United States
Environmental Protection
Agency
Municipal Environmental Research
Laboratory
Cincinnati OH 45268
Research and Development
Evaluation of
Operation and
Maintenance
Factors Limiting
Municipal
Wastewater
Treatment Plant
Performance
EPA 600 2-79-034
June 1979
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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-600/2-79-034
June 1979
EVALUATION OF OPERATION AND MAINTENANCE
FACTORS LIMITING MUNICIPAL
WASTEWATER TREATMENT PLANT PERFORMANCE
by
Bob A. Hegg
Kerwin L. Rakness
James R. Schultz
M & I, Inc., Consulting Engineers
Fort Collins, Colorado 80525
Contract No. 68-03-2224
Project Officers
John M. Smith
Benjamin W. Lykins
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.
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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 program.
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 publication is one of the products of
that research; a most vital communications link between the researcher and the
user community.
In this report documentation from comprehensive biological treatment plant
evaluations establishes cause and effect relationships for poor plant perform-
ance and the top ten factors causing poor performance are identified. A proce-
dure, called a Composite Correction Program, was developed and implemented to
improve plant performance. Unlike existing programs, the CCP approach
identifies all factors limiting plant performance at individual facilities and
solutions to all the problems are implemented. Results show that many plants
formerly not in compliance are performing to meet their design standards and
permit requirements without the need for major construction.
Francis T. Mayo, Director
Municipal Environmental Research
Laboratory
iii
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EXECUTIVE SUMMARY
A significant number of wastewater treatment plants constructed with
federal monies have not met design or NPDES permit standards. The emphasis
of this research study was to identify, quantify and rank the causes of this
poor performance. Research objectives were accomplished by conducting compre-
hensive evaluations at selected wastewater treatment facilities. Selected
facilities were initially screened by regional EPA and state pollution control
agency personnel. Research team members further screened facilities during
half-day site visits. Many of the plants chosen for evaluation were operable
facilities which were often violating permit standards.
Comprehensive evaluations were conducted at thirty wastewater treatment
facilities in seven western states. The in-plant research evaluation typi-
cally lasted one week. Sanitary engineers with strong operational backgrounds
collected the research information. To obtain accurate and complete informa-
tion, technical assistance in plant operation was provided to develop a coopera-
tive atmosphere that allowed for a meaningful exchange of information between
plant personnel and research team members.
Factors limiting plant performance were evaluated in four major areas:
operation, design, maintenance and administration. Operations factors were
evaluated by observing and discussing current process control procedures and
by conducting additional testing to determine process conditions that existed
during the comprehensive evaluations. Design factors were evaluated by re-
lating conventional design parameters to existing loading conditions and by
attempting various process adjustments which allowed theoretical design capa-
bilities to be evaluated relative to actual operating abilities. Maintenance
scheduling and recording documents, emergency procedures and the condition of
the plant grounds, buildings and equipment were assessed to determine if
iv
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maintenance related factors were affecting plant performance. Administration
factors were evaluated at the plant site and by interviewing officials other
than in-plant personnel, so that plant operators' opinions did not dominate
the research team's assessment of administrative problems.
For each comprehensive evaluation severity factors potentially limiting
plant performance were quantified in a weighing table which was developed for
use in this research project. Results were combined to form an overall rank-
ing of factors. Also, the leading cause of poor performance at each facility
was documented. The highest ranking factor contributing to poor plant perform-
ance was improper operator application of concepts and testing to process con-
trol. The second highest ranking factor was inadequate sewage treatment
understanding. These two factors were differentiated in meaning in that sewage
treatment understanding was rated when operators had a general lack of know-
ledge concerning sewage treatment. The operator application of concepts fac-
tor was rated when operators had a general knowledge about sewage treatment,
but were not correctly applying appropriate principles to process control.
The implications of these findings are far reaching in that to improve sewage
treatment understanding additional training is necessary. However, trained
operators were not usually able to apply basic sewage treatment concepts to
their individual situations. To overcome this deficiency, dramatic changes
are necessary in the approach to operator training.
Because of the high ranking of performance limiting factors related to
the plant operator, a special study was completed to evaluate operator capa-
bilities. A major finding was that in nearly all facilities surveyed ex-
isting personnel had adequate aptitude to be taught how to achieve better
plant performance. It was also determined that staff salaries and available
staff size did not significantly correlate with good or poor plant perform-
ance for the facilities evaluated. It was concluded that the potential capa-
bilities of present plant personnel are an untapped resource for achieving im-
proved plant performance, but existing efforts to develop this resource are
not sufficient.
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The potential for developing the presently undeveloped capabilities of
existing operators was complicated in light of the third highest ranking per-
formance limiting factor, improper technical guidance. Improper technical
guidance was documented from authoritative sources including design engineers,
state and federal regulatory personnel, operator training program staff, other
plant operators and equipment suppliers. These findings indicate that ex-
ternal sources have dramatically affected the capability of existing opera-
tions personnel to first attain adequate sewage treatment understanding, and
secondly to apply this understanding to process control. It was concluded
that the source of the first two high ranking factors which are plant operator
oriented was not necessarily with the operators themselves, but with the
technical guidance sources that provided training and assistance functions.
The conclusion that the source of most of the present performance problem
is not the plant operations staff was further supported by the fact that the
fifth through the tenth highest ranking factors limiting plant performance are
process design oriented. These factors in order of severity are: sludge
wasting capability, process flexibility, process controllability, secondary
clarifier, sludge treatment and aerator capability. The inability of persons
involved with plant design to apply the technology necessary to develop ade-
quate treatment facilities, coupled with the improper technical guidance from
^
these sources, indicated that a problem exists in an area that has typically
been assumed to be sound. The capabilities of the authoritative sources that
influence faci-lity design and operation must be improved.
Some of the factors identified as limiting plant performance are ad-
dressed by on-going programs. These programs were not evaluated per se, but
selected programs were discussed with respect to observations noted during
the research project. Programs developed to address administrative factors
include the NPDES permit and associated permit enforcement programs, which
potentially influence plant performance by motivating administrative person-
nel. Efforts to achieve permit compliance often led to a major facility up-
grade, and in several facilities poor effluent quality continued even after
the upgrade was completed. The original factors limiting performance were not
addressed, and at some plants a major facility modification was not warranted.
vi
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A more thorough investigation into the existing facilities' capabilities
through improved 0 & M was warranted. To this end, permit enforcement pro-
grams should encourage optimization of existing plant capability before a
major modification is initiated.
Some of the current programs developed to address design factors include
the construction grant, technology transfer, federal and state design criteria
and value engineering programs. The federally funded construction grant pro-
gram encouraged a number of engineers and equipment suppliers to enter the
wastewater treatment plant field. Federal and state design criteria and tech-
nology transfer programs provided these persons with basic information to de-
sign facilities. However, many designs were completed and equipment developed
using the basic information available, but without a thorough understanding of
wastewater treatment process operation and interrelationships. The result was
a large number of marginally designed facilities and equipment and associated
poor performance. Design criteria and technology transfer programs sliould not
be solely blamed for these inadequacies because they were not intended to pro-
vide a total basis for well designed plants. The programs continue to be im-
portant, but should be re-evaluated and restructured to emphasize the identi-
fied high ranking factors which limit performance. The value engineering pro-
gram, because of its minimum cost approach, has the potential of disallowing
some plant features that can contribute to optimum performance. For example,
plant flexibility and plant controllability features, whose absence was noted
repeatedly, may be considered as non-essential and subsequently eliminated
from plant designs as cost saving measures. All value engineering analyses
should be conducted with appropriate appreciation for plant operation so that
design features that potentially aid in operations control are not excluded,
but are included if not present.
Programs developed to address operation and maintenance factors include
operator training, operation certification and plant start-up assistance. Op-
erator training and certification programs were observed to address the
second highest ranking performance limiting factor, sewage treatment under-
standing. However, many operators with a good general sewage treatment under-
standing did not correctly apply even basic concepts of operation to process
vii
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control at their individual wastewater treatment facilities. To significantly
improve plant process control and plant performance, operator skills must be
developed through technical guidance at individual facilities under the direc-
tion of qualified personnel. To this end the plant start-up assistance pro-
gram has much.potential to improve plant operation, but because of the large
amount of improper technical guidance that was noted training of start-up as-
sistance personnel is warranted. The plant start-up assistance program pro-
vides a good opportunity for this self-education.
Optimum performance of a facility occurs when all factors limiting per-
formance are eliminated or substantially reduced. The interrelationship be-
tween the many performance limiting factors and the programs designed to ad-
dress these factors was described in a concept called a Unified Concept for
Achieving Optimum Plant Performance. Two broad types of correction programs
were described, Individual Correction Programs and Composite Correction Pro-
grams.
Individual Corrections Programs described a program that was implemented
to eliminate a specific factor or group of factors at all or at a large number
of facilities. Typically, Individual Correction Programs address only a por-
tion of the many performance limiting factors that occur at an individual
facility. Most existing correction programs, like operator training, technol-
ogy, ^transfer and design criteria are Individual Correction Programs. These
programs should,not be abandoned because of the magnitude of factors limiting
performance, but should be recognized as limited in their ability to achieve
optimum facility performance.
Composite Correction Program described a program that addresses all fac-
tors limiting performance at a given facility. During the research project a
Composite Correction Program was implemented at the Havre, Montana Wastewater
Treatment Facility. A dramatic improvement in effluent quality resulted, and
permit requirements that were previously violated were subsequently met. A
long period of time (12 months) was required to optimize system performance
and to.transfer the capability to maintain optimum performance to the Havre
plant superintendent. It was concluded that effective recommendations to
viii
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optimize biological system performance in most cases should not be made when
the involvement in plant operation is over a short period of time like an
hour, a day, a week or maybe even a month. Several months are required to
properly evaluate biological system response and achieve optimum performance.
This time delay for effective recommendations was considered a major reason
for the prevalence of improper technical guidance, because authoritative
sources are not usually in a position to be held accountable for their opera-
tions recommendations.
The Havre plant superintendent was trained and certified, and was consid-
ered to be an above-average operator. However, proper concepts of sewage treat-
ment were not being applied to his facility's process control. The time in-
volved and the approach used to develop his skills illustrated the need for
drastically altering present operator training procedures. An operator's
skills to correctly apply concepts of sewage treatment to process control
should be developed through technical guidance at his individual facility under
the direction of qualified personnel.
If a Composite Correction Program were completed at all thirty facilities
evaluated, the estimated BOD and TSS reduction was 1350 kg/day (3000 Ib/day),
which represents a 65 percent improvement in the present discharge. Without a
major facility upgrade an additional sixteen facilities would meet federally
defined minimum secondary treatment standards now frequently violated. How-
ever, limitations to implementation of the Composite Correction Program ap-
proach to improving facility performance exist. There is a lack of qualified
personnel to implement programs on a broad scale. Also, present incentives
are not satisfactory to encourage the program's widespread implementation. To
implement Composite Correction Programs, specialized training approaches to
attain qualified personnel should be developed. Training must include in-plant
operations experience at various wastewater treatment facilities over a long
period of time. Conducting a Composite Correction Program and/or observing
its conduct is an excellent training function. The federal construction grant
plant start-up assistance program could also provide a basis for attaining
qualified personnel, if the program is approached as a training function for
both plant and start-up assistance personnel.
ix
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Incentives to encourage Composite Correction Programs are required. A
possible incentive is more aggressive enforcement of NPDES permit requirements
with respect to existing plants' operations capabilities. Another incentive
is to develop a financial assistance program for existing facilities. However,
financial assistance programs must be developed to provide an impetus for im-
plementing Composite Correction Programs and not as a reward to facilities
that currently are not achieving satisfactory performance. Encouraging Com-
posite Correction Programs will not result in immediate optimum performance at
all facilities. However, the soundness of the program has been demonstrated
and the program's development can eventually result in widespread optimum
facility performance.
This report was submitted in partial fulfillment of Contract No. 68-03-
2224 by M & I, Inc., Consulting Engineers, Fort Collins, Colorado, under the
sponsorship of the Environmental Protection Agency. Work described in this
report was accomplished during the period from June, 1975 to December, 1977.
x
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CONTENTS
Disclaimer „ ii
Foreword ill
Executive Summary iv
Figures xiii
Tables xiv
Acknowledgment xv
1. Introduction 1
2. Purpose and Scope 3
3. Conclusions 5
4. Recommendations ..... 15
5. Research Approach 19
General Screening . 19
Preliminary Screening 19
Site Visit Screening .................. 20
Preliminary Surveys - General Discussion 21
Preliminary Surveys - Example Survey . . 29
6. Evaluation of Causes of Limited Plant Performance 34
General ..... 34
Evaluation of Site Visits 36
Evaluation of Preliminary Surveys . . 38
Miscellaneous Evaluations . 54
7. Wastewater Plant Staffing and Plant Performance . 61
General .......... 61
Plant Staffing Relationships and Plant Performance ... 61
Evaluation of Staff Size and Cost Versus
Plant Performance ... ........... 65
Evaluation of Staff Adequacy and Plant Performance ... 70
8. Evaluation of Existing Programs in Relation to Factors
Limiting Performance 82
9. Methods of Achieving Optimum Plant Performance ....... 89
Unified Concept For Achieving Optimum Plant
Performance . .......... . 89
Individual Correction Programs . . ..... 90
Composite Correction Program ....... . . 93
References ...... ................... 102
XI
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Appendices
A. List of Site Visit Only and Site Visit Plus Preliminary
Survey Facilities 103
B. Example Preliminary Survey Information Sheets 104
C. List of Design Inadequacies Observed During the
Research Study 113
D. Plant Evaluation Summary Weighing and Ranking Table
and Definition of Terms 123
E. Individual Plant Evaluation Summary (Ranking Table) Results
for Thirty-Three Plant Site Visits 129
F. Individual Plant Evalution Summary (Ranking Table) Results
for Thirty Preliminary Surveys 139
G. Cost Information for Various Types and Sizes of
Facilities Surveyed 148
xii
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FIGURES
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Plant selection procedure used for the research project . .
Recorded effluent TSS concentrations for Plant 050
Mass of activated sludge wasted at Plant 050
Adjusted effluent TSS concentrations for Plant 050
Types of factors limiting performance in suspended
growth and fixed film facilities
Average treatment costs for facilities surveyed
Plant operations costs for selected flow ranges
Staff size versus plant flow rate
Total salary cost versus plant flow rate
Specific staff size versus plant flow rate
Specific staff cost versus plant flow rate
Staff salary versus plant flow rate
Staff cost versus plant flow rate
Unified Concept for Achieving Optimum Plant Performance . .
Individual Correction Programs and the Unified Concept. . .
Composite Correction Programs and the Unified Concept . . .
Plant flow schematic for the Havre, Montana wastewater
'Final effluent BOD at Havre. Montana
Page
3
20
30
31
32
55
56
58
66
66
67
6ft
69
70
90
91
93
QA
96
Xlll
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TABLES
Number Page
1 Point System for Plant Evaluation Summary Weighing Table ... 35
2 Ranking of Factors Limiting Performance of Thirty-Three
Site Visit Facilities 37
3 Ranking of Factors Limiting Performance of Thirty
Preliminary Survey Facilities 40
4 Summary of Cost Information for Type and Size of Facility
Surveyed 57
5 Electrical Consumption and Costs at Facilities Surveyed. ... 59
6 Summary of Staff Size and Cost for Thirty Facilities
Surveyed 62
7 Summary of Plant Performance for Thirty Facilities
Surveyed 64
8 Manpower Adequacy for Thirty Facilities Surveyed 71
9 Manpower Adequacy for Selected Flow Ranges 72
10 Summary of Operator Time Conducting "Operations", "Mainte-
nance" and "Other" Tasks for Two Facilities Surveyed .... 73
11 Current Operations Capabilities of Existing Personnel at
Thirty Facilities Surveyed 75
12 Summary of Current Operations Capabilities for Selected
Flow Ranges 76
13 Potential Operations Capability of Existing Personnel
at Thirty Facilities Surveyed 78
14 Summary of Potential Staff Operations Capability and Staff
Salary for Selected Flow Ranges 79
15 Performance of Thirty Facilities Evaluated Versus Secondary
Treatment Standards 98
xiv
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ACKNOWLEDGEMENT
The project was conducted by M & I, Inc., Consulting Engineers. The
authors were aided by the following personnel:
Wayne C. Irelan, President
Gerald J. Ott, Engineer
Susan R. Martin, Lab Technician
Appreciation is expressed to all managers, operators and other person-
nel of the various wastewater treatment facilities who participated in the re-
search effort. Appreciation is also expressed to all state and EPA regulatory
agency personnel who developed the various lists of facilities as research
candidates, and who actively participated in various phases of the research
program. Appreciation is specifically expressed to Mr. Bruce Carlson, Super-
intendent, City of Havre, Montana Wastewater Treatment Facility for his assist-
ance in completing the Composite Correction Program accomplished as part of
this research effort.
The direction provided and assistance given by Mr. John Smith, Mr. Ben
Lykins and Mr. John Sheehy, of the Environmental Protection Agency, Office of
Research and Development, Cincinnati, Ohio, are greatly appreciated.
xv
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SECTION 1
INTRODUCTION
The Federal Water Pollution Control Act Amendments of 1972 (PL 92-500)
along with the 1977 amendments (PL 95-217) established goals for the water
quality of the nation's public waters and programs through which' these goals
were to be achieved. As part of the overall program a minimum degree of treat-
ment, "secondary treatment," was established for the 25,000 existing and also
for any future publicly owned treatment works (POTW). Where secondary treat-
ment is insufficient to protect the receiving stream, provisions were made
in the 1972 Act to require more stringent treatment requirements.
The 1972 Act also established an expanded federal construction grants pro-
gram through which the construction of new POTW's or upgrading of existing
POTW's was to be completed to meet the new water quality goals. However, both
the 1973 and 1974 editions of the U.S. Environmental Protection Agency's (EPA)
Clean Water Report to Congress showed that about one-third of all treatment
facilities constructed with federal grant assistance were not meeting design
effluent quality. In response to these findings, the EPA's Office of Research
and Development initiated a three and one-half year research program, the
first phase of which was titled, "Demonstrated Improved Performance and Re-
liability of Selected Biological Treatment Plants." Two 24-month contracts
were awarded simultaneously to private engineering consultants to initiate
the research effort (Phase I), one in the Eastern United States and one in the
Western United States. A second phase follow-up effort also conducted by
private consultants has now been initiated to continue the Phase I investiga-
tion and conduct special studies into areas which warrant further investiga-
tion.
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This report documents the findings of the contractor for the Western
U.S. based on the first 24-month (Phase I) research period. A companion re-
port has been prepared by the Eastern U.S. Contractor. (1) The primary ob-
jective of the research study as described in the EPA Request for Proposal was
to demonstrate improved performance in selected biological treatment facili-
ties through improved 0 & M practices. Under this original objective thirty
to forty plants were to be selected as the subjects of "preliminary studies"
in which factors limiting plant performance were to be identified. Recom-
mendations to eliminate these factors were to be made in technical reports
developed for each facility. Finally, demonstration projects were to be con-
ducted at several selected facilities to document improved performance achieved
through implementation of the recommendations for improved 0 & M practices.
The objective of demonstrating improved performance was later modified
by the EPA because of an increasing need to continue identifying and docu-
menting the most frequently occurring factors which limit plant performance.
Identified factors were quantified and ranked in order of frequency and
severity. This modified objective was accomplished by conducting comprehensive
evaluations of operating wastewater treatment facilities instead of the
formally planned preliminary studies and demonstration projects. In addition,
the causes of the most frequently occurring factors limiting performance and
an evaluation of programs through which these causes could be eliminated was
completed by conducting three special studies. The purpose of conducting
special studies was to analyze specific performance limiting factors or groups
of factors that related to a number of facilities and not necessarily to
"demonstrate improved performance" at a particular facility.
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SECTION 2
PURPOSE AND SCOPE
The purpose of this research project was to identify, quantify and rank
the major factors which limit biological wastewater treatment plant perform-
ance. Comprehensive evaluations were conducted at selected wastewater treat-
ment facilities. When selecting plants, special emphasis was placed on "opera-
ble" facilities where 0 & M practices could be evaluated. The selection pro-
cedure included screening of facilities by the regional EPA offices, state
pollution control agencies and research team personnel.
The scope of the project included research activities in Colorado,
Wyoming, Montana, Utah, South Dakota, Nebraska and Iowa. The research area
is shown in Figure 1. These states are located in EPA's Regions VII and VIII.
Figure 1. Study area of the Western U.S. contractor.
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The regional EPA offices and state pollution control agencies screened treat-
ment facilities within their jurisdiction and suggested a total of 163 facili-
ties as candidates for research. Research team members further screened candi-
date plants and rejected 100 facilities. One-half day plant site visits were
eventually conducted at 63 facilities to make a final selection of 30 facili-
ties for which comprehensive evaluations (called preliminary surveys) were
conducted. The plant selection procedure and criteria are described further
in the Research Approach section of this report.
The term preliminary survey may be confusing in that it suggests some
further study would follow. This was the original intent until the objective
of demonstrating improved performance was modified. The preliminary survey
was the major mechanism through which factors limiting plant performance were
identified, quantified and ranked, and represents the final in-plant research
effort expended at most facilities. Three special studies were also completed
on selected subjects. Individual reports were developed for each site visit,
preliminary survey and special study. The results of one special study, the
site visits and the preliminary surveys are compiled in this report. The re-
sults' of the other two special studies are compiled in a separate report, "A
Demonstrated Approach For Improving Performance and Reliability of Biological
Wastewater Treatment Plants." (2)
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SECTION 3
CONCLUSIONS
1. A plant selection process was necessary to find operable facilities with
cooperative personnel for thirty comprehensive plant evaluations.
2. At some facilities a decision was made by local officials to not partici-
pate in the research effort because possible improvement in existing plant
performance may have lowered the community's position on the State's grant
funding priority list. Present construction grant awarding procedures en-
courage poor performance of existing facilities.
3. The site visit aspect of the plant selection process allowed an evaluation
of obvious performance limiting factors to be made.
A. Excessive I/I was the most frequently observed problem during site
visits. Plants with excessive I/I were excluded from further research
due to the excessive hydraulic overload associated with this problem.
B. Where obvious performance limiting factors were noted, arrangements
were usually in progress to correct the problem(s) because existing
corrective programs (i.e., construction grant funding, state and fed-
eral regulatory inspection, etc.) typically address these more obvious
problems.
4. A specialized research technique was used successfully to identify and
document the subtle as well as the obvious performance limiting factors at the
thirty plants selected for comprehensive evaluations.
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A. Design and administration problems as well as operation and mainte-
nance problems were found to limit performance of operating facilities.
B. Because a plant selection process was used, the results obtained during
the comprehensive evaluations excluded some of the obvious performance
limiting factors noted during the site visits.
5, An average of 15 and a range of four to thirty performance limiting factors
were documented at each of the thirty facilities evaluated. Measureable
improved performance may not result at a particular plant from the elimination
of one or even several factors limiting performance. All factors limiting
performance must be systematically identified and eliminated until the desired
performance is achieved.
6. The two highest ranking factors limiting performance at the thirty evalu-
ated facilities were inadequate operator application of concepts and testing
to process control and sewage treatment understanding. A special study on
wastewater treatment plant staffing was conducted because of this high ranking
of opefator related performance limiting factors.
A.' Total plant staff size, total plant staff cost, specific plant staff
size, specific plant staff cost and plant staff salary did not signi-
ficantly correlate with good or poor plant performance.
B. In nearly all facilities surveyed adequate manpower was provided for
proper plant operations and maintenance. Plant maintenance was sat-
isfactory, but plant operations was unsatisfactory even though a
greater proportion of the operator's time was spent conducting "opera-
tions" tasks.
C. Current operator practices for the smallest facilities surveyed, 0-38
cu m/day (0-0.1 mgd), were poor. For larger facilities surveyed,
380-3800 cu m/day (1.0-10.0 mgd), operator practices were only fair
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to marginal. Improper technical guidance from "authoritative" sources
played a large role in the currently inadequate operations procedures
that operators use at their facilities.
D. Potential operator capability for the largest to the smallest facili-
ties surveyed was good to fair, respectively, and was significantly
better than the current operator abilities. From this evaluation it
was concluded that the good operations potential of the existing plant
personnel is an undeveloped resource for achieving improved plant
performance.
E. Better potential operator capability correlated directly with a high-
er salary. However, a higher salary did not provide operators who
had developed their potential capability. This potential capability
was not developed because a large amount of improper technical guid-
ance is currently being disseminated.
7. A major plant performance problem at 17 of 30 plants was attributed to
technical, "authoritative" sources (i.e., design engineers, state and federal
regulatory personnel, equipment suppliers, etc.).
A. Incorrect operations advice was given by plant design engineers, even
at well-designed facilities.
B. In some instances incorrect operations advice was given by regulatory
personnel, but more often regulatory inspections caused operator pri-
orities to be shifted away from performance improving activities.
Regulatory personnel, in general, have not had adequate training in
process control and therefore tend to address side issues which do
not directly affect performance, such as good housekeeping and safety.
C. Operations recommendations which were correct for a particular situa-
tion were often incorrect at a later date because of changes in the
biological process. Operators were not told to make readjustments,
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or if they were told they did not make needed readjustments because a
logical basis for the recommended change(s) was not presented.
D. The authoritative sources that gave technical guidance were not ac-
countable for their improper and/or inaccurate recommendations, and
operators were often inappropriately blamed for the continuance of the
plant's poor performance.
E. Improper technical guidance not only caused poor performance to contin-
ue, but diverted a search for a legitimate solution to the problem.
8, Six of the ten highest ranking factors limiting treatment plant perform-
ance at the thirty facilities evaluated were attributed to inadequate plant
design, including insufficient sludge wasting capability, process flexibility,
process controllability, secondary clarification, sludge treatment and aerator
capability.
A. Six of the thirty evaluated facilities had no, or totally inadequate
sludge handling facilities.
B. At two facilities an immediate improvement in plant effluent quality
would have occurred with improved process flexibility.
C. Poor process controlability in the form of inadequate measurement and
control capability of return sludge flow limited plant performance at
17 of 20 activated sludge plants surveyed.
D. Poor clarifier surface area development limited performance at 11
plants surveyed.
E. Poor sludge treatment facilities limited sludge wasting capacity and/
or required excessive operator involvement at 15 of the plants sur-
veyed .
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F. Limited aeration capability was observed at eight of ten fixed film
facilities and at one of twenty suspended growth facilities surveyed.
9. Five plant performance limiting factors were not rated in the top ten fac-
tors but were the number one cause of limited performance at six facilities.
These factors were: unit process layout, administrative policies, return pro-
cess streams, equipment malfunction and industrial loading.
A. Totally independent activated sludge process units at one relatively
small facility (one plant operator) required a duplication of effort
by the operator to provide process control. Time limitations restrict-
ed the operator from accomplishing the needed tasks.
B. Administrative policies restricting trickling filter recirculation
rates tthus minimizing pumping costs) was the major cause of limited
performance at two plants.
C. Excessive solids in an anaerobic digester supernatant (20,000 to
30,000 mg/1) limited the performance of one of the trickling filter
facilities evaluated.
D. Aeration basin equipment malfunction was the major cause of poor per-
formance at one plant surveyed. At three other plants substandard
quality equipment was observed to contribute to a degraded effluent
quality.
E. Excessive industrial loading (extent not apparent and not determined
during the plant site visit to be greater than the plant design load)
was the leading cause of poor performance at one facility surveyed.
10. Better plant operation could have resulted in a 40 to 50 percent savings
of electrical power at some facilities surveyed, as well as allowed permit
standards to be met that were being violated.
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11. It was determined that twenty-three of thirty facilities surveyed did not
consistently meet federally defined minimum secondary treatment standards.
A. Self-monitoring records typically did not include excessive solids
loss during, sludge,bulking from activated sludge plants.
B. Federally funded plant modifications at 22 facilities surveyed did not
enable these facilities to meet NPDES permit standards because all the
factors limiting performance had not been properly addressed.
C. Federally funded plant modifications at two plants were not warranted.
The capability of these two facilities was not adequately assessed
with respect to improved operations practices before the major up-
grades were implemented.
D. A more thorough investigation into existing facility capability is
necessary prior to implementation of major plant modifications.
12. -Existing correction programs which have been developed to address a single
factor or group of factors limiting plant performance have been only partially
effective.
A. Required NPDES permit self-monitoring records that show poor plant
performance have not caused administrative officials to initiate cor-
rective actions.
B. Enforcement of NPDES Permit requirements has served to provide an in-
centive for administrative officials to initiate plant correction
action, but enforcement has been limited and sporatic. Corrective
actions observed always included construction of new or modified
facilities.
C. Information dissemination programs like technology transfer and fed-
eral and state design criteria have provided basic information re-
garding various unit processes, but have not resulted in the
10
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application of good engineering judgment and operations understanding
into facility design as evidenced by the high ranking of inadequate
design and improper technical guidance factors limiting performance.
D. Value engineering, because of the actual or implied cost savings ap-
proach, coupled with improper technical guidance, has the potential
of disallowing plant features that may be required to achieve optimum
or even satisfactory plant performance.
E. Federal, state and local operator training and associated state certi-
fication programs need to be expanded and improved to provide opera-
tors with a better sewage treatment understanding. However, even ex-
panded present training techniques cannot provide operators with an
ability to properly apply wastewater treatment concepts to process con-
trol at their individual facilities. To develop the ability to apply
concepts to process control, operators' skills have to be developed
through training at the operator's own facility under the direction of
qualified personnel.
F. Plant start-up assistance that is process oriented as well as equip-
ment oriented has the potential of improving plant performance. How-
ever, because of the large amount of improper technical guidance in
process control that was noted an immediate benefit of improved plant
performance through this program is unlikely. Training of start-up
assistance personnel in process control is warranted, and the first
benefit of the start-up assistance program is that it provides a good
opportunity for this self-education.
G. Plant specific 0 & M manuals generally included good maintenance in-
formation and a good description of the plant's flow schematic, flexi-
bility and controlability. 0 & M manuals alone cannot provide opera-
tors with the information and/or ability to properly apply concepts of
operation to process control.
11
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H. Few maintenance problems were noted at facilities surveyed for a
variety of reasons:
1. 0 & M manuals generally were maintenance oriented.
2. Plant inspections historically have judged good plant "perform-
ance" by the appearance and operational state of equipment.
3. Maintenance problems are highly specific and visible and easily
recognized by the operator and his supervisors.
13. Most existing correction programs, called Individual Correction Programs,
focus on specific areas of need representing a common problem at a large num-
ber of facilities. These programs are important in the overall effort to
achieve better plant performance, but should'be recognized as limited in their
ability to eliminate all or even a sufficient number of factors limiting per-
formance at individual facilities to allow them to meet design or permit ef-
fluent standards.
14. A Composite Correction Program established to focus on all factors limit-
ing performance at a given facility can achieve optimum performance at a
facility if properly implemented. This approach was implemented and docu-
mented at the Havre, Montana Wastewater Treatment Plant.
A. Violations of permit standards were eliminated.
B. Plant effluent BOD and TSS concentrations were reduced from 31 mg/1
to 10 mg/1 and 30 mg/1 to 9 mg/1, respectively.
15. The Havre Composite Correction Program was successful because of a long
time involvement with plant personnel.
A. Factors limiting performance were systematically identified and
eliminated.
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B. Twelve weeks were necessary to achieve desired changes In activated
sludge characteristics.
C. One year was required to transfer to the plant superintendent the
ability to make timely and accurate process control adjustments.
16. The time associated with stabilizing the biological system to achieve op-
timum performance and the time required to train the operator to correctly
apply concepts of operation to process control observed at the Havre facility
supported conclusions regarding two factors limiting performance that were
noted repeatedly during this research effort.
A. Recommendations to improve biological system performance are not ef-
fective when the involvement in plant operations is over a short time
period, like an hour, day, week or even a month. Depending on facili-
ty size and type, a longer time period of a few months to many months
is required.
B. Plant operators with a good education, training and aptitude require
guidance at their individual facilities over a relatively long period
of time to develop their capability to correctly apply concepts of
process control to varying operational situations.
17. A Composite Correction Program without major facility construction com-
pleted at each of the thirty evaluated facilities would improve plant efflu-
ent quality significantly.
