
SECTION  OF DENSITY  CHART SHOWING
         ERRATIC  READINGS
                        42

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                                 SET  POINT @ 6.8 %
FIGURE 18
SECTION  OF  DENSITY  CHART SHOWING
       DENSITY   CONTROL
                                  SLUDGE  PUMP  OFF

                                      SLUDGE  PUMP ON
  FIGURE 20
  SECTION  OF DENSITY  CHART  SHOWING
           A  NORMAL  TRACE
                         43

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      are  required  for  the  following procedure.   After the pump
      has  started and a steady reading is observed,  one technician
      records  the density while the other technician obtains a
      corresponding sample.   The samples are delivered to the
      laboratory for a  total  solids determination.
      At the JWPCP, calibration samples are taken using the
      "encapsulator" device shown in Figure 19.   A one-inch sample
      line extends  from near  the density gauge inlet to a nearby
      sump.   The device itself consists of four  valves, one of
      which is a three-way  valve.  To capture a  sample, the valves
      are first positioned  to allow a steady sampling stream to
      flow into the sump.  Valve no. 1 is closed to stop the sample
      flow and then valve no. 2 is closed to capture the sample,
      see Figure 19. The captured sample is released into a
      container by  reversing  the position of valve no. 3 and
      opening vacuum breaker  valve no. 4.
  2.  Calibration Adjustment  - An instrument technician compares
      the calibration meter reading to the laboratory analysis of
      the sample.   A calibration correction is required if the two
      values differ by  more than one-half percent.   To make this
      adjustment the process  density must again  be steady.  The
      adjustment is made using the CALIBRATION control and can
      be done when  the  meter  is reading any value.
  3.  Water Zero Adjustment - Once a month, the  water zero setting
      for each density  gauge  is checked.  If a calibration cor-
      rection is also required, the water zero check is usually
      made at the same  time.   The check is made  by turning off
      the collector pump and filling the pipeline with water.
      This is accomplished  by connecting a nonpotable water hose
      to the sample piping.  After a steady reading is obtained,
      the zero can  be ajusted by using the ZERO SUPPRESSION
      control.
Time Constant Adjustment
Density control of  each tank in a unit will not occur unless the
                                 44

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                         PUMP  DISCHARGE LINE
FIGURE 19
              SCHEMATIC  OF
SAMPLE  ENCAPSULATOR  USED AT THE JWPCP
                           45

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time constant is properly adjusted.  The time constant makes it
possible to obtain a balance between the noise band and the
process rate of change (or response time).
The time constant is adjusted to read from water zero to process
in 30-45 seconds.  This is approximately the time required to
clear the line of sludge remaining from the previous cycle or
from the previous tank.  A minimum tank timer setting of one
minute gives the controller 15-30 seconds to read the density
actually being pumped from each tank.
As described, the response time is first adjusted and then the
resulting noise band checked.  Figure 20 shows the acceptable
noise band limit, approximately 0.4 percent total solids.  If
the noise band exceeds this amount, it can be reduced by increas-
ing the time constant  (i.e., by damping the system).
Maintenance Requirements
  1.  Daily Checks - This procedure requires approximately ten
      minutes per instrument per day-  The instrument technician
      checks to make sure of the following:
        a.   Chart is inking properly.
        b.   Chart time is correct.
        c.   Chart reading corresponds to meter reading.
        d.   Timers do not stick.
        e.   Noise level is not excessive.
        f.   Trace is not erratic.
  2.  Calibration Adjustment - This procedure requires approxi-
      mately one person-hour per instrument per month.
  3.  Corrective Maintenance - At the JWPCP corrective mainte-
      nance requires approximately one to two person-hours per
      instrument per month.
ANAEROBIC DIGESTER OPERATION
General
Efficient and proper anaerobic digester operation requires care-
ful control of process variables.  Literature on the subject deals

                                46

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primarily with heating and mixing.  For the most part, little
attention is paid to probably the most important variable of
all, the food supply.  Various loading parameters have been
suggested but little has been published regarding methods to
control the loading.
The use of density meters for raw sludge pumping control, coupled
with simple digester feed controls, enables anaerobic digestion
to be performed efficiently.  The control system permits loadings
to a series of digesters to be controlled within close limits and
allows the loading to each individual digester to be varied as
the conditions in each tank warrant.
Description of JWPCP Digester System
The JWPCP has a total of 31 anaerobic digesters arranged in two
separate groups; only single-stage digestion is practiced.  The
first group contains 27 fixed cover, rectangular digesters, each
with a capacity of approximately 2832 cu m  (100,000 cu ft).  The
second group is presently composed of four  (ultimately 12 or more)
fixed cover, circular tanks, each with a capacity of approximately
14,160 cu m (500,000 cu ft).  Despite differences in size, con-
figuration, and location the two groups are identical in operation
and control.  Mixing is provided by gas recirculation, temperature
is maintained in the desired range by steam injection, and loadings
are controlled by the system described below.
Basis of Loading Control
Loading parameters are generally stated in terms of weight of
volatile solids per unit volume of digester capacity.  Unfortu-
nately, automation of volatile solids determination has not yet
been achieved and laboratory determinations are too time consuming
to be of any use during the charging cycle.  However, by using
density control for raw sludge pumping and by incrementally
feeding each digester (5 or 6 times per day), the diurnal
variations in sludge density and volatility are evened out.
Weekly and/or monthly averages of density and volatility,
determined by laboratory analyses of 24-hour raw sludge composites,
                                 47

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provide a satisfactory basis for calculating and controlling
loading by volumetric means as per the following formula:
Volume of raw sludge
= Desired loading  (weight of volatile solids per unit volume)
  Avg % solids  (raw sludge) x Avg % volatile  (raw sludge)
x Digester capacity
Control System Elements
The control panel  for one group of digesters houses 27 sets of
sludge feed controls, one for each digester in that group.  Each
set contains:
  1.  24-hour sludge feed timer - The total number of gallons of
      sludge to be fed to the digester in one 24-hour period is
      set on this  timer.
  2.  Incremental  sludge feed timer - The number of gallons of
      sludge to be fed to the digester per feeding is set on
      this timer.  This setting is normally one-fifth or one-
      sixth of the volume set on the 24-hour timer depending on
      whether the digester is to be fed five or six times during
      the 24-hour period.
  3.  Sludge feed volume totalizer - Displays a running total of
      the volume of sludge fed to the digester.
The volume of sludge is measured by a Venturi meter in the raw
sludge line carrying the flow to the digester group.  The resul-
tant pressure differential signal from this meter is converted
to a flow signal by an adjacent pneumatic transmitter.
The pneumatic signal is received by a flow recorder in the control
panel, recorded on a circular chart and converted to a pulse-time
signal.   This pulse-time signal is received by both the 24-hour
and incremental feed timers.  The incremental timer, having been
preset for a specific volume of sludge,  is clocked out when that
volume of sludge has passed the flow gauging venturi (the 24-hour
timer is also reduced by this amount).
                                48

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Sequence of Operation
Pumping to the digestion system  is  initiated whenever the level
in the raw sludge transfer wet well rises to the  level probe and
starts the pumps.  The sludge then  passes through the delivery
piping and Venturi meter to the  first digester in the series.
When the incremental timer clocks out, the feed valve to that
digester closes, the flow signal is transferred to the next
timer in the series, and the feed valve to that digester opens.
Thus, the feed valve to one digester is always in the open
position or is opening while the preceding valve  is closing.
The control system cycles through every digester, allowing raw
sludge to be fed to the digesters in the amount so indicated on
their incremental timers.  After one complete cycle, the control
system switches back to the beginning of the series, again allow-
ing raw sludge to be fed to the  digesters in the  amount shown on
their incremental feed timers.   However, if in the previous cycle
the amount originally set on the digester total feed counter
(24-hour timer) has been satisfied  for any particular digester,
the control system passes over the  satisfied digester to the
next digester whose total feed counter has not been satisfied.
If a digester is out of service  for cleaning or repair, its
timers are set to zero, and it is bypassed in the feeding sequence
in like manner to a digester whose  feeding has been satisfied.
An "on-off" selector switch for  each tank accomplishes the same
objective.
The start of the 24-hour control period is purposely selected
to begin late in the afternoon after the laboratory analyses are
completed and the condition of each digester can  be evaluated.
Any loading changes to be made are then "dialed in" on the
appropriate timers and the control board is reset by pushing a
single reset button.  If only a portion of the tanks have been
fed on the preceding cycle, the  ''on-off" selector switches for
those tanks which have been fed are turned to the "off" position
before the reset button is pushed.   Thus, the new 24-hour cycle

                                 49

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starts with the tank which would normally be next in line for
feeding.  After resetting the control board, the selector switches
are returned to their normal position.
If the feeding of all of the digesters in the group has been
satisfied or if the 24-hour control period expires before manual
resetting occurs, the control system automatically resets all
timers to the positions they were in at the beginning of the
preceding control period.  The control system then starts to
cycle through the series again as previously described.  Changes
can still be made in the load settings, but it is more difficult
to accomplish than if done before the control board is reset.
Summary
Radioactive density meters have been in operation at the JWPCP
since 1959.  They have proven to be an effective tool for con-
trolling the intermittent withdrawal of raw sludge from primary
sedimentation tanks.  By controlling the sludge density within
narrow limits, they also permit efficient use of digester capac-
ity and make possible digester loading control by simple volu-
metric means.
                                50

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                          SECTION VI
            ACTIVATED SLUDGE - PROCESS AIR CONTROL
INTRODUCTION
Since the activated sludge system is an aerobic process, oxygen
must be supplied to sustain metabolism of the microorganisms.
Oxygen requirements vary depending primarily on organic strength
of the primary effluent, the cell residence time at which the
plant is operated, and whether nitrification occurs or not.
Heterotrophic microorganisms in activated sludge use organic
compounds contained in sewage both as a source of energy and
as a source of carbon for cell synthesis.  Oxygen demand is
exerted by that portion of organics oxidized to carbon dioxide
and water.  An additional oxygen demand is exerted when cellular
organics are consumed for energy, a process termed endogenous
respiration.  The extent of endogenous respiration is primarily
dependent upon mean cell residence time  (MCRT) in the system,
increasing with longer cell residence times.  However, endogenous
respiration is never complete since a fraction of the cellular
organics are resistant to degradation and termed refractory.  The
refractory portion normally represents 10 to 20 percent of the
total cell mass.  Thus, oxygen consumed may vary from as low as
0.5 Ibs 02/lb COD when endogenous respiration is low to as high
as about 0.90 Ibs 02/lb COD when endogenous respiration is
complete.  In normal plant operation, actual oxygen requirements
would fall between these two extremes.
Oxidation of reduced inorganic compounds by autotrophic micro-
organisms can also exert an oxygen demand in the activated sludge
process.  Although many reduced inorganics may be present in
sewage, only ammonia nitrogen is significant in terms of an
                                51

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oxygen demand.  Nitrification is a two-step process in which
ammonia is first oxidized to nitrate by the organism Nitrosomonas
Nitrite is then oxidized to nitrate by the organism Nitrobacter.
  Step i:   NH^ + 3_ 02 	*N02~ + 2H+ + H20           (1)
                   2
  Step 2:   N02~ + ,1 02 	*N03~                       (2)
                   2
  Overall:  NH^ + 202 	^N03  + 2H+ + H20           (3)
The above reactions furnish energy for the growth of the nitri-
fying bacteria, during which some of the nitrogen is assimilated
into bacterial protoplasm, with carbon dioxide being used as a
source of cell carbon.  With an empirical cell formulation of
C5H7O2N, the assimilation reaction can be written as:
            5C02 + NH4 + + 2H20 	^C5H702N + 502+ H+          (4)
Overall oxidation of ammonia to nitrate requires 4.57 mg 02
per mg of NH3 -N oxidized.  However, some oxygen is produced
during cell synthesis and actual oxygen requirements are somewhat
                                         1             234
less than theoretical.  Haug and McCarty,  and others,  ' '
have shown actual requirements to vary between 3.9 to 4.5 mg 02
per mg NH3 -N.  The variation is due to the range of reported
cellular yields for these organisms.
Since nitrification is an aerobic process, the question arises
as to what oxygen tension is required to support the maximum
rate of substrate oxidation.  Loveless and Painter,  showed that
for a pure culture of Nitrosomonas the rate of ammonium oxidation
was 50 percent of the maximum rate when the oxygen concentration
was 0.3 mg/1 at 20°C.  Boon and Ladelout,  showed that for
Nitrobacter the rate of nitrite oxidation was 50 percent of
maximum when the oxygen concentration was 0.25 mg/1 at 18°C and
0.50 mg/1 at 32°C.
Garrett,  working with activated sludge concluded that nitri-
fication was independent of the oxygen concentration as long as

                                52

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it was greater than  3 mg/1.  This  same conclusion was reached
by workers at the Water Pollution  Research Laboratory in
        8            9
England,  .  Wuhrmann,  studying activated sludge pilot plants,
indicated that a dissolved oxygen  concentration of 4 mg/1 was
necessary for rapid  nitrification.  However, Downing and Hopwood,
and Wild, et all,    concluded that nitrification in activated
sludge is not enhanced by oxygen levels greater than 1 mg/1.  This
same conclusion has  been supported by LACSD evaluations of their
nitrifying activated sludge systems.  Therefore, it appears that
the rate of oxidation is largely independent of dissolved oxygen
levels down to concentrations of 1 or 2 mg/1, below which some
rate limitation will be observed.
Nitrification in the activated sludge process tends to be an "all
or nothing" phenomenon.  If the mean cell residence time in the
activated sludge process is below  the generation time of the
organisms, they will be washed from the system and nitrification
                      12
will cease.  Wuhrmann,   reported  that a MCRT greater than four
days was necessary to consistently attain a high degree of nitri-
fication.  This corresponds with a value of about four or five
days reported by Johnson and Schroepher,  .  These values are just
greater than minimum generation times reported for the nitrifying
bacteria.  At reduced temperatures, generation time is increased
so that a longer MCRT would be required.  A design MCRT of ten
                                                               14
days for nitrification was recommended by Jenkins and Garrison,
and should give sufficient safeguard for most purposes.
From the above discussion, oxygen  requirements to stabilize a
wastewater can be determined within reasonably narrow limits,
depending primarily  on influent COD and NH3-N concentrations and
mean cell residence  time.  However, air quantities required to
satisfy the oxygen demand are more variable, depending on the
type of oxygen transfer equipment  used and efficiencies at which
they operate.   Also, in all but completely mixed systems, rates
of oxygen consumption will vary along the length of the aeration
tank.   Process air control, is therefore, critical to the stable
operation of the activated sludge  system.  Not only must total
                                 53

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air quantity be controlled, the rate at which it is supplied along
the aeration tank must also be controlled to provide for stable
and efficient treatment.
LACSD FACILITIES
A variety of techniques are used to control process air at acti-
vated sludge plants operated by the LACSD.  Techniques used can be
divided into two basic types:  (1)  use of a control signal to
throttle a centrifugal compressor and, (2) use of preset timers to
control the number of on-line positive displacement compressors.
Cam programmers, dissolved oxygen probes and plant flow rate are
currently used to provide the command signal for the first type
of control listed above.  Control methods currently used at each
treatment plant are shown in Table 3.
Preset Timers
Use of preset timers is relatively straight forward and will be
described first.  Most treatment plants experience diurnal
variations in both flow rate and sewage strength (as measured
by COD).  In general, as flow rate increases so does sewage
strength.  This means that process air requirements will vary
diurnally as well.  24-hour timers are used at two of the small
LACSD treatment plants to control operation of a number of par-
allel, positive displacement compressors.  Thus, with a knowledge
of the diurnal variation in oxygen demand, timers can be preset
to vary the number of on-line compressors.  In this way, oxygen
supply can be approximately matched with oxygen demand.
Diurnal variation in plant flow rate, COD loading,  and air supply
to the aeration system at District 26 WRP is shown in Figure 21.
Using data from Figure 21, the pounds of oxygen supplied per
pound of COD were determined and plotted in Figure 22.  Resulting
dissolved oxygen concentrations in the aeration system  (measured
at the midpoint)  are also shown in Figure 22.
One advantage of a timer controlled process air system is that
operation is relatively simple and timers can be easily readjusted
to change the operation.  The system is well suited to small
                                54

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                           TABLE 3
      LACSD ACTIVATED SLUDGE PROCESS AIR CONTROL SYSTEMS
Treatment Plant           Air to     D.O.     Cam
                        Flow Ratio  Probe  Programmer  Timers
Whittier Narrows WRP                           X
San Jose Creek WRP                    X
Pomona WRP                  X
Los Coyotes WRP             X
Long Beach WRP                        X
District 26 WRP                                           X
District 32 WRP                                           X
                              55

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en
cr\

           o
           .p
           o
          QrO
          O
          o
                1   I    I   I    I    I    I   I   I    I   I   f
                I    I    I
                                    AIR  SUPPLY
          I   I    I    I    I   I    I    I    I   I    I    I
                                                                                0_
                                                                                  0»
                                                                                  E
                                                                                 UJ
                                                       oU_
                                                       10  '
                                                                                Q  _
                                                           O
                                                           8 -
go
<0 -J
                                                                                     o:
                                                                                    §<
            I2M 0100 0200 0300 0400 0500 0600 0700 0800 0900 1000  1100 I20O 1300 1400  1500 1600 1700 1800  0
                             HOUR  OF THE  DAY-AUGUST  15,1974
      FIGURE 21
ACTIVATED SLUDGE  OPERATIONAL PARAMETERS
  DISTRICT 26  WATER  RENOVATION   PLANT

-------
                              I
                         I    I   I
                                    i	ribs  02/lbCOD
                              DISSOLVED OXYGEN
                                CONCENTRATION
           I    I    I   I    I    I        I    I
                                            II
       I2M 0100 0200 0300 0400 0500 0600 0700 0800 0900 IOOO 1100 1200 1300 1400 1500 1600 1700 1800
                                HOUR OF THE DAY,   8-15-74
FIGURE 22
ACTIVATED SLUDGE OPERATION PARAMETERS
  DISTRICT  26  WATER  RENOVATION PLANT

-------
treatment plants where total air requirements are not large.
However,  preset timer control has some disadvantages which,
in general,  preclude use in larger treatment plants.  Oxygen
demand curves can not be exactly matched since oxygen supply can
only be incrementally changed.  This is evident in Figure 22 where
a sudden increase in mixed liquor DO accompanied start-up of the
second air compressor.  In addition, diurnal patterns of oxygen
demand are subject to daily, weekly, and seasonal variations.
It is difficult to continually readjust timer settings in antici-
pation of such changes.   As a result,  it is likely that most
treatment plants would supply an excess of air to compensate for
fluctuations in the pattern of diurnal variation.
In summary,  timer control of parallel  compressors provides an
adequate process air control system in small treatment plants
where design simplicity is important and excess air can be
supplied without significant economic  loss.
Cam Programmers
Five of the LACSD activated sludge plants have the flexibility
of controlling process air flow by means of cam programmers.  A
schematic diagram illustrating this mode of operation is shown in
Figure 23.  A converter transmits a control set point signal which
is proportional to the position of a cam follower on the edge of
a rotating cam.  The transmitted signal is a DC current signal.
The cam is driven electrically and completes one revolution in
24 hours.
The converter applies its signal to a  ratio controller which changes
the set point of the controlling system by a preset adjustable ratio.
The controlled variable signal is then transmitted to the air flow
controller which compares an input signal  (air flow rate) to the
set point signal from the ratio controller.  The air flow rate
signal is generated by a flow tube and differential pressure
transmitter.  Since the resultant signal is proportional to the
square of the air flow rate, a square  root extractor is used to
produce a signal directly proportional to flow rate.  Ratio set

                                  58

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rruwiroTirci 4-20 ma k RATIO R/i
CONVERTER *
PAM FOI 1 nWFR - ••• ••-

f 0 J J SQUARE ROOT
\^ J EXTRACTOR AIR F
CAM (Irod) T
DIFF, PRESSURE
TRANSMITTER
^ 1 	 J — n
PROCESS AIR <
fTIO SET POINT ^ AIR FLOW
CONTROLLER
4-20 ma
LOWRATE SIGNAL o
8
|
3
1 .^> [
/ V.
^ ^ ^°yi£
TUBE AIR /^-^\ INL.
rnMDDCccno A 	 \ >
J «— '" SIGNAL
J <
-^ i
/ANES
FIGURE 23   SCHEMATIC DIAGRAM OF  PROCESS AIR CONTROL USING A CAM  PROGRAMMER

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point and air flow rate signals are compared in the air flow
controller which transmits an output signal to control posi-
tioning of compressor inlet guide vanes.
Knowing daily variations in flow rate and sewage stength, as
measured by COD and NH3-N concentrations (if nitrification is
desired) the diurnal variation in oxygen demand can be determined.
A cam can then be cut to regulate oxygen supply to meet the
expected oxygen demand.  Should supply not exactly balance
demand, a new cam is cut until, by trial and error, supply
balances demand.  Cam programmers offer an additional advantage
over preset timers (described previously) in that compressor
operation can vary anywhere from 0 to 100 percent of maximum
output.
A modification of cam programmer control is used at the Whittier
Narrows WRP.  At this plant, it is possible to take as much or
as little flow as is desired from the trunk sewer passing the
plant.  Air flow to the aeration tanks is maintained at a
constant rate.  To keep oxygen supply and demand in balance, plant
influent flow rate is varied by a cam programmer to compensate for
changes in sewage strength.  The ratio of peak daily to minimum
daily flow is about 1.5 under this mode of operation.
While performance of the cam programmer system has, in general,
been satisfactory certain disadvantages are inherent in its oper-
ation.  Daily, weekly, and seasonal fluctuations in diurnal
oxygen demand require periodic cam readjustment.  Shock loads,
either in flow or sewage strength, may upset plant performance
since they can not be anticipated when the cams are originally
cut.  Experience has also indicated that it is difficult to main-
tain an exact dissolved oxygen content in the aeration tank.  For
example, if it is desired to maintain 0.5 mg/1 at a certain point
in the aeration tank, the sensitivity of a cam may not be suffi-
cient to assure that DO at all times.
Air to Flow Ratio
Under this mode of operation process air is automatically
                                60

-------
maintained at a preset  (adjustable) ratio to plant flow.  An
electrical signal, proportional to flow rate, is generated by
the plant influent flow meter and used to regulate the quantity
of process air.  Actual ratio of process air to plant flow rate
                                            3
is adjustable over the range from 0 to 5 ft /gallon.  A schematic
diagram of this control system is shown in Figure 24.
This process air control system has operated satisfactorily at
both the Pomona and Los Coyotes WRP's.  An advantage over cam
programmer control is offered since changes in diurnal flow rate
patterns are automatically sensed and compensated for.  Hence,
once the desired air'to flow ratio is selected, operation is
generally automatic.  The system will even respond to shock loads
resulting from increased flow rate.  However, the system will not
respond to sudden increases in waste organic strength.  This
disadvantage may be significant in treatment systems which receive
a large proportion of industrial wastes.  Another disadvantage
lies in the fact that peak flow periods are normally associated
with periods of peak organic strength.  Thus, if the air/flow ratio
is sufficient to maintain adequate DO during the peak flow period,
the ratio may be too high during the low flow period when waste
organic strength is less.  This is partially offset however, as
during the lower flow period when waste strength is less, the
amount of oxygen consumed by endogenous respiration represents a
greater percentage of the total oxygen consumed than it does during
peak load periods.  Simply stated, if the organic strength had no
diurnal variations, a higher air/water ratio would be required
during the lower flow periods than during the higher flow periods.
DO Probe Control
Control of process air by dissolved oxygen probes located in the
activated sludge tanks is the normal mode of operation at the San
Jose Creek and Long Beach Water Renovation Plants.  A schematic
diagram of the system is shown in Figure 25.  In principle,
dissolved oxygen probes provide a feedback signal to control
operation of the air compressors.  This provides a system which

                                61

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NJ
MAGNETIC
FLOWMETER
> MANUAL SET
POINT
1
1 4-20 mn^ RATIO RAT
FLOW TO
CURRENT
CONVERTER

RECORDER

1 " STATION


SQIIARF Rnnr '
^_ EXTRACTOR AIR FL(
r T
DIFF PRESSURE
TRANSMITTER
^1 i 	
PROCESS AIR < 11

\J I — — — «-•
FLOW
TUBE
rt

10 SET POINT ^ AIR FLOW
CONTROLLER
^20 ma i
)WRATE SIGNAL g
z
o
o
a.
o
T
r-1— ^ L
/ \ 	 ^
v UN — ^
AIR X_X INh
^MPRFQQHP 4 \
1VN9IS u-i I
^ \
ET GUIDE
YANES
      FIGURE  24
SCHEMATIC DIAGRAM OF PROCESS AIR  CONTROL USING AIR FLOW  RATIO

-------
       D 0
     SENSOR IN
      AERATOR
       D 0
      INDICATOR
    TRANSMITTER
        V/l
      CONVERTER
     RECORDER
      PROCESS  AIR
SET POINT
(DO mg/l)
OXYGEN
CONTROLLER

SQUARE ROOT
EXTRACTOR
T
DIFF PRESSURE
TRANSMITTER
1
1 r— r
^ RATIO ^ AIR FLOW
STATION " CONTROLLER
j k
i
o
OC
0
o
h-
Q.
|
_^s L
[I I / ^ J
J L- 	 L
FLOW
TUBE
1 "-^ SIGNAL
1 	 ( K ^
AIR X^X INLETGUIDE
rnMPRFQQOR / \ VANES
FIGURE 25
SCHEMATIC DIAGRAM  OF PROCESS  AIR CONTROL USING  DO SENSOR PROBES

-------
can respond to any diurnal fluctuation in oxygen demand as well
as shock loads whether they be in terms of flowrate or waste
strength.
Primary elements for measuring dissolved oxygen are DO probes
located in the aeration tanks.  Optimum number of probes depends
on the type of activated sludge process used.  For a completely-
mixed aeration tank only one DO sensor would be needed since DO
concentrations would be uniform throughout the tank.  The San Jose
Creek and Long Beach WRP's, which normally use DO sensors for
process air control, have nearly plug flow activated sludge systems
which employ step feeding (step aeration) of the waste.  Hence, DO
concentrations vary continuously along the length of the aeration
tank as shown in Figure 26.  This necessitates use of a number of
DO sensors placed strategically along the aeration tanks.
The probes transmit signals proportional to the dissolved oxygen
concentration to dissolved oxygen indicating transmitters (refer
to Figure 25).  The electrical signals are then transmitted to a
control panel where they are recorded.  One signal is automati-
cally or manually selected to be used as a primary input command
signal to the dissolved oxygen controller.  Desired DO concen-
tration to be maintained at the controlling probe can be manually
set at the oxygen controller.  The ratio station receives the
output signal from the oxygen controller and applies a ratio set
point signal to the air flow controller.  This in turn provides
an output signal used to control the position of inlet guide vanes
on each process air compressor.  A signal limiting device is
provided in the controller to prevent closure of inlet guide vanes
beyond the point that would cause compressor surge.
The reason for controlling process air to the activated sludge
system is the necessity of balancing oxygen supply with oxygen
demand.  Beyond that DO levels should be sufficient to assure
that reaction rates are not DO limited.  The most straightforward
method of accomplishing these objectives is to simply monitor the
DO level in the aerator and use that as a feedback signal to

                                64

-------
  O»
  E
  CE


  UJ 9
  O ^
  Z
  O
  O
  g

  Ss
  3
  O
  CO
  CO
         1    I    I   r
TANK I
               1   I    I    F
TANK 2
      Jill
       FEED POINTS
 CONTROLLING  DO PROBE
 SET  POINT AT 1.0 mg/l
               1    r~i   r
TANK 3
                                I       i
                 1    I   I    I
TANK 4
              CONTROLLING
                   DO
                 PROBE
         I    I    I    I   I    I    I   I    I    I   I    I    I    I   I    I    I   I    I
      0  45'  90'  135'  180' 225' 270*  315' 360' 405' 450' 495' 540' 585'  630' 675' 720' 765' 810' 855' 900'
                             DISTANCE  ALONG AERATION  TANK

       AERATION TANK  DO PROFILE AT  LONG  BEACH WATER  RENOVATION PLANT

FIGURE  26                   7-1-74  - 1230-1430 hours

-------
control compressor operation.  Response to changes in diurnal
flow pattern as well as to shock loads of either flow rate or
waste strength are advantages of this type of system.  Experi-
ence with DO probe control systems, however, has revealed several
operational characteristics which will be noted.
As previously discussed, DO levels below 1 or 2 mg/1 will affect
nitrification kinetics by imposing a rate limitation.  If the
MCRT is above 5 or 6 days and the DO set point below about
0.5 mg/1, nitrification may not occur because of the DO rate
limitation.  However, if the DO set point is increased much above
0.5 mg/1, the rate limitation is removed and nitrification will
proceed.  This will produce a sharp increase in oxygen demand and
process air flow will increase dramatically to try and match
the demand.  If the operator is not aware of this phenomenon,
he may spend many anxious moments pondering the sudden increase
in process air flow.  If nitrification is not desired, the best
operational procedure is to keep the MCRT below about four days.
However, this may not produce the best quality effluent in terms
of suspended solids.  The only other recourse is to maintain DO
concentration in the aeration tanks less than 0.5 mg/1 which
limits flexibility of the process air flow system.
In the DO probe system currently used, only one DO probe can be
selected at any time to control process air flow.  Experience
with the system should indicate the position of the controlling
probe that produces the best overall effluent quality.  In LACSD
experience, the controlling DO probe has usually been located
near the midpoint of the aeration tank.  A dissolved oxygen pro-
file along the length of the aerator at the LBWRP is shown in
Figure 26.   The activated sludge system is divided into four
tanks arranged in series.  Return activated sludge enters at the
head end of tank 1 while primary effluent is step fed into the
first three tanks as shown in Figure 26.  The controlling DO
probe was located between the last two inlet gates with the
control set to maintain 1.0 mg/1.  This DO concentration was
maintained at the location of the control probe but varied at
                                66

-------
other locations in the aeration tank.  In general, DO levels
decreased at each feed port and increased significantly in Tank 4
which contained no feed ports.  If the controlling probe had been
located in Tank 4, the same pattern of air supply may have resulted
in excessively low DO levels in the first two tanks.
Theoretically, there would be some advantage to locating the DO
probe near the beginning of the aeration system in that response
to shock loads would not be as delayed.  However, experience has
indicated that compressor operation is more uniform if the con-
trolling probe is located in the latter half of the aeration
system.  Flexibility in probe location is recommended in any
design.  In a more recent LACSD design, each four-pass aeration
system has eight possible locations for mounting DO probes, one
at each end of each pass.  Any four of these locations can be
used at one time, with the control system automatically choosing
for control, the sensor which is producing the lowest reading.
Flexibility also allows any single probe location to be used as
the control point.
It should be noted that the DO control system does not regulate
the pattern of air flow along the aeration tank.  It only regulates
total air flow to the aeration tank in order to maintain a set
point dissolved oxygen concentration at the site of the controlling
probe.  The operator must still adjust air flow patterns to assure
adequate DO at all points in the aeration tanks.  For the DO profile
shown in Figure 26, approximately 60 percent of total air flow was
supplied to the first two tanks with the remaining 40 percent sup-
plied to the latter two tanks.
Plant flow rate, process air flow rate, and dissolved oxygen con-
centration at the controlling oxygen probe are plotted in Figure 27
from data collected at the Long Beach WRP.   Dissolved oxygen con-
centrations are seen to oscillate around the set point value of
3 rag/1 with amplitude averaging about +0.5 mg/1.  Rather large
excursions in DO concentration were noted when the compressors were
placed on manual control.  Upon returning to DO probe control,

                                67

-------
PROCESS AIR FLOW PLANT FLOWRATE, D 0
IQ3SCFM MGD mg/l
_ _ ro ro _ _
oiooiOoi ro •& o> o> o ro A —ro'w^oi


. X, /\ X










• ^
" — ^^









'\XV>





lA /"^J
i/u











-^^
""••N







— \s^





DO SET
A n /\
J V p — '











^
| "S^
^v






V^_
~ nr
i















^ — >.





