v>EPA
••I States
inmental Protf
Agency
Rese;
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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 nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental 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 Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-116
July 1978
THE COUPLED TRICKLING FILTER-ACTIVATED SLUDGE PROCESS:
DESIGN AND PERFORMANCE
by
Richard J. Stenquist
Denny S. Parker
Brown and Caldwell, Consulting Engineers
Walnut Creek, California 94596
William E. Loftin, Consultant
City of Livermore
LLvermore, California 94550
Contract No. 68-03-2175
Project Officer
Richard C. Brenner
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.
ii
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FOREWORD
The Environmental Protection Agency was created because of increasing
public and government concern about the dangers of pollution to the health
and welfare of the American people. Noxious air, foul water, and spoiled
land are tragic testimony to the deterioration of our natural environment.
The complexity of that environment and the interplay between its components
require a concentrated and integrated attack on the problem.
Research and development is that necessary first step in problem solution
and it involves defining the problem, measuring its impact, and searching
for solutions. The Municipal Environmental Research Laboratory develops
new and improved technology and systems for the prevention, treatment,
and management of wastewater and solid and hazardous waste pollutant
discharges from municipal and community sources, for the preservation and
treatment of public drinking water supplies, and to minimize the adverse
economic, social, health, and aesthetic effects of pollution. This publica-
tion is one of the products of that research; a most vital communications
link between the researcher and the user community.
This case history report illustrates the combined use of careful long-range
planning and technical ingenuity in upgrading an existing conventional
trickling filter plant to increase capacity and meet more stringent effluent
discharge requirements. No existing facilities were abandoned in the
upgrading process. The procedures described herein are recommended for
consideration by other engineers faced with similar upgrading situations.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
iii
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ABSTRACT
A case history report was prepared on the upgrading of the Livermore,
California, Water Reclamation Plant from a conventional trickling filter
plant with tertiary oxidation ponds to a coupled trickling filter-activated
sludge plant producing a nitrified effluent low in BOD$, suspended solids,
and coliform organisms.
The report covers planning, design, construction, startup, and operation
and performance of the upgraded Livermore plant. Capital costs and opera-
tion and maintenance expenses are also given. Data and information from
Livermore were used in conjunction with data from other coupled trickling
filter-activated sludge plants to develop general design considerations for
carrying out similar upgradings elsewhere.
Over 7 yr of operating records from Livermore show that the coupled trickling
filter-activated sludge process is extremely stable and reliable. Effluent
BODs and suspended solids concentrations of 10 to 20 mg/1 can be obtained,
along with ammonia nitrogen concentrations less than 1 mg/1. Monthly
median total coliform concentrations of 2.1 MPN/100 ml were consistently
achieved at Livermore using high chlorine dosages and a chlorine contact
tank with good hydraulic characteristics.
The coupled trickling filter-activated sludge process is particularly
adaptable to existing conventional trickling filter plants where stringent,
new discharge requirements have been imposed and where existing structures
and equipment are in good condition and can be used in an upgraded facility.
Principal design considerations are aeration tank size, aeration air supply,
flexibility, reliability, and efficient use of existing facilities.
This report was submitted in fulfillment of Contract No. 68-03-2175 by
Brown and Caldwell, Consulting Engineers, under the sponsorship of the
U.S. Environmental Protection Agency. Plant operating and performance
data are included in this case history report for the period of January 1968
through December 1974.
iv
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CONTENTS
Foreword iii
Abstract iv
Figures vii
Tables xi
Acknowledgments xiii
1. Introduction 1
Objectives and Scope 4
Outline of Report 4
2. Conclusions 6
3. Recommendations 9
4. Background 10
5. Design 16
Process Design 16
Physical Design . . . / 22
6. Construction 33
Preconstruction Activities 33
Construction Activities 34
Construction Sequence 40
Progress Payments 50
Accidents 52
Completion 52
7. Plant Startup and Initial Operating Period 54
Preparation for Startup 54
Startup of Activated Sludge System 55
Initial Operational Period 58
8. Plant Operation and Performance 62
Sampling Methods and Locations 64
Plant Performance Summary 67
Operation of Plant Components 69
Operation and Performance Evaluation Summary ... 108
9. Treatment Costs 114
Capital Costs 114
Operation and Maintenance Costs 115
Total Annual Cost 117
v
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CONTENTS (continued)
10. General Design Considerations 119
Additional Trickling Filter-Activated Sludge
Plants 119
Nitrification Kinetics in the Coupled Trickling
Filter-Activated Sludge Process 133
Design Considerations 139
References 158
Appendices
vi
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FIGURES
Number Page
1 Location of Livermore Water Reclamation Plant 2
2 Aerial view of Livermore - Amador Valley 3
3 Aerial view of upgraded Livermore Water Reclamation
Plant 7
4 Flow diagram for original Livermore plant 12
5 Layout of original Livermore plant 12
6 Flow diagram for upgraded Livermore Water Reclamation
Plant ' 17
7 Layout of upgraded Livermore plant 23
8 Filter circulation sump in original plant 24
9 Filter circulation sump in upgraded plant 26
10 Schematic diagram for filter circulation sump
modification 28
11 Possible modifications for activated sludge feed 29
12 Mixed liquor wasting tank 30
13 Piping diagram for original plant 31
14 Piping diagram for upgraded plant 32
15 Aeration diffusers 38
16 Construction activity 42
vii
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FIGURES (continued)
Number Page
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Aeration blower equipment
Aeration tank reinforcing steel placement in progress . . .
Secondary clarifier structure and mechanical equipment . .
Chlorine storage area
Progress payment rates for major construction items . . .
Cumulative progress payments
Startup sequence for activated sludge process
Activated sludge aeration tank in operation
Ammonia nitrogen removal and blower operation
Photoelectric probe for sensing sludge blanket height . . .
Photoelectric probe being lowered into secondary
clarifier . .
Operations building, Livermore Water Reclamation
Plant
Demonstration of manual sampling technique
Plant analytical laboratory
Probability curves for secondary and final effluent
BOD5
Probability curves for secondary effluent ammonia
nitrogen
Probability curve for final effluent total coliform
organisms
44
45
46
47
51
52
56
57
59
60
60
63
63
66
66
70
71
72
viii
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FIGURES (continued)
Number Page
35 Monthly average, peak-day, and minimum-day flows . . 74
36 Probability curve for peak-to-average flow ratio .... 75
37 Typical diurnal flow variation 76
38 Primary sedimentation tanks 77
39 Primary clarifier performance 78
40 Effect of settling on trickling filter effluent BOD5 .... 81
41 Flow and loading to aeration tank 85
42 Aeration tank dissolved oxygen levels 86
43 Mixed liquor leaving aeration tank over a circular
weir - 88
44 Constant-head tank in the mixed liquor line for
wasting activated sludge 89
45 Secondary clarifier 93
46 Secondary clarifier performance versus hydraulic
loading 94
47 Secondary clarifier performance versus solids
loading 94
48 Original chlorination control system 95
49 Relative amounts of HOC1 and OCl at various pH
levels 97
50 Disinfection performance 98
51 Chlorine contact tank 99
52 Residence time distribution for chlorine contact tank . . 100
ix
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FIGURES (continued)
Number Page
53 Digester gas production 104
54 Sludge lagoons 105
55 Typical annual reclamation pattern 107
56 Flow and annual operating parameters 118
57 Lompoc, California, Regional Waste water
Reclamation Plant flow diagram 122
58 ~ Corvallis, Oregon, wastewater treatment plant flow
diagram 125
59 El Lago, Texas, wastewater treatment plant flow
diagram 126
60 San Pablo, California, wastewater treatment plant
flow diagram 129
61 Effect of solids retention time on effluent ammonia
concentration and nitrification efficiency 139
62 Relation between ammonia nitrogen peaking and
hydraulic peaking for treatment plants with no in-
process flow equalization 148
63 Air requirements for oxidation of carbonaceous and
nitrogenous oxygen demand 152
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TABLES
Number Page
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Design Data for Original Livermore Plant
Performance of Original Plant, 1964
Design Data for Upgraded Livermore Water
Reclamation Plant
Bid Tabulation
Contract Price Breakdown . . .„
Rainfall and Evaporation During Construction Period . . .
Total Construction Cost
Plant Performance: April- December 1967
Principal Sampling Methods and Locations
Wastewater Characteristics Analyzed at Principal
Sampling Points
Performance Summary
Trickling Filter Performance Summary, 1971
Trickling Filter BOD5 Removal
Trickling Filter Performance — Effect of Removing One
Filter from Service
Activated Sludge Performance Summary, 1971
13
15
18
34
35
36
41
53
58
65
67
68
79
82
83
84
xi
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TABLES (continued)
Number Page
17 Summary of pH Chlorination Control Studies 99
18 Disinfection Summary 101
19 Solids Handling and Treatment Summary 102
20 Design and Performance 109
21 Estimated Cost for Expansion of Original Livermore
Plant to 5.0 mgd (0.22 m /sec) Without Upgrading . . 115
22 Operation and Maintenance Costs, Livermore Water
Reclamation Plant 116
23 Work Load Distribution 116
24 Initial Performance of El Lago Treatment Plant — June 4
Through July 6, 1973 127
25 Subsequent Performance of El Lago Treatment Plant
— October 1 Through October 31, 1974 128
26 Performance Data for San Pablo Wastewater Treatment
Plant — July 1973 Through June 1974 130
27 Design Criteria for Upgraded Plants 131
xii
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ACKNOWLEDGMENTS
This study was undertaken for the U.S. Environmental Protection Agency
under Contract No. 68-03-2175 by Brown and Caldwell, Consulting
Engineers, Walnut Creek, California. Richard J. Stenquist and Denny S.
Parker are project engineer and vice president, respectively, for Brown
and Caldwell. William E. Loftin is Superintendent of the Livermore Water
Reclamation Plant and acted as special consultant for the study. Richard
C. Brenner was EPA Project Officer.
Other individuals at Brown and Caldwell who participated in design and
construction of the Livermore Water Reclamation Plant and who contributed
to this study are David H. Caldwell, David L. Eisenhauer, Nestor D.
Vivado, and Warren R. Uhte. We are particularly indebted to the City of
Livermore and the staff of the Livermore Water Reclamation Plant for
information and assistance provided during the course of the study.
xlii
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SECTION 1
INTRODUCTION
Current emphasis in the United States on reducing the level of contam-
inants in wastewater effluents has resulted in many communities finding that
their wastewater treatment facilities, although well designed, constructed,
and operated, cannot meet the stringent, new discharge requirements imposed
by regulatory agencies. It is sometimes more economical to abandon recently
constructed facilities in favor of completely new plants designed to provide
better treatment, but often it is possible to incorporate all or part of existing
plants into upgraded facilities capable of producing the high quality effluent
required today.
Trickling filters using rock media have long been a common form of
biological treatment in the United States. Used mostly in small and moderate
size communities, they are capable of providing good removal of organic con-
taminants and are noted as being stable, reliable, and economical. By them-
selves, however, rock trickling filters (preceded by primary treatment) cannot
provide the high effluent quality often required today. Discharge requirements
often specify much lower levels of 6005, suspended solids, and coliform
organisms than in the past, and ammonia, nutrient, and toxicity removal may
also be required.
For a community utilizing trickling filtration, the most economical way to
meet more stringent discharge requirements may be to incorporate the existing
filters in an upgraded facility. The reliability, resistance to upsets, and
efficient organic removal provided by trickling filters can be used to advan-
tage in developing a treatment scheme to consistently and economically pro-
duce a high quality effluent.
The City of Livermore, California (Figures 1 and 2), followed such a
course in upgrading its wastewater treatment facility to meet new disinfection
requirements imposed in 1965 by the California Regional Water Pollution Con-
trol Board, San Francisco Bay Region. Livermore is located approximately 70
km (45 mi) east of San Francisco in an area where rapid urbanization over the
last 30 yr has led to serious water and wastewater management problems.
The Livermore-Amador Valley contains the city of Livermore, the nearby Uni-
versity of California Lawrence Livermore Laboratory, the city of Pleasanton,
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02468
nsa
SCALE IN MILES
SAN
FRANCISCO
WATERSHED
BOUNDARY,
ALAMEDA CREEK
ABOVE MILES
SANTA CLARA COUNTY
Figure 1. Location of Livermore Water Reclamation Plant.
and the unincorporated communities of Dublin and San Ramon. The valley is
part of the Alameda Creek watershed above the Niles district of the City of
Fremont, California, and has an area of approximately 1,700 km2 (660 mi2).
Although Alameda Creek is tributary to San Francisco Bay, much of the concern
over water quality centers on the creek itself and on the Niles cone, a ground-
water basin which is recharged by waters flowing from Alameda Creek. In-
creased use of local surface water and groundwaters in the Livermore-Amador
Valley, coupled with increased wastewater flows, has resulted in salinity
increases in downstream waters and concern for possible health problems
resulting from recreational use of local streams.
As part of a multifaceted effort to improve water quality in the area, the
Regional Water Pollution Control Board adopted on July 15, 1965, stringent
new discharge requirements for the City of Livermore's wastewater treatment
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Figure 2. Aerial view of Livermore - Amador
Valley. Rapid urbanization in
recent years has led to serious
water quality problems.
plant (Resolution No. 683, see Appendix B). These discharge requirements
included a provision that the 5-day median total coliform concentration not
exceed 5.0 MPN/100 ml. To meet this requirement, the existing Livermore
plant, during expansion from an average dry weather flow (ADWF) capacity of
0.11 m3/sec (2.5 mgd) to 0.22 m3/sec (5.0 mgd), was upgraded from a con-
ventional trickling filter system to a coupled trickling filter-activated sludge
plant capable of producing a nitrified effluent which can be economically dis-
infected to the required level.
This report has been prepared to describe the upgrading of the Livermore
plant, including planning, design, construction, startup, and operation and
performance over a 7-yr period from January 1968 through December 1974.
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Construction and operating costs are also presented, along with general
design considerations for upgrading trickling filter plants to the coupled
trickling filter-activated sludge mode.
OBJECTIVES AND SCOPE
This review of the Livermore plant upgrading has been undertaken to
make available information which may be useful to communities and engineer-
ing consultants who are faced with situations similar to that which occurred
at Livermore. Because the upgraded Livermore Water Reclamation Plant has
been in operation since 1967, a substantial quantity of operating data are
available for study so that a detailed evaluation of plant performance can be
developed.
Specific objectives are identified as follows:
1. Present information on conversion to the upgraded facility. This
includes preliminary planning, detailed design, construction, and
capital costs. Special emphasis is given to incorporation of nitri-
fication in the process flow sheet and the relationship between the
added activated sludge unit and other unit processes.
2. Review operation of the upgraded plant. Difficulties encountered in
startup and operation are discussed, along with operational tech-
niques developed to counter such problems. Performance data for
the startup period and the 7-yr operational period that followed are
presented. Particular attention is given to comparing performance
with design objectives. Operation and maintenance costs are also
documented.
3. Develop general design considerations for upgrading conventional
trickling filter plants to the coupled trickling filter-activated sludge
operational mode. Experience from the Livermore plant is empha-
sized, but information from other planned or constructed plants with
similar flow sheets is also utilized. Special emphasis is given to
process design for nitrification in the activated sludge unit.
OUTLINE OF REPORT
This report has been organized to present first a chronological history of
the Livermore plant and then to discuss specific aspects of plant operation
and performance before setting out general design considerations. Sections 4
through 8 review the background, design, construction, startup, and operation
of the Livermore Water Reclamation Plant. The specific task of comparing
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performance with design objectives is also covered in Section 8. Section 9
reviews in detail both capital and operating costs for the Livermore plant.
Information developed in Sections 4 through 9 is then augmented by informa-
tion from other sources for presentation in Section 10, General Design Con-
siderations.
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SECTION 2
CONCLUSIONS
Use of the coupled trickling filter-activated sludge process for biologi-
cal waste water treatment at Livermore, California, has resulted in reliable,
consistent production of a wastewater effluent low in BOD5, suspended sol-
ids, ammonia nitrogen, and coliform organisms. Constructed on the site of
a conventional rock media trickling filter plant, the upgraded plant (Figure 3)
utilized many portions of the original facility. The excellent performance of
the plant since it was placed in operation in 1967 suggests that the coupled
trickling filter-activated sludge process should be considered by communities
which operate existing trickling filter plants that cannot meet new, more
stringent discharge requirements imposed by regulatory agencies.
The trickling filter acts as a roughing filter ahead of the activated sludge
process to remove carbonaceous oxygen demand. Nitrification in the aeration
tank removes ammonia nitrogen from the waste stream and further reduces the
carbonaceous BOD. The principal advantage of the roughing filter is the pro-
tection it provides for the more easily upset activated sludge process and for
the nitrifying organisms which are susceptible to toxic materials. Acting as
a buffer, it ensures a stability of operation that is not associated with the
activated sludge process alone. Where existing facilities are in good condi-
tion and space is available, upgrading to the coupled trickling filter-acti-
vated sludge process can be undertaken to provide nitrification, either where
ammonia nitrogen removal is desired or ahead of subsequent denitrification
for nitrogen removal.
Specific conclusions can be drawn from the operation of the Livermore
Water Reclamation Plant, from recent designs of other coupled trickling filter-
activated sludge plants, and from the nitrification process kinetics of the
trickling filter-activated sludge process:
1. Secondary effluent BOD^ and suspended solids concentrations
of 10 to 20 mg/1 can be obtained with the coupled trickling
filter-activated sludge process, along with ammonia nitrogen
concentrations of less than 1 mg/1 (nitrification at Livermore
may have been limited by an inadequate air supply). Monthly
median total coliform organism concentrations of 2.1 MPN/100 ml
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Aerial view of upgraded Livermore Water
Reclamation Plant. Plant was upgraded
by placing an activated sludge unit
between rock media trickling filters and
secondary clarifier in flow diagram.
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and 7-day medians of 5.0 MPN/100 ml can also be consistently
obtained if the coupled process is combined with efficient disin-
fection.
2. In designing solids handling facilities for an upgraded plant, account
must be taken of the increased solids production associated with in-
creased BOD removal and the associated difficulty in dewatering the
waste activated sludge produced.
3. Use of emergency holding basins can ensure that discharge of in-
adequately treated effluent will not occur during periods when
process units are shut down. Existing oxidation ponds can often
be modified for use as holding basins.
4. As existing secondary clarifiers will normally need to be modified
substantially to accommodate the activated sludge process, it may
be economical to convert them to other uses in the upgraded plant
and to construct new secondary clarifiers. Possible conversions
include primary sedimentation, sludge thickening, and chlorine
contact.
5. The most efficient use of existing facilities will differ for each
individual case, and considerable ingenuity may be required to
determine the best approach.
6, The characteristics of unsettled trickling filter effluent have not
been studied extensively; this hinders the application of rational
design methods to the coupled trickling filter-activated sludge
process.
8
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SECTION 3
RECOMMENDATIONS
This study has shown that the coupled trickling filter-activated sludge
process as used at Livermore, California, is an extremely stable wastewater
treatment process capable of producing a nitrified effluent low in BOD5 and
suspended solids. Principal recommendations for future study pertain to the
necessity of developing information for use in process design of the coupled
trickling filter-activated sludge system. Specifically, the characteristics of
unsettled trickling filter effluent must be better defined in order to fully de-
velop a rational design procedure for the process.
Measurements of biochemical oxygen demand on unsettled trickling filter
effluent will reflect both unoxidized waste material passing through the trick-
ling filter and biological solids sloughed from the filter media. Data from
Livermore indicate that a reasonable estimate is that 50 percent of the BODs
measured on an unsettled sample is due to sloughed material, but further
evaluation is needed.
Further work is also needed to predict the quantity of organisms entering
the aeration tank from the trickling filter and whether they can be treated in
the same manner as organisms which grow in the aeration tank. In this report
a net yield coefficient is applied to the BOD5 removed in the roughing filter to
obtain a value for cell concentration entering the aeration tank. Values for
this net yield coefficient should be determined as well as decay rate coeffi-
cients for cells in the aeration tank.
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SECTION 4
BACKGROUND
The City of Livermore, California, was first settled in 1869 when the
Southern Pacific Railroad constructed a depot in the area. Named after one
of its early settlers, Robert Livermore, the City was incorporated 7 yr later
in 1876. The City was mostly a farming community in its early days with
grain and cattle its main commodities, and even today agricultural activity
remains an important part of the area's economy. Prior to 1927 sewage treat-
ment was effected in a community septic tank with discharge to land. In that
year an Imhoff tank and percolation beds were constructed west of the City
The plant was expanded in 1942 by the addition of a comminutor and a primary
clarifier* operating in parallel with the Imhoff tank.
After World War II, the City and the Livermore-Amador Valley experienced
the rapid growth associated with the San Francisco Bay Area as a whole. This
resulted in overloading of the treatment plant with consequent odor problems,
principally from sludge disposal. Additionally, wells near the disposal area
were found to contain 40 to 60 mg/1 of nitrate, posing a possible public
health hazard. Nominal capacity of the treatment plant was 0.025 mVsec
(0.58 mgd), and development in the Livermore area was being hindered by
lack of adequate wastewater treatment and disposal facilities.
In 1956,the City began development of a plan for construction of new
treatment and disposal facilities and improvements to the existing sewerage
system. The resulting facility, designed by Brown and Caldwell, Consulting
Engineers, was a O.ll-m^/sec (2.5-mgd) plant located approximately 3 km
(2 mi) west of the city center on existing farmlands. Plant units consisted of
preliminary treatment, primary clarification, trickling filtration, secondary
clarification (in clarifiers intended for conversion to primary sedimentation
tanks during future expansion), and tertiary oxidation ponds. The layout of
the plant as well as the sizing of many units was based on expected ultimate
expansion to an average dry weather flow of 0.44 m^/sec (10 mgd) with
*The terms "clarifier" and "sedimentation tank" are used synonymously in
this report.
10
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hydraulic capacity for 1.6 mVsec (36 mgd). The flow diagram and layout for
the original plant are shown in Figures 4 and 5, respectively. Design data
are presented in Table 1.
Design 6005 and suspended solids removals were 85 percent for primary
plus secondary treatment; these removals corresponded to secondary effluent
concentrations of 50 mg/1 for BODs and 35 mg/1 for suspended solids. Plant
performance data for 1964 are showi in Table 2. Discharge requirements for
the original plant are presented in Appendix A (Regional Water Pollution Con-
trol Board Resolution No. 239, adopted March 21, 1957).
The plant was put into operation in 1957. Although under design condi-
tions effluent was to be discharged from the ponds to Arroyo Las Positas
(which is tributary to Alameda Creek), high percolation and evaporation rates
from the oxidation ponds prevented any surface discharge for several years.
In late 1962 and in 1963 increased flows coupled with clogging of the infiltra-
tive surfaces in the ponds resulted in periodic discharges to the sometimes
dry stream. Complaints about color and detergent foaming in the receiving
waters occurred immediately. At this time a chlorine contact tank was added
to the flow diagram ahead of the oxidation ponds to provide disinfection.
A fortuitous coincidence was the cessation of nonbiodegradable detergent
(alkylbenzenesulfonate or ABS) manufacturing in the United States. Substitu-
tion of linear alkylate sulfonate (LAS) in home laundry detergents resulted in
elimination of the foaming problem within a few months.
In the period 1963-65, the City's population grew rapidly at an annual rate
of 15-20 percent. In April 1964,a feasibility study prepared for the City by
Brown and Caldwell recommended expansion of the existing plant to 0.22 m3/
sec (5.0 mgd) capacity utilizing essentially the same treatment scheme.
However, because of the surface water quality problems which had re-
cently occurred, subsequent discharge requirements issued in July 1965 by
the San Francisco Bay Regional Water Pollution Control Board (Appendix B)
called for effluent BOD^ and suspended solids concentrations of 20 mg/1;
grease, 5 mg/1; settleable solids, 0.5 ml/1; and total coliforms, 5.0 MPN/
100 ml, based on a 5-day median. (The disinfection requirement was subse-
quently changed in 1971 to 2.2 MPN/100 ml, based on a 7-day median.)
The disinfection requirement was unusually stringent and for effluent
from a conventional secondary treatment plant would have required the addi-
tion of sufficient chlorine to react with all the ammonia present in the waste-
water in order to produce free chlorine residuals. The result would have been
high operating costs and possible adverse side effects such as odors and toxic
effects in receiving waters.
11
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EAST
TRUNK 39'
METERING
TV<2'x1
Tw*(
i |
i
!L
i .
T^
PREAERATION
TANKS
SECONDARY
SEDIMENTATION TANK
PRIMARY
SEDIMENTATION TANK
—
1
$ •
I 1
SECONDARY I
RETURN 1
CONTROL VALVE 1
^ •
— *u
.-- — --^
I TRICKLING
DIVERSON STRUCTURE FOR
FUTURE CHLORINE CONTACT TANK
BAR SCREENS INFLUENT
PUMPS SBIT _
(3) WASHER
SOUTH
TRUNK
2«*
if
J RAW SLUDSE SUMP """"
SLUDGE CIRCULATION
T SLUDGE PUMPS , ^PUMPSIZ)
(2)
WASTE GAS
f~| BURNER
EFFLUENT TO
ARROYO LAS POSITAS
GAS CIRCULATION PUMPS (Z)
FUTURE SLUDGE
DRYING BEOS
Figure 4, Flow diagram for original Livermore plant.
OXIDATION POND NO.]
SO 0 _ 5O \OO
OXIDATION POND NO 2
POND INLET
STRUCTURE
SLU06E
ORYIMO
teas
/ ^ / \ ~I~_
/ FUTURE I • FUTURE \ \
FILTER [ FILTER I I
\ I \ It FUTURE SEDIMENTATION
\ / \ / ! TANKS
\
I FUTURE DIGESTERS i
\ > \
WELL SLAB-) 1
Figure 5. Layout of original Livermore plant.
12
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TABLE 1. DESIGN DATA FOR ORIGINAL LIVERMORE PLANT
Design Factor
Value
Design Factor
Value
Initial design, average dry weather
Initial design, maximum dry weather
Initial design, peak storm rate
Future design, average dry weather
Future design, maximum dry weather
Future design, peak storm rate
Design Loadings
Initial design, population equivalent
Future design, population equivalent
Suspended solids, Ib/day*5
Per capita
Initial design
Future design
BOD 5, lb/dayb
Per capita
Initial design
Future design
Incoming Sewer
Diameter, ln.cg
Capacity, mgda
Bar Screens
Number
Initial design
Future design
Width, f^'1
Water depth, (maximum) ft
Water area, ft2 e
Velocity through bar screen, ft/sec"
Present minimum (one channel)
Initial design, ADWF (one channel)
Initial peak storm rate (one channel)
Future design, ADWF (two channels)
Future peak storm rate (two channels)
Parshall Flumes
Number
Throat width, ln.c
Discharge head, ft4
Present minimum (one channel)
Initial design, ADWF (one channel)
Initial peak storm rate (one channel)
Future design, ADWF (two channels)
Future peak storm rate (two channels)
Raw Sewage Pumps
Number
Capacity each, mgda
Static lift, ftd
Preaeratlon Tanks
Number
Initial design '
Future design
Width, ft?
Length, ftd
Average water depth, ft"1
Detention time, hr (one tank)
Air supplied per tank, ft3/mlnf-3
Air supplied. ftVga!9
Maximum hydraulic capacity, mgda
2.5
4.5
10.0
10.0
19.5
36.0
28,900
129,000
0.15
4,300
19,000
0.20
5,800
26,000
42
38
1
2
4
3.5
14
0.9
1.5
2.5
1.3
2.0
2
15
0.25
0.84
2.1
1.3
3.1
3
12
11
2
4
19
38
11.7
0.6
200
0.12
10
Primary Sedimentation Tanks
Number
Initial design 4
Future design
Width, ftd
Length, ft"1
Average water depth, ft
Effluent weir length per tank, ft'
Detention time, hr
Mean forward velocity, ft/mind
Overflow rate at ADWF, gpd/ft2h
Maximum hydraulic capacity, mgda
Assumed removals, percent
Suspended solids
BOD5
Secondary Sedimentation Tanks
Number
Initial design 4
Future design
Width, ftd
Length, ftd
Average water depth, ft
Detention time, hr
Trickling Filter Circulation Pumps
Number
Initial design
Future design
Maximum capacity per unit, mgda
No. 1 (No's 3, 4, 6 future)
No. 2 (No. 5 future)
Average static lift, ft
Trickling Filters
Number
Initial design
Future design
Inside diameter, ft
Average depth of filter media, ft
Size of filter media, ln.c
Net area of filter surface, ft26
Volume, 1,000 ft3/filter£
Circulation ratio to ADWF
Loading
Rate per filter, mgda
Rate per unit surface area, gpd/ft
BGDr, lb/1,000 ftVday1
Assumed removal, filter plus secondary
sedimentation, percent
Suspended solids
BOD 5
Oxidation Ponds
Total area, acres'
Initial design
Future design
Average water depth, ft
Detention time, days (neglecting evaporation
and seepage)
At design ADWF (2.5 mgda)
At future ADWF (10.0 mgda)
BOD5 loading, Ib/acre/day*
Initial design
Future design
2
4
19
124
9
164
1.5
1.4
1,050
10
60
35
0
4
19
160
9
2.0
2
6
7.6
3.8
12.5
1
4
110
4.25
2 to 4
0.218
0.92
1.5 to 3.0
7.5
34.5
110
60
75
37
150
6
30
30
28
28
(continued on next page)
13
-------
TABLE 1. (continued)
Design Factor
Value
Design Factor
Value
Digestion Tanks
Number
Initial design 2
Future design 4
Inside diameter, ft
Initial two tanks 35
Future two tanks 55
Side water depth 5, ftd 27.5
Volume, 1,000 ft3£
Initial tanks S3
Future tanks 157
Total future volume, four tanks 210
Loading, 1,000 Ib dry solids/day15
Initial design 3.8
Future design 16
Unit loading, Ib dry sollds/ft3/day1
Initial design 0.07
Future design 0.08
Assumed solids reduction, percent 45
Assumed gas production at 6.0 ft3/lb
settleable solids™
Initial design, 1,000 ft3/da/ 23
Future design, 1,000 ft3/day* 96
Dry sludge produced, 1,000 Ib/dayb
Initial design 2.1
Future design 8.8
Assumed moisture of digested sludge, percent 95
Volume of digested sludge produced. 1,000 ftVday*
Initial design 0.7
Future design 2.8
Sludge Drying Area. ft2 e
Drained beds
Initial design 22,400
Future design 112,000
Undralned area
Initial design 62,000
Future design 0
NOTES:
1. Channel width of three feet used for initial installation.
For future use, both bar screen channels will be increased
to four feetd width.
2. One preaeratlon tank will be used Initially to aerate trickling
filter effluent prior to secondary sedimentation.
3. For initial design conditions, 200 ft3/minf will be supplied
to primary aeration tank and 100 ft3/minf will be supplied
to secondary aeration tank.
4. One primary sedimentation tank will be used initially for
secondary sedimentation.
5. Future tanks may be constructed with side water depths of
33 ftd. Volume of future tanks computed with 33-ft" side
water depth.
amgd x 0.0438 = m3/sec
blbx 0.4S3 =kg
Cin. x 2.54 - cm
dftx 0.305 = m
eft2 x 0.093 = m2
fft3 x 0.028 = m3
9ft3/galx7.4S = m3/m3
hgpd/ft2 x 0.0407 • m3/day/m2
'lb/1,000 ft3/day x 0.016 = kg/m3/day
acres x 0.415 = hectares
Ib/acre/day x 1.12 = kg/hectare/day
'ib/ftVday x 16.2 = kg/m3/day
raft3/lb x 0.0624 - m3Ag
By incorporating nitrification (conversion of ammonia nitrogen to nitrate
nitrogen) in the treatment process, free chlorine residuals can be obtained
with much lower chlorine dosages. Rock trickling filters, as were used at
Livermore, cannot be depended upon to produce a nitrified effluent of the
required quality. Used in advance of the activated sludge process, however,
trickling filters can reduce the BOD5 loading sufficiently to allow nitrifica-
tion to proceed in the activated sludge aeration tank. Utilizing a coupled
trickling filtration-activated sludge process at Livermore allowed upgrading
of the plant without abandoning any of the existing facilities, which were
less than 10 yr old. Using roughing filters also resulted in a more stable
overall biological process, with the filters acting as a buffer to protect
the more easily upset activated sludge process, an important aspect when high
quality effluent must be consistently produced.
14
-------
TABLE 2. PERFORMANCE OF ORIGINAL
PLANT, 1964
Parameter
Influent
Flow, mgd
BOD,, mg/1
Suspended solids , mg/1
Primary Treatment
f) L.
Overflow rate, gpd/ft
Effluent BOD5 , mg/1
Effluent suspended solids, mg/1
Reduction, percent
BOD5
Suspended solids
Secondary Treatment
Organic loading, lb/1 , 000 ft /day°
Effluent BOD_, mg/1
o
Effluent suspended solids, mg/1
Reduction, percent
BOD,
J
Suspended solids
Overall Reduction, Percent
BOD5
Suspended solids
Value
2.4
260
350
1,000
ISO
110
42
69
74
51
44
66
60
80
87
amgd x 0.044 = m /sec
bgpd/ft2 x 0.041 = m3/m2/day
Clb/l,000 ftVday x 0.016 = kg/m /day
At the time that plans were under-
way to expand and modify the treat-
ment plant, consideration was being
given to utilizing plant effluent for
irrigation purposes. As noted previ-
ously, rapid population growth had
depleted local water spplies, and im-
portation of water from other areas
had become necessary. Farmlands
existed near the treatment plant, and
the City was carrying out plans to
construct an airport and golf course in
the area. Because of these circum-
stances and because of possible prob-
lems with surface discharge of effluent
even though highly treated, the City
began at that time development of a
water reclamation program which has
continued and expanded over the
years.
Imposition of a "no-discharge"
order by the Regional Board required
that the plant be designed and con-
structed as rapidly as possible. A
discussion of plant design, with
emphasis on utilization of existing
facilities, is presented in Section 5.
15
-------
SECTION 5
DESIGN
When the Regional Board issued new, more stringent discharge require-
ments in 1965, the original Livermore plant was only 7 yr old. Further,
piping and pumping facilities had been constructed to allow exapnsion from
0.11 m3/sec (2.5 mgd) to 0.22 m3/sec (5.0 mgd) for the Stage 2 facility and
ultimately to 0.44 m^/sec (10 mgd). These factors encouraged retention of
as much of the original facility as possible and allowed inclusion of a previ-
ously planned additional trickling filter in the revised expansion.
Discussion of plant design can be divided into two aspects: process
design and physical design. Although these aspects cannot be totally di-
vorced from each other, the differentiation is useful in describing the design
of the Livermore plant upgrading. Process design includes the interrelation-
ship among projected influent loadings, required effluent characteristics,
anticipated removals in each unit process, and sizing of added unit pro-
cesses. Physical design is intended to include such factors as general lay-
out, site piping, bypassing procedures, and flexibility for present operation
and future expansion. The flow diagram for the expanded plant is shown in
Figure 6, and design data are given in Table 3.
PROCESS DESIGN
The principal component of interest at the Livermore Water Reclamation
Plant is the biological treatment unit, which uses trickling filtration in series
with the activated sludge process followed by secondary clarification. Other
important units of the Livermore plant are the primary sedimentation tanks,
whose performance determines the loading to the secondary treatment process;
the chlorination unit and the chlorine contact tank, which must reduce coli-
form concentrations to levels meeting disinfection requirements; and solids
handling facilities, which at Livermore consist of two mixed digesters fol-
lowed by sludge lagoons. The design of each of these elements, particularly
as they relate to the secondary treatment process, is discussed below.
16
-------
BYPASS AND RET
Figure 6. Flow diagram for upgraded Livermore
Water Reclamation Plant.
Coupled Trickling Filter-Activated Sludge Process
As noted in Section 4, the controlling factor in process design was the
discharge requirement mandating a 5-day median total coliform concentration
of 5.0 MPN/100 ml. To prevent excessive chlorine demand, it was essential
to oxidize ammonia nitrogen in the wastewater to the nitrate form. Free
rather than combined chlorine residuals would then be formed which could
provide the required wastewater disinfection at much lower chlorine dosage
levels.
In the mid-19601 s,nitrification was not commonly used in wastewater
treatment plants in the United States and thus nitrification kinetics and
proper design criteria were not well documented. The approach taken in de-
sign was to use a low organic loading in the biological treatment process to
attain nitrification. In developing this approach, it was assumed that trick-
ling filter volume was equally as effective as aeration tank volume in bio-
logically treating wastewater.
17
-------
TABLE 3. DESIGN DATA FOR UPGRADED LIVERMORE
WATER RECLAMATION PLANT
Design Factor
Value
Design Factor
Value
Second stage design, average dry weather 5.0
Second stage design, maximum dry weather 10.0
Second stage design, peak storm rete 18.0
Future design, average dry weather 10.0
Future design, maximum dry weather 19.5
Future design, peak storm rate 36.0
Design Loadings
Second stage design, population equivalent 62,500
Future design, population equivalent 129,000
Suspended solids, Ib/day"
Per capita 0.20
Second stage design 12,500
Future design 25.600
BOD 5. Ib/daj*
Per capita 0.2
Second stage design 12,500
Future design 25,600
Screening Equipment
Barminutor
Number 1
Capacity, mgda 14.5
Comminutor
Number 1
Capacity, mgda 11
Parshall Flumes
Number 2
Throat width, ln.c 15
Discharge head, ft*
Two channels, ADWF 0.84
One channel, ADWF 1.3
Raw Sewage Pumps
Number 2
Capacity each, mgda 12 5
Static lift. 11? 11
Preaeratlon Tanks
Number 2
Width, ft* 19
Length, ftd 38
Average water depth, ft 11.7
Detention time. hr 0.6
Air supplied per tank, ft3/mine 150
Hydraulic capacity, mgda 10
Primary Sedimentation Tanks
Number 2
Width, ftd 19
Length, ft 124
Average water depth, ft 9
Effluent weir length per tank, it? 164
Detention time, hr 1.5
Mean forward velocity, fpm£ 1.4
Overflow rate at ADWF, gpd/ft29 1,050
Hydraulic capacity, mgda 10
Primary Treatment
Assumed suspended solids reduction
Percent
lb/dayb
Assumed BOD^ reduction
Percent
lb/dayb
Trickling Filters
Number
Inside diameter, ftd
Average filter media depth, ft
Filter media size, in.c
Net area of filter, ft2 h
Volume, 1.000 ft3/fliter1
Circulation ratio to ADWF
Load ing
Hydraulic loading, gpm/ft2'
Organic loading, Ib BOD5/1,000 ft3/day
Assumed BOD5 reduction
Percent
Ib/day13
Trickling Filter Circulation Pumps
Number
Capacity each, mgda
No.'s 1 and 3
No. 2
Average static lift, ft
Activated Sludge Aeration Tanks
Number
Passes per tank
Length per pass, ftd '
Width, ftd
Average water depth, ftd
Detention time based on raw sewage flow, hr
Air supplied. ft3/lb BOD5 removedl
Volume, ft31
Volumetric loading, Ib BODj/1,000 ft3/dayk
Return sludge, percent
Aeration Blowers
Number
Capacity each, ft /mine
60
7,500
35
4.400
2
110
4.25
2 to 4
9,500
40,000
1.5 to 3.0
0.55
100
50
4,000
7.6
3.8
12.5
1
2
160
30
15
5.2
1,200
144,000
28
10 to 100
3
2,000
Activated Sludge Influent Pumps
Number
Capacity each, mgda
No. 1
No. 2
Average static lift, ftd
Secondary Sedimentation Tanks
Number
Diameter, ft
Detention time at ADWF, hr
Overflow rate at ADWF, gpd/£t
.29
13.5
6.2
12.5
1
90
2.75
787
(continued on next page)
18
-------
TABLE 3. (continued)
Design Factor
Value
Design Factor
Value
Activated Sludge Treatment
Assumed suspended solids reduction
Percent
lb/dayt>
Assumed BOD5 reduction
Percent
lb/dayb
Overall Plant Performance
Assumed suspended solids reduction, percent
Assumed BODj reduction, percent
Effluent suspended solids, mg/1
Effluent BOD 5, mg/1
Chlorine Contact Tank
Volume . ft3 l
Detention time at ADWT. hr
Effluent Cipolletti Weir
Range , mgda
Size, ftd
Head at maximum flow , ft
Emergency Holding Basins
Storage volume, 1 ,000 ft3 '
Detention time at ADWT, hr
86
4,400
86
3,500
96
96
15
15
28,000
1.0
0 to 15
3
1.75
4,140
150
Digestion Tanks
Number
Inside diameter, ft
Side water depth , ftd
Volume, 1,000 ft3 *
Unit loading, ib dry solids/ft3/day
Assumed volatile matter, percent
Volatile matter, 1,000 Ib/day*
Assumed volatile matter reduction, percent
Volatile matter destroyed , 1,000 Ib/day
Assumed gas production, ft3/lb volatile matter
destroyed
Gas produced, 1,000 ftVday*
Assumed solids reduction, percent
Digested sludge, 1,000 Ib dry solids/dayb
Digested Sludge Lagoons
Number
Volume each, 1,000 ft3'
Sludge Drying Beds
Number ,
Total area , f t^
2
35
27.5
53
0.22
75
8.8
60
5.3
15
79
40
7.0
2
320
2
22,400
amgd x 0.0438 = mVsec
blb/day x 0.453 = kg/day
cin. x 2.54 = cm
dftx 0.305 = m
eftVmin x 0.028 = m3/min
fpm x 0.305 = m/min
9gpd/ft2 x 0.0407 = m3/day/m2
hft2 x 0.093 = m2
'ft3 x 0.028 = m3
'gpm/ft2 x 0.679 = l/sec/m2
klb/l, 000 ft3/day,x 0.016 = kg/m3/day
'ftVlbx 0.0624 = mVkg
"Wft3 x 16.2 = kg/m3
An overall loading of 0.56 kg BOD5/m3/day (35 lb/1,000 ftVday) of
aeration tank and/or trickling filter volume was used for design purposes.
On this basis, a biological treatment volume of 6,340 m3 (224,000 ft3) was
required, assuming a plant influent BODs loading of 5,670 kg/day (12,500
Ib/day) and a 35 percent BOD5 removal in the primary sedimentation tanks.
Adding the previously planned second trickling filter would provide a total
filter volume of about 2,260 m3 (80,000 ft3). This meant that an aeration
tank volume of 4,080 m3 (144,000 ft3) was required to provide the total
biological treatment volume of 6,340 m3 (224,000 ft3).
Such an approach was simplistic because it assumed an unproven equiv-
alency between filter volume and aeration tank volume and did not recognize
that nitrification would occur only in the aeration tank following the trickling
19
-------
filters. It was believed however that the approach was conservative be-
cause the series arrangement would provide treatment better than that pre-
dicted by considering the volume as a whole.
This approach also eliminated questions concerning feeding an activated
sludge unit with trickling filter effluent. The absence of a clarifier between
the trickling filters and the activated sludge process presented difficulty in
predicting the characteristics of the activated sludge influent (trickling filter
effluent). An estimate of 50 percent BOD5 removal in the filters was employed
in the design data shown in Table 3, but there was little documentation to
support this value. Further, there was concern that the filter effluent might
be less degradable than primary effluent with the same BOD5 value. Con-
versely, it was believed that trickling filter effluent BODs would in part reflect
biological solids sloughed from the filter media. By considering the trickling
filter and activated sludge units as one biological treatment plant, these
questions could be effectively ignored.
Since the mid-19601 s, the kinetics of nitrification and the criteria for
occurence of nitrification in the activated sludge process have become better
understood. Operation of the Livermore plant in terms of these considera-
tions, as well as problems caused by lack of adequate knowledge at the time
of design, will be discussed more fully in Sections 8 and 10. In particular,
it has been found that the air diffusion system capacity was underdesigned,
requiring the third blower (origianlly intended to be-a standby unit) to be used
to attain nitrification.
It is important to note that the flow diagram for the biological treatment
unit at Livermore differs from the Activated Bio-Filter, which also combines
the trickling filter and activated sludge processes. The Activated Bio-Filter
is a proprietary process which is distinguished by return of activated sludge
to the trickling filter influent line rather than the head of the aeration tank.
The filter thus acts as a reaeration chamber for the activated sludge.
Primary Sedimentation Tanks
The primary clarifiers at Livermore are rectangular and follow preaeration-
grit removal tanks in the treatment scheme. Both tanks were constructed with
the original plant, and one was used to provide secondary sedimentation
following the trickling filter. With the expansion from 0.11 to 0.22 m3/sec
(2.5 to 5.0 mgd), the secondary tank was converted to primary sedimentation
as planned, and a new secondary clarifier was constructed. Design removals
for the primary clarifiers are 60 percent for suspended solids and 35 percent
for BOD5 at an overflow rate of 42.8 m3/day/m2 (1,050 gpd/ft2) and a deten-
tion time of 1.5 hr.
20
-------
Secondary Clarifier
During plant expansion a 27-m (90-ft) diameter secondary clarifier
was constructed to provide separation of the activated sludge from the1
wastewater. The design overflow rate was 32 m3/day/m2 (787 gpd/ft2) at
ADWF, which corresponds to 114 m3/day/m2 (2,800 gpd/ft2) at peak wet
weather design flows. It was anticipated that such high rates could be
avoided by diverting peak flows to the abandoned oxidation ponds, and in
fact wet weather flows have been much lower than indicated in Table 3
Nonetheless, it appear that the high loading rates imposed on the secondary
clarifier have been the limiting factor in effluent BOD5 and suspended
solids levels achieved by the upgraded Livermore plant. A lower overflow
rate would probably be used today. Secondary clarifier performance will be
discussed further in later sections.
Disinfection Facilities
Although not part of the original plant, chlorination equipment and a
60-min detention chlorine contact tank were added to the 0.11-m-Vsec (2.5-mgd)
facility in 1965 after discharge from the oxidation ponds to Arroyo Las
Positas became necessary. During expansion, chlorine feed capacity was in-
creased from 0.11 to 0.22 m^/sec (2.5 to 5.0 mgd). Although chlorination
control by residual measurement through amperometric titration was used at
first, this method was abandoned after difficulties were encountered princi-
pally with maintenance of the amperometric titration units. Dosage control
by pH measurment has been used since. This is possible because the free
chlorine residuals which are obtained in a nitrified effluent cause a de-
crease in pH as chlorine dosage is increased. Although difficulties can
occur with this method of chlorination control (other factors may cause the
pH to decrease giving a false signal to the chlorination system and halting
disinfection), it has been employed with success at Livermore. Further dis-
cussion of chlorination control is presented in Section 8.
Solids Handling and Treatment Facilities
The two digesters constructed with the initial facility were retained, and
no additional capacity was provided for in the expansion to 0.22 m3/sec
(5.0 mgd). The flow increase, coupled with the addition of the activated
sludge process, increased the design unit loadings of the digesters from 1.1
kg dry solids/m3/day (0.07 Ib/ft3/day) to 3.5 kg/m3/day (0.22 Ib/ft3/day).
To maintain adequate digestion capacity, operation was changed frorA a pri-
mary-secondary mode to primary digestion in both digesters with newly con-
structed sludge lagoons acting as secondary digesters. The sludge drying
beds in the original plant were retained but have rarely been used. Super-
natant is periodically withdrawn from the lagoons and returned to the plant
21
-------
headworks. Occasionally the lagoons will have to be dried out and the
residual solids removed to landfill. After 8 yr of operation, they have
reached their capacity.
Summary
The modifications incorporated in the expansion actually involved rela-
tively minor changes in the flow diagram. The only significant change was
the placement of an activated sludge unit between the trickling filters and
the secondary clarifier, thereby substantially increasing the biological treat-
ment capacity and (through nitrification) disinfection efficiency of the plant.
PHYSICAL DESIGN
In the same way that the flow diagram was altered relatively little by
incorporation of the activated sludge process into the plant, most of the
construction involved expansion from 0.11 to 0.22 m3/sec (2.5 to 5.0 mgd)
as previously planned. Influent and primary effluent pumping capacities
were increased, the second trickling filter was added, the secondary sedi-
mentation tank was constructed, disinfection capacity was doubled, and
sludge lagoons (rather than a planned third digester) were added to increase
solids handling capacity. Principal changes from the previously planned ex-
pansion involved construction of the aeration tanks,- modification of the filter
circulation sump to allow its use as both a trickling filter circulation sump
and an activated sludge feed sump, construction of a secondary clarifier suit-
able for settling activated sludge mixed liquor, and abandonment of the oxi-
dation ponds with portions of them being used as emergency holding basins.
Layout of the expanded plant is presented in Figure 7. Comparison with
Figure 5 shows little deviation from the previously planned facility. The
second trickling filter was constructed as planned to the west of the existing
filter. The circular secondary clarifier was placed in the area originally in-
tended for rectangular clarlfiers. Space limitations caused by underground
piping were a factor in selection of clarifier diameter and, hence, overflow
rate.
A two-pass aeration tank was constructed in the area originally intended
for the third and fourth trickling filters. Provision was made for future con-
struction of an additional aeration tank to the north and for expansion of the
initial tank to the west. Such expansion was anticipated because the two
rock filters would not have adequate capacity to receive the ultimate design
flow of 0.44 m3/sec (10.0 mgd). It was expected that biological treatment
for future flow increases would be provided by activated sludge only. Recent
widespread use of plastic media in trickling filtration, however, indicates
22
-------
I I STAGE I
E3 STAGE 2
L~Ij FUTURE
EMERGENCY HOLDING BASIN
-~1 ' / -PONO INLET
EFFLUENT I \f—|/ STRUCTURE
-X-LL.
^BYPASS OUTLET STRUCTURE i
Figure 7. Layout of upgraded Livermore plant.
that it may be possible to increase the capacity of the existing rock media
filters by replacing the rock with plastic media and increasing the filter depth
(such expansion has not yet been carried out, however).
Most of the individual units are of standard design. The following sub-
sections present discussions on three aspects of physical design: (1) the
filter circulation sump, (2) the activated sludge unit, including the aeration
tank and secondary clarifier, and (3) plant piping, with particular emphasis
on bypass procedures.
Filter Circulation Sump
Plan and section views of the original filter circulation sump are shown
in Figure 8. Constructed to eventually serve four primary clarifiers and four
trickling filters at a design flow of 0.44 m3/sec (10 mgd), it was desired to
retain the unit for use in the coupled trickling filter-activated sludge plant.
In the original configuration, primary effluent entered the sump from the
channel to the south. Trickling filter effluent to be recirculated entered the
-------
6" DIGESTER
SUPERNATANT
LINE x
2" CHLORINE
SOLUTION
LINE —
30" DIAPHRAGM
OPERATED BUTTERFLY
VALVE
BLIND FLANGE
r 42" SECONDARY
EFFLUENT AND
BYPASS LINE
FUTURE TRICKLING
FILTER PUMPS NO'S
4. 5, AND 6
-TEMPORARY
PLUGS
FOR FUTURE
27" TRICKLING
FILTER EFFLUENT/
LINES <
36" TRICKLING
FILTER
INFLUENT
LINE
24" SECONDARY
EFFLUENT LINE
30" RECYCLED
TRICKLING FILTER
EFFLUENT LINE
FUTURE PUMP
NO. 3
TRICKLING FILTER
PUMP NO. 1
30" RECYCLED
TRICKLING FILTER
EFFLUENT LINE
r— SUMP BLOCKED OFF
FOR FUTURE USE
DIGESTER
SUPERNATANT
LINE
42" SECONDARY /
EFFLUENT AND '
BYPASS LINE —•>
Figure 8. Filter circulation sump in original plant.
24
-------
sump from the west through a 0.76-m (30-in.) diaphragm-operated butterfly
valve which was controlled by the sump level. Flow to the trickling filter
was provided by two fixed-speed pumps of 0.33- and 0.17-mVsec (7.6- and
3.8-mgd) capacities. Operation of the pumps was controlled manually from
a field station at the sump.
Filter effluent not recirculated was delivered to the secondary clarifier
(intended eventually for conversion to primary sedimentation). Effluent from
the secondary clarifier was delivered from a blocked-off portion of the primary
effluent channel through a temporary 0.61-m (24-in.) line to a concrete box
below the filter circulation sump. From there the secondary effluent flowed
through a 1.1-m (42-in.) pipe, originally to the oxidation ponds and later to
the chlorine contact tank. The concrete box below the filter circulation sump
also received primary effluent which overflowed into the box upon shutdown
of the trickling filter pumps, thus serving as an automatic bypass unit.
The 0.76-m (30-in.) butterfly valve responded to sump level to maintain
a constant flow to the trickling filter by automatically closing as the primary
effluent flow increased (causing a sump level increase) and opening as it
decreased. It,therefore, allowed use of fixed-speed pumps rather than vari-
able-speed pumps for feeding the trickling filter.
Modifications made to the trickling filter circulation sump during plant
expansion are depicted in plan and section in Figure 9. The existing second-
ary clarifier was converted to a primary clarifier as planned, and the old
secondary influent and effluent lines were blocked off. The temporary ma-
sonry plug blocking off the north portion of the sump was removed, and two
aeration tank feed pumps were installed there. A third trickling filter feed
pump with a capacity of 0.33 m^/sec (7.6 mgd) was also installed.
To permit use of fixed-speed pumps for feeding both the trickling filters
and aeration tank, the 0.76-m (30-in.) butterfly valve was relocated on the
discharge side of the aeration tank feed pumps as shown. Automatic control
is provided by a float switch which causes the valve to close as the level in
the sump increases. Normal operation calls for the smaller aeration tank
feed pump, with a capacity of 0.27 m^/sec (6.2 mgd), to run continuously.
If the sump level rises above a specified set-point elevation, the larger
pump (0.59-mvsec or 13.5-mgd capacity) starts and the smaller pump stops.
This operation is reversed by a falling sump level.
Shutdown of the trickling filter circulating pumps under this mode of
operation results in primary effluent being fed directly to the activated sludge
aeration tanks. Shutdown of the aeration tank feed pumps results in overflow
to the chlorine contact tank of a mixture of primary effluent and trickling
filter effluent.
