EPA-600/2-77-017C
July 1977
Environmental Protection Technology Series
SEWER INFILTRATION AND
limN**** *
INFLOW CONTROL PRODUCT AND
1 " • ' -
EQUlilENT GUIDE
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Municipal Research Laboratory
Office o{ Research and Development
I^Mjws „,,„-.,_, '
U.S, Protection Agency
pfeincinnati, Ohio 45288
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-017c
July 1977
SEWER INFILTRATION AND INFLOW CONTROL
PRODUCT AND EQUIPMENT GUIDE
By
William S. Foster
Richard H. Sullivan
American Public Works Association
Chicago, Illinois 60637
Grant No. 803151
Project Officer
Anthony N. Tafuri
Storm & Combined Sewer Section
Wastewater Research Division
Municipal Environmental Research Laboratory (Cincinnati)
Edison, New Jersey 08817
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal
Environmental Research Laboratory, U.S. Environmental
Protection Agency, and approved for publication. Approval does
not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does
mention of trade names or commercial products constitute
endorsement or recommendation for use by the U.S.
Environmental Protection Agency and the American Public
Works Association.
11
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FOREWORD
The Environmental Protection Agency was created because
of increasing public and government concern about the dangers
of pollution to the health and welfare of the American people.
Noxious air, foul water, and spoiled land are tragic testimony to
the deterioration of our natural environment. The complexity of
that environment and the interplay between its components
requires a concentrated and integrated attack on the problem.
Research and development is that necessary first step in
problem solution and it involves defining the problem, measuring
its impact, and searching for solutions. The Municipal
Environmental Research Laboratory develops new and improved
technology and systems for the prevention, treatment, and
management of waste water and solid and hazardous waste
pollutant discharges from municipal and community sources, for
the preservation and treatment of public drinking water supplies,
and to minimize the adverse economic, social, health, and
aesthetic effects of pollution. This publication is one of the
products of that research; a most vital communications link
between the researcher and the user community.
Control of Infiltration/Inflow (I/I) has become a major
early step in reducing the amount of untreated or poorly
treated discharges of municipal sewage to receiving waters. This
product and equipment guide has been presented to provide a
ready fsference for those concerned with identifying and
controlling I/I.
Francis T. Mayo
Director
Municipal Environmental Research Laboratory
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ABSTRACT
The report lists and discusses new and existing equipment,
materials, and practices available to prevent the entry of
unwanted water into the sewer system from infiltration and
inflow, and thereby needlessly usurping the capacity of the
sewerage system.
The report has six sections covering:
A description of sewer cleaning techniques and equipment
needed to help locate points of infiltration and inflow and
to improve the accuracy of flow measurement.
A review of flow-measurement equipment and techniques
needed for a determination of the quantity of infiltration
and inflow.
An examination of equipment and practices used to inspect
the sewers and locate the entry points of unwanted water.
This involves closed-circuit television, photographic
inspection, low-pressure air testing, and smoke inspection.
A discussion of current sewer-grouting practices, equipment,
and material, concentrating on the acrylamide gel, and the
elastomeric grouting compound.
A review of insertion pipe for rehabilitation, sewer fittings,
and a brief discussion of trench backfilling monitored by
nuclear soil-density meters.
An examination of safety practices that should be followed
when crews undertake the task of controlling sewer
infiltration and inflow.
The product and equipment guide and the accompanying
report and manual of practice were submitted in partial fulfill-
ment of Grant No. 803151 between the U.S. Environmental
Protection Agency and the American Public Works Association.
Work was completed'as of November, 1976!
1.
2.
3.
4.
5.
6.
IV
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TABLE OF CONTENTS
Page
Section I: Introduction , . - , •
Section II: Flow Measurement and Monitoring £
A. Principal Suppliers of Flow Measuring/Monitoring Equipment 3
« American Chain and Cable Co., Inc *
« Badger Meter, Inc ,.
• Corning Laboratories, Inc
» Drexelbrook Engineering Co
• Cues, Inc 6
o Environmental Measurement Systems '
« Fitzgerald Engineering Co., Inc
o Leupold & Stevens, Inc • • • >
o Manning Environmental Corp
e Martig Bub-L-Air „
« NB Products, Inc g
• N-Con Systems Co., Inc
e Robertshaw Controls Co.
• Sigamotor, Inc. • g
• Tri-Aid Sciences, Inc Q
• UES Universal Engineered Systems, Inc y
B. Measuring Flumes and Weirs "'''"' '9
• Badger Meter, Inc „
• Flume Co o
• Hinde Engineering Co. of California ' ' 9
• F. B. Leopold Co JQ
• Manning Environmental Corp
* NB Products, Inc 1 „
9 Plasti-Fab, Inc. *Q
« Polcon, Inc ,„
9 Robertshaw Controls Co
» UES Universal Engineered Systems, Inc j"
C. Velocity Meters and Dyes for Velocity Measurements jj
• American Chain and Cable Co., Inc |L
« Badger Meter, Inc ^
• Cues, Inc ' ,,
• Formulabs Fluorescent Dye Tracing Systems Division ||
• Kahl Scientific Instrument Corp ;..,.... 11
• Marsh-McBirney, Inc •
Section III: Sewer Cleaning Techniques and Equipment |8
A. Principal Suppliers of Bucket-Type Cleaners ^
• W. S. Darley & Company J^
• Rockwell International | ^
• W. H. Stewart, Inc
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TABLE OF CONTENTS (continued) page
B. Principal Suppliers of Rotating-Rod Sewer Cleaners 20
• O'Brien Mfg. Division, Conco, Inc 20
• O. K. Champion Corp 20
• Ridge Tool Company 20
• Rockwell International 20
• W. H. Stewart, Inc.. .'..'..'........ 21
C. Principal Suppliers of Spring-Cable Type Cleaners 21
• W. S. Darley & Co '.'.'.'.'.'.'.'.' 21
• Electric Eel Manufacturing Company, Inc 21
• Ridge Tool Company . . . ' 21
D. Principal Suppliers of Wood Cleaning Rods .'.'.'!.'"''' 22
• W. S. Darley & Company 22
• W, H. Stewart, Inc '.'.'.'.'. 22
E. Principal Suppliers of High-Velocity Jet Cleaners . . '. '. .......... ' ' 22
• AAA Pipe Cleaning Corp '.'.''"' 22
• Aquatech, Inc - .... 22
• W. S. Darley & Company 23
• Central Engineering Company, Inc '.'.'.. 23
• Cues, Inc 23
• Elgin Leach Corp .... 23
• Flo-Max, Inc 23
• FMC Corp '.'.'.'.'.'.'.'.'. 23
• Hydra-Dy-Namic Cleaners, Inc '.'.'.'.'.'.'.'. 24
• F. E. Myers & Brother Company '.'.'.'. 24
• Myers-Sherman Company . ' ' 24
• O'Brien Manufacturing Division, Conco, Incorporated 25
• Rockwell International ' 25
F. Principal Suppliers of Sewer Cleaning Ball '.'.'.'.'. 26
• Cherne Industrial, Inc '.'.'.'.'.'.'.'. 26
• Cues, Inc 2g
• Sidu Manufacturing Company '...'.''"' 26
G. Principal Suppliers of Hinged-Disc Sewer Cleaners : 96
• Cues, Inc '.'.'.'.'. 26
• Fitzgerald Engineering Company, Inc 27
H. Principal Suppliers of Suction Manhole-Cleaning Units ...... ' ' ' " ' 27
• Aquatech, Inc 27
• Central Engineering Company 28
• Cues, Inc '.'.'.'. 28
• Elgin Leach Corp 28
• Industrial and Municipal Engineering (I.M.E.) 28
• Naylor Industries . . .- '.'.'.'. 28
• Rockwell International 28
• Super Products 28
I. Principal Suppliers of Chemicals for Root Control I . 29
• Airrigation Engineering Company, Inc . . 29
• Applied Biochemists, Inc '.'.'. 29
• Cities Service Industries 29
• Oxford Chemicals '.'.'.'. 30
• Phelps Dodge Refining Corp 30
• Reliance Chemicals Corp ?Q
• Rohm and Haas Company 30
VI
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TABLE OF CONTENTS (Continued)
Page
Section IV: Sewer Grouting ...................... -, ..... 38
A. Principal Suppliers of Grouting Material and Equipment ..... ...... 4 1
« American Cyanamid Company ................. ...... 41
• Cherne Industrial, Inc .............. • ....... ...... 41
• Cues, Inc ....... • .................... ' ...... 42
• Dolfran, Inc .......................... ", ...... 42
• Fitzgerald Engineering Company, Inc ............. • ...... 42
• Halliburton Services ..................... : ...... 42
• Minnesota Mining & Manufacturing Company - 3M ....... ; ...... 42
• O'Brien Manufacturing Division, Conco, Inc ........... j ...... 42
B. Principal Suppliers of Gunite .................. ...... 43
• IPA Systems, Inc ........................ • ..... 43
• Pressure Concrete Construction Company ........... ...... 43
Section V: Sewer Inspection and Testing ............... ', ...... 46
A. Principal Manufacturers of Smoke-Testing Equipment ...... ; ...... 47
• Air Techniques, Inc ............... ....... ...... 47
• Cues, Inc ........................... ! ...... 47
• Superior Signal Company, Inc .................. ...... 47
B. Principal Manufacturers of Closed-Circuit Television for Sewer Inspection . , . 48
• Cherne Industrial, Inc ..................... ...... 48
• Cues, Inc ........................... ....... .48
• Fitzgerald Engineering Company, Inc ........... . . .; ...... 48
• Flo-Max, Inc .......................... , ..... -49
• Halliburton Services ... .................. ...... 49
• Underground Surveys Corporation ............... ...... 49
C. Principal Manufacturers of Photographic Camera Inspection Equipment .... 50
• Aquatech, Inc ...... ................. - • ...... 50
• Entcor, Inc .................. • ........ ...... 50
• Cues, Inc. .* .......... ......... • ..... ; ...... 50
• Gelco, Photographic Division ................. ...... 50
• Underground Surveys Corporation ............... | ...... 50
• United Survey, Inc. ... ................... . •! ...... 50
D. Principal Suppliers of Sewer Plugs ............... ...... 51
• Cherne Industrial, Inc. ... .............. ...... I ...... 51
• Cues, Inc ........................... ; ...... 51
• Fernco Joint Sealer Co ..................... ...... 51
• NB Products ................. ........ ....... 52
• Naylor Industries ....................... ' ...... 52
• United Survey, Inc ....................... ...... 52
Section VI: Pipe and Appurtenances .............. • • -| ..... -56
A. Principal Suppliers of Plastic Insertion Pipe . . . ..... ... ...... 56
• Celanese Piping Systems ................ . . . J ...... 56
• E. I. DuPont de Nemours & Company ........... , .] ...... 56
• Goodall Rubber Company ................... | ...... 56
• Nipak, Incorporated ...... .............. •• • . ...... 56
• Phillips Products Company, Inc. *. ............... ...... 57
• Joseph T. Ryerson & Sons, Inc ................. ...... 57
• M. L. Sheldon Plastics Corporation ...... .... ..... ....... 57
• Evanston Development Corp. . . ............... [ ...... 57
vu
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TABLE OF CONTENTS (continued) Page
B. Principal Manufacturers of Flexible Connections and Fittings 57
• A-Lok Products Corp 57
• Fernco Joint Sealer Co : ... 58
• The Formcrete Company 58
• GPK Products, Inc !!.'.'! 58
• Interpace Corporation ; ... 58
• Mission Clay Products Corporation '. . . . 58
• National Pollution Control Systems, Inc 58
• Press-Seal Gasket Corporation 58
• Price Brothers Company 58
• Resilient Seal Corporation ^ ... 58
• Rimrock Enterprises, Inc. 59
• Scales Manufacturing Corporation 59
• Thunderline Corporation 59
C. Supplier of Mechanical Manhole Closures 59
• Methods Engineering Corporation 59
D. Principal Suppliers of Nuclear Soil-Density Meters 60
• Campbell Pacific Nuclear Company : ... 60
• Seaman Nuclear Corporation ; ... 60
• Soiltest, Inc 60
• Troxler Electronic Laboratories, Inc. 60
E. Supplier of Deflection Gauges 61
• Quality Test Products '.'.'.'.'.'.'. 61
Section VII: Safety Measures 66
A. Principal Suppliers of Traffic Control Equipment
for Street-Maintenance Operations 68
• R. E. Dietz Co '68
• W. S. Darley & Co '.'.'.'.'.'.'. 68
• Eastern Metal of Elmira, Incorporated 68
• Electro-line Product Company . 68
• Industrial Products Company 68
• Grimco, Incorporated 68
• Lyle Signs, Incorporated 68
• Julian A. McDermott Corporation 68
• Mercury Products Corporation 68
• Minnesota Mining & Manufacturing Company — 3M 68
• Radiator Specialty Company 68
• Safety Flag Company of America 68
• Safety Guide Products 68
• SA-SO, Inc. 68
• Streeter-Amet Division, Mangood Corporation 69
• Toledo Pressed Steel Company 69
• Traffic Safety Supply Company 69
• VePed Traffic Controls, Inc 69
• West Side Iron Works, Inc ' ' \ 69
B. Principal Suppliers of Equipment for Use by Personnel Working
in Manholes and Sewers 72
1. Safety Body Harness 72
• W. S. Darley & Company 72
vm
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TABLE OF CONTENTS (continued)
Page
• Miller Equipment Division, ESB, Inc. 72
• Mine Safety Appliances Company 72
2. Ventilation Tubing 73
• National Mine Service Company 73
3. Toxic Gas Detectors 73
• Bendix Environmental Science Division 73
• Bio Marine Industries 73
• Energetics Science, Inc 73
• Matheson Gas Products 73
• Mine Safety Appliances Company 73
• National Mine Service Company 73
• Naylor Industries 73
4. Combustible Gas and Oxygen Measuring Instruments 74
• Bendix Environmental Science Division 74
• Bio Marine Industries . 74
• Mine Safety Appliances Company -74
5. Self-Contained Breathing Apparatus, NIOSHApproved 74
• Bio Marine Industries : 74
• Globe Safety Products, Inc 74
• Mine Safety Appliances Company 74
• Scott Aviation 74
• SurvivAir Division, U.S. Divers Company 74
6. Supplied-Air Respirators 74
• Mine Safety Appliances Company 74
• Minnesota Mining & Manufacturing Company - 3M 74
• Scott Aviation 74
• SurvivAir Division, U.S. Divers Co 74
• United States Safety Service -74
7. Explosion-Proof Hand Lights 74
• Julian A. McDermott Corp • • 74
Section VIII: References • 77
APPENDIX A
Characteristics of Dangerous Gases Encountered in Sewers,
Sewage Pumping Stations, and Sewage Treatment Plants 78
EXHIBITS
1. Typical Grouting Equipment for Increased Strength AM-9 . . . . 43
IX
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FIGURES Page
1. Groundwater gauge 12
2. Float recorder system 12
3. Scow float recorder system 12
4. Air bubble measuring system 13
5. Sonic flowmeter - 13
6. Sonic flowmeter in open channel flume 14
7. Sonic flowmeter for flumes 15
8. Measuring flume with imbedded sensor 15
9. Flow measuring probes 16
10. V-notch weir 16
11. Standard dimensions of measuring weir 17
12. Bucket-type cleaner with conveyor loader 30
13. Trailer-mounted rodding machine 31
14. Trailer-mounted rodding unit 31
15. High-velocity hydraulic jet sewer cleaner ._ . 32
16. High-velocity sewer cleaners .32
17. High-velocity cleaning hose-reel 33
18. Combination high-velocity jet cleaner and vacuum debris-removal unit 33
19. Combination high-velocity jet cleaner and vacuum debris-removal unit ..... 34
20. Truck-and-trailer combination 35
21. Hydraulically.powered cutter . . . 35
22. Hinged-disc cleaner ; ... 36
23. Operation of hinged-disc cleaner 36
24. Hydraulic manhole and catchbasin cleaner 36
25. Hydraulic-type manhole cleaner 37
26. Combo-hydraulic-type manhole and catchbasin cleaner and street flusher ; . . .39
27. Application of acrylamide-gel grout : ... 44
28. Television camera location of leaks 44
29. Storm-sewer sealed with urethane foam grout 44
30. Urethane grout sealing using special grouting ring 45
31. Smoke testing . 52
32. Illegal connection with sewer 52
33. Isolation of smoke tested line 53
34. Waterproof television camera 53
35. Control center — camera and television monitor 54
36. Sewer plug and connection bypass for service during repair 54
37. Low-pressure air testing 55
38. Low-pressure air testing 55
39. Collapsing sewer line, Baytown, Texas 61
40. Special connection permits pulling of pipe through old sewer 61
41. Manhole Connector 62
42. Sealing boot 63
43. Single-wall plastic pipe •:. 64
44. Vibrating compactor mounted on back hoe 64
45. Nuclear meter — soil density 65
46. Oxygen indicator — atmosphere tester 75
47. Portable indicator — oxygen deficiency & combustible gas 75
48. Rescue personnel safety equipment 76
49. Wrist harness 76
50. Constant-flow air-line respirator • 76
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ACKNOWLEDGEMENTS
The American Public Works Association is deeply indebted to the
following persons and their organizations for the services rendered to the
APWA Research Foundation in carrying out this study.
Willaim S. Foster, P.E.
Consultant
Richard H. Sullivan
Project Director i
U.S. ENVIRONMENTAL PROTECTION AGENCY
Richard Field ;
Anthony N. Tafuri i
David J. Cesareo ,
i
• i
PROJECT STEERING COMMITTEE
Stuart H. Brehm, Jr.
Leland E. Gottstein j
A.E. Holcomb j
William D. Hurst, P.E.
Shelley F. Jones i
James M. MacBride
In addition the cooperation and assitance of the manufacturers listed is
acknowledged for their help in supplying information concerning their
independent product lines.
XI
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SECTION I
INTRODUCTION
The need to prevent infiltration of
groundwater. and other sources of unwanted
water into a community's sewer system is well
known and requires no documentation.
However, one estimate can illustrate the
negative impact of infiltration on the
correction of the nation's water-pollution
difficulties. Testimony at a Congressional
Committee hearing estimated that these
sources of unwanted water usurp at least 15
percent of the hydraulic capacity of the
nation's sewerage systems.1
An estimate2 of 460,000 miles (740,000
km) has been made as the total length of
sewer used in communities of 2,500 or more.
If 15 percent is inoperative because of
infiltration and inflow (I/I), this amounts to
69,000 miles (111,000 km) of sewers, or
about the same as all the sewers now in use in
municipalities of 500,000 or more.
Collection Systems Neglected
While the collection system represents
about 80 percent of the community's
sewerage investment, those involved in this
work have largely neglected it in favor of
development of treatment techniques and
similar studies. A recent review of the
research literature compiled by the Water
Pollution Control Federation showed that less
than 3 percent of the review was devoted to
wastewater collection.3
Scope of Survey
To respond to the need for more
complete information on how this
unnecessary I/I can be prevented, this review
will survey equipment, materials, and
techniques that will:
(1) clean sewers to clear away blockages.
(2) detect"and measure the flow in sewers to
help determine how much infiltration
exists.
(3) inspect the condition of the sewers and
test to see whether problems are evident.
(4) rehabilitate the system by grouting and
other techniques.
(5) list pipe linings and fittings that can be
used in new sewers, or as replacement for
damaged portions of old lines.
(6) outline safety measures that should be
followed when working in sewers and
manholes.
Many have noted a complete change in
the attitudes of designers and operators of
sewerage systems toward infiltration and
inflow. In the past, most were indifferent to
this source of water, arid some may have
welcomed it. Today the policy is to prevent
its entry insofar as it is economically possible.
The I/I detection and control area has
developed rapidly and changes are occurring
daily, resulting in products and practices
becoming obsolete or outdated over a
relatively short period.
This product and equipment guide is not
a complete listing of all products or
manufacturers who have products of use in I/I
detection or correction, but rather lists the
major suppliers identified during the course of
the APWA study. Neither the USEPA nor
APWA by reference in this report
recommends or endorses the use of a
particular item. Prices where given are those
supplied to the APWA in the fall of 1975 and
should be used only as an indication of the
costs.
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SECTION II
FLOW MEASUREMENT AND MONITORING
The investment in a sewer system is from
three to four times that of the wastewater
treatment facilities. Yet few governmental
agencies have made detailed surveys of these
flows or the conditions of the pipes and
manholes in the system. Flow is routinely
measured as it enters the treatment plant or
«,pumping stations, but rarely is flow
monitored in individual sections of the
systems, except for casual inspections at
manholes.
Monitoring in precise form is needed to
help identify more accurately infiltration that
usurps the capacity of the collection system
and treatment works. It also is needed to
calculate the reserve capacities of the various
sections of the sewer systems, and to estimate
their abilities to accommodate new loads.
Locating Infiltration-Prone Areas
The measurement of infiltration and
inflow will be assisted by first determining
where the groundwater levels are high enough
to cause problems. One simple method of
monitoring this level is to force a slotted pipe
into the ground directly above the sewer,
through the manhole wall. This pipe should
be provided with an elbow, with a clear
plastic pipe affixed to it, secured to the
manhole wall, and extending vertically to an
elevation above the anticipated groundwater
level. The groundwater will then rise in the
pipe and can be measured easily so that
variations in the levels can be recorded. Figure
1 shows such a unit.
The weakness of this method is that the
groundwater level at manholes may not be
representative of levels elsewhere. So for
greater precision, observation wells should be
located between manholes in areas of critical
concern.
For a quick location of infiltration and
inflow areas, some have found the simple
thermometer to be a useful tool. By noting a
drop in the wastewater temperature, the
investigator has evidence that cold infiltration
water is entering the sewer.
Desirable Characteristics of Monitoring
Equipment
In a study of sewer flows in Columbus,
Ohio and elsewhere, the investigators listed the
desirable characteristics of monitoring
equipment.4
1. The equipment should make accurate
flow measurements in sewers in wet and
dry weather, including those sewers that
surcharge.
2. It should be economical to purchase,
install, and service.
3. It should be reasonably vandal-proof.
4. It should be reusable at other monitoring
sites during the study.
5. It should maintain a minimum head loss
through the measuring equipment to
minimize unwanted effects on the
hydraulic characteristics of the sewer.
6. It should be able to operate automatically
for a minimum of 24 hours.
The equipment should also be rugged and
dependable. Accurate equipment that requires
a great deal of maintenance can present
drawbacks to metering programs, especially in
remote areas.
Measurement of Wastewater Levels
All flow-monitoring equipment for
infiltration and inflow studies requires
measuring the wastewater level over an
extended period. This can be determined by
any of several techniques.
Floats — The simplest of the measuring
units. They can be spherical or cylindrical
floats attached to appropriate measuring and
recording devices, often in a stilling well, or
they may be the broad-based "scows" placed
in the center of the channels. Both require
attention because of the debris in the
wastewater that can collect on them and
interfere with their accuracy. Figures 2 and 3
show typical units.
Bubbler Tubes — Use a technique adapted
from measurement of water levels in tanks.
They require accurately regulated air or gas
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pressures introduced through a tube at the
.bottoms of the channels, as shown in Figure 4.
Ultrasonics - An adaptation of sonar
equipment to the measurement of wastewater
levels offering the advantage of avoiding
contact with the wastewater itself. Figures
5,6,7, show typical units.
Oscillating Probes - Have the advantage
of not actually entering the wastewater. The
measuring device lowers a probe at designated
time intervals to the surface of the
wastewater. When the probe, makes contact, it
completes a microampere circuit that causes
the lowering motor to stop and retract
slightly, permitting appropriate equipment to
record this elevation. At a set time, the motor
again lowers the probe and retracts it when it
touches the wastewater level.
Capacitance Measuring Probe — Can
measure and record wastewater level
continuously through an electronic circuit.
The probe may be mounted directly in the
wastewater stream or in a stilling well. Figures
8 and 9 show typical units.
For a one-time measurement of velocity,
Shelly and Kirkpatrick5 suggest using an
orange, since it floats partially submerged and
therefore travels close to the mean stream
velocity.
Flow Measurement Using the Pipe
Dimension - Useful flow measurements, not
to the greatest of precision, can be made by
using the pipe itself as a means of
measurement. Flow is determined by the
simple but familiar formula, Q = AV.
Calculations can be based on the height of the
wastewater in the sewer and the measured
velocity of the wastewater. It also can be
based on the venerable but highly respected
Manning formula.
To determine the velocity of the
wastewater, the inspectors can use:
1. Floats, although they require continuous
observation and offer no means of
automatic measurement and recording.
2. Dyes, of potassium permanganate,
fluorescein, or rhodamine, however they
also require the presence of an inspector
to note when the center of the mass of
colored liquid passes, and poses the
uncertainty of whether the observed
dye-cloud is the mean or surface velocity.
3. Salts and radioactive tracers, both
adaptable to equipment that permits
automatic measurement and recording
over an extended period.
4. Self-cleaning vanes, movable but set at an
angle to the flow by a calibrated resisting
force; the degree to which the flow in the
sewer overcomes this force measures
velocity, also adaptable to recording
equipment.
Salt Solution - Inspector places two pairs
of electrodes in the stream at a known
distance apart, and energizes them with an
. electrical current to measure velocity. The
electrodes can then signal the passage of the
introduced salt solution by a recording
galvanometer. By introducing the salt solution
at controlled intervals, the equipment can
measure the velocity over a suitable period of
time. The salt solution can be used to measure
velocities at accuracies of better than ±2
percent.
Radioactive tracers — Provide equally
precise measurements; however, many dislike
placing radioactive material in wastewater.
The Manning Formula - Inspector selects
a length of pipe that is smooth and provides
nonturbulent upstream conditions for 200 ft
(60 m). The course should be free of abrupt
dips, sudden contraction or expansions, and
tributary inflows.
The Manning formula requires a
determination of the slope of the water
surface, rather than the pipe itself. It also
requires an estimate of the roughness factor,
generally assumed to be n := 0.013 for pipe in
good condition, in use; however, this can be
only an approximation at best.
Flumes for Flow Measurement
Parshall-type flumes improve the
accuracy of measurement substantially. They
have good range and accuracy, and are only
slightly affected by changes in flow. Solids in
the wastewater do not interfere materially.
The flumes are rugged, retain their
calibration, and are easily portable. They
create only a slight obstruction in the flow
and require very little operator attendance.
Of these flumes, the Palmer-Bowlus type
as shown in Figure 8 has demonstrated
accuracies of ±3 percent of theoretical rating
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at depths as great as 90 percent of the pipe
diameter. The flume has a round bottom
shape which permits it to be mounted easily
in the pipe invert. The flume can be sealed to
the invert section using mastic. It can be held
firmly in position with a sandbag or other
weight.
The Palmer-Bowlus flume should have a
minimum throat length of one pipe diameter,
but in no case less than 60 percent of the pipe
diameter. The point of upstream depth
measurement should be no more than half the
pipe diameter upstream from the entrance to
the flume. The approach sewer should have a
slope of no more than 2 percent.
The Palmer-Bowlus flume originally was
designed in several pieces that could be put
into a pipe of any given diameter, but this
arrangement required field calibration at each
new point of installation. The flumes now can
be obtained in prefabricated precalibrated
form for a given pipe diameter.