" 	 x



 f\
-AH




\j
\
x















^s
- ' -***~




-+


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\,
VJ









	 •
^^
^





\
COMPRESSO;
*[ M


^

\tn 	 n
ANUALl
J





/ —
f







s
/
/
Y
f








V^->v






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S


















^-=













•DO PROBE CONTROL
^
rf
1


^^-^




-'




CTi
00
       0100   0200
0300    0400
0500
0600
0700    0800
                                                         090O
1000
1 100
                                                                              1200
FIGURE 27
                 CONTINUOUS CHART RECORDINGS OF DO AT CONTROLLING  PROBE, PLANT FLOWRATE,
                 AND PROCESS AIR FLOW AT LONG  BEACH WATER RENOVATION PLANT- 9-22-74

-------
however, oxygen concentrations returned to the set point value.
Oscillation of the DO concentration about the set point value as
shown in Figure 27 is characteristic of control systems employing
proportional band with reset and rate control.  The proportional
function of the controller provides a signal proportional to
difference between the controlled variable (in this case, the DO
concentration) and the set point value.  Reset action (also known
as integral action) produces a corrective signal proportional to
the length of time the dissolved oxygen has been away from the
set point.  Rate action  (also known as derivative action) produces
a corrective signal proportional to the rate at which the con-
trolled variable changes from set point.
All of the above control functions are adjustable.  With regard to
proportional action, for example, the amount of deviation of the
DO concentration from set point required to move the air compres-
sors through their full operating range is known as the "propor-
tional band" and is adjustable within the controller.  This means
that each controller must be tuned to the system it is control-
ling to obtain the proper combination of proportional, reset and
rate actions.
Another operational consideration with regard to a DO probe
control system is that more routine maintenance is required than
with other control techniques previously described.  Most addi-
tional work centers around maintaining and checking probe cali-
brations, replacing probe membranes and performing instrumental
adjustments.  Plant operators, using a portable DO sensor, measure
dissolved oxygen concentrations along the aeration tank on a
daily basis.  If the DO profile is abnormal in any way,  the
operator may decide to have the controlling probe examined.
Instrument maintenance personnel perform in situ calibrations of
the DO probes (again using a portable DO meter)  on approximately
a weekly basis.   Membranes are replaced when probe operation
becomes erratic or the probe can no longer be calibrated.  Exam-
ination of log records indicates that instrument personnel
performed routine maintenance, adjustments, and calibrations on
roughly a weekly basis.
                                69

-------
SUMMARY
All of the process air control systems described above offer
advantages and disadvantages some of which are described in
Table 4.  As sophistication increases, so does the accuracy with
which oxygen supply and demand can be balanced.  But as sophis-
tication increases, so also system costs and maintenance require-
ments increase.  All of these factors must be weighed in assessing
the correct design for a given treatment plant.  In general, as
plant size increases,  the benefit/cost ratio of sophisticated
instrumentation increases.  In addition, many treatment plants
are faced with meeting increasingly stringent effluent standards.
Under these conditions, the expense of process control instrumen-
tation may be justified provided it offers the promise of better
effluent quality.
Latest LACSD designs have incorporated a number of process air
control systems to provide a wide range of flexibility in plant
operation.  For example,  the Long Beach Water Renovation Plant
has instrumentation for controlling process air by cam programmers,
air to flow ratio, and DO probes.  In addition, primary effluent
turbidity can be used to control process air but this system has
never been used.  A schematic instrument flow diagram showing the
interrelationship of process air control systems at the Long
Beach WRP is shown in Figure 28.
                                70

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                           TABLE 4

              SUMMARY OF RESPONSE OF PROCESS AIR

           CONTROL SYSTEMS TO OPERATIONAL VARIABLES
        Variable
   Process Air Control Systems
Preset     Cam       Air/Flow    DO
Timers  Programmers   Ratio    Sensor
Response to predictable
 patterns of flow rate
 and organic strength       Yes       Yes

Response to shock
 loading in flow rate       No        No

Response to shock load-
 ing in organic strength    No        No

Ability to balance
 oxygen supply with
 demand                   Adequate   Good

Sudden increase in
 air supply if
 nitrification
 becomes established        No        No

Maintenance
 requirements             Minimal    Some
                       Yes
                       Yes
                       No
                      Good
 Yes
 Yes
 Yes
Best
                       No
 Yes
                      Some    Significant
                                71

-------
[0
                PANEL I
A
DIVIDER
C
o i

RECORDER
                                                              0-5
                                                              RATIO
                                                              UNITS
PANEL
2

FLOW
RECORDER



F
                       TO OTHER COMPRESSOR    A!R
                       INLET GUIDE  VANES    COMPRESSOR
              FIGURE  29
                                                      SCHEMATIC  INSTRUMENT  FLOW  DIAGRAM

-------
                          SECTION VI

                          REFERENCES

1.  Haug, R.T., and McCarty, P.L., "Nitrification with Submerged
    Filters", J. Water Pollution Control Federation, Vol. 44,
    No, 11,  (1972)

2.  Lees, H., "The Biochemistry of the Nitrifying Organisms:
    1. The Ammonia-Oxidizing System of Nitrosomonas."
    Biochem. J. , 52, 134-139,  (1952)

3.  Wezernak, C.T., Gannon, J.J., "Oxygen-Nitrogen Relationships
    in Autotrophic Nitrification."  Applied Microbiology, 51,5,
    1211,  (1967)

4.  Downing, L.L., Knowles, G., "Nitrification in Treatment Plants
    and Natural Waters: Some Implications of Theoretical Models."
    5th Internation Water Pollution Research Conference, July-Aug.,
    (1970)

5.  Loveless, J.E., Painter, H.A., "The Influence of Metal Ion
    Concentrations and pH Value on the Growth of a Nitrosomonas
    Strain Isolated from Activated Sludge."  J. Gen. Microbiol.,
    52, 1-14,  (1968)

6.  Boon, B., Ladelout, H., "Kinetics of Nitrite Oxidation by
    Nitrobacter Winogradskyi."  Biochemical Journal, 85, 440-447,
    (1962)

7.  Garrett, M.T., "Significance of Growth Rate in the Control
    and Operation of Bio-oxidation Treatment Plants."  Ind. Water
    and Waste Conf., Rice University, Houston, Texas, (1961)

8.  Water Pollution Research Laboratory, "Effect of Dissolved
    Oxygen on Nitrification," Ministry of Technology, Her
    Majesty's Stationary Office, London, (1964)

9.  Wuhrmann, K.,  Advances in Biological Waste Treatment, Edited
    by W.W. Eckenfelder and J. McCabe, Pergamon Press, London,  (1963)

10.  Downing, A.L., Hopwood, A.P., "Some Observations on the
    Kinetics of Nitrifying Activated-Sludge Plants."  Schweiz,
    A. Hydrol., 26, 271,  (1964)
                                73

-------
11.   Wild,  H.E.,  Sawyer,  C.N.,  McMahon,  T.C., "Factors Affecting
     Nitrification Kinetics."   J.  Water  Poll. Cont. Fed., 43, 9,
     (1971)

12.   Wuhrmann,  K., "Objectives, Technology, and Results of
     Nitrogen and Phosphorus Removal Processes, "Advances in
     Water Quality Improvement, 143, Eds.  E.F. Gloyna and
     W.W.  Eckenfelder,  University  of Texas Press,  Austin, (1968)

13.   Johnson, W.K. and  Schroepfer, G.J.,  "Nitrogen Removal by
     Nitrification and  Denitrification,"  J. Water Poll. Cont.
     Fed.,  36,  1015,  (1964)

14.   Jenkins, D.,  Garrison,  W.E.,  "Control of Activated Sludge
     by Mean Cell Residence  Time."  J. Water Poll. Cont.  Fed.,
     40, 1905,  (1968)
                               74

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                          SECTION VII
            RETURN ACTIVATED SLUDGE - FLOW CONTROL
INTRODUCTION
Mechanisms to control sludge blanket levels in secondary clarifiers
have been incorporated in LACSD treatment plant designs since about
1960.  Many early designs were unsuccessful and rather unsophis-
ticated compared to today's control technology.  Nevertheless,
these early attempts at sludge blanket level control led to more
effective control techniques incorporated in current designs.  It
also provided District's personnel with considerable experience
in evaluating various control techniques.
Control of sludge blanket level in the final clarifier is desir-
able for several reasons.  If return flow is too great, sludge
hoppers will be emptied of sludge particularly during low flow
periods when solids loading on the clarifier is low.  This results
in a low concentration of return sludge.  Power requirements are
increased as return pumps must convey a greater volume of thin
sludge.  If anaerobic digestion is used to treat waste activated
sludge, excessive digester capacity is used in treating the thin
sludge.  On the other hand, if return sludge flow rate is too low,
sludge blanket levels could conceivably rise to the level of the
effluent weirs.  This would be somewhat extreme, however, and should
never occur with good plant operation.
Maintaining a constant sludge blanket level offers some additional
advantages to plants that are hydraulically overloaded.  Detention
times are determined by total flow through a clarifier, total flow
being the sum of plant flow and return sludge flow.  Thus, main-
taining a more concentrated return sludge minimizes the hydraulic
loading on the final clarifiers.  Another advantage is that the
detention time per pass through the activated sludge system is
increased.

                                  75

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Another mode of return sludge control is to return a constant
flow rate from the clarifier to the activated sludge unit.
Solids are stored in the clarifier hoppers during high flow
periods.  This control scheme offers several advantages in that
operation is straightforward and virtually no control equipment
is required,  Return sludge is relatively thin during low flow
periods however, and this may be. undesirable if the treatment
plant and/or digesters are overloaded.  LACSD upstream treatment
plants discharge waste sludges back to the sewer for subsequent
treatment at the main treatment facility.  Thus, obtaining the
thickest possible waste sludge is not a normal operating consid-
eration.  Maintaining a constant return rate has proven to be an
adequate control technique under these conditions.  However, as
plant flow rates increase, the incentive to reduce recycle flow
rates also increases.  This prompted the following study on
return sludge flow control techniques.
The Long Beach Water Renovation Plant was the site of a two-month
study designed to obtain operational data on the return sludge flow
control system.  This particular system incorporated latest LACSD
thinking with regard to sludge blanket level control.  The plant
contains six final clarifiers, one of which was used in documenting
the return sludge control system.  The remaining clarifiers were
operated with a constant return rate.
System Description
A schematic diagram of the return sludge control system and
associated experimental apparatus is shown in Figure 29.  Heart
of the system consists of two sludge detector probes installed
in the final clarifier above the return sludge hoppers.  Probes
were model #8100 automatic sludge level detectors manufactured
by the Keene Corporation.  Each probe contains an infra-red diode
light source and a photocell sensor separated by an open gap of
approximately two inches.  When installed in the final clarifier,
the photocell is illuminated by the infra-red diode.   Photocell
resistance is governed by the amount of light received from the
                               76

-------
  -J
DJ
m
73
n
r
5
             V  W.S.
           CLARIFIER

           KEENE
           PROBE
           No. 2
               KEENE
               PROBE
               No. I
 TURB.
RECORD
                        TURB.
                        METER

PF
a
PC
"1 ,
i
tOBE ACT.
VALVE
IS. REC.
g


VALVE
POS.
IND.
                                                          MEDIAN SET POINT
                                                           {%VALVE OPEN
                                                           WITH PROBE No. I
                                                           ACTIVATED)

                                                          MINIMUM SET POINT
                                                           "(% VALVE OPEN
                                                          T WITH NO PROBES
                                                          , ACTIVATED)

                                                          I
                                                                W.S.y
                        TO DRAIN
                                 RETURN SLUDGE
                                   WET WELL

                                 WATER SURFACE
                                 ELEVATION HELD
                                 CONSTANT BY
                                 PROPORTIONAL
                                 BAND WITH RESET
                                 CONTROLLER
C
CO

rn
TJ
           SCHEMATIC DIAGRAM  OF RETURN  SLUDGE  CONTROL SYSTEM
FIGURE 29  AND ASSOCIATED  EXPERIMENTAL APPARATUS  USED  IN  STUDY

-------
infra-red diode.  Thus, a sludge blanket at the probe will de-
crease light transmission and the resulting increase in photocell
resistance is used as a control signal to regulate the return
sludge flow rate.
The controller contains sensitivity adjustments, relays,  timing
devices, and circuitry necessary to regulate operation of the flow
control valve.  If a probe senses a sludge blanket, the timer is
started which in turn activates the control valves.  The valve re-
mains activated until the timer reaches the end of its preset in-
terval.  At this point, the valve will remain activated as long as
the detector probe continues to sense a sludge blanket.  When
sludge is no longer sensed, the valve will deactivate.  Purpose of
the timer circuit is to prevent frequent on-off operation of the
valve which would cause undue wear of the mechanical components.
Valve position is determined by a current trip controller with two
adjustable set points.  One set point controls minimum valve
position with no probes activated.  The other set point determines
median valve position when probe no. 1 (lower probe)  is activated.
Should probe no. 2 activate,  the control valve is positioned to
full open.
Under normal conditions,  the sludge blanket will be located below
the lower Keene probe.  During the low flow period, the draw off
valve will be at its preset minimum opening.  As flow rate in-
creases, solids loading on the clarifier increases and the sludge
blanket level rises.  As the sludge blanket reaches the lower probe
the draw off valve should open to the preset median position.
Return flow rate should then be sufficient to lower the blanket
level or at least maintain a constant elevation.  If,  after the
preset timer interval, sludge level has dropped below the sensor,
the valve will return to minimum open position.  If sludge level
has not dropped by the end of the interval,  the valve will remain
at the median open position until sludge level has dropped.
During normal plant operation, sludge blanket levels  should never
reach probe no.  2 (higher probe).   Should the upper sensor be

                                78

-------
activated, however, draw off valve position will increase to
full open.  Valve position will remain as such until the preset
timer interval expires after which the draw off valve will
return to median position as soon as the sludge level falls
below probe no. 2.
Several pieces of experimental apparatus were assembled for this
study which are not part of the normal control system,  These
included a two-pen recorder for recording probe actuation and
subsequent valve position, a Hach falling stream turbidimeter
to measure light transmission, and a light transmission recorder.
Samples for the turbidimeter could be obtained from any level in
the water column of the clarifier.
Relationship between Plant Operating Parameters and
 Return Flow Rate
Proper valve settings for controlling sludge blanket level depend
upon plant operating parameters and settling characteristics of
the activated sludge.  A schematic diagram of flow distribution
in the secondary portion of an activated sludge treatment plant
is shown in Figure 30.  Performing a mass balance about the
secondary clarifier gives the following:
   (Q± + Qr>X±  =  QeXe +  (Qr + Qw)Xr                          (1)

   Where Q.    =  primary effluent flow rate
         Q     =  secondary effluent flow rate
         Q     =  return sludge flow rate
         Q     =  waste sludge flow rate
          w
         X.    =  aerator effluent MLSS concentration
          i
         X     =  secondary effluent suspended solids
                   concentration
         X     -  return sludge suspended solids concentration

If effluent suspended solids concentrations are within the nor-
mally observed range of 5 to 25 mg/1, the mass rate of solids
                                79

-------
     Qi
CO
o
                 AERATOR
Qi+Qr,Xi
                  SETTLER
Qe,Xe
                              Qr,Xr
                                  |Qr+Qw,Xr

                                  4      Qw,Xr.
    FIGURE 30   FLOW  DISTRIBUTION AND  SOLIDS BALANCE IN ACTIVATED  SLUDGE PROCESS

-------
lost in the effluent can be neglected and equation 1 becomes
   (Q± - Qr)X±  =   (Qr + Qw)Xr                                  (2)
In normal operation of the activated sludge process waste flow
rate, Q^ is usually less than 10 percent of the return flow
rate, Q^.  Neglecting this term equation 2 becomes
   (Q± + Qr)x±  =  Qrxr                                         (3)
Rearranging terms
           Qr  =  ?A                                         (4)
            r     x -x.
                   r  i
Concentration of return sludge, X  , is partly a function of
return rate, Q .  As the return rate decreases sludge depth in
the final clarifier would increase which should result in a
slightly thicker sludge.  Magnitude of this effect would be a
function of sludge settling characteristics and the particular
sedimentation tank design.  Q., X., and X  can be measured and
the values used in equation 4 to predict a return flow rate.
Should operation at the predicted return rate result in changes
in X  and X. , the new values can be used in equation 4 to predict
a new return rate and so on.
Another approach to predicting the return sludge concentration
involves the settling characteristics of the MLSS as measured
by the SVI test.  This latter test is performed at least daily
in most activated sludge plants.  As such, it is a convenient
source of information on the settling characteristics of the
activated sludge.
Average concentration of solids in the one liter graduate used
for the SVI test can be determined as
                                     6
  Sludge concentration in mg/1  =  10 /SVI                     (5)
If it assumed that this same concentration can be obtained in
the return flow from the secondary clarifier, equation 4 becomes

           Q   -    Qixi                                       (6)
                  106 - X.
                  svi    -1
                                81

-------
Whether equation 5 accurately predicts the return sludge
concentration will, again, depend on efficiency of the sec-
ondary clarifier.
Diurnal variations in plant flow rate and MLSS concentrations
must be taken into account when using equations 4 or 6.  During
the low flow period, the minimum return rate should be sufficient
so that the Keene probes rarely, if ever, will actuate.  Thus,
the proper minimum return rate Qr min (both probes deactivated)
can be estimated by using minimum flow conditions in either
equation 4 or 6.
During peak flow periods, the return sludge rate should be
sufficient to maintain a constant sludge blanket level with the
lower Keene probe actuated.  Thus, the median return rate Q    -,
(lower probe actuated)  can be estimated by applying peak flow
conditions to equations 4 or 6.
RESULTS
Return sludge flow control equipment described above was operated
at the Long Beach WRP for a two-month period from July to
September, 1974.  The study was  designed to answer the following
questions:  (1)  could the control equipment described above
maintain a constant sludge blanket level, (2)  what operating
parameters affected performance  of the control equipment,
(3) could equations 4 and 6 be used to estimate proper return
sludge flow rates,  and (4)  how much operator time would be needed
to maintain the control equipment.
SVI data collected over the period of the study is shown in
Figure 31.  Each data point represents the average of two daily
SVI tests, one conducted in the  morning and the other in the
afternoon.  The plant suffered from severe bulking three times
during the study period.   In all cases,  the bulking was caused
by filamentous organisms.  Rising sludge also occurred during
two weeks of the study period.  The plant was being operated to
achieve full nitrification and the rising sludge was caused by
subsequent denitrification in the final clarifiers.  Rising sludge

                                82

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        800
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                       I  I   I  II
                                                              RISING  SLUDGE
                                                                 IN FINALS
                                       I  I   I  I   I  I   I  I   I  I   I  I   I  I   I  I   I  I   I  I
I   I  I   I  I   I  I   I
          7-11  13  15 17  19 21 23 25 27 29 51 8-24  6  8 10  12 14  16 18 20 22 24 26 28 30 9-1 3  5 7  9  II

                                      DAY OF THE MONTH
                DAILY SVI DATA ON AERATION TANK  DURING STUDY  PERIOD
      FIGURE 31

-------
was observed in all secondary clarifiers and was not caused by
the return sludge control equipment.  These problems disrupted
normal plant operation but did allow the control equipment to
be operated with sludges of varying settling characteristics.
Sampling Techniques
One of the study objectives was to determine whether a constant
sludge blanket level could be maintained with the control equip-
ment.  Therefore, some method was needed to determine the sludge
blanket location in the final clarifier.  The first attempt made
use of a Kemmerer sampler which could be lowered to a desired
depth and then tripped by a messenger.  Samples could be collected
at increasing depths until the sludge blanket was detected.  Two
problems arose with this system.  First, the Kemmerer sampler
caused considerable disturbance in the water column.  After the
first sample had been collected, there was no assurance that
subsequent samples represented the true condition of the water
column.  Second, the sampler itself was approximately two feet
in length and the location of the sludge blanket could not be
placed to any greater degree of accuracy.  Since the elevation
difference between probes no. 1 and 2 was usually two feet, the
level of accuracy was not sufficient.
To effect greater accuracy in locating the sludge blanket, a
plexiglas tube, one-inch in inside diameter and 16 feet long,
was constructed.  During sampling, the tube was gently lowered
into the water column until the top of the tube was flush with
the water surface.   The tube was then capped with a stopper and
withdrawn.   This sampling procedure allowed the entire water
column to be visually inspected at one time and also increased
accuracy in locating the sludge blanket.
When the SVI was less than about 150, a well-defined sludge-liquid
interface existed and sludge blanket levels could be visually
determined to within about one foot.  However,  when the SVI
increased much above 300,  a definite interface no longer existed
in the final clarifier.   Instead,  a gradual increase in suspended

                                84

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solids was observed at all depths below the water surface.  This
situation is graphically illustrated  in Figures 32 and 33 where
suspended solids concentration and light transmission are plotted
as a function of depth in the final clarifier.  Samples were
collected using the Kemmerer sampler  and percent transmission was
determined with a spectrophotometer at 600 my wavelength, 1 cm
lightpath.  For the data in Figure 32, the SVI was 224 and,
using the plexiglas tube, the sludge  interface could be visually
determined to within two or three feet.  Subsequent tests with
SVI' s near 100 indicated that the sludge interface could be placed
to within about one foot of depth.  When bulking occurred, however,
it was difficult to visually locate the sludge blanket level as
indicated by the data presented in Figure 33.
To effect greater accuracy in locating the sludge blanket interface
and to avoid the subjective assessments necessary in using the
plexiglas sight tube, the monitoring  equipment illustrated in
Figure 20 was assembled.  Components  of the monitoring system
included an intake manifold, sampling pump, Hach Falling Stream
Turbidimeter and a recorder.  The intake manifold was a multiple
port device designed to minimize approach velocities and avoid
pulling up sludge from lower depths.  The manifold could be located
at any depth in the water column.  The Hach Falling Stream
Turbidimeter is designed for measuring high turbidities and is
commonly used for locating sludge blanket levels.  The amount of
light transmitted through a sample is measured (as opposed to
measuring scattered light) which is similar to the action of the
Keene probe.
Light transmission measured by the turbidimeter was correlated
with suspended solids concentration in the sludge with the results
shown in Figure 34.  This correlation applies only to sludge
encountered during this study and should not be applied to other
types of sludge.  Nevertheless, it provides a useful means of
estimating suspended solids concentrations from light transmission
data.
                                85

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    20   30   40   50    60   70   80
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                                                 I    I     I
                                        PERCENT TRANSMISSION
         SLUDGE LEVEL BY EYE
                                           PROBE No. 2 ELEV.
                                           PROBE No. I  ELEV.
                                      SUSPENDED SOLIDS
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 I    I     I    I    I     I
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                 1000                   2000
             SUSPENDED  SOLIDS CONG, mg/l
  SUSPENDED SOLIDS AND LIGHT TRANSMISSION VERSUS DEPTH IN
               SEDIMENTATION  TANK
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                                                 TRANSMISSION
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                                                            SVI = 565
                                                         PROBE No. 2 ELEV.
                                                         PROBE No. I  ELEV
                                             I     I    I     I    I
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                         1000                    2000
                     SUSPENDED SOLIDS CONC. mg/l

           SUSPENDED SOLIDS AND  LIGHT  PENETRATION AS A FUNCTION OF DEPTH

           IN SEDIMENTATION  TANK

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FIGURE 34  CONCENTRATION HACH FALLING STREAM  TURBIDIMETER 0.25" LIGHT PATH

-------
Sludge Blanket Levels
Average operating parameters at the LBWRP for the month of
June, 1974, are presented in Table 5.  Using equation 4 with
values from Table 5 minimum and median return sludge flow rates
per clarifier were estimated to be approximately 0.26 mgd and
1.11 mgd, respectively.  The minimum return rate was initially
adjusted to 0.3 mgd since flows less than this led to plugging
of the control butterfly valve.  Since further concentration of
the sludge was expected following establishment of a sludge
blanket, the median return rate was set at 0.8 mgd.  Minor adjust-
ment of these initial return rates were made during the study in
response to changing sludge settling characteristics.
During the first week of the study period, it was observed that
actuation of probe no. 2 with subsequent full opening of the
return control valve caused considerable disruption of the
clarifier.  With control valve full open, the return rate increased
to such an extent that the water surface in the clarifier momen-
tarily fell below the effluent weirs.  This was obviously an
unwarranted situation and, as a result, probe no. 2 was discon-
nected from the control circuitry.  Actuation of probe no. 2 was
still recorded but activation did not affect control valve position.
Thus, only two valve positions were used in the remainder of the
study, the minimum position with probe no. 1 deactivated and the
median position with probe no. 1 activated.
Profiles of percent light transmission in the water column above
the return sludge hoppers are plotted in Figures 35 to 38.  The
Figures are arranged in order of increasing SVI.  In Figure 35
mixed liquor SVI was 51 which indicates that the sludge was
capable of very dense compaction.   Sludge level in the return
hoppers was quite low in the early morning low flow period but
increased with increasing plant flow.  By noon, the sludge
interface reached probe no.  1 which caused valve actuation and
increased return sludge flow to 0.8 mgd.  Timer duration, set
to 10 minutes in this test,  was too long since the return hopper
                                  89

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                      TABLE  5




       MONTHLY AVERAGE OPERATING  PARAMETERS




         LONG BEACH WATER  RENOVATION  PLANT




	June,  1974	




Minimum daily flow                        3,1  mgd




Peak daily flow                          13.2  mgd




Average daily flow                        9,1  mgd




Mixed liquor suspended solids          1600 mg/1




Return sludge suspended  solids         5400 mg/1




Number of final clarifiers in service    5
                         90

-------
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                           ACTUATION
                                                  Qmin=0.3mgd  Qmed-0.8mgd
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                                                  actuation- I200hrs)
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                                                            PROBE  No. 2  ELEV.
                           TRANSMISSION
                                                     CLARIFIER  FLOOR   ELEV.
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                                                            PROBE  No.  I  ELEV.
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1000
1100
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FIGURE 35
                        PRORLES  OF  LIGHT  TRANSMISSION

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                                                                   SVI  = 53
                                                                           '98
                                                                    PROBE  No.  2 ELEV.
                                                          PROBE  No.  I  ELEV.
      CLARIFIER  FLOOR   ELEV.
                 0800     0900     1000     1100     1200

                                           8-13-74
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       FIGURE 36
                      PROFILES  OF  LIGHT  TRANSMISSION

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                               99
                                 PROBE No. 2  ELEV.
                                                        90
                                                        TOJ8PROBE No. I  ELEV.
                                                               I
                                                     CLARIFIER  FLOOR  ELEV.
                                                                10
                                                                              HOPPER
                                                                              BOTTOM
                 1000
100
1200
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                                                      1400
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       FIGURE  37
                        PROFILES OF LIGHT  TRANSMISSION

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                                           SVI - 522
                                                                97  PROBE No.  2 ELEV.
                                                         PROBE No. I   ELEV.
                                               \ CLARIFIER  FLOOR  ELEV.
       1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
       FIGURE  38
                      PROFILES OF LIGHT   TRANSMISSION

-------
was almost emptied of sludge.  Interface height subsequently
increased but did not reach the level of probe no. 1.
In a subsequent test, timer duration was reduced to two minutes
to avoid excessive drawdown of the sludge blanket level.  In
this case, however, sludge interface never reached the level of
probe no. 1 and no valve actuation was noted as shown in
Figure 36.  SVI was so low and, hence, the sludge blanket so
compact that the minimum return flow of 0.3 mgd was more than
sufficient to keep the blanket below probe no, 1.  Using equation
6 with average monthly parameters from Table 5 and an SVI of 53,
the return rate necessary to maintain a constant blanket level
under peak flow conditions is estimated to be about 0.24 mgd.
The fact that a return rate of 0.3 mgd did not allow a buildup
in the sludge blanket seems to substantiate the validity of
equation 6.
Constant sludge blanket levels were maintained when the SVI was
in a more normal range of 100 to 150 as shown in Figure 37.
Even so, the minimum return rate was too large to allow a sludge
blanket during the low flow period.  This was the general pattern
observed throughout the study period.  Hopper levels were drawn
down during low flow periods but subsequently increased as plant
flow rate increased.  If the SVI was greater than about 60 or 70,
the blanket would eventually reach the level of probe no. 1.
Subsequent probe actuation was normally quite effective in maintain-
ing the blanket at or below probe no. 1.
Sludge blanket levels increased above probe no. 1 only during
periods of sludge bulking.  Light transmission profiles with a
mixed liquor SVI greater than 500 are shown in Figure 38.  Under
these conditions, the sludge interface became very diffuse and
would normally reach the level of probe no. 2 causing activation.
Recall that activation of probe no. 2 was recorded but caused
no change in return flow rate.  Return sludge control equipment
continued to function in an acceptable manner although the
bulking wats,  at times, quite severe.  Generally, the probes would
not activate during the low flow period but once activated would
                                95