25
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r
48" ACTIVATED
EXISTING
30" BUTTERFLY
VALVE RELOCATED
27" TRICKLING
FILTER EFFLUENT
LINES
ACTIVATED SLUDGE
FEED PUMPS
NO'S 1 & 2
- 30" TRICKLING
FILTER EFFLUENT
LINE
•TRICKLING FILTER
PUMPS NO'S 1, 2, & 3
PRIMARY -
EFFLUENT
CHANNEL
•TRICKLING
FILTER
PUMP
NO. 3
TRICKLING
FILTER INFLUENT
LINE
MA <.( LEV
LEV
BYPASS —
OVERFLOW
-ACTIVATED SLUDGE
FEED PUMP NO. 2
EXISTING 24" LINE
ABANDONED
30" TRICKLING
FILTER EFFLUENT
LINE
Figure 9. Filter circulation sump in upgraded plant.
26
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Schematic drawings of the circulation pumping schemes before and after
modification are given in Figure 10. Retention of the existing structure in
this manner allowed significant cost savings and avoided abandonment of a
facility less than 10 yr old.
Activated Sludge Unit
The activated sludge unit which receives trickling filter effluent con-
sists of, in addition to the aeration tank influent pumps, a two-pass aeration
tank, an air diffusion system, a secondary clarifier, and a sludge return
system. The aeration tank was constructed to allow feed of trickling filter
effluent and return activated sludge (RAS) at seven points to permit the unit
to be operated in plug flow (conventional), sludge reaeration, or step aera-
tion modes as shown in Figure 11.
Generally, the plant has been operated in the plug flow mode (although
significant back-mixing apparently does occur as discussed in Section 8)
with sludge reaeration used for a short period in 1971. Trickling filter efflu-
ent and return activated sludge are introduced to the tank at the east end of
the south pass. Mixed liquor flows from the south to the north pass through
a 4.9-m (16-ft) wide space in the dividing wall at the west end of the tank.
Mixed liquor leaves the aeration tank over' a 2.7-m (9.0-ft) diameter circular
weir at the end of the second pass and flows by gravity to the secondary
distribution box. There, an air-lift pump and a constant-head tank combine
to waste excess activated sludge mixed liquor to the plant headworks. The
rate of mixed liquor wasting is measured by a V-notch weir and is changed by
raising or lowering a circular overflow weir (Figure 12). Wasting of excess
activated sludge is normally accomplished in this manner although provision
has been made for wasting from the RAS line.
From the secondary distribution box,mixed liquor flows to the circular,
center-feed secondary clarifier. Clarified effluent flows to the chlorine
contact tank, and settled activated sludge is returned to the aeration tank.
The RAS pumps are two independent, variable-speed, self-priming pumps
which are manually controlled such that the RAS flow is a fixed percentage of
the influent wastewater flow. Automatic control could be implemented by
using a signal from the influent flowmeter to control pump speed.
Chlorine addition is provided by a diffuser and a flash mixer at the point
where clarified effluent enters a 1.4-m (54-in.) reinforced concrete pipe
connecting the secondary clarifier with the chlorine contact tank. This line
was built as part of the original plant and was used for bypassing from the
headworks to the oxidation ponds as discussed below.
27
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(CONST.)
FROM PRIMARY
SEDIMENTATION
TANK
0, (VAR.)
FILTER
CIRCULATION
SUMP
TO SECONDARY
SEDIMENTATION
TANK
BUTTERFLY VALVE
CONTROLLED BY
SUMP LEVEL
(CONST)
FROM PRIMARY
SEDIMENTATION
TANK
*1 (VAR.)
(a) BEFORE MODIFICATION
FILTER CIRCULATION SUMP
BUTTERFLY VALVE
CONTROLLED BY
SUMP LEVEL
4 (VAR.) jo ACTIVATED
^SLUDGE UNIT
(CONST.)
NOTE: SHORT CIRCUITING OF
PRIMARY EFFLUENT TO
ACTIVATED SLUDGE UNIT
WILL NOT OCCUR IF
°> Q
1
(b) AFTER MODIFICATION
Figure 10. Schematic diagram for filter circulation sump modification.
28
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ML
ML
RAS
WW
(a) CONVENTIONAL ACTIVATED SLUDGE
r
LML
ML (J -
RAS
1 — ww
«—
RAS
WW
(b) SLUDGE REAERATION
I WW
r
L
1 — ww
rww
o_
ML °^
ML
t
1 WW
4-
WW
RAS
(c) STEP AERATION
NOTE: ML = MIXED LIQUOR
RAS = RETURN ACTIVATED SLUDGE
WW = INFLUENT WASTEWATER
Figure 11. Possible modifications for
activated sludge feed.
Plant Piping
A schematic piping diagram for
the original plant, including antici-
pated expansions to 0.22 and 0.44
m3/sec (5.0 and 10.0 mgd) is shown
in Figure 13. When the decision was
made to incorporate the activated
sludge process into the upgraded treat-
ment scheme, it was desired to retain
as much of the existing piping as
possible to reduce costs. In addition,
the stringent discharge requirements
dictated that in the event of a system
upset or unit shutdown, some means
must be available to prevent discharge
of inadequately treated effluent. To
accomplish this, emergency holding
basins were constructed from a portion
of the original oxidation ponds and
flows were diverted from the plant
when necessary.
The piping diagram for the up-
graded plant is presented in Figure 14.
(In Figures 13 and 14, only the main
flow and bypass lines are shown;
solids transfer piping and various
other lines such as chlorine lines and
drains are not indicated.) Principal
modifications are the addition of lines
from the filter circulation sump to the
aeration tank, from the aeration tank
to the secondary clarifier, from the
filter circulation sump to the second
trickling filter and back, and from the
existing bypass line to the emergency
holding ponds. The existing 1.4-m
(54-in.) bypass line was used to
carry secondary effluent from the
secondary clarifier to the chlorine
contact tank and the newly construc-
ted outfall to Arroyo Las Positas.
29
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OVERFLOW
WEIR
V-NOTCH
WEIR
AIR-LIFT PUMP
ADJUSTING RINGS
MIXED LIQUOR
INFLUENT LINE
FROM SECONDARY
DISTRIBUTION BOX
MIXED LIQUOR
RETURN LINE
TO SECONDARY
DISTRIBUTION BOX
WASTE MIXED
LIQUOR LINE
TO PLANT
HEADWORKS
Figure 12. Mixed liquor wasting tank.
Bypassing procedures in the upgraded plant differ from those used in the
original configuration. In the trickling filter-oxidation pond mode, raw
sewage or primary effluent could be directed to the oxidation ponds for a
substantial period without overloading them. Further, because the ponds
would themselves provide adequate treatment, bypassed sewage did not need
to be returned to the plant.
30
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CHLORINE
CONTACT
TANK
Figure 13. Piping diagram for original plant.
In the upgraded mode, bypassing of the treatment units to Arroyo Las
Positas cannot be allowed if discharge requirements are to be met. There-
fore, when bypassing is necessary, flow is directed to the emergency holding
basins; when plant operation is restored, waste water is returned by gravity
to the headworks and passes through all the process units. From the head-
works (raw sewage) or secondary clarifier (secondary effluent), wastewater
flows to the holding basins through the existing 1.4-m (54-in.) bypass line
and a newly constructed 1.1-m (42-in.) line. From the filter circulation
sump (primary effluent or trickling filter effluent), bypass flow passes through
the old 1.1-m (42-in.) and 1.4-m (54-in.) lines connecting the sump with the
original pond inlet structure. An important operational aspect of the latter
case is that the poorly treated wastewater must pass through the chlorine
contact tank. It has been found that this contaminates the tank and creates
subsequent difficulties in meeting disinfection requirements unless the tank
is cleaned prior to being restored to service.
31
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Figure 14. Piping diagram for upgraded plant.
The emergency holding ponds at Livermore are required in part because
the activated sludge process consists of one unit rather than two parallel
units. While shutdown of one of the two primary sedimentation tanks or
trickling filters can be accomplished without a complete plant shutdown, this
cannot be done with the aeration tank or the secondary clarifier; maintenance
on or repair of either unit requires bypassing of plant flow to the holding
basins. Because it is less expensive to construct one unit at a given capac-
ity than two parallel units, each at half capacity, existing ponds or sludge
lagoons should always be considered for emergency holding basins in up-
grading an existing plant.
The flow received by the Livermore plant is presently nearing its 0.22-
m /sec (5.0-mgd) capacity. One of the alternatives being considered for
expansion is to incorporate flow equalization into plant operation through the
use of existing bypass lines and holding ponds, one of which has been lined.
It is anticipated that a flow of perhaps 0.26 m3/sec (6.0 mgd) could be
accommodated in this manner.
32
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SECTION 6
CONSTRUCTION
Construction as well as design of a sewage treatment facility is much
simpler and more straightforward when dealing with a completely new treat-
ment plant than when upgrading an existing plant. Construction schedules
in the latter case are tied to and in some instances controlled by treatment
plant operating procedures. This was less of a problem at Livermore than it
often is, but there was the additional operating constraint of the Regional
Board order which prohibited discharge of inadequately treated effluent to
surface waters. Thus, it was imperative that construction be completed as
quickly as possible and that there be close cooperation between the Con-
tractor and plant personnel.
PRECONSTRUCTION ACTIVITIES
At the completion of the design phase, construction drawings and speci-
fications were prepared. These contract documents were approved by the
City of Livermore and by the San Francisco office of the U.S. Department of
Health, Education, and Welfare (HEW). The City had obtained a federal
grant, No. WPC-CAL-258, to partially finance construction of the upgraded
facilities, and HEW's consent was necessary prior to advertising for bids.
The City Council authorized the construction of the trickling filter-acti-
vated sludge facility, and the contract documents, labeled "Treatment Plant
Enlargement - 1965" , were advertised for bid on January 24, 1966. Copies
were made available to prospective bidders and were distributed to builder's
exchanges in the San Francisco Bay Area.
The requested construction bid was to include the furnishing of all labor,
materials, and equipment for construction of the second trickling filter, aera-
tion tank, secondary sedimentation tank, distribution structure, bypass sys-
tem, effluent discharge facilities, chlorination additions, outfall sewer, and
sludge lagoons; modifications and alterations to existing headworks, primary
sedimentation tanks, filter circulation sump, and pond distribution structure;
paving, grading, painting, piping, and fencing; and all other related work
necessary to provide a complete and operable treatment plant.
33
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Normal prebidding activity was experienced as reflected by the number
of plan holders,'a typical situation in California for a project of tnis size.
Two addenda to the documents were issued during this period. One. was
related to revised prevailing wages as determined by the U. S. Department of
Labor; the other was related to technical clarifications in the plans and spec-
ifications .
The contract documents requested bids on two alternatives: Bid Item I
included the improvements as shown; Bid Item II included the improvements
as shown with the omission of the airport effluent disposal irrigation system.
Included in each item was the sum of $20,000 for contingencies encountered
during construction. Bids were opened on February 24, 1966, and the results
are summarized in Table 4.
TABLE H. BID TABULATION
Name of Bidder
Pacific Mechanical Corp.
Monterey Mechanical Co.
Fred J. Early Ir. Co.
C. Norman Peterson Co.
S. & Q. Construction
Bid Item I
$1,057,800
1,099,000
1,126,800
1,130,500
1,134,399
Bid Item II
$ 985,400
1,032,000
1,049,800
1,059,399
1,085,000
The low bid submitted by Pacific
Mechanical Corporation was found to
be in order, and the contract was
awarded to that company. Approval
from HEW to sign the contract with
the Contractor was obtained by the
City on February 28, 1966, and the
notice to proceed was issued by the
City Engineer on March 16, 1966. The
allowable construction period was 300
days, and the designated completion
date was January 10, 1967.
CONSTRUCTION ACTIVITIES
Policies on construction management were finalized soon after the notice
to proceed was issued to the Contractor. The City's consultant, Brown and
Caldwell, was asked to assist in the review of shop drawings submitted by
the Contractor and to provide periodic field support services as required by
the City. The City was to provide all required inspection services and be
responsible for all change orders, progress payments, interpretation of con-
tract documents, and contact with HEW officials. Whenever required, Brown
and Caldwell engineers would also be available for clarification of contractual
matters, especially the technical provisions.
The contract documents made provisions for listing the major pieces of
equipment in the proposal, both by name and installed cost. Pacific Mechan-
ical Corporation submitted the equipment listed in Table 5.
The low bid had been based on the lowest installed price for each item
of major equipment. The City made its equipment choices known to the
Contractor on March 14, 1966. The selected items were: 1) Armco,
34
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TABLE 5. MAJOR EQUIPMENT ITEMS BREAKDOWN
Item Article in Specifications Manufacturer
1 Sluice gates Armco
Rodney Hunt
2 Trickling filter circulating pump Fairbanks-Morse
Johnston Pump
Worth ington
3 Aeration pumps Fairbanks-Morse
Johnston Pump
Worth ington
4 Air diffusion equipment Chicago Pump
Walker Process
5 Air blowers Roots-Connersville
Sutorbilt
Installed Price,
dollars
22,500
25,000
3,750
3,500
3,500
12,000
12,000
13,000
35,000
40,000
40,000
45,000
Secondary sedimentation tank
equipment
Alternate A
Alternate B
Alternate C
7 Trickling filter distributor
8 Chlorination equipment
Chain Belt
Walker Process
Walker Process
Dorr-Oliver
Walker Process
Wallace 6 Tiernan
Fischer & Porter
50,000
40,000
30,000
20,000
19,000
19,000
20,000
2) Johnston Pump, 3) Johnston Pump, 4) Chicago Pump, 5) Roots-Connersville,
6) Alternate B: Walker Process, 7) Walker Process, and 8) Wallace & Tiernan.
Alternate B of item 6 was not the lowest installed price, but it was chosen
because it provided a sight well which was considered of prime importance
for proper plant operation. The choice of Alternate B added an extra $10,000
to the low bid, and the revised construction cost became $1,067,800. Ap-
proval from HEW for this revised cost was obtained on March 18, 1966.
The Contractor's low bid was a lump sum figure. For cash flow analysis
the Contractor submitted, as required in the contract documents, a breakdown
of his total bid together with his estimated progress schedule. The bid break-
down, summarized in Table 6, was used to determine the monthly progress
payment estimates.
Before describing the sequence of events during construction, it is
worthwhile to briefly review the items constructed, with emphasis on the
mechanical equipment and construction details.
35
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TABLE 6. CONTRACT PRICE BREAKDOWN
Description
Amount, dollars
lob Mobilization
(Purchasing, Engineering, Move On)
Earthwork
Site grading
Structure excavation
Sludge lagoons
Outfall excavation
Piping and miscellaneous excavations
Oxidation pond
Backfill fine grading
Paving
Total
Forming
Secondary sedimentation tank
Aeration tank
Trickling filter
Chlorine contact tank
Miscellaneous structures
Total
Reinforcing Steel
Delivered to job site
In place
Total
Concrete
Secondary sedimentation tank
Aeration tank
Trickling filter
Chlorine contact tank
Miscellaneous structure
Total
Miscellaneous Metal Work
Embedded work
Other items
Total
Equipment
Delivery on site
Installation
Total
Piping
Material at job site
Outfall sewer
Bypass and Interconnecting sewer
Miscellaneous yard piping
Total
Trickling Filter Block and Rock
Other Subcontracts
Electrical
Sprinklers
Boring
Fencing
Painting
Total
Move Off and Clean Up
Contingency
TOTAL
12,000.00
5,000.00
34,100.00
27,500.00
17,600.00
27,500.00
36,500.00
9,100.00
6,900.00
16,000.00
36,100.00
26,300.00
14,100.00
16,500.00
21,500.00
26,500.00
18,200.00
42,000.00
16,500.00
7,600.00
12,700.00
13,000.00
36,000.00
200,000.00
11,800.00
152,000.00
14,700.00
3,400.00
23,500.00
52,000.00
63,000.00
14,700.00
2,500.00
7,300.00
164,200.00
109,000.00
48,000.00
97.000.00
49,000.00
211,800.00
193,600.00
22,000.00
139,500.00
1,700.00
20,000.00
Si,067,800.00
36
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Trickling Filter
The added second filter is of reinforced concrete construction and equiv-
alent to filter No. 1, 34 m (110 ft) in diameter with a 1.2-m (4.0-ft) deep
rock media layer. The maximum rock size is 10 cm (4 in.), and the media
rests on Process Engineers' "Air In" underdrain concrete blocks. The filter
floor slab slopes towards a central collecting channel which also slopes
towards an effluent collecting pipe. The filter walls have rectangular open-
ings at floor slab elevation for air circulation purposes. Four reaction type
distribution arms, "Rotoseal" models manufactured by Walker Process Com-
pany, distribute the flow through 5-cm (2-in.) orifices to the filter media.
Spread deflectors at each orifice provide for even distribution.
Filter Circulation Pump
The No. 3 pumping unit added to the filter recirculation system is a
mixed flow, Model 16 LS pump provided by Johnston Pump Company with a
capacity of 0.33 m3/sec (7.6 mgd) at 5.3 m (17.5 ft) total dynamic head
(TDH). The overall pumping capacity is as follows: pumps Nos. 1 and 3,
0.33 m3/sec (7.6 mgd) each; pump No. 2, 0.17 m3/sec (3.8 mgd).
Aeration Tank
The reinforced concrete aeration tank is 49 m (160 ft) long and includes
two passes, each 9.1m (30 ft) wide. Flow distribution channels along the
outside edge of each pass include openings for removable slide gates. This
arrangement provides for three modes of activated sludge operation as dis-
cussed in Section 5: conventional, step aeration, and sludge reaeration.
Coarse-bubble air diffusers, located along each side of the central wall,
are Chicago Pump's Type Bl Swingfuser Aerators. The air manifold feeds
eight diffuser assemblies in each pass, and each assembly contains 20 syn-
thetic resin "deflectofusers" with four 0.79-cm (5/16-in.) diameter jet open-
ings. Each diffuser includes a 1.35-cm (17/32-in.) control orifice for equal
air distribution. The diffuser manifolds are located 0.61 m (2.0 ft) above the
floor slab and 0.81 m (2.67 ft) from the central wall. The diffusers are
placed onto the central-wall side of the manifolds in a staggered arrange-
ment (Figure 15). The diffuser assemblies can be lifted out of the tank by
using a 1-ton portable manual winch and hoist. The distribution channels
are also equipped with air diffusers.
Aeration air supply units are installed adjacent to the tanks on a concrete
slab at ground elevation and include three rotary lobe, positive displacement,
Model 1021 RAS Roots-Conner sville blowers, complete with inlet silencers
with filters and outlet silencers. Each blower has a capacity of 56.6 m3/min
37
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Figure 15. Aeration diffusers.
Secondary Sedimentation Tank
(2,000 ft3/min) at 48 kN/m2 (7 psi).
Discharge from the blowers is mani-
folded into a header pipe which sup-
plies the air header atop the central
wall of the aeration tank.
Aeration Tank Feed Pumps
Aeration pumps, to lift trickling
filter effluent from the filter circula-
tion sump to the aeration tank, are
located in the filter distribution struc-
ture opposite the trickling filter circu-
lation pumps and are manufactured by
Johnston Pump Company. Pump No. 1
is a propeller type, Model 20 PO, and
has a capacity of 0.59 m3/sec (13.5
mgd) at 3.2 m (10.5 ft) TDK. Pump
No. 2 is a mixed flow, Model 16 LS
pump and has a capacity of 0.27 m3/
min (6.2 mgd) at 3.2 m (10.5 ft) TDK.
The reinforced concrete secondary sedimentation tank is 27 m (90 ft) in
diameter with a 3.7-m (12-ft) side water depth (SWD). It is of the center-
feed type and is equipped with a Type SWP multidraw collector by Walker
Process Equipment Company, complete with "Clariflow" inlet, sight well,
and truss arms. Suction pipes in the revolving truss arms are connected to
a water-level sight well and are provided with telescopic valves for flexi-
bility in sludge draw-off. The revolving arms are also equipped with adjust-
able brass squeegees for sweeping the sludge on the floor slab to the with-
drawal pipes. Secondary effluent flows over a weir plate to a collection
channel inside the tank perimeter. A skimmer assembly, mounted on the
rotating truss, sweeps surface scum to a scum box.
Return Activated Sludge Pumps
Return activated sludge units are pad-mounted next to the secondary
sedimentation tank and include two variable-speed, motor-driven pumps and
a magnetic flowmeter. The pumps are Gorman-Rupp Model T8A-3, each with
a capacity of 0.1 m3/sec (2.3 mgd) at 9.1 m (30 ft) TDH. Electric Machine-
ry's "Ampli-Speed" magnetic drives, Model MDM-13, provide speed varia-
tion. Pump suction is taken from the bottom center of the secondary sedi-
38
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mentation tank. The pump discharge lines are manifolded to a common header
(containing the flowmeter) which ends at the inlet to pass No. 1 in the aera-
tion tank.
Chlorination System
New facilities were added and the existing chlorine contact tank modi-
fied to increase plant effluent disinfection capability. New facilities include
a chlorine storage area, an evaporator, and chlorine residual analyzers. The
chlorine contact tank capacity was doubled.
An open steel structure, with a Robertson Q-Type deck (supported by
structural steel members) serving as a roof, and a concrete floor slab provide
storage for eighteen 907-kg (2,000-lb) chlorine cylinders. For cylinder hand-
ling and weighing,an 1,814-kg (4,000-lb) electric hoist mounted on an over-
head monorail and two load cells were furnished.
A Wallace & Tiernan Series A-785 evaporator with a capacity of 1,8 14kg/
day (4,000 Ib/day) was installed in the existing chlorinator room in the opera-
tions building. The existing Wallace & Tiernan Series A-711 chlorinators
were modified to accept a signal from the chlorine residual analyzer controller
in addition to the flow signal.
Wallace & Tiernan chlorine analyzers, complete with Moyno Model
IL6CDQ sampling pumps, were installed at the effluent discharge structure,
downstream of the chlorine contact tank,and downstream from the bypass man-
hole in the secondary effluent pipeline just outside the secondary sedimenta-
tion tank. The postchlorination application point is at the bypass manhole,
which is equipped with a turbine type mixer made by Cleveland Mixer Com-
pany .
The existing 4.6-m (15-ft) deep, 3.2-m (10.5-ft) wide, two-pass,con-
crete chlorine contact tank was lengthened by 15.6 m (51 ft). Hinde Engi-
neering's Air-Aqua Oxidation System 2542 air tubing was installed in a
serpentine pattern on the floor slab of both the old and new tank sections.
Effluent Disposal Lines
A 1.1-m (42-in.) concrete sewer line 70 1 m (2,300 ft) long was installed
from the effluent discharge structure to the Arroyo Las Positas Creek bed for
effluent disposal. Diversion of plant effluent is provided for at two manholes,
either for airport spray irrigation or for golf course irrigation and storage. The
airport system includes a pumping station with two four-stage Model 12 AC
turbine pumps manufactured by Johnston Pump Company, each with a capacity
of .1. 9 m3/min (500 gpm) at 67 m (220 ft) TDK; sprinkler controllers; pop-up
39
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type sprinkler heads; and approximately 20 ha (50 ac) of land. The land is
located mostly south of the Livermore Municipal Airport runway, which is
about 0.8 km (0.5 mi) west of the treatment plant.
A 0.36-m (14-in) diameter, 1,158-m (3,800-ft) long pipeline was con-
structed for effluent diversion to the Las Positas Golf Course adjacent to and
northwest of the airport. A motor-operated butterfly valve in the upstream
end of the pipeline is responsive to water surface elevation in four inter-
connecting storage lakes which supply the golf course irrigation system.
Miscellaneous Facilities
Miscellaneous items constructed under this contract included pipelines
interconnecting different process units, asphaltic concrete pavement, storm
drains, chain link fence, and landscaping, including a sprinkler system.
Miscellaneous equipment added during plant enlargement included a Worth-
ington Model 25-C-5 comminutor located in the inlet works channel just up-
stream of the raw sewage pumps; a Chicago Pump Tru-Test effluent sampler
complete with a Gorman-Rupp Model 81-1/2-B2-B sampler pump, both located
on the effluent discharge structure top slab; two No. 3 spray water pumps by
Johnston Pump Company, Model 7BC, each with a capacity of 1.1 m^/min
(280 gpm) at 15 m (50 ft) TDK, also located on the effluent discharge struc-
ture slab and used to control foaming in the aeration tank; a 0.9-m (36-in.)
sluice gate with a hydraulic operator at the pond inlet structure for plant ef-
fluent bypass; and other small items. Electrical and instrumentation work
and painting services were also provided by the Contractor under the terms
of the contract.
CONSTRUCTION SEQUENCE
Construction management was directed by the Livermore City Engineer.
At the, job site he was represented by a City inspector who devoted his full
time to construction supervision. In the absence of the inspector (illness,
etc.), the treatment plant superintendent divided his duties between construc-
tion inspection and operation. Change orders and requests for progress pay-
ments originated with the inspector and were submitted to the City Engineer
for approval. Change orders, in turn, were submitted by the City to HEW for
approval. Shop drawings, reviewed by Brown and Caldwell, were handled
and distributed by the City. Brown and Caldwell engineers were also avail-
able for direct consultation with the City inspector and made periodic visits
to the job site to assist in the inspection procedures. On request, Brown and
Caldwell assisted the City Engineer in his dealings with the Contractor.
40
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Record keeping, in addition to correspondence between the Contractor
and the City, included the preparation of a daily report by the inspector from
March 16 to December 15, 1966; construction progress photographs taken
once a month from March 1966 through November 1966; soil and concrete test
reports; field trip reports prepared by the consulting engineering firm; and
general correspondence between the City and its consultant.
Weather had little effect on construction progress as the climate of the
Livermore area is semiarid, with hot, dry summers and cool, moist winters.
Average summer temperatures are above 21 C (70 F) and winter temperatures
are above 7 C (45 F). Rainfall during the period of intensive construction,
March to December 1966, was below average. Total yearly rainfall for 1966
was 25.98 cm (10.23 in.), whereas the long-term average based on the
1931-1960 period is 36.58 cm (14.40 in.) per year. Construction activities
were not seriously curtailed during the rainfall period; there were no job shut-
downs because of inclement weather. There was, however, substantial
reduction of the labor force occasion-
RAINFALL AND EVAPORATION
DURING CONSTRUCTION
PERIOD
TABLE 7. RAINFALL AND EVAPORATION ally because of wet ground. Monthly
precipitation and evaporation values
for January 1966 through April 1967
are shown in Table 7.
The Contractor's activities
started on March 16, 1966, when his
construction quarters were moved to
the job site. Ground alignment, both
vertical and horizontal, was estab-
lished by the City the next day. Four
days later, the Contractor's earth-
moving equipment was at work.
Although the entire construction
period is not included in the inspec-
tor1 s daily reports (as they cover only
the period from March 16 to December
15, 1966), his reports do include
information on the bulk of construction
activities. This diary along with other field information has been used to
establish the Contractor's activities as summarized in Figure 16. The approx-
imate period covered by each activity, excluding the minor breaks or pauses
which exist normally in any construction project, is shown graphically.
Figure 16 cannot be used, however, to explain why some activities took
longer than expected to complete. To help visualize the construction prog-
ress and its many ramifications, each activity is briefly discussed. The
Month
January 1966
February
March
April
May
June
July
August
September
October
November
December
January 1967
February
March
April
Rainfall, in
1.63
0.97
0.20
0.36
0.15
0.10
0.18
0
0.11
0
3.75
2.78
7.44
0.28
5.12
4.31
Recorded at Livermore Water
b
in. x 2.54 = cm
a b a b
. ' Evaporation, in.
1.61
2.26
3.82
7.76
9.55
10.31
10.88
11.93
8.0
6.5
3.0
1.18
2.25
2.18
3.22
3.19
Reclamation Plant.
41
-------
MAR
21 21
APR
II 1« 29
MAY
2 9 It 23
JUN
6 11 20 27
JUL
« 11 II
AUC
15 22
SEPT
5 12 19 2«
OCT
3 10 17 24 31
NOV
14 21 21
DEC
12 19
1967
JAN
2 9 16
..-
EXCAVATION
CONCRETE FLOOR SLAB
CONCRETE WALLS
EQUIPMENT INSIDE STRUCTURE
EQUIPMENT OUTSIDE STRUCTURE
TRICKLING FILTER
EXCAVATION AND BACKFILL
CONCRETE FLOOR SLAB
CONCRETE WALLS
EQUIPMENT INSIDE STRUCTURE
EDIMENTAT10N TANK
CONCRETE FLOOR SLAB
CONCRETE WALLS
EQUIPMENT INSIDE STRUCTURE
EQUIPMENT OUTSIDE STRUCTURE
CHLORINE CONTACT TANK
EXCAVATION
CONCRETE FLOOR SLAB
CONCRETE WALLS
EQUIPMENT
CHLORINE STORAGE .
CONCRETE FLOOR SLAB
STRUCTURE
EQUIPMENT
to
EFFLUENT DISCHARGE STRUCTURE
EXCAVATION
CONCRETE FLOOR SLAB AND WALLS
EQUIPMENT
SECONDARY DISTRIBUTION BOX
FILTER CIRCULATION SUMP
AIRPORT IRRIGATION PUMP STATION
SLUDGE LAGOONS
HOLDING BASINS
PIPING
W-ln. OUTFALL
AIRPORT IRRIGATION SYSTEM
IS-ln. GOLF COURSE IRRIGATION LINE
16-In. MIXED LIQUOR LINES
U-ln. RETURN ACTIVATED SLUDGE LINE
«e-ln. SETTLED SEWAGE FORCE MAIN
30-ln. TRICKLING FILTER SUPPLY LINE
27-ln. TRICKLING FILTER RETURN LINE
12-In. BYPASS LINE AND MANHOLE
10-ln. TANK DRAIN AND 6-ln. SCUM LINE
LANDSCAPING
NOTE: (1) In. X 0.015 * in
(2) Datt IndlciUi Mondly
of Meh wMk,
Figure 16. Construction activity.
-------
relationship of the different units to each other and the location of the piping
systems serving those units were presented previously in Figures 7 and 14
(Section 5), respectively.
Aeration Tank
The proximity of the trickling filter and sludge lagoons to the aeration
tank helped coordination of earthwork activities at these three sites. Ma-
terial excavated from the aeration tank site was used for engineered fill at
the trickling filter structure and for dikes at the sludge lagoons. Embankment
compaction values ranged from 97 to 99 percent relative density.
The quantity of concrete poured in this structure totaled nearly 1,150 m^
(1,500 yd'5); the largest single pour was the floor slab at 516 m^ (675 yd3).
The maximum size of the aggregate for this large pour was 3.8 cm (1.5 in.),
and a bucket-conveyor belt combination was used to pour the entire floor
area. For the remainder of the tank, the aggregate size was reduced to 1.9
cm (0.75 in.)/and the concrete was pumped using a Thompson Ready-Mix
pump. During concrete form construction and rebar placing, the walls were
divided into 12-m (40-ft) sections for each pour and alternate sections were
cast simultaneously, starting at the south wall and ending at the west wall.
Probably because of problems with the concrete pump and mix (three truck-
loads were rejected), large rock-pockets developed at the east end of the
center wall. All loose material was removed in the affected area, and an
epoxy compound was used to bond the new concrete to the existing surfaces.
Equipment delivery problems adversely affected the installation of the air
blowers. Blowers were air-freighted and installed early in 1967. Because
blower motor delivery could not be made until March 1967, the blowers were
temporarily fitted with rented motors. A photograph of the blower equipment
is shown in Figure 17.
The proximity of the aeration tank structure to the existing trickling filter
required close watch of the embankment between these two structures (Figure
18). At one time when the embankment's stability was in question, shoring
and backfill operations were started immediately along the south aeration tank
wall. Backfilling activities were closely inspected, and on two occasions,
the Contractor recompacted those areas where compaction test results were
below the minimum acceptable 95 percent relative density.
Trickling Filter
The new trickling filter was the only structure constructed on engineered
fill. Relative density compaction tests at this fill always resulted in values
higher than the 95 percent required.
43
-------
Figure 17. Aeration blower equipment. Installation
proceeded behind schedule because of
delivery delays.
The concrete volume in this structure was over 265 m3 (350 yd3). The
maximum size of the aggregate for the central collection trough and pier was
3.8 cm (1.5 in.); for other portions it was 1.9 cm (0.75 in.). The floor slab
was poured in two sections. The outside wall was divided into six sections
based on 60-degree central angles. Alternate pie-shape sections were then
poured. The inner wall holding the filter media was also divided in six sec-
tions, and alternate pie-shape sections were poured concurrently.
Underdrain installation was completed by the end of 1966, and filter
media placement by the middle of January 1967. Delivery of the trickling
filter distributor was behind schedule, but since this unit was not as essen-
tial to the overall process as the aeration blowers, it was believed unneces-
sary to air-freight the distributor arms to expedite delivery.
Secondary Sedimentation Tank
Maximum aggregate size for the concrete in which the return activated
sludge pipe was embedded and for the central pier casting was 3.8 cm (1.5
in.); for the remainder of the tank, it was 1.9 cm (0. 75 in.). The total quan-
tity of concrete poured at this tank approached 420 m3 (550 yd3), and half of
44
-------
Figure 18. Aeration tank reinforcing steel placement in progress.
Proximity of aeration tank excavation to the trickling
filter structures caused concern over bank stability.
this total was in the floor slab. The slab was poured in four sections, and
because they were not cast to final grade, a 5-cm (2-in.) grout topping was
required on the structural slab.
The grout topping was placed after the mechanical equipment was instal-
led inside the tank, and the structural steel rotating arms were utilized to
spread and surface-finish the topping. Difficulties with the mechanical
equipment resulted in an uneven and rough surface finish. Months later, it
was noted that the grout was not bonded to the structural floor slab; addi-
tionally, several larger-than-hairline-size cracks appeared on the surface.
Several meetings were held between the Contractor, the City/ and Brown and
Caldwell to resolve the question of responsibility for the required corrective
45
-------
work.. The operation of this tank was essential to the activated sludge
process and was necessary to meet effluent discharge requirements. Accord-
ingly, the City directed the Contractor to replace the grout topping. On
January 27, 1967, the Contractor agreed, under duress, to replace it. The
City's nonacceptance of the Contractor's claim that the grout replacement
constituted extra work resulted in the Contractor's action for legal redress.
The suit by the Contractor against the City and its consultant was decided,
years later, in favor of the City.
Equipment deliveries for this structure were not delayed, and the equip-
ment inside the tank was assembled, welded, painted, and tested by the
middle of November 1966. This equipment is shown in Figure 19. The return
activated sludge pumping equipment, located outside the tank, was installed
by the end of December 1966.
Figure 19. Secondary clarifier structure and mechanical equipment
46
-------
Chlorine Contact Tank
Expansion of the chlorine contact tank, was started and completed early.
An aggregate base was placed on a compacted subgrade, and the concrete was
placed in two pours, one for the floor slab and the other for the walls and
cross beams. Over 160 m^ (210 yd^) of concrete were used with a maximum
aggregate size of 3.8 cm (1.5 in.). The air piping was installed by the end
of September 1966, and 2 mo later the tank was placed in service.
Chlorine Storage Area
Construction activity extended from April through October 1966. Column
footings and floor slabs were in place by June, but because of a delivery
error, the structural frame was not available until July. The structure was
erected, roofed, and drained in 1 mo and the piping and equipment were
installed and painted during October (Figure 20).
Figure 20. Chlorine storage area.
Effluent Discharge Structure
Construction activity at the effluent discharge structure was divided into
two noncontinuous periods. The earlier period corresponded to the concrete
work ; the latter period, the installation of the water pump units and related
piping and effluent sampling equipment.
47
-------
Secondary Distribution Box
The construction of the secondary distribution box also result in two non-
continuous periods of activity similar to those for the effluent discharge
structure. In this case,the latter period involved mostly the installation of
the air-lift piping. The sluice gates inside the box were installed soon after
the completion of the concrete work during the earlier period.
Filter Circulation jump
In addition to the structural modifications to the existing filter circula-
tion sump, construction activity involved the installation of pumping equip-
ment for the trickling filters and aeration tanks. These pumps were in place
by the end of November 1966. However, the electric motors for the aeration
tank feed pumps were missing because of late deliveries. The Contractor was
asked, and he agreed, to air-freight them for a mid-January 1967 delivery.
Installation was accomplished soon after delivery.
Airport Irrigation Pump Station
Completion of the airport irrigation system was scheduled for June 30,
1966. Construction activities at the pump station took place during May and
June, and by the end of June the pumps were installed. Electric motors had
to be rented, however, to meet the deadline. The pump'station was initially
manually operated because the float control and panel were not installed until
July. One of the motors failed in late July because of improper wiring connec-
tions. This same motor failed again 5 mo later when it shorted due to im-
proper insulation.
Sludge Lagoons
Sludge lagoons were started and completed early during the construction
period. Material excavated from the aeration tank area was used for con-
struction of the dikes. Compaction test results averaged 95 percent relative
density. The dikes were shaped and finished by early May 1966, and diges-
ted sludge was hauled in immediately. Supernatant structures and walkways
were installed by December of the same year.
Holding Basins
Water and sludge had to be removed from each oxidation pond prior to
conversion to holding basins. Basin 1 (oxidation pond 2) was completed first
in June 1966. Later activities included demolition of the abandoned dikes
48
-------
and surface grading at basin 1. Dike location in basin 2 was revised during
construction with new dikes being shortened and dikes scheduled to be
abandoned left in service.
Outfall
The 1.1-m (42-in.) outfall from the effluent discharge structure to Arroyo
Las Positas was also completed before the June 30, 1966, deadline. Changes
in horizontal alignment were required to clear private property. A temporary
equipment access way through private property was necessary, and negotia-
tions were handled directly between the Contractor and the individual land-
owner. This pipeline also feeds the irrigation systems at the airport and golf
course.
Airport Irrigation Piping
The installation of the piping and sprinklers at the airport was started in
April 1966, and the equipment ready for testing by the end of June. Leaks
were discovered in the pipeline, and four additional tests were required to
discover and repair all the leaks and pipeline breaks. Thereafter, the sprink-
lers required periodic checking. Also, the controllers for the irrigation
valves were erratic in their operation and it was October before all the com-
ponents were working properly.
Golf Course Irrigation Line
The 0.36-m (14-in.) line feeding the golf course irrigation storage lakes
was installed during May 1966, and water to the lakes was delivered early in
June. Controls for the butterfly valve were installed later.
Mixed Liquor Line
The new 0.91-m (36-in.) mixed liquor line runs from the aeration tank to
the secondary distribution box and then to the secondary sedimentation tank.
Two lines were installed, one for future use as shown previously in Figure 14.
The lines were installed in August 1966; in December, a section next to a flex-
ible coupling just outside the sedimentation tank structure failed. Appar-
ently, the steel plate thickness was less than that shown in the shop drawings.
Return Activated Sludge Line
A 0.30-m (12-in.) return activated sludge line connects the aeration
tank to the return activated sludge pumps. This line was installed in a
common trench concurrently with the two 0.91-m (36-in.) mixed liquor lines.
49
-------
Bypass Line and Manhole
The new 1.1-m (42-in.) bypass pipeline extends from the existing 1.4-m
(54-in.) bypass to the new holding basin (see Figure 14 in Section 5). The
bypass manhole is in the 1.4-m (54-in.) line and connects it to the secondary
sedimentation tank effluent line. The new bypass line was installed between
September 19 and October 25, 1966. The concrete manhole was completed a
few days later. Since the 1.4-m (54-in.) line was in use (it was connected
with the secondary effluent line), it was difficult to make any connection
without affecting plant operation. Thus, a plant shutdown from midnight to
7:00 a.m. was scheduled. However, three such shutdowns were required
before the connections were successfully made.
Aeration Tank Drain and Scum Line
A 25-cm (10-in.) tank drain and 15-cm (6-in.) scum line extended from
the aeration tank to the inlet works. In the vicinity of the inlet works, the
new lines ran alongside an existing supernatant line which had been leaking
for some time; consequently, the ground was moist.
A vitrified clay pipeline for raw sludge was also broken during excavation
in this area. The broken line was repaired, but a leak developed in the re-
paired area at a later date. Because of the nature of the affected pipelines,
it was necessary to shut down the plant to effect the repairs. The excessive
water from the leaks and breaks also affected the size of the excavation, and
the hole grew bigger and bigger. Pea gravel fill material was imported to
protect the inlet works. All this activity was considered extra work by the
Contractor, and it took several meetings to reach a compromise on the amount
of the extra cost.
PROGRESS PAYMENTS
In addition to the daily reports and related information mentioned previ-
ously, the requests for monthly progress payments and extra work also out-
line the Contractor's progress throughout the construction period. The rate
of progress payments, based on the Contractor's bid breakdown, is shown
graphically in Figure 21 for major construction items. The payment percent-
age is related to the total cost of the item. Examination of Figure 21 reveals
that the payments went beyond the time originally allowed for completion.
The cumulative progress payments are shown in Figure 22. Most of the work
had been accomplished by May 1967 when the City partially accepted the
improvements. The big jump in payments during 1967 was the release of
money withheld by the City for uncompleted construction items. Although the
construction work was substantially complete, some of the finishing touches
50
-------
c
0>
CO
UJ
5
<
a.
IU
CC
o
O
cc
a.
100
90
80
70
60
50
30
20
10
• MOBILIZATION
PIPING
SPRINKLER
IRRIGATION /"
SYSTEM -H
EARTHWORK
PAINTING
MECHANICAL
EQUIPMENT
MISCELLANEOUS
METALWORK
TRICKLING FILTER
MEDIA
FENCING
MAMJ JASONDJFMAMJJA
1966 1967
Figure 21. Progress payment rates for major construction items.
had not been completed and this affected the amount of money retained by the
City. Progress payments extend throughout 1967 because of the difficulty in
reaching an agreement on the extent of the extra work orders.
Extra work orders 1 through 33, in the amount of $8,101.40, were finally
paid for on December 29, 1967. The overall cost of the change orders is a
small percentage of the construction cost. A summary of the total construc-
tion cost is shown in Table 8.
51
-------
1.200
o
•o
•o
C
CO
w»
o
i
UJ
1
Ul
oc
13
O
-------
TABLE 8. TOTAL CONSTRUCTION COST
Item
Cost, dollars
Bid price
Add for equipment charge
Deduct contingency fund
Change Orders 1-33
Total payment
1,057,800.00
10.000.00
1,067,800.00
20.000.00
1,047,800.00
8,101.40
1,055,901.40
1,055,901.40
Section 7). As mentioned previously,
the City opted for no liquidated dam-
ages if the new facilities were in
operation in time to meet the regula-
tory agency requirements. Although
the Contractor's time was not offici-
ally extended, the position adopted
by both parties was that the project
would be finished as soon as possible.
Inability to agree on change orders
and the extent of unfinished work
appears to have affected completion
and acceptance of the project. The
City Council agreed on May 9, 1967,
to partially accept the improvements,
and the notice of completion was
is.sued by the City Engineer on August
14, 1967.
53
-------
SECTION 7
PLANT STARTUP AND INITIAL OPERATING PERIOD
During construction of the upgraded Livermore Water Reclamation Plant,
the City was prohibited by the Regional Water Quality Control Board from dis-
charging inadequately treated effluent to the surface waters of Arroyo Las
Positas. To meet the discharge prohibition, the City utilized portable alum-
inum piping and a temporary pumping system to spray irrigate effluent onto
60 ha (150 ac) of leased lands and the nearby municipal golf course. Because
of the expense and limited capacity of this interim disposal method, it was
imperative that, once completed, the plant be fully operational and producing
a satisfactory effluent as soon as possible.
This section describes the startup and initial operating period of the
plant. Procedures used in bringing the activated sludge system on line,
initial operational problems, and performance data from March through De-
cember 1967 are the main topics discussed.
A principal problem discussed below was the inability to consistently
nitrify in the activated sludge unit. After several months of attempting vari-
ous solutions, it was determined that an inadequate air supply was the cause.
Utilizing the third (standby) blower for portions of the day resulted in signi-
ficant improvement, but as discussed in Section 8, the problem has recurred
over the years each time a blower has been shut down for repairs.
PREPARATION FOR STARTUP
In December 1966, approximately 3 mo before the estimated project com-
pletion date, the City increased the plant staff from five to nine by hiring
two more operators, a laboratory technician, and a maintenance mechanic.
A training program was begun which included familiarizing all personnel with
the operation of existing portions of the plant. One-hour-per-day training
sessions on the new portions of the plant lasted approximately 2 mo until the
construction was completed. The existing employees trained the new person-
nel in general operation, preventive maintenance, and laboratory procedures
for the original plant.
54
-------
Materials used for training included the preliminary Operation and Main-
tenance Manual prepared by Brown and Caldwell, an operator training manual
prepared by the California Water Pollution Control Association, and manuals
prepared by various state agencies and universities. A special effort was
made to find training guides oriented toward nitrification in the activated
sludge process, but the only information found was in Journal Water Pollution
Control Federation articles. This again indicates the lack of widespread
knowledge on nitrification which existed at the time.
In addition to utilizing available literature, discussions were held be-
tween the plant staff and design engineers from Brown and Caldwell. These
meetings yielded information and suggestions which were instrumental in
developing an understanding of the plant's capabilities.
Before startup all pumps , valves, blowers, collectors, flowmeters, air
diffusers, and piping were inspected by City inspectors and plant personnel
and were thoroughly tested. All dirt, rocks, and trash were removed from
lines, pumps, valves, and tanks, and systematic testing was made of all
electrical controls. The Contractor confirmed the startup date 10 days before-
hand. After the activated sludge unit was ready for use, a final check was
made of all equipment.
STARTUP OF ACTIVATED SLUDGE SYSTEM
In conjunction with the design engineering firm, a plan was formulated
for making the activated sludge system operational (Figure 23). The first step
consisted of filling the aeration tank one-quarter full with raw sewage and
starting one of the blowers. After a 24-hr period, 45 m^ (12,000 gal) of an-
aerobically digested sludge were added to the aeration tank. The tank was
half filled with raw sewage and kept under aeration for 2 days. At that time,
additional wastewater from the trickling filter was added periodically at a
rate which filled the tank in 5 more days.
Dissolved oxygen (DO), mixed liquor suspended solids (MLSS), and
sludge settleability (sludge volume index or SVT) were analyzed at 4-hr
intervals and DO maintained at 2.5-3.5 mg/1. The MLSS level averaged 1,300
mg/1 during the 5-day period, and the 30-min settled volume decreased from
600 ml/1 to 250 ml/1 by the fifth day. A well-defined floe was noted on
the second day.
The total flow from the trickling filter was added to the aeration tank on
the tenth day, and operation of the secondary clarifier was begun. The sug-
gested loading rate was 15-20 kg BODs/kg MLSS/day; using an estimated
filter effluent BOD5 of 120 mg/1, an MLSS level of 1,400 mg/1 was required.
55
-------
MARCH
1967
APRIL
1967
23 ^
- 24 ««
- 25 -«
- 26
- 27 >
- 28 -«
- 29 -
- 30 •«
- 31 '
_ .j _^
- 2
- 3
- 4
- 5 •*
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17 •*
- 18
FILL AERATION TANK TO ONE-QUARTER MARK WITH RAW SEWAGE;
START BLOWERS
ADD 12.000 gal DIGESTED SLUDGE
FILL AERATION TANK TO HALF-FULL LEVEL WITH PRIMARY EFFLUENT
ADD 100.000 gal OF TRICKLING FILTER EFFLUENT PER DAY
PUT AERATION TANK. SECONDARY CLARIFIER,
AND CHLORINE CONTACT TANK ON LINE
INCREASE CHLORINE DOSAGE FROM 10 TO 25-30 mg/l
NOTE: gal x 3.8= 1
DISCHARGE TO ARROYO LAS POSITAS (ALLOWED BY REGIONAL BOARD)
Figure 23. Startup sequence for activated sludge process.
Effluent from the secondary clarifier contained 20-30 mg/l suspended
solids. Suspended solids levels in the return activated sludge were 0.4-0.5
percent. Secondary effluent was chlorinated at a dosage of 10 mg/l. Com-
bined chlorine residuals of 2-3 mg/l were measured at a contact time of
120-150 min. On the second day of full aeration tank operation, a clear
effluent was monitored with suspended solids concentrations ranging from
15-20 mg/l. A BODs value from a settled aeration tank mixed liquor sample
taken 5 days previously measured 20 mg/l.
56
-------
Total coliform organism MPN's, however, ranged from 50 to 250/100 ml,
far greater than the 5-day median discharge requirement of 5.0/100 ml. To
correct this, the chlorine dosage was increased to 25-30 mg/1, resulting in
residuals of 10-20 mg/1. On the third day of operation, coliform counts were
ranging from 2.2 to 5.0 MPN/100 ml, and after 5 consecutive days with
counts of 5.0 MPN/100 ml or less, the Regional Board allowed surface dis-
charge of effluent, permitting an end to the temporary land irrigation system.
The operating aeration tank is shown in Figure 24.
Figure 24. Activated sludge aeration tank in operation. Tank was
placed on-line on April 1, 1967. Surface discharge was
allowed 17 days later. Roughing trickling filters are in
background.
57
-------
INITIAL OPERATIONAL PERIOD
The performance of the Livermore plant from April through December 1967,
when the new activated sludge unit was operating, is summarized in Table 9.
Although excellent BOD,- and suspended solids removals were obtained, anal-
ysis of final effluent ammonia nitrogen concentrations indicated that complete
nitrification was not occurring. This persisted until early 1968 while several
remedies were tried, none of them successful.
TABLE 9. PLANT PERFORMANCE:
APRIL-DECEMBER 1967
Parameter
Flow, mgda
BOD5
Influent, mg/1
Effluent, mg/1
Removal, percent
Suspended solids
Influent, mg/1
Effluent, mg/1
Removal, percent
PH
Influent
Effluent
Effluent analyses
Grease, mg/1
MBAS, mg/1
Ammonia-nitrogen, mg/1
LWRPb
EQAC
Nitrite-nitrogen, mg/1
LWRPb
EQAC
Nitrate-nitrogen, mg/1
LWRPb
EQAC
Chlorine residual, mg/1
Coltform concentration,
MPN/100 ml
Median
90th percent!le
Value
3.0(est.)
190
15
93
220
11
95
7.6
7.6
5.4
0.52
4.4
11
0.35
0.23
7.9
4.7
7.5
2.1
25
mgd x 0.044 = m-Vsec
Measured by plant staff.
£
Measured by Environmental Quality Analysts, Inc.
During this period, difficulties
were encountered in maintaining a
uniform DO level in the aeration tank.
The level sought was 2.5-3.5 mg/1 at
the effluent overflow weir. Use of
fixed-speed blowers required that ad-
justments be made by turning a blower
on or off. This resulted in constant
checking and adjusting, with DO
levels fluctuating greatly. An addi-
tional problem was the necessity of
making DO analyses in the laboratory,
a time-consuming operation since
measurements were being taken along
the length of the tank. Installation of
a DO analyzer-recorder near the aera-
tion tank overflow weir in July 1968
allowed more immediate monitoring of
DO levels.
Although adequate disinfection
was obtained by utilizing high chlorine
dosages, complete nitrification was
not attained until an increase in air
flow to the aeration tank was tried in
early 1968 (Figure 25). This was ac-
complished by using the third blower
on a regular basis for a portion of the
day. The target DO level near the
effluent weir was increased from about
2.5-3.5 mg/1 to 4.5-5.5 mg/1.
An important aspect of Figure 25 is whether partial nitrification was ocur-
ring continuously from June 1967 through January 1968 or whether nitrification
took place only during low loading periods of the day with major ammonia
58
-------
bleedthrough occurring during peak
loading periods. The values shown
in Figure 25 are based on monthly
averages of 24-hr composites taken
once a week. From the occurrence of
some nitrate in the effluent, it can be
assumed that some nitrification was
taking place. It is probable that this
was during low loading periods of the
day when the quantity of air supplied
was sufficient to keep the DO level
high enough for the nitrifying reac-
tions to occur.
Figure 25. Ammonia nitrogen removal
and blower operation.
The oxygen demand imposed by
ammonia nitrogen in a nitrifying sys-
tem is quite rapid, and a loading
increase can cause rapid DO depletion with subsequent loss of nitrification.
As the DO level increases, nitrification will start again. When nitrogen
analyses are made on 24-hr composite samples, it often appears that low-
level or partial nitrification is occurring continuously when, in fact, the
nitrification level has varied greatly over the 24-hr period.
The reason for the difficulty in solving the problem was the scarcity of
available information on nitrification in full-scale plant operation. The lack
of adequate knowledge for design was discussed in Section 5, and the diffi-
culties encountered in obtaining operator training information were noted
above. More widespread use of nitrification in wastewater treatment since
1967 has resulted in better designs and the availability of better training
materials. Factors pertinent to nitrification in coupled trickling filter-acti-
vated sludge systems will be discussed in Section 10.
Another operational problem which developed early was the occurrence
of denitrification in the secondary clarifier. It was found that the sludge
blanket has to be maintained at a depth of less than 1/3 m (1 ft) after the
collector has passed by; depths greater than this result in denitrification
with clumps of sludge being buoyed to the surface by nitrogen gas. A
photoelectric cell to detect sludge blanket height was built by the plant
staff (Figure 26). It is operated by lowering in into the clarifier until
a decrease in light transmission is detected by the cell (Figure 27). The
length of line under water indicates the depth to the beginning of the con-
centrated sludge blanket.
The unusually high chlorine dosages of 20-30 mg/1 also created problems
in adding chlorine and measuring residuals because the equipment was de-
signed for normal, lower dosages. The problems eventually necessitated
59
-------
Figure 26. Photoelectric probe (on left) for sensing sludge
blanket height. Reading is taken on meter (on right)
Figure 27. Photoelectric probe being lowered into
secondary clarifier. This measurement
is made after sludge withdrawal arms have
passed. Sludge blanket is kept at 1/3 m (1 ft)
60
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abandonment of the chlorine residual analyzers and resulted in development
of a control method utilizing pH as the control parameter. This method will
be discussed further in Section 8.