The Leopold-Lagco flume is somewhat
similar to the Palmer-Bowlus, but
incorporates important differences. It has a
true rectangular throat section throughout the
entire flow range while the throat of the
Palmer-Bowlus is trapezoidal at the bottom
and rectangular at the top.
Weirs for Flow Measurement
Weirs also offer precision in measuring
and recording waste water flows; however, a
weir restricts the capacity of the sewer. The
most common weir shape for this type of
work is the V-notch using a 90° angle. It can
measure flows of 1 cfs (28.3 1/s) or less, and is
as accurate as any other weir profile to flows
as high as 10 cfs (283 1/s); however, head
requirements at these higher flows may rule
them out. Other common types are the
rectangular and the trapezoidal, or Cipolletti
weirs. Figures 10 and 11 show two types of
available units.
Weirs for this work should meet these
general requirements:
1. Have a smooth upstream face that is
perpendicular to the vertical and
horizontal axes of the channel.
2. Be installed so that the crest will be at
least 1 ft (30 cm) above the approach
channel bottom where pipe size permits,
and the minimum head will be at least 0 2
ft (6 cm).
3. Have a thickness not exceeding 0.125 in.
(0.3 cm).
4. The cross-sectional area of the approach
channel should be at least eight times that
of the nappe at the crest for an upstream
distance of 15 to 20 times the height of
the crest.
5. The crest should be thin, preferably
beveled with the sharp edge upstream;
installed so that the wastewater being
measured will not contact the weir
structure downstream but spring past it.
6. The minimum height of the weir crest
should be at least two and preferably
three times the maximum head expected
over the weir.
7. When the water level under the nappe
rises above the weir crest, the flow may
be considered submerged. To determine
the rate of flow under such submerged
conditions, both the upstream and
downstream heads must be measured and
reference made to submerged flow tables.
8. To avoid the effects of "drawdown" as
the flow passes over the weir, the gauging
point should .be located upstream of .the
weir crest a distance of at least three and
preferably four times the maximum head
expected over the weir. A minimum of 18
in. (46 cm) is generally used.
Weirs can be constructed "in shop" if the
construction is precise and the accuracy of
the measurement checked. However,
prefabricated V-notch weirs are commercially
available with calibrations that permit direct
flow readings.
Successful fabrication of a weir requires
use of aluminum or stainless steel mounted on
marine plywood, using nonferrous screws and
a gasket. The edges should extend at least 1
in. (2.5 cm) above the edges of the plywood
to insure a sharp edge to the notch as the
wastewater flows through it. The
weir-supporting bulkhead should be precisely
braced and anchored in place, sealed with
mastic to insure that all the flow will pass
over the V-notch.
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Safety In Installation and Operation
Since the installation of the equipment
requires the entry into the manhole by
personnel, pre-inspection of the manhole for
explosive gases is mandatory, as well as safety
harnesses and other equipment. For a detailed
discussion of safety practices, see Section VII.
Principal Suppliers of Flow
Measuring/Monitoring
Equipment
Wastewater Level Recorders
American Chain and Cable Company, Inc.,
ACCO Bristol Division, Waterbury,
Connecticut 06720. Produces the Bristol
Series 840 L/V (level and velocity)
Monitoring System for use in large sewers
from 4 to 20 ft (1.2 to 6.1 m) in diameter. It
is portable, and designed for use in manholes.
The unit measures velocity by a drag-type
primary element in the probe assembly. As
the moving stream impinges on the target area
of the element, its impact force causes a linear
deflection which is detected by a strain gauge
bridge and recorded electronically in the
Probe-Controls cabinet.
The level-sensing device in the probe
operates through an air-bubbler principle. The
probe has a self-cleaning feature that operates
at 15-minute intervals.
The manufacturer reports a range of
velocity measurement of 0 to 10 ft/s (0 to 3
m/s) with an accuracy range of ±5 percent.
The liquid-level ranges from 8 in. (20 cm) to
.full conduit with an accuracy of ±0.25 in.
(0.64 cm).
A typical assembly for a 5 ft (1.52 m)
sewer will weigh 300 Ibs (136 kg).
Badger Meter, Inc., Precision Products
Division, 6116 East 15th Street, Tulsa,
Oklahoma 74115. Manufactures the ML-MN
transmitter designed for open-channel flow
'head measurement. A float placed in the
waste water stream determines the level which
is transmitted and recorded on an electronic
receiver, Badger's 2700 series.
The float assembly should have frequent
inspections since it risks the possibility of
fouling or damage from material in the
wastewater.
Badger also produces the models UH 200
and UH 210 ultrasonic flow transmitters
which measure liquid levels in flumes, weirs,
sewers, or other open or partially full
channels. A sonic probe makes the
measurement by transmitting sonic energy to
the fluid surface andjneasuring the elapsed
time for the reflected energy to return. The
UH 210 transmitter converts the level signal
to any specified depth-flow relationship
required. The transmitters can be installed
with relative ease in new and existing
locations. The transmitter must be at least 6
in. (15 cm) above the maximum liquid level.
Accuracy is within 2 percent.
Corning Laboratories, Inc., P.O. Box 625,
Cedar Falls, Iowa 50613. Manufactures the
Corning AquaCorder for sensing and
recording water-level fluctuations. When
installed in a manhole, the unit will
electronically sense water levels at preset time
intervals and record data for as long as three
weeks on one cassette tape. The tape then can
be played back and date sequentially flashed
on the screen of a digital readout, eliminating
the need for charts and pens.
The instrument is designed to measure
water depths to an accuracy of 0.1 in. (0.25
cm). It is self-contained, operates with a
6-volt battery, with electrical circuitry and
components in the upper control unit, out of
danger from wastewater surcharge, and
protected from damage in case of fall, by a
styrofoam liner.
The sensing probe is automatically
lowered from its housing at preset time
intervals by being lowered through a stilling
well. When it touches water, it automatically
stops, records the elevation, and retracts. It
can be "backed" out if accidentally
submerged, and returned to working order.
Its current price is $975.00 f.o.b. Cedar
Falls, Iowa.
.Drexelbrook Engineering Co., 205 Keith
Valley Road, Horsham, Pennsylvania 19044.
Manufactures flow gauges for use with weirs,
flumes, nozzles, and pipe channels. It makes
use of a sensing element with no moving
parts, described as a precision
admittance-to-current transducer. A variation
in liquid levels will cause minute amounts of
current to flow from the sensing probe to the
grounded stream. A compensated bridge
circuit measures this change in current to an
accuracy of ±0.5 percent. The probe
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immersion depth can vary from 12 in. (30.5
cm) to 36 in. (91.5cm).
In the Series 508 models, the system will
ignore build-up on the sensing element, which
can be expected when used in wastewater.
For direct, instream use, an optional tilt-away
mounting is available. With it, the probe is
held by an adjustable counterweight but is
free to pivot out of the way when struck by
an object in the flow. It also will tilt to clean
if the probe collects fibrous materials such as
rags, paper, and similar material.
Current prices of the Series 508 systems
range from $553.00 to $1,371.00 depending
upon immersion span and type of indicating
meter used.
Cues, Inc., P.O. Box 5516, Orlando,
Florida 32805. Manufactures the Q-Flow
Surveyor which measures the level of flow in
the sewer by sensing the level of the
wastewater surface. The probe does not enter
the surface but maintains a position directly
above it. A 24-hour or a 7-day chart records
this level.
A three-legged set of clamps permits
installing the Surveyor in the manhole at
street level. Installation time is reported to be
15 minutes.
Q-Flow Surveyors can be supplied in
three sizes for use in sewers with diameters
from 4 to 120 in. (10 to 315 cm).
Environmental Measurement Systems,
Division of Wesmar, 905 Dexter Avenue
North, Seattle, Washington 98109. Supplies
the noncontact Ultrasonic Flow Monitor
UFM-200 and the portable noncontact
Ultrasonic Manhole Monitor UMM-12.
The UMM-12 was designed specifically
for manhole application. It is a portable,
battery-operated unit employing a
noncontact, ultrasonic sensor to measure the
wastewater level. A digital span dial, which
allows dialing in of pipe sizes from 3 in. (7.5
cm) to 100 in. (2.5 m), automatically
programs the device to measure that size. The
dial is set in increments of 0.1 in. (0.25 cm).
The measured and calculated data appear on a
strip chart. The UMM-12 can operate up to 14
days on one battery charge.
The noncontact Ultrasonic Flow Monitor
UFM-200 permanently records liquid flow
through a weir or flume on an inkless strip
chart and a five-digit totalizer. A visual linear
readout meter indicates gallons per minute.
The unit is factory calibrated to the particular
flume (flow curve) or pipe size for which it
will be used. Calibration can be easily changed
in the field. The UFM-200 can be adapted to
battery operation. Accuracy of: 1 percent at
any point on the scale is ensured.
Fitzgerald Engineering Company, Inc.,
2601 Southwest 69th Court, Miami, Florida
33155. Manufactures the Fitzgerald Flow
Measuring Device to determine the elevation of
the invert, the depth of flow, and the amount
of solids above the invert. Accuracy is stated as
generally 90 percent of the volumetric flow.
Determination can be made within 5 minutes
per reading. •
Leupold & Stevens, Inc., P.O. Box 688,
Beaverton, Oregon 97005. Manufactures three
float operated flow measuring instruments,
Models 61M and 61R flow meters and Type F
recorder, plus a line of staff gauges.
The Model 61R flow meter can be used
with any type of weir or flume by a simple
in-field change of flow cam and gears. It will
record from a range as small as 14,000 gal/d
(53 m3/d) up to extremely large flows. Both
English and metric measurements are
available. A standard 50 ft (15.2 m) strip
chart provides continuous recording from 30
to 180 days. An 8-day spring drive clock or
AC synchronous motor provides power for the
chart drive and seven-digit totalizer. Optional
accessories include a sampler switch, a
chlorinator pacing potentiometer, adjustable
controls for auxiliary equipment or alarms,
and a weatherproof enclosure.
The Model 61M flow meter has an
indicator in place of the chart, otherwise it
has the same features as the Model 61R.
The Type F recorder is a water level
recorder with several styles of charts available.
Two of the charts will record flow, one from
Parshall flumes and one from V-notch weirs.
An automatic clock starter accessory permits
the instrument to sit dormant until a predeter-
mined level is reached whereupon it will begin
recording. It will record from four hours up to
eight days and is available with several clock
drives and a wide range of gears.
Current prices range from around
$415.00 for the Type F up to around
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$850.00 for the Model 61R, depending upon
various options.
' Manning Environmental Corp., P.O. Box
1356 Santa Cruz, California 95061. Produces
the Manning L-2000 and L-3000 series
"Dipper" liquid-level recorders. Both consist
of a control module that lowers a thin,
noncorrosive probe on a weighted wire. When
the probe contacts the water surface, it
completes a microampere circuit through the
conductive liquid to a ground return. This
causes the motor in the control module to
reverse its direction and raise the probe above
the surface for the next cycle. The
manufacturer reports liquid-level accuracies of
0.01 ft (3.28 mm). With special attachments
it can operate at 25 ft (7.6 m) above the flow,
or in manholes with offset channels. The
liquid levels are recorded on a chart powered
by a spring-wound clock mechanism that can
be set for 7 days or for 24 hours.
Major features of the L-2000 series
include:
1. Completely hermetically sealed package
which is rated to withstand surcharges of
1 ft (30 cm) of water above the top of
the case for at least two hours.
Built-in desiccator to absorb internal
condensation.
Charts and recording interchangeable
with existing Dippers, usable with
existing manhole brackets, etc.
An external cable winding assembly
which is readily visible and easy to
maintain.
5. Hermetically sealed cable slack switches
and up stop switches, easily adjusted.
6. An optional clear plastic cover which
allows the operation of the equipment to
be visible without opening the meter.
The L-2000 series provides recording of liquid
level only, with models covering ranges of 15,
30, 60, and 120 in. (38, 76, 152, and 305
cm). The L-3000 provides a recording of flow
rate and totalized flow when used with weirs,
flumes, or round pipes. In addition, it can
actuate a sampler in a flow-proportional basis.
Various models can measure over ranges up to
24,48, and 120 in. (0.61,1.26, and 3.05m). An
important feature is that it can record
overages in case of surcharge and go back to
2.
3.
4.
its original measuring point after the
surcharge. .
A special bracket allows the unit to be
mounted just below street level under the
manhole cover. With the use of a Depth
Calibration Gauge, the initial calibration can
be done from the top of the manhole without
entry.
Current prices of the L-2000 series vary
from $1,075.00 to $1,250.00, plus
accessories. Prices of the L-3000 series vary
from $1,425.00 to $1,570.00, plus
accessories.
Manning also produces an ultrasonic
flowmeter, the UTC-2000 Level Sounder and
Flow Computer. The equipment is built to
offer flow totalization, flow proportional
sampling output, level indication, and flow
recording on a 30-day strip chart. The
manufacturer states that it can provide a
head-to-flow conversion accuracy of better
than 0.4 percent with an overall accuracy of 1
percent. The price of the total package is in
the range of $2,000.00.
Martig Bub-L-Air, 2116 Lakemoore
Drive, Olympia, Washington 98502. Supplies
four models of Bub-L-Air sewer flow
monitors with special sensing probes for pipe
diameters ranging from 4 to 30 in. (10 to 76
cm). Model 1 records flow in sewers not
subject to surcharge. Model 2 records flow in
sewers subject to surcharge to 12.5 ft (3.8 m)..
and will also record groundwater levels
outside'the manhole. Model 3 will record
simultaneous flows from two sewer lines
entering one manhole. It also can record flows
through a single sewer line, and intermittent
flows into the manhole, such as catch-basin
inflow, or discharge from a pumping station
force main. Model 4 is a custom designed
package for special applications.
The sensing tube of the Bub-L-Air is
installed in the upstream sewer line, secured
at the entrance to the manhole by a stainless
steel strap. The recorder and air bottle can be
hung to the manhole ladder, or on a 2 x 4 in.
(5x10 cm) board braced within the manhole.
It can be placed on the manhole floor ledge if
no sewage surcharge is anticipated.
Manufacturer states that the monitor will
record direct linear depth readings from 0.25
-------
to 30 in. (0.63 to 76.2 cm) with an accuracy
of 0.125 in. (3.18 mm), and also emphasizes
portability, tight weight, compactness, and
speed of installation, from 6 to 7 minutes.
Current prices for the monitors, including
probes for 8 to 12 in. (20 to 30 cm) pipe
usable in sewers of 4 in. (10 cm) diameter and
larger are: Model 1, $1,197.00; Models 2 and
3, $1,497.00. No prices listed for Model 4.
NB Products, Inc., 35 Beulah Road, New
Britain, Pennsylvania 18901. Produces the
Series F and Series H manhole meters for use
on pipes from 8 to 48 in. (20 to 122 cm).
The Series F is a portable device
consisting of a transducer equipped with a
telescoping support and a scow-shaped float,
and an instrument case containing a control
box and a strip chart recorder. A sensing unit
inside the transducer determines changes in
the level of water by measuring the float arm
angle of inclination. The recorder can run for
30 days.
The Series H manhole meter totalizes the
flow and records elevations on a 30-day strip
chart, and is distinctive in that it is
programmed to account for variations in the
Manning "n" number. Both should be
adaptable to use with a measuring flume or
weir. Both the F and H models are available
for rental.
N-Con Systems Company, Inc., 308 Main
Street, New Rochelle, New York 10801.
Supplies the surface tracking level recorder
designed to measure and record wastewater
levels in sewer mains without the need for
personnel to enter the manhole. Uses an
adjustable mounting bracket that supports the
recorder on the lip of the manhole
immediately under the cover. A dual contact
probe lowers until it touches the surface and
then retracts 0.125 in. (0.32 cm). A rising
wastewater level causes the probe to retract
immediately until it loses contact with the
wastewater.
It is available in three interchangeable
ranges: 0 to 15 in. (0 to 38 cm); 0 to 30 in. (0
to 76 cm); and 0 to 60 in. (0 to 152 cm). The
Surfer employs a dual traverse-recording
system to double the recording range during
surcharges without loss of record or shifting
of the zero setting. Circular charts permit
one-day or seven-day recording.
Tracking interval is 10 seconds. Power
requirements are 12-volt DC which can be
supplied by a 10-amp/hr rechargeable battery,
available with the unit. It can operate at a
maximum of 25 ft (7.6 m) above the
wastewater surface and can be used either
with a flume or weir for precise measurements
of flow.
Robertshaw Controls Co., Industrial
Instrumentation Division, P.O. Box 26544,
Richmond, Virginia 23261. Produces the
level-Tel transmitter model 157 which appears
applicable to manhole installation along with
the model 725 probe. The probe will measure
head level on primary devices such as weirs and
Parshall flumes. It can be installed directly in
the streamflow for fast response, or in stilling
wells. The probe characterization is
accomplished by varying the effective plate
area and by maintaining a constant insulation
thickness. The transmitter can be mounted
directly on the probe. A variety of recorders
and totalizers can be used with the probe and
transmitter.
Sigamotor, Inc., 14 Elizabeth Street,
Middleport, New York 14105. Supplies the
Sigamotor LMS-400 battery operated meter
that measures the level by the bubbler
principle. Designed for use in manholes to
measure wastewater levels in the open
channel, 'or at flumes or weirs. It weighs either
18 or 35 Ibs (8.2 or 15.9 kg), depending on
the battery selected (it can be powered by
115-volt AC or 12-volt DC).
Its size is 13 x 14 in. (33 x 36 cm) by 10
in. (25 cm) deep. It is equipped with a 31-day
pressure-sensitive strip chart and a six-digit
totalizer.
Tri-Aid Sciences, Inc., 161 Norris Drive,
Rochester, New York 14610. Manufactures
the Tri-Aid ultrasonic noncontacting flow
meter, totalizer, and transmitter instruments
for measuring wastewater flows in open
channels with or without a flume or weir. The
small corrosion resistant, explosion proof,
ultrasonic transducer is for bracket mounting
from a 0.75 in. (1.9 cm) conduit above the
wastewater flow. The electronic measurement
system may be mounted up to 500 ft (152.4
m) from the point of flow measurement.
Automatic temperature compensation is
standard on all units. The highly accurate
-------
instruments read out directly in flow rate,
provide totalized flow and may control flow
proportional sampling. Field calibration of
the instruments is accomplished without the
use of external test equipment.
UES Universal Engineered Systems, Inc.,
7071 Commerce Circle, Pleasanton, California
94566. Manufactures five flow monitor
models. Each Flo/Monitor is manufactured
for specific applications. Model 8090 is for
120V-60Hz use. Model 8091 uses a
rechargeable gel battery and is provided for
applications where 120V power is not
available. Model 8092 is manufactured for
remote operation. It includes a remote
transmitter, located near the flume, which
transmits data to the Flo/Monitor over
distances up to 2,000 ft (610 m). All three of
these Flo/Monitors will accept UES
Palmer-Bowlus flumes, sizes 4 to 15 in. (10 to
38 cm), without any calibration by the
owner.
The UES 8097 Flo/Monitor is
manufactured for applications with
Palmer-Bowlus flumes larger than 15 in. (38
cm), all sizes of Parshall flumes, weirs, and
Venturi tubes. This model is programmed by
the factory for the specific primary use. It
utilizes sensors such as capacitance pressure
sensors, pressure transducers, differential
pressure transducers, and float operated
transducers. This 120V-60Hz model gives a
4-20 mA signal to pace samplers, chlorinators,
and other assorted extras.
The 8098 Flo/Monitor has the same
electronics as the 8097 and is equipped with a
remote transmitter for remote operation up
to a distance of 2,000 ft (610 m).
UES states a ±4 percent accuracy for all
of the Flo/Monitors listed above. Each
instrument contains a six-digit totalizer and a
30-day strip chart recorder. Circular chart
recorders are available by special order. These
solid state Flo/Monitors contain no moving
parts other than the totalizer and recorder.
Prices range from $1,580.00 to $1,980.00.
Measuring Flumes and Weirs
Badger Meter, Inc., Precision Products
Division, 6116 East 15th Street, Tulsa,
Oklahoma 74115. Manufactures a measuring
flume designated the Manhole Meter. The unit
can be inserted through a 20 in. (51 cm)
diameter manhole opening and is produced in
6, 8, 10, and 12 in. (15, 20, 25, and 30 cm)
diameters. The manhole is used as the stilling
well. Self-cleansing flaws are reported and
accuracy is reported as ±2 percent.
Flume Company, P.O. Box 575, Westfield,
New Jersey 07091. Manufactures three-piece
flumes of cast-iron, keyed sections designed
to a venturi form that will fit a circular pipe
or U-channels, often without sealing;
however, the manufacturer states that the
joints are easily sealed. Flumes are designed to
fit pipes with diameters varying from 6
through 30 in. (15 through 76 cm).
Manufacturer recommends scow floats and
Leupold & Stevens Model 61R flow meter,
however; most of the equipment that
measures wastewater levels previously listed
should be able to work with this flume.
Manufacturer states that the flume must
be used in sewers producing less than
"critical" velocities; a table in the
manufacturer's literature gives appropriate
information.
Hinde Engineering Company of
California, P.O. Box 56, Saratoga, California
95070. Manufacturers "Accuro-Flo" insert
flume generally of the Palmer-Bowlus type. It
is made of stainless steel, and is a one-piece
unit. Within the normal range of flows, less
than 10 to as large as 90 percent of pipe
capacity, the accuracy is reported to be
within 3 percent. Sizes range from 6 through
27 in. (15 through 69 cm) in diameter.
Maximum recommended slopes, from the
smallest diameter to the largest, vary from 2.2
to 1.3 percent. Similarly, the flume's
maximum flow capacities vary from 0.35 to
14.7 cfs (9.9 to 416 1/s). To measure the
wastewater levels with on-site recorders, the
manufacturer reported that floats with stilling
wells, scow floats, and bubbler systems have
been used successfully.
F B. Leopold Company, Division ot
Sybron Corporation!; 227 South Division
Street, Zelienopole, Pennsylvania 16063.
'Manufactures the Leopold-Lagco flumes made
in a rectangular cross section and moulded of
a fiberglass laminate with the company name
of Leo-Lite. The flumes can be installed
directly in the sewer line, normally at a
standard straight-through manhole. The most
suitable type for I/it studies is the "insert"
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which can be placed in an existing half section
of pipe. The "cutback" type can be used
where space is critical. The manufacturer
reports accuracy to ±2 percent. Sizes range
from 6 in. (15 cm) to 6 ft (1.8 m). Flow
capacities range from 0.25 cfs (7.1 1/s) to
177.7 cfs (5032 1/s). Prices range from
$300.00 to over $3,000.00.
Manning Environmental Corp., P.O. Box
1356, Santa Cruz, California 95061.
Company offers several Palmer-Bowlus flume
designs. The quick-insert flumes can be
installed in any size pipe or manhole invert.
The more permanent flumes will require
grouting into place. The manufacturer states
that the flumes can measure flow in depths of
95 percent of the pipe diameter within
accuracies of 3 percent. The Palmer-Bowlus
flumes are produced to diameters of 30 in.
(76 cm) with larger sizes available on request.
End bulkheads can be installed to match the
smaller flumes to larger channel shapes.
NB Products, Inc., 35 Beulah Road, New
Britain, Pennsylvania 18901. Produces
portable V-notch weirs in several sizes
specifically designed to measure sewer
infiltration. Adapters are provided so that the
weirs can be installed in sewers with diameters
to 42 in. (107 cm). They are made of.
weather-resistant aluminum. The dial face is
cut from transparent plastic and calibrated for
direct readings in gallons per 24 hours.
Individual weirs can be supplied for sizes to
15 in. (38 cm). The adapters are supplied to
fit the 15 in. (38 cm) weir to the larger sizes.
Plasti-Fab, Inc., P.O. Box 227, Tulatin,
Oregon 97062. The company manufactures
fiberglass Parshall flumes in a variety of sizes
1 in. (2.5 cm) and larger. It also produces
Palmer-Bowlus flumes and "cutback" flumes
in fiberglass and stainless steel, as well as
fiberglass H-flumes for measuring wide ranges
of flow varying as much as 100:1. Also
available are fiberglass trapezoidal and
cutthroat flumes. All flumes can be provided
with accessories such as attached floatwells,
bubble pipes, cavities and supports for
capacitance probes, and mounts for sonic
transducers.'
Polcon, Inc., 8050 Watson Road, St.
Louis, Missouri 63119. Supplies the Polcon
portable sewer meter consisting of a PVC tube
in diameters from 8 through 15 in (20
through 38 cm). The tube is made in 12'in.
(30 cm) segments for insertion at the manhole
into the downstream sewer and clamped
'together. A bubbler system measures flow
depth and a portable instrument assembly
records flow data. Slope of the tube must be
determined within 0.1 percent and normal
operating range is between 0.3 to 5.0 percent.
Several types of units are avilable. The
Polcon DAF instrument is a self contained
air/bubble unit. Electrical power and
compressed air are needed from separate
sources. Four self contained units are
available. Model P.I.P. 100 requires a separate
air source and a spring wound recoiler. The
P.I.P. 101 is supplied for use with a bottle of
C02, for 14 day use. The P.I.P. 102 has a
1/12 H.P. air compressor and an electrically
driven recorder. The P.I.P. 112 combines both
the bottle CO2 and the air compressor to
avoid failure in the event of a power failure.
Robertshaw Controls Co., 1701 Byrd
Avenue, Richmond, Virginia 23226. Supplies
the Free-Flow Parshall flume constructed of
polyester-reinforced fiberglass with satin stain
finish on all surfaces exposed to flow. Flume
is manufactured by Free Flow, Inc., P.O Box
4067 Benson Station, Omaha, Nebraska
68104.
Flume reportedly can be adapted to
manhole use. It is equipped with a stilling well
and a capacitance sensing system to measure
and record wastewater levels on a continuous
basis.
UES Universal Engineered Systems, Inc
7071 Commerce Circle, Pleasanton, California
94566. Manufactures measuring flumes
utilizing the Palmer-Bowlus formula
Measuring flumes are plastic and incorporate
the use of a capacitance pressure sensor (CPS)
that utilizes a captive liquid to separate the
sensing element from the flowing stream. This
feature allows measurements to be unaffected
by build-up or coatings from the flowing
stream. UES also manufactures Parshall
flumes that utilize the CPS straight sensor.
The UES Palmer-Bowlus flumes, sizes 4
to 15 in. (10 to 38 cm), are made primarily to
work in conjunction with models 8090 8091
and 8092 UES Flo/Monitors. Sizes larger than
15 in. (38 cm) and Parshall flumes are used in
10
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conjunction with models 8097 and 8098
Flo/Monitors. UES also manufactures weirs
by special order and programs the 8097 or
8098 to _the specific weir. Venturi tubes,
utilized with the 8097 or 8098 Flo/Monitor,
are also manufactured to be used in closed
pipe with various liquids and solids-bearing
liquids.
Prices for the standard 4 to 15 in. (10 to
38 cm) Palmer-Bowlus flumes range from
$170.00 to $476.00. Larger Palmer-Bowlus
flume, Parshall flume, weir, and Venturi tube
prices are available upon request.
Velocity Meters'and Dyes for
Velocity Measurements
. American Chain and Cable Company, Inc.,
ACCO Bristol Division, Waterbury,
Connecticut 06720. The Bristol series 840
• L/V monitoring . system measures both
wastewater level and velocity of wastewater in
sewers with diameters of 4 ft (1.2 m) or more,
and is designed for use in existing manholes.
