WATER POLLUTION CONTROL RESEARCH SERIES
11020 DNO 03/72
A FLUSHING SYSTEM FOR
COMBINED SEWER CLEANSING
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of.
information on the research, development and demonstration
activities in the Environmental Protection Agency, through
inhouse research and grants and contracts with Federal, State,
and local agencies, research institutions, and industrial
organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, Environmental
Protection Agency, Washington, B.C. 20^60.
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A FLUSHING SYSTEM
FOR COMBINED SEWER CLEANSING
by
CENTRAL ENGINEERING LABORATORIES
FMC CORPORATION
1185 Coleman Avenue
Santa Clara, California 95052
for
OFFICE .OF RESEARCH AND MONITORING
ENVIRONMENTAL PROTECTION AGENCY
Program 1X020 DNO-
Contract 14-12-46,6,
Ma-rch 1972
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402 - Price $1.75
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..EPA Review Notice
This report has "been reviewed "by the Environmental -Protection
Agency and approved for publication. Approval does,.not.-
signify that the contents necessarily reflect the views and
policies of the Environmental 'Protection^Agency 'nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use.' *! " •.
ii
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ABSTRACT
Because solids deposits in.lateral sewers are considered to contribute
a significant quantity of pollutional material to storm water overflows
from combined seWers, the use of a periodic flushing operation was
evaluated as a means of maintaining lower levels of these deposited
materials during low-flow» dry weather periods,
Full scale tests were conducted oh two variable Aslope test sewers (12-
and 18-inch diameters)* During the tests,' solids were first allowed
to build up in both test-.sewer,s by passing domestic sewage through the
sewers for durations of 12 to 40 hours ancj. then were removed by
hydraulic flushing. The results from the tests showed that flush waves
generated using flush .volumes ranging from 30,0 to 900 gallons at aver-
age release rates ranging from 200 to 3, 000 gprri were found to re-
move from 20 to 90 percent of the solids deposited in the 800-foot long
test sewers.
* ,
The cost of installing a periodic flughing system in a typical system of
lateral sewers was estimated to be $620 to $1,275 per acre.
This report was submitted in fulfillment of Project Number 11020 DNO,
Contract Number 14-12-466 under the sponsorship of Water Quality
Research, Environmental Protection Agency.
111
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CONTENTS
Section Page
I Conclusions 1
!•
II Recommendations 3
III Introduction 5
IV Design and Construction of the Test Facility 9
V Experimental Operation 21
VI Discussion 39
VII Design and Testing of a Prototype
Flush Station 71
VIII Arrangements for Field Demonstration of
Periodic Flushing of Combined Sewer Laterals ... 81
IX Acknowledgements 8.3
X References 85
XI Glossary of Terms 87
XII Appendices 89
A. Results from Shakedown Testing 91
B. Field and Laboratory Procedures 93
C. Results from Flushing Evaluation Tests 105
D. Statistical Analysis of Design Equations 147
E. List of Design Drawings 155
F. Description of Mathematical Model for Design
of Sewer Flushing Systems 159
v
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FIGURES
1 Periodic Sewer Flushing Test Facility 12
2 Flushing Evaluation Flow Diagram 13
3 Clear Plastic Pipe Section in 12-Inch Sewer 14
4 Influent Supply and Control System 15
5 Effluent Collection and Recirculation System 16
6 Flush Tank with Pneumatically controlled
Discharge Valves 18
7 Flush Control Building 18
8 Sewage Flow Rate Hydrographs Used in Solids
Build-Up Tests 32
9 Inflatable Dam. ' 33
10 Relative Effect of Slope and Flow Rate on the
Distribution of Solids in the Test Sewers 40
11 Typical Correlation of the Independent
Variables to C_c_ ' 42
-tLiDD
12 Suspended Solids Cleansing Efficiency Correlation ... 45
13 Volatile Suspended Solids Cleansing Efficiency
Correlation 47
14 Total Organic Carbon Cleansing Efficiency
Correlation 48
15 Wave Depth Correlation for 12-Inch Sewer 50
16 Wave Depth Correlation for 18-Inch Sewer 51
17 Sewage-Flush Correlation 53
VII
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FIGURES (Continued)
Page-
18 Pipe Joints Misalinement Effects .............. 55
1 - " ! - . v.- ', " ••"'-.'••:• .' v< -
19 Grade Misalinement Effects .................. 56
20 Relative Distribution of Solids Deposits ........... 59
21 Time-Series Build-Up of Solids ....... . ........ 6i
' ' - •• - 1 '•••",- :. • '• •-•:;:".•• - •
22 Alternate Flushing Station Designs .............. 72
t , >.'-'•
» ' . r , V -' "" ' - - ' '**£"— '•* ' , *k "
23 Prototype Flush Station ' ............... ...... 73
: .- O":- . Uj^- ,':, • . . •„ ;. , •:
24 Prototype Flush Station Control and Operation ...... 75
25 Proposed Fabric Bag Flush Station ....... .*."...'.. 78
26 Proposed In-Line Dam Flush Station ....,.;.... ,; . 79
27 High -Range and. Low -Range Correlation of
BOD with TOG for GEL Sewage . . . ..... .-,.*.,.. . ... ,.'-. 99
28 Accuracy of High-Range Correlation of ,
BOD with TOG for GEL Sewage . .............. 100
* ' . ' -' * :. - .'"' :''•'• " '
29 Accuracy of Low-Range Correlation of
BOD_ with TOG for GEL Sewage ..... . . . . 101
5
30 Accuracy of Simplified Cor relation .of
BOD_ with TOG for GEL Sewage .• . . . . . ..... .... 102
5 ' • n
Vlll
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TABLES
No. Page
1 Solids Removal Predictions 68
2 Estimated Flushing Costs 69
3 Results from Friction Coefficient Tests 91
) • K '
4 Results from Hydraulic Mixing Tests Using Sewage • • • 91
5 Results from Hydraulic Mixing Tests Using Fine Sand- • 92
6 Summary of Accuracy of BOD -TOC Relationships .... 103
7 Summary of Results from Solids Distribution Tests • • • 105
•'••''' I . ' '
8 Summary of Results from Clean-Water Flush Tests • • . 106
9 Summary of Maximum Flush Wave Depths Observed
in-12-Inch Sewer -. ... 115
10 Summary of Maximum Flush Wave Depths Observed
in 18-Inch Sewer '... ...%.....'...'.... 127
11 Summary of Stee'p-Slope Equation Verification 139
12 Steep-Slope Check of Wave Depth Equation
(Equation 13A) .'..'.. '.:...'"; ; 140
13 Results from Sewage-Flush Correlation Tests 141
i* • " • i t- >
14 Results from Pipe Misalineme'nt Tests ............ 143
15 Results from Flush Wave Sequencing Tests 144
16 Results from Solids Build-Up Tests 145
17 Results from Prototype Flush Station Tests 146
18 Summary of Statistics for Equation 9 147
19 Summary of Statistics for Equation 10 148
IX
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TABLES (Continued)
No. ' . Page
20 Summary of Statistics for Equation 1J ........... 149
1 s ' • / ' ' ' "
- i-
21 Summary of Statistics for Equation 12 . .-. , . . . 149
' i . " ' ;
22 " Summary of Statistics for Equation ,ISA ............. 150
23 Summary of Statistics for .Equation 13B .......... 151
24 Summary of Statistics for Equatiqn 15. .,..•. 152
25 Summary of Statistics for Equation 16 , . 153
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SECTION I
CONCLUSIONS
1. Satisfactory predictions can be made of several cleansing efficien-
cies and wave depths for the flush waves and sewer sizes studied using
the formulas developed in this project.
a. The percentage removal (cleansing efficiency) of deposited ma-
terial by periodic flush waves is dependent on the following variables:
flush volume, flush discharge rate, sewer slope, sewer length, sewage
flow rate, 'and sewer diameter.
b. Cleansing efficiency is dependent on flush discharge rate and
volume but is not otherwise significantly affected by details of the flush
device inlet to the s'ewer.
c. Slight irregularities in sewer slope and pipe alinement do not
significantly affect the percent cleansing efficiency.
d. Use of settled sewage as the flushing liquid causes only a minor
and predictable reduction in cleansing efficiency.
2. The mathematical design model developed in this project provides
an efficient means of selecting the most economical flushing system to
achieve a desired cleansing efficiency within the constraints set by the
engineer and limitations of the design equations,
3. Where sewers are over 8 ft deep, tanks inserted in existing
manholes will usually provide adequate flush volumes for periodic sewer
flushing.
a. The prototype flush station developed in this project can be in-
serted in a manhole and provides the functions necessary to pick up
sewage from the sewer, store it in a coated fabric tank and releas-e the
stored sewage as a flush wave upon receipt of an external signal.
4. An estimate of the costs of periodically flushing combined sewer
laterals indicated a range of costs from $630 per acre to $1,275 per
acre for average removal efficiencies of 61 percent and 72 percent,
respectively.
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SECTION II
' RECOMMENDATIONS
This project has succeeded in developing an engineering basis for peri-
odic sewer flushing of combined sewer laterals within a limited ,size
range. It is recommended that further studies be made for flushing of
larger sizes of pipe, of wave sequencing, and of solids buildup over
longer time periods. Although some of the additional work can be done
in the existing test facility, a demonstration in an operating combined
sewer system will be required to verify the relationships developed to
date and to extend the range of the correlations.
Some of the more important areas which need further investigation are
listed below:
1. Investigate the downstream redeposition of the solids removed
by flush waves in the upstream section of the sewer.
2. Experimentally develop the flow hydrograph (wave depth as a
function of pipe length and time) associated with the various flush waves
investigated during this study and establish a correlation between these
hydrographs and the cleansing efficiency relationships.
3. Investigate the effect of multiple flush wave release on the flush
wave hydrographs.
4. Study the diurnal deposition and resuspension patterns of various
dry weather sewage flows.
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SECTION III
INTRODUCTION
BACKGROUND AND PURPOSE
Other studies have shown the need to minimize pollutional effects of
stormwater overflows from combined sewer systems. Even though
stormwater provides dilution of sanitary waste, Biological Oxygen De-
mand and suspended solids of the sewage are often very high during
storms when flow is typically diverted to natural water courses.
This project attempts to improve the quality of the combined sewage
flow as an alternative to retention of storm flow or treatment of the over-
flow at the outfall. It appears that in many cases the high pollutional
load of the combined sewage flow is caused by the flushing out of solids
which had settled in the sewer during the low flow of dry weather. The
purpose of periodic sewer flushing as applied to combined sewers is to
remove settled material during dry weather and hydraulically convey it
to the treatment plant. To the degree that this purpose is accomplished
the pollutional load of the combined sewage will be reduced. Only that
sanitary sewage produced during the storm would have to be bypassed .
rather than also bypassing a major portion of the sewage solids produced
prior to the storm.
PROJECT APPROACH
The program for study of the feasibility of a periodic flushing system for
combined sewer cleansing has been divided into the following major
phases.
PHASE I - Feasibility Study, Planning, and Preliminary Facility
Design. This phase was funded under FWPCA Contract No. 14-12-19
completed in 1967. On the basis of literature review, field surveys,
and limited experimental work, there was a strong indication of the
feasibility of this technique.
PHASE II - Flushing Evaluation. This phase was funded under
FWQA Contract No. 14-12-466 and is the subject of this report. This
phase includes preparation of a test facility, hydraulic experiments, and
prototype equipment.
PHASE III - Demonstration in a Combined Sewer System. This
phase will be required to show the application of periodic flushing tech-
niques and their effect on the discharge from a portion of a combined
sewer system.
5
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OBJECTIVES OF PHASE II
The objectives of this phase are:
• To experimentally determine the hydraulic requirements for effec-
tive cleansing of combined sewer laterals and to formulate design
rules and criteria for application of periodic flushing equipment to
existing combined sewer systems;
• To develop a prototype of a unit-flushing-station which would be
applicable for demonstration of periodic flushing in a combined
sewer system; and
• To expedite and promote arrangements for a demonstration as Phase
III of this program of periodic flushing :of laterals in a combined
s~ewer system.
SCOPE OF PHASE II
This step of the project provided for preparation of a test facility, con-
duct of flushing experiments, evaluation of experimental results, and
development of a mathematical design model for application of flushing
equipment to combined sewer systems.
Test Facility
The scope of the experimental study was limited to combined sewer <
laterals of low slope with low sanitary sewage flow. Accordingly, the
test facility required only two sizes of pipe with a moderate length and
limited slope capability. The flush tank sizes were limited to a volume
thought to be practical in an actual system. Means were provided for
supply of sanitary sewage to the test pipes for solids deposition purposes.
Flushing Experiments
The basic philosophy of the flushing experiments was to provide the infor-
mation for an engineering application of flushing. Therefore, the scope
of the experiments was limited to a measurement of what flowed into the
sewer prior to flushing, the flushing conditions, what was removed by
flushing and what remained that could be removed, by a simulated storm
flow.
Such subjects as a complete description of deposition from'sanitary
sewage flow, of the flush wave hydraulic patterns, -and of the interaction
of the flush wave and the sediment layer, and of the effects on main and
trunk sewers are not included in the scope of the flushing experiments.
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Evaluation of Experimental Results
The relationships between the experimental variables were to be esti-
mated using appropriate statistical techniques,
Formulate Mathematical Model
The mathematical model was to be developed for design purposes. It
was not to be a general mathematical description of the sewer system
nor extend beyond the laterals. The model was to predict performance
of flush tanks applied to sewer laterals based on the experimental re-
sults.
Development of Prototype Flush Station
This step includes study of conceptual designs of flushing equipment and
design construction and testing of one type of flush station which is ex-
pected to be needed for a flushing demonstration.
Arrangement for a Flushing Demonstration
This step provided for furnishing information needed to plan a periodic
flushing demonstration for Hammond, Indiana, and for promoting that
demonstration. It also provided for canvassing up to four other poten-
tial demonstration locations in the event that Hammond decided not to
apply for a demonstration grant. , >
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SECTION IV
DESIGN AND CONSTRUCTION OF THE TEST FACILITY
DESIGN OBJECTIVES AND APPROACH
The overall objective of this phase of the project was to design and con-
struct a test facility that could be effectively used to determine the re-
quirements and limitations associated with the hydraulic cleaning of
combined sewers. The primary objective of the project was to study the
cleansing of lateral sewers with mild slopes. As a result, the design of
the facility was limited to relatively small diameter pipes and slopes
between 0. 001 and 0. 01.
The fact that pipe diameter and pipe slope were considered to be of pri-
mary importance in the experimental work of this project greatly
influenced the overall design.of the facility. A minimum of two diameters
of pipe had to be included to allow an effective comparison of pipe diam-
eter effects. The 12 in. and 18 in. diameters were selected because they
were representative of the range of small diameter sewers (8 to 24 in. ).
Establishment of the relative influence of pipe slope on the cleaning pro-
cess required that the design allow for independent slope adjustment of
the two sewers, with a minimum of effort.
Since the primary concern of the proposed experimental work, was "with
solids deposited by sewage flowing through the sewers, the design had to
include a complete sewage supply and control system. Also reliable
sampling systems were needed so that the quality of the influent to test
sewers as well as the discharge from each pipe could be accurately ~
evaluated.
Hydraulically cleaning the sewers required^that flush equipment capable
of supplying known quantities of flush liquid at various rates to different
points along the length of each sewer be included in the facility. Also
the design had to include a system capable of separately cleaning individ-
ual sections of each test sewer to a consistent degree, in order to provide
a constant reference for comparing the effectiveness of the various flush
combinations and to establish the influence of pipe length on the cleansing
process.
The objectives and requirements discussed above were combined with the
economic ^and test site limitations of the project to produce a facility de-
signed to meet the experimental needs of the project. A detailed descrip-
tion of the facility is given later in this next section.
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PROBLEMS ENCOUNTERED
There were several problems encountered during the design and con-
struction phases of this project which would be helpful to know about if
another facility of this type is ever constructed. Most of the problems
encountered during the mechanical design phase were satisfactorily . ..
solved and can be, avoided by using the general arrangement described
later in this section. Although the problems encountered during the con-
struction phase were not too serious, several of them caused unexpected
delays. .
The problem that caused the most concern was the result of the high
length tolerances of the vitrified clay sewer pipe. Despite careful
grading of the pipe purchased, the effective length of the 18 in. section .
varied from near nominal to as much as 3 in... over nominal and the 12 in.
section varied from slightly longer^than nominal to as much as 2 in. less
that nominal. As a result of these high tolerances, several special sec-
tions of pipe had,to be cut to compensate .for the buildup of tolerances..
Another problem that developed during the construction .of the facility;
resulted from the fact that the outside diameter of the clay sewer pipe
varied somewhat and many of the pieces were not round. This caused
unexpected problems with the joints where the clay pipe was to be cou-
pled to simulated manholes which were made of steel. . -
• .... .----- - - i
The fact that the clay sewer pipe is quite brittle also caused some pro-
blems. Two sections of pipe were cracked slightly when they were in-
stalled and the cracks were not apparent until after the installation was
completed and water was run through the pipe. These cracked sections,
which were near-the center of the pipe span, had to be replaced, which
was found to be a very difficult operation. The probability of this
problem occurring undetected can be reduced by running water through
the. pipe periodically when it is being installed. "
TEST FACILITY DESCRIPTION "' .
The test facility combines two variable-slope test sewers with accurate
and flexible influent quantity and quality control and complete effluent
sampling and handling capabilities. The facility also includes a flush
system that allows'controlled induction of water pr sewage at numerous
points along the length of the test sewers. Figures 1 and 2 show the
relative size and general arrangement of the overall test facility. A.
complete description of the mechanical design of the facility is given in
the as-built drawings that are listed by number in Appendix E;
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Variable-Slope Test Sewers
The pipeline assembly (see Figures 1 and 2 ) consists of two pipes that
run parallel to each other. Each pipe is supported along its entire length
by an I-beam. Attached to the top of each beam is a series of pipe saddles
in which the pipe rests. The two I-beams are suspended between the legs
of fabricated steel frames by means of long screws. Each beam spans
the distance between two consecutive frames and is connected to the next
beam by means of a single pin, making the connection flexible in the ver-
tical direction. The screws which support the beams are attached to the
top of the steel frames in such a manner as to allow the screws to be
used to adjust the vertical heights of the beams. The two pipe lines are
separately supported and their slopes can be independently adjusted.
Between the two pipelines, a wooden catwalk runs the entire length of the
pipeline assembly. The walk is supported by the I-beam which supports
the larger of the two test pipes. Since the position of the catwalk and the
test pipes remains relatively constant, it provides easy access to the test
pipes at all heights.
The test sewers are constructed of 12 in. and 18 in. clay sewer pipe.
Each line is approximately 800 ft. long and consists of about 620 ft. on a
straight-run and 180 ft. on a curve. (Approximately 300 ft. of straight
run is upstream of the curve and the remainder downstream.) At the
beginning and at the third point along each pipeline, there are fabricated
steel sections that simulate manholes. In every 18 ft. section of pipe,
with the exception of the curved section, there is one tee with a 12 in.
side outlet this is positioned vertically to allow visual observation of
flow in the pipeline. Also, a section of clear plastic pipe (6 ft. long in
the 18 in. sewer and 5 ft. long in the 12 in. sewer) was used to replace a
section of clay pipe in both test sewers to allow more extensive visual
observation of the flow in the pipes (See Figure 3). These plastic sections
have the same inside diameter as the clay pipe and are presently located
approximately 140 ft. downstream of the influent end of the sewers.
-+
The test pipes can readily be adjusted to virtually any slope desired be-
tween the limits of 0 and 0. 01. Slope changes are accomplished by ad-
justing the screws which support the pipe at each support frame. The
adjustment of the screws is easily accomplished through use of an air
driven wrench. This system allows complete slope changes to be made
in a matter of only a few hours.
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. Figure 1 PERIODIC SEWER FLUSHING TEST. FACILITY
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SANITARY SEWER
(City of Santa Clara).
WET
WELL
| WASTE|
COMMINUTOR
2 — CHICAGO
PUMP NON-CLOG
SEWAGE PUMPS
FLOW
CONTROLLER
PARSHALL FLUME
C3" ACCURA-FLO)
J
CHICAGO PUMP
TRU-TEST
SEWAGE SAMPLER
j SAMPLE BOTTLE|
FLOW
SPLITTER
SOLIDS SLURRY
FEEDER #2
DRY SOLIDS
FEEDER
SOLIDS SLURRY
FEEDER #1
18" TEST SEWER
1
• *"*/~\ M c* m
L2" TEST SEWER}
FLUSHING SYSTEM
CONE— BOTTOMED
COLLECTION TANK
3150 GALLON
MAXIMUM CAPACITY
CONE — BOTTOMED
COLLECTION TANK
3150 GALLON
MAXIMUM CAPACITY
CHICAGO PUMP
MODEL VPMOM 4
NON-CLOG PUMP
PROPERTY OF
FMC CORPORATION
Figure 2 FLUSHING EVALUATION FLOW DIAGRAM
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Figure 3 CLEAR PL'ASTIC PIPE SECTION
IN 12 IN. SEWER
•Influent Supply and Control
The sewage supplied to the Flushing Evaluation Facility is taken from an
18 in. sewer line that belongs to the City of Santa Clara, California. The
sewage is transported by gravity through a 12 in. clay sewer line into a
wet well at the bottom of a.concrete pump pit. The sewage is then pump-
ed from the wet,well through a 6 in,. C.I. line by means, of one or both of
two nonclog pumps, to a point where the flow is divided and part of the
flow is diverted to other FMC experimental.projects. The flow not di-
verted to the other projects passes through a 6 in. pressure line to the
beginning of the Flushing Evaluation Facility.
The influent supply and control system of the test facility is shown in
Figure 4 . TheUnfluent enters first a flow control box where the portion
of'flow,desired'for testing is diverted into a 10 in. wide fabricated steel
flume. The portion of flow not needed for testing is wasted back to the
city .sewer. The,*influent .passes from the 10 in. flume through a 3 in.
Parshall flume'where the rate of flow is recorded and controlled by a
float-activated'flowmeter and pneumatic controller. The flow through
the Parshall flume is -recorded on a single pen, 24 hr. circular chart.
The .pneumatic controller1 can be manually set for a desired flow rate,
which can be adjusted by the operator at any given time.
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FLOW
CONTROL
BOX
DRY
, SOLIDS
FLOW CONTROLLER: FEEDER
AND RECORDER
TIMERS FOR
-SOLIDS FEEDERS
Figure 4 INFLUENT SUPPLY AND CONTROL SYSTEM
The controller continuously compares the actual flow as measured by
the flow meter with the value set by the operator and corrects for any
difference by sending the proper pneumatic signal to the pneumatic
lever motor, which actuates and corrects the position of the flow di-
verter.
The effluent from the Par shall flume passes through, approximately 19
ft. of fabricated steel flume 7 in. wide and approximately 6 ft. of flume •
18 in. wide,: all on a slope of 0. 67 percent, to a fabricated steel splitter.
box where the total test flow is divided between the two,test pipes. The
splitter is manually operated and'.is capable of dividing.-the total flow in-j
to any two proportions desired.
The quality of the influent to the test facility can be'altered by the
addition of foreign materials such as sludge, paper, etc. Solids in the
form of slurries can be added to the influent by use of one or both of the
two available solids feeders (See Figure 2). These feeders each consist
of a 40 gal. steel fabricated circular storage tank and-a vertically acting
dipper, actuated by a single solenoid air cylinder. The/maximum feed
rate of each of these feeders is more than. 6. .0 Ib. pe-r min.. The 30-min.
timer gives the feeder almost infinite feed"rate central.
Dry solids such as sand and gravel,,, can bemadded to,the influent by
means of the dry solids feeder ass-embly. This assembly consists of a
20 gal. "cone-bottomed hopper that'discharges into a Syntron vibratory
15
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feeder. The fi-e.xibili.ty of the speed controller on the Syntronfeeder
combined with that of the 30 min. cycle timer makes the feed rate of the
assembly almost infinitely adjustable from 1,250 lb., per hr. to zero.
The influent to the test sewers can be sampled either continuously or
intermittently. A dipper type composite sampler is installed in the 7 in.-
wide steel flume between the solids feeders and. the flow splitter box.
The sampler is driven by a 2 rpm electric motor that is coupled to a 30
min. cycle timer. The timer allows the sampling frequency to be ad-
justed from a low of 1 per hr. to a maximum of 120 per hr.
Effluent Handling Equipment
The catch basin assembly (See Figure 5) is completely contained •within
a concrete pit 14 ft. wide, 24 ft. long, and 12 ft. deep. This portion of
the test facility was specifically designed for handling and sampling the
effluent from the test pipes.
Figure 5 ' EFFLUENT COLLECTION AND
RECIRCULATION SYSTEM
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There are two steel cone-bottom collection tanks that have a maximum
capacity of approximately 3, 150 gal, each. On top of these two tanks
are two troughs that are gated such that either pipe can be discharged to
either collection tank or wasted to the city sewer.
On the floor of the pit below the collection tanks is a 20 hp nonclog pump
designed to pump 800 gpm at a total discharge head of 67 ft. The pump
is incorporated into a 6 in. piping and valving system that is designed to
perform the following three separate tasks:
1. The pump can be used to pump the contents of either or both
collection tank(s) to the city sewer by way of an 8 in. waste sewer.
2. It can also be used to hydraulically mix the contents of either tank
by rapid recirculation. The contents of the tank can be circulated by
pumping from the top and into the bottom or vice versa.
3. The contents of either or both tanks can also be pumped to any
one of seven possible locations along the test sewers and discharged into
either test pipe at each location. This arrangement makes possible con-
tinuous recirculation of effluent from either test pipe. .;
Flushing System
Experimental flushing operations can utilize any one or all of three avail-
able elevated flush tanks (Figure 6). The flush tanks are constructed
of steel and are designed such that they can be pressurized up to 20 psig.
The primary flush tank is the largest, 5 ft in diameter and 6 ft high with
a capacity of 900 gal. , and is located at the influent end of the test pipes.
The other two tanks are also 5 ft in diameter, but only 5 ft in height.
One of the smaller tanks is located approximately 1/3 of the total dis-
tance downstream from the primary tank and the other 2/3 of the way.
All three of the tanks are elevated above: the test pipes allowing gravity
flushing.
The release of water from each flush tank is controlled by a 12 in. and an
18 in. butterfly valve. The 12 in. valve is installed in a 12 in. steel pipe
which runs down from the flush tank and discharges into the larger test
pipe. The 8 in. valve is installed in an 8 in. line which runs down from
the flush tank and discharges into the smaller test pipe.
The flush control valves are actuated by double-acting air cylinders equip-
ped with pneumatic positioners. The flush control valves can be actuated
either manually or automatically. The controls used for manual and auto-
matic control of the valves are located on the instrument panel in the con-
trol building located near the catch basin (see Figure 7).
17
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Figure 6 FLUSH TANK WITH PNEUMATICALLY
CONTROLLED DISCHARGE VAL.VES
Figure 7- FLUSH CONTROL BUILDING
18
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The valves are operated manually by opening the control line to the de-
sired flush valve and transmitting a pneumatic signal to it by means of a
pressure regulator. The control valve is completely closed when the
pneumatic signal is 3 psigy and completely open when the signal is 15
psig. The percentage change in the signal is directly proportional to
the percentage change in valve opening. The control valves at each tank
can be manually operated independently of those at the other tanks. The
8 in, and 12 in. valves at each tank can be operated independently only if
they are operated at different times. If both valves are to be operated
simultaneously, they must be operated using the same pneumatic signal.
All of the flush control valves can be automatically controlled by means
of a circular cam. programmer. This programmer is electrically driven
at one revolution per 8 min. and produces a pneumatic signal -which is
used as the set point for a pneumatic controller, which continuously ad-
justs the valve being used to obtain the liquid level desired. The water
level in each tank is continuously monitored by a differential pressure
transmitter with a fixed operating range of 0 to 100 in. of water. The
transmitter receives the difference in pressures between the bottom and
top of the flush tank (water level) and converts this pressure to a pneu-
matic signal (3 to 15 psig) which is transmitted to the pneumatic recorder
and controller.
The 8 in. and 12 in. control valves at the flush tanks can be automatically
operated independently or simultaneously. However, only those valves that
are to be operated under the same control sequence can be operated sim-
ultaneously. If the control sequence is different for different valves, each
of these valves must be operated separately.
The recorder that receives the signal from" the transmitter is a three-pen
(one for each tank), strip-chart-type pneumatic recorder. The recorder
continuously monitors the liquid level in all three flush tanks. The signal
received by the controller is the actual liquid level in the flush tank and
is compared by the controller with the desired liquid level as indicated by
the cam programmer. If a difference in the actual and desired liquid
levels is present, the controller pneumatically adjusts the valve to com-
pensate for the difference.
19
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SECTION V
EXPERIMENTAL OPERATION
SHAKEDOWN AND PRELIMINARY TESTING
The 2'-week period immediately following completion of the construc-
tion of the experimental equipment was used to ready the facility for full-
scale testing. During this period, the experimental equipment was oper-
ated and adjusted for proper function and the tentative test procedures
were checked experimentally to establish their reliability.
Equipment Check
The sewage supply equipment was checked for proper operation and
accuracy. This was accomplished by collecting the total discharge from
the test sewers in the calibrated collection tanks and recording the actual
flow rate and fluctuation in flow rate as indicated by the time-rate-of-
change of the volume of effluent collected. The flow rate recorded by
the influent flow recorder was found to correlate satisfactorily (within
3 percent) over the expected operating flow range of 10 gpm to 100 gpm.
The flow controller, after minor adjustments were made, was found to
be capable of maintaining constant rates of flow, in the above range, with
only minor fluctuations of extremely short duration. The flow splitter
was checked and found to be capable of dividing the flow between the two
test sewers within + 1 percent of the desired proportions.
The flush control system was adjusted to obtain constant discharge rates
and the tank level recorder was calibrated. These adjustments were
accomplished by making numerous flush releases using total flush vol-
umes ranging from 200 to 900 gal. The accuracy of the tank level
recorder was checked by direct measurement of the tank volume and
level and found to be satisfactory ( + 0. 5 percent over the given range).
The discharge rate was verified using the calibrated tank level recorder.
The solids feeders were adjusted and feed rate of each established. The
dry solids feeder was operated using uniformly-graded clean sand and
the maximum feed rate was found to be approximately 1, 250 Ib. per hr.
for continuous operation. The slurry feeders were operated using a
water-paper mixture and their maximum feed rates were found to be
approximately 6. 7 Ib. per min. Note should be taken that although
these solids feeders were installed and calibrated, the suspended solids
content of the influent sewage remained consistently high throughout the
testing and therefore they were not required during any of the actual ex-
perimental work.
21
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Friction Coefficient Evaluation
The two test sewers were adjusted to the slope values (0-. 001 for the 18
in. sewer and 0. 002 for the 12 in. sewer) selected as the minimums to
be used in the proposed testing program, and a series of basic hydraulic
tests was run using clean water. This test series had two objectives.
The first was to check the actual discharge of the 20 hp recirculation
pump at various discharge heads and the second was to experimentally
check the flow characteristics of the clean sewers. The recirculation
pump was used to pump clean water at various constant rates to the up-
stream end of the test sewers and the depth of the flow and corresponding
average discharge rate were recorded for each sewer. The measure-
ments of the depth of the flow were made using a graduated depth gate at
several different points along each sewer. The average discharge rate
was determined by collecting 2, 850 gal. of the discharge from each test
sewer in the effluent collection tanks and recording the total elapsed
time.
The results from the above tests (see Table 3, Appendix A) indicated
that the performance of the recirculation pump closely followed the
published performance curve, and that the Manning1 s-n values for the
clean sewers ranged from 0. 008 to 0. 0135. The Manning1 s-n values
were generated by solving Manning's Equation (Equation 1) for n using
the experimentally determined flow rate and flow-depth data.
sl/2 R2/3 A (1)
Where:
Q is the average discharge in cubic ft. per sec.
n is the empirically determined friction coefficient,
S is the slope of the pipe in ft. per ft. ,
R is the hydraulic radius in ft. :
A is the cross-sectional area in sq. ft.
Although the tests were not precise enough to be all conclusive, the
values obtained show good correlation with those usually used for clean
vitrified clay pipe.
Effluent Mixing Evaluation
Several tests were conducted to establish the overall efficiency a'nd re-
liability of the proposed effluent mixing and sampling procedures. The
reliability of these procedures depend almost exclusively on the ability
22
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of the hydraulic mixing process to produce a mixture which very closely
approximates a homogeneous mixture, without significant modifications
in the characteristics of the particulate matter present.
The circulation patterns developed by the mixing process were visually
evaluated by mixing various volumes of clean water (1, 200 to 2, 850 gal.)
and introducing small amounts of Methylene Blue at several different
points in the collection tank. In all cases, the circulation patterns
appeared to be uniform throughout the tank and appeared to produce com-
plete dispersion of the dye within one complete volume displacement.
The homogeneity of the mixture produced by the mixing process was
checked by mixing given volumes of water containing known quantities of
the fine sand, taking depth integrated grab samples after various mixing
times, and analyzing these samples for suspended solids concentration.
The results of these tests (Table 5, Appendix A) show that the suspended
solids''concentrations of the grab samples taken after one and two volume
displacements were consistently within 2 percent of the expected values.
These results indicate that the mixing required for representative sam-
pling is accomplished by the recirculation operation when mixing times
that are equivalent to one or more volume displacements are used.
The character 9f the particulate matter presented in sewage was found
not to be significantly altered by the mixing process. Several quantities
of sewage of known suspended solids concentrations were placed in the
collection tanks and mixed continuously for one and two complete volume
displacements. In each case, the suspended solids concentrations of the
samples taken after mixing'were consistently within 5 percent of the sus-
pended solids concentration of the composite sample taken before the
sewage was mixed (see Table 4 , Appendix A).
Sand Transport Test
i
The distribution of solids deposits along the length of the two test sewers
was visually evaluated. This was accomplished by using the dry solids
feeder to add approximately 200 ppm of uniformly graded fine sand to'
clean water passing through the 18 in. and 12 in. test sewers at 50 gal.
per min, and 30 gal. per min". , respectively, and observing the resulting
deposits of sand at various points along the sewer.
More than 50 percent of the sand appeared to settle out in the first 100 to
150 ft, of the pipe. .Significant quantities of sand could be resuspended
and transported only by flush waves generated by flush releases of 300
gal. or more at flush rates of 500 gpm and greater. The amount of sand
23
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resuspended appeared to be more dependent upon the rate of flush release^
than on the volume of release, whereas the distance the sand was carried
after resuspension appeared to depend more on the volume of the flush f
release. , . s ."!
Preliminary Flushing Evaluation Tests
Several preliminary flush tests were run to establish a realistic and
workable plan of attack. During the first few of these tests, no sewage
was used. Instead, clean water was used and. the general characteristics
of flush waves generated by various combinations of volume and rate of
release were observed. Also, the .time required for completion of the
various testing operations was established to allow better time planning
for future testing. . .
The second portion of thes.e preliminary tests was run using sewage and
in accordance with the preconceived test operational methods. Although
data was gathered during these tests, it was not used in the final evalu-
ation due to procedural' errors and changes made during this learning
phase. These tests served to increase the efficiency and reliability of
the final tes(t procedures,, which will be described in the following section.
TEST .PROCEDURES
The experimental work performed during the course of this project was
designed and organized to empirically define the physical limitations and
requirements associated with hydraulic cleansing of small sewers. The
major portion of the work'was directed at defining the relative influence
of the various experimental parameters (flush rate, flush volume,., pipe
diameter, pipe slope, pipe length, and sewage base flow) on the efficiency -
of the cleansing process, with physical conditions such as pipe alinement
and slope uniformity optimized. The remainder of the experimentation
attempted to evaluate the changes in the cleansing efficiency when the
various physical conditions were somewhat less,than optimum.
The, overall testing plan consisted of eight general groups of tests.
Although each pf the .test groups had different objectives, all of them were
operated in the same basic manner. The following discussion will first
describe the general operational procedures common to, most of the tests,
and then discuss, in more detail the specific operation of each of the groups.
of tests. ...
24
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Basic Operation
Solids Buildup. The first step in nearly all of the tests run during this
project was to build up solids in the test sewers. This was accomplished
by adjusting the influent flow controller to maintain a constant flow rate,
usually between 40 and 60 gpm, and setting the flow splitter to attain
the desired apportionment of the total flow between the two test sewerSt
The selected sewage base flow was then allowed to continue flowing
through the sewers for a specific length of time and was continuously
sampled by the composite sewage sampler before entering the sewers.
No solids were externally added to the sewage since the solids content in
the sewage remained high enough for adequate solids buildup. This also
avoided difficulty associated with correlating the quantity and quality of
solids added to actual field conditions. The solids buildup periods
usually extended from early afternoon until early the following morning,
giving average durations of between 12 and 20 hrs. However, approxi-
mately one-fifth of these buildup periods extended over weekends and
therefore had correspondingly longer duration times. Not in all cases
was the sewage base flow held constant throughout the buildup period.
This inconsistency resulted from the'fact that during the early morning
hours, the supply of domestic sewage Was often not sufficient to main-
tain the flows desired and the flow would cease. When this stoppage of
flow occurred, the duration time was taken as the time during which the
sewage was actually flowing, based on the records from the flow recorder.
Pretest Preparation. Before the flush waves were released, several pre-
test operations were performed. First the sewage flow recorder chart
was checked for any indication of abnormal flow conditions. Thus, if the
' solids buildup flow discontinuities were not excessive, the depth of the
sewage base flow was measured and the general appearance and quantity
of the solids deposited was recorded at several points along the length of
each of the test sewers.
The maximum depth of the flush waves generated by the various com-
binations of the test variables was measured at several positions along
each sewer. This was accomplished by inserting quarter-inch diameter
steel rods, coated with a paste-type water level indicator, into the up-
turned tees at approximately 60 ft. intervals before release of the flush
wave. Then after the flush waves had passed all of the stations, the rods
were individually removed and maximum wave depth recorded by meas-
uring the maximum depth shown by the water-level indicator. The accu-
racy of these measurements is estiniated to be within +_ 1/4 in. , with the
majority of the reading being slightly higher than the actual depth.
25
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Flush Release. The flush release, when included in the test, was made •
immediately after the end of the solids buildup period. A given quantity,
of flush liquid, usually 300 to 900 gals, was placed in the primary flush
tank located at the upstream end of the test sewers. Then the sewage
base flow to the 12 in. test sewer was shut off and at the same instant
the flush release was made to the 12 in. sewer. Then the flush tank was
refilled and the above process repeated for the 18 in. sewer. "When the
first appearance of the flush wave, indicated by an increase in depth of
flow, was observed at the effluent end of the sewers, the discharge was
diverted from waste to one of the cone-bottomed collection tanks (one for
each sewer).
After collecting the complete flush discharges, the contents of tanks
were individually mixed, using the hydraulic mixing process previously
discussed, and samples of each taken for laboratory analysis. Also the
total volume of each flush discharge was recorded by reading the corres-
ponding tank-level indicator. "When the flush volumes being investigated
were small, clean water was added to the collection tanks before they
were mixed, in order to allow use of the recirculation mixing process.
Storm Simulation. The storm simulation step was the final cleansing
which the test sewers received in all of the tests. The flow rate used
was in all cases approximately 1, 000 gpm, the maximum allowed by the
pumping system, and was designed to clean the sewer to.the highest
degree possible.
The first section of the 12 in. sewer was cleaned by pumping clean water
from one of the cone-bottbmed collection tanks to a point approximately
160 ft from the downstream end and collecting the total discharge from
the sewer in the remaining collection tank, where it was mixed and sam-
pled. The tank containing the discharge from the sewer was emptied and
cleaned, and the other-tank was again filled with clean water. Then the
process was repeated for the downstream 160 ft of 18 in. sewer.
After cleaning the first 160 ft.downstream section of each test sewer, in
the manner described above, the flow induction point was moved up-
stream another 108 ft and the next 108 ft section of each sewer was like-
wise cleaned. Then the flow induction point was moved upstream another
260 ft along the 18 in. sewer and 247 ft along the 12 in. sewer and the
next corresponding sections of each sewer cleaned. Finally the flow in-
duction point was moved to the upstream end of each of the sewers and
the last or upstream 267 ft section of each pipe cleaned.
26
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Solids Distribution. Tests
The purpose of this group of tests was to establish the relative distribu-
tion of the solids along the length of the test sewers as deposited by the
various sewage base flows. These tests were generally conducted as
described in basic operation section above, except that no flush release
was made. Instead, the test sewers were cleaned using only the storm
simulation process.
At the minimum slope values of 0. 001 for the 18 in. sewer and 0. 002 for
the 12 in. sewer, a total of six tests were run on each sewer. Two tests
were run for each of the sewage base flows of 10,' 30, and 50 gpm for the
18 in. sewer and 10, 20, and 30 gpm for the 12 in. sewer.
At the slopes of 0. 002 and 0. 004 for the 18 and 12 in. sewers, respec-
tively, a total of four tests were run on each pipe. Two tests were run
for each of base sewage flows of 10 and 30 gpm for the 12 in. sewer and
10 and 50 gpm for the 18 in. sewer.
A total of six tests were run on each pipe when the two test sewers were
at slopes of 0. 004 (18 in.) and 0. 006 (12 in.). Three tests were run for
each of the sewage base flows of 10 and 30 gpm for the 12 in. sewer and
10 and 50 gpm for the 18 in. sewer.
Two tests were run on the 12 in. sewer at a slope of 0. 008. The base
sewage flows used were 10 and 30 gpm.
Clean-Water Flush Tests
The clean-water flush tests were run to determine the relative influence
of pipe diameter, pipe slope, sewage base flow, pipe length, flush vol-
ume, and flush rate on the ability to clean sewers hydraulically. These
tests were all operated as described in the basic operation previously,
using clean water as the flush liquid.
A total of 72 tests were run on each sewer. At the minimum slope values
of 0. 001 for the 18 in. sewer and 0. 002 for the 12 -in. sewer, a total of
45 tests were run. During these tests, the cleansing of the 12 in. sewer
was related to flush volumes of 300, 600, and 900 gal. , each of which
were combined with three different flush rates ranging from 300 to
2, 000 gpm. The effective cleansing of each of these combinations of
flush rate and flush volume was evaluated at base sewage flows of 10, 20,
and 30 gpm. The 18 in. sewer was tested in the same manner, except
that the flush rates ranged from 200 to 3, 000 gpm and the sewage base
flows tested were 10, 30, and 50 gpm.
27
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n ic minimum.
Twenty-three tests were run on both pipes, 12 at slopes of 0. 002 for
the 18 in. sewer and 0. 004 for the 12 in. sewer and 11 at slopes of
0. 004 for the 18 in. sewer and 0. 006 for the 12-in. sewer. Four tests
were run at a slope of 0. 008 on the 12 in. sewer only, as a steep-slope
check of the empirical relationships developed from the results of the
tests run at the lower slopes. In all of these tests, the relative cleans-
ing of flush waves generated by flush volumes of 300 and 900 gal. each
released at a high and a low flush rate (200 to 3, 000 gpm) were evaluated
with sewage base flow of 10 and 30 gpm in the 12 in. sewer and 10 and
50 gpm in the 18 in. sewer.
Sewage-Flush Correlation Tests
The purpose of this group of tests was to determine if using sewage in
place of clean water affected significantly the cleansing ability of vari-
ous flush waves and if so, to empirically define the effect. In general,
the operation of these tests was the same as that used in the clean water
tests previously described, with the only difference being that strained
sewage, with known solids content was used as the flush liquid instead of
clean water. All of these tests were run at slopes of 0. 002 and 0. 004
for the 18 in. and 12 in. sewers, respectively.
The sewage used as the flush liquid was strained because the sewage
used in actual practice will need to be strained to allow reliable handling
by passing raw sewage through a 1/4 in. mesh screen. The strained
sewage was collected in one of the cone-bottomed collection tanks,
where it was mixed and sampled for laboratory analysis. The mixed
sewage was then pumped to the primary or upstream flush tank and was
used in the tests in the same manner as the clean water previously used.
A total of eleven tests were run during this phase of the experimentation.
This number is higher than was originally anticipated. The increase re-
sulted from the fact that the results from the first few tests indicated a
decrease in the.efficiency of the cleansing processes when sewage was
used for flushing as opposed to when clean water was used. Therefore,
extra tests were run to establish the relative magnitude of the
difference.
-N
Flush Wave Sequencing Tests .
The purpose of this group of tests was. to determine the effect that the
time-sequencing of multiple flush waves has on the efficiency of the
flushing operation. The general operation of these tests followed the
basic operation procedures outlined previously with one exception.
28
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Instead of making one flush release at the upstream end of the sewers,
as done in previous testing, up to three separate releases were made
from three different locations along the test sewers and the sequential
ordering and timing of these releases were varied.
A total of 10 tests were run on each sewer. All of these tests were run
at slopes of 0. OOZ and 0. 004 and sewage base flows of 50 gpm and 10 gpm
for the 18 in. and 12 in. sewers, respectively. The first six tests were
run by placing 300 gal. of clean water in each of the three flush tanks
(one at the upstream end and the other two at approximately 260 ft inter-
vals downstream) and varying the rate and the relative sequence of re-
lease. Two tests, one using a low rate of release (less than 1, 000 gpm)
and one using a higher rate of release (greater than 1, 000 gpm) were run
at each of the following three timing sequences:
1. The flush volumes were released independently beginning with the
flush tank nearest the downstream end of the sewer (Tank Number 3)
and were timed so that each of the three flush waves generated
passed through the sewers independently.