A. Sixteen of twenty-three facilities would meet federally defined sec-
ondary treatment standards now violated. The other seven facilities
would require major facility modifications to meet secondary treat-
ment standards consistently.
B. The mass of BOD,, and TSS discharged would be reduced by an estimated
490 metric tons per year (540 tons/year) and 470 metric tons per year
(515 tons/year), respectively.
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C. The masses of BOD,, and TSS discharged would be reduced by an esti-
mated 38 percent and 37 percent, respectively.
18. Plant underloading did not promote good plant performance. Hydraulic
loading averaged only 61 percent of design, yet 23 of 30 plants did not meet
secondary treatment standards.
19. Broad scale implementation of Composite Correction Programs can achieve
optimum performance at a large number of facilities, but qualified personnel
and incentives to conduct programs are required.
A. Training to develop qualified personnel must include guided, in-plant
operations experience at various wastewater treatment plants over a
long period of time to develop capabilities for correct application
of concepts and to develop a respect for the time associated with
biological system response.
B. Incentives are required to encourage treatment plant administrators
to consider Composite Correction Programs. Enforcement actions can
be used to encourage Composite Correction Programs. However, en-
forcement coupled with the construction grant program has resulted
in the construction of new or modified facilities which have failed
to achieve desired effluent goals.
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SECTION 4
RECOMMENDATIONS
1. In conducting studies to determine the sources of plant performance prob-
lems, use a research approach which identifies the subtle as well as the ob-
vious factors which limit performance.
2. Modify existing operator training procedures and materials.
A. Develop operators' skills through technical guidance at their respec-
tive facilities under the direction of qualified personnel as an
extension to their classroom training experience.
B. Eliminate or correct inaccurate, incomplete and misleading training
information by using plant design and operation specialists to evalu-
ate classroom training programs and program materials.
3. Reduce improper technical guidance given by authoritative sources.
A. Improve training for private and governmental persons disseminating
operations technical assistance. Training must include guided in-
plant process control experience at various wastewater treatment
facilities to develop capabilities for proper application of waste-
water treatment concepts to process control and to develop an aware-
ness of the time associated with biological system response.
B. Increase the awareness of state and federal regulatory personnel of
the high priority that most operators place on recommendations they
make and of the misunderstanding operators have concerning process
control suggestions that are mentioned.
15
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C. Encourage training of plant design engineers in plant operations and
process control in formal classroom training and through guided in-
plant operations experience.
D. Encourage process equipment suppliers to emphasize and provide for
plant flexibility, controlability and operability instead of empha-
sizing and providing equipment under the guise of minimum 0 & M
requirements.
E. Select plant operators to teach short course training programs who
understand and properly apply concepts of wastewater treatment, and
not necessarily because they work at or are in charge of a plant that
has good effluent quality.
F. Hold persons who disseminate operations technical guidance accounta-
ble for their recommendations. As a minimum, follow-up phone calls
or plant visits should be used to determine if recommendations given
were correct and still apply.
4. Improve design of new or modified wastewater treatment facilities, es-
pecially for those high ranking design features observed during this research.
A. Include and emphasize the need for adequate sludge handling features
in smaller plants. Emphasize design, operation and management of
sludge handling facilities at larger plants.
B. Emphasize optimizing the surface area development of secondary clari-
fiers in all plant designs.
C. Implement more conservative design requirements for fixed film bio-
logical reactors.
D. Allow and encourage separate treatment of anaerobic digester super-
natant or require increased wastewater treatment process unit sizes
to adequately receive and treat this recycle flow.
16
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E. Encourage plant flexibility which would allow bypassing of ponds
following mechanical plants and flexibility to operate activated
sludge plants in various modes.
F. Emphasize good controllability of return activated sludge flows.
5. Recognize that existing federal and state programs are limited in their
capability to substantially improve plant performance at individual treatment
facilities.
6. Direct federal and state regulatory efforts toward areas of enforcemet
and accountability.
A. Expand enforcement of NPDES Permits to encourage optimum performance
from existing facilities.
B. Require that Composite Correction Programs (CCP's) be implemented
prior to or in conjunction with construction of new or modified facil-
ities to insure that the existing facilities capability is examined
and optimized before the upgrade, and the end result will be minimiza-
tion of the construction of un-needed facilities.
C. Evaluate incentives such as financial assistance and enforcement for
implementing CCP's at facilities which have recently been constructed
but do not achieve design and permit standards.
D. Structure information dissemination and training programs to empha-
size the highest ranking factors limiting plant performance.
E. Conduct value engineering analyses with appropriate appreciation for
plant operation so that design features like plant controllability and
plant flexibility that potentially aid in operation are not excluded
as cost savings measures, but are included if not present.
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F. Orient plant start-up assistance programs toward improving process
control. Allow adequate time at an individual facility for biologi-
cal response and training. Recognize that the program's initial
benefit is an aid for development of qualified personnel to conduct
future plant start-up activities and/or a Composite Correction Pro-
gram, which eventually will serve to achieve the desired benefit of
improved plant performance.
7- Plant administrators who concentrate only on obtaining a grant to help
construct a major plant modification should consider other alternatives for
improving the plant's performance.
A. Verify the performance potential of an existing plant by conducting
a Composite Correction Program, and if required include a major
plant modification as part of that program.
B. Include training and education as part of the plant operating budget.
1. Encourage classroom training and associated certification to ex-
pand the operator's sewage treatment understanding.
2. Recognize that on-site training such as provided in the conduct
of a Composite Correction Program is the most effective method
to develop an operator's capability to properly apply wastewater
treatment concepts to process control.
C. Attract personnel with better potential operations capability by of-
fering higher salaries and benefits.
D. Realize that once an operator is adequately trained, as through a
Composite Correction Program, that the training investment for that
operator must be protected by keeping him employed at the plant.
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SECTION 5
RESEARCH APPROACH
GENERAL SCREENING
Plants chosen for a preliminary survey were carefully selected. A random
sampling procedure was not used. The selection process consisted of general
screening, preliminary screening and site visit screening as shown in Figure 2.
General screening criteria were defined by the EPA and limited plant selection
to the Western U.S. (for this western area contract); biological processes;
0 - 37,850 cu in/day (0 - 10 mgd) design size; plants not severely hydrauli-
cally and/or organically overloaded; plants which had all major units in ser-
vice; and plants in which enforcement action was not pending. Facilities vio-
lating these criteria were rejected in the general screening phase of the plant
selection procedure.
PRELIMINARY SCREENING
Preliminary screening was conducted by regional EPA offices, state pol-
lution control agencies and research team personnel. Initially, EPA and state
personnel selected facilities as candidate plants using the general screening
criteria. In total, 163 candidate facilities were submitted to research team
members for further review. Team members screened facilities with respect to
plant type and hydraulic loading. The type of treatment process was important
in that a cross-section of facility types was desired. Plants with new and
less common processes were desired so their 0 & M requirements and performance
could be evaluated. Plant design flow and the current operating flow were
considered so that plants with a cross-section of flows within the general
criteria could be studied. It was desired to survey various plants of a
19
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GENERAL SCREENING
I ALL FACILITIES!
• WESTERN U.S. AREA
• BIOLOGICAL PLANTS
• 0-10 MGD SIZE
• FLOW < DESIGN
• ORGANIC LOADING < DESIGN
• NO ENFORCEMENT PENDING
PLANTS SELECTED
I 30 FACILITIES
"OPERABLE" FACILITIES
INTERESTED OPERATORS
PRELIMINARY SCREENING
1163 FACILITIES I
• REGIONAL EPA DESIRES
• STATE AGENCY DESIRES
• UNIQUE DESIGN INCLUDED
• TYPE OF FACILITY
• SIZE OF FACILITY
SITE VISIT SCREENING
I63 FACILITIES I
• LOCAL COOPERATION
• OPERATOR AVAILABILITY
• EXCESSIVE I/I
• MAJOR DESIGN DEFICIENCIES
• ALL UNITS IN SERVICE
PLANTS
REJECTED
MOOl
PLANTS
REJECTED
I33l
Figure 2. Plant selection procedure used for the research project.
similar type and size, so costs, major performance limiting factors and other
criteria could be compared. Based on these criteria, 63 facilities were
selected for on-site investigation.
SITE VISIT SCREENING
Site visit screening was completed by research team members. Typically,
a one-half day visit using two team members was conducted at each plant. The
research team leader was a sanitary engineer with experience in plant opera-
tions. State personnel, particularly area district engineers, were encouraged
to accompany research team members on site visits and on preliminary surveys.
When available, state personnel provided historical information on plant per-
formance and previous 0 & M problems. They were familiar with the plant
operators and administrative personnel and introduced research team members to
these plant officials.
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Site visit screening rejected facilities that had non-operational units,
major design deficiencies, excessive infiltration/inflow and other obvious
factors which precluded potentially good performance. A few facilities were
rejected because town officials or plant personnel expressed a desire to not
participate in the study. Some small facilities were rejected because the
operator was not available to work with research team members. Some plants
were chosen because they were considered to have good 0 & M practices. In
total, 30 of the 63 facilities where site visits were conducted were selected
for preliminary surveys.
Originally, the sole purpose of site visits was to insure that plants
chosen for preliminary surveys would provide valuable and reliable research
information. The scope of the site visit portion of the research effort was
later expanded to include formal documentation of the information collected.
The basic information recorded included general plant information (design
flow, population served, receiving stream, etc.), general process description
(wastewater and sludge flow schematic) and general plant 0 & M information
(number of operators, lab facilities available, plant maintenance completed,
etc.). An investigation checklist was used to insure that similar data was
collected for each site visit. Additional documentation included factors
which were noted to limit performance and the reasons the plant was not
selected for further study. Information was obtained during discussions with
the plant operator and during a tour of the treatment facilities. A separate
report was developed for each site visit facility that was not selected for a
preliminary survey. Those plants for which a site visit only was conducted
and those for which a site visit plus a preliminary survey were conducted are
referenced in Appendix A.
PRELIMINARY SURVEYS - GENERAL DISCUSSION
The majority of the research effort was expended by conducting thirty
preliminary surveys. The primary emphasis of each survey was a detailed evalu-
ation of 0 & M factors that limited the facility's performance. However, the
evaluation was not limited to performance limiting factors in the areas of
operation and maintenance, but included design and administration factors also,
21
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Typically, the term 0 & M has been inappropriately used to describe a multitude
of factors that result in inadequate treatment. Staffing requirements, opera-
tor salaries, design deficiencies, management techniques, industrial wastes,
poor maintenance and inadequate budget are but a few of the items that are com-
monly described as 0 & M problems. These specific factors limiting perform-
ance and others that were evaluated in this research effort were more appro-
priately placed into four general categories: operation, maintenance, design
and administration.
The approach used to evaluate factors limiting plant performance is ex-
tremely important because the results and conclusions made are heavily influ-
enced by the method of evaluation. An improper approach easily results in
a biased opinion rather than definitive conclusions. For example, a plant
operator's evaluation concerning reasons for poor performance typically ex-
cludes or minimizes operator problems. An evaluation by the plant design
engineer typically excludes or minimizes design problems. Despite the biased
opinions of these sources, many performance evaluations have been conducted
by simply questioning the persons that are directly associated with and often
the source of the problems being assessed. An option to this approach is to
obtain an evaluation from persons that are external to the plant performance
problem. However, an evaluation by persons that are external to a plant
performance problem and in a position to be more objective is limited by their
unfamiliarity with the facility. This unfamiliarity is typically overcome
through discussions with plant officials, plant personnel and/or the design
engineer. During these discussions the evaluator typically encounters ani-
mosity from operations personnel toward outsiders reviewing their facilities;
reluctance of design engineers to allow their facilities to be reviewed and
fear from administrators regarding possible regulatory action concerning plant
performance. Therefore, it was necessary when evaluating 0 & M problems to
avoid taking information at face value. For this reason, a specialized re-
search approach was implemented during this study with full awareness of the
problems encountered when making an external evaluation.
22
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Each survey consisted of a period of in-plant investigation followed by
an analysis and documentation of the findings in a report titled, "Preliminary
Survey of Wastewater Treatment Facilities." Four engineers were involved in
conducting the thirty surveys. Two engineers were team leaders and two were
team members. Each team leader had formal training in sanitary engineering
and had extensive experience in plant operation in the form of providing in-
plant operations assistance at wastewater treatment facilities. This experi-
ence and capability of the team leaders was used during the research effort to
provide assistance at survey facilities in order to remove the natural barriers
to communication and thus allow for a better assessment of factors limiting
performance. A range of effort was expended during each in-plant survey using
one team leader and one team member. In smaller facilities, the in-plant
investigation was completed by these persons in three to four days. In larger
plants, seven to ten days were required. Factors limiting performance that
were identified during the survey were verified by conducting follow-up tele-
phone communication and in some cases follow-up plant visits.
A similar approach to conducting the field portion of the preliminary
survey was employed at each facility. Each survey was initiated with a dis-
cussion about the research contract. The background and objectives of the
research effort were described so that plant personnel were familiar with the
purpose and scope of the project. Specific areas of research that were de-
pendent upon the plant personnel's participation were stressed so that these
tasks could be scheduled to minimize conflict with routine duties.
An important aspect of the initial discussion was the opportunity it
provided to initiate the atmosphere in which the survey was conducted. The
plant superintendent was assured that the work conducted in conjunction with
the survey would not be used for enforcement action against him or the city.
Yet, many operators outwardly expressed apprehension toward the research team
during the initial discussion. One operator made the opening statement, "You
know, if it would have been up to me you wouldn't even be here, because when
I heard this had something to do with EPA I figured nothing good could come
of it." Another plant superintendent stated flatly, "If anything bad becomes
of this, I'm going to sue you and your company." To overcome the initial
23
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animosity of most operators toward a review of their facilities, an emphasis
was placed on providing assistance to the operator during the course of the
research effort.
After the introductory discussion the operator was asked to show the re-
search team through the plant. During the plant tour, which typically lasted
from one to four hours, many questions were asked about plant design, opera-
tion, administration and maintenance. Questions were also asked about opera-
tions procedures that were normally used, that had been tried and that were
possible. Many obvious plant deficiencies were usually identified during the
initial plant tour. Later during the survey more subtle factors limiting per-
formance were identified. It is important to note that the investigative ap-
proach allowed two levels of information to be identified, obvious and subtle.
The importance of these levels of information is discussed later in the report.
During each in-plant evaluation period an emphasis was placed on dis-
cussing basic principles of wastewater treatment plant operation with plant
personnel and how these principles applied to their facility. The intent was
to provide the operator with something of value by participating in the re-
search project and to develop his confidence in the survey team's technical
abilities. Several specific techniques were used to gain operator confidence
and.overcome operator animosity. One technique was to discuss alternate opera-
tions procedures in terms of "more desirable," rather than present procedures
as "wrong." Another technique was to allow the operator to come to a desired
conclusion by directing his thoughts with questions or to help him by "think-
ing out loud." Often, treatment concepts and their application to plant oper-
ation that were discussed were obviously confusing and/or totally new, even to
operators with a high level certification and many years of experience. In
these cases to avoid embarassment and ill feelings one of the research team
members asked questions of the other member. One might have asked, "Do you
mean . . .?" or "How does that apply here?" These and other specific tech-
niques formed an approach that was expanded to include the entire involvement
at the plant. An atmosphere was developed that allowed for a meaningful and
more complete exchange of information between plant personnel and research
team members.
24
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The methods used to optimize the exchange of information were coupled
with other techniques used to evaluate factors limiting performance in the
four major categories of design, operation, maintenance and administration.
Design factors were evaluated using conventional procedures such as plans and
specifications review, field measurements and calculation of typical design
parameters. However, a modification to the conventional design evaluation was
also employed. With the help of the plant operator, a more thorough evaluation
of design features was made by actually attempting various operations adjust-
ments. For example, activated sludge return flow rates were adjusted over
broad ranges in order to evaluate if return control was a plant design limita-
tion. Actually using or attempting to use the existing facilities allowed
theoretical design capabilities to be evaluated relative to actual operating
abilities. A list of plant design deficiencies observed during the research
effort is contained in Appendix C.
Operations factors limiting plant performance were assessed by evaluating
procedures used for process control and by observing process conditions (i.e.,
sludge color, trickling filter appearance, clarifier appearance, etc.). Pro-
cess control testing was also conducted. These tests primarily included
solids concentration tests, sludge settling tests, dissolved oxygen tests and
sludge blanket depth determinations. Where applicable, other tests like alka-
linity, volatile acids and specific oxygen uptake were conducted. Performance
monitoring tests were also conducted as part of the research effort. Perform-
ance monitoring primarily included biochemical oxygen demand (BOD ), total
suspended solids (TSS) and coliform analyses. Monitoring analyses were used
to determine total and intra-plant performance characteristics. When practi-
cal, samples were split with the plant operator as a quality control check.
Process control tests were used to assess the operating conditions at
facilities surveyed. Wherever possible, process control test procedures were
demonstrated to plant personnel who in turn were asked to conduct the tests
prior to the conclusion of the in-plant survey. The joint conduct of the
tests coupled with the subsequent test result discussion served as a basis
for a common ground of communication between research team members and plant
personnel. This was especially important to overcome misunderstandings due
25
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to the widely differing terminology that was frequently used to describe
equivalent process control parameters. Using this procedure, plant operation
was evaluated with respect to process understanding and not terminology memor-
ization and usage.
In most of the plants evaluated, process control test results and as-
sociated discussions indicated that process adjustments were warranted. A
great deal of caution was exercised in making operations changes since bio-
logical system response which resulted from process changes normally did not
evolve during the in-plant evaluation period. The slow response of biologi-
cal systems and its associated impact on poor plant performance is further dis-
cussed later in this report. When operations adjustments or procedures were
found to be grossly out of line, changes were recommended and were often imple-
mented during the survey to bring the facility within an acceptable operating
range. More importantly, the concepts on which the recommendations were based
were thoroughly described so that the operator better understood why the recom-
mendations were made. Using this approach, the operator was less likely to
misuse or misinterpret the recommendations.
The technical assistance approach used to evaluate the operational fac-
tors limiting plant performance also enabled the research team to accurately
evaluate the operator's existing and potential capabilities. This evaluation
was verified by maintaining telephone contact with the plant operator(s) or
by conducting.follow-up plant visits. This follow-up contact also served to
reinforce the operator's understanding of wastewater treatment concepts des-
cribed during the survey and insured the success of the recommendations which
were implemented during the in-plant research effort.
Maintenance factors were evaluated by reviewing maintenance schedules
and records, by observing the condition of plant equipment and by discussing
maintenance activities with plant personnel. Preventive maintenance schedules
for key equipment were documented on the "Preliminary Survey Information
Sheets." Blank samples of these sheets are included in Appendix B. Indivi-
dual pieces of equipment that required excessive or unusual maintenance were
documented and are listed within the plant design inadequacies recorded in
26
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Appendix C. Emergency maintenance procedures were observed in some plants
where breakdowns during the research effort created an emergency maintenance
situation. Most often, emergency maintenance procedures were only discussed
with plant personnel.
Administrative factors were evaluated through discussions with operators
and with personnel other than in-plant personnel. It was necessary to inter-
view persons outside the environment of the plant to insure that the personal
prejudices of the plant operators did not dominate the research team's assess-
ment of a potential administrative problem. In addition, more accurate 0 & M
costs could usually be attained from these persons. Typically, cost informa-
tion was obtained from the city clerk, city manager, sanitation district mana-
ger or others familiar with the wastewater treatment budget. These persons
were contacted early in the week of the preliminary survey and were informed
of the scope of the cost information needed. The most important issues were
that the cost information was to include treatment plant costs only and actual
costs as opposed to budgeted costs. In addition, it was desired to reorganize
the city's cost information into the specific categories established for this
research project as shown in Appendix B. Later in the week a joint meeting
was held among the plant superintendent, the individual supplying the cost
information and a research team member. During this meeting persons repre-
senting the city were asked to help rearrange the categories to the research
format. The research team member usually made suggestions as to how each
category could be separated or combined.
The actual costs for smaller treatment plants was most difficult to as-
sess. Typically the wastewater treatment plant budget was combined with
potable water treatment costs or included within the general budget, which
normally included monies for street repair, water treatment, water distribu-
tion and/or wastewater collection. Under this arrangement the separation
of costs for the wastewater plant only was sometimes difficult. Also, opera-
tors of the smaller treatment plants usually worked part-time at the plant and
part-time at other city utilities, and often the actual time worked at the
treatment plant was quite different than the budgeted time. The detailed
procedure used for determining cost information was necessary in order that
27
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accurate costs for wastewater treatment could be obtained. A summary of the
cost information collected for the facilities surveyed is presented in Appen-
dix G.
The in-plant investigation for each preliminary survey was concluded with
a discussion among the plant staff and research team members. In most plants
surveyed this discussion was much more open and comfortable than the discus-
sion which was held the first day of the survey. However, nearly all opera-
tors were still concerned about written documentation of survey results that
would be contained in the preliminary survey report. Many seemed to realize
that their understanding of wastewater treatment process control was probably
not adequate and were concerned that the evaluation report would document
this limitation. Therefore, to avoid possible surprises to the operators this
final discussion period was used to review and summarize the major conclusions
and recommendations that would be included in the written report.
Preliminary survey reports were typically 25 to 50 pages long and in-
cluded sections on Recommendations, Introduction, Plant Evaluation and Summary
and Conclusions. In these sections existing plant performance and the major
factors limiting performance were discussed. Factors which limited perform-
ance were discussed in the Plant Evaluation section under four general topics:
administration, maintenance, design and operation. The discussion in the text
of the reports was substantially limited to areas in which conclusions and
recommendations were made. For some plants additional information was in-
cluded to describe background information on an unconventional process that
was being evaluated.
Two appendices were also included in all survey reports. One appendix
consisted of "Preliminary Survey Information Sheets," which were developed
specifically for the contract to provide a thorough documentation of diverse
information about each facility. Information such as permit requirements,
design and operating loads on individual processes, plant operator coverage,
user fees for wastewater treatment, plant maintenance scheduling, individual
equipment maintenance schedules and meeting schedules of the city council were
28
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documented on the Preliminary Survey Information Sheets. An example copy of
these information sheets is included in Appendix B. The second appendix in
the survey report for every facility was the EPA inspection form 7500-5.
Copies of each survey report were distributed to the facility surveyed, the
state pollution control agency, the regional EPA office and the EPA research
project officer. Copies were also given to the facility design engineer upon
request from the city.
PRELIMINARY SURVEYS - EXAMPLE SURVEY
The research approach used to identify factors limiting performance was
developed to obtain information that is normally intentionally or unintention-
ally "covered up" by plant personnel. Intentional cover-up occurs for a vari-
ety of reasons including a fear of regulatory action concerning plant perform-
ance. Intentional cover-up for this reason was overcome by emphasizing that
the project was research oriented and was not connected with enforcement. Un-
intentional cover-up occurs because of the plant operators' desire to demon-
strate their knowledge and capabilities to the outsiders reviewing their facil-
ity. This form of cover-up was overcome by developing a common ground communi-
cation between operators and research members through the technical assistance
provided and by creating an atmosphere that did not intimidate the plant oper-
ators. The approach was instrumental in identifying performance limiting
factors that were less obvious or non-apparent. Additionally, the approach
was instrumental in improving the performance at some facilities. An example
of both benefits is described in the preliminary survey conducted at Plant 050.
Plant 050 was a recently constructed, small extended aeration activated
sludge plant with chlorine disinfection. Sludge from the facility was stored
in a modified Imhoff tank and wet-hauled to farmland. Brush rotors of the
type generally used in oxidation ditches provided oxygen transfer and aeration
basin mixing. Design flow of the facility was 680 cu m/day (0.18 mgd). The
actual flow rate was 650 cu m/day (0.17 mgd). When the facility was con-
structed effluent treatment standards of 30 mg/1 BOD^ and 30 mg/1 TSS were
required. Subsequently, more stringent effluent requirements of 10 mg/1 BOD ,
20 mg/1 TSS and 2 mg/1 ammonia nitrogen were adopted.
29
-------
Plant 050 was a facility in which the operator expressed much initial
apprehension to the research team. Despite his initial feelings the operator
became much less apprehensive as the survey progressed. In fact, the operator
expressed an increasing interest in the process control tests that were being
demonstrated and used to assess the operating conditions of his facility. An
atmosphere was eventually developed in which the operator was eager to learn
as much as he could to improve his operation.
While this atmosphere was being developed, routine analysis of plant ef-
fluent quality was accomplished. Figure 3 shows effluent TSS derived from in-
plant monitoring results for the first six months of 1977. Effluent quality
appeared to be consistently good from the first of 1977, with a general trend
of improvement starting just before the research effort that continued after
the study was initiated. On the surface plant performance appeared satisfac-
tory, but the research approach used resulted in dramatically different con-
clusions.
80
^.RESEARCH
INITIATED
Prior to the research study the plant operator was conducting mixed liquor
suspended solids (MLSS) tests and sludge settling tests, but was incorrectly
interpreting test results for process
control. During the study the opera-
tor's testing program was expanded to
include return sludge concentration
tests and depth of clarifier sludge
blanket determinations, but more impor-
tantly test results were more accurate-
ly applied to process control. The op-
erator reported that for a two-month
time period prior to the survey sludge
had not been wasted intentionally from
the system because solids loss from the
clarifier to the effluent had occurred
to the extent that the mixed liquor had
decreased. The operator realized that
30
10
FEB MAR APR
1977
MAY JUN
the continued solids loss was a problem,
Figure 3. Recorded effluent TSS
concentrations for Plant 050.
30
-------
but had been advised by the design engineer to keep the mixed liquor concen-
tration high. Therefore, the operator discontinued wasting to hold the MLSS
concentration as high as possible. The need for sludge wasting had been
further de-emphasized during plant construction. The operator had been ad-
vised by the aeration equipment supplier and design engineer that it would
only be necessary to waste sludge a couple times per year, if at all. Based
on this improper technical guidance the operator determined that routine sludge
wasting was not necessary.
During the preliminary survey the need for routine sludge wasting was
discussed and a regular sludge wasting program was initiated. Also, the re-
turn sludge flow rate was more appropriately adjusted to coincide with the
sludge settling characteristics. The mass of sludge in the system was slowly
reduced to a controllable level, and the operator continued the -routine wast-
ing program to control system sludge inventory. A graphical illustration of
the sludge wasting pattern is shown in Figure 4. An average of 76 kg/day
(168 Ib/day) of sludge was intentionally wasted during the four-month period
after the preliminary survey, whereas no sludge was intentionally wasted for
a two-month period prior to the survey.
400
350
300
250
RESEARCH INITIATED
<200
5150
100
50
0
JAN
FEB
MAR
1977
APR
Figure 4, Mass of activated sludge wasted at Plant 050,
31
-------
In Figure 3 relatively good plant effluent TSS concentration values were
reported both prior to and after the preliminary survey, even though repeated
excessive solids loss occurred prior to the survey. According to the plant
operator the effluent samples that were collected and analyzed for TSS con-
centrations were grab samples taken when excessive solids loss did not occur.
Therefore, the recorded effluent TSS concentrations shown in Figure 3 do not
reflect the actual daily average TSS concentration discharged. The operator
reported that during the two months prior to the survey excessive solids loss
occurred nearly every day, but during the four months after the survey exces-
sive solids loss occurred on only two days. These two days were just after
the research team had completed the in-plant investigation. Based on this in-
formation the effluent TSS concentration for the two-month time period prior
to the survey was adjusted to reflect a more accurate value. The adjusted
effluent TSS concentration was calculated assuming that the quantity of sludge
wasted after the survey was similar to that lost in the plant effluent prior
to the survey. Appropriate adjustments for plant sewage flow rate and system
sludge inventory were included in calculating the TSS concentration. Effluent
TSS concentration prior to the survey was estimated to be around 93 mg/1 as
shown in Figure 5. The recorded TSS values after the survey were considered
to accurately reflect effluent quality
since a routine sludge wasting program
had been adopted and excessive solids
loss from the final clarifier had been
stopped.
There are two important conclu-
sions from the above study. One is
that sludge must be routinely wasted
from extended aeration activated sludge
facilities before they can be expected
to achieve optimum performance. The
second conclusion, which is most im-
portant with respect to the results ob-
tained from this research project, is
that the investigative approach used
90
80
70
60
50
40
30
20
10
n
• ADJ
- TS
REC
TSi
/•^«-
\
USTED
3
3RDED
A
)
/\->
)
(
L
^•RESEARCH
INITIATED
' — s
7^
j
\
Y. —
-^-
Figure 5. Adjusted effluent TSS
concentrations for Plant 050.
32
-------
during the preliminary surveys was instrumental in uncovering information that
was not readily obvious. At Plant 050 the sampling procedure and improper
technical guidance were two items of information that were uncovered that were
not apparent until the operator responded to the cooperative atmosphere
created through the technical assistance provided. A similar assistance ori-
ented research approach was used at all thirty facilities evaluated and re-
sulted in significantly improved performance at some facilities such as Plant
050. However, the most important aspect of the research approach in light of
the objectives of the project was that both the non-apparent and obvious
factors that were limiting treatment plant performance were identified.
33
-------
SECTION 6
EVALUATION OF CAUSES OF LIMITED PLANT PERFORMANCE
GENERAL
For each treatment facility in which a preliminary survey was conducted
an in-depth evaluation was made to determine what factors were limiting per-
formance. The results of each evaluation were documented in a "Plant Evalua-
tion Summary." The Plant Evaluation Summary was originally developed to
quantify and rank the factors limiting performance only at the thirty facili-
ties where preliminary surveys were conducted. However, because it was found
that a meaningful amount of information especially for design related para-
meters could be obtained during the half-day site visits, the Plant Evaluation
Summary was also completed for each of the thirty-three facilities where only
a site visit was conducted.
The Plant Evaluation Summary was developed as part of the research effort
and consisted of-two parts, a) a weighing table and b) a ranking table. The
weighing table included seventy different factors that could possibly limit
plant performance. Each factor was defined according to its specific cause
of poor plant performance or reliability. The extent of each factor's detri-
mental impact on performance was quantified according to the weighing shown
in Table 1. Each factor that received two or three points was included in
the ranking table, in descending order of detrimental effect on plant perform-
ance. A copy of the Plant Evaluation Summary ranking and weighing tables and
a copy of the definitions for the seventy factors evaluated are included in
Appendix D.
34
-------
TABLE 1. POINT SYSTEM FOR PLANT EVALUATION SUMMARY WEIGHING TABLE ..
Weighing Effect of Specific Factor on
Points Plant Performance
0 No significant effect on plant
performance.
1 Minor effect on plant performance.
2 Minimum indirect effect on plant per-
formance on continuous basis or major
direct effect on plant performance on
a periodic basis.
3 Major direct effect on plant perform-
ance.
The purpose of the Plant Evaluation Summary was to quantify and rank the
factors which significantly affected plant performance. During the evalua-
tions it was determined that many interrelated factors often impacted perform-
ance. A typical example occurred at Plant 050 which was discussed earlier.
At Plant 050, the sludge wasting procedure was incorrect and was identified
as a major cause of poor performance. This cause may have been brought about
by many different performance limiting factors. It may have been the result
of a poor application of the basic wasting concept by the operator, a lack of
sewage treatment understanding by the operator and/or inadequate facilities
for routine wasting. However, using the described research approach a more
definitive factor was identified. At Plant 050 the operator was told by both
the design engineer and the equipment supplier that frequent wasting was not
necessary. Therefore, for Plant 050 in which the area of activated sludge
mass control was identified as limiting performance, the more basic factor of
poor technical guidance was determined to be the most significant performance
limiting factor. In a similar manner the research approach was used to iden-
tify the most definitive factors limiting performance at each of the facili-
ties evaluated.
35
-------
EVALUATION OF SITE VISITS
Site visits were conducted at sixty-three facilities. Thirty of these
facilities were selected for follow-up preliminary surveys. Site visit re-
sults are discussed separately from preliminary survey results because limited
time was spent at each site visit and the nature of the plant selection criter-
ia separated these facilities into a distinctly different group. The evalua-
tion of factors for site-visited facilities did not include the same distri-
bution of weighing points as for preliminary surveyed facilities. Only the
more obvious factors limiting performance were documented during the half-day
site visits, whereas more of the subtle factors were determined during the
5-day preliminary surveys. For this reason, only those factors that were
given a weight of two or three points were listed for site visits. Factors
which would have received one point for having only a minor effect on plant
performance were not documented. The completed ranking table portion of the
Plant Evaluation Summary for each site-visited facility is shown in Appendix E.