The system measures velocity by a
drag-type primary element in the probe
assembly, and is equipped with strain gauges.
The moving stream deflects the element; the
deflection is measured by the strain gauges
and translated into velocities. Velocity range
is from 0 to 10 ft/s (0 to 3 m/s) with
accuracies of ±5 percent.
Badger Meter, Inc., Precision Products
Division, 6116 East 15th Street, Tulsa,
Oklahoma 74115. Produces the Badger Model
UF 310A open channel, ultrasonic flowmeter
designed to measure flow in sewers, flumes,
and other types of open or partially filled
channels. A pair of ultrasonic velocity probes,
one on each side of the channel and
submerged,. measures the velocity while an
ultrasonic depth gauge measures flow depth.
The manufacturer states that the instrument
can be installed in new or existing locations
with relative ease, and results in essentially
obstructionless flow with little or no head loss.
Cues, Inc., P.O. Box 5516, Orlando,
Florida 32805. Provides fluorescent tracer
dyes in fluorescent yellow and red in 1 and 5
Ib (0.5 and 2.3 kg) packages.
Formulabs Fluorescent Dye Tracing Sys-
tems Division, P.O. Box 1056, Escondido,
California 92025. Supplies fluorescent dyes
in a variety of solid forms: tablets 0.08
oz (2.3 gm), cakes 1.90 oz (53.9 gm), donuts
ll 6 to 41.2 oz (0.33 to 1.17 kg), and logs
in diameters of 3 in. (7.6 cm) and lengths
to 4 ft (1.2 m) and weighing 18.9 Ib (8.6 kg)..
Dyes are reported nontoxic in red and yellow
colors designed to produce distinguishable
colors in concentrations of 1 mg/1.
Current prices are:
tablets
cakes
cones
donuts (small)
3 in. (7.6 cm)
donuts (large)
4 in. (10.2cm)
logs 4 ft (1.2m)
liquid concen-
trate
$0.07 each (2,600 minimum)
$1.11 each
$1.39 each, 3 oz(85gm);
$2.49each,6oz(170.gm)
$4.15 each, red;
$3.90 each, yellow
$15.00 each, red;
$ 11.20 each, yellow
$96.00 each
.$14.65 per gal
($3.87 perl)
Kohl Scientific Instrument Corp., P.O.
Box 1166, El Cajon, California 92022. Can
supply fluorescent dyes in either red or
yellow-green colors. When used in a sewer, the
dye will last for several days. Provides tablets
with diameters of 0.75 in. (2.20 cm) in
packages of 100 per bottle. One tablet will
provide a concentration of one part per
.billion in 0.2 gal. (0.45 m3). Larger dye cubes
also are available but are designed tor
oceanographic studies.
Marsh-McBirney, Inc., 2281 Lewis
Avenue, Rockville, Maryland 20851. Produces
the Marsh-McBirney Model 201 portable
current meter powered by standard D-size
batteries. The meter is calibrated in three
switchable ranges: Q-2,,5 ft/s (0-47 cm/s), 0-5
ft/s (0-152 cm/s), and 0-10 ft/s (0-3 04 cm/s).
Accuracy is reported at 0.05 ft/sec (0.015
m/sec). The meter must be held by the
operator and can provide a quick check on
Manning flow calculations.
The current velocity is measured by an
electromagnetic sensor. No moving
mechanical equipment is involved. The price
is $1,150.00.
The Model 250 sewer flowmeter
combines measurements of level and water
velocity into flow. The same basic
electronic velocity sensor as used in the Model
201 has been reconfigured to fit in the
bottom of a pipe and has been streamlined so
11
-------
debris. Additionally, a
been included in the
as not to collect
bubble device has
transducer.
The level information obtained from the
bubble gauge and the velocity information
obtained from the electromagnetic sensor are
combined in a signal processor so as to yield a
single output that is a measure of the flow in
mgd. This device can be field calibrated to
SECURE TUBE
TO STEPS
accuracies better than 5 percent of average
flow and is unaffected by blockages
downstream in the sewer that cause the water
level to rise and the velocity to slow down.
No knowledge of the slope or roughness
factor of the pipe is necessary. In addition,
the device also operates in filled pipes and will
give correct readings even during sewer
surcharges. Prices start at $1,950.00.
Source: NB Products, Inc., New Britain, Pennsylvania
Figure 2. The NB Products recording unit in a
GROUNDWATER manhole. Note the scow-type float
GAUGE used to measure liquid levels.
I
INVERT--/
Soorco: American Pipe Services, Minneapolis, Minnesota
Figure 1. Groundwater Gauge
Figure 3. A Leupold & Stevens model 61R | 1
recorder used in a manhole installs- ft jj
tion with a scow float. T "
Source: Leupold & Stevens, Inc., Beaverton, Oregon
12
-------
Source
: Martig Bub-L-Air, Olympia, Washington
Figure 4. The Martig Bub-L-Air system in.
place, measuring the wastewater
level in the inlet pipe. The same
system can be used with flumes or
weirs.
Fiqure 5. The Badger Meter sonic flowmeter
measures both velocity and waste-
water level.
ELECTRONIC UN IT
UF-100 Unidirectional
UF-110 Bidirectional
PFIOBE CABLES
TYPICAL INSTALLATION
OF ULTRASONIC METER
-------
RIGID CONDUIT TO TRANSMITTER ENCLOSURE
LIQUID-TIGHT CONNECTOR
FLEXIBLE CONDUIT
LIQUID-TIGHT CONDULET
HUB FOR
SPLICE OF COAXIAL
CABLE & (2) NO. 18 WIRES
ULTRASONIC
TRANSDUCER "HEAD
16 in. MIN.
(AT HIGH J
FLOW)
3 ft MAX.
(AT ZERO
FLOW)
•NOTE: Bottom surface of transducer
Source: Trl-Aid Sciences. Inc.. Rochester, New York •
Fi9Ure 6'
ultrasonic
14
-------
FOR- RECTANGULAR WEIRS * CIPPOLETTI WEIRS * TRAPEZOIDAL WEIRS * "V NOTCH" WEIRS
PARABOLIC FLUMES * PARSHALL FLUMES * LEOPOLD-LAGCO FLUMES^
Recorder
Proportional
Control
Signal
Source: Environmental Measurement Systems, Seattle, Washington
Fiaure? Environmental Measurement Systems ultrasonic measuring devices have been
' designed for use with flumes of all types and weirs.
FLUWIE INSTALLATION
000124 ELECTRONIC SENSOR INSTALLATION
i- :
Source:
Figure
UES Universal Engineered Systems, Inc.,
Pleasanton, California
8. The UES measuring flumes can be
installed in manhole locations or
into a sewer line. A sensor element
embedded in the flume measures
liquid levels.
000124 ELECTRONIC
" _ 'SENSOR
FLOW' '
PAI MER BOWLUS INSERT
... PAUMEH BV 000124 ELECTRONIC
SENSOR
PALMER BOWLUS INSERT END VIEW
15
-------
5L
EXTERNALLY
CHARACTERIZED
(SHAPED)
SENSING PROBE
INTERNALLY
CHARACTERIZED
SENSING PROBE
I
(——MS^^B;;.
\\\^~ FLOW
|~^ **"~"^ SENSOR
^iU-C::^^^9!
WEAl
PROC
ELEC
UNIT
J
•HER: i
TRONIC OPTIONAL REMOTE
\ r — ~*~*-4]
- ' ' *
T^^
OUTPU
CURRE
117 VOLTS
50/60 CYCLES
SERIES 508 FLOWMETER
Sourca: Drexalbrook Emergency Company, Horsham, Pennsylvania
Figure 9. The Drexelbrook flow-measuring systems utilize characterized probes that can be
des,gned to t,.t out of the stream if they hit wood or other iefSatTng[debris
Sourco: NB Products, Inc., New Britain, Pennsylvania
Figure 10. The NB Products V-notch weir can be provided with adaptors so that it can be fitted
to a wide variety of pipes.
16
-------
GAGING POINT
MA X
WE AD , H- — - — —
DRAWDOWN
^^ ^^ N^\.
MINIMUM CREST HEIGHT, 2-3H
NAPPE
"wllR
CHANNEL FLOOR-
3-4H |
MINIMUM
Figure 11. A weir, to function as a precision measuring device, should meet these
minimum standard dimensions.
11
-------
SECTION III
SEWER CLEANING TECHNIQUES AND EQUIPMENT
Before infiltration, inflow, or flow in the
sewers can be measured, sewers should be
cleaned. With clean sewers, flow readings will
be more accurate, inspection by closed-circuit
television or other means will be more
meaningful, areas subject to infiltration and
inflow can be detected with greater accuracy
and the full capacity of the sewer restored'
Cleaning makes it possible to detect poor
house laterals, joints that have become offset,
and breaks in the sewer caused by poor
construction or other reasons. Sewers must
also be cleaned prior to grouting or lining.
Classifications of Cleaning Methods
Sewer cleaning equipment, for
convenience, can be grouped into six general
categories:
1. Bucket-type machines.
2. Rodding equipment, both rotating steel
and jointed wood rods.
3. High-velocity water jetting.
4. Hydraulically propelled cleaners,
including sewer balls and hinged-disc
types.
5. Plain flushing.
6. Chemicals.
The sixth category, chemicals, is not
really a cleaning method, but a way to inhibit
the intrusion of roots into sewers. The
persistent entry of roots into the sewer
system, even through pipe joints that are well
prepared and do not leak, is undoubtedly one
of the most troublesome elements in sewer
maintenance.
Bucket Cleaning Machines
Bucket machines are strong, positive
cleaning units. They can open heavily blocked
sewers even though clogged with large masses
of roots, sand, or clay. When a crew
completes its cleaning work using this type of
machine, the sewer should be in good flowing
condition, unless it contains broken and
damaged sections. Figure 12 shows a typical
unit.
One preliminary detail needs attention -
crew members must find a way to pass the
cable through the length of sewer to be
cleaned. One method is to float a light rope
through the pipe, assuming that the
wastewater flow is large enough to carry it.
Another, more positive method is to push the
cable through, using lengths of sewer-cleaning
rods.
A bucket cleaner consists essentially of
two powered winches, each equipped with
sufficient steel cable to reach between the
two manholes, generally not over 750 ft (229
m). The cleaning crew will center one winch
over the influent and the other over the
effluent manhole connecting the line being
cleaned.
A specially designed bucket serves as the
connecting link between the two cables
permitting the winches to pull the bucket in
either direction. The bucket is designed so
that one end opens and closes. One of the
winches can then pull the bucket into the
sewer, with the bucket end open, so that it
can be filled with debris to be removed. When
the bucket is full, the other winch pulls it out
closing the bucket end through a mechanical
linkage.
Most models of these cleaners can draw
the bucket completely out of the manhole
and, by use of a small swinging boom or
conveyor chute, discharge the debris into a
dump truck.
After the operators have removed the
bulk of the debris from the sewer line they
,can replace the bucket with a "porcupine."
This is a drum-like cleaning tool with stiff
wire cables protruding outward from the
cylindrical side. By drawing it back and forth
in the sewer, the operator can remove hair
roots, and grease deposits that the bucket
cannot dislodge.
For a final, wiped-clean finish, the
operator then can replace the procupine with
a rubber "squeegee." Crew members
frequently fabricate these from old belting
roughly 0.5 in. (1.3 cm) thick, and cut to fit
snugly inside the pipe to be cleaned. However
the manufacturers of the cleaning equipment
can supply them if desired.
18
-------
After the squeegee passes through the
pipe, the sewer should be close to its original,
free-flowing condition if it has no outright
breaks or other flaws.
Principal Suppliers of Bucket-Type Cleaners
W. S. Darley & Company, 2600 Anson
Drive, Melrose Park, Illinois 60160. Can
supply bucket-type cleaners mounted on
three-wheeled trailers, powered by either a
16-horsepower or a 25-horsepower gasoline
motor. Two such units are required. The
supplier states that the machines utilize power
trains from the engine shaft to the cable drum
incorporating a torque limiter that can
transmit the full power of the engine to the
transmission without slippage or overload
failures. The transmission has four forward
speeds and one reverse. The main drum can
hold 1,000 ft (305 m) of 0.5 in. (1.3 cm) steel
cable. An auxiliary drum is provided with
each pair of machines. Both buckets and
porcupines range from 6 to 22 in. (15 to 56
cm) in diameter.
Current prices are $1,800.00 per machine
for the 16-horsepower unit and $2,045.00 for
the 25-horsepower. As noted, two are
required.
Rockwell International, Municipal and
Utility Division, P.O. Box 47767, Dallas,
Texas 75247. Manufactures three basic
models of bucket machines: (1) the Pick-Up
Loder which is designed to dump directly
onto the street or into containers for transfer
to the disposal area; (2) the Truck Loder
which carries the bucket up a conveyor to
dump into a truck; and (3) the regular Pull-in
Machine. Sizes range from 9 horsepower to
100 horsepower for cleaning a wide variety of
sewer pipes. The manufacturer makes special
sizes of buckets for large pipes and for use in
various manhole sizes.
W. H. Stewart, Inc., P.O. "Box 767,
Syracuse, New York 13201. Manufactures
bucket machines in six sizes with engines
varying from 10 to 65 horsepower. The units
have three-speed transmissions and are
capable of dumping 48 in. (122 cm) buckets.
They are designed to load into either
containers or trucks.
Rotating-Rod Sewer Cleaners
Rotating-rod sewer cleaning equipment
such as shown in Figures 13 and 14 also has
proved practical and useful in returning
clogged sewers to service. These consist of
high-strength flexible rods of an oil-tempered
spring steel, supplied in sections so that if a
rod breaks the broken section can be removed
and the machine returned to service. The rods
generally are 3/8 in. (1 cm) in diameter.
A powered sewer-rodding machine can
push the rods through, a sewer for a distance
as great as 800 ft (244 m). It can also
maneuver around curved sections. In one
unusual cleaning incident, the rods
successfully removed a latex spill that
produced a plug 250 ft (76 m) long in a 10 in.
(25 cm), two-barrel sewer siphon.
-The rods can be supplied with a variety of
tools to expedite the cleaning operation. To
open a line that is completely plugged, the
operator can place a small spear or round-wire
"corkscrew" device on the end of the rod.
The cleaning unit will rotate the rod into the
plugged sewer to make an opening large
enough to permit the wastewater to start
flowing.
The operator can then replace the
corkscrew with an "auger" or a heavy-duty
corkscrew, as conditions dictate. These are
spiral-shaped cutting devices with diameters
equal to or slightly smaller than that of the
pipe to be cleaned. The cleaning machine
rotates the rods with the cutters, forcing them
into the sewer to capture as much of the
clogging material on the spiral-shaped cutting
device as it can, and then removes the rod and
the material.
The rodding machine should be
positioned from 8 to 10 ft (2.4 to 3.0 m)
downstream from the manhole connecting
with the sewer to be cleaned. This assumes
that the operators will insert the rods
upstream so that they can withdraw them,
and the debris, downstream. At this distance
from the manhole, the rod sections can be fed
into the rod guide channel and then into the
sewer with as few sharp bends as possible.
The operator always must adjust the
footage indicator on the machine to zero
before inserting the rods into the sewer. This
identifies how far the cleaning tool is in the
sewer at all times. All models automatically
add and subtract footage.
19
-------
When inserting the rod and cleaning tool
the operator always should allow the cleaner
to build up rotating speed to a maximum
before moving the rods forward. If the line is
fairly clean, the rotating rod can be moved
quickly and easily. The safety-overload device
releases or indicates pressure when cleaning
becomes difficult. Operations can continue if
the pressure is minor, but the forward speed
should be reduced and the rod spin kept at a
maximum.
If the rods and the cutter appear to be
making no forward progress and the safety
overload device shows continued heavy
pressure, the cutters probably have
encountered a heavy mass of roots or other
obstructions. To clear them, the operator
should reverse the controls, remove the rods
and cutter, clean the cutter of entangling
roots, and then run the rod and cutter back to
break through the obstruction.
Rods can be pulled back without
rotating, but in general they should not be.
However, the spring-blade cutters can be
attached successfully at the upstream
manhole and pulled back with the cutter
rotating at maximum speed.
On most machines, the operator can exert
extra power to break through difficult
obstructions by tightening the overload safety
device slightly. This may be necessary if the
sewer is badly sanded. Power rodders also are
available with hydraulic systems, and the
hydraulic units themselves may be set so that
an overload system is a safe way to operate. It
also permits the unit to perform at maximum
efficiency.
Many cleaning tools can be used by the
powered rodding machines. Among them are:
1. Root saws.
Corkscrews with back cutter edges.
Expandable cutters fitted with two or
three knife-shaped blades that can adjust
to the diameter of the sewer being
cleaned. These blades can be removed for
sharpening.
Sand cups which are rubber discs
designed to stop the flow of wastewater,
but to permit passage of a portion
through holes in the disc, thereby
creating jets which flush the material
ahead to the downstream manhole.
2.
3.
4.
5. A pick-up tool which is an auger-like unit
designed to retrieve broken rods from the
sewer line.
Principal Suppliers of Rotating-Rod
Sewer Cleaners
O'Brien Mfg. Division, Conco, Inc., 5640
Northwest Highway, Chicago, Illinois 60646.
Can supply five different types of sewer
rodding machines. Three are trailer-mounted
units and two are truck-mounted. The
machines are variable in that they can make
use of rods with lengths of 36, 39, or 48 in.
(91, 99, or 122 cm). The machines can be
equipped with engines of varying horsepower.
O.K. Champion Corp., P.O. Box 585,
Hammond, Indiana 46320. Can supply six
models of truck-mounted, rotating-rod sewer
cleaners, powered either by separate engine or
truck power take-off. Rod diameters vary
from 0.375 to 0.461 in. (1 to 1.2 cm).
Current prices range from $5,130.00 to
$8,346.00.
The company also can provide four
models of trailer-mounted power rodders.
Current prices range from $2,561.00 to
$3,887.00.
Ridge Tool Company, 400 Clark Street,
Elyria, Ohio 44036. Manufactures two models
of small rodding machines designed to clean
sewers with maximum diameters of 24 in. (61
cm), to a maximum sewer length of 500 ft
(152 m). Both are mounted on rubber-tired
platforms and are easily moved.
The K-1000 rodder is powered by a
five-horsepower gasoline motor and has a
gearshift providing three speeds forward and
one reverse. Its weight is 229 Ibs (104 kg).
The K-2QOO is powered by a 1,500-watt
electric generator with a 3.8 horsepower .
gasoline motor. The generator has two extra
115-volt outlets for other electrical tools.
Complete shipping weight is 393 Ibs (178 kg).
Both also can be adapted to spiral-wound
cables for cleaning (see following discussion
of spring cable cleaners).
The company can provide a variety of
cleaning tools for use with the K-1000 and
the K-2000 rodders.
Rockwell International, Municipal and
Utilities Division, P.O. Box 4776, Dallas,
Texas 75247. Can supply five different
sectional rodding machines. All can be truck
20
-------
mounted. The first, the RHRS, features
hydraulic power with infinite variable speeds.
The rod-driving unit can be slanted toward
the manhole, reducing the angleof entry. The
rod-storage -reel is in line with the lateral
movement of the rods, thereby reducing rod
bends and the chance of breakage.
The second, the SSR-2, is trailer
mounted and has a counter-balanced,
cone-type reel that helps prevent rod-twisting
under power.
The third, the SCPS, is an intermediate
size, built for those who want a smaller
machine at a slightly lower price.
The fourth, the RPRS Pipe RODer,® has
been designed for use in the smaller sewer
systems where cleaning is fairly infrequent
but the safety and mechanical speed of
cleaning are desired. The company offers a
wide variety of cleaning tools to be used with
the rodding equipment.
The company also provides a small unit
mounted on two wheels, the PD50RL, for
cleaning smaller lines and presumably service
connections. It is powered by a
three-horsepower motor.
W. H. Stewart, P.O. Box 767, Syracuse,
New York 13201. Produces the two model
series powered by engines from 10 to 65
horsepower, all with hydrostatic
transmissions. Units are built for trailer or
truck mounting and supplied with a wide
variety of cleaning tools. All units are capable
of variable speed with an in-line feed
arrangement. The company produces smaller
machines powered by 3.5- and 5-HP engines
with three- and five-speed transmissions for
smaller sewer districts.
Spring-Cable Sewer Cleaners
Another type of sewer cleaner, developed
originally to open service lines and clogged
plumbing, consists of a double spiral cable,
with one spiral inside the other turning in
opposite directions thus reducing the
possibility of helixing either cable, regardless
of which direction it is being turned.
The suppliers can provide a variety of
cutters to be attached to the cleaning end of
the cable. The other end is connected to a
power source, either a gasoline-engine or
electric.
Principal Suppliers of Spring-Cable
Type Cleaners
W. S. Darley & Company, 2000 Anson
Drive, Melrose Park, Illinois 60106. Supplies
two models of spring-cable cleaners, the
model H314 and the model Ml69. Both will
clean sewers to 12 in. (30 cm) in diameter.
The H314 is mounted on a pipe frame with a
pair of 8 in. (20 cm) pneumatic tires to aid in
moving, and is powered by a 0.25-HP electric
motor. The Ml69 is mounted on a dolly and
is powered by a 0.5-rHP electric motor. Both
are supplied with a limited assortment of
cleaning knives.
The current price of the H314 is $496.75
and of the Ml 69, $768.65.
Electric Eel Manufacturing Company,
Inc., 501 West Leffel Lane, Springfield, Ohio
45501. Supplies a gasoline-powered cleaner,
model 325, able to clean sewers to 14 in. (36
cm) in diameter for a maximum of 500 ft
(152 m). The machine can be operated by one
man, can develop rotating speeds of from 350
to 1,050 rpm, has a single reverse speed, and
is mounted on a wheeled dolly.
The current price of the model 325 is
$750.75. A transporting trailer, cable reel 500
ft (152 m) capacity, cable, cleaning tools, and
accessories are extra.
Ridge Tool Company, 400 Clark Street,
Elyria, Ohio 44036. Manufactures a variety of
small cable-type cleaners, electrically or
gasoline powered and able to clean lines from
200 to 300 ft (61 to 91 m) long. Also
produces the K-1000 and the K-2000 rodders
which are adaptable to flexible cables and
able to clear lines of 500 ft (152 m).
Jointed Wood Cleaning Rods
The manually operated, jointed, wood
cleaning rods have the longest continuous
record of service in sswer maintenance of any
other tool or equipment. They vary from 3 to
4 ft (0.9 to 1.2 m) in length, and are equipped
with metal couplings so that they can be
joined and thrust into the sewer for as great a
length as the maintenance personnel are
physically able to handle. The wood rods are
used in storm drains and culverts where heavy
21
-------
deposition of mud and stones cause steel rods
to burrow in. The rods generally need to be
lifted to an angle of 90° to be uncoupled, so
the possibility of their being uncoupled while
in the sewer is not great. An assortment of
tools is available to be secured to the lead rod
to assist in the cleaning work.
Principal Suppliers of Wood Cleaning Rods
W. S. Darley & Company, 2000 Anson
Drive, Melrose Park, Illinois 60160.
W. H. Stewart, Inc., P.O. Box 767,
Syracuse, New York 13201.
High-Velocity Sewer Cleaning
High-velocity sewer cleaning using water
pressure as the cleaning agent is a relatively
recent development that is producing
excellent results. Under favorable conditions,
it has demonstrated an ability to clean a line
faster, and with greater efficiency, than any
of the older methods.
It has many advantages. It operates at
street level without requiring anyone to climb
down the manhole; it requires very little time
to set the cleaning machine in place; and an
operator can quickly and thoroughly flush
out a sewer at least 500 ft (152 m) long, and
possibly 1,000 ft (305 m) if the cleaning is
not difficult. Figures 15, 16, and 17 show
typical units.
Although the system uses water at high
pressures, tests have shown that the water
does not usually harm the pipe joints. The
method should be especially useful in cleaning
curvilinear laid lines of plastic or.
•asbestos-cement where the buckets and
cutters might harm the pipe walls.
The cleaning unit can carry an
independent supply of water, generally 1,000
gal. (3,785 1). It will be supplied with a pump
with a capacity generally of 60 gpm (227 1/m)
delivering water at a pressure of 1,000 psi (70
kgf/cm2) or more. The cleaner usually is
supplied with 500 to 600 ft (152 to 183 m)
of 1 in. (2.5 cm) heavy-duty hose.
The hose nozzle provides the cleaning
action. The nozzle is equipped with a
backspray that forces it and the hose down
the sewer to be cleaned. A single hole in the
front of the nozzle releases a jet of water that
opens a path for the nozzle and hose.
When the operator withdraws the hose,
the backspray water jets scour the sewer clean
and move the debris to the manhole where
the hose and nozzle have been inserted into
the sewer. The most satisfactory way of
removing the debris is with one of the various
suction-type units, making it possible for all
the work to be performed from the safety of
the street level as shown in Figures 18, 19,
and 20.
The hose and nozzle should be inserted at
the downstream manhole and moved
upstream in the sewer so that the principal
cleaning can take place in the downstream
direction of the wastewater flow as the nozzle
is retracted. If root intrusion is very strong,
most of the units can be equipped with a
hydraulically operated root cutter and nozzle,
as shown in Figure 21.
Principal Suppliers of High-Velocity Jet Cleaners
AAA Pipe Cleaning Corp., 10620 Cedar
Avenue, Cleveland, Ohio 44106. The
company will rent a variety of sewer-jet
cleaning equipment suitable for pipe with
diameters from 4 through 74 in. (10 through
188 cm). The c.ompany also will rent suction
manhole and catchbasin cleaning equipment
as well as all other major equipment types on
a nationwide basis.
Aquatech, Inc., P.O. Box 1907,
Cleveland, Ohio 44106. Manufactures six
basic truck-mounted sewer jets: models
600/60, 1060, 1260, 1560, 2060, and 3060.
Tank sizes range from 600 to 3,000 gal.
(2271 to 11,3561). Nozzle pressures range to;
2,100 psi (148 kgf/cm2), and volume to 71.4
gpm (270 1/m). Also produces tandem-axle
trailer units with pressure capabilities to
2,100 psi (148 kgf/cm2). :
Manufacturer states that all units can
clean 1,000 ft (305 m) of sewer at a single
pass, and can be powered either by truck
power-takeoff attachment or by diesel or
gasoline engines.
Cleaning nozzle variations include both
single and double units for deposits of heavy
sand in pipe diameters from 15 to 72 in. (38
to 183 cm). Other variations include the
lance/thrust nozzle designed to penetrate
heavy obstructions such as hard-packed
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grease; and the multi-8 jet vortex nozzle
designed to remove excessively large deposits.
Accessories include a hydraulic-powered root
cutter which the manufacturer states can
sever roots 1 in. (2.5 cm) in diameter. As an
optional item, the Aquatech cleaners can be
supplied with a root-chemical reservoir which
can introduce a root-growth inhibitor as a
foam into the stubs and inhibit further
growth.
The company also produces the VE-1000
Sewer Vac for removing deposits from the
manhole as the jet unit is operating.