2. The flush release at the upstream end of the sewer (Flush Tank
Number 1) was made first. The flush release at the next down-
stream flush tank (Tank Number 2) was then released when the max-
imum depth of the flush wave generated by the first release was
observed at this location. Then the third release was made from
the flush tank located nearest the downstream end of the sewer
(Tank Number 3) when the flush wave generated by the two previous
releases was observed to be at its maximum depth at this location.
3. The release from, the upstream tank (Tank Number 1) was made first
and the wave allowed to pass completely through the sewers. Then
the other two releases were made in the same manner beginning
with the next downstream tank (Tank Number 2).
The four remaining tests were all run! using the same timing sequence.
Each release was made when the flush wave generated upstream reached
its maximum depth at the respective induction point. In one of the tests,
an average release rate of 1, 450 gpm was used to release 900 gal. of
flush liquid from, the upstream flush tank (Tank Number 1) and 300 gal.
from each of the other two tanks. Three tests were run using only two
of the flush tanks. Release rates ranging from 200 gpm to 1, 600 gpm
were used to release 600 gal. of flush liquid from the upstream flush
tank (Tank Number 1) and 300 gal. from thie downstream flush tank
(Tank Number 3). .
29
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Flow Obstruction-Tests - . j
This group of tests was designed to study the overall effect of various ./
flow obstructions on the efficiency of the flushing operation. The flow -,v
obstructions studied included manhole channel covers, service connec- •
tions, pipe misalinements, and slope discontinuities.
The effects of manhole-channel covers and service connections were not
evaluated by means of tests specifically designed for this purpose. In-
stead, the effects of these discontinuities were qualitatively estimated
based on the observed flow characteristics of the various flush waves
that were generated and tested during the entire testing program. .
> .
Pipe misalinements were simulated by inserting steel rings into the pipe
joints at various points along the length of each pipe. The effect of these
discontinuities on the overall efficiency of the flushing operation was
studied by duplicating several tests that were previously run with pipe
misalinements minimized. A total of five tests were run on each sewer,
all of which were run at slopes of 0. 002 and 0. 004 and sewage base flows
of 50 gpm and 10 gpm for the 18 in. and 12 in. sewers, respectively.
In all of the tests, three simulated misalinements were placed at approxi-
mately 260 ft intervals in the 18 in. sewer and six at approximately
130 ft intervals were placed in the 12 in. sewer, with the first being lo-
cated near the upstream end of each sewer. Four of the tests were run
with the steel rings extending 1/2 in. above the invert of the pipes
and the remaining test was run with the steel rings extending 1 in.
above the inverts. Flush volumes of 300 and 900 gal. were each com-
bined with flush rates ranging from 200 gpm to 3, 000 gpm and were tested
in each sewer.
A total of three tests were run to study the effect of grade misalinements
on the flushing operating efficiency. All of these tests were run at slopes
of 0. 002 and 0. 004 and sewage base flows of 50 gpm and 10 gpm for the
18 in. sewer and 12 in. sewer, respectively. Forty-three grade discon-
tinuities were created at approximately 18 ft intervals in each sewer, by
placing wedges under a .given pipe joint to raise the inverts a specified
distance above true grade. One test was run on each sewer with the mis-
aline.ments one-half in. above grade and two tests were run with the mis-
alinements one in. above grade. Flush waves were generated by combin-
ing flush volumes of 300 gal. and 900 gal. with flush rates /that were
previously used in.the testing done with grade discontinuities minimized.
30
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The purpose of this portion of the investigation was to study the effect of
changes in the configuration (size and shape) of the flush induction inlet
on the flushing operation. There were no tests run specifically to evalu-
ate this influence. The evaluation was made based on the observed flow
patterns of the flush waves generated in the rest of the experimental
testing.
Solid^s BMldup Tests
The purpose of this group of tests was to establish the growth of the
solids deposits expected to occur in small sewers as a function of time.
This was accomplished by allowing domestic sewage to run through the
two test sewers for various lengths of time and determining the corres-
ponding quantity of solids deposited.
Three separate tests were run during this investigation. All three tests
were run at slopes of 0. 002 and 0. 004 for the 18 in. and 12 in. sewers,
respectively. The sewage flows used were continuously varied by the
influent controller which was programmed by a cam to vary the set point
and simulate the daily flow patterns normally found to occur in lateral
sewers during dry weather tests (.1.),' (3.), (4), (5). The average 24 hr. flow
rates selected for these tests were .6 gpm for the 12 in. sewer and
12 gpm for the 18 in. sewer. These flows were derived based on the
following assumptions:
1. The 800 ft of 12 in. sewer was assumed to be an upstream lateral
section directly serving 25 single-family dwellings.
2. The 800 ft of 18 in. sewer was assumed to be an intermediate lateral
section directly serving 25 single-family dwellings and carrying the
flow from an upstream section serving 25 single-family dwellings.
3. The single-family dwellings were assumed to contribute an average
flow of approximately 350 gal. per day, based on an average occu-
pancy of 3. 5 persons per dwelling and an average per capita dis-
charge of 100 gal. per capita per day.
4. The flows in the sewers were assumed to be dry weather flows and
therefore totally the result of the domestic wastes generated.
Figure 8 shows the typical 24 hr. hydrograph of the flow through the two
sewers as used during all of the tests (1), (3), (4), (5). During the first
test, the sewage was allowed to flow through each sewer for a duration
31
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30--
to
SEWAGE FLOW
RATE (gpm)
NOTE: The flow was varied linearly
between the points shown.
12
TIME (hours)
22 24
Figure 8 SEWAGE FLOW RATE HYDROGRAPHS USED IN SOLIDS BUILDUP -TESTS
-------
'of approximately 42 hours, after which it was shut off. The quantity of
deposited solids was then determined by completely cleaning each sewer,
using the storm simulation operation in the manner previously described.
Then the sewage flow was again started and the operation repeated for
durations of approximately 94 hours and 188 hours.
Inflatable Dam Evaluation
The purpose of this group of tests was to study the operational feasibility
of an in-line inflatable dam as a means of storing and releasing sewage
;to flush downstream sections. The dam used was made of neoprene-
coated fabric and was patterned after the Firestone Fabridam. The dam
•was attached to the invert of an 18 in. O.D. stainless steel tube, as
shown in Figure 9- The steel tube was then inserted into the 18-in.
sewer, approximately 260 ft from the upstream end.
The testing done using the dam was quite brief. The tests consisted pri-
marily of collecting various volumes of sewage in the sewer behind the
dam and then observing the characteristics of flush wave produced.
Also the solids deposits at several points above and below the dam were
visually examined before and after the dam was deflated.
7.
Figure 9 ' INFLATABLE DAM
33
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FIELD AND LABORATORY PROCEDURES
, The field data taken in all of the tests were recorded on the field data
i sheets shown in Appendix B. The first form, is the form used to record
!the flow and volume data pertaining to each of the samples taken during
" the tests. The second form is the form on which the observed character-
istics of the solids deposits pi^esent at various points along the length of
each sewer were recorded before and after the flush release. This form
was also used to record the measured depth of the sewage base flow and
flush wave at various positions along the sewers.
All of the samples taken during the course of the project were analyzed
in the laboratory for Total Suspended Solids, Volatile Suspended Solids,
and Total Organic Carbon. All of these analyses were conducted in
accordance with commonly accepted laboratory procedures and techni-
ques. The laboratory procedures used are outlined in Appendix B.
Also, Appendix B includes a summary of the results obtained in a study
performed by FMC's Central Engineering Laboratories, which corre-
lates the Total Organic Carbon concentration of the sewage used in the
tests, to the 5-day BOD concentration.
•DATA ANALYSIS
The experimental data taken in the field were combined with the results
from the laboratory analyses, by means of a series of calculations, to
determine the cleansing efficiency of the various flush waves tested.
A Suspended Solids (SS), a Volatile Suspended Solids (VSS), and a Total
Organic Carbon (TOC) cleansing efficiency were determined for each
sewer in each test. However, each of these parameters was determined
in the same manner and for the remainder of this section the term "solids"
will represent all three.
Solids Distribution Test
Before the efficiency of the various flush wave could be evaluated, the
relative distribution of solids deposits had to be known. The data from
the Solids Distribution Tests were used to predict the distribution of
solids along each sewer, as deposited by each of the various base sewage
flows used in the tests at each of the slopes tested. The following com-
putational steps were used to make the predictions for each test sewer.
1. The quantity of solids deposited in each of the four sections of sewer
(S ) was computed as follows:
SDi = 8. 34 x 10"6 Ci Vi, (2)
34
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where:
8. 34 x 10 is the product of the conversion of Vi from gal. to
Ib and the conversion of Ci from ppm to Ib per Ib
S^. is the total quantity of solids deposited in section
Ci is the concentration of solids in the sample taken
of the discharge from the sewer when section i was
being cleaned (mg/1), and
Vi is the total volume of discharge collected when
section i was being cleaned (gal)
2. The fractional contribution of each section (Pi) to the total solids
deposited in the total length of sewer was determined as follows:
Pi = T-^i— (3)
S,
Di
i=l
where P. is dimensionless.
i
Clean-Water Flush Tests
The data taken during the Clean-Water Flush Tests were combined with
the results from the Solids Distribution Test and the average cleansing
efficiency of each section of sewer as well as that for the entire pipe
length was determined using the .following computational steps:
1. The solids removed from the entire pipe length by the flush wave
(SF-T) was determined using the following equation:
S = 8. 34 x 10"6 C,., V , (4)
T ; *
where:
S^ is in Ibs,
T
35
-------
C is the concentration of solids in the sample taken of the
discharge from the sewer following the flush (mg/1), and
V is the total volume of discharge collected in the collection
, tank (gal.)
2. The total quantity of solids remaining in each of the sections of pipe
(SRJ) was determined in the same manner that S^j ;was calculated
previously.
1 . • t
3. The total pounds of solids deposited in the sewer during the solids
buildup period (Sj^-p) was determined by taking the summation of
the solids remaining in each section of pipe
\
S . i and adding it to the solids removed from the sewer by the
/
/
flushing wave (S-p ).
4. The total pounds of solids deposited by the sewage base flow in each
of the sections of pipe was estimated using the following relationship:
SD. . Pi SD (5)
5. The average cleansing efficiency of the flush wave in each section of
pipe (S-j£^) was determined as follows:
S - S
C = Di Ri x 100% (6)
El SDi
6. The average cleansing efficiency of the flush wave (Cg) was deter-
mined for the combined pipe sections in the following manner:
TL (S - S )
*Di
L =
36
-------
Where CE . '
is the average cleansing efficiency over the length of pipe,
L = AL} + •• ALn , in percent (ALq is the length of the first up-
stream section of pipe in feet and n is the number of pipe sec-
tions included).
,] 4
Sewage-Flush Correlation Tests ' f
The data from the Sewage-Flush Correlation Tests were handled in the
same manner as that from the Clean-Water Flush Tests, except that the
calculation used to determine the total quantity of solids removed by the
flush wave (Sp-p) ^-a<^ to be corrected to account for the solids added to
the system by the sewage used for the flush. To accomplish this correc-
tion, the following relationship was used:
S = 8 34 x 10 /C V - C V N (8)
O^-, — U. ~J~£ JL J.VS / VJ V _ — VJ_ V T-l I \<->/
Where
Cp is the concentration of solids in the sewage used for the
flush (mg/1) and
Vp is the volume of sewage used for the flush (gal.).
Miscellaneous Other Tests
The data taken during the Solids Buildup Tests were handled in the same
manner as the data taken during the Solids Distribution Tests. The data
taken in all of the other tests were analyzed in the same fashion as that
described for the Clean-Water Flush Tests.
37
-------
SECTION VI
DISCUSSION
TEST RESULTS
The experimental data from all of the tests run during the course of this
project were analyzed using'the computational procedures previously
outlined in Section V. The results from these various computations are
summarized in Appendix C of this report.
Solids Distribution Tests
The results of the Solids Distribution Tests were used in the analysis of
the data from all of the Flushing Evaluation Tests to predict the relative
distribution of solids deposits along the sewers. The figures given in
Table 7 (Appendix C) were obtained by averaging the P^ values, obtained
from Equation 3, that were observed in two separate test run-s on each
sewer at each of the given combinations of pipe slope and sewage flow rate.
In all cases, the P^ values that were averaged to obtain P^ were within
5 percent of each other. •
Examination of the values of P^ given in Table 7 (Appendix C) shows that
in nearly every case the heaviest deposition of suspended solids occurred
in the first 526 ft of pipe. However, as the pipe slopes (So) and sewage
flows (Qjj) were increased, this phenomenon became progressively less
significant and the solids were deposited more uniformly along the length
of the sewers.
The effect of slope and flow rate on the relative distribution of the sus-
pended solids deposits along the length of both the 12 in. and 18 in.
sewer is demonstrated by the plot in Figure 10. The solid line repre-
sents the mean suspended solids distribution along the length of the
sewers. This mean distribution was determined by taking the average
of the distributions .that were observed for each of_the pipe sections at
all of the various combinations of pipe slope and flow rate (Table 7, Appen-
dix C). The broken line shown above the mean line represents the relative
suspended solids distribution found to exist when a slope of 0. 001 was com-
bined with a sewage flow of 10 gpm. The broken line shown below the
mean line represents the experimentally determined suspended solids
distribution that resulted when a 30 gpm sewage flow was combined with
a slope of 0. 008. A visual comparison of the three curves shown in
Figure 10 shows that the slope of the lower dashed line is much more
uniform than that of either of the other two lines, which indicates that a
more uniform distribution of solids along the length of the sewers
39
-------
1.0
0.8 -
0.6--
FRACTION OF
SOLIDS DEPOSITED
0.4 ••
0.2 ••
UPPER LIMIT CURVE,
(So x QB) = 0.010 gals
LOWER LIMIT CURVE,
(So x Q) = 0.240 gals.
MEAN DISTRIBUTION CURVE,
(So xQB> = 0.08 gals. .
300 400 500
PIPE LENGTH — FEET
600
700
800
Figure 10 RELATIVE EFFECT OF SLOPE AND FLOW RATE
- ' - ON THE DISTRIBUTION OF SOLIDS
IN THE TEST SEWERS
resulted at the higher values of slope and sewage flow rate. -Also, the
relative shapes of the curves indicate that the uniformity of the distri-
bution of solids along the sewer is a function of the product of the slope
and sewage flow rate values. The results given in Table 7 show that in
the tests where the product of slope and sewage flow rate was less than
approximately 0. 080 gpm (which is the arithmetic average of SOQ]3 for
all the tests), the resulting distribution curves typically fall above the
mean curve. In those tests where the product of slope and sewage flow
rate was greater than the average value of 0. 008 gpm, the resulting
distribution curves typically fall below the mean curve.
The relative distribution of Volatile Suspended Solids and Total Organic
Carbon along the length of each sewer changes with variations in slope • ,
and sewage flow in much the same manner as described above. However,
the VSS and TOC results given in Table 7 (Appendix C) show that
the distribution of these materials is consistently more. uniform than
the total solids distribution. This indicates that the equalization
of the total solids distribution as a function of S and
can be
40
-------
primarily attributed to the fact that the increased velocities, resulting
from steeper slopes and higher sewage flows, cause the lighter organic
materials to be carried further along the sewer before they are
deposited.
Clean -Water Flush Tests
The results from the Clean-Water Flush Tests are given in Tables 8,
9, and 10 (Appendix C). Each of the Suspended Solids, Volatile Sus- •
pended Solids, and Total Organic Carbon cleansing efficiencies given in
Table 8 (Columns 2, 3, and 4, respectively) are the average cleansing
efficiencies over the corresponding pipe lengths shown adjacent
(Column 5) and were determined using Equation 7 (Cg). The wave
depths given in Tables 9 and 10 are the results of the measurements
made during each test. Each value represents the maximum depth that
the flush wave reached at the given distances (Column 3) from the up-
stream end of each sewer.
Correlation of Suspended Solids Cleansing Efficiency. The correlation
of the observed values of suspended solids cleansing efficiency (Cggg)
to the six independent variables, pipe length (L), flush volume (V;jr),
flush rate (Q;p), pipe slope (So), pipe diameter (D), and sewage base
(Qjj) was accomplished in two general steps. In the first step, several
groups of results were randomly selected and systematically plotted, in
the manner shown in Figure 11, to establish the general relationship
between each of the independent variables (Vj>, Qp, L, So, QJJ, an{i
and the dependent variable
The curves in Figure 11 are typical of those found for all of the combi-
nations of results plotted. Examination of these curves shows that in
general the value of Cggg increases when the values of Qjp, Vjr, S0,
and D are increased and decreases when the values of L and Qjj are
increased.
In the second step of the analysis the correlation between Cjjgg and the
independent variables was evaluated mathematically by means of a
series of regression analysis. The complete set of results were first
subjected to a stepwise regression analysis using a general multiple
correlation equation. The standard error of the estimate was minimized
by separately varying the exponents of each of the independent variables.
The relationship which resulted from the analysis is given inEquation 9.
The cumulative reduction in the sum of squares was 0. 621 (or 228., 904)
and the standard error of the estimate was 12. 82.
41
-------
100- •
QB=.022 CFS.
QB=,067CF.S.
0B=. I 11 C.F.S.
NOTE-
S.=000l
0=1.5 FT.
CB)
gXQp / Cf X C.F.5A
L * FT. I
IOO--
1.5 FT.
Figure 11 TYPICAL CORRELATION OF THE INDEPENDENT
VARIABLES TO C_--
iLibb
42
-------
01 -05
' f~* ^ ^ Q Q i C*. C*. *7 / \7" •«»• (~\ \ i C f\"7 /~\ *
CESS - - ?39' 8 + 66' ? (VF X QF} + 5' °? °B
01 n R n i
+ 312. 6 L, + 57. 7 S + 111. 1 DU* ,
o
where
VF = Flush Volume, cubic feet
Q^ = Flush Rate, cubic feet per second
J?
Q = Sewage Base Flow Rate, cubic feet per second
L = Pipe length, feet
S = Pipe Slope, percent
D = Pipe diameter, feet
The multiple correlation coefficient and computed F(D.F. = 5, 538) for
the regression were 0.788 and 173.05, respectively, indicating that a
correlation between C and the set of independent variables does
exist. The relative oraer in which the independent variables influence
the correlation between Equation 9 and the observed results is indicated
by the order of their appearance in Equation 9, with the product of Vp
and QJT demonstrating the greatest influence. The information given
in Table 18 of Appendix D gives a more complete statistical character-
ization of Equation 9 and indicates that the relationship is representa-
tive of a majority of the observed results. Also, the figures given in
Table 18 for the reduction of the variance in each step of the regression,
show that all of the independent variables significantly decrease the
variance and therefore need to be included in the analysis to obtain maxi-
mum correlation.
Because of the shape of the curves shown in Figure 11 and the exponents
of the independent variables in Equation 9, a logarithmic correlation of
the results was attempted. The relative correlation of all of the'depend-
ent variables was found to be increased when each was replaced by its
base 10 logarithm and the above multiple correlation regression re-
peated. After trying various arrangements of the variables, the rela-
tionship given by Equation 10 was found to give the maximum correla-
tion. The values of the standard error and the multiple correlation
coefficient were found to be 12. 13 and 0. 806 respectively, indicating
that the correlation of Equation 10 was significantly better than obtained
43
-------
by Equation 9. An attempt was made to increase the correlation of
Equation 10
V1.3Q0.9S1.4D1.8
C
ESS - ' ' 10 1.6 1.2
L QB
by eliminating from the analysis some of the results, which were ob-
viously not consistent with the bulk of the observed values. The results
from three tests (12 observations) were eliminated and as a result the
standard error and multiple correlation coefficient values were de-
creased to 11. 34 and 0. 828, respectively. However, the value of the
intercept and the regression coefficient did not change significantly,
indicating that the basic equation had not changed. Further elimination
of questionable observed values from the analysis reduced the standard
error and multiple correlation coefficient but did not significantly
change the basic equation.
Based on the above analyses, the relationship given by Equation 10 was
found to provide the best estimate' of the observed suspended solids
cleansing efficiencies. The relative correlation of Equation 10 is given
statistically in Table 19 (Appendix D) and is shown graphically in
Figure 12.
Examination of the plot given in Figure 12 shows that the estimate of
CESS that is provided by Equation 10 is quite acceptable for the range
of Vjr, Qjf, L, S0, Q-g, and D values that were included in the experi-
mentation. However, when this equation is to be used for the purpose
of designing flush equipment for sewers with lengths, slopes, sewage
flows, or diameters, which are not within the range of values that were
tested during the experimental development of the equation, the relia-
bility of the estimate may be reduced.
Correlation of Volatile Suspended Solids Cleansing Efficiency. The
volatile suspended solids cleansing efficiencies (CjEVSS) given in
Table 8 (Appendix C) were correlated directly to the log function in Equa-
tion 10. This was done because time limitations did not allow for a complete
analysis and because the observed values of ^EVSS showed consist-
ently the same patterns of variation as those shown by the observed
44
-------
Ln
ioo- •
90--
80-
70--
60--
AVERAGE 50- -
CLEANSING
EFFICIENCY
^ESS
(PERCENT)
40--
30--
20--
10--
.••«.;;"'-.y*
EQUATION 10,
,. = -13.70 + 24.68 LOGln (H)
NOTE: + ESTIMATED VALUES
• OBSERVED VALUES
V*-3Q 0-9S.1-4D1'a
.x 10^
0 0.5 1.0 1.5 2.0
'2.5i 3.0
LOG (H)
H 1 1 1
3.5 4.0 4.5 5.0
Figure 12 SUSPENDED SOLIDS CLEANSING EFFICIENCY CORRELATION
-------
values of CESS- The relationship that was developed is given in
Equation 11. Figure 13 shows
- 4
CEVSS= .- 0.34 + 21. 72 iog10 - _ fc ° - x 10 (11)
graphically the correlation of Equation 11 to the observed results, and
the statistical characterization of the relationship is included in
Table 20 (Appendix D). The plot in Figure 13 shows that Equation 11
correlates quite well with the majority of the observed values of
CEVSS-
Correlation of Total-Organic Carbon Cleansing Efficiency. The total
organic carbon cleansing efficiency values given in Table 8 were cor-
related to the log function given in Equation 10 and the result is given
by Equation 12. As can be seen by examining the plot given in
Figure 14 and the statistics given in Table 21 (Appendix D) (only a 0. 165
reduction in the sum of the squares), the estimate provided by Equation 12
is not reliable. There are two possible "reasons for this poor correlation.
First, time did not. allow a complete correlation analysis to be made on
the results and therefore the-.equation form used (Equation 10) may not
be the most representative. Second, the TOG data gathered during the
course of the project was not as consistent as the other data due to
large variations in>the quality of the discharges from several canneries
which discharge into. the sewer which was used as the source of sewage
for the tests.
CETOC = 22' 36
.
QB
Correlation of Flush Wave Depth. The results from, the wave depth
measurements, given "in Tables 9 and 10 (Appendix C), were plotted against
pipe length (L.). for each test. The resulting curves indicated that the flush
wave 'depths generally deer eased with increased values of L and SQ
and increased wiMi values of Vp, Qjp, and D. Also, the wave depths
appeared to decrease as a function of the square root of L.
Using the above general relationships, for reference, an analysis was '
run on the complete set of results in Tables 9 and 10. The statistical
results from .this analysis, indicated 'that there was good correlation with
all of the independent variables, except pipe diameter (D). The
46
-------
100
80
70
60
AVERAGE 50
CLEANSING
.EFFICIENCY
' CEVSS
(Percent)
30-
20"
10-
; '**.••. • ..'
'-«• • "''•*•
=-0.34 + 21.72 LOG10 (H)
NOTE: + ESTIMATED VALUES
• OBSERVED VALUES
'
H h
Figure 13 VOLATILE SUSPENDED SOLIDS CLEANSING
EFFICIENCY CORRELATION
-------
00
100
90--
80-.
-60i-
AVERAGE 50
CLEANSING
EFFICIENCY
EETOC
(PERCENT)
40
30-
10'
EQUATION 12.
CHTOC = 22-36+10.3 LOG10
•5 .
NOTE: + ESTIMATED VALUES
• OBSERVED VALUED
Q°-9 S.1'4 D1'8
x 10
0 0.5 1.0 1.5 2.0
2.5 3.0
LOG (H)
•3.5 4.0 4.5 5.0
Figure 14 TOTAL ORGANIC CARBON CLEANSING
EFFICIENCY CORRELATION
-------
influence of pipe diameter was shown to be quite small. In order to
verify this, the results in the two tables were analyzed separately and
the relationships developed are given by Equations 13a and 13b.
Equation 13a was generated using the results from the 12 in. sewer
(Table 9) and Equation 13b was developed using the results from the
18-in. sewer (Table "10)."""The statistics associated" w'ithTeactr of the* ;
relationships are given in Tables 22 and 23 (Appendix D). The relative
correlation of Equations 13a and 13b is shown graphically in Figures 15
and, 16, J respectively. Examination of Figures 15 and 16 shows that the
two,equations generated are quite similar and that, each shows good
correlation with the majority of the observed values. Although the
.overall relationship appears to be curvilinear and the correlation
•'might possibly be improved further by a more extensive analysis of
•the results, in the range of interest in this study it is represented
quite well by the straight line relationship. :'
W - = 8. 45 + 0. 0230 V^ + 0. 534 Q ' - 0. 261 L°' 5 - ll 0 S + 2. 36 Q^
i-J, ' £ • £ •' O ±5
?
: - ,. " (13a)
W_ = 8. 84 -f 0. 0189 V_, + 0. 408 (3 J'O. 322 L°' 5 - 0. 215 S + 7. 29 Q^
L) .• D £ O 'Jj
' ' . (13b)
where Wj-. is the maximum wave-depth in inches.
Steep-Slope Equation Check. All of the relationships that were developed
in the above analyses are somewhat questionable with respect to their
ability to make accurate predictions about flushing sewers where the
values of L, S0, Qg, and D are not in the range of the values that were
tested during the experimental work in this project. For this reason,"
four flush tests were .run on the 12 in. sewer at a slope of 0. 008 to
attempt' to check the ability of these empirical relationships to make pre-
dictions about flushing sewers with slopes steeper than those previously
tested. . The cleansing efficiency results from these four tests are given
in Table-11-(-Appendix-G); Also shown-in Table ll-'are the .correspond-
ing values of CESS> CEVSS> and ^TOO that were predicted using
Equations 10, 11, and 12, respectively. Comparison of these observed
and estimated cleansing efficiencies shows that Equations 10 (C^ss) ....'•
and 11 (C^ygg) were quite accurate in their predictions. . However,
Equation 12 (^ETOC^ ^ac^ a rnuc^L poorer correlation with the observed
results, as would be expected because of its unreliable representation
of the original experimental results.
49
-------
18--
NOTE: + ESTIMATED VALUES
• OBSERVED VALUES
H = 0.023 VF .+ 0.534 Qp - 0.261 L°'5 - 1.0 So + 2.36 QB
-5 -4
VALUE OF (H)
Figure 15 WAVE DEPTH CORRELATION FOR 12-INCH SEWER
-------
18 +
16--
14-
" 12-
NOTE: + ESTIMATED VALUES ' . ....
1 • OBSERVED VALUES , -, ".;.-.'
,'.'"•' • • .10-
H = 0.0189 VF + 0.408 Qp - 0.322 Luo - 0.215 So + 7.29 QB . .
* • • •
* * • • * • " tt
. JUH-1"
ft*^ »
EQUATION 13B . •. . yjp"''*." • . •
\ • '.. .&**;: ". ••;: . : - • • e-
\ . . LrtiPF^ . . .
, • \ • _ *J4I~M*'* •• •• • • • •• • • •
• M •• C* **•*••*• *j||U|l*^ »«*« ••**** •"••»"** * ^"
• • * • • • *M •^Bf:» ••• ••*•*• •• **
• • •• * W • •• » Hf"' •* • •••• «
• •**«*fc*** * fgfffl m* • •* « • * • *
tf-
-------
The wave depth measurements made during these tests are compared to
the values estimated by Equation 13a in Table 12 (Appendix C). The
correlation between the estimated and observed results are very good
and indicates that Equation 13a is capable of giving quite reliable esti-
mates of the flush wave depths at this steeper slope value.
\
Sewage -Flush Correlation Tests
The results from these tests, where sewage was used as the flush liq-
uid, are given in Table 13 (Appendix C). The cleansing efficiency val-
ues given in the table were determined using Equation 8 and were used
to calculate the change in cleansing efficiency that resulted from using
sewage. This was accomplished using the following equation:
,..._, . .
where Cggg was determined from Equation 10 for the given values of
Vp, Qp, L, S0, QB, and D and C^gg1 is the corresponding suspended
solids cleansing efficiency observed during the Sewage -Flush Tests.
The resulting values of ACESg are given in Table 13 and were subjected
to a multiple correlation regression analysis. The relationship given by
Equation 15 was found to give the best correlation. The statistical pa-
rameters associated with
ACESg =.14.3 - 0. 14 VF - 0.242 QF + 0.00711 L (15)
Equation 15 are given.in Table 24 (Appendix D). Figure 17 shows the
relationship between the observed values of C Egg' and the clean-water
> cleansing efficiency equation (Equation 10). Examination of the plot
shows that in general the overall cleansing efficiency was reduced
slightly by using sewage instead of clean water. Also shown in Figure 17
is the plot of Equation 16, which is representative of Equation 10
(Cj£gg) after.being corrected by Equation 15 (AC-jpgg for flushing with
sewage. The statistical parameters associated with Equation 16 are
given in Table 25 (Appendix D). The standard error of the estimate
(10.94) andthe correlation coefficient (0. 763) indicate that Equation 16
gives an adequate representation of the experimental values of
F
T3 7 lno.
Z3.7 log1()
F o
Ty^O1-2
L QB
* V 10
'CESS' - - 13'70 + 23'7 lo« - - - - 10 (16>
52
-------
en
oo
NOTE : o THE OBSERVED RESULTS FROM
THE SEWAGE-FLUSH TESTS
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
(EQUA.,16., SEWAGE-FLUSH)
= -13.7 +- 24.68 LDS,0 I
( EQUA. 10, CLEAN WATER -FLUSH )
Figure 17 SEWAGE-FLUSH CORRELATION
-------
Flush Wave Sequencing Tests. The results from these tests, where moil-
tiple flush waves were used to clean the test sewers, are summarized in.
Table 15 (Appendix C). The observed values of cleansing efficiency given
in the table are the values of Cjrjgg that were determined for the total
length of the sewers. The equivalent volume of flush (Vp') that is given
for each of the multiple flush combinations is the weighted average vol-
ume for the total length of sewer and was determined as follows: -
i=4 -
where V. is the total volume of flush water that passed through section i
in gallons and L. is the length of section i in feet.
The values of Cggg that were estimated for each' of the equivalent
single-flush volumes was determined by solving Equation 10, using the
corresponding average .flush rate and the equivalent single -flush volume.
Comparison of the values of C^ggg that were observed during each of
the three different flush release sequences, indicates that the sequence
of release of multiple flush waves is not very critical to the overall
cleansing operation, as long as the upstream releases are made first.
When the flush waves were released separately beginning at the tank
nearest the downstream ends of the sewers, the observed values of
^ESS were consistently lower than those obtained using the other two
release sequences. The difference between releasing at maximum wave
depth and releasing after the upstream wave has passed was found, as
shown by the close correlation of the observed Cggg values in each
case, to be insignificant.
The estimated C^SS values for the equivalent single -volume flushes
show fairly good correlation to the CjrjsS values determined for the
various multiple flushes tested. This indicates that in general the
efficiency of multiple flush release was not significantly different from ,
the efficiency of the equivalent single -flush release, at least in the rela-
tive short lengths of pipes used in these tests (800 ft). In longer lengths
of pipe, where pipe length becomes the primary influence on the cleans-
ing efficiency, the use of multiple flush waves may very possibly become"
a very important consideration.
54
-------
Flow Obstruction Tests
Three general types of flow obstructions were studied in this portion of
the investigation. The data from the tests that were run were analyzed
using Equation 7 and the results are given in Table 14 of Appendix C.
Pipe-Joint Misalinement Tests
The suspended solids cleansing efficiencies determined during these
tests, where steel rings were used to simulate pipe joint misalinements,
are given in Table 14. Figure 18 shows the relative correlation of the
values of ^>ESS observed during these tests to the values of ^ES
were predicted, for the corresponding values of Vp, Qjr, L, S0
and D, using Equation 10. As can be seen by examining Figure 18, the
simulated misalinements had a negligible effect on the overall cleansing
operation. Also, there was no consistent difference demonstrated
between the results from the tests where 1/2 -in. high rings were used
and the tests where 1 in. high rings were used.
!
Grade Misalinement Effects. The suspended solids efficiencies deter-
mined during these tests, where grade misalinements were simulated
by raising several sections of pipe above true grade, are given in
Table 14. Figure 19 shows that the values of C^gg observed during
these tests correlate quite well with the Cggg values predicted using
Equation 10, indicating that the grade misalinements had little effect on
the overall cleansing operation. The only flush waves that were notice-
ably affected by the discontinuities in the grade of the sewer were'those
that were generated by very low flush volumes and flush rates.
Manhole-Channel Covers and Service Connection Effects. The effect of
covering the channels in manholes was determined to be insignificant,
based on the observed wave patterns and the results from the other flow
obstruction tests. . Interference in the flow pattern of the flush wave
can only occur, as a result of these covers, when the depth of the wave
is greater than one-half the diamete'r of the pipe. Consequently, the
only flush waves that would be hydraulically affected by the installation
of these covers are those generated by large flush volumes and rapid
rates of release, and these are the flush waves that were shown in the
flow obstruction tests previously described to be the least affected by
physical discontinuities.
The effect of service connections on the overall efficiency of the cleans-
ing operation was alsojfound to be insignificant based on the same rea-
sons that were given above for the insignificant effects of covering the
channels in manholes.
55
-------
01
j? 1004
Hi
y 80-
o
§ 60-f
-Z
UJ
1
LU
20-
NOTES: (|)o OBSERVED RESULTS FROM TESTS
USING 12" SEWER
(2) O OBSERVED RESULTS FROM TESTS
USING 18" SEWER
Figure"18 "PIPE JOINTS MISALINEMENT EFFECTS
-------
Ul
•1
VI
Hi
O
LLj
o
U)
IOO--
80.--
60--
40--
UJ
£ 20--
O
NOTE, (l) o OBSERVED RESULTS FROM TESTS
USING 12" SEWER
(2)0 OBSERVED RESULTS FROM TESTS
USING 18" SEWER
O
O
EQUAT ION 10 ( Cess - -13.7 4 24.68 LOG
20 2.5
LOGIO(H)
3.0
3.5 4.0 4.5 5.0
Figure 19 GRADE MISALINEMENT EFFECTS
* \
-------
Inlet Configuration Effects
During the early stages of the investigation, the inlet configuration used
to induce the flush liquid into the sewer was considered to be one of the
primary factors affecting the relative efficiency of the flushing opera-
tion. However, the flow patterns that were observed for the various
flush waves tested during this project show that these inlet effects are
quite insignificant, except in limiting the rate of flush release. The
volume of flush liquid and the ..rate at which this volume is added to the
sewer are the important factors affecting the cleansing operation.
Directing the flow downstream in the sewer, by means of an elbow or
other device, would only affect the cleansing operation in the first few
feet of pipe. Moreover, the .effect in the first few feet of pipe would be
significant only for a very short time after the beginning of the release,
because the flush volumes and rates necessary for realistic cleansing ;
are high enough that the sewer becomes surcharged shortly after the
release is made.
Solids Buildup Tests , ;
The complete set of results from the three Solids Buildup Tests that were
conducted are given in Table 16 (Appendix C). These results were derived
from the experimental data in the manner described in Section V.
Analysis of the results given in Table 16 shows that a relatively high
percentage of the solids deposited in the sewers consisted of organic or
volatile material. An average of 60.7 percent (Standard Deviation
= ± 5. 90) of the deposited materials were volatile solids and 19. 4 per-
cent (Standard Deviation = ±3. 0) was organic carbon. These percent- ;
ages are quite representative of those found in all the tests and can be
used to estimate the proportions of volatile solids and organic solids
based on the total solids distributions and .buildups that will be dis-
cussed in the remainder of this section.
The distribution of the solids deposits over the length of the sewers is
shown graphically in Figure 20, for each of the 'sewage flow duration
times tested. Examination of the distribution curves in Figure 20 shows .
that in all cases 77 to 90 percent of the solids deposited were deposited
in the first 520 ft of pipe. In general, the longer the buildup, period the
higher the percentage of solids iri the first portion of the sewers. This
heavy deposition of solids found to occur in the upstream portion of the
sewers indicates that in lateral sewers where, the sewage.-is added more
or less uniformly along the length of the pipe, instead of to the upstream
end as was done in these tests, the major portion of solids will probably
58
-------
171
sO
12 --
l/>
:o
o
a.
10--
Q
UJ
8 --
O - *
O
Q_
LU
Q
-------
be deposited.-within-a--relatively short distance downstream of where they
are introduced to.the sewer.
;..
' •*
The build-up of solids deposits in the test sewers, as a function of time,
is shown by the curves in Figure 21. The curves show that the total
quantity of solids deposited in the 12 in. sewer was approximately one-
half that deposited in the 18 -in. sewer after 188 hours. However, the
deposition of solids in the 18 in. sewer reached a peak after approxi-
mately 120 hours, whereas "the deposition of solids in the 12 in. sewer
had not reached a maximum even after 188..hours. These two facts,
combined with the fact that the sewage flow:rate in the smaller sewer -•
was approximately one-half that in the larger sewer, indicate that the
difference in total quantity .of-material deposited in the two sewers may
well be the result of the difference in the total quantities of solids that
passed through the two sewers, rather than purely a hydraulic
phenomenon.
The quality.of the sewage that was supplied to the sewers during these \
tests should be considered when evaluating the total quantities of solids
deposited iri"the sewers. The suspended solids concentration (SS) of the
influent sewage varied from a high of approximately 150 'mg/1 to a low
of 120 mg/1,- with approximately 90 percent of the composite samples •
taken having concentrations within ±10 mg/1 of an average of 133 mg/1.
The volatile suspended solids concentrations (VSS) varied from approxi-
mately 94 mg/1 to 114 mg/1 with the majority of the composite Samples
taken having concentrations within ± 5 mg/1 of the average of 102 mg/1.
The total organic carbon concentration (TOG) varied over" a wider range
of approximately 94 mg/1 to 148 mg/1, with only about 50 percent of the
composite samples taken having concentrations within ± 20 mg/lr of the"
average of 112 nig/1.
The figures given above for the solids content of the influent sewage are
not as high as those that are sometimes found for domestic sewage, and
therefore should be considered when evaluating the magnitude of the :
solids deposits. However, the quality of the sewage does not s.eriously
alter the^relative effect of time. Although much more extensive testing
would.be required before absolute relationships could be developed, the
test results given in Figure 21 show that more than'three times as many
solids were deposited in the sewers after 5 days as were deposited
after 1 day. This:is definitely a significant increase,in p Dilution al-
material and deserves serious consideration.
60
-------
12 --
10 +
o
a.
NOTE; TOTAL SOLIDS DEPOSITED AND THE
TOTAL LENGTH OF THE TWO SEWERS
(LENGTH OF 18"SEWER =795 FT,
LENGTH OF 12" SEWER -782 FT. )
S.S.- 18 SEWER
S.S. -12 SEWER
VSS-|2"SEWER
80 100 120
TIME CHOURS)
200
Figure 21 TIME SERIES .BUILDUP OF SOLIDS
-------
Inflatable Dam Evaluation
: . -i
The inflatable dam (see Figure 9) was installed in the 18 in. test sewer - ,
and its general operation observed. The dam was inflated to several •
heights, ranging from 4 in. to 16 in. , and the resulting flush wave ob-f.
served. During these operations two major problems were found with
this method of storing and releasing flush liquid. First, the solids de-
posits above the dam appeared to be much heavier than experienced dur?-.
ing unobstructed sewage flows and the release of the stored sewage did
not appear to decrease the deposits appreciably. The second problem
encountered was with the mechanical design of the dam, in that it,would
not deflate rapidly enough to get the full benefit out of the volume of sew-
age stored behind it. The occurrence of these problems was the pri-
mary motivation for the proposed changes in the dam design which are
discussed later in this section. .
In spite of the above problems, discharge rates of up to 1,0.00 gpm were
attained. Also, the solids deposited downstream of the dam appreared
to be significantly decreased by the release of the sewage stored behind
the dam. '-.....••
SUMMARY OF RESULTS ' .
The results of the tests run during the course of this_project are quite
comprehensive, but definitely not all conclusive. The reliability of the
relationships that were developed from the experimental results are ^
limited not only by the statistical variations in the results, but more
important they are limited by the range of cpnditions included in-the test-
ing program. The statistical variations in the experimental results do
not cause as great a problem as do the physical limitations of the testing
program, because their effects are predictable, at least to a degree.
The most serious limitation on the general equations that were developed
is a result of the fact that only two diameters of pipe were used in the
tests. This makes the reliability of making predictions about sewers
with diameters significantly different from those tested somewhat ques-
tionable. However, since the effect of diameter was found to be
relatively small in relationship to the effect of flush volume and flush
rate and the effect of diameter on the relationships generated for the
12 iru and 18 in. sewers were quite small, the predictions provided '
by the general equations for sewers with diameters close to those
tested (8 in. to 24 in.) will quite probably be within the range of stand-
ard error that was determined for each of the relationships.
62
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Using sewage instead of clean water for flushing was found to cause a
general, minor decrease in the efficiency of the cleansing operation.
As shown in Figure 17, the effect is relatively small and is probably
the result of the redeposition of solids by the trailing edge of the flush
wave; This conclusion was made based on the fact that when clean water
was used for flushing, the first portion of the wave carried nearly all of
the resusperided solids and the trailing low-velocity portion of the wave
was essentially clean water. When sewage was used for flushing the
trailing, low-velocity portion of the wave contained relatively high con-
centrations of solids (equal at least to the concentration of solids in the
strained sewage that was used for flushing) and significant quantities of
these solids were redeposited along the length of the sewers.
The effects of the flow obstructions tested were found to be insignificant
in the range of flush volumes and flush rates that would normally be
expected to be used in actual practice. Also, since the flow obstructions
that would be encountered in existing sewers are almost impossible to
locate and even more difficult to relate to the simulated obstructions
tested, a relationship to correct for these effects would not be very-
realistic. • - .
The effects of flush wave sequencing were found to be insignificant as
long as the flush releases were made progressively from the upstream
end of the sewer. Also, the cleansing efficiencies obtained by using
various combinations of flush waves were found to be quite similar to
those obtained using single flushes of equivalent volumes and similar
release rate Si However, both of-these hypotheses are based on the
limited findings from tests run on relatively short sewers and therefore
further testing is required to give a complete picture of the relative im-
portance' of these two factors on the overall performance of a complete
flushing system. '
The inflatable dam was found to have some fundamental problems asso-
ciated with Its use for flushing sewers. However, the in-line dam. is
the easiest and least expensive, of all the flushing devices investigated,
to construct, install, operate, and maintain. This combined with the
fact that these dams could easily be used to reduce'the quantity of storm
water overflows and equalize the hydraulic loadings on treatment facil-
ities, makes further investigation of their capabilities quite desirable.
The TOC results' given can be used to estimate the equivalent 5-day BOD
of the deposited s'olids, by using the correlation relationship described
in Appendix B. The discussion in Appendix B shows that the sewage used
in the tests consistently had BOD5 concentrations of 1. 8 times the TOC
concentration.
63
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MATHEMATICAL MODEL DEVELOPMENT
Need for •Mathematical Model - - . , • $ •
In a typical combined sewer installation a large number of periodic flush
stations will be required to periodically remove the solids that are/.set-
tled in the sewers. The efficiency {i. e. , percent of solids removed from
the sewers) of the flush system depends on:. c
• • • ' v - "" - ./"-.-•
• System Parameters - Quantity of flush water and the rate of flush/
i discharge . •
• Physical Characteristics - Location, length, diameter and'slope of
the sewers, and amount of flush water
available
• Load Characteristics - Amount of solids settled in the sewers and
• j - average base flow rate.'
Given the physical and load characteristics of a combined sewer instal-
lation, there exist a large number of alternative selections of the flush
system to achieve a specified cleansing efficiency. , The problem of.
determining the best alternative is'rather'complex and calls for. a mathe-
matical model. • . - ',...••. • .
Objective of Model r .,-.-..
The objective of the model is to select the best configuration for locating
the flush stations and determine their capacities to achieve a specified •
cleansing efficiency. The criterion for evaluation, depending on the
availability of cost information, can be either of the following:
• Minimize the total cost of the station's equipment-and flush water
required for operation of the flush stations. .'
o Minimize the quantity of flush water required.
64
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The first approach is provided to be used when cost figures are avail-
able.whereas the second is provided so that the model can be used to
determine the minimum water (or sewage) requirements even without
adequate cost information.