-------
stay on continuously until flow rate again decreased.
Strip chart recordings of light transmission at the level of
probe no. 1 and probe actuation are presented Figures 39 and 40.
For data in Figure 39, SVI was 534 and probe no. 1 was actuated
during most of the high flow period between 1000 and 1600 hours
and deactivated during the early morning low flow period.  Light
transmission and probe actuation recordings for an SVI of 183
are shown in Figure 40,  Both charts are representative of normal
probe operation at their respective SVI levels.
The percentage of time a probe was actuated was found to be a
function of mixed liquor SVI.  Ranges observed in the time of
probe actuation are presented in Table 6.   Actuation rarely, if
ever, occurred below an SVI of 50.  At an SVI of 100, the probe
was never actuated more than 10 percent of the time.  The length
of probe actuation increased rapidly with increasing SVI up to
values of about 400 above which probe actuation occurred between
40 and 70 percent of the time.
Probe no. 2 rarely actuated at SVI values below 200 and most of
the actuation which did occur was thought to be due to periodic
plugging of the probe by biological solids.  Above SVI levels
of 400, however, probe actuation did occur regular y during the
peak flow period.
Scheduled Maintenance
A point of major concern during the study was whether the Keene
probes would become fouled with return sludge or other biological
growths.   If fouling occurred, the probe would react as if it
sensed sludge resulting in unnecessary as well as undesired valve
operation.
During periods of rising sludge,  the probes were observed to
actuate even though the turbidimeter showed no decrease in light
transmission.  The probes rarely actuated for periods longer than
the timer interval.  This was undoubtedly caused by clumps of
rising sludge passing the probe and causing activation.   The
rising sludge apparently passed by the probe without fouling
                                96

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-------
                      TABLE 6

                  PROBE ACTUATION

                         Time of Probe Activation
                         Expressed as a Percentage
                              of Total Time

SVI Range	Probe No. 1   Probe No. 2

   50                       0-2              0

  100                       1-10             0-1

  200                      10-45             0-2

  300                      30-60             0-4

  400                      40-70             0-20

  500                      40-70           0.1-20

  600                      45-70             3-20
                         99

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because the probes deactivated following the timer interval.
In any event, the problem was not serious and did not signifi-
cantly affect probe performance.
Fouling of the probes to such an extent as to cause continuous
probe actuation was observed three times during the study period.
In all cases, the fouling material was easily removed by raising
and lowering the probe in the water column.  Based upon this
experience, the probes should be cleaned at least weekly to
avoid gradual accumulations of biological growths,
SUMMARY
Based upon results collected during a two-month study period, the
following conclusions can be drawn with regard to return sludge
flow control using Keene probes.
  1.  Return sludge flow control is practical and offers the
      advantage of increased return and waste sludge solids
      concentrations.
  2.  In general, the sludge blanket could be maintained at a
      constant level during peak flow conditions but was always
      drawn down during low flow periods.
  3.  A definite sludge blanket interface existed for SVI values
      below about 200.  Increasing SVI resulted in a gradual loss
      of the interface until at SVI levels greater than 500 no
      definite interface existed.   Instead a gradual increase in
      solids concentration was observed with no distinct liqaid-
      sludge interface.
  4.  Sludge bulking did not adversely affect probe performance
      although the time of probe actuation increased significantly,
  5.  Equations 4 and 6 can be used to estimate proper return
      sludge flow rates.
  6.  Fouling of the probes was not a severe problem and could
      generally be avoided by regular probe cleaning on a weekly
      basis.
  7.  Two probes were not required to maintain a constant sludge
      blanket level and probe no.  2 was not used to control valve

                                100

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operation in this study.  In future designs, probe no. 2
can either be completely eliminated or used as an alarm
to signal adversely high blanket levels.  Should the probe
function as an alarm, a timer should be included so that
the probe must sense sludge continuously for at least 15
minutes before the alarm is actuated.
Equalization of wastewater flows prior to secondary
treatment is being considered as a method of increasing
plant capacity.  Under these conditions, flow rate to the
final clarifiers would be constant.  Return sludge control
equipment could then maintain a constant sludge blanket
level at all times and not just during the high flow period,
Maximum return and waste sludge concentrations would also
be realized.
                           101

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                         SECTION VIII
             WASTE ACTIVATED SLUDGE - FLOW CONTROL
INTRODUCTION
The fundamental equation describing cell growth in a biological
reactor is
    Where dX/dt   =  growth rate of microorganisms
              Y   =  cell yield coefficient
          dF/dt   =  rate of food utilization
              b   =  endogenous respiration coefficient
              X   =  cell mass
Equation 1 basically states that net production of new cells is
a function of both rate of food utilization and loss of cells
due to endogenous respiration.  Dividing equation 1 by X yields
          dX/dt   =  y dF/dt _ b                               (i)
            X            X
In this equation
            X     -A   =  mass of cells in the system        ,_.
          dX/dt       c     mass of cells grown per day
If the biological reactor is at steady state, or nearly so, the
mass of organisms grown per day will equal the mass of organisms
wasted per day.  Thus, if the system is at steady state, 6   will
                                                          \^-
equal the average retention time of a cell in the system which is
commonly referred to as mean cell retention time (MCRT) .  Also
in equation 2
          dF/dt   =  rate of food utilization                  (4)
            X        mass of organisms in system
                               102

-------
                        =  food to microorganism  ratio  (F:M)
Thus,
                   i-   =  Y  (F:M) - b                          (5)
                    c
The terms Y and b should be approximately constant  for  a given
waste and, hence, MCRT and F:M are inversely proportional.
Lawrence and McCarty,  applied equation 1 to the  activated  sludge
process and found that effluent substrate concentration was a
function of the mean cell residence time, decreasing with increas-
ing MCRT,  Since MCRT is, in  turn, related to the food  to micro-
organism ratio, it implies that either parameter  can be used to
theoretically describe effluent quality from the  activated  sludge
process.  In practice, however, effluent quality  is not as
pronounced a function of MCRT.  This is because effluent quality
is determined to a large extent by settling properties  of the
mixed liquor.  Nevertheless,  MCRT and F:M have a  sound  theoretical
basis for use as control parameters for the activated sludge
process.
Which of the parameters, either MCRT or F:M, to use in  practice
has been the subject of much  debate in the technical literature.
Use of F:M ratio requires considerable laboratory work  since it
is necessary to know both the amount of food removed and the
mass of organisms in the system.  This requires tests for total
BOD or COD in the influent and soluble BOD or COD in the effluent
as well as volatile suspended solids, VSS, in the aeration tanks.
COD tests are usually used to avoid delays associated with the
BOD test.  In addition, VSS is a relatively poor measure of the
true active mass of microorganisms in the mixed liquor  (sometimes
referred to as viability).  In practice, however, this  latter
disadvantage may not be significant since the active mass is
probably a fairly constant percentage of the VSS.  However,
little laboratory data exists to substantiate this latter claim.
Conceptually MCRT is an easier parameter to use.  Should the
operator desire a 5-day MCRT,  he need waste 20 percent  of the

                               103

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total plant solids each day.  Viability or active mass of the
mixed liquor need not be considered since if 20 percent of the
total solids are wasted daily, then 20 percent of the active
mass is also wasted.  Thus, the operator must know the total
solidsf TS, in the system as well as the TS lost from the system
each day.
In LACSD practice, the MCRT is normally used as the control
                                           2
parameter for the activated sludge process, .   A given fraction
of solids, therefore, must be wasted daily.  It remains then
to describe control schemes for solids wasting.
CONTROL SCHEMES FOR SOLIDS WASTING
Two different control schemes have been proposed to accomplish
solids wasting from the activated sludge process.  One involves
wasting mixed liquor directly from the aeration tank while the
other involves wasting from the return sludge line coming from
the secondary clarifier.  Both of these will be described so as
to better evaluate the advantages and disadvantages of control
techniques used by LACSD.
Wasting from the Aeration Tank
A schematic diagram of an activated sludge process in which
wasting is accomplished directly from the mixed liquor is shown
in Figure 41.  The wasting rate (Q ), required to achieve a
given MCRT in this system can be determined through use of
equation 3.  The total mass of solids in the system is the sum
of solids held in the aeration tank and final clarifier.  Total
solids mass in the aeration tank can be described as XV , where
                                                       Si
X is the concentration of solids if the aeration tank is complete-
ly mixed or the average concentration if the reactor is not.
Estimating solids mass in the secondary clarifier is more diffi-
cult since a sludge blanket normally forms at the bottom of the
clarifier.  Average solids retention time in the sludge blanket
is difficult to ascertain.  Burchett and Tchobanoglous,  suggested
that the mass of organisms in the secondary clarifier is approx-
imately equal to the volume of the clarifier times the MLVSS, V X,
                                                               s
                               104

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PRIMARY EFFLUENT FLOWRATE
WASTE  SLUDGE FLOWRATE
RETURN SLUDGE FLOWRATE
VOLUME OF AERATOR
VOLUME OF CLARIFIER
MIXED LIQUOR  VOLATILE  SUSPENDED  SOLIDS
 CONCENTRATION
SECONDARY  EFFLUENT VOLATILE  SUSPENDED
 SOLIDS CONCENTRATION
RETURN  SLUDGE VOLATILE SUSPENDED SOLIDS
 CONCENTRATION
          SCHEMATIC DIAGRAM OF ACTIVATED SLUDGE PROCESS
FIGURE 41    WITH WASTING  FROM MIXED LIQUOR
                          105

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This is strictly true only if the. detention  time  of  the  solids in
the clarifier equals the liquid detention  time.   Nevertheless, it
should provide a reasonable approximation  of the  true  mass.   Deaner
and Martinson,  have recently questioned whether  cell  mass  stored
in the final clarifier should be included  in the  cell  balance.
While this point is of theoretical interest,  it is beyond the
scope of this report and cell storage in the final clarifier  will
be considered in the cell balance,
Organisms are wasted from the system from  two places,  intention-
ally from the aeration basin and unintentionally  in  effluent  from
the secondary clarifier,  A third source of  possible wasting  is
the surface skimmings collected in the secondary  clarifier.   Such
skimmings may represent a significant loss of solids if  foaming or
sludge baulking occur in the aeration system.  Under  normal operation,
however, 'this loss is not significant and  need not be  considered
in this discussion.
Mass of solids wasted intentionally from the aeration  tank is
represented by XQ  , while that in the effluent as  (Q-Q )X .
                 w                                    we
Using equation 3, MCRT can be described as
                           xv  + xv
                           XQw +  (Q-Qw)Xe
If the treatment plant is operating properly, effluent solids loss
should be a small fraction of the solids intentionally wasted.
Under these conditions, equation 6 can be simplified to

                   «    -  X(Va + V                            (7)
                              QwX
Solving for Q
             w
                               c
If solids are wasted directly from the mixed liquor, the wasting
rate is a function only of the aeration and clarifier tank
volumes and the desired MCRT,  No laboratory measurements are
                               106

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necessary.  Despite these advantages, the number of treatment
                                                3 4
plants employing this control scheme is limited, ' .  The
reason for this is that a greater volume of waste sludge must
be handled and an additional "/aste activated sludge clarifier
is required.  In addition, laboratory measurements required to
waste from the return sludge line are usually performed as a
routine part of plant operation.  As such, wasting from the
mixed liquor offers little advantage in saving laboratory work
since the control tests are performed anyway.
Wasting from the Return Sludge Line
A schematic diagram of an activated sludge process with sludge
wasting from the return sludge line is shown in Figure 42.
Employing the same procedure as previously described, the MCRT
can be described as
                   n    _  XV  + XV,
                   8c   -  — $ - * -                   (9)
                           Qw Xr + (Q-Qw)Xe
Solving equation 9 for Q  gives
                   Q    =  x(va + ys) - ec(Q-Qw)xe
                   "W      -
                                    V Q
                                    Vc
Since Q  is normally much smaller than the plant flow rate, Q,   it
can be neglected on the right side of equation 10 allowing a
direct solution for Q .
                    *
                   Q    =     a    a  -  ce
                    w      -
                                 X  9
                                  r  c
Thus, to determine the required wasting rate from the return
sludge line, the plant operator must know the volumes of both the
aerator and final clarifier and must measure mixed liquor, return
sludge and secondary effluent suspended solids concentrations.
Since return sludge is more concentrated than mixed liquor, a
smaller volume of waste sludge need be handled and additional
waste sludge clarifiers are not required.  These considerations
                                107

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       vs =
       X =
                AERATOR
                 Va,X
                             CLARIFIER )Q-Qw»xe
                               vs
                     Qr ,Xr
Q  =  PRIMARY  EFFLUENT FLOWRATE

Qw=  WASTE SLUDGE  FLOWRATE

Qr -  RETURN SLUDGE FLOWRATE

Va =  VOLUME  OF  AERATOR

      VOLUME  OF  CLARIFIER
     MIXED LIQUOR VOLATILE SUSPENDED SOLIDS
      CONCENTRATION

     SECONDARY  EFFLUENT VOLATILE SUSPENDED
      SOLIDS CONCENTRATION
     RETURN  SLUDGE VOLATILE SUSPENDED SOLIDS
      CONCENTRATION
         SCHEMATIC DIAGRAM  OF ACTIVATED SLUDGE PROCESS
FIGURE 42    WITH  WASTING  FROM  RETURN SLUDGE  LINE
                          108

-------
have led the LACSD to incorporate sludge wasting from the return
sludge line in its activated sludge plant designs.  The LACSD
recognizes, however, that wasting from the mixed liquor is a
viable alternative and that the particular wasting scheme in
any design must be chosen after consideration of all factors.
CONTROL OF RETURN SLUDGE WASTING
Several different schemes have been used to control solids
wasting from the return sludge line.  Two of the most popular
control techniques are (1) wasting a constant percentage of the
return sludge flow  (sometimes referred to as hydraulic control)
and  (2) wasting a fixed volume of return flow.  Both of these
control schemes will be described since the control calculations
and required laboratory measurements depend on the techniques
chosen.
Wasting a constant percentage of the return sludge flow was
described by Walker,  in 1965 and is sometimes referred to as
hydraulic control.  Referring to Figure 42, to maintain a given
MCRT, it is necessary to waste 100/MCRT percent of the total
plant solids each day.  However, 100/MCRT percent of the return
sludge flow can not be wasted since solids make several passes
through the return line each day.  Total flow rate through the
aeration tank and secondary clarifier is Q + Q .  Thus, the
liquid makes a total of (Q + Q ) / (V  + V ) passes per day.  The
                              r    a    s
solids should make the same number of passes per day provided
there is no accumulation in the secondary clarifier which is
unlikely.  Thus, for a conventional plant, the continuous wasting
rate, W, figured as a percent of the gross return sludge flow
rate (Q  + Q )  can be calculated as

                              (Va + V                         (12)
                               (Q + Qr)

For a given plant, the aeration and clarifier tank volumes are
fixed.  Thus, the operator need know only the desired MCRT, average
plant flow rate, and return sludge flow rate to calculate the

                               109

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percentage of return sludge to be wasted.  Mixed liquor and return
sludge concentration need not be determined.  Should mixed liquor
and return sludge concentrations vary diurnally, as they usually
do, it in no way affects the wasting percentage, W.  One disad-
vantage of this control technique, however, is that variations in
return sludge flow rate necessitate readjustments of the wasting
percentage.  If the return rate is constant, as it is in many
plant designs, the wasting percentage is fixed.  But if it varies,
as it might if Keene probes were used to maintain a constant sludge
blanket level (see Section VII) constant readjustment of the wasting
percentage would be required.
Operating practice at LACSD activated sludge plants involves using
equation 11 to calculate a waste sludge flow rate.  24-hour composite
samples of mixed liquor, return sludge and secondary effluent sus-
pended solids collected the previous day are used in equation 11 to
predict the wasting flow rate.  Thus, calculations are always one
day behind.  This is not a serious drawback, however, since mean
cell residence times are normally on the order of 5 to 15 days and
operating parameters should not change significantly in the course
of a single day-
It is important that 24-hour composite samples be used to calculate
mixed liquor, return sludge, and effluent suspended solids concen-
trations used in equation 11.  Diurnal variations in these parameters
would be expected in any treatment plant experiencing diurnal flow
variations.  A representative sample of return sludge concentrations
experienced at the LBWRP is shown in Figure 43.  Samples were
collected every 15 minutes over a 24-hour period in 1973 with each
bar representing the average results of a 4-hour composite sample.
Return flow rate was constant during the time of sampling.  Equa-
tion 11 only predicts the flow rate required to waste a given mass
of solids.   Therefore,  composite samples are an absolute neces-
sity.   In addition,  the flow rate predicted by equation 11 must
be maintained constant  so as to waste evenly from all sludge
concentrations experienced throughout the day.
                                 110

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ouvv
E 5000
M
^JCENTRATION
e samples)
^
o
o
o
8 0 300°
UJ c"
e> 5
1"
^ .C 2000
Z *
tr *-*
UJ 1000
(T

1
1
_
	
2260
	
—
	
1
4270




1
1
5255





1
1
1
1
1 1
^_^_
4283




1
3790




1
	
2598



1
	
	
	
1
       0700
 1100
1500
1900       2300
   11/23/73
   0300
•> 11/24/73
0700
FIGURE 43
DIURNAL VARIATION IN RETURN SLUDGE CONCENTRATIONS AT
     LONG BEACH WATER  RENOVATION PLANT

-------
LACSD ACTIVATED SLUDGE WASTING FACILITIES
A schematic diagram of the waste sludge control system employed
at LACSD activated sludge plants is shown in Figure 44.  Heart
of the system is the flow measurement device used to generate a
control signal.  Any number of flow measuring devices, including
orifice plates, venturi meters, magnetic and propeller flowmeters,
could be used.  The only requirement is that the device generate
a signal that is a function of flow rate,  LACSD design practice
has been to use propeller meters which are considerably less
expensive than comparable magnetic flowmeters and create less
headloss than orifice plates.  The main disadvantage of a pro-
peller meter is that it is subject to fouling by material con-
tained in the flowstream.
Treatment plants which employ anaerobic digestion of primary
sludge commonly return digested supernatant back to the primary
tanks.  Depending on digester performance, the supernatant may
contain quantities of stringy material which could buildup in
the activated sludge mixed liquor.  If such were the case, pro-
peller meters would require regular cleaning to avoid fouling.
All of the LACSD activated sludge plants using propeller meters
discharge primary sludges back to the sewer for subsequent treat-
ment at the District's Joint treatment plant.  Thus, the waste
sludge is relatively free of fouling material.
Examination of maintenance records indicated that propeller meters
in the waste sludge lines were cleaned about twice a year on the
average.   Generally,  cleaning was performed only if the operator
observed erratic response from the meter.  A propeller meter
removed from the waste sludge line after three months of contin-
uous operation was found to be completely free of fouling material,
The pulse signal generated by the propeller meter is sent to a
pulse to current converter.  Converter output is a 4 to 20 ma
signal proportional to flow rate.  This signal is compared with
a set point value and used to control the position of a motorized
throttling valve.   The signal also actuates a recorder, flow

                               112

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               AERATION   TANK
PROPELLER
FLOWMETER
to
                                      SECONDARY  EFFLUENT
                                                   RETURN SLUDGE
                                                   WET  WELL
                                                        LOCAL
                                                      INDICATION a
                                                     TOTALIZATION
                                                  P'l
                                               CONVERTER
                                   THROTTLING
                                      VALVE
                           O

                           I
                           O
                           O
                                                    L.
                                    RECORDER
                                      AND
                                    TOTALIZER
CURRENT
 TRIP
          WASTE
          ACTIVATED
          SLUDGE
                                              T
                                            SET  POINT
                                              (MGD)
NO WASTE
ACT.  SLUDGE
  ALARM
      FIGURE 44
  SCHEMATIC  DIAGRAM  OF WASTE SLUDGE FLOW CONTROL SYSTEM

-------
totalizer, and a no-flow alarm.  Thus, if something should
accidently stop the propeller, an alarm is immediately sounded
alerting the operator.
The valve actuator is either an electro-hydraulic or electro-
pneumatic device which positions the actuator stem proportionally
to the input current command signal.  Both butterfly and diaphram
valves are currently used in LACSD installations.  Both types of
valves have given good service.
OPERATIONAL EXPERIENCE
Daily operational practice at LACSD activated sludge installa-
tions utilizes the automatic collection of 24-hour composite
samples  (one sample every 15 minutes) of aeration tank mixed
liquor, return sludge, and secondary effluent suspended solids.
These values are then applied to equation 11 to predict the waste
sludge flow rate required to achieve a certain mean cell resi-
dence time.  It is essential that 24-hour composite samples be
used since solids concentrations will vary diurnally-  Also,
it is essential that the wasting rate calculated from equation 11
remain constant throughout the day so as to waste evenly from all
return sludge concentrations.
The technique of wasting a constant flow rate from the return
sludge line has been used in LACSD installations for many years.
The control equipment functions with a minimum of maintenance.
However, the main test of any sludge wasting technique is whether
it actually wastes the correct mass of cells and can maintain
desired MCRT values.  Years of operational experience with daily
treatment plant solids inventories indicates that the wasting
technique and associated control equipment function properly.
Analysis of several months operational data indicated that, in
general,  waste flow rate could be maintained within about 2 or 3
percent of the desired set point value.  With a fixed set point,
however,  daily waste volumes were reproducible to within 0.5
percent.
Certain characteristics of the control equipment are worthy of

                               114

-------
discussion.  Should the propeller meter become fouled, control
signal to the electronic controller will indicate a no-flow
condition.  The controller will signal for additional valve
opening in an attempt to readjust the flow rate to the desired
set point value.  This will continue until the valve is in a full
open position and solids are being wasted at an extremely high
rate.  Since the propeller meter is fouled, it will continue to
register zero flow.  Fortunately, the no-flow alarm will actuate
under these conditions alerting the plant operator.  If the
operator is slow to respond to the alarm, however, considerable
solids will be lost from the plant.
Conditions somewhat less extreme than the above will result if
the propeller meter loses its calibration.   This could happen,
for example, if fouling material slowed propeller response to a
given flow rate.  Under these conditions, an excessive amount of
solids would be wasted from the plant but no alarm would be
sounded to alert the operator.  His only control is to watch the
solids inventory in the plant and check for any sharp reduction
in total plant solids.  Loss of calibration in this manner has
not been a significant problem in LACSD installations.
One might suspect that control valve plugging by suspended solids
would be a potential problem.  It is not, however, because of the
nature of the feedback control loop.  Should the control valve
plug (as butterfly valves,  in particular, are prone to do when
only partially open) the decreased flow rate would be sensed by
the flowmeter.  The controller in turn would call for increased
valve opening to readjust the flow rate.   Thus,  valve plugging
is not a problem unless the line remained plugged with the valve
fully open which is extremely unlikely.
                                115

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                         SECTION VIII

                          REFERENCES

1.   Lawrence,  A.W.,  and McCarty, P.L.,  "Unified Basis for
    Biological Treatment Design and Operation", Journal of the
    Sanitary Engineering Division,  ASCE,  Vol. 96, No. SA3,
    757-778, (1970)


2.   Jenkins, D.,  and Garrison,  W.E., "Control of Activated Sludge
    by Mean Cell  Residence Time."  J. Water Pollution Control
    Fed.,  40,  1905,  (1968)


3.   Burchett,  M.E.,  and Tchobanoglous,  G.,  "Facilities for
    Controlling the  Activated Sludge Process by Mean Cell
    Residence Time."  J. Water Pollution  Control Fed., Vol. 46,
    No. 5,   (may,  1974)


4.   Garrett, M.T., Jr., "Hydraulic  Control  of Activated Sludge
    Growth Rate." Sew. & Ind.  Wastes,  30,  253, (1958)


5.   Walker, L.F., "Hydraulically Controlling Solids Retention
    Time  in the Activated Sludge Process."   J.  Water Pollution
    Control Fed., 43,  30, (1971)


6.   Deaner, D.G., and  Martinson,  S., "Definition and Calculation
    of Mean Cell  Residence Time."  J. Water Pollution Control
    Fed.,  46,  2422,  (1974)
                               116

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                          SECTION IX
                  COMPUTER CONTROL APPLICATIONS

INTRODUCTION
The Sanitation Districts of Los Angeles County have developed an
on-line computerized data management system capable of providing
a treatment plant operator with daily reports including opera-
tional calculations and effluent compliance checks.  The system
also produces monthly summaries of all data for management
review and monitoring reports submitted to regulatory agencies.
The evolution of the present system was a staged process, each
step of which was a response to increasing demands for additional
information relative to the status of treatment plant operations.

HISTORY
During the mid-1960's the Sanitation Districts operated four
activated sludge treatment plants.  To provide management with
monthly status reports on operation conditions, a system was
devised whereby the operator of each plant entered certain daily
data onto summary sheets.  At the end of the month, these sheets
were forwarded to the administration office where an engineer,
with the aid of the desk top calculator, performed certain
calculations.  The raw data and calculations were then typed
onto final sheets and circulated among management.  Obviously,
this procedure provided no opportunity to immediately recognize
at the operational level significant trends in other than raw
data.  In response to the heavy demand this procedure placed
upon the engineer's time, his role was eliminated by sending
the raw data directly to the Districts' Data Processing Depart-
ment at the end of each month for keypunching.  The Districts'
                               117

-------
computer at that time consisted of a Univac 9300, a business
oriented computer which could, however, support FORTRAN language
programs.  The computer performed the necessary calculations,
and the results, along with the raw data, were typed onto
appropriate sheets for circulation among management.
By 1970 it became obvious that some method was needed to perform
many of these calculations on a daily basis and make the results
available to the operator as soon as possible, so that un-
desirable operating trends could be recognized and quickly
corrected.  After review of possible alternatives, the
Sanitation Districts chose to install teletype terminals at
each of the treatment facilities and to lease time-sharing
computer services.  In addition, the Districts leased a high
speed printer terminal at the administrative office building
to provide, on a monthly basis, the summaries of data for
management review.  The main criterion for selection of a
commercial time-sharing service organization was that the
stored data base be available to both low speed teletype
terminals, to be installed in each treatment facility, and to
the high speed printer to be installed at the administrative
office.  In addition, as a secondary criterion, the commercial
organization needed to provide some programming assistance and
expertise to assist the Districts' staff in developing the
necessary software.   In 1970 there were few organizations which
provided services meeting both criteria.
From 1970 through mid-1974 this computerized data management
system underwent several revisions in number of calculations
performed and format of the monthly summaries of data.  As the
Districts placed three new activated sludge treatment plants
into service (1970-1973),  each was provided with a teletype
terminal and utilized the computer services.
In mid-1974 two events occurred which required a significant
expansion of the District's computer services.  The first was
                              118

-------
the decision to obtain an in-house computer.  Usage of the com-
mercial time-sharing services, both for the treatment plant data
and, also, for various other work combined with increased
accounting and personnel workloads on the Univac 9300, made it
obvious that obtaining in-house hardware would be more cost-
effective than continuing to lease such services.  The second
factor was the issuance of two new independent discharge permits
for each of the seven activated sludge treatment plants.  These
new permits were promulgated under the National Pollutant Dis-
charge Elimination System (NPDES) Permit Program and under the
California Water Code.  Each permit requires that monthly moni-
toring reports containing extensive statistical evaluations of
data be prepared for each facility.  The revised computer system
now in use incorporates the previous system, which performed
plant operational calculations only, and a complete data manage-
ment system which monitors the status of all information re-
quired for reporting purposes, performs daily effluent statisti-
cal calculations and informs operations'  personnel of violations
of specified effluent limits.  In addition, the data management
system can inform the operator which data, while not constitu-
ting violations of discharge requirements, are not within a
desired range of values.

EQUIPMENT
Hardware
Each treatment plant is equipped with a Teletype Corporation TWX
model 33 terminal capable of a 110 baud (bits per second) trans-
mission rate.  The information is transmitted over normal voice
grade telephone lines to the Districts' administrative office,
the site of the computer hardware.  The computer is an IBM 370
model 125.  The Central Processing Unit (CPU)  of the computer
is a multiprogramming, fixed partition environment having a 196K
byte real storage memory.  Supporting the CPU are three IBM
model 3340 disc drive storage units each with a 70M byte storage
                               119

-------
capacity-   The Virtual Storage (VS)  concept of exchanging CPU
storage with disc storage is utilized to effectively increase
the CPU capacity to 1.4M bytes.   Additional hardware in use
includes an IBM model 3504 card reader, an IBM model 3203 high
speed printer capable of 1100 lines per minute, two IBM model
3410 tape drives capable of 800 or 1600 bits per inch recording
densities and operating speeds of 50 inches per second, and four
local IBM model 3270 CRT terminals operating at channel speeds.
These latter terminals are utilized by various departments at
the administrative office,
Software
There are two operating systems which control all work in the
computer.  The first, Disc Operating System/Virtual Storage (DOS/
VS) supervises all work not involving the on-line applications,
that is, the computer jobs submitted in batch at the main office.
The on-line applications, which include the treatment plant data
management system, are controlled by the second operating system,
Customer Information Control System/Virtual Storage (CICS/VS),
working in conjunction with DOS/VS.
One of the four fixed partitions of the CPU is dedicated exclu-
sively to CICS.  This partition has a 40K byte real storage
capacity.  In addition, CICS shares up to an additional 66K byte
real storage capacity with the other partitions of the CPU, the
amount shared at any time depends upon the demand DOS places
upon this capacity-  The Virtual Storage operation gives the
CICS partition an effective working capacity of 528K bytes.
The software required to run the on-line time-sharing operations
consists of approximately 240,000 lines of programming instruc-
tions, most of which were supplied by the equipment hardware
manufacturer.  In addition, there are approximately 12,000 lines of
programming instructions to operate the data management system
described herein.  These latter instructions are broken up
into separate programming modules or programs.  All programs are
                                120

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written in PL/I language.