W. S. Darley & Company, 2000 Anson
Drive, Melrose Park, Illinois 60160. Supplies
the Darley hydraulic high-pressure sewer
cleaner which the company states can be
mounted on most makes and models of
trucks. The complete unit will carry a water
tank holding 1,500 gal. (5,678 1). The pump
mounts on the front of the truck. It is a
four-stage, series design centrifugal unit able
to deliver 60 gpm (227 1/m) at 1,000 psi (70
kgf/cm2). A hydraulically driven hose reel is
mounted at the back. Both the pump and the
reel are driven by a truck power-takeoff unit.
The reel can carry 500 ft (152 m) of hose.
The hose is 1 in. (2.5 cm) in diameter, has a
nylon inner tube, braided polyester
reinforcing, and polyurethane cover to resist
acids, chemicals, and oils.
Central Engineering Company, Inc., 4429
West State Street, Milwaukee, Wisconsin
53208. Produces the Vac-All combination
high-pressure sewer cleaner. The unit
combines the water-jet sewer cleaning
principle with a vacuum system for
simultaneous removal of debris and water
from the manhole through a 12 in. (30 cm)
vacuum intake hose. The water is returned to
the sewer through a 6 in. (15 cm) drain while
the debris is retained in the body for
discharge at a disposal site.
The unit is equipped with a 16 yd3 (12
m3 ) vacuum body and an independent water
tank with provision for combining the body
and tank capacities. The pump produces a
pressure of 2,000 psi (141 kgf/cm2), is of the
three-piston type, and can produce variable
pressures. The jet hose is mounted on a
power-traversing reel for operation from the
left side, the right side, or from the rear of the
unit depending on traffic and street width.
The same unit can be used to clean
catchbasins, sumps, sludge beds, and similar
areas.
Cues, Inc., P.O. Box 5516, Orlando,
Florida 32805. Supplies the Cobra
high-velocity sewer cleaner which can be
mounted on a truck or trailer. These machines
are made with a pressure unit able to deliver
the nozzle water at 1,000 or 2,500 psi (70 or
176 kgf/cm2). Tanks can hold either 1,200 or
1.500 gal. (4,542 or 5,678 1). Manufacturer
can provide a variety of nozzles for special
projects such as cleaning a 4 in. (10 cm) house
connection, sand accumulations, and heavy
grease incrustations.
Elgin Leach Corp., Til West Adams
Street, Chicago, Illinois 60606. Manufactures
the Elgin Jet-Eductor designed primarily to
clean catchbasins, sumps, and manholes,
operates on a hydraulic venturi principle. As an
accessory, the company supplies a
sewer-cleaning nozzle with a single forward jet
to open the sewer, and a series of backflow
jets that wash the debris back to the manhole
where the Eductor's Aqua-Vac nozzle can
remove it.
Flo-Max, Inc., P.O. Box 125, Boerne,
Texas 78006. Supplies the Rooter Snooper
Yin Yang hydraulic cleaners in several models.
The standard model is built as a single-axle
trailer unit. Skid-mounted models are
available for use on iflat bed trucks. The unit
is powered by a two-cylinder, air-cooled
engine. Both hand-start and electric-start
models are available. Cleaning pressure is
developed by a two plunger, positive
displacement pump capable of delivering 22
gpm (83 1/m) at 1,000 psi (70 kgf/cm2).
Holding tank capacities up to 150 gal. (568 1)
are available. Hydraulic cleaning nozzles,
special purpose nozzles and two-stage
chemical application nozzles are available.
FMC Corporation, Agricultural
Machinery Division, 5601 East Highland
Drive, Jonesboro, Arkansas 72401.
Manufactures two basic models of jet-type
sewer cleaners. The 300 gal. (1,136 1) trailer
model No. 3510, designed for smaller
communities, can be purchased skid mounted
and also mounted on a 1 ton (909 kg) truck. A
second model, No. 6520, can be supplied with
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1,250 and 1,750 gal. (4,738 and 6,625 1)
tanks and is truck mounted.
The Model 3510 is powered by a Ford
104 four-cylinder engine which powers a
three-piston, Bean positive-displacement
horizontal pump that delivers 35 gpm (132
1/m) at 1,250 psi (88 kgf/cm2). The hose reel
is hydraulically powered. Two nozzles are
supplied with the unit: one with the back jets
at a 15° angle for small pipe and tough
obstructions and the other at a 35° angle for
pipe with less difficult obstructions. This
model has a current list price of about
$10,900.00.
The truck-mounted Model 6540 is
powered by a Ford 300 cubic inch (0.0049
m3) six-cylinder engine which also powers a
Bean positive-displacement three-piston
horizontal pump. It delivers 67 gpm (246 1/m)
at 1,250 psi (88 kgf/cm2 ) standard; 1,600 psi
(112 kgf/cm2) is optional. List price is about
$13,500.00. It also has two nozzles identical
with those supplied with Model 3510.
Accessories for both models include items
such as a root cutter, sand nozzle, penetrator
nozzle, lateral line cleaning kit and others.
Hydra-Dy-Namic Cleaners, Inc., Division,
T.V. Pipe Inspection Company, Box 125,
Boerne, Texas 78006. Supplies various models
of the Dy-Namic Hydra Cleaner high-velocity
water jetting equipment. The unit may be
mounted on a 22,000 Ib (9,979 kg) GVW
truck having a 94 in. (2.1 .m) carrying platform.
The unit is also available mounted on a heavy
duty, dual axle trailer or skid mounted for use
on a flat bed truck.
Water pressure is generated by a triplex
plunger, positive displacement pump powered
by a six- or eight-cylinder industrial engine.
The truck-mounted model is available with a
split-shaft power takeoff drive which uses the
truck engine to provide power for the unit.
The triplex pump is rated at 80 gpm (303
1/m) at 1,230 psi (86 kgf/cm2).
The cleaner unit is equipped with a tank
holding at least 1,120 gal. (4.2 m3) of water
and having six baffled compartments. The
tank fill system has an air-gap safety valve to
prevent cross connections when filling from a
hydrant. The hose reel is powered and carries
a 1 in. (2.5 cm) plastic hose.
A variety of special nozzles, root cutters,
and other accessories are available.
F. E. Myers & Brother Company, Division
of McNeil Corporation, 400 Orange Street,
Ashland, Ohio 44805. Produces the
truck-mounted MHV6 cleaner able to jet-flush
sewer runs to 1,000 ft (305 m) in one pass;
supplied in six gasoline or diesel engine
models with tanks of 1,000, 1,500, or 2,000
gal.-(3,785, 5,678, or 7,571 1). Pump pressure
is a maximum of 1,650 psi (116 kgf/cm2).
Accessories include sand and grease nozzles,
penetrator nozzles, root cutters, and remote
controls.
Also produces the trailer-mounted PC20
which can be skid-mounted on a flat bed
truck with a minimum bed length of 8 ft (2.4
m). Carries a 300 gal. (1,136 1) heavy steel
tank with antisiphoning filler pipe. Equipped
with 400 to 500 ft (122 to 152 m) of 0.63 in.
(1.6 cm) fabric-reinforced hose that is oil and
grease resistant. Pump is rated at 20 gpm (76
1/m) with nozzle discharge pressures of 1,250
psi (88 kgf/cm2).
The model PC20 is supplied with the
same accessories as provided for the MHV6.
Other accessories supplied to both models
include: footage counter that measures the
amount of hose in use at any time;
lateral-cleaning kit to clear sewers with
diameters of 4 in. (10 cm) or more; sewer
sweeper kit with heavy rubber diaphragm; and
a vortex nozzle designed to clean sanitary
lines with heavy grease and sand
accumulations arid also useful for cleaning
corrugated steel culverts. The Myers trailer
model PC20 cleaner has a price range of
$7,000.00 to $9,000.00 depending upon
accessory variations. The truck-mounted
MHV6 sewer cleaners have a pricing variation
from $13,000.00 to $20,000.00, less truck.
The price variables again are dependent upon
accessory selection, engine selection, tank
size, etc. Myers presently offers 24 models in
the MHV6 series.
Myers-Sherman Company, Streator,
Illinois 61314. Supplies the Vactor-Jet
Rodder that jet-cleans the sewer and
simultaneously provides suction removal of
the debris which reportedly lowers back
pressure and thereby increases cleaning
production. Excess water removed with the
debris by suction action passes through a
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filter that separates it from the debris, and is
returned to the manhole.
The Vac-Jet Rodder carries a 16 yd3 (12
m3) box to receive the debris (holds 2,700
gal. [10.2 m3 ] of water), and an independent
1,500 gal. (5.69 m3) tank for jet rodding. An
interchange arrangement permits combining
both tanks if this is desirable. A variable
pressure pump can deliver the jet water at
2,000 psi( 14 lkgf/cm2).
The same unit also can be used to clean
basins or to flush streets.
O'Brien Manufacturing Division, Conco
Incorporated, 5632 Northwest Highway,
Chicago, Illinois 60646. Produces four
principal models of jet cleaners:
• The SKJ-1, truck mounted with remote
control and an independent water supply.
• the SKJ-4, mounted either on a pick-up
truck or four-wheeled trailer, equipped
with a 30 gal. (114 1) surge tank and able.
to develop the same jet pressure as the
larger unit.
• the SKJ-3 and the SKJ-5, each mounted
on a two-wheeled trailer or skid-mounted.
These also carry 30 gal (114 1) surge
tanks.
The principal accessory is the O'Brien
Root Cutter available for use with any
water-jet cleaner. At speeds of 800 rpm, the
cutter can develop 300 in-lbs (346 cm-kg) of
torque and cut through most root stoppages.
Rockwell International, Municipal and
Utility Division, P.O. Box 47767, Dallas,
Texas 75247. Produces the 701 Hi-Velocity
Cleaner and the more complete Hi-Velocity
Cleaner and Reclaiming Unit. The first carries
1,200 gal. (4.54 m3) tank that can be
refilled from a nearby fire hydrant. The
second carries a 2 in. (5 cm) suction line to
remove the debris and water. A cyclone
separator removes the solids from the water
so that it can be recycled in the jet. cleaner.
Sewer-Ball Cleaning
Over the years, the use of a large,
rubberized 'ball to clean sewers that have not
become completely blocked has proved its
effectiveness. An experienced operator will
manipulate the ball to permit wastewater to
escape around its lower perimeter at high
velocity, thus forcing the obstructing material
ahead, into the downstream cleanout
manhole. To use the sewer balls, a_crew must
be equipped with:
1. at least 600 ft (183 m) of 0.5 in. (1.2 cm)
synthetic-fiber rope mounted on a spool
supported on a rack so that the spool is
free to move. For balls over 15 in. (38
cm) in diameter, steel cable is preferred.
2. a rotating swivel with a clevis that serves
to attach the rope or cable to the ball.
3. 400 ft (122 m) of 2.5 in. (6.3 cm) hose,
and a nonrising stem, air-break gate valve,
fitted with connections to attach to a
hydrant. The air-break valve prevents
cross connections between the potable
water in the hydrant and the wastewater.
4. a "hole jack" that has a small, free
• running wheel to be fitted into the
influent manhole, used to control the
rope or cable.
5. rubber buckets, appropriate shovels,
boots, and safety harnesses for use when
crew members may have to enter the
manhole.
Before using the sewer-cleaning balls, the
crew should plug basement drains with
mechanical or pneumatic plugs. This protects
adjacent residences and businesses from
backflooding.
The hole jack then must be placed in the
influent manhole using the screw-type
adjustment that anchors the jack rigidly and
firmly in place. The wheel of the jack should
be above and opposite the sewer opening
which serves as the entry point of the ball.
This permits the cleaning crew to remove the
ball from the sewer and to release the built-up
wastewater that has collected in the manhole.
A metal elbow trap must be placed in the
downstream manhole. This will confine much
of the solid material flushed out by the ball
but still will allow passage of the wastewater
into the downstream line. Then the rope or
cable must be threaded through the jack
pulley, secured to the ball, and then the ball
must be pushed into the pipe. Any equipment
not necessary for cleaning work should then
be removed. Finally, water should be
introduced into the manhole by the fire hose,
raising the level of thejiquid in the upstream
manhole to a depth of approximately 3 ft
(0.9 m).
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A few sharp tugs on the rope, permitting
some wastewater to escape around the
perimeter of the ball, will start the ball
moving. Most of the water will escape around
the lower surface of the ball since the ball's
buoyancy will hold it against the top of the
pipe. The static head of wastewater will then
force the ball to move rather easily. The
operator must keep the rope or cable tight to
prevent it from overriding the ball if the ball
is not inflated to give a snug fit. As the ball
travels, it will break loose small clusters of
roots, sand, mud, or any normal buildup of
grease. The operator must be alert to keep
from being pulled into the mechanism that is
releasing the cable in the hole.
The ribbed ball flutters, rather than spins,
in the pipe. It will develop about 6 in. (15
cm) of turbulent water on the downstream
side, and this water will lift the dirt and debris
and float it to the downstream manhole into
the elbow trap where it can be shoveled out
or removed by suction equipment.
If the ball becomes trapped in the sewer,
it can be loosened by a sharp, short
withdrawal on the rope or cable. This will
draw the ball back, creating a partial vacuum
that will level the debris and allow the ball to
proceed forward again.
In general, the ball should be inflated
with enough air to require the operator to
press it slightly when forcing it into the sewer.
However, conditions can arise that will
require the ball to be underinflated slightly to
do a thorough job of cleaning. Daily cleaning
runs of 5,000 to 15,000 ft (1,524 to 4,572 m)
can be accomplished. The operators must
learn through experience how much inflation
will be required in the ball. Large cleaning
balls are harder to control than small, and
more difficult to pass through the manhole
from one sewer to the next.
In addition to cleaning sewers, some have
found these sewer balls useful in testing newly
constructed sewers when means of inspection,
such as closed-circuit television and air testing
are not available. By passing one of these balls
through the new sewer, the inspector can
determine whether the contractor built it free
of obstructions and obstacles.
Principal Suppliers of Sewer-Cleaning Balls
Cherne Industrial, Inc., 5701 South
County Road, 18, Edina, Minnesota 55436.
Supplies the Cherne Jet cleaning ball in
diameters from 6 through 18 in. (15 through
45 cm).
Cues, Inc., P.O. Box 5516, Orlando,
Florida 32805. Supplies sewer-cleaning balls
in sizes from 6 through 18 in. (15 through 45
cm).
Sidu Manufacturing Company, 3831
Catalina Street, Los Alamitos, California
90720. Manufactures balls 6 to 48 in. (15 to
122 cm).
Hinged-Disc Sewer Cleaners
The hinged-disc cleaner operates in a
manner similar to that of the ball. The device
is dropped through a manhole and into the
outgoing sewer line. The flow is stopped and
the accumulated head causes the machine to
roll down the pipe. This will continue until
debris is encountered. The machine will then
stop, causing an accumulation of head behind
and upstream, along with a lowering of the
water level in the line downstream. A line
attached to the unit is then pulled causing the
valve to open and discharge the accumulated
head into the voided area ahead. The velocity
of this moving water is generally three to four
times the normal velocity of the sewage and
washes the material downstream, where it is
removed at the next manhole.
Where larger obstructions are
encountered, the machine is pulled back a
short distance, at the same time causing the
above-mentioned flushing action, and when
released has a hydraulic ram effect on the
obstruction. This operation provides a
completely clean pipe of all loose and
removable material and also provides a
messenger line that can be left in the pipe for
the pulling of the TV camera and/or the
sealing apparatus.
The force of the hydraulic action
increases with the square of the difference of
the diameter, while the amount of debris
increases only in proportion to the difference
in the diameter. As a consequence, the
machine's ability and efficiency increases with
the size of the pipe. Figures 22 and 23 show
typical units.
Principal Suppliers of Hinged-Disc Cleaners
Cues, Inc., P.O. Box 5516, Orlando,
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Florida 32805. Supplies the hydraulically
propelled Bee-Liner which consists of a
piston-like head with a flexible outer rim. The
head is hinged so that the upper half can be
retracted by the operator manipulating the
control cable. Manufacturer states that a small
crew can clean 3,000 ft (914 m) of sewer per
day. Can fit pipe sizes from 6 to 36 in. (15 to
91 cm).
Fitzgerald Engineering Company, Inc.,
2601 Southwest 69th Court, Miami, Florida
33155. Supplies the Sewer Scooter,
hydraulically propelled, with shields to fit
sewers with diameters varying from 6 to 96
in. (15 to 244 cm).
Plain Flushing
Plain flushing is a simple and rather crude
technique that probably can be justified for
use in flat areas where solids tend to settle out
and become septic and odorous. It requires
only a hose connected to a nearby fire
hydrant. The hydrant should be equipped
with a thoroughly reliable suction breaker to
prevent back-siphonage of sewage into the
water mains in case of heavy demands on the
water system. The hose used for flushing
should not be used for the transmission of
potable water without being first thoroughly
sterilized.
Suction Cleaning of Manholes
As the preceding discussion indicated,
many of the cleaning techniques involve
flushing the debris to the downstream
manhole and then removing it. This can be
done manually, using long-handled shovels
and scoops with special right-angle shapes.
Small cranes with buckets designed to pass
through the manhole openings also have
proved successful. The most popular equipment
today are pneumatic and hydraulic, and can
remove the debris without causing nuisances
at the street level.
The pneumatic suction units can be
mounted either on trucks or trailers. Each will
consist of a large body with a tailgate at one
end and a high-pressure blower able to
• develop the required vacuum in the body. A
flexible tube, generally about 12 in. (30.5 cm)
in diameter, extends sufficiently far so that it
can reach into the manhole and draw out the
debris by tne vacuum action. By this
arrangement, the debris does not have to pass
through the blower itself. When the body is
full, it is transported to the disposal area and
emptied by th;e usual dump-truck
mechanisms.
The attractiveness of this method is its
adaptability to other maintenance tasks
within an urban governing body. The unit can
clean catchbasins, pick up street debris
gathered and discharged by mechanical
sweepers, collect leaves, clean out sumps,
pump wet wells, and perform other tasks that
otherwise would be arduous and disagreeable.
The hydraulic suction cleaning method
has a much longer performance record. The
cleaning action is created by two pipes
secured together. One delivers high-pressure
water, at about 100 psi (7 kgf/cm2) to the
cleaning nozzle. An elbow and a venturi direct
the water up the cleaning pipe. Through the
Bernoulli hydraulic principle, the high water
velocity creates a pressure drop in the
cleaning nozzle sufficient to remove both the
water and the debris in the manhole. The
truck carries a water-tight body of 6 to 10
yd3 (4.6 to 7.6 m3). The principal limitation
on this type of equipment is that the cleaning
nozzle is 4 in. (10 cm) in diameter and
consequently cannot remove much of the
larger debris. Figures 24, 25, and 26 illustrate
the range of equipment available.
Principal Suppliers of Suction
Manhole-Cleaning Units
Aquatech, Inc., P.O. Box 1907,
Cleveland, Ohio 44106. Manufactures the
model VE-1000 Sewer Vac designed to
remove debris transported to the manhole by
the company's sewer-jet equipment. The unit
removes both liquids and solids, separates
them by a baffle system within the tank, and
discharges the water to the sewer system,
retaining the solids. The 1,000 gal. (3,785 1)
holding tank is expected to serve for six to
eight hours of hydraulic flushing time. The
unit is equipped 'with a 3 in. (8 cm)
self-priming, nonclogging centrifugal suction
pump which can handle solids up to 2.8 in.
(7.3 cm) in diameter with the impeller coming
into direct contact with the solids being
removed. The power supply is a
13-horsepower, air-cooled engine with an
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electric starter. The unit is usually trailer
mounted but can be placed on a truck chassis.
Central Engineering Company, 4429 West
Street, Milwaukee, Wisconsin 53208.
Produces the Vac-All Street and Catchbasin
Cleaner designed to clean manholes,
catchbasins, lift-station sumps, sewage plant
digesters, grit chambers, sludge beds, and
drying beds. Three models are available with
10, 13, and 16 yd3 (7.7, 10, and 12.2 m3)
capacity. A high vacuum is developed in the
body by means of a blower driven by a
gasoline or diesel engine. Muck, water, and
objects up to 12 in. (30.5 cm) diameter, are
sucked up by a 12 in. (30.5 cm) diameter
intake hose supported by a hydraulic power
boom and push button control. Water is
separated from the muck and returned to the
manhole through a 6 in. (15 cm) diameter
drain hose. The solid material is transported
to the disposal site and dumped by means of a
hydraulic hoist. The Vac-All also cleans
sewers through high-velocity water jets with
simultaneous pickup of material from the
manhole.
Cues, Inc., 3501 Vineland Road, Orlando,
Florida 32805. Manufactures the Muck-Suck
debris-removal trailer. The trailer carries a
1,000 gal. (3,785 1) water-tight box which the
manufacturer states can receive 4 yd3 (3 m3)
of debris solids. The trailer is self-dumping.
Elgin Leach Corp., 222 West Adams
Street, Chicago, Illinois 60602. Manufactures
the Elgin Jet-Eductor which cleans by the
hydraulic venturi action. It carries a
water-tight box of 6 to 10 yd3 (4.6 to 7.6
m3) on a suitable dump truck. It is supplied
with an agitator hose which assists in keeping
the debris in suspension so that it can be
removed. The manufacturer states that the
Eductor nozzle can operate at depths of 20 ft
(6m) and that the cleaning action generates a
very low noise level. The manufacturer also
states that the Eductor can remove water and
debris from a manhole at the rate of 345 gpm
(1,3061/m).
By changing the Eductor nozzle, the
machine also can be used for high-velocity
sewer cleaning.
Industrial and Municipal Engineering,
(I.M.E.), P.O. Box 61, U.S. Route 34, East
Galva, Illinois 61434. Manufactures vacuum
inductors with solids handling capabilities.
Vacuum pumps are used with up to 800 cfm
(22.7 m3/min) to 29 in. (73.7 cm) of vacuum.
Hydraulic hoists lift the 1,100 to 4,400 gal.
(4,160 to 16,650 1) tanks enabling them to
dump the solids. The units can be used for
sludge hauling, disposal, and spreading.
Naylor Industries, P.O. Box 6507,
Pasadena, Texas 77506. Manufactures the
ST-1000 Veri-Kleen unit that eliminates
manual removal of .solids from manholes. A 3
in. (7.5 cm) solids handling pump capable of
handling 2.8 in. (7.3 cm) solids is used on
the unit. The unit is used in conjunction with
the high-velocity sewer cleaners presently on
the market. The 1,000 gal. (3,785 1) capacity
tank can also be used to haul sludge.
Rockwell International, Municipal and
Utilities Division, P.O. Box 4776, Dallas,
Texas 75247. Produces a small vacuum-type
manhole cleaner for use with the high-velocity
cleaning machines.
Super Products, P.O. Box 27225, 8532
West National Avenue, Milwaukee, Wisconsin
53227. Manufactures Supersucker Vacuum
street and sewer cleaner. The unit has a liquid
volume of 14 yd3 (10.7 m3) and uses suction
hose diameters of 8, 10, or 12 in. (20.3, 25.4,
or 30.5 cm) with a maximum vacuum of 200
in. (5.1 m) of water.
Chemical Root Control
The intrusion of roots into sewers is
probably the most destructive single element
that faces those maintaining a wastewater
collection system.
Over the years, many have attempted to
inhibit the growth of roots in sewers by
various chemicals, chiefly with copper sulfate
placed in the manhole invert, and occasionally
by flushing the chemical down the service line
through the toilet bowl. However, this has
never proved popular because of the belief
that copper sulfate will damage the treatment
processes, especially those that depend upon
biological action. Also, the chemical will not
inhibit the growth of roots that do not
come in contact with the flowing waste water.
Roots generally enter sanitary sewei pipe
joints from the top portion and grow down
until the tips reach the wastewater where they
normally die from lack of oxygen in the
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water. However, they continue to grow above
the flow, in the sewer atmosphere which is
usually saturated with water and nutrient
vapor. These conditions enhance root growth
and may ultimately block the sewer.
However, research at the University of
California, Davis, and full-scale testing at the
Sacramento County (California) Utilities
Division of the Public Works Department have
shown the value of using a soil fumigant type
of weed killer to inhibit the growth of the
roots as they enter the sewer. The fumigant
consists of 24.5 percent anhydrous metham
(sodium methyldithiocarbonate), 1.77 j)ercent
dichlobenil — 2,6 dichlorobenzonitrile, and
.balance of inert ingredients containing grease
emulsifiers, nonionic surfactants, and foaming
agents. 6
With the application methods developed,
roots will absorb the killing agent and
inhibitor. Even more important, inorganic
colloids and soil in the sewer joints and breaks
in the pipe will absorb the inhibitor allowing
it to be effective for long periods, for as much
as three or four years in open joints.
This inhibitor may be applied by the
"soak" method, by plugging the lower end of
the line to be treated, filling it with solution
at 1 percent for an hour or longer, and then
allowing the solution to flow downstream to
the next pipe to be treated.
A second, more recently developed and
apparently superior method is to introduce
the fumigant into the sewer as a foam. This
requires plugging the sewer at the upstream
manhole using a plug that can receive a 1 in.
(2.54 cm) pipe connection. The plug must be
strong enough to resist a back pressure from
the wastewater of 30 psi (2 kgf/cm2). A foam
generator is then connected to the plug, and
the foam carrying the fumigant is introduced,
completely filling the sewer until it appears in
the downstream manhole. After the plug is
removed, the wastewater slowly moves under
the foam and compresses it into the top
portion of the sewer but does not
immediately remove it. The foam will cling to
the top of the sewer for 30 minutes or more,
giving the roots ample time to absorb the
fumigant.
To reduce the risk of having the foam
enter the house connections, the operator can
insert the hose at the downstream manhole to
the mid-point of the sewer and start the
foaming at that point. Then he can pull the
hose slowly back to the downstream manhole
as foaming continues. This procedure should
prevent pressure buildup that would force the
foam into the house laterals.
To inhibit root entry into large mains
sufficient for personnel to enter, the root
inhibitor can be sprayed into the upper
portion of the sewer at the point where root
entry appears. The line must be thoroughly
ventilated for this work, .not only for the
general safety of personnel, but also to avoid
problems from the inhibitor. The supplier
states that metham can decompose and
release MIT, a gas which is used for alcoholic
aversion therapy. Long-term tests of five or
more years indicate only a minor regrowth
problem. Mutations in the mat structure have
also been observed which appear to reduce
the number of hair roots which mat and
collect grease.
Volumes I and II of this report contain
additional information concerning root
control practices.
Principal Suppliers of Chemicals
for Root Control
Airrigation Engineering Company, Inc.,
Box H, Carmel Valley, California 93294.
Supplies Vaporooter root inhibitor consisting
of anyjidrous sodium methyldithiocarbamate,
dichlobenil — 2,6 dichlorobenzonitrile, and
certain inert ingredients, either in the "soak"
or the "foam" formulation. Also supplies the
Foamaker generator and appropriate
application plugs and accessories. The
generator will produce and inject 20 gal. (76
1) of fumigant foam from each 1 gal. (3.8 1) of
the 5 percent Vaporooter solution. Five gal.
(19 1) of water and 1 qt (0.9 1) of foaming
fumigant will produce 100 gal. (3,785 1) of
foam. A sewer 12 in. (30 cm) iii diameter
will require 6 gal. (23 1) of foam per foot
(30 cm) of length.