Increased solids production also caused immediate problems. Difficul-
ties were encountered in maintaining a high solids content in the raw sludge
pumped to the anaerobic digesters. This adversely affected volatile matter
reduction in the two mixed digesters and caused subsequent sludge lagoon
odor problems about 2 mo after startup of the activated sludge unit. These
problems have never been fully solved, although water depth in the lagoons
is now maintained at the 3-m (10-ft) maximum depth, instead of the 1-m
(3-ft) depth originally used, and chemical odor control equipment has been
installed. Solids handling data and associated problems are discussed more
fully in the following section.
61
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SECTION 8
PLANT OPERATION AND PERFORMANCE
Since its completion in early 1967, the Livermore Water Reclamation
Plant (Figures 28 and 29) has been able to consistently produce a high quality
effluent from the coupled trickling filter-activated sludge process. Because
of the advanced nature of the treatment process and the stringency of the dis-
charge requirements, operation and performance records for the 0.22-m3/sec
(5-mgd) plant are unusually complete. They allow a complete discussion of
operating procedures and plant performance for a full 7 yr of record from 1968
through 1974.
Although the overall performance record is good, some operational prob-
lems have occurred. In most cases, procedural changes or equipment modi-
fications have resulted in improvement. Problems which have occurred and
their possible remedies are important in the present context in order to give
guidance to designers of plants which might be constructed in the future.
Additionally, an evaluation of plant performance, coupled with recently de-
veloped knowledge of nitrification kinetics, can allow more precise, rational
design of future plants with less reliance placed on empirical approaches.
The purpose of this section is to discuss and evaluate the operation and
performance of the Livermore plant since its initial period of operation in
1967. Operational problems have included removal of solids from the primary
sedimentation tanks, a long-term breakdown of one of the two trickling filters
in 1968 and 1969, difficulties with the automatic control system for the filter
circulation sump, an undersized aeration air supply to the aeration tank, a
high secondary clarifier overflow rate, accumulation of solids in the chlorine
contact tank, and sludge lagoon odors. Performance of the plant has been
extraordinarily good because of lower than expected loadings, a well-trained
staff, and the existence of emergency holding ponds which allow shutdown of
portions of the plant without bypassing of inadequately treated wastewater to
the receiving waters.
As an introduction to this section, a description of sampling methods and
locations is given below. Following this and preceding detailed discussions
of individual plant components is a brief summary of overall plant perfor-
mance . Finally, a critical evaluation of plant performance compares operating
62
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Figure 28. Operations building, Livermore Water
Reclamation Plant.
Figure 29. Livermore plant control room.
63
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data with predicted values and summarizes the weaknesses and strengths of
the Livermore Water Reclamation Plant. Information from this section is
drawn on extensively in the discussion of general design considerations pre-
sented in Section 10.
SAMPLING METHODS AND LOCATIONS
Sampling of the wastewater stream is undertaken at five locations: raw
wastewater, primary effluent, trickling filter effluent, secondary effluent,
and final (or chlorine contact tank) effluent. Two major changes in the sam-
pling program during the period of interest require mention. During 1969 and
earlier,no samples were taken of effluent from the secondary clarifier. Final
effluent samples reflected settling of particulate matter in the chlorine tank
and possible changes induced by the high doses of chlorine required for dis-
infection. Beginning in 1970, sampling of secondary clarifier effluent was
incorporated in the regular sampling program.
The second change involved raw wastewater sampling. During 1969 and
earlier^raw wastewater was sampled by hand from the raw wastewater sump
following the metering flumes. An automatic sampler was installed in 1970,
but the high level of turbulence in the sump occasionally allowed air to
enter the sample line and created sampling difficulties. The raw wastewater
sampling point was then moved to the preaeration and primary sedimentation
tank influent channel following the raw sewage pumps. This resulted in im-
proved operation of the automatic sampler but has had an adverse effect on
measured raw wastewater characteristics because the activated sludge waste
mixed liquor and sludge lagoon supernatant are recycled to the headwords
ahead of the new sampling point. Review of operating records indicates that
an increase in raw wastewater 8005 and suspended solids concentrations of
30 to 50 mg/1 has resulted from this change in sampling point location. This
should be kept in mind when evaluating primary treatment removals and over-
all plant performance during and after 1970.
Sampling methods and main-stream sampling locations are presented in
Table 10. The constituents analyzed by the plant staff (Figures 30 and 31)
at these locations,along with the frequency of analysis, are listed in Table 11.
In addition to the constituents shown in Table 11, additional analyses of
plant effluent characteristics are made by an outside laboratory and include
measurement of a wide range of chemical constituents, including heavy met-
als. The full list of these constituents is given in Appendix D.
In addition to analyses of the main waste stream, plant records are
maintained for other operating parameters, principally aeration tank mixed
liquor characteristics and solids handling and treatment data. A list of these
data is also given in Appendix D.
64
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TABLE 10. PRINCIPAL SAMPLING METHODS AND LOCATIONS
Point in
flow stream
Location of
sampling point
Sampling method3
Raw waste-water
1969 and earlier
1970 and later
Primary effluent
Trickling filter effluent
Secondary effluent
(during and after
1970)
Final effluent
Raw wastewater sump
Preaeration tank influent
channel
Primary clarifier effluent
troughs
Aeration tank influent
over flow channel
(after 1973: at spigot
tap installed on discharge
side of one of the aera-
tion tank feed pumps)
Secondary clarifier
effluent channel
Chlorine contact tank
effluent line
24-hour, flow-proportional
composite; hand-sampled
hourly
24-hour, flow-proportional
composite; automatic
sampler with refrigerated
compartment; sampled
hourly
24-hour, flow-proportional
composite; hand-sampled
hourly
24-hour, flow-proportional
composite; hand-sampled
hourly
24-hour, flow-proportional
composite; hand-sampled
hourly
24-hour, flow-proportional
composite; automatic
sampler with refrigerated
compartment; sampled
hourly
aFor once-a-week composites. Some parameters may be monitored on a daily
basis.
An important limitation of the Livermore data is the absence of organic
nitrogen measurements ahead of the final effluent. In plants designed for
nitrification, organic nitrogen can be transformed to ammonia during biologi-
cal treatment and subsequently nitrified. Thus, the sum of the ammonia
nitrogen and organic nitrogen (total Kjeldahl nitrogen or TKN) is often used
to compute nitrification efficiencies. Raw domestic wastewater organic
nitrogen concentrations will usually be 40 to 70 percent of the ammonia ni-
trogen concentration.
65
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Figure 30. Demonstration of manual sampling technique.
Primary effluent is hand-sampled at the
primary clarifier effluent troughs.
Figure 31. Plant analytical laboratory. Wastewater and
sludge analyses are performed here.
66
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TABLE 11. WASTEWATER CHARACTERISTICS ANALYZED AT
PRINCIPAL SAMPLING POINTS
Parameter
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids, mg/1
Dissolved oxygen, mg/1
Settleable solids, ml/1
Total solids, mg/1
pH
Grease, mg/1
MBAS, mg/1
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Turbidity, JTU
Temperature, C
Total dissolved solids, mg/1
Fixed dissolved solids, mg/1
Specific conductivity, um
Chlorides, mg/1
Raw
sewage3
Wc
w
w
w
w
w
w
w
w
w
Primary
effluent
W
W
W
W
W
W
W(P)
Trickling
filter
effluent
W
W
Wd(P)
Wd(P)
Wd(P)
W(P)
W^P)
Wd(P)
Secondary
effluent^
W
W
W
D
W
W
W(P)
W(P)
W(P)
Plant
effluent
W
W
w
D
W
W
W
W
w
W(P)
W(P)
W(P)
D(P)
D(P)
W
W
W
W
Lluring and after 1970, raw sewage samples contain waste mixed liquor and sludge lagoon supernatant
returned to headwords.
bOnly for 1970 and later.
°W = weekly, D = daily, (P) = partial record
Not recorded on monthly logs.
PLANT PERFORMANCE SUMMARY
A brief summary of plant performance over the 7-yr period from 1968
through 1974 is presented in Table 12,which provides an overview of plant
performance prior to detailed discussions of specific plant components.
Wastewater flowing to the Livermore plant is primarily domestic and com-
mercial in origin as little industrial activity exists in the area. This results
in a consistent influent quality which has aided in the production of a high
quality effluent.
Flows have remained fairly constant over the period, ranging from 0.16
m3/sec (3.7 mgd) in 1968 to 0.20 m3/sec (4.6 mgd) in 1972. It has been
postulated exfiltration problems are in part responsible for the flow decreases
in 1973 and 1974, but this has not been substantiated.
The effect of recycled waste mixed liquor and sludge lagoon supernatant
is reflected by the increase in raw wastewater BOD5 and suspended solids
67
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TABLE 12. PERFORMANCE SUMMARY
Parameter
Flow, mgda
Raw Influent
BOD5, mg/1
Suspended solids, mg/1
Primary Effluent
BOD5
Concentration, mg/1
Removal, percent
Suspended solids
Concentration, mg/1
Removal, percent
Ammonia nitrogen, mg/1
Secondary Effluent
BOD s
Concentration, mg/1
Removal, percent0
Suspended solids
Concentration, mg/1
Removal, percent0
Ammonia nitrogen
Concentration, mg/1
Removal, percent0
Final Effluent
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids, mg/1
Ammonia nitrogen, mg/1
Organic nitrogen, mg/1
Nitrate nitrogen, mg/1
Total nitrogen, mg/1
Total solids, mg/1
Total dissolved solids , mg/1
Fixed dissolved solids, mg/1
Grease, mg/1
MBAS, mg/1
PH
Alkalinity, mg/1
Hardness, mg/1
Total coliforms, MPN/100 mle
Overall Removals, percent
BOD5d
Suspended solids**
Ammonia nitrogen0
1968
3.7
180
210
140
22
95
55
-
-
-
-
-
-
-
9.6
9.5
7
4.9
1.8
14
21
1,090
1,050
800
4.0
0.39
7.5
110
280
2.1
95
95
—
1969
4.0
180
180
130
28
76
58
-
-
-
-
-
-
-
6.6
12
8
0.51
1.3
22
24
800
770
510
2.6
0.15
7.3
85
210
2.1
96
93
—
1970
3.8
240
230
140
42
83
64
43
14
90
19
77
0.95
98
8.1
12
9
<0.11
1.0
22
23
780
760
490
2.5
0.07
7.0
74
200
2.1
97
95
>99
1971
3.9
210
230
130
38
79
66
41
10
92
22
72
1.7
96
7.3
13
4
<0.2
2.2
22
24
780
770
530
2.3
0.04
6.7
68
200
2.1
97
94
>99
1972
4.6
230
260
130
43
110
58
36
15
88
40
64
1.0
97
8.1
22
14
0.3
2.7
22
25
760
740
480
5.1
0.08
6.9
52
190
2.1
96
92
99
1973
4.1
220
240
120
45
80
67
52
16
87
28
65
1.5
97
9.4
28
18
1.2
2.6
23
27
860
840
540
5.2
0.06
6.9
58
210
2.1
96
88
98
1974 Overall
average
4.1
210
250
130
38
79
68
41
19
85
24
70
1.7
96
11
18
16
0.73
1.5
25
27
800
780
540
7.1
0.17
6.7
32
190
<2.1
95
93
98
4.0
210
230
130
38
86
63
43
15
88
27
69
1.4
97
8.6
16
11
1.1
1.9
21
24
840
820
560
4.1
0.14
7.0
68
210
2.1
96
93
99
amgd x 0.044 = m3/sec
Includes waste mixed liquor and lagoon super-
natant recycled to headworks during and after 1970
Based on primary effluent
Based on raw influent
BMedian
68
-------
values after the change in sampling points at the beginning of 1970. This
effect does not appear to extend beyond the raw wastewater values, however;
the data indicate that all of the recycled solids are removed by primary sedi-
mentation .
Removal of suspended solids and BOD5 in the chlorine contact tank is
indicated in Table 12. Although this provides a slightly better quality ef-
fluent, it also necessitates periodic cleaning of the tank, which requires
plant shutdown. This problem will be discussed in more detail later.
An informative method of illustrating the consistency of plant performance
involves plotting effluent quality in probability form; effluent concentration
(of BOD5, for example) is compared with the percentage oi time during which
that value is exceeded. Probability curves for secondary and final effluent
BOD5 concentrations in 1973 are plotted in Figure 32. Median values are 14
and 9 mg/1, respectively. Ninetieth (90th) percentile values, those con-
centrations which are exceeded only 10 percent of the time, are 26 and 15
mg/1, respectively. Similar results were achieved in other years.
High secondary effluent ammonia nitrogen concentrations affect the dis-
infection efficiency of the plant by preventing formation of free chlorine
residuals. Ammonia nitrogen probability curves for three years, 1970 through
1972, are plotted in Figure 33. Median values range from 0.82 to 0.99 mg/1,
and 90th percentile values fall between 1.3 and 1.9 mg/1. One value over
10 mg/1 was recorded during the 3-yr period and resulted from temporary
shutdown of one of the three blowers and consequent loss of full nitrification.
Final effluent coliform concentration (MPN/100 ml) probability curves
are shown for the same 3-yr period in Figure 34. The median, 90th percen-
tile, and 95th percentile values are approximately 2, 15, and 40 MPN/100 ml,
respectively.
Data presented above and in subsequent discussions have been chosen
for their illustrative value and, except where otherwise noted, are represen-
tative of general plant operation. Often, to reduce the amount of material
presented in the text, data from only a portion of the full 7-yr period are used
in graphs or tables. In addition, some data are completely omitted from the
text on the basis that their general interest is minimal. Appendix E comprises
monthly and yearly averages of most of the operating and performance para-
meters normally monitored at Livermore. The reader is referred to that appen1-
dix for more complete information on plant operation and performance.
OPERATION OF PLANT COMPONENTS
To provide a more detailed discussion of plant operations and performance,
it is convenient to divide the facility into several units or components and
69
-------
0
O
03
40
30
20
10
9
8
7
6
5
3 -
2 -
I I I I I I
I
SECONDARY EFFLUENT, 1973
FINAL EFFLUENT. 1973
I
I I
I
I
I
I
12 5 10 20 30 40 50 60 70 80 90 95 98 99
PERCENTAGE OF SAMPLES FOR WHICH CONCENTRATION WAS EXCEEDED
Figure 32. Probability curves for secondary and final effluent BOD,..
cover them individually. For purposes of this presentation, the Livermore
plant has been divided into eight components: (1) flows and flow metering,
(2) preliminary and primary treatment, (3) trickling filtration, (4) activated
70
-------
0.01 0.050.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99
PERCENTAGE OF SAMPLES FOR WHICH GIVEN CONCENTRATION WAS EXCEEDED
99.8 99.9 99.99
Figure 33. Probability curves for secondary effluent ammonia nitrogen.
sludge, (5) secondary clarification, (6) chlorination, (7) solids handling,
and (8) reclamation. For each component, a discussion is presented cover-
ing its operational characteristics and any changes in operating procedures
developed by the plant staff in response to problems encountered. Perfor-
mance data are graphically or tabularly presented, and, where relevant,
actual performance is compared with predicted performance. Subsequent to
71
-------
1,000
800
600
500
400
_ 300
E
8 2°°
\
Q.
5 100
Z 80
I-
50
40
30
20
cc
O
O
O
10
8
6
5
4
3 -
2 -
1
0.01 0.050.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70
PERCENTAGE OF SAMPLES IN WHICH GIVEN MPN IS EXCEEDED
80
Figure 34. Probability curve for final effluent total coliform organisms.
the discussions on individual plant components, an overall evaluation of
plant performance is presented, focusing on the relations among design load-
ings, experienced loadings, unit sizes, predicted plant performance, and
actual performance.
72
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Flows and Flow Metering
Influent flows to the Livermore plant are measured with two Parshall
flumes, each with a throat width of 0.38 m (15 in.). These are located in
the inlet works downstream from the comminutor and barminutor. Provision
has been made in the influent structure to allow addition of a third flume in
subsequent construction stages. Depth information from the meter is trans-
formed to a flow rate and is recorded and totalized at the control panel in the
operations building. All wastewater entering the plant must pass through the
flumes. In addition, any flow subsequently diverted to the holding ponds
from any point downstream of the inlet works must eventually be returned
through the flumes and will thus be measured a second time. This error is
insignificant on a long-term basis but may result in a discernible measured
flow increase over a several-day period when the ponds are being emptied.
Wastewater flow leaving the plant is measured by a Cipolletti weir lo-
cated downstream of the chlorine contact tank. The metered information is
recorded and totalized at a nearby instrument panelboard. This flow meter
has experienced erratic operation since its installation and has a long history
of equipment malfunction and consequent repairs by factory personnel.
Monthly average, peak-day, and minimum-day raw wastewater flows (in
mgd) recorded at the plant during the period of study are presented in Figure
35. The record shows an overall increase in flow from 1971 through 1972
with a subsequent decrease in 1973 and 1974. The precipitous decrease in
early 1973 prompted a field check of the influent and effluent flow meters in
July and August of that year. The results of those tests (discussed in more
detail below) indicated no reason for the sudden decrease; possible exfiltra-
tion from the sewer system remains the principal hypothesis.
It was noted in Section 5 that the design peak wet weather flow/average
dry weather flow ratio was 0.79 m3/sec £ 0.22 mVsec (18.0 mgd/5.0 mgd) =
3.6. In Figure 36,the probability curve for the ratio of daily peak flows to the
average long-term flow is plotted for the period September 1973 through
November 1974. This curve indicates that infiltration/inflow problems are
much less severe than anticipated, which has been attributed to quality con-
struction of new sewers and improved storm drainage systems. This has un-
doubtedly benefited plant operation, particularly with regard to secondary
clarifier loadings, which will be discussed below. A typical diurnal flow
curve for the plant influent is reproduced in Figure 37.
As noted above, the sudden flow decrease in early 1973 caused the
City to undertake a program to evaluate the influent and effluent flow meters.
The influent flow meter was checked two ways: (1) temporarily installing a
rectangular weir and flow recorder upstream from the comminutor and bar-
minutor and (2) operating the permanent recorder in conjunction with both the
73
-------
8.0
7.0 —
6.0 —
5.0 -
*
4.0 -
3.0 -
2.0 -
1.0
J
AVERAGE
MAXIMUM DAY
MINIMUM DAY
NOTE: mgd x 0.044 = m^day
1968
1969
1970
1971
1972
1973
1974
Figure 35. Monthly average, peak-day, and minimum-day flows.
permanently installed Parshall flumes and the temporary weir. The results of
the study indicated that while the plant recorder was operating correctly, the
Parshall flumes were incorrectly calibrated, resulting in a reading approxi-
mately 15 percent below the actual flow.
Flows recorded since September 1973 have been adjusted to account for
the error, and all flow values prior to that date have been increased by 15
percent for use in this report. A dye tracer study undertaken in 1971 (and
74
-------
2.6
2.4
2.2
2.0
O
cf 1.8
1.6
1.4
1.2
1.0
NOTE:
(1) PERIOD OF RECORD: SEPTEMBER 1973
THROUGH NOVEMBER 1974
(2) AVERAGE FLOW FOR PERIOD
= 4.2 mgd (0.18 m3/sec)
_L
_L
_L
_L
JL
_L
0.01 0.05 0.1 0.2 0.5 1 2 5 10 20 30 40 50 60 70 80 90
PERCENTAGE OF DAYS DURING WHICH GIVEN FLOW RATIO WAS EXCEEDED
95
98 99
Figure 36. Probability curve for peak-to-average flow ratio.
discussed later in the subsection on disinfection) tends to confirm the 15-
percent correction factor. Mean chlorine contact tank residence times mea-
sured in the tracer study were essentially equal to the calculated contact
time adjusted for the 15-percent increase above the recorded flow.
The Cipolletti weir effluent meter was checked by installing a temporary
recorder at the weir and comparing its results with those obtained through use
of the permanent recorder. Over a 6-day period, daily flows measured utiliz-
ing the temporary recorder ranged from 11 to 53 percent greater than those
indicated by the permanent recorder. It should be noted that effluent flows
were low during this period (less than 0.066 mvsec or 1.5 mgd) because of
diversions to the holding ponds, and that the greatest discrepancy, 53 per-
cent, was associated with the lowest flow, 0.032 m3/sec (0.72 mgd). Com-
parison of influent and effluent flows indicated that the Cipolletti weir was
properly calibrated.
As a result of the metering studies, influent flow values were subse-
quently adjusted and plans were made to improve metering performance
during the next plant modifications (undertaken in 1975).
75
-------
I
4.0
3J>
2JJ
MONDAY. JULY 30.1973
I I I
NOTE: mgd x .0438 • m °/sec
I I [_
0300
0600
0800
1200
1500
1800
2100
2400
Figure 37.
Typical diurnal
flow variation.
Preliminary and Primary Treatment
Preliminary treatment at the Liver-
more plant consists of prechlorlnation,
comminution, and preaeration-grit
removal. Wastewater entering the
plant passes through the comminutor
or barminutor placed upstream from
each of the two Parshall flumes. Pre-
chlorination for odor control is prac-
ticed with a dosage of 2-8 mg/1. The
chlorine addition point is the influent
manhole upstream from the headworks.
Raw sewage pumps lift the waste-
water into the influent channel ahead
of the preaeration-grit removal tanks.
Detention time at design flow is 36 min. A water-operated ejector,which dis-
charges to a grit washer*removes grit from the hopper in the tank bottom.
Problems associated with the preaeration-grit removal tanks are occa-
sional plugging of the grit ejector and formation of greaseballs which remain
in the preaeration tank. Greaseballs must be removed by hand, which is
unpleasant and at times hazardous. The average quantity of grit removed has
ranged from 0.04 m3/day (1.4 ft3/day) in 1969 and 1970 to 0.15 m3/day (5.3
ftVday) in 1974.
The primary sedimentation tanks (Figure 38) are located downstream from
the preaeration-grit removal tanks in the same structure. These are conven-
tional rectangular tanks 37.8 m (124 ft) long and 5.8 m (19 ft) wide with an
average water depth of 2.7 m (9 ft).
Primary clarifier BODg and suspended solids removals for 1968 and 1969
are plotted as a function of overflow rate in Figure 39. As indicated previ-
ously, the inclusion of waste mixed liquor in the sampled raw wastewater
after 1969 makes calculated removals for those years erroneously high. The
removals shown for 1968 and 1969 are somewhat lower than anticipated.
Reasons for this are uncertain as the design overflow rate, detention time,
and weir loading rate are within values which would be expected to provide
better performance. A possible explanation is that the waste mixed liquor
added at the headworks does, in fact, affect primary effluent quality.
Performance has not been of concern, partly because flows have been
below the design value, but principally because influent BOD5 and sus-
pended solids concentrations have been far less than the design concentra-
76
-------
Figure 38. Primary sedimentation tanks. These tanks
performed more poorly than predicted, but
low hydraulic and suspended solids loadings
have minimized this effect.
tions of 300 mg/1, which corresponds to loadings of 5,670 kg/day (12,500
Ib/day) at a flow of 0.22 m3/day (5.0 mgd). Concentrations in 1968 and
1969 were in the 180-220 mg/1 range, and from estimates of the effect of
waste mixed liquor in more recent years, the influent values appear to have
remained low. Thus, even though primary sedimentation removals have been
less than predicted, loadings to the biological treatment units have not ex-
ceeded design levels. The reason for the difference between predicted and
actual influent loadings is that the design concentrations were based on
measurements using 8- or 16-hr composite samples, which resulted in higher
measured concentrations. A comparison of predicted and actual removals for
all the plant units is presented in the summary evaluation later in this sec-
tion.
The principal operational problem associated with primary treatment has
involved sludge removal using the air-lift pumps. Removal is controlled
manually by the plant operator who adjusts the removal rate on the basis of
visual observation of sludge entering the raw sludge sump. This has proved
to be a poor method of control with underpumping or overpumping often
occurring. Poor sludge removal control is an important problem at Livermore
because of limited solids treatment capacity. A reduction in raw sludge
solids content decreases the hydraulic and solids retention times in the mixed
digesters,which in turn will reduce digestion efficiency. This aspect is dis-
77
-------
too
1 1 1 1 1 1
NOTE: (1) POINTS REPRESENT MONTHLY AVERAGES
(2) gpd/ft2 x 0.041 = m3/day/m2
O 1968
Q 1969
SUSPENDED
SOLIDS
DESIGN VALUE FOR
SUSPENDED SOLIDS
SUSPENDED SOLIDS
DESIGN
VALUE
400
500
600 700 800
OVERFLOW RATE, gpd/ft2
900
1000
1100
Figure 39. Primary clarifier performance.
cussed further in the subsection on solids handling and treatment. Improve-
ment in sludge removal could be accomplished either by installing automati-
cally controlled, positive displacement sludge pumps or by combining a more
accurate determination of sludge solids content with the existing manual con-
trol.
Trickling Fitters
The two rock-media trickling filters are used ahead of the activated
sludge unit to enhance removal of organic material and allow nitrification to
occur in the aeration tank. There are no clarifiers between the trickling filters
and the aeration tank; thus, the measured BODg loading to the activated
sludge unit reflects sloughing of biological solids from the filter media sur-
face. While this sloughed biological material will undergo endogenous res-
piration in the aeration tank and may thus affect air requirements, it does not
constitute substrate for the activated sludge organisms in the usual sense.
78
-------
Calculation of a food-to-microorganism ratio (F/M) should be modified to
reflect this. Similarly, in calculating activated sludge solids retention times,
the significance of including or excluding the effect of entering sloughed bio-
logical solids must be understood. These points will be discussed further in
conjunction with the activated sludge unit and in Section 10, General Design
Considerations.
Trickling filter performance for 1971 is summarized in Table 13. At a flow
equal to about 80 percent of design, the average BODc loading on the filters
was 0.85 kg/m3/day (53 lb/1,000 ftVday), or about one-half the design
value. This again reflects the lower-than-expected raw wastewater
concentrations experienced at Livermore.
TABLE 13. TRICKLING FILTER PERFORMANCE SUMMARY, 1971
Parameter
Flow, mgda
Filter Influent BOD 5 loading ,
lb/1,000 ft^day13
Filter influent concentrations, mg/1
BOD5
Suspended solids
Volatile suspended solids
Ammonia nitrogen
Filter effluent concentrations , mg/lc
BOD 5
Suspended solids
Volatile suspended solids
Ammonia nitrogen
Reductions (increases), percent
BOD5
Suspended solids
Volatile suspended solids
Ammonia nitrogen
High
month
4.1
62
160
98
88
51
130
140
117
44
19
(43)
(33)
18
Low
month
3.7
45
110
60
33
34
46
74
63
22
58
(19)
(91)
35
Annual
average
3.9
52
130
79
61
41
93
110
92
33
28
(39)
(51)
20
amgd x 0.044 = m /sec
blb/l,000 ft3/day x 0.016 = kg/m3/day
Analyses made on unsettled effluent
Average BOD5 removal across the filters for 1971 (based on unsettled
effluent) was 28 percent. As shown in Appendix E, removals for other years
in the operating period range from 15 percent in 1972 to 42 percent in 1969.
Although a design removal of 50 percent was previously indicated in Table 3,
there was little basis for this number, and it was in fact not relevant to the
process design. It was noted in Section 5 that design of the activated sludge
79
-------
system was based on the assumption that equal filter and aeration tank vol-
umes are equivalent in providing biological wastewater treatment.
Sloughing of biological solids from the filter rock is reflected in Table 13
by the increases in suspended solids (39 percent) and volatile suspended
solids (51 percent). Some solids entering the trickling filter can be expected
to be oxidized by the filter slime; thus, the numerical increase in solids con-
centration across the filter (110-79 = 31 mg/1 in 1971) may be less than the
actual solids yield of the filter biological process. Use of a trickling filter
without a secondary clarifier has been so rare that little work has been done
on the characteristics of the unsettled effluent.
Average ammonia nitrogen removal for 1971 was 8 mg/1, or 20 percent.
This is largely due to incorporation of nitrogen into the biological cells pro-
duced. Approximately 1 kg of nitrogen is required for every 20 kg of BODc
removed by biological treatment.
Settling of Trickling Filter Effluent—
While precise analysis is difficult, it is useful to attempt to estimate the
actual removal of BODc across the filters along with the quantity of biological
solids produced. To this end, Figure 40 was prepared which relates unsettled
trickling filter effluent BOD5 to the value obtained after allowing the sample
to settle 1 hr (data available only for 1974). From the figure, the settled
BODc, concentration is approximately one-half the unsettled value. A useful
assumption is that the settleable material is sloughed biological solids. Re-
lating Figure 40 with Table 13 indicates that the actual BOD5 removal in 1971
was approximately Q.30-(93/2JQ /130 = 64 percent rather than the 28 percent
shown in Table 13. For comparison, as indicated previously in Table 2
(Section 4), an average BODc removal of 66 percent was achieved across the
trickling filter-secondary clarifier combination in 1964 at an average organic
loading of 1.2 kg BOD5/m3/day (75 lb/1,000 ft3/day).
Trickling filter BODc, removals (based on estimates of settled effluent
concentrations) for the 7 yr of record are compared with trickling filter am-
monia nitrogen removals in Table 14. The average estimated BODc removal
for the full period was 84 mg/1. Using the value referred to above of 1 kg
nitrogen utilized per 20 kg BODc removed, the expected ammonia nitrogen
removal associated with this BOD,, removal is 4.2 mg/1. This is very close
to the measured average removal, 5 mg/1, implying that settling the trickling
filter effluent for 1 hr provides a good estimate of actual BOD5 removal.
Operation with One Trickling Filter—
Breakdown of the recently installed trickling filter distributor in 1968 and
1969 required that the plant be operated with only one filter for three separate
80
-------
80
60
in
Q
O
co 40
Q
LU
20
NOTE: (1) TIME PERIOD--FEBRUARY-NOVEMBER 1974
(2) SETTLED BODg VALUES BASED
ON ONE - HOUR SETTLING
(3) AVERAGE VALUES, mgfi:
INFLUENT ( PRIM. EFFL. )M30
UNSETTLED EFFLUENT : 68
SETTLED EFFLUENT- 35
(4) POINTS REPRESENT O
DAILY VALUES O
BOD5 = 0.5 BOD5
SET. UNSET.
20
40
60 80 100
UNSETTLED BODg, mg/l
120
140
160
Figure 40. Effect of settling on trickling filter effluent
periods totaling 10 mo. During this time,the total flow was put through one
filter, resulting in a substantially increased loading. The data summarized
in Table 15 shows that while the average BODs loading increased from 0.72
kg/m3/day (45 lb/1,000 ft3/day) with both filters in operation to 1.92 kg/m3/
day (120 lb/1,000 ft3/day) with one filter out of service, BOD5 removal de-
creased only slightly irom 40 to 32 percent (based on unsettled effluent). The
slightly higher suspended solids increase for one filter is probably due to
initial sloughing under the higher hydraulic loadings.
Filter Circulation Sump--
It was noted in Section 5 that the use of fixed-speed pumps for
delivering wastewater from the filter circulation sump to the activated
sludge aeration tank is made possible by the use of an automatically con-
trolled butterfly valve in a return line to modulate the flow. Difficulties
have occurred with this approach; during peak and low flows, the control
system tends to "hunt" and causes fluctuations in the flow to the aeration
tank. Because of the inadequate air supply in the aeration tank, high
loadings can adversely affect nitrification there. Continual checking by
the plant operators is necessary to ensure that problems do not occur.
81
-------
TABLE 14. TRICKLING FILTER
BOD, REMOVAL
Year
1968
1969
1970
1971
1972
1973
1974
Average
BODs
removed ,
mg/la
93
92
90
84
75
71
- 86
84
Ammonia
removed
Measured
-
-
6
8
2
6
5
5
nitrogen
, mg/1
Estimated b
4.7
4.6
4.5
4.2
3.8
3.6
4.3
4.2
Activated Sludge Aeration Tank
As discussed in Section 5, the
activated sludge aeration unit is a
single, two-pass tank utilizing dif-
fused air aeration for oxygen supply.
Three fixed-speed blowers supply the
system, and underdesign of these
units has been one of the principal
operational problems faced at the
plant.
Despite this problem, the acti-
vated sludge system has been able to
consistently provide excellent results.
This has been due to the lower-than-
expected loadings received at the
plant, the consistency of influent
flows and loadings, and the buffering
effects of the roughing filter. A sum-
mary of activated sludge system per-
formance for 1971 is presented in
Table 16. The average and maximum-
month secondary effluent BOD5 con-
centrations of 10 and 17 mg/1, respectively, attest to the quality and consis-
tency of performance. Secondary effluent ammonia nitrogen concentrations
ranged from monthly values of 0.46 to 6.7 mg/1 and averaged 1.7 mg/1 for the
year. The high value occurred in March and resulted from shutdown of one
of the three blowers for repairs. The low value for air supplied, 45 m^/kg
(720 ftVlb) BODg + NOD (nitrogen oxygen demand)* removed, also occurred
during March.
The overall average of 1.7 mg/1 is somewhat higher than should be ex-
pected from nitrification in an activated sludge system; it may be due to
bleed-through of ammonia at peak loading periods, which will be discussed
further below. Solids retention times varied from 4.2 to 8.6 days during the
year. As will be discussed below, these values are retention times for the
nitrifying organisms and ignore the effect of biological solids entering the
aeration tank from the trickling filter.
3BOD
5 - 0.5 x unsettled BOD
5out
3Based on 0.05 Ib NH4 - N removed/lb BODs removed
*kg TKN x 4.56 = kg NOD. For this report, NH^ - N concentrations are sub-
stituted for TKN in calculating NOD since TKN concentrations were not
routinely determined.
82
-------
TABLE 15. TRICKLING FILTER PERFORMANCE—EFFECT OF
REMOVING ONE FILTER FROM SERVICE
Parameter Two filters3 One fliterb
Flow, mgd
BOD5. , mg/1
BOD5out, mg/1
BOD5 loading, lb/1,000 ft3/day
Suspended solids increase, percent
BOD 5 reduction percent
3.3
130
78
45
21
40
4.1
140
95
120
29
32
aTwo filters operating: Jan-Sept '68; Jan, Feb, Aug-Oct '69
One filter operating: Oct-Dec '68; Mar-July, Nov, Dec '69
°mgd x 0.044 = m3/sec
dlb/l,000 ftVday x 0.016 = kg/m3/day
Air Supply—
Air for the activated sludge system at Livermore is supplied by three
rotary-lobe, positive displacement blowers and air diffusion spargers. The
blowers operate at a fixed speed and deliver 57 mVmin (2,000 ft3/min) each
to the aeration tank and waste mixed liquor air-lift pumps. Originally de-
signed to be operated with one blower as a standby unit, the high oxygen
demand imposed by the nitrification process has dictated that all three blow-
ers often be used simultaneously. The result has been that any lengthy
shutdown for repairs causes a partial loss of nitrification. The most common
maintenance problem has been bearing failure in the blowers. With replace-
ment bearings kept on hand, repair usually requires 20 to 40 hr; longer
shutdowns have occurred, however. In September 1974, for example, major
repairs to one blower required 10 days to complete.
In addition to supplying the aeration tank, the three fixed-speed blowers
also supply the air-lift pumps utilized for wasting mixed liquor from the sys-
tem. Increasing or decreasing the number of operating blowers causes the
83
-------
TABLE 16. ACTIVATED SLUDGE PERFORMANCE SUMMARY, 1971
Parameter
High
month
Low
month
Annual
average
Plant influent flow, mgda
Aeration tank influent concentrations, mg/1
BOD5
Suspended solids
Ammonia nitrogen
Secondary effluent concentrations, mg/1
Suspended solids
Ammonia nitrogen
Nitrate nitrogen
Reductions, percent
BOD$
Suspended solids
Ammonia nitrogen
Volumetric loading, lb/1,000
ft3/dayc'
4.1
130
140
44
17
31
6.7
20
93
86
99
3.7
46
74
22
5.2
15
0.46
17
85
65
84
3.9
93
110
33
10
22
1.7
18
89
80
95
BOD
BODj +NOD
Food: microorganism ratio, Ib BODg applied
/lb MLVSS/dayb'd
Mixed liquor suspended solids, mg/1
Mixed liquor wasted, mgd
Solids retention time, autotrophic
nitriflers, days6
Return activated sludge suspended
solids, mg/1
Return activated sludge flow , percent
of influent flow
Air supplied, ftVftb BODs + lb NOD removed)f
28
67
0.27
2,320
0.226
8.6
8,800
38
1,470
10
36
0.12
1,700
0.083
4.2
6,650
30
720
21
55
0.21
2,010
0.159
5.6
7,890
34
99,0
mgd x 0.044 = m /sec
bBased on unsettled trickling filter effluent
Clb/l,000 ftVday x 0.016 = kg/m3/day
Based on a VSS/SS ratio of 0.79 measured in 1973-74
Calculated as combined mass VSS lost per day
in waste sludge and secondary effluent divided
by mass MLVSS in aeration tank
fft3/Ibx 0.0624 =m3/kg
waste mixed liquor flow rate to decrease or increase, meaning that the flow
rate must be checked and adjusted each time a blower is turned on or off.
The immediacy of nitrogenous oxygen demand in nitrification systems
requires the use of peak rather than average ammonia loadings for design
purposes. A typical daily BOD5 + NOD loading to the activated sludge aera-
tion tank is shown graphically in Figure 41. Although the average BOD5 +
NOD loading for the day was 5,070 kg/day (11,200 Ib/day), the peak mea-
sured rate was 9,450 kg/day (21,000 Ib/day), almost 90 percent above the
average. For design, either instantaneous peak rates or short-term averages
such as the maximum 3-hr average should be used.
84
-------
•&
AVERAGE FLOW
= 3.9 mod
AVERAGE BOD5 + NOD
LOAD ING = 11,200 Ib/day
DATE: JANUARYS, 1970
NOTE: (1) mgd x 0.044 = m-/sec
(2) Ib/day x 0.45 = kg/day
500
1000 1500
TIME, hours
2000
to
•o
Q
O
LO
Q
O
m
2400
Figure 41. Flow and loading to aeration tank.
DO levels in the aeration tank are an important parameter in operating a
nitrification system and, of course, directly reflect the quantity of air sup-
plied and the loading of oxygen demanding substances. DO measurements at
Livermore were initially taken near the effluent end of the two-pass aeration
85
-------
tank. Readings were taken hourly, and the number of operating blowers was
increased or decreased according to the values obtained. In early 1972,in-
vestigations were undertaken by the plant staff to determine the desirability
of taking DO measurements nearer the head of the aeration tank. The results
of the several-week test indicated that the same level of performance could
be obtained with an overall reduction of air usage of approximately 10 percent.
A further advantage was the reduction in frequency of blower adjustments re-
quired. Previously, the number of blowers being used had to be changed
three to six times per day. Subsequent to the modification in operating pro-
cedure, two or three adjustments have usually been adequate.
With plug flow operation of the aeration tank (as at Livermore), the low-
est and thus limiting DO level occurs at the head end of the tank because the
oxygen demand is greatest at that point. By taking DO measurements at this
point, more precise and efficient control can be maintained. Figure 42 shows
DO concentrations for the two ends of the tank over a 1-day period after use
of influent-end DO levels for control was begun. The influent-end DO in-
creased during the night when the loadings were low and started to decrease
around 7 a.m. as the loadings became higher. At noon,the third blower was
put into operation, and the influent-end DO level remained at a nearly con-
stant level for the remainder of the day. Although the hourly loading fluctua-
tions are not available for that date, the pattern is probably similar to that
manifested in Figure 41. Records of
monthly average DO concentrations
4.0
3J)
X
o
a
ui
IX)
FEB. 28. 1972:
AIR USAGE =
740 ft 3 AlR/(lb
BOD6 + Ib NOO)
REMOVED
NOTE: ft3/lb x 0.062 •
m3/kj
TWO BLOWERS
THREE BLOWERS
I
1
are given in Appendix E.
Residence Time Distribution—
In the conventional activated
sludge process, primary effluent and
return activated sludge are added to
the aeration tank at the head end and
leave the tank at the downstream end.
The Livermore plant is normally opera-
ted in this manner, although it can be
operated in the sludge reaeration or
step aeration modes (see Section 5).
To evaluate the effect of hydraulic
load patterns, the plant was operated
in the sludge reaeration mode for a
1400 i«x) i8oo 2000 »»«"short period in 1971. Return activated
sludge was added to the head end of the
Figure 42. Aeration tank dissolved aeration tank, and trickling filter ef-
0200 0400 0600 0800
1000 1200
TIME
oxygen levels.
fluent was added at the quarter point.
86
-------
Nitrification was immediately adversely affected, and a return to the conven-
tional mode was made after several days. It was concluded that the reduced
contact time in the sludge reaeration mode of operation caused bleed-through
of ammonia which was not oxidized during the shorter aeration period.
Measurements of MLSS levels during the period when sludge reaeration
was utilized indicated little change in MLSS concentrations along the tank
length. This indicates that considerable back-mixing occurs in the tank and
suggests that under conventional operation the residence time distribution
differs significantly from ideal plug flow, a condition in which all water parti-
cles are in the tank for approximately the same length of time. If back-mixing
occurs, a significant fraction of the flow may leave the tank before ammonia
oxidation has been completed. Ammonia bleed-through will be exaggerated by
operation in the sludge reaeration mode because the aeration contact period
will be significantly reduced.
Calculation of an "axial dispersion number" also indicates that the resi-
dence time distribution in the Livermore aeration tank is quite different from
plug flow. This parameter is defined by D/uL, where D is the axial disper-
sion coefficient in mvhr, u is the mean displacement velocity along the tank
length (including recycle) in m/hr, and L is the tank length in m. A valid
empirical relation for D for both fine and coarse bubble diffused air systems
is:1
D= 0.290 W2 (A)°*346* (1)
where: W = tank width, m, and
A = air flow per unit tank volume, standard m3/min/l,000 m^.
The"axial dispersion number"is zero for true plug flow tanks and infinite
for true complete-mix tanks. Tanks with D/uL < 0.2 are usually classified
as plug flow reactors, while for complete-mix reactors, values are generally
greater than 4.0.
For the Livermore plant,the'axial dispersion number"at Q = 0.18 mVsec
(4.0 mgd) with 40 percent recycle is equal to 0.46. Because this is larger
than 0.2, it indicates that plug flow is not well approximated in the aeration
tanks.
*D = 3.122 W2 (A) °'346, D in ft2/hr, W in ft, A in standard ft3/min/l ,000 ft3.
87
-------
Sludge Wasting—
The mixed liquor suspended solids (MLSS) level in an activated sludge
aeration tank is controlled by wasting excess activated sludge from the sys-
tem. At Li vermore/wasting is accomplished from the mixed liquor line between
the aeration tank and secondary clarifier (Figures 43 and 44). An air-lift pump
delivers a portion of the mixed liquor to a constant-head tank consisting of a
circular overflow weir and line (leading back to the mixed liquor line) with
adjustable rings to control liquid head and a V-notch weir to measure and con-
trol waste activated sludge flow (refer to Figure 12 in Section 5). Waste
mixed liquor is returned to the headworks, where essentially all the solids
are removed during primary treatment so that there is little effect on subse-
quent units.
Figure 43. Mixed liquor leaving aeration tank
over a circular weir.
88
-------
In practice, flow over the constant-head tank, circular weir is affected by
flow from the air-lift pump, which in turn is dependent on the number of blow-
ers operating. This has necessitated adjustment of the overflow weir each
time a blower is started or stopped.
The more conventional method of wasting sludge is from the return acti-
vated sludge line. This can be done at Livermore, although metering is not
available. Generally, wasting of return activated sludge has been confined
to 1-hr periods, three or four times per month, in order to quickly reduce the
aeration tank MLSS level when it has become too high.
Solids Retention Time—
A parameter often used in operating activated sludge systems is the
solids retention time (often termed "mean cell residence time" or "sludge
Figure 44. Constant-head tank in the mixed liquor
line for wasting activated sludge.
89
-------
age"), or 9 ec is defined as the inverse of the growth rate, u-K,, of the
organisms wnich oxidize the waste matter. In the conventional activated
sludge process where oxidation of carbonaceous matter is the principal objec-
tive, the volatile suspended solids levels of the pertinent flow streams are
usually taken as representing the heterotrophic organism concentrations of
those streams.
The solids retention time can be computed for this situation by developing
a mass balance around an activated sludge system as follows:
Rate of change Organisms Net organism Organisms
of organism = entering + growth rate - leaving
mass in system system in system system
dX
Q-T7S=QX +(u-K)VX -(QX
dt R d
where: Q = aeration tank influent flow rate, excluding sludge recycle,
r
^H = heterotrophic organism concentration rate of change in system,
dt
= heterotrophic organism concentration entering aeration tank
1 in influent flow,
X = heterotrophic organism concentration in aeration tank,
HML
X__ - heterotrophic organism concentration in secondary effluent,
H2
XTT = heterotrophic organism concentration in waste sludge stream,
Q = sludge wasting flow rate,
y = heterotrophic organism growth rate,
K, = organism decay rate, and
V = aeration tank volume .
At steady state conditions, — rr- = O, and Equation 2 becomes:
90
-------
Q _ y . QW
X
ML ML
H ML ML ML
VX
MT
which further reduces to: 6 = •— - — — - - — — (4)
CH QXH2 + QWXHW " QXH1
where: 6 = heterotrophic organism solids retention time.
CH
In the usual situation where primary effluent enters the system, X^ is
11 1
taken as zero since it is assumed that very few organisms are entering the
reactor. Where a roughing filter precedes the activated sludge unit, however,
some significant fraction of the aeration tank influent volatile suspended
solids are biological cells sloughed from the filter media, and XH cannot be
taken as zero. 1
The above derivation considers only aeration tank volatile suspended
solids inventory in determining solids retention time. Some investigators
prefer to calculate activated sludge solids retention time based on total sec-
ondary system volatile suspended solids inventory. In this case, the numer-
ator of Equation 4 represents volatile suspended solids held in the secondary
clarifier as well as in the aeration tank. Solids retention times calculated
using the total system inventory will be larger than those calculated using aera-
tion tank inventory only, substantially so if a deep sludge blanket is main-
tained in the secondary clarifier. The difficulty encountered in employing the
total system inventory method is obtaining an accurate estimate of the average
volatile suspended solids mass in the secondary clarifier over a 1-day or
several-day period.
Because nitrifying organisms are not produced in a roughing filter appli-
cation, the concentration of nitrifiers in the filter effluent is negligible, and
the equation for the nitrifier solids retention time, 9 , will be as follows:
CN
e = _
CN QXN +
IN IN 2
where: XM = nitrifying organism concentration in aeration tank,
ML
91
-------
X = nitrifying organism concentration in secondary effluent,
2 and
= nitrifying organism concentration in waste sludge stream.
W
Because the nitrifying organism concentrations can be taken as a constant
fraction, f, of the respective heterotroph concentrations, Equation 5 becomes:
VfXR
» '
CN QKH. + VH... QXH. + QWX
with the volatile suspended solids levels used for X.
Comparison of Equations 4 and 6 shows that the nitrifier solids retention
time will be shorter than that for the heterotrophs. 9 should be used when
designing and operating coupled trickling filter-activated sludge systems for
nitrification. Further discussions of this concept will be presented in Sec-
tion 10.
As shown previously in Table 16, the monthly average solids retention
times at Livermore in 1971 ranged from 4.2 to 8.6 days and averaged 5.6 days;
these values were computed for the autotrophic nitrifiers (Equation 6) and
are based upon use of the aeration tank volume as V.
The biological solids entering the activated sludge unit from the trickling
filter cannot be ignored in process design. Although they do not directly
affect the nitrifier solids retention time and although (as noted previously)
settled BODij values should be used in determining waste loadings to the
activated sludge unit, the sloughed biological solids will affect aeration tank
size. This will also be discussed further in Section 10.
Secondary Clarifier
The diameter of the secondary clarlfier (Figure 45) at Livermore was
limited by physical constraints at the site as noted in Section 5. Addition-
ally, higher design overflow rates were generally used at that time. The
result was a 27-m (90-ft) diameter clarifier with an ADWF overflow rate of
32.1 m3/day/m2 (787 gpd/ft2). Average annual secondary effluent suspended
solids concentrations are plotted against hydraulic overflow rate and solids
loading rate, respectively, in Figures 46 and 47. The excellent correlations
between these loading rates and clarifier performance suggest that clarifier
size strongly affects performance at Livermore.
92
-------
Figure 45. Secondary clarifier.
It should be pointed out that when the above parameters are plotted using
daily or monthly averages, the scatter is significantly greater than found in
Figures 46 and 47. Further, there is no strong correlation between secondary
effluent BODr concentrations and these loading rates or between BOD5 and
suspended solids levels. In fact, it has not been possible to correlate ef-
fluent BODc values with any single loading parameter. This is probably due
to the fairly narrow range of loadings experienced, the number of different
parameters which can affect performance, and normal scatter. Nonetheless,
the 5-yr average (1970-74) secondary effluent BOD5 and suspended solids
concentrations of 15 and 27 mg/1, respectively, are testimony to the excellent
performance that the coupled trickling filter-activated sludge system is cap-
able of providing.
An equipment breakdown in late 1974 necessitated shutdown of the sec-
ondary clarifier while repairs were made. During this period, trickling filter
effluent was diverted to the holding ponds. The retaining bolts and brackets
holding the sludge withdrawal lines in place over the circular trough on the
93
-------
40
CO
a
8
o
Ul
a
IU
8s
3
IU
20
10
NOTE: (1) PLOTTED POINTS REPRESENT
ANNUAL AVERAGES. 1970-74
(2) gpd/ftzx 0.041
• m3/d»y/m2
clarifier bottom had failed due to cor-
rosion, allowing water from the higher
levels of the tank to be withdrawn
through the return activated sludge
(RAS) lines. The problem was mani-
fested by a low RAS solids content and
high effluent suspended solids concen-
tration. The cause of the problem was
discovered when a portion of the me-
chanism extending above the waterline
was noticed to be out of alignment.
Clarifier dewatering and repair using
stainless steel bolts and nuts followed.
Disinfection
560 600 650 700
OVERFLOW RATE, gpd/ft2
Figure 46. Secondary clarifier
performance versus
hydraulic loading.
I
8
S
a
Ul
o
Ul
SO
40
30
20
10
NOTE: (1) PLOTTED POINTS REPRESENT
ANNUAL AVERAGES, 1970-74
(2) to/*t2/d*y x 4.88 - kg/mZ/
-------
(see Appendix C) by the Regional Board to 2.2 MPN/100 ml based on a 7-day
median. Sampling frequency was changed from 5 days/wk to 7 days/wk,
and as before, sampling was done at the period of peak flow, approximately
1:00 p.m.
Chlorination Control—
In the initial design, chlorination control was accomplished by utilizing
a compound-loop system comprising a flow vacuum control unit and two am-
perometric chlorine residual analyzer-controllers (Figure 48). The flow vac-
uum control unit measured the wastewater flow rate upstream of the chlorine
injection point to regulate chlorine dosage proportional to hydraulic flow.
Immediately following chlorine injection, a wastewater sidestream was con-
tinuously pumped to the first residual analyzer-controller, which measured
chlorine concentration and transmitted a signal to the chlorinator. This re-
sulted in adjustment of chlorine dosage based on initial chlorine demand. At
the end of the chlorine contact tank, another wastewater sidestream was con-
tinuously pumped to the second residual analyzer-controller (to measure chlo-
rine residual prior to discharge) from which an override set-point signal was
transmitted to the first residual analyzer-controller.
CHLORINATOR
CONTROL
ANALYZER
MONITOR
ANALYZER
CHLORINE
METERING
ORIFICE
VACUUM
REGULATING
VALVE
ELECTRIC
SIGNAL
Figure 48. Original chlorination control system.
95
-------
During the first full year of operation, 1968, man/ problems were en-
countered with this control system. Both sampling pumps required a complete
overhaul, and the analyzers were a constant source of trouble, principally due
to leaks and plugged tubing.
In the following year/an attempt was made by the plant staff to develop a
new method of chlorination control based on the concept of using wastewater
pH instead of chlorine residual as the control parameter. Addition of suffi-
cient chlorine to water containing ammonia (approximately 10 parts by weight
of chlorine is required for each part ammonia nitrogen) results in the produc-
tion of hydrogen ions and a lowering of pH according to the following break-
point reaction:
1.5Cl0+NHt »-0.5N0' +4H++3C1~ (7)
Chlorine added to wastewater after the breakpoint is reached reacts ac-
cording to the following equation:
(8)
This further lowers the wastewater pH. The product of this reaction, hypo-
chlorous acid (HOC1), exists in equilibrium with its dissociation product,
hypochlorite ion (OC1~), according to the equation.
HOC1 ^ ^ OCl" + H+ (9)
The sum of the hypochlorous acid and hypochlorite ion existing in solu-
tion is known as "free available chlorine", which is a significantly better
disinfecting agent than the combined chlorine compounds (principally mono-
chloramine, NH2C1) that are the disinfecting agents occurring in non-nitrified
wastewater effluents .
Of the two free available chlorine compounds , hypochlorous acid is a
much stronger disinfectant than hypochlorite . Equation 9 indicates that hypo-
chlorous acid is formed by a hydrogen ion concentration increase (pH de-
crease) which drives the reaction to the left. The effect of pH on HOC1 and
OCl" distribution is shown in Figure 49 .2 It can be seen that if the pH is
lowered to about 6.5, a significant fraction of the free chlorine will be in the
hypochlorous form.
This principle forms the basis for the control system developed at Liver-
more in 1969 and used continuously since that time. Chlorine is added to
the nitrified effluent at a rate which causes the pH to drop to about 6.5 in
the chlorine contact tank. Although this control method could be automated,
funds have not been available to purchase the required equipment and manual
control has proven to be satisfactory.
96
-------
100
90
80
70
60
S.
o
O 40
30
20
10
20 C
OC
0
10
20
30
40
50
«>
70
80
90
8 9
pH
10
11
12
.100
Disinfection performance obtained
during initial experimental studies
conducted with the pH control system
is summarized in Figure 50. Total
coliform survival ratio, y/y , is
plotted against the product of chlorine
residual, R and the chlorine contact
time , t. Although values of y the
unchlorinated secondary effluent coli-
form MPN, were not measured during
the study period, tests made at other
times indicated values around 106
MPN/100 ml; this value was taken as
yQ in preparing Figure 50.
3
Selleck and Collins in laboratory
studies of primary effluent chlorine
disinfection, found the kill of coliform
organisms followed the empirical rela-
tion:
Figure H9.