DATA MANAGEMENT SYSTEM
The operation of the existing Water Renovation Plant Data Mana-
gement System (WRPDMS) will be described in seven sections:
Overview, Data Preparation, Data Entry, Plant Operational Calcu-
lations, Effluent Compliance Calculations, Reports, and System
Management Programs.
Overview of System
Shown in Figure 45 is a schematic diagram of the WRPDMS.  Note
that not all operations are performed under CICS, the on-line
portion of the system.  Batch processing, which includes report
generations, file maintenance, and performing 30-day average
calculations are reserved for the p.m. shift when the on-line
system is not in service.  Calculation of the 30-day averages
is a time consuming process and if performed on-line will
interrupt all other work of the computer.  Hence, by reserving
these calculations for the p.m. shift, the time spent at a
terminal is decreased and the overall computer throughput is
increased.
Figure 46 illustrates the interrelationship of the various
programs developed for the on-line system.  There are nine
different transaction options the operator can use to enter
or retrieve stored data and calculation results from the system.
The step-by-step process of each of these transactions is shown
in Figure 46 and each will be described below.
Data Preparation
Shown in Figure 47 are the raw data sheets used at the Long Beach
Water Renovation Plant.  All other treatment plants use nearly
identical sheets; however, the first and last pages vary with
each plant to account for differences in numbers of discharge
points and numbers of aeration systems.  These sheets include
all of the data gathered at the five activated sludge treatment
                               121

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                                 OPERATING
                                   SYSTEM
                                  (DOS/VS)
 [   Report
 Specif i cation
  Data  Base
  Information
                                DATA BASE/
                           DATA COMMUNICATION
                                   SYSTEM
                                  (CICS/VS)
                                  ON-LINE
                                APPLICATION
                                 PROGRAMS
  OFF-LINE
APPLICATION
 PROGRAMS
                          Performance
                           Statistics
                            Ana lyzer
                           Reorganization/
                           Backup  Module
                                Data
                                Base
                                                              Reports
            Performance
              Statistics
                          Performance
                            Reports
FIGURE 45
                      WATER  RENOVATION  PLANT
                      DATA  MANAGEMENT  SYSTEM
                                   122

-------
           (UPDATE , LIST ,  RECALC,
           LOOKUP, DIGEST, EFFCMP)
                                                                                 (STATUS)
                                          r(CALCS .STORE)
                                           (C A LCS, STORE, UPDATE)
             (RECALC .LOOK.UP
             DIGEST, EFFCMP)
                                                   (UPDATE ,STORE)
                   RECALC,LOOKUP)
             (DIGEST,EFFCMP)

                   (EFFCMP)
                                                             UPDATE
                                                             STORE)
(C A LCS, RECALC, LOOKUP)
                                              (CALCS,RECALC)
             (DIGEST,
             EFFCMP)
                     (CALCS.RECALC)
                   Solids
                  Handling
                   Calcs
              (CALCS, RECALC)
                               (CALCS, RECALC, LOOK UP)
                      (CALCS,RECALC,
                      DIGEST)
(CALCS,
RECALC,
EFFCMP)
                       (CALCS,RECALC,
                              (CALCS, RECALC)
                                                                          UPDATE
                                                                          STORE)
                                                     (CALCS,RECALC)
                                           (CALCS, RECALC.EFFCMP)
                      (CALCS,RECALC)
                           (CALCS, RECALC,
                                        (UPDATE,STORE;
                                                     (CALCS, RECALC
FIGURE  46
     WRPDMS-SCHEMATIC  DIAGRAM  OF  ON-LINE  PROGRAMS
                                         123

-------
PLANT= LONG  BEACH WRP
                              MONTH =
                                            197
                              FLOWS
             TOTAL
                      PLANT
                                         EFFLUENT DISCHARGE POINTS
    AVERAGE
     DAILY
PEAK
DAILY
 TOTAL
 RETURN
ACTIVATED
 SLUDGE
 WASTE
ACTIVATED
 SLUDGE
PROCESS
  AIR
NO. 001
COYOTE
CREEK
     mgd
 mg d
                   mgd
         mgd
                    mcf/day
                                        mgd
 10
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
AVG.
DATE
REMARKS'
FIGURE  47
       EXAMPLE  OF   RAW  DATA
         COLLECTION  SHEETS
                               124

-------
PLANT'
LJ
H
O
1
2
3
4
5
SUSPENDED
RAW
SEWAGE
mg/l
10





PRIMARY
EFFL.
mg/l
1 1





SEC.
EFFL.
mg/l
12





FILTER
EFFL.
mg/l
13
/
/
/
/
/
FINAL
EFFLUENT
mg/l
14





Ibs/doy
•p^/!52£*





MONTH-
SOLIDS
197

REQUIREMENTS GOVERNING DISCHARGE TO •
NAVIGABLE WATERS 8 TRIBUTARIES
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS DATA
FINAL
EFFLUENT
mg/l
$$"! 6'Xt





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PLANT
REMOV.
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THERETO
ARITHMETIC MEAN
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CALENDAR DAYS
FINAL EFFLUENT
DATA
mg/l
X^XisXX^





Ibs/day
-JXX2 O'J'y'J





ALLOWABLE REUSES
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS
FINAL EFFLUENT
DATA
mg/l
X'5<2ly9 •'.'/,





ALLOWABLE REUSES
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS
FINAL EFFLUENT
DATA
mg/l
'//,40'///





Ibs/day
///4\'///





  EXAMPLE  OF RAW DATA  COLLECTION  SHEETS
(NOTE: ONLY  TOP PORTION OF EACH SHEET IS SHOWN)
FIGURE 47 (CONTINUED)
                       125

-------
PLANT- MONTH' 197
UJ
<
Q
1
2
3
4
5
BACTERIA
CHLORINE CONTACT
CHAMBER EFFLUENT
DAILY GRAB SAMPLES
TOTAL
COL 1 FORM
MPN/IOO ml
42





FECAL
COLIFORM
MPN/IOOml
43





REQUIREMENTS GOVERNING DISCHARGE TO •
NAVIGABLE WATERS a TRIBUTARIES THERETO
GEOMETRIC MEAN OF
FECAL COLIFORM DATA
DURING PAST*
30 DAYS
MPN/IOO ml
>XXX>44j>>$<<^<





7 DAYS
MPN/IOOml
X^-^4 5^/^^-





MEDIAN OF
LAST 7
TOTAL COLIFORM
SAMPLES
MPN/IOOml
JS^xS^&S*-; 4 6 x^X&^P'x*





ALLOWABLE REUSES
MEDIAN OF
LAST 7
TOTAL COLIFORM
SAMPLES
MPN/IOO ml
>9S^SS(S55c4 7 J9999562





PLANT= MONTH' 197
Ld
H
<
Q
1
2
3
4
5
RESIDUAL CHLORINE
CHLORINE CONTACT
CHAMBER EFFLUENT
MINIMUM
DAILY
VALUE
mg/l
48





MAXIMUM
DAILY
VALUE
mg/l
49





DAILY GRAB
SAMPLES
CHLOR-
INATED
mg/l
50





DECHLOR-
INATED
mg/l
51





pH
FINAL
EFFLUENT
DAILY
GRAB
SAMPLE

52





OIL AND GREASE
FINAL
EFFLUENT
DAILY
GRAB
SAMPLE
mg/l
53





Ibs/day
6£554><5<5<$





ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS
EXCLUDING DAYS
OF REUSE
mg/l
5<55v555Jx5<





1 bs/day
>5«56Ji





Ibs/day
x/O'GSX/^





REUSE
DISCHARGE
mg/l
XX*67XX





Ibs/day






AERATION
SYSTEM
AMMONIA
OXID.
%
^X69^XX





  EXAMPLE OF  RAW  DATA  COLLECTION  SHEETS
(NOTE' ONLY TOP PORTION  OF EACH SHEET IS SHOWN)
FIGURE 47 (CONTINUED)
                      126

-------
PLANT' MONTH: 197
UJ
1-
<
Q
1
2
3
4
5
TURBIDITY
SECONDARY
EFFLUENT
TU
70





FILTER
EFFLUENT
TU
71
/
/
/
/
/
FINAL EFFLUENT
DAILY
24- HOUR
COMPOSITE
TU
72





CONTINUOUS READING
METER
MINIMUM
DAILY
VALUE
TU
73





MAXIMUM
DAI LY
VALUE
TU
74





SECCHI DISC
SECONDARY
EFFLUENT
feet
75





FILTER
EFFLUENT
feet
76
/
/
/
/
/
PLANT' MONTH^ 197
UJ
H
<
Q
1
2
3
4
5
SETTLEABLE SOLIDS
DAILY
24-HOUR
COMPOSITE
ml/1
77





PAST 30-DAY AVERAGE
NAVIGABLE
WATER
DISCHARGE
ml/I
'/?^w/7)





REUSE
DISCHARGE
ml/I
',:7A7 y,WA





TDS
DAILY
24- HOUR
COMPOSITE
180° C EVAP. TEMP.
mg/l
80





Ibs/day
w.eix^





SPECIF.
CONDUC.
DAILY
24-HOUR
COMPOSITE
^mho/cm
82





TEMP.
DAILY
GRAB
SAMPLE
°F
83





COLOR
SECONDARY
EFFLUENT
UNITS
84





FILTER
EFFLUENT
UNITS
85
/
/

/
/
PLANT- MONTH: 197
UJ
I-
<
Q
1
2
3
4
5
CHLORIDE
DAILY
24-HOUR
COMPOSITE
mg/l
86





Ibs/day
-V.'x87 .•'.''/





SULFATE
DAILY
24-HOUR
COMPOSITE
mg/l
88





Ibs/day
•vX-89 '•'/.





CHLORIDE PLUS
SULFATE
ARITHMETIC SUM
OF THE TWO
ANALYSES
mg/l
'•'//•30 •'•'''.'





Ibs/day
.•.;.-.'9|- '.'.'.





DETERGENTS
(MBAS)
DAILY
24-HOUR
COMPOSITE
mg/l
92





  EXAMPLE OF  RAW DATA  COLLECTION SHEETS
(NOTE = ONLY TOP PORTION OF EACH  SHEET IS SHOWN)
FIGURE 47 (CONTINUED)
                       127

-------
PLANT • MONTH= 197
LJ
1-
<
Q
1
2
3
4
5
MISCELLANEOUS
RETURN
SLUDGE
SUSPENDED
SOLIDS
mg/l
93





UNITS OUT OF SERVICE
PRIMARY
TANKS

94





AERATION
TANKS

95





Fl NALS
SYSTEM
NO. 1

96





FINALS
SYSTEM
NO. 2

97





FINALS
SYSTEM
NO. 3

98





FILTERS

99
/
/
/
/
/


100







101







102







103





PLANT= MONTH= 197
UJ
<
Q
1
2
3
4
5
AERATION SYSTEM NO. 1
SUSPENDED SOLIDS
24-HOUR COMPOSITES
TANK
1
mg/l
104





TANK
2
mg/l
105





TANK
3
mg/l
106





TANK
4
mg/l
107





RETURN
ACTIVATED
SLUDGE
FLOW
RATE
mgd
108





AERAT.
VOLUME
mg
109





MIXED
LIQUOR
DISSOLVED
OXYGEN
MAX.
mg/l
110





MIN.
mg/l
III





LOADING PATTERN
TANK
1
%
112





TANK
2
%
113





TANK
3
%
114





TANK
4
%
115





SVI GRAB SAMPLE
SETTL.
SOLIDS
ml/1
116





SUSP.
SOLIDS
mg/l
117





SVI
ml/g
118





VOL AT.
SOLIDS
%
119





N02
LOW
FLOW
GRAB
SAMPLE
mg/l
120





HIGH
FLOW
GRAB
SAMPLE
mg/l
121





N03
LOW
FLOW
GRAB
SAMPLE
mg/l
122





HIGH
FLOW
GRAB
SAMPLE
mg/l
123





M
00
               EXAMPLE OF  RAW DATA COLLECTION SHEETS
             (NOTE: ONLY TOP PORTION  OF  EACH SHEET IS  SHOWN)
             FIGURE 47 (CONTINUED)

-------
plants that do not have solids handling processes.  For the
District 26 Water Renovation Plant and the District 32 Water
Renovation Plant, which process solids by anaerobic digestion,
centrifugation and/or air flotation, additional data sheets are
utilized.  Shown in Figure 48 are these data sheets.
Examination of Figure 47 shows that there are a maximum of 84
raw data columns on the sheets.  Note, however, that not all are
presently used.  Many have been crossed out because applicable
treatment process are not now in operation.  However, within
several years, it is anticipated that all plants will have some
form of tertiary treatment involving filtration.  The sheets
have been designed to handle additional data to be generated
when this additional treatment begins.  The remaining 39 columns
on the sheets are reserved for inserting calculated values
generated by the computer.
As shown in Figure 48 there are a maximum of 54 columns of data
to handle the digestion and solids processing equipment at the
two applicable treatment plants.  In actual practice, neither
treatment plant measures all parameters on a daily basis.
Data Entry
Because several of the data, e.g. BOD5 and coliform bacteria,
require several days of laboratory testing time before results
are available, whereas most other data are available within one
day, the WRPDMS is designed to accept both types of data when
they first become available.  Obviously, a system user could
become easily confused as to which data have been entered and
which have not.  To avoid this, the first transaction the treat-
ment plant operator should run each day is STATUS.  Figure 49
shows a typical STATUS transaction.  The data specified ON-LINE
refer to all data columns except those eight specifically listed
in the printout, and include all daily data for which results
are available on the day following the day in question.  Those
specific data listed in the STATUS transaction either take more
                               129

-------
U)
o
PLANT' MONTH' 197
DATE
i
SOLIDS HAN -D LING
SLUDGE
RAW
FLOW
MGD
143

TOTAL
SOLIDS
%
144

VOLA-
TILE
SOLIDS
°/
145

WASTE ACTIVATED
FLOW
TO
CENTRI-
FUGE
MGD
146

FLOW
TO
A F
UNIT
MGD
147

TOTAL
SOLIDS
%
148

CENTRIFUGE
CENTRATE
FLOW
MGD
149

TOTAL
SOLIDS
%
150

CAKE
FLOW
MGD
151

TOTAL
SOLIDS
%
152

VOLA-
TILE
SOLIDS
01
153


TIME
IN
OPERA-
TION
hours
154

AIR FLOTATION UNIT
UNDERFLOW
FLOW
MGD
155

TOTAL
SOLIDS
%
156

CAKE
FLOW
MGD
157

TOTAL
SOLIDS
%
158

VOLA-
TILE
SOLIDS
%
159

TIME
IN
OPERA-
TION
hours
160

PLANT MONTH' 197
DATE

i
SOLIDS HANDLING
SMALL DIGESTION SYSTEM
PRIMARY DIGESTER
RAW
SLUDGE
FLOW
MGD
161

CENT.
DEWAT.
W.A.S.
FLOW
MGD
162

A.F.
DEWAT.
WAS
FLOW
MGD
163

pH

164

ALKA-
LINITY
mg/l
165

VOLA-
TILE
ACIDS
mg/ 1
166

TEMP
°F
167

EFF.
TOTAL
SOLIDS
%
168

EFF
VOLA-
TILE
SOLIDS
%
169

SECONDARY DIGESTER
RAW
SLUDGE
FLOW
MGD
170

CENT.
DEWAT.
W.A.S
FLOW
MGD
171

A F
DEWAT.
W.AS.
FLOW
MGD
172

pH

173

VOLA-
TILE
ACIDS
mg/l
174

SUPER-
NATANT
SOLIDS
% T S
175

HAULED
SLUDGE
FLOW
MGD
176

HAULED
SLUDGE
TOTAL
SOLIDS
%
177

HAULED
SLUDGE
VOLA-
TILE
SOLIDS
%
178

GAS
PRODUC-
TION
MCF
179

PLANT- MONTH' 197
DATE
i
SOLIDS HANDLING
LARGE DIGESTION SYSTEM
PRIMARY DIGESTER
RAW
SLUDGE
FLOW
MGD
ISO

CENT.
DEWAT
W.AS.
FLOW
MGD
181

A F.
DEWAT.
W.A.S.
FLOW
MGD
182

pH

183

ALKA-
LINITY
mg/l
184

VOLA-
TILE
ACIDS
mg/l
185

TEMP
°F
186

EFF.
TOTAL
SOLIDS
%
187

EFF
VOLA-
TILE
SOLIDS
%
188

SECONDARY DIGESTER
RAW
SLUDGE
FLOW
MGD
189

CENT.
DEWAT.
W.A.S.
FLOW
MGD
190

A.F.
DEWAT.
WAS.
FLOW
MGD
191

pH

192

VOLA-
TILE
ACIDS
mg/l
193

SUPER-
NATANT
SOLIDS
% T.S.
194

HAULED
SLUDGE
FLOW
MGD
195

HAULED
SLUDGE
TOTAL
SOLIDS
%
196

HAULED
SLUDGE
VOLA-
TILE
SOLIDS
%
197

GAS
PRODUC-
TION
MCF
198

        RAW DATA

        FIGURE 48
COLLECTION SHEETS USED FOR SOLIDS HANDLING UNIT  PROCESSES

 (NOTE'ONLY TOP PORTION OF EACH SHEET IS SHOWN)

-------
   WRPDMS,STATUS

LACSD VHP DATA MANAGEMENT  SYSTEM
FOR SYSTEM AVAILABILITY  CALL:  JAO  (213)  699-7411  EXT.  499
STATUS FOR: LONG  BEACH  WRP
DATE:  6/24/75    TIME:  13/15
ON-LINE DATA  :    I/  1/75  THROUGH   6/22/75

*** DATA  ***    LAST  ENTERED
 BOD             6/17
 TOTAL COLI        6/21
 FECAL COLI        6/21
 NITROGEN          6/10
 T D S             6/10
 CHLORIDE          6/10
 SULFATE           6/10
 DETERGENTS        6/10
TRANSACTION COMPLETE


            EXAMPLE  OF  PRINTOUT  OF
              A  STATUS  TRANSACTION
FIGURE   49
                            131

-------
than one day for analysis or are normally entered at less than a
daily frequency.  From the STATUS transaction then, the operator
can determine his latest entries of data, and from this enter new
data in correct chronological sequence.
Having determined from the STATUS transaction his most recent en-
tries, the operator next determines if he has available data such
as BOD  or bacterial data taken on days  for which other data have
already been entered.   If this is the case, he would use an UPDATE
transaction to enter the data.  The UPDATE transaction will re-
trieve the already created data record for that day and insert the
data in the appropriate storage column.   In addition, if the data
include bacterial, BOD5, total nitrogen,  TDS, chloride, or sulfate
data, the appropriate calculations associated with these para-
meters will also be automatically calculated and stored.  Figure
50 shows the results of a typical UPDATE  transaction, in which
influent  and effluent BOD- data and effluent total coliform and
fecal coliform data were entered.
After updating all necessary data records, the operator next
begins to enter those data for the day following the last day for
which data are stored.  To do this, he has two transaction options
available to him: STORE and CALCS.  The  former will only store
data, while the latter will perform necessary calculations with
the data, and, if successful in this latter task, will store both
raw data and results of calculations.  Figure 51 shows the results
of a typical STORE transaction.
If the data entry is achieved with the CALCS transaction, no fur-
ther steps are necessary.  If, however,  all new data are entered
with the STORE transaction, the operator  next performs RECALC, the
transaction which simultaneously performs plant operational cal-
culations and effluent compliance calculations.  Of course, if the
data are being entered with a CALCS transaction, these calcula-
tions would be automatically performed.
Plant Operational Calculations
The daily plant operational calculations  can be divided into five
groups of calculations:
                               132

-------
   WRPDMS,UPDATE,06/01/75

LACSD WRP DATA MANAGEMENT  SYSTEM
FOR SYSTEM AVAILABILITY  CALL: JAO (213)  699-7411 EXT.

 BEGIN DATA ENTRY
/    31,181
/    33,6
/    42,<2
/    43,<2
/    EOD/
TRANSACTION COMPLETE--  DATA STORED
            EXAMPLE  OF  PRINTOUT  OF
            AN  UPDATE  TRANSACTION
FIGURE  50
                         133

-------
             WRPDMS,STORE,06/14/75

         LACSD WRP DATA MANAGEMENT SYSTEM
         FOR SYSTEM AVAILABILITY CALL:  JAO  (213)  699-7411 EXT. 499

           BEGIN DATA ENTRY
         /    1,1.78
         /    2,2.35
         /    3, .8
         /    4,0
         /    5,6.62
         /    6,1.78
         /    10,344
         /    1 1, 172
         /    12,108
         /    14,13
         /    23,715
         /    24,484
         /    29,63
         /    30,46
         /    42,<2
         /    50,2.9
         /    52,7.1
         /    58,27
         /    60,14
         /    61,E
         /    62,E
         /    72,6.5
         /    75,2.5
         /    77,<.l
         /    83,78
         /    93,7638
         /    94,0
         /    95,0
         /    96,0
         /    104,5801
         /    105,2605
         /    104,5393
         /    105,2447
         /    106,1917
         /    108,.8
         /    109,.235
         /    110, 1 . 1
         /    1 11, . 1
         /    112,0
         /    113,100
         /    114,0
         /    116,350
         /    117,2658
         /    118,132
         /    119,83
         /    120,E
         /    121,E
         /    122,E
         /    123,E
         /     143,.0042
         /     144,3.23
         /     147,0
         /     160,0
         /     161,.0042
         /     163,0
         /     164,7.45
         /     165,3800
         /     166,20
         /     167,96
         /     170,0
         /     172,0
         '     176,0
         /     177,0
         /     178,0
         /    EOD/
         TRANSACTION COMPLETE-- DATA STORED
FIGURE   51      TYPICAL   STORE    PRINTOUT
                                  134

-------
Loading Calculations - Table 7 lists the formulas used in calcu-
lation of the following COD and Process Air Loading Parameters.
1.  Total Mass of COD Applied to the Aeration System Per Day -
    The units calculated are Ibs/day-  To convert to the metric
    units of kg/day multiply by 0.4536.
2.  Total Mass of COD Applied Each Day to the Total Mass of Vola-
    tile Suspended Solids in the Secondary Treatment System - The
    Calculated units are Ibs COD/lb TPVSS/day.  The metric units
    of kg COD/kg TPVSS/day are identical.
3.  Total Mass of COD Applied Each Day to the Mass of Volatile
    Suspended Solids in the Mixed Liquor in the Secondary Treat-
    ment System - The calculated units are Ibs COD/lbs MLVSS/day.
    Again, metric units of kg COD/kg MLVSS/day are identical
    numbers.
4.  Cubic Feet of Air Applied per Gallon of Measured Flow Per Day -
    To convert to the metric units of m3 of air/m3 of flow multi-
    ply by 7.48.
5.  Cubic Feet of Air Applied per Unit of Mass of COD Removed in
    the Secondary Treatment System - The calculated units are
    ft3/lb COD.  To convert to the metric units of m3/kg COD
    multiply by 0.0624.
Solids Calculations - Table 8 lists the formulas used in the cal-
culation of the following solids parameters:
1.  Total Mass of Suspended Solids in the Aeration System - The
    calculated units are Ibs.  To convert to kg multiply by
    0.4536.
2.  Total Mass of Suspended Solids in the Mixed Liquor Portion of
    the Aeration System - The Sanitation District's activated
    sludge treatment plants employ the step-feed process, wherein
    primary effluent is introduced at several points along the
    aeration system.  There i~s thus a continual variation in
    suspended solids ranging from that of undiluted return
    sludge at the upstream end of the aeration system, to complete
    mixed liquor at the furthest downstream portion of the system.
                                135

-------
               Table 7.   LOADING CALCULATIONS FORMULAS
AERATION SYSTEM LOAD - (COD LOAD)

   (ASL)  =  (PECODT)(Qp)(3.34)

where:
  ASL     =  Aeration system load,
               Ibs/day

  PECODT  =  Primary effluent COD,
               total, mg/1

          =  Total plant flow, mgd
   P
  8.34
          =  Ibs/M.G.  per  mg/1
TOTAL PLANT LOADING
  (TPL)

where:

  TPL
  ASL


  TPSS


  PV
                    (ASL)
             (TPSS)(PV)/(100,%)
Total plant loading,
  Ibs COD/lb TPVSS/
  day
Aeration system load,
  Ibs/day
Total plant suspended
  solids, Ibs
Percent volatile
suspended solids, %
MIXED LIQUOR LOADING
  (MLL)

where:

  MLL


  ASL


  MLSS


  PV
                    (ASL)
             (MLSS)(PV)/(100,
Mixed liquor loading,
Ibs COD/lb MLVSS/day
Aeration system load,
  Ibs/day

Mixed liquor suspend-
 ed solids, Ibs

Percent volatile sus-
  pended solids, %
                                   AIR RATE   (AIR RATIO)
                                   where:
       (AR)



       AR

       Q,
                                                        P
                                                      Air rate, ft3/gal

                                                      Process air flow,
                                                        mcf/day

                                                      Total plant flow,
                                                        mgd
                                   AIR RATE
where:
    AR


    ^a


    QP
  PECOD
                                          T
                                          '
                                     SECOD  =
                                          S
                                     8.34

                                     106
                                              (PECODT-SECODS)(Q )(8.34)
Air rate, ft3/lb COD
  removed

Process air flow, mcf/
  day

Total plant flow, mgd

Primary effluent COD,
  total, mg/1
Secondary effluent COD,
   soluble, mg/1
Ibs/M.G. per mg/1
ft3/million ft3
                                  136

-------
               Table 8.   SOLIDS CALCULATIONS FORMULAS
TOTAL AERATION SOLIDS
                 (SSl + SS2 + ...SSMT)(TAV)(8.34)
               = -   NT  NT -

where:
        TAS    =  Total aeration solids, Ibs
        SS.    =  Suspended solids in tank or pass i,  i=l  to NT,  mg/1
        TAV    =  Total tank volume of aeration system,  MG
        NT     =  Number of tanks or passes in aeration  system
        8.34   =  Ibs/MG per mg/1
MIXED LIQUOR SUSPENDED SOLIDS
        (MLSS) =  [(SSi)(TLxi-RSAL)/(TL)+(SSi+i+...SSNT)](AV)(8.34)
where:
and:
        MLSS   =  Mixed liquor suspended solids,  Ibs
        SS     =  Suspended solids in tank or pass,  mg/1
        TL     =  Aeration tank length, ft
        i      =  Tank or pass number in which centroid of loading
                    is located
        RSAL   =  Return sludge aeration length,  ft
        NT     =  Total number of tanks or passes in aeration  system
        AV     =  Aeration tank volume, MG
        RSAV   =  Return sludge aeration volume,  MG
        XS     =  Aeration tank cross-section area,  ft2
        8.34   =  Ibs/MG per mg/1
        7.48   =  gallons/ft3
        106    =  gallons/M.G.
                                  137

-------
           Table 8 (continued).  SOLIDS CALCULATIONS FORMULAS
SECONDARY EFFLUENT SUSPENDED SOLIDS MASS EMISSION RATE
     (SESSMER) =  (SESS)(Qp)(8.34)
where:
      SESSMER  =  Secondary effluent suspended solids mass emission rate,
                    Ibs/day
        SESS   =  Secondary effluent suspended solids, mg/1
        Q      =  Total plant flow, mgd
        8.34   -  Ibs/M.G. per mg/1
TOTAL PLANT SUSPENDED SOLIDS
       (TPSS)  =  (TAS)+(SSf)(VOLf)(8.34)
where:
        TPSS   =  Total plant suspended solids, Ibs
        TAS    -  Total aeration solids, Ibs
        VOL.c   -  Volume of final  sedimentation tanks in service, M.G.
        8.34   =  Ibs/M.G. per mg/1
        SSr    -  Suspended solids concentration at end of final
                    aeration tank, mg/1
MASTED  SUSPENDED SOLIDS
       (WSS)   =  (RSSSMQ )(8.34)
                          w
where:
        WSS    =  Wasted suspended solids,  Ibs/day
        RSSS   =  Return sludge suspended  solids,  mg/1
        Qw     =  Total waste activated sludge flow, mgd
        8.34   =  Ibs/M.G. per mg/1
                                  138

-------
           Table 8 (continued).  SOLIDS CALCULATIONS FORMULAS
DAILY NET GROWTH
where:
(DNG)  =  (TPSS)-(PTPSS)+(WSS)+(SESS)

DNG    =  Daily net growth, Ibs/day
TPSS   =  Total plant suspended solids, Ibs/day
PTPSS  =  Previous day's total plant suspended solids,  Ibs/day
WSS    =  Wasted suspended solids, Ibs/day
SESS   =  Secondary effluent suspended solids, Ibs/day
AVERAGE NET GROWTH
where:
        (ANG)  =
        ANG
        AQ
          w
        ARSSS
        A%
        ASESS
        ATAS
        AV
        ASSEF
        AFNLS
        FV
          (AQJ(ARSS)+(AQp)(ASESS)
          (ATAS)(AV)+(ASSEF)(AFNLS)(FV)

          Average net growth,  Ibs growth/lbs system solids/day
          Average waste activated sludge flow, mgd
          Average return sludge suspended solids,  mg/1
          Average total plant flow, mgd
          Average secondary effluent suspended solids,  mg/1
          Average total aeration solids, mg/1
          Aeration tank volume, M.G.
          Average suspended solids effluent to finals,  mg/1
          Average number of finals in service
          Final sedimentation tank volume, M.G.
                                  139