Applied Biochemists, Inc., P.O. Box 25,
Mequon, Wisconsin 53029. Supplies copper
sulfate.•
Cities Service Industries, Chemical
Division, P.O. Drawer 50360, Atlanta,
Georgia 30302. Supplies copper sulfate.
29
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Oxford Chemicals, P.O. Box 80202,
Atlanta, Georgia 30341. Distributes Oxford.
XL 222 delayed action pellets to keep sewer
lines open by removing organic matter.
Phelps Dodge Refining Corp., 300 Park
Avenue, New York, New York 10022.
Supplies copper sulfate.
Reliance Oiemicals Corp., P.O. Box
19343, Houston, Texas 77042. Supplies
copper sulfate in tablet form as Rootox. Also
supplies Bionetics, described as a preserved
culture of T>eneBcial micro organisms that can
digest sludge, grease, and organic debris.
Rohm and Haas Company, Independence
Hall West, Philadelphia, Pennsylvania 19150.
Grout Root Inhibitors. Major suppliers of
sewer grout supply. formulations with a root
inhibitor. See discussions in Section IV.
Source: Rockwell International, Dallas, Texas
Figure 12. A bucket-type cleaner with a conveyor loader can be towed easily behind a dump truck.
30
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Source: Aquatech, Inc., Cleveland, Ohio
Figure 13. A trailer-mounted rodding machine in operation, Note two spare cutters on manhole
lid.
Source: Rockwell, International, Dallas, Texas
Figure 14. A trailer-mounted rodding unit with the power portion on a small dolly has
proven popular among the smaller municipalities.
31
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Sourco: FMC Corporation, Agricultural Machinery Division,
Jonosboro, Arkansas
Figure 15. High-velocity, hydraulic-jet sewer cleaners have demonstrated great
usefulness in this phase of sewer maintenance.
Source: RockweH, International, Dallas, Texas
Figure 16. High-velocity sewer cleaners can be provided with a manhole wash-
down gun, held by the operator, as well as the usual sewer-cleaning
nozzle and the hose roller placed in the manhole.
32
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Figure 17. High-velocity cleaning hose leaves
A the reel and enters the manhole
T to perform the jet sewer cleaning.
Source: Rockwell, International, Dallas, Texas
Source: Central Engineering Company, Inc., Milwaukee, Wisconsi.n
Figure 18. Combination cleaning unit that cleans the sewer by high-velocity water jets and
removes the debris by vacuum action.
33
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Source: Myers-Sherman Company, Streator, Illinois
Figure 19. Operation of a combination high-velocity jet cleaner and vacuum debris-removal unit.
34
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Source: Aquatech, Inc., Cleveland, Ohio
Figure 20. This truck-and-trailer combination brings together high-velocity water-jet cleaning
along with vacuum removal of the debris. •
Source: Aquatech, Inc., Cleveland, Ohio
Figure 21. Hydraulically powered cutter
secured to the nozzle of a high-
velocity cleaner can sever roots m
that resist the action of the water
jets.
35
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Figure 22. The hinged-disc cleaner can be pro-
L vided with a variety of heads to fit
T various sewer pipe sizes.
Source: Cues, Inc., Orlando, Florida
Figure 23. Operation of the hinged-disc cleaner,
Propelled by the pipeline water, the hinged disc squeeges
deposits through the pipe toward a lower manhole.
If progress slows, the'hinged disc is tripped and the head of
wate° flushes away the accumulation. Release the control
line and rapid cleaning continues.
Source: Cues, Inc., Orlando, Florida
Figure 24. The hydraulic manhole and catch-
basin cleaner develops its cleaning
power through its specially designed
nozzle incorporating a 1 in. (2.5 cm)
venturi that develops a strong suction,
able to draw the debris from the
manhole.
Source: fclQln Leach Corporation, Chicago, Illinois
36
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Source: Cues. Inc.. Orlando. Florida
Figure 25. A hydraulic-type manhole cleaner has a capacity of 1,000 gal. (3,785 I) or a settled
debris capacity of four cubic yards.
Source: Elgin Leach Corporation, Chicago, Illinois
; Figure 26. A hydraulic-type manhole and
catchbasin demonstrates its
versatility by also performing
as a street f lusher.
37
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SECTION IV
SEWER GROUTING
The prevention of infiltration and
exfiltration in existing sewers by grouting the
leaking joints or small circumferential
fractures in the pipes represents a relatively
new sewer-rehabilitation technique. The
technique is about 20 years old. The results to
date have been promising, and the savings in
sewer-maintenance costs have often been
substantial.
Chemical grouts are most commonly used
to seal leaking joints in structurally sound
sewer pipes. Radial cracks may also be sealed,
but grouting should not be used as a
structural repair for broken, cracked, or badly
crushed pipe or appurtenant structures. Under
normal backfill and groundwater conditions,
grouting is generally accomplished with a
minimum of difficulty. If there is strong
groundwater or earth movement, special
techniques may need to be used.
Two patterns of grouting have been used,
the first, grouting only joints which appear to
have sufficient infiltration to be
cost-effective, and the second, to test and seal
each joint. Either system may not be totally
effective since ungrouted joints may fail at a
later date due to high hydrostatic
groundwater levels, earth movement, or root
intrusion. Thus, for minimum infiltration to
be maintained, inspection and grouting should
be part of the regular preventative
maintenance program.
Types of Grout
Two types of chemical grout are generally
used for this work:
1. An acrylamide gel, known either as AM-9
Chemical Grout, Q-Seal, or PWG.
2. A liquid prepolymer that cures to form a
flexible, cellular-rubber urethane foam
gasket known as 3M Brand Grouting
Compound.
The first stabilizes the surrounding soil
adjacent to the faulty joint or crack and fills
it completely with impermeable grout,
including the joint or crack (Fig. 27). The
second does not attempt to penetrate the soil,
but seals the leaking joint or crack itself.
Acrylamide Gel
The use of the acrylamide gel for sewer
rehabilitation is an example of technology
transfer. It is an application to sewer
technology of chemical soil stabilization that
has successfully prevented •' the flow of
groundwater around dams and similar
structures, and has prevented the entry of
groundwater into tunnels, mines, and other
underground structures. It has been used for
at least 20 years. With the principles well
developed, all that was needed was to adapt
them to the special, confined conditions of
sewer infiltration and inflow.
The acrylamide gel consists of two
organic monomers: acrylamide; and N,
N-methylenebisacrylamide. A dilute aqueous
solution of the mixture, usually 10 percent by
weight, will react to form a gel when
catalyzed.
The catalyst commonly used is
B-dimethylaminopropionitrile, known more
simply as DMAPN. It is a slightly caustic
liquid, with no more than 0.5 to 1.5 percent
by weight of the total solution needed to
activate the reaction.
Beginning in 1975, procedures have been
developed to use admixtures with the
acrylamide gel to overcome difficulties of
application which had previously limited the
use of the product under certain situations.
Gel Time
A strong oxidizing salt, ammonium
persulfate, initiates the reaction. The gel time
beings with its addition. Usually 0.5 to
3.0 percent is needed on a weight basis. The
gel time can be varied from 1 to 500 seconds,
depending on the amount of DMAPN and
ammonium persulfate used. For most sewer
grouters using this product 20 seconds is
common. When the gel is used for structural
waterproofing, a longer time is needed to
permit deeper penetration.
Gel Capabilities .
The gel grout can penetrate small leaks
and cracks even though water is flowing
38
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through them. Since the gel has a slightly
greater specific gravity and viscosity than
water, the grout tends to displace rather than
mix with the groundwater in the area of the
pipe. However, if it is injected into coral,
sand, gravel, or coarse rock, the volume of
water may be great enough to reduce the
effectiveness of the gel. Under conditions like
this, one supplier, American Cyanamid,
suggests adding a fine, light filler such as
diatomaceous earth (Celite 209, a product of
Johns Manville Co.), or fiyash to the gel to
increase strength and viscosity. This technique
has been used successfully by several major
sewer service companies.
The acrylamide gel performs well when
blocking infiltration in leaking sewer joints
laid in fine sand below the water table. It has
performed successfully in stabilizing and
sealing leaking joints in sewers laid in virgin
soil.
There appears to be some tendency for
the grout to dehydrate where soil conditions
are very dry, such as for shallow storm-sewer
lines. This possibility can be minimized with
the addition of ethylene glycol to the gel.
When additives such as diatomaceous earth or
calcium chloride are added for strength or to
minimize dehydration, the pumping and
mixing facilities may need modification as
shown in Exhibit 1.
Grouting Procedure
Using Acrylic Gel
Before a sewer with infiltration problems
can be grouted the pipe must be thoroughly
cleaned and freed of obstructions and
intruding service connections. This is
necessary to permit use of the sealing packer;.
The packer consists of a hollow metal
cylinder with inflatable rubber sleeves at each
end as shown in Figure 27. With the help of a
closed-circuit television camera, the operator
positions the packer on the joint or crack
requiring sealing and inflates the sleeves to
create a tight seal with the pipe walls. He then
pumps the grouting chemical into the annular
space outside the cylinder and between the
two inflated sleeves. The pumping pressure
forces the grout through the joint or crack
and into the soil surrounding the pipe.
After the period of time selected by the
operator has passed, the grout solidifies into a
gel and produces a seal outside and within the
joint or pipe crack. The operator then deflates
the sleeves and moves the packer to the next
trouble spot in the sewer. Some packing units
have a third inflatable section in the center
which is used to "push'* the liquid grout into
the joint. Television is often used to assist in
positioning the packer and observing results.
A central unit is shown in Figure 28.
Since the acrylamide powder is somewhat
toxic, personnel should be equipped with
goggles, gloves, and respirators when handling
the grout powder.
In all the grouting operations with this
product, some gel will remain in the sewer;
however, it will be carried away with the
wastewater and causes no more problems at
the pumps or comminutors than any other
solids in the sewage. The packer will dislodge
any grout left in the pipe.
Acrylamide gel dries to roughly 80
percent of the liquid volume used. The
amount of grout which is used per joint
should be carefully controlled. Two schools
of thought exist. About 1 gal (3.81) per inch
(2.5 cm) diameter is used to fill the joint or
crack and provide a band of material about
the perimeter of the pipe. Others regularly
inject three to four times this amount in order
to create a large, impenetrable mass to fill
void spaces. This practice is sometimes
followed on the basis of providing
"insurance." Long term tests are needed to
determine if the use of the extra grout is
cost-effective.
Combination test and grout equipment
uses air pressure to detect joints which will
not hold pressure for a given period of time.
Following grouting, an air test is again
performed to test the performance of the
grouting procedure.
Root Inhibitor
American Cyanamid blends 200 ppm of
dichlobenil with the gel to inhibit the
penetration of roots into the sealed joint or
crack. The supplier expects the inhibitor to
remain effective for a minimum of two years
when applied as follows:
1. The sewer line to be repaired is first
cleaned, and roots removed to the extent
39
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that a packer unit can be placed and
operated satisfactorily within the lines.
2. The joints containing roots are sealed
with AM-9 Plus according to
manufacturer's directions for AM-9
chemical grout.
3. For those jobs where neither root cutting
nor packer placement is feasible, pre-treat
the lines with Vaporooter® Plus fumigant
according to the manufacturer's
directions. After a sufficient period to
accomplish root deterioration (1-2
months) follow the steps outlined above
in items 1 and 2.
Sealing Small Service Lines
To seal a small service line, generally 4
inches (10 cm) in diameter, the operator
would have to utilize a television camera and
packer able to function in this restricted
space. This equipment can be obtained, but if
it is not easily available the line can be
plugged at each end and completely filled
with the gel, subjecting.it to sufficient
pressure to permit it to grout all leaks at once.
Urethane Foam Grout
3M® Brand Grouting Compound, the
second type available for this work, is a
low-viscosity (300-350 centipoise)
prepolymer. Solids in the grout constitute 82
to 88 percent of its weight.
When mixed with water, the prepolymer
first foams and then forms a flexible cellular
rubber. The volumetric increase is about
tenfold forcing the grout into the joint or
crack that is subject to leakage. After the
foaming period ends the grout then solidifies
to become the cellular rubber barrier designed
to provide sufficient strength and adhesive
qualities to prevent the entry or exit of water.
Control of Cure Time
An accelerator whose composition is not
identified can be added to hasten the cure
time. At a 0.4 percent concentration in the
grout, the reduction in cure time is reported
by the 3M Company specification sheet for
sewer grouting accelerator as follows:
Ambient Temperature
of the
Grout and Water
40" F ( 4.4"C)
70°F (21.1°C)
100°F (37. 7° C)
Cure Time
Water With
0.4 Percent
Water Only Accelerator
15min 5.5 min
8.2 min 3.5 min
4.6 min 2.5 min
Maximum linear shrinkage is approximately
18 percent.
Physical Characteristics
The supplier reports that the cured
material has a density of 14 lb/ft3 (212
kg/m3), a tensile strength of 80 to 90 psi (5.6
to 6.3 kgf/cm2) and a resilience that will
permit elongation of 700 to 800 percent of its
original length. It resists most organic
solvents, mild acids, and alkalis, and retains its
characteristics whether the soil is wet or dry.
Because of its adhesive characteristics,
shrinkage has little effect.
Grouting Procedure Using
Urethane Foam
Before a sewer with infiltration problems
can be grouted, the pipe must be thoroughly
cleaned and freed of obstructions and
intruding service connections. This is
necessary to permit use of the sealing packer.
Joints must be free of protruding roots and
only minimum amounts of sand or debris can
be in the invert.
The packer that applies the chemical
consists of a hollow metal cylinder with three
inflatable elements. The outer overall sleeve is
coated with a material that will not adhere to
the foaming chemical. By use of a closed
circuit television camera, the operator
positions the packer at the joint or crack to
be sealed. The two end elements are inflated
to form seals against the inside pipe wall on
each side of the point to be sealed.
The urethane prepolymer and water are
injected into the annular space created by the
two inflated end elements and is allowed to
react for the "foam" period, about 35
seconds at 60°F (15.6°C). After the material
foams, the overall sleeve of the packer is
inflated on the joint for the recommended
time to permit the chemical to properly cure.
This time will vary depending upon
40
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temperature and the use of accelerator in the
water. The operator then deflates the packer
elements and moves the packer to the next
treatment point. Water is used for testing of
pipe joints in the absence of visible
infiltration. A drop in water pressure indicates
the need for sealing. Joints may be
immediately retested following the sealing
procedure to insure a proper seal.
In mid-1975 extensive revisions were
made to the packer equipment for use with
3M Brand Grouting Compound. Equipment
supplied to early users is either being replaced
or retrofitted to reduce operational problems.
The new models appear to overcome the
extensive cleaning problems and premature
foaming associated with earlier units.
A desirable feature of the grout system is
that the grout is pumped directly from its
container. The accelerator is mixed with
water which is used both for testing and
foaming.
To inhibit root growth, formulations
are available with dichlobenil.
Effectiveness
Those who are experienced with 3M
Brand Grouting Compound report that it is
most successful when used to check
infiltration through leaking joints and cracks
in concrete pipe and manholes where
adhesion is excellent. In some cases it has
been found to be less successful on vitrified
clay pipe with its smooth, nonporous surface
because of reportedly poorer adhesive
qualities.
Evidence of the grout's ability to perform
as a gasket for long periods rests with an
installation placed in a concrete lift station in
Minnetonka, Minnesota, in 1970, at a point
that was experiencing inflow at the rate of
40,000 gal (151 m3) per day. The grout
successfully stopped the inflow and has
shown no signs of distress during the ensuing
period.
Care must be used in selecting the volume
of grout to be applied to each joint. If too
much is used, the excess will form a "skin"
hanging from the top of the pipe — or along
the invert. One extensive test in Gonzales,
Texas, indicated that sewer cleaning would
not pull out the grout: However, this
possibility is a matter of concern to many
until more experience is obtained. Cured
foam which is dislodged from the joint could
also present a problem at pumps.
Equipment Cleaning
The equipment used to apply the
urethane grout requires a detailed cleaning
procedure. Acetone is needed to clean and
purge the packing unit. For the balance of the
system a specially prepared cleaner is
required. The compound is flammable, and
thus requires appropriate safety practices. It is
also caustic, so those using it should be
protected with appropriate gloves and safety
goggles.
Principal Suppliers of
Grouting Material
and Equipment
American Cyanamid Company —
Industrial Chemicals & Plastics Division, 859
Berdan Avenue, Wayne, New Jersey 07470.
Supplies acrylamide gel under the trade name
of AM-9, produced to provide controllable gel
times. The manufacturer states that it can
tolerate some dilution, react in moving water,
and produce a continuous, irreversible,
impermeable stiff gel in the soil around the
sewer joints to control infiltration.
The company also supplies AM-9 Plus
chemical grout containing 200 ppm 2,
6-dichlorobensonitrile (dichlobenil) for root
control. Dichlobenil is reported to inhibit the
penetration of roots into polyacrylamide gel
for up to six years when properly applied.
American Cyanirnid does not provide
grouting equipment. (For a discussion of
Vaporooter, see Sec. Ill, Sewer Cleaning
Chemical Root Control).
Cherne Industrial, Inc., - 5701 South
County Road 18, Edina, Minnesota, 55436.
Supplies the Poly-Meric Sealing System with a
• wide range of vehicle types, from small
trailers to large vans.', The sealing material is
the 3M Brand Grouting Compound which can
be fed through the system without
preformulation or mixing.
The sleeve packer has a built-in watertest
41
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feature that can be used to confirm that a
leak exists. If the leak is detected, the
polymer can be injected into the water in the
central cavity of the packer, allowed to react,
and then compressed into the leak area. The
packer can operate in sewers from 6 through
24 inches (15 through 61 cm) in diameter.
This company also supplies the Cherne
Elast-O-Seal system designed to seal leaks in
large pipe, from 27 to 120 inches (69 to 305
cm) in diameter. This equipment requires
personnel in the sewer to position the packer
and apply the poly-meric sealing material by a
probe applicator. A control cart which also
carries the sealing material has been designed
for use in the sewer. The same equipment can
be used to seal leaks in manholes. The
equipment requires appropriate safety
precautions governing personnel required to
work in sewers (See Section VII, Safety).
Cherne Industrial is also the distributor
for the 3M Brand Sewer Grouting
Compounds. The sewer grouting chemical is
available with or without root inhibitor. The
company provides a training program to
familiarize the new owner with equipment
and procedures to be used.
Cues, Inc. - P.O. Box 5516, Orlando,
Florida 32805. Supplies the acrylamide gel
grout under the trade name of Q-Seal as well
as Cues Seal Root Kill and other chemical
grouts for sealing applications. The company
has developed over a 10-year period, a variety
of equipment units for applying the grout not
only to leaking joints and cracks in sewers,
but also to leaking manholes, wetwells, and
other similar structures. The company
provides a training period to familiarize the
new'owner with the equipment.
Dolfran, Inc. - P.O. Box 13627, Tampa,
Florida 33618. Will custom-build equipment
or pressure-grout .and seal a sewer to prevent
infiltration and inflow. Supplies grout with a
root inhibitor.
Eitzgerald Engineering Company, Inc. —
2601 SW 69 Court, Miami, Florida 33155.
Manufactures a complete test and seal unit
capable of television inspection and testing of
joints and grouting with acrylamide gel. The
grouting unit features an inflatable center
section to force the grout into the leak and
reduce the use of excess gel which would be
left inside the pipe. The unit is more costly
than two inflatable sealing units; but, the
manufacturer claims this is justified because
of material savings and fewer resealed joints
due to leaking gel.
Halliburton Services — Duncan,
Oklahoma 73533. Provides the Halliburton
Telespection and Telegrout Systems. The
grout system makes use of the acrylamide gel
under the company trade identification of
PWG. The system uses color-coded mixing
tanks and air-driven chemical grout pumps.
The' group packers can be provided for sewer
pipe 6 through 27 inches (15 through 69 cm)
in diameter. The system can be purchased,
rented, or leased.
Minnesota Mining & Manufacturing
Company - (3M), 3M Center, St. Paul,
Minnesota 55101. Manufactures a foaming,
low-viscosity prepolymer grout, and a
sewer-grouting "Accelerator" that shortens
and adjusts the foam and cure time. The
company also provides a grout cleaner to
remove cured and partially cured grout from
fittings and hoses.
The company provides sewer sealing
chemical with or without a root inhibiting
material. Cheme Industrial, Inc., designs and
manufactures the equipment to use the 3M
Sewer Grouting Chemicals.
Obrien Manufacturing Division, Conco,
Inc. — 5632 Northwest Highway, Chicago,
Illinois 60646. Supplies the Search and Seal
system which combines television inspection
with air testing and grouting with acrylamide
gel. The system can be supplied in vans or
trailers of various sizes.
Larger Facilities
Rehabilitation of larger facilities such as
accessible sewers and manholes can be
accomplished by the use of several methods.
Figures 29 and 30 show the use of grouting
equipment. Most manufacturers of grouting
equipment have units for large diameter work.
Other methods which have been used
include GUNITE, a sprayed on concrete
mixture with a steel reinforcement for sewer
pipes and the use of a troweled on water stop
in manholes.
42
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Principal Suppliers
IPA Systems, Inc. - 390 Reed Road,
Broomall, Pennsylvania 19008. Manufactures
and distributes IPANEX Concrete Admixtures
for troweling on to manhole walls to stop
passage of water and rehabilitate the
structure.
Pressure Concrete Construction Co. -
25th floor, First American Center, Nashville,
Tennessee 37238. Provides rehabilitation of
manually accessible sewers by the use of
"Gunite."
EXHIBIT 1
TYPICAL
Agitator
GROUTING EQUIPMENT FOR INCREASED STRENGTH AM-9
Sight
gauge
gauge
Connectors Q
V 1 ~~1
I 1. 4
i\ =L
M 1
f \
— N —
— N —
1 —
1 1
J 1
J
J
Pressure
Pump
^uick —
Disconnects
Mixing Packer
fim..t Tank - Water AM-9 grout, and DMAPN using appropriate formulation.
AP Tank - Water, ammonium persulphate (AP) and Celite 209 diatomaceous earth, ,n
h tank to reduce the dissolving time and to keep the solids
s-ucopenng valves are used to maintain equal pressure and equal volume of the
chemical grout and the ammonium persulphate mixtures in the Packer
Mixing Packer - The mixing packer consists of inflatable neoprene rubber ends on a
stainless steel tube with smooth ID tubings leading to the chemical grout and the
am±Lrn persulphate parts. The ports are .ocated one-half inch apart m the center
section of the packer.
43
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source:
Figure 27. Application of the acrylamide-gel grout. Note the gel
that has been pumped to the outside of the joint to
stabilize soil and help make it impervious to water
entry. The television camera is at left.
Source: Panetryn System, Inc.
Figure 28. Locating a leaking joint
by use of the television
camera so that trie
packer can be placed
over it.
Source: Minnesota Mining 8, Manufacturing Company,
St. Paul, Minnesota
Figure 29. Joints of a 60-inch
(142 cm) storm-sewer
sealed with urethane
foam grout.
44
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B sr.-ssg
The Elast-0-Seal System is also
used to control manhole intil-
tration. A probe applicator
easily injects the sealant into
leaking manhole walls.
by usin9 a special 9routina rin9' The
h
same equipment can be used to seal in manholes.
45
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SECTION V
SEWER INSPECTION AND TESTING
Sewer inspection and testing, as applied
to this report, detects weaknesses and faults
in pipe and joints that permit the unwanted
entry of infiltration and inflow water. Certain
of the techniques are also useful for testing
the watertight integrity of newly installed
sewers as well as insuring the quality of
construction. However, since the
mileage of existing sewers is far greater than
new construction, and since the prevention of
unwanted infiltration and inflow insures that
the sewerage system will be used effectively,
the primary purpose is far more important.
Infiltration/Inflow Defined
Infiltration is the entry of groundwater
into the sanitary sewer through imperfections
in the pipe wall, pipe joints and manhole
wells, and occurs when the groundwater level
is above the pipe.
Exfiltration can o.ccur when the
groundwater level drops below the pipe,
permitting the wastewater to escape through
the same pipe and joint imperfections. What
can be called false infiltration represents
condensation on the pipe walls. This may
amount to as much as 50 gal/in/mi/d (46.3
1/cm/km/day).
Inflow is the entry of surface water into
the sanitary sewer. This may be through
illegal connections with the service laterals,
introducing flow from: roof downspouts,
foundation drains, driveway drains, yard
drains and similar sources. It may also come
from rodent passageways leading to breaks in
the pipe, joint or perforations in manhole
covers in areas where the manholes are
subject to flooding. (If a manhole is flooded
with 6 in. [15 cm] of water over the cover, a
single ventilation hole 1 in. [2.5 cm] in
diameter can admit over 416 gal [1.5 m3 ] of
inflow per hour).
Manhole ventilation holes located in areas
subject to these ^floods should be sealed, and
maintenance forces should be aware that such
manholes will be subject to a much greater
risk of dangerous and explosive gases than
those with ventilation holes.
Types of Testing and Inspection Methods
Testing of sewers for weaknesses that will
permit infiltration and inflow can be grouped
into four general categories:
1- Smoke testing.
2. Internal inspection with closed-circuit
television inspection of the pipe interior
or still color photography.
3. Low-pressure air testing.
4. Infiltration testing.
For internal inspection, most prefer
television because of the quick location of
problem areas. The television .camera also
permits a photographic record of those areas
where a record is needed.
Smoke Testing
Smoke testing of sewers as shown in
Figures 31 and 32 is practical and convincing
under proper ground and weather conditions.
Many sources of infiltration and inflow exist'
that are detected easily and positively by smoke. •
This method can find leaks and breaks in
pipes as shown in Figure 33. It can disclose••
connections between roof and cellar drains
with the sanitary and combined sewers. These
connections can impose heavy peak loads on
the systems during a storm and can cause
flooded basements and similar damage. Smoke
testing can identify leaky manholes that can
introduce unwanted water, and can locate
rodent passages that will do the same.
Types of Smoke
Smoke can be supplied either by
"candles" or "bombs" that produce a
zinc-chloride mist or by a generator that'
creates "smoke" composed of DOP
(dioctylphthalate) aerosol which consists of
particles 0.6 microns in size and thus is able.
to pass through relatively dense soil
successfully. Both types can be supplied in
colors varying from white to grey. Suppliers
state that the smoke leaves no residue to stain
building surfaces or clothing and that it is
noncorrosive. Both are nontoxic but can
produce a coughing spasm if breathed in large
amounts.
46
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To be effective, the candle> bomb, or
generator should produce a smoke volume no
more than five to six times that of the volume
.of the sewer section being tested. A
"three-minute" bomb should suffice for a
sewer run of 300 ft (91 m), and a "five
minute" bomb for larger.
Preliminary Details
Before undertaking a smoke test, the
sewer authorities should notify both the
police and fire departments so that they will
be prepared when they receive calls about
unexpected smoke emerging from
unsuspected locations, especially from
buildings. All residents in homes connected
with the sewer to be tested should be
notified, as well as those connected with
adjoining lines in case the smoke works its
way into them. Residents should also be
encouraged to check that a water seal exists in
trapped drains.