Scope of Model
The proposed model will be applicable to the "lateral" sections of a
combined sewer installation. These are the sewers carrying the sew-
age from households, commercial buildings, etc. to the "main" sewers.
The scope of the model is limited mainly due to the limitations of the
design relationships. There are,however, other important reasons,
e.g.:
• The "laterals" are the sewers where the majority of solids are
deposited during the low flow periods. Hence, cleansing of these
sections will maintain the amount of solids in the entire sewer sys-
tem at a specified level, thus reducing the concentration of solids
in the bypassed flows during the storm.
• The."mains" in the sewer system can be treated independently.
Given the load in sections of the main sewer (from the direct
connections and from the "laterals") the same model can be applied
for selecting and locating flush stations along the "mains" to"
achieve a specified cleansing efficiency. However further experi-
mental testing is required before the design relationships developed
in this project can be used for the larger diameter mains.
General Approach
A dynamic programming approach was used to determine optimality of
each feasible combination of flush stations. The model implicitly eval-
uates all possible alternatives to achieve a specified efficiency within -
the constraints imposed and selects the best one. The selection of the
best flushing system is based on values given to the following design
parameters. . .
1. Cleansing efficiency of the flush station
• as a function of flush volume and rate
• as a function of pipe size, length, and slope
• as a function of sewage load.
65
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2. Physical parameters
• potential locations along the "lateral"
• lengths, diameters, and slopes of sewers between these
locations " ;
• engineering constraints at each location e. g. , size of flushing
tank; amount of flush water available, etc.
• average daily load in each sewer. t
j
3. Costs >! ' - -' -" -
• of flush station for given capacity
v of flush water at each location.
The design equations used in the model are those that were developed
during the experimental phase of this project. The cleansing efficiency
of each flush system evaluated is determined using the clean-water sus-
pended solids cleansing efficiency (CESS) equation (Equation 10) when
clean water is to be used as the flush medium and the sewage-flush sus-
pended solids (CESS') equation (Equation 16) when sewage is used. A
complete description of the analytical procedures used in the model is
provided in Appendix F. Also included in Appendix F is a listing of the
computer program, accompanied by complete operational documentation
and examples.
Limitations
The use of the model is limited to the analysis of single laterals with
physical characteristics (pipe diameters, pipe slopes, etc.) similar to
those used in developing the design equations. However, the model is
designed so that it can readily be adapted to virtually any sewer, by
experimental verification of the design relationships.
The model, as it now exists, cannot determine the quantity of solids
expected to be deposited in a given section of sewer. This parameter
must be determined, by the user, based on the sewage characteristics
and flow patterns of the given system, and supplied to the model as an
input parameter.
No specific provision is made in the model for variations in the relative
sequence of flush releases. The overall cleansing efficiencies of the
selected combinations of flush stations are determined based on the
assumption that the flush releases are sequenced so that the flushes will
be made progressively beginning frdm the upstream end of the sewer.
66
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ECONOMIC CONSIDERATIONS
A study of the materials deposited in storm water runoff areas in Tulsa,
Oklahoma, indicated that an average of approximately 0. 015 Ib of solids
were deposited daily per ft of street (2). This is approximately 5 times
the quantity of solids found to be deposited in the test sewers, during the
solids buildup tests. However, the average BOD5 of the solids deposited
in the storm runoff areas was only about 0.000415 Ib per day per ft
of street (2) as compared to an average BOD5 of the solids deposited in
the test sewers of approximately 0. 002 Ib per day per ft of sewer
(estimated using the TOG values determined in the testing and the TOC-
BOD5 correlation of BODs=l. 8 TOG given in Appendix B). Comparison
of these figures indicates that the solids deposited in lateral sewers dur-
ing dry weather periods have a significant effect on the concentration of
pollutants in the combined sewer overflows resulting from relatively
intense storms following extended dry weather periods. Consequently,
if the quantity of solids deposited in the lateral sewer during dry weather
periods can be minimized, a significant reduction in the pollution caused
by subsequent storm overflows from, combined sewer will,result.
The test results indicate that during the first 24 hours from 15 to 30
percent of the total quantity of suspended solids that were carried
through the test sewers by the sewage flows of 10 to 50 gpm were left
deposited in the 800 ft long sewers. The solids that were deposited
were on the average more than 60 percent volatile material.
The results from the Flushing Evaluation Test have shown that by using
reasonably small flush volumes, the solids deposits in the lateral sew-
ers can be reduced by 60 to 75 percent each day. The results of the
Solids Buildup Tests have shown that the solids deposited at the end of
5 days is at least three times the solids deposited at the.end of one day.
If we continue with the assumption that the percentage removal is un-
affected by the amount or age of the solids deposited .(within the limits
of the following example) the solids removed can be calculated as indi-
cated in Table 1. Compared to the solids deposited in 5 days with no
flushing this would result in net removals of:
V
100(3 - . 66) -r 3 = 78% for 60% daily removal
and
100(3 - . 333) -f 3 = 89% for 75% daily removal.
67
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Table 1 SOLIDS REMOVAL PREDICTIONS
(Daily Solids Deposited = 1)
Day
1
2
3
4
5
1
2
3
4
5
Solids
Deposits
Prior to
'Flushing
1
1.4
I
1.56
1.62
1.65
. 1
1.25
1.313
1.328
1.332
Percent
Remaining
40
. 40
- 40
40
40
25
25
25
25
25
Solids
Remaining
After
Flushing
.4 ;
.56
.62
.65
.66
.25
.313
. 328
.332
.333
Solids
With
No •
Flushing
1
..
(
-
3
1
-
_
_
3
Net
Removal
60% r
M
_
_
78%
75%
_
_ , .
_
89%
From this example for a period of 5 days between storms it can be seen
that the improvement by sewer flushing is increased for longer periods
between storms.' For a specific installation the predicted net removal
for each possible period between storms would have, to be weighted by
the probability of that period occurring, based on historical records,
and by the pollution load for that period to obtain the expected net re-
moval. The expected net removal should then be comparable to per-
formance obtained by other overflow pollution control methods being
considered. The correctness of the assumptions made and the effect of
removal in laterals on the pollutional load at an overflow point should be
verified by a demonstration in a combined sewer system.
The mathematical model has been set up to determine the least cost of
performing periodic sewer flushing to achieve a given daily removal of
settled material. In order to determine the cost for a specific installa-
tion it would, of "course, be necessary to enter the particular installa-
tion and operating cost factors which apply to that local situation. The
resulting minimum cost and the expected net removal will provide the
basis for an economic comparison with other pollution control methods.
For the case of the laterals being considered for a possible demonstra-
tion in Detroit, two system layouts are being considered to give either
61 percent daily removal or 72 percent daily removal depending on the
number of flush stations used. Rough cost estimates were made as
shown in Table 2.
68
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Table 2 ESTIMATED FLUSHING COSTS
Alternate
Number of flush stations per lateral
;Area per lateral — acres
Daily solids removal - percent
Installed cost of fabric flush tanks
Cost of telemetry and controls
Monthly power cost
Monthly maintenance cost
Capital cost per acre
Monthly maintenance and power cost
per acre
1
2
9 '
61
$5,556
1 2
4
9
72
$11,246
not estimated
$1.95
$100
$617
$11. 32
$4.09
$200.
$1,250
$22.70
The cost for telemetering and remote control of the flushing system
would be dependent on the degree of automation needed as .well as the
physical layout of the system in relation to the control center.
69
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SECTION VII
DESIGN AND TESTING OF A PROTOTYPE FLUSH STATION
There are numerous possible ways to mechanically acquire, store, and
release the liquid volumes necessary to flush sewers. The objective of
this phase of the project was to investigate these various schemes and
to select, design, construct, and test a promising arrangement.
DESIGN AND CONSTRUCTION
Several flush station designs were considered starting from the concepts
shown in Figure 22. Other layouts were studied as reported in the
drawing list, Appendix E. The design that was selected to be the proto-
type tested in this project was selected because it appeared to be one of
the most functional and promised to have reasonable construction costs
and low installation cost.
The prototype flush station was designed so that it can be easily in-
Stalled in and/or removed from almost any standard-type manhole. The
complete station is built as a single unit for maximum ease in handling
and installation (see Figure 23). The unit is held rigid by a 22 -in.
diameter steel frame that supports the sewage supply and control equip-
ment. The frame is surrounded by a polyurethane-coated nylon bag,
which is 4 ft in diameter and is designed to fit inside a standard manhole
8 ft or more in depth. The bag was designed to push against the walls of
the manhole when filled with liquid and then be completely collapsible
when emptied. This allows the complete unit, including the bag, to be
lifted into or out of a manhole with a minimum disassembly required.
The sewage supply and control equipment consists of a self-priming
pump, two electrically actuated four-way valves, a spring loaded
diaphragm-type actuator connected to a poppet-type dump valve, two
level control floats, and a 24 hour timer. The equipment is arranged
so that the bag can be repeatedly filled with sewage and rapidly emptied
in a completely controlled fashion (see Figure 24A).
The bag is filled by positioning the four-way valves, one on the suction
side and one on the discharge side of the supply pump, so that sewage is
pumped from a screened intake in the sewer to the bag (Figure 24B).
During this filling process, the dump valve is held closed by the spring
in the diaphram-type actuator. When the level of sewage reaches the
desired maximum, the level control float located near the top of the bag
is activated and the pump is turned off and both four-way valves are
rotated to the hold positions as shown in Figure 24C,.
71
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PREFABRICATED FLUSH TANK
FOR EXISTING MANHOLES
VACUUM FILL FLUSH TANK
SURFACE FLUSH TANK
SEPARATE SUBSURFACE
FLUSH TANK-
Figure 22 ALTERNATE FLUSHING STATION DESIGNS
72
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Fabric storage tank with the pump
and valves mounted underneath.
The discharge valve operator and bottom
bag support arms are shown above the
bottom support plate of the prototype flush
station with the fabric tank removed.
Figure 23 , PROTOTYPE FLUSH STATION
-------
The bag remains full and the control valves remain in the hold position"
until the timer rotates the valve 90 degrees to the next position shown
in Figure 24D, and restarts the pump. The pump then pumps sewage
from the bag to the dump valve actuator which opens the dump valve
and allows the sewage to be discharged back to the sewer. When the
level of sewage in the bag reaches the desired minimum, the level con-
trol float located near the bottom of the bag is activated and causes the
pump to shut off and the four-way valves to rotate to the positions,
shown in Figure 24E, where the dump valve actuator is vented through
the intake screen and the dump valve is allowed to close.
When the bag is to be filled again, the timer rotates the two four-way
valves 90 degrees back to the fill position (Figure 24"B.) and starts the
pump. The complete cycle is then repeated.
PROTOTYPE TESTING ... *
The operation of the prototype flush station was field tested to deter-
mine its reliability and feasibility. The various components of the
prototype were first tested individually and. then their combined per-
formance was evaluated (Table 17, Appendix C).
After the function of the various components had been verified, the pro-
totype was assembled and was installed over a manhole near the efflu-
ent end of the test sewers. The sequence of operation previously des-
cribed, was run through several times to determine the average
discharge rate and to verify the reliability of the supply and control
system. Also the lifting mechanism, designed to allow the unit to be
lifted in and out of manholes, was operated several times to insure cor-
rect performance.
DISCUSSION.
The prototype flush station (Figure 23) was tested mechanically and
found to be very functional and quite capable of performing the opera-
tions necessary to hydraulically flush sewers (see Table 17). The sew-
age supply and release mechanisms were tested using sewage from the
test sewers and were found to provide reliable operation. The general
design of the flush station was shown to be a promising and potentially
inexpensive method of holding and releasing sewage for the purpose of
flushing sewers.
Although the basic design of the prototype was found to be very func-
tional, there are several improvements that can be made. Several
beneficial design changes became evident during the construction and
74
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RESERVOIR
BAG
HYDRAULIC SCHEMATIC
PUMP
INLET
VALVfl
a
DUMP VALVE -
^ ACTUATOR "~
M PUMP DISCHARGE
VALVE
]
PUMP
GND =
A,
ELECTRICAL SCHEMATIC
TIMER MOTOR
PUMP MOTOR
TIME DELAY^ RELAY
POPPET
TYPE
DUMP
VALVE
_ DISCHARGED
ACTUATOR
RELAY #2
LOWER FLOAT SWITCH
Figure 24 PROTOTYPE FLUSH STATION CONTROL
AND OPERATION
75
-------
WATER LEVEL RISING
I —-{
DUMP
VALVE
PUMP ACTUATOR
DISCHARGE
VALVE
PUMP
POPPET
TYPE
DUMP
VALVE
, SEWER
HOLD POSITION
(AFTER FILL)
WATER LEVEL AT TOP
DUMP
VALVE
pUMp ACTUATOR'
DISCHARGE
VALVE
PUMP
.POPPET
TYPE
I DUMP
VALVE
DUMP
POSITION
(AFTER HOLD)
WATER LEVEL FALLING
DUMP
M} VALVE
PUMP ACTUATOR
DISCHARGE -
VALVE
PUMP
D
ACTUATOR
VENT
POSITION
(AFTER DUMP)
SEWER
WATER LEVEL AT BOTTOM
DUMP
M) VALVE
PUMP ACTUATOR
DISCHARGE
VALVE
PUMP
SEWER
POPPET
TYPE
DUMP
VALVE
(IN
PROCESS
OF
CLOSING)
SEWER '
Figure 24 PROTOTYPE FLUSH STATION CONTROL
AND OPERATION (CONTINUED)
-------
testing of the prototype. These changes were incorporated into the
proposed improved design shown in Figure 25. This design will allow
considerable simplification in the construction and installation of the
flush station and assembly of the piping. Also the number and complex-
ity of the control circuits required has been greatly decreased by this
design.
An improved design of the in-line type dam is shown in Figure 26. This
design allows the excess sewage to flow out under the dam, thus reduc-
ing the solids buildup in the sewer behind the dam. Also the dam as-
sembly ;is arranged so that the dam can rapidly be removed up from the
sewer by applying a vacuum, thus allowing the stored sewage to be re-
leased quickly to develop maximum cleansing velocities. This also
allows the dam to be pulled completely clear of the sewe-r during,storms
when the fabric of the dam might be damaged. Also the dam is proposed
to be installed in the center of a manhole which allows easy, installation
and maintenance, of the dam. The overflow weirs that are shown on
either side of the sewer immediately upstream of the dam provide the
necessary protection against accidental flooding of the sewer upstream
of the dam.
77
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00
DISCHARGE
EE DETAIL C
IR LINES
INTAKE LINE
PLAT FOR M-J
INTAKE HOSE-
TANK — SYNTHETIC
COATED NYLON
FABRIC C
MANHOLE
PNEUMATIC
DIAPHRAGM
PUMP VIEW B-B
fPNEUMATIC -SCALE-1/4
OPERATOR
pj ,-^-.SEE DETAIL A
T.8" SEWER PIPE
VIEW C-C
SCALE-1/4
DETAIL C
SCALE-1/4
COARSE CLEARANCE FIT
— 2" STANDARD PIPE
•SHOE
DETAIL A
SCALE-1/4
Figure 25 PROPOSED FABRIC BAG FLUSH STATION
-------
BOLT TO
BOTTOM
OF
MANHOLE
\!
DIAPHRAGM
ELASTOMER L
COATED —
FABRIC
STREET LEVEL
MANH.QLE
HOSE TO PUMP
RIGID AIR CELL
SEAL DIAPHRAGM
TO RIGID AIR CELL
DIAPHRAGM PULLED
BY VACUUM OUT OF
THE WAY INTO UPPER
PORTION OF RIGID
AIR CELL
BY-PASS WEIR
18" SEWER PIPE
FLOW
GATE I'N INFLATED POSITION
GATE IN DEFLATED POSITION
Figure 26 PROPOSED IN-LINE DAM FLUSH STATION
-------
SECTION VIE
ARRANGEMENTS FOR FIELD DEMONSTRATION OF
PERIODIC FLUSHING OF COMBINED SEWER LATERALS
Any pollution control technique must be demonstrated under practical
field conditions before it can be widely accepted and used. The objec-
tive of this phase of the project was to expedite a demonstration
(Phase III) of the periodic sewer flushing technique in an operating sewer
system.
SOLICITATIONS FOR DEMONSTRATION LOCATIONS
1968-69 Hammond, Indiana. Worked with consulting engineers
Consoer, Townsend and Associates to get an expression of interest of
the Sanitary District of Hammond to explore the possibility of setting up
a demonstration. Prepared two tentative flushing system layouts and
demonstration plans for the Tapper Avenue area. The Sanitary District
expressed a preference for the Walnut Avenue area because relief sew-
ers had already been installed there. Prepared tentative flushing sys-
tem layout'for the Walnut Avenue area. The Sanitary District of
Hammond finally ruled out the possibility of a periodic flushing system
demonstration based on the work load in the sanitary district, the fear
of legal action if any flooding were to occur, and the cost to the district.
1969> Cleveland, Ohio. Cleveland responded favorably to suggestions
for a sewer flushing demonstration. Information was supplied to the
consulting engineers Engineering Science, Inc. to serve as a basis for
including sewer flushing as one of several methods of storm water over-
flow pollution control to be demonstrated. The area for the sewer flush-
ing study was to be from West'102nd Street to West lllth Street between
Clifton Boulevard and Baltic Road. Part of the flushing water was to be
supplied from storm water collected in a demonstration of local deten-
tion and storage.
Cleveland had taken no action on the proposal prepared for them by
Engineering Science because of the press of more urgent matters. Al-
though no time table can be given for action on the proposal, it is not
necessarily dead.
1969, San Francisco, California. Requested Gene Kazmierczak, Chief
Engineer, Engineering Science, Inc. , Consulting Engineers, Arcadia,
California, to review possibilities of interest in a Sewer Flushing Dem-
onstration Grant Application with client, City Engineer, San Francisco,
81
-------
in connection with Combined Sewer Demonstration Project concerning
Outfall Treatment. Kazmierczak reported no interest.
1970, Alexandria, Virginia. Reviewed possibility of a Sewer Flushing
Demonstration Project as a solution for minimizing Combined Sewer
Overflow pollution with Carl Rehe, Greeley and Hansen; Chicago,Illi-
nois; consultants for Alexandria, Virginia; re: Enforcement Proceed-
ings. Rehe reported interest would be subject to study program find-
ings and doubted any significant pollution from storm overflows.
1970, Detroit, Michigan. Reviewed background information on periodic
flushing of laterals with A. C. Davanzo and John W. Brown, Acting
Sanitary Engineer. Their reaction was favorable with a particular in-
terest in using inflatable dams for in-line storage of sewage for flush-
ing. They supplied a sewer map of a tentative demonstration location
for preliminary layout of a flushing system. A commitment to use the
area for a demonstration was to be contingent on details of the system.
The tentative flush system layout was made for an area bounded by
Fenkell Avenue, Lamphere Avenue, Midland Avenue, and Rockdale
Avenue. Three parallel laterals will be used with identical slopes,
diameters and lengths. One of the laterals will be used as a control
with no flushing. Inflatable flush gates will be installed for in-line
flushing liquid storage in one of the laterals. The other lateral will be
flushed from sewage stored in fabric flush tanks inserted in the existing
manholes similar to the prototype flush station developed under this
contract.
The information on the proposed demonstration has not been in the
hands of the Detroit personnel long enough for there to be a reply at the
time this report is being prepared.
82
-------
SECTION IX
•- • "*'
ACKNOWLEDGEMENTS
The two inflatable darns that were tested were supplied without charge
by Imbertson Engineering, Los Angeles, California.
Consulting on the structural design of the test facility was provided by
the San Jose Office of Consoer, Townsend and Associates.
Mr. Milton Spiegel, FMC Corporation Staff Consultant, was responsi-
ble for much of the promotional and inve stigational work done in the
negotiations for flushing demonstration si£es.
Mr. William Kannenberg and Mr. Manher Naik of the FMC Corporation
Management Information Systems group were primarily responsible for s
development of the mathematical model.
The equipment design, field testing, laboratory analysis, data reduction
and the report preparation were all accomplished through the efforts of
the Environmental Engineering Department of FMC Corporation's Cen-
tral Engineering Laboratories, under the supervision of D. W. Monroe
and J. P. Pelmak and the direction of F. F. Sako.
The support of the project,by th.e Environmental Protection Agency and
the guidance and help provided by the Contract Officers, Messrs.
A. D. Beattie and L. L. Weiribrenner and by Messrs. G. A. Kirkpatrick
and W. A. Rosenkranz is acknowledged with sincere appreciation.
83
-------
SECTION X
REFERENCES
1. Clark, John W. and Viessman, Warren, Jr. , Water Supply and
Pollution Control, International Textbook Company, Scranton,
Pennsylvania, pp 166-Z18 (1965).
2. Cleveland, Jerry G. , Ramsey, Ralph H. , and Walters, Paul R. ,
"Storm Water Pollution from Urban Land Activity, " Combined
Sewer Overflow Abatement Technology, FWQA Report No.
11024-06/70, pp 1-55 (June 1970).
3. Cohn, Morris M. , Sewers for Growing America, Certain-teed
Productions Corporation, Ambler, Pennsylvania (1966).
4. Design and Construction of Sanitary and Storm Sewers, WPCF
Manual No. 9j Water Pollution Control Federation, Washington,
D. C. (1970).
5. Fair, Gordon M. , Geyer, John C. , and Okun, Daniel A. , Water
and Waste Engineering, Vol. 1, Water Supply and Wastewater
Removal, John Wiley & Sons, Inc. , New York, N. Y. , pp 5-1 to
5-25 (1958).
6. Ford, Davis L. , "Total Organic Carbon as a Wastewater Param-
eter" Public Works 99, 89 (April 1968).
7. Schaffer, R. B. , Van Hall, C. E. , DcDermott, G. N. , Earth, D. ,
Stenger, V. A. , Sebesta, S. J. , and Griggs, S. H. "Application
of a Carbon Analyzer in Waste Treatment" J. WPCF 37_, 1545
(1965).
85
-------
SECTION XI
GLOSSARY OF TERMS
Average Cleansing Efficiency - The percent of deposited solids
removed from a given length of sewer.
Deposited Solids - The quantity of suspended solids that settled out of
the sewage passing through the sewer and is left deposited over the
given length of sewer.
Periodic Flushing - Systematic induction of stored liquid into sewers at
relatively high rates of release.
Suspended Solids - Particulate materials suspended in sewage.
Volatile Suspended Solids - That portion of the suspended solids that is
organic in nature.
Total Organic Carbon '- The total quantity of carbon present in the sus-
pended solids as a result of the presence of organic materials.
5 -Day BOD - A measure of the oxygen required for the biochemical
degradation of organic material.
Average Flush Rate - The average rate at which the flush liquid is dis-
charged into the sewer.
Volume of Flush - The total volume of liquid added to the sewer by the
flush release.
Relative Solids Distribution - The distribution of deposited solids over
the length of the sewer.
Relative Correlation - A measure of the ability of a general relationship
to predict the value of an experimental parameter.
Depth of Flush Wave - The maximum depth that a given flush wave
reaches a specified distance downstream of the induction point.
Flush Wave - The unsteady flow condition resulting from the rapid in-
crease in the flow rate in an open channel or gravity sewer.
87
-------
Dry Weather Flows - The flows in a combined sewer that result from
domestic sewage discharges with no significant contribution by storm
water runoff.
Combined Storm Flow - The flows in a combined sewer that result from
the combination of domestic sewage discharges and storm water runoff.
Combined Sewer Overflows - The quantities of combined storm flow
that are discharged without treatment to receiving streams and lakes.
88
-------
SECTION XII
APPENDICES ' .
, . .Page.
>' '
A. Results from Shakedown Testing 91
B. Field and Laboratory Procedures 93
C. Results from Flushing Evaluation Tests 105
D. Statistical Analysis of Design Equations 147
E. List of Design Drawings 155
F. Description of Mathematical Model 159
89
-------
APPENDIX A
RESULTS FROM SHAKEDOWN TESTING
Table 3 RESULTS FROM FRICTION COEFFICIENT TESTS
Pipe
Diameter
-D-
(in.)
18
18
18
12
12
-__ l*
Pipe
Slope
-S-
(ft/ft)
0.001
0.001
0. 001
0. 002
0. 002
0. 002
Average
Discharge
-Q-
(gpm)
819
658
285
829
693
291
Average
Flow
Depth.
-d-
(in. )
7. 56
7. 20
4.80
9.00
8.40
5. 51
Average
Velocity
-V-
(fps)
2. 58
2. 21
1. 63
2.91
2. 63
1.89
Average '
Mannings
Friction
Coefficient
~n-
0.0088
0.0100
0.0109
0.0104
0.0113
• 0.0135
Table 4 RESULTS FROM HYDRAULIC MIXING
TEST USING SEWAGE
Volume of
Sewage
(gals. )
1200
2000
2800
2000
Mixing
Time
(min)
1.2
2. 0
2.8
4.0
Volume s
Displaced
1
1
1
2
Average Suspended
Solids Concentration
mg/liter
Before Mixing
178
163
180
130
After Mixing
187
159
171
138
Pumping rates were constant at approximately 1, 000 gpm.
91
-------
Table 5 RESULTS FROM HYDRAULIC MIXING TESTS USING FINE SAND
vO
Volume
of Water
(gal)
1200
2000
2800
1200
2000
2800
. 1200
2000
2800
Sand
Added
db)
0. 50
0. 84
1. 17
2. 00
3.34
4.66
6.00
10.00
14.00
Actual
Concen-
tration
of Sand
(mg/liter)
50
50
' 50
200
- 200 !
200
600
600 •
600
0. 5 Volumes
Displaced
Mixing
Time
(min)
.0. 6
1.0
1.4
0.6
1.0
1.4
:0.6
;1.0
ii.4 .
Sand
Concen-
tration
in Sample
(mg/liter)
. 54. 2
40. 1
- 39.3
182.
215
; 150
- - 510 -
620 .
585
1. 0 Volumes ^
Displaced ,
Mixing
Time
(min)
1.2
2. 0
2.8
1,2
2.0
•2.8
1.2
2.0
2. 8
Sand
Concen-
tration
in Sample
(mg/liter)
50. 5
•51. 0
49. 2
202
200
202
202
598 • -
' 597 '
2. 0 Volumes
Displaced
Mixing
Time
(min)
2.4
4.0
5/6'.
2.4
4.0
5.6
2.4
4.0
5.6
Sand
Concen-
tration
in Sample
(mg/liter)
50.2
49. 6
50. -8
200
198
199
201
603
597
The pump rate was constant at 1, 000 gpm. '
-------
APPENDIX B
FIELD AND LABORATORY PROCEDURES
SEWER FLUSHING EVALUATION
FIELD SAMPLING RECORD
DATE: 2-18-70
PAGE 1 OF 1
INVESTIGATOR:
TEST NO. 46
L.N.
SLOPE: 18" PIPE
12" PIPE
.001
.002
Test Period Description
No. 1
Solids
Build up
Flush
Evalua-
tion
Storm
Simu-
lation
Tests
Sample
Numbers
Tank J
No. 1 2
Tank
No. 1
Tank
No. 3
Test 5
No. 1 4
Test 7
No. 2 ,
o
Test 9
No. 3g
Test
No. 41()
Test
No. 5
Test
No. 6
Test
No. 7
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
* 12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
Time — PST
Begin
End
Average
Discharge
(gpm)
50 ^
10
Average
Depth
of Flow
(in.)
2. 1
1.3
Average
Velocity
(fps)
Total
Elapse
Time
(min)
657
19.5
Total
Discharge
(gals. )
39.420
19"
18"
9"/15 sees.
5"/15 sees.
24"
24"
26"
24"
38"
36"
40"
40"
Length of Pipe
Downstream of
Flow Induction
Point (ft)
5psi 900
3 psi at 5psig900
900 gals.
at 5 psig
93
-------
SEWER FLUSHING EVALUATION
FIELD HYDRAULIC AND SOLIDS DATA SHEET
DATE: 2-18-70
'INVESTIGATOR:
L. N. & DEL.
Page 1 of, 3
TEST No. 46
Inspec-
tion
Point
No.
1
2
3
4
5
6
7
8
Test
Pipe .
1 8" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe,.
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
18" Pipe
12" Pipe
Location of
Point With
Respect to
Downstream
End of Pipe
(ft)
3-4
3-4
io - 11
10 - 11
15 - 16
15-16
21 - 22
, 21 - 22
41 - 42
41-42
52 - 53
52 - 53
Comments
(Approximate)
1/32" of solid buildup, flow 2"
1/32" of solid buildup, flow 1"
1/8" of solid buildup, flow 2-1/2"
1/16" of solid buildup, flow 1"
1/16" of solid buildup, flow 2-1/4"
1/32" of solid buildup, flow 2"
1/8" of solid buildup, flow 2"
1/16" of solid buildup, flow 1-1/4"
1/3 2". of solid buildup, flow 2"
1/32" of solid buildup, flow 1-1/4"
1/64" of solid buildup, flow 1"
1/64" of solid buildup, flow 1-1/2"
94
-------
LABORATORY PROCEDURES
•',<"*, ~
I TOTAL SUSPENDED SOLIDS ANALYSIS
A. Apparatus
1 1. Millipore filtering equipment
2. Whatman glass filter paper, GF/C 4.25 CMS
3. Pipets, graduated cylinder
B. Procedure
1. Weigh a filter paper on the analytical balance and place
it in position on the filtering apparatus.
2. Depending on the type of sample, pipet or measure by
graduated cylinder an appropriate size sample to the
- - filter paper and apply vacuum.
3. Rinse the measuring device and filter funnel with dis-
tilled water and after the water has been extracted,
remove the filter paper and place it in drying oven for
30 minutes at 103 to 105° C.
4. Cool the filter paper in a desiccator and reweigh.,
5. Run a blank in the same manner using distilled water.
C. Calculation
' /T* o J j ™ «. (A -B) + (C -D) x 1000
mg/liter Suspended Matter = - ~= '
.where
A = Weight of filter paper and dried solids _,
Sample
-B = Weight of filter paper only
C = Weight of filter paper only
Blank
D = Weight of filter paper dried
; E = ml sample
II VOLATILE SUSPENDED SOLIDS ANALYSIS
A. Apparatus
1. Muffle Furnace, OtolLOO°C
95
-------
B. Procedure
1. Place the dried filter paper from the total suspended
. " solids analysis in an alundum crucible and place in
muffle furnace.
2. Ignite the residue on the filter paper at 600 C for
approximately 1 hr. .
3. Cool the crucible and its substance in a desiccator and
reweigh the filter paper only.
4. Run the blank from the total suspended solids analysis
in the same manner.
C. Calculation
/T«. ^r i *-i o j j ™ «. (A - B) - (C - D) x 1000
mg/liter Volatile Suspended Matter = - *-= —
E
where
A — Weight of .filter paper and residue
B = Weight of filter'paper and residue after
ignition . .
C = Weight of filter paper only
Sample
Blank
D = Weight of filter paper after ignition
E = ml sample "...
in TOTAL ORGANIC CARBON ANALYSIS. '
A. Apparatus . . ...'.-. . •
1.. - Beckman IR-315 Carbonaceous Analyzer
2. Hamilton #705 N/LT Microsyringe, 50 nl capacity
3. Waring blender
B. Reagents
1. Glacial acetic acid: ACS grade
2. Hydrochloric acid: 1 + 5
C. Standardization
1. Accurately weigh 1. 000 gm of glacial acetic acid into a
1-liter volumetric flask and dilute to volume with CO2~
free distilled water. 1 ml = 1.0 mg of Acetic acid =
0. 400 mg of C.
96
-------
2. Prepare 5, 10, 15, 20, and 25 ml aliquots from stock
solution and dilute to volume in 100 ml volumetric flasks.
The above dilutions represent 20, 40, 60, 80, and 100
mg/liter of carbon respectively.
3. Starting with the highest concentrations, inject a 20 jzl
sample and adjust the instrument to that concentration
by moving the gain control located on the front panel.
4. Continue to inject samples from the same concentration
and adjusting the gain control until successive results
are obtained.
5. Proceed with the remainder of the standards.
6. Plot the average peak heights obtained against the stand-
ard concentration on a graph.
D. Procedure
1. Place a portion of the sample in a Waring blender and
mix thoroughly for 2 minutes. ,
2. If sample is to be determined for total organic carbon
(TOG), add a few drops of HC1 solution and remove CC>2
by bubbling Helium through the sample.
3. Prepare the necessary dilution and inject a 20 pi sample
and record the peak height.
4. Repeat paragraph 3 until successive results are obtained.
5. If sample is to be analyzed for Total Carbon (TC), make
the necessary dilutions and repeat steps 3 through 4.
6. Estimate the concentration in the sample by comparing
the reading with the standard curve.
NOTE; For additional information, refer to instruction
manual Beckman 61008.
97
-------
BOD5 - TOG RELATIONSHIPS FOR CENTRAL
ENGINEERING LABORATORIES (GEL) WASTEWATERS
INTRODUCTION
During the testing of various types of activated sludge treatment at GEL
over a period of 18 months, concentrations of BODg and TOG were mea-
sured for many samples of sewage. These accumulated results are the
basis for the correlations of BODs with TOG presented in the following
discussion.
GEL SEWAGE
In most wastes, the primary source of BODg is the biological oxidation
'of organic carbonaceous material. For this reason, the BOD5 should be
directly related to the waste's TOG. As shown in Figure 27, there are
two straight line relationships between BODg and TOG. For a TOG
below 300, the BOD 5 is equal to 1. 5 times the TOG; above a TOG of 300,
the BODs is equal to 1. 8 times the TOG. The high-range relationship
should prove satisfactory for a first order estimate over the entire
range.
STATISTICAL ANALYSIS
A statistical analysis was performed on the correlations of BOD5 with
TOG to determine the accuracy with which the BODg can be calculated
from the TOG. For each pair of BODs and TOG analyses, the predicted
BODg was calculated using the appropriate correlation. The deviation
of the, predicted BOD5 from the measured BOD5 was calculated as a per-
cent of the predicted BOD5. The distribution of the error in the pre-
dicted BOD5 was determined by plotting this error on probability paper
in Figures 28 through 30. A summary of the accuracy, on the corre-
, lations at'the 80 percent confidence level is presented in Table 6.
V
CONCLUSIONS
The literature indicates that the BOD5 of various wastewater can be cor-.
related with their TOG. This report has shown that a correlation be-
tween BODg and TOG exists for GEL sewage.
The BOD 5 of the sewage was shown to be equal to 1. 5 times the TOG for
a TOG < 300 mg/liter and equal to 1. 8 times the TOG for a
TOG > 300 mg/liter. The prediction of BOD5 can be simplified with
little loss in accuracy by using the high range relationship for all sewage
strengths.
98
-------
2000
1800-
1600-
1400-
1200- •
CONCENTRATION
OF 5-DAY BOD 1000
(tug/liter)
800--
BOD5 = 1.8 x TOC
BOD5 = 1.5 x TOC
• FIRST TEST SERIES
X SECOND TEST SERIES
•i 1-
200 400 600 800
CONCENTRATION OF TOTAL ORGANIC CARBON (mg/liter)
1000
Figure 27 HIGH-RANGE AND LOW-RANGE CORRELATION OF
BOD5 WITH TOC FOR CEL SEWAGE
99
-------
PERCENT
ERROR
IN THE
PREDICTED
BOD,.
40
30
20
10
n
-10
-20
-30
-50
• •<
2 5 10 20 30 50 70 80 90 95 98
PERCENT OF THE VALUES LESS THEN THE INDICATED VALUES
Figure 28, ACCURACY OF HIGH-RANGE CORRELATION OF
BOD5 WITH TOG FOR GEL SEWAGE
(BOD5 = 1.8 x TOG for TOG > 300)
i i ',
100
-------
60
50
40
30
20
10
PERCENT
ERROR
IN THE :0
PREDICTED .
BOD5 f-
-10
-20
-30
-40
-50
Figure 29
X
25 10 20 30 40 50 60 70 8,0 90^, 95 98
PERCENT OF THE VALUES THAN THE INDICATED VALUES
ACCURACY OF LOW-RANGE CORRELATION OF
BOD5 WITH TOG FOR GEL SEWAGE
(BOD5 =1.5 x TOC for TOG < 300)
101
-------
60
50
40
30
20
10
PERCENT
ERROR
IN THE
PREDICTED
0
-10
-20
-30
-40
-50
7
Z
12 5 10 20 30 40 50 60 70 80 90 95 98 99
PERCENT OF THE VALUES LESS THEN THE INDICATED VALUE
Figure 30 ACCURACY OF SIMPLIFIED CORRELATION OF
BOD5 WITH TOG FOR GEL SEWAGE
(BOD5 = 1.8 x TOG for ALL TOG)
102
-------
Table 6 SUMMARY OF ACCURACY
OF BOD -TOC RELATIONSHIPS
Waste
Correlation
Percent Error in the
Predicted BODr at
5
80 Percent Confidence
Level
CEL Sewage
(High Range)
BODr = 1. 8 x TOC
5
TOC > 300
-17 to 17
CEL Sewage
(Low Range)
BODr = 1. 5 x TOC
5
TOC ^ 300
-15 to 20
CEL Sewage
(Simplified
Correlation)
BOD = 1. 8 x TOC
All TOC
-9 to 26
103
-------
Table 7 SUMMARY OF RESULTS FROM SOLIDS DISTRIBUTION TESTS
o
Ul
Sewer
Descrip-
tion
1 8 Inch
Sewer
12 Inch
Sewer
Number
of
Tests
Run
3
1
2
2
2
3
3
2
1
2
2
2
3
3
1
1
Pipe
Slope
0.001
0.001
0.001
0.002
0.002
0.004
0.004
0.002
0.002
0.002
0.004
0.004
0.006
0.006
0.008
0.008
Sewage
Base
Flow
(gpm)
10
30
50
10
50
10
50
10.
20
30
10
30
10
30
10
10
Average
Quantity
of SS
Deposited
in the
Sewer
(Ibs)
4.36
5.70
3.75
3.50
5.51
3.26
4.44
1.89
4.37
3.54
2.34
2.21
1.66
3.01
6.93
s 0.93
Average Proportional
Distribution of SS
Along the Pipe- Length
In the
Firs!;
267 ft
0.495
0.426
0.356
0.483
0.441
0.500
0.481
0.568
0.490
0.413
0.483
0.410
0.491
0.423
0.384
0.291
In the
Next
255 ft
0.376
0.426
0.476
0.400
0.392
0.315
0.296
0.214
0.230
0.245
0.284
0.303
0.237
0.299
0.301
0.347
In the
Next
108 ft
0.053
0.070
0.088
0.050
0.078
0.083
0.105
0.106
0. 109
0.112
0.096
0.121
0.099
0.098
0.223
0. 120
In the
Last
160 ft
0.076
0.078
0.080
0.067
0.089
1
0. 102
0. 118
0.112
0.171
0.230
0. 137
0. 166
0. 173
0.180
0.092
0.242
Average
Quantity
of VSS
Deposited
in the
Sewer
(Ibs)
2.68
2.05
1.97
2.08
1.89
1.88
2.42
1.07
1.62
2. 15
1.48
0.83
1.00
1.61
1.57
0.36
Average Proportional
Distribution of VSS
Along the Pipe Length
In the
First
267 ft
0.441
0.351
0.261
0.392
0.388
0.405
0.385
0.505
0.409
0.312
0.396
0.353
0.413
0.408
0.302
0.157
In the
Next
255 ft
0.430
0.470
0. 510
0.497
0.417
0.379
0.339
0.186
0.227
0.268
0.335
0.315
0.281
0.318
0.255
0.261
In the
Next
108 ft
0.047
0. 0'81
0. 114
0.044
0. 101
0.097
0.128
0. 133
0. 130
0.128
0.092
0.138
0.113
0.123
0. 144
0.321
In the
Last
160 ft
0.082
0.098
0.115
0.067
0. 144
0.119
0.148
0.176
0.234
0.292
0.177
0.194
0. 193
0.151
0.299
0.261
Average
Quantity
of TOC
Deposited
in the
Sewer
(Ibs)
1.22
1.29
0.97
0.80
0.88
1.32
1.41
0.56
1. 16
1.09
0.89
0.67
0.77
1. 11
0.62
0.49
Average Proportional
Distribution of TOC
Along the Pipe Length
In the
First
267 ft
0.267
0.243
0.219
0.387
0.259
0.332
0.340
0.314
0.268
0.222
0.472
0.426
0.295
0.303
0.275
0.282
In the
Next
255 ft
0.466
0.470
0.474
0.382
0.387
0.342
0.313
0.282
0.258
0.233
0.212
0.253
0.275
0.300
0.330
0.229
In the
Next
108ft
0.092
•0.114
0.136
0.092
0. 148
0.165
0.167
0.208
0. 182
0.156
0.116
0.129
0. 180
0. 157
0.152
. 0. 191
In the
Last
160 ft
0.175
0.173
0.171
0.139
0.206
0. 161
0.180
0.196
0.292
0.389
0.200
0.192
0.250
0.240
0.243
0.298
H
en
a
en
a ^
w tl
ffi H
o
M
s
H
CO
a
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH TESTS (1 of 9)
Obser-
vation .
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
5?
53
54
55
56
57
58
59
60
61
62
63
SS
Clean-
,. sing
jpff.
-°ESS~
(%)
35.1
24.0
20.4
26.7
79.3
71.0
59.7
64.2
57.9
11.5
15.5
15.8
71; 6
68.9
64.0
57.3
61.4
45.5
45.8
44.1
78.7
70.8
66. 3
58.2
27.6
25.4
25.0
22.9
61.3
44.6
40.6
36.0
9.8
15.2
9.6
16.9
77.8
67.3
60.0
64.4
55.4
32.8
36.2
35.9
75.9
75.6
73.8
43.8
66.2
50.7
50.6
51.3
67.8
70.4
70.7
68.3
89.6
67.1
61.4
64.3
90. 1"
85.2
77.2
vss
Cleanr
sing
Eff.
~CEVSS"
(%)
35.5
28.6
27.8
26.7
84.3
72.9
63.8
70.2
73.9
7.9
16.3
19.3
75.5
71.1
67.5
63.1
87.5
68.3
70.5
64.1
93.0
88.1
86.4
72.2
44.6
29.0
32.6
35.2
74.0
51.7
51.6
47.3
0.0
0.0
0.0
0.0
77.9
65.6
58.6
66.0
59.5
44.4
46.9
46.8
76.1
77.3
75.4
46.5
74.4
63.4
63.1
63.6
77.4
77.7
77.4
73.8
91.5
76.8
71.4
74.2
90. 1
86.9
79.4
TOG
Clean-
sing
_Eff.
"CETOC"
(%}
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
51.6
43.0
37.6
35.0
46.7
51.5
49.5
47.5
69.4
63.0
62. 1
63.0
63.7
66.7
65.6
61.4
31.7
39.0
35.8
39.7,
63.9
50.7
52.9
43.3
2.9
18.4
20.4
34.0
30.7
14.2
17. 1
33.3
21.6
21.3
29.4
38.0
54.6
62.3
65.2
55.2
64.6
65.2
60.5
62.5
45.3
63.6
68.3
69.1
81.0
76.5
68.7
74.1
37.6
52.1
51.2
Tobal
Length
of
Sewer
-L,-
(ft)
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
Pipe
Slope
-So-
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
. 002
.002
. 002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
Sewage
Base
Flow
-QB-
(gpm)
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
30
30
30
30
20
20
20
20
30
30
30
30
20
20
20
20
30
30
30
30
20
20
20
Flush
Rate
-v
(gpm)
711
711
711
711
250
250
250
250
1519
1519
1519
1519
1053
1053
1053
1053
1639
1639
1639
1639
1102
1102
1102
1102
451
451
451
451
632
632
632
632
1543
1543
1543
1543
1269
1269
1269
1269
525
525
525
525
294
294
294
294
1904
1904
1904
1904
1063
1063
1063
1063
2768
2768
2768
2768
2094
2094
2094
Flush
Volume
-v
(gal. )
368
368
368
368
680
680
680
680
380
380
380
380
527
527
527
527
355
355
355
355
331
331
331
331
165
165
165
165
190
190
190
190
257
257
257
257
233
233
233
233
674
674
674
674
662
662
662
662
698
698
698
698
674
674
674
674
692
692
692
692
698
698
698
Pipe
Diameter
(in)
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
106
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH TESTS (2 of 9)
Obser-
vation
No.
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
SS
Clean-
sing
Eff.
"CESS~
(%)
81.1
63.6
28.4
25. 1
22.8
57.5
39.8
36.1
33.8
58.9
28.0
28.0
26.2
68.4
61.7
58.8
54.9
63.7
3 3. -6
29.1
22.1
77.7
59.8
55.6
48.8
51.5
39.3
37.5
32.9
80.3
59.0
57.4
58.3
57.1
37.4
39.9
29.0
61.4
41.4
36.0
32.0
82.7
65.0
59.8
54. 5
84.3
64.6
60.4
53.4
63.1
30.1
28.9
25.2
28.4
21.7
21.6
18.4
57.6
24.5
' 25.7
25.9
73.5
47.0
1 vss
Clean-
sing
Eff.