A combined overall ranking of performance limiting factors for all site-
visited facilities is shown in Table 2. Twenty-eight different factors which
were given two or three points are included. In Table 2 each factor was ranked
according to the cumulative number of points received for the thirty-three
site visits. Also shown are the Plant Evaluation Summary reference number for
each factor, the number of times each factor occurred, the number of times a
factor ranked No. 1'at a facility and the number of plants for which each
factor was given a weight of three points and two points. The reference
number indicates the major category in which the factor occurred (A.... is
administration, B...." is maintenance, C.... is design and D—. is operation).
Three of the twenty-eight factors noted were in the administrative category,
two were in the maintenance category, seventeen were in the design category
and six were in the operations category. Most of the factors identified were
in the design category since design problems were more obvious than other types
of problems and were identified during the relatively short plant visits, and
obvious design deficiencies was a major criteria for plants falling into this
category. The difference between site visit factors and preliminary survey
factors limiting performance is further described later in this report.
36
-------
TABLE 2. RANKING OF FACTORS LIMITING PERFORMANCE OF THIRTY-THREE SITE VISIT FACILITIES
Ranking*
1
2
3
4
5
6
7
7
7
10
11
12
13
14
14
14
14
14
14
14
21
21
21
21
21
21
21
21
Table**
Reference
Clf
D3a
C2c3
C2g
C2c2
C2f
Ala
Clc
C2cl
Die
C31
C2e
D2a
A2bl
B2a
Clb
C2c4
C3dl
D3b
D5a
A2al
Bla
Cle
cig
C2h
C3a
C3k
D2b
No. of Times
Factor Limiting Performance Factor Occurred
Infiltr at ion/ Inflow
Operator Application of Concepts
and Testing to Process Control
Aerator
Sludge Treatment
Process Controllability
Sludge Wasting Capability
Administrative Policies
Industrial Loading
Process Flexibility
Sewage Treatment Understanding
Plant Inoperability due to Weather
Disinfection
Performance Monitoring
Motivation (Staff)
Lack of Maintenance Program
Hydraulic Loading
Clarif ier
Flow Back-Up
Technical Guidance
Equipment Malfunction
Staff Number
Housekeeping
Seasonal Variation
Return Process Streams
Ultimate Sludge Disposal
Plant Location
Equipment Accessibility for
Maintenance
Process Control Testing
11
10
i
i
6
6
4
4
6
4
4
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
No. of Times*** Point Breakdown
Factor Ranked #1 3pt 2pt Total
4
4
5
3
2
1
1
3
1
2
1
0
0
1
1
1
1
1
0
1
0
0
0
0
0
0
0
0
5
4
4
3
4
3
4
4
0
3
1
1
0
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
6
6
3
4
2
3
0
0
6
1
3
1
2
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
27
24
18
17
16
15
12
12
12
11
9
5
4
3
3
3
3
3
3
3
2
2
2
2
2
2
2
2
* Ranking is based on total points.
** This reference refers to the item number on the "Plant Evaluation Summary" (A is Administration;
B is Maintenance; C is Design, and D is Operation).
*** Number of times the factor limiting plant performance was the leading cause of poor performance at
an individual facility.
-------
At the site-visited facilities an Infiltration/Inflow (I/I) problem was
the highest ranking factor limiting performance. Excessive I/I occurred in
eleven of the thirty-three plant site visits and was the leading cause of poor
performance in four facilities. Excessive I/I problems were usually apparent
to research team members and were also emphasized by the operator at plants
where excessive I/I existed. Other types of obvious performance limiting
factors were excessive organic loading from industrial sources, excessive hy-
draulic overload (not I/I source) due to plant undersizing and major mainte-
nance problems. At these facilities arrangements were usually in progress to
correct the obvious problems.
Because of the nature (i.e., time, approach and objective of the visit)
of the investigation, obvious factors which limited plant performance were
identified during site, visits. Many of the obvious factors were screening
criteria used to exclude facilities from a preliminary survey. Because of
this screening process the results obtained from the preliminary surveys are
biased away from some of the performance limiting factors noted in the site-
visited facilities. However, this does not detract from the value of the
results of this research effort)because when the more obvious performance
limiting factors are corrected at the site-visited facilities, factors similar
to those identified in the preliminary surveys will likely be encountered.
EVALUATION OF PRELIMINARY SURVEYS
The Plant Evaluation Summary was developed to identify, quantify and rank
the factors limiting performance at the thirty facilities where preliminary
surveys were conducted. At each facility every factor in the weighing table
was evaluated and quantified in relation to its adverse affect on plant perform-
ance. The number of factors that received one or more points at a facility
ranged from four to thirty. The average facility had 15 performance limiting
factors, and at no facility was only a single factor observed to be limiting
performance. The completed ranking tables for each of the facilities surveyed
are shown in Appendix F.
38
-------
The number of points received by each of the factors in the Plant Evalu-
ation Summary weighing table was compiled for the thirty preliminary surveys.
Based on this compilation an overall ranking of factors is shown in Table 3.
Also shown are the Plant Evaluation Summary reference number; the number of
times each factor occurred (i.e., given one point, two points or three points);
the number of plants in which the factor was ranked as the number one problem
(from the individual ranking tables) and the number of plants for which a
factor was given one, two or three points.
Many different performance limiting factors were noted at facilities sur-
veyed. Sixty of the seventy factors evaluated received at least one point in
at least one plant. The ranking procedure allowed for the relative severity
of the factors to be established. In this report the ten highest ranked
factors are discussed. In addition, five factors that were the leading cause
of poor performance in at least one facility are discussed.
The highest ranking factor limiting performance at facilities surveyed,
with fifty-three total points, was inadequate operator application of concepts
and testing to process control. This factor was identified in twenty-eight of
thirty facilities surveyed and was the leading cause of poor performance in six
facilities. The operator application of concepts factor described a situation
for a satisfactorily designed plant operated by a "trained" operator that did
not achieve good performance. This factor was ranked when incorrect control
adjustments and/or incorrect control test interpretation occurred, or when the
use of existing inadequate design features continued when seemingly obvious
operations alternatives or minor plant modifications could have been imple-
mented to improve performance. The proper application of concepts required
that an operator recognize when the plant limited his operational capability
to apply basic fundamentals of wastewater treatment operation to process con-
trol. At some plants operator ingenuity was observed to overcome minor plant
design limitations which was beneficial to improving plant effluent quality.
Operator application of concepts rated high in many plants because operators
were observed to understand the mechanics of process control features, but
did not relate available operational controls to the needs of the biological
39
-------
TABLE 3. RANKING OF FACTORS LIMITING PERFORMANCE OF THIRTY PRELIMINARY SURVEY FACILITIES
Ranking*
1
2
3
4
5
6
7
8
9
9
11
12
£
14
15
15
15
18
18
20
21
22
22
22
22
26
26
28
28
Weighing**
Table
Reference
D.3.a.
D. I.e.
D.3.b.
D.2.b.
C.2.f .
C.2.C.I.
C.2.C.2.
C.2.C.4.
C.2.g.
C.2.C.3.
D.2.a.
C.2.e.
C.2.h.
C.3.I.
C.2.f .
C.3.b.
A. l.a.
C.l.f .
C.3.e.
A. 2. a. 2.
A.l.b.
D.4.a.
C.l.g.
D.l.b.2.
D.l.a.l .
A. 2.a.l .
B.l.c.
C.3.d.3.
A.2.b.4.
Factor Limiting Performance
Operator Application of Concepts and
Testing to Process Control
Sewage Treatment Understanding
Technical Guidance
Process Control Testing
Sludge Wasting Capability
Process Flexibility
Process Controllability
Clarifier (Secondary)
Sludge Treatment
Aerator
Performance Monitoring
Disinfection
Ultimate Sludge Disposal
Laboratory Space and Equipment
Alternate Power Source
Unit Process Layout
Policies (Administrators)
Infilt rat ion/ Inflow
Alarm Systems
Plant Coverage
Familiarity with Plant Needs
(Administrators)
Adequacy (0 & M Manual)
Return Process Streams
Training (Operations)
Aptitude (Operators)
Number (Staff)
Scheduling & Recording (Maintenance)
Flow Proportioning to Units
Working Conditions
No. of Times
Factor Occurred
28
20
17
21
18
16
20
11
15
9
15
10
12
14
13
6
7
11
12
10
7
8
6
8
6
7
8
6
7
No. of Plants***
Factor Ranked #1
6
4
5
0
3
2
0
2
0
2
0
0
0
0
0
1
2
0
0
0
0
0
1
0
0
0
0
0
0
Point
1 pt.
12
7
3
8
9
5
9
4
11
3
13
5
10
13
13
1
3
10
12
9
4
7
4
7
3
6
8
5
7
Breakdown
2 pts. 3
7
4
8
13
3
6
11
4
4
2
2
4
0
1
0
3
2
1
0
1
3
1
1
1
3
1
0
1
0
+
pts.
9
9
6
0
6
5
0
3
0
4
0
1
2
0
0
2
2
0
0
0
0
0
1
0
0
0
0
0
0
Total Points"1"1"
53
42
37
34
33
32
31
21
19
19
17
16
16
15
13
13
13
12
12
11
10
9
9
9
9
8
8
7
7
-------
TABLE 3. Continued
Weighing**
Table No. of Times
Ranking* Reference Factor Limiting Performance Factor Occurred
28
28
32
32
32
32
32
32
38
38
38
38
38
38
44
44
44
44
48
48
50
50
50
50
54
54
54
54
54
A.
C.
C.
A.
D.
A.
D.
A.
A.
C.
D.
B.
B.
B.
C.
A.
C.
C.
B.
B.
C.
C.
C,
C.
C.
C.
D.
C.
C.
2 .
2.
3.
2.
5.
2.
1.
3.
2.
3.
1.
1.
2.
1.
1.
3.
3.
3.
.2.
1.
.1.
, 1.
.1.
.3.
3.
,3.
.1.
, 1.
,3.
b.2
a.
1.
b.3.
a.
c.
d.
a.
b.l.
d.l.
b.l.
a.
a.
d.
c .
b.
c.
a.
c.
b.
b.
d.
e.
j-
h.
m.
a. 2.
a.
d.2.
Pay (Operators)
Preliminary (Design)
Plant Inoperability due to Weather
Supervision
Equipment Malfunction
Productivity (Operators)
Insufficient Time on the Job
Insufficient Funding
Motivation (Operators)
Flow Backup
Level of Certification
Housekeeping
Lack of Program (Maintenance)
Manpower (Maintenance)
Industrial (Loading)
Unnecessary Expenditures
Lack of Unit Bypass
Plant Location
Spare Parts Inventory
Equipment Age
Hydraulic (Loading)
Toxic (Loading)
Seasonal Variation (Loading)
Process Accessibility for Sampling
Lack of Stand-By Units for Key Equipment
Quality of Equipment
Level of Education
Organic (Loading)
Submerged Weirs
5
7
4
4
4
5
5
6
5
3
5
4
4
4
2
4
4
3
3
3
2
2
2
2
1
1
1
1
1
No. of Plants*** Point Breakdown"1"
Factor Ranked #1 1 pt. 2 pts. 3 pts. Total Points"1"1"
0
0
0
0
1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
7
2
2
3
4
4
6
5
1
5
3
3
3
1
4
4
2
3
3
2
2
2
2
1
1
1
1
1
2
0
2
2
0
1
1
0
0
2
0
1
1
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7
7
6
6
6
6
6
6
5
5
5
5
5
5
4
4
4
4
3
3
2
2
2
2
1
1
1
1
1
-------
TABLE 3. Continued
Weighing**
Table No. of Times
Ranking* Reference Factor Limiting Performance Factor Occurred
54
60
60
60
60
60
60
60
60
60
60
60
C.
A.
A.
B.
B.
B.
B.
C.
C.
C.
D.
D,
.3.
.2
,3,
,2,
,3,
,3.
.3.
.2
,3.
.3,
.4,
,5,
.g.2.
.d.
. c.
.b.
.a.
.b.
. c.
.b.
• g.l.
.k.
.b.
.b.
Process Automation Control
Personnel Turnover
Bond Indebtedness
References Available
Staff Expertise (Emergency Maintenance)
Critical Parts Procurement
Technical Guidance (Emergency Maintenance)
Unit Design Adequacy, Primary
Process Automation, Monitoring
Equipment Accessibility for Maintenance
0 & M Manual, Use by Operators
Shift Staffing Adequacy
1
1
0
0
0
0
0
0
0
0
0
0
No. of Plants*** Point Breakdown"1"
Factor Ranked //I 1 pt. 2 pts. 3 pts. Total Points++
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
* Ranking is based on total points received.
** Weighing Table reference number (A is Administration; B is Maintenance; C is Design; and D is Operation).
*** Number of plants in which the factor was the leading cause of poor performance as obtained from the ranking table.
+ Number of plants in which the factor received one point, two points, and three points.
++ Total points received at thirty preliminary survey facilities.
-------
system. This factor represented the gap which existed between poor and op-
timum plant performance at satisfactorily designed plants with a well-trained
operator.
The second highest ranking performance limiting factor, with forty-two
total points, was a general lack of sewage treatment understanding. This
factor was identified in twenty of thirty facilities surveyed and was the
leading cause of poor performance at four facilities. The first two leading
causes of poor plant performance, operator application of concepts and testing
to process control and sewage treatment understanding, are quite similar, but
each represents a different aspect of operator abilities. Sewage treatment
understanding was ranked as a factor limiting performance when it was noted
that the operator had a general lack of knowledge concerning sewage treatment.
These operators were not able to explain even to a limited degree the purpose
or function of the treatment processes at their plant. Their only concern was
that the equipment was functional.
The implications of the high ranking of sewage treatment understanding as
a factor limiting performance are far reaching in that to improve understanding
additional training is necessary. However, existing training has produced op-
erators that were usually not able to apply basic wastewater treatment concepts
to their individual situations as evidenced by the number one ranking of the
operator application of concepts factor. Because of the high ranking of both
of these plant operator related factors, the research effort included a de-
tailed evaluation of plant staffing to quantify operator capabilities. The
results of this special study are included in Section 7 of this report.
Improper technical guidance was the third highest ranking performance
limiting factor at facilities surveyed. It occurred at seventeen of thirty
plants surveyed and was the leading cause of poor performance in five facili-
ties. Improper technical guidance included misinformation from "authoritative"
sources including design engineers, state and federal regulatory agency per-
sonnel, equipment suppliers, operator training staff and other plant operators.
Only those sources Lhac were observed to have a direct affect on plant perform-
ance were included. It was determined that improper technical guidance was
43
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given by design engineers twelve times, by regulatory personnel five times, by
equipment suppliers two times, through operator training one time, by another
operator one time and by a college professor one time. It is noted that the
total of the sources of improper technical guidance is greater than seventeen
because inaccurate advice was given by more than one source at some plants.
Improper technical guidance was not only harmful in that incorrect recommenda-
tions were followed, but was also harmful in that it sidetracked the search
for a legitimate solution to the problem.
Design engineers were found to be the most prevalent source of improper
technical guidance. The high frequency of occurrence for design engineers was
probably due to the fact that plant operators usually looked to their design
engineer for advice before they sought advice from other sources. Design
engineers were considered to have given improper technical guidance when speci-
fic incorrect statements were made with respect to plant operation and not
when a facility's design obviously lacked the necessary operations controls. A
facility's lack of proper design features was evaluated with respect to speci-
fic design factors listed in the Plant Evaluation Summary weighing table. A
list of all design features limiting performance that were noted at facilities
surveyed is presented in Appendix C. The list includes numerous design defi-
ciencies which inhibited the operational capabilities of the plants surveyed.
If design engineers were aware of operations needs it would be expected that
the various design deficiencies observed would not have been so universally
noted. However, improper technical guidance from design engineers did not
only occur in poorly designed facilities. Even in plants that had relatively
good design features, improper technical guidance from the design engineer was
documented. Based on this observation it appears that operations training is
required for design engineers. This aspect is discussed further in this re-
port.
State and federal regulatory personnel were another source of improper
technical guidance. It was observed that poor plant performance continued as
a result of the regulatory person's response or non-response to process con-
trol problems. In some plants obviously wrong operating procedures were ob-
served because of incorrect recommendations from regulatory personnel. In
44
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other cases the regulatory person's non-response to an incorrect practice was
interpreted by the operator as a vote of confidence. Because of the apparent
or actual influence possessed by regulatory personnel and because of the real
or imagined threat of enforcement action, plant operators generally tried to
implement recommendations received from these persons whether or not the recom-
mendations were properly prioritized. All deficiencies detected by regulatory
personnel were generally interpreted as major deficiencies in the plant. Thus,
the operations effort was often directed toward conducting less important tasks
and away from conducting priority activities that directly influence plant
performance. For example, items such as cleaning-up plant grounds, keeping
screenings in covered containers, skimming final clarifiers, scrubbing weirs,
etc. were implemented as priority recommendations while items such as con-
trolling the mass of sludge in the system through wasting went unattended.
This is not meant to imply that meaningful recommendations are not given by
regulatory personnel, but even in cases where correct operations recommenda-
tions were given for the situation, different adjustments were required later
due to biological system changes. The authority associated with state or fed-
eral regulatory agency inspections and the potential adverse impact on plant
performance that could result warrants a review and modification of the pre-
sent conduct of plant inspections and associated recommendations.
Equipment suppliers were observed to have a significant detrimental im-
pact on some plant designs and on plant operation. Historically, plant equip-
ment and associated operations concepts have been presented to design engi-
neers and town administrators under the guise of minimum 0 & M requirements.
The emphasis by the equipment suppliers has been to remove from their equip-
ment and associated processes as many operations related requirements as pos-
sible. The result has been the construction of plants with inadequate opera-
tions control features and a general misconception by plant administrators and
operators of the operational necessities at treatment facilities. Some equip-
ment suppliers have made process claims that are misleading and completely
contrary to the basic concepts of biological wastewater treatment plant opera-
tion. For example, the aeration equipment supplier for Plant 050 had said
that sludge would not have to be wasted, but it was documented that sludge
had to be routinely wasted to prevent excessive solids loss to the receiving
45
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stream. A more detailed discussion of the adverse effect on plant effluent
quality of this improper technical guidance was presented earlier. It should
be noted that the plant design engineer had also made a similar recommendation
about a limited sludge wasting requirement at that facility.
Improper technical guidance from other plant operators was also noted.
Plant over-design, unique design features and in some cases even luck has
allowed some plants to perform quite well without the operator truly under-
standing why. This has elevated the position of these operators so that opin-
ions on operation are accepted even though they are incomplete or fundamentally
wrong. Acceptance of wrong opinions has prevented other operators from im-
proving their plants' performance. Improper technical guidance from plant
operators was not extensive on an individual operator to operator level. It
was observed where the local operator was selected by training officials as a
short course instructor. In that capacity the operator was considered an ex-
pert in the field and his advice was accepted.
Operator training through local, state and other programs was observed to
be helpful in that it enhanced the general working knowledge of sewage treat-
ment for many of the operators. Most of the operators who had attended most
available training programs were familiar with sewage treatment processes and
sewage treatment terminology. However, many times some very basic misconcep-
tions about process control were noted. It was difficult to ascertain where
the misconceptions .originated. The training programs themselves may have been
the source of some misconceptions, but even if they were not the source they
were apparently not able to correct the misconception. If existing training
programs by themselves are expected to produce operators with sufficient know-
ledge to optimize plant performance, it can be concluded that training programs
are grossly inadequate. However, it is the opinion of the research team that
training programs as currently established in magnitude and scope should not
be expected to accomplish this goal. Training programs address general sewage
treatment understanding and cannot address application of concepts by nature
of the short-term, classroom type programs established. It should be noted
that it was in this context that training was evaluated in the Plant Evalua-
tion Summary weighing table. Operator training was evaluated in terms of an
46
-------
operator's non-attendance at available training programs and the possible
resulting detrimental effect on performance. The adequacy of the training
programs themselves was not included as part of this analysis. The weighing
table factor of training tied for a ranking of twenty-second among the causes
of limited plant performance. It received points at eight facilities sur-
veyed, but was not considered a high ranking cause of poor performance at any
facility. Operator training is discussed further later in this report.
A general observation that applies to all sources of improper technical
guidance is related to the characteristics of biological treatment systems.
It was observed that in instances where correct operations recommendations
were made for a particular situation, they were often incorrect at a later
date because of changes in the biological process. Operators continued to
make adjustments under the original recommendations since many of them did
not completely understand the biological process and the limits to the appli-
cation of the recommendation. This time related factor associated with bio-
logical systems is also discussed later in this report. Based on this obser-
vation it was concluded that a general re-evaluation of the approach taken
to the dissemination of technical guidance is necessary, and should include
increased accountability by "authoritative" sources for the guidance that is
given.
The fourth ranked factor limiting plant performance was process control
testing. Inadequate process control testing involved the absence or wrong
type of sampling and/or testing for operations purposes, which in turn caused
improper operations decisions to be made. Inadequate process control testing
was never considered a leading cause of poor performance because it was usually
a secondary factor to an operator's understanding and applying treatment con-
cepts to process control. However, better process control testing was con-
sidered necessary to achieve improved plant performance, and was identified
as a performance limiting factor in twenty-one facilities surveyed.
Inadequate sludge wasting capability was the fifth highest ranking per-
formance limiting factor at facilities surveyed and was documented in eighteen
facilities. Sludge wasting capability was included as a factor when sludge
47
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handling facilities had inadequate capacity or lacked ability to adequately
measure and control a desired volume of waste sludge. Sludge wasting capa-
bility was rated as having a major impact on plant performance (i.e., 3
points) when no sludge handling facilities or extremely inadequate sludge
handling facilities were present. This situation existed at six facilities,
and inadequate sludge wasting capability was the leading cause of poor perform-
ance in three facilities. Lower ratings of one or two points were assigned at
twelve facilities where waste capacity was adequate, but sludge flow measure-
ment and/or control were inadequate.
The sixth and seventh ranked factors limiting plant performance were in-
adequate process flexibility and process controllability, respectively. Pro-
cess flexibility was the availability of valves, piping and other appurte-
nances required to operate in various modes or to include or exclude existing
processes as necessary to optimize performance. Examples of good process
flexibility are the ability to operate an activated sludge plant in the con-
tact stabilization, step loading and/or conventional modes and the ability to
bypass polishing ponds or other downstream processes to discharge high quality
secondary clarifier effluent. Improper process flexibility limited perform-
ance at sixteen plants surveyed and was the leading cause of poor performance
at two facilities. At these two plants an immediate improvement in plant ef-
fluent quality would have occurred with improved process flexibility.
Process controllability was the ability to adequately measure and control
various flow streams such as return sludge flow or trickling filter recircu-
lation rates. Process controllability was not rated as a major cause of poor
performance (i.e., 3 points), but at twenty facilities the capabilities for
process controllability limited performance to some extent. Adequate control
and measurement of return activated sludge flow was the most frequent reason
for rating the process controllability factor. Good measurement and control
capability of return activated sludge flow was observed in only three of twenty
activated sludge plants surveyed.
The eighth ranked factor limiting plant performance was inadequate sec-
ondary clarifier design. Performance limiting clarifiers were found in eleven
48
-------
plants surveyed and were the leading cause of poor performance in two facili-
ties. The secondary clarifier factor was identified when poor clarification
occurred due to the size of the clarifier, placement of the weirs, weir length
or type of clarifier. The secondary clarifier factor was not noted as a per-
formance limiting factor when solids loss due to a slow settling sludge (i.e.,
bulking sludge) was observed.
The most common clarifier problem observed was a poorly developed clari-
fier surface area. A poorly developed clarifier surface area results in the
inability to maintain uniform upward velocity of treated wastewater so that
the sludge blanket can remain equidistant from the liquid surface (i.e., level)
even when the blanket is within 0.3 m (one foot) of the overflow weirs. The
inability of clarifiers to maintain a sludge blanket in this condition was ob-
served in both circular and rectangular clarifiers, but more often in rectangu-
lar clarifiers where the weirs were placed toward one end. In clarifiers with
a poorly developed surface area, excessive solids carryover occurred even
though relatively good activated sludge settling characteristics existed.
Poor rectangular clarifier design was observed in ten plants surveyed. At
these plants the weir location was typically at one end of the clarifier and
the clarifier inlet and sludge withdrawal points were located at the opposite
end. Excessive solids carryover occurred when the sludge blanket was as much
as 0.9 m (3 feet) to 1.2 m (4 feet) below the liquid surface in the rest of
the clarifier. Poor circular clarifier design was observed at one plant. At
this plant the clarifier was relatively large (diameter of 27.4 m (90 feet))
and had a peripheral feed and peripheral withdrawal design. The center area
of the clarifier was underdeveloped with weirs, and excessive solids carryover
occurred when the sludge blanket was 1.5 m (5 feet) from the liquid surface in
the center area of the clarifier. Good secondary clarifier surface area
development was observed at some facilities surveyed. These clarifiers were
observed to greatly improve the plants' operations capabilities and perform-
ance potential.
Sludge treatment tied with aerators as the ninth ranked performance lim-
iting factor. Inadequate sludge treatment was found in fifteen facilities
surveyed. It was identified as a performance limiting factor when the size
49
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or type of sludge stabilization process limited plant performance directly by
limiting sludge wasting capacity or indirectly by requiring excessive amounts
of operator time which could be more productively spent conducting other tasks.
Sludge treatment was not ranked as a major cause (i.e., 3 points) of poor
performance at any facility surveyed, but its persistant reoccurrence as an
associated factor resulted in the high ranking received. In comparison to
sludge wasting capability which ranked fifth, sludge treatment was not rated
as critical to plant performance as was the need to waste sludge from the
treatment system. Also, it was observed that other approaches could be util-
ized to overcome some sludge treatment limitations. For example, some opera-
tors had initiated sludge hauling to an ultimate disposal site to relieve a
sludge treatment bottleneck. This is not meant to imply that disposal of in-
adequately treated sludge is acceptable. However, substituting ultimate dis-
posal of inadequately treated sludge did provide a temporary alternative for
achieving improved plant effluent quality at some facilities. Recycle flow
streams from sludge treatment processes were evaluated as a separate factor in
the Plant Evaluation Summary weighing table and are discussed later in this
report.
Many inadequacies were observed in the area of sludge handling with re-
spect to acceptable sludge treatment and disposal techniques. In some cases,
the methods used represented a nuisance problem and potential health problem
from the standpoint of being a breeding ground for insects. In other cases,
poor sludge handling was a potential water pollution problem. At one plant
undigested sludge was spread on land adjacent to a stream bed. This procedure
exposed the stream to a possible pollutional load during periods of heavy
runoff and/or created the potential for ground water contamination through
percolation. Fly and odor problems were also evident. This condition was not
rated as a major factor limiting performance because it did not directly
affect plant effluent quality. It did represent a potential stream and ground
water pollutional problem, an aesthetics problem and a potential health prob-
lem. This type of sludge disposal practice was not acceptable, but represented
another aspect of the broad scope of sludge handling problems associated with
wastewater treatment facilities. Two of the ten highest ranking causes of
limited plant performance, sludge wasting capability and sludge treatment, are
50
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sludge handling related. This indicated that a much greater design, operation
and management emphasis must be placed on sludge removal, treatment and dis-
posal capability at existing and proposed treatment facilities.
Deficient aerators were found in nine facilities surveyed and were the
number one cause of limited performance in two facilities. Aerator, as used
in this evaluation, means the facility utilized for the conversion of soluble
organic matter into settleable organic matter. Examples of aerators as used
in this context are trickling filters, activated sludge aeration basins, ro-
tating biological contactors and activated bio-filters. Aerators were as-
signed points (i.e., received 1, 2 or 3 points) when they exhibited limited
capability to convert dissolved and colloidal organic matter to settleable
solids or encouraged the development of an unstable or difficult to control
sludge. Eight of the nine facilities for which an inadequate aerator was
noted as a factor limiting performance were fixed film facilities, including
trickling filters, rotating biological contactors and activated bio-filter
systems. The ninth facility was an activated sludge plant in which the aera-
tion basin which was so small and heavily loaded that it encouraged the devel-
opment of an unstable (i.e., bulky) sludge.
A more intensive investigation was undertaken to examine the differences
in performance between fixed film and suspended growth systems in a separate
study also conducted under this research contract. (2) It was determined that
fixed film facilities in general had a stable effluent quality but marginal
performance in relation to secondary treatment standards. The performance of
these facilities could not be significantly improved with better operations
because major design modifications were necessary. Suspended growth systems
in general had a less stable effluent quality and poorer performance, but
unlike fixed film facilities effluent quality could be significantly improved
through better operations. Based on these conclusions, a general recommenda-
tion was made that a more conservative design approach be considered for fixed
film facilities and better operations be developed for suspended growth facil-
ities.
51
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The ten highest ranking performance limiting factors accounted for the
number one cause of poor performance in twenty-four of the thirty facilities
surveyed. The number one cause in the other six facilities included five ad-
ditional factors which ranked from fifteenth to forty-fourth based on total
points received. These factors are unit process layout, administrative poli-
cies, return process streams, equipment malfunction and industrial loading.
Unit process layout was identified as the number one cause of poor per-
formance at one facility and was documented as a problem at six facilities.
Unit process layout was included as a factor when the physical and/or piping
arrangement of the process units were limiting plant performance. In at least
two facilities the piping arrangement required that parallel units always op-
erate as independent treatment plants. This resulted in doubling plant opera-
tional requirements for small service populations. Dual system operation has
advantages, and flexibility for such operation should be provided; but the
requirement for continuous separate operation limited plant performance in
these instances because the limited time available for process control had to
be split between two independent systems.
Administrative policies were the leading cause of poor performance in two
facilities. Administrative policies limited performance when certain policies
or rules established by the plant's governing body were a direct source of
limited performance. At the two trickling filter plants where performance was
significantly limited by administrative policies, plant effluent quality could
likely have been significantly better if the plants were operated as two-stage
trickling filters and/or with increased filter recirculation. This flexibility
had been incorporated into the plant designs, but it was a policy of each
plant's governing body to continue status quo in favor of reduced power cost.
At another facility the administration had made a decision to not repair an
item of equipment (note: not considered a maintenance problem) because of the
possibility that a new facility would be constructed in the future as the plant
progressed toward the top of the state's priority list for federal grant eligi-
bility. Similarly, at a plant where only a site visit was conducted, the ad-
ministration had made a decision to avoid operations help. In this case it
was an administrative policy to do nothing that would possibly lower the city's
52
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relatively high position on the state's priority list for federal grant as-
sistance. In some plants where administrative policies were rated, the govern-
ing body required unnecessary approval of nearly every decision made by the
operator, which in turn caused necessary tasks affecting performance to be un-
duly delayed.
Administrative policies were observed to indirectly affect plant perform-
ance with respect to the type of person hired as the operator, the attitude
extended toward plant operation and the attitude extended toward plant design.
However, administrative policies were not rated for these reasons. It should
be recognized that elected and/or appointed personnel comprising a plant's
governing body are typically not in a position to evaluate technical policies.
They rely heavily on outside technical guidance, some of which may have been
incorrect. Therefore, some of the policies observed may not necessarily be
the fault of, the administration.
Return process streams tied as the twenty-second highest ranking factor
limiting performance in facilities surveyed. It existed at six facilities and
was the leading cause of poor performance at one facility. The major return
flow stream limiting performance was anaerobic digester supernatant. At the
facility in which the return flow stream factor was the leading cause of poor
performance,the excessive solids concentration of the anaerobic digester super-
natant recycle stream (20,000 mg/1 to 30,000 tng/1) was too great for the
trickling filter wastewater treatment process to adequately handle. Fairly
good trickling filter performance was observed to be associated with four
facilities that did not recycle the anaerobic digester supernatant through
the facility. At these facilities performance was much better than was ob-
served at similar facilities that had anaerobic digester supernatant recycle.
Based on these results it is recommended that strong consideration be given
during a plant design evaluation to treating anaerobic digester supernatant
recycle separately or to increasing, appropriately the wastewater treatment
process unit size to adequately receive and treat this recycle flow.