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    To classify the aeration into two components,  return sludge
    aeration and mixed liquor aeration,  the concept of Centroid
    of Loading is used.   The centroid of loading is that hypothe-
    tical point in the aeration system which,  if all primary
    effluent were introduced there,  would be equivalent to the
    step feed pattern used.   The total mass of suspended solids
    in the mixed liquor,  then is calculated as those suspended
    solids downstream of  the centroid of loading.   The calculated
    units are Ibs.  To convert to metric units of  kg multiply by
    0.4536.
3.   Total Mass of Suspended Solids in the Entire  Secondary Treatment
    System Including Aeration Tanks  and  Final  Clarifiers - This
    parameter is called Total Plant  Suspended  Solids and the units
    are Ibs.   To convert  to  the metric units of kg multiply by
    0.4536.
4.   Total Mass of Activated  Sludge Intentionally Wasted from the
    Treatment System Each Day - The  calculated units are Ibs/day.
    To convert to kg/day  multiply by 0.4536.
5.   Total Mass of Suspended  Solids Discharged  Each Day in the
    Treated Effluent - The calculated units are Ibs/day.  To
    convert to kg/day multiply by 0.4536.
6.   Daily Net Growth - This  calculation  is a mass  balance on the
    suspended solids in the  aeration system, and represents the
    mass of suspended solids grown in the treatment system each
    day.  This calculation can yield a negative result.  The cal-
    culated units are Ibs/day.   To convert to  kg/day multiply by
    0.4536.
7.   Average Net Growth -  The theory  of biological  reactors and
    the equations derived therefrom  in Section VIII are based on
    the assumption that the  biological reactor is  in a steady
    state of operation.   In  reality, however,  this is many times
    not the case.  Thus,  it  is that  from day to day there can be
    significant changes in the Daily Net Growth and Daily Cell
    Residence Time (to be discussed  in the next section).  To
    overcome these short-term fluctuations, which  disappear if
                               140

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data are averaged over a long period of time, the concept of
average net growth was developed. The average net growth is cal-
culated using the average of all necessary parameters over the
period of time equal to the previous days' cell residence time.
However, there are minimum and maximum time limits to this ave-
raging period of 7 and 15 days respectively. These are necessary
to insure that sufficient number of days of data are being ave-
raged to smooth out the fluctuations and, for the other limit,to
prevent the computer from averaging an excessive number of days
which would make the results meaningless and restrict other com-
puter usage for an excessive period of time. The units calculated
are pounds of growth per day per pound of system solids, or days  <
Aeration Time Calculations - Table 9 lists the formulas used in
the calculation of the following aeration time parameters:
1.  Return Sludge Hydraulic Aeration Time - This parameter is the
    reaeration time the concentrated return sludge receives in
    the aeration system upstream of any introduction of primary
    effluent.  It is calculated using the assumption that 20 feet
    (6.1 meters)  upstream of the first feed gate, the aeration
    system is essentially undiluted return sludge. Note that for
    all treatment plants it is not possible to calculate this
    parameter, for the first feed gate is within 20 feet of the
    furthest upstream end of the aeration system. The calculated
    units are hours.
2.  Mixed Liquor Hydraulic Aeration Time - This parameter is cal-
    culated using the assumption that all primary effluent and all
    return sludge are introduced at the most upstream end of the
    aeration system.  The calculated detention time is the maxi-
    mum that could occur, for it assumes a plug flow reactor
    whereas the step feed process simulates a series of complete
    mix reactors. The calculated units are hours.
3.  Return Sludge Centroidal Aeration Time - This parameter is
    the aeration time upstream of the hypothetical point of
    centroidal loading.  The calculated units are hours.
                               141

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              Table 9.  AERATION TIME CALCULATIONS FORMULAS
RETURN SLUDGE AERATION TIME (HYDRAULICS)
where:
and:
(HRSAT)  -


(HRSAV)  =

HRSAT
HRSAV

RAS
XS
FG1

24
133700   =
                   (24)(HRSAV)
                      IRAS)
                   (XS)(FG1-20)
                     (133700)
                   Return sludge aeration time, hrs
                   Hydraulic return sludge aeration volume, M.G.
                     (if HRSAV <=0, HRSAT=0)
                   Return activated sludge flow, mgd
                   Aeration tank cross - section area, ft2
                   Distance from upstream end of aeration system to
                     first feed gate location, ft
                   hours/day
                   ft3/M.G.
MIXED LIQUOR AERATION TIME (HYDRAULIC)
      (HMLAT)  =   -	(HRSAV)
where:
      HMLAT
                     (Qp)/NS + (RAS)
             Mixed  liquor  aeration  time,  hrs
      HRSAV
      %
      NS
      RAS
      24
             Hydraulic  return  sludge  aeration  volume,  M.G,
             Total  plant  flow,  mgd
             Number of  aeration systems  in  operation
             Return activated  sludge  flow,  mgd
             hours/day
                                  142

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            Table 9 (continued).   AERATION TIME CALCULATIONS FORMULAS
RETURN SLUDGE AERATION TIME (CENTROIDAL)
      (CRSAT)  =   (RSAVM14I

where:
      CRSAT    =   Return sludge aeration time, hrs
      RSAV     =   Return sludge aeration volume, M.G.
      Q        =   Return activated sludge flow, mgd
      24       =   hours/day

MIXED LIQUOR AERATION TIME (CENTROIDAL)
                   (TAV - RSAV) (24)
where:
      CMLAT    =   Mixed liquor aeration time, hrs
      TAV      =   Total tank volume of aeration system, M.G.
      RSAV     =   Return sludge aeration volume, M.G.
      Q        =   Total plant flow, mgd

      Q        =   Return activated sludge flow, mgd

      NS       =   Number of aeration systems in operation
      24       =   hours/day
                                   143

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4.   Mixed Liquor Centroidal Aeration Time - This parameter
    is the aeration time downstream of the hypothetical
    point of centroidal loading.  The calculated units are
    hours.

Cell Residence Time Calculations - Table 10 lists the for-
mulas used in the calculation of the following parameters:
1.   Daily Cell Residence Time - As explained in Section VIII,
    the mean cell residence time of a biological reactor at
    steady state is calculated using the assumption that the
    mass of organisms grown per day equals the sura of mass of
    organisms intentionally wasted per day from the return
    sludge line and those organisms unintentionally wasted
    in the secondary effluent.
2.   Average Cell Residence Time - This parameter is the
    reciperocal of the Average Net Growth.  As previously
    explained, it represents the average of appropriate
    data over a period of time ranging from 7 to 15 days.
3.   Waste Activated Sludge Rate to Maintain Desired Cell
    Residence Time Using Daily Data. - The formula used in
    this calculation is derived from equation (3)  of
    Section VIII, using the assumption that the mass of
    cells grown per day equals the solids discharged in
    effluent and wasted from the return sludge line.
    Obviously, with daily fluctuations in plant perfor-
    mance,  this particular waste rate may be inappropriate.
    The calculated units are mgd.  To convert to m3/day
    multiply by 3785.
4.   Waste Activated Sludge Rate to Maintain Desired Cell
    Residence Time Using Average Data - This calculation is
    based on the average of data over the same period used
                            144

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           Table 10.  CELL RESIDENCE TIME CALCULATIONS FORMULAS
AVERAGE CELL RESIDENCE TIME

      (ACRT)   =   ^

where:
      ACRT     =   Average cell residence time, days
      ANG      =   Average net growth, Ibs growth/day/lb system solids

DAILY CELL RESIDENCE TIME
      (DCRT)
                    (SESS)+(WSS)
where:
      DCRT     =   Daily cell residence time, days
      TPSS     =   Total plant suspended solids, Ibs
      SESS     =   Secondary effluent suspended solids, Ibs/day
      WSS      =   Wasted suspended solids, Ibs/day
                                    145

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       Table 10 (continued).   CELL  RESIDENCE TIME CALCULATIONS FORMULAS
DAILY WASTE RATE FOR DESIRED CRT
where:
(DWR)

DWR
TAS
AV
SSEF
FNLS
FV
DSCRT
%
SESS
RSSS
(TAS)(AV) + (SSEF) (FNLS) (FV)-(DSCRT) (Qp) (SESS)

                (DSCRT)(RSS)

Daily waste rate,  mgd
Total plant aeration solids, mg/1
Aeration tank volume, rug
Suspended solids effluent to finals, mg/1
Number of finals in service
Final sedimentation tank volume, mg
Desired cell residence time, days
Total plant flow,  mgd
Secondary effluent suspended solids, mg/1
Return sludge suspended solids, mg/1
AVERAGE WASTE FLOW FOR DESIRED CRT
where:
(AWF)


AWF
ATAS
AV
ASSEF
AFNLS
FV
DSCRT
      ASESS
      ARSSS
                   (ATAS)(AV)+(ASSEF)(AFNLS)(FV)-(DSCRT)(AQ )(ASESS)
                                     (DSCRT)(ARSSS)
Average waste flow for desired CRT, mgd
Average total aeration solids, mg/1
Aeration tank volume, mg
Average suspended solids effluent to finals, mg/1
Average number of finals in service
Final sedimentation tank volume, mg
Desired cell residence time, days
Average total plant flow, mgd

Average secondary effluent suspended solids, mg/1
Average return sludge suspended solids, mg/1
                                   146

-------
    to calculate the Average Cell Residence Time.  This value
    is less affected by short-term fluctuations and is,
    therefore, a more appropriate waste sludge rate to use.
    Obviously, if the biological treatment system has been
    operating in a state of steady state for some time,
    this calculation should agree closely with the one
    derived from daily data only.  The calculated units
    are mgd.  To convert to m3/day multiply by 3785.
Solids Handling Calculations
The District 26 Water Renovation Plant and the District 32
Water Renovation Plant both process solids, generated in the
primary and secondary treatment processes, by a combination
of thickening and anaerobic digestion.  To better understand
the operational calculations used to monitor and control
these processes the following description of these processes
is presented.
Figure 52 presents a schematic flow diagram of the thickening
and digestion processes.  Raw sludge from the hoppers of the
primary sedimentation tanks is of sufficient thickness to be
fed directly to the anaerobic digester.  However, the waste
activated sludges require treatment to increase solids content
prior to digestion.  At the District 26 Water Renovation Plant
centrifuges are used for this purpose, while at the District
32 Water Renovation Plant dissolved air flotation units are
utilized.  The combination of the two sludges is fed into the
first of a series of two digesters.   This first digester is
referred to as the primary digester and employs gas recircula-
tion to maintain a complete mix state.  It is in the primary
digester where the major portion of the anaerobic stabilization
of the solids occurs.   The effluent from the primary digester
flows into the second of the series of digesters, referred to
as the secondary digester.  This latter digester is not mixed
or heated.  Solids settle to the bottom, while the supernatant
                              147

-------
     PRIMARY  SLUDGE
WASTE ACTIVATED
    SLUDGE
Thickening
 Process
                     a:
                     UJ
                     o
                       LU
                       LU

                                 r
                                       LARGE  DIGESTION SYSTEM
                                      Primary
                                      Digester
                                      Secondary
                                      Digester
                                       SMALL  DIGESTION  SYSTEM
Primary
Dig ester
Secondary
Digester
                                               I
                                    RETURN TO AERATION  SYSTEM
                                                                    I
                                                                    I
                                                                             m
                                                                             m
                                                                             o
                                                          o
                                                          r~
                                                          o
                            HAULED BY TRUCK TO NEARBY DISPOSAL SITES
FIGURE  52   SCHEMATIC  FLOW DIAGRAM OF THICKENING AND ANAEROBIC
                 DIGESTION  PROCESS  AT  THE  DISTRICT 26  & 32  WRPs

-------
is returned to the aeration system of the activated sludge
process.  Daily monitoring of the solids content of this
latter supernatant is maintained.  When supernatant solids
concentrations reach 0.5%, the solids which have settled
in the secondary digester are removed and trucked to nearby
farm land for tilling into the soil.  Both the District 26
Water Renovation Plant and the District 32 Water Renovation
Plant have two of these digestion systems, each consisting
of the series of two digester tanks.  The two systems at
each plant are referred to as "Small Digestion System" and
"Large Digestion System."
Several deviations from the above mentioned flow pattern can
be implemented.  Each plant also has the capability to feed
primary sludge and/or thickened waste activated sludge directly
into the secondary digester.
The computer transaction which performs the Solids Handling
Calculations is called DIGEST.  It can be executed as a
separate transaction, or provisions are available to make it
an extension of the CALCS or STORE/RECALC transactions.
Whichever method of execution is used, the process consists
of entering appropriate data and then performing pertinent
calculations.  Table 11 lists the formulas used in these
calculations.  Each is briefly discussed below.
1.  Total Raw Sludge Flow - This is the total flow of sludge
    put into the digesters each day.  Note that under normal
    operating conditions all raw sludge is fed into the primary
    digester, and hence, the second term of the equation is
    normally zero.  The units are million of gallons per day.
    To convert to cubic meters per day multiply by 3785.
2.  Raw Solids Loading-Individual Digesters - This represents
    the total mass of raw sludge, including volatile and inert
    solids, loaded into either the primary or secondary
    digester each day.  The calculated units are Ibs/day.  To
                              149

-------
    convert to kg/day multiply by 0.4536.
3.  Total Raw Solids Loading-All Digesters - This is the sum
    of the individual loadings calculated above.  The units
    are identical as above.
4.  Total Dewatered Waste Activated Sludge Flow - This is the
    volume of thickened waste activated sludge fed to the
    digesters each day.  Again,  under normal conditions, no
    flow would go to the secondary digesters.  The calculated
    units are mgd.  To convert to m3/day multiply by 3785.
5.  Dewatered Waste Activated Sludge Solids Loading-Individual
    Digester - This is the mass  of total solids fed to either
    the primary or secondary digester each day.  The units  are
    Ibs/day.  To convert to kg/day multiply by 0.4536.
6.  Total Dewatered Waste Activated Sludge Solids Loading - This
    is the sum  of the above calculations  made for both digesters
7.  Centrifuge/Air Flotation Unit Solids Loading - This calcu-
    lation gives the mass loading rate of  the particular sludge
    thickening process.  The calculated units are Ibs/hour.  To
    convert to pounds per day multiply by  24.  To convert to
    kg/day multiply by 10.89- To convert  to kg/hour multiply
    by 0.4536.
8.  Centrifuge/Air Flotation Unit Solids Recovery - This is
    the percentage of the suspended solids in the unthickened
    waste activated sludge which end up in the flow to the
    digesters.
9.  Primary Digester Volatile Solids Loading - This calculation
    gives the mass of volatile solids loaded into the primary
    digester per day per unit of volume of digester capacity.
    As most of the digestion occurs only in the primary digester,
    no similar calculation is made for the secondary digester.
    The calculated units are pounds of volatile solids per' day
    per cubic foot of digester volume.   To convert to the
                               150

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                 Table 11.  SOLIDS HANDLING CALCULATIONS
TOTAL RAW SLUDGE FLOW
where:
(TRSF)

TRSF
PDRSF
SDRSF
(RSRSF)+(SDRSF)

Total raw sludge flow, mgd
Primary digester raw sludge flow, mgd
Secondary digester raw sludge flow, mgd
RAW SOLIDS LOADING   INVIDIVUAL DIGESTERS
where:
(RSL)

RSL
RSF
TS
8.34
(RSF)(TS)(8.34)(10l+)

Raw sludge loading, Ibs total solids/day
Raw sludge flow, mgd
Total solids content of raw sludge, %
Ibs/M.G./ppm
ppm/%
TOTAL RAW SOLIDS LOADING - ALL DIGESTERS
where:
(TRSL)

TRSL
PDRSL
SDRSL
(PDRSL)+(SDRSL)

Total raw solids loading, Ibs TS/day
Primary digester raw solids loading, Ibs TS/day
Secondary digester raw solids loading, Ibs TS/day
                                   151

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           Table 11  (continued).   SOLIDS HANDLING CALCULATIONS
TOTAL DEWATERED WASTE ACTIVATED SLUDGE FLOW
      (TDWASF) -   (PDWASF)+(SDWASF)
where:
      TDWASF   =   Total  dewatered waste activated sludge flow, mgd
      PDWASF   =   Primary digester waste activated sludge flow, mgd
      SDWASF   =   Secondary digester waste activated sludge flow, mgd

DEWATERED WASTE ACTIVATED SLUDGE SOLIDS LOADING - INDIVIDUAL DIGESTER
      (DWASSL) =   (DWASF)(TS)(8.34)(101+)
where:
      DWASSL   =   Dewatered waste activated sludge solids loading,
                     Ibs/day
      DWASF    =   Dewatered waste activated flow,  mgd
      TS       =   Total  solids, %
      8.34     =   Ibs/M.G./ppm
      104      =   ppm/%
                                   152

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           Table 11 (continued).  SOLIDS HANDLING CALCULATIONS
TOTAL DEWATERED WASTE ACTIVATED SLUDGE SOLIDS LOADING
     (TDWASSL) = (PDDWASSL)+(SDDWASSL)
where:
     TDWASSL   =  Total dewatered waste activated sludge solids loading,
                    Ibs TS/day
     TDDWASSL  =  Primary digester dewatered waste activated sludge
                    solids loading, Ibs TS/day
     SDDWASSL  =  Secondary digester dewatered waste activated sludge
                    solids loading, Ibs TS/day

CENTRIFUGE/AIR FLOATATION UNIT SOLIDS LOADING
     (CASL)    -  (WASF)(TS)(8 34)(10tt)

where:
     CASL      =  Centrifuge/air floatation unit solids loading, Ibs/hr
     WASF      =  Waste activated sludge flow, M.G.
     TS        =  Total solids, waste activated sludge, %
     TIO       =  Time in operation, hours
     8.34      =  Ibs/M.G./ppm
     104       =  ppm/%
                                   153

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           Table  11  (continued).   SOLIDS  HANDLING CALCULATIONS
CENTRIFUGE/AIR FLOATION UNIT SOLIDS RECOVERY

     (CASR)
(CTS)[(NASTS)-(TS)](100.)
   (WASTS)[(CTS)-(TS)J ""
where:
     CASR
     CTS
     WASTS
     TS
Centrifuge/air floation unit solids recovery,
Cake total  solids content, %
Waste activated sludge total solids content, 5
Centrate or underflow total  solids content, %
PRIMARY DIGESTER VOLATILE SOLIDS LOADING
     (SL)

where:
     SL
     RSL
     VS
     DWASSL

     PDV
     1.34xl05
(RSL)(VS)+(DWASSL)(VS)
   (PDV)(1.34xl05)
Solids loading, Ibs VS/day/ft3
Raw solids loading, Ibs TS/day
Corresponding volatile solids content, %
Dewatered waste activated sludge solids loading,
  Ibs TS/day
Primary digester volume, M.G.
ft3/M.G.
                                    154

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           Table 11 (continued).  SOLIDS HANDLING CALCULATIONS
HYDRAULIC DETENTION TIME (Primary Digester)
     (PHDT)
where:
     PHDT
     PDV
     PDRSF
     PDWASF
                        (PDV)
   (PDRSF)+(PDWASF)

=  Primary digester hydraulic detention time,  days
=  Primary digester volume, M.G.
=  Primary digester raw sludge flow, mgd
=  Primary digester dewatered waste activated  sludge
   flow, mgd
VOLATILE SOLIDS DESTRUCTION
     (VSD)
      (VOLI)-(EVS)(10-2)
   (VOLI)-(VOLI)(EVS)(10-2)
whPrP- (VOID  -  [(PDRSF)(RSPV)+(PDWASF)(UASPV)]10
wnere. \VULIJ  -           (PDRSF+WASF)
                                                   -2
and
     VSD       =  Volatile solids destruction, %
     VOLI      =  Volatile solids influent to digester, %
     PDRSF     =  Primary digester raw sludge flow, mgd
     RSPV      =  Raw sludge volatile content, %
     PDWASF    =  Primary digester waste activated sludge flow,  mgd
     WASPV     =  Waste activated sludge volatile content, %
     EVS       =  Primary digester effluent volatile content, %
     10~2      =  Conversion from percent to decimal
                                  155

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           Table 11 (continued).   SOLIDS HANDLING CALCULATIONS
VOLATILE MATTER DESTROYED
     (VMD)
   (SL)(VSD)(1000)
-  ~(ioo)
where:
     VMD
     SL
     VSD
     1000
     100
=  Volatile matter destroyed, Ibs VS/day/103ft3
=  Solids loading, Ibs VS/day/ft3
=  Volatile solids destruction,  %
=  Ft3/thousand ft3
=  Conversion from %
GAS PRODUCTION
     (GP)
where:
     GP
     GF
     VMD
     PDV
     106
     1000
     1.34xl05
     (GF)(106)(1000)
   (VMD)(PDV)(1.34xl05)
   Gas production,  ft3/lb VMD
   Gas flow,  MCF
   Volatile matter  destroyed, Ibs  VS/dayl03ft3
   Primary digester volume,  M.G.
   ft3/MCF
   ft3/thousand ft
   ft3/M.G.
                                  156

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           Table 11 (continued).  SOLIDS HANDLING CALCULATIONS
HYDRAULIC DETENTION TIME (Secondary Digester)
     (SHOT)

where:
     SHOT
     SDV
     PDRSF
     PDWASF
     SDRSF
     SDWASF
                                (SDV)
(PDRSF)+(PDWASF)+(SDRS)+(SDWASF)

Secondary digester hydraulic detention time,  days
Secondary digester volume, M.G.
Primary digester raw sludge flow,  mgd
Primary digester waste activated  sludge flow, mgd
Secondary digester raw sludge flow,  mgd
Secondary digester dewatered waste,  mgd
  activated sludge flow, mgd
SOLIDS HAULED
     (SH)
where:
     SH
     HSF
     HSTS
     8.34
(HSF)(HSTS)(8.34)(101+)


Solids hauled, Ibs/day
Hauled sludge flow, mgd
Hauled sludge total solids content,
Ibs/M.G./ppm
ppm/%
VOLATILE SOLIDS HAULED
      (VSH)
where:
     VSH
     SH
     HSVS
     100
(SH)(HSVS)
   (100)
Volatile solids hauled, Ibs/day
Solids hauled, Ibs/day
Hauled sludge volatile solids content,
Conversion from %
                                 157

-------
    metric units of kilograms of volatile solids per day per
    cubic meter multiply by 16.02.
10. Hydraulic Detention Time in Primary Digester - This gives
    the average detention time assuming a complete mix system.
    The calculated units are days.
11. Volatile Solids Destruction - This gives the percentage of
    volatile solids destroyed in the primary digester.
12. Volatile Matter Destroyed - This gives the mass of volatile
    matter destroyed each day per thousand units of digester
    volume.  The units are pounds per day per 1,000 cubic feet.
    To convert to the metric units of kilograms of volatile
    solids per day per cubic meter multiply by 0.01602.
13. Gas Production in Primary Digester - This is the volume
    of gas produced per unit mass of volatile matter destroyed.
    The units are cubic feet per pound of volatile matter
    destroyed.  To convert to metric units of cubic meters
    per kilogram of volatile solids destroyed multiply by
    0.06243.
14.  Hydraulic Detention Time in Secondary Digester - This
    gives a theoretical average detention time in the
    secondary digester assuming the unit is completely mixed
    which it is not.   The calculated units are days.
15. Solids Hauled from Plant - This represents the mass per
    day of solids hauled by truck to the farm land for tilling.
    The units are Ibs/day.   To convert to kg/day multiply by
    0.4536.
16.  Volatile Solids  Hauled from Plant - This is the mass of
    volatile solids hauled from the plant each day.  Again,
    the units are Ibs/day.   To convert to kg/day multiply by
    0.4536.
Effluent Compliance Calculations
Each of the activated sludge treatment plants operated by the
                              158

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Sanitation Districts has two independent sets of effluent
discharge requirements established by the Regional Water Quality
Control Board, the state regulatory agency which establishes
and enforces discharge requirements in California.  One set of
requirements at each plant governs the discharge into navigable
waters and tributaries thereto, and hence is regulated by dis-
charge criteria promulgated in PL92-500, the 1972 Amendments to
the Federal Water Pollution Control Act.  These discharge re-
quirements are contained in the National Pollutant Discharge
Elimination System (NPDES) permit issued for each plant, and
are referred to in this report as NPDES requirements.  The
other set of requirements for each plant are those issued by
the Regional Water Quality Control Board under criteria promul-
gated in the California Water Code to govern those discharges
of effluent which involve or result in a reuse of the effluent.
For this report these discharge requirements are referred to
as REUSE requirements and all calculations associated therewith
are referred to as REUSE calculations.
The calculations involved in the evaluation of compliance to
discharge requirements are part of the routine in the CALCS
and the RECALC transactions.  There is a transaction which
will produce the report only.  It is called EFFCMP (for EFFluent
CoMPliance).  Shown in Figure 53 is the printout of a typical
EFFCMP report.  Note that the calculations are divided into
three groups:  those involving data specifically for the day
in question, those involving data averaged over the latest
7-day period, and those involving data averaged over the
latest 30-day period.  Each is discussed below.
Daily Calculations - Table 12 lists the formulas used to
calculate these daily parameters.  Note, however, in Figure
53, that the concentration data listed for the various para-
meters are input data, not calculated values.  The mass emission
rates listed are based on the flow to either NPDES discharge or
to REUSE discharge and may not be based on total plant flow.
                               159

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   WRPDMS/EFFCMP/05/01/75

LACSD WRP DATA MANAGEMENT  SYSTEM
FOR SYSTEM AVAILABILITY  CALL:  JAO (213) 699-7411 EXT.  499
  WQCB COMPLIANCE CALCS  NOW IN PROGRESS

  NO PLANT EFFLUENT  COMPLIANCE VIOLATIONS
SAN JOSE CREEK VRP
DAILY VALUES
 WQCB COMPLIANCE CALCULATIONS

NPDES REUSE
  DATE:   5/  1/75

     NPDES REUSE
FLOW               05/01
    MG  **
SUSPENDED  SOLIDS   05/01
  2 CONC/  MG/L  **
  3 MER/ LBS/DAY
TDSO80  DEG)       05/01
  6 CONC/  MG/L  •*
  7 MER/ KLBS/DAY  *
OIL £ GREASE       05/01
  10 CONC,  MG/L
  11 MER/ LBS/DAY
SULFATE
  14 CONC>  MG/L  *
  15 MER/ KLBS/DAY  *
SETTLEABLE SOLIDS  05/01
  18 CONC,  ML/L
             TURBIDITY
 15.4   9.8     1 CONC/  TU
             BODC 5-DAY)
    994 CONG,  MG/L  »*
 1156   739     5 MER/ LBS/DAY
             TOTAL NITROGEN
  654   654     8 CONC/  MG/L
         54     9 MER/ LBS/DAY
             CHLORIDE
< 1.0          12 CONC/  MG/L  »
< 128          13 MER, KLBS/DAY
             SULFATE+CHLORIDE
               16 CONC/  MG/L  *
               17 MER/ KLBS/DAY
             DETERGENTS
<  . 1 <  .1    19 CONC/  MG/L  **
                                                        05/01
05/01
7-DAY  VALUES

SUSPENDED  SOLIDS   05/01
  20 CONC/  MG/L
  21 MER/ LBS/DAY
TOTAL  COLIFORM     05/01
  24 MEDIAN/ MPN/100  ML

30-DAY VALUES

SUSPENDED  SOLIDS   05/01
  26 CONC/  MG/L
  27 MER, LBS/DAY
  28 REMOVAL/ X
OIL*  GREASE       05/01
  32 CONC/  MG/L
  33 MER/ LBS/DAY
SETTLEABLE SOLIDS  05/01
  36 CONC/  ML/L
             BOD(5-DAY)
   10         22 CONC/ MG/L
 1490         23 MER/ LBS/DAY
             FECAL COLIFORM
    2     2   25 G.M./ MPN/100
             BODC5-DAY)
    6    10   29 CONC/ MG/L
 1063   873   30 MER/ LBS/DAY
 98.5         31 REMOVAL/  %
             TOTAL NITROGEN
:  1.1         34 CONC/ MG/L
=  204         35 MER/ LBS/DAY
             FECAL COLIFORM
 3.0

  12
1541
05/01
         9
       1289
05/01
ML   <
05/01
05/01
05/01
   5
 863
98.4

15.4
2729
3.0

 12
985
                9
              830
              37 G.M., MPN/100 ML
 » NPDES VALUE  APPLIES  TO DISCHARGE TO UNLINED RIVERS  ONLY
** NPDES VALUE  HAS  NO NPDES MAXIMUM LIMIT

    PRINTOUT OF  A TYPICAL  EFFCMP  TRANSACTION
FIGURE  53
                                  160

-------
         Table 12.  EFFLUENT COMPLIANCE DAILY CALCULATIONS FORMULAS
DAILY MASS EMISSION RATES (Suspended Solids, BOD, Total  Nitrogen, TDS,
  Chloride, Sulfate, Chloride plus  Sulfate
     (MER)     =  (CONC)(DISCH)(8.34)
                  for CONC>0 & DISCH>0
where:
     MER       =  Mass emission rate of particular parameter, Ibs/day
     CONC      =  Concentration of particular parameter, mg/1
     DISCH     =  NPDES discharge for 'navigable water & tributaries'
                    (NPDES) calculation, mgd
     DISCH     =  REUSE discharge for 'allowable reuse' calculation,
                    mgd
     8.34      =  Ibs/M.G./mg/l
FINAL EFFLUENT OIL & GREASE MASS EMISSION RATE
     (OGMER)

where:
     OGMER

     FEOG
     NPDES
     8.34
=  (FEOG)(NPDES)(8.34)
   for FEOG>0, NPDES>0

=  Final effluent oil & grease mass emission rate,
     Ibs/day
=  Final effluent oil & grease concentration, mg/1
=  NPDES discharge, mgd
=  Ibs/M.G. per mg/1
                                   161

-------
Table 12 (continued).  EFFLUENT COMPLIANCE DAILY CALCULATIONS FORMULAS



FINAL EFFLUENT TOTAL NIIROGEN
     (TN)
    (ORG)+(NH3)+(N02)+(N03)
    for ORG>0 & NH3>0 & N02>0 & N03>0
where:
     TN        =  Final effluent total nitrogen (as N), mg/1
     ORG       =  Final effluent organic nitrogen, mg/1
     N03       =  Final effluent NH3-N, mg/1
     N02       =  Final effluent N02-N, mg/1
     N03       =  Final effluent N03-N, mg/1
FINAL EFFLUENT TOTAL NITROGEN MASS EMISSION RATE
     (TNMER)   -  (TN)(DISCH)(8.34)
                  for TN>0
where:
     TNMER

     TN
     DISCH

     DISCH

     8.34
=  Final effluent total nitrogen mass emission rate,
     Ibs/day
=  Final effluent total nitrogen concentration, mg/1
=  NPDES discharge for 'navigable water & tributaries'
     (NPDES) calculation, mgd
=  REUSE discharge for 'allowable reuse' calculation,
     mgd
=  Ibs/M.G.  per mg/1
                                  162