"CEVSS"
(%)
81.8
65.5
29.2
26.1
25.6
64.3
39.7
36.4
37.3
55.6
35.9
36.0
35.3
76.4
63.9
62.1
61.0
54.8
47.2
43.5
35.5
86.5
63.3
59.6
52.3
60.3
51.3
50.4
45.3
86.4
76.2
74.9
66.7
56.6
45.5
40.9
35.5
67.0
40.3
35. 1
35.1
83.7
67.4
62.3
57. 5
85.5
60.6
56.1
52.2
61.2
35.5
34.6-
32.2
35.8
23.3
24. 1
23.1
64.4
26.1
27.7
29.1
73.2
42.6
TOC
Clean-
sing
Eff.
"CETOC"
(%)
65.5
67.7
28.2
30.7
32. 1
43.8
28.9
36.4
39.7
49.3
40.7
36.3
32.8
61.0
41.4
40.6
42.8
35.6
45.5
44.0
41.3
70.9
52.6
53.1
52.2
74.6
57.2
53.4
52.3
54.7
51.4
56.4
54.7
43.3
. 52.6
51.9
52.0
39.6
38.8
36.1
41.7
77.7
71.8
71.2
69.8
• ' 76.7
56.0
60.4
60.2
77.2
73.2
72.7
73.3
47. 1
47.0
50.8
52.2
64.2
56.9
57.0
56.8 '
65.3
50.2
Total
Length
of
Sewer
-L-
(ft)
782
267
527
635
795
267
514
•' 622
782
, 267
527
635
795
267
514
622
782
• 267
527
635
795
267
514
622
782
267,
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
• 267
527
635
795
267
514
Pipe
Slope
-So-
.002
.001
.001
.001
.001
.002
.002
.002
.002
. 001
. 001
.001
.001
.002
.002
.002
.002
.001
.001
.001
. 001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001_
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
. 002
Sewage
Base
Flow
-QB-
(gpm)
20
30
30
30
30
20
20
20
20
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
30
30
30
30 .
20
20
20
20
30
30
30 *
30
20
20
20
20
30
30
30
30
20
20
20
20
30
30
30
30
20
20
Flush
Rate
-QF-
(gpm)
2094
560
560
560
560
343
343
343
343
3031
3031
3031
3031
2205
2205
2205
2205
1732
1732
1732
1732
1361
1361
1361
1361
1680
1680
1680
1680
1139
1139
1139
. 1139
1837
1837
1837
1837
1372
1372
1372
1372
2695
2695
2695
2695
1815
1815
1815
1815
882
882
882
882
205
205
205
205
964
964 .
964
964
840
840
Flush
Volume
-VF-'
(gal. )
698
355
355
355
355
355
355
355
355
404
404
404
404
257
257
257
257
404
404
404
404
386
386
386
386
196
196
196
196
190
190
190
190
398
398
398
398
343
343
343
343
404
404
404
404
302
302
302
302
• 300
300
300
300
300
300
300
300
300
300
300
300
300
300-
Pipe
Diameter
(in.)
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
,18
• 18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
107
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH TESTS (3 of. 9)
Obser-
vation
No.
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
SS
Clean-
sing
_E£f.
•CESS"
(%)
42.1
37.5
87.9
75.2
71.8
65.9
86.2
74.5
71.7
63.1
89.0
82.4
78.0
74.6
84.4
73.6
69.7
62.8
54.5
47.5
45.2
41.7
60.3
55.5
55.3
40.5
89.0
89.0
87.2
85.0
84.2
77. 2
73.0
64.2
89.2
84.0
82.5
80. 1
87". 0
80.0
73.9
64.9
84.7
80.1
77.8
75.3
30.2
41. 1
44.8
39.5
66.6
71.2
70.1
68.6
39.9
33.9
33.0
37.7
81.6
73.3
70.7
68. 1
79.0
VSS
Clean-
sing
Eff.
"CEVSS"
(%)
38.8
37.9
88.7
80.6
77.7
71.1
86.6
72.7
70.1
62.9
90.6
85.4
81.0
77.5
84.5
71.9
68.0
62.0
70. 1
56.3
53. 1
48.4
71.2
62.7
61.6
45. 1
94.5
94.1
92.4
89.8
82.6
75.8
71.1
59.7
87.5
86.3
85.2
82.4
78.3
74.0
66.8
58.6
91.8
87.0
84.5
82.1
46.6
46.1
50.1
41.5
63.9
67.0
64.6
63.2
69.8
68.4
67.2
70.4
87.3
74.1
70.9
68.5
86.0
TOG
Clean-
sing
_Ef£.
~CETOC~
(%)
43.6
47.7
80.0
76.7
68.3
65.1
58.8
58.7
60.2
58.9
84.0
85.6
82.0
78.8
72.3
74.5
47.2
52. 1
52.3
50.0
46.3
44.0
41.3
41.4
46.4
38.5
87.9
86.4
80.4
71.0
50.7
40.4
42.4
46.5
88.6
91.6
88'. 7
86.6
80.8
77.8
70.0
61.4
65.2
75.1
65.7
60.1
44.8
37.9
32.8
41.5
40.9
52. 1
45.3
47.4
16.4
25.6
34.4
51.4
73.6
66.5
63.7
64.9
61.4
Total
Length
of
Sewer
-L-
(ft)
622
782
267 .
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
Pipe
Slope
-So-
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
Sewage
Base '
Flow
-QB-
(gpm)
20
20
30
30
30
30
20
20
20
20
30
30
30
30
20
20
20
20
30
30
30
30
20
20
20
20
10
10
10
10
30
30
30
30
10
10
10
10
30
30
30
30
10
10
10
10
30
30
30
30
10
10
10
10
30
30
30
30
10
10
10
10
30
Flush
Rate
-v
(gpm)
840
840
3381
3381
3381
3381
2278
2278
2278
2278
2058
2058
2058
2058
1347
1347
1347
1347
441
441
441
441
264
264
264
264
2131
2131
2131
2131
1267
1267
1Z67
1267
3381
3381
3381
3381
1911
1911
1911
1911
420
420
420
420
323
323
323
323
367
367
367
367
294
294
294
294
1470
1470
1470
1470
1029
Flush
Volume
-VF-
(gal. )
300
300
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
600
600
600
600
600
600
600
600
600
600
600
600
600
Pipe
Diameter
(in.)
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18 .
18
18
18
12
12
12
12
18.
18
18
18
12
12
12
12
18
18 .
18
18
12
12
12
12
18
18
18
18
12
108
-------
Table 8 SUMMARY.'OF RESULTS FROM CLEAN-WATER
FLUSH TESTS'(4 of 9)
Obser-
. vation •
I No-
1
•-
190
. 191
-: 192
. 193
• 194
195
196
197
198
i., 199
- 200
201
. 202
. 203
' 204
, 205
206
* 207
208
v 209
f 21°
:, 211
', 212
213
214
'• 215
" 216
217
' 218
219
220
•'" 221
• 222
'- 223
', 224
225
, 226
,'; 227
•„ 228
229
230
' 231
232
: 233
. 234
fe 235
: 236
237
<• 238
, 239
240
. 241
.-. 242
. 243
• 244
. 245
, 246
>, 247
248
;? 249 -
•-, 250
251
& 252
| S3-
' Clean -
4 sing
\ _Eff.
,:, ~°ESS-
1 (%)
; 75.0
' 70. 2
"- 66. 9
: 77.1
-. 73. 1
:>• 70. 3
? 67.3
> 81.9
- 62. 4
65.1
>L 56. 2
'- 83.3
•' 63. 2
' 50.3
'• 49. 2
73.5
3 6; 6
h 27,9
•i 28.3
J' 83. 1
"; 43. 1
41.0
. 39.3
• 31.5
' 21.0
'. 18.7
"' 24.1
,; 66.1
. 61.9
58.1
,• 54.1
.- 83.8
57. 1
\ 49.1
46.5
' 87. 6
81.4
,' 77.2
72.2
* 86.8
''' 81.8
, 79.2
. 75.5
' 86.5
68.'1
.; 64.2
., 59.1
; 56.5
'• 48.2
,.43.4
40.6
:' 36.7
? 29.4
* 19.5
:; 21.7
,; 69.2
:, 56.5
I 50.5
S 40.5
?; 12-3
'- 16.4
; 19. 1
.< 16.2
vss
Clean-
sing
Eff.
"CEVSS"
(%)
83.4
80.2
79.1
84.0
82.4'
81.0
79.4
78.9
51.8
57. 1
55.8
79.0
73.2
69.4
67.0
49.7
23. 1
29.6
36.2
91.8
41.6
40.7
40.3
47.0
32.5
28.5
33.9
66.4
65.7
62.6
60.2
79.4
56.3
• 49.3
. 48.2
84.7
82.6
78.2
73.5
86.8
, 80. 1
77.4
72.8
86.5
77.2
73.3
66.9
36.-0
. 43.3
42.2
41.9
40.0
36.6
26.4
29.0
71.6
• 54.9
50.4
43.4
25.0
21.4
. 25.8
22.2
TOC
Clean-
sing
Eff.
~CETOC~
• (%)
68.4
67.4
68.8
69.5
71.4
64.4
62.3
64.7
57.7
47.2
52:6
76.5
62.2
56.3
50.9
26.6
13. 1
18.1
., 35.6
69.8
56.3
57.2
60.5
- 47.8
33.5
36.2
46.7
31.6
53.5
• 52.'0
53.9
79.7
- 59.0
57.0
65.1
81.9
83.3
' 79.3
78.2
83.6
' 80.7
77.9
75.7
88.2
82.0
75.5
" 74. 1
. 67.4
. 47.9
52.0
." 49.9
• 40.3
50.3
• 43.2
. 45.2
- 51.7
43.3
43.7
39.4
32.5
: 36.4
36.4
35.0
Total
Length
of
Sewer
-L-
(ft)
514
622
782
• 267
527
635
795
' 267
514
' 622
782
267
! 527
635
- 795
• 267
514 '
i 622
; 782
267
527
, 63,5
795
267
514
, 622
•' 782'
267
527
, 635
795
267
514"
' 622
•; 782
. 267
527
635
795
267
• 514
' 622
- 782
' 267
527
635
795'
267
514''
622
782
•'. 267
527
635'
- 795
267
514
622
782
267
527'
' 635
'_ .795'.. .
Pipe
Slope
1
-S6-
.002
.002
.002
.001
.001
.001
.001
.002
1 .002
.002
.002
.001
•• .001
.001
.001
.002
.002
.002
. 002'
' .001
.001
.001
.001
.002
_ .002
.002
.002
.001
.001
.001
.001
.002
.002
, .002
.002
• .001
.001.
.001
.001
.002
.002'
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
' .001
.001
. 001
.002
.002
. .002
' .002
.001
.001..
.001
.001'
Sewage
Base
Flow
-QB-
(gpm)
30
30
30
10
10
10
10
30
30
30
30
10
10
10
10
30
> 30
30
30
10
10
10'
10
30
30
. 30
30
1 10
10 '
10
10
30
30
30
30
30
30
30
30
20
20
20
20
30
30
30
30^
20
20
20
' 20
50
50
50
50
10
10 "
10 -
10
50
50
50.
', 50
Flush
Rate
-QF-
(gpm)
1029
1029
1 029
2021
2021
2021
2021
1878
1878
1878
1878
343
343
343
343
196
196
196
196
790
790
-790
790
679
679
679
679
1212
1212
1212
1212
1580
1580
1580
1580
2572
2572
2572
2572
2094
2094
2094
2094
I960
1960
1960
I960'
294
' 294
294
294
624
624
624
624
1102
1102
1102
1102
269
269
. 269
269, -
Flush
Volume
-V
' (gal.)
600
600
600
600
600
600
600
.600
600
600
600
300
300
300
300
300
300
300
300
300
300
300
300
300"
300
300
300
300
300
300
300
300
300
300
300
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
300
300
300
300
300
300
300
300
300
300
300
. 300, -.
Pipe
Diameter
(in.)
12
12
12.
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
•12
18
18
18
18
12
12
12
12
18
18
18
18
. 12
12
12
12
18
18
18
18
12
12
12
12
18
18
' 18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
109
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH TESTS (5 of 9)
Obser-
vation
No.
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
, 282
283
284
285
286
287
288
28,9.
; 290,
29,1
292
293
294
295
296
• 297
298 .,
299.
300.
301
302
303
304
305
306
307
308
309
310
3li
312,
313'
314
315
SS
Clean-
sing
Eff.
•CESS~
(%)
71.9
66.0
62.3
56.7
46.6
40.9
33.4
27. 2
92.4
85.9
82.7
73.4
61.9
49.1
48.8
45.9
65.6
61.5
60.3
S3. 6
82.2
72.9
70.6
67.7
64.6
59.3
59.1
56.6
82.0
56.6
56.0
55.2
77.2
41.8
38.2
35.5
86.1
77.0
75.4
71.7
85.2
81.0
78.0
72.8
1 85.. 7
77.3
72.9
70.4
63.0 .
51.7
45.6
' 46.3
81.1
63.2
60.8
58.7
30.4
21.2
20.2
23.5
51.5
41.7
41.8
VSS
Clean-
sing
Eff.
"CEVSS"
(%)
81.8
73.4
70.1
65.6
45.1
53.5
- 44. .4
39.4
90.9
85.0
82.9
76.8
63.2
57.3
58.0
56.0
74.8
67.5
66.9
63.8
88.8
81.7
80.2
78.2
58.7
59.9
60. 9,
62.0
86.0
60. 5
59.8
59.0
74.2
52.1.
49.6
' 46.5
86..\8
: 8^.4
79.8,
< 75.9
92,1
, 8,7.3
84,7
1 80. 9>
' 91-0. ,
86. 5
83.0,
,80.5
44,2
• 5.0. 5
• 46,, 9
. 52.4
89.5
74.6
71.6
69.3
43.8
30.8
29.1
1 33. 9
57.4
47.8
47.7
'TOG
Clean-
sing
^ff.
"CETOC"
(%)
68.4
.68.1
66.8 .
57.7
46.7
45.6
•39.5
40. 1
75.8
71.3
72.4
63.8
76.8
66.2
55.4
56.4
82.0
66.3
70.1
54. 1
12.3
52.9
54.0
' 56.1
66.4
67.3
58.2
. 63.1
65.5
39.6
' 43. .4 .
47.9-
47. '8
34.7
43.4
52.2
88.,i
81.8
70.2
69.8
92.2
81. 0 •
82.0
77. 5
. 40.4
70.0
65,4.
65v3
33.4
50.2
42.4
53.0
90.3
58.5
56.4
58.5
0.0
0.0
0.0
0.0
58.3
. 50^,7
53.6
Total
Length
of
Sewer
-L-
(ft)
267
514
622
782
267
527
635
795
267
; 514
622
782
267
527
635
795
267
514
622
782
267
5-27
. 635
i 795.-
! 267
' 514
622
782
267
527
635
795
•267
514
622.
782
267
527
635
795
; 267
1 514
622
782.
267
. 527
635
795
267
514
622 .
782
267
527
635
795
267
514.
622
782
267
527
635
Pipe
Slope
-So-
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002 '
.002
• .001
r .001
.001
.ooa
, .obi1-
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
. 001 •
.001
, . 001
.001
.002,
.002
(; . 002
*, .002
.001
.001
.001
.001
.002
.002
.002
' . 002 •
.001
.001-
.001
.001
. .002.
: .002
.002
.OQ2
.001
.001
.001
Sewage
Base
-QB-
(gpm)
10
10
10
10
50
50
50
50
10
10
10
10
50
50
50
50
10
10
, 10
10
10
10
10
: 10
• 30-
30
30
30
10
10
10
10
30
30
30
30
so
50
50.
' 50
10
10
10
10
10
10
10
10
30
30
30
30
10
10
10
10
30
30
30
30
50
50
50
Flush
Rate
-V
(gpm)
1078
1078
1078
1078
759
759
759
759
2058
2058
2058
2058
441
441
441
441
245
245
245
245
385
385
385
385
1176
1176
1176
1176
330
330
330
330
698
698
698
698
3234
3234
3234
3234
1127
1127
1 1 27'™
1127
2499
2499
2499
2499
1065
1065
1065
1065
1323
1323
1323
1323
238
238
238
238
1506 ,
1506
1506
Flush
Volume
-v
(gal. )
600
600
600'
600
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900
600
600
600
600
9o'o
900
900
900,
300'
300
300
300
300
300
300
300
900
900
900
900
900 '
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
600
600
600
600
300
300
300
Pipe '
Diameter
(in. ) .
12'
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12
12
12
12
18
18
18
18
12:
12
12
12
18
18
18
18
12
12
12
12
18
18
18
110
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH TESTS (6 of 9)
Obser-
vation
No.
316
317
318
319
320
321
322
323
324
325
326
327
• 328 ,
329
330
331
332
333
334
335
336
337
338
339
340
341 •
342
343 j
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
37,6
377 "
378
SS
Clean-
sing
Eff.
•°ESS'
(%)
40.3
69.4
51.7
49.4
41.5
80.0
54.6
54.3
52.3
90.7
79.6
73.1
67.1
68.2
43.1
41.8
39.2
78.0 :
66. 7
62.6
57.4 .
80. 1
25.7
24.2
24.5
.18.3
12.4
13.0 ,'
18.0
87.8
61. 1
57.4
54.1
72.8
51.7
46.1
45. 1
92.6
78.1
75.6
70.7 ,
89.8
70.4
63.0
57.6
93.4
92.0
90.2
87.1
93.6
90.8
89.3
86.5
85.5
72.2
69.2
64.9
80.8
75.4
73.4
, 65.2
VSS
Clean-
sing
_Ef£.
~CEVSS"
(%)
46.7
74:5.
57.2
55.9
49.4
75.8
65.4
64.8
61.8
92.6
81.2
74.7
69.6
65.8
53.3
53.0
52.0
82.6
72.5
69.7
67.0
86.7
31.5
29.4
30.3
32,5
18.7 •
18.2
24.2
92.1
75. 1
71.9
69.2
71.7
55.4
51.4
52.2
96.7
85.6
83.0 '
79.2 .
89.7
73.3
64.7
60.7
• 95. 9 '
95.6 '
95.1
93.0
94.9
92. 2 • .
90. 8
87.0
89.4
81.3
77.6
74.4
80.5
71.6 "
70.2
70.8
194.1 ; 96.7
9U8 | 95.1
TOG
Clean-
sing
Eff.
"CETOC"
(%)
52.2
51.0
40.4
51.5
51.8
70.6
63.9
60.5
- 58.5
83.9
69.7
66.6
59.4
49.6
43. 1
46.0
51.4
.59.7
' 45.9
-47.8
51.9
..94.8
• 30.4
••32.4
3,8.5
. .30. 5
21.8
,, 30.5
39.0
• 89.0
74.2
73. 3 •
• 70. 7 '
65.7
50. 1 '
56.4
• 63.4
. . 54. 9
•• 68.9
66.3
.. 64.2
84.2
..55.4
39.4
52. 5
79.2
82.4
68.4
67.4'
58.7
45.8
,34.8
40.3
67.0
58.2
52.9
52.2
65.9
57.4
53.4
50.9
54. 1
53.2
Total
Length
of
Sewer
-L-
(ft)
795
267
514
622
782
267
527
635
795
267
514
622
782
267 .
527
635
795
267
514
622
782 •
267
527
635
795 .
267
514
622
782
267
'527
635
. 795
• 267
514
.,,622
• .782
' 267'
.527
. 635,
795.
267
514
, 622
782
267
527
635
795
• 267
. 514
622
782
267
527
- 635
795
. 267
.514
622
782
267
527
Pipe
Slope
_
. -So-
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
.002
.002
.001
.001
.001
.001
.002
.002
- .002
.002
.001
..001
.001
-.001
...002
.002
..002
, .. 002 '
. -. 001
,,.001
. .001
.001 •
.002
. 002
.002
.002
.002
.002
.002
.002
, .004
. . 004 .
. 004
.004
. .002
.002
.002
.002 '
.004
.004
.004
. 004
.002
.002
Sewage
Base
-QB-
(gpm)
50
10
10
10
10
50
50
50
50
20
20
20
20
50
50
50
50
20
20
, 20
20
10
10
10
. 10
20
20
20
20
10
~ 10
10
10
30
30 •
30 '
30 .
10
10 ,
10
10
30 .
30 /,.
. 30 •
. 30 '
10
10
10
10 ,
30 '
30 1
• 30 .
30
10
10-
10
10
30
30
30
30
10
10
Flush
'Rate
-v
(gpm)
1506
171
171
171
171
1947
1947
1947
1947
1543
1543
1543
1543
1029
1029
1029
1029
1065
1065
1065
1065
1764
1764
1764
1764
257
257
257
257
1690
1690
1690
1690
1617
1617
1617
1617
710
710
710
710
,-1347
•,1347
1347
1347
,2940
. . 2940
2940
2940
. 1911
.-, ;9u
1911
1911
1323
1323
1323
1323
1568
1568
1-568
1568
•441
-441
Flush
Volume
-v
(gal. )
300
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
600
600
600
600
300
300
300
300-
600
600
600
600
300
300
300
300
300
300
300
300
300
300
300
' 300
300
300
300
300
900
900
900
900
900
900
900
900
300
300
300
300
300
300
300
300
900
900
Pipe
Diameter
(in.)
18
12
12
12
12
18
18
18
18
12
12 ;
12
12
18
18
18
18
12.
12
12
12
18
18
18
18
12
12
12
12
-18
18
18
18
12
12
12
12
18
18
18
18
12
12"
12
12-
18
18
18
• 18
12
12
12
12
18
18
18
18
12
12
12
. 12
18
:18
111
-------
Table 8 .SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH 'TESTS (7 'of 9)
Obser-
vation
No.
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433 .
434
435
436
437
438
439
440
441
SS
Clean-
sing
Eff.
~CESS~
(%)
90.5
89.2
83.1
73.4
72.4
67.7
80.6
61.8
59.0
57.3
56.7
48.8
46.3
40.8
77:0
78.4
76.7
73.5
83.2
81,3
80.6
76.4
88.6
68.2
61.7
60. 1
86.4
81.2
78.5
71.6
49.8
61.7
59.7
58.5
83.5
81.6
80.2
77.2
71.8
66.0
66.0
66.7
78.7
76.1
74.3
73.7
72.0
65.4
62.8
61.0
85.6
80.3
78.6
74.7
82.0
75.7
75.0
71.6
84.1
76.5
67.4
63.4
88.1
VSS
Clean-
sing
_Eff.
~CEVSS~
(%)
94.2
93. 1
89.2
81.6
81.8
76.2
85.8
66.8
64.0
62.4
66.9
56.9
48.1
46.1
76.0
80.0
78. 1
74.9
91.9
89.8
88.4
83.1
90.0
67.1
64.0
61.1
93.3
87.2
85,2
. 78.3
52.4
63.3
59.6
58.7
88.5
85.7
81.5
81.9
79,9
74.3
74.6
74.2
80.2
79.0
79.0
77.3
68.1
66.2
63.8
64.1
89.1
83.3
80.7
78.2
87.6
84.0
83.0
78.5
84.7
76.4
65.0
60.9
91.9
TOC
Clean-
sing
_Ef£.
~C-ETOC~
(%}
49.8
50.9 •
70.4
46.0
34.6
35.0
43.8
36.5
27.5
25.0
60.3
43.2
39.3
17.9
50.3
62.4
59.4
56.7
84.7
76.3
70. 1
66.2
38.6
41.8
43.9
44.0
78.3
61.8
41.2
42.5
41.7
53.3
50.5
45.9
76.3 .
. 67.8
64.1
61.0
63.8
44. 1
46.2
. 47.2
63.1
55.6
43. 1
45.4
37.4
38.8
39. 0
39.4
81.1
65.7
61.1
69.4
68.3
67.7
67.7
62.0
79.5
71.5
58. 5
. 54. 1
82.9
Total
Length
of
Sewer
-L,-
-------
., TableS SUMMARY OF RESULTS FROM'CLEAN-WATER
FLUSH TESTS (8 of . 9)
Obser-
vation
No.
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461'
462
463
• 464
465
466"
467
' 468
469
470 '
471
472
473
474
475
476'
477
478
479
480
481
482
483
484
485
486'
487
488-
489
490
491
492
493'
494
495-
496
497
498
499
500
501
502
503,
- 50.4. . ;
'• ss
Clean-
sing
_Eff.
"CESS"
(%)
81.9
80.3
78.3
90.4
80.5
79.9
74.8
81:0
56.4
' 55.7
51.6
93.0
87.6
85:7
82.7
94.0
88.3
85.2
83.0
87.6
83.5
81.2
76.6
90. 1
-61.4
56.7
52.6
89.2
79.'4
76.19
72..9
89.!9
' 79.9
78.5
77.1
81.7
75.6
72.8
69.3
56.1
29.0
25.6
22.7
77.9
61.J1
55.6
53.0
83.3
75.2
72.0
66.1
87.1
83.8
81. '5
72.8
73.1
60.2
60.0
57.5
81.2
76.2
72.5
67. '5
vss
Clean-
sing
_Eff.
"CEVSS"
(%)
87.4
85.9
83.9
92.3
82.7
82.7
80.1
77.6
61.3
59.5
54.9
92.3
68.1
85.5
83.4
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
' 88. 1
62.4
57.1
52.4
90.5
80.4
77.0
71.9
92.3
85.4
83,9
82.7
83.3
75.9
73.0
68,8
63. 6
35.-9
31.0
27.5
78. 1
61.7
56.7
55.2
80.4
75.7
72.9
67.8
90.'2
85.8
83.6
75.5
68.9
58.7
60.2
57.,8
83.7
79.8
75.5
67.7..
TOC
Clean-
sing
_Eff.
~CETOC~
' (ft)
78.3
77.2
77.5
' 92.9
84.7
77.2
74:8
25^3
33j4
32.2
29.3 *•'
46.1
33.9
32.6
35.5
77.4
76.' 3 "
75.4
70:4
46.2
' 45J3
' 42.7
47.6 '
64.9
29.<6
20.: 2
12.9
57.2
46.9
52.4
55.7
66.0
49.7
46.3
45.0
60.1
33.2
19.4
30.5
56.3
23.0
19.:3
27.2
27.9
17.8
23.9
31.4
70.'5
57.9
55.5
52.0
52.9
55.8
54.2
46.5
53.2
53.7
' 50.7
53.5
59.4
56.9
54.4
55.4 , ,
Total
Length
of
Sewer
-L-
(ft)
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782 •
267 '
527
635
795
267
514
622
782
267
527
635
795
267
,' 514 \
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267 ' '
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
' 267
514
622
' . 782 .....
Pipe
Slope
-So-
.002
.002
. 002
.004
.004
.004
.004
.002
.002
.002
.002
.004
.004
.004
.004
.004
.004
.004
.004
.006
.006
.006
.006
.004
.004
.004
.004
.006
.006
.006
.006
.004
.004
.004
. 004
.006
.006
.006
.006
.004
. 004
.004
. 004
.006
.006
.006
.006
.004
.004
.004
* .064
.006
.006
.006
.006
.004 .
.004
.004
.004
.006
.006
.006
,006 . .
Sewage
Base
-
-------
Table 8 SUMMARY OF RESULTS FROM CLEAN-WATER
FLUSH. TESTS (9 of 9)
Obser-
vation
No.
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
;ss
Glean-
jsing
Ef£.
"CESS"
><%>
60.6
48.0
38.6
?3.7
49.7
31.2
25.6
i9.7
84.7
83.4
82.2
§1.3
78.9
55.4
57.1
55.9
89.9
79.3
77.2
75.2
93.6
71.5 -
71.0
7i3.1
87.9
84.0
81.2
80. 1
9*2. 5
90. 3
88.8
87.6
84. 8
61.3
55.7
S3. 4
83.4
70.0
74.3
6J1.6
s
i
*
vss
Clean-
sing
Eff.
"°EVSS"
(%)
51.3
46.4
38.6
36.8
59.0
39.7
34.3
23.4
84.9
87.1
86.4
84.1
82.2
60.4
61.8
57.2
87.3
77.2
74.7
73.3
88.8
65.7
65.5
65.8
76.1
74.9
71.5
71.8
93.3
91.7
91.0
89.9
78.6
57.5
50.5
47.8
81.2
65.5
63.2
60.6
TOC .
Clean-
sing
_E£f. •
"CETOC"
(%)
18.7
25.2 •
25.1
21.6
32.8
32.4 •
19.9
21.1
50.8 •
65.2
67.2 .
66.4
73.4
57.4 '
53.0
56.1
56.1
53.2
52.4
54.0
64.0
51.2
38.9
42. 1
52.5
99.9
40.2
34.6 .
61.0
52.0
45. 7 '
- • 49.4
53.7 '
38.4 ;
33.5
31.9
15.5
28. 2
28.3
" 36.0
Total
Length
of
Sewer
-L-
(ft)
267
' 527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
267
527
635
795
267
514
622
782
Pipe
Slope
-So-
.004
.004
.004
.004
.006
.006
.006
.006
.004
.004
.004
.004
.006
.006
.006
.006
.004
.004
.004
.004\
.006
.006
.006
.006
.004
.004
. 004 '•
.004
.006
:oo6
.006
.006
.004
.004
.004
.004
: .006
.006
.006
.006
'
Sewage
Base
-QB-
(gpm)
10
•10
10
10
30
30
30
30
10
.10
10
10
30
30
30
30
10
10
10
10
30
30
30
30
50
50
50
50
10
10
10
10
50
50
50
50
10
10
10
10
Flush
Rate
-
-------
Table 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 12-INCH SEWER, (1 of 1.2) {
Obser-
vation ,
No.
1
Z
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Maximum
Flush
Wave
Depth
-wD-
(in. )
11.5
10.5
10.0
. 9.3
13.0
11.5
11.-8
11.0
' 7.1
6.5
6.3
6.5
6.1
6.0
5.9
6.3
12. 0
11.0
8.5
9.0
12.0
10.3
9.3
8.5
5. 0
4.8
4.8
4.8
12. 0
9.0
7.8
6.5
6.3
4. 5
7.0
6.5
12.0
12.0
11.0
9.0
6.5
6.0
6.1
6.5
8.0
6.8
6.0
5.5
Distance
Down-
stream
of Flush
Release
(ft)
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
. 218
290
92
164
218
390
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
Pipe
Slope
-So-
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
. 002
.002
.002
.002
. 002
. 002
.002
.002
.002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
Sewage
Base
Flow
-v
(gpm)
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
20
20
20
20
20
20
20
20
10
10
10
10
Flush
Rate
-QF-
(gpm)
1267
1267
1267
1267
1911
19U
1911
1911
323
323
323
323
294
294
294
294
1029
1029
1029
1029
1878
1878
1878
' 1878
196
196.
196
196
679
679
679
679
1580
1580
1580
1580
2090
. 2090
2090
2090
294
294
294
294
1102
1102
1102
1102
Flush
. Volume
. -v
(gal. )
900
900
900
900
900
900 ,
900
900
900
900
900
900
600
600
• 600
600
600
600
600
600
600
600
600
600
300
300
300
300
300
300
300
300
'300
300
300
300
•900
900
900
900
900
900
900
900
300
300
300
300
115
-------
Table 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED' IN: 12-INCH SEWER' (2 of"l2)
• Obser-
i vation
- No.
i ,49
50
51
52
I «
i 54
55
56
i 57
58
' 59
60
61
i 62
63
64
65
!, 66 •
• 67
V 68
I 69
.;• 70
71
\ 72
f,
t 73
74
75
.; 76 -
;, 77
> 78
i 79
! 80
81
82
: 83
; 84
: 85
86
87
i 88 •
': 89
• 90
91
92
93.
94
95
96
Maximum
Flush
Wave
Depth
-wD-
(in.)
12.0
12. 0
9.5
8.3
12.0
12.0
12. 0
9.0
•6.3
5.8
6. 1
6. 1
12.0
11. 0
11. 0
10. 5
11.0
8. 5
7.3
6.3
12.0
11. 5
11.0
10.0
; 12.0
11.0
7.8
- 9.0
5. 8
5. 3
5.-3
5.5
4.- 5
4.3
4.3
4.0
12.5
10. 5
10. 5
•9.5
12.'0
8.6
-9.4
8.0
12.0
10. 5
9.0
5. 8
; Distance
•' Down-
i stream
j of Flush
I Release
: (ft) ,
| 92
| 164
! 218
I 290
> 92
i 164
'; 218
i 290
1 92
! 164
j 218
I 290
1 92
| 164
j 218
[ 290
i 92
| 1'64
i 218
j ' 290
92
i 164
i 218
J 290
92
164
218
! 290
.92
164
218
290
92
: 164
218
290
92
164
218
290
92
164
218
290
92
'164
218
290
Pipe
Slope
-So-
.002
.002
.002
.002
.002
,002
.002
! .002
.002
.002
.002
.002
.002
:oo2
. 002
.002
. 002
.002
. 002
.002
. 002
.002
.002
. 002
. 002
.002
; .002
. 002
. 002
. 002
.002
. 002
; . 002
.002
j .002
' .002
.002
.002
; .-002
. 002
. 002
.002
. 002
.002
. 002
. 002
.002
.002
Sewage
Base
Flow
(gpm)
10
10
10
10
10
10
10.
10".
10
10
10
10
30
30
3V
30
30
30'
•: 30-
' -30
10
10
10
10,
30
30
' 30
30
; 30
3 0
30
30
10
10
10
10
20
20
20
20
20
20
20
20
20
20
20
20
Flush
Rate
(gpm)
1078
1078
1078
1078
2058
2058
2058
2058
245
245
245
.245
1176
1176
1176
1176
698
698
698
-698
1127
; 1-127
\ 1127
1127
1065
1065
1065
1065
238
238
-238
238
54
- ' 54
. 54
54
1543
• 1543
1543
1543
1065
1065
1065
1065.
25?'
257
257
257
Flush
Vo'lum e
-v
(gal. )
600
600
600
600
900
900
900
900'
900
900
900
900
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
6.00
300
300
300
300
600
600
600
600
600
600
600
600
600
: 600
600
600
1-16
-------
Table. 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 12-INCH SEWER (3 of 12)
Obser-'
vation
;' No.
97 •
98
99
100
101
102
103
104
" 105
1 106
' 107
108
109
110
111
' 112
< 113
114-
115
. 116
' 117
118
119
120
121
122
123
124
125
126
; 127
128
129
130
131
132
133
134 ,
135
136
137
138
139
140
141
142
143
144
Maximum
Flush
Wave
• Depth
.: -WD-
. (in-)
- 12.0
9.0
8.0
6.5
8.0
8.0
7.3
6.0
^ 10.0
" 8. 0
: 8.5.
8..0
10.5
8.0
7.3
6.0
5. 3
.5.8
6.0
. 6.3
4.3
4.5
4.5
4.5
12.0
12. 0
; 12.0
10.0
10.;0
7.8
6.5
5.3
4. 5
5. 5
6.0
' 6.3
11. 3
10.3
8.8
7.3
12.0
10. 5
8..0
7.8
11.0
8,5
7. 5
6.0
Distance
Down-
stream
< of Flush
Release
(ft. )
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290.
92
164
218
290
92
164
218
290
; Pipe
Slope
-So-
.002
.002
. 002
.- . 002
.002
. 002
. 002
.002
.004
. 004
• . 004
.004
. .004
.004
.004
. 004
.004
.004
. . 004
.004
.004
.004
.004
. 004
- . 004
. 004
. 004
.004
' .004
.004
.004
.004
. 004
. 004
,004
1 . 004
.004
. 004
.004
. 004
.004
. 004
.004
.004
.004
.004
.004
.004
Sewage
Base
Flow
• -QB-
(gpm)
30
30
30
30
30
30
30
-, 30
30
• 30
30
30
30
SO-
SO
30
30
30
30
30
30
30
30
30
10 .
10
10
10
10
10
; 10
: 10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
Flush
Rate
• -V
(gpm)
1617
1617
1617
1617
. 1347
1347
• 1347
1347
. 1911
1911
19H
1911
1568
1568
1568
1568
29.4
294
294
294
196
196
196
196
1862
1862
1862
1862
; 1225
1225
1225
1225
245
245
245
245
980
-980
980
980
882
882
882
882
1519
1519
1519
1519
Flush
Volume
' ~VF~
(gal. )
300
300
300
300
300
300
300
300
900
900
9oa
900
300
300
300
300
900
- 900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
'600
600
600
600
600'
600
600
300
300
300
300
117
-------
Table. 9, . SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
.OBSERVED IN 12-INCH SEWER (4 of 12)
Obser-
, vation ;
No.
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170'
171
172
173
174
' 175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
Maximum
Flush
Wave '
Depth
-WD-
(in. }
.. 8.8
7. 5
7.3
5.5
11.0
9.5
10.5
10.5
10.0
6.5
7.3
5. 5
5.0
5.0 ,
'5.5
.6.0
4.5
4.8
4.8
.4.8
11.0
8.0
10.0
8.0
6.5
4.5
6.5
~5.3
4.3
4.3
4.5
• 5.0
5.3
6.0
6.0
. 6.0
7.0
5.3 '
6.3
"4.3
12.0
6.3
10. 8
9.8
11.5
7.0
7.0
5.8
Distance
Down-
stream
of Flush
Release
(ft)
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
9'2
164
218
290
92
164
218
290
92
164
218
290
92
164
218 •
290
Pipe
Slope
-So-
. 004
. 004 :
.004
.004
.006
. .006
.006
.006
.006
.006
. 006
.006
.006
. 006
.006
.006
.006
.006
. 006
.006
.006
. 006
.006
.006
.006
. 006
.006
.006
.006
.006
.006
.006
. 006
.006
.006
.006
.006
.006
. 006
.006
. 006
.006
.006
.006
.006
.006
.006
.006
Sewage
Base
Flow
-QB-
(gpm)
10
.10
10
10
10
10
10
, 10
10
10
10
10
' 10
.10
10
10
10
10
10
'. I'O
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
"30
30
. 30
30
30
10
10
10
10
10
10
10
10
Flush
Rate
-QF-
(gpm)
548
548
548
548
-I960
I960
1960
I960
1470
1470
1470
1470
'294
294
294
294
220
220
220
220
1911
1911
1911
1911
1176
1176-
1176
1176
196
196
196
196
245
245
245
245 -
1323
a 3 23
'1323
1323
1764
1764
1764
1764
1323
1323
1323
1323
Flush
Volume
-VF-
(gal.) -
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
- 900
900
300
.300
300
300
118
-------
Table 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN IZ^INCH SEWER (5 of 12)
Obser-
vation
No.
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207 ;
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
Maximum
Flush
Wave ;
Depth
-w -
D
(in.)
8.3
5. 8
5.3
6.5
7. 5
6.3
5.5
5.3
' 6.1
4.8
4.3
6.0
6.8
4.8
3.5
5.4
8.0
4,8
4.0
6.0
7.5
5.3
4.3
5.8 ,
4. 1
3.0 ,
3.3
3/8
5.0
4.0
3.5
4.5
5. 1
4.5 •
4. 0
'.4.3
7.3
5. 5
5.4
6.0
5.0
' 5.3
4.6
5.5
4.0
3.. 4
'3.0
3. 5,
Distance
Down-
stream
of Flush
Release '
(ft)
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361 :
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
Pipe
Slope
-So-
.002
. 002
.002
. 002
. 002
.002
.002
.002
.002
.002
.0.02
. 002
.002 •
. 002
.002
.002
.002
. 002
. 002
.002
.002
..002
. 002
.002
.002
.002
. 002
.002
. 002
'.002
.002
.002
. 002
. 002
.002
.002
.002
|
. 002
.002
. 002
.002
. 002
.002
. 002
.002
.002
.002
. 002
Sewage
Base
Flow
j
-Q~- •
B
(gpm)
30 ;
30
30
30
30
30 ;
30
•30
30
30
30
30
30 -
30
30
30
30
30
30
30
30 ;'
30
30
30 •
30
30
30
30
30 '
30
30
30
30
30
30
30
20
. 20
20
20
20
20
20
20
10
10
10 ;
10
Flush
Rate
-QTT-
F
(gpm)
1267
1267
1267
1267
1911
1911
1911
1911
323
323
323
323
294
294
294
294
1029
1029
1029
1029
1878
1878
1878 '-
1878
196
196
196
196
679
679
679
' 679 .
1580
1580
1580 .
1580
2093
2093
' 2093 .
2093
294
294
294
294
ll02
1102
1102
. 1102 ,
Flush
Volume t
• , '
-V -
F
(gal.)
900 .
90"0
900
900
900
900
900
900
900
900
900
900- .
600 :
600
600
600
600
600
600
600
600
600
600
600
300
300
300
300
300
300
3'00
300
300
300
300
300
900
• 900
900
'900
900
900
900
900
300
300
300
300
119
-------
Table *9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 12-INCH SEWER .('6 of 12)
Obser-
vation
No. .
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
Maximum '
Flush '
Wave
Depth
-WD-
(in. )
6.8
4.8
4.6
5.4
-7.8
6.4
5. 3
6.3
5.8
4.3
4.0
5. 5 ;
8.8
5.8
6.6
7.0
5.0
3.5
3.0
4. 5
8.3
6.0
5.8
6.3
7.3
5.0
5. 0
5/6
5. 3
4.5
3.9
5.0
3.4
3.0
2.3
3.0
6.5
5.5
4. 5
5.5
6.4
5.0
4.3
5.4
5.5
4.5
4.0
4. 0 '
Distance
Down-
stream
of Flush
Release
(ft)
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473 .
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
53'5
361
442
473
535
361
442
473
535
Pipe
Slope
-So-
.002
.002
. 002
. 002
.002
.002
.002
.002
.002
.002
.002
. 002
. 002
.002
.002
. 002
.002
. 002
.002
. 002
. 002
.002
. 002
.002
. 002
.002
. 002
.002
. 002
.002
.002
.002
.002
. 002
. 002
. 002
.002
.002
.002
.002
. 002
. 002
.002
. 002
.002
.002
.002
.002
Sewage
"Base
Flow
-QB-
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
30
30
30
30 '
30
30
' 30
30
10
10
10
10
30
30
30
30
30
30
30
30
10
10
10
10
.20
20
20
20
20
20
20
20
20
20
20
20
Flush
Rate
-QF-
(gpm)
1078
1078
1078
1078
2058
2058
2058
2058
245
245
245
245
1176
1176
1176
1176
'698
698
698
698
1127
1127
1127
1127
1065
1065
1065
1065
238
238
238
238
147
147
147
147
1543
1543
1543
1543
1065
1065
1065
1065
257
257
257
257
Flush '
Volume
-V - .
F
(gal. )
600
600
600
600
900
900
900
900
900
900
900
900
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
6;00
600
600
600
300
300
300
300
600
600
600
"600
600
600
600
600
60'0
;60'0
600
600
120
-------
Table 9 SUMMARY OF-MAXIMUM FLUSH .WAVE DEPTHS
OBSERVED'IN 12-INCH SEWER (7 of .1?)
Obser-
vation
No. '
V
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
3,17
318
319
320
321
322
,323
324
325
326
327
328
329
330
331
332
333
334
335
336
Maximum
Flush
Wave
Depth
-%- '•
(in.)
5.0
3.5
3.5
4.3
5.0
3.0
3.5
3.5
9.0
.7.5
7.0
6i5
5.0
4.0
3.8
4.-3
6.0
.5.tO
4.5
5.5
4.0
3.5 >
3.5
3.8
8.0
6.5
5., 8
6. .5
4. 5
3.5
,3.3
4.0
5.8
4.8
4.5
5.3
6.5
5.5
5..0
5.5
7.3
6..0
5.5
5. 5
5.3
4.3
3.. 8
4.3
Distance
Down-
stream
of Flush
Release
(ft)
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
.442
473
535
Pipe
Slope
-So-
. 002
.002
.002
. 002
.002
.002
.002
• °.°,2
. 004
.004
.004
..004
.004
.004
.004
.004
.004
.004
.004
.004
. 004
,.004
.004
.004
.004
.004
. 004
. 004
. 004
. 004
.004
.004
.004
. 004
.004
.004
.004
.004
.004
.004
. 004
.004
. 004
. 004
.004
. 004
.004
.004
- {
Sewage j
Base ]
Flow . 1
'-%- !
(gpm)
30 ']
30 !
30 l
30
30 ;
30
30 l
30
30 ;
.30
30
,30
30
30
30
30 |
30
30
30
30
30
30
30
30
10
10
..10
10
10
1.0
10.
10
10
10
10
10
10
. 10 '.
10
10
30
30 |
30 j
30 {
•30 !
30, !
3Q
30 ;
Flush
Rate
-QF-
(gpm)
1617
1617
1617
1617
1347
1347
1347
1347
1911
1911
1911
1911
1568
1568
1568
1568
294
294
, 294
294
196
196
196
196
1862
1862
1862
1862
1225
1225
1225
1225
245
245
245
, 245
980
980
' 980
980
882
882
882
882
1519
• 1519
1519
. 1519
Flush
Volume ?
j
-v
(gal.)
300
300,
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
121
-------
/Table 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
j ' OBSERVED IN 12-INCH SEWER .(8 of 12)
Obser-
vation
No.
337
338
339
340
341
'342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
;• 362
, '363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384 '
Maximum
Flush
Wave
Depth
-WT>-
D
(in.)