Relative amounts of HOCI
and OCI at various pH
levels (Ref. 2).
= A (RT)
-3
(10)
where R is the total chlorine residual
in mg/1 and T is contact time in min-
utes. Selleck and Collins found that A = 64 for primary effluent, and this re-
lation is shown in Figure 50 for comparison. Plant-scale disinfection studies
at Rancho Cordova, California,4 with non-nitrified secondary effluent yielded
a similar relation with A = 4.0; this is also shown in Figure 50.
Although there are insufficient data available from Livermore to completely
confirm the minus-three slope, this value has been assumed for the line drawn
through the plotted points in Figure 50. The Livermore data indicate that for
free chlorine disinfection of nitrified secondary effluent, A = 0.65.
Livermore has utilized pH control of chlorine addition since 1969 with
excellent results, but difficulties can occur with this method. A principal
problem stems from the fact that it is a very indirect control method and de-
pends on a wastewater consistency,which does not always occur. Factors
other than chlorine addition can cause a pH drop and an accompanying dosage
decrease (although this can be compensated for by monitoring pH prior to
chlorination).
97
-------
1.0
10'1
ID'
1C
(0
-------
TABLE 17.
SUMMARY OF pH
CHLORINATION
CONTROL STUDIES
Parameter
Value
8.6 MPN/100 ml. These are very
close to the mean and 90th percentile
values shown previously in Figure 34,
which is based on the full contact
time provided by the pipe and the con-
tact tank.
Chlorine Contact—
After chlorine is added at the by-
pass manhole, the wastewater flows
through the 76-m (250-ft) long, 1.4-
m (54-in.) diameter pipe and into the
: two-pass chlorine contact tank (Fig-
ure 51). Each pass is 30.5 m (100 ft)
long, 3.2 m (10.5 ft) wide, with a
water depth of about 4 m (13 ft). Mean detention time in the contact tank at
design flow is 1 hr. The 1.4-m (54-in.) pipe adds another 8 min to the design
contact time, and because flow in the pipe is very close to plug flow, the
overall residence time distribution is very favorable for disinfection.
In the original design, plastic tubing was laid on the bottom of the con-
tact tank to provide mixing through air addition. Mixing prevents settling of
particulate matter and improves residence time distribution by helping to
Chlorine dose, mg/1
Chlorine residual, mg/1
Contact time, min
Secondary clarifier pH
Contact tank Influent pH
Coliform concentration, MPN/100 ml
Median
90th percentile
22.5
6.8
9.9
7.4
6.6
2.1
8.6
Figure 51. Chlorine contact tank. Air mixing
takes place in pass on right.
99
-------
eliminate dead space. Air addition also increases the DO concentration and
raises pH. The high chlorine residual concentrations had an adverse effect
on the tubing,and the air diffusion holes soon became plugged. Without air
addition, the chlorine contact tank had to be cleaned at 1- to 2-mo intervals
to remove settled matter; if it were not cleaned, disinfection performance was
adversely affected.
In 1969,air diffusion spargers were added to the second pass to improve
mixing. Surface spray heads were installed in the first pass to aid removal
of floating material, principally filter flies, entering the contact tank. Peri-
odic shutdown is still required for cleaning the first pass.
In 1971,a study was undertaken by the California State Department of
Public Health to determine the residence time distribution of the chlorine con-
tact unit, including both the 1.4-m (54-in.) pipe and the tank.5 A slug of
dye tracer was added at the bypass manhole where chlorine injection takes
place. Fluorescence was then measured over time at the chlorine contact
tank exit. The results are shown in Figure 52. Fluorescence, in arbitrary
units, is plotted against t/Tcaic, where t is time and Tcajc is the calculated
detention time, V/Q. Curves are shown for experiments with and without air
added to the second pass. Each curve is based on two tests.
Performance is reflected by how closely the residence time distribution
matches plug flow. In an ideal plug-flow system, all the tracer would leave
the tank at t/T , =1.0. Two useful measures of performance are the time
required for tracer to be first detected, or t^t and the time at which effluent
tracer concentration is a maximum; the latter is termed the modal time, or tm.
Figure 52 shows that dye first
appeared in the contact tank effluent
at t /T caic = 0.4 to 0.5. Addition of
air to the second pass inproved the
flow characteristics by increasing t_/
WITH AIR ADDED
Tcalc from 0.72 to 0.83.
m'
m
CALC
Figure 52. Residence time distribution
for chlorine contact tank.
The values for both ti/Tcalc and
/Tcalc indicate excellent flow char-
acteristics , far better than could be
expected with the contact tank alone.
The improvement is apparently due to
the presence of the 1.4-m (54-in.)
pipe ahead of the tank which provides
flow characteristics very close to
plug flow.
100
-------
The mean residence time can be measured from the residence time distri-
bution curve and theoretically should be equal to the calculated detention
time, T i = V/Q. Because some tracer may remain in dead spaces of the
tank for times much longer than tm, measured mean residence times, Tmeas
are usually lower than calculated values. Tmeas/Tcaic values were 0.88
without air added and 0.97 with air; these indicate reasonable agreement be-
tween the flow measurement (corrected as discussed earlier) and dye tracer
measurement studies.
The probability distribution for effluent total coliform MPN's was shown
previously in Figure 34 and demonstrates the excellent performance of the
Livermore Water Reclamation Plant in meeting the stringent disinfection re-
quirements. Disinfection performance, including dosage, total chlorine
residual, contact time, and median and 90th percentile coliform concentrations,
is summarized in Table 18 for the 7-yr study period. Because samples for
coliform determination are taken at the period of peak flow, the contact times
shown represent the minimum for the day.
TABLE 18. DISINFECTION SUMMARY
Parameter
Flow, mgda
Chlorine dose, mg/1
Chlorine residual, mg/1
Contact time, min
Coliform concentration, MPN/100 ml
Median
90th percentile
1968
3.7
20
>7.2b
99
2.1
32
1969
4.0
20
>8.5b
64
2.1
IS
1970
3.8
25
>8.8b
72
2.1
19
1971
<• 3.9
32
14
75
2.1
15
1972
4.6
29
16
54
2.1
15
1973
4.1
34
17
60
2.1
15
1974
4.1
39
18
62
<2.l
—
Average
4.0
28
16C
69
2.1e
15e
amgd x 0.044 = m3/sec
Affected by maximum meter reading
CBased on 1971-74
Based on maximum flow during day
SMedian
Solids Handling and Treatment
In the plant expansion from a 0.11- to a 0.22-m /sec (2.5- to 5.0-mgd)
flow capacity, no increase in anaerobic digester capacity was included. The
two existing digesters were retained, and their operational mode was changed
from the conventional primary-secondary operation to dual primary (or mixed)
digesters. In order to treat the increased solids loading resulting from the
101
-------
increased plant flow and from incorporation of the activated sludge process in
the plant flow diagram, two anaerobic sludge lagoons were constructed, each
with a volume of 9,062 m3 (320,000 ft3). The original sludge drying beds
were retained but have been rarely used because of long drying time's and
difficulties in cleaning the beds.
A summary of solids handling and treatment data for 1968-1974 is pre-
sented in Table 19. A more complete compilation is presented in Appendix E.
The average hydraulic and solids retention time was 20 days. At a solids
loading of 1.8 kg dry solids/m3/day (0.11 Ib/ft3/day), approximately one-
half the design value, volatile solids reduction in the digesters has averaged
about 53 percent, slightly less than the assumed value of 60 percent shown
previously in Table 3.
Solids handling ability has been a problem for the plant staff over the
years, and odors from the sludge lagoons have often been noted. Because
TABLE 19. SOLIDS HANDLING AND TREATMENT SUMMARY
Parameter
Sewage flow, mgda
Sludge flow to digesters , gpdb
Sludge flow to lagoons , gpd*3
Solids retention time , daysc
Raw sludge total solids, percent
1968
3.7
17,100
18,400
23
3.8
1969
4.0
18.000
17.500
22
3.8
1970
3.8
18,800
18,700
21
3.5
1971
3.9
20,600
20,300
19
3.5
1972
4.6
22,300
21,900
18
3.7
1973
4.1
22,800
22,600
• 17
3.3
1974
4.1
21,400
21,200
19
3.3
Overall
average
4.1
20,100
20,100
20
3.6
Raw sludge volatile solids, percent
of total 80 82 84 84 83 83 84 83
Digested sludge total solids , percent
Digester No. 1
Digester No. 2
Digested sludge volatile solids ,
percent of total
Digester No. 1
Digester No. 2
Volatile matter reduction , percent
Digester No. 1
Digester No. 2
Gas produced, 1,000 ft3/dayd
Digester No. 1
Digester No. 2
1.8
2.3
67
68
49
46
21.7
6.9
2.2
2.1
67
68
56
54
15.3
11.4
1.7
1.5
71
71
53
54
14.1
12.6
1.6
1.6
71
71
54
54
12.7
18.4
2.0
1.7
70
71
52
51
14.2
16.4
1.7
1.4
69
68
54
55
9.4
32.7
1.6
2.3
71
72
53
52
11.1
16.8
1.8
1.8
69
70
53
52
14.0
16.5
amgd x 0.044 = m3/sec
gpd x 0.0038 = m3/day
Nominal value. Grit and scum accumulation reduced usable volume by about one-third by 1974.
dl,000 ft3/day x 28.3 = mVday
102
-------
the solids retention time is equal to the hydraulic retention time for mixed
digesters, a low solids concentration in the raw sludge will adversely affect
performance. This situation has occurred occasionally due to the difficulty
in determining the solids content of sludge being withdrawn from the primary
sedimentation tanks.
As was noted in the discussion of primary clarifier performance, solids
withdrawn from the clarifiers are discharged into an open sump with an invert
approximately 3 m (10 ft) below a grated opening. This sump is checked by
the plant operator on an hourly basis, and the sludge withdrawal is increased
or decreased accordingly. Because of the difficulty in judging the solids con-
tent in this manner, sludge underpumping or overpumping often occurs. In
particular, the beginning of each operator shift seems to be associated with
the occurrence of such problems.
The system was part of the original trickling filter plant and seems to
have operated well under those circumstances. Operating data from 1964
shows an average raw sludge solids concentration of 5.9 percent. With acti-
vated sludge added to the plant flow diagram, average yearly values dropped
to a range of 3.3 to 3.8 percent (Table 19), slightly lower than the values of
4 to 5 percent often cited as typical for combined primary and settled acti-
vated sludge.^f7
Digester operation has generally been satisfactory over the years, al-
though upsets have occasionally occurred. When upsets have occurred, the
digester has been emptied and the digestion process started again.
Digester heating is provided by burning gas produced in the process,
although provision has been made for use of natural gas when required. In
1970,the sludge circulation lines were insulated to improve digester heating.
Although Livermore's digesters are operated in a completely mixed mode,
mixing has apparently been insufficient to prevent some stratification from
occurring. In 1973,both digesters were checked and it was found that un-
digestible solids and grease had accumulated in each tank, reducing usable
volumes by one-third and making calculated detention times erroneously high.
One was cleaned in 1974, and the other is scheduled for cleaning soon.
Digester gas production is summarized in Figure 53. Monthly average
gas production is plotted against volatile matter destroyed. The design value
of 0.94 m3/kg (15 ft3/lb) is indicated as a straight line. Problems with gas
flow meters have plagued the plant over the years, usually resulting in low
readings. In developing Figure 53, readings taken during a period when prob-
lems were occurring were not used.
103
-------
50
I
40
2
o,
Q
O
oc
a.
30
20
10
NOTE:
(1 )ftjx 0.028 = m3
(2) Ib x 0.45 = kg
(3) PLOTTED POINTS
REPRESENT
MONTHLY AVER AGES
DESIGN: Q 1968
15ft3/lb * 1969
VOLATILE MATTER
DESTROYED (0.93 m3/kg)
• 1971
X 1972
+ 1973
-------
Figure 54. Sludge lagoons {left foreground). These lagoons
have a history of odor problems. Piping for odor
masking chemicals is located on bank. Little-
used sludge drying beds are in right background
To minimize the odor problem, the maximum water depth of 3 m (10 ft) is
maintained in the lagoons. In addition, odor masking equipment was installed
in 1969 adjacent to the downwind side of the ponds and consists of a diffuser
system to spray deodorant chemicals into the air. At first, various masking
agents were tried but without much success. At present, a patented deodor-
ant chemical is being used which has effected an improvement, although odor
complaints have not been entirely eliminated.
Studies with other sludge lagoons, principally at Auckland, New Zealand,
indicate that to prevent odor nuisances, the lagoon volatile solids loading
should be less than about 100 kg/1,000 m2/day (20 lb/1,000 ft2/day). In
recent years,the loadings at Livermore have approached 300 kg/1,000 m^/day
(60 lb/1,000 ft2/day).
Lagoon supernatant returned to the headworks is not regularly monitored
for BOD5 and suspended solids, but limited testing in 1969 indicated a BOD5
level of 1,000 to 1,500 mg/1 and a suspended solids concentration of 300 to
105
-------
400 mg/1. During the first year of operation, fairly large amounts of lagoon
supernatant were returned in short time periods, causing problems from slug
loading. Since that time, however, the return procedure has been modified
and problems have not recurred.
The four sludge drying beds were part of the original plant and were re-
tained in the expansion to 0.22 m3/sec (5.0 mgd). They are conventional
sand drying beds with 0.6-m (2.0-ft) vertical concrete walls around the sides,
0.3 m (12 in.) of sand in the bottom, and perforated metal pipe designed to
collect filtrate from gravel drains and return it to the headworks. Even during
Stage 1 operations, some difficulties occurred because of inadequate capacity.
The drains became plugged immediately, and evaporation and subsurface per-
colation were relied on to remove the water. After expansion,they have rarely
been used because of the difficulties in cleaning the sand and because 3- to
4-mo drying times are required for 0.5 m (20 in.) of sludge. About 99 percent
of the digested sludge has been treated in the lagoons. The dried sludge re-
moved from the beds has been used as a soil conditioner by the City.
Reclamation Program
Reclamation of wastewater effluent for irrigation purposes has provided
the City with an important supplemental water source in an area where impor-
tation has become necessary. Presently, about 162 ha (400 ac) are avail-
able to receive effluent, including 61 ha (150 ac) at the golf course, 20 ha
(50 ac) at the municipal airport, and about 81 ha (200 ac) of privately owned
farmland. Crops grown include sugar beets, cucumbers, squash, Sudan, and
oats.
Wastewater effluent used for reclamation purposes in California must
meet quality requirements set by the State Department of Public Health. For
landscape irrigation of the golf course and airport, the applicable requirement
states that the effluent must be "an adequately disinfected,oxidized waste-
water" . Adequate disinfection is assumed if the effluent total coliform MPN
does not exceed 23/100 ml as a 7-day median.8
For surface irrigation of food crops which are to be processed in such a
manner that pathogenic organisms are destroyed, a quality equivalent to
primary effluent was required during the period covered by this report. This
has recently been modified. Now, surface irrigation of any food crop requires
the equivalent of secondary treatment and disinfection to a total coliform
MPN of 2.2/100 ml as a 7-day median. The requirements now state that
exceptions to the above requirements may be made where the food crop will
undergo extensive commercial processing sufficient to destroy pathogenic
agents.
106
-------
The requirements for spray irrigation of food crops has been similarly-
modified. Previously, the requirement considered only food crops which would
be processed to destroy pathogenic organisms and stipulated a disinfected,
oxidized waste water with a 7-day median coliform MPN not exceeding 23/100
ml. The requirement now applies to all food crops and stipulates that the
waste water be "adequately disinfected, oxidized, coagulated, clarified, (and)
filtered". Disinfection requirements now stipulate that the 7-day median
total coliform MPN not exceed 2.2/100 ml with a maximum of 23/100 ml
allowed in no more than one sample per month. Exceptions may again be al-
lowed for processed food crops.
Livermore Water Reclamation Plant effluent can meet any of the require-
ments except the coagulation and filtration requirements for spray irrigation of
unprocessed food crops, and plant modifications recently completed will allow
this requirement to be met.
The wastewater reclamation pattern shown for 1972 in Figure 55 is typical
of irrigation demand in California. Little or no water is used in the wet months
of October through March, but the demand is fairly constant from April through
September.
6.0
5.0
4.0
3.0
2.0
1.0
0"—'
NOTE^mgd x .044 = m3/day
PLANT INFLUENT
RECLAMATION
17 PERCENT OF
WASTEWATER
FLOW RECLAIMED
FOR IRRIGATION
Figure 55. Typical annual reclamation pattern.
107
-------
OPERATION AND PERFORMANCE EVALUATION SUMMARY
The information presented in this section indicates that, while some diffi-
culties have been encountered in operating the upgraded Livermore Water
Reclamation Plant, overall operation has been stable and has resulted in an
effluent which is consistently low in contaminants.
Selected plant design parameters are listed in Table 20 along with corres-
ponding performance data for 1968 and 1972, the years of lowest and highest
measured influent flows, respectively. Many of the operational aspects dis-
cussed in this section are reflected in Table 20: low influent loadings, low
primary treatment BOD5 and suspended solids reductions, the influence of
overflow rate on secondary clarifier performance, and the excellent final ef-
fluent quality. Because of the problem referred to previously of determining
the significance of unsettled trickling filter effluent, loadings and removals
for the combined biological treatment process are also shown in Table 20.
The discussion below summarizes major points made in this section with
emphasis on problems which have been encountered. Items include (1) over-
all stability and performance, (2) influent loadings, (3) trickling filter effluent
characteristics, (4) aeration capacity, (5) secondary clarifier performance,
(7) disinfection, (8) bypassing, and (9) solids handling and treatment. The
reader is referred to previous portions of this section where appropriate.
Overall Stability and Performance
More than 7 yr of operating experience have shown the coupled trickling
filter-activated sludge system to be a highly stable and reliable biological
treatment process configuration, capable of producing a nitrified effluent low
in BOD5 and suspended solids and amenable to disinfection to a very low total
coliform MPN. The plant superintendent has expressed confidence in the
process and has indicated that his experience with it has been very favorable.
Summary plant performance data have been presented in Table 12 and Figures
32-34. Detailed monthly operating and performance data are presented in
Appendix E. Operational difficulties discussed below have been due primarily
to lack of adequate knowledge during design of the unique characteristics of
this process configuration.
Influent Loadings
Reliance on previous 8- and 16-hr composite samples for determination
of influent BOD5 and suspended solids concentrations led to greatly over-
estimated projected BODs and suspended solids loadings. While the design
loading for both parameters was 5,670 kg/day (12,500 lb/day)f annual
average values have not exceeded about 3,400 kg/day (7,500 Ib) excluding
the effects of waste mixed liquor and lagoon supernatant in the influent.
108
-------
TABLE 20. DESIGN AND PERFORMANCE
Parameter
Design
1968
1972
Influent
Flow, mgda
BOD5,
Suspended solids, lb/dayb
Primary Treatment
Overflow rate, gpd/ft2
BOD5 reduction, percent
Suspended solids reduction, percent
Trickling Filter - Activated Sludge Process
Organic loading, Ib BODS/1,000 ft3
trickling filter plus aeration tank volume/day6
BODS reduction, percent
Suspended solids reduction, percent
Ammonia nitrogen reduction, percent
Trickling Filters
Organic loading, Ib BOD5/1,000 ft3/day6
BODg reduction, percent
Activated Sludge Aeration Tank
Volumetric loading, Ib BODs/1,000 ft3/daye
Air supplied, ft3/(lb BOD5 + Ib NOD removed)11
Secondary Clarifier
Overflow rate, gpd/ft2
Effluent BOD 5, mg/1
Effluent suspended solids, mg/1
BODg reduction, percent
Based on activated sludge influent
Based on raw wastewater
Suspended solids reduction, percent
Based on activated sludge influent
Based on raw wastewater
Final Effluent
BOD5, mg/1
Suspended solids, mg/1
Median total coliform organism concentration,
MPN/100 ml
Solids Handling
Digester loading, Ib dry solids/ftVdayl
Volatile matter reduction, percent
Gas production, ftVlb volatile matter destroyed
5.0
12,500
12,500
1,050
35
60
35
92
87
100
509
289
1,200'
787
15
15
869
96
869
96
20 3
20 1
0.22
60
15
3.7
,000
,700
780
22
55
19
_ f
_ f
f
50
339
209
582
If
f
f
_f
_f
9.6
9.5
0.10
48
14
4.6
8,700C
9,900°
970
43C
58°
21
88
75
97
62
159
329
821
725
15
40
86g
93C
67g
90C
8.1
22
2.1*
0.13
52
10
mgd x 0.044 = mvsec
blb/day x 0.454 = kg/day
Affected by waste mixed liquor and sludge lagoon
supernatant recycled to headworks
dgpd/ft2 x 0.041 = m3/mz/day
elb/l .000 ft3/day x 0.016 = kg/m3/day
Secondary effluent quality not measured in 1968
9Based on unsettled trickling filter effluent
ft3/lb x 0.0624 = mVkg
Based on BODs only, two of three blowers operating
Requirements set by California Regional Water
Pollution Control Board, see Appendices B and C
Monthly median
hb/ft3 x 16 = kg/m3
109
-------
These low loadings have greatly aided plant performance. In particular/
removals in the primary sedimentation tanks have been slightly lower than
anticipated, and the air supply for the activated sludge aeration tanks
was significantly underdesigned. Serious operational problems would have
developed if loadings had been as high as anticipated. In addition, the
inadequacies in the solids handling and treatment portion of the plant would
have been even more apparent.
Trickling Filter Effluent Characteristics
One of the most perplexing problems facing the designers of the upgraded
plant was prediction of the relationship between the trickling filters and the
activated sludge process. Very little information was available about the
characteristics of the unsettled filter effluent that was to enter the aeration
tank.
The design engineers avoided this problem by designing the biological
treatment portion of the plant on the basis of total trickling filter plus aeration
tank volume. The operating record of the plant has contributed to a greater
understanding of the trickling filter-activated sludge interrelationship, but
complete answers to some questions are still missing.
It is clear that much of the BODg measured in unsettled trickling filter
effluent is not waste material from the plant influent stream but rather bio-
logical solids sloughed from the filter media. Allowing filter effluent to
settle 1 hr reduces the measured BOD,- concentration by about 50 percent.
Although this probably underestimates slightly the aeration tank influent
BOD5 concentration, it is a more accurate value than that based upon un-
settled trickling filter effluent. The sloughed biological solids must be
accounted for, however, in design of the activated sludge unit.
Aeration Capacity
The most serious operational problem has been a lack of adequate air
supply for the activated sludge aeration tanks. The three fixed-speed blowers,
which are capable of providing 57 m3/min (2,000 ft3/min) of air each, must
all be used simultaneously during a portion of the day, eliminating the use of
one blower for standby purposes. Blower shutdowns, usually resulting from
bearing failures which require 20 to 40 hr to repair, cause a temporary loss of
nitrification due to low DO concentrations. The resulting high effluent am-
monia nitrogen levels make adequate disinfection more difficult to attain
because of combined chlorine residual formation.
Because ammonia nitrogen is not sorbed by cell material to undergo oxi-
dation later, it must be oxidized during the period that the waste water is in
the aeration tank. As the ammonia loading can vary greatly over a 24-hr
110
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period, the oxygen demand at peak periods can be quite high. It is possible
that even with all three blowers operating at Livermore, ammonia bleed-
through occurs at times. The bleed-through would not be apparent because
measurements made on 24-hr composite samples would tend to mask this
effect.
Secondary Clarifier Performance
Underdesign of the secondary clarifier has resulted in a secondary ef-
fluent suspended solids level somewhat higher than expected. The design
ADWF overflow rate of 32.1 m3/day/m2 (787 gpd/ft2) reflects the higher val-
ues often used at that time and the necessity of restricting the size to allow
plant piping to be installed. The effects of hydraulic and solids loadings on
effluent suspended solids levels were indicated preciously in Figures 46 and
47, respectively. Higher loadings have resulted in deterioration of effluent
quality.
Disinfection
The restrictive, 7-day median, effluent coliform requirement of 2.2 MPN/
100 ml (5.0 MPN/100 ml during the first portion of the study period) makes
proper operation of the disinfection step extremely important. After experienc-
ing much difficulty during the first 2 yr of operation using a conventional com-
pound loop chlorination control system with amperometric residual chlorine
analyzers, the plant staff developed a chlorination control method which in-
volves adding chlorine until a specified pH, usually around 6.5, is reached.
If the wastewater is low in ammonia nitrogen, free chlorine residuals will be
formed and, at the low pH,hypochlorous acid (HOCl) will be predominant over
hypochlorite ion (OC1 ). The former compound is a much stronger disinfecting
agent, and the objective of this control method is the production of a high
percentage of HOCl.
It was noted that there are inherent problems with this control method,
specifically that a change in wastewater characteristics such as ammonia
nitrogen concentration, pH, or alkalinity can affect the performance. The
consistency of the raw wastewater quality at Livermore has allowed the plant
staff to use this control method with singular success for more than 6 yr.
However, caution should be used in considering this control method for other
plants.
Chlorine contact is provided by a conventional chlorine contact tank with
a 60-min detention time at design ADWF. Preceding the open tank is a 76-m
(250-ft) long, 1.4-m (54-in.) diameter, full-flowing pipe from the secondary
clarifier. Studies undertaken during initial experiments with pH chlorination
control in 1969 indicated that adequate disinfection was being attained at the
111
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point where the 1.4-m (54-in.) pipe enters the contact tank. The advantage
of additional contact time in the open tank is therefore uncertain, although it
certainly provides an extra measure of protection in ensuring that the dis-
charge requirements will be met.
Presently, air mixing is undertaken in the second pass of the contact
tank to reduce dead space, raise the DO level, and raise the pH. No mixing
occurs in the first tank with the result that contamination from solids deposi-
tion requires cleaning at 4- to 6-wk intervals to ensure that disinfection re-
quirements can be met.
Bypassing
Conversion of portions of existing oxidation ponds to emergency holding
basins during plant upgrading has greatly aided plant operation by allowing
temporary discharge of raw or partially treated wastewater during periods of
process unit shutdown. This is particularly valuable at Livermore because of
the stringent discharge requirements and the absence of parallel units for the
aeration tank and secondary clarifier. Wastewater stored in the basins is
returned to the plant headworks during low flow periods after the plant is re-
turned to service.
The principal problem occurring in bypassing is that primary or trickling
filter effluent must pass through the chlorine contact tank to reach the holding
basins. This contaminates the tank through deposition of solids, and it must
be cleaned prior to returning it to service.
Solids Handling and Treatment
Plant expansion and the addition of the activated sludge process greatly
increased solids production at the Livermore plant. Although sludge lagoons
were added during expansion, sludge handling difficulties have occurred and
have been manifested principally by odors from the lagoons.
The problem begins with the air-lift pumps which withdraw primary sludge
and waste activated sludge from the primary sedimentation tanks. Installed
originally to withdraw primary and trickling filter sludge from the clarifiers,
the air lifts now pump a raw sludge with a solids content generally less than
4 percent. The two digesters, constructed with the original plant, are opera-
ted as parallel, mixed digesters whose effluent is discharged to the sludge
lagoons. The low solids content and deposition of sand in a large fraction of
the digester volume has reduced the solids retention time for the mixed diges-
ters, resulting in a volatile solids reduction of around 50 percent in compari-
son with the design value of 60 percent. The lagoons receive nearly all
112
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this less than completely digested sludge as the sludge drying beds con-
structed with the original plant can accept less than 1 percent of the total.
Continued digestion thus takes place in the lagoons, thereby precipitating
periodic odor complaints from nearby residents.
Conclusions
The Livermore Water Reclamation Plant has provided excellent wastewater
treatment through use of a coupled trickling filter-activated sludge bio-
logical treatment unit. The problems which have occurred are ones which can
be eliminated in future plants of this type. Specific design suggestions
for upgrading existing trickling filter plants to coupled trickling filter-
activated sludge plants will be discussed in Section 10, General Design
Considerations.
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SECTION 9
TREATMENT COSTS
Presented in this section are summaries of capital and operating ex-
penses for the upgraded Liver-more Water Reclamation Plant. Capital costs
cover detailed design, construction, and construction inspection; operating
expenses include salaries, power and chemicals, operating supplies, direct
maintenance, and administrative overhead. Costs are categorized where pos-
sible to aid evaluation.
CAPITAL COSTS
Because the upgrading of the Livermore plant involved both an expansion
in flow capacity as well as modifications to the treatment flow daigram,
it is useful to attempt to differentiate between these two categories in
documenting capital costs. Although it is difficult to provide a complete
breakdown of costs into the two categories of expansion and upgrading, this
has been done to the extent possible.
Bids for construction were received on February 24, 1966, and the con-
tract was awarded on February 28, 1966. The contract price was $1,067,000
(including $20,000 for contingencies) and corresponded to a San Francisco
area ENR Construction Cost Index of 1150. Work was begun in March 1966
and completed in mid-1967. A breakdown of the bid was shown previously in
Table 6 (Section 6). An installed cost breakdown for major equipment items
was given in Table 5. The final total construction cost was $1,056,000
(rounded off) as summarized previously in Table 8.
Detailed engineering design work for the project totaled approximately
$62,000, or 5.9 percent of the construction cost. This included periodic
assistance during construction; full-time resident engineering services were
not provided by the consultant. Also, preliminary planning costs are not in-
cluded in the above figure. Costs borne by the City during construction for
resident engineering and inspection were approximately $12,000, or 1.1 per-
cent of the contract price. This includes only direct salary and fringe bene-
fits for the single inspector employed by the City. Other costs, such as
114
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administrative overhead and direct expenses associated with inspection by
the City,are not available. Adding these figures together yields a total proj-
ect capital cost of $1,130,000.
Because the costs given above are for both upgrading and expansion, it
is useful to present a previously developed estimate for expansion only,
maintaining the original trickling filter-oxidation pond treatment scheme.
These costs are given in Table 21 and are taken from a feasibility study pre-
pared for the City by Brown and Caldwell in April 1964. Over half the total
is for additional land for ponds.
OPERATION AND MAINTENANCE COSTS
Costs for operating the Livermore Water Reclamation Plant have been
tabulated for the years 1968 through 1974 in Table 22. Salary costs include
direct salaries plus fringe benefits for plant personnel. Power and chemicals
comprise electric power, natural gas
TABLE 21. ESTIMATED COST FOR
EXPANSION OF ORIGINAL
LIVERMORE PLANT TO
5.0 MCD (0.22 M3/SEC)
WITHOUT UPGRADING
Plant Unit
Pretreatment and raw
sewage pumping
Trickling filter
Secondary clarifier
Digested sludge lagoons
Chlorine contact tank
Oxidation ponds
Percolation beds for golf
course irrigation water
Subtotal
Engineering and
contingencies, 23 percent
Total
Purchase of 120 acres for
oxidation ponds
Total project cost
Construction Cost,
dollars3
12,100
148,000
182,000
18,100
30,200
113,000
12,100
515,500
119,600
635,100
725,000
1,360,100
for augmenting digester heating, and
chlorine. Operating expenses are
normal supplies and direct expenses
attributable to plant operation. Main-
tenance includes direct costs for re-
pairs and contractual maintenance for
specific items. Administrative over-
head consists of the costs allocated
to the administrative and clerical
staffs of the City Department of Public
Works.
Total labor time at the Livermore
plant is divided into five categories:
operation, maintenance, repair, labo-
ratory and monitoring, and yard work.
A summary of the work load distribution
for the 7-yr period from 1968 through
11974 is presented in Table 23. After
19 69, the total number of man-hours
worked increased very little, only 4
percent from 1969 through 1973. The
final column shows the average per-
centage of the total allocated to each
classification: 45 percent of the total
ENR Construction Cost Index =1150
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TABLE 22. OPERATION AND MAINTENANCE COSTS, LIVERMORE
WATER RECLAMATION PLANT
Category
Salaries
Power and chemicals
Operating expenses
Maintenance and repair
Administrative overhead
Total
Percent Increase
1968
101
30
36
12
17
196
-
1969
126
33
39
12
22
232
18
Annual
1970
134
39
30
14
34
251
8
cost, thousand
1971
150
43
32
15
25
265
6
dollars
1972
155
48
32
15
27
277
5
1973
160
63
34
17
33
307
11
1974
178
84
43
36
40
381
24
TABLE 23. WORK LOAD DISTRIBUTION
Item
Time, man-hours
Cperation
Maintenance
Repair
Laboratory and
monitoring
Yard
Part-time ,
unclassified3
Total
Annual increase.
percent
Average salary cost.
dollars per man-hour
Annual increase.
percent
1968 1969
7,210 7,805
2,506 2,160
2,450 2,855
2,801 3,214
1,844 1,585
1,182
16,811 18,801
12
6.01 6.70
11
1970
8,605
2,923
2,800
3,272
1,916
-
19,516
4
6.87
3
1971
8,820
2,567
2,630
2,913
1,600
-
18,530
-5
8.09
18
1972
9,062
2,748
2,695
2,570
1,762
-
18,837
2
8.23
2
1973
9,150
2,997
2,963
2,895
1,544
-
19,549
4
8.18
-1
1974
8,714
3,795
3,714
3,004
1,632
-
20,859
7
8.53
4
Average ,
percent
of total
45
15
15
15
10
-
100
4b
-
6
Summertime student employees.
3
Average annual increase.
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man-hr under operation; 15 percent each under maintenance, repair, and
laboratory and monitoring; and 10 percent under yard work.
Normal staffing at the Livermore plant consists of a superintendent,
seven operators, a laboratory technician, and a maintenance mechanic. Yard
work is provided through the Department of Public Works as a direct cost.
Clerical work is provided as an overhead item. The plant is staffed on a 24-
hr, 7-day basis.
Annual quantities of labor, chlorine, and electric power are plotted along
with average annual flow for the years 1968 through 1974 in Figure 56. Labor
required for plant operation has been fairly stable over the years, as is to be
expected. Power costs have been related to flow/ also as expected. Chlorine
usage rose sharply, however, increasing from just over 100,000 kg/yr
(220,000 Ib/yr) in 1969 to almost 215,000 kg/yr (470,000 Ib/yr) in 1972,
a 215 percent increase in 4 yr. This was due principally to an increase in
chlorine dosage necessitated by the changing of the disinfection requirement
from 5.0 to 2.2 total coliform MPN/100 ml in late 1971 and to the changeover
to pH control of chlorine addition.
TOTAL ANNUAL COST
Capital costs and operation and maintenance costs can be combined to
give a total annual cost or total treatment cost for any particular treatment
plant. Common methods of expressing such costs are dollars/yr or cents/m^
(cents/1,000 gal) of wastewater treated.
To determine total annual cost, the capital costs must be amortized at a
specific interest rate over a period of time. An interest rate and payment
period often used for planning purposes are 7 percent and 20 yr, respectively.
Based on these values, the capital cost of $1,130,000 is equivalent to
$107,000/yr.
The operation and maintenance cost for 1968 was $196,000 at a flow of
0.16 mVsec (3.6 mgd). Adding this figure to the annual cost of capital
yields a total annual cost of $303,000/yr.
It is useful to attempt to adjust this figure by expressing capital and
operating costs on the same basis. The capital costs are associated with an
ENR Construction Cost Index for the San Francisco area of 1150 in early 1966.
By mid-1968,the Index had risen to 1250, resulting in an adjusted capital cost
of $1,228,000. The equivalent annual cost at 7 percent and 20 yr is$115,000/
yr. Combining the 1968 operation and maintenance cost with the amortized
cost results in a total annual cost of $311,000/yr in 1?^8 dollars.
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eo r 60°
50
40
o.
S
o
c
•
E
o
o
o
500
•400
•
a
30
ac
o
m
20
VO
0 "-
§
in
3
IU
z
o
X200
100
o L-
6.0
5.0 -
4.0
3.0
2.0
1.0
NOTE: (1) mdg x 0.044 - m3/iec
(2) Ib x 0.45 - kg
FLOW
6.000
5.000
4.000 ;
a
3,000
2,000 0
_>
in
1.000
1968
1969
1970
1971
1972
1973
1974
YEAR
Figure 56. Flow and annual operating parameters.
Another often-used parameter for expressing total treatment cost is the
cost in cents per unit volume of wastewater treated. In 1968, the average
daily flow in the 0.22-m3/sec (5.0-mgd) plant was 0.16 m3/sec (3.6 mgd).
Except for power and chemicals, most operating costs can be reasonably
assumed to be independent of flow. Adjusting the 1968 operating cost to
reflect the increase in power and chemical costs which would be expected at
design flow yields an annual operation and maintenance cost of $208,000.
The total annual cost in 1968 dollars is then $323,000/yr,or 4.7 cents/m3
(17.7 cents/1,000 gal) based on design flow.
Although construction costs can be adjusted to reflect changes which
occur over time by utilizing one of the several available construction cost
'indices, no similar simple adjustment can be made for operating costs. Thus,
to estimate future total treatment costs, separate estimates must be made for
construction and operation.
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SECTION 10
GENERAL DESIGN CONSIDERATIONS
Experience gained from operation of the Livermore, California, Water
Reclamation Plant can be of benefit in carrying out similar treatment plant
modifications at other locations. Two coupled trickling filter-activated
sludge plants are presently being constructed at Lompoc, California, and
Corvallis, Oregon. Other operating plants include those at El Lago, Texas,
and San Pablo, California. Except for San Pablo, these plants previously
utilized conventional trickling filtration for secondary treatment and were
upgraded after imposition of discharge requirements necessitating nitrifi-
cation. The coupled trickling filter-activated sludge process is an alter-
native that should be considered by cities facing more stringent discharge
requirements for their trickling filter plants.
The purpose of this section is to present design information on the com-
bined trickling filter-activated sludge process developed from operation of
the Livermore plant, design and operation of other plants, and information
which has become available in recent years on design for nitrification in the
activated sludge process. This is not intended to be a comprehensive design
manual, but rather a brief outline of pertinent information with an indication of
those areas where further data are needed. For a complete discussion of nit-
rification kinetics and process design, the reader is referred to the EPA Tech-
nology Transfer publication, Process Design Manual for Nitrogen Control.9
Presented in the following subsection are descriptions of the plants at
Lompoc, Corvallis, El Lago, and San Pablo. Following these discussions is
a brief review of nitrification process chemistry and biochemistry presented to
provide a better understanding of the complexities encountered in design.
Finally, the subsection on design considerations covers several aspects of
plant design, including process design, aeration requirements, flexibility,
reliability, use of existing facilities, and expected effluent quality.
ADDITIONAL TRICKLING FILTER-ACTIVATED SLUDGE PLANTS
Although this report deals primarily with the Livermore plant, data from
other coupled trickling filter-activated sludge plants can be used to supple-
ment the information developed at Livermore. The Corvallis and Lompoc
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upgraded plants were designed by Brown and Caldwell subsequent to the
earlier Livermore upgrading. Certain changes in design parameters were
adopted for these later plants. Other full-scale plants for which operating
data are available include El Lago, Texas, and San Pablo, California. In
addition to the coupled trickling filter-activated sludge process, the El Lago
plant provides denitrification, phosphorus removal, and tertiary filtration.
Lompoc. California
The Lompoc Valley in Santa Barbara County, California, is the site of a
coupled trickling filtration-activated sludge plant, presently under construc-
tion, which will provide consolidated waste water treatment for four sewerage
systems in the region. As at Livermore, the upgraded plant is being construc-
ted on the site of an existing trickling filter plant and will utilize many of the
available structures. Because of predicted flow increases, the anticipated
loadings on the rock media filters would have been very high, possibly caus-
ing odors. Thus, the rock media filters are being converted to deep plastic
media filters during the upgrading.
Lompoc is located approximately 16 km (10 mi) from the Pacific Ocean in
a valley which is 19km (12 mi) long and 5 km (3 mi) wide. In addition to the
City of Lompoc, sewage treatment and disposal will be provided for the Fed-
eral Correctional Institution and two residential developments, Mission Hills
and Vandenberg Village. In 1972,Brown and Caldwell undertook development
of a regional wastewater management program for the Lompoc Valley. Because
of long-term depletion of the local groundwater reservoir and deterioration of
groundwater quality, a prime consideration in plan development was possible
groundwater recharge using reclaimed wastewater. Recharge can be imple-
mented either in special spreading basins or in the bed of the Santa Ynez
River, which receives effluent from the treatment plant. Design effluent con-
centrations, whether intentional reclamation is practiced or not, are 15 mg/1
BODg and suspended solids, 0.1 mg/1 ammonia nitrogen, and 2.2 MPN total
coliform organisms/100 ml.
Previous Plant—
The Lompoc Water Pollution Control Plant provided secondary treatment
by trickling filtration for a design flow of 0.077 m3/sec (1.75 mgd), although
measured flows had reached 0.092 m-Vsec (2.1 mgd) by 1972, resulting in
noncompliance with discharge requirements. The plant was constructed in
1959 and replaced oxidation ponds which had previously provided treatment.
The plant was initially designed and constructed to operate as a two-
stage trickling filter system with discharge to the Santa Ynez River. Between
1961 and 1966, however, a number of modifications to the plant were under-
taken, including incorporation of the previously abandoned 43,000-m^
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(35 acre-ft) oxidation pond into the system to provide tertiary treatment, and
rerouting of digester supernatant from the first-stage trickling filter to the
primary sedimentation tank.
Upgraded Plant—
The Lompoc Regional Wastewater Reclamation Plant will provide treat-
ment for 0.26 m-Vsec (6 mgd) ADWF and is planned for ultimate expansion to
0.53 m /sec (12 mgd). The flow diagram is shown in Figure 57. The plant
will provide secondary treatment with nitrification and can be upgraded to
include nutrient removal, filtration, and demineralization if future circum-
stances require such steps.
As at Livermore, emphasis has been placed on retaining existing facili-
ties. The existing secondary clarifier will be converted to a sludge thickener,
which will eliminate the need for increasing digestion capacity. Sludge la-
goons will be placed on the site of previously existing drying beds, and the
oxidation pond will be converted to an emergency holding basin, providing
a detention time of about 2 days at design flow.
The total biological treatment volume is based on a unit loading of 0.53
kg BODs/mVday (33.2 lb/1,000 ft3/day) of trickling filter plus aeration
tank volume. Any two of the three blowers will provide 99 nP air/kg (1,580
ft3/lb) BODs + NOD entering the aeration tank (on a. daily average basis).
During the peak 3-hr loading period, the air supply rate with two blowers
operating will drop to 82 m-Ykg (1,320 ft3/lb).
The low bid for the Lorapoc plant upgrading was $14.2 million, including
$250,000 for contingencies. Construction was started in December 1974 and
completion scheduled for mid-1977.
Corvallis. Oregon
The City of Corvallis is presently expanding and upgrading its municipal
wastewater treatment plant from a 0.26-m3/sec (5.9-mgd) trickling filter plant
to a 0.42 -m3/sec (9.7-mgd) coupled trickling filter-activated sludge process
with design effluent concentrations of 10 mg/1 BODj- and suspended solids
and 1.0 mg/1 ammonia nitrogen. Provisions are being made for ultimate ex-
pansion to 0.76 m^/sec (17.3 mgd), which is expected to serve the community
beyond the year 2000.10
The principal objectives of the Corvallis plant and the problems found
there are somewhat different from those at Livermore. Corvallis is situated
on the Willamette River in western Oregon. For more than half a century, the
Willamette has been the disposal site for liquid wastes from Corvallis and
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INFLUENT
PUMPING
TRICKLING
FILTER
DISTRIBUTION
STRUCTURE
TRICKLING
FILTERS
THICKENER r MIXED
LIQUOR
BYPASS
EMERGENCY
HOLDING
BASIN
1
. +
CHLORINE
CONTACT
i
.!, '
!
SECONDARY
CLARIFIERS
DISCHARGE
TO SANTA
YNEZ
RIVER
CHLORINE
Figure 57. Lompoc, California, Regional Wastewater
Reclamation Plant flow diagram.
other cities and industries along its route. As recently as 30 yr ago, sub-
stantially all wastes were discharged to the river without treatment. This
practice resulted in gross pollution of certain stretches of the river, and
during periods of low river flow, portions of the river were robbed of oxygen
by the pollutants to a point where the river could no longer sustain fish and
other desirable aquatic life.
122
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Through diligent action by local, state, and federal agencies, the trend
has been reversed in the last 20 yr and the quality of the river has improved
to the point where it has once again taken its rightful place as a major aes-
thetic and recreational asset. To provide continued water quality improvement
in the Willamette in the face of increasing wastewater discharges, the Oregon
Department of Environmental Quality (DEQ) is planning to impose stiff limits
on the oxygen-demanding constituents in wastewater effluents. Summer dis-
charge requirements for Corvallis include mean BODc and suspended solids
concentrations of 10 mg/1. Although there is presently no requirement for
ammonia removal, the plant is designed to achieve complete nitrification.
Previous Plant—
The first units of the existing sewage treatment plant were constructed in
1952 and consisted of an influent pumping station, an aerated grit chamber,
a comminutor, a primary sedimentation tank, two floating-cover sludge diges-
ters, and a control building. Primary effluent was discharged to the river
after chlorination. In 1965,the plant was modified to provide secondary treat-
ment by biological filtration. Principal components of the 1965 construction
program included two trickling filters with a filter circulation pumping station,
a secondary clarifier, and a third digester with a fixed cover.
During the peak of the food processing season in September, the 8005
load applied to the trickling filters has been up to three times the amount
which the filters can treat effectively. As a result, the filters release odors
which at times have reached serious nuisance proportions. Odor nuisance
has not been a problem when the cannery is not operating.
Upgraded Plant—
In 1973,the City hired Brown and Caldwell to prepare a wastewater man-
agement program to allow the City to meet predicted future discharge require-
ments. The plan involved three principal elements: (1) construction of a
stormwater overflow treatment and holding pond to reduce wet weather dis-
charges from the City's combined sewers, (2) diversion of food processing
wastes, which had periodically overloaded the municipal plant, to land treat-
ment and disposal sites, and (3) conversion of the existing municipal plant to
a coupled trickling filtration-activated sludge system for treatment of the
community's municipal wastes.*"
Experience obtained at the Livermore plant has allowed several important
design improvements to be incorporated into the Corvallis facility. The
design BOD5 loading rate, in kg BOD5/m3 (lb/1,000 ft3) of biological treat-
ment capacity (trickling filter plus aeration tank)/day, will be decreased from
about 0.55 to 0.32 kg BOD5/m3/day (35 to 20 lb/1,000 ft3/day), a value
123
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which has been obtained in practice at Livermore. The design air supply
will be increased to 86 m3 air/kg (1,370 ft3/lb) peak BODc + NOD and sized
to account not only for average nitrogenous oxygen demand, but for peak load-
ing periods as well.
Secondary clarifier overflow rates will be reduced from those at Livermore
to 21.2 m3/day/m2 (520 gpd/ft2) at ADWF and will be based on a limiting wet
weather rate of 61 m3/day/m2 (1,500 gpd/ft2). To improve the settling char-
acteristics of the mixed liquor, flocculation wells will be constructed at the
center of each clarifier, providing 20-30 min of flocculation time at ADWF.
Provision will be made for alum addition ahead of the clarifiers.
The existing secondary clarifier, which is unsuitable for settling acti-
vated sludge, will be used as a chlorine contact tank. Sludge removal equip-
ment will be retained to periodically remove material escaping the secondary
clarifier.
Solids handling and treatment will be unchanged at the new plant. One
digester will be operated in the primary (or mixed) mode, and two will be
operated as secondary digesters. Digested sludge will continue to be dis-
posed of on land, and secondary digester supernatant will be returned to the
plant headworks. Digester design loadings will be much lower than at Liver-
more, 1.8 kg dry solids/m3/day (0.11 Ib/ft3/day) for the primary digester
and 1.3 kg/m3/day (0.08 Ib/ft3/day) for the secondary digesters, with an
assumed volatile solids reduction of 55 percent.
The flow diagram for the upgraded Corvallis plant is shown in Figure 58.
Instead of relying on holding basins for emergency situations, the Corvallis
plant emphasizes multiple units, allowing a brief shutdown of one aeration
tank, for example, with minimal effect on overall plant efficiency. Further
reliability is provided by a separate facility for treatment of sewage overflows,
which occur routinely during wet weather.
The low construction bid for the Corvallis plant was $7.7 million. Con-
struction was started in November 1975 with completion scheduled in
November 1977.
El Lago. Texas
El Lago is a small suburban community of 3,000 people located near the
Lyndon B. Johnson Space Center in Texas. The agency responsible for waste-
water treatment is the Harris County Water Control and Improvement District
No. 50, which currently operates a 0.013-m3/sec (0.3-mgd) treatment plant.
In 1969,the District received an order from the Texas Water Quality Control
Board that mandated protection of nearby Clear Lake from excessive eutrophi-
cation. Two means were available for compliance with the order at that time:
124
-------
CHLORINE
RAW
SEWAGE
PUMPS*
PRELIMINARY
TREATMENT AND
FLOW METERING
PRIMARY
SEDIMENTATION
TANK
PRELIMINARY
TREATMENT AND
FLOW METERING*
r
NOTE: ASTERISK (*) DENOTES
NEW FACILITY
(PREVIOUS
SECONDARY
CLARIFIER)
WASTE
ACTIVATED
SLUDGE
BYPASS
PRIMARY
SEDIMENTATION
TANK*
CHLORINE*
RETURN 1
ACTIVATED
SLUDGE
FINAL DISPOSAL
TO LAND
CHLORINE
ALUM
Figure 58. Cor vail is, Oregon, wastewater treatment
plant flow diagram.
(1) export of wastewater from the basin or (2) providing nutrient removal prior
to discharge to Clear Lake. The second option was chosen and the District
obtained an EPA grant to demonstrate full-scale nitrogen and phosphorus
removal. ^
The original plant consisted of a rock trickling filter plant (actually two
plants in parallel) with anaerobic sludge digestion for solids processing. The
modified flow sheet incorporating nutrient removal is shown in Figure 59.
Added facilities are identified by asterisks and include new aeration tanks for
nitrification, denitrification columns, tertiary filtration, and facilities for
metal salt, polymer, and methanol addition. All existing structures were
incorporated into the upgraded plant. Two separate types of denitrification
125
-------
FeCI3 AND POLYMER
RECIRCULATION
FINAL EFFLUENT TO
RECEIVING WATERS
NOTE: ASTERISK**) DENOTES NEW FACILITY
Figure 59. El Lago, Texas, wastewater treatment plant flow diagram.
columns, with fine and with coarse media, were provided to allow comparison
of alternative designs. A minor operational difference from other coupled
trickling filter-activated sludge plants discussed in this report is recircula-
tion of clarifier effluent rather than trickling filter effluent to the trickling
filter influent line. This results in a reduced organic loading to the filter
with a corresponding increase to the aeration tank.
Tables 24 and 25 are tabular summaries of initial performance of the
plant and performance 1 yr later, respectively. The improvements in all
parameters of effluent quality obtained after a year of operating experience
are evident.
The capital costs for the modifications to the El Lago facility were incur-
red over a 2-yr period (1971-1973) and totaled $312,365, including change
orders. This cost includes the provision of dual denitrification facilities;
had only one type of denitrification system been included, it is estimated that
the total cost would have been about $75,000 less. The only increase in
operating costs has been for chemicals and power, which has totaled
126
-------
TABLE 24. INITIAL PERFORMANCE OF EL LACO TREATMENT
PLANT—JUNE H THROUGH JULY 6, 1973 (REF. 11)
Constituent
Total phosphorus, mg/1
Soluble phosphorus, mg/1
Suspended solids, mg/1
Ammonia nitrogen, mg/1
Total Kjeldahl nitrogen, mg/1
Nitrate nitrogen, mg/1
BOD 5, mg/1
COD, mg/1
Temperature, C
Raw
waste-water '
12.8
10.3
113
18.7
42.6
175
297
26.5
Primary
influent
15.4
4.7
289
21.7
38.6
222
488
-
Primary
effluent
8.4
4.1
72
21.5
30.2
181
-
Nitrified
effluent
7.3
3.4
37
0.9
3.7
15.2
65f
121f
-
Denitrified
effluent c'd
6.6
5.5
17
0.8
2.4
2.6
9
72
-
Final
effluent
4.8
3.6
3
0.6
3.3
2.3
9
51
-
Average flow to plant: 0.307 mgd (0.013 m3/sec)
Peak dally flow to plant: 1.0 mgd (0.044 m3/sec)
°Average flow to denitrification columns: 0.254 (0.011 m3/sec)
Peak daily flow to denitrification columns: 0.420 mgd (0.018 m^/sec)
"Nitrite nitrogen always less than 0.2 mg/1
f,
Includes methanol
f\
2.5£/nr (9.6£/l,000 gal). It was found that the plant operators previously
employed could adapt to advanced waste treatment processes and that no in-
crease in staff was required.
San Pablo. California
The San Pablo Sanitary District operates a 0.55-m3/sec (12.5-mgd)
coupled trickling filter-activated sludge plant designed for year-round nitri-
fication. The original plant consisted of primary sedimentation with effluent
chlorination and digestion for solids processing. Additions completed in 1972
resulted in the plant flow diagram shown in Figure 60. New facilities included
additional primary sedimentation tanks, a plastic media roughing trickling
filter, aeration-nitrification tanks, secondary clarifiers, an additional chlo-
rine contact tank, dissolved air flotation sludge thickeners, and two addi-
tional digesters. The San Pablo plant differs from the other plants discussed
in this report in that the previous plant did not include a trickling filter.