Equipment malfunction was the leading cause of limited performance in one
facility surveyed and tied as the thirty-second highest ranking performance
53
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limiting factor. Equipment malfunction was rated as a limiting factor when
the breakdown of equipment occurred because of faulty installation or sub-
standard quality. In the identified facility the bearings of the aerators in
a new activated sludge aeration basin failed shortly after the in-plant survey
was completed. The aerators have been replaced. In three other facilities
where equipment malfunction was rated, the facility preventive maintenance pro-
gram was satisfactory and the equipment malfunction was due to sub-standard
quality. In these cases the makes and models of the equipment that was mal-
functioning were no longer manufactured, repair parts were difficult to obtain
and the operators were preparing to replace the equipment with better models.
Industrial loading was a leading cause of poor performance in one facili-
ty surveyed. It tied as the forty-fourth highest ranking cause of poor per-
formance and was found in two facilities surveyed. The infrequency of occur-
rence of industrial loading as a performance limiting factor does not mean
that only a few facilities surveyed had significant industrial contributors.
Many facilities had large industrial contributors; however, industrial loading
was not considered a factor limiting performance when the facility had been
specifically designed to handle the industrial load it was receiving. Another
reason for the infrequency of industrial loading as a performance limiting
factor is that an excessive plant organic or hydraulic overload was part of
the plant selection screening criteria. At the two facilities in which the
industrial loading factor was rated, it had been indicated during the plant
site visit that the facility was designed to handle the organic load from the
industry. However, the extensive investigation during the preliminary survey
revealed that the industrial organic load was much greater than that for which
the facility was designed.
MISCELLANEOUS EVALUATIONS
An evaluation was made of the major performance limiting factors for two
general types of facilities surveyed: suspended growth (i.e., activated
sludge) and fixed film (i.e., trickling filter, rotating biological contactor
- RBC and activated bio-filter - ABF). For both plant types the relative
percentage of performance limiting factors was determined for the four major
54
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areas evaluated: administration, maintenance, design and operation. The re-
sults of this evaluation are illustrated in Figure 6. As shown, maintenance
and administration type problems were relatively minor when compared to the
design and operations problems that were identified.
At fixed film facilities, design features were the most prevalent perform-
ance limiting factors. Within the design category, inadequate aerator capa-
bility occurred most often. In the operations category inadequate operator
application of concepts and testing to process control was found most fre-
quently. Fixed film facility design must include better facilities for or-
ganic conversion to settleable solids to improve plant performance. Also, im-
proved and modified training techniques are necessary to improve operator ap-
plication of concepts and testing to process control.
At suspended growth facilities inadequate plant operation was the most
prevalent group of factors limiting performance. Within plant operation, im-
proper operator application of concepts and testing to process control occurred
most often. Within the design category, inadequate sludge wasting capability
was noted most frequently. At suspended growth facilities better plant opera-
tion practices must be implemented. Also, better facility design, especially
sludge wasting capability, is required.
SUSPENDED GROWTH
FIXED FILM
Figure 6. Types of factors limiting performance in suspended
growth and fixed film facilities.
55
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MISCELLANEOUS
An evaluation was also made of the
operations costs at facilities surveyed.
Cost information for each facility is
shown in Appendix G, and the average for
each cost category is shown in Figure 7.
The size of plants surveyed ranged from
26 to 30,660 cu in/day (0.007 to 8.1
mgd). In Figure 7, all costs to the
users of the treatment facilities are
shown, including the cost of capital
improvements (primarily bond debt re-
tirement) . Nearly one-half of the total
Figure 7. Average treatment costs
user costs was for capital improvements, . n nnn IT ,- ,- •-, . •
* v 'in C/1000 gallons for facilities
even though most facilities surveyed surveyed.
had been built with partial grant
funding. These capital improvement costs were somewhat independent of facili-
ty type and size and more dependent on administrative policies, construction
grant funding opportunities, plant age, bond interest rates, etc. Therefore,
capital improvement cost is not included in the following 0 & M cost compari-
sons among plant size and type.
SUPPLIES
4 8
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TABLE 4. SUMMARY OF COST INFORMATION FOR TYPE AND SIZE OF FACILITY SURVEYED
Parameter
Number of Facilities
Size Range (mgd)**
Salary (c/k gal)***
Utilities (C/k gal)
Supplies (C/k gal)
Chemicals (c/k gal)
Transportation (c/k gal)
Training and Education
(C/k gal)
Miscellaneous****
(C/k gal)
Total - 0 & M Costs*****
(C/k gal)
Suspended Growth
5*
< 0.1
44.8
13.2
11.7
3.0
0.2
0.02
20.3
93.32
12*
0.1-1.0
18.1
12.2
4.4
1.3
1.0
0.1
8.0
45.1
3
1.0-10.0
10.0
4.4
1.0
1.7
0.1
0.03
3.0
20.23
Fixed Film
0 4
< 0.1 0.1-1.0
17.0
4.8
6.9
4.3
0.4
0.2
0.6
34.2
6
1.0-10.0
4.8
1.1
0.6
0.8
0.1
0.02
1.5
8.92
* One plant not included in cost summary; information not available.
** mgd x 3785 = cu m/day
*** (C/k gal) = (C/1000 gal)
**** This category includes costs such as testing by private laboratories, repair services, plant in-
surance, computer service and some consulting services.
Does not include costs for capital improvements (primarily bond debt retirement).
-------
The overall 0 & M costs for dif-
ferent types and sizes of facilities
surveyed are illustrated in Figure 8.
The average cost per unit of flow was
greater for smaller facilities than
for larger facilities, and the average
0 & M cost for suspended growth facili-
ties was more than for fixed film
facilities. The larger fixed film
facilities had the lowest costs. How-
ever, for the thirty facilities sur-
veyed seven were felt to require major
design modifications before minimum
secondary treatment standards could be
met consistently, and all seven were
fixed film facilities. The suspended
RANG
0-0 1 MGD 01-10MGD 10-100MGD
SUSPENDED
01-10 MGD 1 0-10 0 MGD
FIXED FILM
Figure 8. Plant operations costs
for selected flow ranges.
growth facilities surveyed were felt to have the potential for meeting stan-
dards if major operations changes were implemented. If all fixed film facili-
ties had the potential of meeting standards like the suspended growth facili-
ties, then a higher than indicated 0 & M cost for fixed film facilities may
have been reflected. This does not mean that the costs for fixed film facili-
ties would be higher than for the suspended growth facilities, but the costs
could be higher than those shown in Figure 8. The range of 0 & M costs for
the categories evaluated does not provide a basis for straightforward conclu-
sions due to the broad range of costs documented in each category and the
overlapping of costs between categories.
An evaluation was also made of the electrical energy consumption and costs
at facilities surveyed. Data for individual facilities are included in Table
5. At facilities surveyed the cost per unit of electrical power varied from
1.17c/kwh to 3.85c/kwh, including power demand and power factor charges. This
variation of electrical charge inhibits the direct comparison of cost for elec-
tricity. Therefore, the analyses of electrical energy consumption is
presented in terms of usage (kwh per 1000 gallons). Higher energy usage is
shown for suspended growth facilities, especially those with lower wastewater
58
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TABLE 5. ELECTRICAL CONSUMPTION AND COSTS AT FACILITIES SURVEYED
Plant
No.
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
041
047
048
050
053
055
060
061
063
Plant
Type*
ASEA
ODEA
TF/CS
AS
AS
TF
ASEA
ASEA
ODEA
ASEA
ABF
ASEA
AS
ASCS
AS
TF
TF
TF
TF
ODEA
RBC
TF
ASEA
AS
ASEA
ASEA
ASEA
ABF
ASCS
AS
cu m/day
1,628
155
30,660
1,892
3,785
6,434
132
26
2,233
45
18,550
568
20,820
568
5,185
833
20,820
20,060
6,056
795
1,438
492
189
1,287
643
416
1,136
1,855
643
2,650
Actual Flow
mgd** %
0.43
0.041
8.1
0.5
1.0
1.7
0.035
0.007
0.59
0.012
4.9
0.15
5.5
0.15
1.37
0.22
5.5
5.3
1.6
0.21
0.38
0.13
0.05
0.34
0.17
0.11
0.30
0.49
0.17
0.7
Design
54
59
68
63
50
47
54
28
66
80
69
30
55
60
78
50
68
98
87
51
60
33
80
89
96
68
52
47
34
47
KWH/1000
gal***
3.0
3.2
0.83
2.7
2.4
1.0
4.3
_
0.87
-
0.43
—
1.3
2.1
2.7
0.40
-
0.52
0.61
2.3
0.72
1.1
3.1
4.3
2.7
4.2
-
2.3
5.8
-
C/KWH
1.53
3.06
2.28
2.23
1.89
1.50
2.20
_
3.54
—
1.37
—
1.26
2.49
1.17
3.28
-
1.96
2.36
3.85
1.51
2.87
3.24
2.56
3.58
2.96
-
3.31
2.35
—
C/1000 gal
A***
4.6
9.8
1.9
6.0
4.5
1.5
9.5
_
3.1
-
0.6
-
1.6
5.2
3.2
1.3
-
1.0
1.4
8.9
1.1
3.2
10.0
11.0
9.7
12.4
-
7.6
13.6
-
* ASEA - Activated Sludge Extended Aeration
ODEA - Oxidation Ditch Extended Aeration
TF/CS - Trickling Filter Plus Contact Stabilization
AS - Activated Sludge
TF - Trickling Filter
ABF - Activated Bio-Filter
ASCS - Activated Sludge Contact Stabilization
RBC - Rotating Biological Contactor
** mgd x 3785 - cu m/day
*** Kwh/1000 gal x 0.264 = kwh/cu m
**** o/1000 gal x 0.264 = c/cu m
59
-------
flows. However, the contact stabilization facility, Plant 061, which had the
highest energy usage at 1.53 kwh/cu m (5.8 kwh/1000 gal), had dual units
loaded at only 34 percent of design flow. Both units were in service, but
better plant operation could have enabled only one unit to be used. A con-
siderable savings in electricity could have been achieved by taking one unit
out of service. For this reason, as well as the fact that many of the facili-
ties shown in Table 5 were not operating at optimum levels, data presented
should not be interpreted as the most economical use of electrical energy.
60
-------
SECTION 7
WASTEWATER PLANT STAFFING AND PLANT PERFORMANCE
GENERAL
This section describes the results of a special study on wastewater treat-
ment plant staffing conducted as part of the research effort. Plant staffing
was evaluated in detail because of the frequent occurrence and high ranking of
operations related factors limiting the performance of plants evaluated. As
discussed earlier, each preliminary survey involved about one week of on-site
field work. During that week numerous items of information were obtained con-
cerning the facility. Also, an effort was extended toward improving plant per-
formance. Using this approach, research team members worked closely with
plant personnel and were in a position to evaluate their capabilities and
their influence on plant performance.
PLANT STAFFING RELATIONSHIPS AND PLANT PERFORMANCE
The analysis of the facilities' staffing cost included only the personnel
working directly with the plant. As such, city administrators, the town clerk,
staff working on collection lines and other personnel indirectly involved with
the facility were not included. Table 6 presents a summary of staff size and
cost for each of the thirty plants where preliminary surveys were conducted.
The percentage of the plant salary cost to the total operations cost is also
shown. Capital improvement and bond debt retirement costs were not considered
part of the total operations budget and were excluded from this analysis.
In Table 6 three selected unit costs are shown to present staffing infor-
mation for the various sized plants on a common basis. These unit costs are
61
-------
TABLE 6. SUMMARY OF STAFF AND COST FOR THIRTY FACILITIES SURVEYED
Plant No,
-
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
041
047
048
050
053
055
060
061
063
Type
Type of
Treatment
-
Activated
Activated
Trickling
Activated
Activated
Trickling
Activated
Activated
Activated
Activated
Activated
Filter
Activated
Activated
Activated
Activated
Trickling
Trickling
Trickling
Trickling
Activated
Sludge
Sludge
Filter
Sludge
Sludge
Filter
Sludge
Sludge
Sludge
Sludge
Bio-
Sludge
Sludge
Sludge
Sludge
Filter
Filter
Filter
Filter
Sludge
Rotating Bio-
logical Surface
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Filter
Activated
Activated
Filter
Sludge
Sludge
Sludge
Sludge
Sludge
Bio-
Sludge
Sludge
Flow
Actual
Flow of
(mgd)*
0.43
0.041
8.1
0.5
1.0
1.7
0.035
0.007
0.59
0.012
4.9
0.15
5.5
0.15
1.4
0.22
5.5
5.3
2.5
0.21
0.38
0.13
0.05
0.34
0.17
0.11
0.30
0.49
0.17
0.70
Percent
Design
(%)
54
59
68
63
50
47
54
28
66
80
69
30
55
60
78
50
68
98
87
51
60
33
80
89
96
68
52
47
34
47
Staff
Man-
Year
(my)
3.0
0.30
12
3.0
5.0
3.0
0.60
0.26
1.5
0.30
7.3
1.6
7.5
0.88
4.0
0.35
7.0
4.2
3.8
1.0
1.3
1.5
0.30
1.9
0.57
0.73
0.50
3.0
0.80
4.0
Budget
Unit
Staffing Percent of Specific
Costs Operations Staff
Budget Size
($)
28
3
189
34
50
30
5
2
17
3
84
18
118
9
51
3
87
54
49
10
13
15
3
18
7
13
4
36
10
57
,685
,540
,970
,164
,000
,312
,191
,500
,878
,600(est)
,141
,186
,782
,610
,732
,780
,917
,162
,746
,000
,316
.755
,132
,470
,717
,400
,992
.500
,296
,148
(%) (my/mgd)
27.5
17.2
64.0
43.2
49.6
43.1
23.1
52.7
37.0
SO.O(est)
40.5
57.4
43.2
42.2
47.1
30.5
50.4
52.4
58.6
25.0
54.6
56.9
60.0
45.0
30.2
64.8
18.8
45.3
30.9
66.3
7.0
7.3
1.5
6.0
5.0
1.8
17
37
2.5
25
1.5
11
1.4
5.9
2.9
1.6
1.3
0.79
1.5
4.8
3.4
12
6.0
5.6
3.4
6.6
1.7
6.1
4.7
5.7
Relationships
Adjusted
Salary
Specific
Staff
Cost
($/my) (c/k-gal)
9,562
11,800
15,831
'11,388
10,000
10,104
8,652
9,615
11,919
12,000
11,526
11,366
15,838
10,920
12,933
10,800
12,560
12,896
13,091
10,000
10,243
10,503
10,440
9,721
13,539
18,483
9,984
12,167
12,870
14,287
18
24
6.4
19
14
4.9
41
98
8.2
82
4.7
33
5.9
18
10
4.7
4.4
2.8
5.5
13
9.6
33
17
15
12
33
4.6
20
17
22
* mgd x 3785 = cu m/day
62
-------
number of man-years per million gallons per day of sewage treated (my/mgd -
specific staff size), staff cost per man per year ($/my - adjusted salary
cost), and staff cost per one thousand gallons of sewage treated (C/1000 gal -
specific staff cost). Specific staff size relates staff size for all facili-
ties to a common basis of one mgd. Adjusted salary relates staff salary,
including fringe benefits, to a common basis of the salary for one full-time
man for one full year. Specific staff cost relates staff cost to a common
basis for treating one thousand gallons of wastewater.
In Table 6 much scatter exists in the data presented. The actual sewage
flow for facilities ranged from a low of 26 to a high of 30,660 cu m/day (0.007
to 8.1 mgd). Hydraulic loadings on facilities ranged from 28 to 98 percent
of design. Because of the difference in size and type of facilities surveyed,
expected differences occurred in total staff size and associated total salary
cost. Total staff size ranged from 0.26 to 12 man-years. Total staffing cost
ranged from $2,500 to $189,970 per year. At the same time, large differences
existed in calculated unit costs. The specific staff size ranged from 0.79 to
37 my/mgd. The adjusted staff salary cost ranged from $8,652/my to $18,482/my.
The specific staff cost ranged from 2.8C/1000 gal to 98C/1000 gal.
A detailed evaluation of the performance capabilities of each facility
was completed under this research contract. (2) A summary of this information
is presented in this report so that plant staffing can be related to facility
performance. The effluent from 23 of 30 plants evaluated did not consistently
meet minimum secondary treatment standards, even though the mean hydraulic
loading for these twenty-three plants was only about 61 percent of the design
flow. However, sixteen of the twenty-three facilities could meet standards
by implementing changes in plant operation and in some cases minor design
changes. The remaining seven would require substantial design modifications
plus operations changes before standards could be met. The seven facilities
that met standards had an average hydraulic loading of 59 percent of design
flow, which is very similar to those that did not meet standards. Table 7
depicts which treatment facilities are included in each of the three categories
(i.e., standards met; standards not met - operation changes required; and
standards not met - design and operation changes required).
63
-------
TABLE 7. SUMMARY OF PLANT PERFORMANCE
FOR THIRTY FACILITIES SURVEYED
Minimum Secondary
Flow Treatment Standards****
Plant
No.
Actual Percent
Type of Treatment Flow Design Met
(mgd)*
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
041
047
048
050
053
055
060
061
063
Activated
Activated
Trickling
Activated
Activated
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Trickling
Trickling
-Trickling
Trickling
Activated
, Rotating
Surface
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Sludge
Sludge
Filter
Sludge
Sludge
Filter
Sludge
Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
Sludge
Sludge
Filter
Filter
Filter
Filter
Sludge
Biological
Filter
Sludge
Sludge
.Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
0.43
0.041
8.1
0.5
1.0
1.7
0.035
0.007
0.59
0.012
4.9
0.15
5.5
0.15
1.4
0.22
5.5
5.3
2.5
0.21
0.38
0.13
0.05
0.34
0.17
0.11
0.30
0.49
0.17
0.70
Not
Met
(%) - Operation**
54
59
68
63
50
47
54
28
66 X
80
69
30 X
55
60
78
50
68
98 X
87 X
51
60
33 X
80
89
96
68
52 X
47
34
47 X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Not
Met
Design***
& Operation
X
X
X
X
X
X
X
* mgd x 3785 = cu m/day
** Standards could be met with changes in plant operation procedures and in
some cases minor design modifications. (2)
*** Standards could be met with substantial modifications to plant design
and also some changes in plant operating procedures. (2)
**** As defined in Federal Register, Volume 38, Number 159, Part II,
August 17, 1973.
64
-------
EVALUATION OF STAFF SIZE AND COST VERSUS PLANT PERFORMANCE
Among the items associated with good or poor plant performance are plant
type, sewage characteristics, plant design, plant age, staff number and staff
qualifications. The scope of this evaluation included only plant staff con-
siderations. Since plant operators are most directly involved with the treat-
ment facility, it was presumed that they are in a position to directly influ-
ence facility performance. Several staffing relationships that influence
plant performance were investigated. Some biases existed. The facilities
selected for a preliminary survey were screened, as previously discussed, and
surveys were not made at some very small facilities where the operator was
unable to spend an adequate amount of time at the facility to accomplish the
objectives of the research. As such, the staffing number and cost values pre-
sented may be biased upward for the smallest size range of facilities.
Total staff size and total staffing cost were expected to increase as
plant size increases. At facilities surveyed a general increase in staff
size and staff cost versus plant flow rate was observed, as shown in Figures
9 and 10, respectively. However, a large variation in the number of staff
persons and associated staffing cost was observed for any given plant flow
rate. For example, for the three plants whose actual flow was between 0.2 and
0.3 mgd the total number of staff persons ranged from 0.35 to 1.0 my and the
total staffing cost ranged from $3,700 to $10,000/year. For the three plants
whose actual flow was between 5.0 and 6.0 mgd the total number of staff per-
sons ranged from 4.2 to 7.5 my and the total staffing costs ranged from
$54,000 to $118,500/year.
In Figures 9 and 10, fully shaded dots represent plants where standards
were met. If staff size or staffing cost alone were responsible for good
plant perforance, then all or a significant number of plants where standards
were met would have a relatively higher staff size and staff cost. This con-
dition would be represented by a significantly large number of fully shaded
dots above the least squares lines of best fit shown for staff size and staff-
ing cost. However, four of the seven plants meeting standards had relatively
low staff size and staffing costs. Conversely, many facilities where standards
65
-------
DC
111
m
10
1.0
(
r> 1
\ \
\ \
• STANDARDS MET
O STANDARDS NOT MET (DESIGN & OPERATION CHANGE
O STANDARDS NOT MET (OPERATION CHANGESI
CU M/D= MGD " 3785
X
x
-O-
-^r
s
/
y<
s
^
s
r\x^
*' u
,
o
u
^c
3
x
*~
f
\
ry/
X'o
/' w
X
*
y
'?
J
1
1 1
S]
1-
.01
0.1 1.0
PLANT FLOW RATEIMGD)
10
Figure 9. Staff size versus plant flow rate.
1,000,000
oc
LU
-------
were violated had relatively high staff size and staffing cost values. Based
on this data no definite correlation existed between total staff size or total
staff cost and plant performance.
Specific staff size (i.e., staff size per unit of plant flow) and speci-
fic staff cost (i.e., staff cost per unit of plant flow) were also evaluated
respective to plant performance and actual plant flow rate. Specific staff
size versus plant flow rate is shown in Figure 11. Specific staff cost versus
plant flow rate is shown in Figure 12. Significantly wide variations in the
data exist, particularly in plants below 3785 cu m/day (1 mgd). However, the
specific staff size and specific staff cost values, in general, decrease as
the plant flow rate increases. Relative to plant performance, a definite cor-
relation between specific staff size and specific staff cost would exist if a
significant number of fully shaded dots were located near the top of the data
points presented. These points are widely scattered, and for the plants eval-
uated no definite correlation existed. It was concluded that a large specific
Q
o
UJ
N
CO
CO
o
o
UJ
a.
CO
28
24
20
16
12
8
4
0
o
0
'
D
||
• STANDARDS MET
O STANDARDS NOT MET (DESIGN A OPERATION CHANGES!
0 STANDARDS NOT MET [OPERATION CHANGES!
CU M/D = MGD x 3785
MY/CU M/D = 0.00026 MY/MGD
•
O
O
o
o
0
0 '
o
0
p
f
J
«
<
o
o
•
•l
I8
1
5
.01
0.1 1.0
PLANT FLOW RATE [MGD!
10
Figure 11. Specific staff size versus flow rate.
67
-------
SPECIFIC STAFF COST I it/1000 GAL)
>° _L _i N> to w co r
uitn O en o en o in c
V
(
D
(
0..
I
1
1
1
• STANDARDS MET
O STANDARDS NOT MET
(DESIGN & OPERATION CHANGES!
O STANDARDS NOT METIOPERATION CHANGESI
CU M/D=MGDX3785
«/1000 L = 3.785 x «/1000 GAL
o
0
o
D
O 4
Q
IS
(i
C
O
•
1
1
p
o
o
t
»
.01
0.1 1.0
PLANT FLOW RATE IMGD]
10
Figure 12. Specific staff cost versus plant flow rate.
staff size and high specific staffing cost did not alone improve plant perform-
ance. Conversely, a small specific staff size and low specific staffing cost
were not alone responsible for poor plant performance.
An evaluation was also made to determine if higher salaries correlated
with good performance by attracting more highly qualified personnel. Figure
13 shows the relationship between staff salary, plant flow rate and plant per-
formance. It should be noted that staff salary includes base pay plus fringe
benefits and that part time salaries were developed on a basis of one man for
one year- Staff salary appeared to increase as plant flow rate increased.
This fact is noteworthy and. will be discussed later in this report. A corre-
lation between staff salary and plant performance would be indicated on Figure
13 if the fully shaded dots were located near the top of the data points pre-
sented. These points again are widely scattered, and for the plants evaluated
staff salary alone does not. appear to be responsible for good or poor plant
performance.
68
-------
18,000
16,000
14,000
cc
< 12,000
U_ 10,000
00
8,000
6,000
.01
>
o
J
c
>
o
• STANDARDS MET
O STANDARDS NOT M
(DESIGN & OPERAT
O STANC
CU M/D
o
o
1
•
O
»
)AR
= Ml
0
0
OS NOT ME
3D x 3785
P
C
0
1
1
1
ET
ION CHANGES!
T [OPERATION CHANGES!
O
ft
C
-
;•
0
o
J
--
K
-
-
-
>
—
— i —
-t
-+-
0.1 1.0
PLANT FLOW RATE I MGD )
10
Figure 13. Staff salary versus plant flow rate.
Another correlation evaluated was the percentage of staffing cost to the
total operations budget. This evaluation is shown in Figure 14. As shown,
the percent of staff cost to the total operations budget varied from 17 percent
to 67 percent and did not appear to correlate directly with good or poor plant
performance. Good plant performance occurred at a staff budget percentage of
less than 20 percent. However, 5 of the 7 good performing facilities had
staff budget percentages greater than 50 percent. The implications of this
data are difficult to interpret, especially in view of the fact that total
staffing cost and staff salary alone did not appear to correlate with good
plant performance. A possible explanation could be that the high staffing
budget percentage reflects competent operations judgement on the part of the
operators, which reduced other operation expenditures and therefore propor-
tionally elevated the staff cost in relation to the total operations cost.
Competent staffing will be discussed further.
69
-------
UJ
O
Q
ID
m
co
U. LU
LL Q.
< O
CO -J
80
70
60
50
40
30
20
10
1
Q
• STANDARDS MET
O STANDARDS NOT MET [DESIGN 4 OPERATION CHANGES!
O STANDARDS NOT MET (OPERATION CHANGES!
CU M/D = MGD x 3785
O
<
>
O
•*
O
fi
a
0
4
0
0
c
O
i
«
i
1
V,
O
O
f>
n
0
(
>
.01
0.1 1.0
PLANT FLOW RATE (MGDl
10
Figure 14. Staff cost versus plant flow rate.
EVALUATION OF STAFF ADEQUACY AND PLANT PERFORMANCE
An adequate plant staff to achieve good plant performance incorporates
many features. Four items of particular importance are sufficient manpower
for maintenance, sufficient manpower for operations, judicious use of availa-
ble operations time and competency in making wise operations decisions. These
items were individually evaluated for the thirty plants surveyed.
To evaluate manpower for maintenance and operations activities a rating
was given ranging from good to poor, where:
Rating
Good
Fair
Marginal =
Poor
Points
0
1
2
3
Description
Sufficient number of manpower available
Additional manpower helpful
Additional manpower desirable
Additional manpower necessary
70
-------
Results are shown in Table 8. Manpower adequacy was quite good for near-
ly all facilities surveyed. In only two instances was plant maintenance man-
power marginal and in only two instances was plant operations manpower margin-
al.
TABLE 8. MANPOWER ADEQUACY FOR THIRTY FACILITIES SURVEYED
Plant
No.
Flow
Type
Manpower Adequacy**
Actual Percent
Flow of Design Maintenance
Operations
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
Activated
Activated
Trickling
Activated
Activated
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Trickling
Trickling
Trickling
Trickling
Activated
Rotating
Sludge
Sludge
Filter
Sludge
Sludge
Filter
Sludge
Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
Sludge
Sludge
Filger
Filter
Filter
Filter
Sludge
Biological
Surface
041
047
048
050
053
055
060
061
063
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Filter
Sludge
Sludge
Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
0.43
0.041
8.1
0.5
1.0
1.7
0.035
0.007
0.59
0.012
4.9
0.15
5.5
0.15
1.4
0.22
5.5
5.3
2.5
0.21
0.38
0.31
0.05
0.34
0.17
0.11
0.30
0.49
0.17
0.70
54
59
68
63
50
47
54
28
66
80
69
30
55
60
78
50
68
98
87
51
60
33
80
89
96
68
52
47
34
47
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
2
0
0
0
2
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
2
0
0
0
* mgd x 3785 = cu m/day
** Good = 0; Fair = 1; Marginal = 2; and Poor = 3
71
-------
A summary of manpower adequacy for selected flow ranges is shown in Table
9. Adequate manpower for maintenance was not considered to be a significant
problem in any plant size range. In nearly all facilities surveyed, key equip-
ment was observed to be in good operational condition and was adequately
maintained. Also, the operators appeared to have sufficient knowledge or ac-
cess to knowledgeable persons in the general areas of preventive and emergency
maintenance. Staff manpower for operations was also considered quite good.
The only exception was for the smaller facilities 0 - 380 cu m/day (0 to 0.1
mgd), where operations manpower was rated at an overall value of 0.6 points.
This rating was still fairly good, but poorer than the other sized facilities.
It should be noted that none of the plants in this lower flow range met mini-
mum secondary treatment standards.
TABLE 9. MANPOWER ADEQUACY FOR SELECTED FLOW RANGES
Flow Range
(mgd)**
0. - 0.1
0.1 - 1.0
1.0 - 10
Number of
Plants
Surveyed
Average
for
Staff Adequacy*
Manpower
Maintenance Operations
5
17
8
0
0.24
0
0.60
0.12
0.13
* Good = 0; Fair = 1; Marginal = 2; and Poor = 3
** mgd x 3785 = cu m/day
Since it was concluded that a lack of adequate manpower to accomplish the
needed maintenance and operations tasks was not a problem, it may be that
judicious .use of available operations time and/or a lack of competency in
making wise operations decisions accounts for much of the observed poor plant
performance.
Judicious use of available time was further investigated in two plants
surveyed by determining the relative amount of time spent conducting "opera-
tions" tasks, "maintenance" tasks and "other" tasks. Operations tasks included
plant observation, sampling, laboratory testing, process control adjustments,
72
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data calculations, etc. Maintenance tasks included housekeeping, preventive
maintenance and corrective maintenance activities. Other activities included
coffee breaks, non job-related discussion sessions, etc. A summary of the
percentages of time spent at each of the three categories of tasks is shown in
Table 10.
TABLE 10. SUMMARY OF OPERATOR TIME CONDUCTING "OPERATIONS",
"MAINTENANCE" AND "OTHER" TASKS FOR TWO FACILITIES SURVEYED
Plant No.* Plant No.*
048 060
Activated Sludge Activated Bio-Filter
Percent of Time Spent on
"Operations" Tasks
Percent of Time Spent on
"Maintenance" Tasks
Percent of Time Spent on
"Other" Tasks
58
36
63
33
^Neither treatment facility met minimum secondary treatment standards.
A lesser amount of time (i.e., 36% and 33%) was spent on maintenance tasks,
but both plants had relatively good maintenance as evidenced by the general
appearance and condition of the plant equipment. The majority (i.e., 58% and
63%) of the operators' time was spent conducting operations tasks including
laboratory testing and making operational adjustments. Although not evaluated
in the detail that was used for Plants 048 and 060, it was observed that at
most of the thirty facilities surveyed; the majority of the available staff
time was used for operations oriented activities. It was concluded that the
lack of operations time was not a major performance limiting factor.
Since operation time was not a factor, possibly operators' competency
in making wise operations decisions was a performance limiting factor. An
evaluation was conducted for all facilities surveyed utilizing a rating
system to evaluate operator capabilities whereby:
73
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Rating Points Description
Good 0 Adequate capability - good judgement in
nearly all areas.
Fair 1 Poor judgement in some areas.
Marginal 2 Poor judgement in most areas.
Poor 3 Inadequate capability - poor judgement
in nearly all areas.
Results are shown in Table 11. Operator capabilities were given greater
weight if the plant staff, primarily the operations decision making individual,
was not making appropriate decisions to optimize plant performance. For exam-
ple, a poorer rating was given if available process controls were not appro-
priately used, if appropriate process control testing was not being completed,
or if operational decisions were made that resulted in poorer rather than
improved plant performance. Examples of operations tasks that were conducted
without a complete understanding of fundamental concepts of operation to pro-
cess control include: activated sludge not being wasted because it "completely
burned itself up," activated sludge return flow rates being set significantly
too high or too low, activated sludge settling tests used to determine sludge
concentration results without regard to sludge quality characteristics (i.e.,
bulking sludge) and trickling filter recirculation flow directed through the
primary clarifier without regard to decreased clarifier performance from the
higher clarifier overflow rate.
To obtain a good rating in making competent operations decisions, the
operator was required to understand the important concepts of operation rela-
tive to his facility and to make appropriate adjustments with available pro-
cess controls. Additionally, the operator was required to recognize the need
for a minor plant design modification which was necessary for him to make the
appropriate process adjustments. It may be concluded that the requirement to
recognize design limitations is not the operator's responsibility. However,
it was observed that operators who understood the concepts of process control
and recognized the need for design modifications were in a position to correct,
or at least identify and document the design problems that existed. Most op-
erators with good capabilities were able to correct minor plant limitations.