4.8
3.3
3.8
4.0
7.0
8.0
7.8
7.0
5. 0
4.0
3.5
4.0
4.8
4.3
4.5
4.8
4.0
2.5
3.3
3.8
8.0
7.3
7.0
6.8
4.8
4.0
4.5
4.3
3.8
3.5
3.3
3.5
4.8
4.5
4.8
5.0
5.0
4.0
4.3
4.0
8.5
7.5
8.0
6.8
5.3
• 4.5
4.5
4.5
Distance
Down-
stream
of Flush
Release
(ft)
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
361
442
473
535
Pipe
Slope
-So-
. 004
. 004
.004
.004
.006
.006
.006
.006
.006
. 006
.006
.006
. 006
.006
. 006
. 006
.006
.006
.006
. 006
.006
. 006
.006
.006
.006
. 006
. 006
.006
.006
.006
.006
.006
.006
. 006
.006
.006
.006
. 006
.006
. 006
.006
. 006
.006
.006
. 006
.00'6
.006
.006
Sewage
Base
Flow
-Q_-
B
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
' 30
30
30
30
10
10
10
10
10
10
10
10
Flush
Rate
-Q -
F
(gpm)
1475
1475
1475
1475
I960
1960
1960
1960
1470
1470
1470
1470
294
294
294
294
220
220
220
220
1911 '
1911
1911
1911
1176
1176
1176
1176
196
196
196
196
245
245
245
245
1323
• 1323
1323
1323
1764
1764
1764
1764
1323
1323
1323 .
1323
Flush
Volume
-V -
F
(gal. )
300
^00
"300
300
'900
900
900
900
300
300
300
300
900
; 900
900
900
300 .
• 300
300
300
900
900
900
900
300
300
300
300
300
300
300
300
900
900
900
900 :
300
300
300
300
900
900
900
900
300
300
300
300
1 • '. 122
-------
Table 9 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 12-INCH SEWER (9 of 12)
Obser-
vation '
'NO.
, t
385
.386 !
•387
388 •
389 '
390
391
392
393
394
395
396
397
398
• 399
400
.401
402 •
403
404
405
406
407
408
409 ;
410
411
412
413
414
415
416
417
418
419
420
421 ;,
422 •
423 '
424
425
.426 .
427
428
429 '
430 '
, 431
432
Maximum
Flush
Wave
Depth
-WD-
(in. )
6.0
5.7 -
5.6
5. 1
6.3
6.0
6.0
6.0
- 5.5
5.8
5.8
5.8
4.9
5.0
4.8
4.9
5.3
5.0
5.3 .
. 5.3
5.0
5.0
5.0
3.3
3.5
3.5 .
3. 5
2.8 ,
4.3 [
4.3 ;
4.0
4. 5
4.3
4.3
4.3
4.3
5.5
5.0
4.8
5.0 '
5.0
5.0
4.8
4.5
3.0
3. 1
3.5
3.6
Distance'
Down-
stream
of Flush •
Release
(ft)
614
680
732
770
614 <
680
732
770
614
680
732
770
614 :
680
732
770
614 .
680
732 '
770
614
.680
, 732
770 ,
614
680
732
770
614
680
732
770
614
. 680
732 •
770
614
680
732
770
614
680 •
732
770
614
680
732
770
Pipe
Slope
-So-
.002
.002
. 002
. 002
. 002
.002 ''
.002
.002
.002
. 002
. 002
. 002
..002
.002
. 002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
. 002 '
.002 -
. 002
.002
.002
.002 .
.002
. 002
. 002
.002
.002
. 002
.002
. 002
. 002
Sewage
Base
Flow
-QB-'
(gpm)
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
' 30
30
30
30
30 ;
30
20 '
' 20
20
20
20
20
20
20
10
10
10
10
Flush
Rate
-QF- -'
(gpm)
1267 ,
1267 !
1267 "
1267
1911
1911 .
1911 '
1911
323
323
323
323
294
294
294
294
1029
1029
1029
1029
1878
1878
1878
1878
196
. 196
196
196
679
679
679
679
1580
1580
1580
1580
2096
. 2096
2096
2096 •
294
294
294
294
1102
1102
1102
1102
Flush
Volume
(gal.) '.
900 '•,
900 ,'
900 '
900 :
900
900 :.
900
900
900
900
900
900
600
600
600
600
600
600
600
600
600
600
600
600
300
300
300
300
300
300 "
300 -
,300 '
300
300
300
300
900
900
900
900 : ;
900 '
900
900 •
900 ;
300 t
300 '
300 •
300
123
-------
Table 9- SUMMARY OF :MAXIMUM FLUSH "WAVE DEPTHS
'OBSERVED IN 12-INCH SEWER (10 of 12)
Obser-
vation ;
No.
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
Maximum
Flush
Wave
Depth
-WD-
(in. )
4.8
5.0
4.8
4.8
5.8
5.5
5.4
5.8
5.3
5.0
5.0
5-'l
6.1
6.0
6.3
6.3
4.0
4.0
3'. 5
3'. 0
5.5
5. 5
5.5
5.5
5.0
-5.3
5.1
5.3
4-. 1
4.5
4.5
4.8
2,8
'2.9
3.0
3. 1
4.8
4.6 :
4.8
4.8
4.8
5.0
4.8
4.8
4.3
4.5
4.0
4.8
Distance
Down-
stream
of Flush
Release
(ft)
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
Pipe
Slope
-So-
. 002
.002
: 002 .
.002
. 002
. 002
.002
.002 .
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
. 002
.002
. 002
.002
.002
.002
.002
. 002
.002
. 002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
.002
.002
Sewage
Base
Flow
-QB- ',
(gpm)
10
10
'10
10
10
10
•10
10
10
^10
10
10
30
30
30
30
•30
30
30
30
10
-10
10
10
30
30
30
30
30
30
30
30
10
10
10
10
• 20
20
20
20
20
20
20
20
20
20
20
20
Flush
Rate
-QF-
(gpm)
1078
1078
1078
1078
2058
2058
2058
2058
245
245
245
245
1176
1176
1176
1176
698
698
698
698
1127
1127
1127
1127
1065
1065
1065
1065
• 238
238
238
238
226
226
226
226
1543
' 1543
1543
1543
1065
1065
1065
1065
257
257
257
257
Flush '
Volume
-v
(gal. )
600
600
60b
600
900
900
900
900
900
900
900
900
9'00
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
600
600
600
600
600
600
600
600
600
600
600
600
124
-------
Table 9 SUMMARY OF MAXIMUM FLUSH 'WAVE DEPTHS
OBSERVED IN 12-INCH SEWER (11 of 12)
Obser-
vation
No.
.481
48.2
483
484
485
486
487
488
489
490
491
492
493
494
495
496
49?
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
Maximum
Flush
Wave
Depth
-WD-
(in.)
4.0
4.0
4.3
4.3
3.8
3.5
3.5
4.0
6.0
6.5
7.0
6.8
4.3
4.3
4.3
4.0
5.8
. 5.8
5.5
5.8
3.8
3.8
3.8
3.5 ' -v
6.3
• 6.3
6.5
6.0
4.0
3.8
3.8
3.5
5.5
5. 5
5.5
5.3
5.0
5. 5
5.3
5.3
5.5
5.3
5.8
. 5.5
4.5
4. 5
4.5
4.3
Distance
Down-
stream
of Flush
Release
(ft)
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680 ,
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614
680
732
770
614 .
680
732
770
614
680
732
770
Pipe
Slope
-So-
.002
.002
.002
.002
.002
.002
.002
.002
.004
. 004
.004
.004
. 004
.004
.004
. 004
.004
.004
. 004
.004
.004
.004
.004
.004
.004
.004
.004
. 004
.004
.004
.004
.004
. 004
.004 .
- .004
.004
.004
. 004
. 004
.004
.004
.004
.004
.004
.004
.004
.004
.004
Sewage
Base
Flow
-V
(gpm)
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
30
10
10
10
10
10
10
10
10
10
10
10
10
•10
10
10
10
30
30
30
30
30
30
30
30
Flush
Rate
-•QF-
(gpm)
1617
1617
1617
1617
1347
1347
1347
1347
1911
1911
1911
1911
1568
1568
1568
1568
294
294
294
294
196
196
196
196
1862
1862
1862
1862
' 1225
1225
1225
1225
245
245
245
245
980
980
980
980
• 882
882
882
882
1519
1519
1519
1519
Flush
Volume
-v
(gal.)
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
125
-------
Table 9 SUMMARY OF MAXIMUM FLUSH,,WAVE DEPTHS
OBSERVED IN 12-INCH SEWER (12 of 12)
Obser-
vation
No.
;.'529
530
531 '
, 532
1 533
534
535
536
537
538
539
540
541;
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
• 557
558
559
560
561
562
563
564
565
566
567
568
569
570
' 571
572,
573
. 574'
575
576
Maximum
Flush .
•Wave '
Depth
-W -
D
(in.)
4.0
4.0
4.0
3.8'
. 6.5
5.8
6.5
6.0
4.0
4.0
'4.5
~ 4.3
4.8
. 4.5
5.8
4.8
3.8
_ 3.5
3.5
3.3
6.5
6.3
6.3
6.3
4.3
4. 0
5.0
4.8
M.
3.3
3.8 •
3.8 .
5.0 .
. 4.8 "
5.8
5.3 •
4.0
4.3 .
4.3
4.0
' 5.5
6.5
. 6.5.
6.5
4.3 .
4.3
4.3
4.0
Distance
Down-
stream
of Flush
Release
(ft)
614
680
732
770
- 614
680
732
770
.- 614
680
732
770
614
680
732
770
614
680
732
770
; 614
680
732
770
614
680
' 732
. 770
614
680
732
, 770
614
680
732
770
614
680
732
770
. 614
680
732
770
.. 614
• 680
732 .
770
Pipe
Slope
-So-
.004
.004
.004
.004
. 006
.006
.006
. 006
.006
. 006
.006.
.006
.006
. .006
.006
.006
.006
.006
.006
.006
.006
.006
. .006
. 006
.006
. 006
.006
.006
. .006
.006
.006
.006
.006'
.006
.006
.006
.006
.006
. 006
.006
.006
.006
. .006
. .006
. 006
: .006
; .006
f .006
Sewage
-Base
' Flow
-QT>-
B
(gpm)
• 10.
10
10 "
10
10 ,
• 10
10
10
10
10
10
".- -i o
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
30
30 .
30 ,
30
30
30
' 30
30
. 30
30
30
30
10
10
10
10
10
10 ,
10 ,
10
Flush
Rate
-QT--
F
(gpm)
2268
. 2268
2268
2268
I960
1960
1960
; 1960
1470
1470
1470
1470
294
' 294
294
294
' 220
220
220
220
1911
1911
1911
1911
1176
. 1176
1176
1176
196
196 .
196
196
245
245
245
245
1323
1323 •
1323
1323 .
1764
1764 "",
1764
1764
1323
'1323
1323 -
1323 _
Flush..
Volume
,
-v_-
F
(gal. )
300
. 300
; 300
300
900
900
900
900
300
300
300
300
. 900
: 900
900
900
300
300
300
; 300
900 _
900
900
900
300
300
300
300
300
300
300
300
•900
900
900
900
300
300
300
300
900 ,.
900
900 .
900
300
300
. 300 •-
300
126
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (1 of 12)
Obser-
vation
' No.
1 ;
2 '•
3
4 '
5 ''
6
7
8
9 '
10 • -
11
12 '
13 :
14 •• '*
15
16
17
18 •
19
20 '
21
22
23
24
25
26
27
28
29
30
31
32
33
34 '- -
35 '
36
37
38
39
40
41
42
43
44
45 •'
46 '
47 -
48
Maximum
Flush
-Wave
Depth
;WD-
(in.)
13.0
11.5
10.0
; 8.5
'l3.0
12.5
8.0
10. 0
6.8
6.8
5.5
5.5
6.0
6.5
5.8
5.6
12.0
11.0
9.5
6.8
15.5
11.5'
9.0
7.0 .
, 5.8
5.1 •
4.3
3.8
7.5
6.3
5.5
- 3.8
8. 3
7.5
5.1
'4.0
13.0'
12.0'
•12.0
11.0
12.0
13.0
13.0
40.0
'- 7.5
55.8
5.5
4.5
Distance
Down-
stream
of Flush
Release
(ft)
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
• 164
218
290
92
164
218 '
290
92
' 164 '
218 ;
290
92
• 164 '
218 :
290
92
164
. 218
290 :
92
164
218
290
Pipe
Slope
-So- •
.001
.001
.001
.001
.001
. 001
.001
. 001
.001
. 001
. 001
.001
.001
. 001
.001
;. 001
.001
.001
.001
.001
.001
'.001
.001
.001
% 001
.001
-.001
.001
.001
.001
: 001
.001
.001
.001
.001
. 001
'. 001
.001
.001
.001
.001
.001
.001
. 001
.001
..001
\ 001
.001 •
Sewage
Base
Flow
-v
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
50
50
50
50
Flush
Rate
-v
(gpm)
2131
2131
2131
2131
3381
3381
3381
3381
420
420
420
420
367
367
367
367
1470
1470
1470
1470
2021
2021
2021
2021
343
343
343
343
790
790 .
790
790
1212
1212
1212
1212
2572
2572 '
• 2572
2572
1960
I960
I960
I960
1 624
624
624
624
Flush
Volume
-v
(gal. )
• 900 '
900
• 900
900
900
900
900
900
900
900
900
900
600
600
600
600
600
600
600
600
600
600
600
: 600
300
300
300
300
300
300
300
300
. 300
300
; 300
300
900
900
900
900
900
. 900
900
900
300
300
300
300
127
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED ,IN 18 -INCH SEVERS-j[2" of 12)
1 Obser-
vation
No.
"49
50
51
52
53
54
'55
56
57
58
59
60
6i ;
62
63
64
65
66
67
68
69
70
71
,72
73
74
75
.76
77
'78
79
80
,81
82
83
84
85
86
,87
88
89
90
91
92
93
94
95
96
Maximum
Flush
Wave
Depth
-WD- -
(in. ) ^
5. 3
5.0
4. 0
, 4.3
8.5
8.5 !
7. 1
' ,7.0
6.8
6. 6 :
. 5.6
5.6 ;
6.3 ,
6.0
5.0
4.8
,5.1
4.5 •
3. 5 ,
,2.8 '
18.0
.14.0
12.0
10.0
15. 0 .
11.0 ;
8.5 ,
6-. 5
11.0
"7:i
, 5.9
4. 1
13.0 ."
10. 0
7.3 ,
'. 5. 8 -
1.4. 0 '
14. 0 .
LI . 0 .
. 8. 8 >f
. 8. 9 •
8.4
7. 0 :
,6.5 '
12.0
7. 5
7.3
,7.0 ;
Distance
Down-
stream
of Flush
Release •
(ft)
92
164
218
290
92
164 •
218
,290
92
164 •
218
290
92
164
218
290
92
, 164
218
290
, 92
164
218 -
290
92
164
' 218
"290
92 •
164
218
290
S92 '•
164
218
'290
. 92
164
218
290
92
164
218
290
92
164
218
290
Pipe .•
Slope
-So-
.001 :
. .001
. 001
.001 ,
.001
. 001
,.001 '
.001 :
. ^001
. 001 .
.001 .
.001
.001
,.,001
•001
.001
. 001 ,
.001
.001
.001
'.001 "
. 001
.001
.001
.001
.001
,001
.001 '
.001
.001
.001
. 001
.001 •
. 001
.001
.001
. 001
:.001 '
.001
. 001
.001
. .001
.001
..001
.001
.001 '
. 001 ;
".001
Sewage
Base
Flow .
-QB- -
(gpm) •
50
50
50
50
50
50
50
50
50
50
50
' 50
10
10
10
. 10
10
,io
10
10
50
50
50
50
10
10
10
10
id
10 '•
10
10
'50
50
50
50
50
.50
50
50
50
50
.50
50
10
10
10
10
Flush '
Kate
:V :
(gpm)
269
269
269
269
.759
759 '
759
759
441
441 .
,441
441 ,
385
385
385
385
330
330
330
330
3,234
3234
3234
3234
2499
2499
2499
2499
1323
1323
1323
1323
1506
, 1506
1506
1506 '
1947
•1947
1947
1947 .
1029
1029
1029
1029
. 1764
1764
1764
1764
Flush
Volume ?
^
r
-v ;
(gal.) ;
-300
,.300
i 300
.300 '
',9,00 '
900 ;
900
900
9,00
900
900
900 f
600 ;
600 '.
600
600 ;
300 ;
300 :
300 ,
300 -
900
900
900
900 ;
600
600 i
600
600 -
300 ;
300
.300
,300 I
300
300
300
300 ''
900 !
900,
•900
900 :
600 ;*
.600
600
.600
300
300
3_QO
300
128
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (3 of 12)
Obser-
vation
No.
97
98
99
100
101 .
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119 '
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
.144
Maximum
Flush
Wave
Depth
-WD-
(m.) ,
12.0
9.0
6.0
4.5
7.0
7.0
5.3
5.3
11.0
8.5
8.3
8.5
8.5
6.5
5.3
4.5
6.8
6.0
5.8
5.8
5.3
4.5
4.3 .
3.8
13.0
13.0
13.0
9.0
9.5
8.5
8.0
6.0
6.5
6.0
5.5
5.5
8.0
6.5
6.5
6.3 .
7.0
1 7.0
6.5
6.3
7.5
7.0
6.0
4.8
Distance
Down-
stream
of Flush
Release
(ft)
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
*92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
Pipe
Slope
-So-
.001
.001
.001
.001
. 001
. 001
.001
.001
. 002
.002
.002
. 002
.002
.002
.002
.002
.002
. 002
. 002
.002
. 002
.002
.002
.002
.002
. 002
. 002
.002
.002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
. 002
Sewage
Base
Flow
-QB-
(gPm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
10
10
10
10
10
10
10
10
Flush
Rate
-v
(gP"1)
1690
1690
1690
1690
710
710
710
710
2940
2940
2940
2940
1323
1323
1323
1323
441
441
441
441
343
343
343
343
2989
2989
2989
2989
•1127
1127
1127
1127
441
441
441
441
882
882
882
882
980
980
980
980
. 931
931
931
931
Flush
Volume
-v
(gal. )
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
129
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (4 of 12)
Obser-
vation
. No.
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
Maximum
Flush
Wave
Depth
-WD-
(ln.)
. 7. 5
6.5
6.0
4. 5
18,0
16.0
10.5
11. 0
13.0
5.3
6.3
5.5
6.0
5. 5
5. 8
6.0
7.5
6.0
5. 3
4.5
13.0
7. 0
11.0
6.0
7. 5
6.0
6.0
5. 0
4. 5
. 4. 5
4.3
4.3
6.5
4.3
4.3 ,
4. 5
7.3
6.0
5.5
5.0
8.8
8.0
9.0
7.5
10. 5
7.5
6.5
4.5
Distance
Down-
stream
• of Flush
Release
(ft)
92
164
218
290
92
164 .
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164 '
218
290
92
164
218
290
92
164
218
290
92
164
218
290
92
164
218
290
Pipe
Slope
-So-
.002
. 002
.002
. 002
.004
.004
. 004
.004
. 004
.004
. 004
.004
.004
. 004
.004
.004
.004
.004
, . 004
.004
. 004
.004
.004
. 004
.004
.004
. 004
. 004
.004
. 004
.004
.004
. 004
.004
.004
.004
. 004
. 004
.004
. 004
. 004
.004
.004
.004
-. 004
, 004
. 004
.004
Sewage
Base
Flow
-QB-
(gpm)
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50
50
Flush
Rate
-QF-
(gpm)
931
931
931
931
2989
2989
2989
2989
1911
1911
1911
1911
490
490
490
490
98
98
98
98
2450
2450
2450
2450
1470
1470
1470
1470
343
343
343
343
196
196
196
196
784
. 784
784
784
1176
1176
1176
1176
1617
1617
1617
1617
Flush
Volume
-VF-
(gal. )
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
130
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN'18-INCH SEWER (5 of 12)
Obser-
vation
No.
193
194
195
196
197
198
199
200
201
202
203
204
205
206 '
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
Maximum
Flush
Wave
Depth
-WD-
(in. } '
7.0
4.8
4.5
4.8
8.5
5.3
5.8
5.0
5.0
' 4.8
4.5
4.4
5.6
3. 5
5.5
5.0
5.3
3.8
4.0
3.8
5.5
4.0
3.8
3.5
3.5
3.0
3. 0
2.8
3. 5
3.0
2.5
2.8
3.0
3.0
3.3
2.6
8.8
7.5 '
7.3
7. 0
7.6
5. 5
6.0
5.5
4. 0
3.0
3. 5
3.5
Distance
Down-
stream
of Flush
Release
(ft)
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
Pipe
Slope
-So-
.001
. 001
.001
.001
.001
.001
.001
.001
. 001
.001
.001
. 001
.001
. 001
. 001
.001
.001
. 001 ,
-.001 •
.001
.001
.001
. 001
.001
.001
.001
.001
.001
. 001
.001
.001
.001
.001
. 001
.001
.001
.001
.001
.001
.001
. 001
.001
.001
. 001
.001
. 001
.001
.001
Sewage
Base
Flow
-v
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
50.
50
50'
50
Flush
Rate
-v
(gpm)
2131
2131
2131
2131
3381
3381
3381
3381
420
420
420
420
367
367
367
367
1470
1470
1470
1470 '
2021
2021
2021
2021
343
343
343
343
790
790
790
790
1212
1212
1212
1212
2572
2572
' 2572
2572
1960
I960
I960
I960
624
624
624
•624 '
Flush
Volume
~VF~
(gal. )
900
900
900
900
900
900
900
900
900
900
900
900
600
600
600
600
600 .
600
600
600
600
600
600
600
300
300
300
300
300
300
300
300
.300
300
300
300
900
900
900
900
900
900
900
900
300
300
300
300
131
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (6 of 12)
Obser-
vation
No.
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
374
275
276
277
278
279
280
281
282
283
284
285
286
287
•288
Maximum
Flush
Wave
Depth
-WD-
(in. )
"3.8
3.5
3.5
3.5
6.3
5.5
5.8
5.4
5.3
5.5
5. 1
5.0
4.0
4.0
3.8
3.4
2.5
2.8
2.5
2.3
7.5
6.0
6.0
5.6
5.0
4.3'
4.0
3.6
3.3
3.3
3. 1
2.3
5.0
4.5
4.0
3.3
7.0
6.0
5.8
5.4
5.5
4.9
4.8
4.3
5.0
2.8
4.3
3.5
Distance
Down-
stream
of Flush
Release
(ft)
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
Pipe
Slope
-So-
.001
. 001
.001
.001
.001
.001
.001
.001
.001
.001
.001
. 001
.001
.001
.001
.001
.001
.001
. 001
.001
.001
.001
.001
.001
. 001
.001
.001
.001
.001
.001
.001
.001
. 001
.001
. 001
.001
.001
.001
.001
.001
.001
.001
.001
.001
. 001
.001
.001
. 001
Sewage
Base
Flow
-
-------
Table 10 SUMMARY OF MAXIMUM FLUSH "WAVE DEPTHS
OBSERVED' IN 18-INCH SEWERS (7 of 12)
6bser-
vati'on
No.
'I
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
3(27
328
329
330
331
332
333
334
335
336'
Maximum
Flush
Wave
Depth
-WD-
. (in-)
3.5
3.0
3.3
2.8
3.5
2.5
2.5
2.5
7.3
5.0
5. 0
5.3
3. 5
3.3
3.3
3.0
5.8
5.0
5.0
"5.0
3. 5
3.0
2.0
3.3
7.3
4.8
4.0
5.0
5.5
4.8
4.3
4.5
5.3
4.8
4.8
'4.5
5. 5
4.8
4.3
4.5
5.3
4.0
3., 8
4.3
3. 5
3.5
3.0
3.3
Distance
Down-
stream
of Flush
Release
. (ft) ,
361
432
490
548
361
432
49.0
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
54'8
361
' 432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
Pipe
Slope
-So-
.001
..'001
. 001
.001
.001
. 001
.001
. 001
.002
.002
.002
.'002
.002
.002
.002
..002
.002
. 002
. 002
.002
. 002
.002
.002
. 002
.002
. 002
.002
.002
.,002
. 002
.002
. 002
.002
'. 002
.002
. 002
. 002
.002
. 002
.002
.002
.002
.002
. 002
. 0'02
.002
.002
.002
Sewage
Base
Flow :
-v
(gpm)
10
10
10
10
10
10
1.0
10
10
10
10
10
10
10
10
10
10
10
10
10
10,
10
io
10
50
50
50
50
50
50
50
50
50
50
50
50
50
5Q
50
50'
10,
10
10
10
10
10
10
10
Flush
Rate
-'V
(gpm) .
t
1690
1690
1690
1690
710
710
710
710
2940
2940
2940
2940
1323
1323
1323
1323
441
,441
441
441
343
,343
343
343
2989
2989
2989
2989
1127
1127
1127
1127
441
441
441
441
882
• 882
882
882
980
980
980
980
931
931
931
931
Flush
Volume
-v
. (gal. )
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900,
900
90Q
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300,
300
133
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (8 of 12)
Obser-
vation
No.
337
338
339
. 340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
Maximum
Flush
Wave
Depth
-wD-
(in.)
4.0
3.5
2.5
3.8
9.0
7.0
7.0
6.5
4.5
3.8
3.5
4.0
5.3
5.3
5.0
6.0
4.3
2.5
3. 5
3.8
5.5
5.3
5.8
6.0
4.3
3.5
2.5
3.8
3. 5
2.8
3.3
3.3
4.5
4.0
4.3
4.8
4.3
3.8
3.3
2.5
7.0
4.5
6.5
5.5
4.8
4.0
2.5
4.0
Distance
Down-
stream
of Flush
Release
(ft)
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
361
432
, 490
548,
361
432
490
548
361
432
490
548
361
' 432
490
548
361
432
490
548
361
432
490
548
361
432
490
548
Pipe
Slope
-So-
. 002
.002
.002
.002
. 004
.004
.004
.004
.004
. 004
.004
.004
.004
.004
. 004
.004
.004
.004
.004
.004
. 004
.004
.004
.004
.004
. 004
.004
. 004
.004
.004
. 004
.004
.004 .
. 004
.004
. 004
.004
.004
.004
.004
.004
. 004
.004
.004
. 004
.004
. 004
.004
Sewage
Base
Flow
-QB-
(gpm)
50
50
50
50
50
50
50
50 •
50
50
50
50
50
50
50
50
50
50
50
50
10
10
10
10 >
10
10
10
10
10
10
10
10 "
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50 •
50
Flush
Rate
-V
(gpm)
• 931
931
931
931
2989
2989
2989
2989
1911
1911
19H
1911
490
490
490
490
98
98
98
98
2450
2450
2450
2450
1470
1470
1470
1470
343
343
343
343
196
196
196
196
784
• 784
784
784
1176
1176
" 1176
1176
1617
1617
1617
1617
Flush
Volume
,-VF-
(gal. )
300
300
300
300
900 -
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
, 900
900
300
300
300
300
300
300
300
300
990
900
900,
900
300
300
300
' 300 .
900
900
900
900
300
300
'300
: 300
134
-------
Table 10 StTMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (9 of 12)
Obser-
vation
No.
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404,
405
406
407
408
409
410
411
412
.413
414
415
416
417
418
419,
420
421
422
423
424
425..
426
427
428
429
430
.431
432
Maximum
Flush
Wave
Depth
-wD-
(in. )
4.3
4.0
3.8
3.8
4.8
4.5
4.3
3.8
4. 1
4. 0
3.9
3.8
4.8
4.8
• 4.5
3.9
3.5
3.4
3.3
3.3
3.4
3.3
3.0
3.0
2. 8
2. 5
2.5
2. 5
2.5
2.3
2.0
2.5
2.3
2.3
2.0
2.3
5.8
6.0
5.3
4.3
4.8
4.6
4.4
4.0
, 3. 1
3.0
3.0
3.0
Distance
Down-
stream
of Flush
Release
(ft)
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
' 691
744
780
614
691
744
780
614
. 691
744
780
614 "
691
744
780
Pipe
Slope
-So-
.001
. 001
. 001
.001
.001
.001
.001
.001
.001
.001
.001
.001
.001
.,001
. 001
.001
. 001
.001
.001
. 001
.001
.001
. 001
.001
.001
.001
. 001
.001
.001
.001
.001
.001
.001
.001
.001
.001
.001
.001
.001
. 001
. 001
. 001
. 001
.001
.001
. 001
.001
.001
Sewage
Base
Flow
-v
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
-10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
30
30
30
30
30
30
30
30
50
50
50
50
Flush
Rate
-QF-
(gpm)
2131
2131
2131
2131
3381
3381
3381
3381
420
420
420
420
367
367
367
367
1470
1470
1470
1470
2021
2021
2021
2021
343
343
343
343
790
790
790
790
1212
1212
1212
1212
2572
• 2572
2572
2572
1960
1960
I960
I960
624
624
624
624
Flush
Volume
-v
(gal. )
900
900
900
900
900
900
900
900
900
900
900
900
600
600
600
600
600
600 -
600
600
600
600
600 .
600
300
300
300
300
300
300
300
300
300
300
300
300
900
900
900
900
900
900
900
900
300
300
300
300
135
-------
Table LO SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
• OBSERVED IN 18-INCH SEWERS (10 of 12)
Ob'ser-
•vation
No.
433
434
435
436
437
438
439
440
441
442
443
444
445 -
446
447
448
449
450
451
45Z
453
454
455
456
457
458
459
460
461
462
463 '
464
465
466
46,7
468
• 469
470
47,1
472
473
474
475
476
477
478
479
480
Maximum
Flush
' Wave
Depth
-WD-
(in. )
3.3
3. 1
3.3
3.1
4.8
4. 5
4.3
4.0
4.5
1 4.5
4.5
• 4. 0
3.0
3.0
3.0
3.0
2.0
2.0
2."0
2.0
5.0
4.8
4.5
4.4
3." 3
3.3
3.0
3.3
2.'3
2.3
2.3
• 2.;5
3.3
2.4
2.".4
3.3
4.' 8
4.8
4.4
4.0
4.-.0
4.0
3:3
3. .5
3.0
2.0
2.0
2., 8
Distance
Down-
stream
of Flush
Release
(ft)
614
6?1
744
780
614
691
744
780
614
691
744
780
614
691 -
744 •
1 780
' 614
691
744 -•
780 '
614
691
744
780
614
691
744
780
614
691
744
780
614
691 '
744 '
780
614
691^
744
780
614
691
744
780
614 '
691
744
780
Pipe
Slope
- -So-
.001
. 001 '
.001
.doi
.001
.001
.001
. 001 -
.001
. 001
.001
.001
.001
. 001
.doi
. 001
.001
.001
.001
. 001
.001
. 001
. 001
.001
.001
. 001
.001
. 001
.001
.001
. 001
. 001
. 001
.001
. 001
.001
.001 '
.001
.001
. 001
.001
. 001
.001
.001
. 001
. 001
.001
. 001
Sewage
. Base
Flow •
-QB-
(gpm)
50
50
50
50
50
50
50
50
50
50
50
50
10
1-0
10
10
10
10
10
10
5.0
50
50
50
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50
50
50
50
50
50
10
10
10
10
- Flush
Rate
-QF-
(gpm)
269
269
269
269
759 '
759
759
759
441 -
441
441
441
385
385
385
385
330
330
330
330
3234
3234
3234
3234
2499
2499
2499
2499
1323
1323
1323
1323
1506
1506
1506
15.06
1947
1947
1947
1947
1029
1029
1029
1029
17,64
1764 -
1764
1764
.Fhish
Volume
-v
(gal. )
- 300
300
300
300
900
900
900
900
900
900
900
900
600
600
600
600
300
300
' 30*0
300
900
900
9QO
900
60*0
600
6QO
600
300
300
300
300
300
300
300
300
900
900
900
900
600
600
600
60*0
300
300
300
300
136
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (11 of 12)
Obser-
vation
No. '
481
482 •
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
Maximum
Flush
Wave
Depth
-W -
D
(in.)
2.8
2.8
2.5
2.5
2.5
2.5
2.3
2.3
4.8
4.8
4.5
4.5
3.0
2.8
2.8
2.8
4.5
4.5
4.3
3.8
2.8
2.8
3.0
2.8
4.8
4.5
4. 5
4.0
3.8
4.3
4.3
3.8
4.3
4.3
4.3
3.8
4.3
4.0
4.0
4.0
3.8
3.8
3.8
3.8
3.0
2.8
2.8
3.0
Distance
Down-
stream
of Flush
Release
(ft)
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744 '
780
Pipe
Slope
-So-
.001
.001
.001
.001
.001
.001
.001
.001
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
. 002
. 002
.002
.002
.002
.002
.002
. 002
.002
.002
.002
.002
. 002
.002
. 002
.002
.002
.002
.002
.002
.002
.002
.002
Sewage
Base
Flow
-Q»-
B
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
10
• 10
10
10
10
10
10
10
Flush
Rate
-&•*-
F
(gpm)
1690
1690
1690
1690
710
710
710
710
2940
2940
2940
2940
1323
1323
1323
1323
441
441
441
441
343
343
343
343
2989
2989
2989
2989
1127
1127
1127
1127
441
441
441
441
882
- 882
882
882
980
980
980
980
931
931
931
931
Flush
Volume
-V -
F
(gal. )
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
600
600
600
600
600
600
600
600
300
300
300
300
137
-------
Table 10 SUMMARY OF MAXIMUM FLUSH WAVE DEPTHS
OBSERVED IN 18-INCH SEWERS (12 of 12)
Obser-
vation
No.
529
530
531
532
533
534
535
536
537
538
, 539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562 .
563
564
565
566
567
568
569
570
571
572
573
574
575
576
Maximum
Flush
Wave
Depth
-WD-
(in.)
3/8
3.0
3.3
' 3.0
5.5
5.5 •
5. 5
5. 5
3.5
3.5
3.5
3.3 .
5.0
4.8
5.0
4.8
3. 5
3.5
3.5
3.3
4.8
4.8
4.8
4.5
3.3
3.5
3.5
3.3
3.0
2^8 '
2.8
2.8
4. 5
4.0
4.3
4.0
3.3
3.3
3.3
3.3
5.5
• 4.8
5.0
4> 5
3.8
3.8
3.5
3.5
Distance
Down-
stream
of Flush
Release
(ft)
614 •
691
744.
780
'614
691
744
.780
'614
691
. 744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
614
691
744
780
Pipe
Slope
-So-
. 002
.002
.002
.002
.004
,. 004
.004 .
.004
. 004
.004
.004
.004
.004
. 004
.004
.004
.004
• .004
'. 004
.004
.004
.004
.004
.004
. 004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
. 004
.004
.004
.004
. 004
.004
. 004
.004
. 004
. 004
Sewage
Base
Flow
-QB-
(gpm)
50
50
50
50
50
50
50
50
50
50
50.
50
50
50
50
50
50
50
50
50
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
• 50
50
50
50
50
50
50
50
Flush
Rate
-QF-
(gpm)
931
931
931
931
2989
2989
2989
2989
1911
1911
1911
1911
490
490
490
490
98
98
98
98
2450
2450
2450
2450
1470
1470
1470
1470-
343
343
343
343
196
196
196
196
784
• 784
784
784
1176
1176
1176
1176
1617
1617
1617
1617
Flush
Volume
-v
(gal. )
300
300
• 300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
900
900
900
900
300
300
300
300
300
300
300
300
900
900
900
900
300
300
300
• 300
900
900
900
900
300
' ' 300
300
300
138
-------
Table 11 SUMMARY OF STEEP-SLOPE EQUATION VERIFICATION
Pipe
Diam-
eter
-D-
(i«.)
12
12
12
12
12
12'
12
12
12
12
12
12
12
12
12
12
Pipe
Slope
-So-
.008
.008
.008
.008
. 008
.008
.008
.008
.008
.008
.008
. 008
.008
.008
.008
.008
Flush
Rate
~QF~
(gpm)
' 1421
1421
1421
1421
1715
1715
1715
1715
1813
1813
1813
1813
1372
1372
1372
1372
Flush
Volume
-VF-
(gal. )
300
300
300
300
900
900
900
900 -
900
900
900
900
300
300
300
300
Pipe
Length
-L-
(ft)
267
514
622
782
267
514
, 622
782
267
514
622
782
267
514
622
782
Sewage
Base
Flow
-Q-
(gpm)
10
10
10
10
10
10
10
. 10
30
30
30
30
30
30
30 ..
30
SS Clean Effluent
-C~ - (%)
©
Observed
Value
94. 1
87.2
87.5
73.5
98. 0
98.5 "
93.5
91.8
98.0
90.9
80.0
76.4
86.3
68.3
67.0
63.9
(D
Estimated
Value
97.4
86.2
82.9
76.3
100. 0
100.0
98.3
94/4
100.0
90. 0.
86.7
82.8
82.9
71.7
68.4
64. 5
VSS Clean Effluent
-C - (%)
©
Observed
Value
93.9
88.8
80.0
71.4
97.1
93.4
89.3
86.3
94. 1
89. 1
86.5
82.2
84.9
74.0
70.5
66.2
CD
Estimated
Value
97.5
87.6
84.7
76.2
100.0
100.0
100.0
96. 5
100.0
90.9
88.0
84.6
84.7
74.8
71.9
68.4
TOC Clean Effluent
-C" - (%)
ETOC
©
Observed
Value
71.3
72.3
47.0
46. 7
53.9
54.2
32. 1
39.6
79.7
53.3
54.8
55.0
65. 5
62.2
58.0
56.0
@
Estimated
Value
68.8
64.1
62.7 '
61.1
75.2
70.5
69.1
67.5
70.4
65.7
64.3
62.7
62.7
58.0
56.7
55.0
l/J
NOTES: @ Observed values were taken from test data, Tests 123 through 126.
(2) Estimated values were taken from Equation No. 10.
© Observed values were taken from Equation No. 11.
@ Estimated values were taken from Equation No. 12.
-------
Table 12 STEEP-SLOPE CHECK OF WAVE DEPTH EQUATION (Equation 13A)
Pipe
, Diameter
-D-
(in. )
12®
12©
12©
12©
12©
12©
12®
12©
Pipe
Slope
-So-
.008
.008
.008
.008
.008
.008
.008
.008
Flush
Rate
-
-------
Table 13 RESULTS FROM SEWAGE FLUSH CORRELATION
TESTS (1 of 2) ' •
Observation
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
Predicted ®
Clean-Water
Cleansing
Efficiency
•
-°ESS~
(%)
68.9
57.6 '
54.4
50.4
85.4
74.2 •
• 70. 9
67.0
84.2
72.9
69.7
65.7
100.0
93.4
90.1
86.2
67.6
56.4
53. 1
49.2
86.0
74.8
71.5
67.6.
85.2
74.0
70.7
66.8
100.0
94.0
•90.8 .
86.8
100.0
• 93.7
90.4
86.5
83.6
72.4
69.1
65.2
85. 6
74.4
Observed
Sewage
Flush
Cleansing
Efficiency
' -CESS"
(%) '
70.9
53.9
44.2
41, ^
79.3
79.3
73.9
• 63.5
86.3
74.7
72.6
62.'6
89.9
85.0
79.--9
70.5 •
65.7 '
56.0
i 53.4
46.2
79. t
• 68.4
65.0
54.3
86.4
.73.2
67.5
59.9
94.2
88.4
83. -1
71.4
91.9
86.5
84.0
74.3
50.7
43.6
41.9
32.9
• 68.3
61.6
Percent ®
Reduction
^ Sss
Resulting
From Sewage
Flush
-ACESS-
(* '
- 2.90
+ 6.42"
+ 18'. 75
'.+17.06
+ 7.14
- 6.87
- 4.23
+ 5.22
- 2.49
- 2.47
- 4:lfr
+ 4V72
+ 10. 10
+ 8.99
+11.32
+18'. 21 .,
• +2.81
+00.71
- 0.56
+ 6.10
"+ 7.33
+ 8. 56
+ 9.09
+ 19.67
- K4-I
+ 1.08
+ 4.53
+10.33
+ 5.80
+ 5.96
+ 8.48 -
+17j74
+ 8.10.
+ 7.68
•+ 7.08
+14\ 10
• +39:35
+39.78
+39.36
+45. 54
+20.21
+17.20
Length
of
Sewer
Flushed
-L- .
(ft)
267
514 .
622
782
267
514 •
622
782
. - 267
514
'• 622
- 782 '
" 267
514
622
- 782
267
514
' 622
782
- 2'67
514
622 .
782
267
514
622
. 782
267.
514
622
782
267 .
514
622
782
267 • .
514
622
782
267
514 ,
Flush
Rate
-QF-
(gpm)
220
220
220
220
1225
1225
1225
•1225
220
220
220
• 220
1838
1838
1838
1838
,1,94
194
194
194
1298
1298
1298
1298
245
245
245
245
1960
1960
•1960
1960
1886
1886
1886
1886
208
208
208
208
1250
1250
Flush
Volume
-v
(gals. )
300
300
300
300 .
300.
300
300
300 .
900
900
900
'900 '
900
900
900
• 900
300
300 "
300
300
300
300
300
300
900
900
900
900
900
900
900
900
900
900
900
900
900
900
900 ..
900
• 300
300
Pipe
Slope
-So-
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004 .
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.-004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
.004
Sewage
Base
F'low
-QB-
(gpm)
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
io
10
10
10
10
10
10
10
10
10
10
10
10
10
10
• 10
10
LO
10
10
10
10
10
10
10
10
10
Pipe
Diameter
-D-
(in.)
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
. 12
12
- 12
-. 12
12
12
12
12
". 12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
NOTES: (T)
Computed using Equation 10.
Computed using Equation 15.
141
-------
Table 13 RESULTS FROM SEWAGE FLUSH CORRELATION
TESTS (2 of 2)
Observation
No.
„
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
6.1
62
63
64
65
66
67
68
' 69
70
71
72
73
74
75
76
77
• 78
79
80
81
82 ,
83
> 84
Predicted®
Clean-Water
Cleansing
Efficiency
"°ESS"
(%)
71.1
67.2
47.6
45.9
32.7
28.8
61.3
49.7
46.5
42.6
62.8
51.1
47.9
44.1
82.8
71. 1
67.9
64.1
47.1
35.5
32.3
28.4
61.3
49.7
46.5
42.6
65.2 ,
53.5
50.3 i
46.5 .
86.4.... .
74.8 ,.
71.6,
67.7
64. l'.
52.4 .'»
49.2
45.4 , •'
60. 5,,
48.8..
45.6 -'
41.8 .
Observed
Sewage
- Flush
Cleansing
Efficiency
'CESS~
(%)
56.0
52.2
56.0
42.2
37.8
32.3
70.1
70.2
64.2
55.1
62.5
64.1
53.7
41.2
83.5
59.2 '
46.6 ,
30.4
33.3
32.0
24.9 :
18.5
75.3 '
75.5
65.5 •
56.2
61.8
56.7 ,
51..5
45.6.
89.7,
76.3
71.0
> 63.7
• 67. 3. .
, 63..S
61.6
58. 4 -.
76.7 .
64.9
59.6
53.2
Percent ©
Reduction
In 5ESS
Resulting
From Sewage
Flush
'^ESS-
CM
. +21.24
+22.32
-17.65
+ 8.06
-15.60
-12.15
-14.36
-41.25
-38.06
-29.34
+ 0.48
-25.44
-12.11
+ 6.58
- 0.85 . '
' +16.74
+31.37
+52.57
+29.30 .
+ 9.86
+22.91 ,
+34. 86
-22.84
-51.91
-40.86
-31.92
+ 5.21
- 5.98
- 2.39
+ 1.94 ,
- 3.82
- 2.01
+ 0.84,
+ 5.91
- 4.99
-21.76
-25.20
-28.63
-26.78
-34.09
-30.70.
-27. 27
Length
of
Sewer
Flushed
-L-
(ft) •
622
782
267
527
635
795
267
527
635
795
2.67
527
635
795
267
527
635
•795
267
• 527
635
795
267
527
635
795
267
527
635
795
267 '
527 •
635
795
267
527
635
795
267
527
635,
795 .
Flush
Rate
-v
(gpm)
1250
1250
270
270.
270
270
1127
L127
1127
1127
268
268
268
268
2132
' 2132
2132
2132
, 258
258 ,
' 258
'258
1127
1127
1127
1127
343
343
343
343
3112
3112
3112.
3112
306
306
306
'306
1029
1029
1029
1029
Flush
Volume
-v
(gals.)
300
300
300
300
300
300
300
300
300
300,
900
900
900
900
900
900
900 ,
900
300
300
300
300
300
. 300
300
300
900
900
900
900
900 -
900
900
900
900 '
900
900
900
300 *
300
300
300
Pipe
Slope
-So-
.004
.004
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
. 002'
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
.002
Sewage
Base
Flow
-v
(gpm)
10
:io
50
50
50
50 •
' 50
50
50
50
" 50
• 50
50
50
50
50
50
50
. 50
50
50
50 '
50
50
50
. 50
50
50 '
50
50
50
50
50
50
50
50
50
50
50
50
50 . '.'
_50
Pipe
Diameter
-D-
(in.)
12
12
18
18
is
18
18
18
18
18
18
•18
18
18
18
18
18
18
18
18
18
18
18
1.8
,1«
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
18
NOTES:
Computed using Equation 1.0.
Computed u;sing Equation .15.,
142
-------
Table 14 RESULTS FROM PIPE MISALJNEMENT TESTS
Tests
'
'
Pipe
Misalinement
Grade
Misalinement
Pipe
Diameter
-D-
.(in. )
12 ©T
12©
12© !