127
-------
TABLE 25. SUBSEQUENT PERFORMANCE OF EL LAGO TREATMENT
PLANT—OCTOBER 1 THROUGH OCTOBER 31, 1974
(REF. 11)
Constituent
Total phosphorus, mg/le
Soluble phosphorus, mg/1
Suspended solids, mo/1
Ammonia nitrogen, mg/1
Total Kjeldahl nitrogen, mg/1
Nitrate nitrogen, mg/1
BOD5/ mg/1
COD, mg/1
Temperature , C
Primary
influent3 'D
12
1.8
295
-
-
-
-
Primary
effluent
3.6
1.0
51
18
24
-
-
Nitrified
effluent
3.1
0.41
81
0.4
2.6
15
62 f
113f
21
Denitrified
effluent0 'd
Column No. 1
_
-
51
-
-
1.9
16
44
-
Denitrified
effluent0 'd
Column No. 2
_
-
44
0.4
1.5
0.9
12
36
-
Final
effluent
0.41
0.40
1
0.3
0.9
0.6
3
19
-
Average daily flow to plant: 0.301mgd (0.013 m /sec)
Peak dally flow to plant: 0.47 mgd (0.021 m3/sec)
°Average flow to denitrification columns: 0.282 mgd (0.012 m /sec)
Peak daily flow to denitrification columns: 0.470 mgd (0.021 m /sec)
eReduction of P due to ferric chloride addition to primary and nitrification step (37 mg/1 as Fe), Also
polymer, DOW A-23, added to primary at 0.23 mg/1 and to tertiary filter at 0.17 mg/1
Includes methanol
Current discharge requirements are essentially those defined by EPA for
municipal secondary treatment plants with additional requirements set on
effluent toxicity. In addition, the effluent pH is restricted to the range of
6.5 to 8.5. The acid production from nitrification and subsequent chlorina-
tion normally forces the effluent pH below 6.5. This has necessitated the
addition of caustic to the final effluent to raise the pH above 6.5. Toxicity
requirements state that fish bioassays must be run on the undiluted effluent
and that 90 percent of a series of 10 consecutive tests must show 70 percent
fish survival for 96 hr. Experience at this plant has indicated that the re-
quirements cannot be met without removal of ammonia through nitrification. ^
A primary design consideration in laying out the plant for nitrification
was the presence of a significant volume fraction (11 to 13 percent) of poten-
tially toxic industrial wastes in the influent waste water. Tank truck washing
residues and the waste from a manufacturer of organic peroxide and phenol
formaldehyde are the major industrial waste sources. The roughing filter is
used in the treatment plant to protect the nitrifying organisms from influent
wastewater toxicity. Toxic dumps have caused severe sloughing and loss of
growth on the media in the roughing filter, but nitrification remained un-
affected.12
128
-------
RAW
WASTEWATER
PRELIMINARY
TREATMENT
PRIMARY
SEDIMENTATION
TANKS (EXISTING)
FLOWS IN EXCESS OF 30 mgd
-*•
SUPERNATANT
TO HEADWORKS
DIGESTED SLUDGE
TO DRYING BEDS
SUBNATANT
TO HEADWORKS
PRIMARY
SEDIMENTATION
TANKS (NEW)
TRICKLING
FILTER
RAW
SLUDGE
ANAEROBIC
DIGESTERS
DISSOLVED
AIR
FLOTATION
THICKENER
SECONDARY
CLARIFIER
ACTIVATED
SLUDGE
ADDITION
EFFLUENT TO
RECEIVING WATERS
Figure 60. San Pablo, California, wastewater treatment
plant flow diagram.
Consistent year-round nitrification is obtained in this plant as indicated
in Table 26. While only once-weekly and once-monthly analyses of nitrogen
are included in Table 26, the consistency of nitrification in the plant is con-
firmed by daily ammonia nitrogen analyses of grab samples,which normally
129
-------
TABLE 26. PERFORMANCE DATA FOR SAN PABLO WASTEWATER
TREATMENT PLANT—JULY 1973 THROUGH JUNE 1974
Parameter
Flow. mgda
Return sludge ratio
Temperature, C
MLSS, mg/1
MLVSS, percent
SVI, ml/gm
Solids retention
time, days
Aeration time.
hr
Air use, million
ftVdayb
Roughing filter
effluent
BODs.mg/10
COD, mg/lc
SS, mg/lc
Secondary effluent
BOD5, mg/ld
COD, mg/ld
SS, mg/ld
Organic nitrogen
mg/le
Ammonia nitroger
mg/ld
Nitrate nitrogen.
mg/le
Nitrite nitrogen,
mg/ld
Year and
Month
1973
July
6.3
0.30
22.2
1,400
79
73
12.3
10.8
_
121
279
-
16
78
8
7.8
<0.2
18.6
0.05
Aug
5.6
0.34
23.6
1,500
80
68
13.9
12.1
_
125
306
97
4
56
7
3.8
<0.2
19.8
0.02
Sept
5.7
0.25
24.4
1,760
76
48
15.4
11.9
20.0
134
283
67
6
55
8
3.1
<0.2
18.2
0.02
Oct
5.9
0.31
23.2
1,770
76
66
11.8
11.5
19.4
131
281
95
6
62
6
3.4
<0.2
20.4
0.02
Nov
9.7
0.24
20.3
1,610
72
73
9.1
7.0
19.4
88
281
59
7
54
3
3.4
0.7
24.8
0.26
Dec
8.4
0.29
18.5
1,550
73
85
12.1
8.1
20.0
81
212
73
4
59
7
4.8
0.1
17.6
0.05
Jan
9.1
0.22
17.0
1,480
74
87
7.4
7.5
_
91
249
96
3
53
4
4.8
<0.2
17.0
0.22
Iteb
6.6
0.29
17.8
1,420
78
96
9.2
10.3
_
92
240
79
4
53
4
2.2
<0.2
15.8
0.02
1974
Mar
8.3
0.19
18.2
1,520
74
101
7.5
8.2
18.3
107
314
135
4
61
6
2.8
-------
Summary of Plant Design Data
A summary of design data for the Livermore, Lompoc, Corvallis, El Lago,
and San Pablo treatment plants is presented in Table 27. The basis for
design in these cases are essentially empirical, with design changes made
to solve problems encountered at previously constructed plants. The next
subsection provides a review of nitrification kinetic theory, which can be
used as the basis for development of more rational design procedures.
TABLE 27. DESIGN CRITERIA FOR UPGRADED PLANTS
Design parameter
Flow, mgda
Before upgrading
ADWF
After upgrading
ADWF
PDWF
PWWF
Future ultimate
ADWF
Influent Concentrations . mg/1
BOD 5
Suspended solids
Ammonia nitrogen
Influent Loadings , lb/dayk
BOD5
Suspended solids
Ammonia nitrogen
Average
Peak
Primary Treatment
Assumed BODs removal, percent
Assumed suspended solids removal, percent
Trickling Filters
Number
Diameter, ftc
Filter media depth, ftc
Circulation ratio to ADWF ,
Loading, Ib BOD5/1 ,000 ft3/day
Assumed BOD 5 removal, percent
Livermore
2.5
5.0
10.0
18.0
10.0
300
300
- '
12,500
12,500
-
-
35
60
2
110
4.25
1.5 - 3.0
100
50f
Corvallis
4.0
9.7
13.4
28.0
17.3
135
140
-
10,000
11.500
-
-
30
65
2
160
8
1.2 - 2.4
24
47f
El Lago
0.5
0.5
-
-
-
160
195
25
670
810
105
-
25
70
2
-
6.5
1.6
12
-
Lompoc
1.8
5.0
9.1
16.0
-
300
300
25
15,500
17,000
2,100
3,300
35
65
2-
85
20e
1.5
71.7
43£
San Pablo
-
12.5
-
30.0
-
340
300
-
35,400
31,300
-
-
-
—
1
52
18e
1.0 - 2.4
350
-
(continued on next page)
',131
-------
TABLE 27. (continued)
Design parameter
Activated Sludge Aeration Tanks
Number
Length per tank, ft
Width, ftc
Water depth, ftc
Total volume , 1 , 000 ft3 9
Detention time, hr, based on ADWF and
raw sewage flow
MLSS
Volumetric loading, Ib BOD5/1,000 ftVday"
Aeration Blowers
Number
Capacity each, ft3/min:
Air supplied, ft3/(lb BODs + Ib peak NOD
removed)
Secondary Sedimentation Tanks
Number
Diameter, ftc
Side water depth, ftc
Overflow rate , gpd/ft2
ADWF
PWWF
Activated Sludge Treatment
Assumed BOD removal, percent
Assumed suspended solids removal, percent
Assumed ammonia nitrogen removal, percent
Overall Plant Performance
Assumed BODj removal, percent
Assumed suspended solids removal, percent
Assumed ammonia nitrogen removal , percent
Effluent BOD5 concentration, mg/1
Effluent suspended solids concentration.
mg/1
Effluent ammonia nitrogen concentration.
mg/1
Effluent coliform concentration, MPN/100 ml
Livermore
I1
160
30
15
144
5.2
-
26
3
2,000
1.2001
(BOD 5 only)
1
90
12
787
2,833
88
86
-
96
96
-
15
15
-
5.0°
Corvallis
2
156
40
15
187
3.4
2,000
22
4
5,900
1,3701
U
2h
115
18
520
1,500
80
80
-
93
93
-
10
10
1
<100
El Lago
2
-
-
-
101
6.1
-
-
2
450
_
2
_
-
320
1.060
-
-
92
97
95
92
5
10
2
~
Lompoc
21
290
30
15
261
4.7
3,050
35
3
5,200
1,580*
3
65
16
503
1,609
86
-
99.6
95
95
99.6
15
15
0.1
2.2
San Pablo
2
252
50
15
378
5.4
-
-
4
6,000
_
2
180x60m
-
580
1,390
-
—
-
-
-
-
-
™
amgd x 0.044 = m /sec
blb/day x 0.454 = kg/day
Cftx 0.305 =m
dlb/l,000 ft3/dayx 0.016 = kg/m3/day
g
Plastic media
Unsettled effluent
91,000 ft3 x28 = m3
With center-well flocculators
Two passes per tank
^ ft3/min x 0.028 = mVmin
kft3/lb x 0.0624 = m3/kg
One blower for standby
Rectangular sedimentation tanks
ngpd/ft2 x 0.041 = m3/m2/day
°5-day median discharge requirement;
later changed to 2.2 MPN/100 ml a s a 7-day
median
132
-------
NITRIFICATION KINETICS IN THE COUPLED TRICKLING FILTER-
ACTIVATED SLUDGE PROCESS
The term nitrification is applied to the conversion of ammonia nitrogen in
wastewater to nitrate nitrogen through biochemical reactions . Nitrification is
often used as a method of ammonia removal, but it can also be used as the
first step in a nitrogen removal process, preceding biological denitrification
which involves reduction of nitrate to nitrogen gas which escapes to the at-
mosphere. Nitrate nitrogen can stimulate aquatic growths, and for this reason,
removal of all nitrogen compounds may be mandated by regulatory agencies .
Ammonia nitrogen, in addition to being a growth stimulant, imposes an oxygen
demand on receiving waters, interferes with chlorine disinfection, and is
toxic to fish life. Its removal may be specifically required by regulatory
agencies, or it may be undertaken in order to meet disinfection or toxicity
requirements .
The information presented below is intended to provide background infor-
mation prior to development of design procedures discussed later. The ma-
terial is taken principally from the EPA Technology Transfer publication,
Process Design Manual for Nitrogen Control.9 The reader is referred to that
manual for a more complete presentation of the concepts discussed briefly
here.
Oxidation and Synthesis Reactions
The two principal genera involved in nitrification are Nitrosomonas and
Nitrobacter. These groups are classed as autotrophic organisms and are dis-
tinguished from heterotrophic organisms in that they derive energy for growth
from oxidation of inorganic nitrogen compounds rather than from oxidation of
organic waste matter. Each group is limited to the oxidation of a specific
species of nitrogen compound. Nitrosomonas can oxidize ammonia to nitrite,
and Nitrobacter can complete the reaction by oxidizing nitrite to nitrate. The
stoichiometric reactions are as follows:
NH* + 1.5 O2 - >-2H+ + H20 + N0~ (11)
N0+0.502 - **N03 (12)
The overall oxidation of ammonia is obtained by adding the two equations:
* ~ +H0 (13)
These reactions furnish energy required for growth of the nitrifying orga-
nisms. Using representative measurements of yields and oxygen consumption
for Nitrosomonas and Nitrobacter and assuming that the empirical formula for
133
-------
bacterial cells is C5H_NO , the overall synthesis and oxidation reaction is:
+ 1.83 02 + 1.98 HCO~ ^0.021 C5H
+ 1.04 H_0+0.98 N0~+ 1.88 H_CO_ (14)
/ o Z o
Two important aspects of the oxidation reaction are oxygen and alkalinity
requirements. From Equation 13, 4.57 kg CL/kg NH^-N are theoretically
required for the oxidation of ammonia. From Equation 14,it is evident that
synthesis lowers actual oxygen requirements for nitrification to 4.18 kg O2/
kg NH.-N. A value sufficiently accurate to be used in engineering calcula-
tions for aeration requirements is 4.6 kg O /kg NH.-N.
2'
The oxygen demand for nitrification is significant. About 140 mg/1 of
oxygen are required to oxidize 30 mg/1 of ammonia nitrogen. It is this high
demand which has created difficulties over the years in operating the Liver-
more plant.
Destruction of alkalinity during the oxidation reaction can create prob-
lems by lowering the wastewater pH. Approximately 7.1 kg of alkalinity as
CaCOo are destroyed per kg NH^-N oxidized. Thus, over 210 mg/1 of alka-
linity as CaCOg will be destroyed during oxidation of 30 mg/1 of ammonia
nitrogen. In many wastewaters /there is insufficient alkalinity initially pres-
ent to leave a significant residual for buffering the wastewater during the
nitrification process. The significance of pH depression is that nitrification
rates decrease as pH level drops. For a full discussion of the effect of pH
on nitrification, see the Technology Transfer publication, Design Manual for
Nitrogen Control. ^
Nitrification Kinetics
A description of ammonia and nitrite, oxidation can be derived from an
examination of the growth kinetics of Nitrosomonas and Nitrobacter . Nitro-
somonas' growth is limited by the concentration of ammonia , while Nitro-
bacter' s growth is limited by the concentration of nitrite .
The kinetic equation proposed by Monod is used to describe the biologi-
cal growth kinetics of either Nitrosomonas or Nitrobacter.
where: y = microorganism growth rate, day ,
y = maximum microorganism growth rate, day ,
134
-------
S = growth limiting substrate concentration, mg/1, and
half velocity constant = substr
the maximum growth rate, mg/1.
K = half velocity constant = substrate concentration at half
S
Since the maximum growth rate of Nitrobacter is considerably larger than that
of Nitrosomonas. the latter representing conversion of ammonia to nitrite, the
Nitrosomonas reaction is the rate limiting step.
The ammonia oxidation rate, q , can be related to the Nitrosomonas
growth rate as follows:
UN ^ N
"
where: ^N = Nitrosomonas growth rate, day ,
u, = peak Nitrosomonas growth rate, day ,
q = ammonia oxidation rate, kg NH -N oxidized/kg
Nitrosomonas/day.
q = ^N = peak ammonia oxidation rate, kg NH .-N oxidized/kg
Y Nitrosomonas/day,
Y = organism yield coefficient, kg Nitrosomonas grown/kg
NH*-N removed,
N = NH*-N concentration, mg/1, and
K = half-saturation constant, mg/1 NH.-N.
The nitrifier growth rate can be utilized in the design of activated sludge
systems by noting its inverse relationship to the system solids retention
time:
1
CN yN
where 9 = nitrifier solids retention time, days. 9 can be calculated
from system operating data by dividing the total amount (or inventory) of
microbial mass in the treatment system by the quantity wasted daily.
The nitrifier growth rate, y^,, is affected by factors other than ammonia
nitrogen concentration, principally wastewater temperature, dissolved oxygen
concentration, and pH. An expression relating UN to all these parameters can
be developed:
135
-------
= 0.47 [>098 ][l- 0.833 (7.2 -PH)
^0.098 (T - 15)
N
(18)
N + 10
0.051 T- 1.158
DO
DO+ 1.3
where: T = temperature, C, and
DO = dissolved oxygen, mg/1.
The first term in brackets indicates that the nitrifier growth rate decreases
with a drop in temperature. This is a well-known phenomenon and must be
taken into account when designing nitrification systems for cold weather
regions. This relation is valid for tenperatures between 8 and 30 C. The
second term in brackets describes the effect of pH on nitrifier growth rate.
The term is taken as unity for pH values above 7.2. The third and fourth
terms are the Monod expressions relating ammonia nitrogen and dissolved
oxygen concentrations, respectively, to growth rate. The inhibiting effect
of low-DO levels at Livermore was discussed in Section 8.
In a combined, single-stage, carbon oxidation-nitrification process, suf-
ficient organic carbon is normally available in the reactor influent to sustain
a flourishing growth of heterotrophic bacteria. In a separate-stage nitrifica-
tion reactor, organic carbon availability is reduced but usually still adequate
to stimulate some heterotrophic organism growth. Since the yield coefficient
for heterotrophic baceterial growth is far greater than for autotrophic nitrifier
growth, it is possible for the growth rate of the heterotrophs to be established
at a level exceeding the maximum possible growth rate of the nitrifying orga-
nisms. This may occur in both combined carbon oxidation-nitrification pro-
cesses and in separate-stage nitrification and depends on the relative substrate
concentrations of organic carbon and ammonia and on the nitrifier solids re-
tention time. When this occurs, the slower growing nitrifiers will gradually
diminish in proportion to the total population and be washed out of the system.
Thus, for consistent nitrification to occur, the following condition must
be satisfied:
± urT (19)
where: y = maximum possible nitrifier growth rate under environmental
conditions of T, pH, DO, and N»KL,, and
= net growth rate of the heterotrophic population .
U.T is related to U.T in the following manner:
N N
136
-------
(20)
N+100.051T- 1.158
0.098 (T-15) || , _ n 000 /170 u\ | | *m (21)
[l -0.833 (7.2 -pH)] [55^3.
where: y = 0.47
Equation 19 is usually expressed in reciprocal form in terms of solids retention
times:
9d > 9m (22)
°N ~ CN
where: 9 = design nitrifier solids retention time, days, and
9 = minimum nitrifier solids retention time, days, for nitrification
N at given pH, temperature, and DO levels.
Because 9C is fixed by environmental conditions, Equation 22 is satis-
N ,1
fied by modifying 9 . The various ways of meeting this criterion can be
c
established by examining the following growth relationship for the hetero-
trophic population.
" = -- m - K (23)
H
H H - d
C
where: 9 = design heterotroph solids retention time, days,
°H
Y = heterotroph yield coefficient, kg VSS grown/kg substrate
- (BOD ) removed,
q = substrate removal rate, kg BOD removed/kg VSS/day, and
H b
K, = heterotroph decay coefficient, day
d
The substrate removal rate is defined:
<24>
HML
137
-------
where: S = aeration tank influent total BOD_, mg/1,
* O
S = aeration tank effluent soluble BODc, mg/1,
L b
t = nominal hydraulic detention time (or aeration time) based on
Q, days, and
X-. = MLVSS, mg/1.
HML
Since both Y and K, are assumed to be constant, 6 can only be altered by
XI ,Q CTT
d "•
manipulating q__; 9 will be increased by reducing q^. One way of doing
H °H H
this is by reducing S. through placing an organic carbon removal step ahead of
the nitrification stage, creating a separate-stage nitrification process. This
function is performed at Livermore by the trickling filter ahead of the activated
sludge process. Solids retention times, 9 , for separate-stage nitrification
f*
processes can be 20 days or longer. H
Another procedure for reducing the substrate removal rate is to increase
the quantity of biological solids in the system. This can be done by increas-
ing the biological solids concentration (MLVSS) in the aeration tank or by
increasing the aeration tank volume.
In most nitrification systems, the level set for heterotroph solids reten-
tion time, 9 , establishes the nitrifier solids retention time, 9 . The
CH CN
coupled trickling filter-activated sludge system is an important exception, as
noted in Section 8 and discussed further below.
With specific values of 0 , T, pH, and DO, Equation 20 can be solved
CN
for the effluent ammonia level. Figure 61 was developed through such a pro-
cedure, assuming T = 15 C, DO = 2 mg/1, and 7.2
-------
"5
O
O
cc
O
z
UJ
25
20
15
10
REMOVAL
EFFLUENT AMMONIA _
100
90
80
70
60 £
UJ
O
50 ul
40 g
30 Si
20 t
10
SF =
'N
m
(25)
e,
'N
5 10 15
DESIGN SOLIDS RETENTION TIME, days
20
Figure 61
A conservative safety factor was rec-
ommended to minimize process varia-
tions caused by pH extremes, low DO
concentrations, and toxicants. The
safety factor can also be used to en-
sure that ammonia breakthrough does
not occur during diurnal peaks in load.
A normal range for safety factors is
2 .0 to 5.0.
The relationships developed above
will be used to compute aeration tank
size requirements in the following
subsection.
DESIGN CONSIDERATIONS
Effect of solids retention
time on effluent ammonia
concentration and
nitrification efficiency
(Ref. 9).
. Principal factors to be considered
in design of a coupled trickling filter-
activated sludge plant are aeration
tank size and air requirements. Other considerations include reliability,
flexibility, use of existing facilities, and expected effluent quality. The
procedure developed below for aeration tank sizing is based on the nitrifica-
tion process kinetics discussed above. The information on air requirements
is adopted from the Process Design Manual for Nitrogen Control.9 The dis-
cussions on physical design and expected effluent quality are based princi-
pally on the coupled trickling filter-activated sludge plants which have been
designed and constructed.
Aeration Tank Size
Difficulties are encountered in computing the required aeration tank size
for a coupled trickling filter-activated sludge process because little is known
about the characteristics of unsettled trickling filter effluent. In particular,
filter effluent contains both waste material which has passed through the
roughing filter unoxidized as well as biological solids sloughed from the filter
media surface. These solids will be measured in a BOD,- test although they
do not represent substrate material for the activated sludge process in the
139
-------
usual sense. The lack of knowledge also creates problems in assigning
values to the coefficients in the equations developed through process kinetics.
Because these sloughed solids will settle fairly rapidly, it is possible
that a more accurate characterization of aeration tank influent BOD,- can be
obtained by settling the roughing filter effluent for a period of time, say 1 hr.
In Section 8 it was noted that at Livermore, the BOD5 of settled roughing filter
effluent was approximately one-half the value for unsettled effluent. Tests
conducted with plastic media filters at Stockton, California, tend to confirm
the 50 percent figure.
One hour's settling under quiescent conditions may also be considered to
reasonably approximate the degree of solids separation achieved in a trickling
filter secondary clarifier. Thus, where past performance of a trickling filter
plant is known, the projected influent loading to the activated sludge unit can
be based on historical trickling filter secondary effluent quality. Where future
filter loadings will be greater because of an increase in plant flow capacity,
estimates of the future BOD5 loading to the aeration tank will have to be made.
Design Procedure—
Expressions for the heterotrophic organism and nitrifier solids retention
times were derived in Section 8 as Equations 4 and 6, respectively:
VX
ML, .
Hn,rT
ML
From Equation 23, the inverse of the heterotroph solids retention time is:
~9~~ = YHqH " Kd (23)
CH
which, when combined with Equation 24, becomes:
_!_ _ YH (S1 - S2> _ ,.
H HML
where Sn is the BOD,, of the settled trickling filter effluent.
1 3
140
-------
Combining Equations 4,6, 23,and 26yields:
QX
Hl YH (S1 " S2)
— = —— - = —il i — - K (97\
e e vxw Y t Kd (27)
CH °N H *
v
Substituting t for— and rearranging terms gives:
XH Y (S - S )
K, =- 1 + H.. l * (28)
6 "d X t v
°N H ^
which solving for the nominal aeration time, t, becomes:
Y (S - S ) + XH
t = * ' ±=- (29)
XH
HML
r i . ..~i
+ K ,
QC d
_ N
The difficulties in applying Equation 29 are principally related to deter-
mining values for S. , K,, and X^ . S, has been assumed to be defined by the
i d Hi i
BOD5 of the trickling filter effluent setted for 1 hr, but a more accurate de-
termination needs to be developed. K, is,the heterotroph decay coefficient.
-1
A value commonly cited is 0.05 day , but organisms entering an aeration
tank from a trickling filter may have a higher decay rate. X is the concen-
Hl
tration of heterotrophic organisms entering the aeration tank. This is difficult
to measure because non-microbial volatile suspended solids are also present
in the trickling filter effluent and volatile suspended solids are normally taken
as representing the microorganisms. The procedure used herein is to apply a
yield coefficient, Y , to the BOD,, removed in the trickling filter as follows:
IF b
X = YTF (So - Sl> (30)
where: S = trickling filter influent total BOD,., mg/1.
o o
An estimate based on limited data indicates that Y =0.5. This is uncertain,
however, and a more accurate estimate is needed. Because Y^F is a "net"
yield coefficient, i.e., it includes the effect of organism death, it can be
expected to be less than Y , which does not include the effect of organism
death.
141
-------
Substituting Equation 30 into Equation 29 provides an expression that can
be used to compute the required nominal aeration time for nitrification in an
activated sludge system preceded by a roughing filter without intermediate
clarification:
Y (S - S ) + Y (S - S )
t = H *x 2 r- , TF -. (3D
HML
For comparison, Equation 31 for an activated sludge process not
preceded by a roughing filter or one preceded by a roughing filter and inter-
mediate clarification ( where x =0 and 9 =6 ^ reduces to:9
CN CH
(32)
Equations 31 and 32 will be utilized in the following design examples
to determine aeration times for several hypothetical plant flow schemes.
Design Examples—
3
Consider a 0.44-m /sec (10-mgd) conventional trickling filter plant
which is to be upgraded to a coupled trickling filter-activated sludge facility.
Assume that the primary effluent BOD5 concentration is 160 mg/1 and that the
two 46-m (150-ft) dia, 1.8-m (6-ft) deep, rock media filters (total volume,
6,000 m3 or 212,000 ft3) produce an effluent with an unsettled BOD5 of 120
mg/1 and a settled BOD,- of 60 mg/1. Further assume that the ammonia
nitrogen concentration in the trickling filter effluent is 25 mg/1 and that the
portion of the organic nitrogen not assimilated into biomass or associated
with refractory organics is 10 mg/1.
Process kinetics design calculations are given below for three cases:
(1) a coupled trickling filter-activated sludge process (i.e., without inter-
mediate clarification), (2) an activated sludge process only, and (3) a
trickling filter-activated sludge process with intermediate clarification. In
addition, an empirical design calculation using loading factors such as em-
ployed for Livermore, Lompoc, and Corvallis will be presented.
Coupled trickling filter - activated sludge process—The design procedure
utilized in the Process Design Manual for Nitrogen Control9 for computing
aeration tank size is as follows:
142
-------
1. Establish the safety factor, SF. Assume SF = 2.5 is required due to
transient loading conditions at this particular plant.
»
2 . Calculate the maximum nitrifier growth rate, MN, at the relevant
temperature, dissolved oxygen, and pH. Using Equation 21 and as-
suming T = 15 C, DO = 2 mg/1, and pH 7.2, results in a value for
{> of 0.285 days"1.
m
3. Calculate the minimum nitrifier solids retention time, 0n •
N
(33)
d
4. Calculate the design nitrifier solids retention time, J9c
fid = SFxflm = = 2.5 (3.51) = 8.78 days (25)
°c.T °c.T
N N
5. Calculate the design nitrifier growth rate, y ,
N
878
6. Calculate the ha If- saturation constant, K , for ammonia oxidation
at 15 C. The proper expression is:
^.,00.0511- 1.158 (35)
where T = temperature , C . For this example ,
KN= 10"°<393= 0.40 mg/1
7. Calculate the steady state ammonia nitrogen content of the effluent .
For plug flow, the Monod substrate removal rate equation must be
integrated over the period of time an element of liquid remains in
the aeration tank.1"*
i %T(N^~NI)
1 N o 1 _ , . ,_-»
-------------- for r < 1 (36)
where r = return sludge rate,
143
-------
N = influent TKN (ammonia nitrogen plus organic
nitrogen), and
N.. = effluent ammonia nitrogen.
Solving Equation 36 using 35 mg/1 for No produces a value for
N, < 0.1 mg/1. Transient loading effects will increase this value ~
and are discussed in the Process Design Manual for Nitrogen Control.
8. Calculate the nominal aeration time, t. From Equation 31:
t =
!1 - V
fTF (S0 - Sl>
H
H
ML
N
Substituting appropriate values into the equation:
SQ =160 mg/1,
S. - 60 mg/1,
S2 =0 mg/1,
Y__ = 0.60 kg VSS/kg BODC removed,
TF
H.
ML
'N
K
t
= 0.50 kg VSS/kg BOD removed,
D
= 1,800 mg/1.
= 8.78 days, and
= 0.07 day"1:
0.6 (60) + 0.5 (160 - 60)
1,
t = 0.26 day = 6.24 hr
V = 9,860 m5 (548,000 ft5)
(31)
144
-------
For the above example, a decay coefficient of 0.07 day"1 was used. This
is slightly higher than the normally cited value of 0.05 and was chosen be-
cause a higher decay rate is believed to be appropriate for those circum-
stances where sloughed organisms enter the aeration tank. Studies involving
the contact stabilization process, which may be considered somewhat similar
to the coupled trickling filtration-activated sludge process, have indicated
such a value for the decay
Activated sludge process only — The procedure for computing aeration tank
size for the activated sludge process alone is the same as for the coupled pro-
cess through Step 7 above. Nominal aeration time is then computed from
Equation 32:
(32)
Yw (S. - SJ
rl l /
XH
HML
^ 1 j. tH
d +Kd
N
For this example, K, will be reduced to 0.05 day
the same values as in the previous example.
Other parameters have
t=
0.6 (160)
78
+ 0
.05~|
t= 0.33 days = 7.92 hr
V =
12.500 m3 (441.000 ft3)
This is more than 25 percent greater than the nominal aeration time obtained
for the coupled trickling filter-activated sludge process. The increase is
caused by Y being greater than Y and by the higher value of
for the former example .
chosen
The same safety factor, 2.5, has been used for both examples. The
presence of toxic wastes would favor the use of a higher safety factor, say
3.5, in the absence of a roughing filter. In this latter case, the difference
in nominal aeration times between the two examples would be greater. For
the activated sludge process without a roughing filter:
0d =SFx©m = 3.5 (3.51) = 12.3 days
"N
t =
N
0.6 (160)
1,
145
-------
t= Q.41 day = 9.84 hr
V = 15/520 m5 (548,000 ft5)
This is more than 55 percent larger than for a coupled trickling filter-activated
sludge process with a safety factor of 2.5.
Such differences in tank size will not be realized in all cases . The pri-
mary advantage of a roughing filter ahead of the activated sludge process is
the stability in overall performance which it provides .
Trickling filter-activated sludge process with intermediate clarification —
Equation 29 indicates that organisms entering the activated sludge process
from the trickling filter influence the aeration time required. If an intermediate
clarifier is used to remove the sloughed material, aeration times can be re-
duced. Aeration time would then be calculated using Equation 28 with X =
0, as previously derived in Equation 32. 1
YH (S1 - S2>
(32)
t = 0.6 (60)
o.os)
t = 0.12 day = JZ.88 hr
V = 4,660 m5 (161,000 ft5)
This is approximately 55 percent smaller than that calculated for the coupled
process without the intermediate clarifier.
Empirical design—In discussions on the designs of the Livermore, Cor-
vallis, and Lompoc plants, it was noted that a loading parameter used in
these cases was kg BOD5/m3 (lb/1,000 ft3) trickling filter plus aeration tank
volume/day. It is instructive to compare aeration tank sizes computed using
such an approach with those calculated using the procedures developed above.
•j O
Using an overall loading of 0.4 kg/m /day (25 lb/1,000 ft /day) requires
a total biological treatment volume of 15,120 m3 (534,000 ft3) for the 0.44-
m3/sec (10-mgd) flow and a primary effluent BOD- of 160 mg/1. Subtracting
146
-------
the filter volume of 6.000 m3 (212,000 ft3) gives an aeration tank volume of
9,120 m3 (322,000 ft3), which corresponds to an aeration time of 5.78 hr,
compared with 6.24 hr calculated using Equation 31.
Aeration Requirements
Care must be exercised in designing aeration systems for activated sludge
nitrification. Unlike BOD^, ammonia is not adsorbed to the biological floe for
later oxidation andjtherefore.must be oxidized during the relatively short
period it is in the nitrification reactor. Sufficient oxygen must be provided to
handle the load impressed on the nitrification process at all times.
The diurnal variation in nitrogen loading is very significantly affected by
in-process flow equalization and by equalization in the wastewater collection
system. Large collection systems serving spread-out urban areas have high
built-in storage providing unintentional flow and loading equalization. This
relationship is indicated in Figure 62 where the nitrogen load peaking (expres-
sed as the ratio of the maximum hourly load to average load) is plotted for
eight treatment plants having no significant in-process equalization. In large
plants, such as the Blue Plains plant at Washington, D.C., and Sacramento,
California, a spread-out collection system causes moderation of both flow and
nitrogen load peaking. In the smaller systems, however, without such flow
equalization, ammonia load peaking can be substantial; for example, at the
Central Contra Costa (California) Sanitary District's (CCCSD) plant, an hourly
peaking factor of 2.4 has been measured. The aeration system must accommo-
date these changes in loads to avoid ammonia bleed-through during the peak-
load period. An early decision must be made during the design process as to
what level of peaking of oxygen-demanding substances will be designed for.
In addition to peaking of ammonia or organic nitrogen, a concurrent peak may
also occur in the loading of organic substances. If very low levels of ammonia
nitrogen are required at all times, care must be used to develop a statistical
base whereby the frequency of peak oxygen loads can be identified. Not only
should average daily peaks be identified, but possibly those occurring on
weekly or monthly bases. The additional aeration capacity required for hand-
ling diurnal variations in nitrogen load, coupled with the extra tankage and
equipment required, may dictate in-plant flow equalization in many instances.
The reductions in capital and operating cost of aeration tankage and aeration
facilities must be compared with the cost of flow equalization to determine
applicability to specific cases. Design procedures for flow equalization are
contained in Chapter 3 of the Process Design Manual for Upgrading Existing
Wastewater Treatment Plants.15
Oxygen Transfer Requirements—
Using diffused air aeration, air rates can be easily modulated to closely
match the incoming oxygen-demanding load merely by turning down or shutting
147
-------
2.5
O
UJ
tr
UJ
- -a
-Q —
3 <
J o
< -J
z <
i z
i§
< 2
oc
o
5
D
5
X
1.0
NOTE: mgd x 0.044 = m 3/sec
Y = 1.457 X-0.217
KEY
PLANT
SAMPLE
LEBANON, OHIO
LIVERMORE, CA
CCCSD. CA
SACRAMENTO, CA
BLUE PLAINS, DC
CHAPEL HILL, NC
CANBERRA. AUSTRALIA -
WESTON CREEK RAW
BELCONNEN RAW
L_
PRIMARY
ROUGHING FILTER
PRIMARY
PRIMARY
PRIMARY
RAW
1.0
10
(X)
1.5 2.0
MAXIMUM HOURLY FLOW, mgd/AVERAGE DAILY FLOW, mgd
2.5
Figure 62. Relation between ammonia nitrogen peaking and
hydraulic peaking for treatment plants with no
in-process flow equalization (Ref. 9).
148
-------
off individual blowers. Thus, the diurnal load variations can be matched with-
out the necessity of overaerating the mixed liquor and wasting power as is
the case with mechanical surface aerators. Fine bubble diffusers can be
arranged across the tank floor, allowing fairly even distribution of energy
input. Also, gentler mixing is provided than with mechanical aeration plants,
providing less tendency for floe breakup.
Oxygen requirements in all practical cases are compounded by the oxygen
required for stabilization of organics. Reasonably exact expressions for
oxygen requirements for heterotrophic organisms and nitrifiers have been
developed.1^ The approach, however, requires pilot plant data to provide
COD balances and sludge yields. In general, this information is not available
and a simpler approach may be adopted.^
In normal activated sludge treatment when nitrification is not required,
the amount of oxygen needed to oxidize the BOD5 can be calculated by the
following equation:
B = X (BOD_) (37)
o
where: B = oxygen required for carbonaceous oxidation, mg/1, and
X = a coefficient.
The coefficient X relates to the amount of endogenous respiration taking place
and to the type of waste being treated. For normal municipal wastewater, the
X value would range from 0.5-0.7 for high-rate activated sludge systems to
1.5 for extended aeration. For conventional activated sludge systems, X can
be taken as 1.0.
For nitrification systems, the oxygen requirement for oxidizing ammonia
must be added to the requirement for BOD,- removal. The coefficient for
ammonia oxidation can be conservatively taken as 4.6 times the TKN content
of the influent to obtain the nitrogen oxygen demand (NOD). (In actual fact,
some of the influent nitrogen will be assimilated into the biomass or is as-
sociated with refractory organics and will not be oxidized.) Using a value of
1.0 for X in Equation 36, the total oxygen demand in a nitrification system can
be approximated as follows:
TOD = BOD. + NOD (38)
0
where: TOD = the total oxygen demand, mg/1, and
NOD = oxygen required to oxidize the TKN, taken as 4.6 times
the influent TKN, mg/1.
149
-------
Since aeration devices are rated using tap water at standard conditions,
the rated performance of the aerator must be converted to actual process condi-
tions by the application of temperature corrections and by factors designated
a and 3 which relate wastewater characteristics to tap water characteristics.
Temperature corrections are made by the relationship:
1.024(T-20'
where T = process temperature, C.
The a factor is the ratio of oxygen transfer in wastewater to that in tap water
and is represented by the following:
KT a (process conditions)
1C. a (standard conditions)
Values of a can vary widely in industrial waste treatment applications, but for
most municipal plants, it will range from 0.40 to 0.90.
The 3 factor is the ratio of oxygen saturation in wastewater to that in tap
water at the same temperature. A value of 0.95 is commonly used. Thus, the
amount of oxygen that will actually be transferred under process conditions (W)
can be estimated from the amount transferred under test conditions (W ) by
the equation:
T _ on 0C ~ GI
W = WQa (1.024)1 ™ 12 -1 (40)
where: W = oxygen transferred at process conditions, kg/day (Ib/day),
W = oxygen transferred at standard conditions (T = 20 C,
DO ~ 0, barometric pressure = 760 mm Hg, tap water),
kg/day (Ib/day),
T = process temperature, C,
C = oxygen saturation concentration in water at temperature T,
mg/1, and
C, = process DO level, mg/1.
The process DO level, C, , must be set high enough to prevent inhibition
of nitrification rates. For this purpose, a minimum value of 2.0 mg/1 is rec-
ommended . This value is also applicable under peak diurnal load conditions,
150
-------
and the practice of allowing the DO to drop below 2.0 mg/1 under peak load
is not recommended. If mixed liquor DO is allowed to drop below the minimum
during peak load conditions, excessive bleed-through of ammonia can be
expected.
Using typical values for domestic sewage (<*= 0.9,3 = 0.95, C. = 2.0
mg/1, T = 20 C,and GS = 9.2 mg/1) in Equation 40, the relationship between
oxygen transfer capability under standard test conditions and under actual
process conditions reduces to:
W = 0.67 W , or (41)
W = 1.5 W (42)
o
The value obtained for W can then be used to project horsepower (hp)
requirements for mechanical aerators or required volumetric air flow rates for
diffused air plants. The latter is accomplished by employing the equation:
3
where: Q = air flow, m /min ,
f\
e = aerator rated oxygen transfer efficiency at standard
conditions, percent,
air composition = 23 percent oxygen (weight basis), and
3
air density = 1.2 kg/m
Applying Equations 42 and 43 and the numbers in the previously stated
example to diffusers of various efficiencies produces air rates of from 90
to 36 m3/(kg BOD5 + kg NOD) (1,450 to 580 ft3/lb) corresponding to standard-
condition diffuser efficiencies of 6 to 15 percent as shown in Figure 63.
Diffuser placement within the aeration tank has been shown in full-scale
tests to have a large effect on oxygen transfer efficiency.^ For oxygen
transfer efficiencies, diffusion system design, and layout, the reader should
refer to the literature as well as to air diffusion equipment manufacturers.
W 3
*Q = 4.02 , Q in ft /min and W in Ib/day
t\ Q ri O
o
151
-------
M
z
li
i| 16
Q.
. Q
u w 14
LU QC
u. < 12
10
Q
N
TEMPERATURE 20C
I 1 I
ft3/lb x 0.0624 = m3/kg
500
1000
1500
1700
AIR REQUIRED, ft/(lb BODg + Ib NOD)
Figure 63. Air requirements for oxidation of carbonaceous and
nitrogenous oxygen demand (Ref. 9).
In addition to determining the total air requirement, attention should also
be given to air distribution within the aeration tanks. If the conventional
(or plug flow) mode of operation is established as the normal operating pro-
cedure, the air requirements will be greatest at the head end of the aeration
tanks.
Design Examples—
Air requirements for the coupled trickling filter-activated sludge process
(or, alternatively, the two-stage trickling filter-activated sludge process
with intermediate clarification) and the activated sludge process alone can be
estimated. The coupled and two-stage processes will have (for preliminary
estimating purposes) the same projected air supply requirements because it is
assumed that only the settled BOD^ (not including the sloughed solids) of the
trickling filter effluent will exert significant oxygen demand in the aeration
tank. Employing the flows and concentrations used in calculation of aeration
tank size and assuming a BOD5 Peaking factor of 1.5 and a NOD peaking
factor of 2.5, the estimated TOD from Equation 38 for either the coupled pro-
cess or the two-stage process with intermediate clarification is:
152
-------
TOD = BOD + NOD (38)
o
= 60 + 4.6 (25 + 10)
= 221 mg/1
q
For a 0.44-m /sec (10-mgd) flow, the average total oxygen-demand loading
is equal to:
0.44
For peak conditions:
W= 0'4V8Q004QO) [GO (1.5) + 4.6 (35) (2.5)] = 18, 725 kg/day (41 ,2 75 Ib/day)
With a coarse bubble diffusion system a 6-percent transfer efficiency
can be expected. From Figure 63, the unit air supply required is 90 m3/(kg
BODj + kg NOD removed) (1,450 ft*/lb) . Assuming essentially complete re-
moval of influent BODs and NOD, the air requirement for average conditions is:
8'4QO <9Q) = 525 mVmin (18,540 ft3/mln)
.X m 4 " \J
For peak conditions, the air requirement is:
18'725^0) = 1,170 mVmin (41,325 ftVmin)
X • Tl TX \J
For the activated sludge process alone:
TOD = BOD,. + NOD (38)
o
= 160 + 4.6 (25 + 10)
= 321 mg/1
For average conditions:
W=0.44(321H86,400) = 12
X • \J \J \J
For peak loads:
C160 (1-5) + 4'6 (35)
= 24,425 kg/day (53, 850 Ib/day)
153
-------
The air requirement for average conditions is :
12.200 (90) 7AC 3, . /97 mi- . 3, t .
- ' ' = 765 m /min (27,015 ft /mln)
For peak conditions , the air requirement is :
74 42^ (<*n\ •} i
* ' ' = 1, 530 in /min (54,025 ftVmin)
In comparison with the coupled trickling filter- activated sludge process
or the two- stage process with intermediate clarification, projected air re-
quirements for an activated sludge process alone are 46 percent and 31 per-
cent higher for average and peak loads, respectively, under the assumed
conditions of the design examples.
Physical Design
In addition to the process design information discussed above, important
physical design considerations can be briefly outlined. These include reli-
ability, flexibility, and use of existing structures. Each plant to be upgraded
will be different, and specific actions taken will vary in all cases. Neverthe-
less, generalizations can be presented and specific examples discussed.
Reliability—
The increased stringency of discharge requirements will make treatment
plant reliability an important design consideration in the future. Discharge of
inadequately treated effluent, either on a long-term basis or as the result of
short-term equipment breakdowns, will provoke increasingly frequent regulatory
agency action against the discharger. Data presented in this report indicate
that the coupled trickling filter-activated sludge process is inherently stable
and can continuously produce an effluent low in BOD,- , suspended solids ,
ammonia nitrogen, and coliform organisms. Reliability in the face of equip-
ment breakdowns is best accomplished by providing duplicate units with suf-
ficiently low loading factors to permit shutdown of one process unit, or in
some cases a unit process, without overloading others. Another means of
incorporating reliability into design is to provide emergency storage which
will allow bypassing of all or a portion of the plant flow for several days.
Both of these may be difficult when dealing with an existing plant. Pro-
vision of duplicate units requires both adequate space and an existing plant
configuration amenable to such modifications. Emergency holding basins re-
quire large areas of land and may be economically most attractive where exist-
ing oxidation ponds can be used. In regard to the plants discussed in this
154
-------
report, the Livermore and Lompoc plants rely on emergency storage to provide
reliability while the Corvallis plant utilizes duplicate units and unit process
bypassing to ensure a high degree of treatment at all times.
Flexibility--
Flexibility has two principal aspects. The first is related to reliability
and is manifested by the ease of bypassing individual plant components with-
out significantly degrading effluent quality. As noted above, incorporation of
such provisions may be hindered by the existing plant layout and can require
considerable ingenuity on the part of the design engineer.
Flexibility also means the ability to accommodate future plant expansion
and upgrading at reasonable cost and with minimum disruption of plant opera-
tions during construction. Future discharge requirements may necessitate
nitrogen removal, phosphorus removal, filtration, and/or activated carbon
sorption.
If nitrification is effected in a coupled trickling filter-activated sludge
plant, nitrogen removal is best accomplished through biological denitrifica-
tion, either with fixed-growth or suspended-growth reactors. Denitrification
is the reduction of nitrate nitrogen to nitrogen gas, usually accomplished
biologically under anoxic conditions. Because the effluent from a trickling
filter-activated sludge plant will contain nitrogen in the nitrate form, denitri-
fication can generally be easily and economically implemented.
Phosphorus removal is best accomplished by chemical precipitation,
utilizing aluminum or iron salts or lime. The point of application may be the
primary clarifiers, the secondary clarifiers, or a separate tertiary unit.
Because nitrification and addition of aluminum or iron compounds both
result in the destruction of alkalinity, care must be taken when using the two
in combination to avoid adverse effects from a drop in pH. If 10 mg/1 of phos-
phorus are removed by alum addition ahead of the primary clarifier, about 70
mg/1 of alkalinity will be destroyed and downstream chemical addition may be
required to prevent low pH values in the nitrification process.
Lime addition to the primary clarifier may have an effect opposite from
alum. The changes in alkalinity in this situation are dependent on lime dose
(or desired pH) and raw wastewater quality. Cases of both increases and de-
creases in alkalinity with lime treatment may be found.
Primary effluent after lime treatment will typically have a pH between
9.5 and 11.0. This is higher than normally acceptable for discharge or intro-
duction into downstream biological processes. To reduce the pH, the normal
practice is to recarbonate the high pH primary effluent. Conventionally, this
155
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involves the introduction of gaseous carbon dioxide (CO2) into the primary
effluent in a reaction basin of at least 20 min detention time. Typically,
carbon dioxide is either drawn from refrigerated storage, or furnace stack
gases containing carbon dioxide are used. The recarbonation reaction can
be thought of as the conversion of alkalinity in the hydroxide form (OH~) to
that in the bicarbonate form (HCOZ) as follows:
Ca(OH)2 + 2 C02 -*• Ca(H2C03)2 (43)
The important point to remember is that in combining nitrification with chemical
addition for phosphorus removal, alkalinity and pH relationships must be
carefully evaluated.
Rapid sand or multi-media filtration and carbon sorption columns are used
to reduce residual suspended solids and organic compounds in treatment plant
effluents . For most economical operation of these units , the influent concen-
trations of organics and suspended solids should be as low as possible.
Because the coupled trickling filter-activated sludge process is capable of
producing high quality effluents , it is very compatible with filtration and
sorption .
Use of Existing Structures —
Possible incorporation of structures which would otherwise be abandoned
into the flow diagram for the upgraded plant will necessarily have to be eval-
uated in each situation. The modification of the filter circulation sump at
Livermore to accommodate the activated sludge process is probably a unique
example which would not be duplicated elsewhere, but it does provide an
excellent illustration of the way that existing structures can be used.
Generalizations may be made, however, about two types of facilities
which will often be available for use in a coupled- process upgrading situation:
the secondary clarifiers and the oxidation ponds which are often used to polish
trickling filter effluent. Because trickling filter secondary clarifiers are
usually designed on the basis of higher overflow rates than used for activated
sludge secondary clarifiers and because they cannot accommodate the high
MLSS levels and sludge removal rates required for the activated sludge pro-
cess, additional secondary sedimentation capacity will normally be included
in plant upgrading. It may be more economical to adapt the existing second-
ary clarifier to other uses than to modify it for use with activated sludge.
At Livermore* it was converted to a primary sedimentation tank (as previously
planned); at Corvallis,it was used as a chlorine contact tank; and at Lompoc,
it was converted to a sludge thickener. The most appropriate use will be
different at each plant.
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Existing oxidation ponds may be converted to emergency holding basins
as was done at Livermore and Lompoc. Another possibility is conversion to
sludge lagoons. Often the entire existing pond area will not be required for
these purposes. New feed and withdrawal lines will normally need to be con-
structed, and banks may need to be relocated.
Expected Effluent Quality
While plant performance will depend on the design criteria used at each
installation as well as such factors as operator competence, it is worthwhile
to project the maximum performance which can be expected from the coupled
trickling filter-activated sludge process. With typical municipal wastewater,
effluent BOD5 and suspended solids concentrations of 10 mg/1 can possibly
be obtained, but 15 to 20 mg/1 would be more conservative estimates. An
effluent ammonia nitrogen concentration of 0.1 mg/1 is expected from the
Lompoc plant, and experience at Livermore indicates that 1.0 mg/1 is not
difficult to obtain. With high chlorine dosages and a chlorine contact tank
which approximates plug flow, monthly median total coliform organism con-
centrations of 2.2 MPN/100 ml should be obtainable. For 7-day medians,
5.0 MPN/100 ml may be a more realistic value.
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REFERENCES
1. Murphy, K.L., and P.L. Timpany, "Longitudinal Mixing in Sprial Flow
Aeration Tanks," JSED, Proc. ASCE, 96, No. SA2, pp. 211-221, 1970.
2. White, G .C., Handbook of Chlorination, Van Nostrand Reinhold Co.,
New York, 1972.
3. Collins, H .F., and R .E. Selleck, Process Kinetics of Wastewater Chlorina-
tion, University of California at Berkeley, Sanitary Engineering Research
Laboratory (SERL) Report No. 72-5, November 1972.
4. Stenquist, R.J., andW.J. Kaufman, Initial Mixing in Coagulation Processes,
U.S. Environmental Protection Agency, Environmental Protection Technology
Series Report No. EPA-R2-72-053, November 1972.
5. Deaner, D.G., California Department of Public Health, Letter report on
chlorine contact tank dye tracer studies, May 14, 1970.
6. Metcalf and Eddy, Inc., Wastewater Engineering: Collection, Treatment,
and Disposal, McGraw-Hill, 1972.
7. Fair and Geyer, Water Supply and Wastewater Disposal, John Wiley and
Sons, Inc., 1967.
8. California Department of Health, "Wastewater Reclamation Criteria,"
California Administrative Code, Title 22, Division 4, 1975.
9. Process Design Manual for Nitrogen Control, U.S. Environmental Protection
Agencyi Office of Technology Transfer, 1975.
10. Brown and Caldwell, "Project Report, Wastewater Treatment Program,"
Prepared for the City of Corvallis, Oregon, November 1973.
11. Description of the El Lago, Texas, Advanced Wastewater Treatment Plant,
Harris County Water Control and Improvement District No. 50, March 1974.
12. Kennedy, Bill, Personal communication with D.S. Parker, San Pablo (Calif,)
Sanitary District, November 1974.
13. Lawrence, A.W., and P.L. McCarty, "Unified Basis for Biological Treatment
Design and Operation," JSED, Proc. ASCE, 96, No. SA3, pp. 757-778, 1970.
158
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14. Gujer, W., and D.I. Jenkins, The Contact Stabilization Process—Oxygen
and Nitrogen Mass Balances, University of California at Berkeley, Sanitary
Engineering Research Laboratory (SERL) Report No. 74-2, February 1974.
15. Process Design Manual for Upgrading Existing Wastewater Treatment
Plants, U.S. Environmental Protection Agency, Office of Technology
Transfer, 1974.
16. Leary, R.D., L.A., Ernest, and WJ. Katz, "Full-Scale Oxygen Transfer
Studies of Seven Diffuser Systems."JWPCF, 41.. No. 3, pp. 459-473, 1969.