-------
Seven Day Average Calculations - Table 13 lists those formulas
used in these calculations.  The seven-day arithmetic and geo-
metric means are required for evaluation of NPDES discharge
only, not REUSE discharges.  Thus, in Figure 53 these parti-
cular parameters are not listed in the REUSE column even though
there was REUSE flow for that day-  The seven-day median total
coliform calculations are required for both types of discharge
and are thus shown in both columns.
Thirty Day Average Calculations - Table 14 lists the formulas
used in these calculations.  Again, some of the parameters are
required for NPDES discharges only, and, hence, the results of
calculations are not listed in the REUSE column.
In addition to calculation of the above parameters, the results
are automatically compared to the discharge limits established
for each facility.  Figure 54 illustrates these limits which
are stored in the computer for one of the treatment plants.  A
similar list exists for the other six facilities.  This printout
of limits is not included as part of the on-line printouts, but
is rather a part of the System Management Programs to be
discussed below.  As an example of how the operator is informed
of violations of limits, the data for one of the treatment
plants were deliberately altered  to cause all  of these limits
to be exceeded.  Figure 55 illustrates the message which pre-
ceeds every EFFCMP printout if there are violations of
effluent discharge standards.  If there were no violations of
effluent discharge standards, this fact too would be printed
at the start of each EFFCMP printout.
Reports
Figure 56 illustrates the portion of the daily report trans-
mitted to the operator  listing the summary of  operational  data.
The  report which lists  the effluent compliance calculations
was  shown in Figure 53.  Shown in Figure 57 is the additional
report obtained at the  two facilities which have solids
                               163

-------
  Table 13.   EFFLUENT COMPLIANCE 7-DAY AVERAGE CALCULATIONS FORMULAS
FINAL EFFLUENT SUSPENDED SOLIDS 7 DAY-MEAN
     (SS7)
where:
     SS7
and:
                  [Z7(FESS
                       N
                  for FESS.>0 & NPDES.>0, N>2, NPDES7>0
=  Final  effluent suspended solids 7-day mean, mg/1
     FESS.     =  Final  effluent suspended solids for day i, mg/1

     NPDES.J    =  NPDES  discharge for day i, mgd

     N         =  Number of days where FESSi 0 and NPDESi 0
     NPDES7    =  Most recent day in the seven day period
FINAL EFFLUENT SUSPENDED SOLIDS MASS EMISSION RATE 7^DAY MEAN
     (SSMER7)  =
                  [E7(FESSi)(NPDESi)(8.34)]
where:
     FESSi
and:
                  for FESS^O & NPDES^O, N>2, NPDES7>0
     SSMER7    =  Final effluent suspended solids mass emission rate
                    7-day mean, Ibs/day
=  Final  effluent suspended solids for day i, mg/1
     NPDESi    =  NPDES discharge for day i, mgd

     N         =  Number of days where FESS^O and NPDES.>0

     8.34      =  Ibs/M.G.  per mg/1
     NPDES7    =  Most recent day in the seven day period
                                  164

-------
Table 13 (continued).  EFFLUENT COMPLIANCE 7-DAY AVERAGE CALCULATIONS
                         FORMULAS
FECAL COLIFORM BACTERIA 7-DAY GEOMETRIC MEAN
     (FCOLI7)  =  L
                   1 = 1
                             ,1/N
where:
and:
     NPDES
          7
                  for FCOLI.^0 & NPDES^O, N>2, NPDES7>0
     FCOLI7    =  Fecal coliform bacteria 7-day geometric mean,
                    MPN/100 ml

     FCOLI.    =  Fecal coliform bacteria count for day  i, MPN/100 ml

     NPDES1    =  NPDES discharge for day i

     N
=  Number of days where FCOLI..>0 and NPDES^O



-  Most recent day in the seven day period
TOTAL COLIFORM BACTERIA  7-DAY MEDIAN
      (TCOLI7)  -
where:

     TCOLI7
     DISCH
   (TCQLIJ

   for DISCH7>0
   Total coliform bacteria 7-day median, MPN/100 ml

   Fourth highest total coliform bacteria count after
     the values of the last 7 days where DISCH>0
     have been arranged in ascending order, MPN/100  ml

   NPDES discharge for 'navigable water & tributaries'
     calculation or REUSE discharge for 'allowable
     reuse'  calculation;  day seven is the most recent
     in the seven day period
                                   165

-------
Table 13 (continued).  EFFLUENT COMPLIANCE 7-DAY AVERAGE CALCULATIONS
                         FORMULAS
F"INAL EFFLUENT BOD,- 7-DAY MEAN
                  b
     (BOD7)


where:
     BOD7
     N
and:
             [E7(FEBODn.)]
              1 = 1	
                   N
             for FEBOD->0 & NPDES^O, N>2, NPDES7>0
          =  Final  effluent BOD5 7-day mean, mg/1
     FEBOD.    -  Final effluent BOD for day i, mg/1
     NPDES     =  NPDES discharge for day i, mgd
          =  Number of days where FEBOD.>0 and NPDES..>0
     NPDES7    =  Most recent day in the seven day period
FINAL EFFLUENT BOD MASS EMISSION RATE 7-DAY MEAN
      (BODMER7) =
where:
                  [Z7(FEBOD.)(NPDES1)(8.34)]
                  for FEBOD^O & NPDES. >0, N>2, NPDES7>0
and:
BODMER7   =  Final effluent BOD mass emission rate 7-day mean;
               Ibs/day
FEBODi    =  Final effluent BOD for day i, mg/1
NPDESn-    -  NPDES discharge for day i, mgd
N         =  Number of days where FEBOD.>0 and NPDES.>0
8.34      =  Ibs/M.G. per mg/1
NPDES7    =  Most recent day in the seven day period
                                  166

-------
    Table 14.  EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION FORMULAS
FINAL EFFLUENT SUSPENDED SOLIDS 30-DAY MEAN
    (SS30)  =

where:
     SS30
     FESS.
     DISCHi
     N
and:
     DISCHi

     DISCH.
     DISCH30
FINAL EFFLUENT
 30
[E (FESS.)J
 i = l
     N
for FESS..>0 & DISCH.>0, N>3, DISCH30>0
=  Final effluent suspended solids 30-day mean,  mg/1
=  Final effluent suspended solids for day i,  mg/1
=  Discharge for day i
=  Number of days where FESS^O, and DISCH^O

=  NPDES discharge for 'navigable waters & tributaries1
     calculation
=  REUSE discharge for 'allowable reuse' calculation
=  Most recent day in the 30-day period
SUSPENDED SOLIDS MASS EMISSION RATE 30-DAY MEAN
                   30
     (SSMER30) =
                  [E (FESS.)(DISCH )(8.34)]
                  for FESS^O & DISCH^O, N>3, DISCH30>0
where:
     SSMER30

     FESS
     DISCHi
     N
     8.34
and:
     DISCHi
     DISCHi
     DISCH30
=  Final effluent suspended solids mass emission rate
   30-day mean, Ibs/day
=  Final effluent suspended solids, mg/1
=  Discharge for day i, mgd
=  Number of days where FESS^O and DISCH^O
=  Ibs/M.G. per mg/1

=  NPDES discharge for  'navigable water & tributaries'
=  REUSE discharge for  'allowable reuse' calculation
=  Most recent day in the 30-day period
                                   167

-------
Table 14 (continued).   EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION
                         FORMULA
FINAL EFFLUENT BOD 30-DAY MEAN
                  [fVEBOD^]
     (BOD30)   =   1=1  M	
where:
     BOD30
     FEBODi
   for FEBOD.>0 & DISCH.>0, N>3, DISCH30>0

=  Final  effluent BOD 30-day mean, mg/1
=  Final  effluent BOD for day i, mg/1
     DISCH.J    =  Discharge for day i
and:
               =  Number of days where FEBOD^O and DISChK>0
     DISCH.J    =  NPDES discharge for 'navigable waters & tributaries
     DISCH-    =  REUSE discharge for 'allowable reuse' calculation
     DISCH
           30
=  Most recent day in the 30-day period
FINAL EFFLUENT BOD MASS EMISSION RATE 30-DAY MEAN
                   30
                     (FEBOD.)(DISCH.)(8.34)]
     (BODMER30)=
                  for FEBOD^O & DISCH^O, N>3, DISCH30>0
where:
and:
     BODMER30  =  Final effluent BOD mass emission rate 30-day mean,
                  Ibs/day
     FEBOD.    =  Final effluent BOD for day i, mg/1
     DISCH.    =  Discharge for day i, mgd
     N         =  Number of days where FEBOD^O and DISCH.>0
     8.34      =  Ibs/M.G. per mg/1
     DISCH.    -  NPDES discharge for  'navigable water & tributaries'
          1         calculation
     DISCH.J    =  REUSE discharge for  'allowable reuse' calculation
     DISCH30   =  Most recent day in the 30-day period
                                  168

-------
Table 14 (continued).  EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION
                         FORMULAS
SUSPENDED SOLIDS PLANT REMOVAL 30-DAY MEAN
     (SSR30)
where:
     SSR30
     RSSSi
     FESS.
     NPDES.
     Nl
     N2
     30            30
   [(E (RSS.))/N1-(Z (FESS.))/N2)](100)
     i=i           1=1
   	——-—$v	•	•———
               (E (RSS.))/N1
   for RSSS.>0, FESS.>0, NPDES.>0, Nl>3 & N2>3,  NPDES30>0

=  Suspended solids plant removal  30-day mean, %
-  Raw sewage suspended solids for day i, mg/1
=  Final effluent suspended solids for day i,  mg/1
=  NPDES discharge for day i, mgd
=  Number of days where RSSS.>0
=  Number of days where FESS.>0
and:
     NPDES30   =  Most recent day in the 30-day period
BODC PLANT REMOVAL 30-DAY MEAN
   o
     (BODR30)
where:
     BODR30
     RSBODi
     FEBOD.
     NPDESi
     Nl
     N2
     30            30
   [(E (RSBOD.))/NT-(E (FEBOD1))/N2](100)

             (E (RSBOD.))/N1
              1 = 1     ""
   for RSBOD^O, FEBOD^O, NPDES.>0, Nl>3 & N2>3,
       NPDES30>0

=  BODr plant removal 30-day mean, %
=  Raw sewage BOD for day i, mg/1
=  Final effluent BOD for day i, mg/1
=  NPDES discharge for day  i, mgd
=  Number of days where RSBOD^O
=  Number of days where FEBOD.>0
and
     NPDES30   =  Most recent day in the 30-day period
                                  169

-------
Table 14 (continued).   EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION
                         FORMULAS
FECAL COLIFORM BACTERIA 30-DAY GEOMETRIC MEAN
                   To       N  1/N
     (FCOLI30) =  [n (FCOLI.)]
                   1 = 1
                  for FCOLI. >0 & NPDES. >0, N>3, NPDES30>0
where:
     FCOLI 30   =  Fecal col i form bacteria 30-day geometric mean, MPN/
                    100 ml
     FCOLI.    =  Fecal coliform bacteria count for day i, MPN/100 ml
     NPDES.    =  NPDES discharge for day i
     N         =  Number of days where FCOLI. >0 and NPDES.. >0
and:
     NPDES30   =  Most recent day in the 30-day period
SETTLEABLE SOLIDS 30-DAY MEAN
      (STS30)
                  [f (STS.)]
                  for STS.>0 & DISCH.>0, N>3, DISCH30>0
where:
     STS30     =  Settleable solids 30-day mean, ml/1
     STS.      =  Settleable solids for day i, ml/1
     DISCH.    -  Discharge for day i
     N         -  Number of days where STS.>0 and DISCH>>0
and:
     DISCH30   =  Most recent day in the 30-day period
                                  170

-------
Table 14 (continued).  EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION
                         FORMULAS
FINAL EFFLUENT TOTAL NITROGEN 30-DAY MEAN
     (TN30)

where:
     TN30
     TN.
     DISCH.
     N
and:
     DISCH..
     DISCHi
     DISCH30
FINAL EFFLUENT
                   30
                   Z (TN.)]
                   1 = 1
   for TN1 >0 & DISCH.. >0, N>3, DISCH30>0
-  Final effluent total nitrogen 30-day mean, mg/1
=  Final effluent total nitrogen for day i, mg/1
=  Discharge for day i
-  Number of days where TN->0 and DISCH. >0

=  NPDES discharge for 'navigable waters & tributaries'
=  REUSE discharge for 'allowable reuse' calculation
=  Most recent day in the 30-day period
TOTAL NITROGEN MASS EMISSION RATE 30-DAY MEAN
                   30
     (TNMER30) =
                  [Z (TN.)(DISCH,)(8.34)]
                   i = i  n
                  for TN.>0 & DISCH^O, N>3, DISCH30>0
where:
     TNMER30
     TNi
     DISCH1
and
     8.34
     DISCH.
     DISCH.
     DISCH
          30
=  Final effluent total nitrogen mass emission rate 30-
     day mean, Ibs/day
=  Final effluent total nitrogen for day i, mg/1
=  Discharge for day i, mgd
=  Number of days where TN.>0 and DISCH.>0
-  Ibs/M.G.  per mg/1

=  NPDES discharge for 'navigable waters & tributaries'
     calculation
=  REUSE discharge for 'allowable reuse' calculation
=  Most recent day in the 30-day period
                                  171

-------
Table 14 (continued).   EFFLUENT COMPLIANCE 30-DAY AVERAGE CALCULATION
                         FORMULAS
FINAL EFFLUENT OIL & GREASE 30-DAY MEAN
     (OG30)

where:
     OG30
     FEOGi
     NPDES
     N
and:
     NPDES30
FINAL EFFLUENT
                   30
                  (I (FEOG.))
   for FE06.>0 & NPDES.. >0, N>3, NPDES30>0

=  Final  effluent oil & grease 30-day mean, mg/1
=  Final  effluent oil & grease for day i, mg/1
=  NPDES  discharge for day i
=  Number of days where FEOG.>0 and NPDES.. >0

=  Most recent day in the 30-day period
OIL & GREASE MASS EMISSION RATE 30-DAY MEAN
      (OGMER30) =
where:
     OGMER30

     FEOG.
     NPDESi
     N
     8.34
and:
                   30
                  (I (FEOG.)(NPDES.)(8.34))
                  for FE06->0 & NPDES^O, N>3, NPDES30>0
     NPDES
          30
=  Final effluent oil & grease mass emission rate 30-day
     mean, Ibs/day
=  Final effluent oil & grease for day i, mg/1
=  NPDES discharge for day i, mgd
=  Number of days where FEOG^O and NPDES.. >0
=  Ibs/M.G. per mg/1
=  Most recent day in the 30-day period
                                  172

-------
                     WRP DATA MANAGEMENT  SYSTEM
                      FILE MAINTENANCE  PROGRAM

PLANT: (ONG_6FACH_WATER_PENQVATION_PLANT

FUNCTION: PRINT

RFCDFD KEY: P0700010
                                     DATE:  06/02/75

                                     TYPE:  WQCB_LIMIT_RECORD
 NPDES
 TEM NO.

    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   ?4
   25
   26
   27
   ?8
   29
   30
   31
   32
   33
   34-
   35
   36
   37
MA XI MUM
   10.
10000.
 4170.
10000.
 3128.
10000.
10000.
10000.
10000.
   15.
 1564.
10000.
10000.
10000.
10000.
10000.
10000.
    0.
10000.
   40.
 4170.
   30.
 3128.
10000.
  400.
   15.
 1564.
  100.
   20.
 2085.
  100.
   10.
 1043.
10000.
10000.
    0.
  200.
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     200
     000
     000
     000
     000
     000
     000
     000
     000
     000
     000
     oco
     000
     000
     000
     000
     000
     000
     100
     000
MI M MUM

   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0,000
   0.000
   0.000
  85.000
   0.000
   0.000
  85.000
   0.000
   0.000
   0.000
   0.000
   0.000
   0.000
 REUSE
ITEM NO.

     1
     2
     3
     4
     5
     6
     7
     3
     9
    12
    13
    14
    15
    16
    17
    18
    19
    24
    26
    27
    29
    30
    34
    35
    36
                                 MAXIMUM   MINIMUM
   10.000
   40.000
 4170.000
   30.000
 3128.000
 1000.000
  104.300
   40.000
 4170.000
  250.000
   26.060
10000.000
10000.000
  500.000
   52.130
    0.200
10000.000
   23.000
   15.000
 1564.000
   '0.000
 2085.000
   30.000
 3128.000
    0. 100
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
  NOTE:  Values of 10,000 (for  maximum limits) and 0 (for minimum
         limits) denote the fact  that no limit exists at this  time;
         however, such limits may be prescribed in the future.


                  EXAMPLE  OF STORED  EFFLUENT

    FIGURE  54        COMPLIANCE  LIMITS
                                  173

-------
            V'RPDMS, EFFCMP, 02/28/75

         LACSD WRP DATA MANAGEMENT SYSTEM
         FOR SYSTEM AVAILABILITY CALL.  JAO  (£13) 699-7411  EXT.
           WQCB COMPLIANCE  CALCS NOW IN PROGRESS
         •'•PLANT EFFLUENT  COMPLIANCE VI OLATI 0,\'S« »*
NPDLS:
DATE
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28

ITEM
1
3
5
10
1 1
!8
20
21
22
23
25
26
27
28
29
30
31
32
33
36
37

VALUE
10. 1
5066. 7
38 15.7
15.1
1889. 1
0.3
40.5
4171.0
30.5
3 128. 5
401 . 0
16.0
1565.0
84. 0
21.0
2086.0
84.0
10.1
1 044, 0
0.2
201.0

LIMIT
10.0
4170.0
3128.0
1,5.0
1 564. 0
0.2
40.0
4170.0
30.0
3 128.0
400. 0
15.0
1564. 0
85.0
20. 0
2085.0
85.0
10.0
1043.0
0. 1
200.0
REUSE:
DATE
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28
2/28

ITEM
1
2
3
4
5
6
7
8
9
12
13
16
17
18
24
26
27
29
30
34
35
36
VALUE
10.1
40.5
5066.7
30. 5
38 1 5. 7
1000. 5
125.0
41.0
5129. 1
250. 5
31.0
500.5
63.0
0.3
24.0
.15.5
1564.5
20. 5
2085.5
31.0
3129.0
0.2
LIMIT
10.0
40.0
4170.0
30. 0
3128.0
1000.0
104.3
40. 0
4170.0
250. 0
26. 1
500.0
52. 1
0.2
23.0
15.0
1 564. 0
20. 0
2085. 0
30. 0
3128.0
0. 1
       NOTE:  Stored data  were intentionally altered to cause
              every limit  to be exceeded.
       INITIAL  PORTION  OF  EFFCMP   PRINTOUT
WHEN  EFFLUENT COMPLIANCE  VIOLATIONS  OCCUR
FIGURE  55
                               174

-------
LONG BEACH WRP
WQCB COMPLIANCE CALCULATIONS
                          DATE:   2/28/75
                       NPDES  REUSE
DAILY VALUES

FLOW               02/28
    MG *•
SUSPENDED SOLIDS   02/28
  2 CONC, MG/L »*
  3 MER, LBS/DAY
TDSC180 DEC)       02/28
  6 CONC, MG/L **
  7 HER, KLBS/DAY  *
OIL A GREASE       02/28
 10 CONC, MG/L
 11 MER, LBS/DAY
SULFATE            02/28
 14 CONC, MG/L *
 15 HER, KLBS/DAY  *
SETTLEABLE SOLIDS  02/28
 18 CONC, ML/L

7-DAY VALUES

SUSPENDED SOLIDS   02/28
 20 CONC, MG/L
 21 MER, LBS/DAY
TOTAL COLIFORM     02/28
 24 MEDIAN, MPN/100  ML

30-DAY VALUES
15.0  15.0
  41
5067

1001
15. 1
1889

 250
  41
4171
SUSPENDED SOLIDS   02/28
 26 CONC, MG/L
 27 MER, LBS/DAY
 28 REMOVAL/  %
0IL £ GREASE       02/28
 32 CONC, MG/L
 33 MER, LBS/DAY
SETTLEABLE SOLIDS  02/28
 36 CONC, ML/L
  16
1565
84.0

10. 1
1044

  .2
  41
5067

1001
 125
 250
  31
        24
  16
1565
                                   NPDES REUSE
TURBIDITY         02/28
  1  CONC, TU            10.1  10.1
BODC5-DAY)        02/28
  4 CONC, MG/L **         31
  5 MER, LBS/DAY        3816
TOTAL NITROGEN    02/28
  8  CONC, MG/L          41.0
  9  MER, LBS/DAY        5129
CHLORIDE          02/28
 12 CONC, MG/L *         251
 13  MER, KLBS/DAY •
SULFATE+CHLORIDE  02/28
 16 CONC, MG/L *         501
 17 MER, KLBS/DAY *
DETERGENTS        02/28
 19  CONC, MG/L »*      <  .1
  31
3816

41.0
5129

 251
  31

 501
  63
      BODC5-DAY)         02/28
       22 CONC,  MG/L            31
       23 MER,  LBS/DAY        3129
      FECAL COLIFORM    02/28
       25 G.M.,  MPN/100 ML     401
BODC5-DAY)        02/28
 29 CONC, MG/L            21
 30 MER, LBS/DAY        2086
 31 REMOVAL, %          84.0
TOTAL NITROGEN    02/28
 34 CONC, MG/L
 35 MER, LBS/DAY
FECAL COLIFORM    02/28
 37 G.M., MPN/100 ML     201
  21
2086
                                    31.0
                                    3129
 * NPDES VALUE APPLIES  TO  DISCHARGE TO  UNLINED RIVERS  ONLY
** NPDES VALUE HAS NO NPDES  MAXIMUM LIMIT
 TRANSACTION COMPLETE


    REMAINING  PORTION   OF  EFFCMP  PRINTOUT
FIGURE  55   (CONTINUED)
                                  175

-------
LONG BEACH WRP
                                            DATE:  5/28/75
 FLOWS (MGD)
   TOTAL PLANT             7.9
   RETURN SLUDGE          3.52
   WASTE ACTIVATED SLUDGE .123

 SUSPENDED SOLIDS (MG/L)
   PRIMARY EFFLUENT        120
   FINAL EFFLUENT          5.0
   RETURN SLUDGE          4200

 PROCESS AIR
   TOTAL (MSCF/DAY)       27.3
   RATIO (SCF/GAL)         3.5
   SCF/LB COD REMOVED     1412

 TOTAL MLSS (LBS)        34200
 SLUDGE VOLUME INDEX (ML/GM)
 AERATION SOLIDS (LBS)

      CENTROIDAL
 MIXED LIQUOR AERATION (MRS)
 RETURN SLUDGE AERATION (MRS)

   HYDRAULIC (V/Q+R)
 MIXED LIQUOR AERATION CHRS)
 RETURN SLUDGE AERATION (MRS)
 OPERATION PARAMETERS
 DATE
  24
  25
  26
  27
  28
 TAS(LBS)
    52300
    52000
    51600
    54100
    49500
COD/TPVSS
     .385
     .396
     .424
     .446
     .442
 SOLIDS MASS BALANCE
                          COD (MG/L)
                            PRIMARY EFFLUENT TOTAL       323
                            FINAL EFF.  TOT/SOLUBLE    38/  30
                            REMOVAL <%  TOTAL)              91
                            AERATION  SYSTEM LOAD
                                (LBS  TOTAL COD/DAY)      21300

                          NITROGEN (MG/L)
                            PRIMARY EFF.  NH3-N           23.8
                            FINAL EFF.    NH3-N             •1
                                         N03-N           18.0
                                         N02-N

                          YESTERDAY'S FINAL EFF.  TDS

                          VOLATILE CONTENT (%)             83

                       UNIT-1  UNIT-2  UNIT-3  TOTAL  AVERAGE
                         168                            168
                       49500                   49500
                         5. 1
                         4. 1
                         6.4
                                             5. 1
                                             4. 1
                                                        6.4
COD/MLVSS  CENT MLAT(HRS)   CRT(DAYS)
 DATE
  24
  25
  26
  27
  28
TPSS(LBS)  WASTED (LBS)
    61500
    61500
    60400
    63200
    58000
      6337
      4419
      3916
      4067
      4294
     .653
     .665
     .719
     .753
     .750
  SESS (LBS)
       197
       237
       493
       473
       330
   5. 10
   5.47
   4.85
   4.99
   5.09
 9.41
13.21
13.70
13.92
12.54
DAILY NET GROWTH(LBS)
           5534
           4656
           3309
           7340
           -575
 AVERAGE CRT (DAYS)        11.1
 AVERAGE NET GROWTH  (LBS SOLIDS/LBS  SYS  SOLIDS/DAY)
                                                  .090
 CALCULATED WASTE RATES (MGD)
   FOR AVERAGE  7 DAY CRT
   FOR DAILY  7 DAY CRT
                            .23
                            . 19
    EXAMPLE OF  PRINTOUT OF  DAILY  OPERATIONAL
FIGURE  56      DATA  AND  CALCULATIONS
                                  176

-------
DISTRICT 26 WRP
WRP/SOLIDS HANDLING
               DATE:  5/ i/75
RAW SLUDGE
DIGESTER FLOW (MGD)
LARGE
PRIMARY .0080
LARGE
SECONDARY
SMALL
PRIMARY .0018
SMALL
SECONDARY
TOTALS

OPERATING PARAMETERS
DEWAT WAS
FLOW (MGD) RAW
CENT. /A. F. (LB





.0042

.0620

LARGE SMALL
PRIMARY PRIMARY
LOADING
TS/DAY)

3740



840



LARGE
WAS LOADING
(LB TS/DAY)
CENT. /A. F.





1930

28440

SMALL
SECONDARY SECONDARY
CRT (DAYS)

LOADING (LB VS/DAY/CF)

VOLATILE DESTRUCTION  (%)
UNIT DESTRUCTION
  (LB VS/DAY/1000  CF)
TOTAL GAS PRODUCTION
  (MCF/DAY)
UNIT GAS PRODUCTION
  (CF/LB VS DESTROYED)

VOLATILE ACIDS  (MG/L)
SLUDGE DEWATERING

LOADING (LB/HR)
SOLIDS RECOVERY  (

SLUDGE HAULING
     .028
   23.000
  .010
26.000
         CENTRIFUGE

           178.0000
           51 .0000

         LARGE SYSTEM
HAULED SLUDGE FLOW  (MGD)
TOTAL SOLIDS  HAULED  (LB/DAY)
VOLATILE SOLIDS  HAULED  (LB/DAY)
                                                  AIR  FLOTATION
                                                  UNIT
            SMALL SYSTEM

                 .0200
             6000.0000
             4700.0000
               EXAMPLE  OF   PRINTOUT  OF
   SOLIDS  HANDLING  DATA  AND   CALCULATIONS
FIGURE   57
                                177

-------
handling equipment.
Shown in Appendix A is the monthly report listing all opera-
tional and discharge compliance data and calculations.
There is an additional transaction, LIST, which prints out for
any particular specified day the raw data and calculations
stored for that day.  This transaction is useful for determining
the source of error if calculations cannot be successfully
performed using the stored data.
System Management Programs
Date Record Management Program -  Shown in Figure 58 are those
parameters for which required entries are needed.  That is, the
effluent discharge permits specify the frequency of analyses
of numerous parameters.  This program then maintains a file
on most recent entry of each of the parameters.  Also, the
program directs the off-line portion of the WRPDMS to perform
necessary 30-day statistical calculations.
Parameter Record Management Program -  Shown in Figure 59 are
typical stored operational data needed to calculate daily
operational parameters.
Lower and Upper Limit Management Program - A program is avail-
able to establish upper and/or lower limits for all columns of
data and calculated results.  Entry of any value lying outside
these limits will cause a message to be transmitted to the
operators that the data are abnormal.  At the present time
this program is not in use.  When normal operational ranges
for all parameters have been established, these limits will be
utilized to signal abnormal operation.
Required Data Record Management Program - This program operates
in conjunction with the Data Record Management Program to keep
track of when data are required.  Thus, if a parameter is
specified to be monitored on a weekly basis, this program
checks if data are entered within the appropriate time.  If
not, a message is sent to the operator informing him of

                              178

-------
                     WRP DATA MANAGE KENT SYSTEM
                      FILE MAINTENANCE PROGRAM
PLANT: WHITTIER_NARROWS_WATER_RECLAMATION_PLANT DATE: 06/02/75
                                                TYPE: DATE_RECORD
FUNCTION: PPINT
RECORD KEY: P0200001
                                 DATE      WRP  DATE
 1. FIRST RECORD                8/  1/74      2039
 2. LAST RECORD                 5/31/75      2342
 3. BOD ENTRY                   5/25/75      2336
 4. TOTAL CDLIFORM ENTRY        5/26/75      2337
 5. FECAL COLIFORM ENTRY        5/26/75      2337
 6. NITROGEN ENTRY              5/20/75      2331
 7. T D S  ENTRY                5/20/75      2331
 8. CHLORIDE ENTRY              5/20/75      2331
 9. SULFATF ENTRY               5/20/75      2331
10. DETERGENT ENTRY             5/20/75      2331
II. OIL 6 GREASE ENTRY          5/31/75      2342
12. SULFATE+CHLCRIOE  ENTRY      5/20/75      2331
13. SUSPENDED SOLIDS  ENTRY      5/31/75      2342
14. SETFLEABLE SOLIDS ENTRY     5/31/75      2342
15. BOD  CALC                 5/25/75      2336
16. TOTAL COLIFOPM CALC         3/27/75      2277
17. FECAL COLIFORM CALC         5/26/75      2337
18. NITROGEN CALC               5/20/75      2331
19. T D S  CALC                 5/20/75      2311
20. CHLORIDE CALC               5/20/75      2331
21. SULFATE CALC                5/20/75      2331
22. OIL £ GREASE CALC           5/31/75      2342
23. SULFATF+CHLCRIDE  CALC       5/20/75      2331
24. SUSPENDED SOLIDS  CALC       5/31/75      2342
25. SETTLEABLE SOLIDS CALC      5/31/75      2342
26. OPERATION DAILY PRINTOUT    5/31/75      2342
NOTE:  WRP Date is  a chronological date numbering system that
      arbitrarily  begins with day 0001 on January 1, 1969.
      DATE  RECORD  MANAGEMENT   PROGRAM  -
FIGURE  58       TYPICAL PRINTOUT
                               179

-------
                     WRP DATA MANAGEMENT SYSTEM
                      FILE MAINTENANCE PROGRAM

PLANT:  wHITTIER_NARRUWS_WATER_RECLAMATION_PLANT DATE:  06/02/75

FUNCTION:  PRINT                                 TYPF:  PARAMETER_RECORD

RECORD KEY:  P0200002
 1. PLANT IDENTIFICATION NUf-'RER.