. 12 9
.18®-
18©
18©
18©
1,2©
18®
1Z©
1.2©
U©
18®
18©
18®
Pipe
Slope
-So-
.004
.004.
.004
.004
.002
.002
.002
.002
.004
.002
..004
. 004'
.004
.002
.002
.002 -
Sewage
Base
Flow
(gpm)
10
10
10
,10 "
50
50
' 50
50 ' '
10
50
10
10
10
' 50 "
50
;so •-
Flush
Volume
-v
(gals. )
900
900
300
300
900
900
300
300
900
900
900 '
900 '
300 '
900
900
300
Flush
Rate
£
1838
196
1372
208
2450
343
1127
270
1862
2254 '
1666
1666
1421
2303 •'
I960
931
Average S. S. Cleansing Efficiency, C _
(Percent) ESS
For the
First
267' of
Sewer
90.4
65.5
79.8
64.4
88.5
42.0
87.0
17.4
91.2
89.1
82.7
95.7
91.6
' 84. 1 '
'96.6
70.4
For the
First
520' of
Sewer
85.4
65.4
72.2
63. 1
82. 1
46.0 '
57.0
15.3
87.4
82,. 7. '
80. 3 "
92.4
84. 7 •'
82. 6 '•'•
87. 0" '
58.2 -
. For the
First
630' of
Sewer
82.5
64.0
69.0
60. 1
78.0
42.5
50.7
8.6
84.0
78.1
77.7
90.2
81.3
•" 77.2
79.9
52.1
For the
Full Length
of Sewer
(790')
76.8
57.0
63.7
54.4
72.8
38.5
44.5
10.9
78.1
74.5
74.2
86.2
73.9
73.6
74.6
44.9
NOTES: (I) Six 1/2-inch steel rings at approximately 130-foot'intervals; simulating-pipe misalinement.
© Three 1/2-iiich steel ring's at-approximately 260-foot intervals, simulating pipe-misalinement.
© Six 1-inch steel rings at approximately 130-foot intervals; simulating pipe misalinement
§ Three l-.inch 'steel rings at approximately 260-foot intervals, •simulating'pipe misalinement.
.' Forty-three' 1/2-inch grade misalinement at approximately 18-foot intervals. '
Forty-three' 1-inch grade misaline'merit at approximately ISrfoot intervals'^
143 • •
-------
Table 17 RESULTS FROM PROTOTYPE FLUSH STATION TESTS
Station
Type
Fabric
Storage
Bag in
Manhole
In-line
Inflatable
Dam
Function
Evaluated
Fill Cycle
Dump Cycle
Lifting
Mechanism
Continuous
Operation
Inflatability
and
Installation
Rate of
Release
Flow
.Interference
Solids
Removal
Findings
The pump was run for approximately 2 hours, at which time the bag was filled. Some
problems were experienced with clogging of the intake screen but were eliminated by
making it flatter.
The dump cycle was tested with the bag half full and completely full. The average
rate of discharge ranged from 800 gpm with the bag full to 670 gpm with the bag half
full.
The lifting mechanism was evaluated and found to function quite well. The bag was
lifted while void of water and was found to lift easily through a 20-inch opening.
The flush station was operated for 3 successive days and was found to perform very
dependably during this period. The control valve functioned very well and no major
clogging problems were experienced.
The bag was found to be easily inflated, once installed. However, the installation
was quite difficult because of the awkward design. It was noted that when the dam,
is inserted directly into the sewer.it is hard to seal around and could possibly cause
problems with upstream flooding at the sewer.
The average release rate was found to be less than that which would be desirable
(ranging from approximately 500 to 1000 gpm depending on the degree of initial
inflation) due to air entrapment and slow deflation near the end of the cycle.
There was no evidence that the deflated dam produced any significant interference.
with 'the .normal sewage flows through the sewer.
Despite the low release rate, the flush wave downstream of the dam was visually
observed and found to remove much of the visable deposited material. However,
upstream of the dam, the solids deposits were very heavy and were not significantly
reduced after release of the stored sewage.
-------
.. Table 16
RESULTS FROM SOLIDS BUILDUP TESTS
Pipe
Diam-
-D-
(in. )
12
12
12
18
18
18
Pipe
Slope
-S -
0
. 004
. 004
.004
. 002
.002
.002
Duration
of the
Flow
-V
(hrs)
42
94
188
42
94
188
Total SS Deposited
(Ibs)
In
First
267 ft
of
Pipe
1. 130
2.560
4.750
1.270
3. 220
2.330
In
First
520 ft
of
Pipe
1.534
2.975
5.470
3.350
8.130
9.490
In
First
630 ft
of
Pipe
1. 695
3.104
5.650
3.636
8.658
10. 100
In
Total
Len-gth
of
Sewer,
790 ft
1.982
•3.629
6.590
3.988
8.993
10. 56
Total VSS Deposited
(Ibs)
In
First
267 ft
of
Pipe
0. 832
1.420
2.930
0.640
1.375
0.700
In
First
520 ft
of
Pipe
1. 130
1.708
2.920
2. 210
5. 075
4. 980
In
First
630 ft
of
Pipe
1. 184
1.798
3.560
2.380
5. 517
5. 210
In
Total
Length
of
Sewer,
790 ft
1.339
2. 208
0. 250
2. 573
5.803
5. 360
Total TOC Deposited
• (Ibs)
In •
First
267 ft
of
Pipe
0. 149
0. 251
1.490
0.206
0.667
0.430
In
First
520 ft
of
Pipe
0.253
0.368
1.580
0.566
1.482
0. 770
In
First
630 ft
of
Pipe
0.325
0. 533
1.760
0.672
1.740
0.930
Tn
Tofal
Length
nf
Sewer,
790 ft
0.405
0. 853
1.760
0. 744
2.040
0.980
-------
Table 15 RESULTS FROM FLUSH WAVE SEQUENCING TESTS
Pipe
Diam-
eter
-D-
(in. )
12
12
12
12
12
18
18
18
18
18
Pipe
Slope,
-S -
0
.004
.004
. 004
.004
.004
.002
.002
. 002
.002
. 002
Sewage
Base
Flow
-QTS-
B
(gpm)
10
10
10
10
10
50
• 50
50
50
50
Average
Flush
Rate
-Qr--
F
(gpm)
230
1220
1370
150
1500
' 640
1200
1470
340
1620
Flush Volume -
-V
(gal)
Tank
No. 1
300
300
900
600
600
300
300
900
600
600
Tank
No. 2
300
300
300
300
300
300
Tank
No. 3
300
300
300
300
300
300
300
300
300
300
Values of C^.,., Observed at
Eoo
the Various Sequences ^
•CESS"
(Tl
Flush Sequence
A
57.7
65. 8 '
44.8
71.9 ',
B
59. 6
82. 2
80. 6 '
53. 5
73.4
68. 2
74.6
75. 5
41,. 8
61.6
C
62.1
66.3
60.6
76.4
Equivalent ^
Single
Flush
Volume
-V®.
F
(gal)
600
600
1200
700
700
600
600
1200
700
700
SS Cleansing
Efficiency
Predicted
from
(%)
58. 8
76. 6
87.5
63. 0
81. 0
46. 1
52. 9
64.7
41. 5
58. 2
NOTES: (I) Flush Release Sequences:
Sequence A — The flush tanks were activated separately beginning with the downstream flush tank (Tank No. 3).
Sequence B — The upstream flush ta,nk (Tank No. 1) was activated first and then Tanks No. 2 and 3 were released,
when the flush wave generated upstream reached its maximum depth at their respective positions.
Sequence C — The flush tanks were activated separately, beginning with the upstream tank (Tank No. 1), so that
each of the three flush waves generated passed separately through the entire length of the sewer.
This parameter was determined by taking the summation of the products of the total quantity of water that passed
through each of the three sections of pipe and the length of each section, and dividing by the total length of the sewer.
-------
APPENDIX D
STATISTICAL ANALYSIS OF DESIGN EQUATIONS
Table 18 SUMMARY OF STATISTICS FOR EQUATION 9
(SS CORRELATION)
Statistical
Parameter
Sum of the
Squares
Reduced
(of 228,904)
Proportion
of Variance
°£ CESS
Reduced
F (DF=
1, 538)
Correlation
Coefficient
Regression
Coefficient
Standard
Error of
Regression
Coefficient
Computed
T for
Regression
Coefficient
Standard
Error of
Estimate
CESS
Intercept
Statistics For Each of the Independent Variables
(VFxQF)°- l
51, 680
0.2258-
155. 1
0.4752 .
66.74
3.365
19. 834
,QB,-°- =
37,953
0. 1658
144.7
0.4070
5.07
0.3717
13.646
(L)-0'1
25,802
0.1127
120.5
0.3355
312. 61
25.20
12.405
«y°-5
24, 669
0. 1078
147.0 '
0.3280
57.72
4. 654
12.404
(D)1'8
2, 052
0.0090
12.5
0.0948
111.01
31.411
3.534
!
Statistics
for the
Complete
Relationship
142, 157
0.6210
173.0
0.7881
12.8178
-379. 8
147
-------
Table 19 SUMMARY OF STATISTICS FOR EQUATION 10
(SS Correlation) •
STATISTICS FOR ALL 544-OBSERVED'VALUES OF C~ESS
Proportion of Variance of C Reduced . , 0. 6414
iL«t>o , . ,
Partial F (DF = 1, 542) '. . . ,969.4868
Cumulative Sum of Squares Reduced 147691. 000
Cumulative Proportion Reduced 0. 6414 (of
230258.9000)
Multiple Correlation Coefficient 0. 8060
F For Analysis of Variable (DF = 1,542) 969.4868
Standard Error of Estimate 12. 1326
,, . , , Regression Standard _ , _
Variable r- tt- • >. TT> r- tt- • <- Computed T
Coefficient Error-Coefficient
Logro(H) 24.0116 . 77U71 31.1366
Intercept (C ) — 13.30284
STATISTICS AFTER DELETIONS -OF 12 OBSERVATIONS (532)
Proportion of Variance of C Reduced .......... 0. 6847
Partial F (DF = 1V530) ..•....•..*.".:;.,-......'. 1150. 9930
Cumulative Sum of Squares Reduced ............. 148131. 7000
Cumulative Proportion Reduced ...'.:/...,...... 0". 6847 (of
..... • ' -216342. 2000)
Multiple Correlation Coefficient ................ 0. 8275
F For Analysis of -Variable (DF = 1,530) ........ 11.3446
„ . ,, Regression Standard •
Variable & -. . • „ „ ,,. . . Computed T
Coefficient Error -Coefficient
Log1Q(H) 24.6802. .727465 • 33.9263
Intercept (C~) — 13.7134
148
-------
Table 20 SUMMARY OF. STATISTICS FOR EQUATION 11
(VSS Correlation)
,_/>'-• . ' , ; / - •
Proportion of Variance of C - Reduced 0. 5597
JiiVofc>
Partial F (DF = 1,530) 673.8613
Cumulative Sum of Squares Reduced 1089.94. 6000
Cumulative Proportion Reduced 0. 5597 (of
, . 194720.2000)
Multiple Correlation Coefficient 0.7482
F For Analysis of Variable (DF = 1,530) 673.8613 ''
Standard Error of Estimate. ...,,. 1'2. 7180
. , , Regression Standard _. , m
Variable 5... . r* tt- • <. Computed T
Coefficient Error-Coefficient ,
Log10 (H) 21.7178 .836625 25.9589
- i ., '
Intercept (C) — .344437
Table 21 SUMMARY'OF STATISTICS FOR EQUATION 12
(TOG Correlation)
Proportion of Variance of Y Reduced , . . . . 0..1645
Partial F (DF = 1, 530) ....': . r 104.3881
Cumulative Sum of Squares Reduced 25:594.4100
Cumulative Proportion Reduced ; 0. 1645 (of
155542.6000)
Multiple Correlation Coefficient 0.4056
F For Analysis of Variable (DF~= 1,530)' 104.3881
Standard Error of Estimate .........: 15.6584
,r . i , Regression Standard
Variable „ &... . L _. _ -,. . , Computed T
Coefficient • Error-Coefficient
Log10 (H) 10.2977 1.00789 , 10.2171
Intercept C" _„ — 22.3553
149
-------
Table 22 SUMMARY OF STATISTICS FOR EQUATION ISA
(Wave Depth (W,-.) Correlation for the 12-inch Sewer)
Statistical
Parameter
Sum of the
Square s
Reduced
(of 2,977)
Proportion
of Variance
WD
Reduced
F (DF =
1,574)
Correlation
Coefficient
Regression
Coefficient
Standard
Error of
Regression
Coefficient
Computed
Tfor
Regression
Coefficient
Standard
Error of
Estimate
Wl
D
Intercept
Statistics For Each of the Independent Variables
L°-5
1207.0
0.4057
391.8
0.637
-0.261
0.00968
-26.96
VF
463.0
0. 1556
203.3
0.3940
0.023
0.00158
14.57
QF
316.0
0.1064
183.2
0.3260
•0.534
0.0387
13.83
So
17.4
0. 0059
10.2
0.0768
-1.00
0.340
-2.95
QB
f
1.32
0.0004
0.75
0.020
2.36
2.717
0.868
Statistics
for the
Complete
Relationship
_
2006.8
0.6740
235.7
0.8210
1.3049
8.454
150
-------
Table 23 SUMMARY OF STATISTICS FOR EQUATION 13B
(Wave Depth (W-p) Correlation for the 18-inch Sewer)
Statistical
Parameter
Sum of the
Square
Reduced
(of 4, 007)
Proportion
of Variance
WD .
Reduced
F (DF =
1,574)
Correlation
Coefficient
Regression
Coefficient
Standard
Error of
Regression
Coefficient
Computed
T of
Regression
Coefficient
Standard
Error of
Estimate
^D •
Intercept
Statistics For Each of the Independent Variables
L°'5
1944.2
0.4852
540.9
0. 6965
-0.322
0.00994
-32.45
QF
683. 1
0. 1705
283.6
0.4130
0.408
0.0306
13.37
_YF
274.7
0.0685
142. 1
0. 1620
0. 0189
0.00170
11. 10
V
52.9
0.0132
28.7-
0. 1150
7.286
. 1.361
5.353'
S
o
0.38
0. 0001
0. 2035
0.0100
-0. 215
0.4777
-0.451
Statistics
for the
Complete
Relationship
2955.3
0.7374
320.2
0. 8587
1.3586
1
8.839
151
-------
Table 24 SUMMARY OF STATISTICS FOR EQUATION 15
(Sewage-Flush Correlation,
Statistical
Parameter
Sura of the
Square
Reduced
(of 36, 175)
Proportion
of Variance
ofASss
Reduced
'• F' (t>F =
1.82)
Correlation
Coefficient
Regression
Coefficient
Standard
Error of
Regression
Coefficient
Computed
T of
Regression
Coefficient
Standard
Error of
Estimate
A°ESS
Intercept
Statistics For Each of
the Independent Variables
VF
2693.4
0. 0745
6.60
0. 2729
-0. 140
0. 0570
-2.449
L
152.7
0. 0042
0.371
0. 0648
-0. 00710
0.0117
-0. 605
- QF
' 15. 5
0/0004 :
0. 0372
0.0200
-0.242
1. 256
-0. 193
Statistics
for the
Complete
Relationship
2721. 6
0.0791
2. 2906
0.2813
20.41
14.30
152
-------
Table 25 SUMMARY. OF STATISTICS FOR EQUATION 16
(Correlation of C„,_,,_,, to LOG, ^ H) -
, . • i • : Eoo -10
Intercept ;
Regression Coefficient ' -
Standard 'Error of 'Regression Coefficient'
Computed T-Value , ]
Correlation Coefficient
{ *
Standard Error of'Estimate
-13.6990
23.6974
1. 602
10.691
0.763
10.940
ANALYSIS OF VARIANCE FOR THE REGRESSION
Source of Variation
Attributable to Regression
Deviation from Regression
i
Total
Sum> of Mean F
D.F. Square Square Value
i 1 13677.410 13677i410 114.288
,82 9813.332 - 119:675
,83 23490.:742
153
-------
APPENDIX E
LIST OF DESIGN DRAWINGS
LIST OF DRAWINGS .FOR THE
PROTOTYPE FLUSH STATION
LAYOUTS:
E4318852
D4318853
D4318856,
E4318945
E4319113
E4319114
E4319115
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FABRIC FLUSH TANK (as built):
D4319173
C4319187
C4319186
B4319194
B4319184
D4319185
D4319181
C4319182
D4319183
C4319195
B4319292
155
-------
LIST OF DRAWINGS FOR THE
TEST FACILITY (1 of 2)
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156
-------
LIST OF DRAWINGS FOR THE
TEST FACILITY (2 of 2)
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157
-------
APPENDIX F
DESCRIPTION OF MATHEMATICAL MODEL FOR
DESIGN OF SEWER FLUSHING SYSTEMS
INTRODUCTION
Since there are a variety of flush station types available, each -with dif-
ferent solids removal characteristics and costs, an efficient method of
selecting types and locations for installation is required. The following
discussion addresses itself to this problem. The problem is to develop
a mathematical model to select the best configuration for locating the
flush stations and determine their capacities to achieve a specified
cleansing efficiency. The criterion for evaluation can'be either of the
following:
• Minimize the total cost of the station's equipment and flush water
required for operation o£ the flush stations.
• Minimize the quantity of flush water required.
An approach known as a dynamic programming technique is used to deter -
mine the optimal location and type of flushing stations. Under this ap-
proach, the analysis proceeds stepwise from the first upstream location
to the last and identifies the most cost effective installation at each
location.
The discussion which follows gives a detailed description of the develop-
ment and use of the model and the computer program. A sample problem
is also included as well as a discussion of ways that the existing model
can be extended to be used for larger, more complex problems.
DESCRIPTION OF FLUSHING STATIONS
A flushing station is designed to release a hydraulic wave of sufficient
magnitude and duration to cause deposited solids to become suspended
and be flushed down the lateral. The idea is to install'a series of these
facilities along a lateral and operate them periodically so as to reduce
the amount of solids which settle out during low flow periods.
The manner in which this wave may be generated is varied: it might be
a discharge of clean water directly into the sewer lateral or possibly a
159
-------
small check dam to contain sewage and then periodically release it. The
method of generating the flushing wave is unimportant as long as the
efficiency of removal can be quantified as a function of the relevant phy-
sical parameters.
The parameters affecting the station efficiency .are of three types:
« Flush Station Parameters; type of flushing installation, quantity of
flush water, and rate of flush discharge
a Physical Characteristics; the length, diameter, and slope of sewer
pipe and the distance between station installations
• Load Characteristics: The average rate of base sewage flow and
the quantity of solids deposited in the flow.
The Central Engineering Laboratories have performed extensive experi-
ments to determine the efficiency of a flushing station as a function of
the cited parameters. The equation as developed by the Central Engi-
neering Laboratories gives the functional relationship of average cleans-
ing efficiency (C^gg) i-n percent over the length (L) as a function of the
length from the installation (L), the volume {V]?) and rate (Qp) of the,
flush release, the slope (So), diameter (D), and the rate (Qg) of base
flow. The experiments show that the percent solids removal is indepen-
dent of the amount of solids in the base flow; of course, the amount in. .
pounds of solids removed is proportionally greater for larger solids
loads.
The average cleansing efficiency is determined using the equation of the
following general form:1 .
~B
where A, B, C, D, E, F, and G are constants determined by a regres-
sion analysis of the experimental, re suits (Equation 10).
Graphically, for constant slope and diameter and a particular flush rate
and volume, the relationship between average efficiency and distance
from point of installation for a variety of base flows is shown on the
following page.
160
-------
100
Average
Solids 50
Removed
.500
Distance, L. (ft)
1000
The above equation is expedient for performing the analysis of the ex-
periment but is difficult to work with for the model developed in this
document. For purposes of this model it is necessary to convert the
curves for average efficiency to a curve for the point efficiency at a dis-
tance u from the installation (Cg). That is, if a 60 percent efficiency
is stated for the distance of 500 ft. , the implication of average efficiency
is that over the entire length of 500 ft. , on the average, 60 percent of the
solids are removed; under the interpretation of point efficiency the im-
plication is that at the distance 500 ft. from the point of installation,
60 percent of the deposited solids are removed. The expression for
point efficiency may be derived from the average efficiency expression
by using the general relationship
y(L) = i f y(u) du,
•I-1 Jo
where y(L) is the average efficiency over L, -and y(u) is the point effi-
ciiency as a function of distance u from the origin, and differentiating
both sides. The result is, , .
E
where F and B are from the above average efficiency expression.
161
-------
There are several assumptions about tb
-------
can be made. For the purposes of the model developed here, "however,
it is assumed that the efficiency at any point follows the maximum effi-
ciency of either curve. In the above example then, the efficiency follows
the curve of station type" B from location n to n4- 1, the curve of station
type C frofm n + 1 to X and the curve of station type B again from X to
n + 2. The argument for this type of removal pattern is based on grading
the solids into an order based on ease of removal. If the least difficult
particles to remove are first on the graded list, then conceptually, the
model assumes that if some particular station type under given condi-
tions will remove 40 percent of the solids, then the upper 40 percent will
be flushed. This is equivalent to saying that the station under the condi-
tions give'n cannot remove the bottom 60 percent of the solids. Such
flushing behavior would be dependent upon the nature of the hydraulic
wave that the flushing station emits. If this is representative of the be-
havior of a flushing station then the assumed pattern of cleansing for
overlapping efficiency curves is valid. As long as the stations are opera-
ted independently (so that the wave of each is not acting simultaneously),
then together they would flush no more solids than each would have
flushed by itself.
The last assumption implicit to the computational procedure is that the
sequence of stations along a lateral are operated in harmony. That is,
that there is no interference in the flushing action of any station by any
of the others. Certainly if there is constructive interference (e. g. ,
additive effects of flushing by multiple stations operating together) the
model will give conservative cleansing efficiencies. Basically this as-
sumption stipulates that, at the least, the operation of flushing stations
will pass to successively downstream locations.
This establishes the necessary operational preliminaries to proceed to
the computational procedure for selecting and locating flushing stations
along a lateral.
THE FLUSHING STATION LOCATION MODEL
In equation form, the model employed to select the locations and station
types for flushing station installations is difficult to interpret and appre-
ciate. Hence, an intuitive approach through a more-or-less narrative,
discussion is the best way to introduce the model. A more precise pre-
sentation is found on page 188. The actual mathematical formulation
is not presented but can be found in the texts referenced.
The solution technique is referred to in the literature as dynamic program-
ming. This approach to problem solving is frequently employed in the
optimisation of sequential decision problems; that is, in problems in
163
-------
which a periodic (either over time or distance) decision must be made.
Before discussing the actual mechanics of the model, however, it is
necessary to establish a couple of points; one is fairly obvious, the
second point is more subtle and introduces an important crutch to the
actual computation.
Consider a simple lateral with defined acceptable locations for flushing
stations as indicated below. There are n possible locations for flush-
ing station installations along the lateral. In actual practice, these
locations may be manholes or otherwise convenient locations to install
a station.
• ' • • •
1 23. 4 n-2 n-1 n
Sewer
Flow Main
The first point to note is that a flushing station will have effects only
downstream of its point of installation. That is, a station installed at
say location 3, may have consequences (either through the removal or
deposition of solids) from location 3 through the last downstream reach
of the lateral, in no case will there be any effects upstream of
location 3.
The second point concerns the specification of cleansing efficiency
along the lateral. The usual approach in assuring that sufficient solids,
have been removed for acceptable system operation is to specify an
average efficiency of total solids removal for the entire lateral. For
example, if engineering analysis has indicated that along some parti-
cular lateral there would be 200 Ibs of solid material deposited in a day
and an acceptable amount-of solids remaining in the lateral were 60 Ibs,
the required efficiency would be specified at 70 percent removal. There
is no direct way in this type of problem to solve for the minimum cost
policy and still be assured of meeting the specified efficiency. To force
the average efficiency to the specified level it is necessary to introduce
an artificial or shadow savings of solids removal. To motivate the
need for this shadow savings consider the following argument. The pri-
mary criterion for evaluation of a configuration is its cost. The least
cost' sequence of flush stations is the configuration with no installation
which incurs a zero cost, but also a zero efficiency. If there is some
installation configuration, then, there has to be a savings implied by the
removal of solids. This savings implied by the removal of solids is the
total shadow savings, referenced above. As an example, suppose for
some station the installation, operation, and maintenance costs are $50
per month. It is assumed that the unit shadow savings are $1.50 per
164
-------
pound of solids removed and the amount of settled solids are . 1 lb/f.t.
Then if the point flushing efficiency over 800 ft is as graphically illus^
trated below,
100
Solids
Removed
800
Distance
the net cost, including the savings of removing solids, of such an instal-
lation is easily calculated:
Average efficiency (CESS)
Total solids removed
Total savings due to removal
Net cost of installation
(.1 lb/ft)(. 50)(800 ft) = 40 Ibs
($1.50/lb)(40 Ib) - $60
$50 - $60..= .$10
The net cost of an installation of the above type is -$10 and hence, is
preferable to no installation at this location.
A problem characteristic of this approach is the difficulty in selecting
the unit value of the shadow savings that will yield the required level of
efficiency. The only information known about the shadow savings is. that
small values imply low cleansing efficiencies while larger values.yield
high cleansing efficiencies. The relative magnitude in relation to the
installation and operating costs is not known but a little practice and a
trial-and-error approach to the solution technique should allow a fairly
rapid determination of the shadow savings implying the required level
of efficiency. The computer program uses a search technique to auto-
matically determine the shadow savings. This is done by recursively
solving the model with a new estimate of the shadow savings. The esti-
mates are generated by doubling previous estimates (starting at $. 01
per unit removed) until successive estimates bracket the desired effi-
ciency. Once bracketed, the shadow savings is more,accurately deter-
mined (and the desired efficiency more closely attained) by a search
technique known as a "golden section search. " Details of the technique
165
-------
are found in Foundations of Optimization by Wilde and Beightler. Essen-
tially the approach is to successively redefine the interval in which the
shadow savings implying the desired efficiency lies until sufficient accu-
racy is attained. More specifically, the model is evaluated at a fraction
of .618 of the interval and either the 61. 8 percent interval or the 38. 2 "
percent interval is discarded depending on which of the intervals bracket
the desired efficiency. The fraction . 618 is recursively applied to the
remaining interval. A manner in which successive estimates of
the shadow savings may be used to give useful information of
investment levels is discussed.
With these preliminaries and the assumptions about flushing station
operation established in the preceding section, sufficient groundwork
has been laid to present the computational procedure for locating flush-
ing stations along a lateral. The approach is to cost out each successive
location selecting that configuration of flushing stations which yields the
minimum cost to the location under consideration. When the last loca-
tion has been reached the sequence of costs leading to the absolute mini-
mum cost is retraced to determine the particular station type at each
location. This is the general approach, but now consider the actual pro-
cedure in more detail.
Begin at the most upstream location; in the example (page 168) this is
designated at Location 1. Suppose the installation alternatives are either
no station or one of three distinct station types. It is a fairly straight-
forward problem to calculate the net cost of any of the particular alter-
native installations at Location 1.
First determine the costs associated with the purchase installation,
maintenance, and operation of each station at Location 1, and then sub-
tract the savings generated by solids removal by applying the unit
shadow savings to the amount of solids removed. Once this is done for
the first location (including the no station alternative of zero cost) the
procedure with slight variation is carried to Location 2 and subsequent
locations. The variation in approach at Location 2 (and subsequent loca-
tions) is tq include the costs and any cleansing associated with the instal-
lation at Location 1 (and all upstream locations). Suppose the station
types are designated A, B, C, and no station is D. Computationally
then, at Location 2, beginning with Station type A, each station type is
considered and the .costs and savings associated with this station type at
Location 2 is evaluated by conditioning on each of the immediately pre-
ceding station types (A, B, C, or D at Location 1). Care must be taken
to assure that downstream effects of an installation are considered. For
each station type at 2, the minimum of the conditioned costs and the
downstream cleansing pattern are retained for subsequent calculations.
166
-------
These retained costs are the minimum costs to the current location for
each station type. These minimum costs are the only costs which need
to be considered in subsequent calculations. For example, suppose
station type B were under consideration at Location 2 and the following
conditioned costs were generated:
Station Type Cost with Type B Installation
at Location 1 at Location 2 ($)
Station type A -19. 50 .
Station type B -34. 60
Station type C not feasible
Station type D -31. 00
Then under the dynamic programming scheme it is necessary to carry
along the cost of -$34. 60 and a preceding station type of B for subsequent
calculations. This may be interpreted that if through subsequent calcula-
tions it is determined that there should be a station type of B at Location
2, then the optimal preceding station type will always be a B at Loca-
tion 1. For each of the possible station types there will be the minimum
cost and preceding station type; for example, the following list might be
obtained:
Station Type Preceding
at Location 2 Minimum Cost ($) Station Type
Station type A -41.40 B
Station type B -34. 60 A
• Station type C not feasible
Station type D -27.00. B
These costs and policies are retained for subsequent calculations.
Proceed to Location 3 for further illustration of the procedure. If any
particular station'type were considered, say type C, the most efficient
means to determine the cost to Location 3 with a type C installation, is
to evaluate the costs and savings of installing a type C station conditioned
on the cost and downstream effects of each possible station type at
Location 2. No direct consideration of installations at Location 1 is re-
quired since these are accounted for in the minimum cost and preceding
station type information carried with the station types at Location 2.
Again after the calculations for cost are completed for each station type,
the minimum cost and preceding station type are retained for purposes
of the subsequent calculations.
167
-------
The feasible station types at each location are evaluated in the above
manner beginning at the first and preceding location by location to the
last location, on the lateral. At the final location, the minimum, costs
associated with each of the station types at this location are perused to
find the absolute, minimum cost over the entire lateral. With this abso-
lute minimum cost, the problem becomes, to identify the sequence of
station types leading to this cost. This is easily accomplished by work-
ing backward from the last location to successively preceding locations.
Using the preceding station type information carried^with each station
type at each location it is fairly direct to recursively identify that station
type at the preceding location which implies the cost at the current loca-
tion. When the sequence has been defined, the computational procedure
is completed. ,
Manually this method becomes quite, tedious, but it can be efficiently
programmed for execution on a computer. At first the approach seems
little better, if at all, than direct enumeration; there are, however,
significant efficiencies. Under direct enumeration for a lateral with say
four possible station types for installation, at five potential locations, there
are 1, 024 (=4^) station configurations to calculate. Using the technique
of dynamic programming the number of calculations (usually of a much
simpler nature) is 68 [= 4 + 4 (4^)J. Although it is not as direct as might
be hoped, it is the most efficient method in the solution of this problem.
EXAMPLE
In order to illustrate the solution technique which was described rather
abstractly in the preceding section, a sample problem is presented below.
This problem has been greatly simplified to minimize the basic computa-
tional requirements. However, the problem satisfactorily demonstrates
the function and flexibility of the optimization technique used in the
mathematical model.
Problem Statement
For the purposes of this example, assume that it is desired -to select the
most economical flushing system to periodically remove 60 percent of
the solids deposited in the lateral sewer described by the following
diagram.
MH1 L B 400. MH2 I. = 800- MH3 L a 600.
Main
JU = 4UU1 lu = »UU' J_, = bUU1
CL
D = 12" D = 12" D = 12"
168
-------
Information Required
Before the problem can be solved, the engineer must supply specific
information about the sewer and the flushing equipment that is being
considered. The following discussions describes the information re-
quired and the reasons for its need.
Physical Description of Sewer. The physical characteristics and geo-
metric configuration of the sewer in question must be completely des-
cribed. ' To accomplish this, the engineer must begin by determining
the locations along the sewer where flush equipment of one type or an-
other can feasibly be installed (this would most often be at the location
of manholes.) He then must number the access locations consecutively
beginning with the number 1 at the location nearest the upstream end of
the sewer. These identification numbers can then be used to describe
the relative position of each access location and the physical character-
istics of the sewer between the successive locations.
The lateral sewer under investigation in this example would be des-
cribed in the following manner:
Sewer
Section
1-2
2-3
3 - M
Sewer
Length
-L-
(ft)
400
800
600
Average
Slope
-S0-
(%)
1. 0
1.0
1.0
Pipe
Diameter
-D-
(ft).
1.0
1.0
1.0
Hydraulic Characteristics. The engineer must also analyze, the sewer
and the area which it serves and describe the expected dry weather
hydraulics. He must either make statistical estimates or field determi-
nations to define the average solids concentration expected to pass
through each of the sections of the sewer. Also, he must determine
what is a reasonable time between successive flushings and what the
expected buildup of solids deposits would'be in each of the sections of
the. sewer during this time interval.
169
-------
In this example, the following hydraulic characteristics will be used:
Sewe.r
Section
1 - 2
2-3
3 - M
Average
Flow Rate
-QB-
(cfs)
0. 05
0.05
0.05
Solids
Deposited
-DS-
(lbs/ft/day)
0. 01
0.01
0.01
Frequency
of Flush
~FF-
(No. /Days
1.0
1.0
1.0
Flush Equipment Characteristics. The engineer must determine the
characteristics and limitations of the various types of flush devices
which are available and then decide which ones can realistically be used
in his situation. He must also analyze each of the access locations
along the sewer in question and determine which of.these devices cannot
be used due to the physical location of the access point and the limita-
tions caused by obstructions in the surrounding area.
Having accomplished the above, he must then list all of the types of
flush devices that can be used on the lateral and determine the following
physical characteristics and cost information for each:
1. Determine the purchase cost, expected life, storage volume, and
average release rate of the smallest available size of each type of
flush device to be used.
2. Estimate the total installation cost and monthly maintenance cost of
each of the flush devices at each of the locations where the specific
type can be used.
3. Determine which of the flush devices.to be investigated will use
clean water as the flush media, and which will use sewage. Also
estimate the unit cost of handling the flush media ($/ft^) that is
associated with each of the flush devices.
4. Determine the maximum size (largest storage volume) of each
device that can be used at each of the access locations.
5. Determine the variable cost of purchasing and installing at each
location, sizes of each device which are larger than -tfhe minimum
sizes available in $/ft'3 of volume in excess of the storage volume
allowed by the smallest available size of each type of flush device.
170
-------
For this example, the physical characteristics and estimated costs to
be used for the flush equipment are described as follows:
1. The general characteristics to be used for the smallest available
size of each type of flush device to be investigated, are as follows:
Station
A
B
Storage
Volume
-V min. -
(ft3)
30
30
Average
Release
Rate
-QF-
(cfs)
1.0
2.0
Purchase
Cost
-5r
500
800
Variable(b)
Purchase
Cost
-ACp-
<$/ft3)
10.0
15.0
Expected
Life
-P-
(years)
20
20
Monthly
Cost
-Cm-
($)
200
200
Cost(c)
Flush
Media
-AC0-
($/ft3)
0.001
0.001
Cost(^'
V olume
Exponent
-KR-
1.0
1.0
Notes: (a) The Type C flush station represents the alternative which must always be investigated,
that of not installing flushing equipment at any of the given locations.
(b) This is the additional cost ($/ft^) of purchasing the specific type of flush device per
cubic foot of volume in excess of the storage capacity of the smallest size unit
available.
(c) This is the average cost of handling and storing each cubic foot of the flush media as
governed by the operation characteristics of each specific type of flush device
(operation cost).
(d) This exponent allows the engineer to express "Variable Costs" as a function of in-
creased volume (volume in excess of that associated with the smallest available size
of flush device in a nonlinear fashion, Ke = 1.0 gives a linear variable cost
function).
2. The cost of installing each type flush device at each of the proposed
access locations:
Location. 1
Location 2
Location 3
Minimum(a) Variable(b) Minimum(a) VariableO3) Minimum(a)
Installation Installation Installation Installation Installation
Cost Cost Cost Cost Cost
Station -Ci- -ACi- -Cj- -ACi- -Ci-
Type ($) ($/ft3) ($) ($/ft3) ($)
A 100 1.00 150 1.50 50
B 50 0.50 100 1.00 50
C -
Variable(b)
Installation
Cost
_ACi-
($/ft3)
0.50
0.50
—
Notes; (a) This is the cost of installing the smallest available size of a given type of
flush device at the given location.
(b) This is the additional cost, per cubic foot of increased volume, of install-
ing, at each given location, flush devices with storage capacities greater
than that allowed by the smallest unit.
171
-------
3. The limits on the maximum sizes of flush devices which can be used
at the various access locations, as governed by the physical charac-
terestics of the access locations.
Station Ratio of the Maximum Allowable Storage Volume
Type to the Storage Volume of the Smallest Unit
-RV-
Location 1 Location 2 Location 3
A
B
C
2.0
3.0
—
3.0
2.0
m t
4.0
3.0
•>•
As can be seen by the simplicity of the hypothetical sewer being used
for this example, and the uniformity of the physical and hydraulic
characteristics and cost relationships selected for the sewer and
flush equipment, the computational procedures involved are much
less complicated and the number of alternatives to be investigated
are considerably less than will normally be the case when a flush
system is to be designed for an actual existing sewer. However,
this example has been simplified to this extent in order to allow the
reader to more readily understand the overall operation of the model
and the optimization technique used.
Application of Model
Once the above information has been established and supplied to the com-
puter program, the computer performs a series of computational opera-
tions which are described in detail in the following discussion.
Volume Determinations. First, the maximum allowable size (storage
volume) is determined for each type of flush station at each of the pro-
spective access locations. This is accomplished by multiplying the vol-
ume of the minimum size of each type of station (V min) by the ratio of
the maximum allowable volume to the minimum volume for each type of
flush station at each access location (Rv). For instance, the maximum
size of station Type A that can be installed at Location 1 is,
V = V . x R
max mm v
= (30ft3) x (2.0)
= 60 ft3
172
-------
Next, two intermediate storage volumes (V^) are selected for each type
of flush station at each of the locations. This is accomplished as
follows:
AV. = (V - V . )/3.0 .
i max mm
V. = V . + AV.
i , mm i
V. = V . + AV.
1 mm i
V_ = V . + 2AV. '
2 mm i
For example, the intermediate volumes for station Type A at Location 1
would be,
AV. = (60 - 30)/3 = 10 ft3
. V2 = 30 .+ 2 (10) = 50 ft
The flush station volumes that would be investigated by the model are:
Volumes at Each Location - Cubic Feet
Station
Type
A
= B-
C
Location 1
V . V. V0 V
mm 1 2 max
30 40 50 60
30 50 70 90
Location 2
V . V. V_ V
mm 1 2 max
30 50 70 90
30 40 50 60
Location 3
V . V, V_ V
mm 1 2 max
30 60 90 120
30 50 70 90
However, in order to ^minimize.the computations, only the maximum and
minimum volumes will be used in the remainder of this example.
Cost Determinations. The total monthly cost of purchasing, installing,
operating and maintaining each size (volume) of each type of station at
each access location must now be determined. This is done in the man-
ner described below. • . .
9 Purchase Cost (Pc)- The monthly purchase cost is determined by the
amortization of-the purchase price over the expected life of the equip-
ment, P, and at an annual discount rate of 6 percent.
173
-------
P .=
1
.
c 12
Kl
J-'J-
C + AC (^Volume to be used -V .
[_ p p V mm'
x (amortization factor at 6% for P years)
f
For example, the monthly purchase cost of the maximum size
(volume) of a Type A flush station to be installed at; Location1 1 is:
P - -L
c ~ 12
L$500 + ( $10 /ft3 ) \60 ft3 - 30 ft3) J
x [amortization factor (6%, 20 years)]
= Y5- [($800) x (.&08718)] ;
12
= $5. 18 per month.
The monthly purchase costs f or-this--example are as follows:
Location 1, > Location 2 Location 3
Station
Type
A
B
" '-.-Size
'"••30
*'• 60
' -' 30
--V90
'.,"' PC
• 3. 63 •
-5.18
5.81
-12. 35
• Size
30
• "90
30
60
pc
($/Mo.)
3.63
7.99 -
5.81, !
' 9.08
Size
(ft3)
30
120
30
90
Pc
($/Mo.)
3.63
10. 17
5.81 .
12. 35 "
NOTE: ('aX Maximum'and minimum sizes only are included iii this
" • example.
\< '• ' Insfeliatl'Qn-Cost.' (Ic). The"mbrithly installation cost is determined
in much'-the -same manner as the 'monthly purchase cost.
r K -
" I -s-i-Jc. + AC. ("-Volume used - V . ) 6
c 12 |_ i i \ mm/
' For'-e&a-mpre, the iiis'tall"ation-covst at the largest Type A station at
• Location 1* is:
174
-------
I = ~[$100 + $1.00/ft3(60 - 30)1>0]
x [amortization factor (6% - 20 years)]
= ~ [($130) x (0.08718)]
= $0. 94/Mo.
The monthly installation costs for this example are as follows:
Location 1 ' Location 2 Location 3
Station
Type
A
B
C
Operating
Size
(ft3)
3°.
60
30
90
-
Cost(G
($/.Mo.
o
P
0.
P
o)«.
..73
.,94
..36
..58
-
The.
Size
) '(ft3)
30
90
30
60
-
monthly
Ic
•($/Mo.)
0.73
1.74
0. 36
0..94
-
,ope.rating.
Size
(ft3)
30
120
30
90
-
cost is
Ic
($/.Mo.)
0.73
0.69
0.36
0.58
-
determi
taking th£ product'.ofythe cost per cubic foot-, of. flush media (AC o),
the volume', of . each .flush ,( Vjr), and. the. flush, frequency (F^), times
365 days/year diyad.ed>y'.12 months per .year. •'•; For example, the
monthly -operating,".c.osis; ,at a Type-,-A.-station;.Qf.;raaximum size at
Location 1 is: .
C =.v(AC . x V^,.x F^ x 365) /.12
, O ' O "£ " .' ,' £
, , ,= v(.Q..,QOL-x..60 x 1^0 x.36.5)/.1.2
The operating costs, fp,r;.this.rexample are:
.Location 1 ..Location 2 . . L,o,cation 3
i
Station
Type
A
B
.Size
(ft3)-.
30
60
30
90
. C s
($;/Mo. )
0.91
,,1V82 ,
0;91
, 2..74 '
•Size
.(ft3)
30
90
30
. -60
'•:C0
•($7,Mo.)
0.91
2.. 7 4
. 'P. 91
1.32
....Size-
/(ft3),,
30
120
. 30
•90
Co
-,(-$/Mo.)
0.91
3;65
0.91
2.74
•c •'• -•
*• : 175
-------
Total Monthly Cost (Mc). The total monthly cost of each type of
station is determined by summing up all of the individual costs.
For example, the total monthly cost of a Type A station of maximum
volume at Location 1 is: •
'M = P + I + C" +-C
c c c o m
Cm is the monthly maintenance cost and was one of the given cost
input parameters.
MC = $5.18 + $0.94 + $1.82 + $2.00
= $9.94 . .
The total monthly costs for this example are:
Location 1 Location 2 Location 3
Station Size Mc Size Mc Size Mc
Type (ft3) ($/Mo.) (ft3) ($/Mo.) (ft3) ($/Mo.) •
A 30 7. 27 30 7.27 30 7.27
60 .9.94 90 14.47 120 16.51
B 30 9. 08 30 9. 08 30 9. 08
90 17.67 -60 13.84 90 17.67
• Maximum Cleansing Determination. The maximum,cleansing effi-
ciency that can be attained within the limits and specifications es-
tablished above is determined, without regard to optimization of
cost, by allowing the value of shadow savings to approach infinity.
"With the value of saving associated with removal of the solids de-
posited in the sewer being very high (the effect and meaning of the
shadow savings is discussed more fully later in this section), the
emphasis is shifted completely from optimization of the system
with respect to cost to maximization of the solids removal. The
maximum cleansing efficiency is determined in the same basic man-
ner as described in the next section for the selection of the optimum
(cost) flush system, except that only one pass is made with an ex-
tremely high value of the shadow savings, say, $10, 000 per pound
of solids removed.
.The maximum cleansing efficiency is determined at the very begin-
ning for two reasons; first, so that the user will know what the
maximum limit of the proposed system is and, second, to make
sure that the desired system efficiency (specified by the user) is
176
-------
possible within the specified limits. Once the maximum cleansing
efficiency has been established, it is checked against the value
specified by the user. If the maximum value is less than the desired
value, the computations are terminated and the maximum allowable
efficiency is printed out so that the user knows that the limits he has
specified for the system are too small and must be increased if the
desired efficiency is to be realized. If the maximum value is greater
than the desired value, the value of the shadow savings is adjusted
downward and the process of optimizing the system with respect to
cost is started and proceeds as described in the following section.