159
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APPENDICES
Page
A. California Regional Water Pollution Control Board
No. 2, San Francisco Bay Region, Resolution No. 239 161
B. California Regional Water Pollution Control Board
No. 2, San Francisco Bay Region, Resolution No. 683 167
C. California Regional Water Quality Control Board,
San Francisco Bay Region, Order No. 71-76 177
D. Performance and Operating Parameters Measured
at the Livermore Water Reclamation Plant 185
E. Monthly Operating and Performance Data 189
160
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APPENDIX A
CALIFORNIA REGIONAL WATER POLLUTION CONTROL BOARD NO. 2
SAN FRANCISCO BAY REGION
RESOLUTION NO. 239
PRESCRIBING REQUIREMENTS AS TO THE NATURE OF WASTE DISCHARGE
INTO ARROYO LAS POSIT AS NEAR THE SOUTHERLY PROLONGATION OF
COLLIER CANYON ROAD AS PROPOSED BY THE CITY OF LIVERMORE
WHEREAS, the City of Livermore has filed with this Regional Water Pollution
Control Board a report on proposed waste discharge, dated November 13, 1956,
in accordance with Section 13054 of the Water Code of the State of California; and
WHEREAS, said report and subsequently submitted data provide the following
information:
(a) The proposed waste discharge consists of mixed domestic sewage and
industrial wastes;
/
(b) Change in manner of treatment and change in point of disposal are
proposed;
(c) Two plant sites, designated as "Proposed Plant Site" and "Possible
Alternate Plant Site", are proposed and their locations are shown
on a map submitted as part of the report;
(d) Subsequent to the filing of the report on proposed waste discharge the
City purchased the "Proposed Plant Site" on Arroyo Las Positas and
advised the Board's staff that waste discharge requirements for the
"Possible Alternate Plant Site" on Arroyo Mocho were no longer needed
by the City;
(e) Treatment plant effluent from the proposed plant site will be discharged
to Arroyo Las Positas at a point about 1000 feet downstream from the
southerly prolongation of Collier Canyon Road;
(f) The present rate of flow is 0.70 mgd and the design rate of flow is
6.0 mgd;
(g) There are no industrial wastes being discharged at present and it is not
known what type of industry will connect in the future;
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(h) The City has asked that requirements be established for two conditions of
discharge into Arroyo Las Positas as follows:
(1) Continuous discharge to the Arroyo after treatment in a plant
consisting of the following: primary clarifier with separate
sludge digestion, high rate trickling filter, secondary clarifier,
chlorinator and chlorine contact tank, and oxidation ponds with
a minimum of 30 days retention based on average dry weather flow;
(2) Intermittent discharge to the Arroyo after treatment in a plant
consisting of the following: primary clarifier with separate
sludge digestion; oxidation ponds with a minimum of 30 days
retention based on average dry weather flow; and chlorinator
and chlorine contact tank;
(i) Under condition (2) above, the City proposes:
(1) To dispose of all effluent from the oxidation ponds on land at its
present sewage disposal site on Rincon Avenue or on land that
is owned by, or under the control of, the City at the proposed
plant site on Arroyo Las Positas whenever there is sufficient land
available for disposal:
(2) To have sufficient land disposal area available at all times so that
there will never be any waste discharge to the Arroyo unless the
sewage flow at the treatment plant exceeds three times the average
dry weather flow;
(3) To limit the rate of flow to the Arroyo to the actual flow at the sewage
treatment plant minus three times the average dry weather sewage
flow; and
WHEREAS, comments and recommendations relative to these proposals have been
received and considered by the Board as follows:
(a) Memorandum from the State Department of Fish and Game, dated
January 3, 1957;
(b) Memorandum from the State Department of Water Resources, dated
February 7, 1957;
(c) Memorandum from the State Department of Public Health, dated
February 7, 1957; and
WHEREAS, investigation by the staff of the Board discloses the following:
(a) The proposed plant site is at present well isolated from residential or
commercial development; and the adjacent lands are used for agriculture;
(b) The land adjacent to Arroyo Las Positas below the proposed point of
waste discharge is entirely agricultural at present except for the
Santa Rita Rehabilitation Center Annex of the County of Alameda;
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(c) There is a dairy, located on the Arroyo about 1.5 miles downstream
from the proposed point of discharge, at which there are four
residences within 200 feet of the Arroyo and at which milk cows pass
through the Arroyo in going from the milking barn to the pastures;
(d) The waters of Arroyo de la Laguna are readily accessible to persons
using the golf course at Hacienda Road;
(e) The waters of Alameda Creek in Niles Canyon are used for bathing,
wading, fish propagation and fishing;
(f) The San Francisco Water Department has certain water rights for the
surface diversion of water at the confluence of Laguna and Alameda
creeks near Sunol;
(g) Alameda Creek recharges the southern Alameda county groundwater
basin which is an important source of supply for domestic, agricultural,
and industrial use;
THEREFORE, BE IT RESOLVED, that the waste of the City of Livermore shall be
of the following quality for discharge to Arroyo Las Positas under conditions
(1) and (2) as described above and that all samples shall be collected and
analyzed in accordance with procedures given in the Tenth Edition of "Standard
Methods for the Examination of Water, Sewage, and Industrial Wastes," by the
American Public Health Association:
Condition 1 - Continuous Discharge
(a) The following requirements for the influent to the oxidation ponds are
based on the proposal by the City that this influent will be chlorinated
and that it will, at all times, be passed through properly designed
operated and maintained oxidation ponds having a minimum retention
time of 30 days based on average dry weather flow prior to discharge
to the Arroyo;
(b) Any 24-hour conposite sample of the influent to the oxidation ponds shall
not exceed the following limits:
5-day BOD - 55 ppm Maximum
Suspended Solids - 75 ppm Maximum
(c) The waste shall be adequately disinfected at all times and adequate
disinfection, for the purpose of this requirement, is any process
equivalent to the maintenance of 0.5 ppm of chlorine residual in the
influent to the oxidation ponds after a chlorine contact period of
30 minutes;
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Condition 2 - Intermittent Discharge
(a) The following requirements for the effluent from the oxidation ponds are
based on the proposal by the City that this effluent will be chlorinated
and that the effluent from the primary clarifier will, at all times, be
passed through properly designed, operated and maintained oxidation
ponds having a minimum retention time of 30 days, based on average
dry weather flow, prior to chlorination and discharge to the Arroyo;
(b) The waste discharge to the Arroyo shall not contain more than 1 ml/liter/
hour of settleable solids at any time;
(c) The waste discharged to the Arroyo shall not contain a most probable
number of coliform organisms greater than 10 per milliliter at any time;
(d) The above coliform limit will be considered as being met if a chlorine
residual of 2.0 ppm is maintained continuously after a chlorine contact
time of 30 minutes;
BE.IT FURTHER RESOLVED, that whenever there is any waste discharge by the
City of Livermore to Arroyo Las Positas, the City shall make at least one
determination per day of the chlorine residual at the end of the chlorine contact
time and that these data together with a record of the corresponding sewage
flow, at the time the chlorine residual is determined, shall be made available
to this Board upon request;
BE IT FURTHER RESOLVED, that none of the following conditions shall occur in
Arroyo Las Positas, Arroyo de la Laguna, or Alameda Creek as a result of any
waste discharge by the City of Livermore:
Floating materials recognizable by eye as being of waste origin at any
point;
Atmospheric odors recognizable as being of waste origin at any point;
Depletion of dissolved oxygen below 4.0 ppm in Arroyo de la Laguna
or below 5.0 ppm in Alameda Creek;
Toxic concentrations of substances deleterious to humans, livestock,
fish, or aquatic life;
BE IT FURTHER RESOLVED, that treatment or disposal of these wastes shall not
cause atmospheric odors recognizable as being of waste origin at any point
beyond the boundaries of the treatment or disposal sites;
BE IT FURTHER RESOLVED, that in the event that the City releases this waste
to another person for use and/or disposal, it shall be necessary for the City to
so advise this Board;
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BE IT FURTHER RESOLVED, that it is the intention of this Board to formulate, at
the earliest practicable date, a policy governing the mineral quality of all waste
discharges in the Alameda Creek watershed and that the above requirements may
at that time be modified to include limiting values of certain effluent constituents
in addition to those listed above;
BE IT FURTHER RESOLVED, that in prescribing requirements for this discharge,
it is the intent of this Board:
(a) To protect the surface and g round waters, that may be affected by these
proposed discharges, for domestic, agricultural and industrial purposes;
(b) To protect the waters of Alameda Creek for fish propagation, fishing,
wading and bathing;
(c) To prevent nuisance and health hazards as a result of the proposed
waste discharges;
BE IT FURTHER RESOLVED, that the Executive Officer is directed to transmit to
the City of Livermore, copies of all the correspondence this Board has received
and considered relative to these discharges, and that this Board requests said
City to take note of the comments and recommendations contained in said
correspondence;
BE IT FURTHER RESOLVED, that these requirements do not authorize the com-
mission of any act causing injury to the property of another, nor protect the
discharger from his liabilities under Federal, State, or local laws;
/
BE IT FURTHER RESOLVED, that if conditions should change materially at some
time in the future it may be necessary to revise these requirements, and in such
event this Board will take up the matter with the City of Livermore at that time;
BE IT FURTHER RESOLVED, that the requirements prescribed herein for continuous
discharge to Arroyo Las Positas are based upon the present downstream develop-
ment and that changes in the character or amount of downstream development
along the Arroyo will be cause for this Board to review the adequacy of these
requirements.
RALPH W. SHAFOR
Acting Chairman
March 21, 1957
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I, John B. Harrison, hereby certify that the foregoing is a true and correct copy
of Resolution No. 239, as adopted by the Regional Water Pollution Control Board
of Region No. 2, at its regular meeting on March 21, 1957.
JOHN B . HARRISON
Executive Officer
Regional Water Pollution Control
Board No. 2
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APPENDIX B
CALIFORNIA REGIONAL WATER POLLUTION CONTROL BOARD NO. 2
SAN FRANCISCO BAY REGION
RESOLUTION NO. 683
RESCINDING RESOLUTIONS NOS. 108 AND 239 AND THOSE PORTIONS OF
RESOLUTION NO. 446 WHICH ARE DIRECTLY APPLICABLE ONLY TO THE
CITY OF LIVERMORE, AND PRESCRIBING REQUIREMENTS AS TO THE
NATURE OF WASTE DISCHARGE INTO ARROYO LAS POSITAS BY THE
CITY OF LIVERMORE, ALAMEDA COUNTY.
I. WHEREAS, a Report on Waste Discharge, dated June 23, 1952,was filed, in
accordance with Section 13054 of the State Water Code, with this Regional
Water Pollution Control Board by the City of Livermore, hereinafter referred
to as the discharger, on June 25, 1952,and requirements as to the nature of
waste discharge were prescribed in this Regional Board's Resolution No. 108
adopted on August 21, 1952; and
II. WHEREAS, a Report on Waste Discharge, dated November 13, 1956,was filed
with the Regional Board by the City of Livermore on November 14, 1956,and
requirements as to the nature of waste discharge by the City into Arroyo Las
Positas were prescribed in this Regional Board's Resolution No. 239 adopted
on March 21, 1957; and
III. WHEREAS, at its February 21, 1963,regular meeting, this Regional Board
adopted its Resolution No. 446 "PRESCRIBING ADDITIONAL REQUIREMENTS
AS TO THE NATURE OF ALL WASTE DISCHARGES TO ALAMEDA CREEK OR
ITS TRIBUTARIES ABOVE NILES, INCLUDING THE CITY OF LIVERMORE,
VALLEY COMMUNITY SERVICES DISTRICT, CITY OF PLEASANTON,
VETERANS ADMINISTRATION HOSPITAL AT LIVERMORE, CASTLEWOOD
CORPORATION, CAMP PARKS, AND THE GENERAL ELECTRIC COMPANY'S
VALLECITOS ATOMIC LABORATORY, ALAMEDA COUNTY"; and
IV. WHEREAS,
A. The Livermore City Council, on November 18, 1963,adopted its Resolution
No. 227-63 authorizing engineering studies and preparation of a report
with recommendations for a program of sewage treatment and disposal
to meet its present and future needs;
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B. On April 22, 1964,the City's consultant submitted an engineering report
which recommended certain treatment plant enlargements and improve-
ments with continuous disposal of effluent into the Arroyo Las Positas;
C. At its September 17, 1964,regular meeting this Board was informed by
the City that plans were underway to enlarge the treatment works to a
capacity of 5.0 mgd (million gallons per day) with continuous disposal
of effluent to the Arroyo Las Positas, as recommended in the aforemen-
tioned report;
D. On September 17, 1964,this Regional Board instructed its staff to prepare
a report relative to the necessity for revision of the City's current
requirements;
E. On October 21, 1964, the Executive Officer requested comments and
recommendations from interested agencies and individuals as to the
necessity for revision of the City's waste discharge requirements; and
V. WHEREAS, at its November 19, 1964,regular meeting this Board, after
- considering a staff report and other pertinent information relative to this
discharge, directed its staff to review the existing requirements for the City
of Livermore and to prepare a tentative Resolution containing revised
requirements for this discharge; and
VI. WHEREAS, the aforesaid consultant's report and other data submitted by the
discharger provide the following information:
A. The waste is sewage and industrial wastes;
B . The waste flow is estimated as follows:
1. Average dry weather flow for
August 1962 1.7 mgd (million gallons per day)
June, July and August 1963 1.8 mgd
September 1964 2.3 mgd
2. Design flow (existing plant) 2.5 mgd
3. Design flow (enlarged plant) 5.0 mgd;
C. The population served is estimated as follows:
1. Present - 23,000 persons
2. Design (existing plant) - approx. 29,000 persons
3. Design (enlarged plant) - approx. 58,000 persons;
D. Treated wastes will be disposed by discharge to Arroyo Las Positas; and
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VII. WHEREAS, the Board has received and considered the following correspon-
dence regarding this waste discharge:
A. Memorandum from State Department of Fish and Game, dated November 4,
1964;
B. Memoranda from State Department of Public Health, dated November 16,
1964, February 16, 1965, June 28, 1965, and July 13, 1965;
C. Memoranda from State Department of Water Resources, dated November 16,
1964, April 14, 1965, and July 12, 1965;
D. Letter from the Alameda County Board of Supervisors transmitting
comments of:
1. The Alameda County Health Department (no date), and
2. The Alameda County Director of Public Works, dated November 6,
1964;
E. Letters from Mr. G. G. Jamieson, owner of Rancho Del Charro, dated
October 27, 1964, and March 17, 1965;
F. Letter from Alameda County Planning Commission, dated October 28,
1964;
G. Letter from Mr. R. M. Wing, dated October 30, 1964;
H. Letter from Mr. Conrad Moldt, dated November 3, 1964;
I. Letter from Headquarters Camp Parks, dated 3 November 1964;
J. Letter from City of Pleasanton, dated November 6, 1964;
K. Letters from City of Livermore, dated November 12, 1964, March 12,
1965, May 20, 1965, May 26, 1965, June 25, 1965, and July 9, 1965;
L. Letters from Pleasanton Township County Water District, dated
November 13, 1964, March 12, 1965, and May 18, 1965;
M. Letters from Alameda County Water District, dated November 13, 1964,
January 14, 1965, March 15, 1965, July 15, 1965, and July 15, 1965;
N. Letter from City of Union City, dated November 19, 1964;
O. Letters from the Alameda County Health Department, dated March 9,
1965, and May 19, 1965;
P. Letter from the Alameda County Flood Control and Water Conservation
District, Zone No. 7, dated May 18, 1965;
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Q. Letters from the Pacific Water Conditioning Association and their
consultants, dated May 10, 1965, May 20, 1965, and June 4, 1965;
R. Letter from the San Francisco Water Department, dated May 4, 1965;
S. Letter from Valley Community Services District, dated July 12, 1965
together with Resolution No. 23-65; and
Vin. WHEREAS, investigation by the staff of the Board discloses that:
A. Beneficial uses of the waters of Arroyo Las Positas, Arroyo de la Laguna
and Alameda Creek downstream from the point of waste discharge
include:
1. Recharge of groundwater basins of the Santa Rita subbasin (near
El Charro Road) and the Niles Cone (near Miles), both basins
being sources of supply for domestic, agricultural and industrial
use;
2. Bathing;
3. Wading;
4. Fish propagation;
5. Fishing;
B. Land near the waste discharge point is used for agricultural purposes
at present;
C. The City of Livermore proposes to develop a municipal airport and golf
course adjacent to the waste discharge point;
D. The San Francisco Water Department has rights for the surface diversion
of water at the confluence of Arroyo de la Laguna and Alameda Creek
near Sunol and the Department also owns and uses the subsurface
water rights to part of the Amador Valley south of Highway 50;
E. The City of Pleasanton owns and thePleasanton Township County Water
District uses the subsurface water rights to part of the Amador Valley
south of Highway 50;
F. The waters of Arroyo de la Laguna are readily accessible to persons
using the golf course at Hacienda Road;
G. The channels of Altamont Creek, Arroyo Las Positas, Arroyo de la
Laguna and Alameda Creek are presently used, by the Alameda County
Water District for the conveyance of water, imported from the
Sacramento-San Joaquin Delta, to the Niles Cone for recharge of the
groundwater basin;
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H. Present plans call for ultimate discharge of South Bay Aqueduct water to
the Alameda Creek system near Sunol and conveyance thence to Niles
through the natural channels of said creek system; now
IX. THEREFORE, BE IT RESOLVED, that it is the intention of this Regional Water
Pollution Control Board to:
A. Prevent nuisance, as defined in Water Code Section 13005, from being
caused by this waste discharge or by treatment or conveyance of wastes
tributary thereto;
B. Make or preserve the waters of Arroyo Las Positas and of Arroyo de la
Laguna suitable for recharge of groundwaters that are a source of supply
for domestic, agricultural and industrial use;
C. Make or preserve the waters of Alameda Creek suitable for the following
beneficial uses:
1. Recharge of groundwaters that are a source of supply for domestic,
agricultural and industrial use;
2. Bathing;
3. Wading;
4. Fish propagation;
5. Fishing;
6. Aesthetic enjoyment;
X. BE IT FURTHER RESOLVED, that in order to fulfill its intentions in the
preceding paragraph, this Board prescribes the following requirements
for this waste discharge:
A. FOR THE PREVENTION OF NUISANCE
1. The discharge to any ponds that may be used for treatment, shall
not cause atmospheric odors recognizable as being of waste origin
at any point outside the property of the discharger;
2. The discharge of Arroyo Las Positas or any tributary of Alameda
Creek shall not cause:
a. Floating, suspended, or deposited macroscopic paniculate
material of waste origin at any place;
b. Atmospheric odors recognizable as being of waste origin at
any place outside the property of the discharger;
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c. Dissolved sulfide concentration of more than 0.1 mg/1 at any
place in the receiving water;
d. Foaming at any place;
e. Turbidity or discoloration in waters of the State at any place
more than 100 feet from the point of discharge;
B. FOR THE PROTECTION OF BENEFICIAL WATER USES
1. The discharge to Arroyo Las Positas or any tributary of Alameda
Creek shall not cause waters of the State to exceed the following
limits of quality:
a. At any place in Arroyo Las Positas or Arroyo de la Laguna:
4.0 mg/1, minimum
None;
(1) Dissolved oxygen
(2) Toxic concentrations of substances
deleterious to humans or livestock
b. At any place in Alameda Creek;
(1) Dissolved oxygen
(2) Substances or combination of
substances in concentration
adverse to fish or aquatic life
c. Any groundwater:
(1) Tastes or odors of waste origin
(2) Arsenic (As)
(3) Barium (Ba)
(4) Cadmium (Cd)
(5) Chromium (hexavalent)
(6) Cyanide (CN)
(7) Fluoride (F)
(8) Lead (Pb)
(9) Selenium (Se)
(10) Silver (Ag)
5.0 mg/1, minimum
None;
.05 mg/1,
.0 mg/1,
.01 mg/1,
.05 mg/1,
.2 mg/1,
.0 mg/1,
. 05 mg/1,
.01 mg/1,
0.05 mg/1,
None
maximum
maximum
maximum
maximum
maximum
maximum
maximum
maximum
maximum;
The quality of the waste discharged to Arroyo Las Positas or any
tributary of Alameda Creek shall be maintained within the following
limits:
a.
For 6-hour composite samples collected one day each week
throughout the year and made up of portions collected at
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hourly intervals in proportion to rate of flow at time of
collection:
(1) 5-day BOD - No more than 50 percent of the
samples in any one month to
exceed 20 mg/1, and no sample
to exceed 40 mg/1, maximum;
(2) Suspended solids - 20 mg/1, maximum
(3) Grease - 5 mg/1, maximum
(4) Settleable solids - 0.5 ml/l/hr, maximum;
(5) (a) Methylene Blue Active Substances or MBAS (as analyzed
by the methylene blue method in accordance with the
Eleventh Edition of "Standard Methods for the Examina-
tion of Water and Wastewater" by the American Public
Health Association)
1.0 mg/1, maximum
(b) The above requirement will be considered as being met
whenever the discharger and all other waste discharges
to Alameda Creek and its tributaries above Niles jointly
develop and implement a program to monitor and con-
trol their discharges in such a manner that they can
continuously demonstrate to the satisfaction of the
Regional Board, that these discharges do not cause
the MBAS concentration in the Arroyo de la Laguna at
Verona Road to exceed 0.5 mg/1 at any time, without
allowing for the dilution effect of water imported by
users downstream from Verona Road;
b. Any grab sample:
(1) Dissolved sulfide 0.1 mg/1, maximum
(2) Settleable solids 1.0 ml/l/hr, maximum;
C. FOR THE PREVENTION OF HAZARDS TO PUBLIC HEALTH
All waste discharged to the Arroyo Las Positas or to any tributary of
Alameda Creek shall be adequately disinfected, and for the purpose of
this Resolution, adequate disinfection shall mean any disinfection which
produces a moving median coliform MPN value not exceeding 5.0 per
100 milliliters at some point in the treatment process/providing that
moving median values shall be determined from:
1. Consecutive results obtained from samples collected on the previous
five sampling days, and
2. Samples shall be collected at a frequency of at least five days each
week, and
173
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3. Samples shall be collected during those periods when the coliform
MPN has been demonstrated to be at its daily maximum;
XI. BE IT FURTHER RESOLVED, that it is the intention of this Board, at the
earliest practicable date to:
A. Adopt quality objectives for groundwaters in the Livermore groundwater
basins;
B. Adopt a policy relative to making allowance for the dilution effect of
water imported by users downstream from Verona Road;
C. Review the quality limits contained herein to assure their adequacy in
achieving the objectives previously established by this Board in its
Resolution No. 226, as amended by Paragraph XVI of Resolution No. 466,
for groundwater in the Niles Cone;
XH. BE IT FURTHER RESOLVED, that this Board hereby adopts the following
objectives for mineral quality of wastes discharged by the City of Livermore
to the Arroyo Las Positas or to any tributary of Alameda Creek:
A. The monthly average concentration of constituents, as listed below and
as determined by 6-hour composite samples collected weekly at the
points designated, shall not exceed the sum of the increment listed for
each plus its weighted average concentration in the water supply
tributary to the discharge (as determined by monthly analyses of each
water source):
Increment as measured in -
The influent to The effluent from
the treatment the treatment
Constituent facilities facilities
Total diss. solids 325 mg/1* **
Chloride 75 mg/1* **
Others ** **
*To be reviewed by the Board whenever data becomes
available which indicates to the staff of the Board
and/or the City that review is necessary;
**To be established by the Board when sufficient data
is available;
B. And, in furtherance of said objectives the discharger is required to
file technical reports pursuant to Sections 13055 and 13055.1,
California Water Code with this Regional Board as follows:
1. By September 1, 1965, a firm and detailed time schedule for actions
which it proposes to take in order to regulate the mineral quality of
wastes discharged into its sewerage system;
174
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2. By January 1, May 1, and September 1, in each calendar year, a
detailed report describing its progress in achieving such regula-
tion;
All the aforementioned reports shall be transmitted with a motion of the
City Council showing that that body has approved and is forwarding
same to the Regional Board;
C. This Board will adopt specific requirements for mineral quality of wastes
discharged by the City of Livermore to the Arroyo Las Positas or to any
tributary of Alameda Creek, to replace the above objectives, whenever
it is not satisfied that discharger is making reasonable progress
toward meeting these objectives;
XIII. BE IT FURTHER RESOLVED, that in accordance with Sections 13055 and
13055.1 of the Water Code, the discharger is required to file technical
reports on self-monitoring work performed according to detailed specifi-
cations developed pursuant to the Regional Board's Resolution No. 398,
and that all sample collection and analysis for the purpose of determining
compliance with the requirements prescribed in this Resolution shall be
performed according to these detailed specifications;
XIV. BE IT FURTHER RESOLVED, that the Executive Officer is directed to
transmit to the discharger copies of all correspondence this Board has
received and considered relative to this waste discharge, and that the
Board requests the discharger to take note of the comments and recom-
mendations contained in said correspondence;
XV. BE IT FURTHER RESOLVED, that these requirements do not authorize the
commission of any act causing injury to the property of another nor protect
the discharger from his liabilities under Federal, State, or local laws;
XVI. BE IT FURTHER RESOLVED, that this Regional Water Pollution Control
Board's Resolutions Nos. 108 and 239 and those portons of Resolution
No. 446 which are directly applicable only to the City of Livermore are
hereby rescinded;
XVII. BE IT FURTHER RESOLVED, that none of the requirements prescribed in
this Resolution are a guarantee to the discharger of a capacity right in
the receiving waters;
XVIII. BE IT FURTHER RESOLVED, that if conditions should change materially
at some time in the future, it may be necessary to review these require-
ments, and in such event this Board will take up the matter with the
responsible persons at this time;
XIX BE IT FURTHER RESOLVED, that pursuant to Section 13054, California
Water Code this Regional Board requires the discharger to file a written
report with the Board when the effluent flow, averaged for a calendar
175
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month during which there is no rainfall, exceeds 85% of the design
capacity of the treatment facilities provided at that time; this report shall
be accompanied by a duly adopted motion of the City Council approving
said report and the report shall contain at least the following information:
A. Average flow for the month and date, time and volume of instantaneous
peak flow during the month, as well as total flow for the calendar
day during which said peak occurred;
B. Discharger's best estimate as to when the average dry weather
effluent flow for the maximum month will reach design capacity;
C. Discharger's intentions with respect to actions to be taken and the
timing of such actions, including engineering studies, etc., to
expand existing facilities or to provide new or supplemental
facilities before the waste flow volume reaches design capacity;
XX. BE IT FURTHER RESOLVED, that it is the intent of this Board to under-
take investigations to determine the need for establishment of ground-
water monitoring wells in the vicinity of the proposed waste discharges
and the discharger will be required to establish and use such wells as
a part of his monitoring program if such work is found by the Board
to be necessary.
GRANT BURTON
Chairman
July 15, 1965
I, John B. Harrison, hereby certify that the foregoing is a true and correct
copy of Resolution No. 683, as adopted by the Regional Water Pollution Control
Board of region No. 2, at its regular meeting on July 15, 1965.
JOHN B. HARRISON, Executive Officer
REGIONAL WATER POLLUTION CONTROL BOARD NO. 2
176
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APPENDIX C
CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD
SAN FRANCISCO BAY REGION
ORDER NO. 71-76
WASTE DISCHARGE REQUIREMENTS
FOR
THE CITY OF LIVERMORE
The California Regional Water Quality Control Board, San Francisco Bay Region
finds that:
1. This Regional Board prescribed requirements for the City of Livermore,
called the discharger below, as follows:
Resolution Date
Number Adopted For Discharge To
683 July 15, 1965 Arroyo Las Positas
752 May 19, 1966 Land (Airport and Golf Course)
67-21 April 28, 1966 Four Temporary Septic Tanks
67-28 May 18, 1967 Land (Amends Resolution No. 752)
68-19 April 30, 1968 Arroyo Las Positas (Amends
Resolution No. 683)
68-20 April 30, 1968 Time Schedule for Compliance with
Mineral Quality Requirements
68-45 August 28, 1968 Amends Time Schedule of Resolution
No. 67-21
68-50 August 28, 1968 Land (Amends Resolution No. 752
and 67-28)
2. Information in the Regional Board's files and in the City's report of waste
discharge dated February 8, 1971,describes the existing waste discharge as
approximately 3.6 mgd (million gallons per day) of sewage serving a
population of 38,000. The current plant capacity is 5.0 mgd. Discharger
proposes to increase plant capacity to 10.0 mgd and provide a higher degree
of treatment. Effluent from the Livermore Water Reclamation Plant is used
seasonally for agricultural irrigation and horticulture on the municipal
airport and golf course grounds.
177
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3. These wastes may affect the following beneficial water uses in Arroyo Las
Positas, Arroyo de la Laguna and Alameda Creek:
Recharge of groundwaters in the Santa Rita subbasin (near El Charro Road)
and the Miles Cone (Near Miles) that are sources of supply for domestic,
agricultural and industrial use;
Bathing in Alameda Creek;
Wading;
Fish propagation in Arroyo de la Laguna and Alameda Creek;
Fishing in Arroyo de la Laguna and Alameda Creek.
4. Land near the waste discharge point is used for residences, recreation,
agriculture and commerce.
5. The San Francisco Water Department has rights for the surface diversion of
- water at the confluence of Arroyo de la Laguna and Alameda Creek near
Sunol and the Department also owns and uses the subsurface water rights to
part of the Amador Valley south of Highway 50. The Alameda County Water
District has rights for surface water diversion to the Miles Cone ground-
water basin from Alameda Creek between Mission Boulevard and Decoto
Road for municipal, industrial and irrigation uses.
6. The City of Pleasanton owns and the Pleasanton Township County Water
District uses the subsurface water rights to part of the Amador Valley
south of Highway 50.
7. The waters of Arroyo de la Laguna are readily accessible to persons using
the golf course at Hacienda Road.
8. The channel of Alameda Creek is and Arroyo de la Laguna may be used for
the conveyance of water, imported from the Sacramento-San Joaquin Delta,
to the Niles Cone for recharge of the groundwater basin.
9. A water quality management study for the Livermore Valley area is currently
underway. The findings of this study will influence the nature of future
treatment and disposal.
10. The Board adopted an Interim Water Quality Control Plan for the San Francisco
Bay Basin on June 17, 1971.
11. The Board in a public meeting heard and considered all comments pertaining
to this discharge.
IT IS HEREBY ORDERED, the discharger shall comply with the following:
178
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A. Waste Discharge Requirements
1. The treatment or disposal of waste shall not create a nuisance as defined
in Section 13050(m) of the California Water Code.
2. The discharge shall not cause:
a. Floating, suspended, or deposited macroscopic particulate matter
or foam, in waters of the State at any place;
b. Bottom deposits or aquatic growths at any place;
c. Alteration of temperature, turbidity, or apparent color beyond
present natural background levels in waters of the State at any
place;
d. Visible, floating, suspended or deposited oil or other products of
petroleum origin in waters of the State at any place;
e. Waters of the State to exceed the following limits of quality at any
point:
Dissolved oxygen in Arroyo
Las Positas, Arroyo Mocho,
or Arroyo de la Laguna
Dissolved oxygen in
Alameda Creek
PH
Dissolved sulfide
Other substances
Minimum 5.0 mg/1
Annual median 80% saturation.
Minimum 7.0 mg/1
Annual median 90% saturation.
When natural factors cause
lesser concentrations, then
this discharge shall not cause
further reduction.
No change in the natural
ambient pH value by more
than 0.1 pH unit.
0.1 mg/1 maximum.
No toxic or other substances
shall be present in concen-
trations or quantities which
will cause deleterious effects
on aquatic biota, wildlife or
waterfowl or which render
any of these unfit for human
consumption either at levels
created in the receiving waters
or as a result of biological
concentration.
179
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f. Groundwater at any point to contain tastes or odors of waste origin.
3.
g. Groundwaters to exceed the following limits of quality at any point:
Arsenic (As)
Barium (Ba)
Cadmium (Cd)
Chromium (hexavalent)
Cyanide (Cn)
Fluoride (F)
Lead (Pb)
Selenium (Se)
Silver (Ag)
The waste as discharged to waters of the State shall meet these quality
limits at all times:
0.05 mg/1,
1.0 mg/1,
0.01 mg/1,
0.05 mg/1,
0.2 mg/1,
1.0 mg/1,
0.05 mg/1,
0.01 mg/1,
0.05 mg/1.
maximum
maximum
maximum
maximum
maximum
maximum
maximum
maximum
maximum
a. In any grab sample:
pH
7.0, minimum (6.5 when the
natural ambient value is as
low as 6.5)
8.5, maximum
Settleable matter
The arithmetic average
of any six or more
samples collected on
any day
80% of all individual
samples collected
during maximum
daily flow over any
30-day period
Any sample
Dissolved sulfide
0.5 ml/l/hr, maximum
0.4ml/l/hr, maximum
1.0 ml/l/hr, maximum
0.1 mg/1, maximum.
b. For 24-hour composite samples collected one day each week through-
out the year and made up of portions collected at hourly intervals in
proportion to rate of flow at time of collection:
Turbidity
5-day BOD and
Suspended Solids
10 units, maximum
The waste as discharged, or at
some point in the treatment
process, shall meet quality
180
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requirements equivalent to
those which would result from
conformance with Section 8047
of Title 17, California Admin-
istrative Code.
The monthly average concentration of constituents, as listed below,
shall not exceed the sum of the increment listed for each, plus its
weighted average concentration in the water supply tributary to
the discharge {as determined by monthly analyses of each water
source):
Increment as measured in
the influent to the treatment
Constituent facilities
Total dissolved solids 325 mg/1*
Chloride 75 mg/1*
Others **
*To be reviewed by the Board whenever data becomes available
which indicates to the staff of the Board and/or the discharger
that review is necessary.
**To be established by the Board when sufficient date are
available.
Methylene Blue Active
Substances or MB AS 1.0 mg/1, maximum.
The waste as discharged, or at some point in the treatment process,
shall be adequately disinfected, and for the purpose of this Order
adequate disinfection shall mean any disinfection which produces a
moving median coliform MPN value not exceeding 2.2 per 100 milli-
liters at some point in the treatment process, providing that moving
median values shall be determined from:
Consecutive results obtained from samples collected on the
previous seven sampling days, and
Samples shall be collected at a frequency of at least seven
days each week, and
Samples shall be collected during those periods when the
coliform MPN has been demonstrated to be at its daily maximum.
181
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4. Wastes used for irrigation shall comply with all requirements above,
and:
a. All equipment, including pumps, piping and valves, storage ponds,
etc. which may at any time contain the waste shall be adequately
and clearly identified with warning signs and discharger shall make
all necessary provisions, in addition, to inform the public that the
liquid contained therein is sewage and is unfit for human consump-
tion.
b. No wastes used for irrigation shall be allowed to escape from the
property of discharger via surface flow.
5. This Regional Board hereby prohibits waste discharges by the City of
Livermore to Arroyo Las Positas or any other tributary of Alameda
Creek above Miles:
a. In excess of 5.0 million gallons per day average dry weather flow
for any calendar month until the City has provided facilities capable
of meeting the requirements above.
b. Subsequent to implementation of the program in "Provision 5" below,
except in conformance with that program.
B. Provisions
1. This Order includes items numbered 1, 2, 6 and 7 of the attached
"Reporting Requirements" dated August 28, 1970.
2. This Order includes items numbered 1, 2, 3, 4, 5 and 6 of the attached
"Notifications", dated January 6, 1970.
3. The City of Livermore shall comply with the following time schedule and
reporting program to assure compliance with the waste discharge
requirements of this order except turbidity in receiving waters and
effluent disinfection and suspended solids.
COMPLETION STATUS REPORT
TASK DATE DATE
Demonstrate compliance with
disinfection requirements
and assure continuing com-
pliance therewith at all times December 1, 1971 December 15, 1971
Report on progress toward
compliance with requirements
for mineral increments January 31, 1972
182
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Complete Final Design September 1, 1972 September 15, 1972
Authorization of Funding October 1, 1972 October 15, 1972
Commence Construction December 1, 1972 December 15, 1972
Report on progress toward
compliance with requirements
for mineral increments January 31, 1973
Compliance with Requirements September 1, 1973 September 15, 1973
The above compliance time schedule is subject to revision at the discre-
tion of this Regional Board.
If the discharger fails to comply with the above time schedule, the
Executive Officer is instructed to bring a recommendation on the
initiation of formal enforcement proceedings to the Regional Board for
its consideration.
4. It is the intention of this Board, at the earliest practicable date to:
a. Adopt quality objectives for groundwaters in the Livermore ground-
water basins.
b. Review the quality limits contained herein to ensure their adequacy
in achieving the objectives previously established by this Board in
its Resolution No. 226, as amended by Paragraph XVI of Resolution
No. 446, for groundwater in the Niles Cone.
5. This Regional Board adopts the following time schedule for long-term
compliance with the objectives of Resolution No. 226, and to assure
adequate protection of Livermore-Amador Valley groundwaters:
The Valley Community Services District, the Cities of Livermore
and Pleasanton and the Alameda County Flood Control and Water
Conservation District - Zone 7, shall complete by April, 1972, a
study which shall be the basis for a comprehensive water quality
management program for the Alameda Creek System above Niles
which is necessary to achieve the above and which is acceptable
to this Board. The schedule, description, and program shall
include consideration of at least the following items:
Facilities necessary.
Definition of the agency or agencies which will implement the
program, operate facilities, etc.
Means for securing a commitment by all agencies involved to
implement the selected program.
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In light of presently available information the agencies named above
are required to complete necessary facilities and to implement this
program no later than January 1975. An earlier date may be
prescribed by this Regional Board after review of additional
information.
6. This Board's Resolutions Nos. 683, 752, 67-21, 67-28, 68-19, 68-20,
68-45 and 68-50 are rescinded.
I, Fred H. Dierker, Executive Officer, do hereby certify the foregoing is a full,
true, and correcto copy of an order adopted by the California Regional Water
Quality Control Board, San Francisco Bay Region, on October 18, 1971.
Executive Officer
184
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APPENDIX D
PERFORMANCE AND OPERATING PARAMETERS MEASURED
AT THE LIVERMORE WATER RECLAMATION PLANT
The advanced nature of treatment and the stringency of the discharge require-
ments have resulted in unusually complete records of operation and performance
being maintained at Livermore. Presented below are the parameters which are
recorded on the monthly logs. Also listed are additional chemical analyses
made for the City by an outside laboratory. Monthly averages for most of the
parameters are tabulated in Appendix E.
Frequency of
Item Measurement5
1. Weather
A. Temperature, F
i. Maximum D
ii. Minimum D
s
B. Precipitation, in. D
C. Evaporation, in. D
D. Wind direction D
2. Sewage Flow
A. Influent
i. Average D
ii. Peak D(P)
B. Effluent
i. Average D
ii. Maximum D
iii. Minimum D
iv. Airport use D
v. Golf course use D
vi. Farmland use D
3. Grit Removed, ft D
= Daily, W = Weekly, I = Intermittently, P = Partial Record.
185
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4. Chemical, Physical, and Biological Characteristics (for Sampling Techniques,
see Table 11, Section 8.
Raw
Trickling
Primary Filter
Parameter
BOD5, mg/1
SS, mg/1
VSS, mg/1
DO, mg/1
Settl. Sol., ml/1
Total Sol., mg/1
PH
Grease, mg/1
MBAS, mg/1
NH+ -N, mg/1
NO; -N, mg/1
Lt
NO' -N, mg/1
Turbidity, JTU
Temperature, C
TDS, mg/1
Fixed DS, mg/1
Spec. Cond., mm
Cr, mg/1
Sewage Effluent Effluent
Secondary Plant
Effluent13 Effluent
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
w
W(P)C
W(P)C
W(P)C
w
W(P)C
W(P)C
W(P)
W(P)
W(P)
D(P)
W(P)
W(P)
W(P)
W(P)
W(P)
w
w
w
D
w
w
w
w
w
W(P)
W(P)
W(P)
D(P)
D(P)
W
w
w
w
aAfter 1970, raw sewage sample contains waste mixed liquor and lagoon super-
natant recycled to headworks.
bFor 1970 and later only.
GNor recorded on monthly logs.
5. Additional analytical work done by Brown and Caldwell (Environmental
Quality Analysts) on plant effluent.
A. Monthly composite of weekly 24-hr composites:
NO~ -N, NO" -N, NH* -N, organic nitrogen, Cl", HCO~, COg, HPO~, H2PO~,
Na+K+, Ca"1"1", Mg**, alkalinity, CO2, hardness, dissolved residue,
specific conductivity, pH, sodium percent, B (boron), F~ (fluoride),
PO|, and turbidity.
B. 6-mo or quarterly composite:
Barium (Ba), Silver (Ag), Lead (Pb), Cadmium (Cd), Arsenic (As),
Selenium (Se), Cyanide (CN) and Hexavalent Chromium (Cr).
186
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6. Disinfection
A. Lb chlorine for pre- and post-chlorination D
B. Time of sampling D
C. Flow rate, mgd D
D. Contact time, min D
E. Chlorine residual, mg/1 D
F. pH, contact tank or effluent D (P)
G. Total coliform MPN's
i. For day D
ii. 5- or 7-day median D
7. Mixed Liquor
3
A. Air used, million ft /day D
B. DO, mg/1 D
C. SS, mg/1, ml/1 D
D. SVI D
E. Waste mixed liquor, 1,000 gpd D
8. Sludge Handling and Treatment
A. Secondary sludge pumped, mgd D
B. Return sludge, percent of influent flow D
C. Return sludge SS, mg/1 D
D. Raw sludge, gpd D
E. Digested sludge to beds, gpd D
F. Digested sludge to lagoons, gpd D
G. Temperature of Digesters 1 and 2, F D
H. Gas produced by Digesters 1 and 2 D
187
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9. Sludge Characteristics
A. Total solids, percent
i. Raw I
ii. Digesters 1 and 2 I
iii. Digested I
B . Volatile solids, percent
i. Raw I
ii. Digesters 1 and 2 I
iii. Digested
C. Volatile acids. Digesters 1 and 2, mg/1 I
D. Alkalinity, Digesters 1 and 2, mg/1 I
E. pH, Digesters 1 and 2 I
10. Electric Power, KWH/day, and Natural Gas,
I,000ft3/day D
11. Boiler Feed Water Hardness, mg/1; Specific
Conductivity, micromhos; and Phosphate, mg/1 I
12. Equipment Operating Times, hours, monthly
A. Well pump
B . Drain pump (2)
C. Barminutor
D. Comminutor
E. Preaeration blower (2)
F. Primary sludge collector (2)
G. Scum collector (2)
H. Sludge airlift (2)
I . Grit washer
J . Air compressor (2)
K. No. 3 HP water pump (2)
L. No. 3 LP water pump (2)
M. Raw sewage pump (2)
N. Digester gas circulation pump (2)
O. Sludge circulation pump (2)
P. Raw sludge pump (2)
Q. Filter circulation pump (3)
R. Activated sludge influent pump (2)
S. Aeration blower (3)
T. RAS pump (2)
U. Secondary sludge collection
V. Effluent irrigation pump (2)
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APPENDIX E
MONTHLY OPERATING AND PERFORMANCE DATA
Presented in this appendix are tabulations of monthly averages of operating and
performance data for the years 1968 through 1974. Included are most of the items
listed in Appendix D. The data are presented in seven table formats designated
Table E-l, Table E-2, etc. Seven tables are used for each format, and each table
represents one year. Thus, for example, Table E-1A represents 1968, and
Table E-1G represents 1974.
The material in each table format is summarized below:
E-l Wastewater Flows, Influent Characteristics, and Weather
Characteristics
E-2 Preliminary Treatment, Primary Treatment, and Trickling Filter
Treatment
E-3 Activated Sludge Aeration Tank and Secondary Treatment
E-4 Disinfection, Final Effluent Characteristics, and Overall Plant
Performance
E-5 Solids Handling and Treatment
E-6 Power, Chemicals, and Labor
E-7 Final Effluent Heavy Metals.
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TABLE E-1A. WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1968
Parameter
Influent Flow
Average, mgd8
Dally peak, mgd
Reclamation Use . Mil Gal
Airport
Golf course
Farmland
Total
Influent Characteristics
BODj, rag/1
BODs, lb/dayc
Suspended solids, mg/l
Suspended solids, lb/d»yc
Volatile suspended solids,
mg/l
Settleable solids, ml/1
PH
Total solids, mg/l
Total dissolved solids ,
mj/1
Fixed dissolved solids,
ma/1
Specific conductivity,
mtcromhos •
Chlorides, mg/I
Weather Characteristics
Air temperature , F
Dally maximum
Daily minimum
Precipitation, In.
. Month
Jan
2.7
-
0
0
-
0
170
3,800
170
3,800
150
9.0
7.6
1,110
840
610
1,300
300
56
31
4.18
Feb
f
2.3f
-
0
0
.
0
160
3,100
180
3,500
160
7.3
7.6
1,120
940
780
1,530
340
63
44
0.91
Mar
f
2.4*
-
0
1.2
.
1.2
210
4,200
300
6,000
230
12.5
7.5
1,480
1,180
970
1,680
440
67
41
2.45
Apr May
£
2.4 3.0
-
0 1.0
9.1 11.6
5.9
9.1 18.5
190 180
3,800 4,800
260 230
5,200 6,100
220 200
11.0 7.3
7.5 7.6
1,480 1,400
1,220 1,170
950 1,000
2,040 1,890
430 450
73 74
39 45
0.58 0.11
June
3.3
-
4.3
18,0
13.8
36.1
180
5,000
230
6,400
190
7.0
7.6
1,300
1,080
900
1,930
420
85
52
0
July Aug
3.5 3.7
-
3.9 5.4
15.2 13.9
11.7 16.3
30.8 35.6
210 200
6,100 6,200
240 280
7,000 8,700
200 210
11.5 10.6
7.6 7.5
1,240 1,280
1,000 1,010
730 800
1,660 1,730
380 380
87 84
54 54
0 0.05
Sept
3.9
-
0
11.1
19.9
31.0
200
6,500
160
5,200
120
9.0
7.4
1,150
990
820
1,550
400
84
51
0
Oct Nov
4.0 4.3
-
0 0
5.2 0,9
0 0
5.2 0.9
180 160
6,000 5,700
150 170
5,000 6,000
130 140
8.5 7.1
7.4 7.4
930 860
700 710
540 530
1,200 1,120
210 200
59
43
0.10 2.27
Dec
3.9
-
0
1.1
0
1.1
160
5,200
160
5,200
140
6.9
7.4
930
780
610
1,150
230
55
34
3.08
High Low
4.3 2.3f
-
5.4 0
18.0 0
19.9 0
36,1 0
210 160
6,500 3,100
300 150
8,700 3,500
230 120
12.5 6.9
7.6 7.9
1,480 860
1,220 700
1 ,000 530
2,040 1,120
450 200
87 55
54 31
4.18 0
Average
3.7«
-
14. 68
87. 3e
67. 6°
169. 5e
180
5,000
210
5,700
170
8.9
7.5
1,180
970
770
1,560
350
72
44
13.736
amgd x 0.044 - mVsec
mil aalx 3,800 • m3
Clb/dayx0.45 -kg/day
dln. X2.54 - cm
Total
Estimate
Excludes estimates
-------
TABLE E-1B.
WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1969
Parameter
Influent Flow
/average, mgda
Dally peak, mgd
Reclamation Use. Mil Galb
Airport
Golf course
Farmland
Total
Influent Characteristics
$005, mg/1
BOD5, lb/dayc
Suspended solids, mg/1
Suspended solids, lb/dayc
Volatile suspended solids,
mg/1
Settleable solids, ml/1
pH
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity.
micromhos
Chlorides, mg/1
Weather Characteristics
Air temperature , F
Dally maximum
Daily minimum ,
Precipitation, in.
Month
Ian
•3.9
-
0
0
0
0
150
4,900
200
6,500
160
9.0
7.6
920
720
550
1,080
210
54
36
5.64
Feb
4.9
-
0
0
0
0
160
6,500
280
11,400
200
8.4
7.5
960
640
400
1,020
150
56
38
5.25
Mar
4.5
-
0.2
1 .9
0
2.1
200
7,500
180
6,700
150
8.7
7.6
1,020
810
590
1,050
230
64
37
0.66
Apr May
4.1 3.1
-
0 0
6.6 14..1
0 0.5
6,6 14.6
190 140
6,800 4,700
180 140
6,400 4,700
150 120
9.0 7.1
7.5 7.5
940 890
840 760
540 460
1,350 1,290
230 200
66 78
41 48
1.23 0,05
June
3.5
-
3.4
14,0
15.2
32.6
200
5,800
130
3,800
70
7.3
7.5
KO^
720
510
1,040
210
74
54
0.01
fuly Aug
-
-
12.9 8.0
15.9 22.7
17,8 20.4
46.6 51.1
210 220
-
160 220
-
140 190
9.1 8.9
7.4 7.3
920 880
750 710
570 530
1,160 1,100
190 140
90 94
54 53
0 0
Sept Oct
3.7*
-
4.4 0.3
13.1 7.8
14.0 0
31.5 8.1
170 180
5,600
160 170
5,300
150 150
7.8 9.6
7.5 7.4
860 880
700 710
440 420
1,070 1,140
140 170
88 74
53 45
0.03 0.99
Nov
_
-
6
3.2
0
3.2
200
-
200
-
170
9.5
7.4
870
660
480
1,080
140
69
37
0.46
Dec
3,1
0
1.2
0
1.2
190
6,300
180
6,000
150
8.8
7.3
860
680
450
1,020
150
62
40
2.24
High
4.9
12,9
22.7
20.4
51.1
220
7,500
280
11,400
200
9.6
7.6
1,020
840
590
1,350
230
94
54
5.64
Low Average
3.1 4.09
0 29. 2e
0 100. 5e
0 67. 9e
0 197.6e
140 180
4,700 6,000
130 180
3,800 6,400
70 150
7.1 8.6
7.3 7.5
850 900
640 730
400 500
1,020 1,120
140 180
54 72
36 45
0 16.566
CO
amgd x 0,044 = mVsec
bmil gal x 3,800 • m3
clb/day x 0.45 = kg/day
dln. x 2.54 - cm
Total
£ Estimate
Excludes estimate
-------
TABLE E-1C. WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1970
Parameter
Influent Flow
Average, mgda
Dally peak, mgd
Reclamation Use. Mil Qalb
Airport
Golf course
Farmland
Total
Influent Characteristics
BOD;, mo/1
BOD5, lb/dayc
Suspended solids, mg/1
Suspended solids, lb/day°
Volatile suspended solids.
mg/1
Settleable solids, ml/1
PH
Total solid*, mg/1
Total dissolved solids,
mg/t
Fixed dissolved solids,
mg/1
Specific conductivity.
mlcromhos
Chlorides, mg/1
Weather Characteristics
Air temperature, F
Dally maximum
Daily minimum
Precipitation, ln.d
Jan
3.8
-
0
0.4
0
0.4
230
7,300
Z90
9,200
200
11.2
7.4
940
650
360
1,040
ISO
60
41
5.79
Feb
3.3
-
0
1.1
0
1.1
240
6,600
300
8,200
280
10. 5
7.3
1,000
700
490
1,230
180
64
39
1.59
Mar
3.5
-
0
6.0
0
6.0
250
7,300
220
6,400
180
13.0
7.7
980
760
570
1,120
170
68
40
0.90
Apr May
3.9 3.8
-
0 4.5
11.3 16.3
0.1 7.9
11.4 28.7
250 240
8,100 7,600
230 230
7,500 7,300
170 200
10.7 11.7
7.4 7.3
960 910
730 680
470 530
1,150 1,170
180 160
68 79
37 48
0.41 0.70
•Month
June
3.4
-
6.6
16.5
16.9
40.0
220
7,300
200
6,600
150
10.9
7.5
910
710
470
1,060
150
80
51
0.28
July Aug
4.0 4.1
-
8.7 5.4
11.7 18.4
24.2 31.9
44.6 55.7
220 260
7,300 8,900
220 210
7,300 7,200
190 180
11.0 14.2
7.4 7.1
910 930
690 710
530 490
1,220 1,080
160 160
88 86
55 50
0 0
Sept Oct
3.7 3.8
-
13.9 0
15.6 7.9
27.6 7.9
57.1 15.8
200 250
6,200 7,900
220 210
6,800 6,600
200 180
12.3 10.6
7.4 7.5
910 900
690 690
420 500
1,070 1,030
170 ISO
87 74
49 44
0 0.38
Nov
3.9
-
0
2.5
0
2.5
260
8,500
270
8,800
230
12.6
7.3
930
670
470
950
130
66
44
5.52
Dec
3.8 4.1
-
0 13.9
0 18.4
0 31.9
0 57.1
250 260
7,900 8,900
210 300
6,600 9,200
160 280
11.5 14.2
7.2 7.7
1,010 1,010
800 800
550 570
1,150 1,230
160 180
56 88
37 55
4.76 5.79
Low
3.3
-
0
0
0
0
200
6,200
200
6,400
150
10.5
7.1
900
650
360
950
130
56
37
0
Average
3.8
-
39. le
107.7*
116. 5e
263. 3e
240
7,600
230
7,400
200
11.7
7.4
940
710
490
1,100
160
73
44
20.33e
CO
amgd x 0.044 •* mVsec
roll gal x 3,800 - m3
clb/day x 0.45 = kg/day
In. x 2.54 - cm
Total
Includes waste mixed liquor and lagoon supernatant for 1970 and later.
-------
TABLE E-1D.
WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1971
Parameter
Influent Flow
Average, mgda
Daily peak, mgd
Reclamation Use, Mil Galb
Airport
Golf course
Farmland
Total
Influent Characteristics*
BOD5, mg/1
BOD5, lb/dayc
Suspended solids, mg/1
Suspended solids, lb/dayc
Volatile suspended solids,
mg/1
Settleable solids, ml/I
PH
Total solids , mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids.
mg/1
Specific conductivity,
mlcromhos
Chlorides, mg/1
Weather Characteristics
Air temperature, F
Dally maximum
Dally minimum
Precipitation, In.
Month
Jan
3.8
-
0
0.5
0
0.5
240
7,600
250
7,900
210
11.8
6.9
1,020
800
590
1,210
170
59
37
1.30
Feb
3.8
-
0
-
0
-
220
7,000
200
6,400
180
11.1
7.4
1,020
810
560
1,210
160
61
35
0.32
Mar
3.7
-
0,4
4.5
0
4.9
240
7,400
220
6,800
ISO
11.4
7.3
1,020
800
620
1,240
170
64
39
1.76
Apr May
3.7 3.9
-
3,2 0
8.1 13.5
3.9 0
15.2 13.5
240 230
7,400 7,500
240 240
7,400 7,800
200 180
11.6 11.1
7.3 7.3
940 1,010
700 770
480 540
1,120 1,030
150 160
67 71
40 45
0.97 0.44
June
4.0
-
6.2
16.6
18.4
41.2
190
6,300
260
8,600
210
16.1
7.2
94b
690
500
1,160
140
79
50
0
July Aug
3.8 3.9
-
1.4 6.7
21.6 20.4
32.4 33.0
55.4 60.1
200 170
6,300 5,500
220 260
6,900 8,400
180 220
12.5 14.3
7.4 6.8
920 900
710 670
540 450
1,080 1,000
160 130
87 87
53 55
0 0.05
Sept Oct
4.1 4.0
-
7.7 0
15.2 8.2
28.8 13.4
51.7 21.6
180 190
6,200 6,300
190 240
6,500 8,000
140 210
9.5 16.9
6.9 6.8
940 870
800 630
450 440
1,160 920
110 110
85 75
52 41
0.07 0.04
Nov
3.9
-
0
4.8
0
4.8
220
7,200
210
6,900
170
13.6
7.3
870
670
460
1,030
120
65
36
0.56
Dec
3.8
-
0
0.4
0
0.4
240
7,600
240
7,600
200
13.6
7.3
920
690
490
1,070
130
55
33
3.79
High
4.1
-
7.7
21.6
33.0
60.1
240
7,600
260
8,600
220
16.9
7.4
1,020
810
620
1 ,240
170
87
55
3.79
Lov* Average
3.7 3.9
-
0 2 5 . 6e
0.5 113.8s
0 129. 9e
0.5 269. 38
170 210
5,500 7,000
190 230
6,400 7,400
140 190
9.5 12.8
6.8 7.2
870 950
630 730
440 510
920 1,100
110 140
55 71
35 43
0 9.30e
CO
CO
amgd x 0.044 = mVsec
bmll gal x 3,800 = m3
clb/day x 0.45 - kg/day
dln. x 2.54 - cm
Total
Includes waste mixed liquor and lagoon supernatant for 1970 and later.