 2. NUMBER OF DATA POINTS

 3. NUMBER OF AERATION SYSTEMS                           1

 4. NUMBER OF TANKS PER SYSTEM                           3

 5. AERATION TANK LENGTH, FT.                          300

 6. AERATION TANK VOLUME, MG                        1.000

 7. AERATION TANK CROSS-SECTIONAL  APFA,  SO.  FT.        450

 8. NUMBER OF FINAL SED. TANKS  (TOTAL  PLANT)             5

 9. FINAL SEDIMENTATION TANK VOLUME  PER  SYSTEMf  MG   1.122

10. NUMBER OF DISCHARGE POINTS                           
-------
of the lacking data.

EXPERIENCES USING THE WRPDMS
The on-line computer system is available for use seven hours
per day, five days per week.  The actual amount of time the
treatment plant operator spends at the teletype terminal can
vary considerably depending upon his typing speed and number
of typing errors committed.  The WRPDMS has program logic
which requires that transaction instructions be typed in an
exact specific order.  Failure to do so elicits diagnostic
error messages from the computer with instructions to repeat
the attempted transaction.  Personnel who have had sufficient
training on the system to know what to do without referring
to printed instructions and whose typing speed averages no
more than 20-30 words per minute have routinely demonstrated
that one day of data can be entered and calculations performed
in approximately 20 minutes.  However, at the other extreme,
personnel with little or no typing ability and a general lack
of understanding of the system have spent over three hours
accomplishing the same task.
Calculation of statistical averages for monitoring reports has
required approximately 24 man-hours per plant per month
utilizing a desk top calculator.  With the WRPDMS, this man-
power requirement has essentially been reduced to zero.

FUTURE MODIFICATIONS
Anticipated future modifications to the WRPDMS include utiliz-
ing the upper and lower limits to signal possible abnormal
trends, to develop statistical predictive equations which can
signal possible effluent compliance violations if recent
trends in data occur, and putting printouts of data and
calculations in a form suitable for direct submittal in
monthly monitoring reports.
                              181

-------
00
to
                                           SAN JOSE CREEK HATER RENOVATION PLANT
                                    COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                    JOHN D. PARKHURST - CHIEF ENGINEER S. GENERAL MANAGER
                                             *** SUMMARY OF OPERATIONS ***
                                                    FEBRUARY 1975
DATE








1
2
3
4
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
TOTAL
FLOWS
TOTAL PLANT


AVERAGE
DAILY
INFLUENT
MGD
1
27.28
28.49
21.68
21.59
22.08
22.43
24.35
21.14
21.87
22.70
22.69
22.39
21 .55
21.76
21.89
21.10
21.58
21.33
20.99
20.90
21.22
19.97
20.80
20.63
21.74
21.95
22.01
21.81
22.14
619.92


PEAK
DAILY
INFLUENT
MGD
2
46.0
42.0
32.0
30.0
30.0
29. 0
28.0
30.0
31.0
31.0
32.0
32.0
31.0
30.0
31.0
32.0
38.0
30.0
31.0
31.0
32.0
31.0
32.0
30.0
30.0
31.0
31.0
31.0
32.0


TOTAL
RETURN
ACTIVATED
SLUDGE
MGD
3
7.16
7.25
6.95
6.59
7.71
6.84
6.44
6.51
6 • 6b
6.54
5.89
6.27
5.86
5.72
6.13
6.11
6.17
6^7
6.05
5.95
6.03
5.40
6.16
6.11
6.24
6.44
6.31
6.03
6.35



WASTE
ACTIVATED
SLUDGE
MGD
4
.011
.008
.072
.248
.315
.306
.297
.331
.359
.335
.282
.257
.326
.367
.213
. 100
.113
.098
.238
.417
.461
.338
.325
.271
.294
.396
.448
.655
.281



PROCESS
AIR

MCF/DAY
5
55.20
54.22
42.36
42.40
45.90
45.34
45.02
41.95
43.53
43.63
43.67
43.33
42.31
42.47
46.01
41.76
43. 74
43.11
42.32
41.87
40.47
38.54
39.92
42.60
43.94
45.23
44. 18
43.19
43.86

EFFLUENT DISCHARGE POINTS
NO. 001
SAN
GABRIEL
RIVER

MGD
6
27.3
28.5
21.7
21.6
22.1
22.4
24.3
21.1
21.9
22.7
22.7
22.4
21.5
21.8
21.9
21.1
21.6
21.3
21.0
20.9
21.2
20.0
20.8
20.6
21.7
21.9
22.0
21.8
22.1
619.9
NO. 002
SAN
JOSE
CREEK

MGD
7
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0


SPREADING
GROUNDS


MGD
8
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000







9






























          A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR,  C-INSUFF1C1ENT SAMPLE VOLUME,  0-HOLI DAY NO ANALYSIS, E-INSUFFICIENT MANPOWER
          F-ON-LINE INSTRUMENT OUT OF SERVICE

                                      EXAMPLE OF  MONTHLY  REPORT

                             SUMMARIZING ALL  DATA  AND  CALCULATIONS

                  APPENDIX

-------
                                            SAN JOSE CREEK WATER RENOVATION PLANT
                                     COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                    JOHN D. PARKHURST - CHIEF ENGINEER L GENERAL MANAGER
                                              *** SUMMARY OF OPERATIONS ***
                                                     FEBRUARY  1975
DATE









1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
SUSPENDED SOLIDS


SEWAGE




MG/L
10
322
234
378
408
432
434
352
282
304
414
322
440
578
412
290
254
244
430
376
426
254
304
340
584
528
496
488
400
383


EFFL.




MG/L
11
146
116
100
116
116
104
106
112
10B
136
122
140
114
90
98
90
108
114
132
104
112
140
124
162
166
146
124
72
119


EFFL.




MG/L
12































EFFL.




MG/L
13































EFFLUENT




MG/L
14
54
65
12
7
10

9

8
10
10
8
3
6
7
7
Q
4
9
8
8
g
4
3
5
7
5
4
11
LBS/DAY
15
12286
15444
2170
1260
1841
1497
1828
1410
1459
1893
1892
1494
1438
1089
1278
1232
1440
712
1576
1394
1416
1332
694
1376
1088
1281
1101
728
2273
REQUIREMENTS GOVERNING DISCHARGE TO:
NAVIGABLE WATERS t TRIBUTARIES THERETO
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS DATA
(- I N A L
EFFLUENT
MG/L
16
13
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
15
14
15
14
14
14
14
14
14
13
15
LbS/DAY
17
3014
3498
3539
3511
3487
3479
3475
3431
3447
3462
3469
3452
3435
3438
3411
3351
3339
3260
3200
3170
3169
3096
3062
3059
2999
2928
2887
2831
3282
PLANT
REMOV.
%
18
96
95
95
95
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
96
ARITHMETIC MEAN
OF PAST 7
CALENDAR DAYS
DATA

MG/L
19
27
35
34
34
33
30
24
17
9
9
g
9
g
6
6
8
3
7
7
7
7
7
7
7
7
7
7
6
14
L8S/DAY
20
6364
8160
7983
7830
7748
6796
5182
3636
1638
1598
1689
1639
1631
1525
1506
1474
1409
1241
1252
1246
1293
1300
1223
1214
1268
1228
1184
1086
2905
ALLOWABLE REUSES
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS
DATA

MG/L
21





























LBS/OAY
22





























oo
CO
         A-SAMPLER MALFUNCTION,  B-ANALYTICAL ERROR, C-1NSUFF1C IENT SAMPLE VOLUME, 0-HOL1DAY NO ANALYSIS, E-INSUFF1C IENT MANPOWER
         F-ON-LINE INSTRUMENT OUT OF SERVICE

                                   EXAMPLE OF MONTHLY REPORT

                          SUMMARIZING ALL  DATA  AND CALCULATIONS

         APPENDIX  (CONTINUED)

-------
00
                                           SAN JOSE CREEK WATER RENOVATION PLANT
                                    COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                   JOHN D. PARKHURST - CHIEF ENGINEER C GENERAL MANAGER
                                            *** SUMMARY OF OPERATIONS ***
                                                   FEBRUARY 1975
DATE





1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
CHEMICAL OXYGEN DEMAND (COD)
RAW
SEWAGE
TOTAL
MG/L
23
460
716
629
961
967
659
983
517
402
530
846
619
641
494
596
400
749
615
1,022
1,155
663
462
571
575
659
571
630
584
667
PRIMARY
EFFLUENT
TOTAL
HG/L
24
290
255
269
312
356
273
375
268
230
292
343
278
313
319
261
222
255
331
350
347
327
290
264
345
338
308
300
311
301
SECONDARY
EFFLUENT
TOTAL
MG/L
25





























SOLUBLE
MG/L
26





























FILTER
EFFLUENT
TOTAL
MG/L
27





























SOLUBLE
MG/L
28





























FINAL
EFFLUENT
TOTAL
MG/L
29
115
100
31
41
36
49
47
42
37
38
31
33
33
40
31
29
31
36
38
33
35
33
33
22
35
29
28
30
40
SOLUBLE
MG/L
30
34
36
18
20
29
38
34
29
30
24
24
22
28
31
22
22
22
31
27
29
27
24
22
20
27
18
22
24
26
          A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFFIC1ENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS,  E-INSUPF 1CIENT MANPOWER
          F-ON-LINE INSTRUMENT  OUT OF SERVICE

                                      EXAMPLE  OF MONTHLY  REPORT

                              SUMMARIZING  ALL  DATA  AND  CALCULATIONS

              APPENDIX (CONTINUED)

-------
                                            SAN JOSE CREEK HATER RENOVATION PLANT
                                     COUNTY SANITATION DISTRICTS  OF LOS ANGELES COUNTY, CALIF.
                                    JOHN 0. PARKHURST - CHIEF ENGINEER & GENERAL MANAGER
                                              *** SUMMARY OF OPERATIONS ***
                                                     FEBRUARY 1975
DATE









1
?
3
4
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
5-DAY BIOCHEMICAL OXYGEN DEMAND (BOD)


RAH

SEWAGE


MG/L
31
333
308
291
388
488
435
455
420
347
280
497
450
460
513
428
320
385
475
438
358
397
292
357
435
658
780
410
288
417


PRIMARY

EFFLUENT


MG/L
32































FINAL

EFFLUENT


MG/L
33
> 22
> 12
7
10
9
Q
7
> 12
> 12

6
6


7
6
y
i^
P
7
5
^
> 12
> 12
5


5
8
LBS/DAY
34
> 5,005
> 2,851
1,266
1,801
1,657
1,497
1,422
> 2,116
> 2,189
1,325
1,135
1,120
1,438
1,270
1,278
1,056
1,260
712

1,220
885
666
> 2,082
> 2,065
907
1,098
918
909
> 1,524
REQUIREMENTS GOVERNING DISCHARGE TO:
NAVIGABLE WATERS t TRIBUTARIES THERETO
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS DATA
FINAL
EFFLUENT
MG/L
35
7
7
8
8
8
Q
8
8
8
a
3
3
8
8
8
8
9
8
8
8
8
8
8
9
9
8
8
8
8
LBS/DAY
36
1,729
1,801
1 ,797
1,802
1,789
1,797
1,804
1,833
1 ,866
1,870
1,867
1,829
1,829
1,813
1,803
1,805
1,832
1,784
1,774
1,755
1,744
1,688
1,692
1 ,730
1,679
1,658
1,653
1,627
1,773
PLANT
REMOV.
*
37
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
98
ARITHMETIC MEAN
OF PAST 7
CALENDAR DAYS
DATA

MG/L
38
> 11
> 11
> 11
> 12
> 12
> 12
> 11
> 9
> 9
> 9
> 9
> 8
> 8
> 8
> 8
7
7
6
7
6
6
6
> 7
> 7
> 7
> 7
> 7
> 7
} 8
LBS/UAY
39
> 2,552
> 2,617
> 2,554
> 2,660
> 2,658
> 2,471
> 2,214
> 1,801
> 1,707
> 1,715
> 1,620
> 1,543
> 1,535
> 1,513
> 1,394
1 ,232
1,222
1 , 162
1 ,169
1, 133
1,069
967
> 1,137
> 1,272
> 1,304
> 1,275
> 1,232
> 1,235
> 1,642
ALLOWABLE REUSES
ARITHMETIC MEAN
OF PAST 30
CALENDAR DAYS
DATA

MG/L
40





























LBS/DAY
41





























CD
        A-SAMPLER MALFUNCTION, B-ANALYTICAL  ERROR, C-INSUFFICIENT SAMPLE VOLUME,  D-HOLIDAY  NO ANALYSIS, E-INSUFF1C IENT MANPOWER
        F-ON-LINE INSTRUMENT  OUT OF SERVICE

                                    EXAMPLE  OF  MONTHLY  REPORT

                            SUMMARIZING  ALL  DATA  AND  CALCULATIONS

          APPENDIX  (CONTINUED)

-------
                                 SAN JOSE CREEK WATER RENOVATION PLANT
                          COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                         JOHN 0. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                  *** SUMMARY OF OPERATIONS ***
                                         FEBRUARY 1975
DATE








1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEDIAN
BACTERIA
CHLORINE CONTACT
DAILY GRAB SAMPLES


TOTAL

MPN/100 ML
42
< 2
< 2
172
> 2400
< 2
4,
< 2
< 2
< 2
< 2
5
Q
^
< 2
< 2
< 2
< 2
2
< 2
5
8
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2


FECAL

MPN/100 ML
43
< 2
< 2
8
175
<. 2
4
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
REQUIREMENTS GOVERNING DISCHARGE TO:
NAVIGABLE WATERS £ TRIBUTARIES

GEOMETRIC MEAN OF
FECAL COLIFORM DATA
DURING PAST
30 DAYS
MPN/100 ML
44
< 2
< 2
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< 3
< J
< 3

7 DAYS
MPN/100 ML
45
< 2
< 2
< 3
< 5
< 5
< 6
< 6
< 6
< 6
< 5
< 3
< 3

< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2

MEDIAN OF
LAST 7
TOTAL
SAMPLES
MPN/100 ML
46
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2
< 2

ALLOWABLE

MEDIAN OF
LAST 7
TOTAL
SAMPLES
MPN/100 ML
47





























A-SA.MPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, O-HOLIDAY NO ANALYSIS, E-INSUFFICIENT MANPOWER
F-ON-LINE INSTRUMENT OUT OF SERVICE

                            EXAMPLE  OF MONTHLY  REPORT

                   SUMMARIZING  ALL  DATA  AND  CALCULATIONS

    APPENDIX (CONTINUED)

-------
                                  SAN JOSE CREEK HATER RENOVATION PLANT
                           COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                           JOHN D. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                    *** SUMMARY OF OPERATIONS ***
                                           FEBRUARY  1975
DATE





1
2
3
4
5
6
7
8
q
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
RESIDUAL CHLORINE
CHLORINE CONTACT
CHAMBER EFFLUENT
MINIMUM
DAILY
VALUE
MG/L
48
Q
.3
.2
« 9
1.4
1 .6
1.4
4.9
4.2
3.8
5.6
4.7
4.1
.2
4.5
5.3
* o
4.4
.2
.2
5.2
5.6
5.2
7.8
5.1
.3
2 .2
3.8
3.0
MAXIMUM
DAILY
VALUE
MG/L
49
> 10. 0
> 10.0
8.6
7.3
> 10.0
> 10.0
> 10.0
> 10.0
> 10.0
9.8
7.4
7.6
7.6
> 10. 0
> 10.0
> 10.0
9.5
9.6
> 10.0
> 10. 0
> 10.0
> 10.0
> 10.0
> 10. 0
> 10.0
> 10.0
7.8
6.5
> 9.3
DAILY GRAB
SAMPLES
CHLOR-
INATED

MG/L
50
3.6
2.2
8.1
. 7
8.0
10.4
12,0
3.0
3.5
4.0
4. a
4. 7
3.4
4.4
5.7
8.4
5.2
3.8
10.8
7.0
4.7
11.3
12.6
9.5
15.2
22.0
7,2
4.8
7.2
DECHLOR-
INATED

MG/L
51





























PH
FINAL
EFFLUENT
n A 1 1 v
UA 1 L T
GRAB
SAMPLE


52
6.60
6.70
6.70
6.70
6.60
6.70
6.80
7.00
6.90
6.80
6.90
6.90
6.90
7.00
6.90
6.70
6. 70
6.80
6.80
6.80
6.90
6.70
6.60
6.60
6.80
6.90
7.00
7.00
6.80
OIL AND GREASE
FINAL EFFLUENT
DAILY GKA8 SAMPLE
CONCEN-
TRATION

MG/L
53
< 1.0
< 5.7
< 1.0
1.2
1.1
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
1. 1
< 1.0
1.7
< 1.0
1.3
2. 1
< 1.0
< 1.0
< 1.0
1.7
< 1.0
< 1.0
< 1.0
1.9
< 1,0
< 1.0
< 1.0
< 1.0
< 1.3
NAVIGABLE
HATER
DISCHARGE
L8S/DAY
54
< 22d
1,354
< 181
216
203
< 187
< 203
< 176
< 182
< 189
208
< 187
306
< 181
237
370
< 180
< 178
< 175
296
< 177
< 167
< 173
327
< 181
< 183
< 184
< 182
< 250
ARITHMETIC MEAN OF
PAST 30 CALENDAR
DAYS DATA USING ONL
DAYS NAVIGABLE HATE
DISCHARGE OCCURRED

MG/L
55
< 1.3
< 1.5
< 1.5
< 1.5
< 1.5
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.4
< 1.3
< 1.4
IBS/DAY
56
< 312
< 350
< 3*8
< 347
< 346
< 335
< 322
< 320
< 318
< 311
< 310
< 308
< 310
< 308
< 307
< 308
< 303
< 301
< 298
< 300
< 298
< 281
< 279
< 282
< 280
< 269
< 268
< 250
< 306
A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR,  C-INSUFF1CIENT SAMPLE VOLUME,  0-HOLIOAY NO ANALYSIS, E-INSUFF 1C IENT MANPOWER
F-ON-LINE INSTRUMENT  OUT OF SERVICE

                             EXAMPLE  OF  MONTHLY  REPORT

                    SUMMARIZING ALL  DATA  AND CALCULATIONS

   APPENDIX  (CONTINUED)

-------
                                           SAN JOSE CREEK WATER RENOVATION PLANT
                                    COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                   JOHN D. PARKHURST - CHIEF ENGINEER & GENERAL MANAGER
                                            *** SUMMARY OF OPERATIONS ***
                                                   FEBRUARY 1975
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
NI TROG&N
24-HOUR FLOW COMPOSITE SAMPLES

PRIMARY
EF FL UE NT
ORGANIC
MG/L
57





























NH3
MG/L
58
25.8
24. 1
19.6
24.9
25.2
18.5
27.4
24.6
25.2
26.6
30.2
28.8
25.2
25.2
24.6
25.2
23.8
2b.2
24.6
23.8
18.5
21.8
23.8
26.6
23.8
24.6
25.8
26.0
24.6

FINAL EFFLUENT
ORGANIC
MG/L
59



1.7





2.0







1.9






1. 1



1.7
NH3
MG/L
60
2.8
3.9
< .1
.9
2.7
4.1
4.9
6.0
4.1
5.6
11.2
9.8
9.4
12.6
7.8
2.1
4.9
8.3
11.9
12.2
13.3
12.2
12.9
12.9
11.8
12.3
13.3
12.9
< 3.1
N02
MG/L
61
.020
.030
.010
.010
.030
E
.010
.030
.030
.040
p
.060
. 060
.080
.080
E
.020
.080
.020
.020
.050
.070
.030
.030
.040
.080
.050
.050
.041
N03
MG/L
62
21.3
26.0
22.0
15.5
17.0
E
9.5
10.0
22.0
11. 1
E
8.0
10.1
3.8
11.5
E
18.0
5.9
2.8
1.6
1.5
2.5
9.0
4.2
2.7
3.5
1.8
6.4
9.4
TOTAL N
MG/L
63



18.1





18.7







16.2






15.6



17.2
LBS/OAY
64



3261





3548







2878






2836



3131
ARITHMETIC MEAN OF PAST
•2/-1 <~ A 1 P Mfl A P l~l A V C
D\J lyALCPJUAK UATj
TOTAL NITROGEN DATA
NlAWlPAAI f- U A T PG
("lAvlOAOl-C MAI t K
DISCHARGE
MG/L
65
19.4
19.4
19.4
19.2
19.2
19.6
19.6
19.6
19.6
19.4
19.4
18.9
18.9
18.9
18.9
18.9
18.9
18.4
lb.4
18.4
17.6
17.6
17.6
17.6
17.2
17.2
17.2
17.2
18.6
LBS/DAY
66
4642
4642
4642
4366
4366
4369
4369
4369
4369
•4204
4204
3915
3915
3915
3915
3915
3915
3708
3708
3708
3334
3334
3334
3334
3235
3235
3131
3131
3901
D p I ICC
n. t U JL
DISCHARGE
MG/L
67





























LBS/DAY
68






























A cp ATI HNI
A C t\ A 1 1 U IN
SYSTEM
A MMflKJ T A
A nnuni i A
n w f n
U A JL U *
%
69
89. 1
83.8
> 99.5
96.4
89.3
77.8
82.1
75.6
83.7
78.9
62.9
66.0
62.7
50.0
68.3
91.7
79.4
67.1
51.6
48.7
28. I
44.0
45.8
51.5
50.4
50.0
48.4
50.4
> 66.9
00
00
         A-SAMPLER MALFUNCTION,  B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, D-HOL1DAY NO ANALYSIS, E-INSUFFICIENT MANPOWER
         F-ON-LINE INSTRUMENT OUT OF SERVICE

                                  EXAMPLE  OF MONTHLY  REPORT

                         SUMMARIZING ALL  DATA  AND  CALCULATIONS

         APPENDIX (CONTINUED)

-------
                                   SAN JOSE CREEK WATER RENOVATION PLANT
                            COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                           JOHN D. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                    *** SUMMARY OF OPERATIONS ***
                                           FEBRUARY 1975
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
2?
23
24
25
26
27
28
MEAN
TURBIDITY

SECONDARY
EFFLUENT


TU
70






























FILTER
EFFLUENT


TU
71





























FINAL EFFLUENT
DAILY
24-HOUR

COMPOSITE
TU
72
42.0
37.0
40.0
6.0
4.0
6.0
2.5
3.5
4.0
5.5
3.0
3.0
3.0
1.6
3.0
2.5
3.0
2.5
3.0
3.0
3.0
3.0
2.5
2.5
2.5
2.5
2.0
2.0
7.1
CONTINUOUS READING
MtTER
MINIMUM
DAILY
VALUE
TU
73
8.0
8.0
7.0
7.0
7.0
5.0
4.0
4.0
3.6
4.0
6.0
3.2
3.2
3.2
2.7
2.6
2.8
2.8
2.6
2.9
3.0
2.9
2.8
2.6
2.8
2.5
2.6
2.4
4.0
MAXIMUM
DAILY
VALUE
TU
74
80.0
98.0
21.0
10.0
8.0
13.0
9.0
5.8
6.1
6.0
6.0
3.6
3.4
3.6
3.8
3.6
3.3
3.2
3.7
3.4
3.4
3.4
3.6
4.6
3.4
4.0
3.5
3.0
11.5
SECCHI DISC



EFFLUENT

FEET
75
6.0
2.5
3.5
4.5
3.5
4.0
4.0
3.0
3.5
3.5
3.5
4.0
4.b
4.5
4.0
4.0
5.0
4.0
4.5
5.0
4.5
3.5
4.0
4.0
5.0
5.0
5.0
4.5
4.2



EFFLUENT

FEET
76





























A-SAMPLER MALFUNCTION, 8-ANALYTICAL EKROR, C-lNSUFF1C IENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS, E-1NSUFF1CIENT MANPOWER
F-ON-LINE INSTRUMENT OUT OF SERVICE

                             EXAMPLE  OF  MONTHLY  REPORT

                    SUMMARIZING  ALL  DATA  AND CALCULATIONS

   APPENDIX  (CONTINUED)

-------
                                  SAN JOSE CREEK WATER RENOVATION PLANT
                           COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                          JOHN 0. PARKHURST - CHIEF ENGINEER E. GENERAL MANAGER
                                   *** SUMMARY OF OPERATIONS ***
                                          FEBRUARY 1975
DATE






1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
SETTLEA8LE SOLIDS

24-HOUR
COMPOSITE

ML/L
77
4.5
3.5
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< . 1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .1
< .4
PAST 30-DAY AVERAGE
NAVIGABLE
WATER
DISCHARGE
ML/L
78
< .4
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
< .5
REUSE
DISCHARGE

ML/L
79





























T D S
DAILY
COMPOSITE
180 DEC C
TEST
MG/L
80
700
569
554
640
650
682
718
615
544
564
621
700
560
667
596
570
587
614
591
661
655
598
553
569
622
656
664
647
620
DISCHARGE
RIVERS
AND/OR
TO REUSE
LBS/DAY
81





























SPECIF.

24-HOUR
COMPOSITE

UMHO/CM
82
1,100
Ii050
975
1,075
1,075
1 ,195
1,230
1,190
1,070
1,075
It 175
1,130
1,160
1,175
1,175
1,000
1,025
1,085
1.210
1,075
1,262
1,175
1,100
1,125
1,260
1,230
1,240
1,112
1,134
TEMP.