Optimum System Selection. The cost optimization of the system is
accomplished using a dynamic programming technique which involves
the use of a corrected multiplier which in this case will be referred
to as the shadow savings. This multiplier can be thought of as
representing the dollar value of removing a pound of deposited solids
from the given sewer. The program is constructed such that the
user can estimate the dollar value of removing a pound of the solids
deposited in the sewer each day, based on the costs of alternate
methods of accomplishing the same function, or the penalty for not
removing the solids, and the model will determine the. most economi-
cal flushing system and corresponding cleansing efficiency such that
the monthly costs of the system do not exceed the total value of
removing the deposited solids, as limited by the value of shadow
savings given. Or the user can supply the model with the desired
cleansing efficiency (average over the length) and the model will, by
trial and error, establish the most economical flush system that can
be used to accomplish this specified level of cleansing. -
Because the basic computational procedures are the same when
•either of the above described approaches is used and because in most
cases the user will probably know most exactly the cleansing effi-
ciency he desires, this example will approach the problem by taking
an assumed value of the shadow savings and correcting it to obtain
the specified cleansing efficiency. As previously described in the
description of The Flushing Station Location Model, the model begins
with a value of shadow savings and correcting it to obtain the speci-
fied cleansing efficiency. As previously described, the model be-
gins with a value of shadow savings of $0. 01 per pound and then
doubles the value repeatedly until the desired cleansing efficiency
is reached or exceeded and then further refines the estimate using
the "golden section search" technique. However, for the purpose
of this example, the initial repetitive computation will be eliminated
by assuming a value of shadow savings of $5. 00 per pound of solids
177
-------
removed, which will give a more realistic cleansing'efficiency based
on the costs and limits that have been arbitrarily selected in this- case.
The first step in the system optimization is to determine the total
cost (including '"the shadow savings) of euch size of each type of
flush station that can be installed at the upstream most access loca-
tion (Location 1). Since the monthly cost of each of the various
sizes and types of flush stations has previously been determined for
this example, the only major determination that is left to be made
is that of the savings that can be accomplished, based on the solids
removal in each case and the value of the -shadow savings. In this.
example, the flush media will be taken as clean water, in all cases,
in order to simplify the .computations. -.However, .41 .sewager is to.be
used as the flush media, the computations .are...much ,the same, ex- ..
cept that the clean water cleansing efficiency must be corrected using
Equations 14 and 15 and the procedures previously described in the
Discussion section of this report. -
The average clean-water cleansing efficiency, over a given length of
sewer, CESS> can be determined using. Equation, 10 as long as the
value of L .used is taken from,the point at which the flush release
is made. However, the computations involved in this model require
that the average cleansing efficiency be determined for sections of
sewer downstream of the point of flush release, .the upstream ends
of which do not coincide with the point of flush release. Therefore
the differential form (with respect to -L) of Equa-tion 10 is more use-
ful (point efficiency equation, C-g). The development of this point
efficiency equation in its general form was described in the preced-
ing section. The specific equation used in this model is:
V'-^'V^D1-8 ,
C_(L) = -30. 87 + 24. 68 log, _ — ——~ x 10 .
E 10 J..o_i.£
J_i . w ..
The above equation for C.-g can,be used to determine the, average
cleansing efficiency for any section of sewe~r downstream of the
point of flush release by integrating it with respect to L between the
specified limits of L (L is always the distance from the point of
release). For example,
L3
C (for Section 2-3) =/*- C_ (L) dL .
JCjDO . J. . . . ,,. . SLi . ,
Where L2 is the distance from the point of flush release to the
178
-------
upstream end of the section, Lo is the distance from the point of
flush release to the downstream end of the section, and Cg (L) is
the point efficiency equation which is a function of L. The quantity
of solids removed by the flush wave from the section of sewer be-
tween Location 2 and Location 3 (Sj^) can be determined,
S0 (from Section 2-3) = S^
K JJ
1
100
j_i
/
CE(L)
where S is the total quantity of solids deposited in Section 2-3.
The model begins at the upstream most location (Location 1) and
determines the total cost (including savings) for each type of station
that can be installed at that location. For this example, the total
cost of the large'st Type A station at Location 1 is determined as
described below.
First, the total quantity of solids deposited in each section of sewer,
Sj), during the interval between flushes is determined. . The total
quantity of solids deposited in the section of sewer between Loca-
tions 1 and 2 is, :
SD=DSL/FF,
= (0. 01 Ibs/ft/day) (400 ft)/(I. 0/day)
= 4.0 Ibs
The quantity of solids deposited between flushes in each of the sewer
sections is given below.
Section Deposited Frequency of
Section Length -L- Solids -Dg _ Flush -FF_
No. (ft) (Ibs/ft/day) (No. /day)
1-2
2-3
3 -Main
400
800.
600
0.01
0.01
0.01
1.0
1.0
1.0
Total Solids .
Deposited
Between Flushes
-Sn- (Ibs)
4. 0
8.0
6.01
Beginning at the upstream most location (Location 1), the quantity of
deposited solids removed from each section of sewer by each size
and type of flush device that can be installed at this location is
179
-------
determined. Then the solids removal quantities are used to determine
the saving and costs associated with each of the installations. The
quantity of deposited solids removed from each section of the sewer
is determined for each type and size of flush station by integrating
the point efficiencies over the length of each section and multiplying
the average cleansing efficiency obtained for each section by the
, total quantity of solids deposited in each section.
In the actual model, the integral in the above relationship for SR is
evaluated more exactly using small increments of L, over the
length of each section. However, for the purposes of this example,
the point efficiency function will be assumed to be linear along the
length of each section. For example, the solids removed from each
of the sections of sewer by the smallest Type A station installed at
Location 1, is determined as follows:
For Section 1-2, ,
ESS
= -13.70 - 24.68 log
10
(400)1*6 (0.05)1'2
x 10
= -13.70 + 24. 68 log (2080)
= 68. 6%
= 4.0(0.686) = 2. 74 Ibs
For Section 2-3,
ESS
C @ 2
C @ 3
• •
- ,, v^g *- u T ^g v- ->j •
= -30.87 + 24.68 log
•4
0 Q 14. 18
(30)1<;> (1.0)"' '(1.0)*' '(1.0J-"
(400) *
= 51.4%
= -30.87 + 24.68 log
JL \J
r 7~
3.02 x 10
1 6
. (1200) ' J
= 32. 3%
So.os)1'2
x 10
C___ = £(51.4 + 32.3) = 41. 8%
JliOO £ —
'S_- = -(8 Ibs) (41. 8%) /100
XV
= 3. 34 Ibs
180
-------
For Section 3 - Main,
ESS
J(CE@3
C @ Main)
-30. 87 + 24. 68 log
'10
(1.
= 25. 1%
(1800)1'6 (0.05)1'2
x 10
ESS
R
= 7(32.3 + 25. 13) = 28.7%
= '(6.0 Ibs) (28. 7%) / 100
= 1.72 Ibs
The solids removals accomplished in the three sections of the sewer
by each size of each type of flush station installed at Location 1 are
given below:
Solids Removed, S-n, (Ibs)
Station
Type
@ 1
A
B
Volume of
Flush
-VF-
(ft3)
30
60 .
30
90
Section
1-2
2.74
3.11
3.00
3.61
Section
2-3
3.34
3.98
3.75
4.97
Section
3-M
1.72
2.27
2.05
3.02
Total
Removed
From
Sewer
7.80
9.36
8.80
11. 60
The total cost of using each size and type of flush station at
Location 1 to clean the section of sewer between Locations 1 and 2
can now be determined by applying the shadow savings (in this case
assumed to be $5. 00 per pound of solids removed) to the solids re-
moved'in this section of sewer by each flush station and then deduct-
ing this savings from total month cost, M , of each station. For
example, the cost of using the largest Type A station at Location 1
to clean Section 1-2 is,
Total Cost =M -[(Shadow Savings) x (Solids Removal, S , in Section 1-2]
C Jtx
= $9. 94 - [($5. 00/lb) (3. 11 Ibs)]
= $5. 61
181
-------
The total costs and solids removals associated with each size and
type of flush station at Location 1 are as follows:
Station
Type
@ 1
A
B
Flush
Volume
-VF-
(ft3)
30
' 60
30
90
Total
Month
Cost
-Mc-
{$)
7.27
9.94
9.08
17. 67
Section
of
Sewer
Cleaned
1-2
1-2
1-2
1-2
Solids
Removed
-------
The total cost of each flush station to be investigated at Location 2
can be determined, in the same manner as that used for Location 1.
The results are as follows:
Station
Type
@ 2
A
B
Flush
Volume
-VF-
(ft3)
30
90
30
60
Total
Month
Cost
-Mc-
($)
7.27
14.47
9.08
13. 84
Section
of
Sewer
Cleaned
2-3
2-3
2-3
2-3
Solids
Removed
-SR-
(Ibs)
4.48
5.73
5.04
5.81
Savings
($)
22. 40
28.70
25.20
29. 10
Total
Cost
($)
-15. 13
-14.23
-16. 12
-15.26
The best combination of flus~h stations at Locations 1 and 2 can be
determined, simply by adding the total cost given above for each
flush station at Location 2 to the total cost of the least-cost alterna--
tive at Location 1. However, before the Type C or no-installation
alternative at Station 2 can be evaluated, the. costs of all the types
and sizes of flush stations at Location 1 must be corrected to include
the additional savings associated with the solids removed by each in
Section 2-3; For example, the adjusted c.ost of the largest Type A
at Location 1 with a Type C station at Location 2 is, - •
Adjusted Solids Removed = (solids removed from Section 1-2)
+ (solids removed from Section 2-3)
= '3. 11 Ibs + 3. 98 Ibs = 7. 09 Ibs •
Adjusted Total Cost = Total Monthly Cost - Sayings
= $9.94 -($5. 00/lb)(7.094b)
= $25. 51
The adjusted costs and solids removals for each of the sizes and
types of flush station at Loc'ation 1 are given below:
183
-------
Station
Type
' @ 1
A
B
*
Flush
Volume
'-VF-
30
.60
30
90
Total
Month
Cost
-Mc-
($)
7.27
9.94
9.08
17.67
Section
of
Sewer
Cleaned
1-3
1 -3
1-3
1-3
Adjusted
Solids
Removed
(Ibs)
6. 08
7.09
6.75
8.58
Adjusted
Savings •
($)
30.40
35.45
33.75
42.90
Adjusted
Total
Cost
($)
-23. 13
-25.51
-24. 67
-25.23
The lowest cost combination of flush stations at Locations 1 and 2
can now be determined in the following manner. First the total
cost and solids removal must be determined for each possible com-
bination. For example, the total cost and solids removal associ-
ated with the installation of the smallest Type A station at Loca-
'
tion 1 and the largest Type A station at Location 2 is,
Total Solids Removed =
(solids removed from Section 1-2 by the
flush station at Location 1)
+ (solids removed from Section 2-3 by
the flush station at Location 2)
3.00 Ibs +'5.73 Ibs
8.73 Ibs
Total Cost = (total cost of flush station at Location 1)
+ (total cost of flush station at
Location 2)
= $6.43 + (-$14.23)
= -$20. 66-
The cost and solids removals for the various combinations of flush
stations at Locations 1 and 2 are given below. ,
184
-------
Combined Stations
Station at Location 1
Type
A
A
V olume
30
30
, Section
Cleaned
1-2
1-2
Station at Location 2
Type
A
B
Volume
30
90
30
60
Section
Cleaned
2-3
2-3
2-3
2-3
Solids
Removed
(Iba)
?7.22
'8.47
7.78
8.55
Section
Cleaned
1-3
1-3
1-3
1-3
Total
Co'st
($)
-21.56
-20.66
-22.55
-21. 69
60
1-3
7.09
1-3
-25.51
Note:
(a) These station types and sizes were selected because they were previ-
ously found to be the least costly for the given section of sewer to be
cleaned.
The cost figures given above indicate that the most economical com-
bination of flush stations at Locations 1 and 2 is a Type A with a
60 ft^ storage capacity at Location 1 and a Type C (no-installation)
at Location 2. This combination with the corresponding cost and
solids removal information is now used to determine the best type
and size of flush station for Location 3.
As was the case at the upstream locations, the quantity of solids
removed and the associated costs must first be determined for each
type and size of flush station at Location 3, when each is used to
clean the next adjacent downstream section of sewer. These figures
are:
Station
Type
@ 3
A
B
Flush
V olume
-VF-
30
120
30
90
Total
Month
Cost
($)
7.27
16.51
9.08
17. 67
Section
of"
Sewer
Cleaned
3 -Main
3 -Main
3 -Main
3 -Main
Solids
Removed
-SR-
(Ibs)
3. 68
4.82
4.07
4.76
Savings
($)
18.40
24. 10
20. 35
24. 30
Total
Cost
($)
-11. 13
-7.59
-11.27
-6.63
Now as was done at Location 2 for the flush stations at Location 2,
the solids removals and costs for the flush stations at Location 2
should be adjusted to allow proper evaluation of the Type C station
(no-installation) at Location 3. However, since a Type C station
(no-installation) is indicated at Location 2, the adjustments must be
made again to the costs and solids removals for the flush stations
at Location 1. The adjustment is made by simply adding the solids
removals and associated savings that each station at Location 1
185
-------
effects in Section 3-Main to the corresponding adjusted solids re-
movals and savings determined previously at.Location 2. The ad-
justed values are given below: " ,
' : Total
Flush Month Section
Station Volume Cost of
Adjusted
Solids ' Adjusted
Removed Adjusted Total •
Type
@ 1
A
B
-VF-
(ft3)
30
60
30
90
($)°
7.27
9.94
' 9.08
17.67
Sewer
Cleaned
1 -Main
1 -Main
1 -Main
1 -Main
-SR-
(Ibs)
7.80
9.36
8.80 t
11.60
Savings
($)
39.00
46.70
44, 00 .
58.00 -:
Cost
($)
-31.73
-36.76
-34.92
-40. 33
The above figures show that the Type B station with a 90 ft-5 capacity-
is the best selection for the evaluation of the Type C (no-installation)
station at Location 3. The solids removals and costs of the various
combinations of flush-stations along the length of the sewer are as
follows:
Combined Stations ,
Upstream Stations
@ Loi
Type
A
AB
cation 1
Volume
(ft3)
60
60
@ Locatiori 2 Station at Location .3
Type
C
C
Volume
(ft3) Type
A
B
Volume
(ft3)
30
120
30
90
Section
Cleaned
3 -Main
3 -Main
3 -Main
3 -Main
.Section
Cleaned
1 -Main
1 -Main
1 -Main
1 -Main
Total
Solids
Removed
. .{Ibs)
10.77
11.91
11. 16
11. '85
Total
Cost
-36.69
-33. 10
-36.78
-32. 14
90
I'-Main 11.60
-40. 33
The figures given above indicated that the best periodic flushing sys-
tem for. this particular lateral sewer, within the limits given and for
a shadow savings of $5. 00 per pound of solids removed, is one
consisting only of a Type B flush station with a volume of 90 ft^
installed at Location 1. The average cleansing efficiency, C^sS'
over the total length of the sewer is determined by dividing the total
quantity of deposited solids removed from the seWer by each flush
(11. 60 Ibs) by the total quantity of solids deposited in the sewer be-
tween flushes (18. 0 Ibs). Thus the average cleansing efficiency,
, for "the proposed flushing system is,
_ 11. 60 Ibs x 100%
ESS " 18.00 Ibs
= 64. 0% -
186
-------
This value of C^ggiis quite close to the value of 60% which was
originally specified, s'p.,-no further refinement is necessary. However,
if the actual value of C^gg ^ia<^ Deen significantly higher than the
desired value, the estimate could be refined by reducing the value of
shadow savings a small amount (say from $5. 00/lb to $4. 50/lb)
and repeating the above procedures until the actual value of Cggg
becomes sufficiently close to the desired value.
EXTENSIONS OF MODEL,
Flushing Efficiency Versus Investment Relationship
The first impression.of using the shadow savings for solids removal is
that it is.an awkard, artificial technique. There is, however, significant
power in the utilization of this artificial cost. Although the average ef-
fectiveness of flushing is usually of prime interest, another and possibly
more realistic question is: What is the best system that can be installed
for X dollars? Whereas, keeping the level of pollutants within some
specified'amount is tije major engineering concern, the communities
installing a flushing network'might typically be interested in considering
the various investment alternatives for control. These communities may
in fact, be evaluating whether to install flushing stations or an alterna-
tive such as temporary storage facilities.
To satisfy'these interests a'flushing efficiency versus investment rela-
tion would be beneficial. An investigation of this is easily motivated by
the shadow savings approach. By performing the optimization repeatedly
beginning with the artificial shadow savings at a small value and continu-
ously increasing the value until either the maximum investment or maxi-
mum feasible efficiency is attained, a curve of flushing efficiency versus
investment can be generated. By proceeding in this manner, there is
always the assurance, that the installation is kept cost effective. The re-
sulting plot would have a form somewhat as that 'shown below.
% V100
Solids-
Removed
(Avg. _ , .
'• . • Each dot represents a
over 50 - • . „ . . ,
Lateral) ' * glV6n fhlshlnS sYstem
Investment ($)
187
-------
Approach For Sewer System Analysis
The model presentation and discussion to this point has been oriented
toward the':analysis of a particular lateral in a sewer system. The
orientation may be expanded to include the entire system if the flow in
the main sewer conduit is sufficient to remove the solid materials which
might be deposited in it, or may be analyzed independently. In such a
case, the model may be applied to each lateral individually using one
specific value of the shadow savings over the entire system. For exam-
ple, if the value of . 15 per unit solids removed were applied to each lat-
eral, some might be flushed to an efficiency of 75 percent while others
sould be 40 percent or 55 percent. The differing flushing efficiencies
indicate that on some laterals the quantity of solids removed is not suf-
ficient to justify expenditures on flushing stations. In general, higher
efficiencies for a given shadow savings would be associated with laterals
with high solids loads. Once the entire system is evaluated'with a given
shadow savings, the overall efficiency is assessed. If necessary, the
unit shadow savings is adjusted and the procedure repeated. This ap-
proach could consume considerably more computation time, but the sav-
ings and advantages of balancing overall effectiveness would justify the
additional expense. The computer model as developed and presented here
would require the manual input and adjustment of shadow savings (even
this requires a special code - see computer model write-up) to obtain
either the system analysis or the efficiency versus investment relation-
ship. The model could be altered without too much additional difficulty
to allow for automatic development of either or both of these features.
DISCUSSION OF DYNAMIC PROGRAMMING
Dynamic programming is a computational technique which finds applica-
tion in the solution of sequential decision problems. The particular
types of problem to which the approach is most easily applied are those
in which benefits yielded at one stage of the problem are additive to bene-
fits accrued in prior stages. A corollary of this is that decisions only
have consequences in successive stages of the problem. This is pre-
cisely the type of problem presented in location flush station facilities.
The theory of dynamic programming is more intuitive than analytic and
is more easily grasped by example than through a mathematical approach.
The reader interested in a more precise development and further areas
for application is referred to any of the standard texts on the .subject
(particularly good presentations are found in G. L. Nemhauser, Intro-
duction to Dynamic Programming, and G. Hadley, Nonlinear and Dynamic
Programming). The fundamental property upon which the theory of -
188
-------
dynamic programming is developed is called "the principle o£ optimality"
and is stated.as:
"An optimal sequence of decisions in a multi-stage decision prob-
lem has the property that whatever the final decision and state
preceding the terminal one, the prior decision must constitute an
optimal sequence of decisions leading from the initial state to that
state preceding the terminal one."
The validity of this property may be verified by contradiction.
Expanding on the computational procedure to include five possible lo-
cations will show the model to be an application of the principle of
optimality. To illustrate this more explicitly, begin at the last stage
of the decision problem, the sewer main. The efficiencies generated
by installation of any of the station types between Location 5 and the
sewer main constitute the various states that can be assumed under
the different decisions of installation. Then by the principle of opti-
mality that sequence of decisions (station.types) and states (resulting
efficiencies) from the initial state (the result from a decision at
Lpcation 1) to the state preceding the terminal state (efficiencies ac-
crued to Location 5, including the installation at 4) must be optimal
for a final optimal decision as to station type at Location 5. And how
is this optimality to the state preceding the terminal state assured?
By redefining the terminal state to be that state from Location 4 to the
end of the lateral and applying the principle of optimality to the state
preceding the installation at 4. To assure that the state preceding the
installation at 4 is optimal, the terminal state is redefined to be that
state from Location 3 to the sewer main. Hence, following this argu-
ment, the principle of optimality is applied recursively with the
terminal state becoming that state from Location 2 to the sewer main
and then from Location 1 to the sewer main. This may be done because
the principle of optimality must be valid over any particular definition
of initial and terminal states. .
At first this may seem backward from the approach taken in the solution
technique; it is in fact the same approach. The above paragraph indi-
cates that it is necessary to successively calculate the optimum sequence
of decisions from the initial state to the terminal state by recursively
redefining the terminal state. This is the manner in which the computa-
tional, technique proceeded: The initial state was the consequence of a
decision at Location 1 to the end; in effect, the terminal state and initial
state were the same. The terminal state was then redefined so as to be
the consequences from Location 2 to the sewer main where the various
states were determined by the decisions at 2 conditioned on the various
states preceding 2 (the states implied by the decisions at 1). When the
189
-------
states associated with a decision at Location 2 have been evaluated, the
terminal state is redefined to be from Location 3 to the sewer main. By
the principle of optimality the optimal return for this reduced problem
is found by conditioning on the preceding states (which are themselves
optimal). This procedure is performed until the last location in the prob-
lem is reached.
There is a mathematical representation for dynamic programming.
Whereas, for completeness it would be nice to present this form, the
definitions necessary for precise formulation make it impractical to do
so. The interested reader will find formulations in the referenced texts.
COMPUTER PROGRAM
Introduction and Use of Program
The program allows the automatic determination of the flushing station
configuration yielding the minimum cost for a specified average cleans-
ing efficiency. As presented, the program is designed for use with the
station types developed by the Central Engineering Laboratories. The
particular impact of this is in the equations expressing cleansing
efficiencies.
The intent of this discussion is to detail the requirements for use of the
program in designing a flushing system. No attempt is made to present
any type of programmer's guide, but the program is documented well
enough internally to allow an analyst to make minor changes if necessary
for a particular application. The analytic features of the program are
discussed in the previous sections of this report.
The inputs for the program may be classified as two types: those data
describing the lateral and the various flow parameters in it, and those
characteristics of the flushing station which effect either the cost Or
performance of the station. These descriptive data plus a specified effi-
ciency are sufficient to allow the program to determine the minimum-
cost station configuration. < .
Before detailing the precise form of inputs and outputs, a summary of the
assumptions on which model is based would be in order to^assure proper
application. The pertinent assumptions are:
• The stations flushing efficiency may be expressed by the equations
developed by the Central Engineering Laboratories. The equation
for average efficiency over the length L using clean water as the -
flushing fluidi ' :. _ -•;••••
190
-------
+ 24,680 log
10
where
ESS = a,ve*age cleansing efficiency over a given length of
sewer L>(%)
' V_' = volume of flush (ft )
X
T,
£
= rate of flush (cfs)
S = average slope of pipe (%)•
D "= diameter of pipe (ft)
QR = rate of base flow (cfs)
1 L = distance from installation (ft)
If the flushing fluid is sewage, it is necessary to apply a correction fac-
tor to the above expression. If ^ESS ^s ^ie average efficiency using
sewage,for flushing, the change is,
ESS
ESS
r AC
1.0-
ESS »
100 /
wher.e
- .'14 V_ -' .242'Q_ + /OOTll L
' ^. Jc: . . X *
• The ^efficiency, (in-percent of ..solids, removed) is independent of the
solids load in the base flow. i .
• Stations, and locations, are'.sufficiently close together, so that the .
point .efficiency never falls below zero. :. , • . ,
• Any flushing station will only have effects downstream of its
installation.'.: ... •-.->-. ! ,..-.•
o When the efficiency curves of.two or more stations overlap, the effi-
ciency at any point is taken as the maximum of the overlapping effi-
ciencies taken individually at that point.
191
-------
• The stations act in concert with one another. At the, least, the .
flushing action will pass to successively downstream locations.
If these assumptions cannot be met or at least generally satisfied, the
model should be applied with judgement. . >
Restrictions
There are various dimensional restrictions on the size of the problem
that can be evaluated as the program is now written. The number' of
station types that can be considered along a lateral is limited to six. A
station type is as specified on a station type card as detailed later in
this discussion. Locations along an individual lateral are limited to 30
sites. A location includes manholes and any other readily accessible
locations. Of course, modifications can be made to the program to per-
mit the evaluation of larger problems.
Timing
Execution time is primarily dependent on four parameters; number of
station types, division of the limits on the volume, number of manhole
locations along the lateral, and the starting value of the shadow savings.
Execution time seems to increase roughly by the square of the number
of station types and the division size, and linearly with the number of
locations. The initial value of the shadow, savings influences the execu-
tion time in a somewhat linear manner but the precise effect is dependent
on the relative magnitudes of the initial value and final solution value.
"Whereas the number of station types and installation locations are de-
fined by the problem and hence fixed as far as reducing execution time,
the division limits and starting value'of the shadow savings can be mani-
pulated to achieve some processing economies. By using an arbitrary
shadow savings and a relatively small number of divisions in the initial
stages of analysis and increasing the number of divisions and more
closely approximating the shadow savings during'more refined'analysis,
a significant reduction in computer costs can be achieved. There are
notes in the program as to where the modifications, can be made.
The example presented later in this appendix required 5 minutes for
execution with the values as defined in the program as listed. •
The following is a list and explanation of the data required to execute the
program. All numeric data are right justified and, if necessary, carry
192
-------
a decimal point in the appropriate position. There are three groups of
cards: a title card of which there is one; location cards consisting of
two cards for each manhole location along the lateral, the first of the
two cards contains lateral characteristics data and the second, data on
installation costs at the manhole; and station cards, one for each station
type detailing operational and cost data about each station. A blank card
separates the location cards from the station type cards. '
Title Card ' ' _ • . -
Card Columns
1 - 40
41 - 48
50
51 -60
Explanation ' - '
Title to be printed on the output
Date computer run performed
Code indicating whether the required efficiency
or a shadow savings value will be specified by
the analyst.
0 or blank required efficiency specified and
program will automatically ,
.determine shadow savings
1 shadow savings input
Required efficiency of cleansing, CESS> to ^e
attained along the lateral in percent or if unit
value of shadow savings is to be an input it is
entered in this field.
Location Cards
Card Columns
Card 1 - Physical Characteristics
Explanation
1 - 5
6 - 10
11-20
21 - 30
Lateral number of the pipe being evaluated.
Manhole number of the location under consider-
ation (number beginning at upstream end of
lateral).
Distance to next manhole or to main, or inter-
ceptor in feet.
Average base flow in the reach to the next man-
hole in cfs.
193
-------
Card Columns Explanation
31 ~ 40 Average quantity of solids deposited in the next
reach in pounds of solids deposited per foot of
sewer. This is dependent on the parameters of
the lateral and the frequency of flush.
41 - 50 Diameter of pipe in feet.
51 - 6o Average slope over the reach to the next
manhole (%).
61-63 Multiple of low volume limit yielding high volume
limit at this location for station described on
first station type card.
64 - 66 Multiple of low volume limit yielding high volume
limit at this location for station described on
second station type card.
67 - 69 Multiple of low volume limit yielding high volume
limit at this location for station described on
third station type card.
70 - 72 Multiple of low volume limit yielding high volume
limit at this location for station described on
fourth station type card.
73-75 Multiple of low volume limit yielding high volume
limit at this location for station described on
fifth station type card.
76-78 Multiple of low volume limit yielding high volume
limit at this location for station described on
sixth station type card.
Card 2 - Installation and Variable Costs
1-5 Lateral number from the above Physical Charac-
teristics card.
6-10 Manhold number from the above Physical Charac-
teristics card.
11 - 14 Minimum cost installation (excluding purchase
cost) for station on first station type card ($).
15 - 18 Variable cost for increasing volume for station on
first station type card ($/ft3). The added cost of
purchasing and installing a flush station of a given
type that is larger than the minimum sized unit,
per cubic foot of increased volume.
194
-------
Card Columns Explanation
19 -21 Exponent on volume for non-constant purchase
and installation costs (for station on first station
type card). [These three cards define the param-
eters of the installation and variable cost
expression.
Cost = minimum cost + (variable cost)
x (volume - minimum volume)exponent]
22 - 25 • Minimum and variable costs, and exponent for
26-29 station on second station type card.
30-32
33-36 Minimum and variable costs and exponent for
37-40 - station on third station type card.
41 - 43
44 - 47 . Minimum and variable costs .and exponent for
48-51 station on fourth station type card.
52 - 54
55-58 Minimum and variable costs and exponent for
59 - 62 station of fifth station type card.
63-65
66-69 . Minimum and variable costs and exponent for
70 - 73 station of sixth station type card.
74-76
NOTE: If a station type is not feasible for the partic-
ular manhole, the corresponding field should be left
blank- or contain zeros. If it is desired to minimize
only the operation costs, the feasible station types
be indicated by a 1 in the right most position of the
appropriate minimum cost field; the infeasible types
should, as before, be left blank.
195
-------
Station Type Cards
Card.,, ' .
Columns Field .Explanation
1-4 4 Code to identify station type.
5 1 Flushing fluid code: 0 if clean water is the
flushing agent and 1 if sewage is to be
employed.
6-9 4 Expected life of the station in years.
10-15 6 Flushing rate of the station in cfs.
16-21 6 Low volume limit in ft3 on the quantity of flush.
28-33 6 Frequency of flushing expressed by the number
of hours between flushes. Normally the fre-
quency is 24 hours. Note that the average
solids load in the sewer will decrease as the
time between flushes (frequency) is reduced.
34 - 39 , 6 Unit cost ($/ft3) to purchase a ft3 of flushing
agent for operation of the station.
40-45 6 Monthly'maintenance cost of station ($).
46 - 51 ( 6. Purchase cost ($} to procure a station of this
type with minimum, capacity.
!
These are the inputs required to execute the program. If more basic
data were used a preprocessorf could, of course, be programmed to
create a file which this program could then,read to obtain the necessary
data.
Output •
A sample output is shown near the end of this discussion. The interpre-
tation of these forms is straightforward, but a detailed description is
contained herein so as .to avoid any ambiguity. On the first page the title
entered on the title card is printed at the top of the page; the date on the
title card is also printed, appearing below the title. The lateral'number
entered in the first field of the Location Cards is output on the next line.
196
-------
MANHOLE
NUMBER
STATION
TYPE
FLUSH
RATE
CFS .
FLUSH
VOLUME
CU FT
INSTALL
COST
DOLLARS
OPERATE
COST
DOLLARS
MAINT.
COST
DOLLARS
Identifying number of the manhole for which
the associated line indicates the installation.
This is the number indicated in the second
field of the location cards and the output list
begins at the most upstream end and works
down the lateral.
Station type to be installed at the manhole loca-
tion indicated. The station type number is as
defined in the first field of the station type
cards.
Flush rate of the station to be installed. This
will be as defined in the flushing rate field of
the station type cards.
Flushing volume required by the particular
station type to achieve sufficient cleansing.
Cost to install the station type specified.
Included in this is the purchase price plus the
direct cost of installation.
Monthly cost to purchase flushing fluid and
operate at the specified frequency.
Monthly maintenance costs of station.' Ob-
tained from input.
SOLIDS
REMOVED
POUNDS
SOLIDS
REMOVED
PERCENT
The number of pounds of solid material re-
moved over the reach to the next manhole
location.
i
The average percentage of solid material
removed over the reach to the next manhold
location. • ' • •
There are totals for the appropriate columns. An average percent of
solids removed over the entire length of the lateral is tabulated as
AVERAGE EFFICIENCY. It is this value that is compared to the input
required efficiency to be certain of attaining sufficient cleansing. The
value tabulated under MAXIMUM EFFICIENCY is the maximum
197
-------
efficiency that can be obtained independent of the cost of the system.
No cleansing efficiency greater than this amount can be attained without
increasing the maximum volume specifications.
The second page of the illustrated output contains more detailed infor-
mation on the flushing performance. The particular cleansing efficiency
for various points along the lateral is tabulated. The points at which
the efficiency is calculated are:
o at each 100 ft along the lateral
a at each manhole or station location, and
• at any points at which efficiency curves cross.
The first column of the output gives the distance from the most upstream
manhole. The second column is the point flushing efficiency at the cor-
responding distance. Also printed is the value of shadow savings cor-
responding to the particular report.
One report will be generated for each value of the shadow savings tested.
The program will terminate when the required level of efficiency (in
percent solids removal) is attained.
Error Messages
There are no informative diagonistic messages output by the program.
The FORTRAN and loading messages normally furnished by the computer
will still be available but no additional tests explicitly for erroneous or
inconsistent data will be made. Interspersed within the program are
statements of the form
STOP XXX.
XXX is an integer and is unique to each STOP statement. These state-
ments may cause the progra.m to terminate execution for a variety of
reasons; none of which is normal. The corrective action when a termi-
nation of this sort occurs is to locate the STOP statement within the pro-
gram by means of the identifier XXX (this number will be printed on the
output) and rectify the problem (which most likely will be in the data) by
examining the program logic immediately preceding the termination.
Example
The following is presented as a rather typical application of the program.
For the lateral illustrated and described on the following page it is
198
-------
required to remove 70 percent of the solids. The lateral carries the
designation 2-3 -B. There are four possible station types. The
installation costs for the different types are schematically illustrated
below. The particular specifications for the station types and manhole
locations are on the following pages.
Installation
Cost
($) .
Station Type 3
Station Type 1
Station Type 2
Station Type 4
Min.
Volume
Max.
Volume
•»•- Flush Volume
Lateral 2 - 3 -B
Main
Length
Diameter
Avg. Base Flow
Avg. Load
Avg. Slope
©
310 ft
8 in.
0026 cfs
Cy
. 200 ft
8 in.
. 0067 cfs
(T)
230 ft
10 in.
.0102 cfs
©
650 ft
12 in.
.0174 cfs
00115 Ib/ft . 00303-Ib/ft
.6% . 4%
Sample Problem
00460 Ib/ft .00781 Ib/ft
.32%
.22%
199
-------
Station Type
Flush Fluid '
Life , .
Flush Rate
Min. Flush Vol
Frequency
Unit Cost
Monthly Maint.
Cost
Purchase
Location
F03C
Clean
... 15 yrs.
2. 00 cfs
3l. 30 ft3
24 hrs.
. 0012$/ft3
$5. 00
$1000
Variable Costs:
Component
Min. Install.
Var. Cost
Exponent
Min. Install.
Var. Cost
Exponent
Min. Install.
Var. Cost
Exponent
Min. Install.
Var. Cost
Exponent
F27C = F36C
Clean . Clean
10 yrs. 10 yrs.
1. 33 cfs' 4. 45 cfs
80 ft3 30 ft3
24 hrs. 24 hrs.
.0012$/ft3 .0012$/ft3 ..
$8. 00 $8. 00
$800 $2500
F03C F27C F36C
300 500
30 .071
..5 - 1.5
500 - 700
10 - .071
1.0 - 1.5
750 300 900
10 40 .071
1.0 .5 1.5
1000 300
10 45
1.0 .5
F03S
Sewage
10 yrs.
2. 00 cfs
30 ft3
24 hrs.
, 0012$/ft3
$12. 00
$1000
F03S
-
-
-
500
0
0
850
0
0
900
0
0
200
-------
Maximum Limit on Volume
The following table lists the maximum volume of water that can be
stored and utilized for flushing. Normally the limit will be a function
of the size of the manhole and depth of pipe at that location; hence, the
limit must be expressed at each location for each station type. Also
the maximum limit as input to the program is expressed as multiples of
minimum flush volume.
Station Type
Location
1
2
3
4
Measure
cubic feet
multi. low
cubic feet
multi. low
cubic feet
multi. low
cubic feet
multi. low
F03C
-
-
65
2.2
90
3.0
105
3.5
F27C
240
3.0
-
-
320
4.0
360
4.5
F36C
110
3.7
135
4.5
185
6.2
-
_
F03S
-
-
60
2.0
85
2.8
120
4.0
The prepared card input and final results of the computer run are found
on the following pages.
201
-------
SAMPLE DATA CARDS
"03S1 10 2'. 00'-'" 3D" 100 £4 0 lEl
/
L' 2 1 -L£ -041000' '10' 1'.' 300' ' 45". 5 900" ' 0" 0 "\ "
e-c
/
5-B' ' -04 650: V0174- ' ' : '. 00781 ' ' I'.'O'O ' ' '. 223'. 54 . 5 ' 4". n ' ^\
2-3-B" ' -'03 75"0' " I'O' 1'.' 3W ' 40' '.5' 900'. 0711'. 5' 85TV ft '0" ' "\
yfe-3-B' -03 £30; '.0102 . 00460 '.83 . 323'. 04'. 06'. 22'. 8 ' "X
*-
/ yE-3-B -02 500 ' 10' 1'. 700', 0711'. 5' 500' '0 0 '" ~"\
/ " / ^-3^-B -0£ • 200'. • ' '. 0067' ' ' '.00303 ' " '. 67- ' '. 402'. 2' ' ' 4'. 52'. 'ft X
/ / /£-3'-TK -(\1 300" ' 30" '.5" 500; 0711". 5 -— " ^\
I / / >fe-3-Br ' -m 31 0; '. O'OES '. 00115 '.67 ; 60' " 3'. 03'. 7' ' -
ANALYSIS' FDR LftTERAL £' -' 3" -' B 10X09V70 70'. 0 "V
0000 0 0 0 0 0 0 0 0 50 0 0 0 0 fl 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 * '; '.'0 ^0 "0 0 0 Q 0 0 0 0 0 ';0 5J 0 0 0 0 0 0 0 0 0 0 0 0 0 9 0 0 0 0 0 0
1 2 3 4 5 E 7 1 9 1011 12!] H IS 16 1718 19 20 21 22 i] /4 2S 25 27 28293J3I 3231 J43S3S37383J «IU24m««««OSJ5l 52535
-------
SUMMARY — INPUT DATA
ANALYSIS FOR LATERAL 2 - 3 - B
DATE 10/09/70
LATERAL N0.2-3-B
LATERAL CHARACTERISTICS
DISTANCE TO
LOCATION NEXT MANHOLE (FT»
-01
-02
-03
-04
310.
20C.
230.
650.
7*
REQUIRED EFFICIENCY .*
AVERAGE BASE
FLCH (CFS)
.00260
.00670
.01020
.01740
AVERAGE BASE
LOAD (LB/FT)
.00115
.00303
.00460
.00781
AVERAGE SLOPE
(X)
0.600
0.400
0.320
0.220
DIAMETER
(FTI
0.670
0.670
0.830
1.000
STATION TYPE CHARACTERISTICS
STATION CODE
FLUSH FLUID CODE
STATION LIFE (YRS)
FLUSH RATE (CFS)
FLUSH VOL-LOH (CUFT)
FREQUENCY (HRS)
MAINTENANCE COST (SI
PURCHASE COST (t>
COST OF HATER 1 $/CUFT|
INSTALLATION COSTS / HIGH
LOCATION
-01 MINIMUM COST
VARIABLE COST
EXPONENT
HIGH VOL MULT
-02 MINIMUM COST
VARIABLE COST
EXPONENT
HIGH VOL MULT
-03 MINIMUM COST
VARIABLE COST
EXPONENT
HIGH VOL MULT
" -04 MINIMUM COST
VARIABLE COST
EXPONENT
HIGH VOL MULT
F03C
0
15
2.00
30.
24.
5.0
1000.
.00120
F27C
0
1C
1.33
80.
24.
8.0
1200.
.00120
VOLUME LIMIT
F03C
0.0
' 0.0
0.0
0.0
see. ooo
1C. 000
1.00
2.20
75C.OOO
10.000
l.OC
3.00
1CCO.OOO
10.000
1.00
3.50
STATION TYPE
F27C
v 300.000
30.000
0.50
3.00
0.0
0.0
C.O
0.0
300.000
40.000
0.50
4.00
300.000
45.000
0.50
4.50
F36C
500.000
0.071
1.50
3.70
700.000
0.071
1.50
4.50
900.000
0.071
1.50
6.20
0.0
0.0
0.0
0.0
F03S
0.0
0.0
0.0
0.0
500.000
0.0
0.0
2.00
850.000
0.0
0.0
2.80
900.000
0.0
0.0
4.00
203
-------
ANALYSIS FOR LATERAL 2 - 3 - B
DATE
10/09/7C
LATERAL NO. 2-3-B
DO
O
MANHOLF
NUMBER
-01
-02
-03
-04
:CIENCY
iCIENCY
FLUSH FLUSH INSTALL
STATION RATE VCLUN-E COST
TYPE CFS CU FT DOLLARS
F27C 1.33 240- 1879.
NONE
NONE
NONE
240. 1879.
67. B5
89.22
MONTHLY MONTHLY
OPERATE MAINTEN SOLIDS
'COST COST REMOVER
DOLLARS DOLLARS POUNDS
8.6't 8. CO 0.356
0.436
0.836
3.186
8.64 8.00 4.815
"
SOLIDS
REMOVED
PERCENT
IOC. 00
72.02
79.01
62.77
-------
EFFICIENCY CURVE
LOCATION PERCENT
0.0 100.00
ICO.00 100.00
200.00 100.00
300.00 IQC.OO
310.00 100.00
310.CO 76.55
410.00 71.76
510.CO ' 68.CI
510.00 82.36
610.00 79.29
710.00 76.69
740.CO 75.98
74C.QO 68.7-2
840.00 66.55
940.CC 64.62
1(140.00 62.89
1140.00 61.31
1240.00 59.87
1340.00 58.54
1390.00 57.91
1390.00 C.O
VALUE CF MATERIAL REMOVAL DDL / LB 38.44
205
-------
PROGRAM LISTING
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
G ,
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
OPTIMUM
SELECTION AND LOCATION OF PERIODIC FLUSHING STATIONS
FOR COMBINED SEWER CLEANSING
W H PALLSEN
28 JULY
OED FMC
ACOST
AEFF
AMOUNT
AREA
AVEFF
BLANK
CODE
CDDE1
COST
COSTN
COSTP
COSTPT
COUNT
CRF
CR
Cl
C2
C3
C4
C5
C1I.
C2I
C3I
C4I
C5I
0
DATE .
OELV,
DIA,' .
EFF-V.
EFFACE
EFF'ERR
EFFHI
EFFINT
EFFLO
EFFMAX
EFFREQ
EFFSTA
EFF-TRP •
EFFY-
EFF1
EFF2
FREQ
GPM .-.
ICOST
ICOSTI
1<37C
. '•-.
ACCUM COST OF THIS STATION - DOLLARS / MCNTH
EFFICIENCY TABLE FOR SELECTED STATION STRING
AMOUNT OF MATERIAL REMOVED BY FLUSHING
AREA UNDER EFFICIENCY CURVE - PERCENT * FT
AVERAGE EFFICIENCY FOR THIS STRING OF STATIONS
t t
CODE FOR TYPE OF PROCESSING -
CODE = 1 INPUT SAVE
CODE - 2 INPfcT REQUIRED EFFICIENCY .
CODE FOP FIRST TIME THROUGH ITERATION CONTROL ROUTINE
COST OF STATICN - DOLLARS / MONTH '• ,,
NET COST CF SELECTED STATICN -
COST,, OF PURCHASE. AND INSTALLATION -/COLLARS
TOTAL -COST OF. PURCHASE AND INSTALLATION - DOLLARS-
COUNT OF THE NUMBER OF ITERATIONS,' . -' -
CAPI-TAL RECOV.ER'Y: FACTOR --. '
CAPITAL RECOVER*, FACTOR
COEFFICIENT OR 'EXPONENT -OF THE ..EFFIC IENCY CURVE
COEFFICIENT- .OR' EXPONENT OF THE EFFICIENCY CURVE-
COEFFICIENT- OR.', EXPONENT >CF TH& '&FFICI ENCY CURVE
COEFFICIENT- OR: -EXPGNENTvQF T HE ,iE F.F.I C LENCY CURVE
COEFF.-IC.IE,NT OP EXPONENT -CF THE -EFFICIENCY CURVE
COEFFICIENT QR-.-EXPOJ^ENT, OF THE :£FFICIENCY CURVE
COEFF.ICIEKT CR EXPONENT, CF THE .EFFIC IENCY CURVE
COEFFie-lE-NT 'OR EXPONENT. OF THE EFFICIENCY. CURVE • -• '
COEFF-I,C.I'E-NT OR EXPONENT GF THE -EFFICIENCY CURVE
COEFFICIENT. OR EXPONENT -CF THE , EFFIC IENCY CURVE
DISTANCE - FT
RERC-RJ. DATE.'.
VOLUME (INCREMENT- f-CR A 'FLUSHING. STATION - GAL '
DIftK€T€-R .QF--PI-PET--.FT- •• •
PO!NT,;'EF:FrCIBNCY. AT D FROM SW:10N
AVER,AGE.,.EF,F,ICIENC,Y- CV.ER ;.TH I S SEGMENT - PERCENT
ERRCR;,FAC.T,CR FO.R -ZEROING IN ,ON 'EF.FKEQ
EFfilCI-ENGY ON.'Hl,GH SIDE ..-OF REQUJRED EFFICIENCY - PERCENT
INT€QRAL*XF EFF •AGAIN-S.frDLSTvANCE-, •
EFFICIENOY CN LOW SIDE >OF REQUIRED EFFICIENCY - PERCENT
MAXIMUM EFFICIENCY.-.ATTA.INABLE, ,
EFFIG-I-E,NC,Y.-RECUIRE£KFQR. -THIS. 5T.R-ING ,OF FLUSH ^STAT IONS
INTeG;E;RA"L 'CF EFFIOlENCYv '-FOR -THIS, STATION .
EFFICIENCY AT LAST .ITERATION CYCLE PERCENT
SUBROUTINE TO FIND THE EFFICIENCY CURVES
EFFICIENCY AT STATION
EFFICIENCY AT END GF SEGMENT - PERCENT
NO..JOF, HOURS BETWEEN, -FLUSHINGS-..