-------
TABLE E-1E. WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1972
Parameter
Influent Flow
Average, mgda
Dally peak , mgd
Reclamation Use. Mil Galb
Airport
Golf course
Farmland
Total
Influent Characteristics f
BOD5 , mg/1
BOD5, lb/dayc
Suipended solids, mg/1
Suipended solids, lb/dayc
Volatile suspended solids,
mg/1
Settleable solids, ml/1
PH
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity.
mlcromhog
Chlorides, mg/1
Weather Characteristics
Air temperature, F
Dally maximum
Dally minimum
Precipitation, ln.d
Month
Jan
3.9
-
0
0
0
0
230
7,500
340
11,100
220
14,8
7.4
1,070
730
470
970
140
55
31
0.75
Feb Mar
4.1 4.4
-
0 1.9
0 9.2
0 0
0 11.1
240 240
8,200 8,800
260 290
8,900 10,600
210 230
14.0 9.7
7.3 7.1
870 900
610 610
440 410
1,080 1,070
140 130
62 71
40 42
0.84 0.16
Apr May
4.5 4.6
-
5.3 10,4
15.2 21.5
10.2 19.4
30.7 51.3
300 180
11,000 6,800
230 210
8,400 7,900
190 120
15.1 12.5
7.3 7.1
910 880
680 700
450 390
1,100 980
120 120
71 78
41 48
0.54 0
June
4.6
-
12.6
21.8
11.0
45.4
280
10,700
240
9,200
160
11.2
7.6
920
680
450
990
120
85
51
0.06
July Aug
4.8 4.9
-
4.2 15.3
23.2 19.9
22.8 19.7
SO. 2 54.9
220 240
8,400 9,800
280 290
10,700 11,800
60 250
17.0 15.8
7.3 7.2
1,060 1,000
720 710
630 520
960 950
140 200
89 88
56 55
0 0
Sept Oct
4.8 4.0
-
11.8 0
10.9 2.9
13.1 4.8
35.8 7.7
230 200
9,200 6,700
250 250
10,000 8,400
180 190
13.4 14.0
7.4 7.2
890 790
640 540
460 280
1,060 1,030
150 130
81 71
SO SO
0.46 2.59
Nov
5.1
-
0
0
0
0
200
8,500
280
11,900
230
15.9
7.3
940
650
500
1.040
140
61
39
5.06
Dae
4.9
-
0
0
0
0
210
8,600
250
10,200
220
13.9
7.2
1,080
830
580
1,110
180
51
32
2.17
High
5.1
15.3
23.2
22.8
54.9
300
11,000
340
11,900
250
17.0
7.6
1,080
830
630
1,110
200
89
56
5.06
Low
3.9
0
0
0
0
180
6,700
210
7,900
60
9.7
7.1
790
540
280
950
120
51
31
0
Average
4.6
61. 5e
124.6*
101.0e
287.1s
230
8,700
260
9,900
190
13.9
7.3
940
680
460
1,030
140
72
45
12.63s
-------
TABLE E-1F. WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1973
Parameter
Influent Flow
Average, mgda
Dally peak, mgd
Reclamation Use. Mil Galb
Airport
Golf course
Farmland
Total
Influent Characteristics*
BODs, mg/1
BODs, lb/dayc
Suspended solids, mg/1
Suspended solids, lb/dayc
Volatile suspended solids,
mg/1
Settleable solids, ml/1
PH
Total -solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity.
mlcromhos
Chlorides, mg/1
Weather Characteristics
Air temperature, F
Dally maximum
Daily minimum ,
Precipitation, in.
Month
Jan
5.3
'-
0
0
0
0
210
9,300
210
9,300
180
11.1
7.5
1,100
890
520
1.300
200
55
34
5.05
Feb
5.4
-
0
0
0
0
220
9,900
230
10,400
160
13.6
7.3
1,120
890
530
1,280
220
-
-
4.26
Mar
5.S
-
0
0.8
0
0.8
240
11,000
230
10,500
190
13.8
7.4
1,160
930
700
1,380
230
-
-
2.54
Apr May
3.0 2.9
-
0 17.2
10.8 17.4
0 0
10.8 34,6
240 220
6,000 5,300
280 240
7,000 5,800
160 190
13.4 16.2
7.2 7.2
1,110 1,040
830 800
660 600
1,400 1,316
220 190
72 79
42 48
0.44 0.04
June
3.1
-
0
21.2
0
21.2
210
5,400
270
6,900
220
14.6
7.2
1,020
750
550
1,230
170
87
53
0
July Aug
3.8 3.8
-
7.7 5.0
16.4
10.0 20.3
34.1 25.3
210 220
6,700 7,000
230 260
7,300 8,300
190 200
14.3 13.9
7.2 7.3
980 1,020
750 760
570 510
1,100 1,260
200 210
86 85
54 54
0 0
Sept Oct
3.8 3.8
5.3 5.2
5.6 0
-
10.3 0.9
15.9 0.9
190 210
6,000 6,700
270 180
8,500 5,700
230 140
14.8 10.9
7.2 7.3
960 920
690 740
520 380
1,050 1,190
170 150
81 76
52 48
0.07 1.75
Nov
4.2
6.0
0
1.1
0
1.1
220
7,700
250
8,800
220
13.6
7.2
990
730
480
1 ,100
180
62
43
5.06
Dec
4.1
6.2
0
0
0
0
230
7,900
230
7,900
170
13.9
7.2
970
740
530
1,050
180
54
32
2.74
High
5.5
6.2
17.2
21.2
20.3
34.6
240
11,000
280
10,500
230
16.2
7.5
1,160
930
700
1,400
230
87
54
5.06
Low Average
2.9 4.1
5.2 5.7
0 35. 5e
0 67. 7e
0 41. 5e
0 144.7s
190 220
5,300 7,200
180 240
5,700 8,000
140 190
10.9 13,7
7.2 7.3
920 1,030
690 790
380 550
1,050 1,220
150 190
54 74
32 46
0 21.958
<£>
en
amgd x 0.044 - mVsec
bmll gal x 3,800 - m3
Clb/dayx0.45 - kg/day
dln. x 2.54 - cm
"Total
Includes waste mixed liquor and lagoon supernatant for 1970 and later.
-------
TABLE E-1G,
WASTEWATER FLOWS, INFLUENT CHARACTERISTICS,
AND WEATHER CHARACTERISTICS, 1974
Parameter
Influent Flow
Average, mgda
Dally peak , mgd
Reclamation Use. Mil Galb
Airport
Golf course
Farmland
Total
Influent Characteristics
BOD 5, mg/1
BOD5, lb/dayc
Suspended solids, mg/1
Suspended solids, Ib/dayC
Volatile suspended solids.
mg/1
Settleable solids, ml/1
PH
Total solids, mg/1
Total dissolved solids,
mgi/1
Fixed dissolved solids,
mg/1
Specific conductivity,
mlcromhos
Chlorides, mg/1
Weather Characteristics
Air temperature, F
Dally maximum
Dally minimum
Precipitation, ln.d
1 Month
Ian
4.0
S.8
0
0
0
0
220
7,300
300
10,000
260
19.5
7.2
1,020
720
580
1,200
ISO
56
37
1.41
Feb
3.9
6.1
0
0
0
0
230
7,500
230
7,500
200
18.1
7.5
1,000
780
600
1,170
180
59
35
0.87
Mar Apr
4.0 4.2
5.8 6.3
0 0
0.3 2.8
0 0
0.3 2.8
250 200
8,300 7,000
230 300
7,700 10,500
190 240
15.0 15.8
7.4 7.1
1,060 1,060
830 750
620 570
1,160 1,260
190 180
63 67
43 42
2.26 1.43
May
4.0
6.4
5.2
13.4
10.4
29.0
240
8,000
200
6,700
160
11.8
7.4
970
780
560
1,110
190
73
46
0
June
3.5
6.4
0
11.9
13.3
25.2
220
6,400
220
6,400
180
13.3
7.1
880
650
520
1,100
150
81
52
0
July Aug
3,3 4.3
6.4 6.6
6.2 13.5
10.8 9.3
8.9 15.1
25.9 37.9
200 220
5,500 7,900
240 280
6,600 10,000
200 240
13.2 14.6
7.1 7.1
910 940
660 670
510 530
1,010 1,070
160 150
66 88
"54 54
0.17 0
Sept Oct
4.5 4.6
6.9 6.5
0 0.5
5.2 5.1
2.4 0
7.6 5.6
200 190
7,500 7,300
220 220
8.200 8,400
180 180
12.9 15.4
7.0 7.0
870 820
650 600
510 400
1,090 1,100
140 130
88 78
51 47
0 0.82
Nov Dec
4,6 4.6
6.8
0.2
0.4
0
0.6
170
6,500
280
10,700
250
14.5
7.1
990
530
540
1,160
140
63
40
0.56 1.31
High
4.6
6.9
13.5
13.4
15.1
37.9
250
8,300
300
10,700
260
19.5
7.5
1,060
830
620
1,260
190
88
54
2.26
Low
3.3
5.8
0
0
0
0
170
5,500
200
6,400
160
11.8
7.0
820
530
400
1,010
130
56
35
0
Average
4.1
6.3
25.6e
59.2s
50. le
134. 9e
210
7,200
250
8,400
210
14.9
7.2
960
700
540
1,130
160
73
45
8.83e
CD
"mgd x 0.044 • mVsec
bmll gal x 3,800 - m3
Clb/dayx0.45 -kg/day
dln. x 2.54 - cm
Total
Includes waste mixed liquor and lagoon supernatant for 1970 and later.
-------
TABLE E-2A. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1968
Parameter
Preliminary Treatment
Grit removed, ft3/daya
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Total solids, mg/1
Ammonia nitrogen, mg/1
PH
Primary Treatment Removals.
Percent
BOD5
Suspended solids
Trickling Filter Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes. Percent
BODs reduction
Suspended solids increase
Volatile suspended solids
Increase
Month
Jan Feb Mar Apr May
1.8 1.7 2,2 2.3 2.6
- - 1.6
120 120 130 140 120
63 72 97 95 93
56 69 49 81 81
0.1 <0.1 0.1 0.4 0.1
950 1,030 1,260 1,300 1,400
-
7.6 7.6 7.6 7.5 7.6
29 25 38 26 33
63 60 68 63 60
88 76 70 93 79
100 110 92 120 97
95 110 39 89 87
-----
27 37 46 34 34
59 53 -5 26 4
70 59 -20 10 7
June July Aug
3.8 3.8 3.6
1.7 1.5 1.4
100 150 150
68 95 120
58 75 94
0.1 0.6 1.6
1,300 1,110 1,110
- -
7.6 7.6 7.5
44 29 25
83 60 57
\
61 97 100
97 100 120
82 84 90
- -
39 35 33
43 50
41 12 -4
Sept Oct
3.6 2.7
1.3 1.3
180 150
160 75
130 64
2.6 <0.1
1,070 780
-
7.4 7.4
10 17
0 50
110 140
190 140
130 120
-
39 7
19 87
0 88
Nov Dec
1,3 1.4
1.2
150 160
110 91
100 84
0.1 3.3
830 830
-
7.4 7.5
6 0
35 43
110 110
160 110
160 100
-
27 31
45 21
60 19
High
3.8
1.7
180
160
130
3.3
1,400
-
7.6
44
83
140
190
160
-
46
87
88
Low Average
1.3 2.5
1.2 1.4
100 140
63 95
49 78
<0.1 0.7
780 1,080
-
7.4 7.5
0 22
0 55
61 94
92 120
39 100
-
7 33
-5 26
-20 28
to
a ,,3
ftVday x 0.028 - mVday
-------
TABLE E-2B. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1969
Parameter
Preliminary Treatment
Grit removed, ftVday
Chlorine added , mg/1
Primary Treatment Effluent
Characteristics
BOD 5, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Total solids, mg/1
Ammonia nitrogen, mg/1
PH
Primary Treatment Removals.
Percent
BOD5
Suspended solids
Trickling Filter Effluent
Characteristics
BOD 5, rag/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes. Percent
BOD; reduction
Suspended solids Increase
Volatile suspended solids
Increase
Month
Ian
1.0
1.1
140
110
91
0.2
820
7.6
7
45
73
120
98
-
48
9
8
Feb
0.8
1.0
no
100
70
0.2
800
7.5
31
64
45
200
130
-
59
100
86
Mar
1.2
1.2
140
94
88
0.1
890
7.7
30
48
84
100
88
-
40
e
6
Apr
1.6
0
no
72
52
0.2
830
7.5
42
60
75
80
46
-
32
11
-12
May
1.2
0
110
62
60
<0.1
790
7.5
21
56
80
110
100
-
27
77
.67
June July
1.5 1.3
1.8
140 150
58 62
32 52
<0.1 <0.1
730 760
7.6 7.5
30 29
55 61
80 97
54 56
36 40
-
43 35
-7 -10
13 23
Aug Sept Oct Nov Dec
1.9 1.4 1.4 1.6 1.3
2,4 - 2.5
130 120 100 140 ISO
72 55 53 100 86
48 53 53 81 82
^O.l <0.1 <0.1 <0.1 <0.1
700 730 700 750 750
7.4 7.6 7.4 7.4 7.3
41 29 44 30 21
67 66 69 50 52
62 86 48 96 77
54 58 56 120 120
20 55 54 99 101
-----
52 28 52 31 49
-25 5 6 20 40
-58 4 2 22 23
High
1.9
2.5
150
110
91
0.2
890
7.7
44
69
96
200
130
-
59
100
86
Low
0.8
0
100
53
32
<0.1
700
7.3
7
45
45
54
20
-
28
-25
-58
Average
1.4
1.7b
130
76
64
<0.1
770
7.5
28
58
75
95
72
-
42
25
13
00
aft3/day x 0.028 * m3/day
Based on six months
-------
TABLE E-2C. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1970
Parameter
Preliminary Treatment
Grit removed, ftVday9
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BODS, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/I
Total soltds , mg/1
Ammonia nitrogen, mg/1
PH
Primary Treatment Removals.
Percent0
BOD 5
Suspended solids
Trickling Filter Effluent
Characteristics
BOD;, mg/1
Suspended solids, mg/1
Volatile suspended solids ,
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Chancres. Percent
BOD5 reduction
Suspended solids increase
Volatile suspended solids
Increase
Ammonia nitrogen reduction
Month
Ian
1.2
2.4
180
160
140
0.2
820
48
7.3
22
45
110
100
87
44
39
-37
-38
8
Feb Mar
2.3 1.3
2.7 2.6
180 130
110 89
100 72
0.6 0.1
870 820
55 40
7.4 7.7
25 48
63 60
140 130
90 81
90 68
44 38
22 0
-18 -9
-10 -6
20 5
Apr
1.6
0
140
96
71
<£>
3 ftVday x 0.028 "= m3/day
Based on seven months
Affected by waste mixed liquor recycled to headworks
-------
TABLE E-2D. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1971
Parameter
Preliminary Treatment
Grit removed, ftVday*
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Total solids, mg/1
Ammonia nitrogen , mg/1
PH
Primary Treatment Removals.
Percent0
BODS
Suspended solids
Trickling Filter Effluent
Characteristics
BOD 5 , mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes. Percent
BOD; reduction
Suspended solids Increase
Volatile suspended solids
Increase
Ammonia nitrogen reduction
Month
Jan
1.6
0
140
80
65
<0.1
860
38
6.9
42
68
130
140
117
34
7
75
80
11
Feb
2.0
0
130
85
66
<0.1
840
51
7.4
41
57
79
120
92
41
39
41
39
20
Mar
1.6
2.5
160
84
69
<0.1
850
48
7.3
33
62
120
130
106
42
25
55
54
12
Apr May
1.9 1.9
2.5 2.5
120 120
74 98
53 71
<0.1 <0.1
760 790
42 39
7.4 7.3
50 48
69 59
110 110
96 120
89 94
33 31
8 8
30 22
.68 32
21 21
June
1.7
2.3
110
81
54
<0.1
740
34
7.3
42
69
74
110
89
27
33
36
65
21
July Aug
l.l 1.4
2.5 2.4
120 110
71 81
33 71
<0.1 <0.1
760 510
34 36
7.5 6.9
40 35
68 69
81 46
100 120
100 101
23 25
32 58
41 48
300 42
32 31
Sept
1.6
2.2
110
60
44
<0.1
740
34
6.9
39
68
82
120
80
22
25
100
82
35
Oct Nov
1.1 1.0
2.3 2.4
110 150
75 63
56 57
<0.1 <0.1
650 700
40 44
7.1 7.4
42 32
69 70
66 110
74 89
63 73
33 36
40 27
-1 41
13 28
17 18
Dec
1.2
4.1
150
94
88
<0.1
760
49
7.4
37
61
100
110
100
44
33
17
14
10
High
2.0
4.1
160
98
88
-
860
51
7.5
50
70
130
140
117
44
58
100
300
32
Low Average
1.0 1.5
0 2.6b
110 130
60 79
33 61
<0.1
510 740
34 41
6.9 7.2
32 38
57 66
46 93
74 110
63 92
22 33
7 28
-1 39
13 51
10 20
O
O
8 ftVday x 0.028 - m3/d«y
Based on ten months
cAffected by waste mixed liquor recycled to headwords
-------
TABLE E-2E.
PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1972
Parameter
Preliminary Treatment
Grit removed, ft3/day*
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BODg , mg/1
Suspended solids, mg/1
Volatile suspended solids ,
mg/1
Settleable solids, ml/1
Total solids, mg/1
Ammonia nitrogen, mg/1
PH
Primary Treatment Removals,
Percent D
BOD5
Suspended solids
Trickling Filter Effluent
Characteristics
BOD5,mg/l
Suspended solids, mg/1
Volatile suspended solids ,
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes. Percent
6005 reduction
Suspended solids Increase
Ammonia nitrogen reduction
Jan
1.1
4,9
170
130
100
<0.1
810
41
7.5
26
62
110
130
-
40
35
0
2
Feb Mar Apr
1.8 2.0 1.8
4.1 3.8 3.5
140 110 170
110 110 80
88 110 66
<0.1 0.4 0.1
800 780 710
44 - 42
7.4 7.3 7.6
42 54 43
58 62 65
110 100 130
140 120 160
_
40 - 38
21 9 24
27 9 100
9 - 10
Month
May June July Aug Sept Oct Nov Dec
1.4 1.1 2.0 2.7 2.6 2.3 1.4 1.6 2.7 1.1 1.8
3.6 4.4 4.5 4.6 4.5 5.4 4.2 3.4 5.4 3.4 4.3
100 130 90 100 120 140 120 140 170 90 130
100 140 130 120 120 100 100 80 130 80 110
81 110 36 88 62 80 78 65 110 36 81
<0.1 1.7 2.2 1.2 1.3 14.0 0.1 0.1 14.0 <0.1 1.8
690 760 820 800 730 610 720 850 850 610 760
40 24 20 30 35 40 38 44 44 20 36
7.2 8.6 8.3 7.9 7.8 7.3 7.5 7.3 8.6 7.2 7.6
44 54 59 58 48 30 40 33 59 26 43
52 42- 54 59 52 60 64 68 68 42 58
75 120 67 120 100 130 100 130 130 67 110
110 86 84 140 120 120 130 130 160 84 120
__ -- --
33 25 18 26 40 37 36 41 41 18 34
25 8 26 -20 17 7 17 7 35 -20 15
10 -39 -35 17 0 20 30 63 100 -39 9
17 -4 10 13 -14 7 5 7 17 -14 6
3 ft3/day x 0.028 - m3/day
Affected by waste mixed liquor recycled to headworks
-------
TABLE E-2F. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1973
Parameter
Preliminary Treatment
Grit removed, fts/daya
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BODj, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Sattlaabla solids, ml/1
Total solids, mg/1
Ammonia nitrogen, mg/1
PH
Primary Treatment Removals.
Percent0
BOD;
Suspended solids
Trickling Filter Effluent
Characteristics
BODj, mg/1
Suspended solids, mg/1
Volatile suspended solids ,
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes. Percent
BODs reduction
Suspended solids Increase
Ammonia nitrogen reduction
Month
Jan
3.1
2.9
120
100
88
0.1
920
-
7.5
43
52
86
99
-
-
28
-1
Feb Mar
3.2 3.5
2.7 2.6
140 120
88 81
32 70
<0.1 0.1
890 960
48
7.4 7.5
36 50
62 65
98 89
120 96
-
46
30 26
36 19
4
Apr
0.9
5.2
140
92
53
0.1
940
68
7.4
42
67
93
98
-
60
34
7
12
May
4.0
5.0
130
72
64
<0,1
820
64
7.3
41
70
130
100
-
54
0
39
'16
June July
2.7 9.0
4.2 4.1
130 130
80 95
66 77
<0.1 <0.1
790 800
74
7.3 7.3
38 38
70 59
98 91
100 120
-
60
25 30
25 26
19
Aug
8.5
4.1
110
73
37
0.1
790
29
7.3
50
72
81
90
-
21
Jib
23
28
Sept
4.0
4.1
110
80
39
<0. 1
740
27
7,4
42
70
94
110
-
22
15
38
19
Oct Nov Dec
4.9 3.8 2.7
4.1 3.7 3.5
130 120 130
53 74 69
41 63 46
0.2 0.2 <0.1
730 780 760
54
7,4 7.3 7.3
38 45 43
71 70 70
120 100 93
84 91 79
-
57
8 17 28
58 23 14
-6 - -
High
9.0
5.2
140
100
88
0.2
960
74
7.5
50
72
130
120
-
60
34
58
28
Low
0.9
2.6
110
53
32
<0. 1
730
27
7.3
36
52
86
79
_
21
0
-1
-6
Average
4.2
3.8
120
80
56
<0 . 1
830
52
7.3
45
67
98
100
_
46
18
25
12
tss
O
NJ
8ft3/day x 0.28 - mVday
Affected by waste mixed liquor recycled to headworks
-------
TABLE E-2G. PRELIMINARY TREATMENT, PRIMARY TREATMENT,
AND TRICKLING FILTER TREATMENT, 1974
Parameter
Preliminary Treatment
Grit removed, ft3/daya
Chlorine added, mg/1
Primary Treatment Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Total solids, mg/1
Ammonia nitrogen , mg/1
pH
Primary Treatment Removals,
Percent0
BOD5
Suspended solids
Trickling Filter Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Ammonia nitrogen, mg/1
Trickling Filter Effluent
Changes , Percent
BOD5 reduction
Suspended solids increase
Ammonia nitrogen reducttor
Month
Jan Feb Mar Apr May fune July Aug
4.1 4.2 4.8 4.1 3.4 4.6 4.9 4.2
3.6 5.5 6.6 7.1 7.5 8.6 8.4 7.0
150 160 160 130 100 140 140 120
100 50 77 85 72 79 74 87
87 55 64 62 53 57 64 73
0.1 0.2 <0.1 0.2 0.4 0.4 0.1 0.1
830 860 850 830 820 750 710 750
-- -21--
7.4 7.5 7.4 7.3 7,4 7.2 7.3 7.3
32 30 36 35 58 36. 30 45
67 78 67 72 64 64 69 69
160 56V160 92 26c/59 43c/85 42c/97 41c/69 23C/61
150 170 84 91 120 75 85 56
-- -- - -
19
-7 65C/0 43 60c/55 57C/15 70C/31 71C/51 81c/49
50 240 97 67-5 15 -36
-- - 10 - -
Sept
5.0
6.7
120
76
60
0.1
660
45
7.1
40
65
42C/70
68
-
35
65c/42
-11
22
Oct
3.8
6.5
120
79
76
<0.1
650
42
7.2
37
64
43c/62
100
-
39
64c/48
27
7
Nov Dec
3.8 5.0
6.5 6.5
120
86
66
0.2
590
57
7.1
29
69
28c/52
72
-
52
77C/57
16
9
High
5.0
8.6
160
100
87
0.4
860
57
7.5
58
78
56C/160
170
-
52
81c/57
240
22
Low
3.4
3.6
100
50
53
<0.1
590
21
7.1
29
64
23c/52
56
-
19
57c/-7
-36
7
Average
5.3
6.7
130
79
65
0.2
760
41
7.3
38
68
38c/88
97
-
36
71c/32
23
12
to
o
CO
aft3/day x 0.28
Vday
'Affected by waste mixed liquor recycled to headworks
'Based on one-hour settling
-------
TABLE E-3A. ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1968
Parameter
Activated Sludge
Aeration Tank
Air used, million ftVday"
Dissolved oxygen, mg/1
Mixed liquor suspended
solids, mg/1
Settleable solids, ml/1
Sludge volume Index (SVI)
Waste mixed liquor flow,
1,000 gpdb
Settled activated sludge
suspended solids, mg/1
Return activated gludge
flow, percent of
Influent flow
Secondary Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids , ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/l
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludaa- Secondary
Clarification Removals.
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan Feb Mar Apr May June
2.9 3.4 4.7 4.4 4.9 5.2
3.9 3.3 2.3 4.2 4.6 4.9
2,150 1.880 1,900 1,690 1,500 1,450
207 206 203 162 134 113
97 109 107 96 90 77
223 191 194 186 120 1S8
7,630 5,450 6,450 7,150 7,880 8,250
45 57 43 35 31 27
-V
>• SECONDARY EFFLUENT NOT MONITORED IN 1968
J
July Aug Sept Oct Nov Dec
5.3 6.7 8.3 8.5 8.6 8.3
4.6 4.0 4.2 4.1 4.3 4.0
1,560 1,620 1,760 1,610 1,880 1.580
118 109 121 101 122 109
75 68 70 62 65 69
155 187 278 100 237 228
8,586 8,880 9,180 7,680 7,570 6,800
28 28 31 35 37 31
High Low Average
8.6 2.9 5.9
4.7 2.3 4.0
2,150 1,450 1,720
207 101 142
109 62 82
278 100 188
9,180 5,450 7,620
57 27 36
to
o
"million ftVday x 28,000 • mVday
bgpd x 0.0038 - m3/day
-------
TABLE E-3B. ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1969
Parameter
Activated Sludge
Aeration Tank
Air used, million ftVday3
Dissolved oxygen, mg/1
Mixed liquor suspended
solids, mg/1
Settleable solids, ml/1
Sludge volume index (SV1)
Waste mixed liquor flow.
1 , 000 gpdb
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow , percent of
Influent flow
Secondary Effluent
Characteristics
BODs, ma/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge-Secondary
Clarification Removals.
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan Feb Mar Apr May
6.1 7.7 7.7 8.0 8.0
3.2 4.4 4.4 3.5 3.4
1,730 1,700 1,690 1,700 1,760 1
109 71 92 102 141
65 42 55 60 80
223 206 190 122 147
7,190 6,830 6,460 6,220 6,570 6
28 24 27 29 33
-
> SECONDARY EFFLUENT NOT MONITORED
June
8.1
3.5
,790
157
87
146
,370
33
\
IN 1969
July Aug Sept Oct Nov Dec
6.7 6.1 6.9 6.4 6.4 6.8
2.5 2.5 2.3 2.8 2.8 2.2
1,800 1,740 1,740 1,680 1,790 1,880
152 140 142 157 144 119
85 81 82 94 80 62
146 141 178 129 132 178
5,990 5,660 5,490 5,590 6,180 5,640
32 33 35 36 32 41
High Low Average
8.1 6.1 7.1
4.4 2.2 3.1
1,880 1,680 1,750
157 71 127
94 42 73
223 122 162
7,190 5,490 6,180
41 24 32
to
o
en
"million ft /day x 28,000 • mVday
bgpd x 0.0038 = mVday
-------
TABLE E-3C. ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1970
Parameter
Activated Sludge
Aeration Tank
Air used, million ftvday*
Dissolved oxygen, mg/1
Mixed liquor suspended
lolldi, mg/1
Settleable solids, ml/1
Sludge volume Index (SVI)
Waste mixed liquor flow,
1,000 gpd°
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow , percent of
Influent flow
Secondary Effluent
Characteristics
BODs, mgA
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge-Secondary
Clarification Removals.
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Ian
7.7
3.2
2,060
146
73
200
5,920
44
19
17
14
0.1
2.3
6.8
1.9
0.54
24
83
83
96
Teb
7.5
3.1
2,210
110
50
80
6,850
45
29
44
38
0.1
2.4
7.0
1.1
0.037
21
79
51
97
Mar Apr
7.9 7.4
3.2 2.9
2,660 2,380
156 179
59 74
96 66
8,780 7,750
38 38
17 18
14 23
10 12
0.4 <0.1
3.3 3.1
7.5 7.3
1.1 0.77
0.052 0.033
22 21
87 86
83 79
97 98
May
7.1
3.0
2,550
242
95
138
8,000
36
18
16
11
:0.1
3.6
7.2
I.I
0.064
21
81
82
97
June
7.1
3.0
2,550
256
100
89
8,380
39
12
18
6
<0.1
4.2
7.6
0.95
0.046
22
83
76
98
July Aug
7.2 7.4
2.9 3.1
2,620 2,650
217 260
83 98
84 100
9,160 8,820
37 36
12 7.0
9 15
4 9
<0.1 <0.1
3,3 4.4
7.3 7.3
0.43 1.3
0.005 0.010
21 17
89 90
84 78
98 99
Sept Oct
6.2 5.8
3.1 3.0
2,450 1,800
274 187
113 104
130 128
8,130 6,360
37 33
9.5 12
13 14
13 9
<0.1 <0.1
4.0 3.5
7.4 7.3
0.63 1.0
0.010 0.033
18 21
84 86
75 78
98 97
Nov
6.0
3.3
1,700
146
86
129
6,540
32
6.6
21
18
<0.1
3.0
7.5
0.76
0.057
20
94
78
98
Dec
6.3
3.2
1,870
147
79
175
7,670
30
10
20
16
<0.1
2.8
7.3
0.31
0.081
19
88
78
99
High
7.9
3.3
2,660
274
113
200
9,160
45
29
44
38
0.4
4.4
7.6
1.9
0.540
24
94
84
99
Low Average
5.8 7.0
2.9 3.1
1,700 2,290
110 193
50 85
66 118
5,920 7,700
30 37
6.6 14
3 19
4 13
«0.1 <0.1
2.3 3.3
6.8 7.3
0,31 0.95
0.005 0.081
17 21
79 86
51 77
96 97
to
o
CD
"million ft3/day x 28,000 - m3/day
bgpd x 0.0038 - mVday
-------
TABLE E-3D.
ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1971
Parameter
Activated Sludge
Aeration Tank
Air used, million ftVday*
Dissolved oxygen, mg/1
Mixed liquor suspended
solids, mgA
Settleable solids, ml/1
Sludge volume Index (SVI)
Waste mixed liquor flow,
1,000 gpdb
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow , percent of
Influent flow
Secondary Effluent
Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge" Secondary
Clarification Removals .
Percent
BOD 5
Suspended solids
Ammonia nitrogen
Jan
6.4
3.1
1,800
185
99
217
7,470
30
8.9
20
15
<0.1
2.3
7.1
0.86
0.065
18
93
86
97
Feb
6.4
3.1
1,760
114
66
197
8,160
30
12
17
11
<0.1
2.3
7.5
1.1
0.32
18
85
86
97
Mar Apr
S.9 8.0
3.4 2.5
1,700 1,750
142 144
79 82
211 226
6,870 6,850
30 30
17 8.7
24 15
16 10
<0.1 <0.1
2.6 2.8
7.5 7.5
6.7 0.94
0.78 0.018
19 19
86 92
82 84
84 97
May
6.3
3.5
1,740
159
91
179
6,650
30
12
19
10
<0.1
3.7
7.4
0.76
0.046
20
89
84
98
Month
June
6.8
3.0
2,110
168
79
160
8,240
33
6.6
24
15
<0.1
3.5
7.6
0.48
0.017
18
91
78
98
July Aug
6.9 7.2
2.9 2.5
2,190 2,160
172 172
78 79
112 101
8,280 8,000
38 37
9.1 5.2
19 31
7 20
0.4 1.1
3.6 3.7
7.8 7.8
0.88 0.88
0.040 0.12
18 19
89 87
81 74
96 96
Sept Oct
7.3 7.3
2.5 2.7
2,120 2,160
156 140
74 64
103 83
8,280 8,380
38 37
5.4 11
19 18
9 14
0.6 0.2
3.3 2.9
7.3 7.3
1.75 1.03
0.17 0.030
18 18
93 83
84 76
92 97
Nov
7.1
3.1
2,280
133
58
141
8,270
37
11
31
20
1.3
3.1
7.7
0.46
0.10
19
90
65
99
Dec
6.5 8.0
3.0 3.5
2,320 2,320
121 185
52 99
176 226
8,800 8,800
38 38
13 17
27 31
24 24
<0.1 1.3
2.9 3.2
7.4 7.8
4.3 6.7
0.13 0.78
17 20
87 93
75 86
90 99
Low
5.9
2.5
1,700
121
52
83
6,650
30
5.2
15
7
<0.1
2.3
7.1
0.46
0.017
17
85
65
84
Average
6.8
2.9
2,010
151
75
159
7,890
34
10
22
14
<0.4
3.1
7.5
1.7
0.077
18
89
80
95
to
o
"million ftVday x 28,000 = m3/day
bgpd x 0.0038 = m3/day
-------
TABLE E-3E. ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1972
Parameter
Activated Sludge
Aeration Tank
Air used, million ft /day8
Dissolved oxygen, mg/1
Mixed liquor suspended
lollds, mg/1
Settleable solids, ml/1
Sludge volume Index (SVI)
Waste mixed liquor flow.
1,000 gpdb
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow , percent of
Influent flow
Secondary Effluent
Characteristics
8005, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
pH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge-Secondary
Clarification Removals,
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan
6.7
2.3
2,240
193
83
172
8,540
37
17
39
21
0.2
2.0
7.3
1.2
0.23
19
as
70
97
Feb
7.8
2.S
2,460
232
94
196
8,500
39
15
50
29
0.5
2,3
7.2
1.1
0.17
21
86
64
97
Mar
7.5
2.4
2,340
156
66
107
8,010
38
14
77
57
0.2
2.5
7.4
-
-
-
87
36
Apr May
7.5 7.6
1.9 0.9
2,550 2,490
172 169
67 68
160 131
8,560 8,530
39 37
12 24
34 44
33 27
0.5 0.1
2.4 2.3
7.8 7.3
0.81 1.1
0.09 0.02
16 20
91 68
79 60
98 97
June
7.6
0.5
2,390
153
64
117
8,080
37
14
39
17
0.6
2.2
8.4
1.1
0.10
17
88
55
96
July Aug
7.6 7.6
0.6 0.4
2,500 2,550
197 211
79 83
122 171
8,120 8,780
36
3.6 7.1
30 20
26 9
1.9 0.9
2,9 2.7
8.1 8.0
0.77 1.1
0.03 0.09
15 17
95 94
64 86
96 96
Sept Oct
7.8 8.0
0.3 0.3
2,690 2,890
254 282
94 98
156 152
9.160 8,150
36 40
19 19
40 32
21 28
1.9 0.1
2.7 2.3
7.9 7.6
1.5 1.2
0.13 0.01
14 20
81 85
67 73
96 97
Nov
8.8
0.3
2,840
224
79
170
8,450
43
12
33
27
<0.1
2.4
7.4
0.48
0.01
20
88
75
99
Dec
8.9
0.2
3,010
238
99
176
9,390
42
22
38
28
0.1
2.5
7.3
1.1
0.22
18
83
71
97
High
8.9
2.5
3,010
282
98
196
9,390
43
24
77
57
1.9
2.9
8.4
1.2
0.23
21
95
86
99
Low Average
6.7 7.8
0.2 1.1
2,240 2,580
153 207
64 80
107 153
8,010 8,520
36 39
3.6 15
20 40
9 27
<0.1 0.6
2.0 2.4
7.2 7.6
0.77 1.0
0.01 0.10
14 18
68 86
36 67
96 97
CO
o
CD
"million ftVday x 28,000 - m3/day
bgpd x 0.0038 - mVday
-------
TABLE E-3F.
ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1973
Parameter
Activated Sludge
Aeration Tank
Air used, million ftvday"
Dissolved oxygen, mg/1
Mixed liquor suspended
solids , mg/1
Settleable solids, ml/1
Sludge volume Index (SVI)
Waste mixed liquor flow,
1,000 gpdb
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow , percent of
Influent flow
Secondary Effluent
Characteristics
BODg , mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge-Secondary
Clarification Removals ,
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan
8.8
0.2
2,770
196
71
190
8,710
38
17
35
32
1.8
2.8
7.5
-
-
-
80
65
Feb
8.8
0.2
2,430
158
66
169
7,780
35
15
31
14
0.1
2.3
7.2
-
-
-
85
74
Mar
8.8
0.2
2,540
126
50
144
8,340
37
15
29
20
0.2
2.0
7.2
0.49
-
16
83
70
99
Apr May
8.7 8.7
0.4 0.9
2,260 2,360
105 133
46 57
128 125
7,580 8,060
36 37
22 15
29 27
18 23
0.1 <0.1
2.5 2.5
7.3 7.4
1.6 1.2
0.31 0.06
20 18
76 88
70 73
97 98
June
8.8
0.8
2,280
158
69
142
7,650
40
8,6
25
20
<0.1
3.0
7.3
1.1
0.04
18
91
75
98
July Aug
8.6 8.9
0.9 0.7
2,190 2,240
166 176
76 78
98 170
7,250 7,440
39 38
19 7.8
20 34
19 7
<0.1 0.2
2.6 2.7
7.2 7.2
1.1
0.05
14
79 90
83 62
95
Sept Oct
8.8 8.8
0.5 1.0
2,060 2,290
144 147
70 65
168 196
7,760 7,730
39 36
14 13
35 13
18 12
<0.1 0.2
2.3 2.9
7.3 7.3
1.8 3.8
0.06 0.40
14 12
85 89
68 85
92 93
Nov Dec
8.9 8.6
0.5 0.6
2,460 2,450
154 136
63 56
172 147
8,540 8,480
-
19 24
21 42
15 20
<0.1 <0.1
2.0 2.2
7.2 7.0
1.1
<0.01
13
81 74
77 47
High
8.9
1.0
2,770
196
78
196
8,710
40
24
42
32
1 .8
3.0
7.5
3.8
0.40
20
91
85
99
Low
8.6
0.2
2,060
105
46
98
7,250
35
7.8
13
7
<0.1
2.0
7.0
0.49
<0.01
12
74
47
92
Average
8.8
0.5
2,360
150
64
154
7,940
38
16
28
18
0.3
2.5
7.3
1.5
0.13
16
84
72
97
O
(£>
amilllon ft3/day x 28,000 = mVday
bgpd x 0.0038 - mVday
-------
TABLE E-3G. ACTIVATED SLUDGE AERATION TANK AND SECONDARY
TREATMENT, 1974
Parameter
Activated Sludge
Aeration Tank
Air used, million ft /day
Dissolved oxygen, mg/1
Mixed liquor suspended
solids , mg/1
Settleable solids, ml/1
Sludge volume index (SVI)
Waste mixed liquor flow,
l,000gpdb
Settled activated sludge
suspended solids, mg/1
Return activated sludge
flow, percent of
Influent flow
Secondary Effluent
Characteristics
BODj, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/1
Nitrate nitrogen, mg/1
Activated Sludge-Secondary
Clarification Removals .
Percent
BOD 5
Suspended solids
Ammonia nitrogen
Month
Ian
8.6
1.3
2,330
121
52
152
8,300
33
23
51
32
0.3
2.0
7.1
-
-
-
86
66
Feb
5.9
0.6
2,510
158
52
129
8,470
38
40
14
10
0.4
1.6
7.3
-
-
-
75
92
Mar Apr
8.8 8.9
1.6 1.5
2,450 2,260
176 129
72 57
144 170
7,530 7,520
45 39
21 24
21 31
18 18
<0.1 0.2
3.6 2.3
7.1 7.0
-
-
-
77 59
75 66
May
8.4
1.1
1,970
138
70
173
7,250
35
25
29
23
<0.1
3.1
7.2
-
_
-
71
76
June
8.2
0.6
2,030
132
65
173
7,550
40
16
25
17
<0.1
3.0
6.9
<0.1
1.0
17
84
67
99
July Aug
8.3 8.3
0.8 0.6
2,060 1,870
137 124
66 69
173 173
7,670 7,350
34 33
13 9.1
16 10
12 8
0.1 0.3
2.3 2.7
7.2 7.2
-
-
-
81 85
81 82
Sept Oct
8.8 8.7
0.4 0.8
1,820 1,970
117 143
65 73
173 173
7,160 6,280
32 41
12 11
13 27
9 27
0.1 0.1
2.1 2.0
7.0 7.0
2.5 2.5
0.12 0.03
16 20
83 82
81 73
93 94
Nov Dec
8.7 8.2
0.9 1.2
2,000 2,090
138 195
70 93
173 173
6,260 5,100
40 59
14
21
13
0.2
1.7 2.0
6.9
1.6
0.148
20
73
71
97
High
8.9
1.6
2,510
195
93
173
8,470
59
40
51
32
0.4
3.6
7.3
2.5
1.0
20
86
92
99
Low
5.9
0.4
1,820
117
52
129
5,100
32
9.1
10
8
<0.1
1.6
6.9
<0.1
0.03
16
59
66
93
Average
8.3
1.0
2,110
142
68
164
7,200
39
19
24
17
0.2
2.4
7.1
1.7
0.32
18
78
75
95
CO
I—I
o
"million ftVday x 28,000 - mVday
bgpd x 0.0038 - mVday
-------
TABLE E-4A. DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1968
Parameter
Disinfection
Chlorine dose, mg/1
Contact time. mln.
Chlorine residual, mg/1
pH, contact tank effluent
Median conform organism
concentration, MPN/lOOml
rinaLEf fluent Characteristics
BODS, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
pH
Grease, ma/1
MBAS, mg/1
Turbidity, JTU
Temperature, C
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/la
Nitrate nitrogen, mg/la
Organic nitrogen, mg/la
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity.
mlcromhos
Chlorides, mg/1
Dissolved residue (by
calculation), mg/la
Alkalinity, mg/la
Hardness, mg/la
Boron, mg/la
Percent sodium3
Overall Plant Removals .
Percent
BOD 5
Suspended solids
Ammonia nitrogen
Tan
_
96
7.0
-
4.8
17
7.0
6.0
<0.1
1.1
7.9
8.0
0.50
-
-
16
0.06
7.1
0.8
1,110
640
610
1,550
390
1,030
170
320
1.0
60
90
96
-
Month
Feb Mar Apr May June July Aug Sept Oct Nov Dec
31 29 36 18 17 17 16 19 18 20 20 36 16 20
117 - 116 93 92. 89, 89, 88 95 122a 92 122 88 99
8.7 7.1 6.6 7.1 >8.7° >6.0d >6.3d >6.3d >5.4d >8.7d >8.8d 8.8d 6.00 77. 2<>
- - .- _- - - -- - -
c
2.1 4.8 <2.1 4.8 2.1 2.1 2.1 c2.1 <2.1 <2.1 <2.1 4.8 <2.1 2.1
15 10 9.0 18 15 16 0.9 0.1 3.1 8.1 3.1 18 0.1 9.6
8.6 10 13 12 8.0 5.8 9.5 7.0 11 14 8.0 14 5.8 9.5
8.2 4.0 8.0 11 7.0 3.8 7.1 5.3 10.3 9.3 7.8 10.8 4.0 7.3
<0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 - - <0.1
1.1 2.3 4.3 4.4 4.7 4.2 2.8 2.1 2.3 2.1 2.9 4.7 1.1 2.9
7.6 7.8 7.6 7.8 7.6 7.8 7.6 7.8 7.6 6.6 6.8 7.9 6.6 7.5
7.4 3.3 3.4 4.4 2.5 1.0 1.8 6.0 2.8 3.1 4.1 8.0 1.0 4.0
0.41 0.53 0.44 0.40 0/40 0.44 0.45 0.36 0.26 0.21 0.30 0.53 0.21 0.39
-- -- -- -- -- --
__ __ -- -- -- - -
7.5 <0.01 28 1.0 <0.01 0.48 0.54 0.33 0.12 - 0.23 28 <0.01 4.9
0.09 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.03 - 0.01 0.09 <0.01 0.02
7.6 15 8.0 14 IS 16 14 21 26 - 11 26 7.1 14
2.S 2.9 3.5 0.7 1.2 - - 2.1 1.7 - 0.63 3.5 0.63 1.8
1,140 1,300 1,470 1,270 1,120 1,090 1,080 1,020 850 800 760 1,470 760 1,090
1,140 1,290 1,460 1,260 1,110 1,090 1,050 1,010 840 790 760 1,460 760 1.050
930 1,010 1,140 1,020 860 870 880 610 600 560 550 1,140 550 800
1,630 1,660 2,180 1,920 1,700 1,720 1,720 1,220 1,160 1,000 1,150 2,180 1,000 1,550
330 450 440 470 360 350 360 350 240 230 250 470 230 350
1.150 1,200 - 1,080 1,050 1,020 300 - - - - 1,200 300 980
110 110 140 100 120 120 96 69 78 - - 170 69 110
280 350 320 300 270 250 240 240 220 - - 350 220 280
1.6 1.3 2.2 2.1 2.5 1.1 1.4 1.0 1.4 - - 2.5 1.0 1.6
62 63 60 64 64 64 63 65 64 - 65 54 52
91 95 95 90 92 92 >99 >99 98 95 98 >99 90 95
95 97 95 95 97 98 97 96 93 92 95 98 92 95
-- -- -- -- -- - _
to
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
cMedlan
Value affected by maximum meter reading of 10 mg/1
-------
TABLE E-4B. DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1969
Parameter
Disinfection
Chlorine dose, mg/1
Contact time, mln.
Chlorine residual, mg/1
pH, contact tank effluent
Median conform organism
concentration, MPN/lOOm!
Final Effluent Characteristics
BOD;, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
pH
Grease, mg/1
MBAS, mg/1
Turbidity, ITU
Temperature, C
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/la
Nitrate nitrogen, mg/la
Organic nitrogen, mg/18
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids.
mg/1
Specific conductivity.
ratcromhos
Chlorides, mg/1
Dissolved residue (by
calculation), mg/la
Alkalinity, mg/18
Hardness, mg/1*
Boron, mg/la
Percent sodium8
Overall Plant Removals .
Percent
BOD5
Suspended solids
Ammonia nltrogenb
Month
Jan
19
87
>7.9
-
<2.1
14
19
14
<0.1
2.5
7.3
5.5
0.25
-
-
4.1
0.13
12
2.9
800
780
530
1,010
230
740
83
230
1.6
57
91
90
~
Feb
16
56
>5.8
-
2.1
7.0
17
10
<0.1
2.8
7.4
3.5
0.09
-
-
0.78
0.01
19
2.6
790
770
480
960
180
700
82
200
1.5
58
96
94
~
Mar
20
67
>8.1
-
<2.1
5.5
12
7
<0.1
3.0
7.4
2.0
0.27
-
-
0.11
0.01
26
0.85
950
940
650
1,140
240
880
98
250
1.8
58
97
93
~
Apr May
20 25
62 61
>6.3 >10.0
-
2.1 <2.1
6.1 3.1
13 6
9 6
<0.1 <0.1
2.0 2 2
7.1 7.1
6.4 1.9
0.15 0.16
-
-
0.03 0.12
0.002 0.001
25 24
2.7 0.09
860 780
840 780
610 460
1,220 1,160
260 220
830 760
82 94
250 140
2.1 1.6
59 59
97 98
93 96
~
June
21
59
>9.5
-
4.8
5,0
6
2
<0.1
2.6
7.2
0.4
0.10
-
-
<0.02
0.01
28
0.02
750
710
502
980
210
750
62
190
1.4
69
97
95
"
July Aug
-
58 56
>8.1 >10.0
-
2.1 4.8
7.1 5.1
4 5
2 3
<0.1 <0.1
2.6 2.9
7.6 7.4
1.9 4.0
0.08 0.07
-
-
0.08 <0.02
<0.01 <0.01
19 19
0,02 0.02
760 740
760 730
540 540
1,020 1,000
200 160
740 700
88 110
210 210
1.4 1.3
60
97 98
97 98
-
Sept Oct
19
60 67
>10.0 >8.9
-
2.1 2.1
8.0 8.1
5 9
5 9
<0.1 <0.1
2.3 2.6
7.1 6.9
1.7 0.8
0.12 0.13
-
-
0.06 <0.01
<0.01 <0.01
21 24
0.02 1.4
740 740
730 720
460 410
1,000 1,000
150 200
700 680
95 58
210 180
1.5 1.3
58 63
95 95
97 97
-
Nov
-
72
>9.6
-
3.4
4.8
21
14
<0.1
4.7
7.3
1.1
0.24
-
-
0.47
<0.01
27
1.7
760
740
470
900
150
750
78
200
1.5
58
98
89
Dec
19
68
>7.4
-
12
6.1
25
18
<0.1
4.8
7.3
2.0
0.10
-
-
0.33
0.02
25
3.8
790
770
480
920
160
760
87
200
1.3
65
97
86
High
25
87
>10.0
-
12
14
25
18
-
4.8
7.6
6.4
0.27
-
-
4.1
0.13
28
3.8
950
940
650
1,220
260
880
no
250
2.1
69
98
98
Low Average
18 20
56 64
>5.8 >8.5
-
<2 . 1 2 . f
3.1 6.6
4 12
2 8
<0.1
2.0 2.9
6.9 7.3
0.4 2.6
0.07 0.15
-
.
<0.01 0.51
<0.01 <0.02
12 22
0.02 1.3
740 800
710 770
410 510
900 1,030
150 200
680 /so
58 85
180 210
1.3 1.5
57 60
91 96
86 93
to
I—"
DO
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
cMedtan
Values affected by maximum meter reading of 10 mg/1
-------
TABLE E-4C.
DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1970
Jan
Disinfection
Chlorine dose , mg/1 25
Contact time, mln. 68
Chlorine residual, mg/1" >8.0
pH, contact tank effluent
Median collform organism
concentration, MPN/1 00ml 2 . 1
Final Effluent Characteristics
BOD5, mg/1 4.9
Suspended solids, mg/1 9
Volatile suspended solids,
mg/1 8
Settleable solids, ml/1 <0.1
Dissolved oxygen, mg/1 4.6
pH 6.6
Grease, mg/1 5.8
MBAS, mg/1 0.06
Turbidity, JTO
Temperature, C
Ammonia nitrogen, mg/la <0.02
Nitrite nitrogen, mg/la 0.02
Nitrate nitrogen, mg/la 20
Organic nitrogen , mg/l° 1 . 1
Total solids, mg/1 770
Total dissolved solids.
mg/1 760
Fixed dissolved solids.
mg/1 370
Specific conductivity.
mlcromhos 900
Chlorides, mg/1 170
Dissolved residue (by
calculation), mg/la 680
Alkalinity, mg/la 47
Hardness, mg/la 180
Boron , mg/la 1 . 4
Percent sodluma 62
Overall Plant Removals.
Percent
BOD5 98
Suspended solids 97
Ammonia nitrogen > 99
Feb
28
77
>5.0
-
4.8
10
35
29
<0.1
4.7
7.3
4.0
0.11
-
-
<0.02
0.01
26
2.8
940
880
530
1,060
200
820
54
200
1.6
61
96
88
>99
Mar
28
78
>7.4
-
2.1
4.0
11
5
<0.1
5.7
7.2
1.9
0.07
-
-
0.44
<0.01
26
1.7
780
780
540
940
180
710
51
200
1.6
61
98
95
99
Apr May
24 24
69 72
>10.0 >10.0
-
2.1 3.4
7.0 13
11 7
6 5
<0.1 <0.1
5.1 5.9
7.0 6,8
1.3 1.4
0.08 0.17
-
-
<0.02 <0.02
<0.01 <0.01
19 23
0.02 0.8
790 740
780 740
550 510
1,060 1,030
190 180
730 690
100 72
240 190
1.4 1.3
54 62
97 95
95 97
>99 >99
Month
June
28
63
>10.0
-
4.8
7.6
8
3
<0.1
5.7
7.4
0.2'
0.03
-
-
0.2
<0.01
21
0.7
720
710
470
980
160
660
76
190
1.2
59
97
96
>99
July Aug
21 18
73 69
>10.0 >9.5
-
<2.1 2.1
12 5.7
4 9
2 7
<0.1 <0.1
4.5 5.7
7.5 7.0
3.2 2.9
0.09 0.06
-
-
<0.1 <0.1
0.02 0.18
18 18
0.8 1.4
750 720
750 720
560 510
1,090 1,010
180 170
660 660
91 89
210 180
0.9 1.4
56 61
95 98
98 96
>99 >99
Sept Oct
24 27
72 76
>7.8 >7.9
-
4.8 2.1
7.6 10
10 6
10 4
<0.1 <0.1
5.3 5.1
7.0 6.9
2.7 1.0
0.04 0.04
-
-
<0.1 <0.1
nil nil
20 24
0.1 1.6
700 730
700 720
400 480
960 920
180 160
640 630
75 60
190 180
1.4 0.8
59 56
96 96
95 97
>99 >99
Nov
25
73
>9.9
-
2.1
5.1
13
11
<0.1
4.9
7.1
1.8
0.04
-
-
nil
nil
24
0.7
760
740
480
810
150
_
84
210
0.1
55
98
95
>99
Dec
25
70
>9.7
-
2.1
10
17
13
<0.1
5.0
6.7
3.3
0.04
-
-
nil
nil
22
0.7
890
sea
520
1,060
180
710
89
230
1.3
54
96
92
>99
High
28
78
>10.0
-
4.B
13
35
29
-
5.9
7.5
5.8
0.17
-
-
0.44
0.18
26
2.8
940
880
560
1,090
200
820
100
240
1.6
62
98
98
>99
Low
18
63
>5.0
-
<2.1
4.0
4
2
-
4.5
6.6
0.2
0.03
-
-
<0.1
<0.01
18
0.02
700
700
370
810
150
630
47
180
0.1
54
95
88
99
Average
25
72
>8.8
-
2.1°
8.1
12
9
<0.1
5.2
7.0
2.5
0.07
-
.