Principal Manufacturers of
Smoke-Testing Equipment
Air Techniques, Inc. - 1717 Whitehead
Rd., Baltimore, Maryland 21207. Can supply
a complete smoke-inspection system or
separate parts as desired. The system operates
using OOP (dioctylphthalate) as the smoke
source. Current prices are:
Complete smoke-inspection system, (TDA-5A)
smoke generator, manhole cover and
blower, electric generator $ 1,800
Same as above without electric
generator $1,425
Smoke generator alone $1,155
DOP solution $35/gal ($9.04/1)
Company quotes operating cost of $35
for 8 hours; production of 1 million ft3
(28.317 m3) of smoke in 5 minutes with
on-off operation; and smoke particle size of
0.6*micron with ability to penetrate 17 ft (5.2
m) of clay.
Cues, Inc. - P.O. Box 5516, Orlando,
Florida 32805. Provides smoke-generating
devices utilizing the zinc-chloride mist. Can be
supplied as 1-minute, 3-minute, or 5-minute
smoke bombs,, as, a smoke grenade, or as a red
or orange smoke pot.
Company also manufactures Q-Air smoke
blowers to be placed directly on the manhole
opening. The blower is' powered by a,
S^-horsepower gasoline engine and is able to
deliver 1,750 cfm (50 m37min) against a
pressure of about 1 in. (2.5 cm) of water. The
blower is mounted on a self-sealing fiberglass
manhole plate; a flexible canvas duct can be
provided for remote operation.
The company also makes
electric-powered blowers able to deliver 1,750
cfm (50 m3 /min). The power must be supplied
by an auxiliary electric generator. Also a small
blower powered by a 12-volt battery is
available.
The blower can 'deliver 600 cfm- (17
m3 /min).
Superior Signal Company, Inc. — West
Greystone Road, Spotswood, New Jersey
08884. Produces a variety of
smoke-generating products, all based on the
use of zinc-chloride mist. Current prices run
as follows:
No. 1A smoke candle, 30 seconds $7.25/doz.
No. 2B smoke candle, 1 minute $8.80/doz.
No. 3C smoke bomb, 3 minutes $ 16.80/doz.
No. 5D smoke bomb, 5 minutes
smoke grenade
professional smoke grenade
white smoke pot
professional white smoke pot
$35.00/doz.
$6.30 each
$6.30 each
$13.55 each
$14.20 each
Internal Inspection
The availability of the closed-circuit
television camera designed to pass through a
sewer and show the quality of its
workmanship and its present condition has
done more to improve sewer construction and
maintenance, and to protect the sewer from
casual damage by other contractors and
utilities than any other development.
Contractors know that the camera can
provide evidence of good or bad
workmanship. Building contractors become
aware that if they harm a sewer, the television
camera will detect it and that they will be
held responsible. Contractors have become
reticent about conducting blasting operations
after a sewer has been installed. They also pay
more attention to sew;er line, grade, bedding
and other details of workmanship.
When the camera first became available,
most sewer authorities preferred retaining the
services of specialists to perform the
47
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inspection. But as the equipment became
more simplified, and maintenance personnel
grew more familiar with it, both sewer
authorities and consultants have acquired the
television equipment. The sewer authorities
now make use of it for more frequent and
thorough inspection of the present condition
of the sewer. The consultants use it to insure
that construction programs under their
supervision are completed to specified
standards. A remote controlled winch for
pulling the camera is a .desirable feature which
allows the operator greater control and may
reduce manpower requirements.
Elements of TV Inspection
A typical closed-circuit television
inspection system consists of:
1. A skid-mounted camera able to pass
through a pipe 8 in. (20 cm) or more in
diameter (cameras are available that will
pass through smaller pipe). [See Figure 34]
2. A light source for the camera.
3. Television cable and steel cable on 1,000
ft (305 m) reels with measuring
equipment to locate the camera precisely
in the sewer.
4. Sheaves or pulleys for the cables, and a
hand-powered winch at one end to pull
the camera through the sewer. The winch
can be electrically powered if desired.
5. A control unit with a television monitor
and generally a polaroid camera to
photograph and record key locations in
the sewer. [See Figure 35]
6. An electric generator to provide power
and a communication system between the
observer and the crew member powering
t'he winch. [See Figure 36 ]
The control unit, generator and
communications system generally are housed
in a closed truck or trailer body. A 16 mm
video-tape motion picture camera also can be
supplied to make a continuing permanent
record of the inspection for future reference.
Principal Manufacturers of
Closed-Circuit Television for
Sewer Inspection
Cheme Industrial, Inc. - 5701 South
County Road 18, Edina, Minnesota 55436.
Produces a customized inspection system
assembled either in a truck body or trailer.
The camera was designed with solid-state
circuitry, contained in a waterproof housing
able to resist 400 psi (28 kgf/cm). The camera
is mounted on an adjustable skid assembly
that will fit sewer pipe with diameters ranging
from 6 to 30 in. (15 to 76 cm) if required.
Lens adjustments are made externally.
Electronic circuitry is designed to eliminate
the need for fuses.
The television monitor carries an
electronic footage readout that identifies the
location of the camera. Photographs of the
monitor automatically include the footage
figure.
The television cable and reel contain
1,000 ft (305 m) of cable incased in PVC and
protected by a strain-relief feature with a
reported strength of over 1 ton (907 kg).
Remote electric power winches, video
display units, video tape recording equipment,
and both standard and low-light-level
television cameras are also available.
Cues, Inc. - P.O. Box 5516, Orlando,
Florida 32805. Produces the Q-TV "sewer
evaluation unit" which includes inspection of
sewer pipe interiors by closed-circuit
television. These evaluation units are supplied
in van-mounted trucks, walk-in trailers, and
exterior-operated trailers.
The equipment is designed to inspect
sewers varying from 4 to 60 in. (10 to 152
cm) in diameter. The operator has complete
control of the movement of the camera
through the line by means of a powered
winch. Information pertaining to the location
of the camera in the line, the date of the
inspection, and the job code, all are
electronically displayed on the video monitor
so that the information can either be
photographed or video-taped for permanent
records.
The Cues television-camera line includes
the normal Q-TV camera, the Q-TV camera
with a low light-sensitivity vidicon tube, and
the Q-TV photo camera which allows the
operator to take 35-mm pictures in the sewer.
of the scene that is viewed above ground at
the television monitor.
Fitzgerald Engineering Company, Inc. —
2601 SW 69th Court, Miami, Florida 33155.
Supplies the Fitz television cameras that will
48
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permit inspection of sewers varying from (6
to 96 in. (15 to 244 cm) in diameter.
Flo-Max, Inc. - Box 125, Boerne, Texas
78006. Supplies the Jaki GC-200 solid state,
2.25 in. (5.7 cm) diameter camera. The
camera has a low light sensitivity image tube
and internal lighting built into the camera
case. Lines as small as 3 in. (8 cm) can be TV
inspected. Camera focus can be adjusted
externally without disassembly of the camera
case.
A telescoping skid for 6 to 15 inches (15
to 38 cm) lines is normally supplied.
Telescoping skids for lines up to 48 inches
(122 cm) are available.
The system can be van or trailer mounted
or operated as a completely portable system
by towing the master trailer on the highway.
The master trailer wheel width can be
reduced from 40 to 29 in. (102 to 74 cm)
for reaching manholes in easements and
difficult locations. A two-speed, hand-
powered winch mounted on a hand cart
carries 1,000 ft (305 m) of 0.125 in.
(0.32 cm) steel towing cable for pulling the
camera through the sewer.
A solid state 9 in. (23 cm) screen monitor
is normally supplied. Larger monitors can
be provided. Other accessories available
include special skids, electric remote footage
meters, video recorders, polaroid camera
mounts, electric power rewinds, and complete
supporting equipment.
Halliburton Services, Duncan, Oklahoma
73533. Supplies a video camera in two
models, 70 and 90, which can operate on 10
percent of the light ordinarily needed.
Both will serve to inspect all lines of 6 in.
(15 cm) or larger. Both the iris and focus can
be adjusted externally. The light assembly for
model 70 consists of two quartz-iodine lamps
requiring approximately 2.25 amps at 28 volts.
The lamps have a rated life of 1,000 hours.
The model 80 camera uses a light assembly
consisting of 30 small incandescent lamps
mounted around the periphery of the
assembly to provide improved light
distribution and reduce the heat transmitted
to the camera components. The light requires
only 30 volts and can provide sufficient light
for the model 70 camera when used in sewers
with diameters of 8 to 76 in. (20 to 193 cm)
with a 6 in. (15 cm) set available for either
camera.
A two-speed winch assembly that draws
the camera through the line being inspected
contains 1,000 ft (305 m) of 0.125 in. (0.32
cm) steel cable rated at 1 ton (907 kg). The
winch, mounted on a 2-wheel, rubber-tired
carrier, is designed to straddle the manhole.
An electrically powered winch can be
provided.
The system-control unit, mounted with
other equipment in a closed truck body is a
solid-state device that controls the electric
power supplied to the camera lights. It also
serves as an electrical protective device for the
entire television system. Power requirements
are 115 volts AC, 500 watts.
The television monitor is a 14 in. (36 cm)
transistorized unit. A three-station,
sound-powered phone system provides the
communications needed for- the inspection
work. A polaroid camera with a close-up lens
can be mounted to photograph pictures
shown on the monitor and provide a
permanent record of existing conditions.
Underground Surveys Corporation - P.O.
Box 6119, Fresno, California 93727.
Produces 'a combination pipeline inspection
camera arrangement that can provide
television viewing on a monitor or
stereoscopic photography of the pipe interior.
Manufacturer states that the entire system
weighs less than 500 Ibs (227 kg) and can be
operated from the back of a pickup truck.
The television camera operates through
an armored covered coaxial cable. The camera
has a silicon-target vidicon-image pickup tube
and produces a system resolution equal to
600 lines. The winch assembly can
accommodate 750 ft (229 m) of the armored
cable or 800 ft (244 m) of polypropylene
rope for a tag line. For a permanent record of
the television survey the operator can select
either a video tape recorder or a Polaroid
attachment. A footage counter appears on the
screen to locate the position of the camera.
The steroscopic camera can be installed
by removing the video unit-and placing it in
the same housing. The camera is 29-mm and
operates through a flash assembly.
Prices for the complete unit including
three days on-site training start at $4,995.
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Photographic Camera Inspection
Inspectors can view the interior of a
sewer system by means of photographic
equipment rather than television. The
equipment is simpler, requires two
hand-operated winches, and a suitably
waterproofed camera (generally 35-mm). The
winches can accommodate 500 to 700 ft (152
to 213 m) of cable. The operator can
photograph the pipe, at whatever frequency he
wishes, generally every 2 to 5 ft (0.6 to 1.5
m). The photographs can be black and white
or color. One supplier offers stereoscopic
photography which permits a third dimension
in the inspection, not possible by television
monitoring.
The principal advantage of photographic
inspection is its lower cost. The principal
disadvantage is the delay in inspection caused
by the need to develop the prints and the
possibility that pictures were not taken due to
malfunction or obstruction of the camera
lens.
Principal Suppliers of Photographic
Camera Inspection Equipment
Aquatech, Inc. - 10620 Cedar Avenue,
Cleveland, Ohio 44106. Produces a 35-mm
camera housed in a waterproof case tested to
100 psi (7 kgf/cm2). The camera is supported
by skids that permit inspection of pipe with
diameters from 6 through 24 in. (15 through
61 cm). A strobe light, powered by a 6-volt
rechargeable battery, provides photographic
illumination. The control winch, holding 500
to 700 ft (152 to 213 m) of cable, has a
footage counter, picture "take" button, test
light and frame counter.
The supplier reports that the average
operating cost is 3 to 4 cents/ft (10 to 13
cents/m) of sewer inspected.
Entcor, Inc. - Box 4713, Rochester, New
York 14612. Provides a pipe-inspection
camera adapted from underwater
photography use.
Cues, Inc. - P.O. Box 5516, Orlando,
Florida 32805. Produces the Q-TV photo
camera as an accessory to its television
inspection equipment.
Gelco, Photographic Division — Box
1998, Salem, Oregon 97308. Supplies camera
equipment for photographic inspection of
large sewers, from 24 to 108 in. (61 to 274
cm) in diameter.
Underground Surveys Corporation — P.O.
Box 6119, Fresno, California 93727. Supplies
29 mm stereoptic photographic equipment as
an accessory to'television inspection.
United Survey, Inc. — 25145 Broadway
Avenue, Cleveland, Ohio 44146. Supplies
photo-inspection equipment consisting of a
16-mm camera mounted on adjustable skids,
gyro balanced to minimize camera "roll
over". Camera is pulled by a 2-speed winch
with 1,000 ft (305 m) of cable. The system
is powered by a 12-volt automobile battery
and can be mounted in a pickup truck, van
or station wagon. Designed to take a
continuous reel of color-positive films
covering 2,000 ft (610 m) of sewer at 2 ft
(0.6 m) intervals.
Low-Pressure Air-Testing of Sewers
When the sewer being tested is above the
groundwater level, low-pressure air testing of
a sewer's resistance to infiltration and
ex filtration has largely supplanted water
testing because of its greater convenience and
speed. The use of water can present problems
for sewers placed at a relatively steep grade.
Also, air pockets in the house laterals and
similar locations can weaken the accuracy of
the results.
Air testing of new construction should be
conducted immediately after backfilling
between two adjacent manholes, permitting
the line to be tested before backfilling, and
allowing the contractor to make repairs
immediately.
While a direct relationship between
low-pressure air testing and water testing has
not been established, experience indicates
that a line that will not pass a water test also
will fail the air test.
The American Society for Testing and
Materials states that this type of testing
should be confined to sewers with maximum
diameters of 12 in. (30 cm); however, the
air-test table lists diameters as large as 42 in.
(107 cm). The ASTM recommendation is for
clay pipe.
The test procedure is to flush and clean
the line being tested since a wetted interior
surface yields more consistent results. The
50
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line should then be plugged, including outlets
and laterals. A desirable feature for a "sewer
plug is the ability to place and retrieve the
plug without the necessity of a workman
entering the manhole. This is desirable both
from a safety and time standpoint. For air
permeable pipe such as concrete, the line
should be soaked for several hours to insure
that it is saturated. Standards have not been
advanced for air testing of nonpermeable
materials such as steel or ductile iron.
Allowances of about 25 percent of that
allowed for vitrified clay pipe have been
advocated. Test procedures are shown in
Figures 37 and 3 8.
Infiltration Testing
If the groundwater level is above the
sewer pipe the sewer can be tested by
measuring infiltration flow as described in
Section II.
Large-Pipe Inspection
Pipe large enough for personnel to enter
can be inspected visually and joints can be
tested individually. A typical joint-testing
device isolates the joints, permits the isolated
annular space to be filled with air or water, and
pressurizes it so that the inspector can measure
the rate of loss. Allowable leakage is measured
in volume per foot of pipe multiplied by the
distance between joints in feet. However, in
actual practice the joint is either bottle
tight or sufficiently flawed to require repair.
Principal Suppliers of Sewer Plugs
Cherne Industrial, Inc. - 5701 South
County Road 18, Edina, Minnesota 55436.
Manufactures four models of pipe plugs: the
Sealdbloc; the Muni-Ball; the Test Ball; and
the Air-Loc Ball.
The Sealdbloc is available in various sizes
to 53 in. (135 cm) in diameter and is
designed to withstand 18 ft (5.5 m) of
hydrostatic pressure. It can be inflated or
deflated by remote control.
The Muni-Ball is available to fit sewers
varying from 6 through 24 in. (15 through 61
cm) and can withstand 30 to 40 ft (9 to 12
m) of hydrostatic pressure. It is equipped
with a by-pass plug which permits the
wastewater to be pumped beyond the isolated
section until the testing or repair work is
complete, thereby avoiding the possibility of
wastewater backing into domestic or
commercial drain systems. The plug has been
designed so that it can be deflated and
removed from the line by personnel working
at street level.
The Test-Ball is available to fit pipe with
diameters 1.25 to 12 in. (3.2 to 30 cm). It has
been designed primarily for the plumbing
industry; however, it has usefulness in many
sewer-maintenance tasks.
The Air-Loc Ball is available in sizes.4
through 24 in. (10 through 61 cm) and is
used for low-pressure air testing of newly
built sewers.
The company also supplies the Joint
Tester designed to test by low-pressure air the
tightness of joints in pipe from 30 to 120 in.
(76 to 305 cm) in diameter. The company
will fabricate a tester for other diameters on
request.
Cues, Inc. - P.O. Box 5516, Orlando,
Florida 32805. Cue-Plugs are available to fit
pipes with diameters 4 through 36 in. (10
through 91 cm). All can be installed at ground
level by use of the Q inserter system. After
completion of the test and repair the
personnel can deflate and remove the plug
by working at ground level. The plugs will
withhold pressure head exceeding 40 ft (12
m) for units used in 4 to 18 in. (10 to 46 cm)
pipe, and 20 ft (6.1 m) for those used in 21 to
36 in. (53 to 91 cm) pips.
The plugs have heavy metallic skids that
protect the inflatable and replaceable
elements from friction. The plugs are
equipped with flow-through connectors which
permit bypassing wastewater flow if
necessary. The plugs can be inflated by a
pressurized air tank that can be operated at
street level.
Fernco Joint Sealer Company - 593
Pleasant, Ferndale, Michigan 48220. The UTP
(Underground Test Plug) is available for 3, 4,
and 6 in. (7.6, 10.2, and 15.2 cm) nominal
pipe size sewer pipe. It is designed to
withstand 10 ft (3 m) of hydrostatic pressure
when installed into the mouth of a smooth
bore pipe. The seal is created by compression,
mechanical parts are not -used.
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Source: Superior Signal Company, Inc., Spotswood, New Jersey
Smoke can be directed into the
manhole with the use of any
blower commonly provided to a
sewer maintenance organization
and the help of a flexible canvas
duct and a suitable cover for the
manhole. However, the air-smoke
blower shown here can be placed
directly on the manhole opening.
As a safety precaution it should
be started before it is placed on
the manhole.
Figure 32. Smoke emerges from a down-
spout indicating an illegal con-
nection with the sewer.
NB Products - 35 Beulah Road, New-
Britain, Pennsylvania 18901. Supplies
inflatable rubber reinforced pipe stoppers for
•8 to 108 in. (20 to 274 cm). All sizes when
deflated will fit through the average manhole
opening. The plugs are provided with loops in
order that they may be secured, inflated and
deflated from the surface. Prices vary from
S29 to $4,500 depending upon size.
Naylor Industries — P.O. Box 6507,
Pasadena, Texas 77506. Manufactures trailer
package for I/I survey work, including smoke
blowers, inspection equipment, manhole
entry kit with blowers, gas detectors, harness,
inflatable plugs, compressor and other
miscellaneous field equipment.
United Survey, Inc. - Products Division,
24145 Broadway, Cleveland, Ohio 44146.
Supplies an Air Test Control Unit with
quadrant rollers, air tank, winch and hoses.
Source: Superior Signal Company, Inc., Spotswood,
New Jersey
52
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Smoke
4
Blower
Smoke .
Manhole
•s , -f. *
^. "••>
Smoke
Sand Bags -"^ ''
Source: Superior Signal Company, Inc., Spotswood, New Jersey
Stop
Figure 33. Line being smoke tested is isolated. Smoke identifies the points of infiltration
and inflow.
1
£. J
Source: Aquatech, Incorporated, Cleveland, Ohio
Figure 34. Typical television camera for inspection work is waterproof, has its own light source,
and is mounted on skids for transport through the line.
53
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Source: Cues, Incorporated, Orlando, Florida
Figure 35. Control center within trailer shows the television monitor with its remote-read footage
meter located directly above it, and the Polaroid camera mounted on a swinging bracket.
A video tape recorder can also be provided.
LINE ISOLATION WHILE MAINTAINING SEWAGE FLOW
Source: Cherne lndustrial,_ Incorporated, Edina, Minnesota
Figure 36. When the sewer plug is provided with an appropriate connection it can permit repair
crews to bypass the damaged portion of the line and maintain service.
54
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Source: cnerne. Industrial, Incorporated, Edina, Minnesota
Figure 37. Testing the integrity of joints in an entire line by low-pressure air
Note location of plugs.
Source: Cherne Industrial, Incorporated, Edina, "Minnesota
Figure 38. Testing individual joints by low-pressure air Plugs
connected by cable and pulled to desired section.
55
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SECTION VI
PIPE AND APPURTENANCES
Material for New Construction
In new sewer systems, or in rehabilitation
work that requires new conduits, the heavy
infiltration characterized by past installations
•need no longer be a problem. Improved pipe,
better jointing materials and techniques, and
more meticulous construction procedures if
accompanied by rigorous inspection, make it
possible to meet stringent, but practical and
realistic infiltration rates as currently are
being specified.
Manufacturers occasionally mention an
ability to meet specifications such as 50
gal/in.-dia/mi/day (46.3 1/cm-dia/km/day).
However, working specifications for actual
construction rarely needs to be that strict, but
should be based on a study of the cost of
treating this relatively small amount of
infiltrated water against the cost of its
elimination. Most working specifications
currently range "between 100 and 250
gal/in-dia/mi/day (92 to 231
1/cm-dia/km/day).
Sewer pipe available to designers today
can be grouped into seven general categories:
(1) clay pipe; (2) concrete, plain, reinforced
and prestressed; (3) corrugated steel; (4)
plastic; (5) cast iron and ductile iron; (6)
asbestos-cement; and (7) fiber.
Detailed information concerning
production standards, testing procedures,
design of systems, and construction practices
are available from manufacturer associations
for the various types of pipes.
Plastic Insertion Pipe
for Rehabilitation
The insertion of a continuously welded,
flexible plastic pipe into a deteriorating sewer
of any type is steadily gaining popularity. The
pipe is joined by butt-fusion. Supporters
argue that its excellent flow characteristics
compensate for the loss of diameter caused by
the pipe insertion. The practice avoids the
costly and unpopular need to make
excavations in well established
neighborhoods. Figures 39 and 40 show
installation practices.
Trenchless Pipe Laying
Trenchless pipe laying is a new use of
butt-fused plastic pipe. A "mole-plow" pulled
by a tractor creates the tunnel in the earth
into which the plastic pipe is pulled. The
system is being tested in Bethany Beach,
Delaware. Supporters have not yet presented
evidence of how well the method will work in
rocky soil, nor in areas with trees and
shrubberies with strong root structures. It will
probably also have difficulties in areas with
other underground utilities as well as
sidewalks and concrete curb and gutters.
Principal Suppliers of Plastic Insertion Pipe
Celanese Piping Systems - 4550
Cemetery Road, Milliard, Ohio 43026.
Produces polyethylene (PE) pipe in diameters.
through 24 in. (61 cm) for relining purposes.
E. I. DuPont de Nemours & Company -
Concord Plaza, Wilmington, Delaware 19898.
Produces Aldyl "D" PE pipe in diameters
from 3 to 48 in. (8 to 122 cm). Company also
provides fittings and tools to draw the
butt-welded pipe into the sewer. Sewage
normally continues to flow through the pipe
during the installation. To secure the pipe in
place at critical locations such as manhole
connections, the manufacturer provides
expandable fittings or non-shrink grout.
House-connection techniques also have been
developed.
Goodall Rubber Company - Whitehead
Road, Trenton, New Jersey 08604. Produces
PE pipe in diameters 2 to 10 in. (5 to 25 cm).
Also provides tapping tool for house
connections and joining equipment.
Nipak, Incorporated - 301 South
Harwood Street, Dallas, Texas 75221.
Produces PE pipe. The company offers the
pipe in diameters from 3 to 48 in. (8 to 122
cm) and a variety of wall thicknesses. Nipak
provides a complete system for sewer renewal,
including the pipe, fittings, tools for insertion
of the pipe, and installation assistance.
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Phillips Products Company, Inc. -
Subsidiary of Phillips Petroleum Company,
2655 Villa Creek Drive, Dallas, Texas 75234.
Supplies Driscopipe 7600, PE pipe in
diameters varying from 3 to 48 in. (8 to 122
cm). Provides the pipe to a contractor or
municipality that will do the actual
installation.
Joseph T. Ryerson & Sons, Inc. - P.O.
Box 8000-A, Chicago, Illinois 60680. Supplies
a high-density PE pipe to serve as a reliner for
existing sewer systems. Pipe varies in diameter
from 1 to 48 in. (2.5 to 122 cm) but can be
fabricated to 80 in. (203 cm). Normal length
is 40 ft (12.2 m). Pipe is joined by
butt-fusion. Company supplies the pipe for
suitably equipped contractor.
M. L. Sheldon Plastics Corporation
—Plastics Pipelines Division, 350 Lexington
Avenue, New York, New York 10016.
Provides high-density PE pressure pipe and
fittings in diameters to 48 in. (122 cm). Pipe
is butt-fused and pulled through the sewer by
an air-actuated vibratory pulling head.
Evanston Development Corporation —
3975 Buxmont Road, Huntington Valley,
Pennsylvania 19006. Provides the Badger
system of trenchless pipelaying, a British
import designed to place an opening at a
controEed depth and insert a PVC or other
type of plastic pipe in it at the same time.
Suppliers state that it can place a pipe as large
as 15 in. (38 cm) in diameter to depths of 5.5
ft (1.7m).
Special Pipe Fittings and
Manhole Connections
With the variety of pipe available today,
special fittings and connectors have had to be
developed. The recognition has grown that
the earth is not static but experiences
considerable movement throughout the year
caused by changes in weather and heavy
traffic loads imposed on it. Connectors and
fittings have to retain their watertight
integrity while adjusting to these changes.
A major point of infiltration in many
systems is at the connection of the house
lateral to the main. In some instances the
lateral has been installed protruding into the
main, causing blockage and preventing
proper cleaning of mains. Where hand-tapping
of the main is permitted, the main will
frequently be fractured. In time, the fracture
may permit root infiltration and/or the
collapse of the main pipe walls. At best, it is a
constant maintenance problem.
There are several ways and means of
connecting laterals to the main.
1. Concreting the lateral to the main is quite
common in' many areas. Concrete when
dry, shrinks, permitting hairline cracks to
occur, thus allowing infiltration.
2. Some saddles or connections react to soil
• acids and may totally disintegrate in a
few years, defeating the purpose of using
the saddle.-or connection.
The following should be considered for
lateral connections.
1. No fracturing of main: Mechanically
cutting a hole in the main overcomes
fracturing and also controls hole size. A
hole can be tapped mechanically in about
3 minutes which is a time saver over hand
tapping.
2. Preventing lateral protrusion into the
main: A properly designed saddle
prevents the lateral from entering the
main and causing a restricted flow thru
the main.
3. Prevent infiltration: Provide proper
sealing between main and lateral.
4. Allow for ground movement: In
backfilling around the lateral after a tap is
made, some settling will take place.
Should the connection to the main be too
rigid, either the lateral will break or the
connection will move permitting
infiltration to take place. As the ground is
always shifting slightly, it is desirable to
have built-in flexibility.
5. Inspection: The ease of making an
inspection governs the time spent in
backfilling which relates to equipment
and labor time.
Figures 41 and 42 show connectors to
manholes where shear often causes pipe
failure.
Principal Manufacturers of Flexible
Connections and Fittings
A-Lok Products Corporation - Box
1476, Trenton, New Jersey 08607.
57
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Manufactures a gasket which is a
pipe-to-manhole seal cast integrally into the
pipe opening of the manhole base at the time
of manufacture. It is a compression joint with
no moving parts.