AVERAGE., BASE FLQh -JN.'A ,PIPE;.-.'CU FT / SEC
INS-T'/VLLATICN CCST— DOLLARS /-MONTH
INSIAL.LATJCN -COST ,OF -THIS TYPE OF, FLUSHING STATION AT -
THIS' LOCATION
206
-------
c
c
c
c
c
c
c
c
c
c
c
c.
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
INC
ITRP
K
KKKGD
KNAME
KODE
KODET
KOOEX
LIFE
LNAME
LOAD
LOADT
M
MAXCNT
MAXTRP
MCOST
M.COSTI
MCOSTT
MNAME
NLOC
NNAME
NSTA
NSTAT
NSTYP
QCOST
OCOSTP
OCOSTT
OPT
PCOST
PCOSTI
QF
QFI
RATE
SAVE
SAVEFF
SAVEHI
SAVELO
SAVING
SHI
SLOPE
SOLIDS
SOLT
SRP
STYP
STYPI
TCOST
TCOSTI
TCOSTI
TITLE
TMSAVE
TNCOST
TOCOST
UCOST
UCOSTI
VALUE
NO CF VOLUMES FCR A STATION TYPE
NO OF ITERATION CYCLES WHICH HAVE SAME EFFICIENCY
CODE FOR TYPE OF FLUSHING WATER 0-CLEAN l-OIPTY
2 CHAR LATERAL NAVE
TABLE TO INDICATE CPTIMUN SELECTION
NO OF THE LAST STATION THAT GIVES LOWEST ACCUM COST WITH
THIS STATION
NO OF THE STRING CF STATIONS GIVING THE LOWEST ACCUM COST
LIFE OF A FLUSHING STATION - YR
3 CHAR LATERAL NAME
AVERAGE LOAD OF DEPOSITS OVER SFGMENT LB / FT
TOTAL POUNDS CF SOLIDS OVER LATERAL
MAXIMUM NO OF ITERATIONS
MAX NO. OF ITERATION CYCLES WHICH HAVE SAME EFFICIENCY
MONJHLY MAINTENANCE COST - OOL
MONTHLY MAINTENANCE COST - COL
TOTAL MONTHLY MAINTENANCE CCST - DOLLARS / MONTH
2 CHAR LATERAL NAME ,
NO CF LOCATIONS
3 CHAR LATERAL NAM-E
NO OF STAt'IGN'S
NO OF STATtDNS
NO CF STATICN, TYPES
OPERATING COST - DCLLATS / MONTH
COST OF MONTHLY OPERATION - DOLLARS / MONTH
TOTAL MONT'HY • QPEP'ATING CCST - DOLLARS / MONTH
CODE- FOR METHCD CF GPT IMUM IZAT ION'
flPT = 1 M'lMKIZE OPERATIONAL COST'
OPT =,2 fiMCIZE TCTAL CCST
PURCHASE CCST . PER MONTH - DCLLARS / MONTH
TOTAL PURCHASE CCST-CF A TYPE OF FLUSHING STATION - DDL
RATE CF FLUSH -FLCW- CU FT / SEC
MAXIMUM FLUSHING FLC-W RATE - CU FT /'SEC
INTEREST RATE."- 6 PERCENT • CCMPOUNDE-D • ANNUALLY
VALUE OF REMOVING MATERIAL DCLLARS'/ POUND
SUBROUTINE- TC'. SAVE THE EFFICIENCY CURVE CF SELECT'- C STRING
VALUE, OF SHADOW' • SAVINGS- ON- HIGH SIDE.' OF EFFREG
VALUE' OF SAAOQWvSAVINGS ON'> L'<3« S-IOE-OP' EFFREJ3
SAVINGS'- OF' SELECTED STATTQN-
A HIGH VALUE' FOR' • REK&VAL.-.OF-HATERi'Ali'. TO'-'FIND THE
HIGHEST KAXIHOM- EFFICIENCY' - DOt-yL-B'
AVERAGE stc-RE-OF PIPE - PERECNT'
AMOUMT. OF SGL.IEJ.S--REWOVED' BY' THIS STA.T-ION— LB
TOTAL- AMOUNT- GF SOLIDS REMOVED - LBV
SOLIDS R'E>»E'VEI): BETWEEN LATERALS-- LB'-
4 CHAR NAME.' FCRv TYPE OF' FLUSH STATION'.
4 CHAR MAB& FCR' TYPE, OF FLUSH' STATTONV
ACCUM- COST 'FOR! THIS' LOCATION
TOTAL, MONTHLY INSTALLATION COST DOLLARS
SAVE AREA'-FOR FIND-ING LOWEST ACCUM 'COST DOLLARS
REPORT TITLE
TOTAL MONTHLY SAVINGS
TOTAL, NET'. C05T.
TOTAL- MGNTHL'-Y OPERATING COST
UNIT ''COST -OF/ FLUSHING. WATER''- DOLLAR'S; /' GAL-
UNIT' COST' OF' FLUSHING WATER- '-• DOLLARS- / GAL
VALUE OF THE SAVING-S' CAUSE'D BY- THE-' INSTALLATION OF THE
STATION - DOLLARS /MONTH'
207
-------
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
VHDUM
VH
VL
VOL
VOLT
x '-
XNtYN
XO.YO
XTT,YTT
XX
Z
ZMIN
ZXP
ZVAR
zz
llll
L
J
I
DUMMY
LARGEST MAXIMUM VOLUME CF WATER DISCHARGED BY A TYPE OF
FLUSHING STATION
SMALLEST NAXI^UM VOLUME OF WATER DISCHARGED BY A TYPE OF
FLUSHING STATION
VOLUME OF WATER DISCHARGED 8Y FLUSHING STATION - CU FT
TOTAL VOUME OF FLUSH TO OPERATE EACH MONTH
DISTANCE BETWEEN STATIONS - FT
EFFICIENCY TABLE FOR CURRENT SELECTION CANDIDATES
EFFICIENCY TABLE FCR PREVIOUS SUBOPTIMuMIZED SELECTION
TABLE FOR HOLDING THE EFFICIENCY CURVE TEMPERARILY
DISTANCE FROM BEGINNING OF THE LINE
DISTANCE FROM STATION AT WHICH EFFICIENCY DROPS TO ZERO
USE WHEN 3 AND C ARE ZERO - FT
MNIMUM INSTALLATICN COST - DDL
INSTALLATION COST EXPCNNENT
VARIABLE INSTALLATICN COST - DGL / FT ** EXP
DISTANCE FROM FLUSHING STATION TO ZERO EFFICIENCY
ACCUM COST - DCLLARS
ROW - TYPE OF STATION
COL - LOCATION
TYPO OF THE PREVIOUS STATION
C
C
C
C
COMMON LOAD (30)
COMMON KKKOD (36)
COMMON NSTAT, NLOC
COMMON X(30), GPM (30), DIA (30), SLOPE (30)
COMMON XTTdOO, 36), YTT(100»36)
COMMON XX (31), Z(36)
COMMON XOdOO, 31), YC(100,31)
COMMON XN (50, 36), YN (5C, 36)
COMMON VOL (36,30),GF(36)
REAL LOAD,LOADT
REAL ICCSTI
REAL ICOST
REAL MCCSTH6), MCOST( 31) , MCCSTT
INTEGER KKKD (7)
INTEGER CODE
INTEGER OPT
INTEGER COUNT
INTEGER LNAME, BLANK
INTEGER STYPI
EQUIVALENCE (NSTA, NSTAT)
DIMENSION SAVING (3C)
DIMENSION COSTN (30)
DIMENSICN KGDEX (30)
DIMENSION SOLIDS(30)
DIMENSICN KODE (36, 30), ACOST (36, 30), ICOST (36, 30)
DIMENSION CCST (36)
DIMENSION TITLE(IC), DATE (2)
DIMENSION KNAME(2G),LNAME(2Q),MNAME(20),NNAME(20)
208
-------
DIMENSION STYPK7), LIFE17), QFl(7), VL(7),
DIMENSION UCCSTU7), PCCSTK7)
DIMENSION ZZ(7)
DIMENSION FfiEG (36), DELV(36)
DIMENSION COSTP (36), CCCSTP (36)
DIMENSION C5K7), ICOSTK7, 30)
DIMENSION UCCST136), PCOSK36), STYP136)
DIMENSION ZMIN (6, 30), ZVAR (6, 30), ZXP
DATA BLANK /• •/
FREQI(7),CR(7)
(6, 30),VH(6,30).
C
C
101
1C2
103
104
108
1C9
110
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
(8110)
(8F1C.O)
( 1CE8.0)
(2{A2,A3),6(2F4.0,F3.0))
(1CA4, 2A4, IX, II, F10.0)
(2(A2,A3),5F1G.C,6F3.0)
(A4, II, 14, .7F6.0)
C
C
C
201 FORMAT
1
2
3
2C2
203
204
205
206
207
210
211
212
213
214
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
5X, 'LOCATION
4X, 'MONTHLY1
11X, 'NO'
'SAVINGS'
(113, 19,
4X,
STATIONS
8X, 'NET' /
, 5X, 'TYPES 7X,
, 7X, 'COST' // )
4F11.2)
•MONTHLY' /
4X, 'INSTALL*,
4X, 'OPERATES
COST
7X, «CCST'f 4X,
(/// • TOTAL MONTHLY INSTALLATION COST', 3X,
(' TOTAL MONTHLY OPERATING CGST', 6X, F10.2)
(' TOTAL MONTHLY SAVINGS', 13X, F10.2)
(' TCTAL NET COST', 20X, F10.2)
(//' AVERAGE EFFICIENCY',F10.2)
(/,' MAXIMUM EFFICIENCY',F10.2)
('!', 24X, 1CA4 //)
(13X, 'DATE', 4X, 2A4 //)
(13X, 'LATERAL NO.',1X,A2,A3)
(62X, 'MONTHLY', 3X, 'MONTHLY' /
F10.2I
1
2
3
4
5
6
5X, 'FLUSHS 3X, 'INSTALLS
3X, 'KAINTENS 4X, 'SOLIDS', 4X, 'SOLIDS' /
STATIONS 6X, 'RATE', 4X, 'VOLUME', 6X, 'COST',
•COSTS 3X, 'REMOVED', 3X, ''REMOVED' /
34X, 'FLUSH',
3X, 'OPERATES
13X, 'MANHOLE
6X, 'COSTS 6X,
14X, 'NUMBERS 5X, 'TYPES 7X, 'CFSS 5X, ' CU FT',
3(3X, 'DOLLARS'), 4X, 'POUNDS' 3X, 'PERCENT' / )
215
216
217
218
219
220
225
8C1
8C2
803
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
L
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
(15X,A2,A3,5X,A4,F10.2,2F10.0,2F10.2,F10.3,F10.21
(39X,5(1X,9('-')) / 39X,2F10.0,2F10.2,F10.3)
(15X,A2,A3, 5X, 'NONES 50X, F10.3, F10.2)
(2F20.2)
CIS 12X, 'EFFICIENCY CURVE' ///
12X, 'LOCATIONS 13X, 'PERCENT' /)
(// ' VALUE OF MATERIAL REMOVAL DDL / LB', F20.2 //)
(15, 4(110, F15.2))
(«!• ,/ / ,3QX,'SUMMARY — INPUT DATA',/,24X,10A4,//)
(13X,'DATE S2A4,/)
(13X,'LATERAL NO.«,A2,A3,T60,'REQUIRED EFFICIENCY',F4.0,
8C4 FORMAT (13X,'LATERAL
1 'AVERAGE BASE
2 16X,'LOCATION
CHAR AC TERISTICS ' ,/,29X, ' DISTANCE TOST47,
AVERAGE BASE AVERAGE SLOPE EIAMETER',/,
NEXT MANHOLE (FT) FLOW (CFS) LOAD ',
MLB/FT) ST82,«m ST96,'(FT)')
209
-------
c
c
c
805
806
807
8C8
809
810
812
813
814
815
816
817
818
819
82C
FORMAT {
FORMAT (
1
FORMAT (
FORMAT (
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT
FORMAT!
1
FURMATC/
FORMAT (
FORMAT <
FORMAT {
c
c
c
c
c
c
c
c
c
(/,18X,A2,A3,T31,F5.C,T49,F6.5»T64,F6.5,T80,F6.3,T95,F5i3)
«,T42,6(F6.5>9X>)
16X,'MAINTENANCE COST <$) ' ,T43,6(F5.1,10X1)
16X,'PURCHASE CCST ($}',T/»2,6(F5.0,10X))
//,13X«INSTALLATICN COSTS / HIGH VOLUME LIMIT',/,SOX,
'STATION TYPE',/,16X,'LOCATION',T44»6 (A4,11X).)
/15X,A2,A3,T26,"MINIMUM COST• ,T40,6(F9.3,6X)) , •
XM^ . ;
(T26,'HIGH VGL VULT', T44,6 (F4.2,1;1X)) i ..• - ;
900 CONTINUE ' .
COUNT =0
EFFTRP = 1E18 " , ,
MAXTRP = 4 ••-,•'-- '-:i ' ' ' • ,
ITRP = 0 .
INC IS THE NUMBER OF DIVISIONS IN THE HIGH»r- LOW SPECIFICATION -
ON THE VOLUME. MORE THAN ANY CTHER VARIABLE THIS EFFECTS THE TIME
REQUIRED FOR EXECUTION, HENCE, THIS SHOULD BE AS SMALL AS PRAC-
TICAL. A PARTITION OF 3 —HIGH, LOW, AND AVERAGE — SEEMS REA-
SONABLE FOR PRELIMINARY WORK AND 5 OR 7 FOR MORE REFINED ANALYSIS,
EXECUTION TIME GOES,UP BY THE RATIO CF SQUARES OF. THE NUMBER OF
INTERVALS. , .'•:• • •
INC =3'
INC = 5 .
EFFLO = 0 .,:•..•:.<-.
LOADT = 0. • . •.-.',.'. '-,:•••'•
SHI = 1E6 • , • • .. ' -
SAVELO =0 :•:.,• < . • ,
SAVEHI = 10CO.
EFFHI = 100.0 , .,..-.
CODE1 = 1 ' • " • , '.-•-•-
RATE = C.C6 •• • ,
MAXCNT
EFFERR
DO 1 J
X (J) = 0
GPM (J) = 0
DO 1 I = 1, 36
KODE (It J) = 0
= 15
= O.C5
= IT 3G
ACOST (I,
ICOST (I,
CONTINUE
DO 27 I =
DO 27 J =
XO (I, J)
XTT I I*
YTT (I,
J)
J)
= 0
= 0
If
1,
100
36
= 1E20'
J) = 1E20
J) = 0
210
-------
27
YO (It
DO 580
z,
1. ZVARUtJ) ?ZXP(I,J),I = 1,6)
GOTO 10
4 NLOC=J-1
WRITE (6,801) TITLE
WRITE (6,802) DATE
WRITE (6,803) KNAME(1) .LNAVE(1),SAVE
WRITE (6,804)
DO 888 J=1,NLCC
888 WRITE (6,805) MNAKE(J),NNA^E(J),X(J»,GPMlJ),LOAD(J),
1 SLOPE(J),DIA(J)
1 = 0
13 CONTINUE
I = I •>
READ (5,
1VHDUM,
GO TO 13
18 CONTINUE
NSTYP
WRITE
WRITE
WRITE
WRITE
WRITE
110,END=18) STYPI (I), KKKD(I), LIFE(I), QFKI), VL(I),
FREQI(I), UCOSTICII, MCOSTKU, PCOSTI(I)
= 1-1
(6,806)(STYPI(I)
(6,807)(KKKD(I )
(6,808)(LlFE( I)
(6,809)(QFI(I)
(6»810)IVL(I)
8<30
WRITE
WRITE
WRITE
WRITE
DO 89Q
WRITE
WRITE
WRITE
WRITE
,1=1,NSTYP)
,I=;1, NSTYP)
,1=1,NSTYP)
,1=1,NSTYP)
,1=1,NSTYP)
, ,1 = 1,NSTYP)
(6,814)(P,COSTIU),I = 1,NSTYP>
(6,815)(PCCSTI(I),1=1tNSTYP)
<6,813MUCGSTI(I),I=1,NSTYP»
(6,816) (STYPI(I),1=1,NSTYP)
J=1,NLOC
(6,817) MNAME(J)tNNAKECJJ,(ZMIN(I,J),1=1,NSTYP)
(6,818) (ZVAR(I,J),1=1,NSTYP)
(6,819) (ZXP(I,J),1=1,NSTYP)
(6,820) (VH(I.J),1=1,NSTYP)
C
C
C
C
C
C
IF (CODE - 1) 56, 46, 56
SAVE DETERMINES THE STARTING VALUE CF THE VALUE GF SOLICS REMOVAL
(SHADOW OR ARTIFICAL SAVINGS). AS SET UP THE VALUE IS $100.0
AS. EXPERIENCE ON A PARTICULAR PROBLEM IS GAINED SCME EFFICIENCY
OF EXECUTION CAN BE ACHIEVED BY CHANGING THIS TO THE APPROXIMATE
EXPECTED VALUE
211
-------
56
48
12
C
C
C
44
242
243
244
245
799
14
17
29
** LIFE(I) / 1(1 + RATE) *# LIFEII) -D/12
CONTINUE
EFFREQ = SAVE
SAVE = 100.G
SAVES = SAVE
SAVE = SHI
CONTINUE
XX (1) = 0
DO 12 J = It NLOC
LOADT = LGADT + LOAD(J)*XU)
XX (J+l) = XX{J) + X (JJ
SET UP TABLES
NSTA = 1 + NSTYP * INC
KKKOD (1) = 0
QF (1) =0
FREQ (1) = FREQl (Z)
UCOST (1) = 0
PCOST (1) = C
MCOST (1) = 0
DO 44 J = 1, NLOC
VOL(lfJ) = 0.
ICOST (1, J) =0
M = 1 „ •
DO 9 I = 1,.,NSTYP
CRF = RATE * (1 * RATE!
CR( I) = CRF
DO 9 15 = 1, INC
M = M + 1
UCOST (M) = UCOSTI
KKKOD (M) = KKKD (I
QF (M) = QFI (I)
FREQ (M) = FREQI (I
PCOST (M) = PCOST I.
MCOST (M) = MCOSTI
DO 799 J = It NLOC
DELV(J) = IVH(ItJ)
IF (VH(I,J).LT.l.)
VOL (M,J) = VL
IF ( 15 - 1) 242,
STOP 242 " " i ' :
CONTINUE ...-.- - - ^
ICOST (M, Jl = CRF * ZKIN (I, J)
GO TO 245
CONTINUE
ICOST (M, J) = CRF * (ZMIN (I, JJ-+ ZVA^ (I, J) * ((15 - 1) *
DELV(J))
CONTINUE
CONTINUE
DO 28 J =
IF (ZMIN
CONTINUE
ICOST (K,
GO TO 28
CONTINUE
IF (ZMIN
CONTINUE
ICOST (M,
I)
I)
I)
* CRF
* VLU)
DELVU)
(I) + (15
243t 244.
- VLIII)/
= 1.
- 1) * DELV(J)
(INC - 1.)
It
(It
NLOC
J))
17f 14f 17
J) = 1E20
(I, J) - 1) 28, 29, 28
J) = 0
212
-------
28 CONTINUE
9 CONTINUE
80 CONTINUE ;
C
C
DO 5 J = It NLOC
DO 35 L = If NSTAT
DO 6 I = 1, NSTAT
C
C FIND THE AMOUNT OF SOLIDS REMOVED BY THIS STATION
C
IF (ICOST * 30 * 24 / FREQ = ICOST + OCOST - VALUE
IF (J — 1) 8, 8, 6
6 CONTINUE
8 CONTINUE
C
C FIND WIN ACCUM COST
C
IF (J - 1> 15, I5t 16
15 CONTINUE
ACOST (L, 1) = COST <1)
GO TO 7
16 CONTINUE
KODET = 1
TCOST = ACOST (lt J-l) + COST U)
DO 19 I = 2, NSTA
TCOST1 = ACOST (I, J-D + CGST (I)
IF (TCCST - TCOST1) 1<5, IS, 20
20 TCOST = TCOST1
KODET =1 .
19 CONTINUE
ACOST (L, J) = TCOST
KQDE (L, J) = KODET
7 CONTINUE
I = KCDE (L, J)
CALL SAVEFF (J, L, I)
35 CONTINUE
5 CONTINUE
C
C FIND STRING OF STATIONS WITH MINIMUM ACCUM COST
C
KODET = 1
TCOST = ACOST (I, NLOC)
DO 21 I = 2, NSTA
IF (TCOST - ACCST (I, NLOC)I 21, 21, 22
213
-------
22 KOOET =1 -
TCOST = ACOST (I, NLCCI
21 CONTINUE
KQDEX (NLOC) = KODET
DO 23 J = 2, NLOC
I = NLCC - J + 1
KOOEX (I) = KCDE (KODET, I + I)
KODET = KODEX (I)
23 CONTINUE
I = KODEX (1)
COSTN (1) = ACOST (I, 1)
DO 24 J = 2, NLOC
II = KODEX (J)
12 = KODEX (J-li
24 COSTN (J) = ACOST (lit J) - ACOST (I2f J-l)
C
C PRINT REPORT
C
46 CONTINUE ;
WRITE (6, 2n» TITLE
WRITE (6, 212) DATE
WRITE (6,213) KNAMEtl),LNAPE(l)
WRITE (6, 214)
VOLT =0
COSTPT =0
OCOSTT =0
SOLT =0
MCOSTT= 0.
DO 705 J = It NLOC
M = KODEX (J)
IF (M - U 706, 706, 707
706 CONTINUE
U = 0
DO 246 I = 1, J
IJ = IJ + KODEX (I)
246 CONTINUE
IF (IJ - J) 247, 247, 248
247 CONTINUE
SOLID =0 .
GO TO 249
248 CONTINUE
CALL SOLD (J, KODEX(NLCC), SCLID)
249 CONTINUE
SRP •= SCLID / LOAD (J) * 100 / X(J)
SOLT = SOLT + SOLID
WRITE (6,217) MNAME(J),NNAPE(J),SOLIC,SRP
GO TO 705
707 CONTINUE
I = (M - 2) / INC + 1 '
COSTPm = ICOST(M,J) /CRU) + PCCSTI(I)
OCOSTP (M).= UCOST (f) * VOL (M,J) * 30 * 24 / FREQ (M)
CALL SOLD (J, KODEX(NLCC), SCLID)
SRP = SOLID / LOAD (J) * 100 / X(J)
WRITE (6,215) MNAME{J),NNANEU),ST.YPI
-------
SOLT = SOLT + SOLIU
7C5 CONTINUE
WRITE (6,216) VOLT, CCSTPT,OCOSTT,MCGSTT,SOLT
AVEFF = SQLT/LOADT * 100.
IF (SAVE - SHI) 250, 251, 251
251 CONTINUE
WRITE (6, 210) AVEFF
EFFMAX=AVEFF
GO TO 252
250 CONTINUE
WRITE (6, 207) AVEFF
WRITE (6,210) EFFMAX
252 CONTINUE
EFFAVE = AVEFF
WRITE (6, 219)
I = KODEX (NLCC)
J = 1
253 CONTINUE
WRITE (6, 218) XO (J, I), YD (J, I)
J = J + 1
IF (XO (J, I) - IE18) 253, 254, 254
254 WRITE (6,220) SAVE
IF (SAVE - SHI) 255, 256, 256
256 CONTINUE
SAVE = SAVES
GO TO 80
255 CONTINUE
C
C CONTROL ROUTINE FCR ITERATIONS
C
IF (EFFAVE - EFFTRP) 202, 301, 302
301 ITRP = ITRP + 1
IF (ITRP - MAXTRP) 303, 304, 304
304 WRITE (6, 305) MAXTPPt EFFTRP
305 FORMAT ('!', 10X, 'SAME EFFICIENCY', 13, 2X, 'TIMES', F20.2,
1 'PERCENT' / •!')
STOP 304
302 CONTINUE
EFFTRP = EFFAVE
ITRP = 0
303 CONTINUE
COUNT = COUNT + 1
IF (COUNT - NAXCNT) 7C3, 704, 704
704 STOP 7C4
7C3 CONTINUE
IF (CODE - 1) 69, 57, 69
57 STOP 57
69 IF (CODE1 - i) 73, 70, 73
70 CONTINUE
IF (EFFAVE - EFFREQ) 71, 76, 76
C 71 STOP 71
71 CONTINUE
SAVELO = SAVE
SAVE = 2 * SAVE
EFFLO = EFFAVE
GO TO 80
76 CONTINUE
CODE1 = 2
73 CONTINUE
IF (ABS (EFFAVE - EFFREQJ / EFFREG - EFFERR) 9999t 9999, 77
215
-------
77 CONTINUE
IF (EFFAVE - EFFREC) 557, 557, 556
557 CONTINUE
SAVELO = SAVE
EFFLO = EFFAVE
SAVE = SAVELO + 0.62 *
-------
34
49
50
51
SUBROUTINE EFFY (I, J, LLf AHCUNTI :- - •
AMOUNT OF MATERIAL REMOVED BY FLUSHING
AREA OF EFFICIENCY CURVE FOR CURRENT CANDIDATE
AREA OF EFFICIENCY CURVE WHICH IS OVERLAPPING s
DISTANCE - FT : . ' :
DISTANCE FROM STATION TC NEXT MANHOLE
DISTANCE FROM STATION TO NEXT POINT ON SAVED: EfF £URVE
DISTANCE FRCM LAST POINT TO ZERO EFFICIENCY - FT
EFFICIENCY AT D ...
EFFICIENCY INCREMENT GAINED .-BY ADDING THIS STATION
EFFICIENCY SUBROUTINE
EFFICIENCY AT Dl - PERCENT
EFFICIENCY AT C2 - PERCENT
EFFICIENCY AT Dl (JLST PAST THE NEXT MANHOLE!
TYPE OF THE PREVIOUS STATION
LOCATION OF THE STATION
COUNTER FCR LOCATIONS
LOCATION OF THE STATION
TYPE CF THE PREVIOUS STATION
TYPE OF THE CURRENT STATION .
COUNTER FCR LCCATICN CF POINTS IN THE XN,YN TABLE
COUNTER FOR POINTS IN THE SAVED EFF TABLE
LOCATION OF THIS STATION IN THE XO,YO TABLE
NO CF LOCATIONS
EFFICIENCY TABLE FOR CURRENT SELECTION CANDIDATES
EFFICIENCY TABLE FCR PREVIOUS SUBOPTIMUMIZED SELECTION
INTERSECTION PCINT CF THE EFFICIENCY CURVES
DISTANCE FROM START OF IhE LATERAL
DISTANCE FROM STATICN TO POINT OF ZERO EFFICIENCY
LOAD (30)
KKKOD (36)
NSTAT, NLOC
X(30)t GPM (30)» OIA (30)t SLOPE (30)
XTTC100, 36), YTT(100,36)
XX (21), Z(36)
XOdOO, 31), YC(100,31) -
XN (50, 36), YN (50, 36)
VOL (36,30),QF(36)
AD
LOADAt LGADO
DELTX = 100
L = I
00 34 N = 1, 50
YN (N, I) = 0
XN (N, I) = 1E19
XN (1, I) = 0
LL=1 MEANS NO STATION AT THIS LOCATION
IF (LL - 1) 49, 50, 51
STOP 49
AMOUNT = 0
RETURN
CONTINUE
DO 36 N = 1, 100
IF (XX (J) - XO (N, LI) 37, 36, 36
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
c
AMOUNT
AREA
AREAO
D
01
02
DA
EFF
EFFSTA
EFFVAL
EFF1
EFF2
EFF3
I
J
K
KK
L
LL
M
MM
N
NLOC
XN,YN
XO,YO
X1»Y1
XX
Z
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
. REAL L
REAL Li
217.
-------
36 CONTINUE
N = 2
37 CONTINUE
C
C FIND EFFICIENCY TABLE OF CURRENT CANDIDATE
V*
M = 0
K = J
KK = J
KK3 = KK + 1 •
MM = N - 1
Dl = XX(K) - XX(J)
5C2 CONTINUE
02 = XO(MM, L) - XX(J)
IF (02) 601, 503, 503
601 02 = 0
503 CONTINLE
IF (J - 1) 504, 505, 5C6 •
504 STOP 5C4
506 CONTINUE
IF (Dl - 02) 505t 5C5» 507
505 CONTINLE
IF (01 - Z(LL)) 508, 3C, 30
508 CONTINUE
CALL EFFVAL (LL, KK, Dl, EFF1)
IF (EFF1) 521t 521, 522
522 CONTINUE
M = M + 1
YN (M, I) = EFF1
XN (M, I) = XX(J) * Dl
IF {M - 1) 515, 509, 517
515 STOP 515
517 CONTINUE
IF (KK - KK3) 721, 5QS, 721
721 CONTINLE
CALL EFFVAL (LL, K«3 , Dl, EFF3)
IF (EFF3) 519, 519, 520
520 CONTINUE
IF (EFF1 - EFF3) 510, 509, 510
510 CONTINUE
M - M + 1
YN (M, I) = EFF3
XN (M, I) = XX(J) + 01
509 CONTINUE
IF {J - 1) 523, 512, 524
523 STOP 523
524 CONTINUE
IF (Dl - D2) 512, 5il, 513
513 STOP 513
511 CONTINUE
MM = KM + 1
02 = XO(MM, L) - XX
-------
731 Dl = D5
KK3 - K
GO TO 503
730 CONTINUE
IF (K - NLOC) 732, 38, 39
732 CONTINUE
K = K + 1
GO TO 503
39 STOP 39
38 CONTINUE
IF (Dl - Z(LL» 702, 30, 30
7C2 CONTINUE
D - Dl
GO TO 32 - '
507 CONTINUE
IF
-------
c
c
c
LQADA =0
AREA = 0
M = 1
52 CONTINUE
M = M + 1
IF (YN(M,I)> 551, 54, 53
551 STOP 551 •
53 CONTINUE
DAREA = (YN(M-1,I) + YN(M,I)) * (XN(M,I) - XN(M-1,II) * 0.5
AREA = AREA + OAREA •
CALL LOADX * 1.00001) 531,531,806 . - -
806 STOP 806 ;
531 CONTINUE .
IF (XN(M, I) - 1E18) 6C2, 566, 566
602 CONTINUE .
IF (YN(M ,I» 559, 566, 559
530 CONTINUE
K = K + 1
IF IXO(K-1,L) - XG(K,D) 532, 533, 907
907 IF (XO(K-1,L> - XO
-------
570 CONTINUE
LCALL X1Y1 (XxS!K;u!iolK!LM;!tio;K,L,>o.o, XN,M,I),YN, XI.YII
Ml = M + 1
DO 55 155 = Mli 50
M2 = 5C + Ml - 155
XN (M2, I) = XN
55 CONTINUE
XN (M, I) = XI
YN (M, I) = Yl
GO TO 560
S6°SMfSl5. 1,-YOIK. Lll 561,561, 562
561 IF^M-l, I.-YO (K-l, Lll 563, 56,, 564
5" DAREO^ CVNCM-1, I) + YN(M, III * CXNCH.II - XN (M-l, I ) )*. 5
AREAO = AREAO + DAREO
CALL LOADX (XN(M,I), DAREC, LOADO)
GO TO 565
564 C"ALL"™IYI . YNCH-I. n. XO«K-I, LI, YO«K-I, LI,
CALL t*m • xfg l|f YN(Mf „ Xl, Yll
DAREO - (YO K-l, L) * Yl) * (XI - XOCK-1, LI) * 0.5
DAREO - 11
AREAO = AREAO + DAREO
CALL LOADX (XN(M,I), DAREC, LOAOO)
565 CONTINUE
IF (YN(M, IJ) 572, 566, 559
572 STOP 572
562 ™! M-l, I)' YO (K-l, Lll 568, 568, 567
567 D°AREON=E (YOU, L, + YO(K-1, Lll * (XO(K, L) - XC(K-1, Lll
! * 0.5
AREAO = AREAO + DAREO
CALL LOADX (XO(K,L), DAREC, LOADC)
GO TO 569
""" '1'' ioli ir.V/, Ji;
AREAO = AREAO + DAREO
CALL LOADX (XO(K,L), DAREC, LOADO)
569 CONTINUE
IF (YO(K, D) 573, 566, 559
573 STOP 573
C
C
566 CONTINUE
AMOUNT = LOADA - LOADC
IF (AMOUNT + 0.00001) 801, 802, 802
801 WRITE (6, 303) AMOUNT, LOADA, LOADC
DO 805 K = 1, 50
8G5 CALL XCYO (K, L)
DO 804 M = 1, 50
804 CALL XNYN
-------
STOP 801
302 CONTINUE ,
803 FORMAT (2F20.6)
RETURN
END
222
-------
SUBROUTINE EFFVAL (I, J, D, EFF)
e
C • SUBROUTINE EFFVAL CALCULATES THE EFFICIENCY VALUES REQUIRED.
C IF CHANGES ARE To BE HADE TO THE EQUATIONS THE CHANGES NEED .
C ONLY ENTERED HERE. NOTE THAT THESE ARE EXPRESSIONS FOR POINT
C EFFICIENCY WHICH HAVE BEEN DERIVED FROM THE AVERAGE EFFICIENCY
C EXPRESSIONS SUPPLIED BY CEL.
C
COMMON LOAD (30)
COMMON KKKOD (36)
COMMON NSTATt NLOC
COMMON X(30), GPM (30), DIA (30), SLOPE (30)
COMMON XTTdOO, 36), YTT( 100,36)
COMMON XX (31), Z(36)
COMMON XOdQO, 31), YC(100,31)
COMMON XN (50, 36), YN (50, 36)
COMMON VOL (36,30),QF(36)
REAL LOAD
DATA ALPHA /l.O/
DATA Al /-13.7/
DATA A2 /2A.68/
DATA C2 /-.0000711/
DATA BETA /1.6/
C D DISTANCE FROM STATION
C DIA DIAMETER OF PIPE - FT
C EFF POINT EFFICIENCY AT D FRCM STATION
C GPM AVERAGE BASE FLOW IN A PIPE - CU FT / SEC
C I TYPE OF STATION
C J LOCATION
C KKKOD CODE FOR TYPE OF FLUSHING WATER 0-CLEAN 1-OIRTY
.C QF RATE OF FLUSH FLCH - CU FT /SEC
C SLOPE AVERAGE SLCPE OF PIPE - PERCENT
C VOL VOLUME OF WATER DISCHARGED BY FLUSHING STATION - CU FT
IF (D) 7, 7t 5
7 EFF = 100
RETURN
9 CONJINLE
A3 = VOL(I,JJ **1.3 * QFU) ** 0.9 * SLOPE(J) ** 1.4 * 1E4 /
1 GPM(J) ** 1.2 * DIA(J) ** 1.8
EFF = Al * A2 * ALOG1C (A3 / D ** BETA) - BETA * A2 / ALOG (10.C)
EFF = AMIN1 (EFF, 100.C)
IF (KKKCDU )) 1, 1,2
1 RETURN
2 CONTINUE
Cl=100 - 14.3 + .1A*VCL(I,J) + .242*GF(I)
Cl = Cl / 1GC
EFF = EFF * (Cl + C2 * D ** ALPHA * (1 + ALPHA)) +
1 (BETA * C2 * A2 * ALPHA * D ** ALPHA/ ALOG(IO.O))
EFF = AMIN1 (EFF, 100.C)
RETURN
END
223
-------
c
c
SUBROUTINE SAVEFF :
COMMON XN (50, 36), YN (50, 36)
COMMON VOL (36,30),QF(36)
REAL LOAD
SLOPE (30*
c
c
DIMENSION YT(lOO), XT (I CO 1
C
C
C
C
C
C
C
C
C
C
C
C
c
c
c
c
c
c
c
c
c
I
J
L
LL
LLL
LOWYN
M
MM
N
NSTAT
SN,YN
XO,YO
XT,YT
XTT,YTT
XI, Yl
I = L
LL = LLL
IF (J -
525 STOP 525
526 CONTINUE
I = LLL
N = 0
528 CONTINUE
.N = N +
YO (N, I
-' 'XO (N, I
YTT(N, I
XTT(N, I
IF (XN(N
527 CONTINUE
IF (LL -
554 STOP 554
552 CONTINUE
DO 550 N
XTT (1,
YTT (1,
DO 550 M
TYPE OF CURRENT STATION "
LOCATION OF STATION
TYPE OF STATION TG BE SAVED
TYPE OF PREVIOUS STATION
TYPE OF PREVIOUS STATION
YN ' \ •. 1
t »'' -. -' ; • .
1 . •-•.,!...-. - • .
) = YN ,(N, i) u » , t . ,
) = XN "'• •
N) = 0
N) = 0 •'• ' "
= 2, 100
.224
-------
XTT (M, N) = 1E19
YTT (M, N) = 0
550 CONTINUE
N = 0
59 CONTINUE
N = N + 1 .
YTT (N, 1) = YO (N, I)
XTT (N, 1) = XO (N, I)
IF (XO (N, I) - 1E18) 59, 64, 64
553 CONTINUE
C FIND LOCATION IN XG,YO TABLE
C
DO 78 N = 1, 100
IF (XN(1 ,1) - XO (N, Lll 79* 58t 58
58 CONTINUE
XTT (N, LLL) = XO (N, L)
YTT (N, LLL) = YO (N, L) ;
78 CONTINUE
N = 2 ••
79 CONTINUE ,
C
C FIND HIGH ENVELOPE
C
M = 1 ,
MM = 0 ,. ,
If — M *— 1
IF~(YN(«, I) - YO(K, Lll 535* 535, 536
535 CONTINUE
LOHYN.,= i , . - -
GO TO' .5.37 , :-••-.
536 CONTINUE - . . ' . '
'' LOWYN = 2
537 CONTINUE
763 CONTINUE
IF IXNCM, I» - XO(K, LI) 540, 538* 748
538 CONTINUE . , b/,
.c , .
IF (XT(MM) - 1E18) 537, 749, t49
544 CONTINUE
XT(MM) = XO(K, L)
YT(KM) = YO(K, L)
K = K * 1 '
M = M + 1
LOWYN =1 ' , , -
IF (XT(MM> - 1E18) 537, 74<5* 749
542 CONTINUE
IF (LOWYN - 2) 546, 545, 546 . .
545 CONTINUE
XTIMM) = XN (M, I)
225
-------
YT(MM) = YN('M, I )
K = K + 1
M = M -f 1 •...•..-;•••-.-•
LOWYN = 2 '"'• ' ' ' " ;' * •*:•''•''••
IF - 1E18) 537, 749, 749 ' * ' ,k '
546 CONTINUE - ' ' . '. ' • .
CALL X1Y1 |XO(K-1, L), YO(K-1, L), XN * 1.00001) 761, 761, 771
761 CONTINUE
775 C^T ' 1|-««^«*i" '"."3,773
K = K + 1 ,«
GO TO 763 . -
762 CONTINUE ' - . -
IF (YN(Mt I) - Yl) 541, 541, 542
748 CONTINUE
IF (YO (K, L)) 754, 755, 758
758 IF
-------
764
773
749
c
c
c
60
62
1C1
1C2
65
64
63
67
CONTINUE
CALL XlYl (XNjP-lfljtVMK-l,!), XO(K,L),0.0, XO(K»L> . 100.0,
1 XMM»I1.tYfc
-------
c
c
c
c
c
c
c
SUBROUTINE X1Y1
-------
SUBROUTINE XOYO (I, J)
COMMON LOAD (30)
COMMON KKKOO (36)
NSTAT, NLOC
X130), GPM (30), DIA (30)»
XTK100, 36), YTT(100,36)
XX (31) , Z(36)
XOdOOt 31) , YC( 100,31')
XN (50, 36), YN (50, 36)
VOL (36,3C),QF(36)
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
REAL LOAD
WRITE (6,
FORMAT (•
RETURN
END
SLOPE (30)
1) It J, XCUt J) , YOU,
XCYO1, 2110, 2F2C.6)
J)
229
-------
SUBROUTINE XNYN (I, J)
COMMUN LOAD (30)
COMMON KKKOD (36)
NSTAT, NLOC
X(30), GPM (301 , DIA (30),
XTTdOC, 36), YTT(1QO,36)
XX (31), Z<36)
XOdOO, 31) , YC(1CC,3U
XN (50, 36) , YN (5C, 36)
VOL (36,30),QF(36)
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
REAL LCAD
WRITE (6,
FORMAT («
RETURN
END
SLOPE (30)
1) It
XNYN'
J, XN( 1, J), YN (I, J)
r 2I1C, 2F2Q.6)
230
-------
SUBROUTINE AREOX (K, L, AREAG)
COMMON LOAD (30)
COMMON KKKOD (36)
NSTAT, NLOC
X(30), GPM (30)t DIA (30)t
XTT(ICOt 36), YTT(100»36)
XX (31) , Z(36)
XOdOOt 31) t YC(10G,3i)
XN (50, 36) , YN (50, 36)
VOL (36»30),QF(36)
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
REAL LOAD
WRITE (6,
FORMAT («
RETURN
END
SLOPE (30)
1) K, L, XG(K,L), YO(K,L)i AREAO
AREAOS 2I10t 3F20.6)
231
-------
c
c
c
c
c
c
SUBROUTINE LOADX (XXX, AREA, LOACA)
AREA AREA UNDER EFFICIENCY CURVE - PERCENT * FT
LOAD AMOUNT OF DEPOSITED MATERIAL - LB / FT
LOACA AMCUNT OF MATERIAL REMOVED - LB
XXX LOCATION OF RIGHT HAND END CF 'AREA SEGMENT
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
REAL LOAD
REAL LOADA
LOAD (30)
KKKOD 136)
NSTAT, NLOC
X(30) , GPP (30), DIA (30)»
XTT(100, 36), YTT(1CO,36)
XX (31), Z(36)
X0(100, 31), YG(1CC,31)
XN (50, 36) , YN (50, 36) '
VOL (36,30) ,GF(36)
SLOPE (30)
DO 1 I = 1, NLCC
IF (XXX - XX( 1 + 1)) 2, 2, 1
1 CONTINUE
I = NLOC
2 J = I
LOADA = LOADA + AREA * LOAD (J) * 0.01
RETURN
END
232
-------
c
c
c
c
c
c
LOCATION
NO OF THE EFFICIENCY CURVE
EFFICIENCY CURVE
AMOUNT OF SOLIDS CN THIS REACH.
SUBROUTINE SOLD (Jf M, SCLID)
J
M
XOYO
SOLID
COMMON
COMMON
COMMON
COMMON
COMMON
COMMON
COM.MCN
COMMON
COMMON
-<• LB
LOAD (30)
KKKOD (36)
NSTAT, NLOC
X(30), GPM (3G), DIA (30), SLOPE (30)
XTT{ICC, 36), YTT(100,36)
XX (31), Z(36)
XOdOO, 31), YC(100t31)
XN (5C, 36), YN (5C, 36)
VOL (36,30),QF(36»
(J) ) 1, it 2
REAL LCAO
SOLID = 0
DO I 1=1, 100
IF (XO (I, M) - XX
CONTINUE
STOP 7788
CONTINUE
DAREA - (XO(I,M) - XQ(L-1,M))
SOLID = SOLID + DAREA * LCAD
IF (XO (I, P) - XX (J + 1)1 3,
1 = 1 + 1
GO TO 2
CONTINUE
"RETURN
END
* (YO(I-l,M)
(J) * 0.01
4, A
+ Y0( I,M)) * 0.5
233
-------
1
Accession Number
w
5
« Subject Field & Group
05D
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
"R\tf P. nr»rr»m*ati rm - San fa HI a ra . naliforni a
Central Engineering Laboratories
Title
A FLUSHING SYSTEM FOR COMBINED SEWER CLEANSING
10
22
Authorfs)
Monroe, Darrell W.
Pelmulder, John P.
i i Project Designation
EPA, WQ0 Contract No. 14-12-466
21 Note
Citation
23
Descriptors (Starred First)
*Deposited Solids, *Combined Sewers, *Lateral Sewers, Storm Water
Overflows, Pollutional Material
05 Identifiers (Starred First)
^-Periodic Flushing, Average Cleansing Efficiency, Solids Removal
27 AOSlracl Because solids deposits in lateral sewers are considered to contribute a sig-
nificant quantity of pollutional material to storm water overflows from combined sewers,
the use of a periodic flushing operation was evaluated as a means of maintaining lower
levels of these deposited materials during low-flow, dry weather periods.
Full scale tests were conducted on two variable-slope test sewers (12-and 18-inch diam-
eters). During the tests, solids were first allowed to build up in both test sewers by
passing domestic sewage through the sewers for durations of 12 to 40 hours and then
were removed by hydraulic flushing. The results from the tests showed that flush waves
generated using flush volumes ranging from 300 to 900 gallons at average release rates
ranging from 200 to 3000 gpm were found to remove from 20 to 90 percent of the solids
deposited in the 800-foot long test sewers.
The cost of installing a periodic flushing system in a typical system of lateral sewers
was estimated to be $620 to $1, 275 per acre.
This report was submitted in fulfillment of Contract Number 14-12-466 under the
sponsorship of the Environmental Protection Agency.
Abstractor
I Institution
SEND. WITH COPY OF DOCUMENT. TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 20240
*U.S. GOVERNMENT PRINTING OFFICE: 1972-484-484/161 1-3
235
------- |