<0.11
<0.03
22
1.0
780
760
490
980
170
690
74
200
1.2
58
97
95
>99
CO
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
Median
Affected by maximum meter reading of 10 mg/1
-------
TABLE E-4D.
DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1971
Parameter
Disinfection
Chlorine dose, ma/1
Contact time, mln.
Chlorine residual, rag/1
pH , contact tank effluent
Median col If or m organism
concentration, MPN/lOOml
Final Effluent Characteristics
BOD5, mg/1
Suspended solids, mg/1
Volatile suspended solids,
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Grease, mg/1
MBAS, mg/1
Turbidity, JTU
Temperature, C
Ammonia nitrogen, mg/la
Nitrite nitrogen, mg/la
Nitrate nitrogen, mg/la
Organic nitrogen, mg/la
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity,
mlcromhos
Chlorides, mg/1
Dissolved residue (by
calculation), mg/la
Alkalinity, mg/la
Hardness, mg/la
Boron, mg/la
Percent sodium9
Overall Plant Removals.
Percent
BOD 5
Suspended solids
Ammonia nitrogen
Month
Jan
36
'••
9.5
-
-
9.3
19
6
<0.1
3.9
6.3
1.8
0.0$
-
-
<0.1
<0.01
23
2.0
890
870
610
1,110
200
720
72
220
1.4
55
96
92
>99
Feb
36
81
16
-
2.1
6.0
13
3
<0.1
3.6
7.0
2.5
0.04
-
-
<0.1
<0.01
14
3.1
860
850
570
1,050
190
730
65
220
2.1
58
97
93
>99
Mar
29
67
7.8
-
2.1
5.2
16
6
<0.1
4.2
6.8
2.3
0.04
-
-
1.3
<0.01
20
1.9
840
820
590
1,100
180
720
89
240
1.5
52
98
93
97
Apr May
25 30
64 67
8.7 16
-
2.1 2.1
3.1 8.5
8 12
3 5
<0.1 <0.1
3.9 5.1
6.8 6.6
2.3 1.8
0.05 0.05
-
-
<0.1 <0.1
<0.01 <0.01
19 30
2.0 0.1
780 780
770 780
520 540
980 940
160 161)
660 700
71 60
200 200
1.1
60 58
99 96
97 95
>99 >99
June
31
76
15
-
2.1
6.8
12
5
<0.1
5.0
6.9
3.3
0.05
-
-
<0.1
<0.01
22
7.8
920
910
700
1,030
150
670
84
200
1.2
58
96
95
>99
July Aug
34 32
74 76
20 18
-
<2.1 <2.1
7.3 8.1
9 17
6 5
<0.1 <0.1
5.0 4.8
6.9 6.6
1.8 2.2
0.03 0.03
-
-
<0.1 <0.1
<0.1 1.5
17 18
1.0 1.3
740 680
730 660
540 440
1,000 910
160 160
640 620
75 82
200 180
1.3 0.5
56 55
96 95
96 93
>99 >99
Sept Oct
26 29
77 82
13 14
-
2.1 2.1
6.1 7.8
11 15
5 2
<0.1 <0.1
4.6 4.1
6.7 6.5
2.2 2.3
0.04 0.03
-
-
<0.1 <0.1
<0.01 <0.01
24 21
0.4 1.7
720 660
710 650
540 440
1,020 770
130 120
620 570
69 31
170 150
0.8 0.5
59
97 96
94 94
>99 >99
Nov
36
80
13
-
2.1
12
12
3
<0.1
4.2
7.1
1.8
0.05
-
-
<0.1
<0.01
25
4.0
730
720
440
910
130
620
41
170
0.5
60
95
94
>99
Dec
36
78
16
-
2.1
7.0
17
2
<0.1
4.5
6.5
4.6
0.04
-
-
0.4
<0.01
25
1.3
760
740
480
940
150
650
52
190
0.9
57
97
93
>99
High Low
36 25
82 64
20 7.8
-
2.1 <2.1
12 3.1
19 8
6 2
-
5.1 3.6
7.1 6.3
4.6 1.5
0.05 0.03
-
-
1.3 <0.1
1.5 <0.01
30 14
7.8 0.1
920 660
910 650
700 440
1,110 770
200 120
730 570
89 31
240 150
2.1 0.5
60 52
99 95
97 92
>99 97
Average
32
75
14
-
2.1C
7.3
13
4
<0.1
4.4
6.7
2.3
0.04
-
-
<0.2
<0.14
22
2.2
780
770
530
980
160
660
68
200
1.1
57
97
94
>99
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
Median
-------
TABLE E-4E
DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1972
Parameter
Disinfection
Chlorine dose, mg/1
Contact time, mln.
Chlorine residual, mg/1
pH , contact tank effluent
Median collform organism
concentration, MPN/lOOm
Final Effluent Characteristics
BODj, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
pH
Grease, mg/1
MBAS, mg/1
Turbidity, JTU
Temperature, °C
Ammonia nitrogen, mg/1
Nitrite nitrogen, mg/la
Nitrate nitrogen, mg/la
Organic nitrogen, mg/la
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids,
mg/1
Specific conductivity.
mlcromhos
Chlorides, mg/1
Dissolved residue (by
calculation) , mg/la
Alkalinity, mg/la
Hardness, mg/1
Boron, mg/la
Percent sodium9
Overall Plant Removals,
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan
31
59
18
6.3
2.1
7.8
33
21
<0.l
4.0
6.5
7.8
0.05
_
_
0.9
0.02
25
3.7
800
770
470
910
140
640
27
180
1.1
58
97
90
98
Feb
32
66
20
6.3
3.4
9.6
23
18
<0.1
4.9
6.6
4.6
0.06
_
_
0.2
<0.01
22
3.6
800
780
440
920
160
640
46
190
1 .4
57
96
91
>99
Mar Apr
31 31
56 56
16 15
6.3 6.4
3.4 2.1
5.9 11
42 13
35 13
<0.1 <0.1
4.9 5.1
6.9 6.9
6.4 2.7
0.07 0.07
_
_
<0.1 <0.1
<0.01 <0.01
24 26
4.8 2.4
810 770
770 750
520 490
950 970
150 150
670 630
63 50
200 190
0.8 0.7
60 55
98 96
86 94
>99
May
32
53
16
6.5
'2.1
13
39
12
<0.1
4.9
6.7
7.9
0.30
_
_
<0.1
<0.01
22
1.7
680
650
350
920
130
_
44
180
1.0
93
81
>33
June
2fc
51
14
6.5
<2.1
11
16
11
<0.1
4.4X
7.0
5,5
0.07
_
_
.
_
_
_
720
700
480
910
140
_
_
_
_
-
96
93
-
July Aug
25 22
51 49
17 15
6.5 6.3
2.1 2.1
3.3 5.4
9 11
3 8
<0.1 <0.1
5.0 5.1
7.3 7.2
7.8 1.1
0.06 0.06
_
_
<0.1 0.5
<0.01 <0.01
20 21
1.7 1.7
810 760
830 740
570 550
850 880
150 200
660
80 77
200 190
1.1 1.4
58 62
98 98
97 96
99 98
Sept Oct
23 33
50 50
11 15
6.3 6.2
2.1 4.8
8.5 6.1
14 11
10 9
<0.1 <0.1
5.5 4.9
7.0 6.7
1.6 1.2
0.05 0.05
_
-
0.41 0
<0.01 <0.01
20 15
1.6 1.6
710 650
690 640
520 340
980 970
160 150
600 560
60 34
170 160
0.8 0.7
58 57
96 97
94 96
99 >99
Nov
29
58
J6
6.2
2.1
7.7
19
15
<0.1
5.0
6.9
2.9
0.04
_
_
0.43
<0.01
25
2.7
720
700
500
900
170
_
47
200
0.8
54
96
93
99
Dec
34
54
18
6.5
2.1
8.1
33
13
<0.1
4.9
6.7
12.0
0.05
_
_
0.44
<0.01
28
4.0
870
840
540
1,040
200
720
48
230
0,9
54
96
87
99
High
34
66
20
6.5
4.8
13
42
35
-
5.5
7.3
12.0
0.30
_
_
0.9
0.02
28
4.8
870
840
570
1 ,040
200
720
80
230
1.4
62
98
97
>99
Low Average
22 29
49 54
11 16
6.2 6.4
<2.1 2.1C
3.3 8.1
9 22
3 14
<0.1
4.0 4.9
6.5 6.9
1.1 5.1
0.04 0.08
_
_
<0.1 0.3
0.01 0.01
15 22
1.6 2.7
650 760
640 740
340 480
850 940
130 160
560 640
27 52
160 190
0.7 1.0
54 57
93 96
81 92
98 99
01
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
GMedian
-------
TABLE E-4F.
DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1973
Parameter
Disinfection
Chlorine dose, mg/1
Contact time, mln.
Chlorine residual, mg/1
pH, contact tank effluent
Median conform organism
concentration, MPN/lOOml
Final Effluent Characteristics
BOD 5, mg/1
Suspended solids, mg/1
Volatile suspended solids.
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Grease, mg/1
MB AS, mg/1
Turbidity, JTU
Temperature, °C
Ammonia nitrogen, mg/la
Nitrite nitrogen, mg/la
Nitrate nitrogen, rag/la
Organic nitrogen , mg/1
Total solids, mg/1
Total dissolved solids,
mg/1
Fixed dissolved solids.
mg/1
Specific conductivity,
micromhos
Chlorides, mg/1
Dissolved residue (by
calculation), mg/la
Alkalinity, mg/la
Hardness, mg/la
Boron, mg/la
Percent sodium3
Overall Plant Removals,
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Ian
27
51
15
6.6
2.1
7.2
34
28
<0.1
4.9
7.4
3.7
0.05
7.0
16
0.34
0.003
29
2.7
960
930
560
1,220
220
840
66
250
1.0
59
97
84
"
Fob
26
51
14
6.5
2.1
9.5
38
23
<0.1
4.2
6.8
1.1
0.04
12
17
0.32
0.002
24
5.2
950
920
520
1,200
250
820
51
230
1.1
60
96
83
Mar Apr
29 S2
51 60
19 18
6.S 6.5
<2.1 2.1
11 12
38 32
21 18
<0.1 <0.1
4.1 4.6
6.8 6.9
2.5 2.8
0.05 0.05
11 14
18 20
0.40 0.41
0.002 0.002
23 25
4.6 6.6
980 960
940 940
670 680
1,250 1,320
250 250
890 870
51 65
230 240
1.5 1.4
65 62
95 95
83 89
99 99
May
50
61
14
6.7
<2.1
9.0
10
8
<0.1
5.0
6.9
1.6
0.03
9.3
23
0.39
0.003
23
2.1
870
860
600
1,290'
210
760
61
230
1.0
57
96
96
99
June
37
59
17
6.5
2.1
8.5
17
13
<0.1
5.0
7.0
3.0
0.04
4.4
25
1.4
0.002
22
4.3
810
790
540
1,100
180
690
67
200
1.0
58
96
94
98
July Aug
30 31
63
12 13
6.8 6.8
2.1 6.7
11 5.3
16 37
12 8
<0.1 <0.1
4.6 5.3
6.7 7.1
3.5 3.8
0.30 0.04
6.2 5.7
25 25
6.4 0.73
0.009 0.003
17 22
2.4 1.0
870 840
860 800
590 510
1,080 1,130
170 210
720 740
80 68
180 190
1.1 1.0
64 66
95 98
93 86
97
Sept Oct
38 38
62 66
17 19
6.5 6.5
<2.1 2.1
7.5 12
26 33
22 15
<0.1 <0.1
5.1 5.3
7.0 7.2
6.7 7.2
0.03 0.03
5.6 6.5
24 22
0.51 1.9
0.002 0.003
23 23
1.1 0.1
760 750
740 720
480 350
960 1,020
180 170
660 650
50 61
180 190
0.8 0.5
61 58
96 94
90 82
98 96
Nov
35
63
20
6.5
2.1
9.6
16
13
cO.l
4.5
6.7
11
0.03
6.4
20
0.34
0.001
24
0.2
850
830
450
990
190
700
56
270
1.1
57
96
94
~
Dec
36
74
22
6.4
2.1
11
36
29
<0.1
4.7
6.5
14
0.07
11
17
1.8
0.002
23
0.7
770
730
540
1,120
180
690
17
170
1.0
65
95
84
-
High
52
74
22
6.7
6.7
11
37
29
_
5.3
7.4
14
0.30
14
25
6.4
0.009
29
6.6
980
940
680
1,320
250
890
80
250
1.5
66
98
96
99
Low Average
26 36
51 60
12 17
6.4 6.6
<2.1 2.1C
5.3 9.4
10 28
8 18
<0.1
4.1 4.8
6.5 6.9
1.6 5.2
0.03 0.06
4.4 8.3
16 21
0.32 1.2
0.001 0.002
17 23
0,1 2.6
750 860
720 840
350 540
960 1,230
170 210
650 750
17 58
170 210
0.5 I.I
57 61
94 96
82 88
96 98
to
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
cMedlan
-------
TABLE E-4G.
DISINFECTION, FINAL EFFLUENT CHARACTERISTICS,
AND OVERALL PLANT PERFORMANCE, 1971
NJ
Parameter
Disinfection
Chlorine dose, mg/1
Contact time, ratn.
Chlorine residual, mg/1
pH , contact tank effluent
Median coLtform organism
concentration. MPN/lOOml
Final Effluent Characteristics
BODj, mg/1
Suspended solids, mg/1
Volatile, suspended solids
mg/1
Settleable solids, ml/1
Dissolved oxygen, mg/1
PH
Grease, mg/1
MBAS, mg/1
Turbidity, JTO
Temperature, °C
Ammonia nitrogen, mg/la
Nitrite nitrogen, mg/la
Nitrate nitrogen, rog/la
Organic nitrogen, mg/la
Total solids, mg/1
Total dissolved solids.
mg/1
Fixed dissolved solids.
mg/1
Specific conductivity,
mlcromhos
Chlorides, mg/1
Dissolved residue (by
calculation) , mg/la
Alkalinity, mg/la
Hardness, mg/la
Boron, mg/la
Percent sodium3
Overall Plant Removals ,
Percent
BOD5
Suspended solids
Ammonia nitrogen
Month
Jan
35
65
19
6.8
<2.1
20
38
34
<0.1
4.5
6.8
11
0.05
14
16
0.25
0.004
30
0.93
850
810
600
1,100
200
770
20
190
0.88
62
91
87
Feb
32
72
19
7.3
2.1
18
23
14
<0.1
4.8
7.3
13
0.04
15
16
5.2
0.011
21
2.9
870
860
600
1,090
210
770
62
200
1.1
60
92
90
Mar
34
73
20
6.6
2.1
13
23
18
<0.1
5.6
6.6
11
0.06
16
18
0.11
0.004
26
2.0
920
900
630
1,100
210
770
15
210
1.1
61
95
90
Apr May
39 42
69 60
17 17
6.4 6.5
2.1 <2.1
9.8 11
23 16
17 19
<0.1 <0.1
4.5 5.4
6.4 6.5
5.5 9.8
0.03 0.03
18 11
19 21
0.45 0.17
0.003 0.002
27 25
2.4 2.3
830 830
800 800
590 540
1,230 1,170
210 200
770 730
16 31
200 190
1.1 0.95
60 61
95 95
92 92
"
June
53
56
19
6.4
<2.1
14
15
11
<0.1
5.2
V.4
5.5
0.27
11
23
0.17
0.002 <
24
0.33
830
810
550
1 ,000
190
670
18
180
0.96
61
94
93
99
July Aug
52 33
56 57
16 16
6.5 6.7
<2.1 <2.1
9.4 5.1
16 11
12 11
<0.1 <0.1
4.8 5.3
6.5 6.7
4.2 3.8
0.30 0.35
8.8 5.6
25 25
1.7 <0.05
0.001 0.009
22 22
1.7 0.22
710 720
700 710
510 480
1,020 980
170 160
680 660
42 26
160 180
0.91 0.8
60 60
95 98
93 96
"
Sept Oct
34 34
58 60
14 18
6.4 7.0
<2.1 <2.1
11 7.8
10 10
5 20
<0.1 <0.1
4.8 4.8
6.4 7.0
3.3 4.4
0.28 0.23
5.7 5.1
25 23
0.73 0.90
0.001 0.002
23 26
0.05 0.60
700 730
690 720
500 450
960 1,030
170 160
620 620
38 29
170 180
0.6 0.9
59 56
95 96
95 95
98 98
Nov Dec
32 51
58
14 21
6.6
<2.1
5.9
15
10
<0.1 <0.1
4.7 4.9
6.6
6.7
0.25
9.0
21
0.39 0.28
0.009 0.005
26 27
2.3 1.9
840
820
540
9jO
160
_
62 29
230 220
0.9 0.8
53 56
97
95
99
High
53
73
21
7.3
2.1
20
38
34
-
5.6
7.3
13
0.35
16
25
5.2
0.011
30
2.9
920
900
630
1,230
210
770
62
230
1 .1
62
98
96
99
Low
32
56
14
6.4
<2.1
5.1
10
5
-
4.5
6.4
3.3
0.03
5,2
16
0.05
0.001
20
0.05
700
690
450
960
160
620
15
160
0.6
53
91
87
98
Average
39
62
18
6.7
<2.1C
11
18
16
<0.1
5.0
6.7
7.1
0,17
11
21
0.73
0.004
25
1.5
800
780
540
1,060
190
710
32
190
0.9
59
95
93
98
Analyses performed by Environmental Quality Analysts, Inc., San Francisco
Based on primary effluent characteristics
Median
-------
TABLE E-5A. SOLIDS HANDLING AND TREATMENT, 1968
Parameter
Sludae Flow, and*
To dlgesteri0
To lagoons
Digester Performance
Total solids, percent
Rawb
Digested
No. 1
No. 2
Volatile solids, percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solids reduction.
percent
No. 1
No. 2
Digester temperature, F
No. 1
No. 2
Digester gas produced,
l,OOOItVdayc'd
No. 1
No. 2
Digested Sludge
Characteristics
Volatile acids, mg/1
No. 1
No, 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No. 2
Jan
22,000
20,300
3.2
1.6
2.0
81
74
74
33
33
70
77
11.1
2.6
470
420
1,740
2,970
6.6
6.8
Month
Feb Mar Apr May June July Aug Sept Oct Nov Dec
17,200 16,800 17,400 17,100 16,400 14,900 15,100 18,500 17,100 16,000 16,800 22,000 14,900 17,100
17,600 18,000 20,000 24.400 23,000 18,500 14,200 18,300 15,900 13,300 17,100 24,400 13,300 18,400
3.7 4.1 3.7 3,8 3.6 3.5 3.9 3.6 4.3 4.1 4,2 4.3 3.2 3.8
1.4 1.9 1.0 1.3 1.8 2.4 1.6 1.9 2.1 2.6 2.1 2.6 1.0 l.B
1.9 2.7 1.9 2.0 2.4 2.3 2.1 2.1 2.6 3.1 3.7 3.7 1.9 2.3
80 78 80 80 82 80 83 80 82 73 79 83 73 80
67 68 66 66 64 67 68 64 64 63 68 74 63 67
69 67 65 67 69 63 70 68 68 64 70 74 63 68
49 40 51 51 59 49 56 54 61 37 44 61 33 49
44 43 54 49 51 57 52 47 53 34 38 57 33 46
81 88 93 93 97 97 96 96 95 95 88 97 70 91
80 85 89 90 91 97 97 93 95 92 87 97 77 89
22.9 25.2 25.4 26.1 26.3 23.8 22.9 19.8 18.1 17.4 20.9 26.3 11.1 21.7
9.1 10.2 8.6 9.S 8.1 7.0 6.0 3.2 2.3 7.6 8.9 10.2 2.3 6.9
260 340 150 130 ISO 420 180 140 280 140 560 560 130 270
320 270 200 180 400 240 250 200 1,280 510 350 1,280 180 390
1,910 2.020 1,840 1,880 1,880 1,680 1,550 1,480 1,840 1,900 1,850 2,020 1,480 1,800
2,430 2,660 2,620 2,740 2,480 2,710 2.400 2,380 2,320 2,900 2,850 2,900 2,070 2^550
6.8 6.9 7.0 7.0 7.0 6.7 6.8 6.8 6.8 6.9 6.7 7.0 6.6 6.8
6.8 7.0 7.0 7.0 7.0 6.9 7.0 6.8 6.4 7.0 6.8 7.0 6.4 6.8
N)
t—'
00
8gpd x 0.0038 - roVday
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
cl,000 ft3 x 0.0283 - 1,000 m3
Digester gas contained an average of 36 percent CO2 In 1968.
-------
TABLE E-5B. SOLIDS HANDLING AND TREATMENT, 1969
Parameter
Sludge Flow, apd"
To digesters'1
To lagoons
Digester Performance
Total solids, percent
Raw0
Digested
No. 1
No. 2
Volatile solids, percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solids reduction.
percent
No. 1
No. 2
Digester temperature , F
No. 1
No. 2
Digester gas produced,
1,000 ftVdayc
No, 1
No. 2
Digested Sludge
Characteristics
Volatile acids, mg/1
No. 1
No. 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No. 2
Month
Ian
19,000
18,000
4.5
3.7
3.1
71
56
67
47
17
84
81
ie.i
8.0
ZOO
550
1,920
2,740
6.9
6.9
Feb
20,700
19,900
4.8
1.8
2.9
73
SB
57
49
51
80
81
16.8
10.3
380
310
1,810
2,740
6.7
6.9
Mar
18,200
18,100
4.6
4.1
2.9
83
61
60
68
71
83
84
10.6
16.3
220
260
2,060
3,040
6.7
7.1
Apr May
16,800 17,100
16,600 17,900
4.1 3.4
1.5 2.7
1.6 1.7
84 85
64 72
64 72
66 65
66 55
87 94
91 93
16,4 15.1
10.9 9.8
230 280
200 200
2,600 3,030
2,750 3,000
7.0 7.1
7.0 7.1
Tune
18,900
15,500
3.5
2.1
2.5
83
72
69
47
54
97
94
17.5
10.3
230
380
2,730
2,760
7.1
7.0
July Aug
16,700 15,900
16,200 16,600
3.2 3.0
1.7 2.1
2.0 1.9
84 80
70 61
71 63
56 61
53 57
98 91
92 93
-
9.6 11.4
200 220
240 240
2,600 2,420
2,470 2,360
7.1 7.0
7.0 7.0
Sept Oct
17,700 17,700
16,100 18,300
3.1 3.8
2.1 2.4
1.5 2.0
86 85
72 73
73 75
58 52
56 47
87 92
97 94
-
11.4 9.6
250 440
210 650
2,560 2,830
2,620 2,470
6.8 6.9
6.9 6.8
Nov Dec
17,700 19,600
17,100 20,100
3.6 3.9
1.6 1.7
1.6 1.4
85 86
70 72
71 71
59 58
57 60
97 92
96 90
-
15.4 13.3
280 240
310 280
3,000 2,840
2,590 2,400
7.1 6.9
7.0 6.9
High
20,700
20,100
4.8
4.1
3.1
86
73
75
68
71
98
97
18.1
16.3
440
650
3,030
3,040
7.1
7.1
Low
15,900
15,500
3.0
1.5
1.4
71
56
57
47
17
80
81
10.6
8.0
200
200
1,810
2,360
6.7
6.8
Average
18,000
17,500
3.8
2.2
2.1
82
67
68
56
54
90
91
15.3
11.4
260
320
2,540
2,660
6.9
7.0
NO
I—•
CO
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
cl,000 ft3 x 0.0283 = 1,000 m3
-------
TABLE E-5C. SOLIDS HANDLING AND TREATMENT, 1970
Parameter
Sludae Flow, and8
To digesters'5
To lagoons
Digester Performance
Total solids, percent
Raw*>
Digested
No. 1
No. 2
Volatile solids, percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solids reduction.
percent
No. 1
No. 2
Digester temperature, F
No. 1
No. 2
Digester gas produced,
1 , 000 ft3/day°
No. 1
No. 2
Digested Sludge
Characteristics
Volatile acids , mg/1
No. 1
No. 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No. 2
Month
Ian
19,500
19,500
3.4
2.0
1.6
83
75
72
39
47
84
84
-
9.7
320
690
2,550
2,240
7.0
6.8
Feb
19,300
18,800
2.8
1.5
0.9
88
69
69
70
70
85
85
10.9
13.7
240
220
2.440
1,710
7.0
6.8
Mar
19,500
19,600
3.5
1.4
1.2
83
70
69
52
54
91
95
14.2
16.3
300
200
2,740
2,020
7.0
6.9
Apr May
19,700 18,400
19,200 18,500
3.4 3.6
1.6 1.6
1.5 1.7
85 84
69 70
72 68
61 56
55 60
90 89
88 94
6.6 20.3
12.3 11.1
1,750 510
1,030 1,270
3,440 2,900
2,740 3,380
6.7 7.0
6.7 7.1
Tune
18,300
18,000
3.5
1.5
1.7
84
69
70
58
56
94
94
18.5
-
190
640
2,610
2,470
7.0
7.0
July Aug
18,900 18,300
18,400 18,600
3.5 3.9
1.7 1.7
1.4 1.8
84 85
71 71
71 72
53 57
53 55
98 97
97 96
13.7 13.2
-
600 730
700 1,020
2,500 2,460
2,270 2,400
7.0 6.8
6.9 6.8
Sept Oct
18,100 18,700
18,200 18,200
3.4 3.8
1.6 1.8
1.6 1.7
83 84
73 73
74 73
45 49
42 49
96 92
96 92
12.6 15.3
-
820 360
560 370
2,500 2,360
2,350 2,540
6.9 7.0
7.0 7.0
Nov
18,600
18,700
3.4
1.6
1.6
82
71
71
46
46
91
94
16.2
-
280
360
2,450
2,420
6.8
6.8
Dec
18,800
18,300
4.1
2.2
1.8
83
71
66
50
57
82
83
14.1
-
370
510
2,610
2,480
6.9
6.8
High Low
19,700 18,100
19,600 18,000
4.1 2.8
2.2 1.4
1.8 0.9
88 82
75 69
74 68
70 39
70 42
98 82
97 83
20.3 6.6
16.3 9.7
1,750 190
1,270 200
3,440 2,360
3,380 1,710
7.0 6.7
7.1 6.7
Average
18,800
18,700
3.5
1.7
1.5
84
71
71
53
54
91
92
14.1
12.6
540
630
2,630
2,420
6.9
6.9
to
to
o
agpd x 0.0038 = mVday
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
Cl,000 ft3 x 0.0283 - 1.000 m3
-------
TABLE E-5D. SOLIDS HANDLING AND TREATMENT, 1971
Parameter
Jan
Sludge Flow. apda
To digesters'3 20,700
To lagoons 19,600
Digester Performance
Total solids, percent
Rawb 3 . 8
Digested
No. 1 Z.O
No. 2 2.1
Volatile solids, percent of
total
Rawb 87
Digested
No. 1 73
No. 2 73
Volatile solids reduction,
percent
No. 1 60
No. 2 60
Digester temperature, F
No. 1 78
No. Z 85
Digester gas produced,
1,000 ft3/dayc
No. 1 14.4
No. 2
Digested Sludae
Characteristics
Volatile acids, mg/1
No. 1 380
No. 2 370
Alkalinity, mg/1
No. 1 2,510
No. 2 2,440
PH
No. 1 6.8
No. 2 6.8
Feb
20,700
20,600
3.1
1.4
1.3
84
73
71
49
53
84
95
12.4
-
280
300
2,380
2,420
6.9
6.9
Mar
21 ,000
20,500
2.8
1.4
1.4
83
73
73
45
45
92
95
13.5
-
240
240
2,500
2,440
7.0
7.0
Apr May
20,700 20,700
20,800 20,300
3.6 3.2
1.5 '1.7
1.7 1.6
82 83
69 72
70 72
51 47
50 47
97 95
98 98
14.9 15.4
19.5 20.0
280 210
260 290
2,460 2,650
2,420 2,340
6.9 6.9
6.9 6.8
Month
June
21,600 21
21,600 21
3.5
1.4
1.5
85
70
71^
59
57
95
98
14.4
19.5
250
260
2,010 2
2,180 2
6.8
6.8
July Aug
,300 20,500
,000 20,200
3.4 3.6
1.6 1.8
1.7 1.5
84 83
68 71
70 70
60 50
56 52
99 98
99 100
15.0 18.5
18.0 16.3
310 1,260
250 800
,020 2,390
,300 2,350
6.9 6.5
6.9 6.6
Sept Oct
18,900 18,700
18,700 18,700
3.8 3.3
1.6 1.4
2.0 1.4
85 84
69 70
69 70
61 56
61 56
98 96
99 98
13.1 7.9
18,7 17.5
350 600
610 340
2,620 2,020
2,650 2,280
6.8 6.5
6.8 6.6
Nov
20,700
20,500
3.8
1.7
1.7
85
73
74
52
50
91
92
11.9
16,2
510
570
2,330
2,370
6.4
6.4
Dec
21,200
20,800
3.7
1.7
1.6
84
70
70
56
56
84
93
10.6
20.3
360
340
2,140
2,160
6.6
6.7
High
21,600
21,600
3.8
2.0
2.1
87
73
74
61
61
99
100
15.4
20.3
1,260
800
2,650
2,650
7.0
7.0
Low
18,700
18,700
2.8
1.4
1.3
82
68
69
45
45
78
85
7.9
16.2
210
240
2,010
2,160
6.4
6.4
Average
20,600
20,300
3.5
1.6
1.6
84
71
71
54
54
92
96
12.7
18.4
420
390
2,340
2,360
6.8
6.8
N>
to
agpd x 0.0038 = m3/day
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
Cl,000 ft3 x 0.0283 - 1,000 m3
-------
TABLE E-5E. SOLIDS HANDLING AND TREATMENT, 1972
Parameter
Sludoe Flow, and8
To digesters0
To lagoons
Digester Performance
Total solids, percent
Rawb
Digested
No. 1
No. 2
Volatile solids, percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solid j reduction.
percent
No. 1
No. 2
Digester temperature, F
No. 1
No. 2
Digester gas produced,
l,OOOftVdayc
No. 1
No. 2
Digested Sludae
Characteristics
Volatile acids, mg/1
No. 1
No. 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No. 2
fan Feb
22,200 22.700
21,000 21.500
4.3
1.4
1.5
85
71
71
57
57
80 82
91 93
13.7 15.7
20.3 20.4
280 300
220 360
2,080 2,020
2,320 2,200
6.8 6.5
6.9 6.7
Month
Mar Apr May June July Aug Sept Oct Nov Dec
21,600 21,600 22,700 20,900 20,900 19,300 21,400 27,600 23,300 24,000 27,600 19,300 22.300
21,500 21,200 21,600 21,100 20,400 19,300 21,600 27,400 22,900 23,700 27,400 19,300 21,900
4.0 3.6 4.0 - 4.5 - 3.5 3.1 3.4 3.0 4.5 3,0 3,7
1.9 1.9 2.8 - 1.5 - 1.6 2.2 2.7 1.7 2.8 1.4 2.0
1.7 1.5 1.2 - 1.3 - 1.3 2.0 2.8 - 2.8 1.3 1.7
78 81 86 - 83 83 87 83 84 87 78 83
68 69 72 - 67 73 68 71 74 74 67 70
70 68 71 - 70 - 72 72 72 - 72 68 71
40 48 58 - 58 45 68 50 46 68 40 52
34 50 60 - 52 - 47 62 47 - 62 34 51
90 92 94 99 97 95 98 95 93 81 99 80 91
95 95 96 98 96 94 96 93 95 81 98 81 94
16,5 10,9 17.5 14,8 16.2 15.4 14.7 7.5 15.1 12.0 17.5 7.5 14 2
18.1 18.1 15.6 12.5 19.2 18.2 17.0 11.2 20.3 3.4 20.4 3.4 16J4
260 850 500 710 200 - 540 2,430 960 310 2,430 200 670
250 240 530 1,620 280 - 490 2,490 1,520 1,000 2,490 220 820
2,220 1,830 2,480 1,800 2,260 - 2,260 3,760 3,180 2,170 3,760 1,880 2,370
2,150 2,010 1,880 2,210 2,210 - 2,080 3,470 2,950 2,140 3,470 1,880 2,330
6.9 6.4 6.7 6.7 6.8 - 6.8 6.6 7.0 6.9 7.0 6.4 6.7
6.8 6.7 6.4 6.3 6.7 - 6.8 6.5 6.7 6.7 6.9 6.3 6.7
to
to
to
agpd x 0.0038 - m3/day
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
cl,000 ft3 x 0.0283 - 1,000 m3
-------
TABLE E-5F. SOLIDS HANDLING AND TREATMENT, 1973
Parameter
Sludge Flow. gpda
To digesters^
To lagoons
Digester Performance
Total solids, percent
Rawb
Digested
No. 1
No. 2
Volatile solids , percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solids reduction,
percent
No. 1
No. 2
Digester temperature, F
No. 1
No. 2
Digester gas produced,
1,000 ftVdayc
No. 1
No. 2
Digested Sludge
Characteristics
Volatile acids , mg/1
No. 1
No. 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No. 2
Month
Ian
24,100
23,600
3.7
2.2
2.2
81
67
67
46
46
79
86
12.5
39.7
400
810
2,270
2,320
6.9
7.0
Feb
23,100
22,500
3.0
1.5
1.0
86
66
59
68
77
79
89
13.2
40.3
510
240
1,760
2,170
6.7
6.9
Mar Apr
23,700 22,500
23,800 22,500
2.9 3.1
1.5 1.4
1.3 1.2
83 83
69 68
67 68
54 56
58 56
83 86
92 94
13.3 7.7
41.0 23.0
370 230
180 180
2,120 2,130
2,260 2,120
6.9 6.9
7.0 6.9
May June
23,200 22,900
22,900 23,100
3.1 3.2
1.5 1.5
1 .2 1.7
81 81
67 68V
69 67
46 50
48 46
89 93
98 100
10.1 10.3
18.6 32.2
420 280
320 230
2,060 2,240
2,280 2,300
6.8 6.9
6.9 7.0
July Aug
21,000 22,800
20,700 23,000
2.7 4.1
1.3 1.5
0.8 1.2
84 83
69 69
70 69
58 54
56 54
95 91
100 95
10.6 10.2
34.8 33.5
280 280
200 310
2,400 2,240
2,180 1,980
7.0 6.8
7.0 6,8
Sept Oct
21,100 22,600
20,500 22,600
3.3 3.8
1.5 1.9
1 .2 1.8
83 84
70 71
70 69
52 53
52 58
94 92
99 99
9.8 7.8
34.6 33.5
260 240
300 250
2,410 2,490
2,340 2,470
6.9 6.9
6.8 6.9
Nov
23,300
23,300
3.5
2.3
1 .7
83
71
73
50
45
87
93
4.4
31.5
570
390
2,200
2,330
6.9
6.9
Dec
22,900
22,900
3.4
2.1
1.9
86
72
72
58
58
87
91
3.3
29.2
440
320
2,580
2,740
7.0
7.1
High
24,100
23,800
4.1
2.3
2.2
86
76
73
68
77
95
100
13.3
41.0
570
810
2,580
2,740
7.0
7.1
Low
21,000
20.500
2.7
1.3
0.8
81
66
59
46
45
79
86
3.3
18.6
230
180
1,760
1,900
6.7
6.8
Average
22,800
22,600
3.3
1.7
1.4
83
69
68
54
55
88
95
9.4
32.7
360
310
2,240
2,290
6.9
6.9
to
CO
agpd x 0.0038 • mVday
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
Cl,000 ft3 x 0.0283 = 1,000 m3
-------
TABLE E-5G. SOLIDS HANDLING AND TREATMENT, 1974
Parameter
Studae Flow, crpd*
To digesters'1
To lagoons
Digester Performance
Total solids, percent
Raw6
Digested
No. 1
No. 2
Volatile solids , percent of
total
Rawb
Digested
No. 1
No. 2
Volatile solids reduction,
percent
No. 1
No. 2
Digester temperature, F
No. 1
No. 2
Digester gas produced,
1,000 ftVdayC
No. 1
No. 2
Digested Sludge
Characteristics
Volatile acids, mg/1
No. 1
No. 2
Alkalinity, mg/1
No. 1
No. 2
PH
No. 1
No, 2
Month
[an
23,300
21,200
3.1
1.5
1.5
86
70
73
62
56
90
85
2.1
28.9
490
850
2,500
2,630
6.9
6.7
Fob
22,600
22,500
3.2
1.4
1.1
86
72
67
56
67
87
85
0
25.5
580
500
2,320
2,440
6.9
7.0
Mar Apr
20,300 21,700
20,200 21,900
3.1 3.0
1.3
1.0
84
70
69
56
58
87 95
88 94
5.2 12.3
19.9 19.2
360 240
330 270
2,280 2,140
2,170 2,110
6.8 6.8
6.8 6.6
May
22,800
22,800
2.9
1.2
1.2
85
72
71
55
57
96
101
11.0
17.4
260
220
2,730
2,950
6.9
6.9
June July
21,200 21,000
20,800 21,500
3.1 3.1
2.0
4.0
82
68
75
53
34
99 99
102 107
15.5 19.2
10.1 10.3
400 260
2,160 2,940
4,020 3,810
5,260 4,340
6.9 6.9
6.0 5.4
Aug
21,400
21,500
3.9
2.1
4.8
84
72
75
51
43
100
103
18.3
10.6
280
3,180
3,440
3,250
6.9
5.4
Sept Oct
20,200 21,800
20,000 22,300
3.3 3.5
1.6
2.0
83
73
70
45
52
102 106
103 107
14.7 11.9
13.9 17.6
620 1,160
1,810 810
2,460 2,700
3,410 2,980
6.8 6.7
7.1 6.9
Nov Dec
21,400 19,600
20,300 19,400
3.4 3.4
1.8
3.1
83
72
72
47
47
104 92
96 90
13.4 10.0
13.5 14.1
580
1,930
2,500
2,490
6.9
6.3
High
23,300
22,800
3.9
2.1
4.8
86
73
75
62
67
106
107
19.2
28.9
1,160
3,180
4,020
5,260
6.9
7.1
Low
19,600
19,400
2.9
1.2
1.0
82
68
67
45
34
87
85
0
10.1
240
220
2,140
2,110
6.7
5.4
Average
21,400
21,200
3.3
1.6
2.3
84
71
72
53
52
96
97
11.1
16.8
480
1,360
2,810
3,090
6.9
6.5
to
to
agpd x 0.0038 = m3/day
From primary sedimentation tanks; Includes waste mixed liquor recycled to headworks
Cl,000 ft3 x 0.0283 - 1,000 m3
-------
TABLE E-6A. POWER, CHEMICALS. AND LABOR, 1968
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power , 1,000 fcwh
Natural gas, 1,000 ft3
Labor. Marihpurs
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Feb Mar Apr May June
16.5 17.4 17.8 21.5 13.6 15.3
140 134 169 163 179 183
229 72.0 141 148 42.8 139
646 608 607 548 648 639
259 246 222 255 188 149
293 136 165 172 168 174
176 262 224 199 211 252
136 160 155 172 168 157
1,510 1,412 1,373 1,346 1,383 1,371
July Aug Sept Oct Nov Dec
16.5 16.2 20.5 19.7 22.9 20.1
177 215 247 258 249 250
104 84.5 114 91.8 98.1 104
350 - 648 660 654
320 - 188 91 170
197 - 194 295 248
286 - 294 220 210
187 - 185 127 90
1,340 - 1,509 1,393 1,372
High Low Total
22.9 13.6 218
258 134 2,360
229 72.0 1,370
660 350 7,210=
320 91 2,506C
295 136 2,450C
294 176 2,801C
187 90 J,844C
1,510 1,340 16,811C
to
N5
cn
1,000 Ib x 0.45 - 1,000 kg
bl ,000 ft3 x 0.0283 - 1,000 m3
Adjusted for a 12-month period
-------
TABLE E-6B. POWER, CHEMICALS, AND LABOR, 1969
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power, 1 ,000 kwh
Natural gas, 1,000 ft»b
Labor, Manhours
Operation
Routine maintenance
Repair '
Laboratory and monitoring
Yard
Part-time, unclassified
Total
Month
Ian Feb Mar Apr May Jure
20.1 21.7 24.2 20.9 16.4 20.3
208 215 230 230 243 230
120 49. J 37.4 29.5 28.4 162
691 S88 651 630 651 592
208 213 174 200 264 103
242 136 120 231 368 236
28S 318 281 277 249 228
98 120 147 185 164 136
- 264
1,525 1,375 1,373 1,523 1,696 1,559
July Aug Sept Oct Nov Dec
18.2 18.4 20.8 20.6 18.2 22.6
219 215 208 210 192 224
77.3 70.8 103 148* 39.1 87.7
651 651 667 651 645 737
250 118 40 277 192 121
195 212 266 259 219 371
251 305 236 269 232 282
16 168 158 188 124 81
538 380 -
1,901 1,834 1,367 1,644 1,412 1,592
High Low Total
24.2 16.4 222
243 192 2,620
162 28.4 952
737 588 7,805
277 40 2,160
368 120 2,855
318 232 3,214
188 16 1,585
538 264 1,182
1,834 1,367 18,801
to
NJ
cn
1,000 Ibx 0.45 - 1,000 kg
bl ,000 ft3 x 0.0283 • 1,000 m3
-------
TABLE E-6C. POWER, CHEMICALS, AND LABOR, 1970
Parameter
Power and Chemicals
Chlorine, 1,000 Ib"
Electric power, 1,000 kwh
Natural gas, 1,000 ft3 b
Labor. Manhours
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Teb Mar Apr May June fuly Aug Sept Oct Nov Dec
27.0 23,3 26.2 23.2 23.7 24,1 23.9 20.1 24.7 28.9 25.3 24.9
242 220 249 233 232 228 238 240 209 208 204 270
59.1 35.0 45.9 87.2 81.5 16.1 17.0 33.8 20.0 90.0 7.3 7.9
713 648 707 692 699 730 735 739 730 749 728 735
138 170 224 242 191 344 622 426 193 54 139 180
267 344 236 208 319 331 315 229 177 198 101 75
343 260 299 282 284 284 270 229 262 270 231 258
94 101 164 173 150 176 213 322 168 174 72 109
1,555 1,523 1,630 1,597 1,643 1,865 2,155 1,945 1,530 1,445 1,271 1,357
High Low Total
28.9 20,1 295
270 204 2,770
90.0 7.3 501
749 648 8,605
622 54 2,923
344 75 2,800
343 229 3,272
322 72 1,916
2,155 1,271 19,516
to
to
1,000 Ibx 0.45 • 1,000 kg
bl,000 ft3 x 0.0283 * 1,000 m3
-------
TABLE E-6D. POWER, CHEMICALS, AND LABOR, 1971
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power, 1 ,000 kwh
Natural aas, 1,000 ft3 b
Labor. Manhours
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Feb Mar Apr May Tune luly Aug
35.1 32.2 22.3 25.6 32.5 33.4 36.0 34.5
211 193 199 214 209 212 227 230
8.1 7.3 8.4 6,6 3.9 3.4 3.7 12.6
736 677 783 720 744 720 744 744
257 214 - 182 202 229 290 138
290 172 - 283 195 196 244 186
250 234 - 252 Z41 246 263 217
121 147 132 165 152 120 192 162
1,654 1,444 - 1,602 1,534 1,511 1,733 1,447
Sept Oct Nov Dec
29.0 32.9 37.7 39.1
230 234 230 230
13.3 14.1 13.4 13.9
720 744 744 744
369 135 193 144
162 183 248 252
239 240 237 251
142 144 71 52
1,632 1,446 1.493 1,443
High Low Total
39.1 22.3 390
234 193 2,620
14.1 3.4 109
783 677 8,820
369 135 2,567C
290 162 2,630C
263 217 2,913C
192 52 1,600
1,733 1,439 18,530C
DO
to
00
1 ,000 lb x 0.45 = 1 ,000 kg
bl,000 ft3 x 0,0283 = 1,000 m3
Adjusted for a 12-month period
-------
TABLE E-6E. POWER, CHEMICALS, AND LABOR, 1972
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power, 1 ,000 kwh
Natural gas, 1 ,000 ft3b
Labor. Manhoyrs
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec
36.7 35.8 39.2 38.6 42.4 34.5 35.0 33.7 33.1 40.2 43.0 47.0
225 243 250 241 252 247 251 248 250 263 282 293
14.0 12.9 14.5 13.2 14.7 13.1 13.0 12.9 12.5 104 14.6 14.5
744 672 844 720 744 720 744 794 730 744 790 816
189 240 164 160 168 336 504 312 195 97 242 141
176 194 244 344 201 244 205 272 154 176 222 263
188 239 288 274 250 202 152 140 156 247 176 258
59 152 178 162 167 195 188 154 158 157 152 40
1,356 1,497 1,718 1,660 1,530 1,697 1,793 1,672 1,393 1,421 1,582 1,518
High Low Total
47.0 33.1 469
293 225 3,040
104 12.5 254
844 672 9,062
504 97 2,748
344 176 2,695
288 140 2,570
195 40 1,762
1,793 1,356 18,837
to
CNO
CO
1,000 Ibx 0.45 = 1,000 kg
1 ,000 ft3 x 0.0283 = 1 ,000 m3
-------
TABLE E-6F. POWER, CHEMICALS, AND LABOR, 1973
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power, 1 ,000 Icwh
Natural 9a«, 1,000 ft3 b
Labor, M,anhours
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Feb Mar Apr May June July
41,3 36.3 45.5 42.8 41.7 31.7 33,9
294 262 289 27B 281 272 289
14.3 68.6 14.0 12.7 13.4 13.3 13.5
819 732 840 706 824 710 814
199 156 240 168 140 387 504
262 170 210 246 258 247 263
259 228 247 209 269 243 247
89 63 128 160 157 216 144
1,628 1.349 1,665 1,489 1,648 1,803 1,972
Aug
34.2
291
13.3
809
315
266
232
264
1,886
Sept Oct Nov Dec
39.9 42.0 40.3 41.9
266 274 272 285
12.7 14.2 13.8 1S.O
690 728 664 314
151 276 299 162
292 260 248 241
242 259 243 217
82 65 113 63
1,457 1,588 1,567 1,497
High Low Total
45.5 31.7 472
294 262 3,350
68.6 12.7 219
840 664 9,150
504 140 2,997
292 170 2,963
269 209 2,895
264 63 1.544
1,972 1,349 19,549
ro
CO
o
1,000 Ib x 0.45 - 1,000 kg
bl,000 ft3 x 0.0283 - 1,000 m3
-------
TABLE E-6G. POWER, CHEMICALS, AND LABOR, 1974
Parameter
Power and Chemicals
Chlorine, 1,000 lba
Electric power, 1,000 kwh
Natural gas, 1,000 ft3 b
Labor, Manhours
Operation
Routine maintenance
Repair
Laboratory and monitoring
Yard
Total
Month
Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec
40.0 34.1 42.4 49.0 50.7 54.1 51.6 43.8 45.8 48.7 43.7
272 195 280 266 262 252 267 268 274 277 267
15.1 13.8 15.1 14.3 14.2 15.1 15.1 14.9 14.4 14.9 14.4
729 648 731 714 738 701 822 720 744 743 698
179 206 208 268 275 399 505 453 266 390 329
288 252 361 313 312 316 306 341 310 334 272
271 208 266 255 246 219 263 271 230 287 238
96 80 80 173 176 160 160 187 160 160 64
1,563 1,394 1,646 1,723 1,747 1,795 2,057 1,972 1,740 1,914 1,601
High Low Total
54.1 34.1 549
280 195 3,141
15.1 13.8 176
822 648 8,714°
506 179 3,795°
361 252 3,714C
287 208 3,004°
187 80 1,632°
2,057 1,394 20,859°
ISJ
CO
al,000 Ibx 0.45 = 1,000 kg
bl ,000 ft3 x 0.0283 - 1 ,000 m3
Adjusted for a 12-morrth period
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TABLE E-7A. FINAL EFFLUENT HEAVY METALS, 1968
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration, mg/1
Mar
<0.01
<0.1
<0.01
<0.003
<0.001
<0.03
0.006
0.013
June Sept Dec
<0.01
<0.1
<0.01
<0.005
0.017
<0.03
<0.001
<0.02
Avg.
<0.01
<0.1
<0.01
<0.004
0.0014
<0.03
0.0035
0.016
6-mo composites used in 1968-71
TABLE E-7B. FINAL EFFLUENT HEAVY METALS, 1969
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration, mg/1
Mar
0.001
0.1
0.004
0.030
0.012
0.03
0.008
0.01
June Sept Dec
0.001
0.3
0.003
0.010
0.004
0.04
0.003
0.05
Avg.
0.001
0.20
0.0015
0.015
0.008
0.035
0.0055
0.030
6-mo composites used in 1968-71
232
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TABLE E-7C. FINAL EFFLUENT HEAVY METALS, 1970
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration, mg/la
Mar
0.002
<0.05
<0.01
<0.01
0.019
0.013
<0.001
<0.01
June Sept Dec
0.001
<0.05
<0.01
<0.01
0.016
<0.01
0.001
<0.05
Avg.
0.0015
<0.05
<0.01
<0.01
0.018
0.07
<0.001
<0.03
6-mo composites used in 1968-71
TABLE E-7D. FINAL EFFLUENT HEAVY METALS, 1971
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration, mg/la
Mar
0.0013
<0.05
<0.01
<0.01
0.07
0.13
0.0015
0.01
June Sept Dec
0.001
<0.1
0.002
<0.01
0.017
0.01
0.003
<0.02
Avg.
0.0012
<0.1
<0.01
<0.01
0.044
0.06
0.0023
0.01
'6-rno composites used in 1968-71
233
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TABLE E-7E. FINAL EFFLUENT HEAVY METALS, 1972
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration,
Mar
<0.001
<0.001
<0.001
<0.01
0.025
0.025
0.001
<0.02
June
0.003
<0.1
<0.1
<0.01
0.009
0.011
0.006
0.01
Sept
0.001
<0.1
0.005
0.005
0.030
0.097
0.002
<0.01
mg/la
Dec
0.003
<0.1
0.005
0.005
0.024
0.037
<0.001
<0.002
Avg.
0.002
<0.075
0.008
0.008
0.022
0.043
0.003
0.011
3-mo composites used in 1972-74
TABLE E-7F. FINAL EFFLUENT HEAVY METALS, 1973
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration,
Mar
0.001
<0.1
0.001
0.001
0.038
0.030
0.014
0.005
June
0.002
<0.1
0.002
0.002
0.074
0.015
0.004
0.007
Sept
0.001
<0.1
0.002
0.001
0.050
0.030
< 0.001
0.005
mg/1
Dec
0.002
<0.1
0.001
0.004
0.055
0.014
0.004
0.002
Avg.
0.001
<0.1
0.001
0.002
0.054
0.022
0.005
0.004
3-mo composites used in 1972-74
234
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TABLE E-7G. FINAL EFFLUENT HEAVY METALS, 1974
Constituent
Arsenic
Barium
Cadmium
Hexavalent Cr
Cyanide
Lead
Selenium
Silver
Concentration,
Mar
0.002
<0.1
0.002
0.004
0.097
0.012
0.003
0.007
June
0.002
<0.1
0.002
0.004
0.070
0.010
0.001
0.005
Sept
<0.001
<0.1
0.001
0.015
0.029
0.003
<0.001
0.004
mg/1
Dec
0.004
<0.1
<0.001
0.004
0.003
0.004
<0.001
0.004
Avg.
0.002
<0.1
0.001
0.006
0.049
0.007
0.001
0.005
3-mo composites used in 1972-74
235
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-78-116
3. RECIPIENT'S ACCESSION>NO.
4. TITLE AND SUBTITLE
THE COUPLED TRICKLING FILTER-ACTIVATED SLUDGE PROCESS:
DESIGN AND PERFORMANCE
5. REPORT DATE
July 1978 (Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S) Richard J. Stenquist
Denny S. Parker
William E. Loftin
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Brown and Caldwell, Consulting Engineers
1501 North Broadway
Walnut Creek, California 94596
1O. PROGRAM ELEMENT NO.
1BC611 SOS#3, Task D-l/24
11. CONTRACTJQBSHMT NO.
68-03-2175
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Protection Agency—Cin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final, 1968-1974
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES
Project Officer: Richard C. Brenner 513/684-7657
16. ABSTRACT
A case history report was prepared on the upgrading of the Livermore, California,
Water Reclamation Plant from a conventional trickling filter plant with tertiary
oxidation ponds to a coupled trickling filter-activated sludge plant producing a nitri-
fied effluent low in 6005, suspended solids, and coliform organisms.
The report covers planning, design, construction, startup, and operation and per-
formance of the upgraded Livermore plant. Capital costs and operation and maintenance
expenses are also given. Data and information from Livermore were used in conjunction
with data from other coupled trickling filter-activated sludge plants to develop gen-
eral design considerations for carrying out similar upgradings elsewhere.
Over 7 yr of records from Livermore show that the coupled trickling filter-acti-
vated sludge process is extremely stable and reliable. Effluent BODs and suspended
solids concentrations of 10 to 20 mg/1 can be obtained, along with ammonia nitrogen
concentrations less than 1 mg/1. Monthly median total coliform concentrations of 2.1
MPN/100 ml were consistently achieved at Livermore using high chlorine dosages and a
chlorine contact tank with good hydraulic characteristics.
The coupled trickling filter-activated sludge process is particularly adaptable
to existing conventional trickling filter plants where stringent, new discharge
requirements have been imposed and where existing structures and equipment are in good
condition and can be used in an upgraded facility.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Sewage treatment, *Activated sludge
process, *Trickling filtration,
*Nitrification, Chlorination,
Upgrading
*Two-stage biological
treatment, Coupled trick-
ling filter—activated
sludge process
13B
13. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
250
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
236
ftU.S. GOVERSMOr PKWTIire OFFICE: 1978— 757-140/1443
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