74
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This is not meant to imply that operators should design plants or indiscrimi-
nately make design changes, but rather that operator changes to design can be
extremely beneficial to improving plant performance if changes are based on
correct concepts of operation.
TABLE 11. CURRENT OPERATIONS CAPABILITIES OF EXISTING STAFF PERSONNEL
AT THIRTY FACILITIES SURVEYED
Plant
No.
Type
Flow
Actual Percent
Flow of Design
(mgd)* (%)
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
Activated
Activated
Trickling
Activated
Activated
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Trickling
Trickling
Trickling
Trickling
Activated
Rotating
Sludge
Sludge
Filter
Sludge
Sludge
Filter
Sludge
Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
Sludge
Sludge
Filter
Filter
Filter
Filter
Sludge
Biological
Surface
041
047
048
050
053
055
060
061
063
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Activated
Filter
Sludge
Sludge
Sludge
Sludge
Sludge
Bio-Filter
Sludge
Sludge
0
0
8
0
1
1
0
0
0
0
4
0
5
0
1
0
5
5
2
0
0
0
0
0
0
0
0
0
0
0
.43
.041
.1
.5
.0
-7
.035
.007
.59
.012
.9
.15
.5
.15
.4
.22
.5
,3
.5
.21
.38
.31
.05
.34
.17
.11
.30
.49
.17
.70
54
59
68
63
50
47
54
28
66
80
69
30
55
60
78
50
68
98
87
51
60
33
80
89
96
68
52
47
34
47
Staff Adequacy
Current
Operations
Capabilities
Good Fair Marginal
1
2
2
2
0
1
1
2
1
2
1
2
1
0
1
2
2
2
2
1
2
Poor
3
3
3
3
3
3
3
3
3
* mgd x 3785 = cu m/day
75
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As shown in Table 11, nine facilities had operators that were considered
to be implementing poor (i.e., received 3 points) operations practices. Only
two facilities had operators that implemented good practices, and many opera-
tors implemented fair to marginal practices. It should be noted that plant
operators were not necessarily given a good rating if their facility met sec-
ondary treatment standards. Some facilities that met standards did so because
of conservative plant design and not necessarily because of good plant opera-
tion. These plants could have achieved significantly better performance with
good operation.
A summary of the current operations practices for selected flow ranges of
the facilities surveyed is shown, in Table 12. None of the three flow ranges
had good staff adequacy in making wise operational decisions and in implement-
ing good operations practices. It appears that significant problems in plant
operation are occurring in the smaller facilities, but at the same time a
large number of operations problems also occur in the larger facilities. The
need to improve operations practices at all sizes of facilities is equally
warranted.
TABLE 12. SUMMARY OF CURRENT OPERATIONS CAPABILITIES FOR SELECTED FLOW RANGES
Flow Range
Number of
Plants Surveyed
Staff Adequacy*
Current Operations
Capabilities
(mgd)**
0.0 - 0.1
0.1 - 1.0
1.0 - 10.0
5
17
8
2.8
1.9
1.4
* Good = 0; Fair = 1; Marginal = 2; Poor = 3
** mgd x 3785 = cu m/day
Currently, staff adequacy in making wise operations decisions contributes
significantly to the existing poor plant performance that was documented. Two
possible reasons for this occurrence were evaluated. They are:
76
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1. Existing operations personnel are not suited for their jobs.
2. Existing operations personnel have not developed and/or are not al-
lowed to implement their capabilities.
The first reason implies that the existing operators cannot adequately
operate treatment facilities because they do not have the required aptitude.
The second reason implies that most operators have an adequate aptitude, but
have either not developed their abilities and/or have not been allowed to ex-
ercise their abilities because of other influences on the plant. In an attempt
to reach a conclusion as to where the problem area occurs, an evaluation was
made, of the potential operations capability of existing operators. The eval-
uation criteria assumed that the operators would receive technical guidance
and training at their facility. The rating system ranged from 0 to 3 points
as follows:
Rating
Good
Fair
Marginal
Poor
Points Description
0 Excellent aptitude and attitude to
accept and Implement technical gui-
dance and training received in a short
period of time.
1 Satisfactory aptitude and attitude to
accept and implement technical guidance
and training received, but would re-
quire a longer period of time.
2 Unsatisfactory aptitude and/or atti-
tude to accept and implement technical
guidance and training received and
would require a significantly long
time period.
3 Unsatisfactory aptitude and/or atti-
tude not conducive to further training.
The results for the potential operations capability of existing staff per-
sonnel are shown in Table 13. As shown, operators at many facilities had good
77
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TABLE 13. POTENTIAL OPERATIONS CAPABILITY OF EXISTING PERSONNEL
AT THIRTY FACILITIES SURVEYED
Plant
No.
-
002
007
012
013
014
015
019
020
021
022
024
026
027
028
029
032
034
035
036
039
040
Type
-
Activated
Activated
Trickling
Activated
Activated
Trickling
Activated
Activated
Activated
Activated
Activated
Filter
Activated
Activated
Activated
Activated
Trickling
Trickling
Trickling
Trickling
Activated
Rotating
Sludge
Sludge
Filter
Sludge
Sludge
Filter
Sludge
Sludge
Sludge
Sludge
Bio-
Sludge
Sludge
Sludge
Sludge
Filter
Filter
Filter
Filter
Sludge
Biological
Surface
041
047
048
050
053
055
060
061
063
Trickling
Activated
Activated
Activated
Activated
Activated
Activated
Filter
Activated
Activated
Filter
Sludge
Sludge
Sludge
Sludge
Sludge
Bio-
Sludge
Sludge
Flow
Actual Percent
Flow of Design
(mgd)*
0.43
0.041
8.1
0.5
1.0
1.7
0.035
0,007
0.59
0.012
4.9
0.15
5.5
0.15
1.4
0.22
5.5
5.3
2.5
0.21
0.38
0.13
0.05
0.34
0.17
0.11
0.30
0.49
0.17
0.70
(%)
54
59
68
63
50
47
54
28
66
80
69
30
55
60
78
50
68
98
87
51
60
33
80
89
96
68
52
47
34
47
Staff Adequacy
Potential Operations Capability**
Good
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Fair
1
1
1
1
1
1
1
1
1
1
Marginal Poor
2
2
2
2
2
2
* mgd x 3785 = cu m/day
** Good = 0; Fair = 1; Marginal = 2; and Poor = 3
78
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and fair potential operations capability. None had poor potential operations
capability and only a few had marginal capability. The potential capability
of the operators in all plants was significantly better than the existing capa-
bility which was shown in Table 12 (i.e., current capability). The conclusion
was that significant improvements are possible in current operations practices
when it is considered that the existing operators would have access to proper
technical guidance and training at their facility.
A summary of the potential operations capability for selected flow ranges
is shown in Table 14. The potential staff operations capability of the small-
est sized facilities was fair, for the intermediate sized facilities was good
to fair, and for the largest sized facilities it was quite good. It appears
that the larger facilities have personnel with a better aptitude for plant op-
erations responsibilities. However, this does not imply that the operators at
the smaller facilities should be replaced. The potential operations capability
rating for the operation of the smaller sized facilities was acceptable. It
does indicate that the operators at the smaller facilities will probably re-
quire proportionally more technical guidance and training relative to- the size
of the facility and therefore should be incorporated into a program that in-
cludes the necessary operations expertise (i.e., regional management or on-
going 0 & M assistance).
TABLE 14. SUMMARY OF POTENTIAL STAFF OPERATIONS CAPABILITY AND
STAFF SALARY FOR SELECTED FLOW RANGES
Flow Range
(mgd)**
0 - 0.1
0.1 - 1.0
1.0 - 10.0
Number of
Plants Surveyed
-
5
17
8
Average Staff
Salary
($/my)
10,501
11,632
13,107
Potential Operations
Capability*
-
1.0
0.88
0.23
* Good = 0; Fair = 1; Marginal = 2; Poor = 3
** mgd x 3785 = cu m/day
79
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Also shown in Table 14 is the average staff salary for the selected flow
ranges. Staff salary correlates well with the potential operations capability
of the existing operators. As the potential operations capability improves
the staff salary increases. A higher salary also correlates well with better
current operations practices as shown in Table 12. However, in Figure 13 it
was shown that a high salary alone was not instrumental in allowing plants to
achieve good performance. It was concluded that a higher salary encourages
operators to the wastewater treatment field that have a better aptitude for
understanding the concepts of operation, but does not provide operators who
can develop proper operation techniques on their own. To encourage personnel
with better potential operations capability into the field of wastewater treat-
ment operation, paying a higher and more adequate salary should be encouraged.
This recommendation must be coupled with an improved approach for operators to
obtain adequate technical guidance and training if an overall improvement in
plant effluent quality is to be achieved.
Improved technical guidance and training will require many modifications
to existing programs and approaches. In many cases operator development has
been limited because conflicting and confusing concepts of plant operation
exist in various training texts and because misleading technical guidance has
often been given. Improper technical guidance was the third highest ranking
performance limiting factor noted in this research project. In other cases
operators have not been able to exercise their capabilities because they are
in a lesser position than others who also Influence plant operation like the
district manager, city engineer, design engineer, state and/or federal regula-
tory agency personnel and federal, state and/or local training officials.
These officials have exerted external pressures that have forced many operators
to maintain "status quo" with their facilities. Three specific recommenda-
tions are made relative to these observations:
1. Conflicting or confusing concepts of plant operation should be veri-
fied for accuracy by plant operation and design specialists and eli-
minated from training texts so that operators may be better able to
more accurately develop their abilities.
80
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2. Proper technical guidance should be given at individual facilities
with consideration to the time required for changes to the biological
system so that operators may learn from the changes that occur and
further develop their plant operations abilities.
3. Proper technical guidance in plant operation should be expanded to
include others who influence plant operators so that the operators'
abilities gained may be implemented to improve plant performance with
appropriate supervision and encouragement.
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SECTION 8
EVALUATION OF EXISTING PROGRAMS IN RELATION TO FACTORS LIMITING PERFORMANCE
The majority of treatment facilities evaluated in this research project
(23 of 30) did not meet federally defined minimum secondary treatment stan-
dards. National trends also confirm that many facilities are not operating at
a satisfactory level of performance. (3) As discussed in the previous sec-
tions of this report, the leading cause of limited plant performance varies
from one plant to another and several factors were noted to contribute to
limited performance in each individual plant. Each of these factors must be
addressed at an individual facility before that facility will achieve optimum
performance. Many of the causes of poor performance have been the subject of
existing programs which were developed specifically to eliminate one particu-
lar factor or group of factors which limit plant performance. These programs
were not evaluated per se, but are discussed in this section of the report as
they relate to the observations and conclusions of the research study.
The established programs that influence plant performance can be sepa-
rated into categories depending upon the factors limiting performance they are
designed to address. These categories are discussed as: 1) administrative
oriented programs, 2) design oriented programs and 3) operations and mainte-
nance oriented programs. Programs that address administrative factors include
the NPDES permit and permit enforcement programs. Those that address design
oriented factors include construction grants, technology transfer, state and
federal established design criteria and/or guidelines, and value engineering.
Operations and maintenance oriented programs include general and plant speci-
fic 0 & M manuals; federal, state and local operator training; state operator
certification and plant start-up assistance.
82
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The existing program that has the greatest potential of influencing
wastewater treatment plant performance is the NPDES permit program. Based on
the objectives of the permit program it is no longer adequate to simply keep
a plant running. The permit program requires a totally new approach in that a
specific degree of treatment is required from every facility. Maximum bene-
fit is achieved from the permit program when it creates an awareness in plant
administrators that they must have an acceptable effluent from their plant.
The self-monitoring aspect of the permit program provides plant performance
information and should emphasize the need for better treatment to both the
facility's operation and administration personnel. However, poor performance
data alone has not caused administrators to initiate actions at many facilities
that violate their permit standards.
Enforcement of NPDES permit requirements has served to provide more
incentive for plant administrators to initiate programs to improve performance.
However, the typical approach observed to achieve compliance was to expand the
facilities by completing some type of construction program without a complete
knowledge and understanding of all factors adversely affecting performance.
For example, at two facilities evaluated the plant design capacity had recent-
ly been doubled; however, neither upgraded facility met permit requirements
for secondary treatment. Additionally, these two major facility upgrades
would not have been required if the priority factors limiting performance had
originally been addressed. Only minor facility modifications would have been
necessary. The original facilities' capability had not been adequately ad-
dressed in the federally funded "201" facilities planning process, and the
overall effort to achieve permit compliance was unsuccessful. Regulatory
agencies could change this approach by encouraging the optimization of the
operational capability of existing plants before a major facility upgrade is
pursued. This suggestion must be implemented with caution due to the wide-
spread prevalence of improper technical guidance provided by both design engi-
neers and state and federal regulatory personnel documented in this research
project and the associated widespread inability of these persons to evaluate
or monitor the evaluation of existing facility capability. It was concluded
that enforcement of the NPDES permit program can provide an incentive to plant
administrators to implement programs to improve performance. However, a more
83
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thorough investigation into existing facility capability through Improved
0 & M is necessary prior to selecting a major plant modification alternative.
This conclusion applies whether facilities are evaluated as part of the fed-
eral "201" facilities planning process or are evaluated outside the scope, of
the federal construction grants program.
The federal construction grants program has encouraged new construction
and upgrades of many wastewater treatment facilities. A large amount of fund-
ing has been available and many consulting engineers and equipment suppliers
have been encouraged to enter the field of wastewater treatment. Local con-
sulting engineers whose expertise was in highways, drainage, hydraulics, etc.
began designing wastewater treatment plants. Equipment suppliers began to
market new equipment to fill the need for the many new and upgraded plants.
Many of these engineers and suppliers were not experienced in all facets of
wastewater treatment. Most engineers and equipment suppliers who entered the
wastewater treatment field were conscientious and sought assistance in plant
design. Assistance was available from information disemination programs like
technology transfer and from federal and state design criteria materials.
These programs and materials provided useful design supplements, but they were
not developed to provide a basis for a comprehensive design. Technology trans-
fer programs were oriented toward process selection and facilities planning
rather than plant flexibility, process controllability and other plant 0 & M
requirements. Design criteria materials were typically broad in scope and
presented only the minimum design requirements. Using this information facil-
ities and equipment were designed and constructed without a thorough under-
standing of the operation and interrelationships of wastewater treatment plant
processes. The result has been marginally designed facilities and equipment
that have limited plant operation and performance. This chain of events may
have occurred by necessity in order that many treatment facilities be con-
structed in a short period of time. The established design criteria materials
and technology transfer programs have been and continue to be important as sup-
plements to a complete design. As such, they should be re-evaluated and re-
structured to include and emphasize the documented high ranking factors which
limit performance.
84
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The value engineering program was recently established in the EPA's
continuing effort to achieve cost-effective, well designed facilities. Two
areas of concern exist with respect to value engineering in view of the high
ranking of certain causes of limited plant performance noted in this research
effort. One concern is that design engineers with operations experience are
limited, as evidenced by the large amount of improper technical guidance noted;
thus only a limited number of good comprehensive value engineering analyses
can be conducted. The second concern is that the actual or implied emphasis
on a cost savings from a value engineering analysis, coupled with improper
technical guidance, combine to potentially disallow plant features that would
improve plant operation and performance. For example, some plant flexibility
and controllability features whose absence was noted repeatedly in plants sur-
veyed could be considered nonessential features in a value engineering analysis
and subsequently eliminated from a plant design as a cost savings measure.
Value engineering analyses can be beneficial, but all value engineering analy-
ses must be conducted with an appropriate appreciation for plant operation so
that design features that potentially aid in process control are not excluded
as cost saving measures but, rather are included if not present.
The federal, state and local operator training and state operator certi-
fication programs are generally geared toward the development of a broad scope
understanding of sewage treatment, yet inadequate sewage treatment understand-
ing ranked high as a factor limiting plant performance and training ranked
relatively low. Training was rated when operators did not participate in ex-
isting available training programs, thus most operators had attended training
programs. The conclusion was that existing training programs did not provide
the basis and motivation to develop good sewage treatment understanding. If
operators attended training programs but had poor sewage treatment understand-
ing, it may be argued that they have inadequate aptitude. However, in the pre-
ceeding section of this report it was judged that plant operators had rela-
tively good aptitude. It was concluded that existing operator training pro-
grams are not sufficient and should be expanded and upgraded to incorporate
new and better training materials and techniques into their curriculum. An
example new technique is described later in this report.
85
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Other major limitations of existing training programs were noted during
the research effort. Training programs were sources of improper technical
guidance and have exposed operators to many different approaches to process
control, some of which were confusing, conflicting or incorrect. For example,
operators related that they had been told at training classes to adjust their
mixed liquor suspended solids concentrations to specific values, but to waste
only on an infrequent basis. The end result was that improper classroom solu-
tions were being implemented in facility operations which caused poor perform-
ance to continue. Increased operator training is essential, but operator
training material should be routinely verified for accuracy by plant operation
and design specialists and inaccurate information should be eliminated from
training materials.
Improved training techniques and corrected operator training material can
provide operators with better sewage treatment understanding. However, many
operators were unable to apply information received at training sessions to
their plants' operation. Training was usually associated with certification,
and facts rather than concepts were stressed. Also, operators typically re-
ceived general training in a classroom or at another facility and did not
apply this training to their facilities which had a different piping arrange-
ment, different valving procedure, different basin size plus other differences.
For example, the operator may have been told in a classroom that the return
activated sludge flow rate was usually adjusted with variable speed pumps,
and since the operator did not have variable speed pumps in his plant he
ignored return flow adjustments rather than searching for alternative methods.
In conclusion, operator training and certification programs were developed to
provide operators with good sewage treatment understanding, which they did
with some degree of success. However, these programs generally did not pro-
vide operators with the skills to correctly apply concepts of operation to
process control at their individual facilities. In order to correctly apply
wastewater concepts to process control, an operator's skills should be developed
through proper technical guidance at the operator's facility under the direc-
tion of qualified personnel. This would require dramatic changes in existing
training techniques which will be discussed later in this report.
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At facilities surveyed it was observed that plant specific 0 & M manuals
generally included good maintenance information and good descriptions of the
plant's flow schematics, flexibility and controllability. On the other hand,
misinformation and/or insufficient information on the use of plant features
was included in most manuals, and overall it was observed that 0 & M manuals
by themselves did not provide operators with an ability to apply concepts of
operation to process control. The use of 0 & M manuals did not lead to good
operations practices, but were beneficial as a reference for plant maintenance
and various piping arrangements described therein.
Few maintenance problems were noted at facilities surveyed. One reason
for good facility maintenance was attributed to the use of maintenance oriented
0 & M manuals. Another reason was that good plant "performance" has histori-
cally been judged by the appearance and operational state of equipment rather
than effluent quality. As a result, plant operators have worked diligently
on plant maintenance. A third and probably primary reason for good mainte-
nance was that maintenance problems are highly specific and visible and can
be directly related to a piece of equipment that is malfunctioning. As such,
operators, supervisors, regulatory agency personnel and others have quickly
recognized maintenance problems. The quick assessment and correction of a
maintenance problem was responsible for the low ranking of maintenance related
factors limiting performance determined in this research. Good plant mainte-
nance should continue to be stressed, but it should be recognized that a well
maintained plant is only a base level from which to work toward good perform-
ance.
The federal construction grant program has recently included plant start-
up assistance conducted by the plant design engineer or others identified by
the design engineer as a grant eligible cost. This assistance program has
much potential to improve plant performance due to the mutual on-site effort
by both the design engineer and plant operator to achieve a well performing
facility. A potential problem exists with the start-up assistance endeavor if
it consists of equipment start-up only and not process start-up. Plant start-
up assistance must not be limited to equipment start-up and hydraulic checks,
but must include process start-up and most importantly a transfer of the proper
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application of concepts of process control to the plant operators so that a
high quality effluent may be discharged. Even with a process start-up empha-
sis improper operations procedures and poor plant performance may continue
because of the limited operations experience by design engineers, as evidenced
by the high ranking of the improper technical guidance and design limiting
factors noted in this research. Process start-up by design engineers will
provide opportunities for operations experience presently not available. Be-
cause of this experience, plant effluent quality will eventually improve, not
only due to the on-site training the operator will receive but also due to the
training that the start-up assistance personnel will obtain.
Grant eligible start-up assistance applies only to new or upgraded facili-
ties. Serious problems were observed at existing facilities that are not
eligible for start-up assistance. Many of these facilities were less than
five years old and were not meeting permit standards. Typically, these facili-
ties had problems in all four major areas evaluated: design, operation, main-
tenance and administration, but the approach to solve the problem was usually
to expand the plant. One option that was not being investigated was technical
assistance in plant operation. It is recommended that plant administrators
be encouraged to obtain operations technical assistance as an option to plant
expansion, or at least prior to plant expansion, in the effort to improve
plant performance. At the same time existing programs discussed in this
section of the report should be directed toward encouraging and supporting
this option. The benefits of technical assistance in plant operation are des-
cribed in the next section of the report.
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SECTION 9
METHODS OF ACHIEVING OPTIMUM PLANT PERFORMANCE
Previous information developed in this report indicates that a broad
range of diverse factors limit performance at most existing treatment facili-
ties. The analysis of individual factors did not lead to specific recommenda-
tions that could be implemented on a broad scale to improve overall plant per-
formance. The evaluation of existing programs indicated that even if these
programs were continued, optimum performance still would not be achieved at
many facilities. The types of factors limiting performance and the numerous
programs to attain their correction indicates the complexity of the 0 & M
problem. In this section of the report, the relationship between the problems
and solutions is described in a "Unified Concept for Achieving Optimum Plant
Performance." The concept describes the interrelationship among the factors
limiting performance and the correction programs that have been and should be
implemented to address these factors.
UNIFIED CONCEPT FOR ACHIEVING OPTIMUM PLANT PERFORMANCE
The Unified Concept for Achieving Optimum Plant Performance is illus-
trated in Figure 15. The goal is to obtain optimum performance from a given
treatment plant. The horizontal line represents the position of a treatment
facility with respect to optimum performance. The length of the horizontal
line represents the magnitude of less than optimum performance. Factors
limiting performance tend to increase the length of the horizontal line and
move a plant further away from the goal. These factors are indicated by the
number of arrows pointing downward and their relative severity is indicated
by the length of the arrows. A large number of factors and/or a few severe
factors would cause a facility to be far removed from optimum performance.
-------
The elimination of factors limit-
ing performance through the implementa-
tion of a correction program would tend
to move a plant's position closer to-
ward the goal of optimum performance.
Correction programs are indicated by
the arrows pointing upward, as shown on
Figure 15= The length and number of
upward arrows indicates the relative
influence and number of correction pro-
grams applied to a given treatment
facility. As factors limiting perform-
ance are eliminated by correction
programs, the plant's position moves
closer toward optimum performance and
GOAL
OPTIMUM PERFORMANCE
FACTORS LIMITING PERFORMANCE
Figure 15. Unified Concept for
Achieving Optimum Plant Performance.
the length of the horizontal line becomes shorter, indicating fewer or less
severe performance limiting factors remain between the current plant status
and optimum plant performance.
As described in the Unified Concept, all of the factors limiting perform-
ance must be addressed and eliminated through some type of correction program
to achieve the desired performance goal. The term correction program is used
to describe any public or private activity, national, regional or local in
scope that eliminates the effect of an adverse factor or group of factors and
causes a facility to move toward optimum performance. Correction programs
to eliminate factors affecting plant performance are many and varied, probably
because the factors that need to be eliminated are so diverse. In this sec-
tion the multitude of correction programs are not discussed separately. Rather,
correction programs are divided into two groups identified as Individual Cor-
rection Programs and a Composite Correction Program.
INDIVIDUAL CORRECTION PROGRAMS
An Individual Correction Program is implemented with the purpose of ad-
dressing and eliminating specific factors or groups of factors at all or at a
90
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large number of facilities. The role
of Individual Correction Programs in
the Unified Concept is depicted in
Figure 16. Three example correction
programs used are the construction
grants program, the NPDES permit en-
forcement program and operator training
programs. These correction programs
attempt to improve performance at many
treatment facilities by directing their
activities toward specific factors
limiting performance at a large number
of plants. The construction grants
program focuses on the construction of
new or upgrading of existing facili-
ties, and thereby addresses factors
0 O A L
OPTIMUM PERFORMANCE
PL ANT
POSITION 2
T
T
T
i PLANT
\POSITION 1
[/UTMRS LIMITING PERFORMANCE
ADMINI5, THA I ION
MA IN T E N A N (. t
O P t R A T I (J N
DEMON
Figure 16. Individual correction
programs and the Unified Concept.
such as hydraulic overload and inadequate clarification capacity. The NPDES
permit program focuses on the effluent quality of facilities and potentially
could use the associated enforcement capability to motivate administrative
personnel. Operator training programs focus on plant operators and address
factors like sewage treatment understanding. In like manner, other Individual
Correction Programs focus on specific factors or groups of factors limiting
performance at many treatment facilities.
The major emphasis since PL 92-500 was enacted in 1972 has been to im-
prove treatment plant performance through Individual Correction Programs. The
results have been partially successful in that some new or upgraded facilities
are performing at a satisfactory level. However, many facilities are not per-
forming well. (2,3) One of the reasons for only a moderate success of the
Individual Correction Programs is the manner in which these programs have been
implemented. Individual Correction Programs were established to concentrate
on specific areas of need representing a common problem at a large number of
treatment facilities. However, every factor that limits performance at a
given facility must be eliminated for that facility to achieve optimum perform-
91
-------
ance. Individual Correction Programs have not, and typically cannot address
the unique combination of performance limiting factors at an individual facil-
ity.
The role of Individual Correction Programs in the Unified Concept theory
is further explained using an example. Consider a facility with two major and
other minor factors limiting performance. Assume the major factors are hy-
draulic overload and improper operator application of concepts and testing to
process control. At this example facility the hydraulic overload factor would
likely be obvious and overshadow the operator application factor. With these
two major factors limiting performance the plant would be far removed from
optimum performance and would be at Plant Position 1 in the Unified Concept as
shown in Figure 16.
Now, assume that by implementing an Individual Correction Program, such
as an engineering study and associated plant upgrade using a construction
grant, that the hydraulic overload problem is corrected. When this overload
problem is corrected the operator application of concepts and testing to pro-
cess control factor becomes prominent in that facility's inability to achieve
optimum, or maybe even satisfactory performance. This example facility
could now be at Plant Position 2 in the Unified Concept as shown in Figure 16.
Addressing only the obvious factor of hydraulic overload would not allow the
example facility to achieve the desired performance goal. This example il-
lustrates why many facilities that have been upgraded have not achieved satis-
factory performance.
In the preceding example it was shown that Individual Correction Programs
do not necessarily influence or eliminate all the factors limiting performance
at a particular facility, thus many facilities continue to operate at poor
performance levels. This is not meant to imply that Individual Correction
Programs should be abandoned. There is a continued need for these programs
because of the multitude of performance limiting factors that exist. However,
Individual Correction Programs are limited in their ability to achieve optimum
performance.
92
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An important aspect of the research study was also described in the ex-
ample given for the limitations of the Individual Correction Program approach.
In the screening process used to select plants for this study, facilities with
gross and obvious limitations such as excessive hydraulic overload, infiltra-
tion/inflow and organic overload were purposely excluded. Included were many
facilities that were believed operable, yet were achieving less than desired
performance. Therefore, this research has documented the less obvious types
of problems that are, or will be encountered by facilities as they move closer
toward optimum performance. These problems must also be eliminated before
optimum, and maybe even acceptable facility performance will result.
COMPOSITE CORRECTION PROGRAM
A program that can advance a significantly large number of facilities to
optimum performance is a Composite Correction Program (CCP). A CCP is differ-
ent from an Individual Correction Program in that it addresses all factors
limiting performance at a given facility. A CCP for a typical plant in rela-
tion to the Unified Concept is illustrated in Figure 17. Factors limiting
performance in the areas of administra-
tion, maintenance, operation and design
tend to move the plant away from the
goal of optimum performance (Plant
Position 1). The CCP addresses all of
these factors, and if properly imple-
mented can achieve optimum performance
at that facility (Plant Position 2).
To demonstrate the value of the CCP a
program was implemented as a part of
this research effort. A separate re-
port was prepared describing the results
obtained. (2) The results are sum-
marized and presented in this report as
they relate to the overall findings of
the research effort.
Figure 17. Composite Correction
Program and the Unified Concept.
GOAL
OPTIMUM PERFORMANCE
T
T
T
PLANT
\POSITION
FACTORS LIMITING PERFORMANCE
ADMINISTRATION
MAINTENANCE
OPERATION
DESIGN
93
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The CCP was implemented at the Havre, Montana Wastewater Treatment Plant.
The Havre facility is an activated sludge plant designed to treat a sewage flow
of 6800 cu m/day (1.8 mgd). Treatment facilities consist of a grit chamber,
flow measurement, comminutors, two aeration basins, two secondary clarifiers,
a chlorine contact chamber, two aerobic digesters and a lagoon for ultimate
sludge disposal. The plant flow diagram is shown in Figure 18.
RAW SEWAGE
GRIT
CHAMBER
I
WASTE SLUDGE
| -f 1 !
EAST
LUNIT
AERATION
BASIN
AERATION
BASIN
5
WEST [
UNIT |
A
CHLORINE
CONTACT
BASIN
DISCHARGE TO
MILK RIVER
AEROBIC
DIGESTERS
WASTEWATER
SLUDGE
Figure 18. Plant flow schematic for the Havre, Montana
wastewater treatment plant.
94
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Havre was selected for a CCP for a variety of reasons, but primarily be-
cause of the plant superintendent's ready acceptance of the program. During
the field portion of the preliminary survey operations assistance was provided.
Modifications to operations data collection and organization, and major adjust-
ments in process control were made. The operations data was used to interpret
process status, observe process response to adjustments made and describe con-
cepts of operation to the plant operators. Following the initial seven-day
field effort, telephone consultation was established on a routine basis (sev-
eral times per week). Telephone contact continued at less frequent intervals
for about one year. Factors limiting performance which were addressed as a
part of the CCP are presented in detail in another report. (2) A summary of
the factors addressed is presented below:
Operations Factors
-Improved and expanded process control testing was initiated.
-Operator skills were developed with respect to applying proper
operation concepts to process control.
Design Factors
-Short circuiting in final clarifiers was eliminated.
-Inherent difficulties with plant design (aerator capacity, return
sludge control, and aerobic digester capacity) were overcome by
increased plant operations.
Administrative Factors
-City council was made aware of importance of plant operation.
-Plant staffing was increased to provide twenty-four hour operator
coverage to overcome limitations in plant design.
Maintenance Factors
-Emergency maintenance procedures were improved because of aware-
ness of impact on the biological system.
Completion of the Havre CCP resulted in many benefits, one of which was
achieving optimum facility performance. Figure 19 shows a seven point moving
95
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RESEARCH
INITIATED
EFFLUENT
STANDARD^N
J FMAMJJ ASONDJ FMAMJ
Figure 19. Final effluent BOD at Havre, Montana.
average of chlorine contact basin effluent BOD concentrations. A dramatic
improvement in plant performance occurred. Effluent quality for the six-month
period prior to initiation of the CCP averaged 31 mg/1 for BOD and 30 mg/1
for TSS. After stabilized process control was achieved, effluent quality for
the seven-month period of December 1976 through June 1977 averaged 9.7 mg/1
for BOD and 9.1 mg/1 for TSS. This translates to a 70 percent reduction in
the former BOD,, and TSS load discharged to the receiving stream. The Havre
facility consistently met its NPDES permit standards that were previously vio-
lated. Another benefit that resulted from the Havre CCP was related to the
fact that the plant served as a training facility for local community college
students in Water and Wastewater Treatment Technology. Students frequently
visited the plant for on-the-job instruction. The impact of a well performing
full-scale plant accentuated the training that the students received.