Fernco Joint Sealer Company -593
Pleasant, Ferndale, Michigan 48220.
Manufactures the Donut adapter, an
elastomeric material designed to seal by
compression for bell and1 spigot type
connections. Most combinations of clay,
concrete, cast iron, asbestos cement, ductile
iron, fibre, or steel pipe can be connected in
size to size or reducing sizes up to 12 in. (30
cm) nominal pipe size. No special tools are
necessary for installation.
Also manufactures the Flexible Coupling,
an elastomeric sleeve designed for plain-end
pipe connections. The flexible sleeve is
installed over the plain pipe ends and sealed
by stainless steel clamping bands on the
exterior of the sleeve. The couplings are
available in size to size or reducing sizes for
material to material or material transitions for
most piping materials. Repairs and fitting
insertions are made possible by using the
coupling.
Sizes are available from 1.5 through 15
in. (3.8 through 38 cm) nominal pipe size.
The Formcrete Company - P.O. Box
1153, Manchester, Connecticut 06040.
Manufactures Quick Seal flexible connections
for precast concrete manholes.
GPK Products, Inc. - P.O. Box 2872,
Fargo, North Dakota 58102. Manufactures
"Sureflow" PVC fittings in sizes from 4 to 15
in. (10 to 38 cm) primarily for PVC pipe.
However, the company also makes some
fittings that can be used with clay, cast iron,
or other materials. Fittings include a saddle
wye; reducing, full, and saddle tees and wyes;
bends from 22.5° to 90 °; and adapters and
couplings that can be used with clay and cast
iron pipe.
Interpace Corporation — P.O. Box 1111,
Parsippany, New Jersey 07054. Manufactures
precast concrete manhole bases and wells with
flexible rubber sleeves to receive any type of
sewer pipe from 6 through 15 in. (15 through
38 cm) in diameter as well as risers and cones.
Mission Clay Products Corporation -
6533 South Magnolia Avenue, Whittier,
California 90608. Manufactures Band Seal
couplings and bushings that will permit
coupling various types of pipe and allow for
changing from one pipe size to another.
National Pollution Control Systems, Inc.
— Tanguay Avenue, Nashua, New Hampshire,
03060. Manufactures the Kor-N-Seal
connector that is not cast-in-place but
inserted into a cored hole and sealed by an
internal toggle band and external clamping
band. The manufacturer states that even a
poor and leaking mortared joint can be cored
out and replaced with one of these boots. The
company asserts that the seal has withstood
leakage at 30 psi (2 kgf/cm2) and can'
withstand 22° of deflection without distress.
The manhole can be cored at the site or at the
plant.
Press-Seal Gasket Corporation - P.O. Box
482, Fort Wayne, Indiana, 46808.
Manufactures the Press Wedge II system
manhole connector which reportedly remains
watertight at an external pressure of 15 psi (1
kgf/cm2) and remains so at a maximum
deflection of 15°. Connectors can be supplied
for pipes with internal diameters from 4
through 42 in. (10 through 107 cm). The
system utilizes an all-rubber gasket anchored
permanently in place in the manhole opening
for the entry pipe. The gasket has a finned
opening on one side. When the sewer pipe has
been inserted into the opening, the installer
pounds a finned rubber wedge into the gasket
opening. The fin permits entry of the wedge
but prevents it from pulling out. The
installation, reportedly, requires 4 minutes
and can be made from either inside or outside
the manhole.
Price Brothers Company — P.O. Box 825,
Dayton, Ohio 45401. Manufactures manhole
connectors.
Resilient Seal Corporation - P.O. Box
374, South Plainfield, New Jersey 07080.
Supplies a flexible watertight seal for
connecting pipes to manholes. The seal
consists of a waffled neoprene rubber gasket
embedded into the manhole wall. A stainless
steel strap is tightened from inside the
manhole. Purchase price is $10 and up,
depending upon diameter.
58
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Rimrock Enterprises, Inc. — P.O. Box 14,
Colorado City Colorado 81019. Produces
sewer tap saddles of acrylonitrile butadiene
styrene (ABS) plastic. Saddles can be bonded
to sewer pipe of clay, concrete, plastic,
asbestos cement or cast iron, using a
quick-settling epoxy. Saddles can connect to
laterals of 4 to 6 in. (10 to 15 cm) in diameter
and can be secured to sewer pipes with
diameters from 8 through 24 in. (20 through
61 cm). Sewer leads are connected to the tap
saddle through the use of "Donuts." (see
Fernco Joint Sealer Company).
Scales Manufacturing Corporation —
Route 17K, P.O. Box 1111, Newburgh, New
York 12550. Manufactures the Res-Seal
flexible connection for precast concrete
manholes.
Thunderline Corporation — 5495
Treadwell, Wayne, Michigan 48148.
Manufactures the Link-Seal flexible connector
for precast concrete manholes with precast
pipe openings. The connector has been
designed to fit the curved opening of the
manhole without adjustments and be used
on pipes from 4 to 84 in. (10 to 213 cm) in
diameter or larger. The seal can be installed
and tightened from inside the manhole and
can be retightened later if a leak occurs
through settlement of the manhole or the
sewer pipe. The manufacturer states that it
remains watertight at 20 psi (1.4 kgf/cm2).
This same "Link-Seal" can be used also as
an annular fitting when a plastic pipe is
inserted into the old, deteriorating line. The
fitting creates a seal between the O.D. of the
plastic insertion pipe and the I.D. of the old
sewer line, thus preventing infiltration water
from entering the manhole.
Manhole Closure
Openings in manhole lids have been
identified in many communities as a point of
inflow. Manholes which are inundated can
allow significant storm water flows to enter
the system.
The problem has been met in several
ways. Some have raised or relocated the
manholes and some have welded the lids to
tie frames aid filled in the pick holes or air
' vents. Rubber plugs have been driven into the
openings to effectively seal the lid. A
mechanical inner lid has also been developed
for those systems where continuous
ventilation is desired.
Supplier of Mechanical Manhole Closures
Methods Engineering Corporation — 1102
South Brom Street, Wilmington, Delaware
19805. Manufactures the MEC-1, MEC-2, and
the MEC-3 watertight manhole insert. The
insert is made of aluminum MEC-1 or
plexiglass MEC-2 and fits before the manhole
lid. Valves allow air to; be drawn into the
sewer system. A hydraulic head on the valve
forces the valve to seal. The MEC-3 includes
frame, cover, and insert: Maximum inflow is 1
gal/day (3.8 1/d).
Nuclear Soil-Density Testing
of .Sewer-Trench Backfilling for
Flexible Sewer Pipe
Careful backfilling of the trench plays an
important role in insuring that flexible pipe
maintains its integrity since the wall is flexible
and requires support. Figure 43 shows the
ASTM standard.
Specifications that govern the backfilling
of trenches containing plastic sewer pipe
require the soil to be compacted to a percent
of the optimum proctor density (ASTM
Designation: D 2321 74). However, an
inspector who tries to determine this density
by the conventional sand cone method is
handicapped because the test does not
provide a rapid determination.
Instead of the sand cone method, nuclear
soil-density testing equipment now is available
that will provide an immediate soil-density
figure. The nuclear. method is fast,
convenient, completely safe, requires only
limited training, and permits making a
number of determinations in a short period.
The Federal Highway Administration, U.S.
Department of Transportation, endorses its
use on Federally assisted highway projects,
and all states use the method on highway
construction almost exclusively. ASTM
Designation, D-2922-71 describes the method
in detail. The probes also can measure the
moisture "content in soil and ASTM
Designation, D-3017-72 describes this use of
the meter. Figures 44 ; and 45 show the
necessary steps.
59
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Types
Current nuclear equipment permits
density determination in either of two modes:
1. direct transmission
2. air-gap backscatter
With the first the inspector inserts the
nuclear probe into the soil through a punched
access hole to depths of from 2 to 8 in. (5 to
20 cm). The source transmits gamma photons
to a detector which translates them into a
density measurement for the soil being tested.
Direct transmission provides the
capability of controlling the depth from
which measurements are made. Surface
effects and chemical composition effects are
also minimized. However, since the test is
used in place of the sand cone method, depth
is limited to less than 1 ft (30.5 cm).
With the air-gap backscatter method,
both the nuclear source and the detector are
placed on the surface of the soil. Gamma
photons are directed from the source into the
soil and scattered back to the detector. Two
readings are required, one with the instrument
in contact with the material and the one on
the air-gap stand. This reading relates to soil
density.
Improvement of Backfilling
of All Sewer Trenches
Because of its convenience, nuclear
density testing now is gaining acceptance as a
means of improving all sewer backfill
operations regardless of the type of sewer
pipe being used. Briefly, the method is to
determine the density of the soil prior to
trench excavation and specify that the
backfilling, after sewer pipe installation, be
placed in 1 ft (0.3 m) lifts and each lift
compacted to a density equal to that of the
soil density before excavation or 10 percent
in excess. The nuclear density meter becomes
the sole control device.
Backfilling controlled in this way will
prevent settlement of the fill material. It also
will insure that the pipe itself is firmly placed,
reducing the danger of pipe movement which
in turn would cause leaks to occur in the pipe
and allow infiltration and inflow to take
place. To achieve satisfactory control, full
inspection must be given and the depth of
each layer of backfill limited to the capability
of the compaction equipment, generally 1 ft
(30.5 cm).
Principal Suppliers of Nuclear
Soil-Density Meters
Campbell Pacific Nuclear Company, —
130 Buchanan, Pacheco, California 94553.
Seaman Nuclear Corporation — 3846 W.
Wisconsin Avenue, Milwaukee, Wisconsin
53208.
Soiltest, Inc. - 2205 Lee Street,
Evanston, Illinois 60202.
Troxler Electronic Laboratories, Inc. —
Research Triangle, P.O. Box 12057, Raleigh,
North Carolina 27709.
Determining Deflection, Plastic Sewer Pipe
When a plastic sewer pipe installation
must be "checked" to determine if the line
has deflections which exceed a specified limit,
some type of deflectometer or go/no-go gauge
must be used to make such a test. A pin-type
go/no-go gauge has been designed to stop at
any area in a flexible underground pipeline
having vertical ring deflection greater than 5
percent, the minimum deflected vertical
inside diameter based on Water Pollution
Control Federation (WPCF) recommended
deflection limit, Manual of Practice No. 9,
page 222. Dimensions are based upon
information contained in the pipe
manufacturer's specifications.
The pin-gauge must have free vertical
movement in the sled bushing. A coating of
automotive grease is recommended on that
part of the pin riding in the bushing. A film of
oil applied to the sled and pins will protect
against corrosion.
Sewers often contain some sand or grit
and the pin-gauge may experience wear after a
period of time. Judgment and accuracy
requirements will determine replacement.
Operation
It is important to determine that the line
is free of stones or other debris before making
a test. This is accomplished by pulling the sled
through the line without the pin-gauge
installed. If debris is evident, flushing or
jetting may be necessary.
A strong cord or cable can be used to pull
.the go/no-go. Hand pulling is recommended
to avoid jamming the gauge in a deflected
60
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area. Light cords which could break or stretch
excessively should not be used.
Suppliers of Deflection Gauge
Quality Test Products - 4400 Wildwood
Drive, Crystal Lake, Illinois 60014.
Manufactures Pin-Type Go/no-go Gauge. The
cost of the sled is $40.00 plus shipping. One
sled accommodates all pin-gauges. Each
pin-gauge is $25.00 plus shipping. State type'
of pipe, diameter, ASTM No. and Class when
ordering.
Source: Phillips Products Company, Inc., Dallas, Texas
Figure 39. A 10-in. (25.4 cm) liner being in-
serted into a collapsing . sewer
line in Baytown, Texas.
Figure 40. Special connection at the leading
end of the pipe permits the installers
to pull the pipe through the old
sewer.
61
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Source: Thundorline Corporation: Wayne, Michigan
Figure 41. Sequence of operation followed when installing the Thunderline manhole connector.
62
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Source: National Pollution Control Systems, Inc.
Nashua, New Hampshire
Figure 42. The cutaway portion of the NPCS Kor-N-Seal boot designed to connect a sewer pipe
to a manhole shows the internal toggle band that seals it to the manhole opening and
the external clamping band that seals to the sewer pipe.
63
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Spring Line
Of Pipe
\
\
\
\
\
\
\
,\
\
\
\
V
V
\
\
^
V
(6 -12 in)
150 - 300 r
f\
X^y
Wv\\\\\\\\\\\\XXXVs
in
\.
\
^
^>
Initial
Backfilj
* (-launching
1 Bedding
Max.
(Gin) '
150 mm
! Foundati
' (May not
required)
^, Enbedment
Material
on
be
Source: Drawing from ASTM Designation D-2321-74
Figure 43. For the installation of single-wall plastic pipe, ASTM standards
recommend compaction specifications to a Proctor density in the
foundation, bedding, and (launching areas.
Figure 44. A vibrating compactor mounted on
4 a backhoe in place of the bucket
T compacts a one-foot backfill lift.
Source: Saaman Nucloar Corporation, Milwaukee, Wisconsin
64
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Source: Seaman Nuclear Corporation, Milwaukee, Wisconsin
Figure 45. Quick soil-density determination of
the compacted lift with nuclear meter.
65
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SECTION VII
SAFETY MEASURES
High-Risk Working Conditions
Work in a sewage collection system
historically has generated a notoriously high
injury rate. Continuing studies by the Water
Pollution Control Federation (WPCF) show
that collection systems account for 30 to 60
disabling injuries per million man-hours
worked. This compares with a rate of about
10 for other systems.
An examination of the records strongly
suggests that many systems are more
injury-susceptible than others. In 1973. for
example, all of the injuries occurred in less
than 30 percent of the collection systems
reporting to the WPCF and half occurred in less
than 3 percent of the reporting systems. Since
the WPCF survey is voluntary. and since many
systems with high injury rates would be
reluctant to report, the actual injury rate is
probably higher than the already high figure'
that the WPCF studies disclose.
Injuries and deaths related to work in
collection systems can involve workers as well
as motorists and pedestrians. Aside from the
pain and general anguish caused by these
injuries the threat of massive damage suits for
negligence is always present. Failure to adhere
to recognized safety standards increases the
risk of liability.
Above-Ground and Below-Ground
Safety Measures
Safety measures can be grouped roughly
into (1) above-ground or street level
precautions; and (2) below-ground measures
in the manhole or the sewer system itself.
Both merit as much attention as the
actual work and possibly more since human
life is being risked.
Above-Ground Protection Measures
Notification of Work
Any work on a collection system that
involves activities at a manhole located in the
street should begin by notifying other
concerned agencies in advance. At a very
minimum these agencies should include:
1. Police Department, especially if it has
responsibility for traffic control.
2. Fire Department, in case fire trucks must
be dispatched through the area.
3. Traffic Engineering Division, if separate
from police.
4. Transit Services, including taxi
companies.
5. Water and Street Divisions
6. Other public and private utilities, such as
gas, electricity, telephone, and cable
television.
Probably the most authoritative guide on
how to control traffic both during normal
conditions and during periods of maintenance
and construction will be found in the
"Manual on Uniform Traffic Control
Devices," (MUTCD) developed by the Federal
Highway Administration, U.S. Department of
Transportation. Its preparation enjoyed the
active support of influential groups such as
the National League of Cities, the National
Association of Counties, the Institute of
Traffic Engineers, and the American
Association of State Highway and
Transportation Officials. It also is used in
legal decisions that involve negligence.
This discussion attempts to comply with
its recommendations. Of use to municipal
officials in urban areas is a handbook on Work
Site Protection developed by the APWA and
available from the U.S. Department of
Transportation.
Detour Requirements
Detours around work in the street should
be planned to meet at least three general
specifications:
1. The motorist should receive ample
advance warning. He should never be
surprised.
2. The detour or bypass should be marked
clearly so that the motorist will have no
difficulty following it. If possible, the
detour should not slow traffic by more
than 10mph(16km/h).
3. The warnings and detours should give
every consideration for the safety of the
motorist, pedestrian and workers.
66
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Warning Signs
Warning signs used for work around
manholes and similar locations must have a
distinctive color, different from
traffic-control signs. The color must be orange
with black lettering, selected to call the
motorists attention to unusual work on the.
roadway in accordance with the MUTCD or
state adopted standards.
The signs must be simple so that the
message can be grasped easily. They also may
carry orange flags or yellow flashing lights as
long as they do not interfere with the
motorists' view of the sign face. If lighting is
necessary, battery-operated lights should be
used rather than torches or the familiar
kerosene "bomb." "Bombs" can be extin-
guished easily by wind and can be dangerous
if an accident involves a ruptured gasoline tank.
Traffic Transition Lanes
When work of this nature takes place in a
street it inactivates at least one lane of
traffic. This requires movement of the traffic
out of the lane into whatever lane still is
available.
To move traffic safely out of a lane
needed for work requires use of a tapering
transition lane. To determine the length of
the taper multiply the width of the traffic
lane by the speed limit or by the estimated
speed of 85 percent of the traffic. If the speed
is 40 mph (64 km/h) and if the lane width is
10 ft (3.0 m) the transition length will be 400
ft (122 m) and the transition change should
be one foot per 40 ft (12.2 m) of roadway
length.
To outline the changing traffic lane
requires the use of traffic cones or tubes large
enough to be seen easily., yet sturdy enough
to remain undamaged if hit by a vehicle. They
should be at least 18 in. (46 cm) high,
' reflectorized, and colored orange. In case of
high winds or traffic-induced air eddy
currents, the cones can be doubled to provide
extra stability or a cone with a ballastable
bottom can be used.
Oil drums also can be used. These are
easily visible, portable, and produce an
appearance of solidity that the drivers respect.
They create more damage when hit than
cones. Drums should be weighted with sand
or concrete to keep them from being moved
by the wind or passing vehicles. Drums should,
be painted orange and white in horizontal
strips 4 to 6 in. (10 to 15 cm) wide. They
should be reflectorized if used at night,
and preferably equipped with flashing
warning lights.
When the manhole must be opened for
inspection, a class B unit high level warning
sign can be quickly set up and may be more
practical than setting up a wedge of traffic
cones or barriers.
Flagpersons
Conditions may dictate the use of flag-
persons to control the traffic if traffic is heavy
enough to cause congestion, or if the work
requires the use of one lane on a roadway with
only two lanes available. If a flagperson is
required, an orange vest should be worn,
preferably fluorescent and reflectorized. The
flagperson definitely should not be a marginal
employee, but should be alert or with good •
sight and hearing and able to direct traffic with
confidence and courtesy. If two flagpersons are
needed, they may be' supplied with walkie-
talkie radios so that they will have better
control when changing the direction of traffic.
The flagperson should be equipped with a
red flag of at least 24 x 24 in. (61 x 61 cm)
on a 3 ft (0.9 m) pole. The flag should be
weighted for easier visibility. As a better and
more understandable alternative, flaggers can
be supplied with a long handled paddle with
"Stop" painted on one side in white letters on
a red background. An octagonal outline
resembling a standard stop sign at least 18 in.
.(46 cm) in diameter should be used. The word'
"Slow" should appear on the opposite side.
Make Personal Check of Traffic Controls
In setting up the protective signs and
barricades the supervisor should • make a
personal check of the. work area, driving
through it to determine that the motorist
receives the needed guidance. Lights can be
misleading. Signs may. be blurred by
background colors. Warning lights which
appear well-placed may actually appear to be
a maze of purposeless blinking. The
supervisor's inspection can discover these
trouble points and correct them.
67
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Truck Used for Barricade
A truck that must usurp the traffic lane
for use by the crew working at the
street-located manhole can serve as a
barricade in one direction. The truck should
be amply supplied with warning lights, and a
rotating light on the cab roof. It also should
carry a large sign reading, "Caution"' The sign
should be detachable so that it can be
reversed, showing a blank side when going to
and from work. Full signing and barricades of
traffic cones are also needed in advance of the
truck.
Other Barricades
The most useful type of barricade is the
sawhorse, generally 6 to 8 ft (1.8 to 2.4 m)
long, mounted on an A frame, and a minimum
'.of 3 ft (0.9 m) high. These customarily carry
diagonal stripes at a 45° angle, alternating
white and orange. If a traffic-lane change or
detour is indicated, the stripes should slope
downward in the direction that the traffic
must travel. If traffic has its choice of moving
to the right or left, then the striping should
slope downward in both directions, starting
from the center of the barricade. Other types
of barricades also can be used. If sawliorses as
such are impractical due to their width,
difficulty to store or transport, bases with
reflectorized boards may be used.
*
Principal Suppliers of
Traffic-Control Equipment for
Street-Maintenance Operation
R. E. Dietz Company - Box 1214,
Syracuse, New York 13201. Supplies a wide
range of hazard lighting and safety equipment
that includes: Electrically powered,
trailer-mounted message and arrow boards;
mini-arrow boards to be mounted on the tops
of cars or trucks; a variety of metal
barricades; fluorescent traffic cones;
•battery-powered flashing lights; reflectorized
and fluorescent vests; warning flags and
stop/slow paddles; and many accessories.
W. S. Darley & Company - 2000 Anson
Drive, Melrose Park, Illinois 61060. Supplies
barricades, traffic cones, and warning lights.
Eastern Metal of Elmira, Incorporated
-1430 Sullivan Street, Elmira, New York
14901. Supplies a variety of warning signs,
barricades in various sizes and types, traffic
cones, flagger directional paddles and nylon
fluorescent warning flags.
Electro-line Product Company — Division
of Waters Instruments, Inc., P.O. Box 6117,
Rochester, Minnesota 55901. Supplies
flashers, electric lanterns and warning signals.
Industrial Products Company — 21 Cabot
Boulevard, Langhbrne, Pennsylvania 19047.
Supplies warning flags and protective vests.
Grimco, Incorporated — 141 Hanley
Industrial Court, St. Louis, Missouri 63114.
Supplies traffic cones and lane dividers.
Lyle Signs, Incorporated - 4450 W. 78th
Street, Minneapolis, Minnesota 55435.
Supplies barricades in various sizes and types,
flags, flagger signs, flashers, high level warning
devices, a variety of warning signs and traffic
cones.
Julian A. McDermott Corporation —
1641 Stephen Street, Ridgewood, Long
Island, New York 11227. Supplies work-area
protection barricades, heavy-duty flashers,
arrow boards, vehicular warning lights, traffic
cones, warning standards and flags.
Mercury Products Corporation —
Miralinks Division, 236 Chapman Street,
Providence, Rhode Island 12905. Provides
barricades, traffic cones and other
traffic-control equipment.
3 M Company — 3 M Center, St. Paul,
Minnesota 55101. Supplies barricade signs
and adhesive attachments for use on cones,
barrels, and other equipment.
Radiator Specialty Company — 1400
West Independence Boulevard, Charlotte,
North Carolina 28208. Supplies barricades,
flags, flashers, warning lights and traffic cones.
Safety Flag Company of America — 390A
Pine Street, Pawtucket, Rhode Island 02862.
Supplies fluorescent safety flags, stop/slow
paddle signs and safety wearing equipment.
Safety Guide Products — International
Plastics, Incorporated, 10 Innovation Lane,
Colwich, Kansas 67030. Supplies cone
barricades, barricade lights, 3 ft (90 cm)
traffic cones, warning flags, high level warning
devices, knit and folding plastic construction
signs, sign stands, rumble strips, delineator
posts, vests and stop/slow paddles.
68
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SA-SO, Inc. - 1186 108th Street, Grand
Prairie, Texas 75050. Supplies barricades and-
traffic cones.
Streeter-Amet Division, — Mangood
Corporation, Grayslake, Illinois 60030.
Supplies the EscoLite flashing warning lights,
rotating lights and barricades.
Toledo Pressed Steel Company — 397
Phillips Avenue, Toledo, Ohio 43612.
Supplies barricades, traffic cones, flags,
flashers, and warning lights.
Traffic Safety Supply Company - 2324
Umatilla Street, Portland, Oregon 97202.
Supplies barricades, traffic cones, flags,
flashers, warning lights, portable sequential
arrow signs, reflective tape, flagger hand-signal
equipment, safety hats and vests.
VePed Traffic Controls, Inc. - 11313 N.
Broadway, Rt. 2, Oklahoma City, Oklahoma
73115. Supplies barricades, traffic cones,
warning signs, and safety vests.
West Side Iron Works, Inc. - 1331
Michigan Street, NE, Grand Rapids, Michigan
49503. Supplies barricades, flags, flashers and
warning lights.
Below-Ground Safety Measures
in Manholes and Sewers
Working conditions in and around
manholes and sewers can be dangerous and
demand careful attention at all times.
Regardless of the task, safe work procedures
should be outlined clearly and all crew
members should be thoroughly familiar with
them. Protective equipment should be
inventoried for the workers. As a minimum,
employees should be provided with:
1. Safety clothing such as "hard hats,"
rubber boots, safety goggles, foot
protectors, and rubber gloves.
2. Safety equipment, such as safety
harnesses, toxic and combustible
g a s - d e t e c t in g equipment,
oxygen-deficiency detecting equipment,
portable blowers, first-aid kits, rescue
breathing apparatus, and fire
extinguishers.
The following regulations pertaining to
work in confined areas are listed under the
U.S. Department of Labor's Occupational
Safety and Health Standards 29 CFR 1910:
• Subpart B, Adoption and Extension of
{Established Federal Standards:
"-" Section ,1910.12 Construction
work
- Section 1910.13 Ship repairing.
-Section 1910.14 Shipbuilding
- Section 1910.15 Shipbreaking.
• Subpart D, WaMng-Working Surfaces:
- Section 1910.23 Guarding floor
and wall openings and holes.
- Section 1910.25 Portable wood
ladders.
- Section 1910.26 Portable metal
ladders.
- Section 1910.27 Fixed ladders.
- Section^ 1910.28 Safety
requirements for scaffolding.
- Section 1910.29 Manually
propelled mobile ladder stands and
scaffolds (towers).
• Subpart E, Means of Egress:
- Section 1910.36 General
Requirements.
- Section 1910.37 Means of egress,
general
• Subpart F, Powered Platforms,
Man lifts, and Vehicle-Mounted Work
Platforms:
— Section 1910.66 Power platforms
for exterior building maintenance.
- Section 1910.67 Vehicle-mounted
elevating and rotating work
platforms.
- Section 1910.68 Manlifts
• Subpart Z, Toxic and Hazardous
Substances (formerly Subpart G)
Occupational Health and Environmental
Control:
- Section 1910.1000 Air
contaminants,
(Plus Sections 1910.1001 through
1910.1017, dealing with specific
contaminants).
• Subpart G, Occupational Health and
Environmental Control:
- Section 1910.94 Ventilation.
• Subpart H, Hazardous Materials:
- Section 1910.101 Compressed
gases (general requirements).
-Section 1910.102 Acetylene.
- Section 1910.103 Hydrogen.
-Section 1910.104 Oxygen
69
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- Section 1910.105 Nitrous oxide.
- Section 1910.106 Flammable and
combustible liquids.
- Section 1910.107 Spray finishing
using flammable and combustible
liquids.
- Section 1910.110 Storage and
handling of liquified petroleum gases.
- Section 1910.111 Storage and
handling of anydrous ammonia.
• Subpart' I, Personal Protective
Equipment:
- Section 1910.132 General
requirements.
- Section 1910.133 Eye and face
protection.