GRAB
SAMPLE

0£G. F
83
72
72
72
72
72

71
71
70
71
71
72
71
72
72
70
72
72
72
73
73
70
71
72
72
72
72
73
72
COLCR

EFFLUENT


UNITS
84






























EFFLUENT


UNITS
85





























A-SAMPLER MALFUNCTION, B-ANALVTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, 0-HOLIDAY NO ANALYSIS, E-INSUFf 1C IENT MANPOWER
F-ON-LINE INSTRUMENT OUT OF SERVICE

                            EXAMPLE  OF  MONTHLY  REPORT

                   SUMMARIZING  ALL  DATA  AND  CALCULATIONS

   APPENDIX  (CONTINUED)

-------
                                     SAN JOSE CREEK WATER RENOVATION PLANT
                             COUNTY  SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                             JOHN D.  PARKHURST - CHIEF ENGINEER (. GENERAL MANAGER
                                       *** SUMMARY OF OPERATIONS ***
                                              FEBRUARY  1975
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
CHLORI DE

DAILY
24-HOUR
COMPOSITE


MG/L
86



135





123







131






15*



136
DISCHARGE
TO UNLINED
RIVERS
AND/OR
TO REUSE
LBS/DAY
87





























SULFATE

DAILY
24-HOUR
COMPOSITE


MG/L
88



78





85







90






104



89
DISCHARGE
TO UNLINED
RIVERS
AND/OR
TO REUSE
LBS/DAY
89





























CHLORIDE PLUS
SULFATE
DAILY
24-HOUR
COMPOSITE


MG/L
90



213.0





208.0







221.0






258.0



225.0
DISCHARGE
TO UNLINEO
RIVERS
A NO /OR
TO REUSE
LBS/DAY
91





























DETERGENT
(MBAS)
UAILY
24-HOUR
COMPOSITE


MG/L
92



. 1





. I







.1






.2



.1
A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR,
F-ON-LINE INSTRUMENT OUT OF SERVICE
                                    C-INSUFFIC IENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS, E-INSUFFICI t'NT MANPOWER
                               EXAMPLE OF  MONTHLY  REPORT

                      SUMMARIZING  ALL  DATA  AND  CALCULATIONS

   APPENDIX  (CONTINUED)

-------
                                   SAN JOSE CREEK WATER RENOVATION PLANT
                            COUNTY SANITATION DISTRICTS OF LCS ANGELES COUNTY, CALIF.
                           JOHN 0. PARKHURST - CHIEF ENGINEER £. GENERAL MANAGER
                                     *** SUMMARY OF OPERATIONS ***
                                            FEBRUARY  1975
DATE






1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN


RETURN
SLUDGE
SUSPENDED
SOLIDS
MG/L
93
6,202
7,464
6,602
6,789
6,220
6,838
6,406
6, 165
5,784
5 ,426
6,493
5,902
5,644
4,724
5,170
5 ,456
6,574
7,233
7,611
7,559
6,534
6,530
5,878
6,383
6,305
6,305
5,889
5,603
6,275



PRIMARY
TANKS

94
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

U N I

AERATION
TANKS

95
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
o
0
0
0
0
0
0
0
0
0
0
0
0

r s OUT
FINALS
SYSTEM
NO. 1

96
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
M I S C E L
OF S E R
: FINALS
SYSTEM
NO. 2

97
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
L A N E 0
VICE
FINAL
SYSTEM
NO. 3

98
1
1
1
I
1
1
1
1
1
1
1
I
1
1
1
1
1
1
1
1
1

1
1
1
1
1
1
1
J S


FILTERS


99



































100



































101



































102



































103





























A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS, E-INSUFF1CIENT MANPOWER
F-ON-LINE INSTRUMENT OUT OF SERVICE

                            EXAMPLE  OF MONTHLY  REPORT

                  SUMMARIZING ALL  DATA AND  CALCULATIONS

 APPENDIX  (CONTINUED)

-------
CO
                                             SAN JOSE CREEK WATER RENOVATION PLANT
                                      COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                     JOHN D. PARKHURST - CHIEF ENGINEER I GENERAL MANAGER
                                               *** SUMMARY OF OPERATIONS ***
                                                      FEBRUARY  1975
DATE







1
2
3
4
5
6
7
8
9
10
1 1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. I
SUSPENDED SOLIDS
24-HOUR COMPOSITES

PASS
1
MG/L
104
2997
3036
3283
3053
3038
3160
3329
3145
3087
2951
2960
2113
3349
2864
2959
2899
2805
3089
3045
3121
3210
3088
3269
3317
3407
3176
3204
2633
3057
PASS
2
MG/L
105
1673
1744
2188
2252
1942
2187
2055
2012
1940
1782
2116
1875
1895
2128
1794
1895
2023
2100
2027
2154
2007
1772
1796
1880
1909
1857
1943
1641
1950
PASS
3
MG/L
106
1411
1562
1606
1557
1602
1535
1797
1639
1638
1634
1751
1712
1785
1652
1517
1502
1515
1604
1576
1576
1612
1486
1618
1593
1652
1615
1532
1497
1599
PASS
4
MG/L
107
1228
1355
1538
1701
1673
1551
1806
1660
1639
1385
1421
1590
1465
868
1600
1457
1463
1553
1667
1598
1705
1491
1549
1469
1559
1529
1507
1315
1515
RETURN
ACTIVATED
SLUDGE
FLOW
RATE
MGD
108
2.29
2.33
2.08
2.19
2.57
2.28
2.18
2. 14
2.08
2.01
1.98
1.94
1.84
1.67
1.89
1.85
1.97
2.01
1.92
1.85
1.87
1.74
1.91
2.03
1.92
2.03
1.94
1.89
2.01
AERAT.
VOLUME
MG
109
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1,093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
U093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
MIXED
LIQUOR
DISSOLVED

MAX.
MG/L
110





























HIM.
MG/L
111





























          A-SAMPLER MALFUNCTION,  8-ANALYTICAL ERROR, C-INSUFF1C IENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS, E-1NSUFF1CIENT MANPOWER
          F-ON-L1NE INSTRUMENT OUT OF SERVICE

                                         EXAMPLE  OF MONTHLY  REPORT

                                SUMMARIZING  ALL  DATA  AND CALCULATIONS

               APPENDIX (CONTINUED)

-------
                                 SAN JOSE CREEK WATER RENOVATION PLANT
                           COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                          JOHN 0. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                   *** SUMMARY OF OPERATIONS ***
                                          FEBRUARY 1975
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
1*
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. I
LOADING PATTERN

PASS
1

%
112
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0

PASS
2

%
113
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0

PASS
3

%
114
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0

PASS
4

%
115
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
-0
.0
.0
.0
.0
.0
.0
.0
SVI GRAB SAMPLE

SETTL.
SOLIDS

ML/L
116
245
220
225
225
230
220
200
190
210
200
200
190
200
200
200
235
240
240
250
250
290
300
345
350
350
380
425
390
257

SUSP.
SOLIDS

MG/L
117
1366
1459
1332
1832
1763
1718
1677
2004
1900
1507
1473
1726
1547
1558
1482
1509
1728
1756
1936
1834
1922
1626
1753
1674
1680
1732
1574
1494
1681


SVI

ML/G
118
179
151
123
123
130
128
119
95
111
133
136
110
129
128
135
156
139
137
129
136
151
185
196
209
208
219
270
261
155

VOLAT.
SOLIDS

£
119
79
78
79
79
77
77
77
79
81
78
76
79
76
77
76
77
78
77
78
79
79
78
82
79
78
78
77
77
78
N02
LOW
FLOW
GRAB
SAMPLE
MG/L
120
.030
.040
,010
.010
.080
.100

.060
.090
.120
.120
E
.100
.110
.120
.110
£
.110
.060
,050
.010
.020
.130
.090
.070
.140
.040
.120
.078
HIGH
FLOW
GRAB
SAMPLE
MG/L
121
.300
.320

< .010
.010
.770
.090
.070
.040
.090
.100
E
.080
.070
.120
.150
E
.090
,050
.050
.050
.060
.035
.090
.110
.100
.080
.100
< .121
N03
LOW
FLOW
GRAB
SAMPLE
MG/L
122
20.0
23.0
17.0
17.0
15.0
10.0
£
9.5
11.0
17.3
3.7

4.0
3.3
7.0
17.8

5.0

1.1
.2
Q
1.5
2.5
6.4
2.9

2.6
8.0
HIGH
FLOW
GRAB
SAMPLE
MG/L
123
30.0
29.3

19.3
20.0
11.0
15.9
13.3
24.9
19.0
9.0
E
9.6
3.5
14.5
24.2
E
8.0
1.4
1.0
1.1
3.1
15.0
7.1
6.4
9.7
7.4
8.3
12.5
A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR,  C-INSUFFIC1ENT SAMPLE VOLUME, D-HOLIOAY NO ANALYSIS, E-INSUFUCIENT MANPOWER
F-ON-LINE INSTRUMf'T OUT OF SERVICE

                           EXAMPLE OF  MONTHLY REPORT

                  SUMMARIZING ALL  DATA AND  CALCULATIONS

  APPENDIX  (CONTINUED)

-------
(Jl
                                              SAN JOSE CREEK WATER RENOVATION  PLANT
                                      COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY,  CALIF.
                                      JOHN 0. PARKHURST - CHIEF ENGINEER £. GENERAL MANAGER
                                               ***  SUMMARY OF OPERATIONS ***
                                                       FEBRUARY  1975
DATE








1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. 2
' SUSPENDED SOLIDS
24-HOUR COMPOSITES


P A C C
r tt J o
1
MG/L
124
2890
3043
3204
2942
2795
3005
3180
2895
3181
2915
3013
3088
3257
3015
306B
2926
2916
3182
3370
3181
3139
2966
3105
3123
3296
3149
3298
2658
3064
pACC • n A C C
" Ao j
2
MG/L
125
1735
1794
2010
2129
2084
1705
2100
1838
1970
1704
2071
1873
1827
2098
2073
1851
1783
2092
2092
2042
2110
1305
1772
1938
2012
1916
2023
1725
1935
r M o j
MG/L
126
1347
1417
1486
1510
1481
1561
1681
1697
1690
1613
1564
1340
1691
1588
1503
1614
1291
1531
1593
1421
1675
1494
1491
1611
1706
1687
1691
1334
1547
n A c c
r A J> o
4
MG/L
127
1306
1397
1539
1489
1434
1580
1644
1614
1639
1392
1563
1544
1705
1884
1674
1576
1447
1697
1575
1685
1655
1564
1408
1529
1612
1647
1638
1504
1569
RETURN
ACTIVATED
SLUDGE

c i rii/j
r L UH
RATE
MGD
128
2.35
2.38
2.28
2.09
2.57
2.09
2.03
2.15
2.28
2.24
2.07
2.20
2.09
2.03
2.19
2.14
2.16
2.22
2.15
2.08
2. 11
1.89
2.12
2.03
2.25
2.31
2.25
2.13
2. 17
A C. D A f
A c H A 1 .
VOLUME
KG
129
1.093
1.093
1,093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1 .093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
MIXED
LIQUOR
DISSOLVED
n if vr P M
U A T LJ C IN
MAX.
MG/L
130





























MIN.
MG/L
131





























           A-SAMPLER MALFUNCTION, B-ANALYTICAL  ERROR, C-1NSUFF1C IENT SAMPLE VULUMfc, D-HOLIDAY NO ANALYSIS, E-1NSUFF1C IENT MANPOWER
           F-ON-LINE INSTRUMENT  OUT OF SERVICE

                                          EXAMPLE OF  MONTHLY  REPORT

                                 SUMMARIZING ALL  DATA  AND  CALCULATIONS

                APPENDIX  (CONTINUED)

-------
                                         SAN JOSE CREEK WATER RENOVATION PLANT
                                  COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                  JOHN D. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                           *** SUMMARY OF OPERATIONS ***
                                                  FEBRUARY  1975
VD
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. 2
LOADING PATTERN

PASS
1

%
132
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0

PASS
2

*
133
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0

PASS
3

Z
134
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0

PASS
4

%
135
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
SVI GRAB SAMPLE

SETTL.
SOLIDS

ML/L
136
250
230
245
245
210
215
200
200
215
210
200
200
220
230
220
240
250
240
260
270
290
320
335
360
350
425
460
430
269

SUSP.
SOLIDS

MG/L
137
1343
1445
1532
1870
1852
1709
1728
1928
1904
1642
1817
1815
1675
1666
1607
1548
1769
1768
2122
1920
1922
1762
1720
1642
1810
1835
1674
1570
1736


SVI

ML/G
138
186
159
131
131
113
126
116
104
113
128
110
110
131
138
137
155
141
136
123
141
42
181
194
219
193
232
275
274
151

VOLAT.
SOLIDS

%
139
79
78
78
79
79
79
1
79
81
79
80
79
76
78
76
77
78
78
79
80
80
79
82
79
79
79
78
77
76
N02
LOW
FLOW
GRAB
SAMPLE
MG/L
140
.060
.050
.040
.020
.050
.100
E
.060
.070
.120
.100

.110
.120
.110
.020
£
.120
.060
.090
.080
.110
.130
.090
.170
.150
.070
.080
.087
HIGH
FLOW
GRAB
SAMPLE
HG/L
141
.350
.370
< .010
.090
.010
.730
.080
.090
.070
.110
.080
p
.060
.060
.220
.130
E
.090
.060
.060
.060
.090
.080
.090
. 100
.120
.060
.080
< .129
N03
LOW
FLOW
GRAB
SAMPLE
MG/L
142
20.0
20.7
22.8
13.9
17.0
8.0
E
8.5
16.0
19.2
3.7
E
3.3
4.0
6.5
20.8
E
7.0
2 5
2.2
L.8
2.4
4.0
7.1
7.6
3.0

1.9
9.0
HIGH
FLOW
GRAB
SAMPLE
MG/L
143
25.0
28.7
17.9
15.9
20.1
10. 0
19.3
15.9
20.0
19.0
7.5
E
6.6
3.0
16.0
31.3
E
10.0
2.4
2.6
2.6
4.8
12.0
7.4
4.1
7.6
4.1
4.1
12.2
        A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, 0-HOLIDAY NO ANALYSIS, E-INSUFFICIF.NT MANPOWER
        F-ON-LINE INSTRUMENT OUT OF SERVICE

                                  EXAMPLE  OF MONTHLY  REPORT

                          SUMMARIZING  ALL  DATA  AND  CALCULATIONS

         APPENDIX  (CONTINUED)

-------
                                    SAN JOSE CREEK dATER RENOVATION PLANT
                            COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                            JOHN D. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                     ***  SUMMARY OF OPERATIONS ***
                                             FEBRUARY  1975
DATE







I
2
3
^
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. 3
SUSPENDED SOLIDS
24-HOUR COMPOSITES

PASS
I
MG/L
144
2899
2935
3216
3282
2986
3215
3235
3020
2882
2860
2803
3098
3023
2905
2888
2735
2370
2721
3090
2988
3055
2762
2959
3063
3183
2984
3063
2606
2958
PASS
2
MG/L
145
1797
1901
2128
2251
2031
2251
2166
1988
1896
1845
1960
2018
1859
1953
2007
1896
1686
1791
2042
2042
2190
1960
1926
1866
2069
1949
1999
1787
1973
PASS
3
HG/L
146
1632
1544
1708
1663
1712
1700
1899
1652
1528
1650
1643
1723
1555
1498
1612
1576
1348
1466
1704
1601
1646
1490
1364
1566
1537
1577
1500
1419
1590
PASS
4
MG/L
147
1469
1446
1871
1848
1553
1745
1724
1665
1433
1443
1530
1601
1667
1492
1554
1439
1200
1683
1623
1535
1651
1492
1457
1604
1548
1525
1629
1518
1569
RETURN
ACTIVATED
SLUDGE
FLOW
RATE
MGD
148
2.51
2.54
2.59
2.31
2.57
2.47
2.22
2.21
2.30
2.29
1.98
2.13
1.93
1.92
2.05
2.11
2.02
2.04
1.98
2.02
2.05
1.76
2. 13
2.05
2.10
2.10
2.12
2.01
2.16
AERAT.
VOLUME
MG
149
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
1.093
MIXED
LIQUOR
DISSOLVED
OXYGEN
MAX.
MG/L
150





























MIN,
MG/L
151





























A-SAMPLER MALFUNCTION,  B-ANALYTICAL ERROR, C-INSUFF1C IENT SAMPLE VOLUME, D-HOL1DAY NO ANALYSIS, E-I NSUFF 1C IENT MANPOWER
F-ON-LINE INSTRUMENT OUT OF SERVICE
                               EXAMPLE  OF  MONTHLY  REPORT
                      SUMMARIZING ALL  DATA  AND  CALCULATIONS
    APPENDIX  (CONTINUED)

-------
                                         SAN JOSE CREEK WATER RtNOVATION PLANT
                                   COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                  JOHN 0. PARKHURST - CHIEF ENGINEER & GENERAL MANAGER
                                           *** SUMMARY OF OPERATIONS ***
                                                  FEBRUARY 1975
DATE







1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
AERATION SYSTEM NO. 3
LOADING PATTERN

PASS


•?
152
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0
30.0

PASS


z
153
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0
45.0

PASS
3

o>
*>
154
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
30.0
25.0
25.0
25.0
25.2

PASS
4

%
155
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
SVI GRAB SAMPLE

SETTL.
SOLIDS

ML/L
156
270
230
210
270
250
245
220
200
210
200
200
180
215
200
210
230
240
200
235
250
270
310
290
330
320
360
380
395
254

SUSP.
SOLIDS

MG/L
157
1533
1436
1532
1990
1816
1704
1896
1993
1858
1544
1655
1651
1612
1480
1467
1435
1636
1421
1824
1877
1993
1742
1540
1583
1520
1760
1505
1445
1659


SVI

ML/G
158
176
160
135
136
138
144
116
100
113
129
120
109
133
135
143
160
147
141
129
133
135
178
188
208
211
205
252
273
155

VOLAT.
SOLIDS

*
159
80
78
78
79
77
77
78
79
81
78
79
79
77
78
75
76
77
78
79
80
80
79
81
79
78
79
77
76
78
N02
LOW
FLOW
GRAB
SAMPLE
MG/L
160
.050
.060
.050
.030
.040
.090
E
.060
.100
.130
.120

.120
.120
.110
.010
£
.120
.060
.090
.080
.070
.150
.100
.180
.150
.150
.090
.093
HIGH
FLOW
GRAB
SAMPLE
MG/L
161
.290
.360
< .010
.040
.010
.730
.090
.070
.020
.100
.090
E
.090
.070
.240
.050
e
.110
.070
.050
.060
.050
.100
.080
.090
.120
.110
.110
< .123
N03
LOW
FLOW
GRAB
SAMPLE
MG/L
162
16.0
21.1
21.2
13.5
15.0
7.5

10.5
15.0
17.0
3.7
c
2.0
5.0
6.5
21.2
p
7.5
3.0
2.3
2.0
1.8
4.6
5.6
7.8
2.5
1.5
4.6
8.7
HIGH
FLOW
GRAB
SAMPLE
MG/L
163
24.6
29.1
23.5
18.3
20.5
10.5
15.0
14.1
23.5
17.5
8.0
E
8.5
3.5
17.0
25.5
E
12.5
3.0
3.2
3.0
4.3
12.5
7.3
3.6
6.2
7.3
8.2
12.7
l-D
00
        A-SAMPLER MALFUNCTION,  B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS, E-INSUFFICIENT MANPOWER
        F-ON-LINE INSTRUMENT OUT OF SERVICE

                                  EXAMPLE  OF MONTHLY  REPORT

                          SUMMARIZING  ALL  DATA  AND  CALCULATIONS

         APPENDIX  (CONTINUED)

-------
i-D
                                           SAN JOSE CREEK WATER RENOVATION PLANT
                                    COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                   JOHN 0. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                             *** SUMMARY OF OPERATIONS ***
                                                    FEBRUARY  1975
DATE







1
2
3
4
5
6
7
3
9
10
11
I?
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
KINETIC PARAMETERS
AIR RATES

FEET/
GALLON
EFFLUENT

164
2.02
1.90
1 .95
1.96
2.08
2.02
1.85
1.98
1.99
1.92
1.92
1.94
1.96
1.95
2.10
1.98
2.03
2.02
2.02
2.00
1.91
1.93
1.92
2.06
2.02
2.06
2.01
1.9fl
1.98

FEET/
POUND
COD

165
948
1,042
933
806
762
1,031
650
996
1, 193
860
723
906
826
813
1,054
1,187
1,043
808
748
755
762
870
951
762
779
852
8t>6
827
884
COD

REMOVAL


%
166
88.3
85.9
93.3
93.6
91.9
86.1
90.9
89.2
87.0
91.8
93.0
92.1
91.1
90.3
91.6
90.1
91.4
90.6
92.3
91.6
91.7
91.7
91.7
94.2
92.0
94.2
92.7
92.3
91.2

AERATION
SYSTEM
LOAD
LBS.
167
66,000
60,600
48,600
56,200
65,600
51, 100
76,200
47,300
42,000
55,300
64,900
51,900
56,300
57,900
47,600
39, 100
45,900
58,900
61,300
60,500
57,900
48,300
45,800
59,400
61 ,300
56,400
55,100
56,600
55,500
TOTAL AERATION

AERATION
SYSTEM
i
LBS.
168
61 ,800
67,900
70,400
70,400
66,500
69,900
71,300
67,600
65,500
61 ,700
68,100
59,600
66,800
59,600
61 ,000
61,600
65,400
70,600
71,300
72,200
69, 100
65,400
65,600
67,700
68,300
66,700
65,500
58,300
66,296
AERATION
SYSTEM
2
LBS.
169
61.400
67,500
68,000
67,700
64,300
66,200
69,400
65,200
66,600
60,900
67,400
63,300
66,000
63,200
63,600
62,500
63, 100
71,200
73,500
71 , 100
69,600
65,100
63,200
67, 100
69,300
67,700
68,000
58,500
66,093
AERATION
SYSTEM
3
LBS.
170
64,200
68,400
71,300
72,700
67,000
72,300
71,800
66,800
62,600
61,800
65,800
66,900
63, 700
59,700
62,300
61,000
58,700
65,900
72,300
70,600
69,300
64,500
62 ,600
66,200
67, 700
65,800
65,200
59,200
65,939
MIXED LIQUOR

AERATION
SYSTEM
1
LBS.
171
26,300
28,000
31,500
31,900
30,300
30,900
33,000
31 ,000
30,500
28,600
31,100
28,800
31, 100
28,700
28,600
28,500
29,100
30,800
30,500
31,100
31,100
28,200
29,700
29,800
30,700
29,700
29,600
26,300
29,836
AERATION
SYSTEM
2
LBS.
172
26,200
27, 500
29, 700
29,900
29,000
28,500
31,700
29,900
31,100
28, 100
30,300
28.000
30,800
31,600
30,400
29,400
26,600
30,900
31,200
29,900
31,700
28,500
28,000
30,000
31,500
30,800
31,600
26,300
29,611
AERATION
SYSTEM
3
LBS.
173
28,900
28,800
32,800
33,200
30,900
33,000
33,800
30,800
28,600
29, 100
29,800
31,300
29, 500
28,900
30,000
28,600
24,700
28,200
31,300
30,200
31,700
28,600
27,900
29,500
30,400
29,600
29,800
27,100
29,893
         A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFFICIENT SAMPLE  VOLUME, D-HOLIDAY NO ANALYSIS, E-INSUFF1CIENT MANPOWER
         F-ON-LINE INSTRUMENT OUT OF SERVICE

                                     EXAMPLE  OF  MONTHLY  REPORT

                            SUMMARIZING ALL  DATA AND  CALCULATIONS

           APPENDIX  (CONTINUED)

-------
                                          SAN JOSE CRFEK WATtR RENOVATION PLANT
                                   COUNTY SANITATION DISTRICTS OF LOS ANGELES COUNTY, CALIF.
                                  JOHN 0. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                           *** SUMMARY OF OPERATIONS ***
                                                  FEBRUARY  1975
DATE







I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
MEAN
KINETIC PARAMETERS
CENTROI DAL
RETURN SLUDGE
AERATION TIMES
AERATION
SYSTEM
1
MRS.
174
1 1.46
11.26
12.61
11.98
10.21
11.51
12.03
12.26
12.61
13.05
13.25
13.52
14.26
15.71
13.88
14.18
13.32
13.05
13.66
14.18
14.03
15.08
13.73
12.92
13.66
12.92
13.52
13.88
13. 13
AERATION
SYSTEM
2
MRS.
175
11. 16
11.02
11.51
12.55
10.21
12.55
12.92
12.20
11.51
11.71
12.67
11.92
12.55
12.92
11.98
12.26
12. 14
11.82
12.20
12.61
12.43
13.88
12.37
12.92
11.66
11.36
11.66
12.32
12. 11
AERATION
SYSTEM
3
HRS.
176
10.45
10.33
10. 13
11.36
10.21
10.62
11.82
11.87
11.41
11.46
13.25
12.32
13.59
13.66
12.80
12.43
12.99
12.86
13.25
12.99
12.80
14.90
12.32
12.80
12.49
12.49
12.37
13.05
12.25
MIXED LIQUOR
AERATION TIMES
AERATION
SYSTEM
1
HRS.
177
4.08
3.93
4.99
4,95
4.68
4.76
4.51
5.06
4.96
4.85
4.87
4.94
5.15
5.20
5.06
5.23
5.07
5.09
5.21
5.27
5.19
5.53
5.25
5.21
5.07
4.97
5.01
5.07
4.97
AERATION
SYSTEM
p
HRS.
178
4.06
3.91
4.88
5.00
4.68
4.85
4.58
5.05
4.85
4.74
4.82
4.81
5.01
5.00
4.90
5.06
4.97
4.98
5.08
5.13
5.06
5.43
5.13
5.21
4.89
4.82
4.84
4.94
4.88
AERATION
SYSTEM
3
HRS.
179
4.00
3.86
4.73
4.88
4.68
4.67
4.49
5.02
4.84
4.71
4.87
4.84
5.10
5.06
4.97
5.08
5.04
5.08
5.17
5.17
5.09
5.52
5.12
5.20
4.97
4.93
4.91
5.00
4.89
HYDRAUL 1C
RETURN SLUDGE
AERATION TIMES
AERAT ION
SYSTEM
1
HRS.
180





























AERATION
SYSTEM
2
HRS.
181





























AERATION
SYSTEM
3
HRS.
182





























MIXED LIQUOR
AERATION TIMES
AERATION
SYSTEM
1
HRS.
183
6.38
6. 14
7.81
7.74
7.32
7.45
7.06
7.91
7.76
7.59
7.61
7,73
8.05
8. 14
7.91
8. 13
7,93
7.97
8.15
8.24
8.13
8.65
8,22
8. 16
7.93
7.7tt
7.83
7.93
7.78
AERATION
SYSTEM
2
HRS.
184
6.35
6.12
7.64
7.83
7.32
7,60
7.16
7.90
7.59
7.41
7.54
7.52
7.84
7.83
7.66
7.92
7.77
7.79
7.95
8.03
7,91
8.50
8.03
8.16
7.65
7.55
7.58
7.73
7.64
AERATION
SYSTEM
3
HRS.
185
6.26
6.04
7.40
7.64
7.32
7.31
7.03
7.85
7.58
7.37
7.61
7.58
7.97
7.92
7.78
7.95
7.89
7.94
8, 10
8.09
7.97
8.63
8.02
8.14
7.78
7.72
7.68
7.83
7.66
O
O
        A-SAMPLER MALFUNCTION. B-ANALYTICAL ERROR, C-INSUFFJCIENT SAMPLE VOLUME, D-HOLIDAY NO ANALYSIS,  E-INSUFFICIENT MANPOWER
        F-ON-L1NE INSTRUMENT OUT OF SERVICE

                                   EXAMPLE  OF MONTHLY  REPORT

                          SUMMARIZING ALL  DATA  AND  CALCULATIONS

         APPENDIX  (CONTINUED)

-------
NJ
O
                                           SAN JOSE CREEK HATER RENOVATION PLANT
                                    COUNTY SANITATION DISTRICTS OF LOS ANGELbS COUNTY, CALIF.
                                    JOHN D. PARKHURST - CHIEF ENGINEER £ GENERAL MANAGER
                                             *** SUMMARY OF OPERATIONS ***
                                                   FEBRUARY 1975
DATE






i
2
3
4
5
6
7
8
g
10
11
12
13
14
15
16
17
18
19
20
21
22
23
2*
25
26
27
28
MEAN
KINETIC PARAMETERS
COO LOADING
LBS. COD/
TPVSS/
DAY

186
.36
.31
.24
.27
.34
.25
.55
.24
.21
.31
.33
.27
.30
.33
.26
.22
.26
.29
.29
.29
.28
.25
.24
.30
.31
.29
.29
.33
.29
LBS. COD/
MLVSS/
DAY

187
1.02
.92
.66
.75
.94
.71
1.46
.65
.57
.82
.90
.75
.81
.84
.71
.59
.73
.84
.84
.83
.77
.72
.66
.84
.85
.80
.78
.93
.81
DAILY
RES.


DAYS
188
17.9
15.6
42.7
17.3
13.6
13.7
15.1
13.7
13.0
13.4
14.5
17.0
14.8
14.6
22.8
40.2
30.2
39.3
16.1
9.6
9.8
12.3
14.3
15.8
15.5
11.3
10.8
7.1
17.6
SOLIDS BALANCE
TOTAL
SUSPEND.
SOLIDS
LBS.
189
229,800
248,300
262,200
265,100
247,200
260,100
267,400
252,000
244,600
229,100
249,200
240,000
247,800
227,500
238, 100
232.500
230,800
260,000
268,700
265,000
261,100
243,200
238,200
249,600
255,800
250,000
249,300
222,000
247,671
WASTED


LBS.
190
569
498
3,964
14,042
16,341
17,451
15,868
17,019
17, 318
15, 160
15,271
12,650
15,345
14,459
9, 184
4,550
6, 195
5,912
15,107
26,289
25,122
18,408
15,932
14,426
15,460
20,823
22,003
30,608
14,499
SEC.
SUSPEND.
SOLIDS
LBS.
191
12,286
15,444
2,170
1,260
1,841
1,497
1,828
1,410
1,459
1,893
1,892
1,494
1,438
1,089
1,278
1,232
1,440
712
1,576
1,394
1,416
1,332
694
1,376
1,088
1,281
1,101
728
2,273
DAILY
GROWTH

LBS.
192
18255
34442
20034
18202
282
31848
24996
3029
11377
1553
37263
4944
24583
-4751
21062
182
5935
35824
25383
23983
22638
1840
11626
27402
22548
16304
22404
4035
16686
AVERAGE
GROWTH
IKGROWTH/
fSYSTEH
DAY
193
.068
.069
.064
.062
.062
.061
.062
.066
.069
.071
.072
.073
.077
.054
.053
.052
.050
.051
.051
.052
.051
.051
.053
.05*
.053
.054
.055
.069
.060
AVERAGE
RES.


DAYS
194
14.6
14.5
15.6
16.0
16.2
16.3
16.0
15.2
14.5
14.1
13.9
13.6
13.0
18.6
13.8
19.3
19.9
19.8
19.7
19.1
19.8
19.8
19.0
18.9
18.9
18.5
18.1
14.5
17.0
          A-SAMPLER MALFUNCTION, B-ANALYTICAL ERROR, C-INSUFF1CIENT SAMPLE VOLUME, D-HOLIOAY  NO ANALYSIS, E-INSUFF1CIENT MANPOWER
          F-ON-LINE INSTRUMENT OUT OF SERVICE

                                      EXAMPLE OF MONTHLY  REPORT

                             SUMMARIZING ALL DATA  AND  CALCULATIONS

             APPENDIX (CONTINUED)

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1 . REPORT NO.
  EPA-600/2-75-058
                                                           3. RECIPIENT'S ACCESSI ON-NO.
4. TITLE AND SUBTITLE
  State  of the Technology
  SEMI-AUTOMATIC CONTROL OF ACTIVATED SLUDGE
  TREATMENT PLANTS
             5. REPORT DATE
              December 1975  (Issuing Date)
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
   Carl  A.  Nagel
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS

   County Sanitation Districts of  Los  Angeles County
   1955  Workman Mill Road
   Whittier, California  90607
             10. PROGRAM ELEMENT NO.

              1BB043; ROAP 21-ASC;  Task 31
             11. CONTRACT/GRANT NO.

              R803 055-01-0
 12. SPONSORING AGENCY NAME AND ADDRESS
                                                           13. TYPE OF REPORT AND PERIOD COVERED
   Municipal Environmental Research  Laboratory
   Office of Research and Development
   U.S.  Environmental Protection Agency
   Cincinnati, Ohio  45268
             14. SPONSORING AGENCY CODE

              EPA-ORD
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT

   This  report documents the theory,  design and operation of continuous on-line
   instrumentation currently in use by the County Sanitation Districts of Los Angeles
   County California and further describes computer applications which provide daily
   operational calculations.

   Instrumentation sections include Water Level Control of Influent Pumping, Density
   Control of Primary Sludge Pumping,  and Process Air, Return Sludge and Waste Sludge
   Control in Activated Sludge Plants.   Theory, design, operation  and maintenance
   characteristics, maintenance requirements,  and results are presented for each system

   A computer application system is described which provides daily operational para-
   meters to the operators and prepares monthly summary of operations reports.  A
   review of other computer applications and a subroutine to compare effluent charac-
   teristics with discharge limits is  included.
   This  report was submitted in fulfillment of Contract Number R 803 055-01-0, by the
   County Sanitation Districts of Los  Angeles County, under the sponsorship of the
   Environmental Protection Agency.   Work was completed as of March 1975.
17.
                               KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                             b.IDENTIFIERS/OPEN ENDED TERMS
                           c.  COS AT I Field/Group
  Automatic control
  Automatic control equipment
  Data  processing
  Data  storage
  Data  retrieval
  Waste treatment
  Waste water
Influent pumping control
Sludge pumping control
Process air  control
Waste activated sludge
  control
13B
13. DISTRIBUTION STATEMEN1
  RELEASE TO PUBLIC
                                              19. SECURITY CLASS (This Report)'
                                              	UNCLASSIFIED
                           21. NO. OF PAGES

                                  212
20. SECURITY CLASS (This page)
     UNCLASSIFIED
                                                                        22. PRICE
EPA Form 2220-1 (9-73)
                                            202
                *USGPO: 1976-657-695/5356 Region 5-1

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