Other benefits from the Havre CCP were more far reaching than the specific
gains made at the Havre facility. At Havre, stabilization of the biological
process required three months of effort during fairly good conditions and with
above average process control. Constant changes to process controls were
96
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required throughout that time period. Some plant upsets occurred which re-
sulted in a great deal of pressure by the plant operators to return the plant
to status quo. Continued training and process guidance by the research team
was required to avoid changing the system back to its original status. If
technical guidance were given for only a short time, the performance improve-
ment gained at Havre would not have been achieved. It was concluded that to
properly evaluate biological system response and achieve system stability a
long time period (i.e., many months) is required. This conclusion demonstrates
the need for altering typical approaches to the evaluation of biological
systems. The conclusion also provides insight into the possible causes of the
high ranking factors limiting performance of improper technical guidance and
inadequate operator application of wastewater treatment concepts to process
control.
Typically, technical guidance to plant operators is provided during short
plant visits by authoritative sources (i.e., design engineer, equipment sup-
plier or state or federal regulatory inspector). Recommendations are made and
implemented. Slow response of the biological system, as demonstrated at Havre,
allows these persons making the recommendations to be far removed from the
facility when the operator encounters difficulties associated with the recom-
mendations. As such, most authoritative sources do not experience the problems
encountered and the limitations of their advice, and thus do not improve their
operations capability. The time delay inherent in stabilizing a biological
process is probably a major reason that improper technical guidance has become
a significant factor limiting biological wastewater treatment plant performance.
Another factor addressed in the Havre CCP was the operator's capability
to properly apply correct concepts of plant operation to process control. The
Havre superintendent had two years of college training and had received formal
training for an additional two years at a Water and Wastewater Technology
School. The superintendent also had an excellent aptitude. Even with this
good background and aptitude, guidance at the operator's facility over a nine-
month period was necessary to properly develop his capabilities to fully apply
concepts to varying operational situations. The time involved and the approach
used to develop the operator's skills in the area of application of concepts
97
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that was demonstrated at Havre provides a basis for drastically altering pre-
sent operator training procedures. It was concluded that an operator's skills
and ability to apply concepts of operation to process control should be de-
veloped through technical guidance at his individual facility under the direc-
tion of qualified personnel.
An important point noted during the research effort was the capability of
operators to achieve optimum facility performance. Much blame has been placed
on plant operators as the source of poor performance. However, this blame was
often not warranted because operators usually were not in a position to ad-
dress a large number of critical factors limiting performance in all four
major areas of operation, maintenance, design and administration. Plant op-
erators were usually limited to addressing operation and maintenance factors
only, and therefore could not and should not be expected to solely achieve
optimum facility performance.
If Composite Correction Programs, excluding major capital improvements,
were applied to the other twenty-nine facilities evaluated in this research
project, dramatic improvements in plant performance would result. In many
cases NPDES permit standards would be met that are now being violated. Im-
provement in performance that could result is described along with the Havre
CCP in the other report developed under the research contract. (2) Table 14
presents a summary of the performance of the thirty facilities surveyed in
relation to permit standards.
TABLE 15. PERFORMANCE OF THIRTY' FACILITIES EVALUATED
VERSUS SECONDARY TREATMENT STANDARDS
Standards
Frequently Violated
Standards
Consistently Met
Prior to Evaluation
Potential After Composite
Correction Programs
23
23
*Seven facilities would require a major facility upgrade, which for purposes
of this evaluation was excluded as part of the Composite Correction Program.
98
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During the preliminary surveys it was determined that twenty-three of
thirty facilities did not meet secondary treatment standards even though their
average hydraulic loading was only 61 percent of design flow. It was estimated
that if CCP's were completed at all thirty plants and if major capital improve-
ments were not an available option, an additional sixteen facilities would con-
sistently meet standards. Seven would continue to violate standards because a
major plant upgrade would be necessary at these facilities before permit com-
pliance could be achieved.
The typical approach to improve plant performance has been to expand the
existing plant through some type of construction modification. However,
simply expanding facilities has not allowed permit standards to be met, as
evidenced by the relatively low hydraulic loading (61 percent of design flow)
of facilities violating standards. A greater level of facility over-design
does not appear warranted. Rather than more construction, the efficient use
of existing facilities developed through CCP's represents a more cost-effective
approach to improving plant performance. If needed, major plant modifications
through construction should be part of and not a substitute for a CCP -
In addition to allowing facilities to consistently meet permit standards,
the implementation of CCP's at all thirty facilities surveyed would dramatical-
ly decrease the BOD^ and TSS pollutional load discharged to the receiving
streams. The potential decrease was an estimated 1340 kg/day (2960 Ib/day)
for BOD and 1278 kg/day (2822 Ib/day) for TSS. This reduction represents an
average 14 mg/1 decrease in both the BOD and TSS concentration in all of the
plant discharges. It is important to realize that this improvement would oc-
cur at existing treatment facilities and without major capital expenditures.
The capability of CCP's to improve the existing facilities' performance re-
quires consideration for their widespread implementation.
Limitations to the widespread use of CCP's to improve facility perform-
ance exists. There is a lack of qualified personnel to successfully implement
programs on a broad scale, as evidenced by the high ranking of the improper
technical guidance factor limiting plant performance. Specialized training
approaches to gain additional qualified technical assistants should be
99
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developed. Specialized training must include in-plant operations experience
at various wastewater treatment facilities over a long period of time to prop-
erly develop capabilities for the correct application of wastewater treatment
concepts to process control and to develop a respect for the time associated
with biological system response. Conducting CCP's is a good mechanism through
which existing technical assistants can be properly trained. In this regard,
initial CCP's will involve costs and time for the training of the technical
assistants. The federal construction grant plant start-up assistance program
could also provide a basis for attaining qualified personnel, if it is process
control oriented, allowed to continue for an adequate time at an individual
facility and approached as a training function for both plant and start-up
assistance personnel.
Another limitation to the widespread use of CCP's is that present incen-
tives for their implementation are not satisfactory. Incentives are usually
directed toward making a plant modification. For example, administrators of
plants that are violating permit standards typically look to a construction
grant (i.e., Individual Correction Program) to upgrade their facility rather
than to a Composite Correction Program to improve the existing facility's per-
formance. An alternative to change this approach is through the permit enforce-
ment program. Enforcement could encourage local administrators to act to im-
prove the existing facility's performance. At the same time a critical review
of the present construction oriented programs for improving performance is
needed to insure that existing facility capability, as developed through a
Composite Correction Program, is evaluated before a construction solution is
initiated. Another incentive to improve plant performance is to develop a
financial assistance program for existing facilities comparable to the plant
start-up assistance program for new facilities. Such a program would have a
dual effect of improving existing facility performance and expanding the basis
for developing qualified technical assistants.
The cost of implementing Composite Correction Programs could vary signi-
ficantly depending on facility size, type and scope of factors limiting plant
performance. The cost would be substantially less than the cost of completing
major facility modifications, and more importantly the end result of optimum
100
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performance would be achieved. Encouraging CCP's will not result in immediate
optimum performance of all facilities. However, the soundness of the program
has been demonstrated and the program's development can potentially result in
widespread improved facility performance.
101
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REFERENCES
1. Gannett, Fleming, Corddry and Carpenter, Harrisburg, Pennsylvania. Report
prepared in partial fulfillment of EPA Contract No. 68-03-2223, U.S. En-
vironmental Protection Agency, Cincinnati, Ohio.
2. Hegg, B. A., K. L. Rakness, and J. R. Schultz. A Demonstrated Approach
for Improving Performance and Reliability of Biological Wastewater Treat-
ment Plants. Report prepared in partial fulfillment of EPA Contract No.
68-03-2224, U.S. Environmental Protection Agency, Cincinnati, Ohio, 1978.
3. Gilbert, Walter G. "Relation of Operation and Maintenance to Treatment
Plant Efficiency," Journal Water Pollution Control Federation, 48, 1822
(1976).
102
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APPENDIX A
LISTING OF SITE VISIT ONLY AND
SITE VISIT PLUS PRELIMINARY SURVEY FACILITIES
STATE
TREATMENT FACILITY
SITE VISIT ONLY
SITE VISIT AND PRELIMINARY SURVEY
Colorado
Kittredge
Colorado Springs
Emp ir e
Georgetown
Vail
Brush
Victor
Cripple Creek
Eaton
Morrison
Englewood
Snowmass Village
Aspen Metro
Fort Morgan
Elizabeth
Elbert
Berthoud
Autora
Iowa
Montana
Clarinda
Shenandoah
Eldora
Iowa Falls
Osage
Tama
Butte
Kalispell
Big Fork
Yellow Bay Biological Sta,
Harlem
Bedford
Elma
Cresco
Reinbeck
Hillbrook Nursing Home, Clancy
Helena
Columbia Falls
Lolo
Missoula
Havre
Chinook
Nebraska
South Dakota
Utah
Wyoming
Elkhorn
Waterloo
Scribner
Norfolk
Platte Center
Waco
Sutton
Granger Hunter District,
Salt Lake City
Laramie
Lusk
Rock Springs
Evanston
Arlington
West Point
Crete
Gretna
Chamberlain
Mobridge
Cottonwood Dist., Salt Lake City
So. Davis N., Salt Lake City
So. Davis S., Salt Lake City
South Cheyenne
103
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APPENDIX B
EXAMPLE PRELIMINARY SURVEY INFORMATION SHEETS
The forms in this appendix were completed for each wastewater treatment
facility where a preliminary survey was conducted. Detailed information in
the areas of plant administration, maintenance, design and operation was
collected through the use of these forms.
104
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I. PLANT IDENTIFICATION
NAME AND LOCATION
NAMD OF FACILITY _
TYPF. OF FACILITY _
OWNFR
ADMINISTRATIVE OFFICE: MAILING ADDRESS
TREATMENT PLANT:
TELEPHONE NO.
MAILING ADDRESS
TELEPHONE NO.
PLANT LOCATION: LEGAL
RECEIVING STREAM AND CLASSIFICATION
RECEIVING WATER
TRIBUTARY TO
MAJOR RIVER BASTN __
_ CLASSIFICATION
CLASSIFICATION
APPENDIX B (CONT.)
I. PLANT IDENTIFICATION (Cont.)
C. PERMIT INFORMATION
PLANT CLASSIFICATION ASSIGNED :
STATE
DISCHARGE PERMIT REQUIREMENTS FROM PERMIT NUMBER
DATE PERMIT ISSUED _
DATE PERMIT EXPIRES _
EFFLUENT LIMITS AND MONITORING REQUIREMENTS:
MAXIMUM
MONTHLY
AVERAGE
MAXTMUM
WEEKLY
AVERAGE
BOD5 - rag/1
TSS - mg/1
Fecal rnl-iC
tf/100 ml
Chlorine Residual -
mg/1
COMPLIANCE SCHEDULE:
OTHER TREATMENT REQUIREMENTS ANTICIPATED:
II. PLANT DESCRIPTION
III. DESIGN INFORMATION
A. PROCESS TVPF,
TYPE
FLOWSHEET - In body of report
E. DESIGN FLOW
PRESENT DESIGN FLOW
INFLUENT CHARACTPBTSTTCS
AVERAGE DAILY FLOW: DERTHN _
CURRENT
MAXIMUM HOURLY FLOW: DEISGN _
CURRENT
'-. UPGRADING AND/OR EXPANSION HISTORY - AGE
PLANT HISTORY (Original construction, date completed, pla
completed)
AVERAGE DAILY TSS:
CURRENT
DESIGN _
CURRENT
_mgd x 3785 =
_mgd X 3785 =
_mgd x 3785 = _
_mgd x 3785 =
lb x 0.454
lb x 0.454
lb x 0.454 =
lb x 0.454 =
D. SERVICE APF.A
NUMBER OF TAPS
GENERAL DESCRIPTION:
INFILTRATION/INFLOW:
SEASONAL VARIATION-
MAJOR INDUSTRIAL WASTES:
KNOWN INHIBITORY WASTES:
COLLECTION SYSTEM:
cu m/day
cu m/day
cu m/day
cu m/day
105
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III. DESIGN INFORMATION (Cont.)
FLOU STREAM NO.
PIWED PTITTS NAME 112H?t HE. fAPACITY
COMMENTS: (F
APPENDIX B (CONT.)
III. DESIGN INFORMATION (ConC.)
I) UNIT PROCESSES (ConC.)
FLOW MEASUREMENT
FLOW STREAM MEASURED
CONTROL SECTION:
TYPE AND SIZE
LOCATION
COMMENTS: (Ope;
RECORDER:
NAME
FLOW RANGE _.__..
CALIBRATION FREQUENCY
DATE OF LAST CALIBRATION
LOCATION
TOTALIZER
COMMENTS: (Operation and
III. DESIGN INFORMATION (Cont.)
UNTT PROCFSSFfi front.j
MECHANICAL BAR SCREEN'
NAME
MODEL
PRELIMINARY TREATMENT
III. DESIGN INFORMATION (Cont.)
PRFUHTNAFY TRFACMF.NT
WITHIN BUILDING? _^_^__
DESCRIPTION OF OPERATION.
SPARE PARTS INVENTORY'
BAR SPACING
CLEANING FREQUENCY
UTTP.TN BUILDING7
SCREENINGS DISPOSAL:
106
-------
III. DESIGN INFORMATION (Cont.)
R. UNIT PROCFSSHS (Cont.)
PRIMARY TREATMENT
PRIMARY CLARIFIER:
NUMBER SURFACE DIMENSIONS
WATER DEPTH (SHALLOWEST)
WATER DEPTH (DEEPEST) __
WEIR LOCATION
WEIR LENGTH
TOTAL SURFACE AREA
TOTAL VOLUME
FLOW (DESIGN)
: 0.305 =
; 0.305 =
(OPERATING)
ft. x 0.305 =
ft " x 0.092° =
_gal x 0.003785 =
_mgd x 3785 =
mgd x 3785
_cu m/day
_ru m/day
WEIR OVERFLOW SATE
(DESIGN) ____
fOPERATING)
_gal/day/fr_ x O.n)24 =
_Kfli/day/ft x 0.0124 -
SURFACE SETTLING RATE
(DESIGN) gal/day/sq ft x 0.0408 = cu m/day/sq m
(OPERATING) gal/day/sq ft x 0.0408 - Cu rn/day/sq m
HYDRAULIC DETENTION TIME (DESIGN)
(OPERATING)
COLLECTOR MECHANISM NAME
MODEL
SCUM COLLECTION AND TREATMENT:
MAINTENANCE:
SPARE PARTS INVENTORY:
APPENDIX B (CONT.)
III. DESIGN INFORMATION (Cont.)
B. UNIT pRnrrr-r.Fs fronr.1
AERATION BASIN:
NO. BASINS __
WATER DEPTH
SECONDARY TREATMENT
SURFACE DIMENSIONS
FLOW (DESIGN) _____
(OPERATING) ___
SEWAGE DETENTION TIME (DESIGN)
(OPERATING)
_mgd x 3785 = _
_mgd x 3785 =
_lb/1000 cu ft/day x 16.0 =
_lb/1000 cu ft/day x 16.0 =
COVFRFT)?
TOTAL VOLI'ME
TYPE OF AFP<\TTON
NAME
£m/cu m/day
pm/cu m/day
p»\ x 0.003785 :
NO. AEPATORS
HORSEPOWER
MORE OF OPERATION:
TYPE OF DIFFUSERS:
NUMBER COttPRESSORS
MODEL
AIR CAPACITY (cfm)
MAINTENANCE:
SPARE PARTS INVENTORY;
_ HORSEPOWER
LOCATION
III. DESIGN INFORMATION (Cone.)
III. DESIGN INFORMATION (Cont.)
SECONDARY TREATMITNT
AFB (Act.
NAME _
MODEL
SURFACE DIMENSIONS
TOTAL SURFACE AREA
MF.DIA DEPTH
ROTATJNG BIOLOGICAL CONTACTOR (RBC):
NO. SHAFTS LENGTH OF SHAFTS
NO. CELLS CELL VOLUME
NAME
E.il x 0 n037«5
-tt
ft
TOTAL MEDA1 VOLUME
RECIRCULATIO;; TA':K:
DISC DIAMETER
RPM
ft x 0. 30/ift -
PERIPHERAL VELOCITY _
TOTAL SURFACE AREA _
PERCENT SUBMERGENCE _
F10W (DESIHNI
_jngd x 3735 =
mgd y 3785 = ________
HYDRAULIC LOADTNH:
(DESIGN)
Ft x 0.0408 =
TEMPERATURE (DESIGN) (OPERATING
ORGANIC LOADING
(DESIGN) Ib BOD/day/1000 so fr - '. .HHS
_kR BOn/d;
(OPERATING) Ib SOD/day/1000 &" ft - 4.8Hri
kg B00/dc
TOTAL DETENTION TIME (DESIGN) hr (n"-PMTf^)
COVERED? ____________________ HEATEO'
SPARE PARTS INVENTORY:
COMMENTS:
107
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III. DESIGN INFORMATION (Cont.)
CONTACT BASIN:
SURFACE DIMENSION
WATER DEPTt'
VOLUME
FLOW (DESIGN)
(OPERATING)
Et x 0.3048 = __
__gal x 0.003785 =
mgd x 3785 =
mgd x 3785 =
_cu m/day
c.u m/rfay
SEWAGE DETENTION TIME (DESIGN)
COVFRED?
COMMENT?:
REAERATION BASIN:
SURFACE DIMENSION
WATER DEPTH
VOLUME
min (OPERATING)
p,ai x o.nrn?85 =
HYDRAULIC DETENTION TIME AT 1002 RETURN
(DESIGN) hr rOPERATINf-)
FLEXIBILITY TO OPERATE AS CONVENTIONAL _________
COVERFD?
COMMENTS:
APPENDIX B (CONT.)
III. DESIGN INFORMATION (Cont.)
SECONDARY TREATMENT
OXYGEN TRANSFER:
TYPE AERATION __
MODEL
NO, AERATORS NAME __
HORSEPOWER
CAPACITY c
NO. COMPRESSORS NAME
HORSEPOWER CAPACITY _
LOCATION __________
SPARE PARTS INVENTORY:
MAINTENANCE:
III. DESIGN INFORMATION (Cont.)
III. DESIGN INFORMATION (Cont.)
B. UNIT PPnr.FSPF.S (ConC.)
TRICKLING FILTER:
NO. FILTERS
B. MNTT PROrFSSFS (Tnnr..1
SECONDARY TREATMENT
SECONDARY TREATMENT
SURFACE DIMENSION
MEDIA DEPTH
SURFACE AREA
MEDIA VOLUME
FLOW (DESIGN)
__ ft x 0.3048 =
_ Et x 0.0929 =
_gal x 0.003785 '
_mgd x 3735 -
_mgd x 3785 =
SFCONDARY CLARTFTFRS:
NO. DIMENSION(S)
WATER DEPTH (SHALLOWEST)
(DEEPEST)
WF.IR LOCATION
WEIR LENGTH _
SURFACE AREA
VOLUME
_ft x 0.305 =
Et x 0.305 =
ORGANIC LOADING (DESIGN)
_lb/JOOO cu ft x 16.0 =
FLOW (DESIGN)
_ft" x 0.0°2° =
_gal x 0.003785
mgd x 3785 =
mgd x 3785 =
(OPERATING)
HYDRAULIC LOADING (DESIGN)
_Ib/1000 ru ft y 16.0 -
gWc
WEIR OVERFLOW RATE (DESIGN)
_gai/day/sq ft f. O.OiOP =
cu m/day/sq
(OPERATING)
(OPERATING)
SURFACE SETTLING RATE (DESIGN)
_8a]/day/Bq ft x 0.0608 =
cu m/day/sq m
RECIRCULATION:
MODF OF OPERATION.
MAINTENANCE:
SPARE PARTS INVENTORY:
;a]/day/sq ft x 0.0408 =
cu m/day/sq i
HYDRAULIC DETENTION TIME (DESIGN)
COLLECTOR MECHANISM NAME
SCUM COLLECTION AND REMOVAL:
SPARE PARTS INVENTORY:
_hr (OPERATING)
108
-------
III. DESIGN INFORMATION (Cont.)
B. UNIT PROCESSES (Hont.)
DISINFECTION
CONTACT BASTr*".
SURFACE DIMF.MSIONS
WATER PFPTH
VOI TTMF
DETENTION TIMF (DESIGN)
COMMENTS :
CHLORINATOR:
NA;IE
CAPACITY
gal x 0.003785 = cu m
min (OPERATING) min
NUMBER
Ib/day x 0.45^ = kp/day
TYPE INJECTION
FErD RATE (.OPERATING)
DOSAGE (OPERATING)
Ib/day x 0 4S4 = kp,/dsy
mc/1
DIFFUSERS
SPARE PARTS It'VrNl ORY :
MAINTENANCE :
COMMENTS :
III. DESIGN INFORMATION (ConC.)
Q. UNIT PROCESSES (Cont.1
SLUDGE HANDLING
ANAEROBIC DIGESTION:
HO. DIGESTERS DIAMETER ft x 0.3048 = m
SIDEWALL DEPTH
CENTER DEPTH
TOTAL VOLUME
ft x 0.30^8 = m
ft Y 0.3ni8 - m
sal y. 0.003785 = cu m
FLOATING COVER?
FLOW (DESIGN)
(OPERATING)
DETENTION TIME (DESIGN)
HEATING:
MIXING:
SUPERNATING CAPABILITY:
SPARE PARTS INVENTORY:
MAINTENANCE :
MODE OF OPERATION:
COMMENTS :
mgd x 3705 = r.u m/day
mgd x 3785 = cu rn/day
APPENDIX B (CONT.)
III. DESIGN INFORMATION (Cont.)
B. UNIT PROCESSES fCnnr.)
SLUDGE HANDLING
AEROBIC DIGESTION:
NO. BASINS SURFACE DIHENSTON(S)
WATER DEPTH ft x 0 3048 - m
COVERED? HEATED?
TYPE OF AERATION
NO. AERATORS NAME
MODEL HORSEPOFER
TYPE 07 DIFFUSERS:
NO. COMPRESSORS NAME
MODEL HORSEPOWER
LOCATION:
SPARE PARTS INVENTORY:
MAINTENANCE:
MODE OF OPERATION:
COMMENTS :
III. DESIGN INFORMATION (Cont.)
SLUDGE HANDLING
SLUDGE DRYING BEDS:
NO. SIZE
COVERED? SUBNATANT DRAIN TO
DEWATERED SLUDGE REMOVAL:
MODE OF OPERATION:
COMMENTS :
OTHER DEWATERINC UNIT(S):
109
-------
III. DESIGN INFORMATION (Cent.)
HTHER DEKTT.N INFORMATION
STAND-BY POWER:
ALARM SYSTEMS:
MISCELLANEOUS:
APPENDIX B (CONT.)
III. DESIGN INFORMATION (Cont.)
D. PLANT AUTOMATION:
c.. LABORATORY CAPABILITY:
LOCATION
FLOOR DIMENSIONS
COUNTER SPACE ^_^ ft = n> HOT HATER?
FILE CABINET? DESK?
TESTS PERFORMED BY WHOM
OPERATIONAL TESTS CONDUCTED (TSS, D.O. , S.V.I., BOD, pH, & OTHERS) AND
FREQUENCY:
MONITORING TESTS CONDUCTED (TSS, BOD, PH, FECAL COLIFORM, OTHERS) AND
FREQUENCY:
QUALITY CONTROL:
IV. PLANT PERFORMANCE
SOURCFS OF PLANT PERFORMANCE DATA:
DATA AND DISCUSSIONS:
OPERATION AND MAINTENANCE PROCEDURES
MAINTENANCE:
SCHEDULING PROCEDURE FOR PREVENTIVE MAINTENANCE:
EMERGENCY MAINTENANCE:
C. 0 f. M MANUAL, SHOP PR^WTNGS, EOlJirMFNT MAMIIA1S, AS-BUILT PLANS, ETC.;
TECHNICAL GUIDANCE:
110
-------
VI. ADMINISTRATION
A. ORCANT7ATTON:
(10VF.RNT.Nn RODY
NO. MFMBERS
TERMS OF ELECTION
SCHEDULED MEETINGS
AUTHORITY AND RESPONSIBILITY:
OHATN QF RFSPDNSIBI'.TTTFS:
APPENDIX B (CONT.)
R. PT.AN.T T>Fi!
PF.RKoi'iNF.T.
RPFNT AT
VI, ADMINISTRATION (Cent.)
TFTCATroM (TITLE, NUMBER, PAY SCALF., ^RACTTON OF TJME
TPFATMENT, CERTIFICATTOW GRADE):
C. PLANT COVERAGE:
WEEKDAYS
WEEKENDS & HOLIDAYS
VI. ADMINISTRATION (Cont.)
VI. ADMINISTRATION (Cont.)
TYPE OF TAP
PU\MT BUDGET (font) .
(Budget Year )
CURRENT ASSESSED VAIJ'ATIOH
CURRENT MILL LEVY
CURRENT ANNUAL REVENUE FROM PROPERTY TAX _
OTHER REVENUE SOURCES;
111
-------
VI. ADMINISTRATION (Cone.)
PLANT BHIIRFT (Conr.)
EXPENDITURES (Cent.)
BOND TYPE YEAR ISSUED DURATION
INTEREST
RATE
PROJECT FINANCED,
APPENDIX B (CONT.)
VI. ADMINISTRATION (Cent.)
PLANT BUDGET (Gout.)
DISCUSSION OF EXPENDITURES:
BUDGET FOR:
SALARIES (INCL. FRINGES)
UTILITIES
SUPPLIES
CHEMICALS
TRANSPORTAT1 'N
TRAINING & EDUCATION
MISCELLANEOUS
OPERATIONS SUBTOTAL
CAPITAL OUTLAY
(Incl. Bond Debt ReCin
DOLLAR AMOUNT PERCTNT OF TOTAL
OPERATIONAL COST PER MILLION GALLONS (OPERATIONS SUBTOTAL 4- YEARLY FLOW)
r mg * 10 = c/1000 gal x 0.264
C/cu m
APPROXIMATE ANNUAL COST PER TAP (TOTAL * NO. TAPS)
*• taps - $
_/tap
VI. ADMINISTRATION (Cont.)
D. PIANT RUPHFT (Tnnt.1
SOURCE OF INFORMATIOi
ELECTRICAL COSTS
Days in
Billing
KWH/1000 gal
KWtt/cu m
COST, SUMMARY
Electrical
Salaries
Total Operations
112
-------
APPENDIX C
LISTING OF DESIGN INADEQUACIES OBSERVED
The following design problems were identified during the 63 plant
site visits and 30 preliminary surveys. Problems listed have
created unnecessary or excessive maintenance, difficult process
control, inaccurate or excessive sampling and decreased perform-
ance. All problems listed are design oriented in that an alternative
design could have prevented or minimized each problem observed.
PLANT LAYOUT
FLOW MEASUREMENT
BAR SCREENS
COMMINUTORS
GRIT REMOVAL
PRIMARY CLARIFIERS
AERATION BASINS
AERATORS
TRICKLING FILTERS
ABF TOWERS
FINAL CLARIFIERS
SLUDGE RETURNS
POLISHING PONDS
CHLORINATION
WASTING CAPABILITY
SLUDGE HOLDING FACILITIES
AEROBIC DIGESTERS
ANAEROBIC DIGESTERS
SLUDGE DEWATERING & ULTIMATE DISPOSAL
LABORATORY FACILITY
MISCELLANEOUS
113
-------
APPENDIX C (CONT.)
PLANT LAYOUT
Covered basins prevent observation of processes
- Return sludge air compressors are located outside and repeatedly
break down
- Plant with multiple units not having the flexibility to operate as
parallel plants
- No flow splitting flexibility to parallel plants
Bar screen located downstream from comminutor
- Freezing of influent sampler located outside
- Plant location inaccessible during inclement weather
- Excessive compressor noise
- Disinfection before polishing pond
- Parallel secondary treatment units not capable of being operated as
one facility
- Inadequate piping flexibility requires shut down of one trickling
filter if one clarifier is down
- One scraper drive for primary and final clarifiers requires operation
of both when operation of one is desired
- Lack of bypasses on individual treatment units, like aeration basin,
trickling filter, etc.
FLOW MEASUREMENT
Discharge through a pipe rather than the control section for which
the recorder is designed
Downstream channel slope and geometry causes backup in Parshall flume
throat
- Parshall flume oversized
Flow measurement inaccurate due to upstream barminutor placement
114
-------
APPENDIX C (CONT.)
- Level transmitting instrumentation not compatible with level
receiving instrument
- During high river flows, Parshall flume on effluent submerged
Flow recorder not calibrated
- Recycle flows (cooling water) included in plant flow measurement
- Roll-up flow chart requires removal to observe flow for more than
the preceeding four hours
- Parshall flume filled with grit deposits
- Wires crossed in totalizer, resulting in wrong reading
Flow measurement not adequately showing flow variations
Humid influent structure causes problem with moisture sensitive
level sensor
- Flow velocity too high in Kennison nozzel
Liquid level sensing float feezes
- Downstream bar screen backs flow into flume throat as screen plugs
BAR SCREENS
Bar spacing too narrow
- Backed up flow released after cleaning causes hydraulic surges
through aeration basin and into clarifier
- Freezing problems with mechanical bar screen located outside
COMMINUTORS
- Bent teeth, no protective bar screen
- Plugging with rags
Repeated mechanical failure of hydraulic drive type comminutor
115
-------
APPENDIX C (CONT.)
GRIT REMOVAL
Excess wear on grit screw center bearing because of exposure to grit
- Odors from organics settling out in grit channel
- Pump discharge to grit chamber directed at grit buckets, and washes
grit from buckets
- Grit auger not functional
PRIMARY CLARIFIERS
Overloaded by excessively large trickling filter humus return pump
Overload due to trickling filter recirculation through primary
- Improper placement of valve limits scum pumping
- Short-circuiting due to inlet baffle construction
- Preaeration in center of clarifier reduces effective clarification area
AERATION BASINS
- Pipe outlet plugs with rags
- Lack of piping to operate as conventional, as well as step load or
contact-stabilization activated sludge
- Receives hydraulic surges when the bar screen is cleaned
Receives hydraulic surges from oversized return pump on a time clock
- Loss of solids due to flooding
No bypass to final clarifier
- Action of aeration rotors and revolving bridge and configuration of
basin creates swells and voids which result in wave-like stresses on
bridge
116
-------
APPENDIX C (CONT.)
AERATORS
- Surface mechanical aerators overheat and shut off under increased flows
due to I/I
- With floating aerators, repeated breaking of cables when operated on
intermittent basis
- With submerged turbine aerators, repeated down time due to bearing and
shaft failure
- Inadequate freeboard for splashing with surface mechanical aerators
Icing problems with surface mechanical aerators
Rag accumulation on surface mechanical aerators
TRICKLING FILTERS
- Recirculation only through primary clarifier
- Inadequate capacity of trickling filter arms
- Leaking distributor seal causing ponding and short-circuiting
Poor flow splitting to trickling filters
ABF TOWER
- Undersized pipe carrying tower underflow back to recirculation tank
No flexibility to vary percent tower underflow returned to recircula-
tion tank
- Sludge return and tower recycle flow are directed into the same pipe
which limits their volume recycled
FINAL CLARIFIERS
Poor flow splitting to clarifiers
- Poor development of surface area with weirs
- Sludge scraper mechanism directing counter-current to wastewater flow
117
-------
APPENDIX C (CONT.)
- Freezing during cold weather
- Inlet and outlet on clarifier circumference. Problem compounded
by large diameter clarifiers, large design overflow rate and
failure to consider process recycle flows.
- Floating trash returned to aeration basin, no ultimate disposal of
scum.
- A common scraper mechanism used in the primary and final clarifiers
allows mixing between the clarifiers.
- Hydraulic restriction causes submerged overflow weirs.
- Short circuiting due to inlet baffle construction.
- Placement of trickling filter recirculation draw-off causes a hy-
draulic overload on the final clarifier.
- Weirs on single launder not balanced to pull evenly from each side.
SLUDGE RETURNS
- Constant speed centrifugal pumps used, difficult to adjust flow
Return sludge flow not visible at any point
- No .measurement
- With multiple clarifiers, balancing return flow was difficult
- Variable speed return pumps that were too large even at the lowest
setting
- Plugging of telescoping valves at lower flows
- With multiple clarifiers, asymetrical piping causes inbalance of
return sludge flows
Sludge returned to a point near the outlet of the aeration basin
- Valve controlling air to air lift returns is shut-off type, not
regulating type
- Measurement with 90 V-notch weir not sensitive enough
Oversized pump draws down final clarifier, then hydraulically overloads
aeration basin
118
-------
APPENDIX C (CONT.)