- Section 1910.134 Respiratory
protection.
- Section 1910.135 Occupational
head protection.
- Section 1910.136 Occupational
foot protection.
- Section 1910.137 Electrical
protective devices.
• Subpart J, General Environmental
Controls:
- Section 1910.144 Safety color
code for marking physical hazards.
— Section 1910.145 Specifications
for accident prevention signs and
tags.
• Subpart K, Medical and First Aid:
— Section 1910.151 Medical services
and first aid.
• Subpart L, Fire Protection:
- All Sections: 1910.156 through
1910.163.
• Subpart M, Compressed Gas and
Compressed Air Equipment:
- All Sections: 1910.166 through
1910.169.
• Subpart P, Hand and Portable Powered
Tools and Other Hand-Held Equipment:
- Section 1910.242 Hand and
portable powered tools and
equipment, general.
- Section 1910.243 Guarding of
portable powered tools.
- Section 1910.244 Other portable
tools and equipment.
• Subpart Q, Welding, Cutting, and
Brazing:
-•Section 1910.251 Definitions
- Section 1910.252 Welding,cutting,
and brazing.
• Subpart R, Special Industries:
- (All pertinent Sections, 1910.261
through 1910.267a).
• Subpart S, Electrical:
- Section 1910.308 Application.
-Section 1910.309 National
Electrical Code.
Readers also should be familiar with Part
1926, CFR Construction, as it pertains to
confined areas, including tunnels, trenches
and open pits.
Source: National Safety News, Feb., 1976.
Safe-Air Conditions
After insuring that the work area is
protected from traffic hazards, and before the
manhole cover has been removed, the
supervisor should test for the oxygen and
combustible-gas content of the atmosphere
within the manhole.
Measurements for oxygen deficiency
should be made first to ascertain that
sufficient oxygen is present for combustible
gas testings as well as for life support A
combustible gas indicator should then be
used. The instrument(s) used should be pro-
vided with a probe that can be inserted through,
a hole in the manhole cover. Figures 46 and
47 show typical equipment.
If the tests show safe conditions the
cover may be removed, permitting the
supervisor to make further tests in the lower
levels of the manhole. Gasoline vapors are
heavier than air and would tend to collect at
the bottom. Tests should be made every 2 ft
(0.6 m) from the top to the bottom of the
manhole. In deep manholes, the test should
confirm the presence of or absence of carbon
monoxide, hydrogen sulfide and ammonia, all
of - them potentially lethal. Colorometric
detector tubes with appropriate sampling
pumps can determine whether these
hazardous gases exist in dangerous
concentrations.
70
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Ventilation of Manholes and Sewers
Any manhole greater than shoulder deep
should be ventilated, whether hazardous gases
are present or not. If tests detect no
dangerous gases, the manhole still should be
ventilated for at least one minute, using a
forced-draft fan capable of delivering at least
100 ft3/min (5.7 m3 /mm). The blower should
have a long, flexible ventilating tube that will
extend well into the manhole. The engine
powering the blower should be located well
away from the manhole, at least 10 ft (3 m)
preferably cross wind, to prevent any
explosive gases from reaching the engine, and
engine exhaust gases from entering the
manhole.
If a breeze is present at ground level,
natural ventilation can be induced by the use
of metal or canvas hoods that will deflect the
breeze into the manhole. This requires
moderatly strong breezes and the removal of
adjacent manhole covers.
Safe Sewers
If the wastewater in the sewer is flowing
freely and is not septic, and if the holes in the
manhole covers are open so that surface air
can enter, aerobic conditions probably exist
and no dangerous gases will be generated.
However, personnel should be trained to
suspect any tightly covered tank, chamber or
manhole, no matter what its depth. Deep
tanks, pump wet well and sludge digestion
tanks, all demand the utmost caution before
entry.
Dangerous Sewers
In general, certain types of sewers carry a
greater risk than others. Those that are
especially suspect are:
1. Trunk sewers, especially those that pass
through industrial areas.
2. Sewers near gas mains or gasoline storage
tanks.
3. Sewers on flat grades with sluggish flow
where solids may settle out and
decompose anaerobically, generating
methane, hydrogen sulfide. and carbon
monoxide.
4. Sewers with long runs, more than 300 ft
(91 m) between manholes, and also those
with inverted siphons.
Manhole Lighting
The safest method for illuminating the
interior of a manhole is through the use of
mirrors that reflect the sunlight into the
manhole or sewer. For convenience,
explosion-proof lights approved either by the
U.S. Bureau of Mines U.L. (Class 1 Group D)
or the U.S. Coast Guard., can provide the
illumination.
Entry into a Manhole
As shown in Figure 48', those entering
manholes should wear . "hard hats"
conforming with standards set by'the
American National Standards Institute
(ANSI) Z89.11969. Tools and materials
should be lowered into the manhole by rope
and never dropped. Small items should be
lowered by bucket.
Manholes generally are equipped with
steps cast into the wall. Many are not
corrosion proof and therefore can be
dangerous. If the steps appear unsafe, the man
entering the manhole should use a strong,
spark-proof ladder.
Safety Body Harness
Personnel should wear safety belts or
body harnesses as shown in Figure 49 any
time they enter a manhole more than
shoulder deep. The belt should be of a type
that will allow the worker to be lifted through
the manhole opening while in a vertical
position. One man should be stationed on the
surface for each worker in the manhole. His
sole duty should be to hold the rope and see
that the man in the harness is in good shape.
Another man at the surface should be
available • for help. Self contained breathing
apparatus should be used by anyone going to
the "rescue" of a person in the manhole.
Belts, harnesses and suspension systems
should meet ANSI Standard A10.14 - 1975.
General Precautions
Even when atmospheric conditions in the
manhole are not hazardous, precautions still
are mandatory. These should be considered
basic:
71
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1. Do not smoke within a manhole or sewer.
2. Train personnel not to raise their hands
above the collar to avoid the risk of
allowing contamination to enter the
body.
3. Wear coveralls or other removable outer
garments to protect regular clothes;
rubber boots or non-sparking safety
shoes; and gloves, preferably rubberized,
to avoid scratches and abrasions.
4. Re test the atmosphere at least every
one-half'hour for toxic and combustible
gases and for oxygen content at regular
intervals to insure continuing safety. If
high temperatures and high humidity are
encountered, order personnel out and
check for danger limits. As indicated in
the WPCF Manual of Practice No. I,7 a
relative humidity of 80 at a temperature
of 110° F (43° C) is dangerous. At these
intolerable points, oxygen deficiency
occurs which can cause collapse and
death if the worker is not quickly
removed.
5. In the case of a manhole that is off the
street in a fairly remote location, insist
that all safety equipment be transported
to the manhole. The temptation will be
strong to risk entry without safety
equipment, and the result unfortunately
has been casualties and deaths.
Emergency Entry into Manholes
Personnel must be trained in the use of
respiratory equipment for the emergency
rescue of workers. Rescue personnel should
be equipped with nonsparking tools, rubber
footwear and safety belts as well as
self-contained breathing apparatus.
The easiest equipment to use is the hose
mask as shown in Figure 50. A face piece fits
snugly to the face and a flexible hose leads
• from the mask to the source of good air. A
discharge'valve exhausts the respired breath.
However, the size of the hose makes it
difficult at times to use.
The hose mask will serve for a distance of
75 ft (22.8 m) without a blower in
atmospheres not immediately hazardous to
life or health and will serve for 300 ft (91 m)
with a blower. (In general, if an atmosphere is
"not immediately hazardous," personnel can
escape without the need for respiratory
equipment.) Also, airline respirators with half
or full face piece, helmets or hoods of
constant flow and pressure demand, or
demand flow, can be used with as much as
300 ft (91 m) of air hose in atmospheres not
immediately hazardous to life or health. When
equipped" with an egress cylinder, rescue
personnel can use this equipment in
atmospheres that are immediately hazardous.
The air supply must be at least Grade D,
ANSI Z86.1 - 1973, American National
Standard Commodity Specifications for air.
Self-contained breathing apparatus should
be preferred in any atmosphere that is
immediately hazardous to life or health.
Personnel equipped with this type of
apparatus should not do strenuous work for
more than a half hour. :
Canister masks, gas masks, or similar
mechanical filter respirators should not be
used in manholes or sewers, especially in an
oxygen-deficient atmosphere. These masks
will prevent entry of the particular gas for
which they were designed, but cannot supply
oxygen above that which is present.
For planned work, rather than emergency
rescue, in an atmosphere not immediately
hazardous, the air-supplied respirator should
be preferred, especially if equipped with an
egress cylinder in case atmospheres
immediately hazardous should be
encountered.
Table in Appendix A, drawn from the
WPCF Manual of Practice, lists characteristics
of dangerous gases that may be encountered
in sewers, manholes, pumping stations and
treatment plants.
Principal Suppliers of Equipment
for Use by Personnel Working
in Manholes and Sewers
Safety Harness
W. S. Darley & Company - 2000 Anson
Drive, Melrose Park, Illinois 60106. Can
supply three types of safety belts and
harnesses. One has a safety-cable feature that
limits a fall to 6 in. (15 cm) in case the access
ladder fails.
Miller Equipment Division — ESB, Inc.,
P.O. Box 271, Franklin, Pennsylvania 16323.
ManuJactures_a_complete_Jine_of safety belts
and harnesses including lifelines, lanyards,
72
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wristlet type rescue harnesses and flexible
side-rail wood or aluminum rung ladders.
Mine Safety Appliances Company — 400
Penn Center Boulevard, Pittsburgh,,
Pennsylvania 15235. Can supply several types
of harness: manhole type, chest harness with
or without leg straps, full-body harness,
chest-waist harness, and wrist-type rescue
harness., designed to draw an injured or
unconscious worker through a small opening.
Three types of buckles are available: tongue,
fixed bar friction., and sliding-bar friction.
Ventilation Tubing
National Mine Service Company — 3000
Koppers Building, Pittsburgh, Pennsylvania
15219. Supplies Flexfab tubing made of
heavyweight, 2-ply PVC-dipped nylon,
reinforced with a spring-steel spiral wire. The
tubing is flame resistant, made in diameters
from 12 to 36 in. (30 to 91 cm) in 10 ft (3 m)
lengths.
Toxic Gas Detectors
(approved by the National Institute for
Occupational Safety and Health, NIOSH)
Bendix Environmental Science Division —
1400 Taylor Avenue, Baltimore, Maryland
21204. Supplies Gastec Model 400
multi-stroke sampling pump (Bendix P N
2417535) through sales representative
National Environmental Instruments, Inc.,
P.O. Box 590, Warwich, Rhode Island 02888.
Tubes presently certified by NIOSH include
those for CO, SO2, CO2, CC14, CH3, H2 S,
NO, N02, NH3, C12, C2 HC13,
(trichloroethylene).
Besides continuing NIOSH
approvals, a complete line of gas sampling
tubes are offered. All tubes are self reading.
Calibration scales are printed on each tube.
Tubes are $9.85 per box of 10 regardless of
the type and pump kits (including spare parts
package) are $75.00.
Bio Marine Industries — 45 Great Valley
Center, Malvern, Pennsylvania 19355.
Supplies a complete line of combustible gas
and oxygen deficiency monitors. These units
include portable continuous measuring
oxygen analyzers and monitors with alarms
and remote sensors, combustible gas
detectors and combination units for
combustible gas and oxygen monitoring with
alarms. Remote sensors are_also available. All
instruments are Bureau of Mines approved.
Energetics Science., Inc. - 85 Executive
Boulevard, Elmsford, New York 10523.
Manufactures toxic gas analyzers capable of
measuring H2S in ranges as low as 0-10 ppm
and as high as 0-5,000 ppm. The ECOLYZER
H2 S Analyzers use electrochemical principals
of detection and can be equipped to alarm
within 30 seconds. The HIPSTER unit weighs
4 Ib (1.8 kg) and costs $1,295. Calibrating
accessories are an additional $200 to $250.
Matheson Gas Products — P.O. Box E,
Lyndhurst, New Jersey 07071. Distributor of
Kitagawa equipment. Supplies for Kitagawa
model 400 aspirating pump, Matheson PN
8014-400, certified for use with appropriate
tubes to detect CO, CO2, SO2, O, NH3,
hydrogen cyanide and 80 other chemicals not
yet certified by NIOSH. Model 8014-400 Kit
$90.00, Tube $8.00-$ 15.00.
Mine Safety Appliances Company — 400
Penn Center Boulevard, Pittsburgh,
Pennsylvania 15235. Supplies Detector Tubes
for CO, H2S, CO2, and NH3 which
have been certified by NIOSH when used with
the MSA part number 83400 Universal
Sampling Pumps. Tubes are also available for
testing other compounds.
Naylor Industries - P.O. Box 6507,
Pasadena, Texas 7750i6. Combination toxic,
combustible, and low oxygen gas detector.
National Mine Service Company, —3000
Koppers Building, Pittsburgh, Pennsylvania
15219. Supplies the National/Drager multi-gas
detector composed of a hand-operated
bellows pump that delivers 6.1 in.3 (100 cm3)
of gas with each stroke,, and a variety of
disposable test tubes to be used with the
bellows pump. Each tube has been designed
to detect and measure a specific gas. Those
pertinent to sewer collection systems and that
have NIOSH certification include: CO, CO2,
H2 S, SO2, toluene, and trichlorethylene. The
.current cost of the detector is $130. A pack
of ten tubes for each gas runs between $11.00
and $13.50 depending on the gas to be
measured.
The company also distributes the Koehler
flame safety lamp that detects and monitors
oxygen deficiency and methane gas in areas
73
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such as manholes and sewers. The lamp will
burn continuously for 12 to 14 hours on one
filling.
Combustible Gas and Oxygen
Measuring Instruments
Bendix Environmental Science Division —
1400 Taylor Avenue, Baltimore, Maryland
21204. Supplies a Micro Methanometer
(Model 1800) for the detection of
combustible gasses through sales
representative National Environmental
Instruments, Inc., P.O. Box 590, Pilgrim
Station, Warwick, Rhode Island 02888; and
Preiser/Mineco, Jones & Oliver Street, St.
Albans, West Virginia 25177. The unit is
approved by the U.S. Bureau of Mines 8C-29
for use in explosive atmospheres.
Bio Marine Industries — 45 Great Valley
Center, Malvern, Pennsylvania 19355.
Supplies a complete line of combustible gas
and oxygen deficiency monitors. These units
include portable continuous measuring
oxygen analyzers and monitors with alarms
and remote sensors, combustible gas detectors
and combination units for combutible gas and
oxygen monitoring with alarms. Remote
sensors are also available. All instruments are
Bureau of Mines approved.
Mine Safety Appliances. Company — 400
Penn Center Boulevard, Pittsburgh,
Pennsylvania 15235. Supplies detector tubes
for carbon monoxide, hydrogen sulfide,
carbon dioxide, ammonia, nitrogen dioxide,
chlorine and sulfur dioxide, acetone, and
trichloroethylene. As of March 1, 1976, those
tubes have been certified by NIOSH when
used with the MSA P/N 93499 Universal
Sampling Pump. Tubes for approximately 120
other compounds, not yet certified by
NIOSH, can be used with the 83499 Universal
Pump.
Self-Contained Breathing
Apparatus, NIOSH Approved
Bio Marine Industries — 45 Great Valley
Center, Malvern, Pennsylvania 19355.
Supplies a 45 minute self-contained breathing
apparatus weighing only 17 Ibs (7.7 kg) with a
chest mounted closed circuit system. NIOSH,
MESA, and Coast Guard approved under
latest schedules - TC-13F-27.
Globe Safety Products, Inc. - 125
Sunrise Place, Dayton, Ohio 45407. Supplies
four models of half-hour, compressed-air,
demand-type units.
Mine Safety Appliances Company — 400
Penn. Center Boulevard, Pittsburgh,
Pennsylvania 15235. Supplies two models of
one-quarter and one-half hour cpmpressed-air,
demand-type breathing apparatus. Also has
pressure-demand types as well as combination
hose-line and self-contained units.
Scott Aviation — Division of ATO, Inc.,
Lancaster, New York 14068. Supplies two
models of half-hour and two of quarter-hour
compressed-air, demand-type breathing
apparatus. Also, pressure-demand types, and
positive-pressure units, self-contained, as well
as combination hose-line and self-contained
units.
SurvivAir Division — of U.S. Divers
Company, 3323 W. Warner Avenue, Santa
Ana, California 92702. Supplies two models
of half-hour compressed-air, demand-type
units.
Supplied-Air Respirators
Mine Safety Appliances Company — 400
Penn Center Boulevard, Pittsburgh,
Pennsylvania 15235. Constant-flow and
demand-type airline respirators and hose
masks without blower.
Minnesota Mining and Manufacturing
Company - (3 M), 3 M Center, St. Paul,
Minnesota 55101. Can supply several models
consisting of helmet, air-regulating valve and
breathing-tube assembly, Vortex cooling and
Vortemp heating and air-supply hose of
varying lengths.
Scott Aviation — Division of ATO, Inc.,
Lancaster, New York 14068. Supplies
demand, constant flow and positive pressure
models with harness, face piece and hoseline
lengths to 250 ft (76m).
SurvivAir Division — U.S. Divers
Company, 3323 W. Warner Avenue, Santa
Ana, California 92702. Can supply four
models consisting of face piece and regulator
assembly, waist belt, and air-line hose of
varying lengths.
United States Safety Service — Parmalee
Industries, Inc., P.O. Box 1237, Kansas City,
Missouri 74141. Respirator consists of hood
74
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assembly, breathing tube assembly, air-supply Explosion-Proof Hand Lights
a quick disconneot and a
Corrosion proof,high impact plastic
cases with adjustable heads.
Source: Mine Safety" Appliance Company, Pittsburgh, Pennsylvania
Figure 46, This oxygen indicator has been designed to test atmosphere iri manholes, sewers,
and similar locations. '
Figure 47. The portable indicator
when equipped with a
suitable probe and charg-
M ing cable, can detect both
oxygesn deficiency and the
presence of combustible
gas.
Source: Mine Safety Appliance Company, Pittsburgh, Pennsylvani;
75
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Sourco:Scott Aviation, Division of ATO, Inc., Lancaster
Now York '.
Figure 48. Rescue personnel equipped with a
supplied-air respirator egress emer-
gency air supply, safety harness,
hard hat and gloves.
Source: Mine Safety Appliances Company,
Pittsburgh, Pennsylvania
^t^^r^
Figure 49. A wrist harness can be used to rescue
unconscious personnel. The harness
brings the arms together overhead
and allows the victim to be lifted out
of closed structures with small
openings.
Figure 50. The Constant-Flow Air-Line Respi-
rator allows personnel to work in
toxic atmosphere not immediately
hazardous to life or health.
Sourco:MIno Safety Appliances Company,
Pittsburgh, Pennsylvania
76
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SECTION VIII
REFERENCES
1. L. E. Gottstein before the House of
Representatives Committee on Public
Works, Water Pollution Control
Legislation - 1970 (92 - 16)
2. Survey of Sewer Main Pipe Serving
Population of 2,500 or more. American
City and County Magazine, Aug. 1975.
3. Journal, Water Pollution Control
Federation, Literature Review Issue,
June, 1975, Vol. 47, No. 6.
4. Vacamar, Grant, and Tomick, Flow
'Monitoring Techniques in Sanitary
Sewers, WPCF Deeds and Data, July,
1974.
5. Shelly, P.E., and G. W. Kirkpatrick. An
Assessment of Automatic Sewer Flow
Samples, EPA-R2-73-261, NTIS PB 223
355.
6. Ahrens, J.F., O. H. Leonard, and N. R.
Townley, Chemical Control of Tree
Roots in Sewer Lines. Journal Water
Pollution Control Federation. September
1970.'.p.. 1643.
7. Water Pollution Control Federation,
WPCF Manual of Practice No. 1, Safety in
Wastewater Works. Water .Pollution
Control Federation, 2626 Penn Ave.
N.W., Washington, D.C. 20037. 1975.
77
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APPENDIX A
CHARACTERISTICS OF DANGEROUS GASES ENCOUNTERED IN SEWERS
SEWAGE PUMPING STATIONS, AND SEWAGE TREATMENT PLANTS
Chemical
OH Formula
Cwbon
Dfcxido C0a
Carbon
Monoxide CO
Chlorine CLj
GitcHne CjN,3
to
CtNie
Hydrogen HI
Hydrogen
Collide H3S
Metharw CH4
Nitrogen Nj
Oxygen Oj
(in.tr)
Sludge -
Gai
Common properties*
Colorless, odorless.
When breathed In large
quantities may cause acid
taste. Nonflammable. Not
generally present in dan-
gerous amounts unless an
oxygen deficiency exists.
Colorless, odorless,
tasteless, flammable.
Poisonous.
Yellow-green color,
choking odor detectable
In very low concentrations*.
Nonflammable.
able at 0.03 percent.
Colorless, odorless, tasteless.
Flammable.
Rotten egg odor In small
concentrations. Exposure
for 2 to 15 minutes at 0.01
percent impairs sense of
smell. Odor not evident at
high concentrations. Color-
less. Flammable,
Colorless, odorless,
tasteless. Flammable.
Colorless, tasteless, non-
flammable. Principal con-
stituent of air (about 79
percent).
Colorless, odorless, tasteless.
Supports combustion.
May be practically odorless,
colorless. Flammable.
Specific Gravity
or
Vapour Density
(Air- 1) Physiological Effect*
1.53 Cannot be endured at
10 percent more than
few minutes, even if
subject is at rest and
oxygen content nor-
mal. Acts on respi-
ratory nerves.
Max Safe Max Safe
60-Min 8-Hr
Exposure Exposure
Percent by Percent by
Vol. in Air Vol. in Air
4.0 to 0.5
6.0
0.97 Combines with hemo- 0.04 0.01
globin of blood. Un-
consciousness in 30
minutes at 0.2 to 0.25
percent. Fata! in 4 hours
at 0.1 percent. Headache
In few hours at 0.02
percent.
2.49 irritates respiratory
tract. Kills most
animals In very short
time at 0.1 percent.
3.0 to Anesthetic effects when
4.0 inhaled. Rapidly fatal
at 2.4 percent. Danger-
ous for short exposures
at 1 .1 to 2.2 percent.
0.07 Acts mechanically to
deprive tissues of
oxygen. Does not
support life.
1.19 Impairs sense of smell
rapidly as concentration
increases. Death in few
minutes at 0.2 percent.
Exposure to 0.07 to
0.1 percent rapidly
causes acute poisoning.
Paralyzes respiratory
center.
0.55 Acts mechanically to
deprive tissues of
oxygen. Does not
support life.
0.97 Physiologically inert.
1.1 1 Normal air contains
20.93 percent of O2 .
Man can tolerate down
to 12 percent. Min Safe
8-hour exposure, 14 to
16 percent. Below 10
percent dangerous to
life. Below 5 to 7 per-
cent probably fatal.
Variable Will not support life.
0.0004 0.0001
0.4 to 0.10
0.7
0.02 to 0.002
0.03
Probably no —
limit provided
oxygen percentage
is sufficient for
life.
No data.
Would vary
widely with
composition.
Explosive Range
Percent by
Vol. in Air Likely Location
Lower Upper of Highest
Limit Limit Concentration
- - At bottom;
when heated
may stratify
at points above
bottom.
12.5 74.0 Near top,
especially if-
present with
illuminating gas.
- — At bottom.
1.3 6.0 At bottom.
4.0 74.0 At top.
4.3 46.0 Near bottom,
but may be
above bottom
if air is heated
and highly
humid.
5.0 15.0 At top,
increasing to
certain depth.
— — Near top, but
may be found
near bottom.
- - Variable at
different levels.
5.3 19.3 Near top of
structure.
Most
Common
Producs of com-
bustion, sewer gas,
sludge. Also issues
from carbonaceous
strata.
Manufactured gas,
flue gas, products
combustion, motor
exhausts, fires of
almost any kind.
Chlorine cylinder
and feed line leaks.
Service stations,
garages, storage tanks,
and houses.
Manufactured gas,
sludge digestion
tank gas, elec-
trolysis of water.
Rarely from rock
strata.
Coal gas, petro-
leum, sewer gas.
Fumes from blast-
ing under some
conditions. Sludge
gas.
Natural gas, sludge
gas, manufactured gas,
sewer gas. Strata of
sedimentary origin. In
Sewer gas, sludge
gas. Also issues from
some rock strata.
Oxygen depletion
from poor ventila-
tion and absorption, or
chemical consumption
of oxygen.
From digestion of
sludge.
From pp. 44-45 "Safety In Waitswator Works." WPCF Manual of Practice No. 1.1975.
78
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/2-77-017c
3. RECIPIENT'S ACCESSION-NO.
TITLE AND SUBTITLE
Sewer Infiltration and Inflow Control
Product and Equipment Guide
5. REPORT DATE
July 1977 (Issuing Date)
6. PERFORMING! ORGANIZATION CODE
AUTHOR(S)
William S. Foster, Richard H. Sullivan
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
American Public Works Association
1313 East 60th Street
Chicago, Illinois 60637
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
803151
2. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory —Cin. , OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final Dates June '74 - Dec. '76
14. SPONSORING AGENCY CODE
EPA/600/14
5. SUPPLEMENTARY NOTES
Project Officer: Anthony N. Tafuri
(201) 321-6679
8 - 340-6679
6. ABSTRACT
The report lists and discusses new and existing equipment, materials, and practices available to prevent the entry of
unwanted water into the sewer system from infiltration and inflow, and thereby needlessly usurping the capacity of the
sewerage system.
The report has six sections covering:
1. A description of sewer cleaning techniques and equipment needed to help locate points of infiltration and inflow
and to improve the accuracy of flow measurement.
2. A review of flow-measurement equipment and techniques needed for a determination of the quantity of infiltration
and inflow.
3. An examination of equipment and practices used to inspect the sewers and locate the entry points of unwanted
water. This involves closed-circuit television, photographic inspection, low-pressure air testing, and smoke
inspection.
4. A discussion of current sewer-grouting practices, equipment, and material, concentrating on the aery lamide gel, and
the elastomeric grouting compound.
5. A review of insertion pipe for rehabilitation, sewer fittings, and a brief discussion of trench backfilling monitored
by nuclear soil-density meters.
6. An examination of safety practices that should be followed when crews undertake the task of controlling sewer
infiltration and inflow.
The product and equipment guide and accompanying report and manual of practice were submitted in partial
fulfillment of Grant No. 803151 between the U.S. Environmental Protection Agency and the American Public Works
Association. Work was completed as of November, 1976.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTlFlERS/OPEN ENDED TERMS
Sewers, Cleaning, Fluid infiltration,
Water influx, Safety, Inspection, Flow
measurement, Renovating, Equipment
18. DISTRIBUTION STATEMENT
.RELEASE TO PUBLIC
c. COSAT1 Field/Group
Product suppliers, In-
filtration/Inflow con-
trol and detection,
Sewer cleaning, Sewer
inspection, Sewer re-
habilitation, Infiltra-
tion/Inflow pqn i pmpn r
19. SECURITY CLASS (ThisReport)'
UNCLASSIFIED
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
13B
21. NO. OF PAGES
91
22. PRICE
EPA Form 2220-1 (9-73)
79
ft U.S. GOVERNMENT PRINTING OFFICE 1978— 757-140/1317
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