- Plugging of ball valve used for return control
When return channel overflows, it overflows to the clarifier as well
as the aeration basin due to channel construction
Partial plugging with rags of butterfly valve used for return sludge
flow control
POLISHING PONDS
No pond bypass
- Sludge wasted to polishing pond
Pond located after disinfection
- All ponds noted to contain large amounts of sludge, some of which was
being discharged
CHLORINATION
- Chlorine diffuser located at center of contact tank rather than at
the inlet
Rotometer on chlorinator too large for present application
- Poor mixing
Chlorine dosage paced by effluent flow, but filter backwash water
removed from combined contact-backwash storage tank shuts off chlor-
ination until it is again filled and discharging
Inadequate contact time in outfall pipe
Inadequate chlorination in final clarifiers
No depth control device on contact tank results in inadequate contact
time and short-circuiting
- Short-circuiting over baffles during high flows
Short-circuiting due to inlet design
119
-------
APPENDIX C (CONT.)
WASTING CAPABILITY
- No digester or sludge holding facility, inadequate drying beds
- Down time of exotic sludge treatment facility causes inadequate wasting
- Insufficient capacity
- No measurement
- None provided
- Partial plugging of waste pump prevents use of pumping rate to calculate
waste volume
SLUDGE HOLDING FACILITIES
- Odors from unaerated, uncovered sludge storage
Potential gas build-up problem with covered, unaerated sludge storage
AEROBIC DIGESTERS
- High groundwater and pressure relief valve prevents batch operation
- Inadequate air supply
Inadequate supernating flexibility
- Undersized
Pump used for sludge removal prevents thickening of sludge
Small digesters and minimum freeboard make foam containment difficult
- Freezing problems
- Common wall with aeration basin structurally insufficient to allow
batch operation
ANAEROBIC DIGESTERS
Inadequate supernatant draw-offs
- With multiple units, inflexibility to waste to desired primary digester
120
-------
APPENDIX C (CONT.)
Water seal on recirculation pump loads digester with cold water
Sludge pumping line from clarifier plugs which prevents digester loading
at concentrations above about six percent
No gas meters
No mixing
- Uneven loading due to breakdown of time clock
Temperature drop due to failure of automatic firing mechanism on boiler
Cold digester produces poor supernatant
- Leaky cover requiring down time for repair
Single gas meter for two digesters
- Uninsulated heating pipes outside
SLUDGE DEWATERING & ULTIMATE DISPOSAL
Repeated maintenance on sludge incineration facilities
- Insufficient sludge drying lagoons
Insufficient drying beds
Drying bed subnatant line crushed by construction equipment
LABORATORY FACILITY
- Vibrations prevent use of scale
- Humidity difficult to work in and hard on equipment
- Noise limits useability
Poor lighting
- Insufficient floor space
121
-------
APPENDIX C (CONT.)
MISCELLANEOUS
Stabilization of sludge with chlorine releases heavy metals to recycled
supernatant
- Wooden gates in flow diversion structure swelled and could not be
removed
- No automatic re-start after power outage
Butterfly valve used between mixed liquor and final effluent leaked
mixed liquor into effluent
122
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APPENDIX D
PLANT EVALUATION SUMMARY
WEIGHING AND RANKING TABLE
AND DEFINITION OF TERMS
This appendix contains a plant evaluation summary that was developed for
the research project to evaluate those factors limiting performance at waste-
water treatment facilities studied. For each plant studied the second part
of the summary, which consisted of the weighing table, was completed. Possi-
ble causes of less than optimum performance in the areas of administration,
maintenance, design and operation were evaluated for each plant using the
factors listed in this table. A point system was used to express the severi-
ty of problems noted at the facilities studied. The first part of the sum-
mary consists of a ranking table where those factors limiting plant perform-
ance were summarized and ranked according to magnitude of importance. A
definition of the terms used in the plant evaluation summary is also in-
cluded .
123
-------
RANKING TABLE
PLANT NO.
PLANT TYPE:
DESIGN FLOW:
ACTUAL FLOW:
YEAR PLANT BUILT:
YEAR OF HOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING TABLE REFERENCE CAUSE POINTS
1
2
3
4
5
6
7
8
9
10
WEIGHTING TABLE (PART 2)
CATEGORY
3. Emereencv
a. Staff Expertise
b. Critical Pares Procurement
c. Technical Guidance
C. DESIGN
1 . Plant: Loading
a. Organic
b. Hydraulic
c. Industrial
e. Seasonal Variation
a. Preliminary
b . Primary
c . Secondary
3. Aerator
A. Clarifier
1.
2 .
3.
«•
5.
e. Disinfection
i. Sludge Wasting Capability
PTS.
COMMENTS
APPENDIX D (CONT.
WEIGHTING TABLE (PART 2)
CATEGORY
A. ADMINISTRATION
a. Policies
2. Plant Staff
a . Manpower
1 . Number
2. Plant Coverage
b . Morale
1 . Motivation
2. Pay
3. Supervision
4. Working Conditions
c . Productivity
3 . Financial
a. Insufficient Funding
b. Unnecessary Expenditures
c. Bond Indebtedness
B. MAINTENANCE
1 . General
a. Housekeeping
b. Equipment Age
c. Schedulipg & Recording
•d. Manpower
2, Preventive
a. Lack of Program
b. References Available
PTR
!
WEIGHTING TABLE (PART 2)
CATEGORY
g. Sludge Treatment
a . Plant Location
c. Lack of Unit Bypass
d. Hydraulic Profile
1 . Flow Backup
2. Submerged Weirs
Units
e . Alarm Systems
f. Alternate Power Source
1. Monitoring
2. Control
h. Lack of Stand-by Units for
Key Equipment
i. Laboratory Space & Equipment
j. Process Accessibility
for Sampling
for Maintenance
1. Plant Inoperability Due
to Weather
m.
n.
D . OPERATION
PTS.
COMMENTS
124
-------
WEIGHTING TABLE
CATEGORY
a. Ability
1 . Aptitude
2. Level of Education
b. Certification
1. Level of Certification
2. Training
c. Sewage Treatment Under-
standing
d. Insufficient time on the
Job (Green crew)
2. Testing
a. Performance Monitoring
b. Process Control Testing
Process Control
b. Technical Guidance
4. 0 & M Manual
a. Adequacy
b. Use by Operators
5. Miscellaneous
a. Equipment Malfunction
b. Shift Staffing Adequacy
(Operations^
c .
d.
e-
f .
(PAR!
PTS.
2)
COMMENTS
APPENDIX D (CONT.)
RANKING TABLE DEFINITION OF TERMS
Actual Flow
aeration activated sludge with polishing pond and with-
out sludge digestion).
riation in flows will be noted.
Year of Most Year last additional major units were put into operation
Recent Upgrades (e.g. digester, chlorine contact chamber, etc.)
Table (Pages 2-7).
sighting Table.
DESCRIPTION OF POINT SYSTEM
WEIGHTING TABLE
DEFINITIONS FOR FACTORS LIMITING PERFORMANCE
EXPLANATION
Effect on
Plant Performance
A. ADMINISTRATION
aused critical decisions to be delayed
Fa-iliarity with
Plant Needs
2. Plant Staff
a. Manpower
1 Number
Does a limited number of people employed
have a detrimental uffect on plant
125
-------
4. Working
Conditions
j. Financial
B. MAINTENANCE
1 General
Is the plant staff motivated to do a good
Housekeeping
APPENDIX D (CONT.)
Has j lack of good housekeeping procedures
(e.g., £ri.t channel cleaning, bar screen
equipment failure rate
Che amount of funds available for other
L. Scheduling an
Recording
2. Preventive
a. Lack of Program
down time that has degraded plant perfo
aiu-e or reliability'
3. Emergency
a. Staff Expertise
rts Ha'
lias the prese
.Muracteristi
plant was des
what is thoug
degraded proc
more of the 1
Lti of "shock" loading
s over and above what the
t t« be tolerable caused
stcd loadings (a-e)9
operations of the existing plant could be
utilized to improve performance (e.g.
operate activated sludge plant in plug,
step, or contact stabilization mode;
discharge good secondary treatment
effluent as opposed to a degraded
"polishing pond" effluent; etc.)?
2. Process Do the existing process control features
Controllability provide adequate adjustment and measure-
ment over the appropriate flows (e.g.
return sludge) in the range necessary to
optimize process performance, or, is the
flow difficult to adjurr, variable once
easilv measurable, etc.?
3. Aerator
Doe
di-
mentation due to the size of the clarifier,
placement of the weir, length of the weir,
type of clanfier, or othur miscellaneous
Any process of wastewater treatment which
upgrades water quality to meet specific
effluent limits which cannot be met by
ment process (i.e., nitrification towers,
chemical treatment, multi-media filters).
(Space has been allowed for in the table
Disinfection
Doe
126
-------
g. Sludge Treatment
n. Ultimate Sludge
Disposal
3. Miscellaneous
a. Plant Location
b. Unit Process Layout
c. Lack of Unit Bypass
d. Hydraulic Profile
1. Flow Backup
Does the type of size of sludge treatment
processes hinder sludge stabilization
(once sludge has been removed from the
wastewater treatment system) which in turn
affects process operation (e.g., causes
odor problems, causes limited sludge
wasting, etc.)?
Are the ultimate sludge disposal facilities
of sufficient size and type to adequately
handle the sludge? Are there any specific
areas that limit ultimate sludge disposal
such as seasonal weather variations, crop
harvesting, etc.?
The design miscellaneous section covers
areas of design inadequacy not specified in
the previous design categories. (Space
has been allowed to accommodate additional
items not listed.)
Does a poor plant location or poor roads
leading into the plant cause it to be
inaccessible during certain periods of the
year (e.g. winter) for chemical or equip-
ment delivery or for routine operation?
Does the arrangement of the unit processes
cause inefficient utilization of operator's
time for checking various processes,
collecting samples, making adjustments,
etc.?
Does the lack of unit bypass cause plant up
set and long term poor treatment when a
short term bypass could have minimized
pollutional load to the receiving waters;
caused necessary preventive maintenance
items to be cancelled or delayed; caused
more than one unit to be out of service
when maintaining only one unit?
Does an insufficient hydraulic profile
cause ground flooding or flooding of u
stream units except clarifiers? Does
periodic release of backed up flow cau
hydraulic surge?
APPENDIX D (CONT.)
2. Submerged Weirs Does an insufficient hydraulic profile
cause flooding of clarifiers and sub-
merged clarifier weirs?
3. Flow Proportioning Has inadequate flow proportion or flow
to Units splitting to duplicate units caused pro-
blems in partial unit overload which
degraded effluent quality or hindered
achieving optimum process performance?
e. Alarm System
t. Alternate Pow
Source
g. Process Automation
1. Monitoring
Ha.
and/or plant perfo
ing devices (D.O. meter, pH meter, etc.)
caused excessive operator time to watch for
slug loads or process upset to occur be-
cause of slug loads? Has a breakdown or
the improper workings of automated process
monitoring features caused disruption of
automated control features and subsequent
degradation of process performance?
devices (time clock) caused excessive
operator time to make process control
changes or necessary changes to be can-
celled or delayed? Has the breakdown or
the improper workings of automatic control
features caused degradation of process
performance?
h. Lack of Stand-by
Units for Key
Equipment
i. Laboratory Space
Has the lack of stand-by units for key
equipment caused degraded process perform-
ance during breakdown or necessary pre-
or delayed?
for Sampling
k. Equipment Access-
ibility for Main-
tenance
cess flow streams (e.g., recycle streams)
for sampling caused needed information to
Has the inaccessibility of various pieces
of equipment caused extensive down time
or difficulty in making needed repairs or
adjustments.
d. Insufficient Time Has a short time on the job caused impri
on job (Green Crew) process control adjustments to be made
2. Testing
Due to Weather
,ely
Are the required monitoring tests being
permit?
at all, or do
performance?
operate as efficiently
OPERATION
1. Staff Qualifications
a. Ability
I. Aptitude
2. Level of
Education
b. Certification
3. Process Control Adjustments
d. Operator Application Has the operator been deficient in the
adjustments?
Has the lack of the capacity for learning
or undertaking new ideas by staff members
or critical staff members caused poor 0 & M
b.
plant performanc
reliability?
technical consultant, caused improper
operation decisions to be continued? Has
a technical person (design engineer, state
Does a low level of education cause poor
0 & M decisions to be made? Does a high
level of education but a lack of process
overlooked?
• 0 6 M Manual resulted in the
1. Level of
Certifica
Does the lack of adequately certified
decisions?
c. Sewage Training
Understanding
Does the operators non-attendance of
available training programs cause poor
process control decisions?
Has the operators' lack of understanding
of sewage treatment in general been a
factor in poor operational decisions and
poor plant performance and reliability?
Miscellaneous
poor treatment that c^uld have been
avoided?
ctions. (Space has been allowed to
127
-------
a. Equipment Malfunction Does malfunctioning equipment causi
deteriorated process performance?
b. Shift Staffing Ha;
be made, or be made at inappropriate times
forrnance?
APPENDIX D (CONT.)
128
-------
APPENDIX E
PLANT EVALUATION SUMMARY (RANKING TABLE) RESULTS
FOR
THIRTY-THREE PLANT SITE VISITS
Plant Evaluation Summary site visit results differ from the "preliminary
survey" results because only a one-half day evaluation was made during the
site visit, whereas a one-week evaluation was made during "preliminary sur-
veys". Therefore, only the obvious factor limiting performance could be de-
termined. Only those factors in the weighing table that were rated at least
two and three points were listed. No factor was listed at one point.
129
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 001
DESIGN FLOW: 15,140 cu m/day (4.0 mgd)
ACTUAL FLOW: 11,350 cu m/day (3.0 mgd)
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent was not meeting permit standards on a consistent basis.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
10
TABLE REFERENCE
C.2.C.3.
CAUSE
POINTS
PLANT NO. 003
PLANT TYPE: Activated Sludge
DESIGN FLOW: 1,140 cu in/day (0.3 mgd)
ACTUAL PLOW: 570 cu m/day (0.15 mgd)
YEAR OF HOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
During the site visit the clarifiers were being repaired as a scheduled
preventive maintenance procedure, and aeration basin effluent was being
bypassed to the receiving stream. Prior to this situation, plant effluent
quality frequently was "bad" according to the State Engineer, due to
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.f.
D.l.c.
D.2.a.
D.2.b .
CAUSE
Sludee Was tin* Cacabilitv
Sewage Treatment Unders tandins
Performance Monitoring
Process Control Testing
POTNTS
T
3
2
?.
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
DESIGN FLOW: 4,160 cu m/day (1.1 mgd)
ACTUAL FLOW: 6,060 cu m/day (1.6 mgd)
YEAR PLANT BUILT: 1954
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant performance was not meeting permit standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.b.
A.I. a.
C.2.C.I.
r.?.e.
C.2.C.3.
CAUSE
Plant Loading (hydraulic)
Process Flexibility
Aerator
POINTS
3
3
2
2
2
PLANT TYPE: Activated Sludge
DESIGN FLOW: 4,920 cu m/day (1.3 mgd)
ACTUAL FLOW: 5,680 cu m/day (1.5 mgd)
YEAR PLANT BUILT:
YEAR OF MOST RECENT UPGRADE: 1968
PLANT PERFORMANCE SUMMARY:
sewage is bypassed to the river.
™
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.3.d.l .
D.3.b.
C.l.f .
C.2.f .
D. I.e.
CAUSE
Flow Backup
Technical Guidance
Infiltration/Inflow
Sludge Wasting Capability
Sewage Treatment Understanding
POINTS
3
3
2
2
2
130
-------
PLAHT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT TYPE: Activated Sludge with Polishina Pond
DESIGN FLOW: 230 cu m/day (0.06 mgd)
ACTUAL FLOW: 150 cu m/day (0.04 mgd)
YEAR PLANT BUILT: 1968
YEAR OF MOST RECENT UPGRADE: 1974
PLANT PERFORMANCE SUMMARY:
Plant performance not meeting permit standards. Mechanical plant effluent
appeared very poor .
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
A.2.b.l.
C.2.f .
C.3.k.
C.2.C.I.
CAUSE
Staff Motivation
Sludge Wasting Capability
Equipment Accessibility for Maintenanc
Process Flexibility
POINTS
3
3
i 2
2
PLANT TYPE: Activated Sludge
DESIGN FLOW: 113,500 cu m/day (30 mgd)
ACTUAL FLOW: 75,700 cu m/day (20 mgd)
YEAR PLANT BUILT:
YEAR OF MOST RECENT UPGRADE: 1973
PLANT PERFORMANCE SUMMARY:
Plant performance not consistently meeting permit standards.
RANKING TABLE1 (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.g.
C.2.C.2.
D.3.a.
C.I. 8.
CAUSE
Sludge Treatment
Process Controllabilic v
Operator Application of Concepts on
POINTS
3
3
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT TYPE: Activated Sludge
DESIGN FLOW: 230 cu m/day (0.06 mgd)
ACTUAL FLOW: 115 cu m/day (0.03 mgd)
YEAR PLANT BUILT: 1973
YEAR OF MOST RECENT UPGRADE :
PLANT PERFORMANCE SUMMARY:
Plant effluent has not consistently met permit standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.2.
C.2.f .
D.3.a.
CAUSE
Process Controllability
Sludge Wasting Capability
Operator Application of Concepts
'
POINTS
3
3
2
PLANT NO. 010
DESIGN FLOW: 950 cu m/day (0.25 mgd)
ACTUAL FLOW: 1,900 cu m/day (0.5 mgd)
YEAR PLAHT BUILT:
YEAR OF MOST RECENT UPGRADE :
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.f.
A. I. a.
CAUSE
Infiltratlnn/Tnf 1 nu
Administrative Policies
POINTS
3
3
131
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. Oil
PLANT TYPE: Activated Sludge
DESIGN FLOW: 5,680 cu m/day (1.5 mgd)
ACTUAL FLOW: 3,785 cu m/day (1.0 mgd)
YEAR PLANT BUILT: 1964
YEAR OF MOST RECENT UPGRADE: 1974
PLANT PERFORMANCE SUMMARY:
RAHKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.4.
C.2.C.2.
CAUSE
Clarifier, Secondary
Process Controllability
POINTS
3
2
PLANT NO. 016
PLANT TYPE: Trickling Filter
DESIGN FLOW: Unknown
ACTUAL FLOW: 3,400 cu m/day (0.9 mgd)
YEAR PLANT BUILT: 1965
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.c.
CAUSE
Industrial Loadings
POINTS
3
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 01?
PLANT NO. 018
PLANT TYPE: Activated Sludge
DESIGN FLOW: 260 cu m/day (0.07 mgd)
ACTUAL FLOW: 230 cu m/day (0.06 mgd)
YF-AR PLANT BUILT: -
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
ing permit standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
B.2.a.
A.I. a.
C.l.f.
C.3.a.
C.3.1.
CAUSE
Lack of Preventive Maintenance ProEram
Sludge Wasting Capabilities
Plant Location
Plant Inoperable due to Weather
POINTS
3
3
2
2
2
PLANT TYPE: Activated Sludge
DESIGN FLOW: 570 cu m/day (0.15 mgd)
ACTUAL FLOW: 950 cu m/day (0.25 mgd winter) 260 cu m/day (0.07 mgd summer)
YEAR PLANT BUILT: 1969
YEAR OF MOST RECENT UPGRADE: 1969
PLANT PERFORMANCE SUMMARY :
Plant effluent was not meeting permit standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.f .
C.3.e.
CAUSE
Infiltration/ Inflow
Plant Inoperability due to Weather
POINTS
3
2
132
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO, 023
PLANT TYPE: Activated Sludge
DESIGN FLOW: 32,170 cu m/day (8.5 mgd)
ACTUAL FLOW: 24,980 cu m/day (6.6 ragd)
YEAR PLANT BUILT: 1969
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
of sludge to creek. Also, fecal colifona density has been high.
charge
RANKING TABLE (PART 1}
RANKING
1
2
3
4
5
6
7
9
10
TABLE REFERENCE
C.l-g.
C.l.e.
CAUSE
Sludge Treatment
Disinfection
POINTS
3
2
PLANT NO. 025
PLANT TYPE: Activated Bio Filter
DESIGN FLOW: 10,220 cu m/day (2.1 mgd)
ACTUAL FLOW: 6,430 cu m/day (1.7 mgd)
YEAR PLANT BUILT: -
YEAR OF MOST RECENT UPGRADE: 1974
PLANT PERFORMANCE SUMMARY:
Charge 10 BOD, 20 TSS) .
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
. C.2.C.3.
C.l.f.
C.l.g.
CAUSE
Aerator
Infiltration/Inflow
Sludge Treatment
POINTS
3
3
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 030
PLANT TYPE: Trickling Filter
DESIGN FLOW: 870 cu m/day (0.23 mgd)
ACTUAL FLOW: 490 cu m/day (0.13 mgd)
YEAR PLANT BUILT: 1963
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
10
TABLE REFERENCE
C.2.C.3.
CAUSE
Aerator
POINTS
2
PLANT TYPE: Activated Sludee with Phosohorus removal and filters
DESIGN FLOW: 120 cu m/day (0.033 mgd)
ACTUAL FLOW: 11 cu m/day (0.003 mgd winter) 60 cu m/day (0.015 mgd summer)
YEAR PLANT BUILT: 1973
YEAR OF MOST RECENT UPGRADE: 1973
PLANT PERFORMANCE SUMMARY:
Plant effluent sometimes does not meet permit standards.
RANKING TABLE (PART 1}
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
A.I. a.
A. 2.a.l .
C.l.e.
CAUSE
Administrative Policies
Staff Number
Seasonal Variation
POTNTS
3
2
2
133
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PUNT HO. 033
PLANT TYPE: Activated Sludge
DESIGN FLOW: 760 cu m/day CO. 2 mgd)
ACTUAL FLOW: 380 cu m/day (0.1 mgd)
YEAR PLANT BUILT: 1949
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.g.
C.2.C.2.
B.I. a.
CAUSE
Sludge Treatment;
Process Control Ubllitv
Housekeeping
POINTS
1
3
2
PLANT NO. 037
PLANT TYPE: Trickling Filter with PolishinE Ponds
DESIGN FLOW: 30,280 cu a/day (8 mgd)
ACTUAL FLOW: 25,740 cu n/day (6.8 mgd)
YEAR PLANT BUILT: 1957
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PERFORMANCE SUMMARY:
Plant effluent sometimes does not meet permit standards. Coliform
RANKING TABLE (PART 1)
RANKING
1
2
3
4-
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.3.
C.2.e.
C.2.C.I.
CAUSE
Aerator
Disinfection
Process Flexibility
POINTS
3
3
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 038
PLANT TYPE: Activated Sludge
DESIGN FLOW: 17,030 cu m/day (4.5 mgd)
ACTUAL FLOW: 13,250 cu m/day (3.5 mgd)
YEAR PLANT BUILT: -
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PE
Plant ef
RFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.a.
C.I. 8.
CAUSE
Operator Application ot concepts and
Sludge Treatment
POINTS
'
2
PLANT TYPE: TricklinR Filter
DESIGN FLOW; 2,270 cu m/day (0.6 mgd)
ACTUAL FLOW: 2,500 cu m/day (0.66 mgd)
YEAR PI-ANT BUILT: 1954
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY :
Plane effluent was Ecmetimes not meeting standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.3.
C.l.f.
CAUSE
Aerator
Infiltration/Inflow
POINTS
2
2
134
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 043
PLANT TYPE: Trickling Filter
DESIGN FLOW: 3,970 cu m/day (1.05 mgd)
ACTUAL FLOW: 3,030 cu m/day (0.8 mgd)
YEAR PLANT BUILT: 1965
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent was not meeting standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.c.
D.3.a.
CAUSE
Industrial
Operator Application of Concepts and
Testing to Process Control
POINTS
3
3
PLANT NO. 044
PLANT TYPE: Trickling Filter
DESIGN FLOW: 1,510 cu m/day (0.4 mgd)
ACTUAL FLOW: 1,400 cu m/day (0.37 mgd)
YEAR PLANT BUILT: 1935
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.f.
CAUSE
Infiltration/Inflow
POINTS
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 045
DESIGN FLOW: 3,030 cu m/day (0.8 mgd)
ACTUAL FLOW: 2,650 cu m/day (0.7 mgd)
PLANT PERFORMANCE SUMMARY: 1
Plant effluent violated standards some of the time.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
g
7
a
9
10
TABLE REFERENCE
D.3.a.
CAUSE
POINTS
2
PLANT TYPE: Activated Sludge Contact Stab, with Polishing Pond
DESIGN FLOW: 2,840 cu m/day (0.75 mgd)
YEAR PLANT BUILT: 1975
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent meeting permit standards most of the time (note: performance
records arc suspect) .
RANKING TABLE (PART 1)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.2.a.
D.3.a.
CAUSE
Performance Monitoring
Testina Co Process Cnnfrol
POINTS
2
2
135
-------
PLANT EVALUATION SUMMARY
PLANT NO. 049
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 051
PLANT TYPE: Activated Sludge
DESIGN PLOW: 1,890 cu m/day (0.5 mgd)
ACTUAL FLOW: 2,840 cu m/day (0.75 mgd)
YEAR PLANT BUILT: 1975
YEAR OF HOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent was not meeting standards on a consistent basis.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.5.a.
C.l.f .
C.l.c.
CAUSE
Equipment Malfunction
Infiltration/ Inflow
Industrial
POINTS
3
3
3
PLANT TYPE: Activated Sludge
DESIGN FLOW: 1,060 cu m/day (.28 mgd)
ACTUAL FLOW: 570 cu m/day (.15 mgd)
YEAR PLANT BUILT: 1975
YEAS OF MOST RECEHT UPGRADE: -
PLANT PERFORMANCE SUMMARY:
Plant effluent met standards, but plant is fairly new.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7.
8
9
10
TABLE REFERENCE
D.3.a.
CAUSE
TestinH to Process Control
POINTS
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
DESIGN FLOH: 260 cu m/day (0.07 mgd)
ACTUAL FLOW: Unknown
YEAR PLANT BUILT: 1970
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent periodically violated standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.l.c.
CAUSE
Sewage Treatment Understanding
POINTS
3
DESIGN FLOW: 570 cu m/day (0.15 mgd)
ACTUAL FLOW: 190 cu m/day (0.05 mgd)
YEAR PLANT BUILT: Primary 1966
YEAR OF MOST RECENT UPGRADE: 1971
PLANT PERFORMANCE SUMMARY:
Plant effluent has not met standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.3.1.
C.2.0.3.
C.l.f.
CAUSE
Plant Inoperability due to Weather
Aerator
Infiltration/Inflow
POINTS
3
3
2
136
-------
PLANT EVALUATION SUMMARY
APPENDIX E (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 056
PLANT TYPE: Activated Sludge
DESIGN FLOW: 14,000 cu in/day (3.7 ragd)
ACTUAL FLOW: 8,330 cu m/day (2.2 mgd)
YEAR PLANT BUILT: 1970
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant Effluent was not meeting standards.
RANKING TABLE (PART 1}
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.I.
D.3.a.
CAUSE
POINTS
2
2
PLANT NO. 057
PLANT TYPE: Activated Sludge
DESIGN FLOW: 110 cu m/day (.03 mgd)
ACTUAL FLOW: 150 cu m/day (.04 mgd)
YEAR PLANT BUILT:
YEAR OF MOST RECENT UPGRADE: -
PLANT PERFORMANCE SUMMARY:
Plant effluent has not met standards.
RANKING TABLE (PART 1)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.l.f .
C.l.h.
CAUSE
Infiltration/Inflow
Ultimate Sludge Disposal
POINTS
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 058
PLANT NO. 059
PLANT TYPE:
tivated Sludge
DESIGN FLOW: 130 cu m/day (0.034 mgd)
ACTUAL FLOW: 50 cu m/day (0.014 mgd)
YEAR PLANT BUILT: I960
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent has not met standards.
RANKING TABLE (PART 1)
TABLE REFERENCE
Sewage Treatment Understanding
PLANT TYPE: Activated Sludge
DESIGN FLOW: 450 cu m/day (0.12 mgd)
ACTUAL FLOW: 640 cu m/day (0.17 mgd)
YEAR PLANT BUILT: 1938
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plant effluent has
RANKING TABLE (PART 1)
TABLE REFERENCE
hi 1 Ity
Plant Inoperability due to Weather
Infiltraion/Inflow
Sludge Treatment
137
-------
PLANT EVALUATION SUMMARY
PLANT NO. 062
PLANT TYPE: Activated Sludge
DESIGN FLOW: 1,290 cu m/day (0.34 mgd)
ACTUAL FLOW: 760 cu m/day (0.2 mgd)
YEAR PLANT BUILT: 1968
YF.AR OF MOST RECENT UPGRADE: 1977
PLANT PERFORMANCE SUMMARY:
Plane effluent was not meeting standards.
RANKING TABLE (PART 1}
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.2.
C.Z.f.
CAUSE
Process Control J.ihl 1 icy
Sludge Hasting Capability
POINTS
T
2
2
APPENDIX E (CONT.)
138
-------
APPENDIX F
PLANT EVALUATION SUMMARY (RANKING TABLE) RESULTS
FOR
THIRTY "PRELIMINARY SURVEY" FACILITIES
The "preliminary survey" ranking tables include the ranking of all fac-
tors that received two and three points. The factors that received one point
were not ranked at individual facilities, but were included in the overall
ranking of factors discussed in the body of this report.
139
-------
PLANT EVALUATION SUMMARY
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 002
PLANT TYPE: Activated Sludge (Extended Aeration) with Waste Sludge Pond
DESIGN FLOW: 3,028 cu Wday (0.8 mgd) Total -^Paralleylants^
ACTUAL FLOW: 1,628 cu in/day (0.43 mgd)
YEAR PLANT BUILT; 1969
YEAR OF MOST RECENT UPGRADE: 1974
PLANT PERFORMANCE SUMMARY:
Plant effluent quality was not monitored prior to the preliminary
The operator said the plant effluent had looked better during the
than many times before. During the survey one of the two parallel
probably would not have consistently met standards if it had been
survey
plants
plant
monitored.
RANKING TABLE (PART 1)
RANKING
1
2
3
L,
5
6
7
8
9
11
TABLE REFERENCE
D.l.c.
D.l.a.l.
D.3.b.
C.2.C.2.
D.2.b.
A.2.b.2.
C.3.1.
A. 2.a.l.
CAUSE
Sewage Treatment Understanding
Staff Aptitude
Ad istration "Plan^Kee'ds"11
Process Controllability
Process Testing
Staff Pay
Staff Coverage
Staff Number
POINTS
3
3
2
2
2
2
2
2
2
2
PLAMT NO. 007
PLANT TYPE: Oxidation Ditch with Sludge Drying Beds
DESIGN FLOW: 265 cu m/day (0.07 mgd)
ACTUAL FLOW: 151 cu m/day (0.04 mgd)
YEAR PLANT BUILT: 1968
YEAR OF MOST RECENT UPGRADE: 1973
PLANT PERFORMANCE SUMMARY:
Plane has not met discharge
over the clarifier weir.
loss
RANKING TABLE (PART 1)
RANKING
1
2
3
5
6
7
8
9
10
TABLE REFERENCE
D.l.c.
C.2.f .
D.2.b.
CAUSE
Sludge Wasting Capability
POINTS
3
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT TYPF- TricklinS Filter with Contact Stabilization and
t-LANi IY^L. Anaerobic Slnripp TUp^t-inn
DESIGN FLOW: 45,420 cu m/day (12 mgd)
ACTUAL FLOW: 30,659 cu m/dav (8.1 med)
YEAR PLANT BUILT: 1953
YEAR OF MOST RECENT UPGRADE: 1972
PLANT PERFORMANCE SUMMARY :
are barely exceeded.
RANKING TABLE (PART 1)
RANKING
1
2
3
t,
5
6
7
S
9
10
TABLE REFERENCE
C.I ,R.
C.2.h.
D.3.a.
C. 2.^.3.
CAUSE
^?,^,1L^SIr"-tranmC
Ultimate Sludee DtsDos.il
Operator Application of Concepts
POINTS
"1
T
2
7
PLANT TYPE: Activated Sludge with Polishing Pond and Aerobic Digestion
DESIGN FLOW: 3,028 cu m/day (0.8 mRd)
ACTUAL FLOW: 3,028 cu m/day (Q.8 mgd)
YEAR PLANT BUILT: 1967
YEAR OF MOST RECENT UPGRADE: 1970
PLANT PERFORMANCE SUMMARY:
treatment standards if discharged. Pond effluent did not meet mini
secondary treatment standards with respect to TSS.
y
jnum
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.b.
D.3.a.
C.3.d.3.
D.I .c.
C.2.C.1 .
C.2.C.2.
A.l.b.
D.2,b.
C.2.C.4.
CAUSE
Technical Guidance
Operator Application of Concepts and
TestinR to Process Control
Hydraulic Profile - Pro^ortionine
Sewage Treatment Understanding
Process Flexibility
Process Controllability
Administration - fffij1^ """
Process Control Testing
Claritier, Secondary
POINTS
3
3
2
2
2
2
2
2
2
140
-------
PLANT EVALUATION SUMMARY
APPENDIX F (CONT.)
PLANT HVA1.UATION SUMMARY
PLANT BO. 014
PI ANT TVPF. ^Y"^. Sludge with Polishing Pond
DESIGN FLOW: 7,570 cu m/day (2 mgd)
ACTUAL FLOW: 5,410 cu m/day (1-43 mgd)
YEAR PLANT BUILT: 1969
YEAR OF MOST RECENT UPGRADE: 1974
PLANT PEP
During tl
effluent
records .
RANKING
2
3
4
5
6
7
8
9
10
FORMANCE SUMMARY:
did not meet the minimum secondary treatment standards . 1
how that the standards were met for the four previous monl
pond
lant
hs.
RANKING TABLE (PART 1)
TABLE REFERENCE
C.2.C.1-
D.3.b.
C.Z.c.2.
CAUSE
Process Flexibility
POINTS
3
2
2
PLANT NO. 015
PLANT 1TPL: nieesLlon ,-inrt SlndCr.bi.nEnnnu B ruier wiu, Anaerobic
DESIGN FLOW: 13,600 cu m/day (3 6 mgd)
ACTUAL FLOW: 6,240 cu m/day (1.65 mgd)
YEAR PLANT BUILT: 1954
YEAR OK MOST RECENT UPGRADE: 1972
PLANT PERFORMANCE SUMMARY:
This plant has met permit effluent standards wliich are presently inghei
than secondary requirements and achieves hagh percentage removals buL
does not meet secondary effluent limits.
RANKING TABLE (PART j)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
A.2,b.3.
A.2.C.
B.2.a.
D.I .c.
A.2.b.2.
CAUSE
Industrial Loading
Supervision
Productivity
Lack of Preventive
Pay
POINTS
3
2
2
2
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 019
PLANT NO. 020
PLANT TYPH: Activated Sludge (Extended Aeration) wl tli Pond
DESIGN FLOW: 246 cu m/day (0.065 mgd)
ACTUAL F.OW: ! 32 ru m/day (0.035 mgd)
YEAR P1ANT BUILT: 1972
YEAR OK HOST RECENT Ul'GRADK: 1972
PI-ANT PERFORMANCE SUMMARY:
Activated sludge plant and pond marginally meeting BOD standards and not
meeling TSS standards.
RANKING TABU; (PART i>
RANKING
I
2
3
4
5
6
7
8
9
10
TABLE RKFKKKNCK
C.2.T.
... £*!*£. \,
C.3.b.
C.2.P.2.
D.2.b.
D.3.b.
CAUSE
Sludge' Wasting Capability
Process Flexibil JLy
Unl t 1'roress Layout
Proi-ciss Control lain "H Ly
Process Control Testing
Tt-cliniral Guidance
POINTS
3
3
3
2
2
2
PLAN')' TYPE: Activated Sludge (Extended Aeration) with Pond
DESIGN FLOW: 95 cu m/day (0.025 mftd )
ACTUAL FLOW: 26 cu in/day (0.007 mfid)
YEAR PLANT BUILT: 1974
YEAR OF MOST RECENT UPGRADE: 1974
PUNT PERFORMANCE SUMMARY:
Activated sludge plant effluent would not have mt-l minimum secondary
effluent standards. Pond effluent was signif icnnUy poorer than activated
sludge plant effluent and did not meet permit standards.
RANKING TAIJI.K (PART I)
RANKING
1
3
4
5
6
7
8
9
10
TABLK REFERENCE
C.2.f .
C.2.C.1 .
C.3.1.
C.3.b.
13. 2. b.
C.2.C.4.
C 2 c 2
CAUSF.
SJudpi- Wasting Capability
Process Flexibility
Uni t Proi-ess Layout
Process Control Testing
Clarifjer Design
Process Control labi ]i Ly
POINTS
3
3
2
2
2
2
2
141
-------
PLANT EVALUATION SUMMARY
PLANT NO. 021
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 022
PLANT TYPE: Activated Sludge (Oxidation Ditch) with Drvint tori.
DESIGN FLOW: 3,400 cu m/day (0.9 mgd)
ACTUAL FLOW: 2,200 cu Hi/day (0.59 mgd)
YEAR PLANT BUILT: 1963
YEAR OF MOST RECENT UPGRADE: 1973
PLANT PE
Plant ha
bulking
RFORMANCE SUMMARY:
udge
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.£.
D.3.a.
CAUSE
Sludge Wasting Capability
Operator Application of Concepts and
Testine to'process Control r
POINTS
.1
2
PLANT TYPE- AcciYa5ed fjl^n (Extended Aeration) with Polishing Pond and
DESIGN FLOW: 56.8 cu m/day (0.015 mgd)
ACTUAL FLOW: 45.4 cu m/day (0.012 mgd)
YEAR PLANT BUILT: 1972
YEAR OF MOST RECENT UPGRADE: 1972
PLANT PERFORMANCE SUMMARY:
Activated sludge plant effluent was of poor quality due to bulking solids.
would not have met standards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.b.
C.2.f .
D.I .c.
C.2.C.2.
D.Z.b.
C.3.I.
D.l.d.
D.l.b.2.
CAUSE
Technical Guidance
Process Controllability
Process Control Testing
Lab Space and Equipment
Insufficient Time on Job
Training
POINTS
3
3
3
2
2
2
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 024
PLANT NO. 026_
DESIGN FLOW: 22,700 cu m/day (6 mgd)
ACTUAL FLOW: 18,500 cu m/day (4.9 mgd)
YEAR PLANT BUILT: 1960
YEAR OF MOST RECENT UPGRADE: 1975
PLANT PERFORMANCE SUMMARY :
Secondary standards for BOD had been met only one month of the first 18
months of operation. Suspended solids removal has been consistently bet-
ter than BOD removal. Effluent standards are now being met (past 2
months). Achievement of the 85 percent removal standards is marginal.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.b.
D.3.a.
C.2.C.3.
C.2.C.2.
CAUSE
Technical Guidance
Operator Application of Concepts and
Aerator
Process Controllability
POINTS
3
1
3
2
.-. .- .- - .-,
DESIGN FLOW: 1,892 cu m/day (0.50 mgd)
ACTUAL FLOW: 568 cu m/day (0.15 mgd)
YEAR PLANT BUILT: 1970
YEAR OF MOST RECENT UPGRADE: 1970
PLANT PERFORMANCE SUMMARY:
The plant was bypassed for extended periods of time from 1970 - 1975 while
modifications to the plant were being completed. Very high-quality
effluent has been produced for the last 15 months, easily meeting permit
limits.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
a
9
10
TABLE REFERENCE
C.3.b.
CAUSE
Unit Process Layout
POINTS
2
142
-------
PLANT EVALUATION SUMMARY
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
PLANT NO. 027
DESIGN FLOW: 37,850 cu m/day (10 mgd)
ACTUAL FLOW: 26,495 cu m/day (5.5 mgd)
YEAR PLANT BUILT: 1963
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PERFORMANCE SUMMARY:
start up after completion of secondary facilities.
RANKING
2
3
4
5
6
7
8
9
10
RANKING TABLE (PART 1)
TABLE REFERENCE
C.2.C.4.
D.3.a.
CAUSE
Clarifier Design
POINTS
3
2
PLANT NO. 028
nn AprnMr IVIPPshPr, and Sludge Drying HMs
DESIGN FLOW: 946 cu m/day (0.25 mgd)
ACTUAL FLOW: 568 cu m/day (Q.1S mgd)
YEAR PLANT BUILT: 1971
YEAR QF MOST RECENT UPGRADE: 1971
PLANT PERFORMANCE SUMMARY:
merit standards.
RANKING TABLE (PART 1)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.h.
C.2.C.2.
C.2.e.
C.Z.g.
CAUSE
Ultimate Sludge Disposal
Process Controllability
Disinfection
Sludge Treatment
POINTS
3
2
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT NO. 032
DESIGN FLOW: 6,800 cu m/day (1-8 mgd)
ACTUAL FLOW: 4,900 cu m/day (1.3 mgd)
YEAR PLANT BUILT: 1949
YEAR OF MOST RECENT UPGRADE: 1975
PLANT PERFORMANCE SUMMARY:
Plant has not been consistently meeting effluent permit standards (minimum
secondary treatment standards).
RANKING TABLE (PART 1)
RANKING
1
2
3
5
6
7
8
9
10
TABLE REFERENCE
D.3.a.
C.2.C.2.
C. 2.e.3.
CAUSE
Operator Application of Concepts and
Process Controllability
Aerator
POINTS
3
2
2
1 __
DESIGN FLOW: 1,890 cu m/day (0.5 mgd)
ACTUAL FLOW: 850 cu m/day (0.224 mgd)
YEAR PLANT BUILT: 1948
YEAR OF MOST RECENT UPGRADE: 1948
PLANT PERFORMANCE SUMMARY:
Historically, the plant effluent quality would not have met minimum
secondary treatment standards. During the sur\ey the standards (fecal
trickling falter performance (summer months).
RANKING TABLE (PART 1)
RANKING
1
2
3
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.I.
D.l.c.
C.Z.e.
D.I. a. I.
D.2.a.
D.2.b.
CAUSE
Process Flexibility
Sewage Treatment Understanding
Disinfection
Operator Aptitude
Performance Monitoring
Process Control Testing
POINTS
3
3
3
2
2
2
143
-------
PLANT EVALUATION SUMMARY
PLANT NO, 034
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
DESIGN FLOU: 30,280 cu m/day (8 mgd)
ACTUAL FLOH: 20,820 cu m/day (5.5 mgd)
YEAR PLANT BUILT: -
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
Plane effluent was not meeting discharge permit requirements.
RANKING TABLE (PART 1)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.3.
C.2.f.
C.2.c.].
C.2.C.4.
C.2.e.
CAUSE
Trickling Filter
Sludge Wasting Capability
Process Flexibility
Disinfection
POINTS
3
2
2
2
2
1 : — : : 1
DESIGN FLOW: 20,200 cu m/day (5.35 mgd)
ACTUAL FLOH: 19,900 cu m/day (5.25 mgd)
YEAR PLANT BUILT: 1962
YEAR OF MOST RECENT UPGRADE: 1966
PLANT PERFORMANCE SUMMARY:
Plant meets permit effluen
t limits of 25 mg/1 BOD and TSS . Calif arm limits
RANKING TABLE (PART 1)
RANKING
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.e.
CAUSE
Disinfection
POINTS
2
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT TYPE: Two-Stage, Low-Rate Trickling Filter Operating as Sinsle-Staee
DESIGN FLOW: 10,700 cu m/day (2. 84 mgd)
ACTUAL FLOW: 6,400 cu m/day (1.68 mgd)
YEAR PLANT BUILT: 1962
YEAR OF MOST RECENT UPGRADE: 1964
PLANT P
The pla
limits .
RFORMANCE SUMMARY:
re not met . 5
oliform
RANKING TABLE; (PART i)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
A.I. a.
C.2.C.
CAUSE
Policies
Disinfection
POINTS
3
2
PLANT TYPE: Oxidation ditch with polishing pond & sludge drying beds.
DESIGN FLOW: 1,550 cu m/day (n.41 mgd)
ACTUAL FLOW: 795 cu m/day (0.21 mgd)
YEAR PLANT BUILT: 1952
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PERFORMANCE SUMMARY:
Plane effluent was meeting secondary treatment standards during the survey.
However, the plant was approaching the point of bulking sludge solids.
The plant was recently upgraded and was just started up about 3 months
prior to the survey.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.I .c.
C.2.f .
D.3.b.
A.l.b.
D.3.a.
D.2.6.
CAUSE
Sewage Treatment Understanding
Sludge Wasting Capability
Technical Guidance (Process Control)
Administration Familiarity with
Plant Needs
Operators Application of Concepts
*nd TflRtinu to Pi-nrpsfi Cnntrnl
Process Control Testing
POINTS
3
2
2
2
2
2
144
-------
PLANT EVALUATION SUMMARY
APPENDIX F (CONTO
PLANT EVALUATION SUMMARY
PUNT NO. 040
DESIGN FLOW: 2,380 cu m/day (0.63 mgd)
ACTUAL FLOW: 1,450 cu m/day (0.384 mgd)
YEAR PLANT BUILT: 1959
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PERFORMANCE SUMMARY:
dards.
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
B
9
10
TABLE REFERENCE
C.2.C.3.
D.I .a.l .
D.I .c.
D.2.b.
CAUSE
Aerator
Aptitude
Se-age *"<-" Understanding
POINTS
3
2
2
2
PLANT NO. 041
DESIGN FLOW: Unknown
ACTUAL FLOW: 530 cu m/day (0.13 mgd)
YEAR PLANT BUILT: 1936
YEAR OF MOST RECENT UPGRADE: 1958
PLANT PERFORMANCE SUMMARY:
except there is no disinfection at the facility.
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.4.
A.I. a.
D.3.b.
CAUSE
Clarifier (secondary)
POINTS
3
2
2
PLANT EVALUATION SUMMARY
PLANT EVALUAT.TON SUMMARY
PLANT NO. 048
PLANT NO. 047
PLANT TYPE: Activated Sludge, extended aeration with polishing pond
DESIGN FLOW: 237 cu m/day (0.0627 mgd)
ACTUAL FLOW: 189 cu m/day (0.05 mgd)
YEAR PLANT BUILT: 1967
YEAR OF MOST RECENT UPGRADE: 1967
PLANT PERFORMANCE SUMMARY:
Activated sludge plant bulked solids every day during survey and according
to the plant: operator has done so quite often. Pond was an estimated 80
percent to 90 percent filled wieh sludge.
RANKING TABLE (PART 1)
RANKING^
I
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.b.
D.l.e.
C.2.f .
C.2.C.4 .
C.2.C.I.
C.3,a.
D.3.a.
CAUSE
Technical Guidance
Sewage Treatment: Understanding
Sludge Wasting
ClariEier
Plant Location
Operator Application of Concepts and
POINTS
3
3
3
2
2
2
2
PLANT TYPE: Activated Sludge with Aerobic Digestion
DESIGN FLOW: 1,410 cu m/day (0.38 mgd)
ACTUAL FLOW: 1,290 cu m/day (0.34 mgd)
YEAR PLANT BUILT: 1971
YEAR OF MOST RECENT UPGRADE: 1971
PLANT PERFORMANCE SUMMARY :
According to the operator the plant has bulked solids typically from one
when not bulking .
RANKING TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.a.
D.3.b.
C.l.f .
D.2.b.
C.2.C.2.
D.2.a.
CAUSE
Operator Application of Concepts and
Tonl-inf l-n PrnrpRfi Hr-mf-ml
Technical Guidance
Infiltration/Inflow
Process Controllability
POINTS
3
3
2
2
2
2
145
-------
PLANT EVALUATION SUMMARY
PLANT NO. 050
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
DESIGN FLOW: 680 cu in/day (0.18 ngd)
ACTUAL FLOW: 640 cu m/day (0.17 mgd)
YEAR PLANT BUILT: 1975
YEAR OF MOST RECENT UPGRADE: 1975
PLANT PERFORMANCE SUMMARY:
fairly frequently. Current more stringent standards cannot be consistently
met with present design.
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.a.
C.2.f .
CAUSE
Operator Application of Concepts and
SludRe Wasting Capability
Process Controllability
3
2
2
I —
DESIGN FLOW: 625 cu m/day (0.165 mgd)
ACTUAL FLOW: 428 cu m/day (0.113 mgd)
YEAR PLANT BUILT: 1976
YEAR OF MOST RECENT UPGRADE: N/A
PLANT PERFORMANCE SUMMARY:
bulking..
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
S
9
10
TABLE REFERENCE
D.3.b.
C.3.b.
CAUSE
Technical Guidance
POINTS
3
3
PLANT EVALUATION SUMMARY
PLANT EVALUATION SUMMARY
PLANT TYPE: Activated Sludge Extended Aeration
DESIGN FLOW: 2,176 cu m/day (.575 mgd)
ACTUAL FLOW: 1,128 cu m/day (.298 mgd)
YEAR PLANT BUILT: Primacy 1964 Secondary 1973
YEAR OF MOST RECENT UPGRADE:
PLANT PERFORMANCE SUMMARY:
The secondary system was performing well. The anaerobic digester was
providing little digestion due to the manner in winch it had been
operating.
RANKING
1
2
3
4
5
6
7
8
9
10
RANKING TABLE (PART 1)
D.l.c.
D.3.a.
A.2.b.3.
A.I .a.
D.3.b.
c.z.g.
C.I. 2.
D.2.b.
B.I. a.
D.4.a.
CAUSE
Sewage Treatment Understanding
Operator Application
Supervision
Policies
Technical Guidance
Return Process Streams
Process Control TestinE
HouselteepinE
0 & M Manual Adequacy
POINTS
3
2
2
2
^ 2
2
2
2
2
2
PLANT TYPE: First Stage Trickling Filter-Second Scar>e ABF With Vacuum Filtei
DESIGN FLOW: 3974 cu m/day (1.05 mgd)
ACTUAL FLOW: 1855 cu m/day (0.49 mgd)
YEAR PLANT BUILT: 1974
YFJU! OF MOST RECENT UPGRADE: 1974
PLANT PERFORMANCE SUMMARY:
Plant not meeting permit standards of 30 mg/1, TSS, and BOD5 .
RANKISG TABLE (PART 1)
RANKING
1
2
3
4
5
6
7
8
9
10
TABLE REFERENCE
C.2.C.3.
D.3.a.
C.2.g.
D.3.b.
B.l.d.
C.2.C.I.
CAUSE
Aerator
?perator Application of Concepts and
estinc to process Control
Sludge Treatment
Technical Guidance
Process Flexibility
POINTS
3
2
2
2
2
2
146
-------
PLANT EVALUATION SUMMARY
PLANT NO. Q61
APPENDIX F (CONT.)
PLANT EVALUATION SUMMARY
PLANT TYPE: Activated Sludge Contact Stabilization (2 plants)
DESIGN FLOW: 1892 cu m/day (0.50 mgd)
ACTUAL FLOW: 643 cu m/day (0.17 mgd)
YEAR PLANT BUILT: 1967
YEAR OF MOST RECENT UPGRADE: 1976
PLANT PERFORMANCE SUMMARY:
One of the two plants was meeting secondary limits, the other was not.
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
8
9
10
TABLE REFERENCE
D.3.a.
C.Z.s.
D.2.b.
C.3.b.
CAUSE
Operation Application of Concepts and
Sludge Treatment
Unit Process Layout
POINTS
T
2
2
PLANT TYPE: Activated Sludge
DESIGN FLOW: 5680 cu m/day (1.5 mgd)
ACTUAL FLOW: 2650 cu m/day (0.7 mgd)
YEAR PLANT BUILT: 1963
YEAR OF MOST RECENT UPGRADE: 1963
PLANT PERFORMANCE SUMMARY:
Plant effluent exceeded discharge standards about 40% of the time.
RANKING TABLE (PART 1)
RANKING
1
2
4
5
6
7
8
9
10
TABLE REFERENCE
D.l.e.
D.3.a.
CAUSE
Sewage Treatment Understanding
POINTS
3
3
147
-------
APPENDIX G
COST INFORMATION FOR VARIOUS TYPES AND SIZES OF FACILITIES SURVEYED
TABLE G-l. (1 of 2) COST INFORMATION FOR 0-380 CU M/DAY (0-0.1 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transportation
Training & Education
Miscellaneous
Operations Subtotal
Capital Outlay
Total
007
0.041
c/iooo
$ GAL.
3540 23.5
2700 17.9
3300 21.9
300 2.0
100 0.7
0 0
1185 7.9
11125 73.9
20600 136.7
31725 210.6
019
0.035
C/1000
$ GAL.
5191 40.6
1200 9.4
1450 11.4
500 3.9
0 0
0 0
2500 19.6
10841 84.9
19250 150.7
30091 235.6
020
0.007
c/iooo
$ GAL .
2500 97.8
450 17.6
300 11.7
150 5.9
0 0
0 0
1340 52.5
4740 185.5
3600 140.9
8340 326.4
* mgd x 3785 = cu m/day
148
-------
APPENDIX G (CONT.)
TABLE G-l. (2 of 2) COST INFORMATION FOR 0-380 CU M/DAY (0-0.1 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY 022 04?
FLOW (mgd)* 0.012 0.05
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transportation
Training &
Education
Miscellaneous
c/iooo
$ GAL.
0)
rH
,0
cd
H
•H
cd
<5
4-*
o
13
C
O
•H
$
3132
1498
297
50
0
12
223
C/1000
GAL.
17.2
8.2
1.6
0.3
0
0.1
1.2
Operations *
Subtotal g 5212 28.6
o
Capital Outlay 3245 17.8
Total 8457 46.4
* mgd x 3785 = cu m/day
149
-------
APPENDIX G (CONT.)
TABLE G-2. (1 of 3) COST INFORMATION FOR 380-3800 CU M/DAY (0.1-1.0 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transpor-
tation
Training &
Education
Miscellaneous
$
28685
11000
14000
1000
3000
500
46203
002
0.43
c/iooo
GAL.
18.3
7.0
8.9
0.6
1.9
0.3
29.4
$
34164
22000
7000
1500
2500
1000
11000
013
0.50
C/1000
GAL.
18.7
12.1
3.8
0.8
1.4
0.5
6.0
$
17878
6800
8595
1200
4500
100
9300
021
0.59
c/iooo
GAL.
8.3
3.2
4.0
0.6
2.1
0.05
4.3
026
0.15
c/iooo
$ GAL.
18186 33.2
2000 3.7
4000 7.3
800 1.5
0 0
0 0
6700 12.2
Operations
Subtotal 104388 66.4 79164 43.3
48373 22.5 31686 57.9
Capital
Outlay
58600 37.3 312000 171.0
31005 14.4 38000 69.4
Total
162988 103.7 391164 214.3
79378 36.9 69686 127.3
mgd x 3785 = cu m/day
150
-------
APPENDIX G (CONT.)
TABLE G-2. (2 of 3) COST INFORMATION FOR 380-3800 CU M/DAY (0.1-1.0 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY 028
FLOW (mgd)* 0.15
C/1000
CATEGORY $ GAL .
Salary 9610 17.6
Utilities 12100 22.1
Supplies 1000 1.8
Chemicals 1000 1.8
Transpor-
tation 1200 2.2
Training &
Education 0 0
Miscellaneous 14850 27.1
Operations
Subtotal 39760 72.6
Capital
Outlay 2000 3.7
Total 41760 76.3
039
0.21
c/iooo
$ GAL.
, — i
,0
cti
•H
cfl
4-1
0
iz
c
0
•H
4-1
nj
o
ti
H
048 050
0.34 0.17
C/1000 c/1000
$ GAL. $ GAL.
18470 14.9 7717 12.3
13500 10.9 14891 23.7
7900 6.4 1784 2.8
1000 0.8 648 1.0
150 0.1 120 0.2
100 0.1 153 0.2
0 0 225 0.4
41120 33.2 25538 40.6
21000 16.9 9332 14.9
62120 50.1 34870 55.5
* mgd x 3785 = cu in/day
151
-------
APPENDIX G (CONT.)
TABLE G-2. (3 of 3) COST INFORMATION FOR 380-3800 CU M/DAY (0.1-1.0 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transpor-
tation
Training &
Education
Miscellaneous
053 055
0.11 0.30
C/1000 0/1000
$ GAL. $ GAL.
13400 32.5 4992 4.6
4870 11.8 13961 12.8
1300 3.2 3323 3.1
100 0.2 0 0
650 1.6 0 0
40 0.1 0 0
330 0.8 2945 2.7
061
0.17
C/1000
$ GAL.
10300 16.6
12800 20.6
3400 5.5
3900 6.3
60 0.1
100 0.2
2800 4.5
$
57148
17107
5241
1078
4965
0
576
063
0.70
c/iooo
GAL.
22.4
6.7
2.1
0.4
1.9
0
0.2
Operations
Subtotal 20690 50.2 25221 23.2
33360 53.8
86115 33.7
Capital
Outlay
Total
7000 6.4
20690 50.2 32221 29.6
10400 16.8
43760 70.6
86115 33.7
* mgd x 3785 = cu m/day
152
-------
APPENDIX G (CONT.)
TABLE G-3. COST INFORMATION FOR 380-3800 CU M/DAY (0.1-1.0 MGD)
FIXED FILM FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transpor-
tation
Training &
Education
Miscellaneous
032
0.22
C/1000
$ GAL.
3780 4.7
4000 5.0
3600 4.5
1000 1.2
0 0
0 0
0 0
0
$
13316
2050
6130
2300
300
150
130
040
.38
c/iooo
GAL.
9.5
1.5
4.4
1.6
0.2
0.1
0.1
$
15755
2500
8000
200
200
200
825
041
0.13
C/1000
GAL.
33.2
5.3
16.9
0.4
0.4
0.4
1.7
0
$
36500
13000
3000
25000
1800
500
700
060
.49
c/iooo
GAL.
20.4
7.3
1.7
14.0
1.0
0.3
0.4
Operations
Subtotal 12380 15.4
24376 17.4 27680 58.3 80500 45.1
Capital
Outlay
100 0.1
19200 13.7 5090 10.7 15000 8.4
Total
12480 15.5
43576 31.1 32770 69.0 95500 53.5
* mgd x 3785 = cu m/day
153
-------
APPENDIX G (CONT.)
TABLE G-4. (1 of 2) INFORMATION FOR 3800-38000 CU M/DAY (1.0-10.0 MGD)
FIXED FILM FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transpor-
tation
Training &
Education
Miscellaneous
Operations
Subtotal
Capital
Outlay
Total
012
8.1
c/iooo
$ GAL.
189970 6.4
62657 2.1
15575 0.5
20000 0.7
3400 0.1
300 0.01
5098 0.2
297000 10.0
82700 2.8
379700 12.8
015 024
1.7 4.9
c/iooo c/iooo
$ GAL. $ GAL.
84141 4.7
19800 1.1
7100 0.4
30000 1.7
0)
5 1000 0.1
a
i — i
•H
| 2400 0.1
j-> 63100 3.5
0
a
o
•H
4_J
co 207541 11.6
s
M
O
1 i i
c
H
98900 5.5
306441 17.1
$
87917
13920
7000
23976
50
73
41360
174296
120000
294296
034
5.5
c/iooo
GAL.
4.4
0.7
0.3
1.2
0.002
0.004
2.1
8.7
6.0
14.7
mgd x 3785 = cu m/day
154
-------
APPENDIX G (CONT.)
TABLE G-4. (2 of 2) INFORMATION FOR 3800-38000 CU M/DAY (1.0-10.0 MGD)
FIXED FILM FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transportation
Training &
Education
Miscellaneous
$
54162
17660
13961
4200
2000
245
11085
035
5.3
c/iooo
GAL.
2.8
0.9
0.7
0.2
0.1
0.01
0.6
$
49746
7586
10742
3655
2000
183
11024
036
2.5
c/iooo
GAL.
5.5
0.8
1.2
0.4
0.2
0.02
1.2
Operations
Subtotal
103313
5.3
84936
9.3
Capital
Outlay
86024
4.4
79545
8.7
Total
189337
9.7
164481 18.0
* mgd x 3785 = cu m/day
155
-------
APPENDIX G (CONT.)
TABLE G-5. COST INFORMATION FOR 3800-38,000 CU M/DAY (1.0-10.0 MGD)
SUSPENDED GROWTH FACILITIES
PLANT
IDENTITY
FLOW (mgd)*
CATEGORY
Salary
Utilities
Supplies
Chemicals
Transportation
Training & Education
Miscellaneous
$
50000
20000
8000
12000
0
0
10850
014
1.0
0/1000
GAL.
13.7
5.5
2.2
3.3
0
0
3.0
$
118782
53228
300
16625
2000
750
86178
027
1.4
0/1000
GAL.
5.9
2.7
0.01
0.8
0.1
0.04
4.3
$
51732
25400
4000
5000
300
750
9000
029
5.5
o/iooo
GAL.
10.3
5.1
0.8
1.0
0.1
0.1
1.8
Operations Subtotal 100850 27.7
Capital Outlay
Total
145000 39.7
245850 67.4
277863 13.8
182465 9.1
460328 22.9
96182
13000
109182
19.2
2.6
21.8
* mgd x 3785 = cu m/day
156
-------
7. AUTHOR(S)
Bob A. Hegg, Kerwin L. Rakness, and James R. Schultz
9. PERFORMING ORGANIZATION NAME AND ADDRESS
M & I, Inc., Consulting Engineers
4710 South College Avenue
Fort Collins, Colorado 80525
REPORT NO.
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
~2.~~~\3. RECIPIENT'S ACCESSION NO.
EPA-600/2-79-034
4. TITLE ANDSUBTITLE
EVALUATION OF OPERATION AND MAINTENANCE FACTORS LIMIT-
ING MUNICIPAL WASTEWATER TREATMENT PLANT PERFORMANCE
6. PERFORMING ORGANIZATION CODE
8, PERFORMING ORGANIZATION REPORT NO.
5 REPORT DATE
June 1979 (Issuing Date)
10. PROGRAM ELEMENT NO.
1BC821; SOS 2; Task Al
11. CONTRACT/CJFKWKT NO.
5-03-2224
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Cin.,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF RE PORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/14
15. SUPPLEMENTARY NOTES See also EPA-600/2-79-035 ,"A Demonstrated Approach for Improving Per-
formance and Reliability of Biological Wastewater Treatment Plants" and EPA-600/2-79-
078,"Evaluation of Operation and Maintenance Factors Limiting Biological Wastewater
Treatment Plant Per f nrmanrp"; Cnnt-arl-- p-ranr-i' Q T,t Evans. Ill (513) 684-7610
16. ABSTRACT
A significant number of wastewater treatment plants constructed with Federal monies
have not met design or NPDES permit standards. The emphasis of this research study was
to identify, quantify and rank the causes of this poor performance. Research objectives
were accomplished by conducting comprehensive evaluations at thirty wastewater treatment
facilities. The two highest ranking factors identified were inadequate operator appli-
cation of concepts and testing to process control and sewage treatment understanding.
Many operators were not trained as evidenced by a lack of sewage treatment understanding
but even trained operators did not apply concepts of operation to process control. The
third highest ranking factor identified was improper technical guidance from authorita-
tive sources. These sources have dramatically affected the capability of existing
operations personnel. Also, six of the ten highest ranking factors were related to
improper plant design. Existing correction programs which address specific performance
limiting factors were found to be limited in their ability to achieve the desired per-
formance from an individual facility. A supplemental program to improve facility per-
formance was developed and demonstrated. The program has potential of reducing plant
construction costs as well as improving plant effluent quality.
This report was submitted in partial fulfillment of Contract No. 68-03-2224 by M & I,
Inc. Consulting Engineers under the sponsorship of the U.S. Environmental Protection
Agency. This report covers the period June 25, 1975 to July 1977, and work was comple-
ted July 1978.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Waste treatment, Activated sludge process,
Trickling filtration, Settling basins,
Wastewater—water pollution
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
EPA Form 2220-1 (Rev. 4-77)
h.IDENTIFIERS/OPEN ENDEDTERMS
Treatment plant performance
[mproving plant performance
or plant performance fac
tors, Composite correction
program (CCP), Wastewater
treatment plant—operation
naintenance, design,
administration
19 SECURITY CLASS (This Report I
UNCLASSIFIED
20 SECURITY CLASS (Tllispagf)
UNCLASSIFIED
c. COSATI Field/Group
13B
21. NO. OF PAGES
172
22 PRICE
157
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